WorldWideScience

Sample records for gd-bopta enhanced t1-weighted

  1. A comparison of Gd-BOPTA and Gd-DOTA for contrast-enhanced MRI of intracranial tumours

    International Nuclear Information System (INIS)

    Colosimo, C.; Knopp, M.V.; Barreau, X.; Gerardin, E.; Kirchin, M.A.; Guezenoc, F.; Lodemann, K.P.

    2004-01-01

    A two-centre intra-individual crossover study was performed in 23 patients with suspected high-grade glioma or metastases to assess and compare the safety and enhancement characteristics of two different MRI contrast media (gadobenate dimeglumine, Gd-BOPTA and gadoterate meglumine, Gd-DOTA) at equivalent doses of 0.1 mmol/kg body weight. T1-weighted spin-echo (SE) and T2-weighted fast SE images were obtained before and T1-weighted images 0, 2, 4, 6, 8 and 15 min after injection. T1-weighted images with magnetisation transfer contrast were acquired 12 min after injection. Qualitative assessment by blinded, off-site readers (reader 1: 19 patients; reader 2: 21) and on-site investigators (23) revealed significant (P ≤0.005) overall preference for Gd-BOPTA over Gd-DOTA for contrast enhancement (Gd-BOPTA preferred in 18, 15 and 18 cases; Gd-DOTA in 0, 1 and 1 and no preference in 1, 5 and 4; off-site readers 1 and 2, and on-site investigators, respectively). A similar significant preference for Gd-BOPTA was expressed by off-site readers and on-site investigators for lesion-to-brain contrast, lesion delineation, internal lesion structure, and overall image preference. Quantitative assessment by off-site readers revealed significantly (p<0.05) greater lesion enhancement with Gd-BOPTA than with Gd-DOTA at all times from 2 min after injection. (orig.)

  2. Hepatic enhancement on Gd-BOPTA-enhanced MR imaging: comparison between cirrhotic and normal livers

    International Nuclear Information System (INIS)

    Shin, Sang Soo; Jeong, Yong Yeon; Kang, Heoung Keun; Lim, Hyo Soon; Yoon, Woong; Seo, Jeong Jin; Park, Jin Gyoon

    2004-01-01

    To compare the enhancement features of hepatic parenchyma between cirrhotic and normal liver, using Gd-BOPTA-enhanced delayed MR imaging. The 60 patients (35 with cirrhotic and 25 with normal liver) included in our study underwent Gd-BOPTA-enhanced MR imaging using a 1.5T system with a phase-array multicoil. In all cases, T1-weighted in-phase and opposed-phase gradient-echo MR imaging was performed before and 60 minutes after intravenous administration of a bolus of Gd-BOPTA. All images were quantitatively analysed by comparing the signal-to-noise ratio (SNR) and signal enhancement (SE) of cirrhotic and normal liver before and after contrast enhancement, and in cirrhotic patients, SNR and SE were also compared in terms of the Child-Pugh classification. For qualitative analysis, the hepatic enhancement patterns of cirrhotic and normal liver were classified as homogeneous or heterogeneous according to the consensual findings of two radiologists. At contrast-enhanced imaging, both cirrhotic (p<0.001) and normal liver (p<0.001) showed substantially increased SNR relative to unenhanced images, and the SNR of cirrhotic liver was significantly lower than that of normal livers at both in-phase (p<0.001) and opposed-phase (p<0.001) imaging. The SE of cirrhotic liver was significantly lower than that of normal liver (in-phase:p=0.002; opposed phase:p=0.011). Both Child-Pugh class A (p<0.001) and B (p<0.001) cirrhotic liver showed a substantial increase in SNR at contrast-enhanced imaging relative to unenhanced imaging and the SNR of Child-Pugh class A was significantly higher than that of Child-Pugh class B at both in-phase (p<0.001) and opposed-phase (p=0.022) imaging. In addition, the SE of class A was significantly higher than that of class B at in-phase imaging (p=0.004). Cirrhotic liver showed heterogeneous enhancement in 20 of 35 patients (57%), whereas normal liver showed homogeneous enhancement in all patients. At Gd-BOPTA-enhanced delayed MR imaging, cirrhotic liver

  3. Off-site evaluation of liver lesion detection by Gd-BOPTA-enhanced MR imaging

    International Nuclear Information System (INIS)

    Gehl, H.B.; Bourne, M.; Grazioli, L.; Moeller, A.; Lodemann, K.P.

    2001-01-01

    The aim of this study was to determine the efficacy of Gd-BOPTA-enhanced MRI in liver lesion detection in comparison with unenhanced MRI and dynamic CT. The image sets of 148 of 151 patients enrolled in a multicenter German phase-III trial were evaluated by two independent radiologists unaffiliated with the investigating centers. Patients underwent a routine MRI protocol comprising T2- and T1-weighted spin-echo and T1-weighted gradient-echo (GE) sequences pre and 1 h post 0.1 mmol/kg Gd-BOPTA (Bracco-Byk Gulden, Konstanz, Germany). Additionally, a serial T1-weighted GE scan was performed after administration of the first half of the dose. All patients underwent dynamic contrast-enhanced CT. The evaluation was performed with regard to the number and size of lesions detected per patient by each modality or sequence. Furthermore, all pre CM and pre + post CM image sets were analyzed for number of lesions per patient. Both readers detected significantly more lesions in the contrast-enhanced image set compared with the unenhanced image set (32 and 39 %, respectively; p < 0.0001). While contrast-enhanced CT detected a similar number of lesions to unenhanced MRI, it was clearly inferior to contrast-enhanced MRI (reader 1: p = 0.0117; reader 2: p = 0.0225). Of the T1-weighted scans performed, the dynamic and late T1-weighted GE exams contributed most to the increased lesion detection rate (reader 1: p = 0.0007; reader 2: p = 0.0037). The size of the smallest lesion detected by means of MRI was significantly larger in the pre-CM image sets than in the pre + post CM image sets (reader 1: p = 0.001; reader 2: p < 0.0001). Gd-BOPTA-enhanced MRI detected significantly smaller lesions than contrast-enhanced CT (reader 1: p = 0.0117; reader 2: p = 0.0925). Gd-BOPTA-enhanced MR imaging improves liver lesion detection significantly over unenhanced MRI and dynamic CT. (orig.)

  4. Off-site evaluation of liver lesion detection by Gd-BOPTA-enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gehl, H.B. [Inst. of Diagnostic Radiology, Medical Univ. of Luebeck (Germany); Bourne, M. [Dept. of Radiology, Univ. Hospital of Wales, Cardiff (United Kingdom); Grazioli, L. [Dept. of Radiology, Univ. of Brescia (Italy); Moeller, A. [MEDIDATA GmbH, Konstanz (Germany); Lodemann, K.P. [BRACCO-BYK GULDEN GmbH, Konstanz (Germany)

    2001-02-01

    The aim of this study was to determine the efficacy of Gd-BOPTA-enhanced MRI in liver lesion detection in comparison with unenhanced MRI and dynamic CT. The image sets of 148 of 151 patients enrolled in a multicenter German phase-III trial were evaluated by two independent radiologists unaffiliated with the investigating centers. Patients underwent a routine MRI protocol comprising T2- and T1-weighted spin-echo and T1-weighted gradient-echo (GE) sequences pre and 1 h post 0.1 mmol/kg Gd-BOPTA (Bracco-Byk Gulden, Konstanz, Germany). Additionally, a serial T1-weighted GE scan was performed after administration of the first half of the dose. All patients underwent dynamic contrast-enhanced CT. The evaluation was performed with regard to the number and size of lesions detected per patient by each modality or sequence. Furthermore, all pre CM and pre + post CM image sets were analyzed for number of lesions per patient. Both readers detected significantly more lesions in the contrast-enhanced image set compared with the unenhanced image set (32 and 39 %, respectively; p < 0.0001). While contrast-enhanced CT detected a similar number of lesions to unenhanced MRI, it was clearly inferior to contrast-enhanced MRI (reader 1: p = 0.0117; reader 2: p = 0.0225). Of the T1-weighted scans performed, the dynamic and late T1-weighted GE exams contributed most to the increased lesion detection rate (reader 1: p = 0.0007; reader 2: p = 0.0037). The size of the smallest lesion detected by means of MRI was significantly larger in the pre-CM image sets than in the pre + post CM image sets (reader 1: p = 0.001; reader 2: p < 0.0001). Gd-BOPTA-enhanced MRI detected significantly smaller lesions than contrast-enhanced CT (reader 1: p = 0.0117; reader 2: p = 0.0925). Gd-BOPTA-enhanced MR imaging improves liver lesion detection significantly over unenhanced MRI and dynamic CT. (orig.)

  5. Gd-BOPTA-enhanced excretory MR urography without administration of diuretics; Gd-BOPTA-gestuetzte MR-Ausscheidungsurographie ohne Diuretikagabe

    Energy Technology Data Exchange (ETDEWEB)

    Allkemper, T.; Tombach, B.; Heindel, W. [Muenster Univ. (Germany). Inst. fuer Klinische Radiologie

    2001-02-01

    Purpose: To evaluate the feasibility and clinical utility of Gd-BOPTA enhanced excretory magnetic resonance urography without additional administration of diuretics in correlation with conventional urography. Method: 15 preoperative patients with pelvic tumors were examined at 1.5 T using a breath-hold high-resolution 3D-FLASH sequence during first-pass as well as 5, 10, 15 minutes after iv. injection of 0.05 mmol/kg BW Gd-BOPTA (MultiHance {sup trademark}) without administration of diuretics. Post-processed coronal and multiplanar MIP reconstructions were compared to conventional excretory urography with regard to morphologic accuracy, anatomic variability, filling defects, cause and level of obstruction or compression, tumor visibility, and time-effectiveness by two independent radiologists. Results: Visualization of the urinary tract by MRU was comparable to conventional excretory urography in 14 of 15 cases. Caliceal fornices were better delineated on conventional urographies, whereas MRU was considered superior in the assessment of the inferior ureter sections, the urinary bladder and obstructive tumors, whose extents could be clearly marked out. Examination times of both techniques were comparable. Conclusion: These first results show that non-diuretic Gd-BOPTA enhanced MRU is comparable to conventional excretory urography for the preoperative diagnosis of pelvic tumors. Further improvements of this technique seem possible by optimization of examination intervals and injection doses. (orig.) [German] Ziel: Abschaetzung der Durchfuehrbarkeit und des klinischen Nutzens der Gd-BOPTA-gestuetzten MR-Ausscheidungsurographie (MRU) ohne zusaetzliche Diuretikagabe im Vergleich zur konventionellen Ausscheidungsurographie. Methoden: 15 Patienten mit Beckentumoren wurden praeoperativ an einem 1.5 T-Ganzkoerpersystem mit Hilfe einer atemgehaltenen, hochaufloesenden 3D-FLASH-Sequenz unmittelbar nach intra-venoeser Applikation von 0,05 mmol/kg KG Gd-BOPTA (MultiHance {sup

  6. Comparison of acquisition time and dose for late gadolinium enhancement imaging at 3.0 T in patients with chronic myocardial infarction using Gd-BOPTA

    International Nuclear Information System (INIS)

    Doltra, A.; Skorin, A.; Gebker, R.; Klein, C.; Fleck, E.; Kelle, S.; Hamdan, A.; Schnackenburg, B.; Nagel, E.

    2014-01-01

    To compare contrast doses and acquisition times for late gadolinium enhancement (LGE) imaging at 3.0 T using gadobenate dimeglumine (Gd-BOPTA) in patients with chronic myocardial infarction. Thirty-four patients with chronic myocardial infarction were randomised to 0.10, 0.15 and 0.20 mmol/kg of Gd-BOPTA. T1-weighted inversion recovery gradient echo sequences were performed at 5, 10, 15 and 20 min post-administration of contrast in a 3.0-T scanner. Scar-to-myocardium contrast-to-noise ratio (CNR), scar-to-blood CNR, scar size and image quality were assessed. Imaging at 5 min was associated with a lower scar-to-blood CNR in comparison to 10, 15 and 20 min at 0.10 mmol/kg, and in comparison to 15 and 20 min at 0.20 mmol/kg. At 0.10-mmol/kg, imaging at 5 min yielded smaller infarct sizes in comparison to 15 and 20 min. Finally, at 0.20-mmol/kg, imaging at 5 min was associated with poorer image quality in comparison to later times. In LGE imaging at 3.0 T, low doses of Gd-BOPTA perform equally well as higher doses. Early acquisition (5 min) is associated with lower infarct sizes and image quality. Studies with sufficient diagnostic quality can be obtained after 10 min using 0.10 mmol/kg Gd-BOPTA. (orig.)

  7. Gd-BOPTA-enhanced excretory MR urography without administration of diuretics

    International Nuclear Information System (INIS)

    Allkemper, T.; Tombach, B.; Heindel, W.

    2001-01-01

    Purpose: To evaluate the feasibility and clinical utility of Gd-BOPTA enhanced excretory magnetic resonance urography without additional administration of diuretics in correlation with conventional urography. Method: 15 preoperative patients with pelvic tumors were examined at 1.5 T using a breath-hold high-resolution 3D-FLASH sequence during first-pass as well as 5, 10, 15 minutes after iv. injection of 0.05 mmol/kg BW Gd-BOPTA (MultiHance trademark ) without administration of diuretics. Post-processed coronal and multiplanar MIP reconstructions were compared to conventional excretory urography with regard to morphologic accuracy, anatomic variability, filling defects, cause and level of obstruction or compression, tumor visibility, and time-effectiveness by two independent radiologists. Results: Visualization of the urinary tract by MRU was comparable to conventional excretory urography in 14 of 15 cases. Caliceal fornices were better delineated on conventional urographies, whereas MRU was considered superior in the assessment of the inferior ureter sections, the urinary bladder and obstructive tumors, whose extents could be clearly marked out. Examination times of both techniques were comparable. Conclusion: These first results show that non-diuretic Gd-BOPTA enhanced MRU is comparable to conventional excretory urography for the preoperative diagnosis of pelvic tumors. Further improvements of this technique seem possible by optimization of examination intervals and injection doses. (orig.) [de

  8. Comparison of gadobenate dimeglumine (Gd-BOPTA) with gadopentetate dimeglumine (Gd-DTPA) for enhanced MR imaging of brain and spine tumours in children

    Energy Technology Data Exchange (ETDEWEB)

    Colosimo, Cesare [Univ. Annunzio, Chieti (Italy). Dept. of Clinical Sciences; Demaerel, Philippe [Univ. Hospital Leuven (Belgium); Tortori-Donati, Paolo [Inst. Gaslini, Genoa (Italy); Christophe, Catherine [Hopital Universitaire des Efants, Brussels (Belgium); Buchem, Mark van [Univ. Hospital Leiden (Netherlands); Hoegstroem, Barry; Pirovano, Gianpaolo; Shen, Ningyan; Spinazzi, Alberto [Worldwide Medical Affairs, Bracco Diagnostics, Inc., Princeton, NJ (United States); Kirchin, Miles A. [Worldwide Medical Affairs, Bracco Imaging SpA, Milan (Italy)

    2005-05-01

    Sixty-three subjects, aged 6 months to 16 years, who were enrolled in a prospective, fully blinded, randomized parallel-group phase III clinical trial, received 0.1 mmol/kg doses of either Gd-BOPTA (n=29) or Gd-DTPA (n=34). The MR images were acquired before and within 10 min of contrast agent injection. The primary objective was to compare the difference from pre-dose to post-dose lesion visualization between Gd-BOPTA and Gd-DTPA. Lesion visualization was determined as the sum of individual scores for three criteria of lesion morphological characteristics (lesion border delineation, internal morphology, and contrast enhancement), each assessed qualitatively using 4-point scales. Quantitative evaluation compared changes in lesion-to-background (LBR) and contrast-to-noise (CNR) ratios and per cent enhancement. Monitoring for adverse events and evaluation of vital signs and laboratory values was performed. Pre-dose to post-dose changes in lesion visualization were significantly better for Gd-BOPTA for both lesion level (2.68{+-}2.17 vs. 1.05{+-}1.90, P=0.0106) and patient level (2.55{+-}2.18 vs. 1.14{+-}1.68, P=0.0079) comparisons. The mean pre-dose to post-dose change in CNR was greater for Gd-BOPTA (9.13{+-}15.36) than Gd-DTPA (2.18{+-}9.90), but the difference was only marginally significant (P=0.0779; 95% CI: -0.553, 14.454) because of wide variations of signal intensity between lesions. Similar findings were obtained for LBR and per cent enhancement. No differences between the agents were noted in terms of safety parameters. (orig.)

  9. Comparison of two brain tumor-localizing MRI agent. GD-BOPTA and GD-DTPA. MRI and ICP study of rat brain tumor model

    International Nuclear Information System (INIS)

    Zhang, T.; Matsumura, A.; Yamamoto, T.; Yoshida, F.; Nose, T.

    2000-01-01

    In this study, we compared the behavior of Gd-BOPTA as a brain tumor selective contrast agent with Gd-DTPA in a common dose of 0.1 mmol/kg. We performed a MRI study using those two agent as contrast material, and we measured tissue Gd-concentrations by ICP-AES. As a result, Gd-BOPTA showed a better MRI enhancement in brain tumor. ICP showed significantly greater uptake of Gd-BOPTA in tumor samples, at all time course peaked at 5 minutes after administration, Gd being retained for a longer time in brain tumor till 2 hours, without rapid elimination as Gd-DTPA. We conclude that Gd-BOPTA is a new useful contrast material for MR imaging in brain tumor and an effective absorption agent for neutron capture therapy for further research. (author)

  10. MRI of the liver with the new contrast medium Gd-BOPTA

    International Nuclear Information System (INIS)

    Vogl, T.J.; Pegios, W.; Balzer, J.; Lissner, J.; Pirovano, G.

    1992-01-01

    A phase 1 study on 8 normals has been carried out to determine the effectiveness and safety during MRI of a new hepatobiliary contrast medium Gd-BOPTA for causing enhancement of the upper abdominal organs. Gradient echo sequences (flash), T 1 and T 2 -weighted spin echo sequences and turbo-flash sequences were used. The contrast medium was given as a single infusion in various concentrations (0.005, 0.05, 0.1 and 0.2 mmol/kg body weight). Optimal contrast of liver parenchyma was obtained with a dose of 0.05-0.1 mmol/kg body weight, resulting in contrast increase of 149.1% during gradient echo sequences and 107.8% during T 1 spin echo sequences. In general, the increased contrast lasted for about two hours. Because of the biliary and renal excretion there was an enormous increase in signal intensity of the bile ducts and a significant increase in the kidneys and ureters. The results of the first in-vivo-trial of Gd-BOPTA encourages the performance of further clinical studies of this new hepatobiliary contrast medium. (orig.) [de

  11. Lumbosacral lipoma : gadolinium-enhanced fat saturation T1 weighted MR image is necessary?

    International Nuclear Information System (INIS)

    Yoon, Man Won; Kim, Hyun Chul; Chung, Tae Woong; Seo, Jeong Jin; Chung, Gwang Woo; Kim, Yun Hyeon; Kim, Jae Kyu; Park, Jin Gyoon; Kang, Heoung Keun

    1999-01-01

    To evaluate the usefulness of contrast-enhanced fat saturation T1-weighted imaging for the evaluation of spinal lipoma, compared with clinical symptoms and surgical findings. Ten patients with lipomyelomeningocele, confirmed by surgery, were included in this study. In all cases, conventional spin echo T1-and T2-weighted MR imaging, and contrast-enhanced fat saturation T1-weighted imaging was performed to evaluate clinical symptoms, the position of the conus medullaris, the presence of cord tethering, and associated anomalies, and to compare the relative usefulness of the techniques. All ten patients were suffering from lipomyelomeningocele without filum terminale fibrolipoma or intradural lipoma. All cases were associated with cord tethering. As associated anomalies, there were seven cases of syringomyelia without hydrocephalus or anorectal anomaly. To evaluate the position of the spinal conus and the presence of cord tethering, conventional T1-weighted imaging was more useful than the contrast-enhanced fat saturation equivalent. In patients with early-stage spinal lipoma, MRI is useful for evaluation of the causes and position of cord tethering and associated anomalies Our results suggest that contrast-enhanced fat saturation T1-weighted images do not provide additional information concerning spinal lipoma, and that for the diagnosis of this condition, conventional T1 and T2-weighted images are more useful than those obtained by contrast-enhanced fat saturation T1-weighted imaging

  12. Contrast-enhanced turbo spin-echo(TSE) T1-weighted imaging: improved contrast of enhancing lesions

    International Nuclear Information System (INIS)

    Choi, Sung Wook; Lee, Ghi Jai; Shim, Jae Chan; Lee, Young Ju; Jeong, Se Hyung; Kim, Ho kyun

    1997-01-01

    The purpose of this study was to evaluate the effect of contrast improvement of enhancing brain lesions by inherent magnetization transfer effect in turbo spin-echo(TSE)T1-weighted MR imaging. Twenty-six enhancing lesions of 19 patients were included in this study. Using a 1.0T superconductive MR unit, contrast-enhanced SE T1-weighted images(TR=3D600 msec, TE=3D12 msec, NEX=3D2, acquistition time=3D4min 27sec) and contrast-enhanced TSE T1-weighted images(TR=3D600 msec, TE=3D12, acquistition time=3D1min 44sec) were obtained. Signal intensities at enhancing lesions and adjacent white matter were measured in the same regions of both images. Signal-to-noise ratio(SNR) of enhancing lesions and adjacent white matter, and con-trast-to-noise ratio(CNR) and lesion-to-background contrast (LBC) of enhancing lesions were calculated and statistically analysed using the paired t-test. On contrast-enhanced TSE T1-weighted images, SNR of enhancing lesions and adjacent white matter decreased by 18%(p<0.01) and 32%(p<0.01), respectively, compared to contrast-enhanced SE T1-weighted images. CNR and LBC of enhancing lesions increased by 16%(p<0.05) and 66%(p<0.01), respectively. Due to the proposed inherent magnetization transfer effects in TSE imaging, con-trast-enhanced T1-weighted TSE images demonstrated a statistically significant improvement in CNR and LBC, compared to conventional contrast-enhanced T1-weighted SE images, and scan time was much shorter

  13. Evaluation of bone marrow by opposed phase T1-weighted images and enhanced MR imaging

    International Nuclear Information System (INIS)

    Amano, Yasuo; Tanabe, Yoshihiro; Miyashita, Tsuguhiro; Hayashi, Hiromitsu; Horiuchi, Junichi; Nomura, Takeo; Kumazaki, Tatsuo

    1994-01-01

    We investigated bone marrow in a control group, cases of aplastic anemia and post-irradiation patients by examining T1-weighted (T1W1), short T1 inversion recovery (STIR), opposed phase T1W1 (op-T1W1) and Gd-DTPA enhanced op-T1W1 images obtained by 0.5 T MRI. Bone marrow was classified into four types based on MR findings. Normal marrow showed low intensity on op-T1W1 and STIR images without enhancement (I). Fatty marrow, which showed high intensity on T1W1 and op-T1W1 images was observed in aplastic anemia and post-irradiation patients (II). Hematopoietic marrow (III) showed low intensity on op-T1W1 and enhanced, while active hematopoietic marrow (IV) revealed high intensity on both STIR and op-T1W1 images and was enhanced following Gd-DTPA infusion. Aplastic anemia of moderate grade included types II, III and IV. Enhanced MR was needed to differentiate between types I and III since both types showed low intensity on op-T1W1 images. Furthermore, type IV was considered as hyperplastic compared with type III. Enhanced MR and op-T1W1 images were useful in evaluating hematopoiesis of bone marrow. (author)

  14. Evaluation of bone marrow by opposed phase T1-weighted images and enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Yasuo; Tanabe, Yoshihiro; Miyashita, Tsuguhiro; Hayashi, Hiromitsu; Horiuchi, Junichi; Nomura, Takeo; Kumazaki, Tatsuo (Nippon Medical School, Tokyo (Japan))

    1994-09-01

    We investigated bone marrow in a control group, cases of aplastic anemia and post-irradiation patients by examining T1-weighted (T1W1), short T1 inversion recovery (STIR), opposed phase T1W1 (op-T1W1) and Gd-DTPA enhanced op-T1W1 images obtained by 0.5 T MRI. Bone marrow was classified into four types based on MR findings. Normal marrow showed low intensity on op-T1W1 and STIR images without enhancement (I). Fatty marrow, which showed high intensity on T1W1 and op-T1W1 images was observed in aplastic anemia and post-irradiation patients (II). Hematopoietic marrow (III) showed low intensity on op-T1W1 and enhanced, while active hematopoietic marrow (IV) revealed high intensity on both STIR and op-T1W1 images and was enhanced following Gd-DTPA infusion. Aplastic anemia of moderate grade included types II, III and IV. Enhanced MR was needed to differentiate between types I and III since both types showed low intensity on op-T1W1 images. Furthermore, type IV was considered as hyperplastic compared with type III. Enhanced MR and op-T1W1 images were useful in evaluating hematopoiesis of bone marrow. (author).

  15. CE-Magnetic Resonance mammography for the evaluation of the contralateral breast in patients with diagnosed breast cancer; Ruolo della Risonanza Magnetica con Gd-BOPTA nella valutazione della mammella controlaterale in pazienti con tumore recentemente diagnosticato

    Energy Technology Data Exchange (ETDEWEB)

    Pediconi, Federica; Venditti, Fiammetta; Padula, Simona; Roselli, Antonella; Moriconi, Enrica; Catalano, Carlo; Passariello, Roberto [La Sapienza Univ., Roma (Italy). Dipartimento di scienze radiologiche; Giacomelli, Laura [La Sapienza Univ., Roma (Italy). Dipartimento di scienze chirurgiche

    2005-07-15

    Purpose. To evaluate the role of contrast-enhanced Magnetic Resonance Mammography (MRM) in the evaluation of the contralateral breast in patients with recently diagnosed breast cancer. Materials and methods. Fifty patients with proved unilateral breast cancer, with a negative contralateral breast at physical examination, ultrasound and mammography, were studied with a 1.5 T magnet (Siemens, Vision Plus, Germany). A bilateral breast surface coil was used. Dynamic 3D Flash T1-weighted sequences were acquired in the axial plane before and 0, 2, 4, 6 and 8 minutes after the administration of 0.1 mmol/kg of Gd-BOPTA at a flow rate of 2 ml/s followed by 10 ml of saline. The level of suspicion was reported on a scale from 0 to 5 following the BI-RADS classification, based on lesion morphology and kinetic features. The results were compared with the histological findings after biopsy or surgery. Results. Fourteen out of 50 patients (28%) had contralateral lesions identified on MRM. Biopsy was performed in four of them for suspicious lesions (BI-RADS 4) while 10 patients underwent surgery because of highly suggestive malignant lesions (BI-RADS 5). Histology diagnosed three fibroadenomas, 5 ductal carcinoma in situ, 2 lobular carcinomas in situ, 3 invasive ductal carcinomas and 1 invasive lobular carcinoma. Contrast enhanced MRM yielded no false negative and three false positives. Conclusions. Our results demonstrate a very good accuracy of Magnetic Resonance Mammography in the detection of synchronous contralateral cancer in patients with newly diagnosed breast cancer. Therefore, contrast-enhanced MRM could be introduced to screen patients with proven breast cancer before they under-go surgery. [Italian] Scopo. Definire il ruolo della Risonanza Magnetica nella valutazione della mammella contro laterale in pazienti con tumore della mammella recentemente diagnosticato. Materiale e metodi. Cinquanta pazienti con tumore monolaterale della mammella e mammella controlaterale

  16. Dynamic contrast-enhanced quantitative perfusion measurement of the brain using T-1-weighted MRI at 3T

    DEFF Research Database (Denmark)

    Larsson, H.B.W.; Hansen, A.E.; Berg, H.K.

    2008-01-01

    Purpose: To develop a method for the measurement of brain perfusion based on dynamic contrast-enhanced T-1-weighted MR imaging. Materials and Methods: Dynamic imaging of the first pass of a bolus of a paramagnetic contrast agent was performed using a 3T whole-body magnet and a T-1-weighted fast...... field echo sequence. The input function was obtained from the internal carotid artery. An initial T-1 measurement was performed in order to convert the MR signal to concentration of the contrast agent. Pixelwise and region of interest (ROI)based calculation of cerebral perfusion (CBF) was performed...... inside the infarct core was, 9 mL/100g/min in one of the stroke patients. The other stroke patient had postischemic hyperperfusion and CBF was 140 mL/100g/min. Conclusion: Absolute values of brain perfusion can be obtained using dynamic contrast-enhanced MRI. These values correspond,to expected values...

  17. Advantages of gadobenate dimeglumine-enhanced MR cholangiography in the diagnosis of post-liver transplant bile leakage.

    Science.gov (United States)

    Fontarensky, M; Montoriol, P-F; Buc, E; Poincloux, L; Petitcolin, V; Da Ines, D

    2013-04-01

    To assess the value of magnetic resonance cholangiography with gadobenate dimeglumine (Gd-BOPTA) where there is a suspicion of bile leakage in the post-liver transplant patient. Eight patients who had undergone a liver transplant underwent 14 MR cholangiograms, five of whom presented bile leakage while the other three had no biliary system complications. The results were compared to conventional bile duct opacification (by endoscopy or t-tube cholangiogram). The analysis covered whether there was opacification of the common bile duct and intrahepatic bile ducts on T1-weighted sequences after an injection of Gd-BOPTA on delayed biliary excretion phase sequences that were carried out on average 74 min after the injection. Enhancing perihepatic collections were also taken into account. Opacification of the bile ducts on delayed-phase MR cholangiogram sequences was always seen in the absence of bile leakage, and was never found when leakage was present. Enhancing perihepatic collections pointed to bile leakage every time. Gd-BOPTA-enhanced MR cholangiography is a simple and non-invasive technique for detecting bile leakage in the post-liver transplant patient. Copyright © 2013 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  18. Estimating kinetic parameters from dynamic contrast-enhanced T(1)-weighted MRI of a diffusable tracer: standardized quantities and symbols

    DEFF Research Database (Denmark)

    Tofts, P.S.; Brix, G; Buckley, D.L.

    1999-01-01

    We describe a standard set of quantity names and symbols related to the estimation of kinetic parameters from dynamic contrast-enhanced T(1)-weighted magnetic resonance imaging data, using diffusable agents such as gadopentetate dimeglumine (Gd-DTPA). These include a) the volume transfer constant K......-limited conditions K(trans) equals the blood plasma flow per unit volume of tissue; under permeability-limited conditions K(trans) equals the permeability surface area product per unit volume of tissue. We relate these quantities to previously published work from our groups; our future publications will refer...

  19. Intracranial arterial wall enhancement using gadolinium-enhanced 3D black-blood T1-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Koichi, E-mail: k-takano@fukuoka-u.ac.jp; Hida, Kosuke; Kuwabara, Yasuo; Yoshimitsu, Kengo

    2017-01-15

    Purpose: We investigated the enhancement of the intracranial arterial walls with gadolinium-enhanced, black-blood three-dimensional T1-weighted imaging (Gd-3DBB) by using an improved motion-sensitized driven-equilibrium (iMSDE)—prepared volumetric isotropic turbo spin-echo acquisition (VISTA). Methods: A total of 115 patients underwent FLAIR, 3D-TOF-MRA and Gd-3DBB with a 1.5-T scanner. The degree and distribution of the arterial wall enhancement on Gd-3DBB was assessed. The association of the degree of wall enhancement with brain infarction/ischemic lesions on FLAIR, luminal changes on 3D-TOF-MRA, and cardiovascular risk factors (CVRFs) was investigated by univariate and multiple logistic regression analyses. Results: Strong enhancement of the arterial walls was observed in 77 vertebral arteries (33.5%), 4 basilar arteries (3.5%), 31 supraclinoid internal carotid arteries (ICAs) (13.5%) and 8 middle cerebral arteries (3.5%). In addition, 221 intrapetrous ICAs (96.1%) showed strong enhancement. After adjusting for confounding factors, multivariate analyses showed that the patient age was independently associated with the strong wall enhancement of the arteries for both the posterior (OR, 1.088; 95% CI, 1.034–1.146) and the anterior circulation (OR, 1.098, 95% CI 1.029–1.172). In addition, the presence of the supratentorial brain infarctions was independently associated with the strong wall enhancement in the anterior circulation excluding the intrapetrous ICAs (OR, 4.097; 95% CI, 1.483–11.319). Conclusions: Although the arterial wall enhancement on the Gd-3DBB probably reflects normal aging, the enhancement in the anterior circulation might be related to brain infarctions. On the other hand, the intrapetrous ICA enhancement is considered a nonspecific finding and should not be mistaken for arterial pathologies such as atherosclerosis or arteritis.

  20. Intracranial arterial wall enhancement using gadolinium-enhanced 3D black-blood T1-weighted imaging

    International Nuclear Information System (INIS)

    Takano, Koichi; Hida, Kosuke; Kuwabara, Yasuo; Yoshimitsu, Kengo

    2017-01-01

    Purpose: We investigated the enhancement of the intracranial arterial walls with gadolinium-enhanced, black-blood three-dimensional T1-weighted imaging (Gd-3DBB) by using an improved motion-sensitized driven-equilibrium (iMSDE)—prepared volumetric isotropic turbo spin-echo acquisition (VISTA). Methods: A total of 115 patients underwent FLAIR, 3D-TOF-MRA and Gd-3DBB with a 1.5-T scanner. The degree and distribution of the arterial wall enhancement on Gd-3DBB was assessed. The association of the degree of wall enhancement with brain infarction/ischemic lesions on FLAIR, luminal changes on 3D-TOF-MRA, and cardiovascular risk factors (CVRFs) was investigated by univariate and multiple logistic regression analyses. Results: Strong enhancement of the arterial walls was observed in 77 vertebral arteries (33.5%), 4 basilar arteries (3.5%), 31 supraclinoid internal carotid arteries (ICAs) (13.5%) and 8 middle cerebral arteries (3.5%). In addition, 221 intrapetrous ICAs (96.1%) showed strong enhancement. After adjusting for confounding factors, multivariate analyses showed that the patient age was independently associated with the strong wall enhancement of the arteries for both the posterior (OR, 1.088; 95% CI, 1.034–1.146) and the anterior circulation (OR, 1.098, 95% CI 1.029–1.172). In addition, the presence of the supratentorial brain infarctions was independently associated with the strong wall enhancement in the anterior circulation excluding the intrapetrous ICAs (OR, 4.097; 95% CI, 1.483–11.319). Conclusions: Although the arterial wall enhancement on the Gd-3DBB probably reflects normal aging, the enhancement in the anterior circulation might be related to brain infarctions. On the other hand, the intrapetrous ICA enhancement is considered a nonspecific finding and should not be mistaken for arterial pathologies such as atherosclerosis or arteritis.

  1. Content-based image retrieval using spatial layout information in brain tumor T1-weighted contrast-enhanced MR images.

    Science.gov (United States)

    Huang, Meiyan; Yang, Wei; Wu, Yao; Jiang, Jun; Gao, Yang; Chen, Yang; Feng, Qianjin; Chen, Wufan; Lu, Zhentai

    2014-01-01

    This study aims to develop content-based image retrieval (CBIR) system for the retrieval of T1-weighted contrast-enhanced MR (CE-MR) images of brain tumors. When a tumor region is fed to the CBIR system as a query, the system attempts to retrieve tumors of the same pathological category. The bag-of-visual-words (BoVW) model with partition learning is incorporated into the system to extract informative features for representing the image contents. Furthermore, a distance metric learning algorithm called the Rank Error-based Metric Learning (REML) is proposed to reduce the semantic gap between low-level visual features and high-level semantic concepts. The effectiveness of the proposed method is evaluated on a brain T1-weighted CE-MR dataset with three types of brain tumors (i.e., meningioma, glioma, and pituitary tumor). Using the BoVW model with partition learning, the mean average precision (mAP) of retrieval increases beyond 4.6% with the learned distance metrics compared with the spatial pyramid BoVW method. The distance metric learned by REML significantly outperforms three other existing distance metric learning methods in terms of mAP. The mAP of the CBIR system is as high as 91.8% using the proposed method, and the precision can reach 93.1% when the top 10 images are returned by the system. These preliminary results demonstrate that the proposed method is effective and feasible for the retrieval of brain tumors in T1-weighted CE-MR Images.

  2. Content-based image retrieval using spatial layout information in brain tumor T1-weighted contrast-enhanced MR images.

    Directory of Open Access Journals (Sweden)

    Meiyan Huang

    Full Text Available This study aims to develop content-based image retrieval (CBIR system for the retrieval of T1-weighted contrast-enhanced MR (CE-MR images of brain tumors. When a tumor region is fed to the CBIR system as a query, the system attempts to retrieve tumors of the same pathological category. The bag-of-visual-words (BoVW model with partition learning is incorporated into the system to extract informative features for representing the image contents. Furthermore, a distance metric learning algorithm called the Rank Error-based Metric Learning (REML is proposed to reduce the semantic gap between low-level visual features and high-level semantic concepts. The effectiveness of the proposed method is evaluated on a brain T1-weighted CE-MR dataset with three types of brain tumors (i.e., meningioma, glioma, and pituitary tumor. Using the BoVW model with partition learning, the mean average precision (mAP of retrieval increases beyond 4.6% with the learned distance metrics compared with the spatial pyramid BoVW method. The distance metric learned by REML significantly outperforms three other existing distance metric learning methods in terms of mAP. The mAP of the CBIR system is as high as 91.8% using the proposed method, and the precision can reach 93.1% when the top 10 images are returned by the system. These preliminary results demonstrate that the proposed method is effective and feasible for the retrieval of brain tumors in T1-weighted CE-MR Images.

  3. Gadoxate-enhanced T1-weighted MR cholangiography: comparison of 1.5 T and 3.0 T

    Energy Technology Data Exchange (ETDEWEB)

    Koelblinger, C.; Schima, W.; Weber, M.; Mang, T.; Nemec, S.; Kulinna-Cosentini, C.; Bastati, N.; Ba-Ssalamah, A. [Universitaetsklinik fuer Radiodiagnostik, Medizinische Univ. Wien (Austria)

    2009-06-15

    Purpose: to qualitatively and quantitatively compare gadoxate-enhanced T1-weighted MR cholangiography at magnetic field strengths of 1.5 T and 3.0 T. Materials and methods: a total of 40 patients with a non-dilated biliary system were retrospectively included in the study. T1-weighted MR cholangiography 20 min after IV administration of 0.025 mmol/kg gadoxate (Primovist trademark) was performed in 20 patients at 1.5 T and in another 20 patients at 3.0 T. Contrast-to-noise ratios (CNR) of the biliary system (common bile duct - CBD, right hepatic duct - RHD, left hepatic duct - LHD) compared to the periductal tissue were measured. Two radiologists also qualitatively assessed the visibility of the intrahepatic and extrahepatic biliary system using a six-point rating scale. The Mann-Whitney U-test and Pearson's correlation coefficient were used for statistical analysis. Results: the CNRs of the intrahepatic and extrahepatic hepatic bile ducts were significantly higher at 3.0 T. Qualitative analysis showed a significant superiority for 3.0 T in the delineation of the intrahepatic biliary system (RHD, LHD, segmental ducts). (orig.)

  4. Contrast-enhanced Magnetic Resonance Imaging of Pelvic Bone Metastases at 3.0 T: Comparison Between 3-dimensional T1-weighted CAIPIRINHA-VIBE Sequence and 2-dimensional T1-weighted Turbo Spin-Echo Sequence.

    Science.gov (United States)

    Yoon, Min A; Hong, Suk-Joo; Lee, Kyu-Chong; Lee, Chang Hee

    2018-06-12

    This study aimed to compare 3-dimensional T1-weighted gradient-echo sequence (CAIPIRINHA-volumetric interpolated breath-hold examination [VIBE]) with 2-dimensional T1-weighted turbo spin-echo sequence for contrast-enhanced magnetic resonance imaging (MRI) of pelvic bone metastases at 3.0 T. Thirty-one contrast-enhanced MRIs of pelvic bone metastases were included. Two contrast-enhanced sequences were evaluated for the following parameters: overall image quality, sharpness of pelvic bone, iliac vessel clarity, artifact severity, and conspicuity and edge sharpness of the smallest metastases. Quantitative analysis was performed by calculating signal-to-noise ratio and contrast-to-noise ratio of the smallest metastases. Significant differences between the 2 sequences were assessed. CAIPIRINHA-VIBE had higher scores for overall image quality, pelvic bone sharpness, iliac vessel clarity, and edge sharpness of the metastatic lesions, and had less artifacts (all P 0.05). Our results suggest that CAIPIRINHA-VIBE may be superior to turbo spin-echo for contrast-enhanced MRI of pelvic bone metastases at 3.0 T.

  5. Fat-suppressed MRI of musculoskeletal infection: fast T2-weighted techniques versus gadolinium-enhanced T1-weighted images

    International Nuclear Information System (INIS)

    Miller, T.T.; Randolph, D.A. Jr.; Staron, R.B.; Feldman, F.; Cushin, S.

    1997-01-01

    Purpose. To investigate gadolinium's role in imaging musculoskeletal infection by comparing the conspicuity and extent of inflammatory changes demonstrated on gadolinium-enhanced fat-suppressed T1-weighted images versus fat-suppressed fast T2-weighted sequences. Design. Eighteen patients with infection were imaged in a 1.5-T unit, using frequency-selective and/or inversion recovery fat-suppressed fast T2-weighted images (T2WI) and gadolinium-enhanced frequency-selective fat-suppressed T1-weighted images (T1WI). Thirty-four imaging planes with both a fat-suppressed gadolinium-enhanced T1-weighted sequence and a fat-suppressed T2-weighted sequence were obtained. Comparison of the extent and conspicuity of signal intensity changes was made for both bone and soft tissue in each plane. Results. In bone, inflammatory change was equal in extent and conspicuity on fat-suppressed T2WI and fat-suppressed T1WI with gadolinium in 19 planes, more extensive or conspicuous on T2WI in three planes, and less so on T2WI in two planes. Marrow was normal on all three sequences in 10 cases. In soft tissue, inflammatory change was seen equally well in 20 instances, more extensively or conspicuously on the T2WI in 11 instances, and less so on T2WI in 2 instances. One case had no soft tissue involvement on any of the sequences. Five abscesses and three joint effusions were present, all more conspicuously delineated from surrounding inflammatory change on the fat-saturated T1WI with gadolinium. The average imaging time for the fat-saturated T1WI with gadolinium was 6.75 min, while that of the T2-weighted sequences was 5.75 min. Conclusion. Routine use of gadolinium is not warranted. Instead, gadolinium should be reserved for clinically suspected infection in or around a joint, and in cases refractory to medical or surgical treatment due to possible abscess formation. (orig.)

  6. Diagnostic Utility of Contrast-enhanced 3D T1-weighted Imaging in Acute Cerebral Infarction Associated with Graves Disease.

    Science.gov (United States)

    Gon, Yasufumi; Sakaguchi, Manabu; Oyama, Naoki; Mochizuki, Hideki

    2017-02-01

    Graves disease is rarely complicated with cerebrovascular steno-occlusive diseases. Previous studies have suggested several hypotheses for this occurrence, including excess thyroid hormone, which stimulates the sympathetic nervous system, which in turn causes an abnormal hemodynamic response with consequent atherosclerotic changes, and antithyroid antibodies cause local vascular inflammation in patients with Graves disease. However, radiological findings of vasculitis in patients with Graves disease and cerebral infarction remain less known. We report the case of a 30-year-old Japanese woman with acute cerebral infarction due to vasculitis associated with Graves disease. She was admitted to our hospital with a 4-day history of intermittent transient dysarthria and limb shaking of the left leg when standing. Three weeks before admission, she went to a local hospital because of general malaise and was diagnosed with Graves disease. Neurological examination revealed paralytic dysarthria, left central facial nerve palsy, and left hemiparesis (manual muscle testing, 4 of 5). Blood examinations showed hyperthyroidism (thyroid-stimulating hormone ≤.010 µU/mL; free T3 ≥25.0 pg/mL; free T4 ≥8.0 ng/dL) and elevation of antithyroid antibody levels (thyroid peroxidase antibody, 87 IU/mL). The vessel wall of the right internal carotid artery was markedly enhanced on contrast-enhanced three-dimensional T1-weighted magnetic resonance imaging, suggesting vasculitis. Magnetic resonance angiography revealed right internal carotid artery occlusion after the branching ophthalmic artery. Arterial stenosis due to vasculitis was considered the cause of hemodynamic ischemic stroke. Vessel wall imaging such as high-resolution contrast-enhanced T1-weighted imaging seems useful for assessing the underlying mechanism of stroke in patients with Graves disease. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  7. Cerebral and meningeal manifestations of AIDS: comparison of plain T2-weighted images and Gd-DTPA enhanced T1-weighted images in 105 patients

    International Nuclear Information System (INIS)

    Jochens, R.; Henkes, H.; Steinkamp, H.J.; Terstegge, K.; Hosten, N.; Ruf, B.; Schoerner, W.

    1994-01-01

    The purpose of the present study was to evaluate the potential of T1-weighted Gd-DTPA enhanced MR imaging in the diagnosis of cerebral manifestations of AIDS. 105 patients with AIDS were imaged with plain T2-weighted images as well as with Gd-DTPA enhanced T1-weighted pulse sequences. Our study revealed comparable sensitivities in the detection of morphological changes as shown on plain T2-weighted images and Gd-DTPA enhanced T1-weighted images in 55% of patients (normal and pathologic findings). Plain T2-weighted images were superior in 28.5% and provided significantly better results in 8.5% of patients. Gd-DTPA enhanced T1-weighted images were superior in only 5% cases and revealed significantly better results in 3%. As a result, T2-weighted plain images were superior in approximately 40% of patients concerning detection of morphologic changes. In almost 10% of patients with parechymal and meningeal lesions, Gd-DTPA enhanced T1-weighted images, however, were superior or even significantly better compared to T2-weighted plain images. The detection of morphologic changes in MR imaging can be further increased with Gd-DTPA. With regard to differential diagnosis and diesease activity, plain T2-weighted images and Gd-DTPA enhanced T1-weighted images revealed comparable results in 42% of patients (normal and pathologic findings). T2-weighted plain images were superior in 2% of cases whereas Gd-DTPA enhanced T1-weighted images were superior in as much as 56% of patient. MR imaging enhanced with Gd-DTPA yielded additional information on disease activity in 73% of patients with pathologic findings in the cerebral parechyma and the meninges. The surplus of information also refers to the etiology of cerebral pathology and differential diagnosis. Because of the frequency of cerebral manifestations in AIDS, early diagnosis for initiation of therapy and follow-up studies to monitor therapy are crucial. (orig./MG) [de

  8. Evaluation of intraaxial enhancing brain tumors on magnetic resonance imaging: intraindividual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine for visualization and assessment, and implications for surgical intervention.

    Science.gov (United States)

    Kuhn, Matthew J; Picozzi, Piero; Maldjian, Joseph A; Schmalfuss, Ilona M; Maravilla, Kenneth R; Bowen, Brian C; Wippold, Franz J; Runge, Val M; Knopp, Michael V; Wolansky, Leo J; Gustafsson, Lars; Essig, Marco; Anzalone, Nicoletta

    2007-04-01

    The goal in this article was to compare 0.1 mmol/kg doses of gadobenate dimeglumine (Gd-BOPTA) and gadopentetate dimeglumine, also known as gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA), for enhanced magnetic resonance (MR) imaging of intraaxial brain tumors. Eighty-four patients with either intraaxial glioma (47 patients) or metastasis (37 patients) underwent two MR imaging examinations at 1.5 tesla, one with Gd-BOPTA as the contrast agent and the other with Gd-DTPA. The interval between fully randomized contrast medium administrations was 2 to 7 days. The T1-weighted spin echo and T2-weighted fast spin echo images were acquired before administration of contrast agents and T1-weighted spin echo images were obtained after the agents were administered. Acquisition parameters and postinjection acquisition times were identical for the two examinations in each patient. Three experienced readers working in a fully blinded fashion independently evaluated all images for degree and quality of available information (lesion contrast enhancement, lesion border delineation, definition of disease extent, visualization of the lesion's internal structures, global diagnostic preference) and quantitative enhancement (that is, the extent of lesion enhancement after contrast agent administration compared with that seen before its administration [hereafter referred to as percent enhancement], lesion/brain ratio, and contrast/noise ratio). Differences were tested with the Wilcoxon signed-rank test. Reader agreement was assessed using kappa statistics. Significantly better diagnostic information/imaging performance (p 0.4). Lesion visualization, delineation, definition, and contrast enhancement are significantly better after administration of 0.1 mmol/kg Gd-BOPTA, potentially allowing better surgical planning and follow up and improved disease management.

  9. Role of MR imaging in the differentiation of benign and nonbenign intracranial meningiomas. The utility of contrast-enhanced T1-weighted images

    International Nuclear Information System (INIS)

    Tanaka, Yasunori; Matsuo, Michimasa

    1996-01-01

    The purpose of this study was to develop useful criteria for distinguishing nonbenign (atypical and malignant) primary intracranial meningiomas from their benign counterparts by using magnetic resonance imaging (MRI). To determine useful MRI findings for this purpose, 12 benign and five nonbenign meningiomas were retrospectively evaluated according to the following items: tumor signal intensity on plain T1-, T2- and proton density-weighted images, degree of perifocal edema on T2-weighted images, morphology of the tumor margin on contrast-enhanced T1-weighted images, presence of irregular nodule and/or mushrooming pattern on contrast-enhanced T1-weighted images, homogeneity of the tumor on contrast-enhanced T1-weighted images, and presence of marked skull destruction. Markedly irregular tumor margin, presence of irregular nodule and/or mushrooming pattern and markedly inhomogeneous enhancing pattern were significantly more frequent in nonbenign meningiomas. We defined these three MRI findings as nonbenign findings, and tried to categorize meningiomas by the number of nonbenign findings. It was found that 10 meningiomas with no or one nonbenign finding were benign lesions, of four meningiomas with two nonbenign findings two were benign lesions and two were nonbenign lesions, and three meningiomas with three nonbenign findings were nonbenign lesions. The two benign meningiomas with two nonbenign findings were accompanied by increased mitotic activity or brain invasion. Contrast-enhanced T1-weighted images were considered very useful in distinguishing benign and nonbenign meningiomas. (author)

  10. Mn-DPDP enhanced T1-weighted magnetic resonance cholangiography: usefulness in the diagnosis and roadmap for the treatment of intrahepatic choIedochoIithiasis

    International Nuclear Information System (INIS)

    Park, Mi Suk; Kim, Ki Whang; Yu, Jeong Sik; Kim, Myeong Jin; Lee, Jong Tae; Yoo, Hyung Sik; Kim, Kyoung Won; Kim, Tae Kyoung; Ha, Hyun Kwon

    2004-01-01

    To assess the preliminary findings of Mn-enhanced T1-weighted MR cholangiography for the evaluation of intrahepatic choledocholithiasis. Seven patients with recurrent pyogenic cholangitis underwent conventional heavily T2-weighted and manganese-enhanced T1-weighted MR cholangiography. For the former, the two reviewers focused on intrahepatic ductal dilatation, calculi, and stricture; and for the latter, ductal enhancement. In seven patients, 13 diseased segments were depicted and intrahepatic bile ductal dilatation was present in all 13 of these in all seven patients. Calculi were present in eight segments in six patients, and stricture in four segments in three patients. Of the 13 diseased segmental ducts, six were seen at manganese-enhanced imaging to be filled with contrast material, suggesting a functioning bile duct. Combined T2-weighted and mangafodipir trisodium-enhanced T1-weighted MR cholangiography provides both anatomic detail and functional detail of the biliary system. Combined MR cholangiography is useful for the evaluation of intrahepatic choledocholithiasis, demonstrating the stricture and function of the segmental ducts involved

  11. The Effect of the Degree of Luminal Contrast-Enhancement on CT Measurement of Plaque Size: A Comparison with T1-weighted Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Choi, Byoung Wook; Hur, Jin; Lee, Hye Jeong; Kim, Young Jin; Choe, Kyu Ok; Kim, Tae Hoon

    2010-01-01

    We studied early and delayed contrast-enhanced CT to determine the effects of the degree of luminal enhancement on the measurement of plaque size compared to T1-weighted MRI. T1-weighted MRI and a two-phase contrast-enhanced CT was performed in 5 New Zealand white rabbits with atherosclerosis. Early-phase images were acquired during an expected peak enhancement period of the lumen; delayed-phase images were acquired 240 sec after administration of the contrast media. Anteroposterior and lateral luminal diameters (APD, LD), luminal area (LA), total vessel area (TVA), and plaque area (PA) of the aorta were measured on MRI and CT, respectively and compared to each other. A total of 78 slices of the aorta were analyzed. PA, measured on T1-weighted MR images, was significantly greater than PA for both early-phase and delayed-phase CT (p 2 (p 2 (p 2 (p = 0.159) for MRI vs. early-phase CT, MRI vs. delayed-phase CT, and early-phase CT vs. delayed-phase CT, respectively. Different luminal densities by contrast enhancement do not affect the CT measurement of plaque area for the detection of obstructive coronary artery disease

  12. Comparison of contrast-enhanced T1-weighted and 3D constructive interference in steady state images for predicting outcome after hearing-preservation surgery for vestibular schwannoma

    Energy Technology Data Exchange (ETDEWEB)

    Kocaoglu, M.; Bulakbasi, N.; Ucoz, T.; Ustunsoz, B.; Tayfun, C.; Somuncu, I. [GATA Department of Radiology, 06018, Etlik, Ankara (Turkey); Pabuscu, Y. [Department of Radiology, Celal Bayar University, Manisa (Turkey)

    2003-07-01

    We compared contrast-enhanced T1-weighted and 3D constructive interference in steady state (CISS) sequences for demonstrating possible prognostic factors in hearing-preservation surgery for vestibular schwannoma. We studied 22 patients with vestibular schwannomas having hearing-preservation surgery. Postoperatively six (27%) had a facial palsy and eight (36%) had hearing loss. There was a significant correlation between the size of the tumour and facial palsy (r=-0.72). Both techniques adequately demonstrated all tumours. Involvement of the fundus of the internal auditory canal (IAC) and a small distance between the lateral border of the tumour and the fundus were correlated significantly with hearing loss (r=-0.81 and -0.75, respectively). The 3D-CISS sequence, by virtue of its high contrast resolution was superior to T1-weighted images (P<0.05) for detection of the fundal involvement. The direction of displacement of the facial nerve did not correlate with facial palsy or hearing loss. We think that 3D-CISS images better show the features influencing surgical outcome, but that contrast-enhanced T1-weighted images are required for diagnosis. (orig.)

  13. Comparison of contrast-enhanced T1-weighted and 3D constructive interference in steady state images for predicting outcome after hearing-preservation surgery for vestibular schwannoma

    International Nuclear Information System (INIS)

    Kocaoglu, M.; Bulakbasi, N.; Ucoz, T.; Ustunsoz, B.; Tayfun, C.; Somuncu, I.; Pabuscu, Y.

    2003-01-01

    We compared contrast-enhanced T1-weighted and 3D constructive interference in steady state (CISS) sequences for demonstrating possible prognostic factors in hearing-preservation surgery for vestibular schwannoma. We studied 22 patients with vestibular schwannomas having hearing-preservation surgery. Postoperatively six (27%) had a facial palsy and eight (36%) had hearing loss. There was a significant correlation between the size of the tumour and facial palsy (r=-0.72). Both techniques adequately demonstrated all tumours. Involvement of the fundus of the internal auditory canal (IAC) and a small distance between the lateral border of the tumour and the fundus were correlated significantly with hearing loss (r=-0.81 and -0.75, respectively). The 3D-CISS sequence, by virtue of its high contrast resolution was superior to T1-weighted images (P<0.05) for detection of the fundal involvement. The direction of displacement of the facial nerve did not correlate with facial palsy or hearing loss. We think that 3D-CISS images better show the features influencing surgical outcome, but that contrast-enhanced T1-weighted images are required for diagnosis. (orig.)

  14. Detection of prostate carcinomas with T1-weighted dynamic contrast-enhanced MRI. Value of two-compartment model

    International Nuclear Information System (INIS)

    Kiessling, F.; Lichy, M.; Farhan, N.; Delorme, S.; Kauczor, H.U.; Grobholz, R.; Heilmann, M.; Michel, M.S.; Trojan, L.; Werner, A.; Rabe, J.; Schlemmer, H.P.

    2003-01-01

    Aim The suitability of dynamic parameters of the two-compartment model for detecting prostate carcinomas and its correlation with tumor microvascular density were evaluated. The study included 43 patients with biopsy-proven prostate carcinoma: 28 were examined by 1.0-T MRI (Turbo-FLASH) and 15 by 1.5-T MRI (FLASH) with infusion of 0.1 mmol/kg Gd-DTPA. Signal time curves were parametrized with an open two-compartment model in amplitude and exchange rate constants (k ep ).The microvascular density of resected prostate carcinomas was determined. The microvascular density in the tumors was significantly higher than in the adjacent healthy prostate tissue and correlated in both sequences with k ep . Prostate carcinomas of the peripheral zone were demarcated by amplitude and k ep . In the Turbo-FLASH sequence there was a significant difference between the tumor tissue and healthy peripheral zone in terms of k ep and in the FLASH sequence in terms of amplitude. Prostate carcinomas can be visualized with dynamic T1-weighted MR sequences using a two-compartment model. Moreover, the parameter k ep reveals the microvascular density in the tumor and can thus provide valuable clinical information for characterizing the tumors. (orig.) [de

  15. SU-F-I-16: Short Breast MRI with High-Resolution T2-Weighted and Dynamic Contrast Enhanced T1-Weighted Images

    International Nuclear Information System (INIS)

    Ma, J; Son, J; Arun, B; Hazle, J; Hwang, K; Madewell, J; Yang, W; Dogan, B; Wang, K; Bayram, E

    2016-01-01

    Purpose: To develop and demonstrate a short breast (sb) MRI protocol that acquires both T2-weighted and dynamic contrast-enhanced T1-weighted images in approximately ten minutes. Methods: The sb-MRI protocol consists of two novel pulse sequences. The first is a flexible fast spin-echo triple-echo Dixon (FTED) sequence for high-resolution fat-suppressed T2-weighted imaging, and the second is a 3D fast dual-echo spoiled gradient sequence (FLEX) for volumetric fat-suppressed T1-weighted imaging before and post contrast agent injection. The flexible FTED sequence replaces each single readout during every echo-spacing period of FSE with three fast-switching bipolar readouts to produce three raw images in a single acquisition. These three raw images are then post-processed using a Dixon algorithm to generate separate water-only and fat-only images. The FLEX sequence acquires two echoes using dual-echo readout after each RF excitation and the corresponding images are post-processed using a similar Dixon algorithm to yield water-only and fat-only images. The sb-MRI protocol was implemented on a 3T MRI scanner and used for patients who had undergone concurrent clinical MRI for breast cancer screening. Results: With the same scan parameters (eg, spatial coverage, field of view, spatial and temporal resolution) as the clinical protocol, the total scan-time of the sb-MRI protocol (including the localizer, bilateral T2-weighted, and dynamic contrast-enhanced T1-weighted images) was 11 minutes. In comparison, the clinical breast MRI protocol took 43 minutes. Uniform fat suppression and high image quality were consistently achieved by sb-MRI. Conclusion: We demonstrated a sb-MRI protocol comprising both T2-weighted and dynamic contrast-enhanced T1-weighted images can be performed in approximately ten minutes. The spatial and temporal resolution of the images easily satisfies the current breast MRI accreditation guidelines by the American College of Radiology. The protocol has the

  16. SU-F-I-16: Short Breast MRI with High-Resolution T2-Weighted and Dynamic Contrast Enhanced T1-Weighted Images

    Energy Technology Data Exchange (ETDEWEB)

    Ma, J; Son, J; Arun, B; Hazle, J; Hwang, K; Madewell, J; Yang, W; Dogan, B [UT MD Anderson Cancer Center, Houston, TX (United States); Wang, K; Bayram, E [GE Healthcare Technologies, Waukesha, Wisconsin (United States)

    2016-06-15

    Purpose: To develop and demonstrate a short breast (sb) MRI protocol that acquires both T2-weighted and dynamic contrast-enhanced T1-weighted images in approximately ten minutes. Methods: The sb-MRI protocol consists of two novel pulse sequences. The first is a flexible fast spin-echo triple-echo Dixon (FTED) sequence for high-resolution fat-suppressed T2-weighted imaging, and the second is a 3D fast dual-echo spoiled gradient sequence (FLEX) for volumetric fat-suppressed T1-weighted imaging before and post contrast agent injection. The flexible FTED sequence replaces each single readout during every echo-spacing period of FSE with three fast-switching bipolar readouts to produce three raw images in a single acquisition. These three raw images are then post-processed using a Dixon algorithm to generate separate water-only and fat-only images. The FLEX sequence acquires two echoes using dual-echo readout after each RF excitation and the corresponding images are post-processed using a similar Dixon algorithm to yield water-only and fat-only images. The sb-MRI protocol was implemented on a 3T MRI scanner and used for patients who had undergone concurrent clinical MRI for breast cancer screening. Results: With the same scan parameters (eg, spatial coverage, field of view, spatial and temporal resolution) as the clinical protocol, the total scan-time of the sb-MRI protocol (including the localizer, bilateral T2-weighted, and dynamic contrast-enhanced T1-weighted images) was 11 minutes. In comparison, the clinical breast MRI protocol took 43 minutes. Uniform fat suppression and high image quality were consistently achieved by sb-MRI. Conclusion: We demonstrated a sb-MRI protocol comprising both T2-weighted and dynamic contrast-enhanced T1-weighted images can be performed in approximately ten minutes. The spatial and temporal resolution of the images easily satisfies the current breast MRI accreditation guidelines by the American College of Radiology. The protocol has the

  17. Free-breathing contrast-enhanced T1-weighted gradient-echo imaging with radial k-space sampling for paediatric abdominopelvic MRI

    Energy Technology Data Exchange (ETDEWEB)

    Chandarana, Hersh; Block, Kai T.; Winfeld, Matthew J.; Lala, Shailee V.; Mazori, Daniel; Giuffrida, Emalyn; Babb, James S.; Milla, Sarah S. [New York University Langone Medical Center, Department of Radiology, New York, NY (United States)

    2014-02-15

    To compare the image quality of contrast-enhanced abdominopelvic 3D fat-suppressed T1-weighted gradient-echo imaging with radial and conventional Cartesian k-space acquisition schemes in paediatric patients. Seventy-three consecutive paediatric patients were imaged at 1.5 T with sequential contrast-enhanced T1-weighted Cartesian (VIBE) and radial gradient echo (GRE) acquisition schemes with matching parameters when possible. Cartesian VIBE was acquired as a breath-hold or as free breathing in patients who could not suspend respiration, followed by free-breathing radial GRE in all patients. Two paediatric radiologists blinded to the acquisition schemes evaluated multiple parameters of image quality on a five-point scale, with higher score indicating a more optimal examination. Lesion presence or absence, conspicuity and edge sharpness were also evaluated. Mixed-model analysis of variance was performed to compare radial GRE and Cartesian VIBE. Radial GRE had significantly (all P < 0.001) higher scores for overall image quality, hepatic edge sharpness, hepatic vessel clarity and respiratory motion robustness than Cartesian VIBE. More lesions were detected on radial GRE by both readers than on Cartesian VIBE, with significantly higher scores for lesion conspicuity and edge sharpness (all P < 0.001). Radial GRE has better image quality and lesion conspicuity than conventional Cartesian VIBE in paediatric patients undergoing contrast-enhanced abdominopelvic MRI. (orig.)

  18. Accurate determination of blood–brain barrier permeability using dynamic contrast-enhanced T1-weighted MRI

    DEFF Research Database (Denmark)

    Cramer, Stig P; Larsson, Henrik B W

    2014-01-01

    Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is increasingly used to estimate permeability in situations with subtle blood-brain barrier (BBB) leakage. However, the method's ability to differentiate such low values from zero is unknown, and no consensus exists on optimal selection...

  19. Detection of Local Tumor Recurrence After Definitive Treatment of Head and Neck Squamous Cell Carcinoma: Histogram Analysis of Dynamic Contrast-Enhanced T1-Weighted Perfusion MRI.

    Science.gov (United States)

    Choi, Sang Hyun; Lee, Jeong Hyun; Choi, Young Jun; Park, Ji Eun; Sung, Yu Sub; Kim, Namkug; Baek, Jung Hwan

    2017-01-01

    This study aimed to explore the added value of histogram analysis of the ratio of initial to final 90-second time-signal intensity AUC (AUCR) for differentiating local tumor recurrence from contrast-enhancing scar on follow-up dynamic contrast-enhanced T1-weighted perfusion MRI of patients treated for head and neck squamous cell carcinoma (HNSCC). AUCR histogram parameters were assessed among tumor recurrence (n = 19) and contrast-enhancing scar (n = 27) at primary sites and compared using the t test. ROC analysis was used to determine the best differentiating parameters. The added value of AUCR histogram parameters was assessed when they were added to inconclusive conventional MRI results. Histogram analysis showed statistically significant differences in the 50th, 75th, and 90th percentiles of the AUCR values between the two groups (p Histogram analysis of AUCR can improve the diagnostic yield for local tumor recurrence during surveillance after treatment for HNSCC.

  20. Evaluation of dynamic contrast-enhanced T1-weighted perfusion MRI in the differentiation of tumor recurrence from radiation necrosis

    DEFF Research Database (Denmark)

    Larsen, Anne Vibeke Andrée; Simonsen, Helle J; Law, Ian

    2013-01-01

    INTRODUCTION: To investigate if perfusion measured with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can be used to differentiate radiation necrosis from tumor recurrence in patients with high-grade glioma. METHODS: The study was approved by the institutional review board...... to measure cerebral blood volume (CBV), blood-brain barrier (BBB) permeability and cerebral blood flow (CBF). Subjects also underwent FDG-PET and lesions were classified as either metabolically active or inactive. Follow-up clinical MRI and lesion histology in case of additional tissue resection was used...... to determine whether lesions were regressing or progressing. RESULTS: Fourteen enhancing lesions could be classified as progressing (11) or regressing (three). An empirical threshold of 2.0 ml/100 g for CBV allowed detection of regressing lesions with a sensitivity of 100 % and specificity of 100 %. FDG-PET...

  1. Gadolinium-enhanced MR imaging of normal renal transplants. An evaluation of a T1-weighted dynamic echo-planar sequence

    International Nuclear Information System (INIS)

    Dupas, B.; Blancho, G.; Havet, T.; Leaute, F.

    1999-01-01

    Purpose: To evaluate the potential usefulness of dynamic MR with echoplanar imaging (EPI) in assessing the renal function in patients with renal allografts. Material and methods: Using a T1-weighted sequence, EPI was performed after injection of a Gd-chelate in 17 patients with normally functioning renal allografts. Time-intensity curves were plotted from the signal intensity (SI) measurements of the cortex and the medulla. Results: The pattern of corticomedullar differentiation (CMD) observed after constrast enhancement was divided into four phases using the T1-EPI. After a rapid decrease in the SI of cortical structures, and a subsequent return to precontrast levels, a gradual fall in the SI of the medulla was observed. The average time between the two periods of signal loss was 60 s. Conclusion: This study illustrated the potential use of dynamic T1-EPI to demonstrate contrast-induced CMD in renal allografts. (orig.)

  2. Low-Molecular-Weight Iron Chelates May Be an Alternative to Gadolinium-based Contrast Agents for T1-weighted Contrast-enhanced MR Imaging.

    Science.gov (United States)

    Boehm-Sturm, Philipp; Haeckel, Akvile; Hauptmann, Ralf; Mueller, Susanne; Kuhl, Christiane K; Schellenberger, Eyk A

    2018-02-01

    Purpose To synthesize two low-molecular-weight iron chelates and compare their T1 contrast effects with those of a commercial gadolinium-based contrast agent for their applicability in dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging. Materials and Methods The animal experiments were approved by the local ethics committee. Two previously described iron (Fe) chelates of pentetic acid (Fe-DTPA) and of trans-cyclohexane diamine tetraacetic acid (Fe-tCDTA) were synthesized with stability constants several orders of magnitude higher than those of gadolinium-based contrast agents. The T1 contrast effects of the two chelates were compared with those of gadopentetate dimeglumine in blood serum phantoms at 1.5 T, 3 T, and 7 T. For in vivo studies, a human breast cancer cell line (MDA-231) was implanted in five mice per group. The dynamic contrast effects of the chelates were compared by performing DCE MR imaging with intravenous application of Fe-DTPA or Fe-tCDTA on day 1 and DCE MR imaging in the same tumors with gadopentetate dimeglumine on day 2. Quantitative DCE maps were generated with software and were compared by means of a one-tailed Pearson correlation test. Results Relaxivities in serum (0.94 T at room temperature) of Fe-tCDTA (r1 = 2.2 mmol -1 · sec -1 , r2 = 2.5 mmol -1 · sec -1 ) and Fe-DTPA (r1 = 0.9 mmol -1 · sec -1 , r2 = 0.9 mmol -1 · sec -1 ) were approximately twofold and fivefold lower, respectively, compared with those of gadopentetate dimeglumine (r1 = 4.1 mmol -1 · sec -1 , r2 = 4.8 mmol -1 · sec -1 ). Used at moderately higher concentrations, however, iron chelates generated similar contrast effects at T1-weighted MR imaging in vitro in serum, in vivo in blood, and for DCE MR imaging of breast cancer xenografts. The volume transfer constant values for Fe-DTPA and Fe-tCDTA in the same tumors correlated well with those observed for gadopentetate dimeglumine (Fe-tCDTA Pearson R, 0.99; P = .0003; Fe-DTPA Pearson R, 0.97; P

  3. MR mammography for diagnosis of breast cancer. Evaluation of usefulness of contrast-enhanced fat-suppressed T1 weight image

    International Nuclear Information System (INIS)

    Kusama, Ritsu; Takayama, Fumiyoshi; Tsuchiya, Shin-ichi

    2005-01-01

    We assessed the value of contrast-enhanced fat-suppressed T1 weight images (CFT1) in diagnosing breast cancers showing mass-like lesions in MR imaging. MR imaging demonstrated 41 carcinoma and 15 fibroadenoma cases. We classified these into 3 groups based on the status of the border and the adjacent zone in CFT1: a well-defined border, an ill-defined border, and linear high signal intensity in the adjacent zone. In carcinoma cases, 23 showed well-defined borders and 18 showed linear high signal intensity in adjacent zone. In fibroadenoma cases, 14 cases revealed well-defined borders and one case an ill-defined border. We compared the borders and adjacent zones of tumors in CFT1 with the pathological findings. Cases of fibroadenoma with well-defined borders in CFT1 showed well-circumscribed nodules with no infiltration of surrounding lymphocytes and fibroblast Cases of carcinoma with ill-defined borders showed infiltration by tumor cells to adjacent tissue without lymphocytes. Cases of carcinoma with linear high signal intensity in the adjacent zone revealed infiltration of the lymph cells and fibroblasts cells in the adjacent zone. The linear high signal intensity was distinguishable from the peripheral enhancement in dynamic MR images. We conclude that the borders and adjacent zones of tumors in CFT1 are useful for diagnosis. (authors)

  4. Qualitative and quantitative comparison of contrast-enhanced fluid-attenuated inversion recovery, magnetization transfer spin echo, and fat-saturation T1-weighted sequences in infectious meningitis

    International Nuclear Information System (INIS)

    Azad, Rajiv; Tayal, Mohit; Azad, Sheenam; Sharma, Garima; Srivastava, Rajendra Kumar

    2017-01-01

    To compare the contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR), the CE T1-weighted (CE-T1W) sequence with fat suppression (FS) and magnetization transfer (MT) for early detection and characterization of infectious meningitis. Fifty patients and 10 control subjects were evaluated with the CE-FLAIR and the CE-T1W sequences with FS and MT. Qualitative assessment was done by two observers for presence and grading of abnormal leptomeningeal enhancement. Quantitative assessment included computation of net meningeal enhancement, using single pixel signal intensity software. A newly devised FLAIR based scoring system, based on certain imaging features including ventricular dilatation, ependymal enhancement, infarcts and subdural effusions was used to indicate the etiology. Data were analysed using the Student's t test, Cohen's Kappa coefficient, Pearson's correlation coefficient, the intraclass correlation coefficient, one way analysis of variance, and Fisher's exact test with Bonferroni correction as the post hoc test. The CE-FLAIR sequence demonstrated a better sensitivity (100%), diagnostic accuracy (95%), and a stronger correlation with the cerebrospinal fluid, total leukocyte count (r = 0.75), protein (r = 0.77), adenosine deaminase (r = 0.81) and blood glucose (r = -0.6) values compared to the CE-T1W sequences. Qualitative grades and quantitative meningeal enhancement on the CE-FLAIR sequence were also significantly greater than those on the other sequences. The FLAIR based scoring system yielded a diagnostic accuracy of 91.6% and a sensitivity of 96%. A strong inverse Pearson's correlation (r = -0.95) was found between the assigned score and patient's Glasgow Coma Scale at the time of admission. The CE-FLAIR sequence is better suited for evaluating infectious meningitis and could be included as a part of the routine MR imaging protocol

  5. Qualitative and quantitative comparison of contrast-enhanced fluid-attenuated inversion recovery, magnetization transfer spin echo, and fat-saturation T1-weighted sequences in infectious meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Azad, Rajiv; Tayal, Mohit; Azad, Sheenam; Sharma, Garima; Srivastava, Rajendra Kumar [SGRR Institute of Medical and Health Sciences, Patel Nagar, Dehradun (India)

    2017-11-15

    To compare the contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR), the CE T1-weighted (CE-T1W) sequence with fat suppression (FS) and magnetization transfer (MT) for early detection and characterization of infectious meningitis. Fifty patients and 10 control subjects were evaluated with the CE-FLAIR and the CE-T1W sequences with FS and MT. Qualitative assessment was done by two observers for presence and grading of abnormal leptomeningeal enhancement. Quantitative assessment included computation of net meningeal enhancement, using single pixel signal intensity software. A newly devised FLAIR based scoring system, based on certain imaging features including ventricular dilatation, ependymal enhancement, infarcts and subdural effusions was used to indicate the etiology. Data were analysed using the Student's t test, Cohen's Kappa coefficient, Pearson's correlation coefficient, the intraclass correlation coefficient, one way analysis of variance, and Fisher's exact test with Bonferroni correction as the post hoc test. The CE-FLAIR sequence demonstrated a better sensitivity (100%), diagnostic accuracy (95%), and a stronger correlation with the cerebrospinal fluid, total leukocyte count (r = 0.75), protein (r = 0.77), adenosine deaminase (r = 0.81) and blood glucose (r = -0.6) values compared to the CE-T1W sequences. Qualitative grades and quantitative meningeal enhancement on the CE-FLAIR sequence were also significantly greater than those on the other sequences. The FLAIR based scoring system yielded a diagnostic accuracy of 91.6% and a sensitivity of 96%. A strong inverse Pearson's correlation (r = -0.95) was found between the assigned score and patient's Glasgow Coma Scale at the time of admission. The CE-FLAIR sequence is better suited for evaluating infectious meningitis and could be included as a part of the routine MR imaging protocol.

  6. Comparison of different magnetic resonance cholangiography techniques in living liver donors including Gd-EOB-DTPA enhanced T1-weighted sequences.

    Directory of Open Access Journals (Sweden)

    Sonja Kinner

    Full Text Available Preoperative evaluation of potential living liver donors (PLLDs includes the assessment of the biliary anatomy to avoid postoperative complications. Aim of this study was to compare T2-weighted (T2w and Gd-EOB-DTPA enhanced T1-weighted (T1w magnetic resonance cholangiography (MRC techniques in the evaluation of PLLDs.30 PLLDs underwent MRC on a 1.5 T Magnetom Avanto (Siemens, Erlangen, Germany using (A 2D T2w HASTE (Half Fourier Acquisition Single Shot Turbo Spin Echo fat saturated (fs in axial plane, (B 2D T2w HASTE fs thick slices in coronal plane, (C free breathing 3D T2w TSE (turbo spin echo RESTORE (high-resolution navigator corrected plus (D maximum intensity projections (MIPs, (E T2w SPACE (sampling perfection with application optimized contrasts using different flip angle evolutions plus (F MIPs and (G T2w TSE BLADE as well as Gd-EOB-DTPA T1w images without (G and with (H inversion recovery. Contrast enhanced CT cholangiography served as reference imaging modality. Two independent reviewers evaluated the biliary tract anatomy on a 5-point scale subjectively and objectively. Data sets were compared using a Mann-Whitney-U-test. Kappa values were also calculated.Source images and maximum intensity projections of 3D T2w TSE sequences (RESTORE and SPACE proved to be best for subjective and objective evaluation directly followed by 2D HASTE sequences. Interobserver variabilities were good to excellent (k = 0.622-0.804.3D T2w sequences are essential for preoperative biliary tract evaluation in potential living liver donors. Furthermore, our results underline the value of different MRCP sequence types for the evaluation of the biliary anatomy in PLLDs including Gd-EOB-DTPA enhanced T1w MRC.

  7. Cerebral staging of lung cancer: is one single contrast-enhanced T1-weighted three-dimensional gradient-echo sequence sufficient?

    Energy Technology Data Exchange (ETDEWEB)

    Ohana, Mickael; Jeung, Mi-Young; Roy, Catherine [Nouvel Hopital Civil-Hopitaux Universitaires de Strasbourg, Service de Radiologie B/Radiology Department, Strasbourg (France); Bazille, Gauthier [Clinique Saint Anne-Groupe Radiologique MIM, Strasbourg (France)

    2014-08-15

    Gadolinium-enhanced magnetic resonance imaging (MRI) is the gold standard for cerebral staging in thoracic oncology. We hypothesize that a minimalist examination, consisting of a single contrast-enhanced T1-weighted three-dimensional gradient-echo sequence (CE 3D-GRE), would be sufficient for the cerebral staging of nonsymptomatic lung cancer patients. Seventy nonsymptomatic patients (50 % men; 62 years ± 10.2) referred for cerebral staging of a lung cancer were retrospectively included. All underwent a standard 3 T MRI examination with T1, FLAIR, T2* GRE, diffusion, and CE 3D-GRE sequences, for a total examination time of 20 min. The sole CE 3D-GRE (acquisition time: 6 min) was extracted and blindly interpreted by two radiologists in search of brain metastases. Hemorrhagic features of potential lesions and relevant incidental findings were also noted. Discrepant cases were reviewed by a third reader. The full MRI examination and follow-up studies were used as a reference to calculate sensitivity and specificity of the sole CE 3D-GRE. Thirty-eight point six percent (27 out of 70) of the patients had brain metastases. Performances and reader's agreement with the sole CE 3D-GRE sequence were excellent for the diagnosis of brain metastases (sensitivity = 96.3 %, specificity = 100 %, κ = 0.91) and incidental findings (sensitivity = 85.7 %, specificity = 100 %, κ = 0.62) but insufficient for the identification of hemorrhages within the metastases (sensitivity = 33.3 %, specificity = 85.7 %, κ = 0.47). In the specific case of lung cancer, cerebral staging in nonsymptomatic patients can be efficiently achieved with a minimalistic protocol consisting of a single CE 3D-GRE sequence, completed if positive with a T2* sequence for hemorrhagic assessment, thus halving appointment delays. (orig.)

  8. Added value of gadoxetic acid-enhanced T1-weighted magnetic resonance cholangiography for the diagnosis of post-transplant biliary complications

    Energy Technology Data Exchange (ETDEWEB)

    Kinner, Sonja [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Schubert, Tilman B. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); Basel University Hospital, Clinic of Radiology and Nuclear Medicine, Basel (Switzerland); Said, Adnan [University of Wisconsin-Madison, Department of Medicine, Madison, WI (United States); Mezrich, Joshua D. [University of Wisconsin-Madison, Department of Surgery, Madison, WI (United States); Reeder, Scott B. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); University of Wisconsin-Madison, Department of Medicine, Madison, WI (United States); University of Wisconsin-Madison, Department of Biomedical Engineering, Madison, WI (United States); University of Wisconsin-Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin-Madison, Department of Emergency Medicine, Madison, WI (United States)

    2017-10-15

    Biliary complications after liver transplantation (LT) are common. This study aimed to ascertain the value of gadoxetic acid-enhanced T1-weighted (T1w) magnetic resonance cholangiography (MRC) to evaluate anastomotic strictures (AS), non-anastomotic strictures (NAS) and biliary casts (BC). Sixty liver-transplanted patients with suspicion of biliary complications and T2w-MRCP and T1w-MRC followed by endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC) were analysed. Two readers reviewed the MRCs and rated image quality (IQ) and likelihood for AS/NAS/BC on Likert scales. Sensitivity, specificity and predictive values were calculated, ROC curve analysis performed, and inter-reader variability assessed. The subjective added value of T1w-MRC was rated. IQ was high for all sequences without significant differences (2.83-2.88). In 39 patients ERCP/PTC detected a complication. Sensitivity and specificity for AS were 64-96 using T2w-MRCP, increasing to 79-100 using all sequences. Use of all sequences increased the sensitivity of detecting NAS/BC from 72-92% to 88-100% and 67-89% to 72-94%, respectively. Kappa values were substantial (0.45-0.62). T1w-MRC was found to be helpful in 75-83.3%. Combining T1w-MRC and T2w-MRCP increased sensitivity and specificity and diagnostic confidence in patients after LT with suspected biliary complications. T1w-MRC is a valuable tool for evaluating post-transplant biliary complications. (orig.)

  9. Radiation necrosis of the optic chiasm, optic tract, hypothalamus, and upper pons after radiotherapy for pituitary adenoma, detected by gadolinium-enhanced, T1-weighted magnetic resonance imaging: Case report

    International Nuclear Information System (INIS)

    Tachibana, O.; Yamaguchi, N.; Yamashima, T.; Yamashita, J.

    1990-01-01

    A 26-year-old woman was treated for a prolactin secreting pituitary adenoma by surgery and radiotherapy (5860 rads). Fourteen months later, she developed right hemiparesis and dysarthria. A T1-weighted magnetic resonance imaging scan using gadolinium contrast showed a small, enhanced lesion in the upper pons. Seven months later, she had a sudden onset of loss of vision, and radiation optic neuropathy was diagnosed. A T1-weighted magnetic resonance imaging scan showed widespread gadolinium-enhanced lesions in the optic chiasm, optic tract, and hypothalamus. Magnetic resonance imaging is indispensable for the early diagnosis of radiation necrosis, which is not visualized by radiography or computed tomography

  10. Comparison between gadolinium-enhanced 2D T1-weighted gradient-echo and spin-echo sequences in the detection of active multiple sclerosis lesions on 3.0T MRI

    Energy Technology Data Exchange (ETDEWEB)

    Aymerich, F.X. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, MR Unit. Department of Radiology (IDI), Barcelona (Spain); Universitat Politecnica de Catalunya - Barcelona Tech (UPC), Department of Automatic Control (ESAII), Barcelona (Spain); Auger, C.; Alcaide-Leon, P.; Pareto, D.; Huerga, E.; Corral, J.F.; Mitjana, R.; Rovira, A. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, MR Unit. Department of Radiology (IDI), Barcelona (Spain); Sastre-Garriga, J.; Montalban, X. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, Centre d' Esclerosi Multiple de Catalunya (Cemcat), Department of Neurology/Neuroimmunology, Barcelona (Spain)

    2017-04-15

    To compare the sensitivity of enhancing multiple sclerosis (MS) lesions in gadolinium-enhanced 2D T1-weighted gradient-echo (GRE) and spin-echo (SE) sequences, and to assess the influence of visual conspicuity and laterality on detection of these lesions. One hundred MS patients underwent 3.0T brain MRI including gadolinium-enhanced 2D T1-weighted GRE and SE sequences. The two sets of contrast-enhanced scans were evaluated in random fashion by three experienced readers. Lesion conspicuity was assessed by the image contrast ratio (CR) and contrast-to-noise ratio (CNR). The intracranial region was divided into four quadrants and the impact of lesion location on detection was assessed in each slice. Six hundred and seven gadolinium-enhancing MS lesions were identified. GRE images were more sensitive for lesion detection (0.828) than SE images (0.767). Lesions showed a higher CR in SE than in GRE images, whereas the CNR was higher in GRE than SE. Most misclassifications occurred in the right posterior quadrant. The gadolinium-enhanced 2D T1-weighted GRE sequence at 3.0T MRI enables detection of enhancing MS lesions with higher sensitivity and better lesion conspicuity than 2D T1-weighted SE. Hence, we propose the use of gadolinium-enhanced GRE sequences rather than SE sequences for routine scanning of MS patients at 3.0T. (orig.)

  11. Disruptive chemical doping in a ferritin-based iron oxide nanoparticle to decrease r2 and enhance detection with T1-weighted MRI.

    Science.gov (United States)

    Clavijo Jordan, M Veronica; Beeman, Scott C; Baldelomar, Edwin J; Bennett, Kevin M

    2014-01-01

    Inorganic doping was used to create flexible, paramagnetic nanoparticle contrast agents for in vivo molecular magnetic resonance imaging (MRI) with low transverse relaxivity (r2). Most nanoparticle contrast agents formed from superparamagnetic metal oxides are developed with high r2. While sensitive, they can have limited in vivo detection due to a number of constraints with T2 or T2*-weighted imaging. T1-weighted imaging is often preferred for molecular MRI, but most T1-shortening agents are small chelates with low metal payload or are nanoparticles that also shorten T2 and limit the range of concentrations detectable with T1-weighting. Here we used tungsten and iron deposition to form doped iron oxide crystals inside the apoferritin cavity to form a WFe nanoparticle with a disordered crystal and un-coupled atomic magnetic moments. The atomic magnetic moments were thus localized, resulting in a principally paramagnetic nanoparticle. The WFe nanoparticles had no coercivity or saturation magnetization at 5 K and sweeping up to ± 20,000 Oe, while native ferritin had a coercivity of 3000 Oe and saturation at ± 20,000 Oe. This tungsten-iron crystal paramagnetism resulted in an increased WFe particle longitudinal relaxivity (r1) of 4870 mm(-1) s(-1) and a reduced transverse relaxivity (r2) of 9076 mm(-1) s(-1) compared with native ferritin. The accumulation of the particles was detected with T1-weighted MRI in concentrations from 20 to 400 nm in vivo, both injected in the rat brain and targeted to the rat kidney glomerulus. The WFe apoferritin nanoparticles were not cytotoxic up to 700 nm particle concentrations, making them potentially important for targeted molecular MRI. Copyright © 2014 John Wiley & Sons, Ltd.

  12. Measurement of brain perfusion, blood volume, and blood-brain barrier permeability, using dynamic contrast-enhanced T(1)-weighted MRI at 3 tesla

    DEFF Research Database (Denmark)

    Larsson, Henrik B W; Courivaud, Frédéric; Rostrup, Egill

    2009-01-01

    Assessment of vascular properties is essential to diagnosis and follow-up and basic understanding of pathogenesis in brain tumors. In this study, a procedure is presented that allows concurrent estimation of cerebral perfusion, blood volume, and blood-brain permeability from dynamic T(1)-weighted...... on a pixel-by-pixel basis of cerebral perfusion, cerebral blood volume, and blood-brain barrier permeability.......Assessment of vascular properties is essential to diagnosis and follow-up and basic understanding of pathogenesis in brain tumors. In this study, a procedure is presented that allows concurrent estimation of cerebral perfusion, blood volume, and blood-brain permeability from dynamic T(1)-weighted...... imaging of a bolus of a paramagnetic contrast agent passing through the brain. The methods are applied in patients with brain tumors and in healthy subjects. Perfusion was estimated by model-free deconvolution using Tikhonov's method (gray matter/white matter/tumor: 72 +/- 16/30 +/- 8/56 +/- 45 mL/100 g...

  13. Magnetic resonance imaging of pelvic entheses - a systematic comparison between short tau inversion recovery (STIR) and T1-weighted, contrast-enhanced, fat-saturated sequences

    International Nuclear Information System (INIS)

    Klang, Eyal; Aharoni, Dvora; Rimon, Uri; Eshed, Iris; Hermann, Kay-Geert; Herman, Amir; Shazar, Nachshon

    2014-01-01

    To assess the contribution of contrast material in detecting and evaluating enthesitis of pelvic entheses by MRI. Sixty-seven hip or pelvic 1.5-T MRIs (30:37 male:female, mean age: 53 years) were retrospectively evaluated for the presence of hamstring and gluteus medius (GM) enthesitis by two readers (a resident and an experienced radiologist). Short tau inversion recovery (STIR) and T1-weighted pre- and post-contrast (T1+Gd) images were evaluated by each reader at two sessions. A consensus reading of two senior radiologists was regarded as the gold standard. Clinical data was retrieved from patients' referral form and medical files. Cohen's kappa was used for intra- and inter-observer agreement calculation. Diagnostic properties were calculated against the gold standard reading. A total of 228 entheses were evaluated. Gold standard analysis diagnosed 83 (36 %) enthesitis lesions. Intra-reader reliability for the experienced reader was significantly (p = 0.0001) higher in the T1+Gd images compared to the STIR images (hamstring: k = 0.84/0.45, GM: k = 0.84/0.47). Sensitivity and specificity increased from 0.74/0.8 to 0.87/0.9 in the STIR images and T1+Gd sequences. Intra-reader reliability for the inexperienced reader was lower (p > 0.05). Evidence showing that contrast material improves the reliability, sensitivity, and specificity of detecting enthesitis supports its use in this setting. (orig.)

  14. Assessment of arterial wall enhancement for differentiation of parent artery disease from small artery disease: Comparison between histogram analysis and visual analysis on 3 dimensional contrast-enhanced T1-weighted turbo spin echo MR images at 3T

    International Nuclear Information System (INIS)

    Jang, Jin Hee; Kim, Tae Won; Hwang, Eo Jin; Choi, Hyun Seok; Koo, Ja Seung; Shin, Yong Sam; Jung, So Lyung; Ahn, Kook Jin; Kim, Bum Soo

    2017-01-01

    The purpose of this study was to compare the histogram analysis and visual scores in 3T MRI assessment of middle cerebral arterial wall enhancement in patients with acute stroke, for the differentiation of parent artery disease (PAD) from small artery disease (SAD). Among the 82 consecutive patients in a tertiary hospital for one year, 25 patients with acute infarcts in middle cerebral artery (MCA) territory were included in this study including 15 patients with PAD and 10 patients with SAD. Three-dimensional contrast-enhanced T1-weighted turbo spin echo MR images with black-blood preparation at 3T were analyzed both qualitatively and quantitatively. The degree of MCA stenosis, and visual and histogram assessments on MCA wall enhancement were evaluated. A statistical analysis was performed to compare diagnostic accuracy between qualitative and quantitative metrics. The degree of stenosis, visual enhancement score, geometric mean (GM), and the 90th percentile (90P) value from the histogram analysis were significantly higher in PAD than in SAD (p = 0.006 for stenosis, < 0.001 for others). The receiver operating characteristic curve area of GM and 90P were 1 (95% confidence interval [CI], 0.86-1.00). A histogram analysis of a relevant arterial wall enhancement allows differentiation between PAD and SAD in patients with acute stroke within the MCA territory

  15. Assessment of arterial wall enhancement for differentiation of parent artery disease from small artery disease: Comparison between histogram analysis and visual analysis on 3 dimensional contrast-enhanced T1-weighted turbo spin echo MR images at 3T

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jin Hee; Kim, Tae Won; Hwang, Eo Jin; Choi, Hyun Seok; Koo, Ja Seung; Shin, Yong Sam; Jung, So Lyung; Ahn, Kook Jin; Kim, Bum Soo [College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2017-04-15

    The purpose of this study was to compare the histogram analysis and visual scores in 3T MRI assessment of middle cerebral arterial wall enhancement in patients with acute stroke, for the differentiation of parent artery disease (PAD) from small artery disease (SAD). Among the 82 consecutive patients in a tertiary hospital for one year, 25 patients with acute infarcts in middle cerebral artery (MCA) territory were included in this study including 15 patients with PAD and 10 patients with SAD. Three-dimensional contrast-enhanced T1-weighted turbo spin echo MR images with black-blood preparation at 3T were analyzed both qualitatively and quantitatively. The degree of MCA stenosis, and visual and histogram assessments on MCA wall enhancement were evaluated. A statistical analysis was performed to compare diagnostic accuracy between qualitative and quantitative metrics. The degree of stenosis, visual enhancement score, geometric mean (GM), and the 90th percentile (90P) value from the histogram analysis were significantly higher in PAD than in SAD (p = 0.006 for stenosis, < 0.001 for others). The receiver operating characteristic curve area of GM and 90P were 1 (95% confidence interval [CI], 0.86-1.00). A histogram analysis of a relevant arterial wall enhancement allows differentiation between PAD and SAD in patients with acute stroke within the MCA territory.

  16. Is there an added value of T1-weighted contrast-enhanced fat-suppressed spin-echo MR sequences compared to STIR sequences in MRI of the foot and ankle?

    International Nuclear Information System (INIS)

    Zubler, Veronika; Zanetti, Marco; Dietrich, Tobias J.; Pfirrmann, Christian W.; Mamisch-Saupe, Nadja; Espinosa, Norman

    2017-01-01

    To prospectively compare T1-weighted fat-suppressed spin-echo magnetic resonance (MR) sequences after gadolinium application (T1wGdFS) to STIR sequences in patients with acute and chronic foot pain. In 51 patients referred for MRI of the foot and ankle, additional transverse and sagittal T1wGdFS sequences were obtained. Two sets of MR images (standard protocol with STIR or T1wGdFS) were analysed. Diagnosis, diagnostic confidence, and localization of the abnormality were noted. Standard of reference was established by an expert panel of two experienced MSK radiologists and one experienced foot surgeon based on MR images, clinical charts and surgical reports. Patients reported prospectively localization of pain. Descriptive statistics, McNemar test and Kappa test were used. Diagnostic accuracy with STIR protocol was 80% for reader 1, 67% for reader 2, with contrast-protocol 84%, both readers. Significance was found for reader 2. Diagnostic confidence for reader 1 was 1.7 with STIR, 1.3 with contrast-protocol; reader 2: 2.1/1.7. Significance was found for reader 1. Pain location correlated with STIR sequences in 64% and 52%, with gadolinium sequences in 70% and 71%. T1-weighted contrast material-enhanced fat-suppressed spin-echo magnetic resonance sequences improve diagnostic accuracy, diagnostic confidence and correlation of MR abnormalities with pain location in MRI of the foot and ankle. However, the additional value is small. (orig.)

  17. Is there an added value of T1-weighted contrast-enhanced fat-suppressed spin-echo MR sequences compared to STIR sequences in MRI of the foot and ankle?

    Energy Technology Data Exchange (ETDEWEB)

    Zubler, Veronika; Zanetti, Marco; Dietrich, Tobias J.; Pfirrmann, Christian W.; Mamisch-Saupe, Nadja [University of Zurich, Faculty of Medicine, Zurich (Switzerland); Orthopedic University Hospital Balgrist, Department of Radiology, Zurich (Switzerland); Espinosa, Norman [University of Zurich, Faculty of Medicine, Zurich (Switzerland); Orthopedic University Hospital Balgrist, Orthopedic Surgery, Zurich (Switzerland)

    2017-08-15

    To prospectively compare T1-weighted fat-suppressed spin-echo magnetic resonance (MR) sequences after gadolinium application (T1wGdFS) to STIR sequences in patients with acute and chronic foot pain. In 51 patients referred for MRI of the foot and ankle, additional transverse and sagittal T1wGdFS sequences were obtained. Two sets of MR images (standard protocol with STIR or T1wGdFS) were analysed. Diagnosis, diagnostic confidence, and localization of the abnormality were noted. Standard of reference was established by an expert panel of two experienced MSK radiologists and one experienced foot surgeon based on MR images, clinical charts and surgical reports. Patients reported prospectively localization of pain. Descriptive statistics, McNemar test and Kappa test were used. Diagnostic accuracy with STIR protocol was 80% for reader 1, 67% for reader 2, with contrast-protocol 84%, both readers. Significance was found for reader 2. Diagnostic confidence for reader 1 was 1.7 with STIR, 1.3 with contrast-protocol; reader 2: 2.1/1.7. Significance was found for reader 1. Pain location correlated with STIR sequences in 64% and 52%, with gadolinium sequences in 70% and 71%. T1-weighted contrast material-enhanced fat-suppressed spin-echo magnetic resonance sequences improve diagnostic accuracy, diagnostic confidence and correlation of MR abnormalities with pain location in MRI of the foot and ankle. However, the additional value is small. (orig.)

  18. Contrast-enhanced MR imaging of metastatic brain tumor at 3 Tesla. Utility of T1-weighted SPACE compared with 2D spin echo and 3D gradient echo sequence

    International Nuclear Information System (INIS)

    Komada, Tomohiro; Naganawa, Shinji; Ogawa, Hiroshi

    2008-01-01

    We evaluated the newly developed whole-brain, isotropic, 3-dimensional turbo spin-echo imaging with variable flip angle echo train (SPACE) for contrast-enhanced T 1 -weighted imaging in detecting brain metastases at 3 tesla (T). Twenty-two patients with suspected brain metastases underwent postcontrast study with SPACE, magnetization-prepared rapid gradient-echo (MP-RAGE), and 2-dimensional T 1 -weighted spin echo (2D-SE) imaging at 3 T. We quantitatively compared SPACE, MP-RAGE, and 2D-SE images by using signal-to-noise ratios (SNRs) for gray matter (GM) and white matter (WM) and contrast-to-noise ratios (CNRs) for GM-to-WM, lesion-to-GM, and lesion-to-WM. Two blinded radiologists evaluated the detection of brain metastases by segment-by-segment analysis and continuously-distributed test. The CNR between GM and WM was significantly higher on MP-RAGE images than on SPACE images (P 1 -weighted imaging. (author)

  19. Computer-assisted analysis of peripheral zone prostate lesions using T2-weighted and dynamic contrast enhanced T1-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Vos, Pieter C; Hambrock, Thomas; Barenstz, Jelle O; Huisman, Henkjan J [Department of Radiology, Radboud University Medical Centre, Nijmegen, 6525GA (Netherlands)], E-mail: p.vos@rad.umcn.nl

    2010-03-21

    In this study, computer-assisted analysis of prostate lesions was researched by combining information from two different magnetic resonance (MR) modalities: T2-weighted (T2-w) and dynamic contrast-enhanced (DCE) T1-w images. Two issues arise when incorporating T2-w images in a computer-aided diagnosis (CADx) system: T2-w values are position as well as sequence dependent and images can be misaligned due to patient movement during the acquisition. A method was developed that computes T2 estimates from a T2-w and proton density value and a known sequence model. A mutual information registration strategy was implemented to correct for patient movement. Global motion is modelled by an affine transformation, while local motion is described by a volume preserving non-rigid deformation based on B-splines. The additional value to the discriminating performance of a DCE T1-w-based CADx system was evaluated using bootstrapped ROC analysis. T2 estimates were successfully computed in 29 patients. T2 values were extracted and added to the CADx system from 39 malignant, 19 benign and 29 normal annotated regions. T2 values alone achieved a diagnostic accuracy of 0.85 (0.77-0.92) and showed a significantly improved discriminating performance of 0.89 (0.81-0.95), when combined with DCE T1-w features. In conclusion, the study demonstrated a simple T2 estimation method that has a diagnostic performance such that it complements a DCE T1-w-based CADx system in discriminating malignant lesions from normal and benign regions. Additionally, the T2 estimate is beneficial to visual inspection due to the removed coil profile and fixed window and level settings.

  20. Clinical Feasibility of Free-Breathing Dynamic T1-Weighted Imaging With Gadoxetic Acid-Enhanced Liver Magnetic Resonance Imaging Using a Combination of Variable Density Sampling and Compressed Sensing.

    Science.gov (United States)

    Yoon, Jeong Hee; Yu, Mi Hye; Chang, Won; Park, Jin-Young; Nickel, Marcel Dominik; Son, Yohan; Kiefer, Berthold; Lee, Jeong Min

    2017-10-01

    The purpose of the study was to investigate the clinical feasibility of free-breathing dynamic T1-weighted imaging (T1WI) using Cartesian sampling, compressed sensing, and iterative reconstruction in gadoxetic acid-enhanced liver magnetic resonance imaging (MRI). This retrospective study was approved by our institutional review board, and the requirement for informed consent was waived. A total of 51 patients at high risk of breath-holding failure underwent dynamic T1WI in a free-breathing manner using volumetric interpolated breath-hold (BH) examination with compressed sensing reconstruction (CS-VIBE) and hard gating. Timing, motion artifacts, and image quality were evaluated by 4 radiologists on a 4-point scale. For patients with low image quality scores (XD]) reconstruction was additionally performed and reviewed in the same manner. In addition, in 68.6% (35/51) patients who had previously undergone liver MRI, image quality and motion artifacts on dynamic phases using CS-VIBE were compared with previous BH-T1WIs. In all patients, adequate arterial-phase timing was obtained at least once. Overall image quality of free-breathing T1WI was 3.30 ± 0.59 on precontrast and 2.68 ± 0.70, 2.93 ± 0.65, and 3.30 ± 0.49 on early arterial, late arterial, and portal venous phases, respectively. In 13 patients with lower than average image quality (XD-reconstructed CS-VIBE) significantly reduced motion artifacts (P XD reconstruction showed less motion artifacts and better image quality on precontrast, arterial, and portal venous phases (P < 0.0001-0.013). Volumetric interpolated breath-hold examination with compressed sensing has the potential to provide consistent, motion-corrected free-breathing dynamic T1WI for liver MRI in patients at high risk of breath-holding failure.

  1. Fat suppression at three-dimensional T1-weighted MR imaging of the hands: Dixon method versus CHESS technique.

    Science.gov (United States)

    Kirchgesner, T; Perlepe, V; Michoux, N; Larbi, A; Vande Berg, B

    2018-01-01

    To compare the effectiveness of fat suppression and the image quality of the Dixon method with those of the chemical shift-selective (CHESS) technique in hands of normal subjects at non-enhanced three-dimensional (3D) T1-weighted MR imaging. Both hands of 14 healthy volunteers were imaged with 3D fast spoiled gradient echo (FSPGR) T1-weighted Dixon, 3D FSPGR T1-weighted CHESS and 3D T1-weighted fast spin echo (FSE) CHESS sequences in a 1.5T MR scanner. Three radiologists scored the effectiveness of fat suppression in bone marrow (EFS BM ) and soft tissues (EFS ST ) in 20 joints per subject. One radiologist measured the signal-to-noise ratio (SNR) in 10 bones per subject. Statistical analysis used two-way ANOVA with random effects (PCHESS sequence and the 3D FSE T1-weighted CHESS sequence (PCHESS sequence (PCHESS sequence in the axial plane (P=0.0028). Mean SNR was statistically significantly higher for 3D FSPGR T1-weighted Dixon sequence than for 3D FSPGR T1-weighted CHESS and 3D FSE T1-weighted CHESS sequences (PCHESS technique at 3D T1-weighted MR imaging of the hands. Copyright © 2017 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  2. Contrast-enhanced magnetic resonance angiography (MRA): evaluation of three different contrast agents at two different doses (0.05 and 0.1 mmol/kg) in pigs at 1.5 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Voth, M.; Vos, B.; Pietsch, H. [Bayer Schering Pharma AG, Diagnostic Imaging, Berlin (Germany); Michaely, Henrik J. [University of Heidelberg, Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Mannheim (Germany); Schwenke, C. [ScoSSiS - Statistical Consulting, Berlin (Germany)

    2011-02-15

    To compare the image quality of contrast-enhanced magnetic resonance angiography (CE-MRA) of the supra-aortic vessels at 0.05 mmol/kg bw and 0.1 mmol/kg bw, between gadobutrol, Gd-DTPA and Gd-BOPTA quantitatively and qualitatively a total of eight pigs were evaluated intraindividually at 1.5 T. Each pig was examined using 0.1 mmol/kg gadobutrol, Gd-DTPA and Gd-BOPTA on day one and 0.05 mmol/kg on day two. MRA datasets for the carotid artery and the infraorbital artery were qualitatively assessed regarding overall image quality on an ordinal four-point scale (4-excellent, 1-non-diagnostic). The signal-to noise-ratio (SNR) was measured. The qualitative assessment of the carotid artery showed a higher median image quality for the 0.1 mmol dose than for the 0.05 mmol dose for all three compounds. No difference was found for the infraorbital artery. Mean SNR of Gd-BOPTA, Gd-DTPA, gadobutrol at 0.05 mmol/kg were 36.0 {+-} 13.4/37.9 {+-} 16.3/43.7 {+-} 0.4 and at 0.1 mmol/kg they were 50.1 {+-} 12.4/46.6 {+-} 6.5 / 54.6 {+-} 10.2. Gd-BOPTA 0.05 revealed a significantly lower SNR than all other agents at normal dose. Full-dose gadolinium MRA results in higher image quality and significantly higher SNR compared with the half dose. Gadobutrol and Gd-BOPTA have similar enhancement properties at full dose but at half dose, gadobutrol appears superior. (orig.)

  3. Detection of prostate carcinomas with T1-weighted dynamic contrast-enhanced MRI. Value of two-compartment model; Detektion von Prostatakarzinomen mit T1-gewichteter Kontrastmittel-unterstuetzter dynamischer MRT. Wertigkeit des Zweikompartimentemodells

    Energy Technology Data Exchange (ETDEWEB)

    Kiessling, F.; Lichy, M.; Farhan, N.; Delorme, S.; Kauczor, H.U. [Abteilung fuer Radiologie, Deutsches Krebsforschungszentrum (DKFZ) Heidelberg (Germany); Grobholz, R. [Abteilung fuer Pathologie, Universitaetsklinikum Mannheim (Germany); Heilmann, M. [Abteilung fuer Physik in der Radiologie, Deutsches Krebsforschungszentrum (DKFZ) Heidelberg (Germany); Michel, M.S.; Trojan, L. [Abteilung fuer Urologie, Universitaetsklinikum Mannheim (Germany); Werner, A.; Rabe, J. [Institut fuer Klinische Radiologie, Universitaetsklinikum Mannheim (Germany); Schlemmer, H.P. [Abteilung fuer Diagnostische Radiologie, Universitaetsklinikum Tuebingen (Germany)

    2003-06-01

    Aim The suitability of dynamic parameters of the two-compartment model for detecting prostate carcinomas and its correlation with tumor microvascular density were evaluated. The study included 43 patients with biopsy-proven prostate carcinoma: 28 were examined by 1.0-T MRI (Turbo-FLASH) and 15 by 1.5-T MRI (FLASH) with infusion of 0.1 mmol/kg Gd-DTPA. Signal time curves were parametrized with an open two-compartment model in amplitude and exchange rate constants (k{sub ep}).The microvascular density of resected prostate carcinomas was determined. The microvascular density in the tumors was significantly higher than in the adjacent healthy prostate tissue and correlated in both sequences with k{sub ep}. Prostate carcinomas of the peripheral zone were demarcated by amplitude and k{sub ep}. In the Turbo-FLASH sequence there was a significant difference between the tumor tissue and healthy peripheral zone in terms of k{sub ep} and in the FLASH sequence in terms of amplitude. Prostate carcinomas can be visualized with dynamic T1-weighted MR sequences using a two-compartment model. Moreover, the parameter k{sub ep} reveals the microvascular density in the tumor and can thus provide valuable clinical information for characterizing the tumors. (orig.) [German] Die Eignung dynamischer Parameter des Zweikompartimentemodells zur Erkennung von Prostatakarzinomen und deren Korrelation mit der Tumormikrogefaessdichte wurden evaluiert. 43 Patienten mit bioptisch gesichertem Prostatakarzinom wurden untersucht, 28 mit 1,0 T- (Turbo-FLASH-) und 15 bei 1,5-T-MRT (FLASH) unter Infusion von 0,1 mmol/kg Gd-DTPA. Signal-Zeit-Kurven wurden nach einem offenen Zweikompartimentemodell in Amplitude sowie Austauschratenkonstante (k{sub ep}) parametrisiert. An resezierten Prostatakarzinomen wurde die Mikrogefaessdichte bestimmt.Ergebnisse Die Mikrogefaessdichte in den Tumoren war signifikant hoeher als im angrenzenden gesunden Prostatagewebe und korrelierte bei beiden Sequenzen mit k{sub ep

  4. Postcontrast T1-weighted brain magnetic resonance imaging in pediatric patients: comparison between postcontrast fat-suppression imaging and conventional T1-weighted or magnetization transfer imaging

    International Nuclear Information System (INIS)

    Lee, Choong Wook; Goo, Hyun Woo

    2004-01-01

    We wished to assess the merits and weaknesses of postcontrast fat-suppression (FS) brain MR imaging in children for the evaluation of various enhancing lesions as compared with postcontrast conventional T1-weighted or magnetization transfer (MT) imaging. We reviewed the records of those patients with enhancing lesions on brain MR imaging who had undergone both FS imaging and one of the conventional T1-weighted or MT imaging as a post-contrast T1-weighted brain MR imaging. Thirty-one patients (21 male, 10 female; mean age, 8.7 years) with 38 enhancing lesions (18 intra-axial, 16 extra-axial and 4 orbital locations) were included in this study. There were 27 pairs of FS and conventional imagings, and 13 pairs of FS and MT imagings available for evaluation. Two radiologists visually assessed by consensus the lesions' conspicuity, and they also looked for the presence of flow or susceptibility artifacts in a total of 40 pairs of MR imagings. For 19 measurable lesions (14 pairs of FS and conventional T1-weighted imagings, 5 pairs of FS and MT imagings), the contrast ratios between the lesion and the normal brain ([SIlesion-SIwater]/[SInormal brain-SIwater]) were calculated and compared. Compared with conventional imaging, the lesion conspicuity on FS imaging was better in 10 cases (7 extra-axial lesions, 2 orbital lesions and 1 fat-containing intra-axial lesion), equal in 16 cases, and worse in one case. Compared with MT imaging, the lesion conspicuity on FS imaging was better in 3 cases (2 extra-axial lesions and 1 intra-axial lesion), equal in 8 cases, and worse in 2 cases. Image quality of FS imaging was compromised by flow or susceptibility artifacts for 7 patients. The contrast ratios for FS imaging were not significantly different from those for conventional imaging (2.2±0.7 vs. 2.2±0.6, respectively, p=0.914) and they were significantly lower than those for MT imaging (2.4±0.8 vs. 4.5±1.5, respectively, p=0.018). Postcontrast FS brain MR imaging appears to be

  5. Bilateral hyperintense basal ganglia on T1-weighted image

    International Nuclear Information System (INIS)

    Baik, Seung Kug; Ahn, Woo Hyun; Choi, Han Yong; Kim, Bong Gi

    1994-01-01

    Bilateral high signal intensity in basal ganglia on T1-weighted images is unusual, the purpose of this study is to describe the pattern of high signal intensity and underlying disease. During the last three years, 8 patients showed bilateral high signal intensity in basal ganglia on T1-weighted image, as compared with cerebral white matter. Authors analyzed the images and underlying causes retrospectively. Of 8 patients, 5 were male and 3 were female. The age ranged from 15 days to 79 years. All patient were examined by a 0.5T superconductive MRI. Images were obtained by spin echo multislice technique. Underlying causes were 4 cases of hepatopathy, 2 cases of calcium metabolism disorder, and one case each of neurofibromatosis and hypoxic brain injury. These process were bilateral in all cases and usually symmetric. In all cases the hyperintense areas were generally homogenous without mass effect or edema, although somewhat nodular appearance was seen in neurofibromatosis. Lesions were located in the globus pallidus and internal capsule in hepatopathy and neurofibromatosis, head of the caudate nucleus in disorder of calcum metabolism, and the globus pallidus in hypoxic brain injury. Although this study is limited by its patient population, bilateral hyperintense basal ganglia is associated with various disease entities. On analysis of hyperintense basal ganglia lesion, the knowledge of clinical information improved diagnostic accuracy

  6. Partial flip angle spin-echo imaging to obtain T1 weighted images with electrocardiographic gating

    International Nuclear Information System (INIS)

    Kawamitsu, Hideaki; Sugimura, Kazuro; Kasai, Toshifumi; Kimino, Katsuji

    1993-01-01

    ECG-gated spin-echo (SE) imaging can reduce physiologic motion artifact. However, it does not provide strong T 1 -weighted images, because the repetition time (TR) depends on heart rate (HR). For odd-echo SE imaging, T 1 contrast can be maximized by using a smaller flip angle (FA) of initial excitation RF pulses. We investigated the usefulness of partial FA SE imaging in order to obtain more T 1 -dependent contrast with ECG gating and determined the optimal FA at each heart rate. In computer simulation and phantom study, the predicted image contrast and signal-to-noise ratio (SNR) obtained for each FA (0∼180deg) and each HR (55∼90 beats per minute (bpm)) were compared with those obtained with conventional T 1 -weighted SE imaging (TR=500 ms, TE=20 ms, FA=90deg). The optimal FA was decreased by reducing HR. The FA needed to obtain T 1 -dependent contrast identical to that with T 1 -weighted SE imaging was 43deg at a HR of 65 bpm, 53deg at 70 bpm, 60deg at 75 bpm. This predicted FA were in excellent agreement with that obtained with clinical evaluation. The predicted SNR was decreased by reducing FA. The SNR of partial FA SE imaging at HR of 65 bpm (FA=43deg) was 80% of that with conventional T 1 -weighted SE imaging. However, this imaging method presented no marked clinical problem. ECG-gated partial FA SE imaging provides better T 1 -dependent contrast than conventional ECG-gated SE imaging, especially for Gd-DTPA enhanced imaging. (author)

  7. Spot Sign in Acute Intracerebral Hemorrhage in Dynamic T1-Weighted Magnetic Resonance Imaging.

    Science.gov (United States)

    Schindlbeck, Katharina A; Santaella, Anna; Galinovic, Ivana; Krause, Thomas; Rocco, Andrea; Nolte, Christian H; Villringer, Kersten; Fiebach, Jochen B

    2016-02-01

    In computed tomographic imaging of acute intracerebral hemorrhage spot sign on computed tomographic angiography has been established as a marker for hematoma expansion and poor clinical outcome. Although, magnetic resonance imaging (MRI) can accurately visualize acute intracerebral hemorrhage, a corresponding MRI marker is lacking to date. We prospectively examined 50 consecutive patients with acute intracerebral hemorrhage within 24 hours of symptom onset. The MRI protocol consisted of a standard stroke protocol and dynamic contrast-enhanced T1-weighted imaging with a time resolution of 7.07 s/batch. Stroke scores were assessed at admission and at time of discharge. Volume measurements of hematoma size and spot sign were performed with MRIcron. Contrast extravasation within sites of the hemorrhage (MRI spot sign) was seen in 46% of the patients. Patients with an MRI spot sign had a significantly shorter time to imaging than those without (Pspot sign compared with those without (P≤0.001). Hematoma expansion was observed in the spot sign group compared with the nonspot sign group, although the differences were not significant. Spot sign can be detected using MRI on postcontrast T1-weighted and dynamic T1-weighted images. It is associated with worse clinical outcome. The time course of contrast extravasation in dynamic T1 images indicates that these spots represent ongoing bleeding. © 2015 American Heart Association, Inc.

  8. Comparison of T1-weighted fast spin-echo and T1-weighted fluid-attenuated inversion recovery images of the lumbar spine at 3.0 Tesla

    International Nuclear Information System (INIS)

    Lavdas, Eleftherios; Vlychou, Marianna; Arikidis, Nikos; Kapsalaki, Eftychia; Roka, Violetta; Fezoulidis, Ioannis V.

    2010-01-01

    Background: T1-weighted fluid-attenuated inversion recovery (FLAIR) sequence has been reported to provide improved contrast between lesions and normal anatomical structures compared to T1-weighted fast spin-echo (FSE) imaging at 1.5T regarding imaging of the lumbar spine. Purpose: To compare T1-weighted FSE and fast T1-weighted FLAIR imaging in normal anatomic structures and degenerative and metastatic lesions of the lumbar spine at 3.0T. Material and Methods: Thirty-two consecutive patients (19 females, 13 males; mean age 44 years, range 30-67 years) with lesions of the lumbar spine were prospectively evaluated. Sagittal images of the lumbar spine were obtained using T1-weighted FSE and fast T1-weighted FLAIR sequences. Both qualitative and quantitative analyses measuring the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and relative contrast (ReCon) between degenerative and metastatic lesions and normal anatomic structures were conducted, comparing these sequences. Results: On quantitative evaluation, SNRs of cerebrospinal fluid (CSF), nerve root, and fat around the root of fast T1-weighted FLAIR imaging were significantly lower than those of T1-weighted FSE images (P<0.001). CNRs of normal spinal cord/CSF and disc herniation/ CSF for fast T1-weighted FLAIR images were significantly higher than those for T1-weighted FSE images (P<0.001). ReCon of normal spinal cord/CSF, disc herniation/CSF, and vertebral lesions/CSF for fast T1-weighted FLAIR images were significantly higher than those for T1-weighted FSE images (P<0.001). On qualitative evaluation, it was found that CSF nulling and contrast at the spinal cord (cauda equina)/CSF interface for T1-weighted FLAIR images were significantly superior compared to those for T1-weighted FSE images (P<0.001), and the disc/spinal cord (cauda equina) interface was better for T1-weighted FLAIR images (P<0.05). Conclusion: The T1-weighted FLAIR sequence may be considered as the preferred lumbar spine imaging

  9. Metastatic spinal tumor. Assessment with fat-saturation T1-weighted MR imaging

    International Nuclear Information System (INIS)

    Kasai, Toshifumi; Sugimura, Kazuro; Uchida, Nobue; Kawamitsu, Hideaki; Komatsu, Akio; Okui, Shouji; Kimino, Katsuji.

    1994-01-01

    The purpose of this study was to compare conventional T1-weighted imaging (T1-WI) and chemical shift fat-saturation T1-weighted imaging (fat-sat T1-WI) by a diagnosis of the bone metastases. Thirty-two patients (143 vertebrae) with non-neoplastic lesions (normal group) and 32 patients (82 vertebrae) with spinal metastases (metastatic group) were evaluated using both images. The signal intensity (SI) distribution of both groups regarding T1-WI provided various patterns, and the SI measurements were not significantly different between the two groups ; however, the metastases which were mixed, showed a low SI. Regarding fat-sat T1-WI, all non-neoplastic lesions had a low-intensity homogeneous appearance ; however, the metastases were mixed to a high SI. The SI measurement data of the metastatic group was significantly higher than that of the normal group. In conclusion, fat-sat T1-WI was useful for evaluating the vertebral metastases. When fat-sat T1-WI demonstrated a mixed to high SI in patients suspected of having vertebral metastasis, Gd-DTPA enhancement was thought to be the problem. (author)

  10. Fast T1-weighted imaging using GRASE sequence for the female pelvis

    International Nuclear Information System (INIS)

    Dohke, Masako; Watanabe, Yuji; Kumashiro, Masayuki; Amoh, Yoshiki; Ishimori, Takayoshi; Oda, Kazushige; Okumura, Akira; Koike, Shinji; Dodo, Yoshihiro

    1998-01-01

    GRASE sequence, a combination of TSE and gradient echo, has been developed as a fast T 2 -weighted imaging technique. We have modified the GRASE sequence to be used for fast T 1 -weighted imaging of the female pelvis. In this article, we compared image quality and incidence of artifacts between T 1 -weighted GRASE images and conventional T 1 -weighted SE images. In a phantom study, signal-to-noise ratio was inferior in the GRASE images relative to corresponding on SE images. Susceptibility and chemical shift artifacts seen in GRASE images were seen with almost equal incidence in SE and TSE images. In a clinical study, we compared GRASE images with SE images in six patients with endometrial cysts and four patients with dermoid cysts. The overall image quality obtained with GRASE sequence was satisfactory in all patients and was almost identical with that obtained with SE sequence. GRASE images demonstrated endometrial cysts and dermoid cysts as clearly as did SE images. T 1 -weighted GRASE imaging, however, has a relatively long TE (35 ms) for T 1 -weighted images, which makes the signal intensity of urine and uterine endometrium with long T 2 values higher than in SE images. In conclusion, GRASE sequence can be used for fast T 1 -weighted imaging of the female pelvis because of short imaging time. (author)

  11. Prostate cancer detection from model-free T1-weighted time series and diffusion imaging

    Science.gov (United States)

    Haq, Nandinee F.; Kozlowski, Piotr; Jones, Edward C.; Chang, Silvia D.; Goldenberg, S. Larry; Moradi, Mehdi

    2015-03-01

    The combination of Dynamic Contrast Enhanced (DCE) images with diffusion MRI has shown great potential in prostate cancer detection. The parameterization of DCE images to generate cancer markers is traditionally performed based on pharmacokinetic modeling. However, pharmacokinetic models make simplistic assumptions about the tissue perfusion process, require the knowledge of contrast agent concentration in a major artery, and the modeling process is sensitive to noise and fitting instabilities. We address this issue by extracting features directly from the DCE T1-weighted time course without modeling. In this work, we employed a set of data-driven features generated by mapping the DCE T1 time course to its principal component space, along with diffusion MRI features to detect prostate cancer. The optimal set of DCE features is extracted with sparse regularized regression through a Least Absolute Shrinkage and Selection Operator (LASSO) model. We show that when our proposed features are used within the multiparametric MRI protocol to replace the pharmacokinetic parameters, the area under ROC curve is 0.91 for peripheral zone classification and 0.87 for whole gland classification. We were able to correctly classify 32 out of 35 peripheral tumor areas identified in the data when the proposed features were used with support vector machine classification. The proposed feature set was used to generate cancer likelihood maps for the prostate gland.

  12. Eu, Gd-Codoped Yttria Nanoprobes for Optical and T1-Weighted Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Timur Sh Atabaev

    2017-02-01

    Full Text Available Nanoprobes with multimodal functionality have attracted significant interest recently because of their potential applications in nanomedicine. This paper reports the successful development of lanthanide-doped Y2O3 nanoprobes for potential applications in optical and magnetic resonance (MR imaging. The morphology, structural, and optical properties of these nanoprobes were characterized by transmission electron microscope (TEM, field emission scanning electron microscope (FESEM, X-ray diffraction (XRD, energy-dispersive X-ray (EDX, and photoluminescence (PL. The cytotoxicity test showed that the prepared lanthanide-doped Y2O3 nanoprobes have good biocompatibility. The obvious contrast enhancement in the T1-weighted MR images suggested that these nanoprobes can be used as a positive contrast agent in MRI. In addition, the clear fluorescence images of the L-929 cells incubated with the nanoprobes highlight their potential for optical imaging. Overall, these results suggest that prepared lanthanide-doped Y2O3 nanoprobes can be used for simultaneous optical and MR imaging.

  13. Is hepatotropic contrast enhanced MR a more effective method in differential diagnosis of hemangioma than multi-phase CT and unenhanced MR?

    Directory of Open Access Journals (Sweden)

    Markiet Karolina

    2011-04-01

    Full Text Available Abstract Background Cavernous hemangiomas are the most frequent neoplasms of the liver and in routine clinical practice they often need to be differentiated from malignant tumors and other benign focal lesions. The purpose of this study is to evaluate whether diagnostic accuracy of magnetic resonance imaging (MRI of hepatic hemangiomas, showing atypical pattern on US, improves with the use of Gd-BOPTA in comparison with contrast-enhanced multi-phase computed tomography (CT. Methods 178 consecutive patients with ambiguous hepatic masses showing atypical hyperechoic pattern on grey-scale US, underwent unenhanced and contrast-enhanced multi-phase multi-detector CT and MR (1.5T with the use of liver-specific contrast medium gadobenate dimeglumine (Gd-BOPTA. After intravenous contrast administration arterial (HAP, venous-portal (PVP, equilibrium phases (EP both in CT and MR and additionally hepatobiliary phase (HBP in MR were obtained. 398 lesions have been detected including 99 hemangiomas and 299 other lesions. Results In non-enhanced MDCT examination detection of hemangiomas was characterized by sensitivity of 76%, specificity of 90%, PPV of 71%, NPV of 92% and accuracy of 86%. Non-enhanced MR examination showed sensitivity of 98%, specificity of 99%, PPV of 99%, NPV of 99% and accuracy of 99%. After intravenous administration of contrast medium in MR the mentioned above parameters did not increase significantly. Conclusion Gd-BOPTA-enhanced MR in comparison with unenhanced MRI does not improve diagnostic accuracy in discriminating hemangiomas that show non-specific appearance in ultrasound examination. Unenhanced MR as a method of choice should directly follow US in course of diagnostic algorithm in differentiation of hemangiomas from other liver tumors.

  14. Detailed T1-Weighted Profiles from the Human Cortex Measured in Vivo at 3 Tesla MRI.

    Science.gov (United States)

    Ferguson, Bart; Petridou, Natalia; Fracasso, Alessio; van den Heuvel, Martijn P; Brouwer, Rachel M; Hulshoff Pol, Hilleke E; Kahn, René S; Mandl, René C W

    2018-04-01

    Studies into cortical thickness in psychiatric diseases based on T1-weighted MRI frequently report on aberrations in the cerebral cortex. Due to limitations in image resolution for studies conducted at conventional MRI field strengths (e.g. 3 Tesla (T)) this information cannot be used to establish which of the cortical layers may be implicated. Here we propose a new analysis method that computes one high-resolution average cortical profile per brain region extracting myeloarchitectural information from T1-weighted MRI scans that are routinely acquired at a conventional field strength. To assess this new method, we acquired standard T1-weighted scans at 3 T and compared them with state-of-the-art ultra-high resolution T1-weighted scans optimised for intracortical myelin contrast acquired at 7 T. Average cortical profiles were computed for seven different brain regions. Besides a qualitative comparison between the 3 T scans, 7 T scans, and results from literature, we tested if the results from dynamic time warping-based clustering are similar for the cortical profiles computed from 7 T and 3 T data. In addition, we quantitatively compared cortical profiles computed for V1, V2 and V7 for both 7 T and 3 T data using a priori information on their relative myelin concentration. Although qualitative comparisons show that at an individual level average profiles computed for 7 T have more pronounced features than 3 T profiles the results from the quantitative analyses suggest that average cortical profiles computed from T1-weighted scans acquired at 3 T indeed contain myeloarchitectural information similar to profiles computed from the scans acquired at 7 T. The proposed method therefore provides a step forward to study cortical myeloarchitecture in vivo at conventional magnetic field strength both in health and disease.

  15. Contrast-enhanced magnetic resonance angiography: first-pass arterial enhancement as a function of gadolinium-chelate concentration, and the saline chaser volume and injection rate.

    Science.gov (United States)

    Husarik, Daniela B; Bashir, Mustafa R; Weber, Paul W; Nichols, Eli B; Howle, Laurens E; Merkle, Elmar M; Nelson, Rendon C

    2012-02-01

    To evaluate the effect of the contrast medium (CM) concentration and the saline chaser volume and injection rate on first-pass aortic enhancement characteristics in contrast-enhanced magnetic resonance angiography using a physiologic flow phantom. Imaging was performed on a 3.0-T magnetic resonance system (MAGNETOM Trio, Siemens Healthcare Solutions, Inc, Erlangen, Germany) using a 2-dimensional fast low angle shot T1-weighted sequence (repetition time, 500 milliseconds; echo time, 1.23 milliseconds; flip angle, 8 degrees; 1 frame/s × 60 seconds). The following CM concentrations injected at 2 mL/s were used with 3 different contrast agents (gadolinium [Gd]-BOPTA, Gd-HP-DO3A, Gd-DTPA): 20 mL of undiluted CM (100%) and 80%, 40%, 20%, 10%, 5%, and 2.5% of the full amount, all diluted in saline to a volume of 20 mL to ensure equal bolus volume. The CM was followed by saline chasers of 20 to 60 mL injected at 2 mL/s and 6 mL/s. Aortic signal intensity (SI) was measured, and normalized SI versus time (SI/Tn) curves were generated. The maximal SI (SI(max)), bolus length, and areas under the SI/Tn curve were calculated. Decreasing the CM concentration from 100% to 40% resulted in a decrease of SI(max) to 86.1% (mean). Further decreasing the CM concentration to 2.5% decreased SI(max) to 5.1% (mean). Altering the saline chaser volume had no significant effect on SI(max). Increasing the saline chaser injection rate had little effect (mean increase, 2.2%) on SI(max) when using ≥40% of CM. There was a larger effect (mean increase, 19.6%) when ≤20% of CM were used. Bolus time length was significantly shorter (P < 0.001), and area under the SI/T(n) curve was significantly smaller (P < 0.01) for the CM protocols followed by a saline chaser injected at 6 mL/s compared with a saline chaser injected at 2 mL/s. With 40% of CM and a fast saline chaser, SImax close to that with undiluted CM can be achieved. An increased saline chaser injection rate has a more pronounced effect on

  16. Degenerative disc disease of the lumbar spine: a prospective comparison of fast T1-weighted fluid-attenuated inversion recovery and T1-weighted turbo spin echo MR imaging

    International Nuclear Information System (INIS)

    Erdem, L. Oktay; Erdem, C. Zuhal; Acikgoz, Bektas; Gundogdu, Sadi

    2005-01-01

    Objective: To compare fast T1-weighted fluid-attenuated inversion recovery (FLAIR) and T1-weighted turbo spin-echo (TSE) imaging of the degenerative disc disease of the lumbar spine. Materials and methods: Thirty-five consecutive patients (19 females, 16 males; mean age 41 years, range 31-67 years) with suspected degenerative disc disease of the lumbar spine were prospectively evaluated. Sagittal images of the lumbar spine were obtained using T1-weighted TSE and fast T1-weighted FLAIR sequences. Two radiologists compared these sequences both qualitatively and quantitatively. Results: On qualitative evaluation, CSF nulling, contrast at the disc-CSF interface, the disc-spinal cord (cauda equina) interface, and the spinal cord (cauda equina)-CSF interface of fast T1-weighted FLAIR images were significantly higher than those for T1-weighted TSE images (P < 0.001). On quantitative evaluation of the first 15 patients, signal-to-noise ratios of cerebrospinal fluid of fast T1-weighted FLAIR imaging were significantly lower than those for T1-weighted TSE images (P < 0.05). Contrast-to-noise ratios of spinal cord/CSF and normal bone marrow/disc for fast T1-weighted FLAIR images were significantly higher than those for T1-weighted TSE images (P < 0.05). Conclusion: Results in our study have shown that fast T1-weighted FLAIR imaging may be a valuable imaging modality in the armamentarium of lumbar spinal T1-weighted MR imaging, because the former technique has definite superior advantages such as CSF nulling, conspicuousness of the normal anatomic structures and changes in the lumbar spinal discogenic disease and image contrast and also almost equally acquisition times

  17. Degenerative disc disease of the lumbar spine: a prospective comparison of fast T1-weighted fluid-attenuated inversion recovery and T1-weighted turbo spin echo MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Erdem, L. Oktay [Department of Radiology, Zonguldak Karaelmas University, School of Medicine, 6700 Kozlu, Zonguldak (Turkey)]. E-mail: sunarerdem@yahoo.com; Erdem, C. Zuhal [Department of Radiology, Zonguldak Karaelmas University, School of Medicine, 6700 Kozlu, Zonguldak (Turkey); Acikgoz, Bektas [Department of Neurosurgery, Zonguldak Karaelmas University, School of Medicine, Zonguldak (Turkey); Gundogdu, Sadi [Department of Radiology, Zonguldak Karaelmas University, School of Medicine, 6700 Kozlu, Zonguldak (Turkey)

    2005-08-01

    Objective: To compare fast T1-weighted fluid-attenuated inversion recovery (FLAIR) and T1-weighted turbo spin-echo (TSE) imaging of the degenerative disc disease of the lumbar spine. Materials and methods: Thirty-five consecutive patients (19 females, 16 males; mean age 41 years, range 31-67 years) with suspected degenerative disc disease of the lumbar spine were prospectively evaluated. Sagittal images of the lumbar spine were obtained using T1-weighted TSE and fast T1-weighted FLAIR sequences. Two radiologists compared these sequences both qualitatively and quantitatively. Results: On qualitative evaluation, CSF nulling, contrast at the disc-CSF interface, the disc-spinal cord (cauda equina) interface, and the spinal cord (cauda equina)-CSF interface of fast T1-weighted FLAIR images were significantly higher than those for T1-weighted TSE images (P < 0.001). On quantitative evaluation of the first 15 patients, signal-to-noise ratios of cerebrospinal fluid of fast T1-weighted FLAIR imaging were significantly lower than those for T1-weighted TSE images (P < 0.05). Contrast-to-noise ratios of spinal cord/CSF and normal bone marrow/disc for fast T1-weighted FLAIR images were significantly higher than those for T1-weighted TSE images (P < 0.05). Conclusion: Results in our study have shown that fast T1-weighted FLAIR imaging may be a valuable imaging modality in the armamentarium of lumbar spinal T1-weighted MR imaging, because the former technique has definite superior advantages such as CSF nulling, conspicuousness of the normal anatomic structures and changes in the lumbar spinal discogenic disease and image contrast and also almost equally acquisition times.

  18. Extrahepatic portal vein obstruction with parkinsonism and symmetric hyperintense basal ganglia on T1 weighted MRI

    Directory of Open Access Journals (Sweden)

    Jayalakshmi Sita

    2006-01-01

    Full Text Available Abnormal high signal in the globus pallidus on T1 weighted magnetic resonance imaging (MRI of the brain has been well described in patients with chronic liver disease. It may be related to liver dysfunction or portal-systemic shunting. We report a case of extra hepatic portal vein obstruction with portal hypertension and esophageal varices that presented with extra pyramidal features. T1 weighted MRI brain scans showed increased symmetrical signal intensities in the basal ganglia. Normal hepatic function in this patient emphasizes the role of portal- systemic communications in the development of these hyperintensities, which may be due to deposition of paramagnetic substances like manganese in the basal ganglia.

  19. An age estimation method using brain local features for T1-weighted images.

    Science.gov (United States)

    Kondo, Chihiro; Ito, Koichi; Kai Wu; Sato, Kazunori; Taki, Yasuyuki; Fukuda, Hiroshi; Aoki, Takafumi

    2015-08-01

    Previous statistical analysis studies using large-scale brain magnetic resonance (MR) image databases have examined that brain tissues have age-related morphological changes. This fact indicates that one can estimate the age of a subject from his/her brain MR image by evaluating morphological changes with healthy aging. This paper proposes an age estimation method using local features extracted from T1-weighted MR images. The brain local features are defined by volumes of brain tissues parcellated into local regions defined by the automated anatomical labeling atlas. The proposed method selects optimal local regions to improve the performance of age estimation. We evaluate performance of the proposed method using 1,146 T1-weighted images from a Japanese MR image database. We also discuss the medical implication of selected optimal local regions.

  20. Assessment of Silent T1-weighted head imaging at 7 T

    Energy Technology Data Exchange (ETDEWEB)

    Costagli, Mauro; Tiberi, Gianluigi; Tosetti, Michela [Imago7 Foundation, Pisa (Italy); IRCCS Stella Maris, Laboratory of Medical Physics and Biotechnologies for Magnetic Resonance, Pisa (Italy); Symms, Mark R. [GE Applied Science Laboratory, Pisa (Italy); Angeli, Lorenzo [University of Pisa, Department of Translational Research and New Technologies in Medicine and Surgery, Pisa (Italy); Kelley, Douglas A.C. [GE Healthcare Technologies, San Francisco, CA (United States); Biagi, Laura [IRCCS Stella Maris, Laboratory of Medical Physics and Biotechnologies for Magnetic Resonance, Pisa (Italy); Farnetani, Andrea [University of Ferrara, Engineering Department, Ferrara (Italy); Materiacustica s.r.l., Ferrara (Italy); Rua, Catarina [University of Pisa, Department of Physics, Pisa (Italy); Donatelli, Graziella [Azienda Ospedaliero-Universitaria Pisana (AOUP), Neuroradiology Unit, Department of Diagnostic and Interventional Radiology, Pisa (Italy); Cosottini, Mirco [Imago7 Foundation, Pisa (Italy); University of Pisa, Department of Translational Research and New Technologies in Medicine and Surgery, Pisa (Italy)

    2016-06-15

    This study aimed to assess the performance of a ''Silent'' zero time of echo (ZTE) sequence for T1-weighted brain imaging using a 7 T MRI system. The Silent sequence was evaluated qualitatively by two neuroradiologists, as well as quantitatively in terms of tissue contrast, homogeneity, signal-to-noise ratio (SNR) and acoustic noise. It was compared to conventional T1-weighted imaging (FSPGR). Adequacy for automated segmentation was evaluated in comparison with FSPGR acquired at 7 T and 1.5 T. Specific absorption rate (SAR) was also measured. Tissue contrast and homogeneity in Silent were remarkable in deep brain structures and in the occipital and temporal lobes. Mean tissue contrast was significantly (p < 0.002) higher in Silent (0.25) than in FSPGR (0.11), which favoured automated tissue segmentation. On the other hand, Silent images had lower SNR with respect to conventional imaging: average SNR of FSPGR was 2.66 times that of Silent. Silent images were affected by artefacts related to projection reconstruction, which nevertheless did not compromise the depiction of brain tissues. Silent acquisition was 35 dB(A) quieter than FSPGR and less than 2.5 dB(A) louder than ambient noise. Six-minute average SAR was <2 W/kg. The ZTE Silent sequence provides high-contrast T1-weighted imaging with low acoustic noise at 7 T. (orig.)

  1. Interactive thresholded volumetry of abdominal fat using breath-hold T1-weighted magnetic resonance imaging

    International Nuclear Information System (INIS)

    Wittsack, H.J.; Cohnen, M.; Jung, G.; Moedder, U.; Poll, L.; Kapitza, C.; Heinemann, L.

    2006-01-01

    Purpose: development of a feasible and reliable method for determining abdominal fat using breath-hold T1-weighted magnetic resonance imaging. Materials and methods: the high image contrast of T1-weighted gradient echo MR sequences makes it possible to differentiate between abdominal fat and non-fat tissue. To obtain a high signal-to-noise ratio, the measurements are usually performed using phased array surface coils. Inhomogeneity of the coil sensitivity leads to inhomogeneity of the image intensities. Therefore, to examine the volume of abdominal fat, an automatic algorithm for intensity correction must be implemented. The analysis of the image histogram results in a threshold to separate fat from other tissue. Automatic segmentation using this threshold results directly in the fat volumes. The separation of intraabdominal and subcutaneous fat is performed by interactive selection in a last step. Results: the described correction of inhomogeneity allows for the segmentation of the images using a global threshold. The use of semiautomatic interactive volumetry makes the analysis more subjective. The variance of volumetry between observers was 4.6%. The mean time for image analysis of a T1-weighted investigation lasted less than 6 minutes. Conclusion: the described method facilitates reliable determination of abdominal fat within a reasonable period of time. Using breath-hold MR sequences, the time of examination is less than 5 minutes per patient. (orig.)

  2. T1-weighted MRI for the detection of coronary artery plaque haemorrhage

    International Nuclear Information System (INIS)

    Oei, May Lin; Ozgun, Murat; Seifarth, Harald; Bunck, Alexander; Fischbach, Roman; Heindel, Walter; Maintz, David; Orwat, Stefan; Botnar, Rene

    2010-01-01

    Hyperintense areas in atherosclerotic plaques on pre-contrast T1-weighted MRI have been shown to correlate with intraplaque haemorrhage. We evaluated the presence of T1 hyperintensity in coronary artery plaques in coronary artery disease (CAD) patients and correlated results with multi-detector computed tomography (MDCT) findings. Fifteen patients with CAD were included. Plaques detected by MDCT were categorised based on their Hounsfield number. T1-weighted inversion recovery (IR) MRI prepared coronary MRI for the detection of plaque and steady-state free-precession coronary MR-angiography for anatomical correlation was performed. After registration of MDCT and MRI, regions of interest were defined on MDCT-visible plaques and in corresponding vessel segments acquired with MRI. MDCT density and MR signal measurement were performed in each plaque. Forty-three plaques were identified with MDCT. With IR-MRI 5/43 (12%) plaques were hyperintense, 2 of which were non-calcified and 3 mixed. Average signal-to-noise and contrast-to-noise ratios of hyperintense plaques were 15.7 and 9.1, compared with 5.6 and 1.2 for hypointense plaques. Hyperintense plaques exhibited a significantly lower CT density than hypointense plaques (63.6 vs. 140.8). There was no correlation of plaque signal intensity with degree of stenosis. T1-weighted IR-MRI may be useful for non-invasive detection and characterisation of intraplaque haemorrhage in coronary artery plaques. (orig.)

  3. Classification of hematopoietic regions in out-of-phase T1-weighted images. A quantitative comparison study with T1-weighted and STIR images

    International Nuclear Information System (INIS)

    Amano, Yasuo; Amano, Maki; Kijima, Tetsuji; Kumazaki, Tatsuo

    1995-01-01

    The hematopoietic regions were classified into two groups on the basis of out-of-phase T 1 -weighted images (op-TlWI): regions with lower intensity than that of muscle (LH) and regions with intensity equal to or higher than that of muscle (HH). We quantitatively evaluated the differences in signal intensity between LH and HH in order to examine this classification. Forty-two hematopoietic areas in aplastic anemia were classified into two groups of 23 LH and 19 HH. The signal ratios of hematopoietic areas to muscle on TlWI and STIR were calculated, and the differences between LH and HH were statistically evaluated. The signal ratios of LH were significantly higher on TlWI and lower on STIR than those of HH (unpaired t-test, p<0.05). This result indicated that LH consisted of more hypocellular marrow than HH. Op-TlWI were useful in differentiating between LH and HH and defining the degree of hematopoiesis in aplastic anemia. (author)

  4. Diagnosis of the hypothenar hammer syndrome by high-resolution contrast-enhanced MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Winterer, J.T.; Ghanem, N.; Schaefer, O.; Lehnhardt, S.; Thuerl, C.; Laubenberger, J. [Department of Diagnostic Radiology, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany); Roth, M. [Center of Geriatric Medicine and Gerontology Freiburg, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany); Horch, R.E. [Department of Plastic and Hand Surgery, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany)

    2002-10-01

    Our objective was to describe the imaging features of hypothenar hammer syndrome using minimally invasive contrast-enhanced MR angiography in comparison with oscillography study. In five patients with hypothenar hammer syndrome Gd-BOPTA-enhanced elliptically reordered 3D pulse sequence MR was compared with oscillography findings and clinical symptoms focusing on angiographic appearance of vessel injury, distribution pattern of hand vasculature and joining branches between the radial and ulnar artery supply. All patients showed segmental occlusion at the site of trauma impact with varying involvement of the superficial palmar arch, common volar digital arteries. Embolic disease was present in 50% of patients and could be clearly identified with MRA. Good correspondence was found between angiographic appearance including the presence of collaterals, clinical symptoms and oscillography. Bilateral comparison was helpful in distinguishing between vessel variants and pathology. Bilateral Gd-BOPTA-enhanced MR angiography is a minimally invasive method to depict clearly the localization and extent of vessel injury in hypothenar hammer syndrome providing valuable information about distribution pattern of hand vasculature and presence of collaterals; however, no flow data can be obtained. (orig.)

  5. Diagnosis of the hypothenar hammer syndrome by high-resolution contrast-enhanced MR angiography

    International Nuclear Information System (INIS)

    Winterer, J.T.; Ghanem, N.; Schaefer, O.; Lehnhardt, S.; Thuerl, C.; Laubenberger, J.; Roth, M.; Horch, R.E.

    2002-01-01

    Our objective was to describe the imaging features of hypothenar hammer syndrome using minimally invasive contrast-enhanced MR angiography in comparison with oscillography study. In five patients with hypothenar hammer syndrome Gd-BOPTA-enhanced elliptically reordered 3D pulse sequence MR was compared with oscillography findings and clinical symptoms focusing on angiographic appearance of vessel injury, distribution pattern of hand vasculature and joining branches between the radial and ulnar artery supply. All patients showed segmental occlusion at the site of trauma impact with varying involvement of the superficial palmar arch, common volar digital arteries. Embolic disease was present in 50% of patients and could be clearly identified with MRA. Good correspondence was found between angiographic appearance including the presence of collaterals, clinical symptoms and oscillography. Bilateral comparison was helpful in distinguishing between vessel variants and pathology. Bilateral Gd-BOPTA-enhanced MR angiography is a minimally invasive method to depict clearly the localization and extent of vessel injury in hypothenar hammer syndrome providing valuable information about distribution pattern of hand vasculature and presence of collaterals; however, no flow data can be obtained. (orig.)

  6. Patients with liver FNH and HCC patients with negative AFP: plain and dynamic enhanced MRI and CT findings

    Directory of Open Access Journals (Sweden)

    LI Mingtong

    2015-05-01

    Full Text Available ObjectiveTo investigate plain and dynamic enhanced magnetic resonance imaging (MRI and computed tomography (CT findings in patients with focal nodular hyperplasia (FNH of the liver and hepatocellular carcinoma (HCC patients with negative alpha-fetoprotein (AFP. MethodsA statistical analysis was performed on the clinical data of 124 cases of liver tumor admitted to Beijing Miyun County Hospital from April 2012 to April 2014. ResultsFifty-five of the 74 patients with FNH underwent CT examination, among whom 38 patients received three-phase dynamic enhanced scan and 16 received only plain scan; 62 cases had plain and enhanced MRI with the application of contrast agent Gd-BOPTA in 42 patients. Among the 50 HCC patients with negative AFP, CT examination was performed in 40 and 10 only had plain scan; 46 patients received plain and enhanced MRI with the use of contrast agent Gd-BOPTA in 30. Delayed scan after 1-2 h demonstrated low signal in 30 lesions of the 30 cases. ConclusionFor patients with liver FNH and AFP-negative HCC patients, their plain and dynamic enhanced MRI and CT scan have respective characteristics. A combination of multiple examination methods can significantly improve diagnostic yield of the two diseases.

  7. MRI findings of sacroiliitis in ankylosing spondylitis: roles of MPGR and delayed post-contrast T1-weighted images

    International Nuclear Information System (INIS)

    Jeon, Eui Yong; Joo, Kyung Bin; Koo, Ja Hong; Moon, Won Jin; Hahm, Chang Kok; Kim, Tae Hwan; Kim, Seong Yoon

    1997-01-01

    For early diagnosis of sacroiliitis in spondyloarthropathy, the MRI findings of sacroiliitis, roles of MPGR(multiplanar Gradient Recalled Acquisition in Steady State), and delayed post-contrast T1-weighted images were evaluated. Twenty six patients with seronegative spondyloarthropathy(Probable clinical diagnosis of ankylosing spondylitis) were grouped as either less than radiographic grade 1(group A) or more than grade 2(group B). The MRI findings of both sacroiliac joints were evaluated in every patient, and predominant sites were determined. The two groups were then compared. In 17 patients, the number of enhancing panni seen on early and delayed post-contrast T1-weighted images was counted and compared between the two groups. Panni were found in all cases, and in both groups, predominant patterns of involvement were the lower and iliac aspects of the sacroiliac joints in both groups; in group A, the synovial joints and punctate pannus were predominantly involved, and in group B, the ligamentous joints as well as the synovial joints and linear pannus. In group B, More periarticular fat accumulation than periarticular osteitis was found. For the evaluation of changes in joint space, MPGR images were superior to spin echo images. For the delineation of enhancing pannus less than radiographic grade I, delayed post-contrast images were statistically superior to those which were early post-contrast. MRI can detect early sacroiliitic change according to the predominant sites of involvement, and deslyed post-contrast images play a role in the diagnosis of early sacroiliitis. MPGR imaging is good for the evaluation of joint space change

  8. MRI findings of sacroiliitis in ankylosing spondylitis: roles of MPGR and delayed post-contrast T1-weighted images

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Eui Yong; Joo, Kyung Bin; Koo, Ja Hong; Moon, Won Jin; Hahm, Chang Kok; Kim, Tae Hwan; Kim, Seong Yoon [Hanyang Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-10-01

    For early diagnosis of sacroiliitis in spondyloarthropathy, the MRI findings of sacroiliitis, roles of MPGR(multiplanar Gradient Recalled Acquisition in Steady State), and delayed post-contrast T1-weighted images were evaluated. Twenty six patients with seronegative spondyloarthropathy(Probable clinical diagnosis of ankylosing spondylitis) were grouped as either less than radiographic grade 1(group A) or more than grade 2(group B). The MRI findings of both sacroiliac joints were evaluated in every patient, and predominant sites were determined. The two groups were then compared. In 17 patients, the number of enhancing panni seen on early and delayed post-contrast T1-weighted images was counted and compared between the two groups. Panni were found in all cases, and in both groups, predominant patterns of involvement were the lower and iliac aspects of the sacroiliac joints in both groups; in group A, the synovial joints and punctate pannus were predominantly involved, and in group B, the ligamentous joints as well as the synovial joints and linear pannus. In group B, More periarticular fat accumulation than periarticular osteitis was found. For the evaluation of changes in joint space, MPGR images were superior to spin echo images. For the delineation of enhancing pannus less than radiographic grade I, delayed post-contrast images were statistically superior to those which were early post-contrast. MRI can detect early sacroiliitic change according to the predominant sites of involvement, and deslyed post-contrast images play a role in the diagnosis of early sacroiliitis. MPGR imaging is good for the evaluation of joint space change.

  9. Developmental patterns of fetal fat and corresponding signal on T1-weighted magnetic resonance imaging

    International Nuclear Information System (INIS)

    Blondiaux, Eleonore; Chougar, Lydia; Ducou le Pointe, Hubert; Garel, Catherine; Gelot, Antoinette; Valence, Stephanie; Audureau, Etienne; Jouannic, Jean-Marie; Dhombres, Ferdinand

    2018-01-01

    Evaluation of subcutaneous fetal fat layer thickness on T1-weighted sequences can be used to predict birth weight. Little is known about normal MR signal patterns of subcutaneous tissue throughout pregnancy. To establish developmental patterns of subcutaneous fetal fat signal on T1-weighted sequences during the 2nd and 3rd trimesters. We retrospectively examined T1-weighted images of 110 fetal MRI scans. We measured signal intensity of subcutaneous fat on thighs, buttocks, trunk, nuchal region, chin and scalp. We then calculated the ratios of the obtained values with fetal muscle, amnios and maternal fat signal, and compared the results with those of immunohistochemical examination of adipose tissue extracted from the abdominal wall of fetuses as part of standard autopsy protocol. We included 60 MRI scans in fetuses without intra-uterine growth restriction or macrosomia of non-diabetic mothers (range 23-37 weeks of gestation). Fat T1 intensity of all anatomical regions was low in all fetuses before 26 weeks of gestation. It became more hyperintense with increasing gestational age, in the following order: chin and nuchal region, then buttocks, thighs and trunk, and eventually the scalp at 33 weeks of gestation. After 33 weeks of gestation, all fetal subcutaneous tissues demonstrated overall hyperintense signal. This progression followed the conversion at immunohistochemistry of fetal adipose tissue composition from predominant brown to white adipose cells in 19 fetuses (19-41 weeks of gestation). Between 26 weeks and 33 weeks of gestation, subcutaneous fetal fat signal changed in an orderly pattern from chin to buttocks and scalp. This may reflect the conversion from predominant brown to white adipose tissues in subcutaneous fetal fat. (orig.)

  10. Hyperintense basal ganglia lesions on T1-weighted MR images in asymptomatic patients with hepatic dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Saatci, I. [Dept. of Radiology, Hacettepe Univ. Hospital, Ankara (Turkey); Cila, A. [Dept. of Radiology, Hacettepe Univ. Hospital, Ankara (Turkey); Dincer, F.F. [Dept. of Radiology, Hacettepe Univ. Hospital, Ankara (Turkey)

    1995-12-31

    Cranial MRI findings in four patients who had hepatic dysfunction, including one with sole hepatic form of Wilson`s disease, were reported. The MR examinations revealed bilateral, symmetric hyperintensity in the globus pallidus, subthalamic nuclei and mesencephalon on T1-weighted images with no corresponding abnormality on T2-weighted sequences. The basal ganglia were normal on CT examinations in all patients. None of the patients had the clinical findings of hepatic encephalopathy. The MR findings in our patients did not correlate with the degree or duration of hepatic dysfunction. (orig.)

  11. T1-weighted fluid-attenuated inversion recovery and T1-weighted fast spin-echo contrast-enhanced imaging: a comparison in 20 patients with brain lesions

    International Nuclear Information System (INIS)

    Al-Saeed, O.; Athyal, R. P.; Ismail, M.; Rudwan, M.; Khafajee, S.

    2009-01-01

    Full text: Tl-weighted fluid-attenuated inversion recovery (FLAIR) sequence is a relatively new pulse sequence for intracranial MR imaging. This study was performed to compare the image quality of Tl-weighted FLAIR with the Tl-weighted FSE sequence. Twenty patients with brain lesions underwent Tl-weighted fast spin-echo (FSE) and Tl-weighted FLAIR during the same imaging session. Four quantitative and three qualitative criteria were used to compare the two sequences after contrast. Two of four quantitative criteria pertained to lesion characteristics: lesion to white matter (WM) contrast-to-noise ratio (CNR) and lesion to cerebrospinal fluid (CSF) CNR, and two related to signals from normal tissue: grey matter to WM CNR and WM to CSF CNR. The three qualitative criteria were conspicuousness of the lesion, the presence of image artefacts and the overall image contrast. Both Tl-weighted FSE and FLAIR images were effective in demonstrating lesions. Image contrast was superior in Tl-weighted FLAIR images with significantly improved grey matter-WM CNRs and CSF-WM CNRs. The overall image contrast was judged to be superior on Tl-weighted FLAIR images compared with Tl-weighted FSE images by all neuroradiologists. Two of three reviewers considered that the FLAIR images had slightly increased imaging artefacts that, however, did not interfere with image interpretation. Tl-weighted FLAIR imaging provides improved lesion-to-background and grey to WM contrast-to-noise ratios. Superior conspicuity of lesions and overall image contrast is obtained in comparable acquisition times. These indicate an important role for Tl-weighted FLAIR in intracranial imaging and highlight its advantage over the more widely practiced Tl-weighted FSE sequence

  12. Diagnostic accuracy of automatic normalization of CBV in glioma grading using T1- weighted DCE-MRI.

    Science.gov (United States)

    Sahoo, Prativa; Gupta, Rakesh K; Gupta, Pradeep K; Awasthi, Ashish; Pandey, Chandra M; Gupta, Mudit; Patir, Rana; Vaishya, Sandeep; Ahlawat, Sunita; Saha, Indrajit

    2017-12-01

    Aim of this retrospective study was to compare diagnostic accuracy of proposed automatic normalization method to quantify the relative cerebral blood volume (rCBV) with existing contra-lateral region of interest (ROI) based CBV normalization method for glioma grading using T1-weighted dynamic contrast enhanced MRI (DCE-MRI). Sixty patients with histologically confirmed gliomas were included in this study retrospectively. CBV maps were generated using T1-weighted DCE-MRI and are normalized by contralateral ROI based method (rCBV_contra), unaffected white matter (rCBV_WM) and unaffected gray matter (rCBV_GM), the latter two of these were generated automatically. An expert radiologist with >10years of experience in DCE-MRI and a non-expert with one year experience were used independently to measure rCBVs. Cutoff values for glioma grading were decided from ROC analysis. Agreement of histology with rCBV_WM, rCBV_GM and rCBV_contra respectively was studied using Kappa statistics and intra-class correlation coefficient (ICC). The diagnostic accuracy of glioma grading using the measured rCBV_contra by expert radiologist was found to be high (sensitivity=1.00, specificity=0.96, pnormalization method showed same percentage of agreement for both expert and non-expert user. rCBV_WM showed an agreement of 88.33% (kappa=0.76,pnormalization of CBV using the proposed method could provide better diagnostic accuracy compared to the manual contralateral based approach. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Diagnostic value of brain chronic black holes on T1-weighted MR images in clinically isolated syndromes.

    Science.gov (United States)

    Mitjana, Raquel; Tintoré, Mar; Rocca, Maria A; Auger, Cristina; Barkhof, Frederik; Filippi, Massimo; Polman, Chris; Fazekas, Franz; Huerga, Elena; Montalban, Xavier; Rovira, Alex

    2014-10-01

    Non-enhancing black holes (neBHs) are more common in multiple sclerosis (MS) patients with longer disease durations and progressive disease subtypes. Our aim was to analyse the added value of neBHs in patients with clinically isolated syndromes (CISs) for predicting conversion to clinically definite MS (CDMS). Patients were classified based on the presence or absence of neBHs and on the number of Barkhof-Tintoré (B-T) criteria fulfilled. Dissemination in space (DIS) was defined as the presence of at least three of the four B-T criteria. Dissemination in time (DIT)1 was defined by simultaneous presence of enhancing and non-enhancing lesions. DIT2 was defined by simultaneous presence of neBHs and T2 lesions not apparent on T1-weighted images. Focal T2-hyperintense brain lesions were identified in 87.7% of the 520 CIS patients, and 41.4% of them presented at least one neBH. Patients meeting DIS, DIT1, and DIT2 had a significantly higher rate of conversion to CDMS. After adjusting for DIS, only patients who fulfilled DIT1 preserved a significant increase in CDMS conversion. Non-enhancing black holes in CIS patients are associated with a higher risk of conversion to CDMS. However, the predictive value of this finding is lost when added to the DIS criteria. © The Author(s) 2014.

  14. MRI of the cervical spine with T1-weighted multislice flash sequences

    International Nuclear Information System (INIS)

    Schubeus, P.; Sander, B.; Schoerner, W.; Tosch, U.; Lanksch, W.R.; Felix, R.; Klinikum Rudolf Virchow, Berlin

    1990-01-01

    A study has been carried out to evaluate contrast and image quality of cervical structures using multislice 2D-flash sequences with long repetition times (TR = 400 ms.) and short echo delay times (TE = 5.8 ms.). The examinations were carried out using ten normals with an MRI of 1.5 Tesla and flip angles of 10, 20, 30, 50, 70 and 90deg. The best contrast between intervertebral disc and surrounding tissue was obtained between 50 and 70deg, best contrast between compact bone and CSF with 10deg. In order to demonstrate degenerative changes of the cervical spine, it appears sensible to use a combination of these angles. The described sequences produce good images of the cervical structures with little image degradation. Compared to T 1 -weighted spin-echo sequences, the method has a number of significant advantages, such as variations in image contrast, higher maximal number of slices, continuous imaging and less imaging time. (orig.) [de

  15. Measurement of brain oxygenation changes using dynamic T1-weighted imaging

    DEFF Research Database (Denmark)

    Haddock, Bryan; Larsson, Henrik B W; Hansen, Adam E

    2013-01-01

    Magnetic resonance imaging (MRI) has proven useful in evaluating oxygenation in several types of tissue and blood. This study evaluates brain tissue oxygenation changes between normoxia and hyperoxia in healthy subjects using dynamic T1 and T2*-weighted imaging sequences. The change in FiO2 induced...... by hyperoxia caused a significant decrease in T1. A model to determine changes in tissue oxygen tension from the T1-weighted MRI signal is presented based on previous findings that T1 is sensitive to oxygen tension whereas T2* is sensitive to blood saturation. The two sequences produce results with different...... regional and temporal dynamics. These differences combined with results from simulations of the T1 signal intensities, indicate an increase in extravascular oxygen tension during hyperoxia. This study concludes that T1 and T2* responses to FiO2 serve as independent biomarkers of oxygen physiology...

  16. Whole-brain intracranial vessel wall imaging at 3 Tesla using cerebrospinal fluid-attenuated T1-weighted 3D turbo spin echo.

    Science.gov (United States)

    Fan, Zhaoyang; Yang, Qi; Deng, Zixin; Li, Yuxia; Bi, Xiaoming; Song, Shlee; Li, Debiao

    2017-03-01

    Although three-dimensional (3D) turbo spin echo (TSE) with variable flip angles has proven to be useful for intracranial vessel wall imaging, it is associated with inadequate suppression of cerebrospinal fluid (CSF) signals and limited spatial coverage at 3 Tesla (T). This work aimed to modify the sequence and develop a protocol to achieve whole-brain, CSF-attenuated T 1 -weighted vessel wall imaging. Nonselective excitation and a flip-down radiofrequency pulse module were incorporated into a commercial 3D TSE sequence. A protocol based on the sequence was designed to achieve T 1 -weighted vessel wall imaging with whole-brain spatial coverage, enhanced CSF-signal suppression, and isotropic 0.5-mm resolution. Human volunteer and pilot patient studies were performed to qualitatively and quantitatively demonstrate the advantages of the sequence. Compared with the original sequence, the modified sequence significantly improved the T 1 -weighted image contrast score (2.07 ± 0.19 versus 3.00 ± 0.00, P = 0.011), vessel wall-to-CSF contrast ratio (0.14 ± 0.16 versus 0.52 ± 0.30, P = 0.007) and contrast-to-noise ratio (1.69 ± 2.18 versus 4.26 ± 2.30, P = 0.022). Significant improvement in vessel wall outer boundary sharpness was observed in several major arterial segments. The new 3D TSE sequence allows for high-quality T 1 -weighted intracranial vessel wall imaging at 3 T. It may potentially aid in depicting small arteries and revealing T 1 -mediated high-signal wall abnormalities. Magn Reson Med 77:1142-1150, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  17. MR staging of pelvic endometriosis. Role of fat-suppression T1-weighted images

    International Nuclear Information System (INIS)

    Oishi-Tanaka, Yumiko; Itai, Yuji; Anno, Izumi; Matsumoto, Kunihiko; Ebihara, Reiko; Nishida, Masato

    1996-01-01

    We examined whether MR can determine the stage of endometriosis according to the scoring system established and revised by the American Fertility Society (r-AFS), a system which is widely used by gynecologists. We also studied the utility of fat suppression T 1 -weighted images in improving accuracy. Seventeen patients with endometriosis examined by conventional MR were included in this study. All the patients had surgically proved stage III or IV disease. We determined the stage by MR using the following criteria according to the r-AFS system: adnexal masses without normal ovarian tissue were considered deep ovarian lesions, while those with normal tissue were considered superficial. A lack of fat between the lesion and surrounding structures was considered a dense adhesion, and hyperintense spots were considered peritoneal implants. The MR scores of patients with and without fat suppression were correlated with the surgical scores. MR staging corresponded to surgical staging in 15 of the 17 patients. In eight patients, peritoneal implants of less than 1.5 cm were depicted only by fat-suppression images. However, these lesions did not change the score significantly. MR imaging could determine the stage in advanced endometriosis. Fat-suppression could highlight smaller implants. These tiny lesions had little clinical meaning in these advanced cases; however, the clinical value of this technique should be evaluated in milder disease. (author)

  18. Deep embedding convolutional neural network for synthesizing CT image from T1-Weighted MR image.

    Science.gov (United States)

    Xiang, Lei; Wang, Qian; Nie, Dong; Zhang, Lichi; Jin, Xiyao; Qiao, Yu; Shen, Dinggang

    2018-07-01

    Recently, more and more attention is drawn to the field of medical image synthesis across modalities. Among them, the synthesis of computed tomography (CT) image from T1-weighted magnetic resonance (MR) image is of great importance, although the mapping between them is highly complex due to large gaps of appearances of the two modalities. In this work, we aim to tackle this MR-to-CT synthesis task by a novel deep embedding convolutional neural network (DECNN). Specifically, we generate the feature maps from MR images, and then transform these feature maps forward through convolutional layers in the network. We can further compute a tentative CT synthesis from the midway of the flow of feature maps, and then embed this tentative CT synthesis result back to the feature maps. This embedding operation results in better feature maps, which are further transformed forward in DECNN. After repeating this embedding procedure for several times in the network, we can eventually synthesize a final CT image in the end of the DECNN. We have validated our proposed method on both brain and prostate imaging datasets, by also comparing with the state-of-the-art methods. Experimental results suggest that our DECNN (with repeated embedding operations) demonstrates its superior performances, in terms of both the perceptive quality of the synthesized CT image and the run-time cost for synthesizing a CT image. Copyright © 2018. Published by Elsevier B.V.

  19. Comparison among T1-weighted magnetic resonance imaging, modified dixon method, and magnetic resonance spectroscopy in measuring bone marrow fat.

    Science.gov (United States)

    Shen, Wei; Gong, Xiuqun; Weiss, Jessica; Jin, Ye

    2013-01-01

    An increasing number of studies are utilizing different magnetic resonance (MR) methods to quantify bone marrow fat due to its potential role in osteoporosis. Our aim is to compare the measurements of bone marrow fat among T1-weighted magnetic resonance imaging (MRI), modified Dixon method (also called fat fraction MRI (FFMRI)), and magnetic resonance spectroscopy (MRS). Contiguous MRI scans were acquired in 27 Caucasian postmenopausal women with a modified Dixon method (i.e., FFMRI). Bone marrow adipose tissue (BMAT) of T1-weighted MRI and bone marrow fat fraction of the L3 vertebra and femoral necks were quantified using SliceOmatic and Matlab. MRS was also acquired at the L3 vertebra. Correlation among the three MR methods measured bone marrow fat fraction and BMAT ranges from 0.78 to 0.88 (P BMAT measured by T1-weighted MRI and bone marrow fat fraction measured by modified FFMRI is 0.86 (P < 0.001) in femoral necks. There are good correlations among T1-weighted MRI, FFMRI, and MRS for bone marrow fat quantification. The inhomogeneous distribution of bone marrow fat, the threshold segmentation of the T1-weighted MRI, and the ambiguity of the FFMRI may partially explain the difference among the three methods.

  20. Comparison among T1-Weighted Magnetic Resonance Imaging, Modified Dixon Method, and Magnetic Resonance Spectroscopy in Measuring Bone Marrow Fat

    Directory of Open Access Journals (Sweden)

    Wei Shen

    2013-01-01

    Full Text Available Introduction. An increasing number of studies are utilizing different magnetic resonance (MR methods to quantify bone marrow fat due to its potential role in osteoporosis. Our aim is to compare the measurements of bone marrow fat among T1-weighted magnetic resonance imaging (MRI, modified Dixon method (also called fat fraction MRI (FFMRI, and magnetic resonance spectroscopy (MRS. Methods. Contiguous MRI scans were acquired in 27 Caucasian postmenopausal women with a modified Dixon method (i.e., FFMRI. Bone marrow adipose tissue (BMAT of T1-weighted MRI and bone marrow fat fraction of the L3 vertebra and femoral necks were quantified using SliceOmatic and Matlab. MRS was also acquired at the L3 vertebra. Results. Correlation among the three MR methods measured bone marrow fat fraction and BMAT ranges from 0.78 to 0.88 in the L3 vertebra. Correlation between BMAT measured by T1-weighted MRI and bone marrow fat fraction measured by modified FFMRI is 0.86 in femoral necks. Conclusion. There are good correlations among T1-weighted MRI, FFMRI, and MRS for bone marrow fat quantification. The inhomogeneous distribution of bone marrow fat, the threshold segmentation of the T1-weighted MRI, and the ambiguity of the FFMRI may partially explain the difference among the three methods.

  1. Robust T1-weighted structural brain imaging and morphometry at 7T using MP2RAGE.

    Directory of Open Access Journals (Sweden)

    Kieran R O'Brien

    Full Text Available PURPOSE: To suppress the noise, by sacrificing some of the signal homogeneity for numerical stability, in uniform T1 weighted (T1w images obtained with the magnetization prepared 2 rapid gradient echoes sequence (MP2RAGE and to compare the clinical utility of these robust T1w images against the uniform T1w images. MATERIALS AND METHODS: 8 healthy subjects (29.0 ± 4.1 years; 6 Male, who provided written consent, underwent two scan sessions within a 24 hour period on a 7T head-only scanner. The uniform and robust T1w image volumes were calculated inline on the scanner. Two experienced radiologists qualitatively rated the images for: general image quality; 7T specific artefacts; and, local structure definition. Voxel-based and volume-based morphometry packages were used to compare the segmentation quality between the uniform and robust images. Statistical differences were evaluated by using a positive sided Wilcoxon rank test. RESULTS: The robust image suppresses background noise inside and outside the skull. The inhomogeneity introduced was ranked as mild. The robust image was significantly ranked higher than the uniform image for both observers (observer 1/2, p-value = 0.0006/0.0004. In particular, an improved delineation of the pituitary gland, cerebellar lobes was observed in the robust versus uniform T1w image. The reproducibility of the segmentation results between repeat scans improved (p-value = 0.0004 from an average volumetric difference across structures of ≈ 6.6% to ≈ 2.4% for the uniform image and robust T1w image respectively. CONCLUSIONS: The robust T1w image enables MP2RAGE to produce, clinically familiar T1w images, in addition to T1 maps, which can be readily used in uniform morphometry packages.

  2. 3T MR Spin Echo T1 Weighted Image at Optimization of Flip Angle

    International Nuclear Information System (INIS)

    Lim, Chung Hwang; Bae, Sung Jin

    2009-01-01

    This study presents the optimization of flip angle (FA) to obtain higher contrast to noise ratio (CNR) and lower specific absorption rate (SAR). T1-weighted images of the cerebrum of brain were obtained from 50 degrees to 130 degrees FA with 10 interval. Signal to noise ratios (SNRs) were calculated for white matter (WM), gray matter (GM), and background noise. The proper FA was analyzed by T-test statistics and Kruskal-wallis analysis using R1 = 1- exp (-TR/T1) and Ernst angle cos = exp ((-TR/T1). The SNR of WM at 130 degrees FA is approximately 1.6 times higher than the SNR of WM at 50 degrees. The SNR of GM at 130 degrees FA is approximately 1.9 times higher than the SNR of GM at 50 degrees. Although the SNRs of WM and GM showed similar trends with the change of FA values, the slowdown point of decrease after linear fitting were different. While the SNR of WM started decreasing at 120 degrees FA, the SNR of GM started decreasing at less than 110 degrees. The highest SNRs of WM and GM were obtained at 130 degrees FA. The highest CNRs, however, were obtained at 80 degrees FA. Although SNR increased with the change of FA values from 50 degrees to 130 degrees at 3T SE T1WI, CNR was higher at 80 degrees FA than at the usually used 90 degrees FA. In addition, the SAR was decreased by using smaller FA. The CNR can be increased by using this optimized FA at 3T MR SE T1WI.

  3. Comparison of vertebral morphometry in the lumbar vertebrae by T1-weighted sagittal MRI and radiograph

    International Nuclear Information System (INIS)

    Tomomitsu, Tatsushi; Murase, Kenya; Sone, Teruki; Fukunaga, Masao

    2005-01-01

    Purpose: In this study, we investigated the usefulness of T1-weighted sagittal MR images at the lumbar vertebrae in the vertebral morphometry, in comparison with lateral radiographs. Subjects and methods: The subjects were 42 men (mean age: 53.0 years) and 41 women (mean age: 57.9 years). Both MRI and radiography of the lumbar spine were performed within 1 month. The vertebral body heights and their ratios were measured by the semi-automatic measuring system. The frequency of a vertebral fracture and the absolute value of vertebral body height in both morphometry were compared. Results: Based on the criteria for prevalent vertebral fracture using vertebral height ratios, the vertebrae were classified into four groups. Group 1 was defined as the vertebrae without fracture (n = 347 vertebrae). Groups 2-4 were defined as the vertebrae with fracture; Group 2 by both MRI and X-ray morphometry (n = 17), Group 3 by MRI morphometry alone (n = 17), and Group 4 by X-ray morphometry alone (n = 4). The rate of prevalent vertebral fracture diagnosed by MRI morphometry (8.8%) was higher than that by X-ray morphometry (5.5%). In Group 1, the values of anterior and posterior vertebral height obtained by MRI morphometry were greater than those obtained by X-ray morphometry. On the other hand, the values of central vertebral height obtained by MRI morphometry were smaller than those obtained by X-ray morphometry. Conclusion: Severe biconcave deformity of vertebra can be detected by both MRI and X-ray morphometry, although mild biconcave deformity can be detected only by MRI morphometry

  4. MR imaging of the wrist in rheumatoid arthritis using gadobenate dimeglumine

    Energy Technology Data Exchange (ETDEWEB)

    Bonel, H.M. [Inst. for Clinical Radiology, Ludwig Maximilians University Munich-Grosshadern, Munich (Germany); Osteoporosis and Arthritis Research Group, University of California San Francisco, San Francisco, CA (United States); Schneider, P.; Reiser, M. [Inst. for Clinical Radiology, Ludwig Maximilians University Munich-Grosshadern, Munich (Germany); Seemann, M.D. [Tuebingen Univ. (Germany). Abt. fuer Radiologische Diagnostik; Huegli, R. [Osteoporosis and Arthritis Research Group, University of California San Francisco, San Francisco, CA (United States); Srivastav, S. [Dept. for Biostatistics, Tulane Univ., New Orleans, LA (United States); Lodemann, K.P. [Bracco-Byk-Gulden GmbH, Konstanz (Germany)

    2001-01-01

    Objective. To determine the dosage of gadobenate dimeglumine (Gd-BOPTA) necessary for MRI of rheumatoid arthritis of the wrist.Design and patients. Seven wrists inflamed with rheumatoid arthritis were imaged using a dedicated 0.2-T MR unit. Four cumulative dosages of 0.0125, 0.025, 0.05 and 0.1 mmol/kg body weight (BW) Gd-BOPTA were tested. Three-dimensional T1-weighted gradient-recalled echo sequences (GRE; TR: 100 ms, TE: 18 ms, flip angle 90 , 4:55 min) were acquired prior to an intravenous injection and after each additional dosage of Gd-BOPTA. Relative enhancement, signal-difference-to-noise ratios (SDNRs) and the size of the inflamed tissue were quantified. Three radiologists independently evaluated the image quality, the size and the contrast of the enhancing tissue.Results. The readers agreed on a dose of 0.05 mmol/kg BW as satisfactory for the evaluation of the size of the inflammatory tissue and for determination of bone involvement ({kappa}=0.9, P<0.001). Highly inflammatory pannus was depicted with adequate image contrast using 0.025 mmol/kg BW Gd-BOPTA. According to the SDNR and relative enhancement findings, a dose of 0.05 mmol/kg BW suffices for both off-center and centered regions of tissue inflammation (t-test, P<0.05).Conclusion. Gadolinium-BOPTA is an alternative contrast agent for MRI of rheumatoid disease. This study shows that a dose of 0.05 mmol/kg BW suffices at low field strength. (orig.)

  5. MR imaging of the wrist in rheumatoid arthritis using gadobenate dimeglumine

    International Nuclear Information System (INIS)

    Bonel, H.M.; Schneider, P.; Reiser, M.; Seemann, M.D.; Srivastav, S.; Lodemann, K.P.

    2001-01-01

    Objective. To determine the dosage of gadobenate dimeglumine (Gd-BOPTA) necessary for MRI of rheumatoid arthritis of the wrist.Design and patients. Seven wrists inflamed with rheumatoid arthritis were imaged using a dedicated 0.2-T MR unit. Four cumulative dosages of 0.0125, 0.025, 0.05 and 0.1 mmol/kg body weight (BW) Gd-BOPTA were tested. Three-dimensional T1-weighted gradient-recalled echo sequences (GRE; TR: 100 ms, TE: 18 ms, flip angle 90 , 4:55 min) were acquired prior to an intravenous injection and after each additional dosage of Gd-BOPTA. Relative enhancement, signal-difference-to-noise ratios (SDNRs) and the size of the inflamed tissue were quantified. Three radiologists independently evaluated the image quality, the size and the contrast of the enhancing tissue.Results. The readers agreed on a dose of 0.05 mmol/kg BW as satisfactory for the evaluation of the size of the inflammatory tissue and for determination of bone involvement (κ=0.9, P<0.001). Highly inflammatory pannus was depicted with adequate image contrast using 0.025 mmol/kg BW Gd-BOPTA. According to the SDNR and relative enhancement findings, a dose of 0.05 mmol/kg BW suffices for both off-center and centered regions of tissue inflammation (t-test, P<0.05).Conclusion. Gadolinium-BOPTA is an alternative contrast agent for MRI of rheumatoid disease. This study shows that a dose of 0.05 mmol/kg BW suffices at low field strength. (orig.)

  6. T1-weighted vs. short-TE-long-TR images. Usefulness for knee MR examinations of ligament and meniscal lesions

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Hideho; Wada, Mitsuyoshi; Shiotani, Seiji [Tsukuba Medical Center Hospital, Ibaraki (Japan); Niitsu, Mamoru; Itai, Yuji

    2000-11-01

    The purpose of this study was to compare short-TE-long-TR images with T1-weighed images in knee MR examinations. Sagittal MR images of the knee were obtained in 31 patients with knee pain. T1-weighted images were obtained by the spin-echo technique (TR/TE =350/15), and short-TE-long-TR images by fast spin-echo (TR/TE =1300/15) with an echo-train length of 5. Contrast-to-noise-ratios (CNRs) of the anterior cruciate ligament and synovial space, meniscus and articular cartilage, and meniscal lesion and normal meniscus were compared between short-TE-long-TR images and T1-weighted images. On each of the three examinations, short-TE-long-TR images provided significantly higher CNRs than T1-weighted images. It was concluded that short-TE-long-TR images can be a useful alternative to T1-weighted images in evaluating the anterior cruciate ligament and meniscal lesions. (author)

  7. T1-weighted vs. short-TE-long-TR images. Usefulness for knee MR examinations of ligament and meniscal lesions

    International Nuclear Information System (INIS)

    Endo, Hideho; Wada, Mitsuyoshi; Shiotani, Seiji; Niitsu, Mamoru; Itai, Yuji

    2000-01-01

    The purpose of this study was to compare short-TE-long-TR images with T1-weighed images in knee MR examinations. Sagittal MR images of the knee were obtained in 31 patients with knee pain. T1-weighted images were obtained by the spin-echo technique (TR/TE =350/15), and short-TE-long-TR images by fast spin-echo (TR/TE =1300/15) with an echo-train length of 5. Contrast-to-noise-ratios (CNRs) of the anterior cruciate ligament and synovial space, meniscus and articular cartilage, and meniscal lesion and normal meniscus were compared between short-TE-long-TR images and T1-weighted images. On each of the three examinations, short-TE-long-TR images provided significantly higher CNRs than T1-weighted images. It was concluded that short-TE-long-TR images can be a useful alternative to T1-weighted images in evaluating the anterior cruciate ligament and meniscal lesions. (author)

  8. Utility decay rates of T1-weighted magnetic resonance imaging contrast based on redox-sensitive paramagnetic nitroxyl contrast agents

    International Nuclear Information System (INIS)

    Matsumoto, Ken-ichiro

    2009-01-01

    The availability and applicability of the combination of paramagnetic nitroxyl contrast agent and T 1 -weighted gradient echo (GE)-based dynamic magnetic resonance imaging (MRI) measurement for redox imaging are described. The time courses of T 1 -weighted GE MRI signal intensities according to first-order paramagnetic loss of a nitroxyl contrast agent were simulated for several experimental conditions. The apparent decay rate calculated based on decreasing T 1 -weighted MRI contrast (k MRI ) can show an approximate value of the original decay rate (k true ) discretionarily given for simulation with suitable experimental parameters. The difference between k MRI and k true can be sufficiently small under T 1 -weighted spoiled gradient echo (SPGR) scan conditions (repetition time=75 ms, echo time=3 ms, and flip angle=45deg), with a conventional redox-sensitive nitroxyl contrast agent, such as 4-hydroxy-2,2,6,6,-tetramethylpiperidine-N-oxyl (TEMPOL) and/or 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl (carbamoyl-PROXYL), and with intravenous (i.v.) doses of below 1.5 γmol/g body weight (b.w.) for mice. The results of this simulation suggest that the k MRI of nitroxyl contrast agents can be the primary index of redox status under biological conditions. (author)

  9. Magnetic Resonance Cholangiopancreatography: Image Quality, Ductal Morphology, and Value of Additional T2- and T1-weighted Sequences for the Assessment of Suspected Pancreatic Cancer

    International Nuclear Information System (INIS)

    Lopez Haenninen, E.; Ricke, H.; Amthauer, H.; Roettgen, R.; Boehmig, M.; Langrehr, J.; Pech, M.; Denecke, T.; Rosewicz, S.; Felix, R.

    2005-01-01

    Purpose: To assess image quality and duct morphology on magnetic resonance cholangiopancreatography (MRCP) and also the value of additional T2- and T1-weighted sequences for differentiation of benignity and malignancy in patients with suspected pancreatic tumors. Material and Methods: One-hundred-and-fourteen patients received MRCP and unenhanced and contrast material-enhanced MR imaging. MR results were analyzed independently by two blinded readers, and subsequently correlated with the results from surgery, biopsy, and follow-up. Assessment included the evaluation of image quality, duct visualization and morphology, and the differentiation of pancreatic lesion status (benign versus malignant).Results: Overall, 49 patients had benign final diagnoses, while 65 had a malignant diagnosis. Image quality of single-shot thick-slab MRCP was rated significantly better than the MIP images of multisection MRCP. With MRCP alone, the two readers' accuracy in the assessment of pancreatic lesion status was 72% (95% CI, 64% to 83%) and 69% (95% CI, 56% to 77%), respectively; with the addition of T2- and T1-weighted images the accuracy significantly improved to 89% (95% CI, 82% to 95%) and 84% (95% CI, 77% to 92%) for readers 1 and 2, respectively. Conclusion: Single-shot thick-slab MRCP and multisection MRCP provide complementary results; however, single-shot MRCP had superior image quality. Moreover, assessment of ductal morphology with MRCP alone facilitated the diagnosis of different pathologic conditions of the pancreatobiliary system in the majority of patients. However, with the addition of T2- and T1-weighted sequences the overall diagnostic accuracy was significantly improved and thus we consider that a comprehensive MR approach should comprise both MRCP techniques and parenchymal sequences

  10. Signal intensity change on unenhanced T1-weighted images in dentate nucleus and globus pallidus after multiple administrations of gadoxetate disodium: an intraindividual comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Conte, Giorgio; Minotti, Marta; De Piano, Francesca [Universita degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan (Italy); Preda, Lorenzo [Universita degli Studi di Pavia, Department of Clinical-Surgical Diagnostic and Pediatric Sciences, Pavia (Italy); National Center of Oncological Hadrontherapy (CNAO Foundation), Division of Radiology, Pavia (Italy); Cocorocchio, Emilia; Ferrucci, Pier Francesco [European Institute of Oncology, Melanoma and Sarcoma Medical Oncology Division, Milan (Italy); Raimondi, Sara [European Institute of Oncology, Division of Epidemiology and Biostatistics, Milan (Italy); Giannitto, Caterina; Petralia, Giuseppe [European Institute of Oncology, Division of Radiology, Milan (Italy); Bellomi, Massimo [European Institute of Oncology, Division of Radiology, Milan (Italy); Universita degli Studi di Milano, Oncology and Haematology/Oncology Department, Milan (Italy)

    2017-10-15

    To investigate whether there is an increased signal intensity (SI) of dentate nucleus (DN) and globus pallidus (GP) on unenhanced T1-weighted magnetic resonance imaging (MRI), in patients who had undergone multiple administrations of gadoxetate disodium. We retrospectively included stage III melanoma patients, who had been previously enrolled in a trial of adjuvant therapy and who had undergone whole-body contrast-enhanced MRIs with gadoxetate disodium every three months for their follow-up. The SI ratios of DN-to-pons and GP-to-thalamus on unenhanced T1-weighted images were calculated. The difference in SI ratios between the first and the last MRI examinations was assessed and a linear mixed model was performed to detect how SI ratios varied with the number of administrations. Eighteen patients were included in our study. The number of gadoxetate disodium administrations ranged from 2 to 18. Paired t-test did not show any significant difference in DN-to-pons (p=0.21) and GP-to-thalamus (p=0.09) SI ratios by the end of the study. DN-to-pons SI ratio and GP-to-thalamus SI ratio did not significantly increase with increasing the number of administrations (p=0.14 and p=0.06, respectively). Multiple administrations of gadoxetate disodium are not associated with increased SI in DN and GP in the brain. (orig.)

  11. New MRI findings in Creutzfeldt-Jakob disease: high signal in the globus pallidus on T 1-weighted images

    International Nuclear Information System (INIS)

    Priester, J.A. de; Wilmink, J.T.; Jansen, G.H.; Kruijk, J.R. de

    1999-01-01

    We report a 49-year-old woman with Creutzfeldt-Jakob disease (CJD). In addition to typical high-signal lesions on proton-density and T 2-weighted images there was high signal in the globus pallidus bilaterally on T 1-weighted images. The latter feature has not been described previously and probably due to deposition of prion protein, as found at autopsy. (orig.)

  12. New MRI findings in Creutzfeldt-Jakob disease: high signal in the globus pallidus on T 1-weighted images

    Energy Technology Data Exchange (ETDEWEB)

    Priester, J.A. de; Wilmink, J.T. [Dept. of Radiology, University Hospital Maastricht (Netherlands); Jansen, G.H. [Department of Neuropathology, University Hospital Utrecht (Netherlands); Kruijk, J.R. de [Department of Neurology, University Hospital Maastricht (Netherlands)

    1999-04-01

    We report a 49-year-old woman with Creutzfeldt-Jakob disease (CJD). In addition to typical high-signal lesions on proton-density and T 2-weighted images there was high signal in the globus pallidus bilaterally on T 1-weighted images. The latter feature has not been described previously and probably due to deposition of prion protein, as found at autopsy. (orig.) With 3 figs., 11 refs.

  13. The value of T1-weighted images in the differentiation between MS, white matter lesions, and subcortical arteriosclerotic encephalopathy (SAE)

    Energy Technology Data Exchange (ETDEWEB)

    Uhlenbrock, D.; Sehlen, S.

    1989-07-01

    The aim of the study was to define reliable criteria for the differentiation of MR imaging between patients with MS and with 'vascular' white matter lesions/SAE. We examined 35 patients with proven MS according to the Poser criteria and 35 patients with other white matter lesions and/or SAE. The result is that with MR a differentiation can be achieved provided that T1-weighted spin-echo sequences are included and the different pattern of distribution is considered. MS plaques are predominantly located in the subependymal region, vascular white matter lesions are mainly located in the water-shed of the superficial middle cerebral branches and the deep perforating long medullary vessels in the centrum semiovale. Infratentorial lesions are more often seen in MS. Confluence at the lateral ventricles is frequently accompanied by confluent abnormalities around the third ventricle, Sylvian aqueduct, and fourth ventricle, which is uncommon in SAE. In MS many lesions visible on T2-weighted images have a cellular or intracellular composition that renders them visible also on T1-weighted ones as regions with low signal intensity and more or less distinct boundary. 'Vascular' white matter lesions and SAE mainly represent demyelination and can therefore be seen on T2-weighted images, but corresponding low signal intensity lesions on T1-weighted images are uncommon. In some exceptions there are such lesions with low signal representing lacunar infarcts or widened Virchow-Robin-spaces. (orig.).

  14. Assessment of T2- and T1-weighted MRI brain lesion load in patients with subcortical vascular encephalopathy

    International Nuclear Information System (INIS)

    Gass, A.; Oster, M.; Cohen, S.; Daffertshofer, M.; Schwartz, A.; Hennerici, M.G.

    1998-01-01

    Previous cross-sectional studies in patients with subcortical vascular encephalopathy (SVE) have shown little or no correlation between brain lesion load and clinical disability, which could be due to the low specificity of T2-weighted MRI. Recent studies have indicated that T1-weighted MRI may be more specific than T2-weighted MRI for severe tissue destruction. We studied 37 patients with a diagnosis of SVE and 11 normal controls with standardised T1- and T2-weighted MRI. All patients underwent detailed clinical assessment including a neuropsychological test battery and computerised gait analysis. Both the T2- and T1-weighted total MRI lesion loads different between patients and controls different, particularly T1. The ratio of T2-/T1-weighted lesion load was lower in controls than in patients. There was no overall correlation of T1- or T2-weighted lesion load with clinical disability, but group comparison of patients with severe and mild clinical deficits showed different lesion loads. We suggest that T1- and T2-weighted MRI lesion loads demonstrate relevant structural abnormality in patients with SVE. (orig.)

  15. Post-contrast T1-weighted sequences in pediatric abdominal imaging: comparative analysis of three different sequences and imaging approach

    Energy Technology Data Exchange (ETDEWEB)

    Roque, Andreia; Ramalho, Miguel; AlObaidy, Mamdoh; Heredia, Vasco; Burke, Lauren M.; De Campos, Rafael O.P.; Semelka, Richard C. [University of North Carolina at Chapel Hill, Department of Radiology, Chapel Hill, NC (United States)

    2014-10-15

    Post-contrast T1-weighted imaging is an essential component of a comprehensive pediatric abdominopelvic MR examination. However, consistent good image quality is challenging, as respiratory motion in sedated children can substantially degrade the image quality. To compare the image quality of three different post-contrast T1-weighted imaging techniques - standard three-dimensional gradient-echo (3-D-GRE), magnetization-prepared gradient-recall echo (MP-GRE) and 3-D-GRE with radial data sampling (radial 3-D-GRE) - acquired in pediatric patients younger than 5 years of age. Sixty consecutive exams performed in 51 patients (23 females, 28 males; mean age 2.5 ± 1.4 years) constituted the final study population. Thirty-nine scans were performed at 3 T and 21 scans were performed at 1.5 T. Two different reviewers independently and blindly qualitatively evaluated all sequences to determine image quality and extent of artifacts. MP-GRE and radial 3-D-GRE sequences had the least respiratory motion (P < 0.0001). Standard 3-D-GRE sequences displayed the lowest average score ratings in hepatic and pancreatic edge definition, hepatic vessel clarity and overall image quality. Radial 3-D-GRE sequences showed the highest scores ratings in overall image quality. Our preliminary results support the preference of fat-suppressed radial 3-D-GRE as the best post-contrast T1-weighted imaging approach for patients under the age of 5 years, when dynamic imaging is not essential. (orig.)

  16. Quantitative analysis of hyperintensity rim sign surrounding MS plaque on T1 weighted images. Comparison with lacunar infarction

    International Nuclear Information System (INIS)

    Komura, Shinji; Ozaki, Yutaka

    2008-01-01

    This study evaluated the incidence of MR findings showing a hyperintensity rim surrounding multiple sclerosis (MS) plaque on T1-weighted images using image analysis software. We also evaluate the efficacy of this MR finding for differentiating between MS and lacunar infarction. We reviewed T1-weighted images in clinically diagnosed MS patients who underwent MR imaging between February 2006 and July 2007. Two hundred and thirty-nine nodular low signal intensities over 5 mm in minimal diameter were observed in 39 MS patients. To compare the incidence of MR findings, we also reviewed T1-weighted images in randomly selected lacunar infarction patients who underwent MR imaging during the same period. There were 51 nodular low signal intensities over 5 mm in shortest diameter in 34 lacunar infarction patients. After standardization of MR images, we calculated each signal intensity at the plaque margin (M.I.) and surrounding white matter (Wh.I.) using plot-profile analysis. We judged that hyperintensity rim sign was positive when the M.I/Wh.I. ratio was over 1.05. Among 239 T1 low intensity plaques in 39 MS patients, hyperintensity rim sign was positive for 81 (33.9%) plaques in 21 (53.8%) patients. Among 51 T1 low intensity lesions in 34 lacunar infarction patients, hyperintensity rim sign was positive for only one lesion in one patient. There were significant differences in the incidence of hyperintensity rim sign between the two patients groups (p<0.0001). On quantitative analysis using imaging standardization and plot-profile analysis, hyperintensity rim sign was observed in one-third of T1 low intensity MS plaques. This finding seems to be useful to differentiate multiple sclerosis from lacunar infarction. (author)

  17. Flair MR imaging in the Detection of subarachnoid hemorrhage : comparison with CT and T1-weighted MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Min, Soo Hyun; Kim, Soo Youn; Lee, Ghi Jai; Shim, Jae Chan; Oh, Tae Kyung; Kim, Ho Kyun [College of Medicine, Jnje University, Seoul (Korea, Republic of)

    2000-03-01

    To compare the findings of fluid-attenuated inversion recovery (FLAIR) MR imaging in the detection of subarachnoid hemorrhage (SAH), with those of precontrast CT and T1-weighted MR imaging. In 13 patients (14 cases) with SAH, FLAIR MR images were retrospectively analyzed and compared with CT (10 patients, 11 cases) and T1-weighted MR images (9 cases). SAH was confirmed on the basis of high density along the subarachnoid space, as seen on precontrast CT, or lumbar puncture. MR imaging was performed on a 1.0T unit. FLAIR MR and CT images were obtained during the acute stage(less than 3 days after ictus) in 10 and 9 cases, respectively, during the subacute stage (4-14 days after ictus) in two cases and one, respectively, and during the chronic stage (more than 15 days after ictus) in two cases and one, respectively. CT was performed before FLAIR MR imaging, and the interval between CT and FLAIR ranged from 24 hours (6 cases) to 2-3 (2 cases) or 4-7 days (3 cases). In each study, the conspicuity of visualization of SAH was graded as excellent, good, fair, or negative at five locations (sylvian fissure, cortical sulci, anterior basal cistern, posterior basal cistern, and perimesencephalic cistern). In all cases, subarachnoid hemorrhages were demonstrated as high signal intensity areas on FLAIR images. The detection rates for SAH on CT and T1-weighted MR images were 100% (11/11) and 89% (8/9), respectively. FLAIR was superior to T1-weighted imaging in the detection of SAH at all sites except the anterior basal cistern (p less than 0.05) and superior to CT in the detection of SAH at the cortical sulci (p less than 0.05). On FLAIR MR images, subarachnoid hemorrhages at all stages are demonstrated as high signal intensity areas; the FLAIR MR sequence is thus considered useful in the detection of SAH. In particular FLAIR is more sensitive than CT for the detection of SAH in the cortical sulci. (author)

  18. High signal intensity of anterior pituitary gland on T1-weighted MR imaging in normal postpartum women

    International Nuclear Information System (INIS)

    Kim, Myung Soon; Yang, Hak Seok; Chung, In Bai

    1995-01-01

    The purpose of this study is to evaluate the signal intensity and size of anterior pituitary gland in postpartum women, and to compare with those of control group. In 34 postpartum women (18-43 years, mean: 27 years) and another 35 control nonpregnant women (20-29 years, mean: 24 years), midsagittal T1-weighted MR images were obtained. The signal intensity and height of the anterior pituitary gland were compared between the post-partum and normal control groups. In postpartum women, the signal intensity of the anterior pituitary gland relative to the pons was higher than that of the control group. Pituitary gland height of postpartum women was higher (5-11. 8mm, mean 8.18 ± 1.8mm) than that of control group (2-9mm, mean: 6.2 ± 1.7mm). It is concluded that the hyperintensity of the anterior pituitary gland on T1-weighted image is a normal finding in postpartum women, which is useful in differentiation from pituitary abnormality

  19. High signal intensity of anterior pituitary gland on T1-weighted MR imaging in normal postpartum women

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myung Soon; Yang, Hak Seok; Chung, In Bai [Wonju College of Medicine, Yonsei University, Wonju (Korea, Republic of)

    1995-01-15

    The purpose of this study is to evaluate the signal intensity and size of anterior pituitary gland in postpartum women, and to compare with those of control group. In 34 postpartum women (18-43 years, mean: 27 years) and another 35 control nonpregnant women (20-29 years, mean: 24 years), midsagittal T1-weighted MR images were obtained. The signal intensity and height of the anterior pituitary gland were compared between the post-partum and normal control groups. In postpartum women, the signal intensity of the anterior pituitary gland relative to the pons was higher than that of the control group. Pituitary gland height of postpartum women was higher (5-11. 8mm, mean 8.18 {+-} 1.8mm) than that of control group (2-9mm, mean: 6.2 {+-} 1.7mm). It is concluded that the hyperintensity of the anterior pituitary gland on T1-weighted image is a normal finding in postpartum women, which is useful in differentiation from pituitary abnormality.

  20. Hyperintense globus pallidus on T1-weighted MR imaging in acute kernicterus: is it common or rare?

    Energy Technology Data Exchange (ETDEWEB)

    Coskun, Abdulhakim; Yikilmaz, Ali; Karahan, Okkes Ibrahim; Manav, Ali [Erciyes University Medical School, Department of Radiology, Kayseri (Turkey); Kumandas, Sefer [Erciyes University Medical School, Department of Neuropediatry, Kayseri (Turkey); Akcakus, Mustafa [Erciyes University Medical School, Department of Neonatalogy, Kayseri (Turkey)

    2005-06-01

    Globus pallidus involvement is a well-known magnetic resonance (MR) imaging finding of acute kernicterus. However, it is not clear how early the involvement of globus pallidus occurs and whether or not it is seen in every case. Therefore, we aimed to investigate the globus pallidus involvement in 13 neonates with acute kernicterus by MR imaging. Thirteen neonates who were admitted with jaundice, encephalopathy and indirect hyperbilirubinemia (mean, 37.0 mg/dl) were prospectively evaluated with cranial MR imaging. Pathological signal changes were noted concerning the globus pallidus. Eight of the 13 patients demonstrated bilateral, symmetric increased signal intensity in the globus pallidus on T1-weighted MR imaging. These lesions were not apparent on T2-weighted images. Multiple parenchymal punctuate T1 hyperintense lesions were detected in one patient without globus pallidus involvement. This appearance was consistent with hemorrhage. The MR imaging findings of the other four patients showed no evidence of abnormality. The symmetric involvement of globus pallidus seen as hyperintense on T1-weighted MR imaging is a common and characteristic finding of acute kernicterus. (orig.)

  1. Hyperintense globus pallidus on T1-weighted MR imaging in acute kernicterus: is it common or rare?

    International Nuclear Information System (INIS)

    Coskun, Abdulhakim; Yikilmaz, Ali; Karahan, Okkes Ibrahim; Manav, Ali; Kumandas, Sefer; Akcakus, Mustafa

    2005-01-01

    Globus pallidus involvement is a well-known magnetic resonance (MR) imaging finding of acute kernicterus. However, it is not clear how early the involvement of globus pallidus occurs and whether or not it is seen in every case. Therefore, we aimed to investigate the globus pallidus involvement in 13 neonates with acute kernicterus by MR imaging. Thirteen neonates who were admitted with jaundice, encephalopathy and indirect hyperbilirubinemia (mean, 37.0 mg/dl) were prospectively evaluated with cranial MR imaging. Pathological signal changes were noted concerning the globus pallidus. Eight of the 13 patients demonstrated bilateral, symmetric increased signal intensity in the globus pallidus on T1-weighted MR imaging. These lesions were not apparent on T2-weighted images. Multiple parenchymal punctuate T1 hyperintense lesions were detected in one patient without globus pallidus involvement. This appearance was consistent with hemorrhage. The MR imaging findings of the other four patients showed no evidence of abnormality. The symmetric involvement of globus pallidus seen as hyperintense on T1-weighted MR imaging is a common and characteristic finding of acute kernicterus. (orig.)

  2. 3.0 Tesla high spatial resolution contrast-enhanced magnetic resonance angiography (CE-MRA) of the pulmonary circulation: initial experience with a 32-channel phased array coil using a high relaxivity contrast agent.

    Science.gov (United States)

    Nael, Kambiz; Fenchel, Michael; Krishnam, Mayil; Finn, J Paul; Laub, Gerhard; Ruehm, Stefan G

    2007-06-01

    To evaluate the technical feasibility of high spatial resolution contrast-enhanced magnetic resonance angiography (CE-MRA) with highly accelerated parallel acquisition at 3.0 T using a 32-channel phased array coil, and a high relaxivity contrast agent. Ten adult healthy volunteers (5 men, 5 women, aged 21-66 years) underwent high spatial resolution CE-MRA of the pulmonary circulation. Imaging was performed at 3 T using a 32-channel phase array coil. After intravenous injection of 1 mL of gadobenate dimeglumine (Gd-BOPTA) at 1.5 mL/s, a timing bolus was used to measure the transit time from the arm vein to the main pulmonary artery. Subsequently following intravenous injection of 0.1 mmol/kg of Gd-BOPTA at the same rate, isotropic high spatial resolution data sets (1 x 1 x 1 mm3) CE-MRA of the entire pulmonary circulation were acquired using a fast gradient-recalled echo sequence (TR/TE 3/1.2 milliseconds, FA 18 degrees) and highly accelerated parallel acquisition (GRAPPA x 6) during a 20-second breath hold. The presence of artifact, noise, and image quality of the pulmonary arterial segments were evaluated independently by 2 radiologists. Phantom measurements were performed to assess the signal-to-noise ratio (SNR). Statistical analysis of data was performed by using Wilcoxon rank sum test and 2-sample Student t test. The interobserver variability was tested by kappa coefficient. All studies were of diagnostic quality as determined by both observers. The pulmonary arteries were routinely identified up to fifth-order branches, with definition in the diagnostic range and excellent interobserver agreement (kappa = 0.84, 95% confidence interval 0.77-0.90). Phantom measurements showed significantly lower SNR (P < 0.01) using GRAPPA (17.3 +/- 18.8) compared with measurements without parallel acquisition (58 +/- 49.4). The described 3 T CE-MRA protocol in addition to high T1 relaxivity of Gd-BOPTA provides sufficient SNR to support highly accelerated parallel acquisition

  3. MR imaging of hematopoietic regions in bone marrow of aplastic anemia. Diagnostic usefulness of opposed phase T1-weighted images

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Yasuo; Tanabe, Yoshihiro; Amano, Maki; Kumazaki, Tatsuo [Nippon Medical School, Tokyo (Japan)

    1996-01-01

    The signal intensity of hematopoietic regions in the marrow of aplastic anemia were investigated on opposed phase T1-weighted images (op-T1WI) with a 0.5-Tesla MR unit. Hematopoietic regions were classified into two groups: low intensity hematopoietic areas (LH) isointense to normal marrow and high intensity hematopoietic regions (HH) with higher intensity than normal marrow on op-T1WI. The signal intensity of LH was significantly lower than that of HH on STIR. LH converted into HH with improvement of laboratory data after therapy, whereas HH decreased with impairment of data. HH were hyperintense to cerebrospinal fluid on op-T1WI. These results indicated that the signal intensity of hematopoietic regions on op-T1WI reflected the cellularity in these regions and that aplastic anemia included hypercellular regions relative to normal marrow. (author).

  4. T1-weighted MRI as a substitute to CT for refocusing planning in MR-guided focused ultrasound

    International Nuclear Information System (INIS)

    Wintermark, Max; Sumer, Suna; Lau, Benison; Cupino, Alan; Tustison, Nicholas J; Demartini, Nicholas; Elias, William J; Kassell, Neal; Patrie, James T; Xin, Wenjun; Eames, Matt; Snell, John; Hananel, Arik; Aubry, Jean-Francois

    2014-01-01

    Precise focusing is essential for transcranial MRI-guided focused ultrasound (TcMRgFUS) to minimize collateral damage to non-diseased tissues and to achieve temperatures capable of inducing coagulative necrosis at acceptable power deposition levels. CT is usually used for this refocusing but requires a separate study (CT) ahead of the TcMRgFUS procedure. The goal of this study was to determine whether MRI using an appropriate sequence would be a viable alternative to CT for planning ultrasound refocusing in TcMRgFUS. We tested three MRI pulse sequences (3D T1 weighted 3D volume interpolated breath hold examination (VIBE), proton density weighted 3D sampling perfection with applications optimized contrasts using different flip angle evolution and 3D true fast imaging with steady state precision T2-weighted imaging) on patients who have already had a CT scan performed. We made detailed measurements of the calvarial structure based on the MRI data and compared those so-called ‘virtual CT’ to detailed measurements of the calvarial structure based on the CT data, used as a reference standard. We then loaded both standard and virtual CT in a TcMRgFUS device and compared the calculated phase correction values, as well as the temperature elevation in a phantom. A series of Bland–Altman measurement agreement analyses showed T1 3D VIBE as the optimal MRI sequence, with respect to minimizing the measurement discrepancy between the MRI derived total skull thickness measurement and the CT derived total skull thickness measurement (mean measurement discrepancy: 0.025; 95% CL (−0.22–0.27); p = 0.825). The T1-weighted sequence was also optimal in estimating skull CT density and skull layer thickness. The mean difference between the phase shifts calculated with the standard CT and the virtual CT reconstructed from the T1 dataset was 0.08 ± 1.2 rad on patients and 0.1 ± 0.9 rad on phantom. Compared to the real CT, the MR-based correction showed a 1 °C drop on the

  5. The interplay of T1- and T2-relaxation on T1-weighted MRI of hMSCs induced by Gd-DOTA-peptides.

    Science.gov (United States)

    Cao, Limin; Li, Binbin; Yi, Peiwei; Zhang, Hailu; Dai, Jianwu; Tan, Bo; Deng, Zongwu

    2014-04-01

    Three Gd-DOTA-peptide complexes with different peptide sequence are synthesized and used as T1 contrast agent to label human mesenchymal stem cells (hMSCs) for magnetic resonance imaging study. The peptides include a universal cell penetrating peptide TAT, a linear MSC-specific peptide EM7, and a cyclic MSC-specific peptide CC9. A significant difference in labeling efficacy is observed between the Gd-DOTA-peptides as well as a control Dotarem. All Gd-DOTA-peptides as well as Dotarem induce significant increase in T1 relaxation rate which is in favor of T1-weighted MR imaging. Gd-DOTA-CC9 yields the maximum labeling efficacy but poor T1 contrast enhancement. Gd-DOTA-EM7 yields the minimum labeling efficacy but better T1 contrast enhancement. Gd-DOTA-TAT yields a similar labeling efficacy as Gd-DOTA-CC9 and similar T1 contrast enhancement as Gd-DOTA-EM7. The underlying mechanism that governs T1 contrast enhancement effect is discussed. Our results suggest that T1 contrast enhancement induced by Gd-DOTA-peptides depends not only on the introduced cellular Gd content, but more importantly on the effect that Gd-DOTA-peptides exert on the T1-relaxation and T2-relaxation processes/rates. Both T1 and particularly T2 relaxation rate have to be taken into account to interpret T1 contrast enhancement. In addition, the interpretation has to be based on cellular instead of aqueous longitudinal and transverse relaxivities of Gd-DOTA-peptides. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. High-resolution T1-weighted 3D real IR imaging of the temporal bone using triple-dose contrast material

    Energy Technology Data Exchange (ETDEWEB)

    Naganawa, Shinji; Koshikawa, Tokiko; Nakamura, Tatsuya; Fukatsu, Hiroshi; Ishigaki, Takeo [Department of Radiology, Nagoya University School of Medicine, 65 Tsurumai-cho, Shouwa-ku, 466-8550, Nagoya (Japan); Aoki, Ikuo [Medical System Company, Toshiba Corporation, Tokyo (Japan)

    2003-12-01

    The small structures in the temporal bone are surrounded by bone and air. The objectives of this study were (a) to compare contrast-enhanced T1-weighted images acquired by fast spin-echo-based three-dimensional real inversion recovery (3D rIR) against those acquired by gradient echo-based 3D SPGR in the visualization of the enhancement of small structures in the temporal bone, and (b) to determine whether either 3D rIR or 3D SPGR is useful for visualizing enhancement of the cochlear lymph fluid. Seven healthy men (age range 27-46 years) volunteered to participate in this study. All MR imaging was performed using a dedicated bilateral quadrature surface phased-array coil for temporal bone imaging at 1.5 T (Visart EX, Toshiba, Tokyo, Japan). The 3D rIR images (TR/TE/TI: 1800 ms/10 ms/500 ms) and flow-compensated 3D SPGR images (TR/TE/FA: 23 ms/10 ms/25 ) were obtained with a reconstructed voxel size of 0.6 x 0.7 x 0.8 mm{sup 3}. Images were acquired before and 1, 90, 180, and 270 min after the administration of triple-dose Gd-DTPA-BMA (0.3 mmol/kg). In post-contrast MR images, the degree of enhancement of the cochlear aqueduct, endolymphatic sac, subarcuate artery, geniculate ganglion of the facial nerve, and cochlear lymph fluid space was assessed by two radiologists. The degree of enhancement was scored as follows: 0 (no enhancement); 1 (slight enhancement); 2 (intermediate between 1 and 3); and 3 (enhancement similar to that of vessels). Enhancement scores for the endolymphatic sac, subarcuate artery, and geniculate ganglion were higher in 3D rIR than in 3D SPGR. Washout of enhancement in the endolymphatic sac appeared to be delayed compared with that in the subarcuate artery, suggesting that the enhancement in the endolymphatic sac may have been due in part to non-vascular tissue enhancement. Enhancement of the cochlear lymph space was not observed in any of the subjects in 3D rIR and 3D SPGR. The 3D rIR sequence may be more sensitive than the 3D SPGR sequence in

  7. Optimal MR pulse sequences for hepatic hemangiomas : comparison of T2-weighted turbo-spin-echo, T2-weighted breath-hold turbo-spin-echo, and T1-weighted FLASH dynamic imaging

    International Nuclear Information System (INIS)

    Wang, Wen Chao; Choi, Byung Ihn; Han, Joon Koo; Kim, Tae Kyoung; Cho, Soon Gu

    1997-01-01

    To optimize MR imaging pulse sequences in the imaging of hepatic hemangioma and to evaluate on dynamic MR imaging the enhancing characteristics of the lesions. Twenty patients with 35 hemangiomas were studied by using Turbo-spin-echo (TSE) sequence (T2-weighted, T2- and heavily T2-weighted breath-hold) and T1-weighted FLASH imaging acquired before, immediately on, and 1, 3 and 5 minutes after injection of a bolus of Gd-DTPA (0.1mmol/kg). Phased-array multicoil was employed. Images were quantitatively analyzed for lesion-to-liver signal difference to noise ratios (SD/Ns), and lesion-to-liver signal ratios (H/Ls), and qualitatively analyzed for lesion conspicuity. The enhancing characteristics of the hemangiomas were described by measuring the change of signal intensity as a curve in T1-weighted FLASH dynamic imaging. For T2-weighted images, breath-hold T2-weighted TSE had a slightly higher SD/N than other pulse sequences, but there was no statistical difference in three fast pulse sequences (p=0.211). For lesion conspicuity, heavily T2-weighted breath-hold TSE images was superior to T2-weighted breath-hold or non-breath-hold TSE (H/L, 5.75, 3.81, 2.87, respectively, p<0.05). T2-weighted breath-hold TSE imaging was more effective than T2-weighted TSE imaging in removing lesion blurring or lack of sharpness, and there was a 12-fold decrease in acquisition time (20sec versus 245 sec). T1-weighted FLASH dynamic images of normal liver showed peak enhancement at less than 1 minute, and of hemangioma at more than 3 minutes;the degree of enhancement for hemangioma decreased after a 3 minute delay. T2-weighed breath-hold TSE imaging and Gd-DTPA enhanced FLASH dynamic imaging with 5 minutes delay are sufficient for imaging hepatic hemangiomas

  8. Temporal and spatial characteristics of the area at risk investigated using computed tomography and T1-weighted magnetic resonance imaging

    DEFF Research Database (Denmark)

    van der Pals, Jesper; Hammer-Hansen, Sophia; Nielles-Vallespin, Sonia

    2015-01-01

    AIMS: Cardiovascular magnetic resonance (CMR) imaging can measure the myocardial area at risk (AAR), but the technique has received criticism for inadequate validation. CMR commonly depicts an AAR that is wider than the infarct, which in turn would require a lateral perfusion gradient within...... and fluorescent microparticle pathology were used to investigate the AAR in a canine model (n = 10) of ischaemia and reperfusion. AAR size by CMR correlated well with CT (R(2) = 0.80), microsphere blood flow (R(2) = 0.80), and pathology (R(2) = 0.74) with good limits of agreement [-0.79 ± 4.02% of the left.......05 ± 0.02 mL/g/min, lateral vs. core, P = 0.001). The transmural extent of MI was lower in the lateral portion of the AAR than the core (28.2 ± 10.2 vs. 17.4 ± 8.4% of the wall, P = 0.001). CONCLUSION: T1-weighted CMR accurately quantifies size of the AAR with excellent agreement compared with three...

  9. Normalization of white matter intensity on T1-weighted images of patients with acquired central nervous system demyelination.

    Science.gov (United States)

    Ghassemi, Rezwan; Brown, Robert; Narayanan, Sridar; Banwell, Brenda; Nakamura, Kunio; Arnold, Douglas L

    2015-01-01

    Intensity variation between magnetic resonance images (MRI) hinders comparison of tissue intensity distributions in multicenter MRI studies of brain diseases. The available intensity normalization techniques generally work well in healthy subjects but not in the presence of pathologies that affect tissue intensity. One such disease is multiple sclerosis (MS), which is associated with lesions that prominently affect white matter (WM). To develop a T1-weighted (T1w) image intensity normalization method that is independent of WM intensity, and to quantitatively evaluate its performance. We calculated median intensity of grey matter and intraconal orbital fat on T1w images. Using these two reference tissue intensities we calculated a linear normalization function and applied this to the T1w images to produce normalized T1w (NT1) images. We assessed performance of our normalization method for interscanner, interprotocol, and longitudinal normalization variability, and calculated the utility of the normalization method for lesion analyses in clinical trials. Statistical modeling showed marked decreases in T1w intensity differences after normalization (P < .0001). We developed a WM-independent T1w MRI normalization method and tested its performance. This method is suitable for longitudinal multicenter clinical studies for the assessment of the recovery or progression of disease affecting WM. Copyright © 2014 by the American Society of Neuroimaging.

  10. Discrete pre-processing step effects in registration-based pipelines, a preliminary volumetric study on T1-weighted images.

    Science.gov (United States)

    Muncy, Nathan M; Hedges-Muncy, Ariana M; Kirwan, C Brock

    2017-01-01

    Pre-processing MRI scans prior to performing volumetric analyses is common practice in MRI studies. As pre-processing steps adjust the voxel intensities, the space in which the scan exists, and the amount of data in the scan, it is possible that the steps have an effect on the volumetric output. To date, studies have compared between and not within pipelines, and so the impact of each step is unknown. This study aims to quantify the effects of pre-processing steps on volumetric measures in T1-weighted scans within a single pipeline. It was our hypothesis that pre-processing steps would significantly impact ROI volume estimations. One hundred fifteen participants from the OASIS dataset were used, where each participant contributed three scans. All scans were then pre-processed using a step-wise pipeline. Bilateral hippocampus, putamen, and middle temporal gyrus volume estimations were assessed following each successive step, and all data were processed by the same pipeline 5 times. Repeated-measures analyses tested for a main effects of pipeline step, scan-rescan (for MRI scanner consistency) and repeated pipeline runs (for algorithmic consistency). A main effect of pipeline step was detected, and interestingly an interaction between pipeline step and ROI exists. No effect for either scan-rescan or repeated pipeline run was detected. We then supply a correction for noise in the data resulting from pre-processing.

  11. A 3D T1-weighted gradient-echo sequence for routine use in 3D radiosurgical treatment planning of brain metastases: first clinical results

    International Nuclear Information System (INIS)

    Hawighorst, H.; Schad, L.R.; Gademann, G.; Knopp, M.V.; Wenz, F.; Kaick, G. van

    1995-01-01

    The authors report on a 3D sequence for MRI of the brain and its application in radiosurgical treatment planning of 35 brain metastases. The measuring sequence, called magnetization - prepared rapid gradient echo (MPRAGE), was compared with 2D T1-weighted spin-echo (SE) sequences following intravenous contrast-medium application in 19 patients with brain metastases. The average diameter of all lesions was similar in both sequences, with 16.8 and 17.0 mm for SE and MPRAGE, respectively. Target point definition was equal in 29 metastases, and in 6 cases superior on MPRAGE, due to better gray-white matter contrast and increased contrast enhancement. In cases of bleeding metastases there was improved depiction of internal structures in 3D MRI. Postprocessing of 3D MPRAGE data created multiplanar reconstruction along any chosen plane with isotropic spatial resolution, which helped to improve radiosurgical isodose distribution in 4 cases when compared to 2D SE. However, sensitivity of 3D MPRAGE to detect small lesions (< 3 mm) was decreased in one patient with more than 50 metastases. We conclude that 3D gradient-echo (GE) imaging might be of great value for radiosurgical treatment planning, but does not replace 2D SE with its current parameters. (orig.)

  12. Bone marrow response in treated patients with Gaucher disease: evaluation by T1-weighted magnetic resonance images and correlation with reduction in liver and spleen volume

    International Nuclear Information System (INIS)

    Terk, M.R.; Dardashti, S.; Liebman, H.A.

    2000-01-01

    Purpose. To determine whether T1-weighted magnetic resonance (MR) images can demonstrate response in the marrow of patients with type 1 Gaucher disease treated with enzyme replacement therapy (ERT) and to determine whether a relationship exists between liver and spleen volume reductions and visible marrow changes.Patients. Forty-two patients with type 1 Gaucher disease were evaluated on at least two occasions. Thirty-two patients received ERT. Of these patients, 15 had a baseline examination prior to the initiation of ERT. The remaining 10 patients did not receive ERT.Design. T1-weighted and gradient recalled echo (GRE) coronal images of the femurs and hips were obtained. Concurrently, liver and spleen volumes were determined using contiguous breath-hold axial gradient-echo images. T1-weighted images of the hips and femurs were evaluated to determine change or lack of change in the yellow marrow.Results. Of the 32 patients receiving ERT, 14 (44%) demonstrated increased signal on T1-weighted images suggesting an increase in the amount of yellow marrow. If only the 15 patients with a baseline examination were considered, the response rate to ERT was 67%. Using Student's t-test a highly significant correlation (P<0.005) was found between marrow response and reduction in liver and spleen volume.Conclusions. Marrow changes in patients receiving ERT can be detected by T1-weighted images. This response correlated with reductions in visceral volumes (P<0.0005). (orig.)

  13. MR imaging of the knee: Improvement of signal and contrast efficiency of T1-weighted turbo spin echo sequences by applying a driven equilibrium (DRIVE) pulse

    Energy Technology Data Exchange (ETDEWEB)

    Radlbauer, Rudolf, E-mail: rudolf.radlbauer@stpoelten.lknoe.a [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, 3100 St. Poelten (Austria); Lomoschitz, Friedrich, E-mail: friedrich.lomoschitz@stpoelten.lknoe.a [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, 3100 St. Poelten (Austria); Salomonowitz, Erich, E-mail: erich.salomonowitz@stpoelten.lknoe.a [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, 3100 St. Poelten (Austria); Eberhardt, Knut E., E-mail: info@mrt-kompetenzzentrum.d [MRT Competence Center Schloss Werneck, Balthasar-Neumann-Platz 2, 97440 Werneck (Germany); Stadlbauer, Andreas, E-mail: andi@nmr.a [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, Propst Fuehrer Strasse 4, 3100 St. Poelten (Austria); Department of Neurosurgery, University of Erlangen-Nuremberg, Schwabachanlage 6, 91054 Erlangen (Germany)

    2010-08-15

    The purpose of this study was to assess the effect of a driven equilibrium (DRIVE) pulse incorporated in a standard T1-weighted turbo spin echo (TSE) sequence as used in our routine MRI protocol for examination of pathologies of the knee. Sixteen consecutive patients with knee disorders were examined using the routine MRI protocol, including T1-weighted TSE-sequences with and without a DRIVE pulse. Signal-to-noise ratios (SNRs) and contrast-to-noise ratio (CNR) of anatomical structures and pathologies were calculated and compared for both sequences. The differences in diagnostic value of the T1-weighted images with and without DRIVE pulse were assessed. SNR was significantly higher on images acquired with DRIVE pulse for fluid, effusion, cartilage and bone. Differences in the SNR of meniscus and muscle between the two sequences were not statistically significant. CNR was significantly increased between muscle and effusion, fluid and cartilage, fluid and meniscus, cartilage and meniscus, bone and cartilage on images acquired using the DRIVE pulse. Diagnostic value of the T1-weighted images was found to be improved for delineation of anatomic structures and for diagnosing a variety of pathologies when a DRIVE pulse is incorporated in the sequence. Incorporation of a DRIVE pulse into a standard T1-weighted TSE-sequence leads to significant increase of SNR and CNR of both, anatomical structures and pathologies, and consequently to an increase in diagnostic value within the same acquisition time.

  14. MR imaging of the knee: Improvement of signal and contrast efficiency of T1-weighted turbo spin echo sequences by applying a driven equilibrium (DRIVE) pulse

    International Nuclear Information System (INIS)

    Radlbauer, Rudolf; Lomoschitz, Friedrich; Salomonowitz, Erich; Eberhardt, Knut E.; Stadlbauer, Andreas

    2010-01-01

    The purpose of this study was to assess the effect of a driven equilibrium (DRIVE) pulse incorporated in a standard T1-weighted turbo spin echo (TSE) sequence as used in our routine MRI protocol for examination of pathologies of the knee. Sixteen consecutive patients with knee disorders were examined using the routine MRI protocol, including T1-weighted TSE-sequences with and without a DRIVE pulse. Signal-to-noise ratios (SNRs) and contrast-to-noise ratio (CNR) of anatomical structures and pathologies were calculated and compared for both sequences. The differences in diagnostic value of the T1-weighted images with and without DRIVE pulse were assessed. SNR was significantly higher on images acquired with DRIVE pulse for fluid, effusion, cartilage and bone. Differences in the SNR of meniscus and muscle between the two sequences were not statistically significant. CNR was significantly increased between muscle and effusion, fluid and cartilage, fluid and meniscus, cartilage and meniscus, bone and cartilage on images acquired using the DRIVE pulse. Diagnostic value of the T1-weighted images was found to be improved for delineation of anatomic structures and for diagnosing a variety of pathologies when a DRIVE pulse is incorporated in the sequence. Incorporation of a DRIVE pulse into a standard T1-weighted TSE-sequence leads to significant increase of SNR and CNR of both, anatomical structures and pathologies, and consequently to an increase in diagnostic value within the same acquisition time.

  15. High signal in the adenohypophysis on T1-weighted images presumably due to manganese deposits in patients on long-term parenteral nutrition

    Energy Technology Data Exchange (ETDEWEB)

    Dietemann, J.L.; Diniz, R.L.F.C.; Reis, M. Jr.; Neugroschl, C.; Soehsten, S. von [Department of Radiology 2, University Hospital of Strasbourg (France); Reimund, J.M.; Baumann, R. [Department of Hepatogastroenterology, University Hospital of Strasbourg (France); Warter, J.M. [Department of Neurology, University Hospital of Strasbourg (France)

    1998-12-01

    Hypermanganesaemia is reported in patients on long-term parenteral nutrition. Deposition of manganese, giving high signal on T1-weighted images, may involve the basal ganglia. MRI in nine patients (mean age 51 years, range 31-75 years) on long-term parenteral nutrition (mean duration 30 months, range 6-126 months), demonstrated high signal in the anterior pituitary gland on T1-weighted sagittal and coronal images. The gland appeared normal on T2-weighted images. Signal intensity in the basal ganglia on T1-weighted images was increased in all patients. Endocrine assessment showed no significant abnormality. Neurological examination showed a mild parkinsonian movement disorder in one patient. Hypermanganaesemia was present in all nine (1.3-2.8 {mu}mol/l, mean 1.87 {mu}mol/l). The high signal in the anterior pituitary gland was probably related to deposition of paramagnetic substances, especially manganese. (orig.) With 2 figs., 1 tab., 17 refs.

  16. High signal in the adenohypophysis on T1-weighted images presumably due to manganese deposits in patients on long-term parenteral nutrition

    International Nuclear Information System (INIS)

    Dietemann, J.L.; Diniz, R.L.F.C.; Reis, M. Jr.; Neugroschl, C.; Soehsten, S. von; Reimund, J.M.; Baumann, R.; Warter, J.M.

    1998-01-01

    Hypermanganesaemia is reported in patients on long-term parenteral nutrition. Deposition of manganese, giving high signal on T1-weighted images, may involve the basal ganglia. MRI in nine patients (mean age 51 years, range 31-75 years) on long-term parenteral nutrition (mean duration 30 months, range 6-126 months), demonstrated high signal in the anterior pituitary gland on T1-weighted sagittal and coronal images. The gland appeared normal on T2-weighted images. Signal intensity in the basal ganglia on T1-weighted images was increased in all patients. Endocrine assessment showed no significant abnormality. Neurological examination showed a mild parkinsonian movement disorder in one patient. Hypermanganaesemia was present in all nine (1.3-2.8 μmol/l, mean 1.87 μmol/l). The high signal in the anterior pituitary gland was probably related to deposition of paramagnetic substances, especially manganese. (orig.)

  17. Aberrant resting-state corticostriatal functional connectivity in cirrhotic patients with hyperintense globus pallidus on T1-weighted MR imaging.

    Directory of Open Access Journals (Sweden)

    Xi-Qi Zhu

    Full Text Available Neurobiological and neuroimaging studies have emphasized the structural and functional alterations in the striatum of cirrhotic patients, but alterations in the functional connections between the striatum and other brain regions have not yet been explored. Of note, manganese accumulation in the nervous system, frequently reflected by hyperintensity at the bilateral globus pallidus (GP on T1-weighted imaging, has been considered a factor affecting the striatal and cortical functions in hepatic decompensation. We employed resting-state functional magnetic resonance imaging to analyze the temporal correlation between the striatum and the remaining brain regions using seed-based correlation analyses. The two-sample t-test was conducted to detect the differences in corticostriatal connectivity between 44 cirrhotic patients with hyperintensity at the bilateral GP and 20 healthy controls. Decreased connectivity of the caudate was detected in the anterior/middle cingulate gyrus, and increased connectivity of the caudate was found in the left motor cortex. A reduction in functional connectivity was found between the putamen and several regions, including the anterior cingulate gyrus, right insular lobe, inferior frontal gyrus, left parahippocampal gyrus, and anterior lobe of the right cerebellum; increased connectivity was detected between the putamen and right middle temporal gyrus. There were significant correlations between the corticostriatal connectivity and neuropsychological performances in the patient group, but not between the striatal connectivity and GP signal intensity. These alterations in the corticostriatal functional connectivity suggested the abnormalities in the intrinsic brain functional organiztion among the cirrhotic patients with manganese deposition, and may be associated with development of metabolic encephalopathy. The manganese deposition in nervous system, however, can not be an independent factor predicting the resting

  18. Abdominal MRI at 3.0 T: LAVA-Flex compared with conventional fat suppression T1-weighted images.

    Science.gov (United States)

    Li, Xing Hui; Zhu, Jiang; Zhang, Xiao Ming; Ji, Yi Fan; Chen, Tian Wu; Huang, Xiao Hua; Yang, Lin; Zeng, Nan Lin

    2014-07-01

    To study liver imaging with volume acceleration-flexible (LAVA-Flex) for abdominal magnetic resonance imaging (MRI) at 3.0 T and compare the image quality of abdominal organs between LAVA-Flex and fast spoiled gradient-recalled (FSPGR) T1-weighted imaging. Our Institutional Review Board approval was obtained in this retrospective study. Sixty-nine subjects had both FSPGR and LAVA-Flex sequences. Two radiologists independently scored the acquisitions for image quality, fat suppression quality, and artifacts and the values obtained were compared with the Wilcoxon signed rank test. According to the signal intensity (SI) measurements, the uniformity of fat suppression, the contrast between muscle and fat and normal liver and liver lesions were compared by the paired t-test. The liver and spleen SI on the fat-only phase were analyzed in the fatty liver patients. Compared with FSPGR imaging, LAVA-Flex images had better and more homogenous fat suppression and lower susceptibility artifact (qualitative scores: 4.70 vs. 4.00, 4.86% vs. 7.14%, 4.60 and 4.10, respectively). The contrast between muscle and fat and between the liver and pathologic lesions was significantly improved on the LAVA-Flex sequence. The contrast value of the fatty liver and spleen was higher than that of the liver and spleen. The LAVA-Flex sequence offers superior and more homogenous fat suppression of the abdomen than does the FSPGR sequence. The fat-only phase can be a simple and effective method of assessing fatty liver. © 2013 Wiley Periodicals, Inc.

  19. Carotid plaque signal differences among four kinds of T1-weighted magnetic resonance imaging techniques: A histopathological correlation study

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Ayumi; Narumi, Shinsuke; Ohba, Hideki; Yamaguchi, Mao; Terayama, Yasuo [Iwate Medical University, Department of Neurology and Gerontology, Morioka (Japan); Sasaki, Makoto; Kudo, Kohsuke [Iwate Medical University, Institute for Biomedical Sciences, Morioka (Japan); Ogasawara, Kuniaki; Kobayashi, Masakazu [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Hitomi, Jiro [Iwate Medical University, Department of Anatomy, Morioka (Japan)

    2012-11-15

    Several magnetic resonance (MR) imaging techniques are used to examine atherosclerotic plaque of carotid arteries; however, the best technique for visualizing intraplaque characteristics has yet to be determined. Here, we directly compared four kinds of T1-weighted (T1W) imaging techniques with pathological findings in patients with carotid stenosis. A total of 31 patients who were candidates for carotid endarterectomy were prospectively examined using a 1.5-T MRI scanner, which produced four kinds of T1W images, including non-gated spin echo (SE), cardiac-gated black-blood (BB) fast-SE (FSE), magnetization-prepared rapid acquisition with gradient echo (MPRAGE), and source image of three-dimensional time-of-flight MR angiography (SI-MRA). The signal intensity of the carotid plaque was manually measured, and the contrast ratio (CR) against the adjacent muscle was calculated. CRs from the four imaging techniques were compared to each other and correlated with histopathological specimens. CRs of the carotid plaques mainly containing fibrous tissue, lipid/necrosis, and hemorrhage were significantly different with little overlaps (range: 0.92-1.15, 1.22-1.52, and 1.55-2.30, respectively) on non-gated SE. However, BB-FSE showed remarkable overlaps among the three groups (0.89-1.10, 1.07-1.23, and 1.01-1.42, respectively). MPRAGE could discriminate fibrous plaques from hemorrhagic plaques but not from lipid/necrosis-rich plaques: (0.77-1.07, 1.45-2.43, and 0.85-1.42, respectively). SI-MRA showed the same tendencies (1.01-1.39, 1.45-2.57, and 1.12-1.39, respectively). Among T1W MR imaging techniques, non-gated SE images can more accurately characterize intraplaque components in patients who underwent CEA when compared with cardiac-gated BB-FSE, MPRAGE, and SI-MRA images. (orig.)

  20. Accounting for the Confound of Meninges in Segmenting Entorhinal and Perirhinal Cortices in T1-Weighted MRI.

    Science.gov (United States)

    Xie, Long; Wisse, Laura E M; Das, Sandhitsu R; Wang, Hongzhi; Wolk, David A; Manjón, Jose V; Yushkevich, Paul A

    2016-10-01

    Quantification of medial temporal lobe (MTL) cortices, including entorhinal cortex (ERC) and perirhinal cortex (PRC), from in vivo MRI is desirable for studying the human memory system as well as in early diagnosis and monitoring of Alzheimer's disease. However, ERC and PRC are commonly over-segmented in T1-weighted (T1w) MRI because of the adjacent meninges that have similar intensity to gray matter in T1 contrast. This introduces errors in the quantification and could potentially confound imaging studies of ERC/PRC. In this paper, we propose to segment MTL cortices along with the adjacent meninges in T1w MRI using an established multi-atlas segmentation framework together with super-resolution technique. Experimental results comparing the proposed pipeline with existing pipelines support the notion that a large portion of meninges is segmented as gray matter by existing algorithms but not by our algorithm. Cross-validation experiments demonstrate promising segmentation accuracy. Further, agreement between the volume and thickness measures from the proposed pipeline and those from the manual segmentations increase dramatically as a result of accounting for the confound of meninges. Evaluated in the context of group discrimination between patients with amnestic mild cognitive impairment and normal controls, the proposed pipeline generates more biologically plausible results and improves the statistical power in discriminating groups in absolute terms comparing to other techniques using T1w MRI. Although the performance of the proposed pipeline is inferior to that using T2-weighted MRI, which is optimized to image MTL sub-structures, the proposed pipeline could still provide important utilities in analyzing many existing large datasets that only have T1w MRI available.

  1. Increased signal intensities in the dentate nucleus and globus pallidus on unenhanced T1-weighted images: evidence in children undergoing multiple gadolinium MRI exams

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Houchun H.; Pokorney, Amber; Towbin, Richard B.; Miller, Jeffrey H. [Phoenix Children' s Hospital, Department of Medical Imaging and Radiology, Phoenix, AZ (United States)

    2016-10-15

    Recent reports have suggested residual gadolinium deposition in the brain in subjects undergoing multiple contrast-enhanced MRI exams. These findings have raised some concerns regarding gadolinium-based contrast agent (GBCA) usage and retention in brain tissues. To summarize findings of hyperintense brain structures on precontrast T1-weighted images in 21 children undergoing multiple GBCA MRI exams. This retrospective study involved 21 patients, each of whom received multiple MRI examinations (range: 5-37 exams) with GBCA over the course of their medical treatment (duration from first to most recent exam: 1.2-12.9 years). The patients were between 0.9 and 14.4 years of age at the time of their first GBCA exam. Regions of interest were drawn in the dentate nucleus and the globus pallidus on 2-D fast spin echo images acquired at 1.5 T. The signal intensities of these two structures were normalized by that of the corpus callosum genu. Signal intensity ratios from these patients were compared to control patients of similar ages who have never received GBCA. Signal intensity ratios increased between the first and the most recent MRI exam in all 21 patients receiving GBCA, with an increase of 18.6%±12.7% (range: 0.5% to 47.5%) for the dentate nucleus and 12.4%±7.4% (range: -1.2% to 33.7%) for the globus pallidus (P<0.0001). Signal intensity ratios were also higher in GBCA patients than in controls (P<0.01). The degree of signal intensity enhancement did not correlate with statistical significance to the cumulative number or volume of GBCA administrations each patient received, the patient's age or the elapsed time between the first and most recent GBCA MRI exams. These results in children are consistent with recent findings in adults, suggesting possible gadolinium deposition in the brain. (orig.)

  2. Closed-form expressions for flip angle variation that maximize total signal in T1-weighted rapid gradient echo MRI.

    Science.gov (United States)

    Drobnitzky, Matthias; Klose, Uwe

    2017-03-01

    Magnetization-prepared rapid gradient-echo (MPRAGE) sequences are commonly employed for T1-weighted structural brain imaging. Following a contrast preparation radiofrequency (RF) pulse, the data acquisition proceeds under nonequilibrium conditions of the relaxing longitudinal magnetization. Variation of the flip angle can be used to maximize total available signal. Simulated annealing or greedy algorithms have so far been published to numerically solve this problem, with signal-to-noise ratios optimized for clinical imaging scenarios by adhering to a predefined shape of the signal evolution. We propose an unconstrained optimization of the MPRAGE experiment that employs techniques from resource allocation theory. A new dynamic programming solution is introduced that yields closed-form expressions for optimal flip angle variation. Flip angle series are proposed that maximize total transverse magnetization (Mxy) for a range of physiologic T1 values. A 3D MPRAGE sequence is modified to allow for a controlled variation of the excitation angle. Experiments employing a T1 contrast phantom are performed at 3T. 1D acquisitions without phase encoding permit measurement of the temporal development of Mxy. Image mean signal and standard deviation for reference flip angle trains are compared in 2D measurements. Signal profiles at sharp phantom edges are acquired to access image blurring related to nonuniform Mxy development. A novel closed-form expression for flip angle variation is found that constitutes the optimal policy to reach maximum total signal. It numerically equals previously published results of other authors when evaluated under their simplifying assumptions. Longitudinal magnetization (Mz) is exhaustively used without causing abrupt changes in the measured MR signal, which is a prerequisite for artifact free images. Phantom experiments at 3T verify the expected benefit for total accumulated k-space signal when compared with published flip angle series. Describing

  3. Brain MR imaging in patients with hepatic cirrhosis: relationship between high intensity signal in basal ganglia on T1-weighted images and elemental concentrations in brain

    International Nuclear Information System (INIS)

    Maeda, H.; Sato, M.; Yoshikawa, A.; Kimura, M.; Sonomura, T.; Terada, M.; Kishi, K.

    1997-01-01

    In patients with hepatic cirrhosis, the globus pallidus and putamen show high intensity on T1-weighted MRI. While the causes of this high signal have been thought to include paramagnetic substances, especially manganese, no evidence for this has been presented. Autopsy in four cases of hepatic cirrhosis permitted measurement of metal concentrations in brain and histopathological examination. In three cases the globus pallidus showed high intensity on T1-weighted images. Mean manganese concentrations in globus pallidus, putamen and frontal white matter were 3.03 ± 0.38, 2.12 ± 0.37, and 1.38 ± 0.24 (μg/g wet weight), respectively, being approximately four- to almost ten-fold the normal values. Copper concentrations in globus pallidus and putamen were also high, 50 % more than normal. Calcium, iron, zinc and magnesium concentrations were all normal. The fourth case showed no abnormal intensity in the basal ganglia and brain metal concentrations were all normal. Histopathologically, cases with showing high signal remarkable atrophy, necrosis, and deciduation of nerve cells and proliferation of glial cells and microglia in globus pallidus. These findings were similar to those in chronic manganese poisoning. On T1-weighted images, copper deposition shows no abnormal intensity. It is therefore inferred that deposition of highly concentrations of manganese may caused high signal on T1-weighted images and nerve cell death in the globus pallidus. (orig.). With 2 figs., 2 tabs

  4. Magnetization transfer imaging identifies basal ganglia abnormalities in adult ADHD that are invisible to conventional T1 weighted voxel-based morphometry

    Directory of Open Access Journals (Sweden)

    Arjun Sethi

    2017-01-01

    Full Text Available In childhood, Attention Deficit Hyperactivity Disorder (ADHD is reliably associated with reduced volume of the striatum. In contrast, striatal abnormalities are infrequently detected in voxel-based morphometry (VBM neuroimaging studies of adults with ADHD. This discrepancy has been suggested to reflect normalisation of striatal morphology with age and prolonged treatment of symptoms. If so, this would indicate that while striatal abnormalities are linked to symptom expression in childhood, they cannot explain the persistence of these symptoms in adulthood. However, this may not be case. Instead, we hypothesized that the lack of evidence for striatal abnormalities in adult ADHD may reflect poor sensitivity of typical (T1-weighted neuroimaging to detect subcortical differences. To address this, we acquired both magnetisation transfer (MT saturation maps optimised for subcortical contrast, and conventional T1-weighted images in 30 adults with ADHD and 30 age, IQ, gender and handedness-matched controls. Using VBM of both datasets, we demonstrate volumetric reductions within the left ventral striatum on MT that are not observed on identically pre-processed T1-weighted images from the same participants. Nevertheless, both techniques reported similar sensitivity to cortical abnormalities in the right inferior parietal lobe. Additionally, we show that differences in striatal iron may potentially explain this reduced sensitivity of T1-weighted images in adults. Together, these findings indicate that prior VBM studies reporting no abnormalities in striatal volume in adult ADHD might have been compromised by the methodological insensitivity of T1-weighted VBM to subcortical differences, and that structural abnormalities of the striatum in ADHD do indeed persist into adulthood.

  5. Histogram Profiling of Postcontrast T1-Weighted MRI Gives Valuable Insights into Tumor Biology and Enables Prediction of Growth Kinetics and Prognosis in Meningiomas.

    Science.gov (United States)

    Gihr, Georg Alexander; Horvath-Rizea, Diana; Kohlhof-Meinecke, Patricia; Ganslandt, Oliver; Henkes, Hans; Richter, Cindy; Hoffmann, Karl-Titus; Surov, Alexey; Schob, Stefan

    2018-06-14

    Meningiomas are the most frequently diagnosed intracranial masses, oftentimes requiring surgery. Especially procedure-related morbidity can be substantial, particularly in elderly patients. Hence, reliable imaging modalities enabling pretherapeutic prediction of tumor grade, growth kinetic, realistic prognosis, and-as a consequence-necessity of surgery are of great value. In this context, a promising diagnostic approach is advanced analysis of magnetic resonance imaging data. Therefore, our study investigated whether histogram profiling of routinely acquired postcontrast T1-weighted images is capable of separating low-grade from high-grade lesions and whether histogram parameters reflect Ki-67 expression in meningiomas. Pretreatment T1-weighted postcontrast volumes of 44 meningioma patients were used for signal intensity histogram profiling. WHO grade, tumor volume, and Ki-67 expression were evaluated. Comparative and correlative statistics investigating the association between histogram profile parameters and neuropathology were performed. None of the investigated histogram parameters revealed significant differences between low-grade and high-grade meningiomas. However, significant correlations were identified between Ki-67 and the histogram parameters skewness and entropy as well as between entropy and tumor volume. Contrary to previously reported findings, pretherapeutic postcontrast T1-weighted images can be used to predict growth kinetics in meningiomas if whole tumor histogram analysis is employed. However, no differences between distinct WHO grades were identifiable in out cohort. As a consequence, histogram analysis of postcontrast T1-weighted images is a promising approach to obtain quantitative in vivo biomarkers reflecting the proliferative potential in meningiomas. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Free-breathing dynamic liver examination using a radial 3D T1-weighted gradient echo sequence with moderate undersampling for patients with limited breath-holding capacity

    Energy Technology Data Exchange (ETDEWEB)

    Kaltenbach, Benjamin, E-mail: benjamin.kaltenbach@kgu.de [Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt am Main (Germany); Roman, Andrei; Polkowski, Christoph; Gruber-Rouh, Tatjana [Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt am Main (Germany); Bauer, Ralf W. [Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt am Main (Germany); Divison of Radiology and Nuclear Medicine, Kantonsspital, St. Gallen (Switzerland); Hammerstingl, Renate; Vogl, Thomas J.; Zangos, Stephan [Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt am Main (Germany)

    2017-01-15

    Highlights: • Respiratory artifacts are a frequent problem in abdominal MR imaging. • Non-diagnostic examinations could be reduced using free-breathing us-radial-VIBE for dynamic liver examination in challenging patients. • Streak artifacts are characteristic for an undersampled radial acquisition but do not affect diagnostic validity. - Abstract: Purpose: To compare free-breathing radial VIBE with moderate undersampling (us-radial-VIBE) with a standard breathhold T1-weighted volumetric interpolated sequence (3D GRE VIBE) in patients unable to suspend respiration during dynamic liver examination. Material and methods: 23 consecutive patients underwent dynamic liver MR examination using the free-breathing us-radial-VIBE sequence as part of their oncologic follow-up. All patients were eligible for the free-breathing protocol due to severe respiratory artifacts at the planning or precontrast sequences. The us-radial-VIBE acquisitions were compared to the patientś last staging liver MRI including a standard breathhold 3D GRE VIBE. For an objective image evaluation, signal intensity (SI), image noise (IN), signal-to-noise ratio (SNR) and contrast-enhancement ratio (CER) were compared. Representative image quality parameters, including typical artifacts were independently, retrospectively and blindly scored by four readers. Results: Us-radial-VIBE had significant lower SNR (p < 0.0001) and higher IN (p < 0.0001), whereas SI did not differ (p = 0.62). Temporal resolution assessed with CER in the arterial phase showed higher values for us-radial-VIBE (p = 0.028). Subjective image quality parameters received generally slightly higher scores for 3D GRE VIBE. In a smaller subgroup comprising patients with severe respiratory artifacts also at reference breathhold 3D GRE VIBE examination, us-radial-VIBE showed significantly higher image quality scores. Furthermore, there were generally more severe respiratory artifacts in 3D GRE VIBE, whereas streaking was characteristic

  7. Comparison of a T1-weighted inversion-recovery-, gradient-echo- and spin-echo sequence for imaging of the brain at 3.0 Tesla

    International Nuclear Information System (INIS)

    Stehling, C.; Niederstadt, T.; Kraemer, S.; Kugel, H.; Schwindt, W.; Heindel, W.; Bachmann, R.

    2005-01-01

    Purpose: The increased T1 relaxation times at 3.0 Tesla lead to a reduced T1 contrast, requiring adaptation of imaging protocols for high magnetic fields. This prospective study assesses the performance of three techniques for T1-weighted imaging (T1w) at 3.0 T with regard to gray-white differentiation and contrast-to-noise-ratio (CNR). Materials and Methods: Thirty-one patients were examined at a 3.0 T system with axial T1 w inversion recovery (IR), spin-echo (SE) and gradient echo (GE) sequences and after contrast enhancement (CE) with CE-SE and CE-GE sequences. For qualitative analysis, the images were ranked with regard to artifacts, gray-white differentiation, image noise and overall diagnostic quality. For quantitative analysis, the CNR was calculated, and cortex and basal ganglia were compared with the white matter. Results: In the qualitative analysis, IR was judged superior to SE and GE for gray-white differentiation, image noise and overall diagnostic quality, but inferior to the GE sequence with regard to artifacts. CE-GE proved superior to CE-SE in all categories. In the quantitative analysis, CNR of the based ganglia was highest for IR, followed by GE and SE. For the CNR of the cortex, no significant difference was found between IR (16.9) and GE (15.4) but both were superior to the SE (9.4). The CNR of the cortex was significantly higher for CE-GE compared to CE-SE (12.7 vs. 7.6, p<0.001), but the CNR of the basal ganglia was not significantly different. Conclusion: For unenhanced T1w imaging at 3.0 T, the IR technique is, despite increased artifacts, the method of choice due to its superior gray-white differentiation and best overall image quality. For CE-studies, GE sequences are recommended. For cerebral imaging, SE sequences give unsatisfactory results at 3.0 T. (orig.)

  8. Comparison of spin echo T1-weighted sequences versus fast spin-echo proton density-weighted sequences for evaluation of meniscal tears at 1.5 T

    International Nuclear Information System (INIS)

    Wolff, Andrew B.; Pesce, Lorenzo L.; Wu, Jim S.; Smart, L.R.; Medvecky, Michael J.; Haims, Andrew H.

    2009-01-01

    At our institution, fast spin-echo (FSE) proton density (PD) imaging is used to evaluate articular cartilage, while conventional spin-echo (CSE) T1-weighted sequences have been traditionally used to characterize meniscal pathology. We sought to determine if FSE PD-weighted sequences are equivalent to CSE T1-weighted sequences in the detection of meniscal tears, obviating the need to perform both sequences. We retrospectively reviewed the records of knee arthroscopies performed by two arthroscopy-focused surgeons from an academic medical center over a 2-year period. The preoperative MRI images were interpreted independently by two fellowship-trained musculoskeletal radiologists who graded the sagittal CSE T1 and FSE PD sequences at different sittings with grades 1-5, where 1 = normal meniscus, 2 = probable normal meniscus, 3 indeterminate, 4 = probable torn meniscus, and 5 = torn meniscus. Each meniscus was divided into an anterior and posterior half, and these halves were graded separately. Operative findings provided the gold standard. Receiver operating characteristic (ROC) analysis was performed to compare the two sequences. There were 131 tears in 504 meniscal halves. Using ROC analysis, the reader 1 area under curve for FSE PD was significantly better than CSE T1 (0.939 vs. 0.902, >95% confidence). For reader 2, the difference met good criteria for statistical non-inferiority but not superiority (0.913 for FSE PD and 0.908 for CSE T1; >95% non-inferiority for difference at most of -0.027). FSE PD-weighted sequences, using our institutional protocol, are not inferior to CSE T1-weighted sequences for the detection of meniscal tears and may be superior. (orig.)

  9. Accuracy of magnetic resonance imaging in planning the osseous resection margins of bony tumours in the proximal femur: based on coronal T1-weighted versus STIR images

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Sarfraz; Stevenson, Jonathan; Mangham, Charles; Cribb, Gillian; Cool, Paul [Robert Jones and Agnes Hunt Orthopaedic Hospital, Department of Musculoskeletal Oncology, Oswestry, Shropshire (United Kingdom)

    2014-12-15

    Assessment of the extent of tumours using magnetic resonance imaging (MRI) is the basis for bone resection in limb-salvage surgery. We aimed to compare the accuracy of T1-weighted MRI and STIR sequences in measuring the extent of proximal femoral tumours, using the macroscopic specimens as the gold standard for comparison. We compared single coronal T1-weighted with STIR sequences in 34 proximal femoral tumours, using bivalved resected macroscopic tumours for comparison. After randomisation, four observers measured longitudinal osseous tumour extent using MRI and specimen photographs on two separate occasions, 3 weeks apart. There were 25 metastatic tumours, 8 chondrosarcomas and 1 myeloma. Eight patients presented with pathological fractures. The Pearson's correlation coefficient for comparison of T1 with macroscopic tumours was 0.91 (95 % confidence interval [CI]: 0.83 to 0.96) for all observers and 0.90 (95 % CI: 0.81 to 0.95) for STIR images. This difference was not statistically significant, and T1 and STIR sequence measurements had similar precision and accuracy. Bland-Altman plots showed T1-weighted imaging to be unbiased, whereas STIR sequences were biased and had systematic error. Moreover, STIR measurements overestimated tumour size by 6.4 mm (95 % CI: -26.9 to 39.7 mm) and 2 patients were outliers. T1 measurements were closer to the macroscopic measurements with a mean difference of 1.3 mm (95 % CI: -28.9 mm to 31.5 mm), with 3 patients falling outside of this. The variance was greater for STIR measurements. This difference between T1 and STIR measurements was statistically significant (p = 0.000003). The intra-observer reliability between separate measurements for MRI and specimen photographs achieved interclass correlation coefficients of 0.97, 0.96 and 0.95 (T1, STIR and macroscopic tumour respectively). T1 had greater interobserver correlation than for STIR and macroscopic tumour measurements (0.88 vs 0.85 and 0.85 respectively). These

  10. Repeated intravenous administration of gadobutrol does not lead to increased signal intensity on unenhanced T1-weighted images - a voxel-based whole brain analysis

    Energy Technology Data Exchange (ETDEWEB)

    Langner, Soenke; Kromrey, Marie-Luise [University Medicine Greifswald, Institute of Diagnostic Radiology and Neuroradiology, Greifswald (Germany); Kuehn, Jens-Peter [University Medicine Greifswald, Institute of Diagnostic Radiology and Neuroradiology, Greifswald (Germany); University Hospital, Carl Gustav Carus University Dresden, Institute for Radiology, Dresden (Germany); Grothe, Matthias [University Medicine Greifswald, Department of Neurology, Greifswald (Germany); Domin, Martin [University Medicine Greifswald, Functional Imaging Unit, Institute of Diagnostic Radiology and Neuroradiology, Greifswald (Germany)

    2017-09-15

    To identify a possible association between repeated intravenous administration of gadobutrol and increased signal intensity in the grey and white matter using voxel-based whole-brain analysis. In this retrospective single-centre study, 217 patients with a clinically isolated syndrome underwent baseline brain magnetic resonance imaging and at least one annual follow-up examination with intravenous administration of 0.1 mmol/kg body weight of gadobutrol. Using the ''Diffeomorphic Anatomical Registration using Exponentiated Lie algebra'' (DARTEL) normalisation process, tissue templates for grey matter (GM), white matter (WM), and cerebrospinal fluid (CSF) were calculated, as were GM-CSF and WM-CSF ratios. Voxel-based whole-brain analysis was used to calculate the signal intensity for each voxel in each data set. Paired t-test was applied to test differences to baseline MRI for significance. Voxel-based whole-brain analysis demonstrated no significant changes in signal intensity of grey and white matter after up to five gadobutrol administrations. There was no significant change in GM-CSF and grey WM-CSF ratios. Voxel-based whole-brain analysis did not demonstrate increased signal intensity of GM and WM on unenhanced T1-weighted images after repeated gadobutrol administration. The molecular structure of gadolinium-based contrast agent preparations may be an essential factor causing SI increase on unenhanced T1-weighted images. (orig.)

  11. Preoperative 3D FSE T1-Weighted MR Plaque Imaging for Severely Stenotic Cervical ICA: Accuracy of Predicting Emboli during Carotid Endarterectomy

    Directory of Open Access Journals (Sweden)

    Yasushi Ogasawara

    2016-10-01

    Full Text Available The aim of the present study was to determine whether preoperative three-dimensional (3D fast spin-echo (FSE T1-weighted magnetic resonance (MR plaque imaging for severely stenotic cervical carotid arteries could accurately predict the development of artery-to-artery emboli during exposure of the carotid arteries in carotid endarterectomy (CEA. Seventy-five patients underwent preoperative MR plaque imaging and CEA under transcranial Doppler ultrasonography of the ipsilateral middle cerebral artery. On reformatted axial MR image slices showing the maximum plaque occupation rate (POR and maximum plaque intensity for each patient, the contrast ratio (CR was calculated by dividing the internal carotid artery plaque signal intensity by the sternocleidomastoid muscle signal intensity. For all patients, the area under the receiver operating characteristic curve (AUC—used to discriminate between the presence and absence of microembolic signals—was significantly greater for the CR on the axial image with maximum plaque intensity (CRmax intensity (0.941 than for that with the maximum POR (0.885 (p < 0.05. For 32 patients in whom both the maximum POR and the maximum plaque density were identified, the AUCs for the CR were 1.000. Preoperative 3D FSE T1-weighted MR plaque imaging accurately predicts the development of artery-to-artery emboli during exposure of the carotid arteries in CEA.

  12. Correlation between neurohypophyseal vasopressin content and signal intensity on T1-weighted magnetic resonance images. An experimental study of vasopressin depletion model using dehydrated rabbits

    International Nuclear Information System (INIS)

    Kurokawa, Hiroaki; Nakano, Yoshihisa; Ikeda, Koshi; Tanaka, Yoshimasa; Fujisawa, Ichiro

    1998-01-01

    We investigated the correlation between the signal intensity on T 1 -weighted MR images and vasopressin (VP) content in the posterior pituitary lobe. Fourteen rabbits were studied. There were 12 water-deprived rabbits (48, 72, 96, 120, 144 and 168 hours: 2 each) and 2 controls. Sagittal T 1 -weighted SE (spin-echo) MR images were obtained before and after dehydration. The signal intensity ratio of the posterior pituitary lobe to the pons was correlated with the VP content in the posterior lobe as measured by radioimmunoassay. Before water deprivation, high signal intensity in the posterior lobe was demonstrated clearly in all 14 rabbits. After water deprivation, the hyperintense signal gradually decreased and became indistinguishable from anterior lobe in four animals. The mean signal intensity ratio before water deprivation was 1.55±0.12 (mean±SD) and after water deprivation, gradually decreased over time and reached to 1.19 after 168 hours of water deprivation. Pituitary VP content and concentration decreased in parallel with the signal intensity ratio of the posterior pituitary. Significantly correlation was observed between the signal intensity ratio and VP concentration of posterior pituitary (r=0.809, p 1 -weighted image may reflect a indicator of pituitary VP content and thus may enable evaluation of disorders of water metabolism. (author)

  13. Diagnosing lung nodules on oncologic MR/PET imaging: Comparison of fast T1-weighted sequences and influence of image acquisition in inspiration and expiration breath-hold

    Energy Technology Data Exchange (ETDEWEB)

    Schwenzer, Nina F.; Seith, Ferdinand; Gatidis, Sergios; Brendle, Cornelia; Schmidt, Holger; Pfannenberg, Christina A; LaFougère, Christian; Nikolaou, Konstantin; Schraml, Christina [University Hospital of Tuebingen, Tuebingen (Germany)

    2016-09-15

    First, to investigate the diagnostic performance of fast T1-weighted sequences for lung nodule evaluation in oncologic magnetic resonance (MR)/positron emission tomography (PET). Second, to evaluate the influence of image acquisition in inspiration and expiration breath-hold on diagnostic performance. The study was approved by the local Institutional Review Board. PET/CT and MR/PET of 44 cancer patients were evaluated by 2 readers. PET/CT included lung computed tomography (CT) scans in inspiration and expiration (CTin, CTex). MR/PET included Dixon sequence for attenuation correction and fast T1-weighted volumetric interpolated breath-hold examination (VIBE) sequences (volume interpolated breath-hold examination acquired in inspiration [VIBEin], volume interpolated breath-hold examination acquired in expiration [VIBEex]). Diagnostic performance was analyzed for lesion-, lobe-, and size-dependence. Diagnostic confidence was evaluated (4-point Likert-scale; 1 = high). Jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis was performed. Seventy-six pulmonary lesions were evaluated. Lesion-based detection rates were: CTex, 77.6%; VIBEin, 53.3%; VIBEex, 51.3%; and Dixon, 22.4%. Lobe-based detection rates were: CTex, 89.6%; VIBEin, 58.3%; VIBEex, 60.4%; and Dixon, 31.3%. In contrast to CT, inspiration versus expiration did not alter diagnostic performance in VIBE sequences. Diagnostic confidence was best for VIBEin and CTex and decreased in VIBEex and Dixon (1.2 ± 0.6; 1.2 ± 0.7; 1.5 ± 0.9; 1.7 ± 1.1, respectively). The JAFROC figure-of-merit of Dixon was significantly lower. All patients with malignant lesions were identified by CTex, VIBEin, and VIBEex, while 3 patients were false-negative in Dixon. Fast T1-weighted VIBE sequences allow for identification of patients with malignant pulmonary lesions. The Dixon sequence is not recommended for lung nodule evaluation in oncologic MR/PET patients. In contrast to CT, inspiration versus

  14. Diagnosing Lung Nodules on Oncologic MR/PET Imaging: Comparison of Fast T1-Weighted Sequences and Influence of Image Acquisition in Inspiration and Expiration Breath-Hold

    Energy Technology Data Exchange (ETDEWEB)

    Schwenzer, Nina F.; Seith, Ferdinand; Gatidis, Sergios [Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076 (Germany); Brendle, Cornelia [Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076 (Germany); Department of Diagnostic and Interventional Neuroradiology, University Hospital of Tuebingen, Tuebingen 72076 (Germany); Schmidt, Holger; Pfannenberg, Christina A. [Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076 (Germany); Fougère, Christian la [Department of Nuclear Medicine, University Hospital of Tuebingen, Tuebingen 72076 (Germany); Nikolaou, Konstantin; Schraml, Christina [Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen 72076 (Germany)

    2016-11-01

    First, to investigate the diagnostic performance of fast T1-weighted sequences for lung nodule evaluation in oncologic magnetic resonance (MR)/positron emission tomography (PET). Second, to evaluate the influence of image acquisition in inspiration and expiration breath-hold on diagnostic performance. The study was approved by the local Institutional Review Board. PET/CT and MR/PET of 44 cancer patients were evaluated by 2 readers. PET/CT included lung computed tomography (CT) scans in inspiration and expiration (CTin, CTex). MR/PET included Dixon sequence for attenuation correction and fast T1-weighted volumetric interpolated breath-hold examination (VIBE) sequences (volume interpolated breath-hold examination acquired in inspiration [VIBEin], volume interpolated breath-hold examination acquired in expiration [VIBEex]). Diagnostic performance was analyzed for lesion-, lobe-, and size-dependence. Diagnostic confidence was evaluated (4-point Likert-scale; 1 = high). Jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis was performed. Seventy-six pulmonary lesions were evaluated. Lesion-based detection rates were: CTex, 77.6%; VIBEin, 53.3%; VIBEex, 51.3%; and Dixon, 22.4%. Lobe-based detection rates were: CTex, 89.6%; VIBEin, 58.3%; VIBEex, 60.4%; and Dixon, 31.3%. In contrast to CT, inspiration versus expiration did not alter diagnostic performance in VIBE sequences. Diagnostic confidence was best for VIBEin and CTex and decreased in VIBEex and Dixon (1.2 ± 0.6; 1.2 ± 0.7; 1.5 ± 0.9; 1.7 ± 1.1, respectively). The JAFROC figure-of-merit of Dixon was significantly lower. All patients with malignant lesions were identified by CTex, VIBEin, and VIBEex, while 3 patients were false-negative in Dixon. Fast T1-weighted VIBE sequences allow for identification of patients with malignant pulmonary lesions. The Dixon sequence is not recommended for lung nodule evaluation in oncologic MR/PET patients. In contrast to CT, inspiration versus

  15. Gadobenate-dimeglumine-enhanced magnetic resonance imaging for hepatic lesions in children

    Energy Technology Data Exchange (ETDEWEB)

    Chavhan, Govind B.; Mann, Erika [The Hospital for Sick Children and University of Toronto, Department of Diagnostic Imaging, Toronto (Canada); Kamath, Binita M. [The Hospital for Sick Children and University of Toronto, Division of Gastroenterology, Hepatology and Nutrition, Toronto (Canada); Babyn, Paul S. [Royal University Hospital, Department of Medical Imaging, Saskatoon (Canada)

    2014-10-15

    Magnetic resonance imaging enhanced by hepatocyte-specific contrast media has been found useful to characterize liver lesions in adults and children. To present our experience with gadobenate dimeglumine (Gd-BOPTA)-enhanced MRI for evaluation of focal liver lesions in children. We retrospectively reviewed gadobenate-dimeglumine-enhanced MR images obtained for evaluation of suspected hepatic lesions in 30 children. Signal characteristics on various sequences including 45- to 60-min hepatobiliary phase images were noted by two radiologists. Chart review identified relevant clinical details including history of cancer treatment, available pathology and stability of lesion size on follow-up imaging. Of the 30 children who had gadobenate-enhanced MRI, 26 showed focal lesions. Diagnoses in 26 children were focal nodular hyperplasia (FNH) in 15, hemangiomas in 3, regenerating nodules in 3, focal fatty infiltration in 2, indeterminate lesions in 3, and one patient each with adenomas, hepatoblastoma and metastasis. Two patients had multiple diagnoses. All FNH lesions (39), all regenerative nodules (19) and an indeterminate lesion were iso- or hyperintense on hepatobiliary-phase images while all other lesions (28) were hypointense to hepatic parenchyma. The average follow-up period was 21.7 months. Our experience with gadobenate-enhanced MRI indicates potential utility of gadobenate in the evaluation of pediatric hepatic lesions in differentiating FNH and regenerating nodules from other lesions. (orig.)

  16. Altered carotid plaque signal among different repetition times on T1-weighted magnetic resonance plaque imaging with self-navigated radial-scan technique

    Energy Technology Data Exchange (ETDEWEB)

    Narumi, Shinsuke; Ohba, Hideki; Mori, Kiyofumi; Ohura, Kazumasa; Ono, Ayumi; Terayama, Yasuo [Iwate Medical University, Department of Neurology and Gerontology, Morioka (Japan); Sasaki, Makoto [Iwate Medical University, Advanced Medical Research Center, Morioka (Japan); Ogasawara, Kuniaki [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Hitomi, Jiro [Iwate Medical University, Department of Anatomy, Morioka (Japan)

    2010-04-15

    Magnetic resonance (MR) plaque imaging for carotid arteries is usually performed by using an electrocardiograph (ECG)-gating technique to eliminate pulsation-related artifacts, which can affect the plaque signals because of varied repetition time (TR) among patients. Hence, we investigated whether differences in TR causes signal alterations of the carotid plaque by using a non-gated plaque imaging technique. We prospectively examined 19 patients with carotid stenosis by using a T1-weighted self-navigated radial-scan technique with TRs of 500, 700, and 900 ms. The signal intensity of the carotid plaque was measured, and the contrast ratio (CR) relative to the adjacent muscle was calculated. CRs of the carotid plaques were 1.39 {+-} 0.39, 1.29 {+-} 0.29, and 1.23 {+-} 0.24 with TRs of 500, 700, and 900 ms, respectively, and were significantly different. Among the plaques, those with a hyperintensity signal (CR > 1.5) and moderate-intensity signal (CR 1.2-1.5) at 500 ms showed a TR-dependent signal decrease (hyperintensity plaques, 1.82 {+-} 0.26; 1.61 {+-} 0.19; and 1.48 {+-} 0.17; moderate-intensity plaques, 1.33 {+-} 0.08; 1.26 {+-} 0.08; and 1.19 {+-} 0.07), while those with an isointensity signal (CR < 1.2) remained unchanged regardless of TR (0.96 {+-} 0.12, 0.96 {+-} 0.11, and 0.97 {+-} 0.13). The signal intensity of the carotid plaque on T1-weighted imaging significantly varies among different TRs and tends to decrease with longer TR. MR plaque imaging with short and constant TR settings that the ECG-gating method cannot realize would be preferable for evaluating plaque characteristics. (orig.)

  17. Breast MRI at 7 Tesla with a bilateral coil and T1-weighted acquisition with robust fat suppression: image evaluation and comparison with 3 Tesla.

    Science.gov (United States)

    Brown, Ryan; Storey, Pippa; Geppert, Christian; McGorty, KellyAnne; Leite, Ana Paula Klautau; Babb, James; Sodickson, Daniel K; Wiggins, Graham C; Moy, Linda

    2013-11-01

    To evaluate the image quality of T1-weighted fat-suppressed breast MRI at 7 T and to compare 7-T and 3-T images. Seventeen subjects were imaged using a 7-T bilateral transmit-receive coil and 3D gradient echo sequence with adiabatic inversion-based fat suppression (FS). Images were graded on a five-point scale and quantitatively assessed through signal-to-noise ratio (SNR), fibroglandular/fat contrast and signal uniformity measurements. Image scores at 7 and 3 T were similar on standard-resolution images (1.1 × 1.1 × 1.1-1.6 mm(3)), indicating that high-quality breast imaging with clinical parameters can be performed at 7 T. The 7-T SNR advantage was underscored on 0.6-mm isotropic images, where image quality was significantly greater than at 3 T (4.2 versus 3.1, P ≤ 0.0001). Fibroglandular/fat contrast was more than two times higher at 7 T than at 3 T, owing to effective adiabatic inversion-based FS and the inherent 7-T signal advantage. Signal uniformity was comparable at 7 and 3 T (P coil and adiabatic inversion-based FS technique produce image quality that is as good as or better than at 3 T. • High image quality bilateral breast MRI is achievable with clinical parameters at 7 T. • 7-T high-resolution imaging improves delineation of subtle soft tissue structures. • Adiabatic-based fat suppression provides excellent fibroglandular/fat contrast at 7 T. • 7- and 3-T 3D T1-weighted gradient-echo images have similar signal uniformity. • The 7-T dual solenoid coil enables bilateral imaging without compromising uniformity.

  18. Quantitative evaluation of hyperintensity on T1-weighted MRI in liver cirrhosis : correlation with child-pugh classification and hepatic encephalopathy

    International Nuclear Information System (INIS)

    Eun, Hyo Won; Choi, Hye Young; Lee, Sun Wha; Yi, Sun Young

    1999-01-01

    To investigate the differences in signal changes in the globus pallidus and white matter, as seen on T1-weighted MR brain images, and to determine whether these differences can be used as an indicator of subclinical hepatic encephalopathy. A total of 25 cases of liver cirrhosis were evaluated and as a control group, 20 subjects were also studied. Using a 1.5T MRI scannet, brain MR images were obtained, and the differences in signal intensity in both the globus pallidus and thalamus and in both white and gray matter were then quantified using the contrast to noise ratio(CNR). On the basis of the Child-Pugh classification, 25patients with liver cirrhosis were divided into three groups, with eight in group A, eight in B, and nine in C. Using clinical criteria, hepatic encephalopathy was diagnosed in seven of the 25 patients. There after, CNRs(CNR1 and CNR2) were conpared between the control and cirrhotic groups and between cirrhotic groups with or without hepatic encephalopathy. In the control group, mean values were 3.2±5.9 for CNR1 and 8.4±8.0 for CNR2. In the cirrhotic group, these values were 10.6±9.0 for CNR1 and 9.8±6.4 for CNR2. A statistically significant difference was noted between normal and cirrhotic groups only for CNR1(p<0.05). CNR values in patients with liver cirrhosis were 8.5±11.5 for CNR1 and 11.7±8.7 for CNR2 in the Child A group, 10.4±5.1 for CNR1 and 9.3±3.2 for CNR2 in the B group, and 12.8±9.7 for CNR1 and 8.7±6.5 for CNR2 in the C group. There was no significant difference in mean CNRI values between patients with or without hepatic encephalopathy. Differences in signal intensities in the globus pallidus and white matter, as seen on T1-weighted MR brain images, cannot be used as an indicator of hepatic encephalopathy in patients with liver cirrhosis

  19. Quantitative evaluation of hyperintensity on T1-weighted MRI in liver cirrhosis : correlation with child-pugh classification and hepatic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Eun, Hyo Won; Choi, Hye Young; Lee, Sun Wha; Yi, Sun Young [Ewha Womans Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-11-01

    To investigate the differences in signal changes in the globus pallidus and white matter, as seen on T1-weighted MR brain images, and to determine whether these differences can be used as an indicator of subclinical hepatic encephalopathy. A total of 25 cases of liver cirrhosis were evaluated and as a control group, 20 subjects were also studied. Using a 1.5T MRI scannet, brain MR images were obtained, and the differences in signal intensity in both the globus pallidus and thalamus and in both white and gray matter were then quantified using the contrast to noise ratio(CNR). On the basis of the Child-Pugh classification, 25patients with liver cirrhosis were divided into three groups, with eight in group A, eight in B, and nine in C. Using clinical criteria, hepatic encephalopathy was diagnosed in seven of the 25 patients. There after, CNRs(CNR1 and CNR2) were conpared between the control and cirrhotic groups and between cirrhotic groups with or without hepatic encephalopathy. In the control group, mean values were 3.2{+-}5.9 for CNR1 and 8.4{+-}8.0 for CNR2. In the cirrhotic group, these values were 10.6{+-}9.0 for CNR1 and 9.8{+-}6.4 for CNR2. A statistically significant difference was noted between normal and cirrhotic groups only for CNR1(p<0.05). CNR values in patients with liver cirrhosis were 8.5{+-}11.5 for CNR1 and 11.7{+-}8.7 for CNR2 in the Child A group, 10.4{+-}5.1 for CNR1 and 9.3{+-}3.2 for CNR2 in the B group, and 12.8{+-}9.7 for CNR1 and 8.7{+-}6.5 for CNR2 in the C group. There was no significant difference in mean CNRI values between patients with or without hepatic encephalopathy. Differences in signal intensities in the globus pallidus and white matter, as seen on T1-weighted MR brain images, cannot be used as an indicator of hepatic encephalopathy in patients with liver cirrhosis.

  20. Pediatric Patients Demonstrate Progressive T1-Weighted Hyperintensity in the Dentate Nucleus following Multiple Doses of Gadolinium-Based Contrast Agent.

    Science.gov (United States)

    Roberts, D R; Chatterjee, A R; Yazdani, M; Marebwa, B; Brown, T; Collins, H; Bolles, G; Jenrette, J M; Nietert, P J; Zhu, X

    2016-12-01

    While there have been recent reports of brain retention of gadolinium following gadolinium-based contrast agent administration in adults, a retrospective series of pediatric patients has not previously been reported, to our knowledge. We investigated the relationship between the number of prior gadolinium-based contrast agent doses and increasing T1 signal in the dentate nucleus on unenhanced T1-weighted MR imaging. We hypothesized that despite differences in pediatric physiology and the smaller gadolinium-based contrast agent doses that pediatric patients are typically administered based on weighted-adjusted dosing, the pediatric brain would also demonstrate dose-dependent increasing T1 signal in the dentate nucleus. We included children with multiple gadolinium-based contrast agent administrations at our institution. A blinded reader placed ROIs within the dentate nucleus and adjacent cerebellar white matter. To eliminate reader bias, we also performed automated ROI delineation of the dentate nucleus, cerebellar white matter, and pons. Dentate-to-cerebellar white matter and dentate-to pons ratios were compared with the number of gadolinium-based contrast agent administrations. During 20 years at our institution, 280 patients received at least 5 gadolinium-based contrast agent doses, with 1 patient receiving 38 doses. Sixteen patients met the inclusion/exclusion criteria for ROI analysis. Blinded reader dentate-to-cerebellar white matter ratios were significantly associated with gadolinium-based contrast agent doses (r s = 0.77, P = .001). The dentate-to-pons ratio and dentate-to-cerebellar white matter ratios based on automated ROI placement were also significantly correlated with gadolinium-based contrast agent doses (t = 4.98, P contrast agent doses is significantly correlated with progressive T1-weighted dentate hyperintensity. Definitive confirmation of gadolinium deposition requires tissue analysis. Any potential clinical sequelae of gadolinium retention in

  1. The value of 3D T1-weighted gradient-echo MR imaging for evaluation of the appendix during pregnancy: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Kyung Mi; Kim, Seong Hyun; Choi, Dongil; Lee, Soon Jin; Rhim, Hyunchul; Park, Min Jung (Depts. of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan Univ. School of Medicine, Seoul (Korea, Republic of)), email: kshyun@skku.edu

    2011-10-15

    Background The use of oral contrast has been essential for the identification of a normal appendix on MR imaging during pregnancy. However, stool could be used as a positive oral contrast as it is characterized by a relatively high signal on T1-weighted imaging, and 3D T1-weighted gradient-echo (T1W-GRE) MR imaging has been used to evaluate 3 mm diameter intestines in fetuses. Purpose To evaluate the added value of 3D T1W-GRE MR imaging in combination with T2-weighted imaging (T2WI) compared to T2WI alone for evaluating the appendix during pregnancy. Material and Methods Eighteen consecutive pregnant patients who were clinically suspected of having acute appendicitis underwent appendix MR imaging which included T2WI with or without spectral presaturation attenuated inversion-recovery (SPAIR) fat suppression, and 3D T1W-GRE with SPAIR fat suppression. Two radiologists reviewed the two image sets (the T2WI set and the combined set of T2WI and 3D T1W-GRE images). Pathologic and clinical results served as the reference standard. The differences in the degree of visibility of the appendix and confidence scale for diagnosing acute appendicitis between two image sets were compared by using the paired Wilcoxon signed rank test. Results For both reviewers, the degree of visibility of the appendix using the combined T2WI and 3D T1W-GRE images was significantly higher than using T2WI alone (P < 0.01), and the confidence levels for acute appendicitis using combined T2WI and 3D T1W-GRE images were significantly different from those using T2WI alone (P < 0.01). In the 13 patients with a normal appendix, both reviewers showed improved confidence levels for appendicitis using combined T2WI and 3D T1W-GRE images than T2WI alone. Conclusion Adding 3D T1W-GRE images to T2WI is helpful for identification of the appendix, as compared to T2WI alone in pregnant women without ingestion of oral contrast material. This may improve diagnostic confidence for acute appendicitis in pregnant

  2. Analysis of artefacts and detail resolution of lung MRI with breath-hold T1-weighted gradient-echo and T2-weighted fast spin-echo sequences with respiratory triggering

    International Nuclear Information System (INIS)

    Biederer, J.; Reuter, M.; Both, M.; Grimm, J.; Heller, M.; Muhle, C.; Graessner, J.

    2002-01-01

    The aim of this study was to evaluate feasibility and limitations of two MR sequences for imaging of the lung using a semi-quantitative rating scale. Ten healthy volunteers were assessed with a breath-hold T1-weighted gradient-recalled-echo (TR/TE=129/2.2 ms, matrix 173 x 256) and a T2-weighted turbo spin-echo (TSE) sequence with respiratory triggering (TR/TE=3000-5000/120 ms, matrix 270 x 512) in axial 6-mm slices. The T1-weighted GRE protocol included a pre-saturation pulse over the mediastinal structures. Artefacts and resolution of vessel/airway structures in each lung segment were evaluated by two observers (10 volunteers, 180 segments). Cardiac and vessel pulsation artefacts predominated on T1-weighted GRE, respiration artefacts on T2-weighted TSE (lingula and middle lobe). Pre-saturation of the mediastinum reduced pulsation artefacts on T1-weighted GRE. T1-weighted GRE images were improved by bright flow signal of vessels, whereas image quality of T2-weighted TSE was reduced by black-blood effects in central parts of the lung. Delineation of lung periphery and the mediastinum was superior with T2-weighted TSE. Segmental/sub-segmental vessels (up to fourth/fifth order) and bronchi (up to third order) were identified. All 180 lung segments were imaged in diagnostic quality with at least one of the two sequences (T1-weighted GRE not diagnostic in 9 of 180, T2-weighted TSE in 4 of 180). Both sequences were found to be complementary: superior identification of gross lung anatomy with T1-weighted GRE and higher detail resolution in the periphery and the mediastinum with T2-weighted TSE. (orig.)

  3. Breast MRI at 7 Tesla with a bilateral coil and T1-weighted acquisition with robust fat suppression: image evaluation and comparison with 3 Tesla

    International Nuclear Information System (INIS)

    Brown, Ryan; Storey, Pippa; McGorty, KellyAnne; Klautau Leite, Ana Paula; Babb, James; Sodickson, Daniel K.; Wiggins, Graham C.; Moy, Linda; Geppert, Christian

    2013-01-01

    To evaluate the image quality of T1-weighted fat-suppressed breast MRI at 7 T and to compare 7-T and 3-T images. Seventeen subjects were imaged using a 7-T bilateral transmit-receive coil and 3D gradient echo sequence with adiabatic inversion-based fat suppression (FS). Images were graded on a five-point scale and quantitatively assessed through signal-to-noise ratio (SNR), fibroglandular/fat contrast and signal uniformity measurements. Image scores at 7 and 3 T were similar on standard-resolution images (1.1 x 1.1 x 1.1-1.6 mm 3 ), indicating that high-quality breast imaging with clinical parameters can be performed at 7 T. The 7-T SNR advantage was underscored on 0.6-mm isotropic images, where image quality was significantly greater than at 3 T (4.2 versus 3.1, P ≤ 0.0001). Fibroglandular/fat contrast was more than two times higher at 7 T than at 3 T, owing to effective adiabatic inversion-based FS and the inherent 7-T signal advantage. Signal uniformity was comparable at 7 and 3 T (P < 0.05). Similar 7-T image quality was observed in all subjects, indicating robustness against anatomical variation. The 7-T bilateral transmit-receive coil and adiabatic inversion-based FS technique produce image quality that is as good as or better than at 3 T. (orig.)

  4. Breast MRI at 7 Tesla with a bilateral coil and T1-weighted acquisition with robust fat suppression: image evaluation and comparison with 3 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Ryan; Storey, Pippa; McGorty, KellyAnne; Klautau Leite, Ana Paula; Babb, James; Sodickson, Daniel K.; Wiggins, Graham C.; Moy, Linda [New York University Langone Medical Center, Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York, NY (United States); Geppert, Christian [Siemens Medical Solutions USA Inc., New York, NY (United States)

    2013-11-15

    To evaluate the image quality of T1-weighted fat-suppressed breast MRI at 7 T and to compare 7-T and 3-T images. Seventeen subjects were imaged using a 7-T bilateral transmit-receive coil and 3D gradient echo sequence with adiabatic inversion-based fat suppression (FS). Images were graded on a five-point scale and quantitatively assessed through signal-to-noise ratio (SNR), fibroglandular/fat contrast and signal uniformity measurements. Image scores at 7 and 3 T were similar on standard-resolution images (1.1 x 1.1 x 1.1-1.6 mm{sup 3}), indicating that high-quality breast imaging with clinical parameters can be performed at 7 T. The 7-T SNR advantage was underscored on 0.6-mm isotropic images, where image quality was significantly greater than at 3 T (4.2 versus 3.1, P {<=} 0.0001). Fibroglandular/fat contrast was more than two times higher at 7 T than at 3 T, owing to effective adiabatic inversion-based FS and the inherent 7-T signal advantage. Signal uniformity was comparable at 7 and 3 T (P < 0.05). Similar 7-T image quality was observed in all subjects, indicating robustness against anatomical variation. The 7-T bilateral transmit-receive coil and adiabatic inversion-based FS technique produce image quality that is as good as or better than at 3 T. (orig.)

  5. Tuning the non-covalent confinement of Gd(III) complexes in silica nanoparticles for high T1-weighted MR imaging capability.

    Science.gov (United States)

    Fedorenko, Svetlana V; Grechkina, Svetlana L; Mustafina, Asiya R; Kholin, Kirill V; Stepanov, Alexey S; Nizameev, Irek R; Ismaev, Ildus E; Kadirov, Marsil K; Zairov, Rustem R; Fattakhova, Alfia N; Amirov, Rustem R; Soloveva, Svetlana E

    2017-01-01

    The present work introduces deliberate synthesis of Gd(III)-doped silica nanoparticles with high relaxivity at magnetic field strengths below 1.5T. Modified microemulsion water-in-oil procedure was used in order to achieve superficial localization of Gd(III) complexes within 40-55nm sized silica spheres. The relaxivities of the prepared nanoparticles were measured at 0.47, 1.41 and 1.5T with the use of both NMR analyzer and whole body NMR scanner. Longitudinal relaxivities of the obtained silica nanoparticles reveal significant dependence on the confinement mode, changing from 4.1 to 49.6mM -1 s -1 at 0.47T when the localization of Gd(III) complexes changes from core to superficial zones of the silica spheres. The results highlight predominant contribution of the complexes located close to silica/water interface to the relaxivity of the nanoparticles. Low effect of blood proteins on the relaxivity in the aqueous colloids of the nanoparticles was exemplified by serum bovine albumin. T 1 - weighted MRI data indicate that the nanoparticles provide strong positive contrast at 1.5T, which along with low cytotoxicity effect make a good basis for their application as contrast agents. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Visual discrimination among patients with depression and schizophrenia and healthy individuals using semiquantitative color-coded fast spin-echo T1-weighted magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Makoto; Kudo, Kohsuke; Narumi, Shinsuke [Iwate Medical University, Advanced Medical Research Center, Morioka (Japan); Shibata, Eri; Ohtsuka, Kotaro; Endoh, Jin; Sakai, Akio [Iwate Medical University, Department of Neuropsychiatry, Morioka (Japan)

    2010-02-15

    Fast spin-echo (FSE) T1-weighted (T1W) magnetic resonance imaging (MRI) at 3T, which is sensitive to neuromelanin-related contrast, can quantitatively detect signal alterations in the locus ceruleus (LC) and the substantia nigra pars compacta (SNc) of depressive and schizophrenic patients; however, its qualitative diagnostic performance remains unknown. We investigated whether visual interpretation of semiquantitative color maps can be used for discriminating between depressive and schizophrenic patients and healthy individuals. We retrospectively examined 23 patients with major depression, 23 patients with schizophrenia, and 23 age-matched healthy controls by using a FSE-T1W MRI technique. Semiquantitative color maps of sections through the LC and SNc were visually interpreted by nine raters using a continuous confidence rating scale for receiver operating characteristic (ROC) analysis. The area under the ROC curve (Az), which reflects the performance in differentiating between depressive patients and controls, was 0.88, and the sensitivity and specificity at the maximum likelihood were 76% and 83%, respectively. In contrast, the Az value, sensitivity, and specificity values between schizophrenics and controls and between depressives and schizophrenics were 0.66 and 0.69, 42% and 48%, and 82% and 84%, respectively. Semiquantitative, color-coded FSE-T1W MRI at 3T can be used for visually differentiating depressive patients from healthy individuals with a substantially high likelihood, but this technique cannot be applied to distinguish schizophrenic patients from the other two groups. (orig.)

  7. Association between duration of coronary occlusion and high-intensity signal on T1-weighted magnetic resonance imaging among patients with angiographic total occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Kenji; Ehara, Shoichi; Hasegawa, Takao; Sakaguchi, Mikumo; Shimada, Kenei [Osaka City University Graduate School of Medicine, Department of Cardiovascular Medicine, Abeno-ku, Osaka (Japan)

    2017-09-15

    To evaluate the association between duration of the coronary occlusion and high-intensity signal (HIS) on noncontrast T1-weighted imaging using a 1.5-T magnetic resonance imager among patients with angiographic coronary total occlusion. The signal intensity of the coronary target area divided by the signal intensity of the left ventricular muscle near the target area at each site (TMR) was measured. Areas with a TMR >1.0 were defined as HIS. Thirty five lesions from 33 patients were divided into the following three groups: subacute occlusion (up to 3 months; n = 7), short-duration chronic total occlusion (SD-CTO: 3-6 months; n = 9) and long-duration CTO (LD-CTO: ≥6 months; n = 19). All subacute occlusion lesions showed a HIS within the occlusion site. Among patients with CTO, the frequency of a HIS within the occlusion site was significantly higher in SD-CTO than in LD-CTO lesions (p = 0.013). In multivariate analyses, only an occlusion duration of less than 6 months was an independent factor associated with the presence of HIS (odds ratio 7.6, 95% CI 1.1-54.5; p = 0.044). The presence of a HIS in the occlusion site was associated more with SD-CTO than with LD-CTO among patients with CTO. (orig.)

  8. Visual discrimination among patients with depression and schizophrenia and healthy individuals using semiquantitative color-coded fast spin-echo T1-weighted magnetic resonance imaging

    International Nuclear Information System (INIS)

    Sasaki, Makoto; Kudo, Kohsuke; Narumi, Shinsuke; Shibata, Eri; Ohtsuka, Kotaro; Endoh, Jin; Sakai, Akio

    2010-01-01

    Fast spin-echo (FSE) T1-weighted (T1W) magnetic resonance imaging (MRI) at 3T, which is sensitive to neuromelanin-related contrast, can quantitatively detect signal alterations in the locus ceruleus (LC) and the substantia nigra pars compacta (SNc) of depressive and schizophrenic patients; however, its qualitative diagnostic performance remains unknown. We investigated whether visual interpretation of semiquantitative color maps can be used for discriminating between depressive and schizophrenic patients and healthy individuals. We retrospectively examined 23 patients with major depression, 23 patients with schizophrenia, and 23 age-matched healthy controls by using a FSE-T1W MRI technique. Semiquantitative color maps of sections through the LC and SNc were visually interpreted by nine raters using a continuous confidence rating scale for receiver operating characteristic (ROC) analysis. The area under the ROC curve (Az), which reflects the performance in differentiating between depressive patients and controls, was 0.88, and the sensitivity and specificity at the maximum likelihood were 76% and 83%, respectively. In contrast, the Az value, sensitivity, and specificity values between schizophrenics and controls and between depressives and schizophrenics were 0.66 and 0.69, 42% and 48%, and 82% and 84%, respectively. Semiquantitative, color-coded FSE-T1W MRI at 3T can be used for visually differentiating depressive patients from healthy individuals with a substantially high likelihood, but this technique cannot be applied to distinguish schizophrenic patients from the other two groups. (orig.)

  9. High Signal Intensity in the Dentate Nucleus and Globus Pallidus on Unenhanced T1-Weighted MR Images: Comparison between Gadobutrol and Linear Gadolinium-Based Contrast Agents.

    Science.gov (United States)

    Moser, F G; Watterson, C T; Weiss, S; Austin, M; Mirocha, J; Prasad, R; Wang, J

    2018-02-01

    In view of the recent observations that gadolinium deposits in brain tissue after intravenous injection, our aim of this study was to compare signal changes in the globus pallidus and dentate nucleus on unenhanced T1-weighted MR images in patients receiving serial doses of gadobutrol, a macrocyclic gadolinium-based contrast agent, with those seen in patients receiving linear gadolinium-based contrast agents. This was a retrospective analysis of on-site patients with brain tumors. Fifty-nine patients received only gadobutrol, and 60 patients received only linear gadolinium-based contrast agents. Linear gadolinium-based contrast agents included gadoversetamide, gadobenate dimeglumine, and gadodiamide. T1 signal intensity in the globus pallidus, dentate nucleus, and pons was measured on the precontrast portions of patients' first and seventh brain MRIs. Ratios of signal intensity comparing the globus pallidus with the pons (globus pallidus/pons) and dentate nucleus with the pons (dentate nucleus/pons) were calculated. Changes in the above signal intensity ratios were compared within the gadobutrol and linear agent groups, as well as between groups. The dentate nucleus/pons signal ratio increased in the linear gadolinium-based contrast agent group ( t = 4.215, P linear gadolinium-based contrast agent group ( t = 2.931, P linear gadolinium-based contrast agents. © 2018 by American Journal of Neuroradiology.

  10. Hyperintensity of basal ganglia on T1-weighted images in patients with liver cirrhosis. Correlation with hepatic encephalopathy and liver function

    International Nuclear Information System (INIS)

    Maeda, Hiroko; Kita, Keisuke; Mizobata, Toshiharu; Kimura, Masashi; Sonomura, Tetsuo; Kishi, Kazushi; Tanaka, Kayo; Sato, Morio; Yamada, Ryosaku

    1995-01-01

    Brain MR imaging was performed in 38 liver cirrhosis (LC) patients and 9 normal volunteers. On T 1 -weighted images, the signal intensity of globus pallidus (S1) and frontal white matter (S2) was measured and S1/S2 ratio was explored. We examined the relationship between S1/S2 ratio and liver function parameters. High signal intensity in bilateral globus pallidus was noted on T 1 W1 in 28 of 38 LC patients. The S1/S2 ratio of 1.186±0.097 in the 38 LC patients was significantly higher than 0.987±0.062 in the 9 normal volunteers (p 2 -weighted images showed no abnormal intensity. Compared with the LC patients with hepatic encephalopathy (HE) (n=7) and without HE (n=31), the former S1/S2 ratio (1.239±0.057) was significantly higher than the latter (1.174±0.097) (p 15 (r=0.501, p 1 -WI and the degree of liver dysfunction. (author)

  11. Registration of FA and T1-weighted MRI data of healthy human brain based on template matching and normalized cross-correlation.

    Science.gov (United States)

    Malinsky, Milos; Peter, Roman; Hodneland, Erlend; Lundervold, Astri J; Lundervold, Arvid; Jan, Jiri

    2013-08-01

    In this work, we propose a new approach for three-dimensional registration of MR fractional anisotropy images with T1-weighted anatomy images of human brain. From the clinical point of view, this accurate coregistration allows precise detection of nerve fibers that is essential in neuroscience. A template matching algorithm combined with normalized cross-correlation was used for this registration task. To show the suitability of the proposed method, it was compared with the normalized mutual information-based B-spline registration provided by the Elastix software library, considered a reference method. We also propose a general framework for the evaluation of robustness and reliability of both registration methods. Both registration methods were tested by four evaluation criteria on a dataset consisting of 74 healthy subjects. The template matching algorithm has shown more reliable results than the reference method in registration of the MR fractional anisotropy and T1 anatomy image data. Significant differences were observed in the regions splenium of corpus callosum and genu of corpus callosum, considered very important areas of brain connectivity. We demonstrate that, in this registration task, the currently used mutual information-based parametric registration can be replaced by more accurate local template matching utilizing the normalized cross-correlation similarity measure.

  12. Association between duration of coronary occlusion and high-intensity signal on T1-weighted magnetic resonance imaging among patients with angiographic total occlusion

    International Nuclear Information System (INIS)

    Matsumoto, Kenji; Ehara, Shoichi; Hasegawa, Takao; Sakaguchi, Mikumo; Shimada, Kenei

    2017-01-01

    To evaluate the association between duration of the coronary occlusion and high-intensity signal (HIS) on noncontrast T1-weighted imaging using a 1.5-T magnetic resonance imager among patients with angiographic coronary total occlusion. The signal intensity of the coronary target area divided by the signal intensity of the left ventricular muscle near the target area at each site (TMR) was measured. Areas with a TMR >1.0 were defined as HIS. Thirty five lesions from 33 patients were divided into the following three groups: subacute occlusion (up to 3 months; n = 7), short-duration chronic total occlusion (SD-CTO: 3-6 months; n = 9) and long-duration CTO (LD-CTO: ≥6 months; n = 19). All subacute occlusion lesions showed a HIS within the occlusion site. Among patients with CTO, the frequency of a HIS within the occlusion site was significantly higher in SD-CTO than in LD-CTO lesions (p = 0.013). In multivariate analyses, only an occlusion duration of less than 6 months was an independent factor associated with the presence of HIS (odds ratio 7.6, 95% CI 1.1-54.5; p = 0.044). The presence of a HIS in the occlusion site was associated more with SD-CTO than with LD-CTO among patients with CTO. (orig.)

  13. T1 weighted brain images at 7 Tesla unbiased for Proton Density, T2* contrast and RF coil receive B1 sensitivity with simultaneous vessel visualization.

    Science.gov (United States)

    Van de Moortele, Pierre-François; Auerbach, Edwards J; Olman, Cheryl; Yacoub, Essa; Uğurbil, Kâmil; Moeller, Steen

    2009-06-01

    At high magnetic field, MR images exhibit large, undesirable signal intensity variations commonly referred to as "intensity field bias". Such inhomogeneities mostly originate from heterogeneous RF coil B(1) profiles and, with no appropriate correction, are further pronounced when utilizing rooted sum of square reconstruction with receive coil arrays. These artifacts can significantly alter whole brain high resolution T(1)-weighted (T(1)w) images that are extensively utilized for clinical diagnosis, for gray/white matter segmentation as well as for coregistration with functional time series. In T(1) weighted 3D-MPRAGE sequences, it is possible to preserve a bulk amount of T(1) contrast through space by using adiabatic inversion RF pulses that are insensitive to transmit B(1) variations above a minimum threshold. However, large intensity variations persist in the images, which are significantly more difficult to address at very high field where RF coil B(1) profiles become more heterogeneous. Another characteristic of T(1)w MPRAGE sequences is their intrinsic sensitivity to Proton Density and T(2)(*) contrast, which cannot be removed with post-processing algorithms utilized to correct for receive coil sensitivity. In this paper, we demonstrate a simple technique capable of producing normalized, high resolution T(1)w 3D-MPRAGE images that are devoid of receive coil sensitivity, Proton Density and T(2)(*) contrast. These images, which are suitable for routinely obtaining whole brain tissue segmentation at 7 T, provide higher T(1) contrast specificity than standard MPRAGE acquisitions. Our results show that removing the Proton Density component can help in identifying small brain structures and that T(2)(*) induced artifacts can be removed from the images. The resulting unbiased T(1)w images can also be used to generate Maximum Intensity Projection angiograms, without additional data acquisition, that are inherently registered with T(1)w structural images. In addition

  14. T1 weighted Brain Images at 7 Tesla Unbiased for Proton Density, T2* contrast and RF Coil Receive B1 Sensitivity with Simultaneous Vessel Visualization

    Science.gov (United States)

    Van de Moortele, Pierre-François; Auerbach, Edwards J.; Olman, Cheryl; Yacoub, Essa; Uğurbil, Kâmil; Moeller, Steen

    2009-01-01

    At high magnetic field, MR images exhibit large, undesirable signal intensity variations commonly referred to as “intensity field bias”. Such inhomogeneities mostly originate from heterogeneous RF coil B1 profiles and, with no appropriate correction, are further pronounced when utilizing rooted sum of square reconstruction with receive coil arrays. These artifacts can significantly alter whole brain high resolution T1-weighted (T1w) images that are extensively utilized for clinical diagnosis, for gray/white matter segmentation as well as for coregistration with functional time series. In T1 weighted 3D-MPRAGE sequences, it is possible to preserve a bulk amount of T1 contrast through space by using adiabatic inversion RF pulses that are insensitive to transmit B1 variations above a minimum threshold. However, large intensity variations persist in the images, which are significantly more difficult to address at very high field where RF coil B1 profiles become more heterogeneous. Another characteristic of T1w MPRAGE sequences is their intrinsic sensitivity to Proton Density and T2* contrast, which cannot be removed with post-processing algorithms utilized to correct for receive coil sensitivity. In this paper, we demonstrate a simple technique capable of producing normalized, high resolution T1w 3D-MPRAGE images that are devoid of receive coil sensitivity, Proton Density and T2* contrast. These images, which are suitable for routinely obtaining whole brain tissue segmentation at 7 Tesla, provide higher T1 contrast specificity than standard MPRAGE acquisitions. Our results show that removing the Proton Density component can help identifying small brain structures and that T2* induced artifacts can be removed from the images. The resulting unbiased T1w images can also be used to generate Maximum Intensity Projection angiograms, without additional data acquisition, that are inherently registered with T1w structural images. In addition, we introduce a simple technique

  15. Probabilistic atlas-based segmentation of combined T1-weighted and DUTE MRI for calculation of head attenuation maps in integrated PET/MRI scanners.

    Science.gov (United States)

    Poynton, Clare B; Chen, Kevin T; Chonde, Daniel B; Izquierdo-Garcia, David; Gollub, Randy L; Gerstner, Elizabeth R; Batchelor, Tracy T; Catana, Ciprian

    2014-01-01

    We present a new MRI-based attenuation correction (AC) approach for integrated PET/MRI systems that combines both segmentation- and atlas-based methods by incorporating dual-echo ultra-short echo-time (DUTE) and T1-weighted (T1w) MRI data and a probabilistic atlas. Segmented atlases were constructed from CT training data using a leave-one-out framework and combined with T1w, DUTE, and CT data to train a classifier that computes the probability of air/soft tissue/bone at each voxel. This classifier was applied to segment the MRI of the subject of interest and attenuation maps (μ-maps) were generated by assigning specific linear attenuation coefficients (LACs) to each tissue class. The μ-maps generated with this "Atlas-T1w-DUTE" approach were compared to those obtained from DUTE data using a previously proposed method. For validation of the segmentation results, segmented CT μ-maps were considered to the "silver standard"; the segmentation accuracy was assessed qualitatively and quantitatively through calculation of the Dice similarity coefficient (DSC). Relative change (RC) maps between the CT and MRI-based attenuation corrected PET volumes were also calculated for a global voxel-wise assessment of the reconstruction results. The μ-maps obtained using the Atlas-T1w-DUTE classifier agreed well with those derived from CT; the mean DSCs for the Atlas-T1w-DUTE-based μ-maps across all subjects were higher than those for DUTE-based μ-maps; the atlas-based μ-maps also showed a lower percentage of misclassified voxels across all subjects. RC maps from the atlas-based technique also demonstrated improvement in the PET data compared to the DUTE method, both globally as well as regionally.

  16. SU-E-J-224: Using UTE and T1 Weighted Spin Echo Pulse Sequences for MR-Only Treatment Planning; Phantom Study

    Energy Technology Data Exchange (ETDEWEB)

    Yu, H; Fatemi, A [Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Sahgal, A [University of Toronto, Toronto, ON (Canada)

    2015-06-15

    Purpose: Investigating a new approach in MRI based treatment planning using the combination of (Ultrashort Echo Time) UTE and T1 weighted spin echo pulse sequences to delineate air, bone and water (soft tissues) in generating pseudo CT images comparable with CT. Methods: A gel phantom containing chicken bones, ping pang balls filled with distilled water and air bubbles, was made. It scanned with MRI using UTE and 2D T1W SE pulse sequences with (in plane resolution= 0.53mm, slice thickness= 2 mm) and CT with (in plane resolution= 0.5 mm and slice thickness= 0.75mm) as a ground truth for geometrical accuracy. The UTE and T1W SE images were registered with CT using mutual information registration algorithm provided by Philips Pinnacle treatment planning system. The phantom boundaries were detected using Canny edge detection algorithm for CT, and MR images. The bone, air bubbles and water in ping pong balls were segmented from CT images using threshold 300HU, - 950HU and 0HU, respectively. These tissue inserts were automatically segmented from combined UTE and T1W SE images using edge detection and relative intensity histograms of the phantom. The obtained segmentations of air, bone and water inserts were evaluated with those obtained from CT. Results: Bone and air can be clearly differentiated in UTE images comparable to CT. Combining UTE and T1W SE images successfully segmented the air, bone and water. The maximum segmentation differences from combine MRI images (UTE and T1W SE) and CT are within 1.3 mm, 1.1mm for bone, air, respectively. The geometric distortion of UTE sequence is small less than 1 pixel (0.53 mm) of MR image resolution. Conclusion: Our approach indicates that MRI can be used solely for treatment planning and its quality is comparable with CT.

  17. Localization of Coronary High-Intensity Signals on T1-Weighted MR Imaging: Relation to Plaque Morphology and Clinical Severity of Angina Pectoris.

    Science.gov (United States)

    Matsumoto, Kenji; Ehara, Shoichi; Hasegawa, Takao; Sakaguchi, Mikumo; Otsuka, Kenichiro; Yoshikawa, Junichi; Shimada, Kenei

    2015-10-01

    This study sought to investigate the relationship between localization of high-intensity signals (HISs) on T1-weighted imaging (T1WI) with the noncontrast magnetic resonance technique and plaque morphology detected on optical coherence tomography, and the clinical severity of angina pectoris. Since the introduction of the T1WI noncontrast magnetic resonance technique for plaque imaging, some groups have reported that HISs in the coronary artery on T1WI are associated with a vulnerable morphology and future cardiac events. However, the association between the localization of HISs, such as coronary intrawall or intraluminal, and plaque morphology has not been investigated. One hundred lesions with either stable or unstable angina were included and divided into 3 groups according to the following criteria using T1WI. First, the plaques with the ratio between the signal intensities of coronary plaque and cardiac muscle ≤1.0 were classified as non-HISs (n = 39). Then, HISs with the ratio between the signal intensities of coronary plaque and cardiac muscle >1.0 were classified into 2 types by using cross-sectional T1WI. Those localized within the coronary wall when the lumen was identified were defined as intrawall HISs (n = 37), whereas those occupying the lumen when the lumen was not, or even if only partly, identified, were defined as intraluminal HISs (n = 24). Multivariate analysis revealed that intrawall HISs were associated with macrophage accumulation and the absence of calcification assessed by using optical coherence tomography. In contrast, thrombus and intimal vasculature were independent factors associated with intraluminal HISs. Furthermore, 50% of patients with intraluminal HISs experienced rest angina, such as Braunwald class II or III. This study shows that intrawall and intraluminal HISs on T1WI in patients with angina are related to the different types of vulnerable plaque morphology and the clinical severity. Copyright © 2015 American College of

  18. Comparison of spin-echo and gradient recalled echo T1 weighted MR images for quantitative voxel-based clinical brain research

    International Nuclear Information System (INIS)

    Barnden, L.R.; Crouch, B.

    2010-01-01

    Full text: New methods to normalise inter-subject global variations in T 1 -weighted MR (T I w) signal levels have permitted their use in voxel based population studies of brain dysfunction. Here we address the question of whether a spin-echo (SE) or a gradient recalled echo (GRE) T I w sequence is better for this purpose. GRE images are commonly referred to as 3D MRL SE has superior signal/noise properties to GRE but is slower to acquire so that typical slice thicknesses are 3-5 mm compared to 1-2 mm for GRE. GRE has better grey/white matter contrast which should permit better spatial normalization. However, unlike SE, GRE is affected by subject-specific magnetic field inhomogeneities that distort the images. We acquired T I brain images for 25 chronic fatigue syndrome (CFS) patients and 25 normal controls (NC) with TRITE/flip-angle of 600 ms/l5 ms/90 deg for SE and 5.76 ms/1.9 ms/9 deg for GRE. For GRE, the magnetic field inhomogeneity related signal level distortions could be corrected, but not the spatial distortions. After spatial normalization we subjected them to voxel-based statistical analysis with adjustment for global signal level using the SPM5 package. Initially, the same spatial normalization deformations were applied to both SE and GRE after coregistering them. Although the SPM regressions of SE and GRE yielded similar spatial distributions of significance, the SE regressions were consistently statistically stronger. For example, in one strong regression, the corrected cluster P value was twenty times stronger (I.Oe-5 versus I.Oe-3). T I w SE have proved better than T I GRE images in quantitative analysis in a clinical research study. (author)

  19. Repeatability of Brain Volume Measurements Made with the Atlas-based Method from T1-weighted Images Acquired Using a 0.4 Tesla Low Field MR Scanner.

    Science.gov (United States)

    Goto, Masami; Suzuki, Makoto; Mizukami, Shinya; Abe, Osamu; Aoki, Shigeki; Miyati, Tosiaki; Fukuda, Michinari; Gomi, Tsutomu; Takeda, Tohoru

    2016-10-11

    An understanding of the repeatability of measured results is important for both the atlas-based and voxel-based morphometry (VBM) methods of magnetic resonance (MR) brain volumetry. However, many recent studies that have investigated the repeatability of brain volume measurements have been performed using static magnetic fields of 1-4 tesla, and no study has used a low-strength static magnetic field. The aim of this study was to investigate the repeatability of measured volumes using the atlas-based method and a low-strength static magnetic field (0.4 tesla). Ten healthy volunteers participated in this study. Using a 0.4 tesla magnetic resonance imaging (MRI) scanner and a quadrature head coil, three-dimensional T 1 -weighted images (3D-T 1 WIs) were obtained from each subject, twice on the same day. VBM8 software was used to construct segmented normalized images [gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) images]. The regions-of-interest (ROIs) of GM, WM, CSF, hippocampus (HC), orbital gyrus (OG), and cerebellum posterior lobe (CPL) were generated using WFU PickAtlas. The percentage change was defined as[100 × (measured volume with first segmented image - mean volume in each subject)/(mean volume in each subject)]The average percentage change was calculated as the percentage change in the 6 ROIs of the 10 subjects. The mean of the average percentage changes for each ROI was as follows: GM, 0.556%; WM, 0.324%; CSF, 0.573%; HC, 0.645%; OG, 1.74%; and CPL, 0.471%. The average percentage change was higher for the orbital gyrus than for the other ROIs. We consider that repeatability of the atlas-based method is similar between 0.4 and 1.5 tesla MR scanners. To our knowledge, this is the first report to show that the level of repeatability with a 0.4 tesla MR scanner is adequate for the estimation of brain volume change by the atlas-based method.

  20. Signal intensity at unenhanced T1-weighted magnetic resonance in the globus pallidus and dentate nucleus after serial administrations of a macrocyclic gadolinium-based contrast agent in children

    Energy Technology Data Exchange (ETDEWEB)

    Rossi Espagnet, Maria Camilla; Bernardi, Bruno; Figa-Talamanca, Lorenzo [Ospedale Pediatrico Bambino Gesu, IRCCS, Neuroradiology Unit, Imaging Department, Rome (Italy); Pasquini, Luca [Ospedale Pediatrico Bambino Gesu, IRCCS, Neuroradiology Unit, Imaging Department, Rome (Italy); University Sapienza, Neuroradiology Unit, Azienda Ospedaliera Sant' Andrea, Rome (Italy); Toma, Paolo [Ospedale Pediatrico Bambino Gesu, IRCCS, Department of Imaging, Rome (Italy); Napolitano, Antonio [Ospedale Pediatrico Bambino Gesu, IRCCS, Enterprise Risk Management, Medical Physics Department, Rome (Italy)

    2017-09-15

    Few studies have been conducted on the relations between T1-weighted signal intensity changes in the pediatric brain following gadolinium-based contrast agent (GBCA) exposure. The purpose of this study is to investigate the effect of multiple administrations of a macrocyclic GBCA on signal intensity in the globus pallidus and dentate nucleus of the pediatric brain on unenhanced T1-weighted MR images. This retrospective study included 50 patients, mean age: 8 years (standard deviation: 4.8 years), with normal renal function exposed to ≥6 administrations of the same macrocyclic GBCA (gadoterate meglumine) and a control group of 59 age-matched GBCA-naive patients. The globus pallidus-to-thalamus signal intensity ratio and dentate nucleus-to-pons signal intensity ratio were calculated from unenhanced T1-weighted images for both patients and controls. A mixed linear model was used to evaluate the effects on signal intensity ratios of the number of GBCA administrations, the time interval between administrations, age, radiotherapy and chemotherapy. T-test analyses were performed to compare signal intensity ratio differences between successive administrations and baseline MR signal intensity ratios in patients compared to controls. P-values were considered significant if <0.05. A significant effect of the number of GBCA administrations on relative signal intensities globus pallidus-to-thalamus (F[8]=3.09; P=0.002) and dentate nucleus-to-pons (F[8]=2.36; P=0.021) was found. The relative signal intensities were higher at last MR examination than at baseline (P<0.001). Quantitative analysis evaluation of globus pallidus:thalamus and dentate nucleus:pons of the pediatric brain demonstrated an increase after serial administrations of macrocyclic GBCA. Further research is necessary to fully understand GBCA pharmacokinetic in children. (orig.)

  1. Breast MRI at very short TE (minTE). Image analysis of minTE sequences on non-fat-saturated, subtracted T1-weighted images

    International Nuclear Information System (INIS)

    Wenkel, Evelyn; Janka, Rolf; Kaemmerer, Nadine; Uder, Michael; Hammon, Matthias; Brand, Michael; Hartmann, Arndt

    2017-01-01

    The aim was to evaluate a minimum echo time (minTE) protocol for breast magnetic resonance imaging (MRI) in patients with breast lesions compared to a standard TE (nTE) time protocol. Breasts of 144 women were examined with a 1.5 Tesla MRI scanner. Additionally to the standard gradient-echo sequence with nTE (4.8 ms), a variant with minimum TE (1.2 ms) was used in an interleaved fashion which leads to a better temporal resolution and should reduce the scan time by approximately 50%. Lesion sizes were measured and the signal-to-noise ratio (SNR) as well as the contrast-to-noise ratio (CNR) were calculated. Subjective confidence was evaluated using a 3-point scale before looking at the nTE sequences (1 = very sure that I can identify a lesion and classify it, 2 = quite sure that I can identify a lesion and classify it, 3 = definitely want to see nTE for final assessment) and the subjective image quality of all examinations was evaluated using a four-grade scale (1 = sharp, 2 = slight blur, 3 = moderate blur and 4 = severe blur/not evaluable) for lesion and skin sharpness. Lesion morphology and contrast enhancement were also evaluated. With minTE sequences, no lesion was rated with ''definitely want to see nTE sequences for final assessment''. The difference of the longitudinal and transverse diameter did not differ significantly (p>0.05). With minTE, lesions and skin were rated to be significantly more blurry (p<0.01 for lesions and p<0.05 for skin). There was no difference between both sequences with respect to SNR, CNR, lesion morphology, contrast enhancement and detection of multifocal disease. Dynamic breast MRI with a minTE protocol is feasible without a major loss of information (SNR, CNR, lesion morphology, contrast enhancement and lesion sizes) and the temporal resolution can be increased by a factor of 2 using minTE sequences.

  2. Breast MRI at very short TE (minTE). Image analysis of minTE sequences on non-fat-saturated, subtracted T1-weighted images

    Energy Technology Data Exchange (ETDEWEB)

    Wenkel, Evelyn; Janka, Rolf; Kaemmerer, Nadine; Uder, Michael; Hammon, Matthias; Brand, Michael [Univ. Hospital Erlangen (Germany). Dept. of Radiology; Geppert, Christian [Siemens Healthcare GmbH, Erlangen (Germany); Hartmann, Arndt [Univ. Hospital Erlangen (Germany). Dept. of Pathology

    2017-02-15

    The aim was to evaluate a minimum echo time (minTE) protocol for breast magnetic resonance imaging (MRI) in patients with breast lesions compared to a standard TE (nTE) time protocol. Breasts of 144 women were examined with a 1.5 Tesla MRI scanner. Additionally to the standard gradient-echo sequence with nTE (4.8 ms), a variant with minimum TE (1.2 ms) was used in an interleaved fashion which leads to a better temporal resolution and should reduce the scan time by approximately 50%. Lesion sizes were measured and the signal-to-noise ratio (SNR) as well as the contrast-to-noise ratio (CNR) were calculated. Subjective confidence was evaluated using a 3-point scale before looking at the nTE sequences (1 = very sure that I can identify a lesion and classify it, 2 = quite sure that I can identify a lesion and classify it, 3 = definitely want to see nTE for final assessment) and the subjective image quality of all examinations was evaluated using a four-grade scale (1 = sharp, 2 = slight blur, 3 = moderate blur and 4 = severe blur/not evaluable) for lesion and skin sharpness. Lesion morphology and contrast enhancement were also evaluated. With minTE sequences, no lesion was rated with ''definitely want to see nTE sequences for final assessment''. The difference of the longitudinal and transverse diameter did not differ significantly (p>0.05). With minTE, lesions and skin were rated to be significantly more blurry (p<0.01 for lesions and p<0.05 for skin). There was no difference between both sequences with respect to SNR, CNR, lesion morphology, contrast enhancement and detection of multifocal disease. Dynamic breast MRI with a minTE protocol is feasible without a major loss of information (SNR, CNR, lesion morphology, contrast enhancement and lesion sizes) and the temporal resolution can be increased by a factor of 2 using minTE sequences.

  3. Signal intensity change on unenhanced T1-weighted images in dentate nucleus following gadobenate dimeglumine in patients with and without previous multiple administrations of gadodiamide

    Energy Technology Data Exchange (ETDEWEB)

    Ramalho, Joana [University of North Carolina Hospital, Chapel Hill, NC (United States); Centro Hospitalar de Lisboa Central, Lisbon (Portugal); Semelka, Richard C.; Castillo, Mauricio [University of North Carolina Hospital, Chapel Hill, NC (United States); AlObaidy, Mamdoh [University of North Carolina Hospital, Chapel Hill, NC (United States); King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia); Ramalho, Miguel [University of North Carolina Hospital, Chapel Hill, NC (United States); Hospital Garcia de Orta, Almada (Portugal); Nunes, Renato H. [University of North Carolina Hospital, Chapel Hill, NC (United States); Santa Casa de Misericordia de Sao Paulo, Sao Paulo (Brazil)

    2016-11-15

    To evaluate the impact of previous administration of gadodiamide and neural tissue gadolinium deposition in patients who received gadobenate dimeglumine. Our population included 62 patients who underwent at least three administrations of gadobenate dimeglumine, plus an additional contrast-enhanced last MRI for reference, divided into two groups: group 1, patients who in addition to gadobenate dimeglumine administrations had prior exposure to multiple doses of gadodiamide; group 2, patients without previous exposure to other gadolinium-based contrast agent (GBCAs). Quantitative analysis was performed on the first and last gadobenate dimeglumine MRIs in both groups. Dentate nucleus-to-middle cerebellar peduncle signal intensity ratios (DN/MCP) and relative change (RC) in signal over time were calculated and compared between groups using generalized additive model. Group 1 showed significant increase in baseline and follow-up DN/MCP compared to group 2 (p < 0.0001). The RC DN/MCP showed a non-statistically significant trend towards an increase in patients who underwent previous gadodiamide (p = 0.0735). There is increased T1 signal change over time in patients who underwent gadobenate dimeglumine and had received prior gadodiamide compared to those without known exposure to previous gadodiamide. A potentiating effect from prior gadodiamide on subsequent administered gadobenate dimeglumine may occur. (orig.)

  4. Evaluation of the Subscapularis Tendon Tears on 3T Magnetic Resonance Arthrography: Comparison of Diagnostic Performance of T1-Weighted Spectral Presaturation with Inversion-Recovery and T2-Weighted Turbo Spin-Echo Sequences.

    Science.gov (United States)

    Lee, Hoseok; Ahn, Joong Mo; Kang, Yusuhn; Oh, Joo Han; Lee, Eugene; Lee, Joon Woo; Kang, Heung Sik

    2018-01-01

    To compare the T1-weighted spectral presaturation with inversion-recovery sequences (T1 SPIR) with T2-weighted turbo spin-echo sequences (T2 TSE) on 3T magnetic resonance arthrography (MRA) in the evaluation of the subscapularis (SSC) tendon tear with arthroscopic findings as the reference standard. This retrospective study included 120 consecutive patients who had undergone MRA within 3 months between April and December 2015. Two musculoskeletal radiologists blinded to the arthroscopic results evaluated T1 SPIR and T2 TSE images in separate sessions for the integrity of the SSC tendon, examining normal/articular-surface partial-thickness tear (PTTa)/full-thickness tear (FTT). Diagnostic performance of T1 SPIR and T2 TSE was calculated with arthroscopic results as the reference standard, and sensitivity, specificity, and accuracy were compared using the McNemar test. Interobserver agreement was measured with kappa (κ) statistics. There were 74 SSC tendon tears (36 PTTa and 38 FTT) confirmed by arthroscopy. Significant differences were found in the sensitivity and accuracy between T1 SPIR and T2 TSE using the McNemar test, with respective rates of 95.9-94.6% vs. 71.6-75.7% and 90.8-91.7% vs. 79.2-83.3% for detecting tear; 55.3% vs. 31.6-34.2% and 85.8% vs. 78.3-79.2%, respectively, for FTT; and 91.7-97.2% vs. 58.3-61.1% and 89% vs. 78-79.3%, respectively, for PTTa. Interobserver agreement for T1 SPIR was almost perfect for T1 SPIR (κ = 0.839) and substantial for T2 TSE (κ = 0.769). T1-weighted spectral presaturation with inversion-recovery sequences is more sensitive and accurate compared to T2 TSE in detecting SSC tendon tear on 3T MRA.

  5. Comparison of T1-weighted 2D TSE, 3D SPGR, and two-point 3D Dixon MRI for automated segmentation of visceral adipose tissue at 3 Tesla.

    Science.gov (United States)

    Fallah, Faezeh; Machann, Jürgen; Martirosian, Petros; Bamberg, Fabian; Schick, Fritz; Yang, Bin

    2017-04-01

    To evaluate and compare conventional T1-weighted 2D turbo spin echo (TSE), T1-weighted 3D volumetric interpolated breath-hold examination (VIBE), and two-point 3D Dixon-VIBE sequences for automatic segmentation of visceral adipose tissue (VAT) volume at 3 Tesla by measuring and compensating for errors arising from intensity nonuniformity (INU) and partial volume effects (PVE). The body trunks of 28 volunteers with body mass index values ranging from 18 to 41.2 kg/m 2 (30.02 ± 6.63 kg/m 2 ) were scanned at 3 Tesla using three imaging techniques. Automatic methods were applied to reduce INU and PVE and to segment VAT. The automatically segmented VAT volumes obtained from all acquisitions were then statistically and objectively evaluated against the manually segmented (reference) VAT volumes. Comparing the reference volumes with the VAT volumes automatically segmented over the uncorrected images showed that INU led to an average relative volume difference of -59.22 ± 11.59, 2.21 ± 47.04, and -43.05 ± 5.01 % for the TSE, VIBE, and Dixon images, respectively, while PVE led to average differences of -34.85 ± 19.85, -15.13 ± 11.04, and -33.79 ± 20.38 %. After signal correction, differences of -2.72 ± 6.60, 34.02 ± 36.99, and -2.23 ± 7.58 % were obtained between the reference and the automatically segmented volumes. A paired-sample two-tailed t test revealed no significant difference between the reference and automatically segmented VAT volumes of the corrected TSE (p = 0.614) and Dixon (p = 0.969) images, but showed a significant VAT overestimation using the corrected VIBE images. Under similar imaging conditions and spatial resolution, automatically segmented VAT volumes obtained from the corrected TSE and Dixon images agreed with each other and with the reference volumes. These results demonstrate the efficacy of the signal correction methods and the similar accuracy of TSE and Dixon imaging for automatic volumetry of VAT at 3 Tesla.

  6. Ultra low-dose of gadobenate dimeglumine for late gadolinium enhancement (LGE) imaging in acute myocardial infarction: A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Galea, Nicola, E-mail: nicola.galea@uniroma1.it [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Francone, Marco, E-mail: marco.francone@uniroma1.it [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Zaccagna, Fulvio, E-mail: f.zaccagna@gmail.com [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Ciolina, Federica, E-mail: federica.ciolina@gmail.com [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Cannata, David, E-mail: davidrum@yahoo.it [Department of Radiological Sciences, Pathology and Oncology, Policlinico Umberto I, “Sapienza” University of Rome, Viale Regina Elena 315, 00161 Rome (Italy); Algeri, Emanuela, E-mail: emanuela_algeri@yahoo.com [Service de Radiologie et Imagerie Cardiovasculaire, Hôpital Cardiologique, Centre Hospitalier Régional et Universitaire de Lille, Avenue Oscar Lambret, 59037 Lille Cedex (France); Agati, Luciano, E-mail: luciano.agati@uniroma1.it [Department of Cardiovascular, Respiratory, Nephrologic, Anestesiologic and Geriatric Sciences, Sapienza University of Rome, Policlinico Umberto I, Via del Policlinico 165, 00161 Rome, Rome (Italy); and others

    2014-12-15

    Highlights: • We compared two gadolinium dose for late enhancement imaging in acute infarction. • We evaluated image quality both qualitatively and quantitatively. • Low dose regimen is feasible and provides better image quality at 5–10 min delay. • Standard dose warrants better image quality and should be routinely preferred. - Abstract: Purpose: To assess the feasibility of using an ultra-low dose (0.05 mmol/kg of body weight [BW]) of high relaxivity contrast agent for late gadolinium enhancement (LGE) imaging in patients with acute myocardial infarction (AMI). Materials and methods: 17 consecutive patients (mean age, 60.1 ± 10.3 years) with ST-segment elevation AMI underwent two randomized cardiac magnetic resonance studies (exam intervals between 24 and 48 h) on a 1.5 T unit during the first week after the event using gadobenate dimeglumine (Gd-BOPTA) at the dose of 0.1 mmol/kg BW (standard dose or SD group) and 0.05 mmol/kg BW (half dose or HD group). Image quality was qualitatively assessed. Quantitative analysis of LGE were performed by measuring signal intensity (SI), signal-to-noise ratio (SNR) in the infarcted myocardium (IM), non-infarcted myocardium (N-IM) and left ventricular cavity (LVC) in images acquired at 1, 3, 5, 10, 15 and 20 min after administration of Gd-BOPTA using both contrast media protocol. Contrast-to-noise ratio (CNR) between IM and N-IM (CNR IM/N-IM) and between IM and LVC (CNR IM/LVC) were also quantified for each time point. Moreover the extent of infarcted myocardium was measured. Results: 102 LGE images were evaluated for each dose group. Quality score was significantly higher for SD at 1, 15 and 20 min (0.002 < p < 0.046) and for HD at 5 min (p = 0.013). SNR has been higher in the SD group compared to the HD group even though not statistically significant at any time-point for both IM (SD vs. HD: 87.7 ± 73 vs. 65 ± 66; 0.15 < p < 0.38) and N-IM (SD vs. HD: 22 ± 61 vs. 9.9 ± 6.5; 0.09 < p < 0.43). LVC SNR was

  7. Preliminary study of 3.0 T contrast-enhanced whole heart coronary MR angiography using 32-channel coils with high acceleration factor

    International Nuclear Information System (INIS)

    Yang Qi; Li Kuncheng; Du Xiangying; Ma Heng; An Jing; Li Han; Xu Dong; Bi Xiaoming; Li Debiao

    2010-01-01

    Objective: To evaluate the diagnostic accuracy of 3.0 T contrast enhanced (CE) whole-heart coronary MRA (CE MRA) using 32-channel coils with high acceleration factor. Methods: Sixty patients with suspected coronary artery disease who were scheduled for coronary angiography (CAG) underwent CE CMRA at 3.0 T MRI scanner. A 32-channel receiver coil was used for data acquisition. For image acquisition, an ECG triggered,navigator-gated, inversion-recovery prepared, segmented gradient-echo sequence was used with an acceleration factor of three in the phase-encoding direction using GRAPPA reconstruction. Gd-BOPTA (0.15 mmol/kg body weight) was intravenously administered at a rate of 0.3 ml/s. The diagnostic accuracy in detecting significant stenoses (≥50% of vessel lumen) was evaluated using χ 2 test with X-ray angiography as the reference. Results: Whole-heart CE CMRA was successfully completed in 56 patients who were scheduled for CAG. The averaged imaging time was (6.0±1.3) min. 3.0 T CE CMRA using 32 channel coils correctly identified significant CAD in 28 patients and correctly ruled out CAD in 23 patients. The sensitivity and specificity were 93.3% and 88.5% respectively. Conclusion: Combined with dedicated 32-channel coils, 3.0 T CE CMRA allows significant reduction in imaging speed and reduced dose of the contrast agent. These improvements resulted in substantially improved overall accuracy of CE CMRA in detecting coronary artery disease. (authors)

  8. Reduction of vascular artifact on T1-weighted images of the brain by using three-dimensional double IR fast spoiled gradient echo recalled acquisition in the steady state (FSPGR) at 3.0 Tesla

    International Nuclear Information System (INIS)

    Fujiwara, Yasuhiro; Yamaguchi, Isao; Ookoshi, Yusuke; Ootani, Yuriko; Matsuda, Tsuyoshi; Ishimori, Yoshiyuki; Hayashi, Hiroyuki; Miyati, Tosiaki; Kimura, Hirohiko

    2007-01-01

    The purpose of this study was to decrease vascular artifacts caused by the in-flow effect in three-dimensional inversion recovery prepared fast spoiled gradient recalled acquisition in the steady state (3D IR FSPGR) at 3.0 Tesla. We developed 3D double IR FSPGR and investigated the signal characteristics of the new sequence. The 3D double IR FSPGR sequence uses two inversion pulses, the first for obtaining tissue contrast and the second for nulling vascular signal, which is applied at the time of the first IR period at the neck region. We have optimized scan parameters based on both phantom and in-vivo study. As a result, optimized parameters (1st TI=700 ms, 2nd TI=400 ms) successfully have produced much less vessel signal at reduction than conventional 3D IR FSPGR over a wide imaging range, while preserving the signal-to-noise ratio (SNR) and gray/white matter contrast. Moreover, the decreased artifact was also confirmed by visual inspection of the images obtained in vivo using those parameters. Thus, 3D double IR FSPGR was a useful sequence for the acquisition of T1-weighted images at 3.0 Tesla. (author)

  9. Utility of real-time prospective motion correction (PROMO) for segmentation of cerebral cortex on 3D T1-weighted imaging: Voxel-based morphometry analysis for uncooperative patients

    International Nuclear Information System (INIS)

    Igata, Natsuki; Kakeda, Shingo; Watanabe, Keita; Narimatsu, Hidekuni; Ide, Satoru; Korogi, Yukunori; Nozaki, Atsushi; Rettmann, Dan; Abe, Osamu

    2017-01-01

    To assess the utility of the motion correction method with prospective motion correction (PROMO) in a voxel-based morphometry (VBM) analysis for 'uncooperative' patient populations. High-resolution 3D T1-weighted imaging both with and without PROMO were performed in 33 uncooperative patients with Parkinson's disease (n = 11) or dementia (n = 22). We compared the grey matter (GM) volumes and cortical thickness between the scans with and without PROMO. For the mean total GM volume with the VBM analysis, the scan without PROMO showed a significantly smaller volume than that with PROMO (p < 0.05), which was caused by segmentation problems due to motion during acquisition. The whole-brain VBM analysis showed significant GM volume reductions in some regions in the scans without PROMO (familywise error corrected p < 0.05). In the cortical thickness analysis, the scans without PROMO also showed decreased cortical thickness compared to the scan with PROMO (p < 0.05). Our results with the uncooperative patients indicate that the use of PROMO can reduce misclassification during segmentation of the VBM analyses, although it may not prevent GM volume reduction. (orig.)

  10. Utility of real-time prospective motion correction (PROMO) for segmentation of cerebral cortex on 3D T1-weighted imaging: Voxel-based morphometry analysis for uncooperative patients

    Energy Technology Data Exchange (ETDEWEB)

    Igata, Natsuki; Kakeda, Shingo; Watanabe, Keita; Narimatsu, Hidekuni; Ide, Satoru; Korogi, Yukunori [University of Occupational and Environmental Health School of Medicine, Department of Radiology, Kitakyushu (Japan); Nozaki, Atsushi [MR Applications and Workflow Asia Pacific GE Healthcare Japan, Tokyo (Japan); Rettmann, Dan [MR Applications and Workflow GE Healthcare, Rochester, MN (United States); Abe, Osamu [University of Tokyo, Department of Radiology, Graduate School of Medicine, Tokyo (Japan)

    2017-08-15

    To assess the utility of the motion correction method with prospective motion correction (PROMO) in a voxel-based morphometry (VBM) analysis for 'uncooperative' patient populations. High-resolution 3D T1-weighted imaging both with and without PROMO were performed in 33 uncooperative patients with Parkinson's disease (n = 11) or dementia (n = 22). We compared the grey matter (GM) volumes and cortical thickness between the scans with and without PROMO. For the mean total GM volume with the VBM analysis, the scan without PROMO showed a significantly smaller volume than that with PROMO (p < 0.05), which was caused by segmentation problems due to motion during acquisition. The whole-brain VBM analysis showed significant GM volume reductions in some regions in the scans without PROMO (familywise error corrected p < 0.05). In the cortical thickness analysis, the scans without PROMO also showed decreased cortical thickness compared to the scan with PROMO (p < 0.05). Our results with the uncooperative patients indicate that the use of PROMO can reduce misclassification during segmentation of the VBM analyses, although it may not prevent GM volume reduction. (orig.)

  11. Automatic, accurate, and reproducible segmentation of the brain and cerebro-spinal fluid in T1-weighted volume MRI scans and its application to serial cerebral and intracranial volumetry

    Science.gov (United States)

    Lemieux, Louis

    2001-07-01

    A new fully automatic algorithm for the segmentation of the brain and cerebro-spinal fluid (CSF) from T1-weighted volume MRI scans of the head was specifically developed in the context of serial intra-cranial volumetry. The method is an extension of a previously published brain extraction algorithm. The brain mask is used as a basis for CSF segmentation based on morphological operations, automatic histogram analysis and thresholding. Brain segmentation is then obtained by iterative tracking of the brain-CSF interface. Grey matter (GM), white matter (WM) and CSF volumes are calculated based on a model of intensity probability distribution that includes partial volume effects. Accuracy was assessed using a digital phantom scan. Reproducibility was assessed by segmenting pairs of scans from 20 normal subjects scanned 8 months apart and 11 patients with epilepsy scanned 3.5 years apart. Segmentation accuracy as measured by overlap was 98% for the brain and 96% for the intra-cranial tissues. The volume errors were: total brain (TBV): -1.0%, intra-cranial (ICV):0.1%, CSF: +4.8%. For repeated scans, matching resulted in improved reproducibility. In the controls, the coefficient of reliability (CR) was 1.5% for the TVB and 1.0% for the ICV. In the patients, the Cr for the ICV was 1.2%.

  12. Diagnostic accuracy of dual-echo (in- and opposed-phase) T1-weighted gradient recalled echo for detection and grading of hepatic iron using quantitative and visual assessment

    Energy Technology Data Exchange (ETDEWEB)

    Schieda, Nicola; Ramanathan, Subramaniyan; Ryan, John; Khanna, Maneesh; Virmani, Vivek; Avruch, Leonard [The University of Ottawa, The Ottawa Hospital, Ottawa, Ontario (Canada)

    2014-07-15

    Detection and quantification of hepatic iron with dual-echo gradient recalled echo (GRE) has been proposed as a rapid alternative to other magnetic resonance imaging (MRI) techniques. Co-existing steatosis and T1 weighting are limitations. This study assesses the accuracy of routine dual-echo GRE. Between 2010 and 2013, 109 consecutive patients underwent multi-echo (ME) MRI and dual-echo GRE for quantification of hepatic iron. Liver iron concentration (LIC) was calculated from ME-MRI. Relative signal intensity (RSI) and fat signal fraction (FSF) were calculated from dual-echo GRE. Four radiologists subjectively evaluated dual-echo GRE (±subtraction). Diagnostic accuracy was compared between techniques and correlated with biopsy using Fisher's exact test, Spearman correlation and regression. The sensitivity of visual detection of iron ranged from 48 to 55 %. Subtraction did not increase sensitivity (p < 0.001). Inter-observer variability was substantial (κ = 0.72). The specificity of visual detection of iron approached 100 % with false-positive diagnoses observed using subtraction. LIC showed a higher correlation with histopathological iron grade (r = 0.94, p < 0.001) compared with RSI (r = 0.65, p = 0.02). Univariate regression showed an association between RSI and LIC (B = 0.98, p < 0.001, CI 0.73-1.23); however, the association was not significant with multi-variate regression including FSF (p = 0.28). Dual-echo GRE has low sensitivity for hepatic iron. Subtraction imaging can result in false-positive diagnoses. (orig.)

  13. Effect of eicosapentaenoic acid/docosahexaenoic acid on coronary high-intensity plaques detected with non-contrast T1-weighted imaging (the AQUAMARINE EPA/DHA study): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Nakao, Kazuhiro; Noguchi, Teruo; Asaumi, Yasuhide; Morita, Yoshiaki; Kanaya, Tomoaki; Fujino, Masashi; Hosoda, Hayato; Yoneda, Shuichi; Kawakami, Shoji; Nagai, Toshiyuki; Nishihira, Kensaku; Nakashima, Takahiro; Kumasaka, Reon; Arakawa, Tetsuo; Otsuka, Fumiyuki; Nakanishi, Michio; Kataoka, Yu; Tahara, Yoshio; Goto, Yoichi; Yamamoto, Haruko; Hamasaki, Toshimitsu; Yasuda, Satoshi

    2018-01-08

    Despite the success of HMG-CoA reductase inhibitor (statin) therapy in reducing atherosclerotic cardiovascular events, a residual risk for cardiovascular events in patients with coronary artery disease (CAD) remains. Long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are promising anti-atherosclerosis agents that might reduce the residual CAD risk. Non-contrast T1-weighted imaging (T1WI) with cardiac magnetic resonance (CMR) less invasively identifies high-risk coronary plaques as high-intensity signals. These high-intensity plaques (HIPs) are quantitatively assessed using the plaque-to-myocardium signal intensity ratio (PMR). Our goal is to assess the effect of EPA/DHA on coronary HIPs detected with T1WI in patients with CAD on statin treatment. This prospective, controlled, randomized, open-label study examines the effect of 12 months of EPA/DHA therapy and statin treatment on PMR of HIPs detected with CMR and computed tomography angiography (CTA) in patients with CAD. The primary endpoint is the change in PMR after EPA/DHA treatment. Secondary endpoints include changes in Hounsfield units, plaque volume, vessel area, and plaque area measured using CTA. Subjects are randomly assigned to either of three groups: the 2 g/day EPA/DHA group, the 4 g/day EPA/DHA group, or the no-treatment group. This trial will help assess whether EPA/DHA has an anti-atherosclerotic effect using PMR of HIPs detected by CMR. The trial outcomes will provide novel insights into the effect of EPA/DHA on high-risk coronary plaques and may provide new strategies for lowering the residual risk in patients with CAD on statin therapy. The University Hospital Medical Information Network (UMIN) Clinical Trials Registry, ID: UMIN000015316 . Registered on 2 October 2014.

  14. SU-E-J-231: Comparison of Delineation Variability of Soft Tissue Volume and Position in Head-And-Neck Between Two T1-Weighted Pulse Sequences Using An MR-Simulator with Immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Wong, O; Lo, G; Yuan, J; Law, M; Ding, A; Cheng, K; Chan, K; Cheung, K; Yu, S [Hong Kong Sanatorium & Hospital, Hong Kong (Hong Kong)

    2015-06-15

    Purpose: There is growing interests in applying MR-simulator(MR-sim) in radiotherapy but MR images subject to hardware, patient and pulse sequence dependent geometric distortion that may potentially influence target definition. This study aimed to evaluate the influence on head-and-neck tissue delineation, in terms of positional and volumetric variability, of two T1-weighted(T1w) MR sequences on a 1.5T MR-sim Methods: Four healthy volunteers were scanned (4 scans for each on different days) using both spin-echo (3DCUBE, TR/TE=500/14ms, TA=183s) and gradient-echo sequences (3DFSPGR, TE/TR=7/4ms, TA=173s) with identical coverage, voxel-size(0.8×0.8×1.0mm3), receiver-bandwidth(62.5kHz/pix) and geometric correction on a 1.5T MR-sim immobilized with personalized thermoplastic cast and head-rest. Under this setting, similar T1w contrast and signal-to-noise ratio were obtained, and factors other than sequence that might bias image distortion and tissue delineation were minimized. VOIs of parotid gland(PGR, PGL), pituitary gland(PIT) and eyeballs(EyeL, EyeR) were carefully drawn, and inter-scan coefficient-of-variation(CV) of VOI centroid position and volume were calculated for each subject. Mean and standard deviation(SD) of the CVs for four subjects were compared between sequences using Wilcoxon ranksum test. Results: The mean positional(<4%) and volumetric(<7%) CVs varied between tissues, majorly dependent on tissue inherent properties like volume, location, mobility and deformability. Smaller mean volumetric CV was found in 3DCUBE, probably due to its less proneness to tissue susceptibility, but only PGL showed significant difference(P<0.05). Positional CVs had no significant differences for all VOIs(P>0.05) between sequences, suggesting volumetric variation might be more sensitive to sequence-dependent delineation difference. Conclusion: Although 3DCUBE is considered less prone to tissue susceptibility-induced artifact and distortion, our preliminary data showed

  15. Signal alteration of the cochlear perilymph on 3 different sequences after intratympanic Gd-DTPA administration at 3 tesla. Comparison of 3D-FLAIR, 3D-T1-weighted imaging, and 3D-CISS

    International Nuclear Information System (INIS)

    Yamazaki, Masahiro; Naganawa, Shinji; Kawai, Hisashi; Nihashi, Takashi; Nakashima, Tsutomu

    2010-01-01

    Three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) imaging after intratympanic gadolinium injection is useful for pathophysiologic and morphologic analysis of the inner ear. However, statistical analysis of differences in inner ear signal intensity among 3D-FLAIR and other sequences has not been reported. We evaluated the signal intensity of cochlear fluid on each of 3D-FLAIR, 3D-T 1 -weighted imaging (T 1 WI), and 3D-constructive interference in the steady state (CISS) to clarify the differences in contrast effect among these 3 sequences using intratympanic gadolinium injection. Twenty-one patients underwent 3D-FLAIR, 3D-T 1 WI, and 3D-CISS imaging at 3 tesla 24 hours after intratympanic injection of gadolinium. We determined regions of interest of the cochleae (C) and medulla oblongata (M) on each image, evaluated the signal intensity ratio between C and M (CM ratio), and determined the ratio of cochlear signal intensity of the injected side to that of the non-injected side (contrast value). The CM ratio of the injected side (3.00±1.31, range, 0.53 to 4.88, on 3D-FLAIR; 0.83±0.30, range, 0.36 to 1.58 on 3D-T 1 WI) was significantly higher than that of the non-injected side (0.52±0.14, range, 0.30 to 0.76 on 3D-FLAIR; 0.49±0.11, range, 0.30 to 0.71 on 3D-T 1 WI) on 3D-FLAIR and 3D-T 1 WI (P 1 WI (1.73±0.60 range, 0.98 to 3.09) (P<0.001). The 3D-FLAIR sequence is the most sensitive for observing alteration in inner ear fluid signal after intratympanic gadolinium injection. Our results warrant use of 3D-FLAIR as a sensitive imaging technique to clarify the pathological and morphological mechanisms of disorders of the inner ear. (author)

  16. MR urography (MRU) of non-dilated ureter with diuretic administration: Static fluid 2D FSE T2-weighted versus 3D gadolinium T1-weighted GE excretory MR

    International Nuclear Information System (INIS)

    Roy, C.; Ohana, M.; Host, Ph.; Alemann, G.; Labani, A.; Wattiez, A.; Lang, H.

    2014-01-01

    •T2w-MRU with multiple orientations and diuretic is sufficient to identify non-dilated ureter.•T2w-MRU offers information on ureteral contractions and could be proposed to detect initial obstruction before hydronephrosis occurs (for instance in cases of endometriosis).•T2w-MRU could also be used to evaluate potential renal donors or in patients unable to receive gadolinium.•CE-MRU rapidly produces an overdistended bladder with a risk of false positive diagnosis of mild obstruction.•CE-MRU is less convenient for patients. T2w-MRU with multiple orientations and diuretic is sufficient to identify non-dilated ureter. T2w-MRU offers information on ureteral contractions and could be proposed to detect initial obstruction before hydronephrosis occurs (for instance in cases of endometriosis). T2w-MRU could also be used to evaluate potential renal donors or in patients unable to receive gadolinium. CE-MRU rapidly produces an overdistended bladder with a risk of false positive diagnosis of mild obstruction. CE-MRU is less convenient for patients. The goal of this prospective study was to compare the efficiency of two types of MRU after diuretic administration to identify the non-dilated ureter. MR pelvic examinations were performed in 126 patients after receiving furosemide. Each patient underwent in addition to their protocol for context, two types of MRU: 2D T2-weighted FSE (T2w-MRU) and 3D Gd T1-weighted GE (CE-MRU). Four segments were checked for each ureter. For the first part of the analysis, readers evaluated the whole image quality using a four points subjective scale and for the second part, they were asked to score separately each ureteral segment as present or absent. 1008 ureteral segments were checked. For the image quality, readers did not find any significant difference (3.8 ± 0.5 vs 3.6 ± 0.7, p value: 0.13) between MRU methods. The interobserver agreement was excellent with a κ correlation coefficient as high as 0.89 for T2w-MRU and 0.92 for CE

  17. Phase sensitive reconstruction of T1-weighted inversion recovery in the evaluation of the cervical cord lesions in multiple Sclerosis; is it similarly eligible in 1.5 T magnet fields?

    Science.gov (United States)

    Shayganfar, A; Sarrami, A H; Fathi, S; Shaygannejad, V; Shamsian, S

    2018-04-22

    In primary studies with 3 T Magnets, phase sensitive reconstruction of T1-weighted inversion recovery (PSIR) have showed ability to depict the cervical multiple sclerosis (MS) lesions some of which may not be detected by short tau inversion recovery (STIR). Regarding to more availability of 1.5 T MRI, this study was designed to evaluate the eligibility of PSIR in 1.5 T for detection of spinal cord MS lesions. In a study between September 2016 till March 2017 the patients with proven diagnosis of MS enrolled to the study. The standard protocol (sagittal STIR and T2W FSE and axial T2W FSE) as well as sagittal PSIR sequences were performed using a 1.5 T magnet. The images were studied and the lesions were localized and recorded as sharp or faint on each sequence. Of 25 patients (22 females and 3 males, with mean age of 33.5 ± 9.8 years and mean disease duration of 5.4 ± 3.9 years) 69 lesions in STIR, 53 lesions in T2W FSE, 47 lesions in Magnitude reconstruction of PSIR (Magnitude), and 30 lesions in phase sensitive (real) reconstruction PSIR were detected. A Wilcoxon signed-rank test showed STIR has a statistically significant higher detection rate of the plaques rather than other three sequences. (STIR and T2W FSE, Z = -4.000, p definition of the plaques rather than other three sequences. This study shows that in the setting of a 1.5 T magnet field, STIR significantly has a superiority over both of the PSIR reconstructions (i.e. real and magnitude) for the detection as well as the boundary definition of the cervical cord lesions of MS. These results have a good relevance to clinical practice by using MRI scanners and sequences routinely available, however, it is discrepant with other reports performed by 3 T Magnet fields. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Dynamic Liver Magnetic Resonance Imaging in Free-Breathing: Feasibility of a Cartesian T1-Weighted Acquisition Technique With Compressed Sensing and Additional Self-Navigation Signal for Hard-Gated and Motion-Resolved Reconstruction.

    Science.gov (United States)

    Kaltenbach, Benjamin; Bucher, Andreas M; Wichmann, Julian L; Nickel, Dominik; Polkowski, Christoph; Hammerstingl, Renate; Vogl, Thomas J; Bodelle, Boris

    2017-11-01

    The aim of this study was to assess the feasibility of a free-breathing dynamic liver imaging technique using a prototype Cartesian T1-weighted volumetric interpolated breathhold examination (VIBE) sequence with compressed sensing and simultaneous acquisition of a navigation signal for hard-gated and motion state-resolved reconstruction. A total of 43 consecutive oncologic patients (mean age, 66 ± 11 years; 44% female) underwent free-breathing dynamic liver imaging for the evaluation of liver metastases from colorectal cancer using a prototype Cartesian VIBE sequence (field of view, 380 × 345 mm; image matrix, 320 × 218; echo time/repetition time, 1.8/3.76 milliseconds; flip angle, 10 degrees; slice thickness, 3.0 mm; acquisition time, 188 seconds) with continuous data sampling and additionally acquired self-navigation signal. Data were iteratively reconstructed using 2 different approaches: first, a hard-gated reconstruction only using data associated to the dominating motion state (CS VIBE, Compressed Sensing VIBE), and second, a motion-resolved reconstruction with 6 different motion states as additional image dimension (XD VIBE, eXtended dimension VIBE). Continuous acquired data were grouped in 16 subsequent time increments with 11.57 seconds each to resolve arterial and venous contrast phases. For image quality assessment, both CS VIBE and XD VIBE were compared with the patient's last staging dynamic liver magnetic resonance imaging including a breathhold (BH) VIBE as reference standard 4.5 ± 1.2 months before. Representative quality parameters including respiratory artifacts were evaluated for arterial and venous phase images independently, retrospectively and blindly by 3 experienced radiologists, with higher scores indicating better examination quality. To assess diagnostic accuracy, same readers evaluated the presence of metastatic lesions for XD VIBE and CS VIBE compared with reference BH examination in a second session. Compared with CS VIBE, XD VIBE

  19. Biliary complications following orthotopic liver transplantation: May contrast-enhanced MR Cholangiography provide additional information?

    Directory of Open Access Journals (Sweden)

    Piero Boraschi

    2016-01-01

    Conclusions: Contrast-enhanced T1-weighted MR Cholangiography may improve the level of diagnostic confidence provided by conventional T2-weighted MR Cholangiography in the evaluation of biliary complications after orthotopic liver transplantation.

  20. Brain MR post-gadolinium contrast in multiple sclerosis: the role of magnetization transfer and image subtraction in detecting more enhancing lesions

    Energy Technology Data Exchange (ETDEWEB)

    Gavra, M.M.; Gouliamos, A.D.; Vlahos, L.J. [Department of Radiology, ' ' Aretaieion' ' Hospital,University of Athens Medical School, Athens (Greece); Voumvourakis, C.; Sfagos, C. [Department of Neurology, ' ' Eginiteion' ' Hospital, University of Athens Medical School, Athens (Greece)

    2004-03-01

    Our purpose was to evaluate the role of magnetization transfer and image subtraction in detecting more enhancing lesions in brain MR imaging of patients with multiple sclerosis (MS). Thirty-one MS patients underwent MR imaging of the brain with T1-weighted spin echo sequences without and with magnetization transfer (MT) using a 1.5 T imager. Both sequences were acquired before and after intravenous injection of a paramagnetic contrast agent. Subtraction images in T1-weighted sequences were obtained by subtracting the pre-contrast images from the post-contrast ones. A significant difference was found between the numbers of enhanced areas in post-gadolinium T1-weighted images without and with MT (p=0.020). The post-gadolinium T1-weighted images with MT allowed the detection of an increased (13) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. A significant difference was also found between the numbers of enhanced areas in post-gadolinium T1-weighted images without MT and subtraction images without MT (p=0.020). The subtraction images without MT allowed the detection of an increased (10) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. Magnetization transfer contrast and subtraction techniques appear to be the simplest and least time-consuming applications to improve the conspicuity and detection of contrast-enhancing lesions in patients with MS. (orig.)

  1. Brain MR post-gadolinium contrast in multiple sclerosis: the role of magnetization transfer and image subtraction in detecting more enhancing lesions

    International Nuclear Information System (INIS)

    Gavra, M.M.; Gouliamos, A.D.; Vlahos, L.J.; Voumvourakis, C.; Sfagos, C.

    2004-01-01

    Our purpose was to evaluate the role of magnetization transfer and image subtraction in detecting more enhancing lesions in brain MR imaging of patients with multiple sclerosis (MS). Thirty-one MS patients underwent MR imaging of the brain with T1-weighted spin echo sequences without and with magnetization transfer (MT) using a 1.5 T imager. Both sequences were acquired before and after intravenous injection of a paramagnetic contrast agent. Subtraction images in T1-weighted sequences were obtained by subtracting the pre-contrast images from the post-contrast ones. A significant difference was found between the numbers of enhanced areas in post-gadolinium T1-weighted images without and with MT (p=0.020). The post-gadolinium T1-weighted images with MT allowed the detection of an increased (13) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. A significant difference was also found between the numbers of enhanced areas in post-gadolinium T1-weighted images without MT and subtraction images without MT (p=0.020). The subtraction images without MT allowed the detection of an increased (10) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. Magnetization transfer contrast and subtraction techniques appear to be the simplest and least time-consuming applications to improve the conspicuity and detection of contrast-enhancing lesions in patients with MS. (orig.)

  2. Contrast-enhanced flair imaging in the evaluation of infectious leptomeningeal diseases

    International Nuclear Information System (INIS)

    Parmar, Hemant; Sitoh, Y.-Y.; Anand, Pooja; Chua, Violet; Hui, Francis

    2006-01-01

    Purpose: The purpose of our study was to compare contrast-enhanced fluid-attenuated inversion recovery (FLAIR) images with contrast-enhanced T1 weighted images for infectious leptomeningitis. Materials and methods: We studied twenty-four patients with a clinical suspicion of infectious meningitis with unenhanced FLAIR, contrast-enhanced T1 weighted and contrast-enhanced FLAIR MR sequences. Twelve patients had cytologic and biochemical diagnosis of meningitis on cerebrospinal fluid (CSF) examination obtained 48 h before or after the MR study. Sequences were considered positive if abnormal signal was seen in the subarachnoid space (cistern or sulci) or along pial surface. Results: Twenty-seven examinations in 24 patients were performed. Of the 12 patients (thirteen studies) in whom cytology was positive, unenhanced FLAIR images were positive in six cases (sensitivity 46%), contrast-enhanced FLAIR images were positive in 11 (sensitivity 85%), and contrast-enhanced T1 weighted MR images were positive in 11 patients (sensitivity 85%). Of the 12 patients (14 studies) in whom cerebrospinal fluid study was negative, unenhanced FLAIR images were negative in 13, contrast-enhanced FLAIR images were negative in 11, and contrast-enhanced T1 weighted MR images were negative in eight. Thus, the specificity of unenhanced FLAIR, contrast-enhanced FLAIR and contrast-enhanced T1 weighted images was 93, 79 and 57%, respectively. Conclusion: Our results suggest that post-contrast FLAIR images have similar sensitivity but a higher specificity compared to contrast-enhanced T1 weighted images for detection of leptomeningeal enhancement. It can be a useful adjunct to post-contrast T1 weighted images in evaluation of infectious leptomeningitis

  3. Contrast-enhanced flair imaging in the evaluation of infectious leptomeningeal diseases

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, Hemant [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore) and Department of Diagnostic Imaging, Hospital for Sick Children, Toronto (Canada)]. E-mail: parurad@hotmail.com; Sitoh, Y.-Y. [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore); Anand, Pooja [Department of Neurology, National Neuroscience Institute, 11 Jalan Tan Tock Seng (Singapore); Chua, Violet [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore); Hui, Francis [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore)

    2006-04-15

    Purpose: The purpose of our study was to compare contrast-enhanced fluid-attenuated inversion recovery (FLAIR) images with contrast-enhanced T1 weighted images for infectious leptomeningitis. Materials and methods: We studied twenty-four patients with a clinical suspicion of infectious meningitis with unenhanced FLAIR, contrast-enhanced T1 weighted and contrast-enhanced FLAIR MR sequences. Twelve patients had cytologic and biochemical diagnosis of meningitis on cerebrospinal fluid (CSF) examination obtained 48 h before or after the MR study. Sequences were considered positive if abnormal signal was seen in the subarachnoid space (cistern or sulci) or along pial surface. Results: Twenty-seven examinations in 24 patients were performed. Of the 12 patients (thirteen studies) in whom cytology was positive, unenhanced FLAIR images were positive in six cases (sensitivity 46%), contrast-enhanced FLAIR images were positive in 11 (sensitivity 85%), and contrast-enhanced T1 weighted MR images were positive in 11 patients (sensitivity 85%). Of the 12 patients (14 studies) in whom cerebrospinal fluid study was negative, unenhanced FLAIR images were negative in 13, contrast-enhanced FLAIR images were negative in 11, and contrast-enhanced T1 weighted MR images were negative in eight. Thus, the specificity of unenhanced FLAIR, contrast-enhanced FLAIR and contrast-enhanced T1 weighted images was 93, 79 and 57%, respectively. Conclusion: Our results suggest that post-contrast FLAIR images have similar sensitivity but a higher specificity compared to contrast-enhanced T1 weighted images for detection of leptomeningeal enhancement. It can be a useful adjunct to post-contrast T1 weighted images in evaluation of infectious leptomeningitis.

  4. Gd-DTPA-enhanced MR imaging in meningitis

    International Nuclear Information System (INIS)

    Han, M.H.; Chang, K.H.; Roh, J.K.; Kim, I.O.; Han, M.C.; Kim, C.W.

    1988-01-01

    Gd-DPTA-enhanced MR imaging was performed in 16 patients with meningitis (seven tuberculous, four bacterial, three fungal, and two viral) on a 2.0-T unit. Hemorrhagic infarcts of basal ganglia and localized enhancement of thickened dura adjacent were demonstrated on T1-weighted images in three patients with tuberculous meningitis and four with bacterial meningitis, respectively, that were not seen on CT. Enhanced T1-weighted images readily differentiated leptomeningeal enhancement from vessels in two cases with CT of equivocal meningeal enhancement. Nonenhanced T2-weighted images were most sensitive for demonstrating ischemia/infarct and edema. Otherwise, MR images generally matched CT scans

  5. Contrast enhanced MRA: do contrast agents with a higher T1 relaxitivity improve the visualization of carotid artery stenoses?

    International Nuclear Information System (INIS)

    Friese, S.; Krapf, H.; Skalej, M.; Kueker, W.; Fetter, M.; Vonthein, R.

    2001-01-01

    CE-MRA is a powerful tool for the non-invasive evaluation of carotid artery occlusive disease. However, due to certain drawbacks, it has not completely replaced DSA. The purpose of this study was to evaluate if Gd-BOPTA, a contrast agent with high T 1 relaxivity, can increase the diagnostic accuracy of CE-MRA. Material and Methods: The CE-MRA examinations of 54 consecutive patients were evaluated by two experienced radiologists, independently. The examinations of 27 patients were contrasted either with 20 ml Gd-BOPTA or with 20 ml Gd-DTPA. The reviewers were blinded to the contrast agent chosen and to the ultrasound results. They rated the overall image quality and the degree of the ICA stenoses. Results: For the estimation of the degree of the ICA stenoses there was a high interrater validity. In comparison to the ultrasound findings, 6 of 50 high-degree stenoses were underestimated as moderate stenoses. In one of seven sonographically occluded vessels, MRA revealed residual patency in the vessel lumen. It was not possible to identify the contrast agent that was taken for a study. Subjective estimation of the image quality (arterial contrast of the ICA, contrast of the other vessels, and general impression) did not significantly change with the contrast agent employed. Conclusion: The diagnostic accuracy of CE-MRA for the evaluation of internal carotid artery stenoses is not improved by Gd-BOPTA if identical volumina of contrast media are applied. The potential of this contrast agent can be the reduction of the amount of contrast without loss of diagnostic information. Further studies are necessary. (orig.) [de

  6. CE-Magnetic Resonance mammography for the evaluation of the contralateral breast in patients with diagnosed breast cancer

    International Nuclear Information System (INIS)

    Pediconi, Federica; Venditti, Fiammetta; Padula, Simona; Roselli, Antonella; Moriconi, Enrica; Catalano, Carlo; Passariello, Roberto; Giacomelli, Laura

    2005-01-01

    Purpose. To evaluate the role of contrast-enhanced Magnetic Resonance Mammography (MRM) in the evaluation of the contralateral breast in patients with recently diagnosed breast cancer. Materials and methods. Fifty patients with proved unilateral breast cancer, with a negative contralateral breast at physical examination, ultrasound and mammography, were studied with a 1.5 T magnet (Siemens, Vision Plus, Germany). A bilateral breast surface coil was used. Dynamic 3D Flash T1-weighted sequences were acquired in the axial plane before and 0, 2, 4, 6 and 8 minutes after the administration of 0.1 mmol/kg of Gd-BOPTA at a flow rate of 2 ml/s followed by 10 ml of saline. The level of suspicion was reported on a scale from 0 to 5 following the BI-RADS classification, based on lesion morphology and kinetic features. The results were compared with the histological findings after biopsy or surgery. Results. Fourteen out of 50 patients (28%) had contralateral lesions identified on MRM. Biopsy was performed in four of them for suspicious lesions (BI-RADS 4) while 10 patients underwent surgery because of highly suggestive malignant lesions (BI-RADS 5). Histology diagnosed three fibroadenomas, 5 ductal carcinoma in situ, 2 lobular carcinomas in situ, 3 invasive ductal carcinomas and 1 invasive lobular carcinoma. Contrast enhanced MRM yielded no false negative and three false positives. Conclusions. Our results demonstrate a very good accuracy of Magnetic Resonance Mammography in the detection of synchronous contralateral cancer in patients with newly diagnosed breast cancer. Therefore, contrast-enhanced MRM could be introduced to screen patients with proven breast cancer before they under-go surgery [it

  7. Contrast-enhanced specific absorption rate-efficient 3D cardiac cine with respiratory-triggered radiofrequency gating.

    Science.gov (United States)

    Henningsson, Markus; Chan, Raymond H; Goddu, Beth; Goepfert, Lois A; Razavi, Reza; Botnar, Rene M; Schaeffter, Tobias; Nezafat, Reza

    2013-04-01

    To investigate the use of radiofrequency (RF) gating in conjunction with a paramagnetic contrast agent to reduce the specific absorption rate (SAR) and increase the blood-myocardium contrast in balanced steady-state free precession (bSSFP) 3D cardiac cine. RF gating was implemented by synchronizing the RF-excitation with an external respiratory sensor (bellows), which could additionally be used for respiratory gating. For reference, respiratory-gated 3D cine images were acquired without RF gating. Free-breathing 3D cine images were acquired in eight healthy subjects before and after contrast injection (Gd-BOPTA) and compared to breath-hold 2D cine. RF-gated 3D cine reduced the SAR by nearly 40% without introducing significant artifacts while providing left ventricle (LV) measurements similar to those obtained with 2D cine. The contrast-to-noise ratio (CNR) was significantly higher for 3D cine compared to 2D cine, both before and after contrast injection; however, no statistically significant CNR increase was observed for the postcontrast 3D cine compared to the precontrast acquisitions. Respiratory-triggered RF gating significantly reduces SAR in 3D cine acquisitions, which may enable a more widespread clinical use of 3D cine. Furthermore, CNR of 3D bSSFP cine is higher than of 2D and administration of Gd-BOPTA does not improve the CNR of 3D cine. Copyright © 2012 Wiley Periodicals, Inc.

  8. Contrast-Enhanced MR Angiography (CEMRA) in Peripheral Arterial Occlusive Disease (PAOD): conventional moving table technique versus hybrid technique

    International Nuclear Information System (INIS)

    Kalle, T. von; Gerlach, A.; Hatopp, A.; Klinger, S.; Prodehl, P.; Arlat, I.P.

    2004-01-01

    Patients and Methods: 80 patients (males n = 60, females n = 20, median age = 70 years, diabetics n = 27) with PAOD were examined with a 1,5T system (40 mT/m) using a dedicated phased array peripheral vascular coil. Protocol A consisted of a single injection of Gd-BOPTA with consecutive craniocaudal image acquisition and protocol B of two injections, with the first injection of Gd-BOPTA followed by image acquisition of the popliteocrural and pedal segments and the second injection followed by acquiring the aortoiliac and femoral segments (hybrid technique). The evaluation of the arterial system was directed to the iliac, femoral, popliteocrural and pedal arteries. Results: The visualization of the entire aortopedal vascular system was of diagnostically good or satisfactory quality in 16 of 40 patients using protocol A and in 29 of 40 patients using protocol B (iliac 40 vs. 37, femoral 40 vs. 40, popliteocrural 35 vs. 37, pedal 16 vs. 29); without the pedal station the number increased to 35 of 40 patients for both protocols. The reason of diagnostic limitations was an arteriovenous overlap in 24 of 80 cases, with 19 of 40 cases for protocol A and 5 of 40 for protocol B, located exclusively in the cruropedal region. Conclusion: Moving table hybrid CEMRA is superior to conventional technique in craniocaudal direction by producing less venous overlap of arteries and is especially more suitable for the diagnostic evaluation of the cruropedal region. (orig.) [de

  9. Gadolinium enhancement of the cerebrospinal fluid in a patient with meningeal fibrosis and cryptococcal infection

    International Nuclear Information System (INIS)

    Sakamoto, S.; Kitagaki, H.; Ishii, K.; Yamaji, S.; Ikejiri, Y.; Mori, E.

    1997-01-01

    We describe the case of a 52-year-old man, with cryptococcal meningitis and meningeal fibrosis who had undergone ventricular shunting. Gd-DTPA-enhanced T1-weighted MRI revealed diffuse meningeal enhancement. Remarkably, there was enhancement of the pia mater and posterior fossa subarachnoid space. (orig.). With 3 figs

  10. Gd-DTPA-enhanced MR imaging of avascular necrosis of the hip

    International Nuclear Information System (INIS)

    Van de Berg, B.; Malghem, J.; Noel, H.; Maldague, B.

    1990-01-01

    This paper evaluates the interest of Gd-DTPA-enhanced MR imaging in the diagnosis of avascular necrosis (AVN) of the hip. MR imaging of 10 patients with various stages of AVN of the femoral head (14 abnormal hips) was performed (1.5-T Gyroscan). T1-weighted images before and after contrast injection and T2-weighted images were obtained in two planes. MR images were compared with pathologic findings in six femoral head specimens (total hip replacement). In the early stages of AVN (Mitchell classes A and B), a peripheral band of contrast-enhanced tissue appears on T1-weighted images after Gd-DTPA injection, mimicking the double line seen on T2-weighted images. In later stages (class C and D), the sequestrated segments, appearing hypointense on T1-weighted images, usually show a significant signal intensity enhancement after Gd-DTPA injection. The truly avascular areas may be limited to a band of thickened subchondral bone

  11. Gadolinium-DTPA enhanced MRI in myocardial infarction

    International Nuclear Information System (INIS)

    Dijkman, P.R.M. van.

    1991-01-01

    This thesis focuses on one aspect of cardiac magnetic resonance imaging (MRI) for noninvasive screening of ischemic heart disease: the identification and quantification of acutely infarcted myocardium using gadolineum-diethylene triamine pentaacetic acid (Gd-DTPA) enhanced T1-weighted MRI in a clinical and experimental setting. (author). 296 refs.; 34 figs.; 4 tabs

  12. Hyperintense hepatocellular carcinoma on gadolinium-enhanced hepatic MRI

    International Nuclear Information System (INIS)

    Yoshikawa, Jun; Matsui, Osamu; Kadoya, Masumi; Gabata, Toshifumi; Arai, Kazunori; Takashima, Tsutomu

    1992-01-01

    We reported a phenomenon in which some hepatocellular carcinomas (HHCs) visualized as hypointense on plain T1 weighted MR images became hyperintense on gadolinium-DTPA (Gd-DTPA) (0.06∼0.23 mmol/kg) enhanced delayed images. Gd-DTPA enhanced images (using a super conducting magnet operating at 1.5T) of 44 HCCs were studied in comparison with contrast enhanced CT using 30∼80g of iodine. Six of 44 HCCs (14%) which were visualized as hypointense on plain T1 weighted image became hyperintense on delayed Gd-DTPA enhanced images. Although these were visualized as low intensity areas on both plain and enhanced CT, the contrast between HCC and the surrounding liver was small on post contrast CT. These findings were thought to be due to a stronger enhancement effect of Gd-DTPA than that of iodine. (author)

  13. Gadolinium-DTPA enhanced MRI in myocardial infarction. An experimental and clinical study

    Energy Technology Data Exchange (ETDEWEB)

    Dijkman, P.R.M. van

    1991-10-30

    This thesis focuses on one aspect of cardiac magnetic resonance imaging (MRI) for noninvasive screening of ischemic heart disease: the identification and quantification of acutely infarcted myocardium using gadolineum-diethylene triamine pentaacetic acid (Gd-DTPA) enhanced T1-weighted MRI in a clinical and experimental setting. (author). 296 refs.; 34 figs.; 4 tabs.

  14. MR-perfusion (MRP) and diffusion-weighted imaging (DWI) in prostate cancer: quantitative and model-based gadobenate dimeglumine MRP parameters in detection of prostate cancer.

    Science.gov (United States)

    Scherr, M K; Seitz, M; Müller-Lisse, U G; Ingrisch, M; Reiser, M F; Müller-Lisse, U L

    2010-12-01

    Various MR methods, including MR-spectroscopy (MRS), dynamic, contrast-enhanced MRI (DCE-MRI), and diffusion-weighted imaging (DWI) have been applied to improve test quality of standard MRI of the prostate. To determine if quantitative, model-based MR-perfusion (MRP) with gadobenate dimeglumine (Gd-BOPTA) discriminates between prostate cancer, benign tissue, and transitional zone (TZ) tissue. 27 patients (age, 65±4 years; PSA 11.0±6.1 ng/ml) with clinical suspicion of prostate cancer underwent standard MRI, 3D MR-spectroscopy (MRS), and MRP with Gd-BOPTA. Based on results of combined MRI/MRS and subsequent guided prostate biopsy alone (17/27), biopsy and radical prostatectomy (9/27), or sufficient negative follow-up (7/27), maps of model-free, deconvolution-based mean transit time (dMTT) were generated for 29 benign regions (bROIs), 14 cancer regions (cROIs), and 18 regions of transitional zone (tzROIs). Applying a 2-compartment exchange model, quantitative perfusion analysis was performed including as parameters: plasma flow (PF), plasma volume (PV), plasma mean transit time (PMTT), extraction flow (EFL), extraction fraction (EFR), interstitial volume (IV) and interstitial mean transit time (IMTT). Two-sided T-tests (significance level pMRP with Gd-BOPTA discriminates between prostate cancer and benign tissue with several parameters. However, distinction of prostate cancer and TZ does not appear to be reliable. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  15. MR of normal pancreas : comparison of five pulse sequences and enhancing patterns on dynamic imaging

    International Nuclear Information System (INIS)

    Jang, Hyun Jung; Kim, Tae Kyoung; Hong, Sung Hwan; Han, Joon Koo; Choi, Byung Ihn

    1997-01-01

    To compare T1-weighted FLASH and turbo spin echo (SE) T2-weighted sequences with conventional T1- and T2-weighted sequences in imaging normal pancreas and to describe the enhancing patterns on dynamic MR imging. Forty-four patients with presumed hepatic hemangiomas were studied at 1.0T or 1.5T by using conventional SE sequences (T1-weighted, T2-weighted, and heavily T2-weighted), turbo-SE T2-weighted sequences, and breath-hold T1-weighted FLASH sequences acquired before, immediately on, and at 1, 2, 3, and 5 or 10 minutes after injection of a bolus of gadopentetate dimeglumine. No patients had either a history or its clinical features of pancreatic disease. Images were quantitatively analyzed for signal-difference-to noise ratios (SD/Ns) between the pancreas and peripancreatic fat. Percentage enhancement of the pancreas was measured on each dynamic MR image. Conspicuity of the pancreatic border was qualitatively evaluated according to a consensus, reached by three radiologists. Turbo-SE T2-weighted images had a significantly higher SD/N ratio (p<0.001) and better conspicuity of the pancreatic border (p<0.001) than SE T2- and heavily T2-weighted images;T1-weighted SE images had a significantly higher SD/N ratio than T1-weighted FLASH images (p<0.001), but there was no significant difference between tham in qualitative analysis (p=0.346). Percentage enhancement immediately on and at 1, 2, 3, 5, and 10 minutes after administration of contrast material was 39.9%, 44.5%, 42.9%, 40.8%, 36.3%, 29.9%, respectively, with peak enhancement at 1 minute. In MR imaging of normal pancreas, turbo-SE T2-weighted imaging is superior to SE T2- and heavily T2- weighted imaging, and SE T1-weighted imaging is superior to T1-weighted FLASH imaging. On serial gadolinium-enhanced FLASH imaging, normal pancreas shows peak enhancement at 1 minute

  16. The advantage of high relaxivity contrast agents in brain perfusion

    International Nuclear Information System (INIS)

    Cotton, F.; Hermier, M.

    2006-01-01

    Accurate MRI characterization of brain lesions is critical for planning therapeutic strategy, assessing prognosis and monitoring response to therapy. Conventional MRI with gadolinium-based contrast agents is useful for the evaluation of brain lesions, but this approach primarily depicts areas of disruption of the blood-brain barrier (BBB) rather than tissue perfusion. Advanced MR imaging techniques such as dynamic contrast agent-enhanced perfusion MRI provide physiological information that complements the anatomic data available from conventional MRI. We evaluated brain perfusion imaging with gadobenate dimeglumine (Gd-BOPTA, MultiHance; Bracco Imaging, Milan, Italy). The contrast-enhanced perfusion technique was performed on a Philips Intera 1.5-T MR system. The technique used to obtain perfusion images was dynamic susceptibility contrast-enhanced MRI, which is highly sensitive to T2* changes. Combined with PRESTO perfusion imaging, SENSE is applied to double the temporal resolution, thereby improving the signal intensity curve fit and, accordingly, the accuracy of the derived parametric images. MultiHance is the first gadolinium MR contrast agent with significantly higher T1 and T2 relaxivities than conventional MR contrast agents. The higher T1 relaxivity, and therefore better contrast-enhanced T1-weighted imaging, leads to significantly improved detection of BBB breakdown and hence improved brain tumor conspicuity and delineation. The higher T2 relaxivity allows high-quality T2*-weighted perfusion MRI and the derivation of good quality relative cerebral blood volume (rCBV) maps. We determined the value of MultiHance for enhanced T2*-weighted perfusion imaging of histologically proven (by surgery or stereotaxic biopsy) intraaxial brain tumors (n=80), multiple sclerosis lesions (n=10), abscesses (n=4), neurolupus (n=15) and stroke (n=16). All the procedures carried out were safe and no adverse events occurred. The acquired perfusion images were of good quality in

  17. Contrast-enhanced fast fluid-attenuated inversion recovery MR imaging in patients with brain tumors

    International Nuclear Information System (INIS)

    Kim, Chan Kyo; Na, Dong Gyu; Ryoo, Wook Jae; Byun Hong Sik; Yoon, Hye Kyung; Kim, Jong hyun

    2000-01-01

    To assess the feasibility of contrast-enhanced fast fluid-attenuated inversion recovery (fast FLAIR) MR imaging in patients with brain tumors. This study involved 31 patients with pathologically proven brain tumors and nine with clinically diagnosed metastases. In all patients, T2-weighted, fast FLAIR, images were visual contrast-enhanced T1-weighted MR images were obtained. Contrast-enhanced fast FLAIR images were visually compared with other MR sequences in terms of tumor conspicuity. In order to distinguish tumor and surrounding edema, contrast-enhanced fast FLAIR images were compared with fast FLAIR and T2-weighted images. The tumor-to- white matter contrast-to-noise ratios (CNRs), as demonstrated by T2-weighted, fast FLAIR, contrast-enhanced fast FLAIR and contrast-enhanced T1-weighted imaging, were quantitatively assessed and compared. For the visual assessment of tumor conspicuity, contrast-enhanced fast FLAIR image imaging superior to fast FLAIR in 60% of cases (24/40), and superior to T2-weighted in 70% (28/40). Contrast-enhanced fast FLAIR imaging was inferior to contrast-enhanced T1-weighted in 58% of cases (23/40). For distinguishing between tumor and surrounding edema, contrast-enhanced fast FLAIR imaging was superior to fast FLAIR or T2-weighted in 22 of 27 tumors with peritumoral edema (81%). Quantitatively, CNR was the highest on contrast-enhanced fast FLAIR image and the lowest on fast FLAIR. For the detection of leptomeningeal metastases, contrast-enhanced fast FLAIR was partially superior to contrast-enhanced T1-weighted imaging in two of three high-grade gliomas. Although contrast-enhanced fast FLAIR imaging should not be seen as a replacement for conventional modalities, it provides additional informaton for assessment of the extent of glial cell tumors and leptomeningeal metastases in patients with brain tumors. (author)

  18. Contrast medium-enhanced MRI findings and changes over time in stage I tuberculous meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Oztoprak, I. [Department of Radiology Cumhuriyet University Faculty of Medicine, 58140 Sivas (Turkey)], E-mail: oztoprak@cumhuriyet.edu.tr; Guemues, C.; Oztoprak, B. [Department of Radiology Cumhuriyet University Faculty of Medicine, 58140 Sivas (Turkey); Engin, A. [Department of Infectious Diseases, Cumhuriyet University Faculty of Medicine, Sivas (Turkey)

    2007-12-15

    Aim: To demonstrate the detailed imaging characteristics of early tuberculous meningitis (TBM) and changes over time on standard gadolinium-enhanced, T1-weighted magnetic resonance imaging (MRI) images. Materials and methods: Contrast-enhanced, T1-weighted, spin-echo MRI images of 26 patients with early TBM were evaluated retrospectively. Meningeal enhancement characteristics were categorized according to distribution and pattern as diffuse, focal, linear, nodular, and mixed. Results: We found that 35% of patients had diffuse meningeal enhancement and 65% of cases had focal meningeal enhancement. There was a predilection for focal meningeal enhancement in basal pial areas, the interpeduncular fossa being the most common. In six patients with diffuse meningeal enhancement admitted to hospital relatively early after the onset of symptoms, the type of meningeal enhancement later changed to the focal form. Conclusion: Reactive diffuse meningeal enhancement occurs in the early period of TBM on contrast medium-enhanced T1-weighted MR images, but later becomes limited to basal areas.

  19. Contrast medium-enhanced MRI findings and changes over time in stage I tuberculous meningitis

    International Nuclear Information System (INIS)

    Oztoprak, I.; Guemues, C.; Oztoprak, B.; Engin, A.

    2007-01-01

    Aim: To demonstrate the detailed imaging characteristics of early tuberculous meningitis (TBM) and changes over time on standard gadolinium-enhanced, T1-weighted magnetic resonance imaging (MRI) images. Materials and methods: Contrast-enhanced, T1-weighted, spin-echo MRI images of 26 patients with early TBM were evaluated retrospectively. Meningeal enhancement characteristics were categorized according to distribution and pattern as diffuse, focal, linear, nodular, and mixed. Results: We found that 35% of patients had diffuse meningeal enhancement and 65% of cases had focal meningeal enhancement. There was a predilection for focal meningeal enhancement in basal pial areas, the interpeduncular fossa being the most common. In six patients with diffuse meningeal enhancement admitted to hospital relatively early after the onset of symptoms, the type of meningeal enhancement later changed to the focal form. Conclusion: Reactive diffuse meningeal enhancement occurs in the early period of TBM on contrast medium-enhanced T1-weighted MR images, but later becomes limited to basal areas

  20. Contrast-enhanced fat- suppression MR imaging of avascular necrosis of femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Tae Kyoung; Shim, Jae Chan; Lee, Ghi Jai; Jeon, Jeong Dong; Bang, Sun Woo; Kim, Ho Kyun [College of Medicine, Inje University, Seoul (Korea, Republic of)

    2000-02-01

    To evaluate the findings and role of contrast-enhanced fat suppression MR imaging in avascular necrosis (AVN) of the femoral head. In 15 patients with AVN of the femoral head, MR T1-weighted and T2-weighted images and contrast-enhanced fat-suppression T1-weighted images were obtained, and the findings were reviewed. Early and advanced groups were classified on the basis of clinical findings and imaging, and the enhancement pattern was classified as either type I, rim enhancement; type II, surrounding diffuse enhancement; type III, intralesional enhancement; or type IV, II + III. Twenty-four cases of AVN of the femoral head were detected; in nine patients, lesions were bilateral. Eight cases occurred in the early group and 16 in the advanced. All eight in the early group showed the 'double line sign' on T2-weighted images, with a type-I enhancement pattern. In the advanced group, type II (8/16) and type IV (8/16) enhancement patterns were seen. Among the cases showing the type-IV pattern, the intralesional enhancing area showed low signal intensity on T1-weighted images and isosignal intensity on T2-weighted in one case, and low signal intensity on T2-weighted in one case, and low signal intensity on T1-weighted images and high signal intensity on T2-weighted in the other cases. There was no difference in the extent of the disease before and after enhancement. Contrast-enhanced fat-suppression MR images may be helpful in evaluating the extent of AVN of the femoral head and predicting the histopathologic findings of the disease. (author)

  1. Contrast-enhanced fat- suppression MR imaging of avascular necrosis of femoral head

    International Nuclear Information System (INIS)

    Oh, Tae Kyoung; Shim, Jae Chan; Lee, Ghi Jai; Jeon, Jeong Dong; Bang, Sun Woo; Kim, Ho Kyun

    2000-01-01

    To evaluate the findings and role of contrast-enhanced fat suppression MR imaging in avascular necrosis (AVN) of the femoral head. In 15 patients with AVN of the femoral head, MR T1-weighted and T2-weighted images and contrast-enhanced fat-suppression T1-weighted images were obtained, and the findings were reviewed. Early and advanced groups were classified on the basis of clinical findings and imaging, and the enhancement pattern was classified as either type I, rim enhancement; type II, surrounding diffuse enhancement; type III, intralesional enhancement; or type IV, II + III. Twenty-four cases of AVN of the femoral head were detected; in nine patients, lesions were bilateral. Eight cases occurred in the early group and 16 in the advanced. All eight in the early group showed the 'double line sign' on T2-weighted images, with a type-I enhancement pattern. In the advanced group, type II (8/16) and type IV (8/16) enhancement patterns were seen. Among the cases showing the type-IV pattern, the intralesional enhancing area showed low signal intensity on T1-weighted images and isosignal intensity on T2-weighted in one case, and low signal intensity on T2-weighted in one case, and low signal intensity on T1-weighted images and high signal intensity on T2-weighted in the other cases. There was no difference in the extent of the disease before and after enhancement. Contrast-enhanced fat-suppression MR images may be helpful in evaluating the extent of AVN of the femoral head and predicting the histopathologic findings of the disease. (author)

  2. Avascular necrosis of femoral head: findings of contrast-enhanced MR imaging

    International Nuclear Information System (INIS)

    Shin, Yong Moon; Kang, Heung Sik; Kim, Chu Wan; Kim, Hee Joong; Kim, Young Min

    1995-01-01

    To evaluate the findings and the role of contrast enhanced magnetic resonance imaging in avascular necrosis of femoral head. Sixteen patients with avascular necorsis of femoral head were examined with MRI. T1-weighted and T2-weighted image and contrast-enhanced T1-weighted images were obtained. Enhancing characteristics of the necrotic area and synovium were determined. Also a change of the disease extent after enhancement was assessed. Twenty seven avascular necrosis of the femoral head including 11 cases of bilateral lesion were detected. Fifteen cases revealed collapse of the femoral head. The portions of the lesion with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images showed contrast enhancement in 15 cases. However, the potions with low signal intensities both on T1 and T2-weighted images showed enhancement in one case. There was no significant change of the disease extent after enhancement. Synovium showed enhancement in 18 cases, and joint effusion was detected in 23 cases. Contrast enhanced MR images may be helpful in predicting histopathologic findings of avascular necrosis of the femoral head, but not useful for evaluating the extent of disease

  3. Avascular necrosis of femoral head: findings of contrast-enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Yong Moon; Kang, Heung Sik; Kim, Chu Wan; Kim, Hee Joong; Kim, Young Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1995-06-15

    To evaluate the findings and the role of contrast enhanced magnetic resonance imaging in avascular necrosis of femoral head. Sixteen patients with avascular necorsis of femoral head were examined with MRI. T1-weighted and T2-weighted image and contrast-enhanced T1-weighted images were obtained. Enhancing characteristics of the necrotic area and synovium were determined. Also a change of the disease extent after enhancement was assessed. Twenty seven avascular necrosis of the femoral head including 11 cases of bilateral lesion were detected. Fifteen cases revealed collapse of the femoral head. The portions of the lesion with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images showed contrast enhancement in 15 cases. However, the potions with low signal intensities both on T1 and T2-weighted images showed enhancement in one case. There was no significant change of the disease extent after enhancement. Synovium showed enhancement in 18 cases, and joint effusion was detected in 23 cases. Contrast enhanced MR images may be helpful in predicting histopathologic findings of avascular necrosis of the femoral head, but not useful for evaluating the extent of disease.

  4. Gd-DOTA enhancement of cerebral and spinal tumors on MR imaging

    International Nuclear Information System (INIS)

    Berry, I.; Manelfe, C.; Chastin, I.; Arrue, P.; Prere, J.

    1987-01-01

    The use of Gd-DOTA as a contrast agent in MR imaging to improve the diagnosis of cerebral and spinal tumors was assessed in 20 patients, ten with brain tumors and ten with spinal tumors. Imaging was performed with a 0.5-T Magniscan 5000 unit. T1-weighted (spin-echo and gradient-echo) and T2-weighted (spin-echo) images were acquired before and after intravenous injection of Gd-DOTA, 0.1 mmol/kg. On T1-weighted images, Gd-DOTA enhanced sites of presumed disruption of the blood-brain barrier. This made some brain tumors more conspicuous and helped target biopsies, but did not reveal any additional lesions. On the other hand, the use of Gd-DOTA significantly improved the reliability of spinal tumor imaging compared to imaging performed without contrast agent, allowing delineation of abnormalities on T1-weighted images, which frequently contain fewer artifacts than the most sensitive T2-weighted images. Images obtained with Gd-DOTA could be used by the physician to rule out residual tumor after surgery and to assess recurrences. Additional work should be done to discover whether spinal tumor exploration with MR imaging could include solely T1-weighted sequences, performed before and after contrast agent administration, without T2-weighted sequences

  5. Brain capillary transit time heterogeneity in healthy volunteers measured by dynamic contrast-enhanced T1-weighted perfusion MRI

    DEFF Research Database (Denmark)

    Larsson, Henrik B.W.; Vestergaard, Mark B.; Lindberg, Ulrich

    2017-01-01

    Purpose: Capillary transit time heterogeneity, measured as CTH, may set the upper limit for extraction of substances in brain tissue, e.g., oxygen. The purpose of this study was to investigate the feasibility of dynamic contrast-enhanced T1 weighted MRI (DCE-MRI) at 3 Tesla (T), in estimating CTH...

  6. Contrast-enhanced FLAIR in the early diagnosis of infectious meningitis

    International Nuclear Information System (INIS)

    Splendiani, Alesssandra; Puglielli, Edoardo; Amicis, Rosanna De; Masciocchi, Carlo; Gallucci, Massimo; Necozione, Stefano

    2005-01-01

    We investigated the accuracy of MRI in the early diagnosis of infectious meningitis with emphasis on the value of gadolinium-enhanced fluid-attenuated inversion recovery (FLAIR) sequence. Twenty-seven patients with clinical suspicion of infectious meningitis were included. MRI was performed within 3 h of clinical evaluation. For all patients, T1-weighted spin-echo, dual-echo T2-weighted fast-spin-echo and FLAIR sequences were performed, followed by gadolinium-enhanced T1-weighted spin-echo and FLAIR sequences. Final diagnosis was based on the clinical findings and the analysis of cerebrospinal fluid, obtained by lumbar puncture after the MRI. Infectious meningitis was confirmed in 12 patients. In all of these patients of the plain studies, FLAIR was positive in only four patients. MRI gadolinium-enhanced FLAIR showed abnormal meningeal enhancement in all 12 patients, while gadolinium-enhanced T1-weighted spin-echo was positive only in six cases. There were no false-positive or false-negative results. It is concluded that MRI could have an important role in the early screening for infectious meningitis, provided a gadolinium-enhanced FLAIR sequence is used. (orig.)

  7. Contrast-enhanced FLAIR in the early diagnosis of infectious meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Splendiani, Alesssandra; Puglielli, Edoardo; Amicis, Rosanna De; Masciocchi, Carlo; Gallucci, Massimo [University of L' Aquila, Department of Radiology, L' Aquila (Italy); Necozione, Stefano [University of L' Aquila, Department of Statistic, L' Aquila (Italy)

    2005-08-01

    We investigated the accuracy of MRI in the early diagnosis of infectious meningitis with emphasis on the value of gadolinium-enhanced fluid-attenuated inversion recovery (FLAIR) sequence. Twenty-seven patients with clinical suspicion of infectious meningitis were included. MRI was performed within 3 h of clinical evaluation. For all patients, T1-weighted spin-echo, dual-echo T2-weighted fast-spin-echo and FLAIR sequences were performed, followed by gadolinium-enhanced T1-weighted spin-echo and FLAIR sequences. Final diagnosis was based on the clinical findings and the analysis of cerebrospinal fluid, obtained by lumbar puncture after the MRI. Infectious meningitis was confirmed in 12 patients. In all of these patients of the plain studies, FLAIR was positive in only four patients. MRI gadolinium-enhanced FLAIR showed abnormal meningeal enhancement in all 12 patients, while gadolinium-enhanced T1-weighted spin-echo was positive only in six cases. There were no false-positive or false-negative results. It is concluded that MRI could have an important role in the early screening for infectious meningitis, provided a gadolinium-enhanced FLAIR sequence is used. (orig.)

  8. Low flip angle spin-echo MR imaging to obtain better Gd-DTPA enhanced imaging with ECG gating

    International Nuclear Information System (INIS)

    Sugimura, Kazuro; Kawamitsu, Hideaki; Yoshikawa, Kazuaki; Kasai, Toshifumi; Yuasa, Koji; Ishida, Tetsuya

    1992-01-01

    ECG-gated spin-echo imaging (ECG-SE) can reduce physiological motion artifact. However, ECG-SE does not provide strong T1-weighted images because repetition time (TR) depends on heart rate (HR). We investigated the usefulness of low flip angle spin-echo imaging (LFSE) in obtaining more T1-dependent contrast with ECG gating. In computer simulation, the predicted image contrast and single-to-noise ratio (SNR) obtained for each flip angle (0-180deg) and each TR (300 msec-1200 msec) were compared with those obtained by conventional T1-weighted spin-echo imaging (CSE: TR=500 msec, TE=20 msec). In clinical evaluation, tissue contrast [contrast index (CI): (SI of lesion-SI of muslce) 2* 100/SI of muscle] obtained by CSE and LFSE were compared in 17 patients. At a TR of 1,000 msec, T1-dependent contrast increased with decreasing flip angle and that at 38deg was identical to that with T1-weighted spin-echo. SNR increased with the flip angle until 100deg, and that at 53deg was identical to that with T1-weighted spin-echo. CI on LFSE (74.0±52.0) was significantly higher than CI on CSE (40.9±35.9). ECG-gated LFSE imaging provides better T1-dependent contrast than conventional ECG-SE. This method was especially useful for Gd-DTPA enhanced MR imaging. (author)

  9. Gadolinium-enhanced MR imaging of the wrist in rheumatoid arthritis: value of fat suppression pulse sequences

    International Nuclear Information System (INIS)

    Nakahara, N.; Uetani, M.; Hayashi, K.; Kawahara, Y.; Matsumoto, T.; Oda, J.

    1996-01-01

    Objective. To determine the usefulness of fat-suppressed gadolinium (Gd)-enhanced MR imaging of the wrist in patients with rheumatoid arthritis (RA). Design and patients. Fat-suppressed Gd-enhanced T1-weighted spin-echo (SE) images were obtained and compared with other standard techniques in 38 wrists of 27 patients (22-77 years) with RA. Scoring based on the degree of synovial enhancement of each joint was developed and the total scores (J-score) were correlated with radiographic stage, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and symptomatic change in the follow-up study. Results. Synovial proliferations showed marked enhancement in all the wrists. In addition, contrast enhancement in the bone marrow and tenosynovium was seen in 36 and eight wrists respectively. Fat-suppressed Gd-enhanced T1-weighted images demonstrated these abnormalities better than other techniques. The J-scores correlated well with values of CRP (P=0.0034), but not with radiographic stages and ESR. Conclusion. Fat-suppressed Gd-enhanced T1-weighted SE images can clearly demonstrate most of the essential lesions in RA including the proliferative synovium, bone erosion, bone marrow inflammatory change, and tenosynovitis. Scoring based on the extent of Gd-enhancement of synovium can be useful in the assessment of the inflammatory status. (orig.). With 8 figs

  10. Gadolinium-enhanced MR imaging of the wrist in rheumatoid arthritis: value of fat suppression pulse sequences

    Energy Technology Data Exchange (ETDEWEB)

    Nakahara, N. [Department of Radiology, Nagasaki University School of Medicine, Sakamoto 1-7-1, Nagasaki 852 (Japan); Uetani, M. [Department of Radiology, Nagasaki University School of Medicine, Sakamoto 1-7-1, Nagasaki 852 (Japan); Hayashi, K. [Department of Radiology, Nagasaki University School of Medicine, Sakamoto 1-7-1, Nagasaki 852 (Japan); Kawahara, Y. [Department of Radiology, Nagasaki University School of Medicine, Sakamoto 1-7-1, Nagasaki 852 (Japan); Matsumoto, T. [Department of Orthopedics, Nagasaki University School of Medicine, Nagasaki (Japan); Oda, J. [Department of Orthopedics, Nagasaki University School of Medicine, Nagasaki (Japan)

    1996-10-01

    Objective. To determine the usefulness of fat-suppressed gadolinium (Gd)-enhanced MR imaging of the wrist in patients with rheumatoid arthritis (RA). Design and patients. Fat-suppressed Gd-enhanced T1-weighted spin-echo (SE) images were obtained and compared with other standard techniques in 38 wrists of 27 patients (22-77 years) with RA. Scoring based on the degree of synovial enhancement of each joint was developed and the total scores (J-score) were correlated with radiographic stage, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and symptomatic change in the follow-up study. Results. Synovial proliferations showed marked enhancement in all the wrists. In addition, contrast enhancement in the bone marrow and tenosynovium was seen in 36 and eight wrists respectively. Fat-suppressed Gd-enhanced T1-weighted images demonstrated these abnormalities better than other techniques. The J-scores correlated well with values of CRP (P=0.0034), but not with radiographic stages and ESR. Conclusion. Fat-suppressed Gd-enhanced T1-weighted SE images can clearly demonstrate most of the essential lesions in RA including the proliferative synovium, bone erosion, bone marrow inflammatory change, and tenosynovitis. Scoring based on the extent of Gd-enhancement of synovium can be useful in the assessment of the inflammatory status. (orig.). With 8 figs.

  11. Importance of contrast-enhanced fluid-attenuated inversion reconvery magnetic resonance imaging in various intracranial pathologic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Kyoung; Lee, Eun Ja; Kim, Sung Won; Lee, Yong Seok [Dept. of Radiology, Dongguk University Ilsan Hospital, Goyang(Korea, Republic of)

    2016-02-15

    Intracranial lesions may show contrast enhancement through various mechanisms that are closely associated with the disease process. The preferred magnetic resonance sequence in contrast imaging is T1-weighted imaging (T1WI) at most institutions. However, lesion enhancement is occasionally inconspicuous on T1WI. Although fluid-attenuated inversion recovery (FLAIR) sequences are commonly considered as T2-weighted imaging with dark cerebrospinal fluid, they also show mild T1-weighted contrast, which is responsible for the contrast enhancement. For several years, FLAIR imaging has been successfully incorporated as a routine sequence at our institution for contrast-enhanced (CE) brain imaging in detecting various intracranial diseases. In this pictorial essay, we describe and illustrate the diagnostic importance of CE-FLAIR imaging in various intracranial pathologic conditions.

  12. T1-weighted MR images in radiographic stage of fragmentation of Legg-Calve-Perthes disease

    Energy Technology Data Exchange (ETDEWEB)

    Kumasaka, Yukiko; Watanabe, Hitoshi; Kishimoto, Harumasa; Higashihara, Tokuro (Kansai Rosai Hospital, Amagasaki, Hyogo (Japan)); Harada, Koshi; Kozuka, Takahiro

    1991-04-01

    Seven femoral heads of Legg-Calve-Perthes disease (LCPD) in radiographic stage of fragmentation were examined in 6 boys by MRI. Characteristic appearances of capital epiphysis and the surrounding cartilaginous structures can be seen. These were proved by four indices for measurement of cartilaginous contour. Cartilaginous contour of epiphysis is enlarged with crescent like deformity resulting from deformity of growth plate. Characteristic layers or honeycomb pattern of extremely low and intermediate signal intensity can be seen. (author).

  13. T1-weighted MR images in radiographic stage of fragmentation of Legg-Calve-Perthes disease

    International Nuclear Information System (INIS)

    Kumasaka, Yukiko; Watanabe, Hitoshi; Kishimoto, Harumasa; Higashihara, Tokuro; Harada, Koshi; Kozuka, Takahiro.

    1991-01-01

    Seven femoral heads of Legg-Calve-Perthes disease (LCPD) in radiographic stage of fragmentation were examined in 6 boys by MRI. Characteristic appearances of capital epiphysis and the surrounding cartilaginous structures can be seen. These were proved by four indices for measurement of cartilaginous contour. Cartilaginous contour of epiphysis is enlarged with crescent like deformity resulting from deformity of growth plate. Characteristic layers or honeycomb pattern of extremely low and intermediate signal intensity can be seen. (author)

  14. Flip-flop method: A new T1-weighted flow-MRI for plants studies.

    Science.gov (United States)

    Buy, Simon; Le Floch, Simon; Tang, Ning; Sidiboulenouar, Rahima; Zanca, Michel; Canadas, Patrick; Nativel, Eric; Cardoso, Maida; Alibert, Eric; Dupont, Guillaume; Ambard, Dominique; Maurel, Christophe; Verdeil, Jean-Luc; Bertin, Nadia; Goze-Bac, Christophe; Coillot, Christophe

    2018-01-01

    The climate warming implies an increase of stress of plants (drought and torrential rainfall). The understanding of plant behavior, in this context, takes a major importance and sap flow measurement in plants remains a key issue for plant understanding. Magnetic Resonance Imaging (MRI) which is well known to be a powerful tool to access water quantity can be used to measure moving water. We describe a novel flow-MRI method which takes advantage of inflow slice sensitivity. The method involves the slice selectivity in the context of multi slice spin echo sequence. Two sequences such as a given slice is consecutively inflow and outflow sensitive are performed, offering the possiblility to perform slow flow sensitive imaging in a quite straigthforward way. The method potential is demonstrated by imaging both a slow flow measurement on a test bench (as low as 10 μm.s-1) and the Poiseuille's profile of xylemian sap flow velocity in the xylematic tissues of a tomato plant stem.

  15. T1-weighted dual-echo MRI for fat quantification in pediatric nonalcoholic fatty liver disease.

    Science.gov (United States)

    Pacifico, Lucia; Martino, Michele Di; Catalano, Carlo; Panebianco, Valeria; Bezzi, Mario; Anania, Caterina; Chiesa, Claudio

    2011-07-07

    To determine in obese children with nonalcoholic fatty liver disease (NAFLD) the accuracy of magnetic resonance imaging (MRI) in assessing liver fat concentration. A case-control study was performed. Cases were 25 obese children with biopsy-proven NAFLD. Controls were 25 obese children matched for age and gender, without NAFLD at ultrasonography and with normal levels of aminotransferases and insulin. Hepatic fat fraction (HFF) by MRI was obtained using a modification of the Dixon method. HFF ranged from 2% to 44% [mean, 19.0% (95% CI, 15.1-27.4)] in children with NAFLD, while in the controls this value ranged from 0.08% to 4.69% [2.0% (1.3-2.5), P steatosis (r = 0.883, P steatosis, the mean HFF was 8.7% (95% CI, 6.0-11.6) for mild, 21.6% (15.3-27.0) for moderate, and 39.7% (34.4-45.0) for severe fatty liver infiltration. With a cutoff of 4.85%, HFF had a sensitivity of 95.8% for the diagnosis of histological steatosis ≥ 5%. All control children had HFF lower than 4.85%; thus, the specificity was 100%. After 12 mo, children with weight loss displayed a significant decrease in HFF. MRI is an accurate methodology for liver fat quantification in pediatric NAFLD.

  16. Hyperintense brain lesions on T1-weighted MRI after parenteral nutrition

    International Nuclear Information System (INIS)

    Saitoh, Yoshiaki; Kimura, Seiji; Nezu, Atsuo; Ohtsuki, Noriyuki; Kobayashi, Takuya; Osaka, Hitoshi; Uehara, Saori

    1996-01-01

    We experienced five children having T 1 -shortening lesions in basal ganglia or thalami on magnetic resonance imaging (MRI), which were supposed to be caused by manganese (Mn) overdoses. Instead of the presence of above-mentioned lesions, no neurological manifestations corresponding to them had developed in all patients. This observation suggests that MRI is useful for detecting side effects caused by overdoses of Mn in patients having parenteral nutrition. (author)

  17. Gadolinium-enhanced MR imaging in evaluation of Bell palsy

    International Nuclear Information System (INIS)

    Wang, A.M.; Wesolowski, D.P.; Bojrab, D.I.; Ernstoff, R.M.; Farah, J.

    1989-01-01

    Eight patients with Bell palsy were evaluated with Gd-DTPA (Magnevist)-enhanced MR imaging in a 1.0-T Siemen's Magnetom unit. Axial pre-and postcontrast and coronal postcontrast T1-weighted MR images of facial nerves were studied. Significant unilateral enhancement of the facial nerve within the internal auditory canal, with or without involvement of the geniculate ganglia, was found in six patients. Three of these patients without satisfactory response to medical treatment underwent surgical decompression, with excellent recovery of facial nerve function. The authors believe that gadolinium-enhanced MR imaging is valuable in the evaluation and management of Bell palsy

  18. Ossificans myositis: inflammatory changes and contrast enhancement of adjacent bone shown by MR imaging

    International Nuclear Information System (INIS)

    David, H.; Jolles, E.; Le Friant, G.; Silvestre, A.; Sarrazin, J.L.; Gordoliani, Y.S.

    1995-01-01

    The authors report a case of ossificans myositis, in which magnetic resonance imaging (MRI) showed inflammatory changes of the adjacent bone. T 1 weighted fat saturation sequence with gadolinium injection showed enhancement of medullary and cortical bone. This potentially mistaking pattern must be known, to avoid mis diagnosing with malignant osseous tumor, specially before achievement of the characteristic pattern of zonal maturation and its calcified rim. (authors). 15 refs., 6 figs

  19. Added value of contrast-enhanced CISS imaging in relation to conventional MR images for the evaluation of intracavernous cranial nerve lesions

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, Akiko; Takahashi, Ayako; Morita, Hideo; Amanuma, Makoto; Endo, Keigo [Gunma University School of Medicine, Department of Diagnostic Radiology and Nuclear Medicine, Gunma (Japan); Sato, Noriko [National Center Hospital of Neurology and Psychiatry, Department of Radiology, Kodaira, Tokyo (Japan); Takeuchi, K. [Takasaki University of Health and Welfare, Department of Health and Welfare, Gunma (Japan)

    2010-12-15

    The normal cranial nerves (CNs) of the cavernous sinus can be clearly demonstrated using contrast-enhanced constructive interference in steady-state (CISS) magnetic resonance imaging (MRI). This study used the method to evaluate pathological CNs III, IV, V{sub 1}, V{sub 2}, and VI in cavernous sinuses affected by inflammatory and neoplastic diseases. MR images from 17 patients with diseases involving the cavernous sinuses and/or causing neuropathy in CNs III-VI were retrospectively evaluated. The patients were divided into inflammatory (n = 11) and neoplastic (n = 6) groups. We defined CNs as abnormal when they exhibited enlargement or enhancement. CNs were evaluated using both contrast-enhanced CISS and T1-weighted MRI. In the inflammatory group, abnormal CNs were identified by contrast-enhanced CISS MRI in 13 of 25 symptomatic CNs (52%) in eight patients, but in only two CNs (8%) in two patients by contrast-enhanced T1-weighted MRI. In the neoplastic group, both sequences of contrast-enhanced CISS and T1-weighted MRI detected abnormalities in the same three of eight symptomatic CNs (37.5%), i.e., the three CNs were all in the same patient with adenoid cystic carcinoma. Contrast-enhanced CISS MRI is useful for detecting CN abnormalities in inflammatory pathological conditions of the cavernous sinuses. (orig.)

  20. Dynamic contrast-enhanced magnetic resonance imaging of articular and extraarticular synovial structures of the hands in patients with psoriatic arthritis

    DEFF Research Database (Denmark)

    Cimmino, Marco Amedeo; Barbieri, Francesca; Boesen, Mikael

    2012-01-01

    Dynamic, contrast-enhanced magnetic resonance imaging (DCE-MRI), the quantification of enhancement within the synovial membrane and bone by extracting curves using fast T1-weighted sequences during intravenous administration of contrast agent, evaluates synovitis and bone marrow edema in psoriati...... arthritis (PsA). In this pilot study, we looked at possible differences between joint synovitis and tenosynovitis in PsA as compared with rheumatoid arthritis (RA)....

  1. The enhancement effects of Gd-DTPA for cerebro-spinal lesions

    International Nuclear Information System (INIS)

    Mano, Isamu; Yoshida, Hideo; Kono, Takeshi; Tsuchida, Takashi; Terao, Hideo; Iio, Masahiro.

    1987-01-01

    Effects of Gadolinium DTPA enhancement in MRI for cerebro-spinal lesions were studied on 20 patients. In this study, pre-contrast T 2 weighted image and the postcontrast T 1 weighted image were, especially, compared. Out of 20 cases investigated, the clinical significance of Gd-DTPA was recognized clearly in 14 cases. In the other 6 cases, some new information, though which did not give us the direct clinical significance, was also obtained. It was confirmed that T 2 weighted sequence without Gd-DTPA was the best in sensitivity, while T 1 weighted sequence after Gd-DTPA administration was superior in specificity of the information in making a discrimination between tumor and edema, gliosis and in the time-course of infarction. (author)

  2. Correlation between chondroitin sulfate iron colloid - enhanced MR imaging and the histological grade of hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Suto, Y. [Dept. of Radiology, Tottori University School of Medcine, Yonago (Japan); Kodama, F. [Dept. of Radiology, Tottori University School of Medcine, Yonago (Japan); Kamba, M. [Dept. of Radiology, Tottori University School of Medcine, Yonago (Japan); Ohta, Y. [Dept. of Radiology, Tottori University School of Medcine, Yonago (Japan)

    1995-01-01

    The association between contrast enhancement by chondroitin sulfate iron colloid (CSIC) and the histological grade of hepatocellular carcinoma (HCC) was evaluated in 24 patients diagnosed by histological examination of surgical specimens (26 nodules: 11 well-differentiated and 15 poorly-moderately-differentiated nodules). In the well-differentiated HCC nodules, the tumor-liver contrast to noise ratio (CNR) was not significantly increased after i.v. CSIC injection on both T1-weighted and T2-weighted images. In the moderately-poorly-differentiated HCC, CNR was significantly increased after CSIC administration on both T1-weighted and T2-weighted images (p<0.01). MR imaging using CSIC may be useful for diagnosing the degree of HCC differentiation. (orig.).

  3. Correlation between chondroitin sulfate iron colloid - enhanced MR imaging and the histological grade of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Suto, Y.; Kodama, F.; Kamba, M.; Ohta, Y.

    1995-01-01

    The association between contrast enhancement by chondroitin sulfate iron colloid (CSIC) and the histological grade of hepatocellular carcinoma (HCC) was evaluated in 24 patients diagnosed by histological examination of surgical specimens (26 nodules: 11 well-differentiated and 15 poorly-moderately-differentiated nodules). In the well-differentiated HCC nodules, the tumor-liver contrast to noise ratio (CNR) was not significantly increased after i.v. CSIC injection on both T1-weighted and T2-weighted images. In the moderately-poorly-differentiated HCC, CNR was significantly increased after CSIC administration on both T1-weighted and T2-weighted images (p<0.01). MR imaging using CSIC may be useful for diagnosing the degree of HCC differentiation. (orig.)

  4. Detection of acute avascular necrosis with dynamic contrast-enhanced MR imaging

    International Nuclear Information System (INIS)

    Nadel, S.N.; Richardson, W.J.; Martinez, S.; Rizk, W.S.; Malizos, K.; Debatin, J.F.

    1991-01-01

    Early detection of avascular necrosis (AVN) may allow earlier intervention and lead to improved treatment success. This paper is designed to compare standard and dynamic contrast-enhanced MR imaging in the detection of acute AVN. A previously described animal model of AVN was used. Five anesthetized dogs underwent right femoral head devascularization, including placement of a supercooling coil around the femoral neck. Within 3 hours the dogs were imaged in a 1.5-T Signa magnet. Standard T1-weighted, T2-weighted, and STIR images were obtained through both hips. A DiGrass sequence with 30 sequential 3.2-second T1-weighted images was used, and 0.2 mmol/kg gadoteridol was injected intravenously at the start of the sequence at 2 mL/sec with an automated injector. Following imaging, oxytetracycline was given intravenously. After 3 days the dogs were killed, and their femoral heads were extracted, coronally sectioned, and analyzed for fluorescence. T1-weighted, T2-weighted, and STIR sequences showed no marrow abnormalities on either the normal or the operated-on side. With contrast material injection, all normal areas and the unoperated portion the femoral neck and diaphysis enhanced markedly 4-9 seconds following the bolus

  5. Magnetic resonance imaging of urinary bladder carcinoma: tumor staging and gadolinium contrast-enhanced imaging

    International Nuclear Information System (INIS)

    Doringer, E.; Joos, H.; Forstner, R.; Schmoller, H.

    1992-01-01

    Forty-nine patients with urinary bladder carcinomas underwent pre-operative examinations using magnetic resonance (MR) imaging. The results of the MR examinations were correlated with the clinical-pathological findings following transurethral resection (TUR) and bimanual palpation (n = 47) or radical cystectomy (n = 2). The results of pre-contrast MR tumor staging (T1, T2), viewing stages Tis-T2 collectively, and subsequent to separate assessments of stages T3b-T4b, were correct 76.6% of the time. Gadolinium-DTPA (Gd-DTPA) contrast-enhanced examinations (pre-contrast T1 and after Gd-DTPA) showed a staging accuracy rate of 85.7%. T2-weighted images did not indicate any advantage when compared to T1-weighted images following Gd-DTPA. The signal intensity ratios of tumor/fat and tumor/muscle tissue were measured on T1-weighted pre-contrast images and following Gd-DTPA and then evaluated statistically, whereby the increased tumor signal intensity was statistically significant (Wilcoxon test, P < 0.01). Due to the relatively short examination time needed for T1-weighted images and the specific tumor enhancement, the administration of Gd-DTPA proves valuable in the diagnosis of bladder carcinomas. T2-weighted images are not necessary. (orig.)

  6. Serial contrast-enhanced magnetic resonance and magnetization transfer in the study of patients with multiple sclerosis

    International Nuclear Information System (INIS)

    Rovira, A.; Alonso, J.; Cucurella, G.; Nos, C.; Tintore, M.; Pedraza, S.; Rio, J.; Montalban, X.

    1997-01-01

    To demonstrate the changes in the magnetization transfer ratio (MTR) of different demyelinating plaques, correlating them with the baseline values in T1-weighted contrast-enhanced magnetic resonance (MR) sequences in order to relate them more closely to the underlying disease. The study was based on 33 demyelinating plaques obtained from six patients clinically diagnosed as having remitting-recurring multiple sclerosis (MS). All the patients underwent two MR studies at a 3 to 5-month interval, including contrast-enhanced T1 and T2- weighted sequences and magnetization transfer images. The latter were used to calculate the MTR for each of the demyelinating plaques included in the study. The statistical analysis of the results obtained revealed statistically significant between initial MTR values and those of subsequent T1-weighted sequences. The MTR demonstrate significant differences between plaques according to contrast-enhanced T1-weigh tes sequences, probably indicating variable degrees of edema, demyelination and tissue destruction. These differences should be taken into account to enable the use of T1-weighted sequences to quantify the lesion load in MS patients. (Author) 35 refs

  7. Hepatocellular carcinoma on MR diffusion weighted imaging and dynamic contrast-enhanced imaging

    International Nuclear Information System (INIS)

    Dong Aisheng; Zuo Changjing; Tian Jianming; Lu Jianping; Wang Jian; Wang Li; Wang Fei

    2009-01-01

    Objective: To evaluate the findings of hepatocellular carcinoma (HCC) on DWI and dynamic Gd-DTPA-enhanced MR imaging. Methods: Eighty one patients with chronic hepatitis or liver cirrhosis underwent both DWI and dynamic Gd-DTPA-enhanced MRI studies of the liver for HCC detection. MR data of were retrospectively analyzed. Two observers determined in consensus the location and the number of focal lesions. The signal manifestation of the lesions on DWI and dynamic Gd-DTPA-enhanced MR imaging were analyzed. Results: DWI and Gd-DTPA-enhanced MR images detected 122 HCCs and 14 benign lesions. One hundred and sixteen HCCs (95.1%) showed hyperintensity on DWI and 6 HCCs in patients with severe cirrhosis showed isointensity. One hundred and five HCCs (86.1%) revealed hypointensity, 11 HCCs (9.0%) showed isointensity and 6 HCCs (4.9%) exhibited hyperintensity on T 1 weighted images. On Gd-DTPA-enhanced MR images, 101 HCCs(82.8%) were significantly enhanced on arterial phase and 99 HCCs showed hypointensity on portal and equilibrium phases. Twenty HCCs (16.4%), 18 of 20 less than 20 mm in diameter, showed isointensity on arterial phase and hyperintensity on DWI. Eight of 14 benign lesions showed hyperintensity and 6 isointensity on DWI. Five benign lesions with hypointensity on T 1 weighted images without contrast and hyperintensity on DWI showed no enhancement on Gd-DTPA-enhanced MR images; 6 benign lesions with isointensity on both T 1 weighted imaging without contrast and DWI exhibited avid enhancement on arterial phase and isointensty on portal and equilibrium phases; one of the two benign lesions, with isointensity before and after contrast images and hyperintentiy on DWI, was a regenerative nodule; another regenerative nodule with hyperintensity on both T 1 weighted images without contrast and DWI was greatly enhanced on arterial phase and showed isointensity on portal and equilibrium phases. Conclusions: Most of the HCCs were greatly enhanced on arterial phase on Gd-DTPA-enhanced

  8. Basivertebral plexus enhancement at MR imaging after Gd-DTPA administration

    International Nuclear Information System (INIS)

    Bronstein, A.D.; Cohen, W.A.; Maravilla, K.R.

    1989-01-01

    This paper presents a study to identify noncontrast versus post-Gd-DTPA MR images of the spine, we analyzed the basivertebral plexus. The authors postulate that there are consistent patterns of enhancement specific with Gd-DTPA. This is a retrospective examination of the normal appearance and enhancement patterns of the basivertebral plexus in 805 vertebrae of 30 patients who underwent pre- and post-Gd-DTPA T1-weighted sagittal MR imaging of the spine. All patients show enhancement of the basivertebral plexus in a significant number of vertebrae when pre-and postcontrast images are compared

  9. Ossificans myositis: inflammatory changes and contrast enhancement of adjacent bone shown by MR imaging; Myosite ossifiante circonscrite: remaniements osseux deceles en IRM

    Energy Technology Data Exchange (ETDEWEB)

    David, H.; Jolles, E.; Le Friant, G.; Silvestre, A.; Sarrazin, J.L.; Gordoliani, Y.S. [Hopital des Armees du Val-de-Grace, 75 - Paris (France)

    1995-07-01

    The authors report a case of ossificans myositis, in which magnetic resonance imaging (MRI) showed inflammatory changes of the adjacent bone. T 1 weighted fat saturation sequence with gadolinium injection showed enhancement of medullary and cortical bone. This potentially mistaking pattern must be known, to avoid mis diagnosing with malignant osseous tumor, specially before achievement of the characteristic pattern of zonal maturation and its calcified rim. (authors). 15 refs., 6 figs.

  10. Biliary enhanced MR imaging by Gd-DTPA

    International Nuclear Information System (INIS)

    Ohkawa, Shinichi; Fujikura, Yuji; Kanai, Toshio; Hiramatsu, Kyoichi.

    1992-01-01

    Biliary enhanced MRI (BEMRI) by Gd-DTPA via PTCD and/or PTGBD tube for obstructive jaundice was performed in 8 patients. In all cases, biliary tract was clearly visualised as high signal intensity on T1 weighted images. On same images, primary lesion such as common bile duct cancer was also visualised as well as portal system. In addition, MR angiography (MRA) by 2D-time of flight method was performed. MRA with BEMRI shows portal encasement on the same image as biliary tract obstruction. This suggests MRA with BEMRI may replace the other modality for obstructive jaundice. (author)

  11. MR-perfusion (MRP) and diffusion-weighted imaging (DWI) in prostate cancer: Quantitative and model-based gadobenate dimeglumine MRP parameters in detection of prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Scherr, M.K., E-mail: michael.scherr@med.uni-muenchen.de [Institute of Clinical Radiology, University of Munich, Munich (Germany); Seitz, M. [Department of Urology, University of Munich, Munich (Germany); Mueller-Lisse, U.G. [Institute of Clinical Radiology, University of Munich, Munich (Germany); Ingrisch, M. [Josef Lissner Laboratory for Biomedical Imaging, Institute of Clinical Radiology, University of Munich, Munich (Germany); Reiser, M.F. [Institute of Clinical Radiology, University of Munich, Munich (Germany); Mueller-Lisse, U.L. [Department of Urology, University of Munich, Munich (Germany)

    2010-12-15

    Background: Various MR methods, including MR-spectroscopy (MRS), dynamic, contrast-enhanced MRI (DCE-MRI), and diffusion-weighted imaging (DWI) have been applied to improve test quality of standard MRI of the prostate. Purpose: To determine if quantitative, model-based MR-perfusion (MRP) with gadobenate dimeglumine (Gd-BOPTA) discriminates between prostate cancer, benign tissue, and transitional zone (TZ) tissue. Material and methods: 27 patients (age, 65 {+-} 4 years; PSA 11.0 {+-} 6.1 ng/ml) with clinical suspicion of prostate cancer underwent standard MRI, 3D MR-spectroscopy (MRS), and MRP with Gd-BOPTA. Based on results of combined MRI/MRS and subsequent guided prostate biopsy alone (17/27), biopsy and radical prostatectomy (9/27), or sufficient negative follow-up (7/27), maps of model-free, deconvolution-based mean transit time (dMTT) were generated for 29 benign regions (bROIs), 14 cancer regions (cROIs), and 18 regions of transitional zone (tzROIs). Applying a 2-compartment exchange model, quantitative perfusion analysis was performed including as parameters: plasma flow (PF), plasma volume (PV), plasma mean transit time (PMTT), extraction flow (EFL), extraction fraction (EFR), interstitial volume (IV) and interstitial mean transit time (IMTT). Two-sided T-tests (significance level p < 0.05) discriminated bROIs vs. cROIs and cROIs vs. tzROIs, respectively. Results: PMTT discriminated best between bROIs (11.8 {+-} 3.0 s) and cROIs (24.3 {+-} 9.6 s) (p < 0.0001), while PF, PV, PS, EFR, IV, IMTT also differed significantly (p 0.00002-0.0136). Discrimination between cROIs and tzROIs was insignificant for all parameters except PV (14.3 {+-} 2.5 ml vs. 17.6 {+-} 2.6 ml, p < 0.05). Conclusions: Besides MRI, MRS and DWI quantitative, 2-compartment MRP with Gd-BOPTA discriminates between prostate cancer and benign tissue with several parameters. However, distinction of prostate cancer and TZ does not appear to be reliable.

  12. Degeneration of uterine leiomyoma: comparison between Gd-DTPA enhanced MR imaging and pathologic findings

    International Nuclear Information System (INIS)

    Shin, M. J.; Kim, G. W.; No, T. Y.; Ahn, W. H.; Baik, S. K.; Kim, B. G.; Choi, H. Y.; Paik, O. J.

    1995-01-01

    Gonadotropin-releasing hormone(GnRH) analogues have been used as a conservative or preoperative therapy in the treatment of uterine leiomyoma. Since these drugs, which can induce a low estrogenic state, affect only undegenerative leiomyoma tissue, the aim of the present study was to differentiate degenerative leiomyoma from undegenerative one by Gd-DTPA enhanced magnetic resonance imaging(MRI). There were 40 masses in 24 patients; all were diagnosed by surgical-pathology. With superconductive 0.5T MR circuit, T1-and T2-weighted images and Gd-DTPA T1-weighted images were obtained. Based on a combination of signal intensities of T2-weighted and enhanced T1 weighted image on the same tumor section all the lesions were classified to one of four MRI patterns. Pattern I was a heterogeneous hyperintensity on the T2-weighted images that was enhancement by Gd-DTPA. Pattern II was a high signal intensity on the T2-weighted MR images but no enhancement by Gd-DTPA. Pattern III was a low to intermediate signal intensity on the T2-weighted MR images and enhancement on the Gd-DTPA T1-weighted images. Pattern IV was a low to intermediate signal intensity on the T2-weighted images and no enhancement by Gd-DTPA. Each of these 4 groups of MRI pattern were co-related to the surgical-pathology findings. Pathologically, pattern I corresponded to an edematous leiomyoma in 3 cases and a connective tissue leiomyoma in one case. Pattern II corresponded to three red degeneration, two cystic degeneration and one infected leiomyoma. Pattern III corresponded to eighteen undegenerative leiomyomas, but some of them showed focal connective tissue proliferation. All of twelve cases in pattern IV corresponded to a hyaline degeneration. MRI with Gd-DTPA enhancement may differentiate undegenerative leiomyoma from degenerated one

  13. Degeneration of uterine leiomyoma: comparison between Gd-DTPA enhanced MR imaging and pathologic findings

    Energy Technology Data Exchange (ETDEWEB)

    Shin, M. J.; Kim, G. W.; No, T. Y.; Ahn, W. H.; Baik, S. K.; Kim, B. G.; Choi, H. Y.; Paik, O. J. [Wallace Memorial Baptist Hospital, Busan (Korea, Republic of)

    1995-05-15

    Gonadotropin-releasing hormone(GnRH) analogues have been used as a conservative or preoperative therapy in the treatment of uterine leiomyoma. Since these drugs, which can induce a low estrogenic state, affect only undegenerative leiomyoma tissue, the aim of the present study was to differentiate degenerative leiomyoma from undegenerative one by Gd-DTPA enhanced magnetic resonance imaging(MRI). There were 40 masses in 24 patients; all were diagnosed by surgical-pathology. With superconductive 0.5T MR circuit, T1-and T2-weighted images and Gd-DTPA T1-weighted images were obtained. Based on a combination of signal intensities of T2-weighted and enhanced T1 weighted image on the same tumor section all the lesions were classified to one of four MRI patterns. Pattern I was a heterogeneous hyperintensity on the T2-weighted images that was enhancement by Gd-DTPA. Pattern II was a high signal intensity on the T2-weighted MR images but no enhancement by Gd-DTPA. Pattern III was a low to intermediate signal intensity on the T2-weighted MR images and enhancement on the Gd-DTPA T1-weighted images. Pattern IV was a low to intermediate signal intensity on the T2-weighted images and no enhancement by Gd-DTPA. Each of these 4 groups of MRI pattern were co-related to the surgical-pathology findings. Pathologically, pattern I corresponded to an edematous leiomyoma in 3 cases and a connective tissue leiomyoma in one case. Pattern II corresponded to three red degeneration, two cystic degeneration and one infected leiomyoma. Pattern III corresponded to eighteen undegenerative leiomyomas, but some of them showed focal connective tissue proliferation. All of twelve cases in pattern IV corresponded to a hyaline degeneration. MRI with Gd-DTPA enhancement may differentiate undegenerative leiomyoma from degenerated one.

  14. Three-dimensional gradient echo versus spin echo sequence in contrast-enhanced imaging of the pituitary gland at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Kakite, Suguru, E-mail: sugkaki@med.tottori-u.ac.jp [Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1, Nishicho, Yonago 683-8503 (Japan); Fujii, Shinya [Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1, Nishicho, Yonago 683-8503 (Japan); Kurosaki, Masamichi [Department of Neurosurgery, Faculty of Medicine, Tottori University, 36-1, Nishicho, Yonago 683-8503 (Japan); Kanasaki, Yoshiko; Matsusue, Eiji; Kaminou, Toshio; Ogawa, Toshihide [Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1, Nishicho, Yonago 683-8503 (Japan)

    2011-07-15

    Introduction: To clarify whether a three-dimensional-gradient echo (3D-GRE) or spin echo (SE) sequence is more useful for evaluating sellar lesions on contrast-enhanced T1-weighted MR imaging at 3.0 Tesla (T). Methods: We retrospectively assessed contrast-enhanced T1-weighted images using 3D-GRE and SE sequences at 3.0 T obtained from 33 consecutive patients with clinically suspected sellar lesions. Two experienced neuroradiologists evaluated the images qualitatively in terms of the following criteria: boundary edge of the cavernous sinus and pituitary gland, border of sellar lesions, delineation of the optic nerve and cranial nerves within the cavernous sinus, susceptibility and flow artifacts, and overall image quality. Results: At 3.0 T, 3D-GRE provided significantly better images than the SE sequence in terms of the border of sellar lesions, delineation of cranial nerves, and overall image quality; there was no significant difference regarding the boundary edge of the cavernous sinus and pituitary gland. In addition, the 3D-GRE sequence showed fewer pulsation artifacts but more susceptibility artifacts. Conclusion: Our results indicate that 3D-GRE is the more suitable sequence for evaluating sellar lesions on contrast-enhanced T1-weighted imaging at 3.0 T.

  15. The usefulness of T2-weighted MR urography and contrast enhanced MR urography in the evaluation of obstructive uropathy: comparisonal study with antegrade pyelography

    International Nuclear Information System (INIS)

    Oh, Chang Hoon; Lee, Jeong Min; Jin, Kong Yong; Chung, Gyung Ho; Cho, Seung Il; Lee, Sang Hun; Kim, Young Kon; Oh, Gyung Jae

    2002-01-01

    To compare the efficacy of contrast-enhanced and T2-weighted magnetic resonance urography (MRU) for the depiction of obstruction and evaluation of the causes of obstructive uropathy with that of antegrade pyelography. Twenty-five patients with obstructive uropathy who underwent percutaneous nephrostomy (PCN) and antegrade pyelography( AGP) were included in the study. We performed MR urography, comprising half-Fourier acquisition single-shot turbo spin-echo (HASTE) T2- weighted imaging and 3-D fast imaging with steady state precession (3-D FISP) T1-weighted imaging after gadolinium enhancement and compared the quality of the images of both the HASTE and 3-D FISP MRU technique in terms of their depiction of the dilated pelvocalyceal system, and the level, type, and causes of obstruction. In terms of anatomical depiction of the pelvocalyceal system (p=0.002) and the causes of obstruction (p=0.003). T1-weighted MRU using 3D-FISP was significantly better than T2-weighted MRU using the HASTE sequence. Regarding level of obstruction, T2-weighted MRU using the HASTE sequence and contrast enhanced T1-weighted MRU using 3D-FISP showed an accuracy of 76% (19/25) and 84% (21/25), respectively. In terms of type of obstruction, the accuracy of T2-weighted MRU and T1-weighted CEMRU was 72% (18/25) and 88% (22/25), respectively. T2-weighted MRU and Ta-weighted CEMRU provided both anatomical information and that relating to impaired renal function. The two modelities played a complementary role and their use could decrease the unnecessary use of invasive diagnostic examination for the evaluation of obstructive uropathy

  16. Gadolinium-enhanced turbo FLASH MR imaging of renal perfusion and excretion

    International Nuclear Information System (INIS)

    Watanabe, A.; Teresi, L.M.; Herbst, M.; O'Sullivan, R.M.; Lee, R.; Smith, C.; Renner, J.; Rappaport, A.; Bradley, W.G. Jr.

    1990-01-01

    This paper describes a novel approach to MR imaging of renal perfusion and excretion using gadolinium-enhanced, T1-weighted TURBP, fast low-angle shot (FLASH) imaging. Five normal volunteers and four patients were studied on a 1.5-T imaging system. Time-intensity curves of the appearance of gadolinium in each kidney and the bladder were then generated. In normal volunteers, marked first-pass enhancement of renal cortex followed by renal pyramids and collecting systems could be demonstrated on the first-pass gadolinium images. Delayed images showed hyperintense gadolinium within the bladder

  17. Gadolinium-DTPA enhancement of experimental soft tissue carcinoma and hemorrhage in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Pettersson, H.; Ackerman, N.; Kaude, J.; Googe, R.E.; Mancuso, A.A.; Scott, K.N.; Hackett, R.H.; Hager, D.A.; Caballero, S.; Florida Univ., Gainesville

    1987-01-01

    An experimental series in the rabbit was performed to test gadolinium-DTPA (Gd-DTPA) enhancement of VX-2 carcinoma and hemorrhages induced in the soft tissues. The recognition of both malignant and benign lesions was greatly facilitated on T1 weighted images after intravenous administration of 0.3 mmol Gd-DTPA/kg body weigth because of reduced T1 relaxation times. Gd-DTPA enhancement reached its maximum after 10-15 minutes and was most apparent in tumor tissue, connective tissue surrounding the tumor and in the area of fresh hemorrhage. (orig.)

  18. Gadolinium-DTPA enhancement of VX-2 carcinoma of the rabbit kidney on Tl weighted magnetic resonance images

    International Nuclear Information System (INIS)

    Yancey, J.M.; Ackerman, N.; Kaude, J.V.; Googe, R.E.; Fitzsimmons, J.R.; Scott, K.N.; Mancuso, A.A.; Hackett, R.L.; Hager, D.A.; Caballero, S.; Florida Univ., Gainesville

    1987-01-01

    Experimental renal carcinoma was induced by percutaneous injection of VX-2 carcinoma cells into the left kidney in New Zealand white rabbits. Magnetic resonance imaging (MRI) was performed at 0.15 T before and after intravenous injection of 0.3 mmol gadolinium-DTPA (Gd-DTPA) per kg body weight. Gd-DTPA enhanced the tumors by increasing the signal intensity on T1 weighted images. The enhancement was evident immediately after Gd-DTPA injection, increasing during the observation time of 30 minutes. Histologically the areas of enhancement corresponded well to the viable tumor tissue. (orig.)

  19. Enhanced

    Directory of Open Access Journals (Sweden)

    Martin I. Bayala

    2014-06-01

    Full Text Available Land Surface Temperature (LST is a key parameter in the energy balance model. However, the spatial resolution of the retrieved LST from sensors with high temporal resolution is not accurate enough to be used in local-scale studies. To explore the LST–Normalised Difference Vegetation Index relationship potential and obtain thermal images with high spatial resolution, six enhanced image sharpening techniques were assessed: the disaggregation procedure for radiometric surface temperatures (TsHARP, the Dry Edge Quadratic Function, the Difference of Edges (Ts∗DL and three models supported by the relationship of surface temperature and water stress of vegetation (Normalised Difference Water Index, Normalised Difference Infrared Index and Soil wetness index. Energy Balance Station data and in situ measurements were used to validate the enhanced LST images over a mixed agricultural landscape in the sub-humid Pampean Region of Argentina (PRA, during 2006–2010. Landsat Thematic Mapper (TM and Moderate Resolution Imaging Spectroradiometer (EOS-MODIS thermal datasets were assessed for different spatial resolutions (e.g., 960, 720 and 240 m and the performances were compared with global and local TsHARP procedures. Results suggest that the Ts∗DL technique is the most adequate for simulating LST to high spatial resolution over the heterogeneous landscape of a sub-humid region, showing an average root mean square error of less than 1 K.

  20. Improved wrist pannus volume measurement from contrast-enhanced MRI in rheumatoid arthritis using shuffle transform.

    Science.gov (United States)

    Xanthopoulos, Emily; Hutchinson, Charles E; Adams, Judith E; Bruce, Ian N; Nash, Anthony F P; Holmes, Andrew P; Taylor, Christopher J; Waterton, John C

    2007-01-01

    Contrast-enhanced MRI is of value in assessing rheumatoid pannus in the hand, but the images are not always easy to quantitate. To develop and evaluate an improved measurement of volume of enhancing pannus (VEP) in the hand in human rheumatoid arthritis (RA). MR images of the hand and wrist were obtained for 14 patients with RA at 0, 1 and 13 weeks. Volume of enhancing pannus was measured on images created by subtracting precontrast T1-weighted images from contrast-enhanced T1-weighted images using a shuffle transformation technique. Maximum intensity projection (MIP) and 3D volume rendering of the images were used as a guide to identify the pannus and any contrast-enhanced veins. Visualisation of pannus was much improved following the shuffle transform. Between 0 weeks and 1 week, the mean value of the within-subject coefficient of variation (CoV) was 0.13 and the estimated total CoV was 0.15. There was no evidence of significant increased variability within the 13-week interval for the complete sample of patients. Volume of enhancing pannus can be measured reproducibly in the rheumatoid hand using 3D contrast-enhanced MRI and shuffle transform.

  1. Dynamic contrast-enhanced, extremity-dedicated MRI identifies synovitis changes in the follow-up of rheumatoid arthritis patients treated with rituximab

    DEFF Research Database (Denmark)

    Cimmino, Marco A; Parodi, Massimiliano; Zampogna, Giuseppe

    2014-01-01

    according to the 1987 ACR criteria were treated with a single course of RTX (2 infusions of 1000 mg, 15 days apart). MRI of the dominant hand was performed with a 0.2T extremity-dedicated machine using pre and post contrast T1 weighted SE, turbo 3D, and STIR sequences at baseline, and after 4 and 24 weeks....... MRI was analysed using the OMERACT-RAMRIS score and the dynamic contrast-enhanced (DCE-MRI) technique for wrist synovitis, which calculates the enhancement ratio as both rate of early enhancement (REE) and relative enhancement (RE). The corresponding ME and IRE parameters were calculated also through...

  2. Serial contrast-enhanced magnetic resonance and magnetization transfer in the study of patients with multiple sclerosis; Resonancia magnetica con contraste y transferencia de magnetizacion en el estudio seriado de pacientes con esclerosis multiple

    Energy Technology Data Exchange (ETDEWEB)

    Rovira, A; Alonso, J; Cucurella, G; Nos, C; Tintore, M; Pedraza, S; Rio, J; Montalban, X [Hospital General i Universitari Vall d` Hebron. Barcelona (Spain)

    1998-12-31

    To demonstrate the changes in the magnetization transfer ratio (MTR) of different demyelinating plaques, correlating them with the baseline values in T1-weighted contrast-enhanced magnetic resonance (MR) sequences in order to relate them more closely to the underlying disease. The study was based on 33 demyelinating plaques obtained from six patients clinically diagnosed as having remitting-recurring multiple sclerosis (MS). All the patients underwent two MR studies at a 3 to 5-month interval, including contrast-enhanced T1 and T2- weighted sequences and magnetization transfer images. The latter were used to calculate the MTR for each of the demyelinating plaques included in the study. The statistical analysis of the results obtained revealed statistically significant between initial MTR values and those of subsequent T1-weighted sequences. The MTR demonstrate significant differences between plaques according to contrast-enhanced T1-weigh tes sequences, probably indicating variable degrees of edema, demyelination and tissue destruction. These differences should be taken into account to enable the use of T1-weighted sequences to quantify the lesion load in MS patients. (Author) 35 refs.

  3. Gadolinium-DTPA enhanced magnetic resonance imaging of bone cysts in patients with rheumatoid arthritis.

    Science.gov (United States)

    Gubler, F M; Algra, P R; Maas, M; Dijkstra, P F; Falke, T H

    1993-01-01

    OBJECTIVES--To examine the contents of intraosseous cysts in patients with rheumatoid arthritis (RA) through the signal intensity characteristics on gadolinium-DTPA (Gd-DTPA) enhanced magnetic resonance imaging. METHODS--The hand or foot joints of nine patients with the cystic form of RA (where the initial radiological abnormality consisted of intraosseous cysts without erosions) were imaged before and after intravenous administration of Gd-DTPA. A 0.6 unit, T1 weighted spin echo and T2* weighted gradient echo were used to obtain images in at least two perpendicular planes. RESULTS--Most cysts showed a low signal intensity on the non-enhanced T1 weighted (spin echo) images and a high signal intensity on the T2* weighted (gradient echo) images, consistent with a fluid content. No cyst showed an enhancement of signal intensity on the T1 weighted images after intravenous administration of Gd-DTPA, whereas synovium hyperplasia at the site of bony erosions did show an increased signal intensity after Gd-DTPA. Magnetic resonance imaging detected more cysts (as small as 2 mm) than plain films, and the cysts were located truly intraosseously. In six patients no other joint abnormalities were identified by magnetic resonance imaging; the three other patients also showed, after Gd-DTPA administration, an enhanced synovium at the site of bony erosions. CONCLUSIONS--It is suggested that intraosseous bone cysts in patients with RA do not contain hyperaemic synovial proliferation. The bone cysts in patients with the cystic form of RA may be the only joint abnormality. Images PMID:8257207

  4. Mediastinal lymphoma: quantitative changes in gadolinium enhancement at MR imaging after treatment.

    Science.gov (United States)

    Rahmouni, A; Divine, M; Lepage, E; Jazaerli, N; Belhadj, K; Gaulard, P; Golli, M; Reyes, F; Vasile, N

    2001-06-01

    To compare changes in gadolinium enhancement at magnetic resonance (MR) imaging with outcome in mediastinal lymphoma after treatment. Thirty-one patients with bulky mediastinal lymphoma (17 with Hodgkin disease, 14 with non-Hodgkin lymphoma) underwent serial MR imaging before and up to 50 months after treatment, with routine follow-up (including computed tomography). Signal intensity ratios between masses and muscle were calculated on T1-weighted, T2-weighted, and contrast material-enhanced T1-weighted spin-echo MR images. The percentage enhancement and signal intensity ratios of mediastinal masses on T2-weighted MR images were calculated at diagnosis and during and after treatment. Twenty-one patients with persistent complete remission had a mean percentage enhancement of residual masses (4%; range, -26% to 40%) that was significantly lower than that of initial masses (78%; range, 41%-124%). Although the mean signal intensity ratio of residual masses on T2-weighted images was significantly lower than that of initial masses, an increase in this ratio was observed in four patients after treatment. In seven patients with relapse, the percentage enhancement value of the residual mass was as high as that of the initial mass. Gadolinium enhancement of lymphomatous masses of the mediastinum decreased markedly after treatment in patients in continuous complete remission but not in patients with relapse.

  5. Contrast-Enhanced MR Angiography (CEMRA) in Peripheral Arterial Occlusive Disease (PAOD): conventional moving table technique versus hybrid technique; Kontrastverstaerkte MR-Angiographie (CEMRA) bei peripherer AVK (pAVK): konventionelle Tischverschiebetechnik versus Hybrid-Technik

    Energy Technology Data Exchange (ETDEWEB)

    Kalle, T. von; Gerlach, A.; Hatopp, A.; Klinger, S.; Prodehl, P.; Arlat, I.P. [Katharinenhospital, Stuttgart (Germany). Radiologisches Inst.

    2004-01-01

    Patients and Methods: 80 patients (males n = 60, females n = 20, median age = 70 years, diabetics n = 27) with PAOD were examined with a 1,5T system (40 mT/m) using a dedicated phased array peripheral vascular coil. Protocol A consisted of a single injection of Gd-BOPTA with consecutive craniocaudal image acquisition and protocol B of two injections, with the first injection of Gd-BOPTA followed by image acquisition of the popliteocrural and pedal segments and the second injection followed by acquiring the aortoiliac and femoral segments (hybrid technique). The evaluation of the arterial system was directed to the iliac, femoral, popliteocrural and pedal arteries. Results: The visualization of the entire aortopedal vascular system was of diagnostically good or satisfactory quality in 16 of 40 patients using protocol A and in 29 of 40 patients using protocol B (iliac 40 vs. 37, femoral 40 vs. 40, popliteocrural 35 vs. 37, pedal 16 vs. 29); without the pedal station the number increased to 35 of 40 patients for both protocols. The reason of diagnostic limitations was an arteriovenous overlap in 24 of 80 cases, with 19 of 40 cases for protocol A and 5 of 40 for protocol B, located exclusively in the cruropedal region. Conclusion: Moving table hybrid CEMRA is superior to conventional technique in craniocaudal direction by producing less venous overlap of arteries and is especially more suitable for the diagnostic evaluation of the cruropedal region. (orig.) [German] Patienten und Methodik: Untersucht wurden 80 Patienten (maennl. n = 60, weibl. n = 20, mittl. Alter 70 J., Diabetiker n = 27) mit pAVK an einem 1,5-Tesla-Geraet (40 mT/m) mit dedizierter Phased-Array-Oberflaechen-Gefaessspule. Protokoll A beinhaltete eine Kontrastmittel-Injektion (Gd-BOPTA) mit konsekutiver kraniokaudaler Bildakquisition. In Protokoll B erfolgte die Akquisition zunaechst der Unterschenkel- und Fussetage mittels einer ersten, anschliessend der Abdomen-Becken- und Oberschenkeletage mittels

  6. Gd-enhanced MR imaging of the herniated lumbar disc: patterns of enhancement

    International Nuclear Information System (INIS)

    Kwag, Hyon Joo; Choi, Hye Young; Kim, Hyae Young; Kim, Yoo Kyung; Kim, Ah Young; Chung, Eun Chul

    1995-01-01

    The purpose of this study is to describe the patterns of enhancement of the herniated lumbar disc with Gd-DTPA enhanced MR imaging. Out of 65 patients, 103 lumbar discs diagnosed to be herniated by MR image were retrospectively analyzed. The MR imaging was performed with 1.5 T MR unit, using T1-and T2-weighted sagittal and axial spin echo techniques. Contrast-enhanced T1 weighted sagittal and axial images were performed after intravenous injection of Gadopentetate-dimeglumine(Magnevist, Shering) (0.1 mmol/kg). Contrast enhancement was seen in 66 cases(64%). Thirteen cases of bulging disc were not enhanced. Twenty-eight cases of protruded disc showed intraannular enchantment in 23 cases, peripheral linear and irregular enhancement in each of one case, and nonenhancement in three cases. Fifty-seven cases of extruded disc showed irregular enhancement in 14 cases, peripheral linear enhancement in 12 cases, peripheral ring enhancement in five cases and intraannular enhancement in five cases. All five cases of sequestered disc showed peripheral ring enhancement. Protruded discs show intraannular enhancement frequently and sequestered discs usually show peripheral ring enhancement. Enhanced MR imaging may be helpful to evaluate the type of herniated lumbar disc and relationship among disc material, nerve root and thecal sac

  7. Contrast-enhanced MR enterography as a stand-alone tool to evaluate Crohn's disease in a paediatric population

    International Nuclear Information System (INIS)

    Spieler, B.; Hindman, N.; Levy, J.; Zabrieski, K.; Sahlein, D.; Seuss, C.; Kim, S.

    2013-01-01

    Aim: To assess the performance of contrast-enhanced T1-weighted magnetic resonance imaging (MRI) alone in the evaluation of Crohn's disease in comparison to all magnetic resonance enterography (MRE) imaging sequences together in an attempt to suggest limitation of the number of overall unenhanced sequences need for the follow-up evaluation. Materials and methods: Twenty-five paediatric patients (mean age 14.1 ± 3.7 years, male = 12, female = 13) underwent MRE at 1.5 T for evaluation of Crohn's disease. Two radiologists reviewed only contrast-enhanced T1-weighted images in consensus on the first session. Whole images including unenhanced (steady-state free precession, single-shot fast spin-echo (HASTE), fat-suppressed T2-weighted) and contrast-enhanced T1-weighted sequences were reviewed in consensus during the second session with a 1 month interval, which was used as a reference standard. The readers evaluated the presence or absence of disease in 10 bowel segments in each patient. For the abnormal bowel segments, the readers then evaluated for active versus inactive disease and for the presence or absence of abscess. Sensitivity, specificity, and overall accuracy were calculated for detecting active inflammation. Results: There were 53/250 bowel segments with active inflammation using the reference standard imaging method. The sensitivity, specificity, and accuracy for diagnosing active inflammation using contrast-enhanced images alone were 83.3%, 86.9%, and 84.9%. In five of the false-positive cases of detecting abscess from contrast-enhanced imaging alone, absence of abscesses was confirmed on the non-fat-suppressed HASTE images. Conclusion: The number of MRE sequences in paediatric Crohn's patients can be decreased while maintaining diagnostic accuracy using contrast-enhanced T1 and non-fat-suppressed HASTE images

  8. Meningeal enhancement on MRI after craniotomy

    International Nuclear Information System (INIS)

    Nomura, Motohiro; Hasegawa, Mitsuhiro; Yamashima, Tetsumori; Yamashita, Junkoh; Suzuki, Masayuki

    1991-01-01

    Gd-DPTA-enhanced MR images in 94 patients who had undergone craniotomy were studied, with particular attention paid to the meningeal enhancement. Such enhancement was noted in 26 of the 94 (27.6%) in the portion surrounding the craniotomy site. Meningeal enhancement, presumably of the subdural neomembrane, was apparent as a third line of a high signal intensity on T 1 -weighted MR images. The outer two high-intensity lines were derived from fat in the subcutaneous tissues of the scalp and fat in the bone marrow of the calvaria. We designated this characteristic enhancement as a 'triple white line'. Of the 26 patients with meningeal enhancement, 22 cases (23.4%) showed such a 'triple white line', 11 cases (11.7%) showed falx enhancement, and 12 cases (12.8%) showed tentorial enhancement. The intervals between surgery and the appearance of the meningeal enhancement ranged from 4 days to 88 weeks. A small amount of bleeding into the dura-arachnoid interface induced by surgery might result in the subdural neomembrane, as has previously been reported. This neomembrane might be enhanced by the leakage of Gd-DTPA through the proliferating capillaries. As meningeal enhancement occurs in approximately a third of the cases following craniotomy, much care should be taken in the differential diagnosis of the infection, inflammation, and metastasis or dissemination of malignant brain tumors. (author)

  9. Dynamic contrast-enhanced perfusion studies of the brain with snapshot FLASH

    International Nuclear Information System (INIS)

    Finelli, D.A.; Kiefer, B.; Deimling, M.; Loeffler, W.; Haase, A.; Schuierer, G.

    1989-01-01

    This paper discusses how MR imaging with Gd-DTPA can improve the diagnostic accuracy of brain examinations. Conventional T1-weighted spin-echo sequences have been most satisfactory for depicting lesion enhancement following Gd-DTPA administration, however, the ability to examine the blood pool and early biodistribution phases has been limited. A new ultrafast MR imaging technique called Snapshot FLASH allows one to acquire entire images in 125-900 msec, with strong T1- or T2-weighted contrast. With this imaging technique, one can observe differential perfusion to the gray matter, while matter, and brain lesions during the first seconds following Gd-DTPA administration

  10. A prospective comparison study of fast T1 weighted fluid attenuation inversion recovery and T1 weighted turbo spin echo sequence at 3 T in degenerative disease of the cervical spine.

    Science.gov (United States)

    Ganesan, K; Bydder, G M

    2014-09-01

    This study compared T1 fluid attenuation inversion recovery (FLAIR) and T1 turbo spin echo (TSE) sequences for evaluation of cervical spine degenerative disease at 3 T. 72 patients (44 males and 28 females; mean age of 39 years; age range, 27-75 years) with suspected cervical spine degenerative disease were prospectively evaluated. Sagittal images of the spine were obtained using T1 FLAIR and T1 TSE sequences. Two experienced neuroradiologists compared the sequences qualitatively and quantitatively. On qualitative evaluation, cerebrospinal fluid (CSF) nulling and contrast at cord-CSF, disc-CSF and disc-cord interfaces were significantly higher on fast T1 FLAIR images than on T1 TSE images (p degenerative disease, owing to higher cord-CSF, disc-cord and disc-CSF contrast. However, intrinsic cord contrast is low on T1 FLAIR images. T1 FLAIR is more promising and sensitive than T1 TSE for evaluation of degenerative spondyloarthropathy and may provide a foundation for development of MR protocols for early detection of degenerative and neoplastic diseases.

  11. Medial tibial pain: a dynamic contrast-enhanced MRI study.

    Science.gov (United States)

    Mattila, K T; Komu, M E; Dahlström, S; Koskinen, S K; Heikkilä, J

    1999-09-01

    The purpose of this study was to compare the sensitivity of different magnetic resonance imaging (MRI) sequences to depict periosteal edema in patients with medial tibial pain. Additionally, we evaluated the ability of dynamic contrast-enhanced imaging (DCES) to depict possible temporal alterations in muscular perfusion within compartments of the leg. Fifteen patients with medial tibial pain were examined with MRI. T1-, T2-weighted, proton density axial images and dynamic and static phase post-contrast images were compared in ability to depict periosteal edema. STIR was used in seven cases to depict bone marrow edema. Images were analyzed to detect signs of compartment edema. Region-of-interest measurements in compartments were performed during DCES and compared with controls. In detecting periosteal edema, post-contrast T1-weighted images were better than spin echo T2-weighted and proton density images or STIR images, but STIR depicted the bone marrow edema best. DCES best demonstrated the gradually enhancing periostitis. Four subjects with severe periosteal edema had visually detectable pathologic enhancement during DCES in the deep posterior compartment of the leg. Percentage enhancement in the deep posterior compartment of the leg was greater in patients than in controls. The fast enhancement phase in the deep posterior compartment began slightly slower in patients than in controls, but it continued longer. We believe that periosteal edema in bone stress reaction can cause impairment of venous flow in the deep posterior compartment. MRI can depict both these conditions. In patients with medial tibial pain, MR imaging protocol should include axial STIR images (to depict bone pathology) with T1-weighted axial pre and post-contrast images, and dynamic contrast enhanced imaging to show periosteal edema and abnormal contrast enhancement within a compartment.

  12. Dural enhancement with primary calvarial lesions.

    Science.gov (United States)

    Arana, E; Martí-Bonmatí, L; Ricart, V; Pérez-Ebrí, M

    2004-11-01

    The purpose of this study was to relate the pathological and imaging features of dural enhancement and meningeal sign ("dural tail") on contrast-enhanced T1-weighted magnetic resonance (MR) images from patients with primary calvarial lesions as well to assess the accuracy of MR imaging in predicting dural invasion. Thirty-two calvarial tumors studied with contrast-enhanced MR imaging and histopathological examination of the dural specimens were reviewed. Sixteen patients presented dural enhancement, eight with tumor invasion. Tumoral invasion of the dura was observed in one case without enhancement. Malignant lesions showed enhanced dura more commonly than benign lesions (P=0.02). Nodular and discontinuous dural enhancement was statistically associated with dural invasion (P=0.05). Dural tail did not show a specific pathological association. Meningeal enhancement is a nonspecific reaction to calvarial lesions unless nodular and discontinuous. False-negative and -positive cases of dural invasion imply some limitation of contrast-enhanced MR imaging in predicting dural invasion by calvarial neoplasms.

  13. Dural enhancement with primary calvarial lesions

    Energy Technology Data Exchange (ETDEWEB)

    Arana, E. [Clinica Quiron, Department of Radiology, Valencia (Spain); Marti-Bonmati, L. [Clinica Quiron, Department of Radiology, Valencia (Spain); Hospital Universitario Dr. Peset, Department of Radiology, Valencia (Spain); Ricart, V. [Hospital de la Ribera, Department of Radiology, Valencia (Spain); Perez-Ebri, M. [Hospital Universitario Dr. Peset, Department of Pathology, Valencia (Spain)

    2004-11-01

    The purpose of this study was to relate the pathological and imaging features of dural enhancement and meningeal sign (''dural tail'') on contrast-enhanced T1-weighted magnetic resonance (MR) images from patients with primary calvarial lesions as well to assess the accuracy of MR imaging in predicting dural invasion. Thirty-two calvarial tumors studied with contrast-enhanced MR imaging and histopathological examination of the dural specimens were reviewed. Sixteen patients presented dural enhancement, eight with tumor invasion. Tumoral invasion of the dura was observed in one case without enhancement. Malignant lesions showed enhanced dura more commonly than benign lesions (P=0.02). Nodular and discontinuous dural enhancement was statistically associated with dural invasion (P=0.05). Dural tail did not show a specific pathological association. Meningeal enhancement is a nonspecific reaction to calvarial lesions unless nodular and discontinuous. False-negative and -positive cases of dural invasion imply some limitation of contrast-enhanced MR imaging in predicting dural invasion by calvarial neoplasms. (orig.)

  14. Tuberculosis versus lymphoma in the abdominal lymph nodes: A comparative study using contrast-enhanced MRI

    International Nuclear Information System (INIS)

    Shao, Heng; Yang, Zhi-gang; Deng, Wen; Chen, Jing; Tang, Si-shi; Wen, Ling-yi

    2012-01-01

    Purpose: The purpose of this study was to determine the differential characteristics on MRI between tuberculosis and lymphoma in abdominal lymph nodes. Materials and methods: We conducted a retrospective analysis for the counter, size, signal intensity, enhancement patterns, and anatomic distribution of lymph nodes in 57 consecutive patients with documented tuberculosis (28 patients; 49.1%) and newly diagnosed, untreated lymphoma (29 patients; 50.9%). Results: Twenty-four cases (85.7%) in the tuberculosis group were hyperintense on T2-weighted images and either hypointense or isointense on T1-weighted images with respect to the abdominal wall muscle. All cases in the lymphoma group were hyperintense on T2-weighted images and isointense on T1-weighted images with respect to the abdominal wall muscle. Concerning the main anatomic distribution of lymph nodes, the lymph nodes in the lower paraaortic region were more frequently involved in the lymphoma group (48.3%) than in tuberculosis (17.9%, p < 0.05). Moreover, mesenteric lymph nodes were more often involved in tuberculosis (32.1%) than in lymphoma (6.9%, p < 0.05). Tuberculous lymphadenopathy showed predominantly peripheral enhancement, frequently with a multilocular appearance; whereas lymphomatous adenopathy often demonstrated uniform homogeneous enhancement (all p < 0.001). Conclusion: Contrast-enhanced MRI can be useful in differentiation between these two entities

  15. A smart T(1)-weighted MRI contrast agent for uranyl cations based on a DNAzyme-gadolinium conjugate.

    Science.gov (United States)

    Xu, Weichen; Xing, Hang; Lu, Yi

    2013-11-07

    Rational design of smart MRI contrast agents with high specificity for metal ions remains a challenge. Here, we report a general strategy for the design of smart MRI contrast agents for detecting metal ions based on conjugation of a DNAzyme with a gadolinium complex. The 39E DNAzyme, which has high selectivity for UO2(2+), was conjugated to Gd(III)-DOTA and streptavidin. The binding of UO2(2+) to its 39E DNAzyme resulted in the dissociation of Gd(III)-DOTA from the large streptavidin, leading to a decrease of the T1 correlation time, and a change in the MRI signal.

  16. Studies on the clinical significance of pallidal high intensity of T1-weighted MR imaging in patients with liver cirrhosis

    International Nuclear Information System (INIS)

    Morino, Koutaro

    1997-01-01

    We investigated the clinical significances of signals in cirrhotic patients with special relation to subclinical hepatic encephalopathy. MRI was carried out in 30 patients with liver cirrhosis in the abscence of hepatic encephalopathy greater than grade II, and in 20 healthy subjects. Signal intensity of the globus pallidus was standardized to GP index. GP index=100 x (signal intensity of the globus pallidus - signal intensity of the putamen)/(signal intensity of the globus pallidus + signal intensity of the putamen). Normal value of GP index obtained in healthy subjects was -0.66∼4.70. Twenty seven of 30 cirrhotic patients showed GP index higher than the normal range. GP index correlated significantly with the blood manganese concentration. This observation suggested that the pallidal high intensity signals were brought about by the deposition of Mn in the globus pallidus. GP index correlated significantly with the central conduction time (CCT) measured by somatosensory evoked potentials. GP index and CCT may reflect the similar pathophysiological changes of the brain in patients with liver cirrhosis. Multivariate analysis revealed that GP index was explained well by the presence of portal systemic shunts and by preceding histories of hepatic encephalopathy but not by the present grade of the liver parenchymal damage. For the earlier diagnosis of subclinical hepatic encephalopathy, GP index showed an excellent parameter similar to those of somatosensory evoked potentials and psychometric tests. GP index is favorable than electrophysiological methods in terms of its non-invasiveness to the patients and simplicity of the examination technique. (K.H.)

  17. Gadopentetate-dimeglumine-enhanced MR imaging of osteonecrosis and osteochondritis dissecans of the elbow: initial experience

    International Nuclear Information System (INIS)

    Peiss, J.; Adam, G.; Casser, R.; Urhahn, R.; Guenther, R.W.

    1995-01-01

    Magnetic resonance imaging (MRI) was performed on seven patients with aseptic osteonecrosis (n=4) and osteochondritis dissecans (OCD; n=3) of the elbow. Precontrast MRI was superior to plain radiographs, which did not show any abnormality in three cases of osteonecrosis. On gadopentetate-dimeglumine-enhanced T1-weighted images, which were obtained in three patients with osteonecrosis and three patients with OCD, all cases of osteonecrosis demonstrated homogeneous enhancement of the lesions. All cases of OCD were diagnosed on plain radiographs. On MRI one showed significant enhancement of the loose body. In another case an incompletely enhancing loose body was surrounded by a diffusely enhancing region. In the third patient only a small marginal enhancement of the defect was observed. Our results suggest that MRI can improve the accuracy in diagnosis of aseptic osteonecrosis of the elbow. The use of gadopentetate dimeglumine allows the viability of the lesions or the loose bodies to be demonstrated and reparative tissue to be detected. (orig.)

  18. The pelvis after surgery and radio-chemotherapy for rectal cancer studied with Gd-DTPA-enhanced fast dynamic MR imaging

    International Nuclear Information System (INIS)

    Blomqvist, L.; Fransson, P.; Hindmarsh, T.

    1998-01-01

    The aim of this work was to study the gadolinium-enhancement of malignant and benign pathology in the pelvis after surgery for rectal cancer. Thirty patients with either local recurrence (n = 17) or benign changes related to treatment for rectal cancer (n = 13) were studied with pelvic MR imaging. T2-weighted fast spin-echo as well as T1-weighted spin- or gradient-echo imaging before and after intravenous contrast was performed and referred to as contrast-enhanced MRI (CEMRI). In addition, between the pre- and postcontrast images, dynamic contrast-enhanced MRI (DCEMRI) was performed using a single-slice, multi-phase, contrast-enhanced T1-weighted fast spoiled gradient-echo sequence. The time between the start of contrast injection to the beginning of enhancement, the duration and rate of enhancement as well as enhancement amplitude were recorded. The data were compared with the clinical diagnosis according to biopsy in 8 patients and surgery in 6 patients. In the remaining 16 patients, the clinical diagnosis was obtained by clinical or radiological follow-up. DCEMRI did not improve the diagnostic information compared with CEMRI. None of the examined parameters were found to help discriminating malignant from benign changes. Characterisation of lesions in the pelvis after rectal cancer surgery was not improved by a dynamic gadolinium-enhanced sequence. (orig.)

  19. Leptomeningeal Contrast Enhancement Is Associated with Disability Progression and Grey Matter Atrophy in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Gleb Makshakov

    2017-01-01

    Full Text Available Leptomeningeal contrast enhancement (LMCE on magnetic resonance imaging (MRI is a newly recognized possible biomarker in multiple sclerosis (MS, associated with MS progression and cortical atrophy. In this study, we aimed to assess the prevalence of LMCE foci and their impact on neurodegeneration and disability. Materials. 54 patients with MS were included in the study. LMCE were detected with a 3 Tesla scanner on postcontrast fluid-attenuated inversion-recovery (FLAIR sequence. Expanded Disability Status Scale (EDSS score, number of relapses during 5 years from MS onset, and number of contrast-enhancing lesions on T1 weighted MRI were counted. Results. LMCE was detected in 41% (22/54 of patients. LMCE-positive patients had longer disease duration (p=0,0098 and higher EDSS score (p=0,039, but not a higher relapse rate (p=0,091. No association of LMCE with higher frequency of contrast-enhancing lesions on T1-weighted images was detected (p=0,3842. Analysis of covariates, adjusted for age, sex, and disease duration, revealed a significant effect of LMCE on the cortex volume (p=0.043, F=2.529, the total grey matter volume (p=0.043, F=2.54, and total ventricular volume (p=0.039, F=2.605. Conclusions. LMCE was shown to be an independent and significant biomarker of grey matter atrophy and disability in MS.

  20. Acute interstitial edematous pancreatitis: Findings on non-enhanced MR imaging

    Science.gov (United States)

    Zhang, Xiao-Ming; Feng, Zhi-Song; Zhao, Qiong-Hui; Xiao, Chun-Ming; Mitchell, Donald G; Shu, Jian; Zeng, Nan-Lin; Xu, Xiao-Xue; Lei, Jun-Yang; Tian, Xiao-Bing

    2006-01-01

    AIM: To study the appearances of acute interstitial edematous pancreatitis (IEP) on non-enhanced MR imaging. METHODS: A total of 53 patients with IEP diagnosed by clinical features and laboratory findings were underwent MR imaging. MR imaging sequences included fast spoiled gradient echo (FSPGR) fat saturation axial T1-weighted imaging, gradient echo T1-weighted (in phase), single shot fast spin echo (SSFSE) T2-weighted, respiratory triggered (R-T) T2-weighted with fat saturation, and MR cholangiopancreatography. Using the MR severity score index, pancreatitis was graded as mild (0-2 points), moderate (3-6 points) and severe (7-10 points). RESULTS: Among the 53 patients, IEP was graded as mild in 37 patients and as moderate in 16 patients. Forty-seven of 53 (89%) patients had at least one abnormality on MR images. Pancreas was hypointense relative to liver on FSPGR T1-weighted images in 18.9% of patients, and hyperintense in 25% and 30% on SSFSE T2-weighted and R-T T2-weighted images, respectively. The prevalences of the findings of IEP on R-T T2-weighted images were, respectively, 85% for pancreatic fascial plane, 77% for left renal fascial plane, 55% for peripancreatic fat stranding, 42% for right renal fascial plane, 45% for perivascular fluid, 40% for thickened pancreatic lobular septum and 25% for peripancreatic fluid, which were markedly higher than those on in-phase or SSFSE T2-weighted images (P fluid. R-T T2-weighted imaging is more sensitive than in-phase and SSFSE T2-weighted imaging for depicting IEP. PMID:17007053

  1. Parallel imaging enhanced MR colonography using a phantom model.

    LENUS (Irish Health Repository)

    Morrin, Martina M

    2008-09-01

    To compare various Array Spatial and Sensitivity Encoding Technique (ASSET)-enhanced T2W SSFSE (single shot fast spin echo) and T1-weighted (T1W) 3D SPGR (spoiled gradient recalled echo) sequences for polyp detection and image quality at MR colonography (MRC) in a phantom model. Limitations of MRC using standard 3D SPGR T1W imaging include the long breath-hold required to cover the entire colon within one acquisition and the relatively low spatial resolution due to the long acquisition time. Parallel imaging using ASSET-enhanced T2W SSFSE and 3D T1W SPGR imaging results in much shorter imaging times, which allows for increased spatial resolution.

  2. MR imaging of postoperative change of dura mater of rabbits; Effect of contrast enhancement of dura mater and correlation with pathological findings

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Fumiaki (Kanazawa Univ. (Japan). School of Medicine)

    1993-01-01

    To explain the mechanism of benign postoperative dural enhancement, the author made experimental model of rabbit's subdual hematoma and performed magnetic resonance (MR) imaging with gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA). On plain T1-weighted images, infused blood or blood cells could not be detected immediately after surgery. On follow up plain T1-weighted images, the infused blood could be identified in only a case with 1 cc blood infusion. Marked dural enhancement could be seen immediately after surgery and continued three to fourteen days after 1 cc or 0.1 cc blood or 0.1 cc red blood cells infusion. To the contrary, no definite dural enhancement could be seen in the cases with plasma or saline infusion. Subdural red blood cells were required for dural enhancement immediately after surgery. Pathological findings revealed three types of reaction to infused blood: newly formed capillarization with fresh hemorrhage from the capillaries; subdural hematoma and no reaction. After vanishment of dural enhancement, pathological findings of the specimens were identical to that of normal dura. Dural enhancement may be induced by increased permeability of the dura associated with subdural hematoma and/or the extravasation of the contrast from newly formed capillaries. (author).

  3. Diagnostic Accuracy of Dynamic Contrast Enhanced Magnetic Resonance Imaging in Characterizing Lung Masses

    Science.gov (United States)

    Inan, Nagihan; Arslan, Arzu; Donmez, Muhammed; Sarisoy, Hasan Tahsin

    2016-01-01

    Background Imaging plays a critical role not only in the detection, but also in the characterization of lung masses as benign or malignant. Objectives To determine the diagnostic accuracy of dynamic magnetic resonance imaging (MRI) in the differential diagnosis of benign and malignant lung masses. Patients and Methods Ninety-four masses were included in this prospective study. Five dynamic series of T1-weighted spoiled gradient echo (FFE) images were obtained, followed by a T1-weighted FFE sequence in the late phase (5th minutes). Contrast enhancement patterns in the early (25th second) and late (5th minute) phase images were evaluated. For the quantitative evaluation, signal intensity (SI)-time curves were obtained and the maximum relative enhancement, wash-in rate, and time-to-peak enhancement of masses in both groups were calculated. Results The early phase contrast enhancement patterns were homogeneous in 78.2% of the benign masses, while heterogeneous in 74.4% of the malignant tumors. On the late phase images, 70.8% of the benign masses showed homogeneous enhancement, while most of the malignant masses showed heterogeneous enhancement (82.4%). During the first pass, the maximum relative enhancement and wash-in rate values of malignant masses were significantly higher than those of the benign masses (P = 0.03 and 0.04, respectively). The cutoff value at 15% yielded a sensitivity of 85.4%, specificity of 61.2%, and positive predictive value of 68.7% for the maximum relative enhancement. Conclusion Contrast enhancement patterns and SI-time curve analysis of MRI are helpful in the differential diagnosis of benign and malignant lung masses. PMID:27703654

  4. Labyrinthine enhancement of Gd-MR in patients with sudden hearing loss and vertigo

    International Nuclear Information System (INIS)

    Seltzer, S.; Mark, A.S.; Chapman, J.C.; Nelson-Drake, J.

    1989-01-01

    In the past, no definitive diagnostic study was available to assess causes of sudden-onset hearing loss and vertigo. Our observations have led to an interesting new finding: labyrinthine enhancement on Gd-enhanced MR imaging in four patients with sudden unilateral hearing loss and/or vertigo. MR findings were correlated with audiologic and vestibular studies. All patients were studied with T2-weighted axial images through the whole brain and with Gd-DTPA-enhanced, 3-mm, axial, T1-weighted images through the temporal bone. No labyrinthine enhancement was seen in 20 control patients referred for other clinical problems. Gd-MR imaging might be able to distinguish patients with retrocochlear lesions from those in whom the abnormal process is in the labyrinth or is intraaxial

  5. Marginal erosive discovertebral ''Romanus'' lesions in ankylosing spondylitis demonstrated by contrast enhanced Gd-DTPA magnetic resonance imaging

    International Nuclear Information System (INIS)

    Jevtic, V.; Kos-Golja, M.; Rozman, B.; McCall, I.

    2000-01-01

    Objective. To assess the value of Gd-DTPA magnetic resonance (MR) imaging in the demonstration of marginal destructive discovertebral Romanus lesions in ankylosing spondylitis.Design and patients. A prospective study of Gd-DTPA MR imaging was performed in 39 patients with a clinical diagnosis of ankylosing spondylitis and typical Romanus lesions seen on radiographs of the thoracolumbar spine. MR morphological appearances and signal intensity changes at the discovertebral junctions were analysed and compared with the radiographic findings.Results. Ninety-nine discovertebral junctions with Romanus lesions showed low signal intensity on T1-weighted and high signal on T2-weighted and T1-weighted postcontrast images at the vertebral corners consistent with oedematous hyperaemic inflammatory tissue. There were nine discovertebral junctions with similar MR findings but normal radiographs. Fifty-three discovertebral junctions showed syndesmophyte formation with increased signal intensity on both T1- and T2-weighted images with no contrast enhancement. Sixty-five discovertebral junctions showed a mixture of radiographic features and varied high and low signal changes at the vertebral rim on MR imaging with rims of enhancement in the vertebral body following contrast administration.Conclusion. Gd-DTPA MR imaging demonstrates a variable signal pattern and degree of contrast enhancement which may reflect the evolutionary stages of discovertebral enthesitis in ankylosing spondylitis. MR imaging may identify early erosive changes in radiographically normal vertebra. The role of MR imaging needs further investigation. (orig.)

  6. Can pre-operative contrast-enhanced dynamic MR imaging for prostate cancer predict microvessel density in prostatectomy specimens?

    Energy Technology Data Exchange (ETDEWEB)

    Schlemmer, Heinz-Peter [Department of Oncological Diagnostics and Therapy, German Cancer Research Center, University Hospital Mannheim, Ruprecht Karls University, Heidelberg (Germany); Department of Diagnostic Radiology, University Hospital Tuebingen, Hoppe-Seyler-Strasse 3, 72076, Tuebingen (Germany); Merkle, Jonas; Kaick, Gerhard van [Department of Oncological Diagnostics and Therapy, German Cancer Research Center, University Hospital Mannheim, Ruprecht Karls University, Heidelberg (Germany); Grobholz, Rainer [Department of Pathology, University Hospital Mannheim, Ruprecht Karls University, Heidelberg (Germany); Jaeger, Tim; Michel, Maurice Stephan [Department of Urology, University Hospital Mannheim, Ruprecht Karls University, Heidelberg (Germany); Werner, Axel; Rabe, Jan [Department of Diagnostic Radiology, University Hospital Mannheim, Ruprecht Karls University, Heidelberg (Germany)

    2004-02-01

    The aim of this study was to correlate quantitative dynamic contrast-enhanced MRI (DCE MRI) parameters with microvessel density (MVD) in prostate carcinoma. Twenty-eight patients with biopsy-proven prostate carcinoma were examined by endorectal MRI including multiplanar T2- and T1-weighted spin-echo and dynamic T1-weighted turbo-FLASH MRI during and after intravenous Gd-DTPA administration. Microvessels were stained on surgical specimens using a CD31 monoclonal antibody. The MVD was quantified in hot spots by counting (MVC) and determining the area fraction by morphometry (MVAF). The DCE MRI data were analyzed using an open pharmacokinetic two-compartment model. In corresponding anatomic locations the time shift ({delta}t) between the beginning of signal enhancement of cancer and adjacent normal prostatic tissue, the degree of contrast enhancement and the contrast exchange rate constant (k{sub 21}) were calculated. The MVC and MVAF were elevated in carcinoma (p<0.001 and p=0.002, respectively) and correlated to k{sub 21} (r=0.62, p<0.001 and r=0.80, p<0.001, respectively). k{sub 21}-values of carcinoma were significantly higher compared with normal peripheral but not central zone tissue. {delta}t was longer in high compared with low-grade tumors (p=0.025). The DCE MRI can provide important information about individual MVD in prostate cancer, which may be helpful for guiding biopsy and assessing individual prognosis. (orig.)

  7. Digital subtraction in gadolinium-enhanced MR imaging of the brain: a method to reduce contrast dosage

    International Nuclear Information System (INIS)

    Chan, J.H.M.; Tsui, E.Y.K.; Chan, C.Y.; Lai, K.F.; Cheung, Y.K.; Wong, K.P.C.; Yuen, M.K.; Chau, L.F.; Fong, D.; Mok, C.K.

    2002-01-01

    The aim of the study was to investigate the feasibility of using digital subtraction in contrast-enhanced MR imaging of the brain to reduce the MR contrast dosage without jeopardizing patient care. Fifty-two patients with intracranial lesions, either intra-axial or extra-axial, detected by computerized tomography were selected for contrast-enhanced MR imaging with half-dose and full-dose of gadopentetate dimeglumine. The half-dose unsubtracted, full-dose unsubtracted, and half-dose subtracted MR images were visually assessed by counting the number of enhancing brain lesions in the images and quantitatively analyzed by computing their lesion contrast-to-background ratios (CBR). The visual conspicuity of the half-dose subtracted MR images was comparable to that of the full-dose unsubtracted MR images (p>0.05), whereas the CBR of the half-dose subtracted images was approximately two to three times higher than that of the full-dose unsubtracted images. The half-dose subtracted T1-weighted spin-echo images might be able to replace the conventional standard-dose T1-weighted spin-echo images in MR imaging of the brain. (orig.)

  8. Dynamic contrast-enhanced breast MRI at 7 Tesla utilizing a single-loop coil: a feasibility trial.

    Science.gov (United States)

    Umutlu, Lale; Maderwald, Stefan; Kraff, Oliver; Theysohn, Jens M; Kuemmel, Sherko; Hauth, Elke A; Forsting, Michael; Antoch, Gerald; Ladd, Mark E; Quick, Harald H; Lauenstein, Thomas C

    2010-08-01

    The aim of this study was to assess the feasibility of dynamic contrast-enhanced ultra-high-field breast imaging at 7 Tesla. A total of 15 subjects, including 5 patients with histologically proven breast cancer, were examined on a 7 Tesla whole-body magnetic resonance imaging system using a unilateral linearly polarized single-loop coil. Subjects were placed in prone position on a biopsy support system, with the coil placed directly below the region of interest. The examination protocol included the following sequences: 1) T2-weighted turbo spin echo sequence; 2) six dynamic T1-weighted spoiled gradient-echo sequences; and 3) subtraction imaging. Contrast-enhanced T1-weighted imaging at 7 Tesla could be obtained at high spatial resolution with short acquisition times, providing good image accuracy and a conclusively good delineation of small anatomical and pathological structures. T2-weighted imaging could be obtained with high spatial resolution at adequate acquisition times. Because of coil limitations, four high-field magnetic resonance examinations showed decreased diagnostic value. This first scientific approach of dynamic contrast-enhanced breast magnetic resonance imaging at 7 Tesla demonstrates the complexity of ultra-high-field breast magnetic resonance imaging and countenances the implementation of further advanced bilateral coil concepts to circumvent current limitations from the coil and ultra-high-field magnetic strength. 2010 AUR. Published by Elsevier Inc. All rights reserved.

  9. Influence of field strength, coil type and image resolution on assessment of synovitis by unenhanced MRI--a comparison with contrast-enhanced MRI

    DEFF Research Database (Denmark)

    Eshed, Iris; Krabbe, Simon; Østergaard, Mikkel

    2015-01-01

    post-contrast T1-weighted sequence was used as gold standard reference. RESULTS: Fair-good agreement (ICC=0.38--0.72) between the standard reference and the different STIR protocols (best agreement with extremity coil and small voxel size at 1.5 T). The accuracy for presence/absence of synovitis...... is only moderately reliable for assessing hand synovitis in RA, when contrast-enhanced MRI is considered the gold standard reference. Contrast injection, field strength and coil type influence synovitis assessment, and should be considered before performing MRI in clinical trials and practice. KEY POINTS...

  10. An efficient sequence for fetal brain imaging at 3T with enhanced T1 contrast and motion robustness.

    Science.gov (United States)

    Ferrazzi, Giulio; Price, Anthony N; Teixeira, Rui Pedro A G; Cordero-Grande, Lucilio; Hutter, Jana; Gomes, Ana; Padormo, Francesco; Hughes, Emer; Schneider, Torben; Rutherford, Mary; Kuklisova Murgasova, Maria; Hajnal, Joseph V

    2018-07-01

    Ultrafast single-shot T 2 -weighted images are common practice in fetal MR exams. However, there is limited experience with fetal T 1 -weighted acquisitions. This study aims at establishing a robust framework that allows fetal T 1 -weighted scans to be routinely acquired in utero at 3T. A 2D gradient echo sequence with an adiabatic inversion was optimized to be robust to fetal motion and maternal breathing optimizing grey/white matter contrast at the same time. This was combined with slice to volume registration and super resolution methods to produce volumetric reconstructions. The sequence was tested on 22 fetuses. Optimized grey/white matter contrast and robustness to fetal motion and maternal breathing were achieved. Signal from cerebrospinal fluid (CSF) and amniotic fluid was nulled and 0.75 mm isotropic anatomical reconstructions of the fetal brain were obtained using slice-to-volume registration and super resolution techniques. Total acquisition time for a single stack was 56 s, all acquired during free breathing. Enhanced sensitivity to normal anatomy and pathology with respect to established methods is demonstrated. A direct comparison with a 3D spoiled gradient echo sequence and a controlled motion experiment run on an adult volunteer are also shown. This paper describes a robust framework to perform T 1 -weighted acquisitions and reconstructions of the fetal brain in utero. Magn Reson Med 80:137-146, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic

  11. Contrast-enhanced dynamic MR imaging in rheumatoid arthritis

    International Nuclear Information System (INIS)

    Koenig, H.; Sieper, J.; Wolf, K.J.

    1989-01-01

    This paper reports on a study for the identification of different pannus formations. Twenty patients with advanced rheumatoid arthritis of the knee joint were examined with MR imaging primary to surgery. The authors used a 1.5-T Magnetom unit, a circular surface coil for signal detection, 0.1 mmol/kg of Gd-DTPA given as a bolus injection, fast low-angle shot (FLASH) sequence (TR, 30 msec; TE, 10 msec; 128 x 128 matrix; excitation angle, 70 degrees) repeated 30 times within 120 seconds, and a T1-weighted spin-echo sequence (Tr, 500 msec; TE, 22 msec) before and 2 minutes after contrast medium injection. Enhancement of pannus and joint effusion has been measured and standardized to muscle tissue

  12. Demonstration of evolution of hemispherical spondysclerosis by contrast enhanced Gd-DTPA magnetic resonance imaging

    International Nuclear Information System (INIS)

    Jevtic, V.; Majcen, N.

    2004-01-01

    Background. The purpose of the study was to estimate the value of Gd-DTPA magnetic resonance imaging (MRI) in demonstrating the evolution of hemispherical spondylosclerosis (HSS). Patients and methods. In eighteen patients with chronic low back pain and typical radiographic findings of HSS seen on plain films, Gd-DTPA MRI of the lumbar spine was performed. MRI morphological and signal intensity appearances of HSS were analysed and compared with radiographic changes. Results. On the basis of MRI features, three distinct groups of cases were identifiable. Within the first group the region of dome-shaped osteosclerosis demonstrated low signal intensity on T1-weighted precontrast spin-echo images, high signal intensity on T2-weighted images and diffuse contrast enhancement on T1-weighted postcontrast images, findings compatible with bone marrow oedema and hyperaemia. The second group showed high signal intensity vertebral body corners surrounded by low signal intensity area, which indicated the combination of fat accumulation and the sclerotic bone. In the third intermediate group anterior disco-vertebral junctions revealed a mixture of MRI appearances characteristic of the first and the second group. Conclusions. Gd-DTPA MRI is capable of demonstrating a spectrum of features which reflect the evolution of HSS. These typical appearances showed by MRI could be of eventual clinical relevance in following the progression of HSS. (author)

  13. Technical innovation in dynamic contrast-enhanced magnetic resonance imaging of musculoskeletal tumors: an MR angiographic sequence using a sparse k-space sampling strategy.

    Science.gov (United States)

    Fayad, Laura M; Mugera, Charles; Soldatos, Theodoros; Flammang, Aaron; del Grande, Filippo

    2013-07-01

    We demonstrate the clinical use of an MR angiography sequence performed with sparse k-space sampling (MRA), as a method for dynamic contrast-enhanced (DCE)-MRI, and apply it to the assessment of sarcomas for treatment response. Three subjects with sarcomas (2 with osteosarcoma, 1 with high-grade soft tissue sarcomas) underwent MRI after neoadjuvant therapy/prior to surgery, with conventional MRI (T1-weighted, fluid-sensitive, static post-contrast T1-weighted sequences) and DCE-MRI (MRA, time resolution = 7-10 s, TR/TE 2.4/0.9 ms, FOV 40 cm(2)). Images were reviewed by two observers in consensus who recorded image quality (1 = diagnostic, no significant artifacts, 2 = diagnostic, 75 % with good response, >75 % with poor response). DCE-MRI findings were concordant with histological response (arterial enhancement with poor response, no arterial enhancement with good response). Unlike conventional DCE-MRI sequences, an MRA sequence with sparse k-space sampling is easily integrated into a routine musculoskeletal tumor MRI protocol, with high diagnostic quality. In this preliminary work, tumor enhancement characteristics by DCE-MRI were used to assess treatment response.

  14. Technical innovation in dynamic contrast-enhanced magnetic resonance imaging of musculoskeletal tumors: an MR angiographic sequence using a sparse k-space sampling strategy

    International Nuclear Information System (INIS)

    Fayad, Laura M.; Mugera, Charles; Grande, Filippo del; Soldatos, Theodoros; Flammang, Aaron

    2013-01-01

    We demonstrate the clinical use of an MR angiography sequence performed with sparse k-space sampling (MRA), as a method for dynamic contrast-enhanced (DCE)-MRI, and apply it to the assessment of sarcomas for treatment response. Three subjects with sarcomas (2 with osteosarcoma, 1 with high-grade soft tissue sarcomas) underwent MRI after neoadjuvant therapy/prior to surgery, with conventional MRI (T1-weighted, fluid-sensitive, static post-contrast T1-weighted sequences) and DCE-MRI (MRA, time resolution = 7-10 s, TR/TE 2.4/0.9 ms, FOV 40 cm 2 ). Images were reviewed by two observers in consensus who recorded image quality (1 = diagnostic, no significant artifacts, 2 = diagnostic, 75 % with good response, >75 % with poor response). DCE-MRI findings were concordant with histological response (arterial enhancement with poor response, no arterial enhancement with good response). Unlike conventional DCE-MRI sequences, an MRA sequence with sparse k-space sampling is easily integrated into a routine musculoskeletal tumor MRI protocol, with high diagnostic quality. In this preliminary work, tumor enhancement characteristics by DCE-MRI were used to assess treatment response. (orig.)

  15. Multivariable analysis of clinical influence factors on liver enhancement of Gd-EOB-DTPA-enhanced 3T MRI

    International Nuclear Information System (INIS)

    Verloh, N.; Haimerl, M.; Stroszczynski, C.; Fellner, C.; Wiggermann, P.; Zeman, F.; Teufel, A.; Lang, S.

    2015-01-01

    The purpose of this study was to identify clinical factors influencing Gd-EOB-DTPA liver uptake in patients with healthy liver parenchyma. A total of 124 patients underwent contrast-enhanced MRI with a hepatocyte-specific contrast agent at 3T. T1-weighted volume interpolated breath-hold examination (VIBE) sequences with fat suppression were acquired before and 20 minutes after contrast injection. The relative enhancement (RE) between plain and contrast-enhanced signal intensity was calculated. Simple and multiple linear regression analyses were performed to evaluate clinical factors influencing the relative enhancement. Patients were subdivided into three groups according to their relative liver enhancement (HRE, RE ≥ 100 %; MRE, 100 % > RE > 50 %; NRE, RE ≤ 50 %) and were analyzed according to the relevant risk factors. Simple regression analyses revealed patient age, transaminases (AST, ALT, GGT), liver, spleen and delta-liver volume (the difference between the volumetrically measured liver volume and the estimated liver volume based on body weight) as significant factors influencing relative enhancement. In the multiple analysis the transaminase AST, spleen and delta liver volume remained significant factors influencing relative enhancement. Delta liver volume showed a significant difference between all analyzed groups. Liver enhancement in the hepatobiliary phase depends on a variety of factors. Body weight-adapted administration of Gd-EOB-DTPA may lead to inadequate liver enhancement after 20 minutes especially when the actual liver volume differs from the expected volume.

  16. Evaluation of carotid vessel wall enhancement with image subtraction after gadobenate dimeglumine-enhanced MR angiography

    International Nuclear Information System (INIS)

    Sardanelli, Francesco; Di Leo, Giovanni; Aliprandi, Alberto; Flor, Nicola; Papini, Giacomo D.E.; Roccatagliata, Luca; Cotticelli, Biagio; Nano, Giovanni; Cornalba, Gianpaolo

    2009-01-01

    Objectives: This study was aimed at testing the value of image subtraction for evaluating carotid vessel wall enhancement in contrast-enhanced MR angiography (MRA). Materials and methods: IRB approval was obtained. The scans of 81 consecutive patients who underwent carotid MRA with 0.1 mmol/kg of gadobenate dimeglumine were reviewed. Axial carotid 3D T1-weighted fast low-angle shot sequence before and 3 min after contrast injection were acquired and subtracted (enhanced minus unenhanced). Vessel wall enhancement was assigned a four-point score using native or subtracted images from 0 (no enhancement) to 3 (strong enhancement). Stenosis degree was graded according to NASCET. Results: With native images, vessel wall enhancement was detected in 20/81 patients (25%) and in 20/161 carotids (12%), and scored 2.0 ± 0.6 (mean ± standard deviation); with subtracted images, in 21/81 (26%) and 22/161 (14%), and scored 2.5 ± 0.6, respectively (P < 0.001, Sign test). The overall stenosis degree distribution was: mild, 41/161 (25%); moderate, 77/161 (48%); severe, 43/161 (27%). Carotids with moderate stenosis showed vessel wall enhancement with a frequency (17/77, 22%) significantly higher than that observed in carotids with mild stenosis (1/41, 2%) (P = 0.005, Fisher exact test) and higher, even though with borderline significance (P = 0.078, Fisher exact test), than that observed in carotids with severe stenosis (4/43, 9%). Conclusion: Roughly a quarter of patients undergoing carotid MRA showed vessel wall enhancement. Image subtraction improved vessel wall enhancement conspicuity. Vessel wall enhancement seems to be an event relatively independent from the degree of stenosis. Further studies are warranted to define the relation between vessel wall enhancement and histopathology, inflammatory status, and instability.

  17. Clinicopathological findings in symptomatic Rathke's cleft cyst. Correlation between enhancement effects on MRI and histopathology of the cyst wall

    International Nuclear Information System (INIS)

    Niwa, Jun; Tanabe, Sumiyoshi; Ibayashi, Yukihiro; Hashi, Kazuo; Satoh, Masaaki

    1996-01-01

    We have studied MR images and the histopathology of eight patients with symptomatic Rathke's cleft cysts. Six cases showed visual disturbance and two showed galactorrhea. In five, the cyst fluid had low signal intensity on T1-weighted images and high intensity on T2-weighted images; in 2, the cyst fluid had high intensity on both T1- and T2-weighted images; in 1, the cyst fluid had high intensity on T1-weighted images and low intensity on T2-weighted images. Enhancement of the cyst wall by Gd-DTPA was able to be distinguished in 6 patients: 2 showed no enhancement, 2 showed thin enhancement and the remaining 2, thick enhancement. Fluid aspiration and total resection of the cyst wall was performed in all patients (3 by the transcranial approach and 5 by the transsphenoidal approach). Normal pituitary glands were found in all cases during the operations. Histopathologically, ciliated epithelium with goblet cells was recognized in 3. Non-ciliated epithelium was recognized in the other 5. Stratified squamous component was recognized in 1 and secondary inflammation, in another. Normal pituitary tissue was recognized in 5. Immunohistochemically, ciliated and non-ciliated epithelium was successfully stained for detecting antibody against epithelial membrane antigen and/or carcinoembryonic antigen. Two cases with no enhancement of the cyst wall by Gd-DTPA showed only ciliated epithelium. Two patients with thin enhancement of the cyst wall had single layer epithelium with normal pituitary tissue. Two patients with thick enhancement of the cyst wall showed single layer epithelium with its stratified squamous component or with secondary inflammation. A close relationship was suggested between the enhancement effect on MRI and histopathology of the cyst wall. (author)

  18. MR imaging of gestational trophoblastic tumor: role of gadolinium enhancement

    International Nuclear Information System (INIS)

    Choi, Si Young; Byun, Jae Young; Kim, Bum Su; Yun, Young Hyun; Mun, Kyung Mi; Park, Kyung Sin; Kim, Byung Kee; Bae, Seog Nyeon; Shinn, Kyung Sub.

    1997-01-01

    The purpose of this study is to investigate the role of gadolinium enhanced MR imaging in the evaluation of gestational trophoblastic tumors (invasive mole and choriocarcinoma). Pre-enhanced T1-and T2-weighted images and gadolinium enhanced T1-weighted images of 34 gestational trophoblastic tumors (15 choriocarcinomas, 19 invasive moles) were retrospectively evaluated and enhancement patterns were analyzed. Morphologica differences and structural characteristics were analyzed by the evaluation of tumor margin, patterns of hemorrhagic necroses, the development of intratumoral vascularity, and molar villi. Graded scores of MR findings between pre- and gadolinium enhanced images were based on the following criteria : 1) visualization of tumor margin 2) distinction between tumor necrosis and zone of trophoblastic proliferation ; and 3) molar villi. Statistical differences between graded scores of pre- and post-enhanced images were analyzed. Gadolinium enhanced MR imaging was helpful for the visualization of tumor characteristics in gestational trophoblastic tumors and in differential diagnosis between invasive mole and choriocarcinoma. (author). 16 refs., 4 tabs., 4 figs

  19. Gadolinium-enhanced MR imaging in evaluation of cholesteatoma

    International Nuclear Information System (INIS)

    Sugihara, M.; Sugimura, K.; Ishida, T.; Fujino, A.; Miyakuni, Y.

    1990-01-01

    It was sometimes difficult to differentiate cholesteatoma from accompanied granuloma, cholesterol granuloma, or mastoiditis on high-resolution CT. This study was designed to assess the reliability with which cholesteatoma can be differentiated from those accompanied lesions by gadolinium-enhanced MR imaging. Eight patients suspected to have cholesteatoma were evaluated with GD-DTPA-enhanced MR imaging with a 1.5-T MR imaging GE Signa unit. axial pre- and postcontrast T1-weighted (TR/TE, 600/20) and T2-weighted (TR/TE, 2,000/70) images were studied. MR imaging findings were compared with histologic findings (13 lesions), which included cholesteatoma (n = 6), granuloma (n = 4), cholesterol granuloma (n = 2), and mastoiditis (n = 1). Cholesteatoma had an intermediate to high signal intensity (SI) similar to that of granuloma on both T1- and T2-weighted images. Cholesterol granulomas showed high SI on both T1- and T2-weighted images. Mastoiditis demonstrated marked high SI on T2-weighted images. Cholesterol granuloma and mastoiditis can be distinguished from cholesteatoma or granuloma on both T1- and T2-weighted images. On Gd-DTPA-enhanced images, there was marked enhancement of all granulomas. However, no cholesteatoma enhancement was seen in all six lesions. Gd-DTPA-enhanced images were able to distinguish cholesteatoma from granuloma and to estimate the exact extent of cholesteatoma. Gd-DTPA-enhanced MR imaging is valuable in the evaluation and management of cholesteatoma

  20. Contrast enhanced MR imaging of postoperative medulloblastoma in childhood: emphasis on meningeal enhancement

    International Nuclear Information System (INIS)

    Choi, Choong Gon; Kim, In One; Kim, Woo Sun; Kim, Ho Chul; Yeon, Kyung Mo

    1993-01-01

    To differentiate the postoperative changes from the recurrence of tumor and to evaluate MR imaging of early postoperative leptomeningeal seeding in medulloblastoma, We have retrospectively analysed 34 cases of MR images of 17 patients who were confirmed as medulloblastoma by histopathology. Noncontrast and postcontrast T1 weighted MR images were obtained in all patients. In 11 patients follow-up MR was done more than once (average: 1.5 times) and average interval of MR imaging was 6 months. The timing of 34 MR images was as follow: 6 case within 2 months, 9 cases between 2 months and 1 year, 19 cases more than 1 year after surgery respectively. MR images within 2 month after surgery revealed contrast enhancement at operation site and adjacent meninges, hemorrhage, residual tumor. In patients who had no evidence of tumor recurrence, these early postoperative changes were markedly decreased within 6 month after surgery. MR images obtained more than 1 year after surgery showed no abnormal contrast enhancement or mild focal dural enhancement at operation site. Diffuse moderate dural enhancement was noted in one patient who had the history of post-surgical subdural hemorrhage. In six patients with tumor recurrences which were detected from as early as 9 months to 6 years after surgery, the findings of recurrence included leptomeningeal enhancement of brain stem and cerebellar surface at early stage, variable sized enhancing leptomeningeal nodules, linear or irregular sulcus obliterating enhancing lesions, enhancing mass at primary or metastatic site. We have concluded that leptomeningeal enhancement detected after 6 months of surgery is an important MR finding suggesting the possibility of tumor recurrence. Small nodular and linear enhancement of leptomeninges at brainstem or cerebellar surface is considered as the early manifestation of intracranial tumor seeding

  1. Contrast enhanced MR imaging of postoperative medulloblastoma in childhood: emphasis on meningeal enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Choong Gon; Kim, In One; Kim, Woo Sun; Kim, Ho Chul; Yeon, Kyung Mo [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

    1993-03-15

    To differentiate the postoperative changes from the recurrence of tumor and to evaluate MR imaging of early postoperative leptomeningeal seeding in medulloblastoma, We have retrospectively analysed 34 cases of MR images of 17 patients who were confirmed as medulloblastoma by histopathology. Noncontrast and postcontrast T1 weighted MR images were obtained in all patients. In 11 patients follow-up MR was done more than once (average: 1.5 times) and average interval of MR imaging was 6 months. The timing of 34 MR images was as follow: 6 case within 2 months, 9 cases between 2 months and 1 year, 19 cases more than 1 year after surgery respectively. MR images within 2 month after surgery revealed contrast enhancement at operation site and adjacent meninges, hemorrhage, residual tumor. In patients who had no evidence of tumor recurrence, these early postoperative changes were markedly decreased within 6 month after surgery. MR images obtained more than 1 year after surgery showed no abnormal contrast enhancement or mild focal dural enhancement at operation site. Diffuse moderate dural enhancement was noted in one patient who had the history of post-surgical subdural hemorrhage. In six patients with tumor recurrences which were detected from as early as 9 months to 6 years after surgery, the findings of recurrence included leptomeningeal enhancement of brain stem and cerebellar surface at early stage, variable sized enhancing leptomeningeal nodules, linear or irregular sulcus obliterating enhancing lesions, enhancing mass at primary or metastatic site. We have concluded that leptomeningeal enhancement detected after 6 months of surgery is an important MR finding suggesting the possibility of tumor recurrence. Small nodular and linear enhancement of leptomeninges at brainstem or cerebellar surface is considered as the early manifestation of intracranial tumor seeding.

  2. Diuretic-enhanced gadolinium excretory MR urography: comparison of conventional gradient-echo sequences and echo-planar imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nolte-Ernsting, C.C.A.; Tacke, J.; Adam, G.B.; Haage, P.; Guenther, R.W. [Univ. of Technology, Aachen (Germany). Dept. of Diagnostic Radiology; Jung, P.; Jakse, G. [Univ. of Technology, Aachen (Germany). Dept. of Urology

    2001-01-01

    The aim of this study was to investigate the utility of different gadolinium-enhanced T1-weighted gradient-echo techniques in excretory MR urography. In 74 urologic patients, excretory MR urography was performed using various T1-weighted gradient-echo (GRE) sequences after injection of gadolinium-DTPA and low-dose furosemide. The examinations included conventional GRE sequences and echo-planar imaging (GRE EPI), both obtained with 3D data sets and 2D projection images. Breath-hold acquisition was used primarily. In 20 of 74 examinations, we compared breath-hold imaging with respiratory gating. Breath-hold imaging was significantly superior to respiratory gating for the visualization of pelvicaliceal systems, but not for the ureters. Complete MR urograms were obtained within 14-20 s using 3D GRE EPI sequences and in 20-30 s with conventional 3D GRE sequences. Ghost artefacts caused by ureteral peristalsis often occurred with conventional 3D GRE imaging and were almost completely suppressed in EPI sequences (p < 0.0001). Susceptibility effects were more pronounced on GRE EPI MR urograms and calculi measured 0.8-21.7% greater in diameter compared with conventional GRE sequences. Increased spatial resolution degraded the image quality only in GRE-EPI urograms. (orig.)

  3. Automatized spleen segmentation in non-contrast-enhanced MR volume data using subject-specific shape priors

    Science.gov (United States)

    Gloger, Oliver; Tönnies, Klaus; Bülow, Robin; Völzke, Henry

    2017-07-01

    To develop the first fully automated 3D spleen segmentation framework derived from T1-weighted magnetic resonance (MR) imaging data and to verify its performance for spleen delineation and volumetry. This approach considers the issue of low contrast between spleen and adjacent tissue in non-contrast-enhanced MR images. Native T1-weighted MR volume data was performed on a 1.5 T MR system in an epidemiological study. We analyzed random subsamples of MR examinations without pathologies to develop and verify the spleen segmentation framework. The framework is modularized to include different kinds of prior knowledge into the segmentation pipeline. Classification by support vector machines differentiates between five different shape types in computed foreground probability maps and recognizes characteristic spleen regions in axial slices of MR volume data. A spleen-shape space generated by training produces subject-specific prior shape knowledge that is then incorporated into a final 3D level set segmentation method. Individually adapted shape-driven forces as well as image-driven forces resulting from refined foreground probability maps steer the level set successfully to the segment the spleen. The framework achieves promising segmentation results with mean Dice coefficients of nearly 0.91 and low volumetric mean errors of 6.3%. The presented spleen segmentation approach can delineate spleen tissue in native MR volume data. Several kinds of prior shape knowledge including subject-specific 3D prior shape knowledge can be used to guide segmentation processes achieving promising results.

  4. Combined gadoxetic acid and gadofosveset enhanced liver MRI for detection and characterization of liver metastases

    International Nuclear Information System (INIS)

    Bannas, Peter; Bookwalter, Candice A.; Ziemlewicz, Tim; Munoz del Rio, Alejandro; Potretzke, Theodora A.; Motosugi, Utaroh; Nagle, Scott K.; Reeder, Scott B.

    2017-01-01

    To compare gadoxetic acid alone and combined gadoxetic acid/gadofosveset trisodium-enhanced liver MRI for detection of metastases and differentiation of metastases from haemangiomas. Ninety-one patients underwent gadoxetic acid-enhanced liver MRI before and after additional injection of gadofosveset. First, two readers retrospectively identified metastases on gadoxetic acid alone enhanced delayed hepatobiliary phase T1-weighted images together with all other MR images (dynamic images, T2-weighted images, diffusion-weighted images). Second, readers assessed additional T1-weighted images obtained after administration of gadofosveset trisodium. For both interpretations, readers rated lesion conspicuity and confidence in differentiating metastases from haemangiomas. Results were compared using alternative free-response receiver-operating characteristic (AFROC) and conventional ROC methods. Histology and follow-up served as reference standard. There were 145 metastases and 16 haemangiomas. Both readers detected more metastases using combined gadoxetic acid/gadofosveset (reader 1 = 130; reader 2 = 124) compared to gadoxetic acid alone (reader 1 = 104; reader 2 = 103). Sensitivity of combined gadoxetic acid/gadofosveset (reader 1 = 90 %; reader 2 = 86 %) was higher than that of gadoxetic acid alone (reader 1 = 72 %; reader 2 = 71 %, both P < 0.01). AFROC-AUC was higher for the combined technique (0.92 vs. 0.86, P < 0.001). Sensitivity for correct differentiation of metastases from haemangiomas was higher for the combined technique (reader 1 = 98 %; reader 2 = 99 % vs. reader 1 = 86 %; reader 2 = 91 %, both P < 0.01). ROC-AUC was significantly higher for the combined technique (reader 1 = 1.00; reader 2 = 1.00 vs. reader 1 = 0.87; reader 2 = 0.92, both P < 0.01). Combined gadoxetic acid/gadofosveset-enhanced MRI improves detection and characterization of liver metastases compared to gadoxetic acid alone. (orig.)

  5. Combined gadoxetic acid and gadofosveset enhanced liver MRI for detection and characterization of liver metastases

    Energy Technology Data Exchange (ETDEWEB)

    Bannas, Peter [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); University Medical Center Hamburg-Eppendorf, Department of Radiology, University Hospital, Hamburg (Germany); Bookwalter, Candice A.; Ziemlewicz, Tim; Munoz del Rio, Alejandro; Potretzke, Theodora A. [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); Motosugi, Utaroh [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); University of Yamanashi, Department of Radiology, Yamanashi (Japan); Nagle, Scott K. [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin-Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin-Madison, Department of Pediatrics, Madison, WI (United States); Reeder, Scott B. [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin-Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin-Madison, Department of Biomedical Engineering, Madison, WI (United States); University of Wisconsin-Madison, Department of Medicine, Madison, WI (United States); University of Wisconsin-Madison, Department of Emergency Medicine, Madison, WI (United States)

    2017-01-15

    To compare gadoxetic acid alone and combined gadoxetic acid/gadofosveset trisodium-enhanced liver MRI for detection of metastases and differentiation of metastases from haemangiomas. Ninety-one patients underwent gadoxetic acid-enhanced liver MRI before and after additional injection of gadofosveset. First, two readers retrospectively identified metastases on gadoxetic acid alone enhanced delayed hepatobiliary phase T1-weighted images together with all other MR images (dynamic images, T2-weighted images, diffusion-weighted images). Second, readers assessed additional T1-weighted images obtained after administration of gadofosveset trisodium. For both interpretations, readers rated lesion conspicuity and confidence in differentiating metastases from haemangiomas. Results were compared using alternative free-response receiver-operating characteristic (AFROC) and conventional ROC methods. Histology and follow-up served as reference standard. There were 145 metastases and 16 haemangiomas. Both readers detected more metastases using combined gadoxetic acid/gadofosveset (reader 1 = 130; reader 2 = 124) compared to gadoxetic acid alone (reader 1 = 104; reader 2 = 103). Sensitivity of combined gadoxetic acid/gadofosveset (reader 1 = 90 %; reader 2 = 86 %) was higher than that of gadoxetic acid alone (reader 1 = 72 %; reader 2 = 71 %, both P < 0.01). AFROC-AUC was higher for the combined technique (0.92 vs. 0.86, P < 0.001). Sensitivity for correct differentiation of metastases from haemangiomas was higher for the combined technique (reader 1 = 98 %; reader 2 = 99 % vs. reader 1 = 86 %; reader 2 = 91 %, both P < 0.01). ROC-AUC was significantly higher for the combined technique (reader 1 = 1.00; reader 2 = 1.00 vs. reader 1 = 0.87; reader 2 = 0.92, both P < 0.01). Combined gadoxetic acid/gadofosveset-enhanced MRI improves detection and characterization of liver metastases compared to gadoxetic acid alone. (orig.)

  6. Evaluation of sacroiliitis: contrast-enhanced MRI with subtraction technique

    Energy Technology Data Exchange (ETDEWEB)

    Algin, Oktay; Gokalp, Gokhan; Baran, Bulent; Ocakoglu, Gokhan; Yazici, Zeynep [Uludag University, Medical Faculty, Department of Radiology, Gorukle, Bursa (Turkey)

    2009-10-15

    The purpose of the study was to investigate the diagnostic value of contrast-enhanced MRI using the subtraction technique in the detection of active sacroiliitis. Magnetic resonance imaging was performed in 8 asymptomatic volunteers and 50 patients with clinically suspected active sacroiliitis. On precontrast MR images, T1-weighted spin-echo images with and without fat saturation (T1WFS and T1W), STIR and 3D-FLASH images with fat saturation were obtained in the semicoronal plane using a 1.5 Tesla imager. Postcontrast MRI was performed using the same T1WFS sequence as before contrast injection for all volunteers and patients. Postcontrast images were subtracted from fat-suppressed precontrast images. Enhancement within the joint space and bone marrow was considered to demonstrate active sacroiliitis. In 50 patients (100 sacroiliac joints [SIJs]), 40 (76 SIJs) were considered to have active sacroiliitis based on MR images. Bone marrow edema was present in 33 patients (62 SIJs) on STIR images. Routine MRI allowed identification of contrast enhancement in SIJs on postcontrast T1WFS images in 31 patients (49 SIJs). Contrast enhancement was observed in 40 patients (76 SIJs) who were examined by MRI using the subtraction technique. Contrast enhancement was significantly more conspicuous on subtraction images than on non-subtracted postcontrast T1WFS images (Mann-Whitney U test, p<0.001). Contrast-enhanced MRI with subtraction technique may be useful for early detection of active sacroiliitis. (orig.)

  7. Analysis of normal tongue by dynamic enhanced MRI

    International Nuclear Information System (INIS)

    Ariyoshi, Yasunori; Shimahara, Masashi

    2003-01-01

    We qualitatively evaluated dynamic enhanced MR images of normal tongues of 26 patients without oral malignancy, inflammatory diseases or systemic diseases. The selected slices were not affected by apparent artifacts including motion and susceptibility, and the tongue shape was delineated as symmetrical on coronal images, which were obtained using a T1 weighted spin echo pulse sequence (repetition time/echo time (TR/TE)=200/20). Slices at the incisor and molar levels were evaluated. Structures that could be identified on each pre-contrast image could also be identified on the post-contrast dynamic enhanced image. However, identification of the intrinsic tongue musculature was impossible on the images that were composed of symmetrical, relatively high signal areas surrounded by a low signal area. Both areas were gradually but apparently enhanced. The sublingual space was easily identified at the molar level, as it was rapidly enhanced and symmetrically delineated on each image, however, it was difficult to determine at the incisor level. Further, the lingual septum could also be identified in almost all images at the molar level, and showed no enhancement pattern, whereas, the mucosal surface of the dorsum tongue was rapidly enhanced, and identified on each image. (author)

  8. Synthesis and Characterization of a Gd-DOTA-D-Permeation Peptide for Magnetic Resonance Relaxation Enhancement of Intracellular Targets

    Directory of Open Access Journals (Sweden)

    Andrew M. Prantner

    2003-10-01

    Full Text Available Many MR contrast agents have been developed and proven effective for extracellular nontargeted applications, but exploitation of intracellular MR contrast agents has been elusive due to the permeability barrier of the plasma membrane. Peptide transduction domains can circumvent this permeability barrier and deliver cargo molecules to the cell interior. Based upon enhanced cellular uptake of permeation peptides with D-amino acid residues, an all-D Tat basic domain peptide was conjugated to DOTA and chelated to gadolinium. Gd-DOTA-D-Tat peptide in serum at room temperature showed a relaxivity of 7.94 ± 0.11 mM−1 sec−1 at 4.7 T. The peptide complex displayed no significant binding to serum proteins, was efficiently internalized by human Jurkat leukemia cells resulting in intracellular T1 relaxation enhancement, and in preliminary T1-weighted MRI experiments, significantly enhanced liver, kidney, and mesenteric signals.

  9. Detection of hepatic metastases by superparamagnetic iron oxide-enhanced MR imaging: prospective comparison between 1.5-T and 3.0-T images in the same patients

    International Nuclear Information System (INIS)

    Sofue, Keitaro; Miyake, Mototaka; Sakurada, Aine; Arai, Yasuaki; Tsurusaki, Masakatsu; Sugimura, Kazuro

    2010-01-01

    To prospectively compare the diagnostic performance of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging at 3.0 T and 1.5 T for detection of hepatic metastases. A total of 28 patients (18 men, 10 women; mean age, 61 years) with 80 hepatic metastases were prospectively examined by SPIO-enhanced MR imaging at 3.0 T and 1.5 T. T1-weighted gradient-recalled-echo (GRE) images, T2*-weighted GRE images and T2-weighted fast spin-echo (SE) images were acquired. The tumour-to-liver contrast-to-noise ratio (CNR) of the lesions was calculated. Three observers independently reviewed each image. Image artefacts and overall image quality were analysed, sensitivity and positive predictive value for the detection of hepatic metastases were calculated, and diagnostic accuracy using the receiver-operating characteristics (ROC) method was evaluated. The tumour-to-liver CNRs were significantly higher at 3.0 T. Chemical shift and motion artefact were more severe, and overall image quality was worse on T2-weighted fast SE images at 3.0 T. Overall image quality of the two systems was similar on T1-weighted GRE images and T2*-weighted GRE images. Sensitivity and area under the ROC curve for the 3.0-T image sets were significantly higher. SPIO-enhanced MR imaging at 3.0 T provided better diagnostic performance for detection of hepatic metastases than 1.5 T. (orig.)

  10. MnDPDP-enhanced MR imaging of the liver. Correlation with surgical findings

    International Nuclear Information System (INIS)

    Kane, P.A.; Ayton, V.; Walters, H.L.; Benjamin, I.; Heaton, N.D.; Williams, R.; Karani, J.B.

    1997-01-01

    Purpose: To compare lesion detection and characterisation predicted by MnDPDP-enhanced MR imaging with surgical excision and pathological examination. Material and Methods: Ninety patients were intravenously infused at a rate of 2 to 3 ml/min with 5 μmol/kg mangafodipir trisodium (MnDPDP, Teslascan). The patients were examined with spin-echo and gradient-echo T1-weighted MR imaging at 1 h and 24 h after the end of infusion. The results were compared with identical pre-contrast sequences. In 20 of these patients, the pre-operative MR findings were compared with intra-operative ultrasonography and histology of the resected liver specimens. Results: In those with liver metastases, there was a good correlation between MR and the hepatic disease in 11 out of 14 cases. In the group with primary liver tumours, MR findings correlated with hepatic disease in 5 out 6 cases. (orig./AJ)

  11. Follow-up of acute myocardial infarction with Gd-DTPA-enhanced MR image

    International Nuclear Information System (INIS)

    Matheijssen, N.A.A.; Dijkman, P.; Rossum, A.C. van der; Laarse, A. van der; Voorthuisen, A. van; Bruschke, A.

    1990-01-01

    MR imaging with Gd-DTPA has been shown to be useful in the identification of acutely infarcted myocardium. The purpose of this paper is to assess the influence of Gd-DTPA on myocardial signal intensity (SI) at different intervals after acute myocardial infarction (SMI). The authors used Gd-DTPA-enhanced MR imaging to study 84 patients at different intervals after AMI. A total of 109 T1-weighted MR studies were performed with a Philips Gyroscan magnet (0.5T) before and 20 minutes after Gd-DTPA (0.15 mmol/kg given intravenously). Four groups were studied. Group 1 underwent MR imaging less than 1 week after AMI; group 2, 1-3 weeks; group 3, 3-6 weeks; and group 4, over 6 weeks after AMI

  12. Topical contrast-enhanced magnetic resonance dacryocystography

    International Nuclear Information System (INIS)

    Yoshikawa, Takeshi; Sugimura, Kazuro; Hirota, Shozo

    2000-01-01

    The purpose of this study was to evaluate the usefulness of magnetic resonance dacryocystography (MRD) with topical administration of normal saline solution and diluted Gd-DTPA solution for the assessment of lacrimal outflow disorders. Two T2-weighted sequences and two T1-weighted sequences were evaluated in this study. The 1:100 diluted Gd solution was prepared by diluting Gd-DTPA (Magnevist) with normal saline solution. A phantom study using tube phantoms of various diameters filled with normal saline solution and 1:100 diluted Gd solution was performed. A preliminary study was performed in ten normal volunteers Eighteen patients with lacrimal outflow disorders underwent clinical MRD, and 14 also underwent conventional dacryocystography (CDG). MRD images were evaluated and compared with clinical symptoms and CDG images. In all sequences, MRD could visualize the full length of 0.7 to 1.7 mm diameter tube phantoms and could show all of the normal lacrimal sacs and nasolacrimal ducts. In the clinical study, MRD findings were compatible with the symptoms in 14 patients but were not compatible with CDG findings in half of the cases. Topical contrast-enhanced MRD provided a simple, non-invasive means of obtaining detailed morphological and functional information on the lacrimal drainage apparatus. (author)

  13. Differential diagnosis between metastatic tumors and nonsolid benign lesions of the liver using ferucarbotran-enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Higashihara, Hiroki [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 5650871 (Japan)], E-mail: h-higashihara@radiol.med.osaka-u.ac.jp; Murakami, Takamichi [Department of Radiology, Kinki University School of Medicine 377-2 Oonohigashi, Osakasayama, Osaka 5898511 (Japan); Kim, Tonsok; Hori, Masatoshi; Onishi, Hiromitsu [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 5650871 (Japan); Nakata, Saki [Department of Radiology, Toyonaka Municipal Hospital, 4-14-1 Shibahara Chou, Toyonaka, Osaka 5608565 (Japan); Osuga, Keigo; Tomoda, Kaname; Nakamura, Hironobu [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 5650871 (Japan)

    2010-01-15

    Purpose: To evaluate ability of ferucarbotran-enhanced MR imaging (MRI) in differentiating metastases from nonsolid benign lesions of the liver according to signal-intensity characteristics. Materials and methods: Sixty-six consecutive patients, who had 138 focal hepatic lesions (26 cysts, 11 hemangiomas, and 101 metastases), underwent ferucarbotran-enhanced MRI. The signal-intensity pattern of each kind of lesion relative to the liver parenchyma on ferucarbotran-enhanced T2* and heavily T1-weighted gradient-echo images were assessed and categorized into the following three categories: high-intensity and iso-intensity, respectively (category A), high and low (category B), and iso- and low-intensity (category C). For category B, lesions were subdivided into two groups based on single-shot half-Fourier RARE images: category B1 (not significantly high-intensity) and category B2 (significantly high-intensity). Results: Category A had 11 hemangiomas and 2 metastatic tumors, category B1 had 97 metastatic tumors, category B2 had 2 metastatic tumors and 9 cysts, and category C had 17 cysts. When a tumor with a signal intensity of category A was considered to be hemangioma, category B1 metastasis, and category B2 and C cyst, the diagnostic accuracy for differentiating these lesions was 97% (134/138). Conclusion: The combination of signal-intensity pattern on ferucarbotran-enhanced T2*- and heavily T1-weighted gradient-echo MRI has ability to differentiate liver metastases from nonsolid benign lesions. However, T2-weighted single-shot half-Fourier RARE imaging should also be employed to achieve better performance.

  14. Differentiating Focal Eosinophilic Infiltration from Metastasis in the Liver with Gadoxetic Acid-Enhanced Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mi Hee; Kim, Seong Hyun; Kim, Hee Jung; Lee, Min Woo; Lee, Won Jae [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2011-08-15

    To determine the most useful findings of gadoxetic acid-enhanced 3.0 Tesla (T) MRI for differentiating focal eosinophilic infiltration (FEI) from hepatic metastasis with verification of their usefulness. Pathologically or clinically proven 39 FEIs from 25 patients and 79 hepatic metastases from 51 patients were included in the study. Gadoxetic acid-enhanced 3.0T MRI was performed in all cancer patients. Size differences measured between T2-weighted and hepatobiliary-phase images for lesions > 1 cm and morphologic findings (margin, shape, signal intensity on T1- and T2-weighted images, enhancement pattern on dynamic images, and target appearance on hepatobiliary-phase images) were compared between two groups via Student's t test as well as univariate and multivariate analyses. Diagnostic predictive values of two observers for differentiating two groups were assessed before (session 1) and after (session 2) recognition of results. Mean size difference (2.1 mm) in FEIs between the two images was significantly greater than for metastases (0.7 mm) (p < 0.05). An ill-defined margin and isointensity on T1-weighted images were independently significant morphologic findings (p < 0.05) for differentiating the two groups. All observers achieved a higher diagnostic accuracy in session 2 (97% and 98%) than session 1 (92% and 89%) with statistical significance in observer 2 (p < 0.05). All observers had significantly higher sensitivities (95%) and negative predictive values (NPVs) (98%) in session 2 than in session 1 (sensitivity, 74% in two observers; NPV, 89% and 88%) (p < 0.05). With the size change, an ill-defined margin and isointensity on T1-weighted images are the most useful findings for differentiating FEI from hepatic metastasis on gadoxetic acid-enhanced 3.0T MRI.

  15. Dynamic contrast-enhanced MRI in patients with luminal Crohn's disease

    International Nuclear Information System (INIS)

    Ziech, M.L.W.; Lavini, C.; Caan, M.W.A.; Nio, C.Y.; Stokkers, P.C.F.; Bipat, S.; Ponsioen, C.Y.; Nederveen, A.J.; Stoker, J.

    2012-01-01

    Objectives: To prospectively assess dynamic contrast-enhanced (DCE-)MRI as compared to conventional sequences in patients with luminal Crohn's disease. Methods: Patients with Crohn's disease undergoing MRI and ileocolonoscopy within 1 month had DCE-MRI (3T) during intravenous contrast injection of gadobutrol, single shot fast spin echo sequence and 3D T1-weighted spoiled gradient echo sequence, a dynamic coronal 3D T1-weighted fast spoiled gradient were performed before and after gadobutrol. Maximum enhancement (ME) and initial slope of increase (ISI) were calculated for four colon segments (ascending colon + coecum, transverse colon, descending colon + sigmoid, rectum) and (neo)terminal ileum. C-reactive protein (CRP), Crohn's disease activity index (CDAI), per patient and per segment Crohn's disease endoscopic index of severity (CDEIS) and disease duration were determined. Mean values of the (DCE-)MRI parameters in each segment from each patient were compared between four disease activity groups (normal mucosa, non-ulcerative lesions, mild ulcerative and severe ulcerative disease) with Mann–Whitney test with Bonferroni adjustment. Spearman correlation coefficients were calculated for continuous variables. Results: Thirty-three patients were included (mean age 37 years; 23 females, median CDEIS 4.4). ME and ISI correlated weakly with segmental CDEIS (r = 0.485 and r = 0.206) and ME per patient correlated moderately with CDEIS (r = 0.551). ME was significantly higher in segments with mild (0.378) or severe (0.388) ulcerative disease compared to normal mucosa (0.304) (p < 0.001). No ulcerations were identified at conventional sequences. ME correlated with disease duration in diseased segments (r = 0.492), not with CDAI and CRP. Conclusions: DCE-MRI can be used as a method for detecting Crohn's disease ulcerative lesions.

  16. Dynamic contrast-enhanced MRI in patients with luminal Crohn's disease

    Energy Technology Data Exchange (ETDEWEB)

    Ziech, M.L.W., E-mail: m.l.ziech@amc.uva.nl [Academic Medical Center, Department of Radiology, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Lavini, C., E-mail: c.lavini@amc.uva.nl [Academic Medical Center, Department of Radiology, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Caan, M.W.A., E-mail: m.w.a.caan@amc.uva.nl [Academic Medical Center, Department of Radiology, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Nio, C.Y., E-mail: C.Y.Nio@amc.uva.nl [Academic Medical Center, Department of Radiology, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Stokkers, P.C.F., E-mail: p.stokkers@slaz.nl [Academic Medical Center, Department of Gastroenterology, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Sint Lucas Andreas Ziekenhuis, Department of Gastroenterology, Jan Tooropstraat 164, 1061 AE, Amsterdam (Netherlands); Bipat, S., E-mail: S.Bipat@amc.uva.nl [Academic Medical Center, Department of Radiology, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Ponsioen, C.Y., E-mail: c.y.ponsioen@amc.uva.nl [Academic Medical Center, Department of Gastroenterology, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Nederveen, A.J., E-mail: a.j.nederveen@amc.uva.nl [Academic Medical Center, Department of Radiology, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Stoker, J., E-mail: j.stoker@amc.uva.nl [Academic Medical Center, Department of Radiology, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands)

    2012-11-15

    Objectives: To prospectively assess dynamic contrast-enhanced (DCE-)MRI as compared to conventional sequences in patients with luminal Crohn's disease. Methods: Patients with Crohn's disease undergoing MRI and ileocolonoscopy within 1 month had DCE-MRI (3T) during intravenous contrast injection of gadobutrol, single shot fast spin echo sequence and 3D T1-weighted spoiled gradient echo sequence, a dynamic coronal 3D T1-weighted fast spoiled gradient were performed before and after gadobutrol. Maximum enhancement (ME) and initial slope of increase (ISI) were calculated for four colon segments (ascending colon + coecum, transverse colon, descending colon + sigmoid, rectum) and (neo)terminal ileum. C-reactive protein (CRP), Crohn's disease activity index (CDAI), per patient and per segment Crohn's disease endoscopic index of severity (CDEIS) and disease duration were determined. Mean values of the (DCE-)MRI parameters in each segment from each patient were compared between four disease activity groups (normal mucosa, non-ulcerative lesions, mild ulcerative and severe ulcerative disease) with Mann-Whitney test with Bonferroni adjustment. Spearman correlation coefficients were calculated for continuous variables. Results: Thirty-three patients were included (mean age 37 years; 23 females, median CDEIS 4.4). ME and ISI correlated weakly with segmental CDEIS (r = 0.485 and r = 0.206) and ME per patient correlated moderately with CDEIS (r = 0.551). ME was significantly higher in segments with mild (0.378) or severe (0.388) ulcerative disease compared to normal mucosa (0.304) (p < 0.001). No ulcerations were identified at conventional sequences. ME correlated with disease duration in diseased segments (r = 0.492), not with CDAI and CRP. Conclusions: DCE-MRI can be used as a method for detecting Crohn's disease ulcerative lesions.

  17. A novel nitroreductase-enhanced MRI contrast agent and its potential application in bacterial imaging

    Directory of Open Access Journals (Sweden)

    Yun Liu

    2018-05-01

    Full Text Available Nitroreductases (NTRs are known to be able to metabolize nitro-substituted compounds in the presence of reduced nicotinamide adenine dinucleotide (NADH as an electron donor. NTRs are present in a wide range of bacterial genera and, to a lesser extent, in eukaryotes hypoxic tumour cells and tumorous tissues, which makes it an appropriate biomarker for an imaging target to detect the hypoxic status of cancer cells and potential bacterial infections. To evaluate the specific activation level of NTR, great efforts have been devoted to the development of fluorescent probes to detect NTR activities using fluorogenic methods to probe its behaviour in a cellular context; however, NTR-responsive MRI contrast agents are still by far underexplored. In this study, para-nitrobenzyl substituted T1-weighted magnetic resonance imaging (MRI contrast agent Gd-DOTA-PNB (probe 1 has been designed and explored for the possible detection of NTR. Our experimental results show that probe 1 could serve as an MRI-enhanced contrast agent for monitoring NTR activity. The in vitro response and mechanism of the NTR catalysed reduction of probe 1 have been investigated through LC–MS and MRI. Para-nitrobenzyl substituted probe 1 was catalytically reduced by NTR to the intermediate para-aminobenzyl substituted probe which then underwent a rearrangement elimination reaction to Gd-DOTA, generating the enhanced T1-weighted MR imaging. Further, LC–MS and MRI studies of living Escherichia coli have confirmed the NTR activity detection ability of probe 1 at a cellular level. This method may potentially be used for the diagnosis of bacterial infections. KEY WORDS: Nitroreductase, MRI contrast agent, Smart imaging probes, Bacterial imaging, Bacterial infection

  18. Changes in signal-to-noise ratios and contrast-to-noise ratios of hypervascular hepatocellular carcinomas on ferucarbotran-enhanced dynamic MR imaging

    International Nuclear Information System (INIS)

    Park, Yulri; Choi, Dongil; Kim, Seong Hyun; Kim, Seung Hoon; Kim, Min Ju; Lee, Jongmee; Lim, Jae Hoon; Lee, Won Jae; Lim, Hyo K.

    2006-01-01

    Purpose: To verify changes in the signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) of hypervascular hepatocellular carcinomas (HCCs) on ferucarbotran-enhanced dynamic T1-weighted MR imaging. Materials and methods: Fifty-two patients with 61 hypervascular HCCs underwent ferucarbotran-enhanced dynamic MR imaging, and then hepatic resection. Hypervascular HCCs were identified when definite enhancement was noted during the arterial dominant phase of three-phase MDCT. Dynamic MR Images with T1-weighted fast multiplanar spoiled gradient-recalled echo sequence (TR200/TE4.2) were obtained before and 20 s, and 1, 3, 5, and 10 min, after bolus injection of ferucarbotran. We estimated the signal intensities of tumors and livers, and calculated the SNRs and CNRs of the tumors. Results: On ferucarbotran-enhanced dynamic MR imaging, SNR measurements showed a fluctuating pattern, namely, an increase in SNR followed by a decrease and a subsequent increase (or a decrease in SNR followed by a increase and a subsequent decrease) in 50 (82.0%) of 61 tumors, a single-peak SNR pattern (highest SNR on 20 s, 1, 3, or 5 min delayed images followed by a decrease) in seven (11.5%), and a decrease in SNR followed by an increase in four (6.6%). Maximum absolute CNRs with positive value were noted on 10 min delayed images in 41 (67.2%) tumors, and maximum absolute CNRs with negative value were observed on 20 s delayed images in 12 (19.7%) and on 1 min delayed images in eight (13.1%). Conclusion: Despite showing various SNR and CNR changes, the majority of hypervascular HCCs demonstrated a fluctuating SNR pattern on ferucarbotran-enhanced dynamic MR imaging and a highest CNR on 10 min delayed image, which differed from the classic enhancement pattern on multiphasic CT

  19. Efficacy of gadolinium enhanced MR imaging for the diagnosis of Legg-Calve-Perthes disease

    International Nuclear Information System (INIS)

    Kim, Jee Eun; Kim, Hyung Sik; Kim, Ji Hye

    2008-01-01

    The purpose of this study was to evaluate the efficacy of gadolinium enhanced MR imaging for making the diagnosis of Legg-Calve-Perthes (LCP) disease. We studied the gadolinium enhanced MR images of 14 hips in 12 children who had the diagnosis of LCP disease. We retrospectively analyzed the extent of necrosis, the epiphyseal revascularization pathways and the metaphyseal changes. The absence of enhancement on gadolinium enhanced MRI was noted in all cases of LCP disease. Diffuse absence of enhancement was observed in 9 femoral epiphyses. Two of them showed normal bone marrow signal intensity on the T1 and T1-weighted images. Focal absence of enhancement was observed in 5 femoral epiphyses. Enhanced MRI showed better epiphyseal revascularization in the lateral column (five cases), in the lateral and medial columns (four cases) and in the transphyseal pathway (three cases). Metaphyseal change was observed in two cases. Gadolinium enhanced MRI allows detection of LCP disease and an accurate analysis of the different revascularization patterns, and this helpful for predicting the prognosis

  20. Gd-DTPA enhanced MR imaging in Bell's palsy

    International Nuclear Information System (INIS)

    Matsumoto, Yasushi; Kawamura, Yuji; Yanagihara, Naoaki; Sadamoto, Masanori; Sadamoto, Kazuhiko.

    1991-01-01

    Magnetic resonance imaging (MRI) was carried out in 27 patients with Bell's palsy. T1-weighted spin-echo images (TR500/TE25-34) were taken before and after the intravenous administration of Gd-DTPA (0.1 mmol/kg) with 0.5T superconductive MRI. There was significant enhancement at the geniculate ganglion and the horizontal segment of the involved facial nerve in 22 patients (81.5%) and at the vertical segment in 20 (74.1%). Enhancement at the meatal fundus was seen in only 4 patients (14.9%) and at the labyrinthine segment in 8 (29.6%). These results corroborate other evidence that the geniculate ganglion is involved most frequently in Bell's palsy. In addition, the enhancement of the proximal portion, i.e. the meatal fundus and the labyrinthine segment of the nerve, although not common, noted in this study may be important in the diagnosis and treatment of Bell's palsy. (author)

  1. Detection of hepatic VX2 carcinomas with ferucarbotran-enhanced magnetic resonance imaging in rabbits: Comparison of nine pulse sequences

    International Nuclear Information System (INIS)

    Kim, Seong Hyun; Choi, Dongil; Lim, Hyo K.; Kim, Min Ju; Jang, Kyung Mi; Kim, Seung Hoon; Lee, Won Jae; Lee, Jongmee; Jeon, Yong Hwan; Lim, Jae Hoon

    2006-01-01

    Objective: To compare the diagnostic performance of a variety of magnetic resonance imaging (MRI) sequences, in order to identify the most effective ferucarbotran-enhanced sequence for the detection of multiple small hepatic VX2 carcinomas in rabbits. Methods: Fifteen rabbits with experimentally induced 135 VX2 carcinomas in the liver underwent ferucarbotran-enhanced MRI using the following nine pulse sequences: a fat-suppressed fast spin-echo (FSE) sequence with two echo times (TE) (proton density- and T2-weighted images), four different T2*-weighted fast multiplanar GRASS (gradient-recalled acquisition in the steady state) (FMPGR) with the combination of three TEs (9, 12, 15 ms, respectively) and two flip angles (20 deg., 80 deg., respectively), T2*-weighted fast multiplanar spoiled GRASS (FMPSPGR), T1-weighted FMPSPGR, and dynamic T1-weighted FMPSPGR. All images were reviewed by three radiologists with quantitative and qualitative analysis. Results: Tumor-to-liver contrast-to-noise ratio of the proton density-weighted FSE sequence was significantly higher than those of the others (p o ) images were superior to those of the others and for the detection of very small hepatic tumors of less than 5 mm, the sensitivities of these sequences were less than 30%. Conclusion: Ferucarbotran-enhanced T2- and proton density-weighted FSE and T2*-weighed FMPGR (TE/flip angle, 12/20 o ) images were found to be the most effective pulse sequences for the detection of multiple small hepatic VX2 carcinomas but these sequences were limited in the detection of very small hepatic tumors of less than 5 mm in size

  2. Acetabular labral tears: contrast-enhanced MR imaging under continuous leg traction

    Energy Technology Data Exchange (ETDEWEB)

    Nishii, T. [Div. of Functional Diagnostic Imaging, Biomedical Research Center, Osaka Univ. Medical School, Suita (Japan); Nakanishi, K. [Dept. of Radiology, Osaka Univ. Medical School, Suita (Japan); Sugano, N. [Dept. of Orthopaedic Surgery, Osaka Univ. Medical School, Suita (Japan); Naito, H. [Div. of Functional Diagnostic Imaging, Biomedical Research Center, Osaka Univ. Medical School, Suita (Japan); Tamura, S. [Div. of Functional Diagnostic Imaging, Biomedical Research Center, Osaka Univ. Medical School, Suita (Japan); Ochi, T. [Dept. of Orthopaedic Surgery, Osaka Univ. Medical School, Suita (Japan)

    1996-05-01

    The objective of this study was to evaluate the effects of continuous leg traction on contrast-enhanced MR imaging of the hip joint and to determine whether MR imaging under these conditions is useful for demonstrating acetabular labral tears. Nineteen hips underwent MR imaging with a T1-weighted spin-echo sequence, followed by MR imaging under continuous leg traction after intravenous injection of gadolinium-DTPA. Joint fluid enhancement and labral contour detection were evaluated. Eleven hips had labral tears shown by conventional arthrography, arthroscopy and macroscopic surgical findings. Assessment of labral tears by MR imaging was correlated with the diagnosis based on these standard techniques. Joint fluid enhancement was obtained in all hips at 30 min after injection. Superior and inferior labral surfaces were completely delineated in 1 hip on the unenhanced MR images, and in 7 and 13 hips, respectively, on the enhanced images under traction. The enhanced images under traction depicted 9 of the 11 labral tears. Comparison between the unenhanced image and the enhanced image under traction avoided mistaking undercutting of the labrum for a tear in 4 hips. Contrast-enhanced MR imaging under traction was valuable for detecting labral tears non-invasively and without radiation. Follow-up examinations using this method in patients with acetabular dysplasia can help to clarify the natural course of labral disorders and enable better treatment planning. (orig./MG)

  3. Fibroadenomas of the breast: histopathological/dynamic contrast-enhanced MR correlation

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, R. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Garnier, C. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Meingan, P. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Zemoura, L. [Dept. of Histopathology C, Inst. Gustave Roussy, 94 - Villejuif (France); Lucidarme, O. [Dept. of Radiology, Hopital Salpetriere, 75 - Paris (France); Guinebretiere, J.M. [Dept. of Histopathology C, Inst. Gustave Roussy, 94 - Villejuif (France); Tardivon, A.A. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Arriagada, R. [Breast Cancer Study Group, Inst. Gustave Roussy, 94 - Villejuif, (France)

    1995-12-31

    A total of 22 women with fibroadenomas had preoperative dynamic MR study (T1-weighted images every 47 s after injection of Gd-DOTA). Their age, hormonal status, breast MR studies and histopathological slides were retrospectively reviewed. Eleven pre- (n = 2) or post-menopausal (n = 9) women showed no early contrast enhancement. The absence of early contrast enhancement correlated with hyalin stromal component. Eleven pre- (n = 7) or post-menopausal (n = 4) women showed focal (n = 9) or diffuse (n = 2) early contrast enhancement. Early focal contrast enhancement correlated with myxoid (n = 9), mixed hyalin/myxoid (n = 1) or hyalin (n = 1) fibroadenomas. Early diffuse contrast enhancement of the breast correlated with myxoid (n = 1) or hyalin (n = 1) stromal component associated with proliferative fibrocystic disease of the breast parenchyma. The presence of contrast enhancement correlated with myxoid fibroadenomas, whereas absence of contrast enhancement correlated with hyalin fibroadenomas. As hyalin fibroadenomas occurs in post-menopausal women, the diagnostic accuracy of dynamic MRI may be improved in this age group. (orig.)

  4. Fibroadenomas of the breast: histopathological/dynamic contrast-enhanced MR correlation

    International Nuclear Information System (INIS)

    Gilles, R.; Garnier, C.; Meingan, P.; Zemoura, L.; Lucidarme, O.; Guinebretiere, J.M.; Tardivon, A.A.; Arriagada, R.

    1995-01-01

    A total of 22 women with fibroadenomas had preoperative dynamic MR study (T1-weighted images every 47 s after injection of Gd-DOTA). Their age, hormonal status, breast MR studies and histopathological slides were retrospectively reviewed. Eleven pre- (n = 2) or post-menopausal (n = 9) women showed no early contrast enhancement. The absence of early contrast enhancement correlated with hyalin stromal component. Eleven pre- (n = 7) or post-menopausal (n = 4) women showed focal (n = 9) or diffuse (n = 2) early contrast enhancement. Early focal contrast enhancement correlated with myxoid (n = 9), mixed hyalin/myxoid (n 1) or hyalin (n = 1) fibroadenomas. Early diffuse contrast enhancement of the breast correlated with myxoid (n = 1) or hyalin (n = 1) stromal component associated with proliferative fibrocystic disease of the breast parenchyma. The presence of contrast enhancement correlated with myxoid fibroadenomas, whereas absence of contrast enhancement correlated with hyalin fibroadenomas. As hyalin fibroadenomas occurs in post-menopausal women, the diagnostic accuracy of dynamic MRI may be improved in this age group. (orig.)

  5. Transudative vs exudative pleural effusions: differentiation using Gd-DTPA-enhanced MRI

    International Nuclear Information System (INIS)

    Frola, C.; Cantoni, S.; Turtulici, I.; Leoni, C.; Loria, F.; Gaeta, M.; Derchi, L.E.

    1997-01-01

    The aim of this study was to investigate the capability of Gd-DTPA-enhanced MRI to differentiate between exudative and transudative pleural effusions. An MRI examination was performed on 22 patients with different types of pleural effusion (10 transudative and 12 exudative effusions). T1-weighted SE images were obtained before and 20 min after administration of Gd-DTPA (0.1 mmol/kg). The degree of enhancement of pleural effusions was evaluated both by visual assessement and by quantitative analysis of images. None of 10 transudative effusions showed significative enhancement, whereas 10 of 12 exudative effusions showed enhancement (sensitivity 83 %, specificity 100 %, positive predictive value 100 %). The postcontrast signal intensity ratios (SIRs) of exudates were significantly higher than corresponding precontrast ratios (P = 0.0109) and the postcontrast SIRs of exudates were significantly higher than those of transudates (P = 0.0300). Exudative pleural effusions show a significant enhancement following administration of Gd-DTPA. We presume that this may be caused by increased pleural permeability and more rapid passage of a large amount of Gd-DTPA from the blood into the pleural fluid in case of exudative effusions. In our limited group of patients, signal enhancement proved the presence of an exudative effusion. Absence of signal enhancement suggests a transudate, but does not exclude an exudate. (orig.). With 5 figs., 2 tabs

  6. Estimating volumes of the pituitary gland from T1-weighted magnetic-resonance images: effects of age, puberty, testosterone, and estradiol.

    Science.gov (United States)

    Wong, Angelita Pui-Yee; Pipitone, Jon; Park, Min Tae M; Dickie, Erin W; Leonard, Gabriel; Perron, Michel; Pike, Bruce G; Richer, Louis; Veillette, Suzanne; Chakravarty, M Mallar; Pausova, Zdenka; Paus, Tomáš

    2014-07-01

    The pituitary gland is a key structure in the hypothalamic-pituitary-gonadal (HPG) axis--it plays an important role in sexual maturation during puberty. Despite its small size, its volume can be quantified using magnetic resonance imaging (MRI). Here, we study a cohort of 962 typically developing adolescents from the Saguenay Youth Study and estimate pituitary volumes using a newly developed multi-atlas segmentation method known as the MAGeT Brain algorithm. We found that age and puberty stage (controlled for age) each predicts adjusted pituitary volumes (controlled for total brain volume) in both males and females. Controlling for the effects of age and puberty stage, total testosterone and estradiol levels also predict adjusted pituitary volumes in males and pre-menarche females, respectively. These findings demonstrate that the pituitary gland grows during adolescence, and its volume relates to circulating plasma-levels of sex steroids in both males and females. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Partial volume effect (PVE) on the arterial input function (AIF) in T1-weighted perfusion imaging and limitations of the multiplicative rescaling approach

    DEFF Research Database (Denmark)

    Hansen, Adam Espe; Pedersen, Henrik; Rostrup, Egill

    2009-01-01

    The partial volume effect (PVE) on the arterial input function (AIF) remains a major obstacle to absolute quantification of cerebral blood flow (CBF) using MRI. This study evaluates the validity and performance of a commonly used multiplicative rescaling of the AIF to correct for the PVE. In a gr...

  8. Utility of unenhanced fat-suppressed T1-weighted MRI in children with sickle cell disease -- can it differentiate bone infarcts from acute osteomyelitis?

    Science.gov (United States)

    Delgado, Jorge; Bedoya, Maria A; Green, Abby M; Jaramillo, Diego; Ho-Fung, Victor

    2015-12-01

    Children with sickle cell disease (SCD) are at risk of bone infarcts and acute osteomyelitis. The clinical differentiation between a bone infarct and acute osteomyelitis is a diagnostic challenge. Unenhanced T1-W fat-saturated MR images have been proposed as a potential tool to differentiate bone infarcts from osteomyelitis. To evaluate the reliability of unenhanced T1-W fat-saturated MRI for differentiation between bone infarcts and acute osteomyelitis in children with SCD. We retrospectively reviewed the records of 31 children (20 boys, 11 girls; mean age 10.6 years, range 1.1-17.9 years) with SCD and acute bone pain who underwent MR imaging including unenhanced T1-W fat-saturated images from 2005 to 2010. Complete clinical charts were reviewed by a pediatric hematologist with training in infectious diseases to determine a clinical standard to define the presence or absence of osteomyelitis. A pediatric radiologist reviewed all MR imaging and was blinded to clinical information. Based on the signal intensity in T1-W fat-saturated images, the children were further classified as positive for osteomyelitis (low bone marrow signal intensity) or positive for bone infarct (high bone marrow signal intensity). Based on the clinical standard, 5 children were classified as positive for osteomyelitis and 26 children as positive for bone infarct (negative for osteomyelitis). The bone marrow signal intensity on T1-W fat-saturated imaging was not significant for the differentiation between bone infarct and osteomyelitis (P = 0.56). None of the additional evaluated imaging parameters on unenhanced MRI proved reliable in differentiating these diagnoses. The bone marrow signal intensity on unenhanced T1-W fat-saturated MR images is not a reliable criterion to differentiate bone infarcts from osteomyelitis in children.

  9. Reversibility of hyperintense globus pallidus on T 1-weighted MRI following surgery for a portosystemic shunt in an 8-year-old girl

    International Nuclear Information System (INIS)

    Ikeda, Shinji; Sera, Yoshihisa; Yoshida, Mituhiro; Ohshiro, Hajime; Uchino, Shinichiro; Seguchi, Sasa; Endo, Fumio

    1999-01-01

    An 8-year-old Japanese girl with a portosystemic shunt had shown hyperammonaemia since she was 3 years of age. MRI of her brain showed bilateral hyperintense globus pallidus. A portosystemic shunt was evident on US and angiography. She underwent surgical banding of the shunt, after which the lesion and clinical symptoms disappeared. (orig.)

  10. Utility of unenhanced fat-suppressed T1-weighted MRI in children with sickle cell disease - can it differentiate bone infarcts from acute osteomyelitis?

    International Nuclear Information System (INIS)

    Delgado, Jorge; Bedoya, Maria A.; Green, Abby M.; Jaramillo, Diego; Ho-Fung, Victor

    2015-01-01

    Children with sickle cell disease (SCD) are at risk of bone infarcts and acute osteomyelitis. The clinical differentiation between a bone infarct and acute osteomyelitis is a diagnostic challenge. Unenhanced T1-W fat-saturated MR images have been proposed as a potential tool to differentiate bone infarcts from osteomyelitis. To evaluate the reliability of unenhanced T1-W fat-saturated MRI for differentiation between bone infarcts and acute osteomyelitis in children with SCD. We retrospectively reviewed the records of 31 children (20 boys, 11 girls; mean age 10.6 years, range 1.1-17.9 years) with SCD and acute bone pain who underwent MR imaging including unenhanced T1-W fat-saturated images from 2005 to 2010. Complete clinical charts were reviewed by a pediatric hematologist with training in infectious diseases to determine a clinical standard to define the presence or absence of osteomyelitis. A pediatric radiologist reviewed all MR imaging and was blinded to clinical information. Based on the signal intensity in T1-W fat-saturated images, the children were further classified as positive for osteomyelitis (low bone marrow signal intensity) or positive for bone infarct (high bone marrow signal intensity). Based on the clinical standard, 5 children were classified as positive for osteomyelitis and 26 children as positive for bone infarct (negative for osteomyelitis). The bone marrow signal intensity on T1-W fat-saturated imaging was not significant for the differentiation between bone infarct and osteomyelitis (P = 0.56). None of the additional evaluated imaging parameters on unenhanced MRI proved reliable in differentiating these diagnoses. The bone marrow signal intensity on unenhanced T1-W fat-saturated MR images is not a reliable criterion to differentiate bone infarcts from osteomyelitis in children. (orig.)

  11. Utility of unenhanced fat-suppressed T1-weighted MRI in children with sickle cell disease - can it differentiate bone infarcts from acute osteomyelitis?

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, Jorge; Bedoya, Maria A. [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Green, Abby M. [The Children' s Hospital of Philadelphia, Division of Oncology, Philadelphia, PA (United States); Jaramillo, Diego; Ho-Fung, Victor [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA (United States)

    2015-12-15

    Children with sickle cell disease (SCD) are at risk of bone infarcts and acute osteomyelitis. The clinical differentiation between a bone infarct and acute osteomyelitis is a diagnostic challenge. Unenhanced T1-W fat-saturated MR images have been proposed as a potential tool to differentiate bone infarcts from osteomyelitis. To evaluate the reliability of unenhanced T1-W fat-saturated MRI for differentiation between bone infarcts and acute osteomyelitis in children with SCD. We retrospectively reviewed the records of 31 children (20 boys, 11 girls; mean age 10.6 years, range 1.1-17.9 years) with SCD and acute bone pain who underwent MR imaging including unenhanced T1-W fat-saturated images from 2005 to 2010. Complete clinical charts were reviewed by a pediatric hematologist with training in infectious diseases to determine a clinical standard to define the presence or absence of osteomyelitis. A pediatric radiologist reviewed all MR imaging and was blinded to clinical information. Based on the signal intensity in T1-W fat-saturated images, the children were further classified as positive for osteomyelitis (low bone marrow signal intensity) or positive for bone infarct (high bone marrow signal intensity). Based on the clinical standard, 5 children were classified as positive for osteomyelitis and 26 children as positive for bone infarct (negative for osteomyelitis). The bone marrow signal intensity on T1-W fat-saturated imaging was not significant for the differentiation between bone infarct and osteomyelitis (P = 0.56). None of the additional evaluated imaging parameters on unenhanced MRI proved reliable in differentiating these diagnoses. The bone marrow signal intensity on unenhanced T1-W fat-saturated MR images is not a reliable criterion to differentiate bone infarcts from osteomyelitis in children. (orig.)

  12. Gadolinium-enhanced fat-suppression MR imaging of the female pelvis

    International Nuclear Information System (INIS)

    Shin, Joo Yong; Kim, Jung Sik; Kim, Hong

    1998-01-01

    To compare the value of Gd-DTPA enhanced, fat-suppression T1-weighted (Gd-FST1SE) MR images in the diagnosis of female pelvic disorders with that of fast spin-echo T1-weighted(T1FSE) and fast spin-echoT2-weighted(T2FSE) MR images. Materials and Methods : Pelvic MR images of 42 women (24 ovarian disorders, 19 uterine disorders) were reviewed by two radiologists. Discrimination of normal anatomic structures, identification of pathologic lesions and recognition of internal structure of the lesions such as solid and cystic portion,papillary nodule, septa and wall were evaluated using a scoring system. The Friedman two-way ANOVA test was used for data analysis. Results : T2FSE was useful for evaluation of the uterine cervix(T1/T2/Gd, 2.5/3.9/2.8,respectively), junctional zone(1.6/3.1/2.5), endometrium (2.0/3.3/3.0), ovary(1.1/2.1/1.7) and uterine myoma(1.7/2.4/2.1)(P<0.001), but secondary degeneration was best visualized on Gd-FS T1SE. The Gd-FS T1SE ;lymphadenopathy(3.4/1.5/3.7) was better visualised on this modality than on either TIFSE or T2FSE. Gd-FS T1SE images also clearly depicted papillary projection(2.4/3.1/3.8) and the solid component (2.9/3.1/3.5) of ovariancystic neoplasm(P<0.01). The confidence level in the identification of ovarian mass, internal septation and surrounding wall of cystic neoplasm was not improved on Gd-FS T1SE. Conclusion : The Gd-FS T1SE images were useful for the evaluation of metastatic lymphadenopathy in uterine cervical malignancy and for identification of the solid component and papillary projection of ovarian cystic neoplasm

  13. Efficacy of Gd-DTPA-enhanced MRI in hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Okamoto, Shinya; Aoki, Toshikazu; Konishi, Tokuji; Nakano, Takeshi; Yamakado, Kyoichiro; Sakuma, Hajime; Takeda, Kann; Nakagawa, Takashi

    1991-01-01

    The cabability of magnetic resonance (MR) imaging to detect tissue characterization or myocardial degeneration process of the hypertrophied myocardium was evaluated in 15 patients with hypertrophic cardiomyopathy. T1-weighted MR images were obtained with a 1.5 T MR unit by using ECG-gated spin-echo techniques. MR images were visually reviewed before and after enhancement of Gd-DTPA. Four patients had an increase in signal intensity mainly in the endocardium of the left ventricular septum on non-enhanced MR images, 3 of whom had widespread high intensity in addition to two-thirds of the wall. Gd-DTPA enhanced-MR images showed high intensity over the whole septum in 5 patients and also in the antero-lateral endocardium in 4 patients. Decreased intensity on non-enhanced MR images, as shown in 4 patients, became clear on enhanced-MR images. According to findings on enhanced-MR images, signal intensity was defined as normal (N), septum (S), and diffuse (D). Patients in Group D tended to be younger and have more frequently family history. Regarding both interventricular septum thickness and left ventricular posterior wall thickness, there was no significant difference among the three groups. Both left ventricular diastolic diameter and left ventricular systolic diameter were significantly larger in Group D than the other two groups. Left ventricular ejection fraction was significantly lower in both Group S and Group D. Widespread abnormal intensity on Gd-DTPA enhanced MR images was associated with findings similar to dilated cardiomyopathy, such as dilated left ventricular lumen and decreased ejection fraction. Gd-DTPA enhanced MR imaging seemed to be useful for visualizing myocardial degeneration in hypertrophic cardiomyopathy.(N.K.)

  14. Diagnostic accuracy of dynamic contrast-enhanced MR imaging of renal masses with rapid-acquisition spin-echo technique

    International Nuclear Information System (INIS)

    Eilenberg, S.S.; Lee, J.K.T.; Brown, J.J.; Heiken, J.P.; Mirowitz, S.A.

    1990-01-01

    This paper compares the diagnostic accuracy of Gd-DTPA-enhanced rapid-acquisition spin-echo (RASE) imaging with standard spin-echo techniques for detecting renal cysts and solid renal neoplasms. RASE imaging combines a short TR (275 msec)/short TE (10 msec), single excitation pulse sequence with half-Fourier data sampling. Eighteen patients with CT evidence of renal masses were first evaluated with standard T1-and T2-weighted SE sequences. Pre- and serial postcontrast (Cd-DTPA, 0.1 mmol./kg) RASE sequences were then performed during suspended respiration. A final set of postcontrast images was obtained with the standard T1-weighted SE sequence. Each set of MR images was first reviewed separately (ie, T1, T2, pre- and post-contrast RASE, etc)

  15. Multivariable analysis of clinical influence factors on liver enhancement of Gd-EOB-DTPA-enhanced 3T MRI; Multivariable Analyse klinischer Einflussfaktoren auf die Signalintensitaet bei Gd-EOB-DTPA 3T-MRT der Leber

    Energy Technology Data Exchange (ETDEWEB)

    Verloh, N.; Haimerl, M.; Stroszczynski, C.; Fellner, C.; Wiggermann, P. [University Hospital Regensburg (Germany). Dept. of Radiology; Zeman, F. [University Hospital Regensburg (Germany). Center for Clinical Trials; Teufel, A. [University Hospital Regensburg (Germany). Dept. of Gastroenterology; Lang, S. [University Hospital Regensburg (Germany). Dept. of Surgery

    2015-01-15

    The purpose of this study was to identify clinical factors influencing Gd-EOB-DTPA liver uptake in patients with healthy liver parenchyma. A total of 124 patients underwent contrast-enhanced MRI with a hepatocyte-specific contrast agent at 3T. T1-weighted volume interpolated breath-hold examination (VIBE) sequences with fat suppression were acquired before and 20 minutes after contrast injection. The relative enhancement (RE) between plain and contrast-enhanced signal intensity was calculated. Simple and multiple linear regression analyses were performed to evaluate clinical factors influencing the relative enhancement. Patients were subdivided into three groups according to their relative liver enhancement (HRE, RE ≥ 100 %; MRE, 100 % > RE > 50 %; NRE, RE ≤ 50 %) and were analyzed according to the relevant risk factors. Simple regression analyses revealed patient age, transaminases (AST, ALT, GGT), liver, spleen and delta-liver volume (the difference between the volumetrically measured liver volume and the estimated liver volume based on body weight) as significant factors influencing relative enhancement. In the multiple analysis the transaminase AST, spleen and delta liver volume remained significant factors influencing relative enhancement. Delta liver volume showed a significant difference between all analyzed groups. Liver enhancement in the hepatobiliary phase depends on a variety of factors. Body weight-adapted administration of Gd-EOB-DTPA may lead to inadequate liver enhancement after 20 minutes especially when the actual liver volume differs from the expected volume.

  16. Cholangiocarcinoma in Cirrhosis: Value of Hepatocyte Specific Magnetic Resonance Imaging.

    Science.gov (United States)

    Piscaglia, Fabio; Iavarone, Massimo; Galassi, Marzia; Vavassori, Sara; Renzulli, Matteo; Forzenigo, Laura Virginia; Granito, Alessandro; Salvatore, Veronica; Sangiovanni, Angelo; Golfieri, Rita; Colombo, Massimo; Bolondi, Luigi

    2015-10-01

    The diagnosis of intrahepatic cholangiocellular carcinoma (ICC) remains elusive at imaging, which is a critical issue in cirrhotic patients in whom a diagnosis of hepatocellular carcinoma (HCC) can be established only by imaging. The aim of the study was to evaluate the potential of MRI in the diagnosis of ICC in cirrhosis using 'hepatocyte-specific' Gadolinium (Gd)-based contrast agents. Sixteen histologically proven and retrospectively identified ICCs on cirrhosis were investigated with hepatocyte-specific magnetic resonance contrast agents (6 in Bologna with Gd-EOB-DTPA and 10 in Milan with Gd-BOPTA). The control group consisted of 41 consecutively and prospectively collected nodules (31 HCCs) imaged with Gd-EOB-DTPA. Fifteen ICC nodules (94%) displayed hypointensity in the hepatobiliary phase, suggesting malignancy. Thirteen cholangiocarcinomas (81%) showed hyperenhancement in the venous phase. Only 2 cholangiocarcinoma nodules showed hypoenhancement in the venous phase, corresponding to washout, in both cases preceded by rim enhancement in arterial phase. All the hepatocarcinomas showed hypointensity in hepatobiliary phase, but was always preceded by hypointensity in the venous phase; arterial rim enhancement was never observed in any hepatocarcinoma or regenerative nodule. MRI with hepatocyte-specific Gd-based contrast agents showed a pattern of malignancy in almost all the ICCs, concurrently avoiding misdiagnosis with hepatocarcinoma. These findings suggest a greater diagnostic capacity for this technique compared with the results of MRI with conventional contrast agents reported in the literature in this setting. © 2015 S. Karger AG, Basel.

  17. Enhancement of intracranial meningeal lesions with Gd-DTPA MR imaging

    International Nuclear Information System (INIS)

    Brown, E.; De La Paz, R.

    1989-01-01

    Pathologic intracranial meningeal enhancement on Gd-DTPA MR images (T1-weighted spin-echo sequence, 800/20 [repetition time msec/echo time msec] 1.5 T) was evaluated in 23 patients. Diagnoses included metastatic neoplasm (13 cases), benign neoplasm (four), infection (one), subarachnoid hemorrhage (three), and subdural hematoma (two). Eleven patients had undergone previous surgery. Diffuse enhancement occurred in 11 patients: eight with malignant infiltration, two with postoperative inflammation, and one with meningitis. Focal enhancement occurred in 12 patients, equally divided between those with malignant and benign processes: six cases were adjacent to intra- or extra-axial malignancy; three were at sites of recent (1--3 weeks) subarachnoid hemorrhage; and three were postoperative, adjacent to a craniotomy or subdural hematoma. Meningeal lesions were rarely diagnosed on the precontrast images, and Gd-DTPA enhancement was needed to distinguish between thickened meninges and thin fluid collections. Precontrast T1- and T2-weighted images were needed to discriminate high-signal meningeal enhancement from subacute subdural or subarachnoid hemorrhage, diploic marrow, normal vascular structures, and benign dural plaques. Meningeal enhancement was not pathology specific, and precontrast images are recommended to avoid misdiagnosis of subacute hemorrhage and misinterpretation of normal anatomy

  18. Benign and malignant hepatocellular tumors: evaluation of tumoral enhancement after mangafodipir trisodium injection on MR imaging

    International Nuclear Information System (INIS)

    Coffin, C.M.; Diche, T.; Mahfouz, A.E.; Alexandre, M.; Caseiro-Alves, F.; Rahmouni, A.; Vasile, N.; Mathieu, D.

    1999-01-01

    The aim of this work was to study the ability of mangafodipir trisodium (Mn-DPDP)-enhanced MR imaging in differentiating malignant from benign hepatocellular tumors. Eleven patients with pathologically proved hepatocellular carcinomas, six with focal nodular hyperplasias, and one with a single hepatocellular adenoma were examined by spin-echo and gradient-echo T1-weighted sequences before, 1 h after, and 24 h after intravenous injection of Mn-DPDP (5 μmol/kg). Quantitative analysis including enhancement and lesion-to-liver contrast-to-noise ratio, and qualitative analysis including the presence of a central area and a capsule were done on pre- and post-Mn-DPDP-enhanced images. Enhancement was observed in all the tumors with significant improvement (p < 0.05) in contrast-to-noise ratio 1 h after, and 24 h after intravenous injection of Mn-DPDP. There were no significant differences in the mean enhancement and the mean contrast-to-noise ratio (CNR) between benign and malignant tumors. No enhancement was seen within internal areas observed in 7 hepatocellular carcinomas, and in 5 focal nodular hyperplasias, and within capsules which were observed in 9 hepatocellular carcinomas. In our study, Mn-DPDP increased CNR of both benign and malignant tumors but did not enable differentiation between benign and malignant tumors of hepatocellular nature. (orig.)

  19. VIBE with parallel acquisition technique - a novel approach to dynamic contrast-enhanced MR imaging of the liver

    International Nuclear Information System (INIS)

    Dobritz, M.; Radkow, T.; Bautz, W.; Fellner, F.A.; Nittka, M.

    2002-01-01

    Purpose: The VIBE (volume interpolated breath-hold examination) sequence in combination with parallel acquisition technique (iPAT: integrated parallel acquisition technique) allows dynamic contrast-enhanced MRI of the liver with high temporal and spatial resolution. The aim of this study was to obtain first clinical experience with this technique for the detection and characterization of focal liver lesions. Materials and Methods: We examined 10 consecutive patients using a 1.5 T MR system (gradient field strength 30 mT/m) with a phased-array coil combination. Following sequences- were acquired: T 2 -w TSE and T 1 -w FLASH, after administration of gadolinium, 6 VIBE sequences with iPAT (TR/TE/matrix/partition thickness/time of acquisition: 6.2 ms/ 3.2 ms/256 x 192/4 mm/13 s), as well as T 1 -weighted FLASH with fat saturation. Two observers evaluated the different sequences concerning the number of lesions and their dignity. Following lesions were found: hepatocellular carcinoma (5 patients), hemangioma (2), metastasis (1), cyst (1), adenoma (1). Results: The VIBE sequences were superior for the detection of lesions with arterial hyperperfusion with a total of 33 focal lesions. 21 lesions were found with T 2 -w TSE and 20 with plain T 1 -weighted FLASH. Diagnostic accuracy increased with the VIBE sequence in comparison to the other sequences. Conclusion: VIBE with iPAT allows MR imaging of the liver with high spatial and temporal resolution providing dynamic contrast-enhanced information about the whole liver. This may lead to improved detection of liver lesions, especially hepatocellular carcinoma. (orig.) [de

  20. Characterization of liver metastases: the efficacy of biphasic magnetic resonance imaging with ferucarbotran-enhancement

    International Nuclear Information System (INIS)

    Hong, H.S.; Byun, J.H.; Won, H.J.; Kim, K.W.; Lee, S.S.; Lee, M.G.; Yun, S.C.

    2010-01-01

    Aim: To retrospectively evaluate the efficacy of biphasic magnetic resonance imaging (MRI) of the liver with ferucarbotran-enhancement for the characterization of hepatic metastases. Materials and methods: Thirty-six patients underwent MRI of the liver with separate acquisition of double-contrast enhancement consisting of gadolinium and ferucarbotran. A total of 106 focal hepatic lesions (51 metastases, 31 cysts, 23 haemangiomas, and one eosinophilic abscess) were included. Two sets of MRI were analysed: (1) ferucarbotran set: ferucarbotran-enhanced T1-weighted (T1W) dynamic imaging combined with ferucarbotran-enhanced T2*-weighted (T2*W) delayed imaging and (2) double set: gadolinium-enhanced T1W dynamic imaging combined with ferucarbotran-enhanced T2*W delayed imaging. The diagnostic accuracy of the two sets was evaluated using alternative free-response receiver operating characteristic curve analysis. Sensitivity and specificity were compared using the McNemar test. The enhancement pattern of focal hepatic lesions was analysed on gadolinium and ferucarbotran-enhanced T1W dynamic imaging. Results: There was no significant difference in the accuracy of characterizing hepatic metastases between the two sets. Sensitivity and specificity were not significantly different between the sets (p > 0.05). Peripheral rim enhancement was exhibited in 57% of metastatic lesions on ferucarbotran-enhanced T1W dynamic imaging. The majority (96%) of hepatic haemangiomas demonstrated typical peripheral nodular enhancement with progression on ferucarbotran-enhanced T1W dynamic imaging and were easily differentiated from metastases. Conclusion: Biphasic MRI of the liver with ferucarbotran-enhancement alone provided comparable diagnostic efficacy to double-contrast MRI for the characterization of hepatic metastases.

  1. Lumbar meningeal enhancement after surgery in the posterior cranial fossa: a normal finding in children?

    International Nuclear Information System (INIS)

    Krampla, W.; Urban, M.; Newrkla, S.; Hruby, W.; Schatzer, R.; Knosp, E.

    2002-01-01

    Purpose: Spinal meningeal Gd-DTPA enhancement after cranial surgery is a known observation of a not well understood underlying mechanism. This paper demonstrates that this MRI finding is a normal meningeal reaction to subarachnoid hemorrhage, which should not be mistaken for metastatic spread. Material and methods: Three pediatric patients were examined by MRI for metastatic spread of malignant infratentorial tumors along the spinal canal two to nine days after the removal of the primary cerebral lesion. The findings were compared with a control group that underwent cranial surgery (cyst resection or fenestration of the posterior cranial fossa) without major bleeding into the subarachnoid space. Unenhanced and enhanced sequences were obtained to prove that the high singal within the CSF is caused by an abnormal Gd-DTPA uptake and not by methemoglobin. Results: Meningeal enhancement was observed in all patients with intraoperative bleeding resembling subarachnoid masses on enhanced T 1 -weighted images. This was not present in any patient of the control group. This finding lasts for approximately two weeks. Conclusion: The meningeal enhancement renders immediate postoperative studies inconclusive for the detection of metastatic spread. Consequently, the obligatory tumor staging along the spinal canal should ideally be done prior to the resection of a cerebral tumor. (orig.) [de

  2. Contrast-enhanced magnetic resonance imaging for the detection of acute haemorrhagic necrotizing pancreatitis

    International Nuclear Information System (INIS)

    Piironen, A.; Kivisaari, R.; Pitkaeranta, P.; Poutanen, V.P.; Laippala, P.; Laurila, P.; Kivisaari, L.

    1997-01-01

    Eleven piglets with haemorrhagic necrotizing pancreatitis and nine piglets with oedematous pancreatitis were imaged using a multi-breath-hold TurboFLASH (TR 6.5 ms, TE 3 ms, TI 300 ms, flip angle 8 , three slices) pre-excited T1-weighted sequence with an IV bolus injection of gadopentetate dimeglumine (Gd-DTPA, 0.3 mmol/kg) as a contrast agent to show dynamic contrast enhancement of the pancreas by MRI. All piglets were imaged according to the same protocol before inducing the disease. Following the IV Gd-DTPA bolus, time-enhancement curve of the pancreas during haemorrhagic necrotizing pancreatitis was significantly lower than during oedematous pancreatitis. The enhancement curves for the healthy piglets and piglets with oedematous pancreatitis did not differ significantly. Each piglet served as its own control. Because the results of this initial study are similar to those obtained with contrast-enhanced CT, we conclude that our results may encourage further clinical trials, and contrast-enhanced dynamic MRI may be an alternative to the established method of CT for diagnosing acute haemorrhagic necrotizing pancreatitis. (orig.). With 3 figs

  3. Prognostic value of contrast-enhanced MR mammography in patients with breast cancer.

    Science.gov (United States)

    Fischer, U; Kopka, L; Brinck, U; Korabiowska, M; Schauer, A; Grabbe, E

    1997-01-01

    The objective of this study was to evaluate the prognostic value of contrast-enhanced MR mammography in patients with breast cancer. A total of 190 patients with breast cancer (37 noninvasive carcinomas, 153 invasive carcinomas) underwent dynamic contrast-enhanced MR mammography preoperatively. Using 1.5-T unit, T1-weighted sequences (2D FLASH) were obtained repeatedly one time before and five times after IV administration of 0.1 mmol gadopentetate-dimeglumine per kilogram body weight. The findings on MR imaging were correlated with histopathologically defined prognostic factors (histological type, tumor size, tumor grading, metastasis in lymph nodes). In addition, immunohistochemically defined prognostic factors (c-erbB-1, c-erbB-2, p53, Ki-67) were correlated with the signal increase on MR mammogram in 40 patients. There was no significant correlation between the findings on MR mammography and the histopathological type of carcinoma, the grading, and the lymphonodular status. Noninvasive carcinomas showed a higher rate of moderate (38 %) or low (27 %) enhancement on MR imaging than invasive carcinomas (6 and 3 %). The results on MR mammography and the results of immunohistochemical stainings did not correlate significantly. Noninvasive carcinomas showed significantly lower enhancement than invasive carcinomas. However, the signal behavior of contrast-enhanced MR mammography is not related to established histopathological prognostic parameters as subtyping, grading, nodal status, and the expression of certain oncogenes/tumor suppressor genes.

  4. Prognostic value of contrast-enhanced MR mammography in patients with breast cancer

    International Nuclear Information System (INIS)

    Fischer, U.; Kopka, L.; Brinck, U.; Korabiowska, M.; Schauer, A.; Grabbe, E.

    1997-01-01

    The objective of this study was to evaluate the prognostic value of contrast-enhanced MR mammography in patients with breast cancer. A total of 190 patients with breast cancer (37 noninvasive carcinomas, 153 invasive carcinomas) underwent dynamic contrast-enhanced MR mammography preoperatively. Using 1.5-T unit, T1-weighted sequences (2D FLASH) were obtained repeatedly one time before and five times after IV administration of 0.1 mmol gadopentetate-dimeglumine per kilogram body weight. The findings on MR imaging were correlated with histopathologically defined prognostic factors (histological type, tumor size, tumor grading, metastasis in lymph nodes). In addition, immunohistochemically defined prognostic factors (c-erbB-1,c-erbB-2, p53, Ki-67) were correlated with the signal increase on MR mammogram in 40 patients. There was no significant correlation between the findings on MR mammography and the histopathological type of carcinoma, the grading, and the lymphonodular status. Noninvasive carcinomas showed a higher rate of moderate (38 %) or low (27 %) enhancement on MR imaging than invasive carcinomas (6 and 3 %). The results on MR mammography and the results of immunohistochemical stainings did not correlate significantly. Noninvasive carcinomas showed significantly lower enhancement than invasive carcinomas. However, the signal behavior of contrast-enhanced MR mammography is not related to established histopathological prognostic parameters as subtyping, grading, nodal status, and the expression of certain oncogenes/tumor suppressor genes. (orig.). With 5 tabs

  5. Dual contrast enhanced magnetic resonance imaging of the liver with superparamagnetic iron oxide followed by gadolinium for lesion detection and characterization

    International Nuclear Information System (INIS)

    Kubaska, Samantha; Sahani, Dushyant V.; Saini, Sanjay; Hahn, Peter F.; Halpern, Elkan

    2001-01-01

    AIM: Iron oxide contrast agents are useful for lesion detection, and extracellular gadolinium chelates are advocated for lesion characterization. We undertook a study to determine if dual contrast enhanced liver imaging with sequential use of ferumoxides particles and gadolinium (Gd)-DTPA can be performed in the same imaging protocol. MATERIALS AND METHODS: Sixteen patients underwent dual contrast magnetic resonance imaging (MRI) of the liver for evaluation of known/suspected focal lesions which included, metastases (n = 5), hepatocellular carcinoma (HCC;n = 3), cholangiocharcinoma(n = 1) and focal nodular hyperplasia (FNH;n = 3). Pre- and post-iron oxide T1-weighted gradient recalled echo (GRE) and T2-weighted fast spin echo (FSE) sequences were obtained, followed by post-Gd-DTPA (0.1 mmol/kg) multi-phase dynamic T1-weighted out-of-phase GRE imaging. Images were analysed in a blinded fashion by three experts using a three-point scoring system for lesion conspicuity on pre- and post-iron oxide T1 images as well as for reader's confidence in characterizing liver lesions on post Gd-DTPA T1 images. RESULTS: No statistically significant difference in lesion conspicuity was observed on pre- and post-iron oxide T1-GRE images in this small study cohort. The presence of iron oxide did not appreciably diminish image quality of post-gadolinium sequences and did not prevent characterization of liver lesions. CONCLUSION: Our results suggest that characterization of focal liver lesion with Gd-enhanced liver MRI is still possible following iron oxide enhanced imaging. Kubaska, S. et al. (2001)

  6. The clinical application of static-fluid MRU and enhanced MRU for the diagnosis of upper urinary tract disease

    International Nuclear Information System (INIS)

    Hu Bing; Ye Binbin; Kang Zhuang; Zou Yan

    2005-01-01

    Objective: To evaluate the clinical utility of heavy T 2 -weighted MR urography (static-fluid MRU) and gadolinium-enhanced T 1 -weighted MR urography (enhanced MRU) for the diagnosis of upper urinary tract disease. Methods: Eleven patients were examined with static-fluid MRU and enhanced MRU. The images of static-fluid MRU and enhanced MRU were ranked and diagnosed by two radiologists. And the results were compared later. Results: The ranked image quality was analyzed with a Wilcoxon sign-rank test. The difference between two kinds of MRU images was not significant (P>0.05). The number of correct diagnosis of static-fluid MRU was 19(86.4%) by observer A and 18 (81.8%) by observer B; of enhanced MRU was 21 (95.5%) by observer A and 19 (86.4%) by observer B. Conclusion: With static-fluid MRU, the intraluminal anatomy of urinary tract can be displayed, but the function of kidney can not be evaluated. With enhanced MRU, the intraluminal anatomy can be displayed, and the function of kidney can be evaluated as well. Most of upper urinary tract disease could be diagnosed by static-fluid MRU or enhanced MRU. (authors)

  7. Fat-saturated, contrast-enhanced spin echo sequences in magnetic resonance tomographic diagnosis of peritoneal carcinosis

    International Nuclear Information System (INIS)

    Ricke, J.; Hosten, N.; Stroszczynski, C.; Amthauer, H.; Felix, R.; Sehouli, J.; Buchmann, E.; Rieger, J.

    1999-01-01

    Purpose: To evaluate contrast-enhanced, fat-saturated spin echo sequences for the detection of peritoneal carcinosis with MRI. Material and Methods: 61 patients, 35 with and 26 without peritoneal carcinosis, were examined with abdominal MRI. Fat-saturated, T 1 -weighted spin echo sequences were performed before and after administration of Gd-DTPA. In addition, 22 patients with peritoneal carcinosis were examined with contrast-enhanced abdominal CT. Results: 32 of 35 patients with peritoneal carcinosis demonstrated contrast enhancement of the visceral and 30 to 35 enhancement of the parietal peritoneum (91 and 86%, respectively). Wall thickening of the intestine or parietal peritoneum were noted in 21 and 20 of 35 patients (60 and 57%, respectively), ascites in 18 of 35 patients (51%). False positive contrast enhancement of the peritoneum was noted in 4 of 26 patients (15%). In the direct comparison of MRI and CT, 22 of 22 patients versus 7 of 22 patients showed contrast enhancement of the visceral peritoneum (100 and 32%, respectively). For other signs of peritoneal carcinosis (e.g., ascites, peritoneal seedings), no differences in diagnostic reliability were demonstrated. Conclusions: The use of fat-saturated, spin echo sequences facilitates the diagnosis of peritoneal carcinosis by artifact reduction and improved detection of peritoneal contrast enhancement. MRI with fat-saturated sequences was superior to CT. (orig.) [de

  8. Contrast-enhanced MR imaging of the endolymphatic sac in patients with sudden hearing loss

    International Nuclear Information System (INIS)

    Naganawa, Shinji; Koshikawa, Tokiko; Fukatsu, Hiroshi; Ishigaki, Takeo; Nakashima, Tsutomu; Ichinose, Nobuyasu

    2002-01-01

    Our objective was to evaluate the frequency of contrast enhancement of the endolymphatic sac in patients with sudden hearing loss. Forty consecutive patients with sudden sensorineural hearing loss (20 males and 20 females; age range 11-82 years), 40 age-matched control subjects, and 5 patients with Meniere's disease were examined using the same imaging protocol on a 1.5-T MR system. Pre- and post-contrast-enhanced T1-weighted 3D spoiled gradient-echo sequence (3D SPGR; TR/TE=23/10 ms, no. of excitations=1, flip angle=30 ) images were obtained using a voxel size of 0.6 x 0.7 x 0.8 mm 3 . Contrast enhancement in the area of the endolymphatic sac was assessed by two radiologists, and the frequency of contrast enhancement was compared between the three study groups. Enhancement of the ipsilateral endolymphatic sac was observed in 30 of the 40 patients with sudden hearing loss (75%). Twenty of these 30 patients also showed enhancement on the contralateral side, and 1 patient showed enhancement only on the contralateral side. Only 1 of the 5 patients with Meniere's disease showed enhancement. Nine of the 40 control subjects (22.5%) showed enhancement (bilateral enhancement in 5 subjects, unilateral in 4). The frequency of enhancement in patients with sudden hearing loss was significantly higher than that in control subjects (P<0.0001) or patients with Meniere's disease (P<0.05). The frequency of contrast enhancement of the endolymphatic sac is significantly increased in patients with sudden hearing loss, but further study is necessary to clarify the relationship between this finding and the pathophysiology of sudden hearing loss. (orig.)

  9. MR findings of medulloblastomas and the significance of contrast enhanced MR of brain and spine for the staging

    International Nuclear Information System (INIS)

    Chung, Jae Joon; Kim, Dong Ik; Chung, Tae Sub; Lee, Yeon Hee; Suh, Jung Ho

    1994-01-01

    The purpose of this study were to analyze the MR findings of medulloblastoma, and to evaluate the subarachnoid dissemination and the significance of contrast enhanced MR of brain and spine for tumor staging. The preoperative brain MR studies of 18 patients (9 males, 9 females; mean age, 9.4 years) with surgically proved medulloblastomas were retrospectively reviewed to characterize these neoplasms with regard to their location, size, MR signal intensity, appearance after contrast enhancement, presence of cyst and necrosis, subarachnoid dissemination, and other associated findings. In 14 patients postoperative spine MR studies were evaluated for staging and therapeutic planning. The most frequent location of medulloblastoma was the inferior vermis and the mean tumor size was 4.1 x 3.6 x 3.9 cm. On T1-weighted image, medulloblastomas generally had low to intermediate signal, predominantly hypointense relative to white matter. On T2-weighted image, medulloblastomas showed moderately high signal, hyperintense relative to white matter. Inhomogeneous contrast enhancement was demonstrated in 13 patients(72.2%) after injection of gadopentetate dimeglumine(Gadolinium). Cyst and necrosis within the tumor were visualized in 15 patients(83.3%). Subarachnoid disseminations of medulloblastomas were noted in 11 patients(61.1%), of which 6 demonstrated intracranial and 2 intraspinal dissemination. Three had both intracranial and intraspinal dissemination. In nine cases with intracranial lesions, there were intraparenchymal mass formation(7), subarachnoid nodules(5), infundibular lesions(2) and diffuse gyral enhancement(1). In five cases with intraspinal lesions, there were extramedullary intradural small nodules(3), central canal nodules(2), intradural masses(1) and fine nodular and sheet-like leptomeningeal enhancement(1). Other associated findings included intratumoral hemorrhage(11.1%), peritumoral edema(44.4%), tonsillar herniation(44.4%), hydrocephalus(88.9%) and

  10. Dynamic gadolinium-enhanced magnetic resonance imaging allows accurate assessment of the synovial inflammatory activity in rheumatoid arthritis knee joints: a comparison with synovial histology

    DEFF Research Database (Denmark)

    Axelsen, Mette Bjørndal; Stoltenberg, M.; Poggenborg, R.

    2012-01-01

    , the average grade of histological synovial inflammation was determined from four biopsies obtained during surgery. A preoperative series of T(1)-weighted dynamic fast low-angle shot (FLASH) MR images was obtained. Parameters characterizing contrast uptake dynamics, including the initial rate of enhancement...... capsule of the knee joint (Precise ROI). Intra- and interreader agreement was assessed using the intra-class correlation coefficient (ICC). Results: The IRE from the Quick ROI and the Precise ROI revealed high correlations to the grade of histological inflammation (Spearman's correlation coefficient (rho......) = 0.70, p = 0.001 and rho = 0.74, p = 0.001, respectively). Intraand inter-reader ICCs were very high (0.93-1.00). No Whole slice parameters were correlated to histology. Conclusion: DCE-MRI provides fast and accurate assessment of synovial inflammation in RA patients. Manual outlining of the joint...

  11. Differentiation of recurrent breast cancer from radiation fibrosis with dynamic gadolinium-enhanced MR imaging

    International Nuclear Information System (INIS)

    Dao, T.H.; Campana, F.; Fourquet, A.; Rahmouni, A.

    1991-01-01

    This paper assesses the ability of dynamic gadolinium-enhanced MR imaging to differentiate radiation fibrosis from tumor recurrence of breast cancer after conservative treatment. Twenty-five women with previous breast cancer treated with radiation therapy underwent MR imaging examination. Tumor recurrence was suspected on palpation of masses (18 cases) or at mammography (7 cases). The MR imaging protocol was performed on a 0.5-T imager with a breast coil and included T1 and T2 spin-echo, short To inversion recovery (STIR), and dynamic gadolinium-enhanced T1-weighted sequenced to evaluate the hemokinetics of the lesion. Ratios of signal intensity of suspected lesions to that of fat, surrounding breast gland, and background noise were calculated. Percutaneous biopsies were performed in all cases after MR imaging. Curves of signal-to-noise ratio of recurrences (5 cases) showed an early enhancement within the first minutes after injection, although localized fibrosis (20 cases) was not significantly enhanced. T2 and STIR sequences were not contributive in differentiating fibrosis from tumor recurrence

  12. Clinical significance of quantitative analysis of facial nerve enhancement on MRI in Bell's palsy.

    Science.gov (United States)

    Song, Mee Hyun; Kim, Jinna; Jeon, Ju Hyun; Cho, Chang Il; Yoo, Eun Hye; Lee, Won-Sang; Lee, Ho-Ki

    2008-11-01

    Quantitative analysis of the facial nerve on the lesion side as well as the normal side, which allowed for more accurate measurement of facial nerve enhancement in patients with facial palsy, showed statistically significant correlation with the initial severity of facial nerve inflammation, although little prognostic significance was shown. This study investigated the clinical significance of quantitative measurement of facial nerve enhancement in patients with Bell's palsy by analyzing the enhancement pattern and correlating MRI findings with initial severity of facial palsy and clinical outcome. Facial nerve enhancement was measured quantitatively by using the region of interest on pre- and postcontrast T1-weighted images in 44 patients diagnosed with Bell's palsy. The signal intensity increase on the lesion side was first compared with that of the contralateral side and then correlated with the initial degree of facial palsy and prognosis. The lesion side showed significantly higher signal intensity increase compared with the normal side in all of the segments except for the mastoid segment. Signal intensity increase at the internal auditory canal and labyrinthine segments showed correlation with the initial degree of facial palsy but no significant difference was found between different prognostic groups.

  13. Oxygen-enhanced MRI of the lungs. Intraindividual comparison between 1.5 and 3 Tesla

    International Nuclear Information System (INIS)

    Dietrich, Olaf; Thieme, S.F.; Maxien, D.; Nikolaou, K.; Reiser, M.; Schoenberg, S.O.; Fink, C.

    2011-01-01

    Purpose: To assess the feasibility of oxygen-enhanced MRI of the lung at 3 Tesla and to compare signal characteristics with 1.5 Tesla. Materials and Methods: 13 volunteers underwent oxygen-enhanced lung MRI at 1.5 and 3 T with a T 1-weighted single-slice non-selective inversion-recovery single-shot half-Fourier fast-spin-echo sequence with simultaneous respiratory and cardiac triggering in coronal orientation. 40 measurements were acquired during room air breathing and subsequently during oxygen breathing (15 L/min, close-fitting face-mask). The signal-to-noise ratio (SNR) of the lung tissue was determined with a difference image method. The image quality of all acquisitions was visually assessed. The mean values of the oxygen-induced relative signal enhancement and its regional coefficient of variation were calculated and the signal enhancement was displayed as color-coded parameter maps. Oxygen-enhancement maps were visually assessed with respect to the distribution and heterogeneity of the oxygen-related signal enhancement at both field strengths. Results: The mean relative signal enhancement due to oxygen breathing was 13 % (± 5.6 %) at 1.5 T and of 9.0 % (± 8.0 %) at 3 T. The regional coefficient of variation was significantly higher at 3 T. Visual and quantitative assessment of the enhancement maps showed considerably less homogeneous distribution of the signal enhancement at 3 T. The SNR was not significantly different but showed a trend to slightly higher values (increase of about 10 %) at 3 T. Conclusion: Oxygen-enhanced pulmonary MRI is feasible at 3 Tesla. However, signal enhancement is currently more heterogeneous and slightly lower at 3 T. (orig.)

  14. The diverse pathology and kinetics of mass, nonmass and focus enhancement on MR imaging of the breast

    Science.gov (United States)

    Jansen, Sanaz A.; Shimauchi, Akiko; Zak, Lindsay; Fan, Xiaobing; Karczmar, Gregory S.; Newstead, Gillian M.

    2011-01-01

    Purpose To compare the pathology and kinetic characteristics of breast lesions with focus, mass and nonmass-like enhancement. Materials and Methods 852 MRI detected breast lesions in 697 patients were selected for an IRB approved review. Patients underwent dynamic contrast enhanced MRI using one pre and three to six post-contrast T1 weighted images. The ‘type’ of enhancement was classified as mass, non-mass or focus, and kinetic curves quantified by the initial enhancement percentage (E1), time to peak enhancement (Tpeak) and signal enhancement ratio (SER). These kinetic parameters were compared between malignant and benign lesions within each morphologic type. Results 552 lesions were classified as mass (396 malignant, 156 benign), 261 as nonmass (212 malignant,49 benign) and 39 as focus (9 malignant,30 benign). The most common pathology of malignant/benign lesions by morphology: for mass, invasive ductal carcinoma/fibroadenoma; for nonmass, ductal carcinoma in situ (DCIS)/fibrocystic change(FCC); for focus, DCIS/FCC. Benign mass lesions exhibited significantly lower E1, longer Tpeak and lower SER compared with malignant mass lesions (p < 0.0001). Benign nonmass lesions exhibited only a lower SER compared to malignant nonmass lesions (p<0.01). Conclusions By considering the diverse pathology and kinetic characteristics of different lesion morphologies, diagnostic accuracy may be improved. PMID:21591007

  15. Impact of liver cirrhosis on liver enhancement at Gd-EOB-DTPA enhanced MRI at 3 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Verloh, N., E-mail: niklas.verloh@stud.uni-regensburg.de [Department of Radiology, University Hospital Regensburg, Regensburg (Germany); Haimerl, M.; Rennert, J.; Müller-Wille, R.; Nießen, C. [Department of Radiology, University Hospital Regensburg, Regensburg (Germany); Kirchner, G. [Department of Gastroenterology, University Hospital Regensburg, Regensburg (Germany); Scherer, M.N. [Department of Surgery, University Hospital Regensburg, Regensburg (Germany); Schreyer, A.G.; Stroszczynski, C.; Fellner, C.; Wiggermann, P. [Department of Radiology, University Hospital Regensburg, Regensburg (Germany)

    2013-10-01

    Purpose: The purpose of this study was to assess differences in enhancement effects of liver parenchyma between normal and cirrhotic livers on dynamic, Gd-EOB-DTPA enhanced MRI at 3 T. Materials and methods: 93 patients with normal (n = 54) and cirrhotic liver (n = 39; Child–Pugh class A, n = 18; B, n = 16; C, n = 5) underwent contrast-enhanced MRI with liver specific contrast media at 3 T. T1-weighted volume interpolated breath hold examination (VIBE) sequences with fat suppression were acquired before contrast injection, in the arterial phase (AP), in the late arterial phase (LAP), in the portal venous phase (PVP), and in the hepatobiliary phase (HBP) after 20 min. The relative enhancement (RE) of the signal intensity of the liver parenchyma was calculated for all phases. Results: Mean RE was significantly different among all evaluated groups in the hepatobiliary phase and with increasing severity of liver cirrhosis, a decreasing, but still significant reduction of RE could be shown. Phase depending changes of RE for each group were observed. In case of non-cirrhotic liver or Child–Pugh Score A cirrhosis mean RE showed a significant increase between AP, LAP, PVP and HBP. For Child–Pugh B + C cirrhosis RE increased until PVP, however, there was no change in case of B cirrhosis (p = 0.501) and significantly reduced in case of C cirrhosis (p = 0.043) during HBP. Conclusion: RE of liver parenchyma is negatively affected by increased severity of liver cirrhosis, therefore diagnostic value of HBP could be limited in case of Child Pugh B + C cirrhosis.

  16. Impact of liver cirrhosis on liver enhancement at Gd-EOB-DTPA enhanced MRI at 3 Tesla

    International Nuclear Information System (INIS)

    Verloh, N.; Haimerl, M.; Rennert, J.; Müller-Wille, R.; Nießen, C.; Kirchner, G.; Scherer, M.N.; Schreyer, A.G.; Stroszczynski, C.; Fellner, C.; Wiggermann, P.

    2013-01-01

    Purpose: The purpose of this study was to assess differences in enhancement effects of liver parenchyma between normal and cirrhotic livers on dynamic, Gd-EOB-DTPA enhanced MRI at 3 T. Materials and methods: 93 patients with normal (n = 54) and cirrhotic liver (n = 39; Child–Pugh class A, n = 18; B, n = 16; C, n = 5) underwent contrast-enhanced MRI with liver specific contrast media at 3 T. T1-weighted volume interpolated breath hold examination (VIBE) sequences with fat suppression were acquired before contrast injection, in the arterial phase (AP), in the late arterial phase (LAP), in the portal venous phase (PVP), and in the hepatobiliary phase (HBP) after 20 min. The relative enhancement (RE) of the signal intensity of the liver parenchyma was calculated for all phases. Results: Mean RE was significantly different among all evaluated groups in the hepatobiliary phase and with increasing severity of liver cirrhosis, a decreasing, but still significant reduction of RE could be shown. Phase depending changes of RE for each group were observed. In case of non-cirrhotic liver or Child–Pugh Score A cirrhosis mean RE showed a significant increase between AP, LAP, PVP and HBP. For Child–Pugh B + C cirrhosis RE increased until PVP, however, there was no change in case of B cirrhosis (p = 0.501) and significantly reduced in case of C cirrhosis (p = 0.043) during HBP. Conclusion: RE of liver parenchyma is negatively affected by increased severity of liver cirrhosis, therefore diagnostic value of HBP could be limited in case of Child Pugh B + C cirrhosis

  17. Gd-DTPA enhanced MR imaging in Bell's palsy

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Yasushi; Kawamura, Yuji (Takanoko Hospital, Matsuyama, Ehime (Japan)); Yanagihara, Naoaki; Sadamoto, Masanori; Sadamoto, Kazuhiko

    1991-09-01

    Magnetic resonance imaging (MRI) was carried out in 27 patients with Bell's palsy. T1-weighted spin-echo images (TR500/TE25-34) were taken before and after the intravenous administration of Gd-DTPA (0.1 mmol/kg) with 0.5T superconductive MRI. There was significant enhancement at the geniculate ganglion and the horizontal segment of the involved facial nerve in 22 patients (81.5%) and at the vertical segment in 20 (74.1%). Enhancement at the meatal fundus was seen in only 4 patients (14.9%) and at the labyrinthine segment in 8 (29.6%). These results corroborate other evidence that the geniculate ganglion is involved most frequently in Bell's palsy. In addition, the enhancement of the proximal portion, i.e. the meatal fundus and the labyrinthine segment of the nerve, although not common, noted in this study may be important in the diagnosis and treatment of Bell's palsy. (author).

  18. Contrast-enhanced MR imaging of the breast in patients with breast implants after cancer surgery

    International Nuclear Information System (INIS)

    Bone, B.; Aspelin, P.; Isberg, B.; Perbeck, L.; Veress, B.

    1995-01-01

    The purpose of the study was to determine the value of contrast-enhanced MR imaging in the assessment of local recurrence in breast cancer patients who underwent mastectomy and breast reconstruction with an implant. Eighty-three patients have been evaluated by semidynamic contrast-enhanced MR imaging. The T1-weighted FLASH 3-D sequence was repeated twice postcontrast for evaluation of the entire breast bilaterally. The findings were compared to physical examination, mammography and histopathology. Recurrence verified by histopathology occurred in 14 of 83 patients (17%). Contrast-enhanced MR imaging was superior to palpation and mammography in revealing recurrences, especially when these were located close to the chest wall. MR was also more sensitive in detecting multiple foci of cancers. Our study revealed that MR imaging was influenced by size, type and composition of the tumor, as illustrated by the false-negative results. Therefore, the use of all 3 investigation methods is necessary for detecting recurrence at an early stage during the postoperative follow-up. (orig.)

  19. Gadodiamide injection for enhancement of MRI in the CNS. Applications, dose, field and time dependence

    Energy Technology Data Exchange (ETDEWEB)

    Aakeson, P

    1996-10-01

    Gadodiamide injection was comparable to Gd-DTPA with regard to both safety and diagnostic efficiency in the central nervous system. The contrast effect of Gd contrast agents is higher at 1.5 T than at 0.3 T both in phantoms and patients with a maximum ratio (signal lesion/signal grey matter) more than 50% higher at 1.5 T. To achieve high contrast effect, heavily T1-weighted images are important. Prolonging the TR from 400 ms to 600 ms reduced the ratio by 15-45% depending on concentration. The effective time window for imaging of BBB (Blood-Brain Barrier) damage is between 2-5 and 25-30 minutes after injection and several scans can be performed without loss of enhancement. To provide maximum detectability of BBB damage in patients, higher doses of Gd contrast media should be useful, especially at low field strengths, as the doses used clinically today do not utilize the maximum contrast effect. High-dose (0.3 mmol/kg b.w.) contrast enhanced MRI (0.3 T) with Gadodiamide injection allowed detection of significantly more and smaller metastases (i.e. BBB damage) than standard dose (0.1 mmol/kg b.w.) High dose contrast-enhanced MRI (0.3 T) did not increase the diagnostic information for the evaluation of patients with failed back surgery syndrome compared to standard dose MRI. 55 refs, 9 figs, 10 tabs.

  20. Dynamic contrast-enhanced MRI of the prostate. Comparison of two different post-processing algorithms

    International Nuclear Information System (INIS)

    Beyersdorff, Dirk; Franiel, T.; Luedemann, L.; Dietz, E.; Galler, D.; Marchot, P.

    2011-01-01

    Purpose: To evaluate the usefulness of a commercially available post-processing software tool for detecting prostate cancer on dynamic contrast-enhanced magnetic resonance imaging (MRI) and to compare the results to those obtained with a custom-made post-processing algorithm already tested under clinical conditions. Materials and Methods: Forty-eight patients with proven prostate cancer were examined by standard MRI supplemented by dynamic contrast-enhanced dual susceptibility contrast (DCE-DSC) MRI prior to prostatectomy. A custom-made post-processing algorithm was used to analyze the MRI data sets and the results were compared to those obtained using a post-processing algorithm from Invivo Corporation (Dyna CAD for Prostate) applied to dynamic T 1-weighted images. Histology was used as the gold standard. Results: The sensitivity for prostate cancer detection was 78 % for the custom-made algorithm and 60 % for the commercial algorithm and the specificity was 79 % and 82 %, respectively. The accuracy was 79 % for our algorithm and 77.5 % for the commercial software tool. The chi-square test (McNemar-Bowker test) yielded no significant differences between the two tools (p = 0.06). Conclusion: The two investigated post-processing algorithms did not differ in terms of prostate cancer detection. The commercially available software tool allows reliable and fast analysis of dynamic contrast-enhanced MRI for the detection of prostate cancer. (orig.)

  1. Gadodiamide injection for enhancement of MRI in the CNS. Applications, dose, field and time dependence

    International Nuclear Information System (INIS)

    Aakeson, P.

    1996-01-01

    Gadodiamide injection was comparable to Gd-DTPA with regard to both safety and diagnostic efficiency in the central nervous system. The contrast effect of Gd contrast agents is higher at 1.5 T than at 0.3 T both in phantoms and patients with a maximum ratio (signal lesion/signal grey matter) more than 50% higher at 1.5 T. To achieve high contrast effect, heavily T1-weighted images are important. Prolonging the TR from 400 ms to 600 ms reduced the ratio by 15-45% depending on concentration. The effective time window for imaging of BBB (Blood-Brain Barrier) damage is between 2-5 and 25-30 minutes after injection and several scans can be performed without loss of enhancement. To provide maximum detectability of BBB damage in patients, higher doses of Gd contrast media should be useful, especially at low field strengths, as the doses used clinically today do not utilize the maximum contrast effect. High-dose (0.3 mmol/kg b.w.) contrast enhanced MRI (0.3 T) with Gadodiamide injection allowed detection of significantly more and smaller metastases (i.e. BBB damage) than standard dose (0.1 mmol/kg b.w.) High dose contrast-enhanced MRI (0.3 T) did not increase the diagnostic information for the evaluation of patients with failed back surgery syndrome compared to standard dose MRI. 55 refs, 9 figs, 10 tabs

  2. Age-related contrast enhancement study of normal bone marrow in lumbar spinal MR imaging

    International Nuclear Information System (INIS)

    Kim, Young A; Ha, Doo Hoe

    1999-01-01

    The purpose of this study was to evaluate the degree of contrast enhancement of normal bone marrow in L-spine relating to aging and to determine the range of contrast enhancement in normal bone marrow. We analyzed a total of 120 patients (20 per decade) who had undergone lumbar spinal MRI and who ranged in age from the 2nd decade to more than the 7th. Bone marrow revealed no abnormal pathology. Sagittal T1-weighted spin echo sequences were obtained before and after gadolinium administration. For each sequence, a region of interest was drawn within the L1 vertebral body from the midsagittal slice. Signal intensity (SI) values of each sequence were ascertained and the percentage increase in SI was calculated. After contrast enhancement, lumbar MRI revealed no statistically significant in the percentage increase in SI of normal bone marrow in relation to aging. Most patients (99%) however showed an SI increase of between 10% and 49%. In only four, none of whom were aged over 40, was this increase above 50%. Lumbar MRI, revealed no statistically significant difference in percentage increase in SI in normal bone marrow relating to aging, but when the increase is above 50% in a patient aged over 40, bone marrow pathology should be further investigated

  3. Secretin-enhanced magnetic resonance cholangiopancreaticography: value for the diagnosis of chronic pancreatitis

    International Nuclear Information System (INIS)

    Heverhagen, J.T.; Burbelko, M.; Schenck zu Schweinsberg, T.; Funke, C.; Wecker, C.; Walthers, E.M.; Rominger, M.

    2007-01-01

    Endoscopic retrograde cholangiopancreaticography (ERCP) is the morphologic gold standard for the diagnosis of chronic pancreatitis. Magnetic Resonance Imaging (MRI) enables the visualization of not only the pancreatic duct but also the surrounding parenchyma using T2- and T1-weighted sequences before and after the application of a contrast agent. Moreover, it allows the depiction of ductal segments distal to a stenosis or occlusion. However, conventional Magnetic Resonance Cholangiopancreaticography (MRCP) was not able to achieve accuracy similar to that of ERCP. Despite many technological innovations, such as fast breath-hold acquisitions or respiratory-gated 3D sequences, this drawback could not be overcome. In recent years, secretin-enhanced MRCP has been used for the diagnosis of chronic pancreatitis. A recent study showed that secretin not only improves the visibility of the pancreatic duct and its side branches but it also enhances the diagnostic accuracy of MRCP. The sensitivity, specificity, and positive and negative predictive values were improved by the application of secretin. Moreover, the agreement between independent observers increased after the use of secretin. In addition, quantitative post-processing tools have been developed that enable the measurement of the exocrine pancreatic output non-invasively using secretin-enhanced MRCP. These tools facilitate applications, such as functional follow-up after pancreaticogastrostomy and pancreaticogastric anastomoses, evaluation of the functional status of the graft after pancreas transplantation and follow-up of pancreatic drainage procedures and duct disruption. (orig.)

  4. Differentiation of intrahepatic mass-forming cholangiocarcinoma from hepatocellular carcinoma on gadoxetic acid-enhanced liver MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Rihyeon; Shin, Cheong-Il; Yoon, Jeong Hee; Joo, Ijin; Kim, Seong Ho; Hwang, Inpyeong [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Lee, Jeong Min; Han, Joon Koo [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Hospital, Institute of Radiation Medicine, Seoul (Korea, Republic of); Lee, Eun Sun; Choi, Byung Ihn [Chung-Ang University Hospital, Department of Radiology, Seoul (Korea, Republic of)

    2016-06-15

    To determine the different imaging features of intrahepatic mass-forming cholangiocarcinoma (IMCC) from hepatocellular carcinoma (HCC) on gadoxetic acid-enhanced magnetic resonance imaging (MRI). This retrospective study was institutional review board approved and the requirement for informed consent was waived. Patients who underwent gadoxetic acid-enhanced MRI with histologically confirmed IMCCs (n = 46) or HCCs (n = 58) were included. Imaging features of IMCCs and HCCs on gadoxetic acid-enhanced MRI including T2- and T1-weighted, diffusion weighted images, dynamic study and hepatobiliary phase (HBP) images were analyzed. Univariate and multivariate logistic regression analyses were performed to identify relevant differentiating features between IMCCs and HCCs. Multivariate analysis revealed heterogeneous T2 signal intensity and a hypointense rim on the HBP as suggestive findings of IMCCs and the wash-in and ''portal wash-out'' enhancement pattern as well as focal T1 high signal intensity foci as indicative of HCCs (all, p < 0.05). When we combined any three of the above four imaging features, we were able to diagnose IMCCs with 94 % (43/46) sensitivity and 86 % (50/58) specificity. Combined interpretation of enhancement characteristics including HBP images, morphologic features, and strict application of the ''portal wash-out'' pattern helped more accurate discrimination of IMCCs from HCCs. (orig.)

  5. Use of subvoxel registration and subtraction to improve demonstration of contrast enhancement in MRI of the brain

    International Nuclear Information System (INIS)

    Curati, W.L.; Williams, E.J.; Oatridge, A.; Hajnal, J.V.; Saeed, N.; Bydder, G.M.

    1996-01-01

    To assess the potential of registration of images before and after contrast medium for improving the demonstration of contrast enhancement, we compared conventional 2 D T 1-weighted spin-echo images with precisely registered 3 D volume images and subtraction images derived from them in 2 normal subjects and 30 patients with a variety of brain disease. The volume images were registered to subvoxel accuracy using a rigid body translation and rotation, sinc interpolation and a least-squares fit; subtraction images were obtained from these. Normal contrast enhancement was demonstrated better with positionally registered volume and subtraction images than with conventional images in the meninges, ependyma, diploic veins, scalp, skin, orbit and sinuses. Abnormal enhancement was seen better in meningeal disease, multiple sclerosis and tumours as well as on follow-up studies. Subvoxel registration of images before and after contrast medium may be of considerable value in the recognition of contrast enhancement where there are small changes, or where the changes affect tissues with high or low baseline signal values. The technique also appears likely to be of value in demonstrating contrast enhancement in tissues at inferfaces and at other areas of complex anatomy, and in follow-up studies. (orig.). With 4 figs., 4 tabs

  6. Enhancement effects and relaxivities of gadolinium-DTPA at 1.5 versus 3 tesla. A phantom study

    International Nuclear Information System (INIS)

    Sasaki, Makoto; Shibata, Eri; Kanbara, Yoshiyuki; Ehara, Shigeru

    2005-01-01

    The purpose of this study was to investigate the difference in enhancement effects and relaxivities of the gadolinium chelate at 1.5 and 3 Tesla (T) and to elucidate the contribution of the high magnetic field to contrast enhancement in spin-echo (SE) and gradient-echo (GRE) images. Phantoms containing water with or without gadopentetate dimeglumine (Gd-DTPA) at different concentrations were scanned using 1.5T and 3T MRI scanners of the same manufacturer and under the same temperature conditions and scanning parameters. Relaxivities of gadolinium, R 1 and R 2 , were estimated from serial T 1 and T 2 values of the phantoms using linear regression. Contrast enhancement ratios in SE and GRE T 1 -weighted images were compared at 1.5 and 3T. The R 1 and R 2 of Gd-DTPA at 1.5 and 3T were 4.79 and 5.14, and 4.50 and 5.09, respectively. Although the relaxivities at 3T were slightly lower than those at 1.5T, the contrast enhancement ratio improved in both SE and GRE images as a result of T 1 prolongation of the water at 3T. The decrease in relaxivities of the Gd-DTPA at 3T appears to be so small that T 1 prolongation of the water improves contrast enhancement, suggesting a potential clinical advantage in administration of Gd-DTPA at high field strength. (author)

  7. Contrast enhancement kinetics of normal breast parenchyma in dynamic MR mammography: effects of menopausal status, oral contraceptives, and postmenopausal hormone therapy

    International Nuclear Information System (INIS)

    Hegenscheid, Katrin; Seipel, Rebecca; Laqua, Rene; Hosten, Norbert; Puls, Ralf; Schmidt, Carsten O.; Ohlinger, Ralf

    2012-01-01

    To investigate effects of menopausal status, oral contraceptives (OC), and postmenopausal hormone therapy (HT) on normal breast parenchymal contrast enhancement (CE) and non-mass-like enhancing areas in magnetic resonance mammography (MRM). A total of 459 female volunteers (mean age 49.1 ± 12.5 years) underwent T1-weighted 3D MRM 1-5 min after bolus injection of gadobutrol. Quantitative analysis was performed in normal breast parenchyma by manually tracing regions of interest and calculating percentage CE. Semiquantitative analysis was performed in non-mass-like enhancing areas, and signal intensity changes were characterised by five predefined kinetic curve types. The influence of OC (n = 69) and HT (n = 24) on CE was studied using random effects models. Breast parenchymal enhancement was significantly higher in premenopausal than in postmenopausal women (P < 0.001). CE decreased significantly with the use of OC (P = 0.01), while HT had negligible effects (P = 0.52). Prevalence of kinetic curve types of non-mass-like enhancement differed strongly between pre- and postmenopausal women (P < 0.0001), but was similar in OC users and non-OC users (P = 0.61) as well as HT users and non-HT users (P = 0.77). Normal breast parenchymal enhancement and non-mass-like enhancing areas were strongly affected by menopausal status, while they were not affected by HT use and only moderately by OC use. (orig.)

  8. Contrast enhancement kinetics of normal breast parenchyma in dynamic MR mammography: effects of menopausal status, oral contraceptives, and postmenopausal hormone therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hegenscheid, Katrin; Seipel, Rebecca; Laqua, Rene; Hosten, Norbert; Puls, Ralf [Ernst-Moritz-Arndt University Medical Center Greifswald, Department of Diagnostic Radiology and Neuroradiology, Greifswald (Germany); Schmidt, Carsten O. [Ernst-Moritz-Arndt University Medical Center Greifswald, Institute for Community Medicine, Greifswald (Germany); Ohlinger, Ralf [Ernst-Moritz-Arndt University Medical Center Greifswald, Department of Gynecology and Obstetrics, Greifswald (Germany)

    2012-12-15

    To investigate effects of menopausal status, oral contraceptives (OC), and postmenopausal hormone therapy (HT) on normal breast parenchymal contrast enhancement (CE) and non-mass-like enhancing areas in magnetic resonance mammography (MRM). A total of 459 female volunteers (mean age 49.1 {+-} 12.5 years) underwent T1-weighted 3D MRM 1-5 min after bolus injection of gadobutrol. Quantitative analysis was performed in normal breast parenchyma by manually tracing regions of interest and calculating percentage CE. Semiquantitative analysis was performed in non-mass-like enhancing areas, and signal intensity changes were characterised by five predefined kinetic curve types. The influence of OC (n = 69) and HT (n = 24) on CE was studied using random effects models. Breast parenchymal enhancement was significantly higher in premenopausal than in postmenopausal women (P < 0.001). CE decreased significantly with the use of OC (P = 0.01), while HT had negligible effects (P = 0.52). Prevalence of kinetic curve types of non-mass-like enhancement differed strongly between pre- and postmenopausal women (P < 0.0001), but was similar in OC users and non-OC users (P = 0.61) as well as HT users and non-HT users (P = 0.77). Normal breast parenchymal enhancement and non-mass-like enhancing areas were strongly affected by menopausal status, while they were not affected by HT use and only moderately by OC use. (orig.)

  9. Characterization of Metabolic, Diffusion, and Perfusion Properties in GBM: Contrast-Enhancing versus Non-Enhancing Tumor.

    Science.gov (United States)

    Autry, Adam; Phillips, Joanna J; Maleschlijski, Stojan; Roy, Ritu; Molinaro, Annette M; Chang, Susan M; Cha, Soonmee; Lupo, Janine M; Nelson, Sarah J

    2017-12-01

    Although the contrast-enhancing (CE) lesion on T 1 -weighted MR images is widely used as a surrogate for glioblastoma (GBM), there are also non-enhancing regions of infiltrative tumor within the T 2 -weighted lesion, which elude radiologic detection. Because non-enhancing GBM (Enh-) challenges clinical patient management as latent disease, this study sought to characterize ex vivo metabolic profiles from Enh- and CE GBM (Enh+) samples, alongside histological and in vivo MR parameters, to assist in defining criteria for estimating total tumor burden. Fifty-six patients with newly diagnosed GBM received a multi-parametric pre-surgical MR examination. Targets for obtaining image-guided tissue samples were defined based on in vivo parameters that were suspicious for tumor. The actual location from where tissue samples were obtained was recorded, and half of each sample was analyzed for histopathology while the other half was scanned using HR-MAS spectroscopy. The Enh+ and Enh- tumor samples demonstrated comparable mitotic activity, but also significant heterogeneity in microvascular morphology. Ex vivo spectroscopic parameters indicated similar levels of total choline and N-acetylaspartate between these contrast-based radiographic subtypes of GBM, and characteristic differences in the levels of myo-inositol, creatine/phosphocreatine, and phosphoethanolamine. Analysis of in vivo parameters at the sample locations were consistent with histological and ex vivo metabolic data. The similarity between ex vivo levels of choline and NAA, and between in vivo levels of choline, NAA and nADC in Enh+ and Enh- tumor, indicate that these parameters can be used in defining non-invasive metrics of total tumor burden for patients with GBM. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Characterization of Metabolic, Diffusion, and Perfusion Properties in GBM: Contrast-Enhancing versus Non-Enhancing Tumor

    Directory of Open Access Journals (Sweden)

    Adam Autry

    2017-12-01

    Full Text Available BACKGROUND: Although the contrast-enhancing (CE lesion on T1-weighted MR images is widely used as a surrogate for glioblastoma (GBM, there are also non-enhancing regions of infiltrative tumor within the T2-weighted lesion, which elude radiologic detection. Because non-enhancing GBM (Enh− challenges clinical patient management as latent disease, this study sought to characterize ex vivo metabolic profiles from Enh− and CE GBM (Enh+ samples, alongside histological and in vivo MR parameters, to assist in defining criteria for estimating total tumor burden. Methods: Fifty-six patients with newly diagnosed GBM received a multi-parametric pre-surgical MR examination. Targets for obtaining image-guided tissue samples were defined based on in vivo parameters that were suspicious for tumor. The actual location from where tissue samples were obtained was recorded, and half of each sample was analyzed for histopathology while the other half was scanned using HR-MAS spectroscopy. Results: The Enh+ and Enh− tumor samples demonstrated comparable mitotic activity, but also significant heterogeneity in microvascular morphology. Ex vivo spectroscopic parameters indicated similar levels of total choline and N-acetylaspartate between these contrast-based radiographic subtypes of GBM, and characteristic differences in the levels of myo-inositol, creatine/phosphocreatine, and phosphoethanolamine. Analysis of in vivo parameters at the sample locations were consistent with histological and ex vivo metabolic data. CONCLUSIONS: The similarity between ex vivo levels of choline and NAA, and between in vivo levels of choline, NAA and nADC in Enh+ and Enh− tumor, indicate that these parameters can be used in defining non-invasive metrics of total tumor burden for patients with GBM.

  11. Differentiation of Enhancing Glioma and Primary Central Nervous System Lymphoma by Texture-Based Machine Learning.

    Science.gov (United States)

    Alcaide-Leon, P; Dufort, P; Geraldo, A F; Alshafai, L; Maralani, P J; Spears, J; Bharatha, A

    2017-06-01

    Accurate preoperative differentiation of primary central nervous system lymphoma and enhancing glioma is essential to avoid unnecessary neurosurgical resection in patients with primary central nervous system lymphoma. The purpose of the study was to evaluate the diagnostic performance of a machine-learning algorithm by using texture analysis of contrast-enhanced T1-weighted images for differentiation of primary central nervous system lymphoma and enhancing glioma. Seventy-one adult patients with enhancing gliomas and 35 adult patients with primary central nervous system lymphomas were included. The tumors were manually contoured on contrast-enhanced T1WI, and the resulting volumes of interest were mined for textural features and subjected to a support vector machine-based machine-learning protocol. Three readers classified the tumors independently on contrast-enhanced T1WI. Areas under the receiver operating characteristic curves were estimated for each reader and for the support vector machine classifier. A noninferiority test for diagnostic accuracy based on paired areas under the receiver operating characteristic curve was performed with a noninferiority margin of 0.15. The mean areas under the receiver operating characteristic curve were 0.877 (95% CI, 0.798-0.955) for the support vector machine classifier; 0.878 (95% CI, 0.807-0.949) for reader 1; 0.899 (95% CI, 0.833-0.966) for reader 2; and 0.845 (95% CI, 0.757-0.933) for reader 3. The mean area under the receiver operating characteristic curve of the support vector machine classifier was significantly noninferior to the mean area under the curve of reader 1 ( P = .021), reader 2 ( P = .035), and reader 3 ( P = .007). Support vector machine classification based on textural features of contrast-enhanced T1WI is noninferior to expert human evaluation in the differentiation of primary central nervous system lymphoma and enhancing glioma. © 2017 by American Journal of Neuroradiology.

  12. Comparison of gadolinium-EOB-DTPA-enhanced and diffusion-weighted liver MRI for detection of small hepatic metastases.

    Science.gov (United States)

    Shimada, Kotaro; Isoda, Hiroyoshi; Hirokawa, Yuusuke; Arizono, Shigeki; Shibata, Toshiya; Togashi, Kaori

    2010-11-01

    To compare the accuracy of gadolinium ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI with that of diffusion-weighted MRI (DWI) in the detection of small hepatic metastases (2 cm or smaller). Forty-five patients underwent abdominal MRI at 3 T, including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), heavily T2WI (HASTE), DWI with a b-value of 500 s/mm(2) and contrast-enhanced MRI with Gd-EOB-DTPA. Two groups were assigned and compared: group A (T1WI, T2WI, HASTE and contrast-enhanced study with Gd-EOB-DTPA), and group B (T1WI, T2WI, HASTE and DWI). Two observers independently interpreted the images obtained in a random order. For all hepatic metastases, the diagnostic performance using each imaging set was evaluated by receiver-operating characteristic (ROC) curve analysis. A total of 51 hepatic metastases were confirmed. The area under the ROC curve (Az) of group A was larger than that of group B, and the difference in the mean Az values between the two image sets was statistically significant, whereas, there were three metastases that lay near thin vessels or among multiple cysts and were better visualised in group B than in group A. Gd-EOB-DTPA-enhanced MRI showed higher accuracy in the detection of small metastases than DWI.

  13. Assessment of inflammatory activity in Crohn's disease by means of dynamic contrast-enhanced MRI.

    Science.gov (United States)

    Pupillo, V A; Di Cesare, E; Frieri, G; Limbucci, N; Tanga, M; Masciocchi, C

    2007-09-01

    Our aim was to perform a dynamic study of contrast enhancement of the intestinal wall in patients with Crohn's disease to quantitatively assess local inflammatory activity. We studied a population of 50 patients with histologically proven Crohn's disease. Magnetic resonance imaging (MRI) was performed using a 1.5-T magnet with a phased-array coil and acquisition of T2-weighted single-shot fast spin echo (SSFSE) half Fourier sequences before intravenous administration of gadolinium, and T1-weighted fast spoiled gradient (FSPGR) fat-saturated sequences before and after contrast administration. Before the examination, patents received oral polyethylene glycol (PEG) (1,000 ml for adults; 10 ml/Kg of body weight for children). Regions of interest (ROI) were placed on the normal and diseased intestinal wall to assess signal intensity and rate of increase in contrast enhancement over time. Data were compared with the Crohn's Disease Activity Index (CDAI). The diseased bowel wall showed early and intense uptake of contrast that increases over time until a plateau is reached. In patients in the remission phase after treatment, signal intensity was only slightly higher in diseased bowel loops than in healthy loops. There was a significant correlation between the peak of contrast uptake and CDAI. Dynamic MRI is a good technique for quantifying local inflammatory activity of bowel wall in patients with Crohn's disease.

  14. Craniopharyngiomas - the utility of contrast medium enhancement for MR imaging at 1.5 T

    International Nuclear Information System (INIS)

    Hald, J.K.; Eldevik, O.P.; Brunberg, J.A.; Chandler, W.F.

    1994-01-01

    To evaluate the efficacy of i.v. contrast medium administration in MR imaging at 1.5 T in patients with craniopharyngiomas, MR studies of 10 men and 6 women with pathologically proven craniopharyngiomas were made. The MR images were obtained as 3- to 5-mm-thick coronal (n=13) or axial (n=3) T1-weighted images (T1WI) prior to an following i.v. Gd-DTPA administration. Proton density-(PD) and T2-weighted images (T2WI) were also obtained. Conspicuity of tumor margins, cystic versus solid components, size, location and effect upon adjacent structures were separately characterized in all imaging sequences. In 6 patients contrast medium-enhanced T1WI, PD and T2WI demonstrated cystic tumor components not seen on unenhanced T1WI. There were significant differences (p<0.004) on 2-tailed Student's t-test comparing tumor conspicuity on contrast medium-enhanced T1WI with unenhanced T1WI, PD and T2WI. Optimal tumor delineation on MR imaging of patients with craniopharyngiomas justifies the use of i.v. contrast medium. (orig.)

  15. Hemophilic arthropathy of the knee joint: static and dynamic Gd-DTPA - enhanced MRI

    Energy Technology Data Exchange (ETDEWEB)

    Naegele, M. [Dept. of Radiology, Univ. Bonn (Germany); Bruening, R. [Dept. of Radiology, Univ. Muenchen (Germany); Kunze, V. [Dept. of Radiology, Univ. Bonn (Germany); Eickhoff, H. [Dept. of Orthopedic Surgery, Troisdorf (Germany); Koch, W. [Dept. of Orthopedic Surgery, Troisdorf (Germany); Reiser, M. [Dept. of Radiology, Univ. Muenchen (Germany)

    1995-12-31

    A total of 17 patients with hemophilic arthropathy of the knee joint were studied with static and dynamic MRI before and after an IV bolus injection of Gadolinium-DTPA (Gd-DTPA; 0.1 mmol/kg body weight). The T1-weighted spin-echo (SE) and gradient-echo (fast-field echo [FFE]) sequences were applied. The FFE sequences of eight consecutive scans carried out over a time interval of 160 s were used in order to determine the time to signal intensity (SI) curves of the synovial proliferations surrounding soft tissue, bone marrow, and joint effusion. After the administration of a contrast agent, synovial proliferations exhibited an increase on FFE and SE images of 47.7% (SD {+-} 14.3%) and 37.4% (SD {+-} 11.2%), respectively, whereas muscle and fatty tissue, tendons, bone marrow, and joint effusion revealed only a minor increase in SI. The gradient of SI (ratio SI/time) of pannus was 39.6%/min (SD {+-} 7.7%/min) and differed significantly (P < 0.001) from that of bone marrow, fatty tissue, muscle tissue, tendons, and joint effusion (P < 0.05). In contrast to synovial proliferations in rheumatoid arthritis, no differentiation between various pannus vascularities based on the degree of enhancement was possible. The Gd-DTPA-enhanced MRI studies delineate and quantify the synovial proliferations in hemophilic arthropathy. Dynamic studies in hemophilic arthropathy do not provide qualitative assessment of the inflammatory process. (orig.)

  16. Hemophilic arthropathy of the knee joint: static and dynamic Gd-DTPA -enhanced MRI

    International Nuclear Information System (INIS)

    Naegele, M.; Bruening, R.; Kunze, V.; Eickhoff, H.; Koch, W.; Reiser, M.

    1995-01-01

    A total of 17 patients with hemophilic arthropathy of the knee joint were studied with static and dynamic MRI before and after an IV bolus injection of Gadolinium-DTPA (Gd-DTPA; 0.1 mmol/kg body weight). The T1-weighted spin-echo (SE) and gradient-echo (fast-field echo [FFE]) sequences were applied. The FFE sequences of eight consecutive scans carried out over a time interval of 160 s were used in order to determine the time to signal intensity (SI) curves of the synovial proliferations surrounding soft tissue, bone marrow, and joint effusion. After the administration of a contrast agent, synovial proliferations exhibited an increase on FFE and SE images of 47.7% (SD ± 14.3%) and 37.4% (SD ± 11.2%), respectively, whereas muscle and fatty tissue, tendons, bone marrow, and joint effusion revealed only a minor increase in SI. The gradient of SI (ratio SI/time) of pannus was 39.6%/min (SD ± 7.7%/min) and differed significantly (P < 0.001) from that of bone marrow, fatty tissue, muscle tissue, tendons, and joint effusion (P < 0.05). In contrast to synovial proliferations in rheumatoid arthritis, no differentiation between various pannus vascularities based on the degree of enhancement was possible. The Gd-DTPA-enhanced MRI studies delineate and quantify the synovial proliferations in hemophilic arthropathy. Dynamic studies in hemophilic arthropathy do not provide qualitative assessment of the inflammatory process. (orig.)

  17. The experimental study of the pancreatic enhancement on MR imaging with Mn-DPDP

    International Nuclear Information System (INIS)

    Gong Jingshan; Zhou Kangrong; Zeng Mengsu; Peng Weijun; Yan Fuhua; Shen Jizhang; Chen Caizhong; Shi Weibin; Zhang Shujie

    2002-01-01

    Objective: To investigate whether the exocrine glandular cells of the pancreas take in Mn-DPDP or its metabolite. Methods: A fistula tube was inserted into the major pancreatic duct through the major duodenal papillae in a group of six male dogs. The pancreatic juice was collected before and after the intravenous infusion of Mn-DPDP at a rate of 2-3 ml/min with a dose of 2 ml/kg body weight. The Mn content of pancreatic juice was measured using atomic absorption spectroscopy (AAS). T 1 -weighted spin-echo images and SPGR T 1 W images were obtained prior to and approximately 30 min after the administration of Mn-DPDP. Results: The Mn content of the pancreatic juice increased by (6.17 x 10 -3 - 1.58 x 10 -2 ) mmol/L (median 1.09 x 10 -2 mmol/L) after the administration of Mn-DPDP with statistical significance (Z = 2.20, P 1 -weighted spin echo images and SPGR images, respectively. Conclusion: The experimental study confirmed that the exocrine glandular cells of the pancreas could take in the manganese and excrete it through the pancreatic juice, which played a leading role in pancreatic enhancement on MR imaging with Mn-DPDP. The Mn-DPDP-enhanced MRI can be used for diagnosing pancreatic abnormality and has the potential ability to evaluate the exocrine function of the pancreas

  18. Functional evaluation of transplanted kidneys by Gd-DTPA enhanced turbo FLASH MR imaging

    International Nuclear Information System (INIS)

    Nakashima, Rumi; Yamashita, Yasuyuki; Tomiguchi, Seiji; Tsuji, Akinori; Takahashi, Mutsumasa

    1996-01-01

    We evaluated the usefulness of dynamic turbo FLASH MR imaging in the differential diagnosis of complications after renal transplantation in 17 patients (10 from living relatives and 7 from cadavers). Coronal turbo FLASH dynamic images were obtained every 5 sec for 5 min after an intravenous bolus injection of Gd-DTPA. Corticomedullary differentiation (CMD) on spin echo coronal T 1 -weighted images and MR renogram patterns of the renal cortex and medulla were obtained for quantitative analysis of the Gd-DTPA-enhanced dynamic turbo-FLASH images. The signal intensity ratio of the medulla to cortex after Gd-DTPA enhancement was compared among four groups: normal (n=9), acute tubular necrosis (ATN) or cyclosporine A (CyA) tubulopathy (n=6), acute rejection (AR) in the living related donor kidney (n=4), and AR in the cadaveric kidney (n=5). Although loss of CMD was seen in severe renal dysfunction in the transplanted kidneys, there was considerable overlap among the four groups. On dynamic study, there was significant differences in the signal intensity ratio of the medulla to cortex between normally functioning kidneys or ATN/CyA tubulopathy and AR (p<0.01). In patients with severe renal dysfunction, the arterial cortical peak was indistinct. In conclusion, MR renograms obtained from dynamic turbo FLASH MR imaging played a significant role in evaluating dysfunction of the renal transplant. (author)

  19. Enhanced MR imaging of tenosynovitis of hand and wrist in inflammatory arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Tehranzadeh, J.; Ashilyan, O.; Anavim, A.; Tramma, S. [Univ. of California, Orange (United States). Dept. of Radiological Sciences

    2006-11-15

    The purpose of this study is to describe the appearance of tenosynovitis in various tendon groups in the wrist and hand and to compare MR enhanced and non-enhanced imaging evaluation of tenosynovitis of hand and wrist in inflammatory arthritis. We reviewed 72 MRI studies of hands and wrists, including coronal, axial and sagittal images in 30 consecutive patients with inflammatory arthritis and tenosynovitis. We compared the degree of synovitis on T2-weighted vs contrast-enhanced T1-weighted images, using a predetermined scale. We also measured the extent of tenosynovitis in three dimensions. The tendons were assigned to volar, dorsal, ulnar and radial groups in the wrist and to extensor, flexor and thumb groups in the hand. Degree of tenosynovitis (graded 0-3), cross-sectional area and volume of the inflamed synovium in various tendon groups were then compared by statistical analysis. Review of the medical records revealed the following diagnoses in our patient population: rheumatoid arthritis (n=16), unspecified inflammatory polyarthritis (n=9), psoriatic arthritis (n=2), CREST syndrome (n=1), systemic lupus erythematosus (n=1), paraneoplastic syndrome with arthritis (n=1). The average T2 brightness scores and post-gadolinium enhancement scores were 1.0 and 1.7 respectively (P<0.001) in the wrist studies. The average T2 brightness scores and post-gadolinium enhancement scores were 0.7 and 1.4, respectively (P<0.001) in the hand studies. The average sensitivity of T2-weighted imaging for detection of tenosynovitis was 40% in the hand and 67% in the wrist tendons, when contrast-enhanced images were used as a reference. Carpal tunnel flexor tendons were the most frequently affected tendons of the wrist. The most frequently affected tendons of the hand were second and third flexor tendons. The hand flexors demonstrated higher degrees of enhancement and larger volumes of the inflamed tenosynovium than did the hand extensors and tendons of the thumb.

  20. Enhanced MR imaging of tenosynovitis of hand and wrist in inflammatory arthritis

    International Nuclear Information System (INIS)

    Tehranzadeh, J.; Ashilyan, O.; Anavim, A.; Tramma, S.

    2006-01-01

    The purpose of this study is to describe the appearance of tenosynovitis in various tendon groups in the wrist and hand and to compare MR enhanced and non-enhanced imaging evaluation of tenosynovitis of hand and wrist in inflammatory arthritis. We reviewed 72 MRI studies of hands and wrists, including coronal, axial and sagittal images in 30 consecutive patients with inflammatory arthritis and tenosynovitis. We compared the degree of synovitis on T2-weighted vs contrast-enhanced T1-weighted images, using a predetermined scale. We also measured the extent of tenosynovitis in three dimensions. The tendons were assigned to volar, dorsal, ulnar and radial groups in the wrist and to extensor, flexor and thumb groups in the hand. Degree of tenosynovitis (graded 0-3), cross-sectional area and volume of the inflamed synovium in various tendon groups were then compared by statistical analysis. Review of the medical records revealed the following diagnoses in our patient population: rheumatoid arthritis (n=16), unspecified inflammatory polyarthritis (n=9), psoriatic arthritis (n=2), CREST syndrome (n=1), systemic lupus erythematosus (n=1), paraneoplastic syndrome with arthritis (n=1). The average T2 brightness scores and post-gadolinium enhancement scores were 1.0 and 1.7 respectively (P<0.001) in the wrist studies. The average T2 brightness scores and post-gadolinium enhancement scores were 0.7 and 1.4, respectively (P<0.001) in the hand studies. The average sensitivity of T2-weighted imaging for detection of tenosynovitis was 40% in the hand and 67% in the wrist tendons, when contrast-enhanced images were used as a reference. Carpal tunnel flexor tendons were the most frequently affected tendons of the wrist. The most frequently affected tendons of the hand were second and third flexor tendons. The hand flexors demonstrated higher degrees of enhancement and larger volumes of the inflamed tenosynovium than did the hand extensors and tendons of the thumb

  1. Differentiation of prostate cancer from normal prostate tissue in an animal model: conventional MRI and dynamic contrast-enhanced MRI

    International Nuclear Information System (INIS)

    Gemeinhardt, O.; Prochnow, D.; Taupitz, M.; Hamm, B.; Beyersdorff, D.; Luedemann, L.; Abramjuk, C.

    2005-01-01

    Purpose: to differentiate orthotopically implanted prostate cancer from normal prostate tissue using magnetic resonance imaging (MRI) and Gd-DTPA-BMA-enhanced dynamic MRI in the rat model. Material and methods: tumors were induced in 15 rats by orthotopic implantation of G subline Dunning rat prostatic tumor cells. MRI was performed 56 to 60 days after tumor cell implantation using T1-weighted spin-echo, T2-weighted turbo SE sequences, and a 2D FLASH sequence for the contrast medium based dynamic study. The interstitial leakage volume, normalized permeability and the permeability surface area product of tumor and healthy prostate were determined quantitatively using a pharmacokinetic model. The results were confirmed by histologic examination. Results: axial T2-weighted TSE images depicted low-intensity areas suspicious for tumor in all 15 animals. The mean tumor volume was 46.5 mm3. In the dynamic study, the suspicious areas in all animals displayed faster and more pronounced signal enhancement than surrounding prostate tissue. The interstitial volume and the permeability surface area product of the tumors increased significantly by 420% (p<0.001) and 424% (p<0.001), respectively, compared to normal prostate tissue, while no significant difference was seen for normalized permeability alone. Conclusion: the results of the present study demonstrate that quantitative analysis of contrast-enhanced dynamic MRI data enables differentiation of small, slowly growing orthotopic prostate cancer from normal prostate tissue in the rat model. (orig.)

  2. Dural invasion of meningiomas adjacent to the tumor margin on Gd-DTPA-enhanced MR images: histopathologic correlation

    International Nuclear Information System (INIS)

    Hutzelmann, A.; Palmie, S.; Freund, M.; Heller, M.; Buhl, R.

    1998-01-01

    In intracranial meningiomas a flat, contrast-enhancing, dural structure adjacent to the tumor can occasionally be observed on gadolinium-DTPA-enhanced MR images. We wished to evaluate whether there is a correlation between MR images and meningeal invasion of intracranial meningiomas. The study included 54 patients with intracranial meningioma and the meningeal sign. MR studies included T2-weighted and gadolinium-DTPA-enhanced T1-weighted images in axial, coronal, and sagittal planes. Histopathologic examinations were done on the meningiomas adjacent to the dura mater. The meningeal sign on MRI was observed from 2 up to 35 mm from the main tumor mass in 31 (57 %) of the 54 patients. In 20 of these 31 the histopathologic examination showed tumor invasion, while 11 patients had no tumor invasion but tissue proliferation, hypervascularity, and vascular dilatation. Seven of the 23 meningiomas without the meningeal sign had histologically proven infiltration of the adjacent dura. MR imaging is not able to determine definitive whether or not there is dural infiltration of the meningiomas. In conclusion, resection of the tumor with a wide margin is necessary to achieve complete excision of meningioma and to avoid recurrence. (orig.)

  3. The Right Hemisphere Planum Temporale Supports Enhanced Visual Motion Detection Ability in Deaf People: Evidence from Cortical Thickness.

    Science.gov (United States)

    Shiell, Martha M; Champoux, François; Zatorre, Robert J

    2016-01-01

    After sensory loss, the deprived cortex can reorganize to process information from the remaining modalities, a phenomenon known as cross-modal reorganization. In blind people this cross-modal processing supports compensatory behavioural enhancements in the nondeprived modalities. Deaf people also show some compensatory visual enhancements, but a direct relationship between these abilities and cross-modally reorganized auditory cortex has only been established in an animal model, the congenitally deaf cat, and not in humans. Using T1-weighted magnetic resonance imaging, we measured cortical thickness in the planum temporale, Heschl's gyrus and sulcus, the middle temporal area MT+, and the calcarine sulcus, in early-deaf persons. We tested for a correlation between this measure and visual motion detection thresholds, a visual function where deaf people show enhancements as compared to hearing. We found that the cortical thickness of a region in the right hemisphere planum temporale, typically an auditory region, was greater in deaf individuals with better visual motion detection thresholds. This same region has previously been implicated in functional imaging studies as important for functional reorganization. The structure-behaviour correlation observed here demonstrates this area's involvement in compensatory vision and indicates an anatomical correlate, increased cortical thickness, of cross-modal plasticity.

  4. Contrast-enhanced MRI of the knee in children unaffected by clinical arthritis compared to clinically active juvenile idiopathic arthritis patients

    International Nuclear Information System (INIS)

    Nusman, Charlotte M.; Hemke, Robert; Benninga, Marc A.; Kindermann, Angelika; Schonenberg-Meinema, Dieneke; Berg, J.M. van den; Kuijpers, Taco W.; Rossum, Marion A.J. van; Maas, Mario

    2016-01-01

    To evaluate enhancing synovial thickness upon contrast-enhanced magnetic resonance imaging (MRI) of the knee in children unaffected by clinical arthritis compared with clinically active juvenile idiopathic arthritis (JIA) patients. A secondary objective was optimization of the scoring method based on maximizing differences on MRI between these groups. Twenty-five children without history of joint complaints nor any clinical signs of joint inflammation were age/sex-matched with 25 clinically active JIA patients with arthritis of at least one knee. Two trained radiologists, blinded for clinical status, independently evaluated location and extent of enhancing synovial thickness with the validated Juvenile Arthritis MRI Scoring system (JAMRIS) on contrast-enhanced axial fat-saturated T1-weighted MRI of the knee. Enhancing synovium (≥2 mm) was present in 13 (52 %) unaffected children. Using the total JAMRIS score for synovial thickening, no significant difference was found between unaffected children and active JIA patients (p = 0.091). Additional weighting of synovial thickening at the JIA-specific locations enabled more sensitive discrimination (p = 0.011). Mild synovial thickening is commonly present in the knee of children unaffected by clinical arthritis. The infrapatellar and cruciate ligament synovial involvement were specific for JIA, which - in a revised JAMRIS - increases the ability to discriminate between JIA and unaffected children. (orig.)

  5. Contrast-enhanced MRI of the knee in children unaffected by clinical arthritis compared to clinically active juvenile idiopathic arthritis patients

    Energy Technology Data Exchange (ETDEWEB)

    Nusman, Charlotte M.; Hemke, Robert [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Benninga, Marc A.; Kindermann, Angelika [University of Amsterdam, Department of Pediatric Gastroenterology, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Schonenberg-Meinema, Dieneke; Berg, J.M. van den; Kuijpers, Taco W. [University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Rossum, Marion A.J. van [University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Reade, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Maas, Mario [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands)

    2016-04-15

    To evaluate enhancing synovial thickness upon contrast-enhanced magnetic resonance imaging (MRI) of the knee in children unaffected by clinical arthritis compared with clinically active juvenile idiopathic arthritis (JIA) patients. A secondary objective was optimization of the scoring method based on maximizing differences on MRI between these groups. Twenty-five children without history of joint complaints nor any clinical signs of joint inflammation were age/sex-matched with 25 clinically active JIA patients with arthritis of at least one knee. Two trained radiologists, blinded for clinical status, independently evaluated location and extent of enhancing synovial thickness with the validated Juvenile Arthritis MRI Scoring system (JAMRIS) on contrast-enhanced axial fat-saturated T1-weighted MRI of the knee. Enhancing synovium (≥2 mm) was present in 13 (52 %) unaffected children. Using the total JAMRIS score for synovial thickening, no significant difference was found between unaffected children and active JIA patients (p = 0.091). Additional weighting of synovial thickening at the JIA-specific locations enabled more sensitive discrimination (p = 0.011). Mild synovial thickening is commonly present in the knee of children unaffected by clinical arthritis. The infrapatellar and cruciate ligament synovial involvement were specific for JIA, which - in a revised JAMRIS - increases the ability to discriminate between JIA and unaffected children. (orig.)

  6. Optimal gadolinium dose level for magnetic resonance imaging (MRI) contrast enhancement of U87-derived tumors in athymic nude rats for the assessment of photodynamic therapy

    Science.gov (United States)

    Cross, Nathan; Varghai, Davood; Flask, Chris A.; Feyes, Denise K.; Oleinick, Nancy L.; Dean, David

    2009-02-01

    This study aims to determine the effect of varying gadopentetate dimeglumine (Gd-DTPA) dose on Dynamic Contrast Enhanced-Magnetic Resonance Imaging (DCE-MRI) tracking of brain tumor photodynamic therapy (PDT) outcome. Methods: We injected 2.5 x 105 U87 cells (derived from human malignant glioma) into the brains of six athymic nude rats. After 9, 12, and 13 days DCE-MRI images were acquired on a 9.4 T micro-MRI scanner before and after administration of 100, 150, or 200 μL of Gd-DTPA. Results: Tumor region normalized DCE-MRI scan enhancement at peak was: 1.217 over baseline (0.018 Standard Error [SE]) at the 100 μL dose, 1.339 (0.013 SE) at the 150 μL dose, and 1.287 (0.014 SE) at the 200 μL dose. DCE-MRI peak tumor enhancement at the 150 μL dose was significantly greater than both the 100 μL dose (p DTPA dose provided the greatest T1 weighted contrast enhancement, while minimizing negative T2* effects, in DCE-MRI scans of U87-derived tumors. Maximizing Gd-DTPA enhancement in DCE-MRI scans may assist development of a clinically robust (i.e., unambiguous) technique for PDT outcome assessment.

  7. Comparison of triple dose versus standard dose gadolinium-DTPA for detection of MRI enhancing lesions in patients with primary progressive multiple sclerosis.

    Science.gov (United States)

    Filippi, M; Campi, A; Martinelli, V; Colombo, B; Yousry, T; Canal, N; Scotti, G; Comi, G

    1995-01-01

    This study was performed to evaluate whether a triple dose of gadolinium-DTPA (Gd-DTPA) increases the sensitivity of brain MRI for detecting enhancing lesions in patients with primary progressive multiple sclerosis (PPMS). T1 weighted brain MRI was obtained for 10 patients with PPMS in two sessions. In the first session, one scan was obtained five to seven minutes after the injection of 0.1 mmol/kg Gd-DTPA (standard dose). In the second session, six to 24 hours later, one scan before and two scans five to seven minutes and one hour after the injection of 0.3 mmol/kg Gd-DTPA (triple dose) were obtained. Four enhancing lesions were detected in two patients when the standard dose of Gd-DTPA was used. The numbers of enhancing lesions increased to 13 and the numbers of patients with such lesions to five when the triple dose of Gd-DTPA was used and to 14 and six in the one hour delayed scans. The mean contrast ratio for enhancing lesions detected with the triple dose of Gd-DTPA was higher than those for lesions present in both the standard dose (P DTPA many more enhancing lesions can be detected in patients with PPMS. This is important both for planning clinical trials and for detecting the presence of inflammation in vivo in the lesions of such patients. Images PMID:8530944

  8. Gadolinium-Enhanced Three-Dimensional Magnetization - Prepared Rapid Gradient-Echo (3D MP-RAGE) Imaging is Superior to Spin-Echo Imaging in Delineating Brain Metastases

    International Nuclear Information System (INIS)

    Takeda, T.; Takeda, A.; Nagaoka, T.; Kunieda, E.; Takemasa, K.; Watanabe, M.; Hatou, T.; Oguro, S.; Katayama, M.

    2008-01-01

    Background: Precisely defining the number and location of brain metastases is very important for establishing a treatment strategy for malignancies. Although magnetic resonance imaging (MRI) is now considered the best modality, various improvements in sequences are still being made. Purpose: To prospectively compare the diagnostic ability of three-dimensional, magnetization-prepared rapid gradient-echo (3D MP-RAGE) imaging in detecting metastatic brain tumors, with that of two-dimensional spin-echo (2D SE) T1-weighted imaging. Material and Methods: A total of 123 examinations were included in this study, and 119 examinations from 88 patients with known malignancies were analyzed. All patients underwent T1- and T2-weighted 2D SE transverse imaging, followed by gadolinium-enhanced T1-weighted transverse and coronal 2D SE imaging and 3D MP-RAGE transverse imaging. Four radiologists interpreted the images to compare the accuracy and the time required for interpretation for each imaging. Results: 3D MP-RAGE imaging was significantly better than 2D SE imaging for detecting metastatic brain lesions, regardless of the readers' experience. The sensitivities of the 3D MP-RAGE and 2D SE imaging for all observers were 0.81 vs. 0.80 (P>0.05), specificities were 0.93 vs. 0.87 (P 0.05), and accuracies were 0.84 vs. 0.78 (P<0.05), respectively. There was no significant difference in the time required for image interpretation between the two modalities (15.6±4.0 vs. 15.4±4.1 min). Conclusion: 3D MP-RAGE imaging proved superior to 2D SE imaging in the detection of brain metastases

  9. Early versus late GD-DTPA MRI enhancement in experimental glioblastomas.

    Science.gov (United States)

    Farace, Paolo; Tambalo, Stefano; Fiorini, Silvia; Merigo, Flavia; Daducci, Alessandro; Nicolato, Elena; Conti, Giamaica; Degrassi, Anna; Sbarbati, Andrea; Marzola, Pasquina

    2011-03-01

    To compare early versus late enhancement in two glioblastoma models characterized by different infiltrative/edematous patterns. Three weeks after inoculation into nude mice of U87MG and U251 cells, T1-weighted images were acquired early (10.5 min), intermediate (21 min) and late (30.5 min) after a bolus injection of Gd-DTPA at 300 μ mol/kg dosage. EARLY(TH) and LATE(TH) were the corresponding volumes with an enhancement higher than a threshold TH, defined by the mean (μ) and standard deviation (σ) on a contralateral healthy area. ADD(TH) was the enhancing volume found in LATE(TH) but not in EARLY(TH). T2 imaging of both tumors was performed, and T2 mapping of U251. In all tumors, LATE(TH) was significantly higher than EARLY(TH) for TH ranging from μ+σ to μ+5σ. The ADD(TH) /EARLY(TH) ratio was not significantly different when U251 and U87MG tumors were compared. In the U87MG tumors, some enhancement was observed outside the regularly demarcated T2-hyperintense area. In the U251 tumors, irregularly T2 demarcated, a large portion of ADD(μ+3σ) had normal T2 values. At histology, U251 showed a higher infiltrative pattern than U87MG. In these models, the increase over time in the enhancing volume did not depend on the different infiltrative/edematous patterns and was not closely related with edema. Copyright © 2011 Wiley-Liss, Inc.

  10. Dynamic contrast enhanced MRI in the differential diagnosis of adrenal adenomas and malignant adrenal masses

    International Nuclear Information System (INIS)

    Inan, Nagihan; Arslan, Arzu; Akansel, Gur; Anik, Yonca; Balci, N. Cem; Demirci, Ali

    2008-01-01

    Objective: To evaluate the value of dynamic MR imaging in the differential diagnosis of adrenal adenomas and malignant tumors, especially in cases with atypical adenomas. Materials and methods: Sixty-four masses (48 adenomas, 16 malignant tumors) were included in this prospective study. Signal loss of masses was evaluated using chemical shift MR imaging. Five dynamic series of T1-weighted spoiled gradient echo (FFE) images were obtained, with the acquisition starting simultaneously with i.v. contrast administration (0-100 s) followed by a T1-weighted FFE sequence in the late phase (5th minute). Contrast enhancement patterns in the early (25th second) and late (5th minute) phase images were evaluated. For the quantitative evaluation, signal intensity (SI)-time curves were obtained according to the SIs on the 0th, 25th, 50th 75th and 100th second. Also, the wash-in rate, maximum relative enhancement, time-to-peak, and wash-out of contrast at 100 s of masses in both groups were calculated. The statistical significance was determined by Mann-Whitney U test. To evaluate the diagnostic performance of the quantitative tests, receiver operating characteristic (ROC) analysis was performed. Results: Chemical shift MR imaging was able to differentiate 44 out of 48 adenomas (91.7%) from non-adenomas. The 4 adenomas (8.3%) which could not be differentiated from non-adenomas by this technique did not exhibit signal loss on out-of-phase images. With a cut-off value of 30, SI indices of adenomas had a sensitivity of 93.8%, specificity of 100% and a positive predictive value of 100%. On visual evaluation of dynamic MR imaging, early phase contrast enhancement patterns were homogeneous in 75% and punctate in 20,83% of the adenomas; while patchy in 56.25% and peripheral in 25% of the malignant tumors. On the late phase images 58.33% of the adenomas showed peripheral ring-shaped enhancement and 10.41% showed heterogeneous enhancement. All of the malignant masses showed heterogeneous

  11. Bone marrow blood supply in gadolinium-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Saifuddin, A.; Bann, K.; Ridgway, J.P.; Butt, W.P.

    1994-01-01

    A retrospective study was performed to determine whether bone blood supply can be assessed on gadolinium-enhanced magnetic resonance imaging. Lumbar spine magnetic resonance imaging (MRI) examinations of 49 patients attending for post-laminectomy examination were reviewed (30 male, 19 female, mean age 46.4 years, age range 23-84 years). Each study included sagittal T1-weighted spin echo sequences before and after gadolinium administration. Regions of interest were drawn within the L3 vertebral body from a parasagittal slice from each sequence. Signal intensity (SI) values were ascertained and the percentage increase in SI was calculated. For each patient, changes in receiver gain for pre- and post-gadolinium images were corrected by an image scaling factor. In all cases, a measurable increase in SI was found (mean 15.3%, range 4.4-55.7) due to bone vascularity. The results give no indication of the quantity or timing of blood supply but provide a basis for further work. (orig.)

  12. The efficacy of fat suppressed and gadolinium enhanced dynamic MR imaging in pancreatic adenocarcinomas

    International Nuclear Information System (INIS)

    Gabata, Toshifumi

    1994-01-01

    The efficacy of both fat suppressed T1-weighted imaging (T1WI) and dynamic gadolinium-enhanced MR imaging (dynamic MRI) was compared with conventional MR sequences and dynamic CT in 22 patients with histologically proven pancreatic adenocarcinoma (PAC). In the control group of 30 patients without pancreatic disease, the pancreas was shown as a markedly higher signal intensity on fat suppressed T1WI than on conventional MR sequences. The signal noise ratio (SNR) of the normal pancreas and the contrast noise ratio (CNR) between the normal pancreas and muscle were significantly higher on fat suppressed T1WI than the other MR sequences. In the group of PAC patients without chronic pancreatitis (n=14), CNR between the tumor and the normal pancreas significantly differed among imaging techniques, including fat suppressed T1WI, dynamic MRI, and the other conventional MR sequences. In the group of PAC with chronic pancreatitis (n=8), CNR between the tumor and the associated chronic pancreatitis was remarkably diminished on both fat suppressed T1WI and conventional T1WI; however, it was significantly higher on dynamic MRI than the other pulse sequences. The early phase of dynamic MRI clearly identified the tumors in the group of PAC. The capability of conventional T1WI and dynamic CT to demonstrate peripancreatic tumor extension was significantly higher than that of fat suppressed T1WI. In conclusion, fat suppressed T1WI and dynamic MRI were useful in detecting pancreatic carcinoma. (N.K.)

  13. Role of Gd-DTPA enhanced fat-suppression MR imaging on ovarian tumors

    International Nuclear Information System (INIS)

    Kang, Heoung Keun; Moon, Woong Jae; Seo, Jeong Jin; Kim, Jae Kyu; Park, Jin Gyoon; Choi, Ho Sun

    1995-01-01

    To determine the value of Gd-DTPA enhanced fat-suppression (GEFS) MR imaging in the characterization and differentiation of benign from malignant ovarian tumors. MRI findings of thirty-seven patients with surgically proved 44 ovarian tumors (30 benign, 14 malignant) were studied retrospectively. MR imaging with conventional spin echo (CSE; T1-weighted image TR/TE 450/20, T2-weighted image TR/TE 3500/30, 90) and GEFS were performed with a 1.5T GE signa. MRI findings of tumors including cystic or solid, wall and septal thickness, necrosis, invasion to adjacent organ, ascites and lymphadenopathy were assessed separately by using CSE and GEFS images, and then tumors were characterized as benign or malignant. Compared with CSE image, GEFS MR image showed better visualization of solid component in 5 malignant lesions, wall thickness in 5 malignant and 1 benign lesions, septal thickness in 3 malignant and 1 benign lesions, necrosis in 1 malignant lesion, and adjacent soft tissue invasion in 5 malignant lesions. Correct characterization of malignant tumors was increased from 71% on CSE image to 93% on GEFS image. However, correct characterization of benign tumors was 93% on both images. GEFS MR imaging could be useful for characterization of ovarian tumors, especially in malignant cases, and employed for differentiation of benign from malignant tumors

  14. Comparison of detection pattern of HCC by ferumoxide-enhanced MRI and intratumoral blood flow pattern

    International Nuclear Information System (INIS)

    Itou, Naoki; Kotake, Fumio; Saitou, Kazuhiro; Abe, Kimihiko

    2000-01-01

    We compared the detection rate and pattern of ferumoxide-enhanced magnetic resonance imaging (Fe-MRI) with the intratumoral blood flow pattern determined by CT angiography (CTA) and CT portography (CTAP) in 124 nodes (34 cases) diagnosed as hepatocellular carcinoma (HCC) or borderline HCC, based on the clinical course. Sequences to obtain a T1-weighted images (T1W), proton density-weighted images (PDW), T2-weighted images (T2W), T2*-weighted images (T2*W) were used in Fe-MRI. In nodes shown to be hypervascular on CTA, the detection rate by Fe-MRI was 69.7%. In nodes shown to be avascular by CTAP, the detection rate by Fe-MRI was 67.3%. These rates were higher than with other flow patterns. In nodes showing high signal intensity (HSI) on any sequences, arterial blood flow was increased and portal blood flow decreased in comparison with nodes without high signal intensity. All nodes showing HSI, both on Fe-MRI T2W and T2*W, were hypervascular on CTA, and portal blood flow was absent on CTAP. Nodes showing HSI on both T2*W and T2W were considered to have greater arterial blood flow and decreased portal blood flow compared with nodes appearing as HSI on T2*W, but only as iso- or low signal intensity on T2W (Mann-Whitney U-test; p<0.05). (author)

  15. Assessment of image display of contrast enhanced T1W images with fat suppression

    International Nuclear Information System (INIS)

    Miyazaki, Isao; Ishizaki, Keiko; Kobayashi, Kuninori; Katou, Masanobu

    2006-01-01

    The effects of imaging conditions and measures for their improvement were examined with regard to recognition of the effects of contrast on images when T 1 -weighted imaging with selective fat suppression was applied. Luminance at the target region was examined before and after contrast imaging using phantoms assuming pre- and post-imaging conditions. A clinical examination was performed on tumors revealed by breast examination, including those surrounded by mammary gland and by fat tissue. When fat suppression was used and imaging contrast was enhanced, the luminance level of fat tumors with the same structure as the prepared phantoms appeared to be high both before and after contrast imaging, and the effects of contrast were not distinguishable. This observation is attributable to the fact that the imaging conditions before and after contrast imaging were substantially different. To make a comparison between pre- and post-contrast images, it is considered necessary to perform imaging with fixed receiver gain and to apply the same imaging method for pre- and post-contrast images by adjusting post-contrast imaging conditions to those of pre-contrast imaging. (author)

  16. Leptomeningeal contrast enhancement in moyamoya: its potential role in postoperative assessment of circulation through the bypass

    International Nuclear Information System (INIS)

    Komiyama, M.; Nakajima, H.; Nishikawa, M.; Yasui, T.; Kitano, S.; Sakamoto, H.

    2001-01-01

    Leptomeningeal contrast enhancement (LMCE) is one of the MRI features of moyamoya. Its clinical significance, however, is not elucidated. Our purpose was to characterise LMCE on MRI and to evaluate its role in the assessment of circulation through a surgically established bypass in moyamoya. We studied 16 patients with idiopathic moyamoya (seven males, nine females, includingt four children, aged 7 to 54 years, mean 24 years) who underwent T1-weighted MRI before and after intravenous contrast medium. The presence of LMCE, its intensity and anatomical distribution, catheter angiographic findings, and relation of LMCE to the bypass surgery were assessed. More LMCE was seen in the cerebrum in most patients with moyamoya than in normal controls. LMCE in the brain stem and cerebellum was minimal, similar to that seen in the controls. LMCE was less prominent following surgery than before operation or in patients who did not undergo surgery. In three patients examined both before and after operation LMCE became less prominent following bypass surgery. As LMCE becomes less prominent after ''effective'' bypass surgery, this may be used for evaluation of effectiveness of surgery in moyamoya. (orig.)

  17. Enthesitis of lumbar spinal ligaments in clinically suspected spondyloarthritis: value of gadolinium-enhanced MR images in comparison to STIR

    Energy Technology Data Exchange (ETDEWEB)

    Agten, Christoph A.; Zubler, Veronika; Rosskopf, Andrea B.; Pfirrmann, Christian W.A. [Balgrist University Hospital, Radiology, Zurich (Switzerland); University of Zurich, Faculty of Medicine, Zurich (Switzerland); Weiss, Bettina [Balgrist University Hospital, Rheumatology, Zurich (Switzerland); University of Zurich, Faculty of Medicine, Zurich (Switzerland)

    2016-02-15

    To compare detection of spinal ligament enthesitis between gadolinium-enhanced fat-saturated T1-weighted gadolinium-enhanced fat-saturated T1-weighted (T1+Gd) and STIR sequences in patients with suspected spondyloarthritis. Sixty-eight patients (37 males, 42 ± 14 years) with a sacroiliac-joint (SIJ) and lumbar spine MRI for suspected spondyloarthritis were prospectively included. Sagittal T1+Gd and STIR images of the lumbar spine were assessed by two readers for enthesitis of interspinous/supraspinous ligaments, and for capsulitis of facet-joints between T12-S1. Patients' MRI were grouped according to ASAS (Assessment of SpondyloArthritis international Society) criteria in positive (group A) or negative (group B) SIJs. Enthesitis/capsulitis were compared between groups. Interreader agreement was assessed. Enthesitis/capsulitis per patient was statistically significantly more frequent with T1+Gd compared to STIR (p ≤ 0.007), except for interspinous ligaments for reader 1 (p = 0.455). Interspinous enthesitis, supraspinous enthesitis, and capsulitis were present with T1+Gd(STIR) in 64.7 %(72.1 %), 60.3 %(17.7 %), and 61.8 %(29.4 %) for reader 1, and 51.5 %(41.2 %), 45.6 %(7.4 %), and 91.2 %(45.5 %) for reader 2. There were 76.5 %(52/68) patients in group A and 23.5 %(16/68) in group B. Total number of enthesitis/capsulitis on T1+Gd was statistically significantly higher in group A than B (4.96 vs. 2.94, p = 0.026; 8.12 vs. 5.25, p = 0.041 for reader 1 and 2, respectively). Interreader agreement showed mixed results for interspinous/supraspinous/capsulitis but was higher on T1+Gd (ICC = 0.838/0.783/0.367; p ≤ 0.001) compared to STIR (ICC = 0.652/0.298/0.224; p ≤ 0.032). In patients with suspected spondyloarthritis, enthesitis/capsulitis in the lumbar spine are common findings and more frequently/reliably detected with T1+Gd than STIR. In patients with positive SIJ-MRI, the total number of enthesitis/capsulitis in T1+Gd was higher compared to patients with

  18. Contrast-enhanced peripheral MRA. Technique and contrast agents

    International Nuclear Information System (INIS)

    Nielsen, Yousef W.; Thomsen, Henrik S.

    2012-01-01

    In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast agents. Peripheral CE-MRA is defined as an MR angiogram of the arteries from the aortic bifurcation to the feet. Advantages of CE-MRA include minimal invasiveness and lack of ionizing radiation. The basic technique employed for peripheral CE-MRA is the bolus-chase method. With this method a paramagnetic MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic field strength of the MRI system, receiver coil configuration, use of parallel imaging, contrast bolus timing technique, and k-space filling strategies. Furthermore, it is possible to optimize peripheral CE-MRA using venous compression techniques, hybrid scan protocols, time-resolved imaging, and steady-state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged intravascular stay, due to macromolecular structure or protein binding. These agents can be used for first-pass, as well as steady-state MRA. Some Gd-based contrast agents with low thermodynamic stability have been linked to development of nephrogenic systemic fibrosis in patients with severe renal insufficiency. Using optimized technique and a stable MRI contrast agent, peripheral CE-MRA is a safe procedure with diagnostic accuracy close to that of conventional catheter X

  19. Perfusion characteristics of late radiation injury of parotid glands: quantitative evaluation with dynamic contrast-enhanced MRI

    International Nuclear Information System (INIS)

    Juan, Chun-Jung; Chen, Cheng-Yu.; Hsueh, Chun-Jen; Huang, Guo-Shu; Jen, Yee-Min; Liu, Hua-Shan; Wang, Chao-Ying; Chung, Hsiao-Wen; Liu, Yi-Jui; Chou, Yu-Ching; Chai, Yao-Te

    2009-01-01

    We aimed to quantitatively investigate the alteration of parotid perfusion after irradiation using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) based on a two-compartment tracer kinetic model. This study enrolled 19 patients (53.2±14.9 years) treated by head and neck radiotherapy and 19 age-relevant and sex-matched subjects as a control group. Perfusion parameters (K el , k 21 and A) of parotid glands were analyzed based on the Brix model from T1-weighted DCE-MRI. Suitability of the Brix model was evaluated via Monte Carlo simulation for the goodness-of-fit. Analysis of nonlinear goodness-of-fit showed that the Brix model is appropriate in evaluating the parotid perfusion (R 2 = 0.938±0.050). The irradiated parotid glands showed significantly lower K el (P 21 (P < 0.05) and consequently significantly higher value of peak enhancement (P<0.0005) and time-to-peak (P<0.0005) compared with non-irradiated ones, suggestive of gradual and prolonged accumulation and delayed wash-out of contrast agent due to increased extracellular extravascular space and decreased vascular permeability in the irradiated glands. Linear regression analysis showed dose-dependent perfusion changes of the irradiated parotid glands. We conclude that quantitative DCE-MRI is a potential tool in investigating parotid gland perfusion changes after radiotherapy. (orig.)

  20. Renal enhancement and excretion of the hepatobiliary contrast agent Gd-EOB-DTPA

    International Nuclear Information System (INIS)

    Zangos, S.; Hammerstingl, R.; Mack, M.G.; Straub, R.; Engelmann, K.; Eichler, K.; Vogl, T.J.

    2001-01-01

    Purpose: To evaluate the clinical value of the renal clearance using MR imaging with different doses of gadolinium ethoxybenzyl-DTPA (Gd-EOB-DTPA) in comparison to gadolinium DTPA (Gd-DTPA). Material and Methods: In a double-blind and randomized clinical phase II study. MR imaging at 1.5 T was performed in 61 patients with five different doses of Gd-EOB-DTPA (3, 6, 12.5, 25 and 50 μmol/kg b.w. as a bolus injection). The study protocol comprised T 1 - and T 2 -weighted spin-echo magnetic resonance and two-dimensional fast low-angle shot imaging before and at increasing intervals for up to 45 min after injection of Gd-EOB-DTPA. These images were compared with Gd-DTPA-enhanced imaging (0.1 mmol/kg b. w. as a bolus injection). Results: After bolus injection of the hepatobiliary MR contrast agent Gd-EOB-DTPA a renal elimination was observed. Immediately after the injection of Gd-EOB-DTPA until the eighth minute a corticomedullary enhancement of the kidney was conspicuous. After the fourth minute a contrast enhancement could be seen in the renal pelvis. The best enhancement was noted after 20 minutes in the FLASH GRE and T 1 -weighted images with good pelvicaliceal contrast. After 45 minutes an outflow of Gd-EOB-DTPA into the ureter could be observed. Conclusion: In addition to the hepatobiliary secretion Gd-EOB-DTPA appears useful for the evaluation of renal structures and renal function on account of the renal excretion without diuretic preparation of the patients. (orig.) [de

  1. Optimizing signal intensity correction during evaluation of hepatic parenchymal enhancement on gadoxetate disodium-enhanced MRI: Comparison of three methods

    International Nuclear Information System (INIS)

    Onoda, Minori; Hyodo, Tomoko; Murakami, Takamichi; Okada, Masahiro; Uto, Tatsuro; Hori, Masatoshi; Miyati, Tosiaki

    2015-01-01

    Highlights: •Signal intensity is often used to evaluate hepatic enhancement with Gd-EOB-DTPA in the hepatobiliary phase. •Comparison of uncorrected signal intensity with T 1 value revealed signal intensity instability. •Measurement of uncorrected liver SI or SNR often yields erroneous results on late-phase gadoxetate MRI due to shimming and other optimization techniques. •Signal intensity corrected by scale and rescale slope from DICOM data gave comparable results. -- Abstract: Objective: To compare signal intensity (SI) correction using scale and rescale slopes with SI correction using SIs of spleen and muscle for quantifying multiphase hepatic contrast enhancement with Gd-EOB-DTPA by assessing their correlation with T 1 values generated from Look-Locker turbo-field-echo (LL-TFE) sequence data (ER-T 1 ). Materials and methods: Thirty patients underwent Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) in this prospective clinical study. For each patient, breath-hold T 1 -weighted fat-suppressed three-dimensional (3D) gradient echo sequences (e-THRIVE) were acquired before and 2 (first phase), 10 (second phase), and 20 min (third phase) after intravenous Gd-EOB-DTPA. Look-Locker turbo-field-echo (LL-TFE) sequences were acquired before and 1.5 (first phase), 8 (second phase), and 18 min (third phase) postcontrast. The liver parenchyma enhancement ratios (ER) of each phase were calculated using the SI from e-THRIVE sequences (ER-SI) and the T 1 values generated from LL-TFE sequence data (ER-T 1 ) respectively. ER-SIs were calculated in three ways: (1) comparing with splenic SI (ER-SI-s), (2) comparing with muscle SI (ER-SI-m), (3) using scale and rescale slopes obtained from DICOM headers (ER-SI-c), to eliminate the effects of receiver gain and scaling. For each of the first, second and third phases, correlation and agreement were assessed between each ER-SI and ER-T 1 . Results: In the first phase, all ER-SIs correlated weakly with ER-T 1 . In the second

  2. Dynamic