MR imaging of carotid webs

International Nuclear Information System (INIS)

Boesen, Mari E.; Eswaradass, Prasanna Venkatesan; Singh, Dilip; Mitha, Alim P.; Menon, Bijoy K.; Goyal, Mayank; Frayne, Richard

2017-01-01

We propose a magnetic resonance (MR) imaging protocol for the characterization of carotid web morphology, composition, and vessel wall dynamics. The purpose of this case series was to determine the feasibility of imaging carotid webs with MR imaging. Five patients diagnosed with carotid web on CT angiography were recruited to undergo a 30-min MR imaging session. MR angiography (MRA) images of the carotid artery bifurcation were acquired. Multi-contrast fast spin echo (FSE) images were acquired axially about the level of the carotid web. Two types of cardiac phase resolved sequences (cineFSE and cine phase contrast) were acquired to visualize the elasticity of the vessel wall affected by the web. Carotid webs were identified on MRA in 5/5 (100%) patients. Multi-contrast FSE revealed vessel wall thickening and cineFSE demonstrated regional changes in distensibility surrounding the webs in these patients. Our MR imaging protocol enables an in-depth evaluation of patients with carotid webs: morphology (by MRA), composition (by multi-contrast FSE), and wall dynamics (by cineFSE). (orig.)

MR imaging of carotid webs

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Boesen, Mari E. [University of Calgary, Department of Biomedical Engineering, Calgary (Canada); Foothills Medical Centre, Seaman Family MR Research Centre, Calgary (Canada); Eswaradass, Prasanna Venkatesan; Singh, Dilip; Mitha, Alim P.; Menon, Bijoy K. [University of Calgary, Department of Clinical Neurosciences, Calgary (Canada); Foothills Medical Centre, Calgary Stroke Program, Calgary (Canada); Goyal, Mayank [Foothills Medical Centre, Calgary Stroke Program, Calgary (Canada); University of Calgary, Department of Radiology, Calgary (Canada); Frayne, Richard [Foothills Medical Centre, Seaman Family MR Research Centre, Calgary (Canada); University of Calgary, Hotchkiss Brain Institute, Calgary (Canada)

2017-04-15

We propose a magnetic resonance (MR) imaging protocol for the characterization of carotid web morphology, composition, and vessel wall dynamics. The purpose of this case series was to determine the feasibility of imaging carotid webs with MR imaging. Five patients diagnosed with carotid web on CT angiography were recruited to undergo a 30-min MR imaging session. MR angiography (MRA) images of the carotid artery bifurcation were acquired. Multi-contrast fast spin echo (FSE) images were acquired axially about the level of the carotid web. Two types of cardiac phase resolved sequences (cineFSE and cine phase contrast) were acquired to visualize the elasticity of the vessel wall affected by the web. Carotid webs were identified on MRA in 5/5 (100%) patients. Multi-contrast FSE revealed vessel wall thickening and cineFSE demonstrated regional changes in distensibility surrounding the webs in these patients. Our MR imaging protocol enables an in-depth evaluation of patients with carotid webs: morphology (by MRA), composition (by multi-contrast FSE), and wall dynamics (by cineFSE). (orig.)

Chondromalacia patellae: diagnosis with MR imaging.

Science.gov (United States)

McCauley, T R; Kier, R; Lynch, K J; Jokl, P

1992-01-01

Most previous studies of MR imaging for detection of chondromalacia have used T1-weighted images. We correlated findings on axial MR images of the knee with arthroscopic findings to determine MR findings of chondromalacia patellae on T2-weighted and proton density-weighted images. The study population included 52 patients who had MR examination of the knee with a 1.5-T unit and subsequent arthroscopy, which documented chondromalacia patellae in 29 patients and normal cartilage in 23. The patellar cartilage was assessed retrospectively for MR signal and contour characteristics. MR diagnosis based on the criteria of focal signal or focal contour abnormality on either the T2-weighted or proton density-weighted images yielded the highest correlation with the arthroscopic diagnosis of chondromalacia. When these criteria were used, patients with chondromalacia were detected with 86% sensitivity, 74% specificity, and 81% accuracy. MR diagnosis based on T2-weighted images alone was more sensitive and accurate than was diagnosis based on proton density-weighted images alone. In conclusion, most patients with chondromalacia patellae have focal signal or focal contour defects in the patellar cartilage on T2-weighted MR images. These findings are absent in most patients with arthroscopically normal cartilage.

Rickets on MR images

International Nuclear Information System (INIS)

Ecklund, K.; Jaramillo, D.; Doria, A.S.

1999-01-01

Background. The pathologic changes at the physis in patients with rickets have been well demonstrated histologically. Radiographs can depict only the associated osseous abnormalities. Patients and methods. We report two children in whom MR imaging demonstrated rachitic changes in the physeal cartilage beyond the well-recognized bony features. Results. The striking appearance of the physes and the physes of the secondary ossification centers confirm that MR imaging can successfully evaluate the cartilaginous structures of the developing skeleton. Conclusion. Though MR imaging is clearly unnecessary for the diagnosis of rickets, it is important that the typical features are not misinterpreted as other pathology. (orig.)

CT and MR imaging of craniopharyngioma

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Tsuda, M. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Radiology; Takahashi, S. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Radiology; Higano, S. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Radiology; Kurihara, N. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Radiology; Ikeda, H. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Neurosurgery; Sakamoto, K. [Tohoku Univ. School of Medicine, Sendai (Japan). Dept. of Radiology

1997-05-01

We reviewed imaging findings of CT and MR imaging in 20 cases of surgically confirmed craniopharyngioma in an attempt to determine their relation to patterns of tumor extent. The relationship between these patterns and the frequency of preoperative CT diagnosis and MR imaging diagnosis according to the surgical diagnosis were determined. The CT technique was superior to MR imaging in the detection of calcification. The MR imaging technique was superior to CT for determining tumor extent and provided valuable information about the relationships of the tumor to surrounding structures. Thus, CT and MR imaging have complementary roles in the diagnosis of craniopharyngiomas. In cases of possible craniopharyngioma, noncontrast sagittal T1-weighted images may enable the identification of the normal pituitary, possibly leading to the correct diagnosis. (orig.)

CT and MR imaging of craniopharyngioma

International Nuclear Information System (INIS)

Tsuda, M.; Takahashi, S.; Higano, S.; Kurihara, N.; Ikeda, H.; Sakamoto, K.

1997-01-01

We reviewed imaging findings of CT and MR imaging in 20 cases of surgically confirmed craniopharyngioma in an attempt to determine their relation to patterns of tumor extent. The relationship between these patterns and the frequency of preoperative CT diagnosis and MR imaging diagnosis according to the surgical diagnosis were determined. The CT technique was superior to MR imaging in the detection of calcification. The MR imaging technique was superior to CT for determining tumor extent and provided valuable information about the relationships of the tumor to surrounding structures. Thus, CT and MR imaging have complementary roles in the diagnosis of craniopharyngiomas. In cases of possible craniopharyngioma, noncontrast sagittal T1-weighted images may enable the identification of the normal pituitary, possibly leading to the correct diagnosis. (orig.)

Clinical stage T1c prostate cancer: evaluation with endorectal MR imaging and MR spectroscopic imaging.

Science.gov (United States)

Zhang, Jingbo; Hricak, Hedvig; Shukla-Dave, Amita; Akin, Oguz; Ishill, Nicole M; Carlino, Lauren J; Reuter, Victor E; Eastham, James A

2009-11-01

To assess the diagnostic accuracy of endorectal magnetic resonance (MR) imaging and MR spectroscopic imaging for prediction of the pathologic stage of prostate cancer and the presence of clinically nonimportant disease in patients with clinical stage T1c prostate cancer. The institutional review board approved-and waived the informed patient consent requirement for-this HIPAA-compliant study involving 158 patients (median age, 58 years; age range, 40-76 years) who had clinical stage T1c prostate cancer, had not been treated preoperatively, and underwent combined 1.5-T endorectal MR imaging-MR spectroscopic imaging between January 2003 and March 2004 before undergoing radical prostatectomy. On the MR images and combined endorectal MR-MR spectroscopic images, two radiologists retrospectively and independently rated the likelihood of cancer in 12 prostate regions and the likelihoods of extracapsular extension (ECE), seminal vesicle invasion (SVI), and adjacent organ invasion by using a five-point scale, and they determined the probability of clinically nonimportant prostate cancer by using a four-point scale. Whole-mount step-section pathology maps were used for imaging-pathologic analysis correlation. Receiver operating characteristic curves were constructed and areas under the curves (AUCs) were estimated nonparametrically for assessment of reader accuracy. At surgical-pathologic analysis, one (0.6%) patient had no cancer; 124 (78%) patients, organ-confined (stage pT2) disease; 29 (18%) patients, ECE (stage pT3a); two (1%) patients, SVI (stage pT3b); and two (1%) patients, bladder neck invasion (stage pT4). Forty-six (29%) patients had a total tumor volume of less than 0.5 cm(3). With combined MR imaging-MR spectroscopic imaging, the two readers achieved 80% accuracy in disease staging and AUCs of 0.62 and 0.71 for the prediction of clinically nonimportant cancer. Clinical stage T1c prostate cancers are heterogeneous in pathologic stage and volume. MR imaging may

MR imaging of prostate cancer

International Nuclear Information System (INIS)

Heuck, A.; Scheidler, J.; Sommer, B.; Graser, A.; Mueller-Lisse, U.G.; Massmann, J.

2003-01-01

Accurate diagnosis and staging of prostate cancer (PC) is developing into an important health care issue in light of the high incidence of PC and the improvements in stage-adapted therapy. The purpose of this paper is to provide an overview on the current role of MR imaging and MR spectroscopy in the diagnosis and staging of PC.Material and methods Pertinent literature was searched and evaluated to collect information on current clinical indications, study techniques, diagnostic value, and limitations of magnetic resonance imaging and spectroscopy. Major indications for MR imaging of patients with supected PC are to define tumor location before biopsy when clinical or TRUS findings are inconclusive, and to provide accurate staging of histologically proven PC to ascertain effective therapy. Current MR imaging techniques for the evaluation of PC include multiplanar high-resolution T2-weighted FSE and T1-weighted SE sequences using combined endorectal and phased-array coils. Using these techniques, the reported accuracy of MR imaging for the diagnosis of extracapsular tumor extension ranges between 82 and 88% with sensitivities between 80 and 95%, and specificities between 82 and 93%. Typical MR findings of PC in different stages of disease, as well as diagnostic problems, such as chronic prostatitis, biopsy-related hemorrhage and therapy-related changes of prostatic tissue are discussed. In addition, the current perspectives and limitations of MR spectroscopy in PC are summarized. Current MR imaging techniques provide important diagnostic information in the pretherapeutic workup of PC including a high staging accuracy, and is superior to TRUS. (orig.) [de

Fibrolipomatous hamartoma: MR imaging findings

International Nuclear Information System (INIS)

De Maeseneer, M.; Jaovisidha, S.; Lenchik, L.; Witte, D.; Schweitzer, M.E.; Sartoris, D.J.; Resnick, D.

1997-01-01

Objective. To analyze the MR imaging features of fibrolipomatous hamartoma (FLH) of nerves. Design and patients. MR imaging studies from six patients (three men and three women) were retrospectively reviewed by three musculoskeletal radiologists. In four patients, a biopsy of the nerve lesion was performed. In two patients, biopsy data were unavailable and the diagnosis was based on the clinical history combined with the MR imaging findings. Results and conclusion. MR imaging demonstrated fusiform nerve enlargement that was caused by fatty proliferation and thickening of nerve bundles. Nerve bundles appeared as serpentine tubular structures, hypointense on both T1- and T2-weighted images. The degree of fatty proliferation varied among patients. In addition, significant variation in the distribution of fat along the course of the nerves was noted. In three patients, FLH followed the branching pattern of the nerves, a characteristic pathologic finding. In two patients, intramuscular fat deposition (biceps and tibialis posterior muscles) was present. MR imaging findings of FLH are typical, allowing a confident diagnosis. The variation of fatty proliferation among patients and involved nerves as well as the tendency of the abnormalities to follow the branching pattern of the nerves is well demonstrated with MR imaging. FLH may present as an isolated nerve lesion, may be associated with intramuscular fat deposition, or may occur as a feature of macrodystrophia lipomatosa (MDL). (orig.). With 5 figs., 2 tabs

Whole heart cine MR imaging of pulmonary veins in patients with congenital heart disease. Comparison with Spin Echo MR imaging

International Nuclear Information System (INIS)

Mitsui, Hideaki; Saito, Haruo; Ishibashi, Tadashi; Takahashi, Shoki; Zuguchi, Masayuki; Yamada, Shogo

2002-01-01

We evaluated the accuracy of Whole Heart Cine (WHC) magnetic resonance (MR) imaging in the depiction of pulmonary veins (PVs) in patients with congenital heart disease (CHD) compared to that of spin echo (SE) MR imaging. Among our 35 patients, 4 patients had anomalous PV return. Detectability of four PVs on each MR examination images were evaluated. MR imaging is an effective modality for the clarification of PVs, and WHC MR imaging is more useful in delineating PV anomalies than SE MR imaging. (author)

Rickets on MR images

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Ecklund, K.; Jaramillo, D. [Department of Radiology, Children`s Hospital, Boston, MA (United States); Doria, A.S. [Department of Radiology, Instituto da Crianca - Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo (Brazil)

1999-09-01

Background. The pathologic changes at the physis in patients with rickets have been well demonstrated histologically. Radiographs can depict only the associated osseous abnormalities. Patients and methods. We report two children in whom MR imaging demonstrated rachitic changes in the physeal cartilage beyond the well-recognized bony features. Results. The striking appearance of the physes and the physes of the secondary ossification centers confirm that MR imaging can successfully evaluate the cartilaginous structures of the developing skeleton. Conclusion. Though MR imaging is clearly unnecessary for the diagnosis of rickets, it is important that the typical features are not misinterpreted as other pathology. (orig.) With 6 figs., 6 refs.

A comparative study of MR imaging scores and MR perfusion imaging in pre-operative grading of intracranial gliomas

International Nuclear Information System (INIS)

Wu Honglin; Chen Junkun; Zhang Zongjun; Lu Guangming; Chen Ziqian; Wang Wei; Ji Xueman; Tang Xiaojun; Li Lin

2005-01-01

Objective: To compare the accuracy of MR imaging scores with MR perfusion imaging in pre-operative grading of intracranial gliomas. Methods: Thirty patients with intracranial gliomas (8 low-grade and 22 high-grade, according to WHO criteria) were examined with MR perfusion imaging pre-operatively. The lesions were evaluated by using an MR imaging score based on nine criteria. rCBV of the lesions were calculated by comparing the CBV of the lesion and that of contralateral normal white matter. The scores and ratios in high-grade and low-grade tumours were compared. Results: The MR imaging score of low grade (grades I and II) gliomas (0.67±0.29) were significantly lower than that of grades III (1.32 ± 0.47) (t=-3.48, P=0.003) and IV (1.56 ± 0.20) (t=-7.36, P=0.000) gliomas. There was no statistical difference when MR imaging scores of grades III and IV gliomas (t=-1.39, P=0.182) were compared. The maximum rCBV ratio of low grade (grades I and II) gliomas (2.38 ± 0.66 ) were significantly lower than that of grades III (5.81 ± 3.20) (t=-3.57, P=0.003) and IV (6.99 ± 2.47) (t=-5.09, P=0.001). There was no statistical difference when rCBV ratios of grades III and IV (t =-0.93, P=0.365) gliomas were compared. The accuracy of MR imaging scores in the noninvasive grading of untreated gliomas was all most the same as that of MR perfusion imaging (90.00% vs 89.29%). Conclusion: The MR imaging scores and MR perfusion imaging are two very useful tools in the evaluation of the histopathologic grade of cerebral gliomas. The overall accuracy in the noninvasive grading of gliomas may be imp roved if MR imaging scores and MR perfusion imaging are combined. (authors)

MR imaging of hemimegalencephaly in children

International Nuclear Information System (INIS)

Kalifa, G.; Sellier, N.; Demange, P.; Ponsot, G.; Chiron, C.; Robain, O.

1986-01-01

Hemimegalencephaly is a rare brain malformation characterized by cerebral asymmetry and cortical dysplasia. Affected infants are seen initially with early seizures and a severe encephalopathy. The author report five new cases studied with MR imaging. MR imaging clearly demonstrated brain hemihypertrophy, abnormal gyration, and poor differentiation between gray and white matter. A highly abnormal disposition of the cellular layers was observed. MR imaging turned out to be the most efficient diagnostic method for hemimegalencephaly. The examination may facilitate understanding and classification of this rare entity. Autopsy findings correlated well with MR imaging appearances

CT and MR imaging of the kidney and adrenal glands: MR imaging of the kidney and adrenal glands

International Nuclear Information System (INIS)

Lee, J.K.T.

1987-01-01

The normal anatomy of the kidney is clearly demonstrated with MR imaging. The renal cortex can be differentiated from the renal medulla; renal vessels can also be identified. MR imaging can differentiate cystic from solid lesions. The signal intensity of a renal cell carcinoma varies and overlaps with the signal intensities of renal neoplasms of other etiologies. MR imaging is superior to CT in distinguishing vascular from nonvascular structures. It can distinguish collateral vessels from lymph nodes and can disclose tumoral thrombi. MR imaging can also aid in the differentiation of acute rejection from acute tubular necrosis in renal transplant recipients. Both normal and abnormal adrenal glands can be seen on MR imaging. A normal adrenal gland has a signal intensity higher than or equal to that of muscle but lower than that of fat. T1-weighted images offer excellent antomic resolution; T2-weighted images provide additional information about internal characteristics of adrenal neoplasms. Preliminary data indicate that MR imaging is useful in distinguishing nonfunctioning adenomas from adrenal metastases. The role of MR imaging of the kidney and adrenal gland is discussed

Dynamic MR imaging of the musculoskeletal system

International Nuclear Information System (INIS)

Shah, A.S.; Hylton, H.; Hentz, V.R.; Schattner, P.

1991-01-01

This paper reports on dynamic MR imaging which is an MR technique that allows imaging of the musculoskeletal system in motion. Current methods for observing the articulation of muscles and joints are limited to acquisition of stationary images at different spatial orientations. These images are then replayed from computer memory to simulate motion. Unlike stationary acquisition, dynamic MR imaging allows the volume of interest to be subjected to motion and dynamic stress, which is important for detecting stress-induced pathology. To demonstrate the utility of dynamic MR imaging, a system for imaging a moving wrist has been developed. The system consists of apparatus capable of providing simultaneous radialulnar deviation and flexion-extension, and hardware for system control and acquisition gating. The apparatus is mounted on the patient bed and is transferable to a variety of standard clinical MR imaging systems. Images were obtained during motion, and the ability of dynamic MR imaging to accurately image the moving wrist with very little motion artifact was demonstrated

Ankle ligamints : comparison of MR arthrography with conventional MR imaging in amputated feet

International Nuclear Information System (INIS)

Yoo, Jae Sung; Lee, Sang Yong; Lee, Jeong Min; Han, Young Min; Chung, Kyung Ho; Kim, CHong Soo

2001-01-01

To compare magnetic resonance (MR) arthrography with conventional MR imaging in the evaluation of ankle ligaments. Eight freshly amputated human feet underwent conventional MR imaging and MR arthrography. For the former, 1.5-T magnets in the axial, coronal and sagittal planes were used, and T1-weighted sequences were obtained. Following the injection of 6-10 ml of diluted contrast media (Gd-DTPA 1:250), T1-weighted images were obtained in the same positions as conventional MR images. Paired conventional MR imaging and MR arthrography of each ankle ligament were rated on a five-point scale, and to reflect inter-group differences a Wilcoxon singed-rank test was used to compare the different measurements (p<0.05). In two ankles, MR images of the ligaments were correlated with ankle dissection. Anterior and posterior talofibular ligaments were more clearly revealed by MR arthrography than by conventional MR imaging, while calcaneofibular ligaments showed no difference between these two modalities. With regard to deltoid ligaments, visualization of the anterior and posterior tibiotalar ligament was much improved when contrast material was used to outline the ligament's articular aspect. Visualization of the posterior inferior tibiofibular ligament and inferior transverse ligament were also improved when the use of contrast material provided delineation of the articular side of the ligaments and separated them from adjacent bone. In addition, MR arthography was very useful for indentification of the posterior intermalleolar ligament, though its use did not enhance visualization of the calcaneofibular, tibiocalcaneal, spring or tibiospring ligaments. MR arthrography accurately revealed the anatomic details of ankle ligaments, and may therefore be more useful than conventional Mr imaging for evaluation of these structures

MR imaging of von Hippel-Lindau disease

International Nuclear Information System (INIS)

Sato, Y.; Waziri, M.H.; Smith, W.L.; Frey, E.E.; Franken, E.A.

1986-01-01

Sixteen patients with von Hippel-Lindau disease (VH-L) and 11 asymptomatic family members underwent a total of 29 central nervous system (CNS) and 23 body MR imaging evaluations during a 2-year study period. Nineteen CNS and spinal lesions and nine abdominal visceral lesions were identified on MR imaging and were confirmed at surgery or by other imaging modalities. MR imaging is superior to CT in the evaluation of intraocular vitreous abnormalities and cerebellar and spinal hemangioblastomas because of superior tissue characterization and lack of bone artifacts. MR imaging adequately demonstrated the abdominal visceral lesions. MR imaging is a sensitive and reliable imaging modality for the various lesions of VH-L

MR imaging of pituitary dwarfism

International Nuclear Information System (INIS)

Kashimada, Akio; Machida, Kikuo; Honda, Norinari; Mamiya, Toshio; Takahashi, Taku; Kamano, Tsuyoshi; Muramatsu, Masayuki; Inoue, Yusuke

1993-01-01

Pituitary MR imaging was performed in 32 patients with clinically diagnosed pituitary dwarfism and 12 normal controls. The patients were divided into two groups according to the severity of pituitary dwarfism based on endocrinological data. The two patients with severe dwarfism showed transection of the pituitary stalk, ectopic posterior lobe and atrophy of the anterior lobe on MR imaging, while the 27 patients with mild dwarfism showed no abnormal MR findings of the pituitary gland. The former group corresponds to typical pituitary dwarfism and the latter to partial GH deficiency, which was recently proposed as another type of pituitary dwarfism. In conclusion, pituitary MR imaging may differentiate partial GH deficiency from typical (stalk-transected) pituitary dwarfism. (author)

MR imaging of pituitary dwarfism

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Kashimada, Akio; Machida, Kikuo; Honda, Norinari; Mamiya, Toshio; Takahashi, Taku; Kamano, Tsuyoshi; Muramatsu, Masayuki; Inoue, Yusuke (Saitama Medical School, Kawagoe (Japan). Medical Center)

1993-02-01

Pituitary MR imaging was performed in 32 patients with clinically diagnosed pituitary dwarfism and 12 normal controls. The patients were divided into two groups according to the severity of pituitary dwarfism based on endocrinological data. The two patients with severe dwarfism showed transection of the pituitary stalk, ectopic posterior lobe and atrophy of the anterior lobe on MR imaging, while the 27 patients with mild dwarfism showed no abnormal MR findings of the pituitary gland. The former group corresponds to typical pituitary dwarfism and the latter to partial GH deficiency, which was recently proposed as another type of pituitary dwarfism. In conclusion, pituitary MR imaging may differentiate partial GH deficiency from typical (stalk-transected) pituitary dwarfism. (author).

Normal anatomy of the fetus at MR imaging.

Science.gov (United States)

Amin, R S; Nikolaidis, P; Kawashima, A; Kramer, L A; Ernst, R D

1999-10-01

Owing to recent advances in magnetic resonance (MR) imaging, the role of obstetric MR imaging has increased in cases in which the results of ultrasonography are equivocal. Fast MR imaging sequences, such as T2-weighted fast spin-echo (SE), half-Fourier single-shot fast SE, 0.5-signal-acquired single-shot fast SE, and echo-planar imaging, have virtually eliminated the need for fetal premedication, with a concomitant improvement in image resolution and diminished blurring. Artifacts related to maternal respiratory motion and fetal motion no longer limit the anatomic detail that can be demonstrated with MR imaging. With such advances in obstetric MR imaging, knowledge of normal fetal anatomy at MR imaging is essential to detect disease in utero. MR imaging can demonstrate fetal anatomy in detail, especially the brain, thorax, abdomen, pelvis, and vasculature. Major developmental structures of the fetus, particularly the cranial nervous system, naso- and oropharynx, lungs, and major abdominal viscera, can be adequately evaluated with targeted fast MR imaging as early as the beginning of the second trimester. However, MR imaging of the heart remains limited. Fetal MR imaging during the first trimester remains controversial secondary to biosafety issues and is limited due to diminutive fetal size.

Brain MR imaging in child abuse

International Nuclear Information System (INIS)

Sato, Y.; Ellerbroek, C.J.; Alexander, R.; Kao, S.C.S.; Yuh, W.T.C.; Smith, W.L.

1988-01-01

Intracranial injuries represent the most severe manifestation of child abuse. CT of the brain is the current standard for evaluation of these infants; however, MR imaging offers several potential advantages. MR imaging and CT were performed in ten infants who suffered intracranial trauma owing to child abuse. CT was slightly better at demonstrating subarachnoid hemorrhage and had definite advantages for defining fractures. MR imaging was superior in the demonstration of subacute extraaxial hemorrhage, deep brain injuries owing to shearing effects from shaking, and anoxic injuries. MR imaging has a definite complementary role in the evaluation of acute intracranial trauma in child abuse victims

MR imaging of normal bone marrow; Obraz MR prawidlowego szpiku kostnego

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Stajgis, M.; Paprzycki, W. [Osrodek Diagnostyki Obrazowej IR, Akademia Medyczna, Poznan (Poland)

1994-12-31

Principles of MR bone marrow imaging on the basis of retrospective analysis of MR examinations of bone marrow in different anatomic sites in 200 patients have been discussed. Significance of different physiologic factors and processes such as age, steatosis, osteoporosis, conversion and reconversion, which influence on MR bone marrow images, have been emphasized. T1-weighted images obtained with spin-echo sequences give the most of information about bone marrow structure in MR. Thorough knowledge of bone marrow physiology and clinical status of the patient is indispensable in correct interpretation of hypointensive lesions on T1-weighted images. When presence of disseminated bone marrow disease is suspected, authors propose routine imaging of lumbar vertebral column, pelvis and proximal parts of femoral bones. (author) 7 refs, 7 figs

MR imaging of rotator cuff tears

International Nuclear Information System (INIS)

Kumagai, Hideo

1992-01-01

A total of 115 patients with clinical symptoms and signs suggesting rotator cuff tears underwent MR imaging with a 1.5-Tesla system. The body coil was used as the receiver coil in 24 patients and a single 10 cm surface coil in 91. Arthrography or MR imaging with intra-articular Gd-DTPA (MR arthrography) was performed in 95 of the 115. T2-weighted images with the body coil showed high signal intensity lesions in rotator cuffs in only seven of the 10 patients who had tears demonstrated by arthrography or MR arthrography. On the other hand, T2-weighted images with the surface coil demonstrated high signal intensity lesions in cuffs in all 27 patients who were diagnosed to have tears by arthrography or MR arthrography. In 12 patietns, T2-wighted images with the surface coil showed high signal intensity lesions in cuffs, while arthrography and MR arthrography did not show tears. Surgery was performed in four of the 12 patients and partial tears were confirmed. A single 10 cm surface coil, 3 mm slice thickness and 2.5 second repetition time seem to account for the fine visualization of cuff tears by the T2-weighted images. These results suggest that T2-weighted images obtained with the surface coil are superior to arthrography and MR arthrography. (author)

MR imaging of septic sacroiliitis

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Stuerzenbecher, A.; Hamm, B.; Bollow, M. [Humboldt-Universitaet, Berlin (DD). Bereich Medizin (Charite); Braun, J. [Freie Univ. Berlin (Germany). Universitaetsklinikum Benjamin Franklin; Paris, S. [Unfallkrankenhaus Berlin (Germany). Dept. of Radiology; Biedermann, T. [Krankenhaus Berlin-Buch (Germany). II. Kinderklinik

2000-08-01

Objective. To investigate the diagnostic value of magnetic resonance (MR) imaging in detecting septic sacroiliitis and to determine whether the MR characteristics allow this entity to be differentiated from sacroiliitis in spondylarthropathy (SpA).Patients and design. The imaging findings of 11 patients with septic sacroiliitis were retrospectively analyzed by two experienced radiologists. Radiographic surveys of the pelvis as well as computed tomography (CT) and MR images of the sacroiliac joints were available in all cases. Seven of the patients additionally underwent a follow-up MR examination. The MR imaging protocol comprised combinations of coronal and transverse T1-weighted spin-echo (SE) or fast SE sequences, T2-weighted gradient-echo (GE) sequences and short tau inversion recovery sequence (STIR) sequences as well as dynamic contrast- enhanced T1-weighted acquisitions.Results. Three patients with a short disease history showed anterior and/or posterior subperiosteal infiltrations (''lava cleft phenomenon''), transcapsular infiltrations of juxta-articular muscle layers, which obscured the fasciae, and periarticular bone marrow edema. The eight patients with more advanced stages of sacroiliitis additionally showed abscess formation, sequestration, and erosion. At follow-up MR examination (n=7) under systemic antibiotic treatment, the morphologic characteristics showed progression (n=1), regression (n=4), unchanged findings (n=1), or a mixed response (n=1). Clinical improvement precedes resolution of the MR findings.Conclusions. Anterior and/or posterior subperiosteal infiltrations and transcapsular infiltrations of juxta-articular muscle layers were depicted in all patients. These MR imaging findings are characteristic of septic sacroiliitis and may be used to differentiate this entity from sacroiliitis in SpA. (orig.)

MR imaging of the neonatal brain: Pathologic features

International Nuclear Information System (INIS)

McArdle, C.B.; Richardson, C.J.; Nicholas, D.A.; Hayden, C.K.; Amparo, E.G.

1986-01-01

Seventy-three neonates, aged 29-43 weeks since conception, were studied. US and/or CT correlations were obtained in most infants with pathology. In the first 4-5 days after hemorrhage, US and CT were superior to MR imaging, but after that time MR imaging was the single best modality for imaging blood. In early premature infants with very watery white matter, US detected infarction and brain edema that were poorly seen on both MR imaging and CT. However, in late premature and full-term infants, MR imaging was better than CT in distinguishing between normal white matter and infarction. Only MR imaging disclosed delayed myelination in 13 term infants with hydrocephalus and severe asphyxia. MR imaging with play an important role in imaging neonates once MR imaging-compatible monitors and neonatal head coils become widely available

MR imaging of the knee

International Nuclear Information System (INIS)

Mink, J.H.

1987-01-01

There is increasing evidence that MR imaging of the knee can accurately evaluate the menisci and the cruciate and collateral ligaments with an accuracy equal to that of conventional anthrography. MR imaging can, as a simple test, definitively assess a wide spectrum of the causes of knee pain, including osteonecrosis/osteochondritis dissecans, chondral and bony fractures, abnormal plicae, and chondromalacia. The presentation focuses on the optimal imaging parameters that will ensure accuracy and maximize patient throughput. The etiology and significance of meniscal signal is discussed, and the criteria for an MR imaging-based diagnosis of meniscal tears, cruciate and collateral ligament and extensor mechanism abnormalities, osteonecrosis, and stress fractures are presented

Serial MR imaging in Creutzfeldt-Jakob disease

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Uchino, A.; Hata, H.; Ohno, M. (Kyushu Rosai Hospital, Kitakyushu (Japan). Dept. of Radiology); Yoshinaga, M.; Shiokawa, O. (Kyushu Rosai Hospital, Kitakyushu (Japan). Stroke Care Unit)

1991-08-01

Serial magnetic resonance (MR) imagings of two autopsied patients with Creutzfeldt-Jakob disease (CJD) are presented. Both patients showed a dramatic progression of brain atrophy. The initial MR imagings were, however, interpreted as normal except for localized mild cortical atrophy in one patient. When a normal MR image is obtained in a demented middle-aged or aged patient, CJD may still need to be ruled out: follow up MR imaging may be useful. (orig.).

Serial MR imaging in Creutzfeldt-Jakob disease

International Nuclear Information System (INIS)

Uchino, A.; Hata, H.; Ohno, M.; Yoshinaga, M.; Shiokawa, O.

1991-01-01

Serial magnetic resonance (MR) imagings of two autopsied patients with Creutzfeldt-Jakob disease (CJD) are presented. Both patients showed a dramatic progression of brain atrophy. The initial MR imagings were, however, interpreted as normal except for localized mild cortical atrophy in one patient. When a normal MR image is obtained in a demented middle-aged or aged patient, CJD may still need to be ruled out: follow up MR imaging may be useful. (orig.)

Cellular MR Imaging

Directory of Open Access Journals (Sweden)

Michel Modo

2005-07-01

Full Text Available Cellular MR imaging is a young field that aims to visualize targeted cells in living organisms. In order to provide a different signal intensity of the targeted cell, they are either labeled with MR contrast agents in vivo or prelabeled in vitro. Either (ultrasmall superparamagnetic iron oxide [(USPIO] particles or (polymeric paramagnetic chelates can be used for this purpose. For in vivo cellular labeling, Gd3+- and Mn2+- chelates have mainly been used for targeted hepatobiliary imaging, and (USPIO-based cellular imaging has been focused on imaging of macrophage activity. Several of these magneto-pharmaceuticals have been FDA-approved or are in late-phase clinical trials. As for prelabeling of cells in vitro, a challenge has been to induce a sufficient uptake of contrast agents into nonphagocytic cells, without affecting normal cellular function. It appears that this issue has now largely been resolved, leading to an active research on monitoring the cellular biodistribution in vivo following transplantation or transfusion of these cells, including cell migration and trafficking. New applications of cellular MR imaging will be directed, for instance, towards our understanding of hematopoietic (immune cell trafficking and of novel guided (stem cell-based therapies aimed to be translated to the clinic in the future.

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)

MR imaging of posttraumatic spinal ligament injury

International Nuclear Information System (INIS)

Pathria, M.N.; Emery, S.; Masaryk, T.J.; Wilber, R.G.; Bohlman, H.

1988-01-01

The accuracy of MR imaging in the detection of ligamentous injury was evaluated in 29 patients (24 male, five female) with spinal injury resulting in fractures (n=27), evidence of instability (n=11), or neurologic deficit (n=2). MR examinations were performed acutely (average, 7.5 days posttrauma) with T1- and T2-weighted imaging and were blindly evaluated. Subsequently, plain films (n=27), tomograms (n=10), and CT scans (n=22) were evaluated. Eighteen patients underwent surgery. Fourteen patients had torn ligaments as indicated by clinical and surgical findings. MR imaging demonstrated ligament damage in 13. One case imaged 40 days following trauma was not detected. No patients with intact ligaments had evidence of ligamentous damage on MR images. MR imaging demonstrated retropulsed fractures in six patients in whom the posterior longitudinal ligament was intact but displaced from the vertebra. MR imaging was more reliable than radiography and CT for detection of ligamentous injury, and T2- weighted sequences are essential in such cases

Multidisciplinary Functional MR Imaging for Prostate Cancer

International Nuclear Information System (INIS)

Kim, Jeong Kon; Jang, Yun Jin; Cho, Gyung Goo

2009-01-01

Various functional magnetic resonance (MR) imaging techniques are used for evaluating prostate cancer including diffusion-weighted imaging, dynamic contrast- enhanced MR imaging, and MR spectroscopy. These techniques provide unique information that is helpful to differentiate prostate cancer from non-cancerous tissue and have been proven to improve the diagnostic performance of MRI not only for cancer detection, but also for staging, post-treatment monitoring, and guiding prostate biopsies. However, each functional MR imaging technique also has inherent challenges. Therefore, in order to make accurate diagnoses, it is important to comprehensively understand their advantages and limitations, histologic background related with image findings, and their clinical relevance for evaluating prostate cancer. This article will review the basic principles and clinical significance of functional MR imaging for evaluating prostate cancer

MR imaging of normal bone marrow

International Nuclear Information System (INIS)

Stajgis, M.; Paprzycki, W.

1994-01-01

Principles of MR bone marrow imaging on the basis of retrospective analysis of MR examinations of bone marrow in different anatomic sites in 200 patients have been discussed. Significance of different physiologic factors and processes such as age, steatosis, osteoporosis, conversion and reconversion, which influence on MR bone marrow images, have been emphasized. T1-weighted images obtained with spin-echo sequences give the most of information about bone marrow structure in MR. Thorough knowledge of bone marrow physiology and clinical status of the patient is indispensable in correct interpretation of hypointensive lesions on T1-weighted images. When presence of disseminated bone marrow disease is suspected, authors propose routine imaging of lumbar vertebral column, pelvis and proximal parts of femoral bones. (author)

Practical Considerations for Clinical PET/MR Imaging.

Science.gov (United States)

Galgano, Samuel; Viets, Zachary; Fowler, Kathryn; Gore, Lael; Thomas, John V; McNamara, Michelle; McConathy, Jonathan

2018-01-01

Clinical PET/MR imaging is currently performed at a number of centers around the world as part of routine standard of care. This article focuses on issues and considerations for a clinical PET/MR imaging program, focusing on routine standard-of-care studies. Although local factors influence how clinical PET/MR imaging is implemented, the approaches and considerations described here intend to apply to most clinical programs. PET/MR imaging provides many more options than PET/computed tomography with diagnostic advantages for certain clinical applications but with added complexity. A recurring theme is matching the PET/MR imaging protocol to the clinical application to balance diagnostic accuracy with efficiency. Copyright © 2017 Elsevier Inc. All rights reserved.

Simultaneous PET/MR imaging in a human brain PET/MR system in 50 patients—Current state of image quality

International Nuclear Information System (INIS)

Schwenzer, N.F.; Stegger, L.; Bisdas, S.; Schraml, C.; Kolb, A.; Boss, A.; Müller, M.

2012-01-01

Objectives: The present work illustrates the current state of image quality and diagnostic accuracy in a new hybrid BrainPET/MR. Materials and methods: 50 patients with intracranial masses, head and upper neck tumors or neurodegenerative diseases were examined with a hybrid BrainPET/MR consisting of a conventional 3T MR system and an MR-compatible PET insert. Directly before PET/MR, all patients underwent a PET/CT examination with either [ 18 F]-FDG, [ 11 C]-methionine or [ 68 Ga]-DOTATOC. In addition to anatomical MR scans, functional sequences were performed including diffusion tensor imaging (DTI), arterial spin labeling (ASL) and proton-spectroscopy. Image quality score of MR imaging was evaluated using a 4-point-scale. PET data quality was assessed by evaluating FDG-uptake and tumor delineation with [ 11 C]-methionine and [ 68 Ga]-DOTATOC. FDG uptake quantification accuracy was evaluated by means of ROI analysis (right and left frontal and temporo-occipital lobes). The asymmetry indices and ratios between frontal and occipital ROIs were compared. Results: In 45/50 patients, PET/MR examination was successful. Visual analysis revealed a diagnostic image quality of anatomical MR imaging (mean quality score T2 FSE: 1.27 ± 0.54; FLAIR: 1.38 ± 0.61). ASL and proton-spectroscopy was possible in all cases. In DTI, dental artifacts lead to one non-diagnostic dataset (mean quality score DTI: 1.32 ± 0.69; ASL: 1.10 ± 0.31). PET datasets of PET/MR and PET/CT offered comparable tumor delineation with [ 11 C]-methionine; additional lesions were found in 2/8 [ 68 Ga]-DOTATOC-PET in the PET/MR. Mean asymmetry index revealed a high accordance between PET/MR and PET/CT (1.5 ± 2.2% vs. 0.9 ± 3.6%; mean ratio (frontal/parieto-occipital) 0.93 ± 0.08 vs. 0.96 ± 0.05), respectively. Conclusions: The hybrid BrainPET/MR allows for molecular, anatomical and functional imaging with uncompromised MR image quality and a high accordance of PET results between PET/MR and PET

Simultaneous PET/MR imaging in a human brain PET/MR system in 50 patients-Current state of image quality

Energy Technology Data Exchange (ETDEWEB)

Schwenzer, N.F., E-mail: nina.schwenzer@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Stegger, L., E-mail: stegger@gmx.net [Department of Nuclear Medicine and European Institute for Molecular Imaging, University of Muenster, Muenster (Germany); Bisdas, S., E-mail: sbisdas@gmail.com [Department of Diagnostic and Interventional Neuroradiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Schraml, C., E-mail: christina.schraml@med.uni-tuebingen.de [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Kolb, A., E-mail: armin.kolb@med.uni-tuebingen.de [Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Department of Preclinical Imaging and Radiopharmacy, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Boss, A., E-mail: Andreas.Boss@usz.ch [Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen (Germany); Institute of Diagnostic and Interventional Radiology, University Hospital Zuerich, Zuerich (Switzerland); Mueller, M., E-mail: mark.mueller@med.uni-tuebingen.de [Department of Nuclear Medicine, Eberhard-Karls University Tuebingen, Tuebingen (Germany); and others

2012-11-15

Objectives: The present work illustrates the current state of image quality and diagnostic accuracy in a new hybrid BrainPET/MR. Materials and methods: 50 patients with intracranial masses, head and upper neck tumors or neurodegenerative diseases were examined with a hybrid BrainPET/MR consisting of a conventional 3T MR system and an MR-compatible PET insert. Directly before PET/MR, all patients underwent a PET/CT examination with either [{sup 18}F]-FDG, [{sup 11}C]-methionine or [{sup 68}Ga]-DOTATOC. In addition to anatomical MR scans, functional sequences were performed including diffusion tensor imaging (DTI), arterial spin labeling (ASL) and proton-spectroscopy. Image quality score of MR imaging was evaluated using a 4-point-scale. PET data quality was assessed by evaluating FDG-uptake and tumor delineation with [{sup 11}C]-methionine and [{sup 68}Ga]-DOTATOC. FDG uptake quantification accuracy was evaluated by means of ROI analysis (right and left frontal and temporo-occipital lobes). The asymmetry indices and ratios between frontal and occipital ROIs were compared. Results: In 45/50 patients, PET/MR examination was successful. Visual analysis revealed a diagnostic image quality of anatomical MR imaging (mean quality score T2 FSE: 1.27 {+-} 0.54; FLAIR: 1.38 {+-} 0.61). ASL and proton-spectroscopy was possible in all cases. In DTI, dental artifacts lead to one non-diagnostic dataset (mean quality score DTI: 1.32 {+-} 0.69; ASL: 1.10 {+-} 0.31). PET datasets of PET/MR and PET/CT offered comparable tumor delineation with [{sup 11}C]-methionine; additional lesions were found in 2/8 [{sup 68}Ga]-DOTATOC-PET in the PET/MR. Mean asymmetry index revealed a high accordance between PET/MR and PET/CT (1.5 {+-} 2.2% vs. 0.9 {+-} 3.6%; mean ratio (frontal/parieto-occipital) 0.93 {+-} 0.08 vs. 0.96 {+-} 0.05), respectively. Conclusions: The hybrid BrainPET/MR allows for molecular, anatomical and functional imaging with uncompromised MR image quality and a high accordance

MR imaging and MR angiography in popliteal artery entrapment syndrome

International Nuclear Information System (INIS)

Atilla, S.; Akpek, S.; Yuecel, C.; Tali, E.T.; Isik, S.; Ilgit, E.T.

1998-01-01

Popliteal artery entrapment (PAE) syndrome is an uncommon congenital anomaly seen in young adults causing ischemic symptoms in the lower extremities. It is the result of various types of anomalous relationships between the popliteal artery and the neighboring muscular structures. The purpose of this study was to define the role of MR imaging combined with MR angiography in the diagnosis of PAE cases. Four cases with segmental occlusion and medial displacement of popliteal artery in digital subtraction angiography (DSA) examinations were diagnosed as PAE syndrome by MR imaging and MR angiography. The DSA and MRA images are compared. All of the cases showed various degrees of abnormal intercondylar insertion of the medial head of the gastrocnemius muscle. The MR images showed detailed anatomy of the region revealing the cause of the arterial entrapment. Subclassification of the cases were done and fat tissue filling the normal localization of the muscle was evaluated. The DSA and MRA images demonstrated the length and localization of the occluded segment and collateral vascular developments equally. It is concluded that angiographic evaluation alone in PAE syndrome might result in overlooking the underlying cause of the arterial occlusion, which in turn leads to unsuccessful therapy procedures such as balloon angioplasty. Magnetic resonance imaging combined with MR angiography demonstrates both the vascular anatomy and the variations in the muscular structures in the popliteal fossa successfully, and this combination seems to be the most effective way of evaluating young adults with ischemic symptoms suggesting PAE syndrome. (orig.)

MR imaging features of craniodiaphyseal dysplasia

Energy Technology Data Exchange (ETDEWEB)

Marden, Franklin A. [Mallinckrodt Institute of Radiology, Washington University Medical Center, 510 South Kingshighway Blvd., MO 63110, St. Louis (United States); Department of Radiology, St. Louis Children' s Hospital, Children' s Place, MO 63110, St. Louis (United States); Wippold, Franz J. [Mallinckrodt Institute of Radiology, Washington University Medical Center, 510 South Kingshighway Blvd., MO 63110, St. Louis (United States); Department of Radiology, St. Louis Children' s Hospital, Children' s Place, MO 63110, St. Louis (United States); Department of Radiology/Nuclear Medicine, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, MD 20814, Bethesda (United States)

2004-02-01

We report the magnetic resonance (MR) imaging findings in a 4-year-old girl with characteristic radiographic and computed tomography (CT) features of craniodiaphyseal dysplasia. MR imaging exquisitely depicted cranial nerve compression, small foramen magnum, hydrocephalus, and other intracranial complications of this syndrome. A syrinx of the cervical spinal cord was demonstrated. We suggest that MR imaging become a routine component of the evaluation of these patients. (orig.)

Changes of renal blood flow after ESWL: Assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index

Energy Technology Data Exchange (ETDEWEB)

Abd Ellah, Mohamed, E-mail: dr_m_hamdy2006@hotmail.co [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Kremser, Christian, E-mail: christian.kremser@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Pallwein, Leo, E-mail: leo.pallwein-prettner@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Aigner, Friedrich, E-mail: friedrich.Aigner@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Schocke, Michael, E-mail: michael.schocke@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Peschel, Reinhard, E-mail: reinhard.peschel@uki.a [Innsbruck Medical University, Urology Dept., Anich St. 35, 6020 Innsbruck (Austria); Pedross, Florian, E-mail: florian.pedross@i-med.ac.a [Innsbruck Medical University, Medical Statistics Dept., Anich St. 35, 6020 Innsbruck (Austria); Pinggera, Germar-Michael, E-mail: germar.pinggera@uki.a [Innsbruck Medical University, Urology Dept., Anich St. 35, 6020 Innsbruck (Austria); Wolf, Christian, E-mail: christian.wolf@bkh-reutte.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Alsharkawy, Mostafa A.M., E-mail: drmostafamri@yahoo.co [Assiut University, Radiology Dept., Assiut (Egypt); Jaschke, Werner, E-mail: werner.jaschke@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Frauscher, Ferdinand, E-mail: ferdinand.frauscher@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria)

2010-10-15

The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12 h before and 12 h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI (p < 0.001) was found in both treated and untreated kidneys. ASL MR imaging also showed significant changes in both kidneys (p < 0.001). Contrast enhanced dynamic MR imaging did not show significant changes in the kidneys. ESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow.

A 16-channel MR coil for simultaneous PET/MR imaging in breast cancer

International Nuclear Information System (INIS)

Dregely, Isabel; Lanz, Titus; Mueller, Matthias F.; Metz, Stephan; Kuschan, Marika; Nimbalkar, Manoj; Ziegler, Sibylle I.; Nekolla, Stephan G.; Schwaiger, Markus; Bundschuh, Ralph A.; Haase, Axel

2015-01-01

To implement and evaluate a dedicated receiver array coil for simultaneous positron emission tomography/magnetic resonance (PET/MR) imaging in breast cancer. A 16-channel receiver coil design was optimized for simultaneous PET/MR imaging. To assess MR performance, the signal-to-noise ratio, parallel imaging capability and image quality was evaluated in phantoms, volunteers and patients and compared to clinical standard protocols. For PET evaluation, quantitative 18 F-FDG PET images of phantoms and seven patients (14 lesions) were compared to images without the coil. In PET image reconstruction, a CT-based template of the coil was combined with the MR-acquired attenuation correction (AC) map of the phantom/patient. MR image quality was comparable to clinical MR-only examinations. PET evaluation in phantoms showed regionally varying underestimation of the standardised uptake value (SUV; mean 22 %) due to attenuation caused by the coil. This was improved by implementing the CT-based coil template in the AC (<2 % SUV underestimation). Patient data indicated that including the coil in the AC increased the SUV values in the lesions (21 ± 9 %). Using a dedicated PET/MR breast coil, state-of-the-art MRI was possible. In PET, accurate quantification and image homogeneity could be achieved if a CT-template of this coil was included in the AC for PET image reconstruction. (orig.)

MR imaging in hemophilic arthropathy

International Nuclear Information System (INIS)

Baunin, C.; Railhac, J.J.; Younes, I.; Gaubert, J.; DuBoullay, C.; Dirat, G.; Robert, A.

1990-01-01

This paper reports on twenty children with hemophilia examined to determine if MR imaging could be used to assess hemophilic arthropathy. Twenty-eight joints were imaged (17 knees, 10 ankles, 1 elbow) with plain radiography, US, CT, and MR imaging. The results were compared with the surgical view and histologic study of the articular components when synovectomy was done. These results show the usefulness of MR imaging: fluid collections in the joint space were evaluated, and it was possible to distinguish blood from inflammatory fluid. Synovial hypertrophy was appreciated, and findings correlated well with histologic study. Anomalies of articular cartilage, joint-space narrowing, and bone lesions were demonstrated early, when plain radiography findings were still normal

Does MR imaging effectively replace diagnostic arthroscopy

International Nuclear Information System (INIS)

Ruwe, P.; McCarthy, S.; Wright, J.; Randall, L.; Lynch, K.; Jokyl, P.

1990-01-01

This paper determines if MR imaging reduces the number of diagnostic arthroscopic procedures required in patients with knee complaints and if MR imaging is cost-effective compared with diagnostic arthroscopy. The cohort analysis consists of 100 patients seen in a sports medicine clinic by two orthopedic surgeons who agreed on well-defined criteria for performing MR imaging and arthroscopy. Each orthopedic surgeon referring a patient for MR imaging checked a form regarding the plans for arthroscopy. Outcome analysis was conducted at 6 months

MR imaging of recurrent hyperparathyroidism in comparison with other imaging modalities

International Nuclear Information System (INIS)

Auffermann, W.; Thurnher, S.; Okerland, M.; Levin, K.; Gooding, G.W.; Clark, O.H.; Higgins, C.B.

1987-01-01

Thirty patients with recurrent hyperparathyroidism were evaluated with MR imaging, performed using a saddle-shaped surface coil producing 5-mm sections with T1 and T2 weighting. Twenty-six and 22 of these patients also underwent T1-201 scintigraphy and high-resolution US, respectively. MR imaging accurately localized abnormal parathyroid glands in 75% evaluated prospectively and 86% retrospectively. Scintigraphy localized 64% prospectively and 72% retrospectively. US demonstrated 57% prospectively and 67% retrospectively. MR imaging showed three of four mediastinal adenomas evaluated prospectively retrospectively. There were two false-positive studies with MR imaging, two with scintigraphy, and one with US. Thus, MR imaging was the most effective imaging modality for parathyroid localization in recurrent hyperparathyroidism

MR imaging of persistent primitive trigeminal artery

International Nuclear Information System (INIS)

Ashikaga, Ryuichiro; Araki, Yutaka; Ono, Yukihiko; Ishida, Osamu; Mabuchi, Nobuhisa.

1997-01-01

The persistent trigeminal artery is the most common anomaly of the primitive carotid-vertebrobasilar anastomoses. We reviewed MR images and MR angiographies of 11 patients with primitive trigeminal artery. In 8 of the 11 cases, PTA were identified with conventional long TR spin-echo images. In 8 of 11 cases, a hypoplastic basilar trunk associated with PTA was seen on both MR images and MR angiographies. In 7 of 11 cases, a hypoplasia or agenesis of the ipsilateral posterior communicating artery was seen on MR angiographies. (author)

High-field MR imaging of tethered cord

International Nuclear Information System (INIS)

Sigal, R.; Bicetre, L.; Blass, C.; Doyon, D.; Pariente, D.

1986-01-01

MR imaging examinations of 12 patients with tethered cord syndrome have been performed on a 1.5-T MR imaging unit. Patients ranged in age from 3 to 60 years. MR findings were compared with those of myelography and metrizamide CT in all cases. Five patients underwent surgical control and postoperative MR imaging. Sagittal and axial sections were obtained using a spin-echo multisection, multiecho technique. T1-axial weighted images (SE 600/25) were sufficient to locate the position of the tip of the conus. They also allowed identification of extraspinal and intraspinal lipomas and clear-cut demarcation form associated tethered cord. Drawbacks of MR imaging were lack of precise depiction of the bone structures and the fact that clear identification of abnormal roots was problematic. The craniovertebral junction was always checked; two asymptomatic Chiari malformations were visualized. This study leads the authors to conclude that MR imaging should be used as the examination of first choice in the management of tethered cord syndrome

Overhauser-enhanced MR imaging (OMRI)

DEFF Research Database (Denmark)

Golman, K; Leunbach, I; Ardenkjaer-Larsen, JH

1998-01-01

Purpose. To evaluate a new single-electron contrast agent for Overhauser-enhanced MR imaging. The contrast agents that are currently available give enhancement factors that are too low to make the technique a valid option for routine clinical use. Material and Methods. MR images were generated di...

Overhauser-enhanced MR imaging (OMRI)

International Nuclear Information System (INIS)

Golman, K.; Leunbach, I.; Ardenkjaer-Larsen, J.H.; Wistrand, L.G.; Petersson, J.S.; Ehnholm, G.J.; Jaervi, A.; Vahasalo, S.

1998-01-01

Purpose: To evaluate a new single-electron contrast agent for Overhauser-enhanced MR imaging. The contrast agents that are currently available give enhancement factors that are too low to make the technique a valid option for routine clinical use. Material and Methods: MR images were generated directly following the injection of the substance into rats. The MR scanner was operated at a main magnetic field of 0.01 T and equipped with a separate rf-transmitter tuned to the electron paramagnetic resonance frequency of the contrast agent. Results: As expected, the images generated show a high level of enhancement in areas where the contrast agent was present, and a maximum enhancement of 60 times the normal proton signal was obtained in the vascular area. The signal-to-noise ratios in the images were superior to those previously attained. Conclusion: The new contrast agent makes it possible to generate MR images with both morphological and functional information at 0.01 T. The signal-to-noise ratios found in the generated images were of the same order as, or better than, those obtained with the standard clinical routine. (orig.)

Evaluation of Marfan syndrome: MR imaging versus CT

International Nuclear Information System (INIS)

Soulen, R.L.; Fishman, E.K.; Pyeritz, R.E.; Gott, V.L.; Zerhouni, E.A.

1986-01-01

Twenty-five patients with Marfan, syndrome underwent both CT and MR imaging. MR imaging were interpreted in blinded fashion and then compared with CT scans MR imaging was found to be equivalent to CT in the detection of aortic, dural, and hip abnormalities in patients not operated on. MR imaging was superior to CT in the evaluation of postoperative patients because the artifact produced by Bjork-Shirley or St. Jude valves precludes adequate evaluation of the aortic root on CT while producing only a small inferior field distortion (a ''pseudo-ventricular septal defect'') on MR imaging. The absence of radiation exposure is another major advantage of MR imaging in this relatively young population requiring serial studies. The authors conclude that MR imaging is the modality of choice for the evaluation and follow-up of patients with Marfan syndrome and offers an appropriate means of screening their kindred

MR imaging of acute cervical spine injuries

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyu Hwa; Lee, Jung Hyung; Joo, Yang Goo [School of Medicine, Keimyung University, Daegu (Korea, Republic of)

1995-01-15

To describe magnetic resonance (MR) findings of the patients with acute cervical spinal injury and to assess the usefulness of the MR imagings. We retrospectively reviewed the MR images of 32 patients with acute cervical spinal injury. MR images were obtained with a 2.0 T superconductive MR imaging units (Spectro-20000, Gold-Star, Seoul), using spin-echo and gradient-echo technique. Most of patients were in their 3rd-4th decades and motor vehicle accident was the most frequent cause of acute cervical trauma. We assessed the MR findings with respect to the spinal cord, ligaments, paravertebral soft tissues, intervertebral disk, and bony spine. Spinal cord injury was the most common (65%), where cord swelling, edema, and/or hematoma were demonstrated most frequently at C5-6 level. Traumatic intervertebral disk herniations were the second most common (62.5%) and frequently occurred at the lower cervical levels, mostly at C5-6. Paravertebral soft tissue injury, vertebral body fracture, bone marrow edema and displacement were also well shown on MR images. MR imaging appears to be essential for the evaluation of traumatic disk herniations, spinal cord abnormalities, and injury of paravertebral soft tissue in the acute injury of the cervical spine.

MR imaging of acute cervical spine injuries

International Nuclear Information System (INIS)

Kim, Kyu Hwa; Lee, Jung Hyung; Joo, Yang Goo

1995-01-01

To describe magnetic resonance (MR) findings of the patients with acute cervical spinal injury and to assess the usefulness of the MR imagings. We retrospectively reviewed the MR images of 32 patients with acute cervical spinal injury. MR images were obtained with a 2.0 T superconductive MR imaging units (Spectro-20000, Gold-Star, Seoul), using spin-echo and gradient-echo technique. Most of patients were in their 3rd-4th decades and motor vehicle accident was the most frequent cause of acute cervical trauma. We assessed the MR findings with respect to the spinal cord, ligaments, paravertebral soft tissues, intervertebral disk, and bony spine. Spinal cord injury was the most common (65%), where cord swelling, edema, and/or hematoma were demonstrated most frequently at C5-6 level. Traumatic intervertebral disk herniations were the second most common (62.5%) and frequently occurred at the lower cervical levels, mostly at C5-6. Paravertebral soft tissue injury, vertebral body fracture, bone marrow edema and displacement were also well shown on MR images. MR imaging appears to be essential for the evaluation of traumatic disk herniations, spinal cord abnormalities, and injury of paravertebral soft tissue in the acute injury of the cervical spine

Semiautomated spleen volumetry with diffusion-weighted MR imaging.

Science.gov (United States)

Lee, Jeongjin; Kim, Kyoung Won; Lee, Ho; Lee, So Jung; Choi, Sanghyun; Jeong, Woo Kyoung; Kye, Heewon; Song, Gi-Won; Hwang, Shin; Lee, Sung-Gyu

2012-07-01

In this article, we determined the relative accuracy of semiautomated spleen volumetry with diffusion-weighted (DW) MR images compared to standard manual volumetry with DW-MR or CT images. Semiautomated spleen volumetry using simple thresholding followed by 3D and 2D connected component analysis was performed with DW-MR images. Manual spleen volumetry was performed on DW-MR and CT images. In this study, 35 potential live liver donor candidates were included. Semiautomated volumetry results were highly correlated with manual volumetry results using DW-MR (r = 0.99; P volumetry was significantly shorter compared to that of manual volumetry with DW-MR (P volumetry with DW-MR images can be performed rapidly and accurately when compared with standard manual volumetry. Copyright © 2011 Wiley Periodicals, Inc.

Meniscal tear. Diagnostic errors in MR imaging

International Nuclear Information System (INIS)

Barrera, M. C.; Recondo, J. A.; Gervas, C.; Fernandez, E.; Villanua, J. A.M.; Salvador, E.

2003-01-01

To analyze diagnostic discrepancies found between magnetic resonance (MR) and arthroscopy, and the determine the reasons that they occur. Two-hundred and forty-eight MR knee explorations were retrospectively checked. Forty of these showed diagnostic discrepancies between MR and arthroscopy. Two radiologists independently re-analyzed the images from 29 of the 40 studies without knowing which diagnosis had resulted from which of the two techniques. Their interpretations were correlated with the initial MR diagnosis, MR images and arthroscopic results. Initial errors in MR imaging were classified as either unavoidable, interpretive, or secondary to equivocal findings. Eleven MR examinations could not be checked since their corresponding imaging results could not be located. Of 34 errors found in the original diagnoses, 12 (35.5%)were classified as unavoidable, 14 (41.2%) as interpretative and 8 (23.5%) as secondary to equivocal findings. 41.2% of the errors were avoided in the retrospective study probably due to our department having greater experience in interpreting MR images, 25.5% were unavailable even in the retrospective study. A small percentage of diagnostic errors were due to the presence of subtle equivocal findings. (Author) 15 refs

Breast cancer staging with MR imaging

International Nuclear Information System (INIS)

Smathers, R.L.; D'Amelio, F.; Stockdale, F.

1989-01-01

Forty-three patients with biopsy-proved breast cancer underwent MR staging of the cervicothoracic spine, lumbosacral spine, liver, and thorax. In all cases, these findings have been compared with the results of clinical staging, laboratory tests, chest radiography, and radionuclide bone scanning. MR imaging was a valuable staging tool for patients with more than minimal breast cancer and indications for radionuclide bone scanning. MR imaging had the greatest clinical importance when it identified thoracic soft-tissue abnormalities, including axillary., lateral thoracic, supraclavicular, and mediastinal lymphadenopathy. The coronal and sagittal views were very valuable for detection of chest wall invasion, sternal involvement, and internal mammary adenopathy. Negative MR staging clinically reassured patients that aggressive local therapy bad curative potential. Positive MR staging avoided inappropriate aggressive local therapy and mastectomy. MR imaging can be recommended for improved breast cancer staging in patients with newly diagnosed breast cancer who have more than minimal disease

Re-Purposing an OER for the Online Language Course: A Case Study of "Deutsch Interaktiv" by the Deutsche Welle

Science.gov (United States)

Dixon, Edward M.; Hondo, Junko

2014-01-01

This paper will describe pedagogical approaches for re-purposing an open educational resource (OER) designed and produced by the Deutsche Welle. This free online program, "Deutsch Interaktiv," consists of authentic digital videos, slideshows and audio texts and gives a contemporary overview of the culture and language in Germany, Austria…

MR imaging of prostate cancer; MR-Tomographie des Prostatakarzinoms

Energy Technology Data Exchange (ETDEWEB)

Heuck, A.; Scheidler, J.; Sommer, B.; Graser, A. [Radiologisches Zentrum Muenchen-Pasing (Germany); Mueller-Lisse, U.G. [Institut fuer Klinische Radiologie, Universitaet Muenchen (Germany); Massmann, J. [Gemeinschaftspraxis Pathologie, Muenchen (Germany)

2003-06-01

Accurate diagnosis and staging of prostate cancer (PC) is developing into an important health care issue in light of the high incidence of PC and the improvements in stage-adapted therapy. The purpose of this paper is to provide an overview on the current role of MR imaging and MR spectroscopy in the diagnosis and staging of PC.Material and methods Pertinent literature was searched and evaluated to collect information on current clinical indications, study techniques, diagnostic value, and limitations of magnetic resonance imaging and spectroscopy. Major indications for MR imaging of patients with supected PC are to define tumor location before biopsy when clinical or TRUS findings are inconclusive, and to provide accurate staging of histologically proven PC to ascertain effective therapy. Current MR imaging techniques for the evaluation of PC include multiplanar high-resolution T2-weighted FSE and T1-weighted SE sequences using combined endorectal and phased-array coils. Using these techniques, the reported accuracy of MR imaging for the diagnosis of extracapsular tumor extension ranges between 82 and 88% with sensitivities between 80 and 95%, and specificities between 82 and 93%. Typical MR findings of PC in different stages of disease, as well as diagnostic problems, such as chronic prostatitis, biopsy-related hemorrhage and therapy-related changes of prostatic tissue are discussed. In addition, the current perspectives and limitations of MR spectroscopy in PC are summarized. Current MR imaging techniques provide important diagnostic information in the pretherapeutic workup of PC including a high staging accuracy, and is superior to TRUS. (orig.) [German] Der Diagnostik des Prostatakarzinoms kommt wegen seiner hohen Inzidenz und den verbesserten stadienadaptierten Therapiemoeglichkeiten eine grosse Bedeutung zu. Dabei spielen bildgebende Verfahren bei den klinisch oft unzureichend diagnostizierbaren Faellen eine wesentliche Rolle fuer die praetherapeutische

MR Imaging of Articular Hyaline Cartilage

OpenAIRE

Uetani, Masataka

2005-01-01

MR imaging is still an evolving technique for the diagnosis of joint cartilage lesions. Early morphologic changes in the degenerative cartilage are not reliably diagnosed even with use of tailored MR imaging techniques. The detection of the biochemical changes of cartilage or high-resolution MRI will serve as an important tool for the early diagnosis of cartilage degeneration in near future. Further prospective studies are needed to establish the role of MR imaging in clinical use.

Fast FLAIR MR images of intracranial hemorrhage

International Nuclear Information System (INIS)

Chun, Eun Ju; Choi, Hye Young; Cho, Young A; Kim, Wha Young

1998-01-01

The purpose of this study is to evaluate the signal characteristics of intracranial hemorrhage, as seen on fluid attenuated inversion recovery (FLAIR) MR imaging according to various stages, and to compare FLAIR imaging with spin-echo T1- and T2-weighted MR imaging. We retrospectively evaluated fast FLAIR images along with spin-echo T1- and T2 weighted MR images of 32 lesions in 25 patients (12 males and 14 females, aged 3 - 84 yrs) with intracranial hemorrhagic lesions. For imaging, 1.5 T unit was used, and the nature of the lesions was found to be as follows : intracranial hemorrhage (n=15); tumor (n=9); infarction (n=4); arteriovenous malformation (n=3); and arachnoid cyst with hemorrhage (n=1). On the basis of spin-echo MR imaging, lesions were classified as acute, early subacute, late subacute, early chronic, or late chronic stage. The signal characteristics of intracranial hemorrhage were analysed in accordance with each staging, as seen on MR FLAIR imaging, and compared to the staging seen on spin-echo T1- and T-2 weighted MR imaging. The signal intensity of intracranial hemorrhage, as seen on FLAIR imaging, was not characteristic; it was similar to that of T2WI during the acute and subacute stages, and similiar to that of T1WI during the chronic stage. When used together with spin-echo T1- and T2-weighted MR imaging, however, FLAIR imaging may be useful for the classification of chronic intracranial hemorrhage as either early or late stage. (author). 20 refs., 2 tabs., 6 figs

MR imaging of skeletal muscle injury in rabbit : comparison between diffusion and T2-weighted MR images

International Nuclear Information System (INIS)

Kim, Ki Jun; Lee, Sung Yong; Lee, Jae Hee; Kwon Oh Han; Lee, Jae Mun; Lim, Yeon Soo

2000-01-01

The purpose of this study was to apply the diffusion-weighted MR imaging technique to the early detection of skeletal muscle injury and to evaluate the usefulness of this imaging sequence. Thirty rabbits, divided into two groups, were included in this study . Skeletal muscle injury was experimentally induced in the right thigh muscles of each rabbit by clamping with a hemostat for one minute. Four-stage clamping was applied to the rabbits in group I, but for group II there was only one stage. Diffusion and T2-weighted MR images were obtained using a 1.5T MR unit. Serial 5-and 30-minute, and 2-, 24-, and 48- hour delayed images were obtained after injury. The initial time of signal intensity change was recorded and the signal intensities of the injured sites and corresponding normal sites were measured and compared. On 5-minute delayed images in group I, diffusion-weighted MR images showed signal intensity changes in injured muscle in all 15 cases, but on T2-weighted images, change was not detected in three cases. In group II, 5-minute delayed T2-weighted images failed to depict the lesion in six cases, but on diffusion-weighted images, all lesions were detected. In addition, one lesion was not detected on 30-minute delayed T2-weighted images. In group II, the sensitivity of lesion detection was significantly higher on diffusion-weighted than on T2-weighted images (p=3D0.0169). Diffusion-weighted MR imaging was shown to be more sensitive than T2-weighted imaging for the detection of signal intensity changes immediately after artificial injury, especially when this was of a lesser degree. These results suggest that diffusion-weighted MR imaging may be useful for the detection of early stage skeletal muscle injury. (author)

MR imaging of acute subarachnoid hemorrhage

International Nuclear Information System (INIS)

Spickler, E.; Lufkin, R.B.; Frazee, J.; Lylyk, P.; Vinuela, F.; Bentson, J.R.; Dion, J.E.

1987-01-01

Subarachnoid hemorrhage was produced in four Macaca nemestrina monkeys using the technique of Frazee. CT and MR imaging were performed immediately after the procedure and at frequent intervals up to 2 weeks after hemorrhage. The imaging studies were compared with clinical evaluations and pathologic specimens of all animals. Additional human clinical CT/MR studies of subarachnoid hemorrhage were also studied. Acute hemorrhage was recognized on MR as an increase in signal in the region of clot compared with surrounding cerebrospinal fluid. This most likely reflects T1 shortening due to proton binding rather than a pure paramagnetic effect. While CT is sensitive to the hemoglobin protein in acute hemorrhage, the superior resolution of the basal cisterns on MR images results in equal or better definition of acute subarachnoid hemorrhage on MR in many cases

Role of MR imaging in chronic wrist pain

Energy Technology Data Exchange (ETDEWEB)

Zanetti, Marco; Saupe, Nadja [University Hospital Balgrist, Department of Radiology, Zurich (Switzerland); Nagy, Ladislav [University Hospital Balgrist, Department of Orthopedic Surgery, Zurich (Switzerland)

2007-04-15

Magnetic resonance (MR) imaging for chronic wrist pain is challenging. Correct assessment of the triangular fibrocartilage, hyaline cartilage, ligaments, and tendons has become mandatory for comprehensive decision making in wrist surgery. The MR technique, potential and limits of MR imaging in patients with chronic wrist pain will be discussed. MR arthrography with injection of gadolinium-containing contrast material into the distal radioulnar joint is suggested for evaluation of the triangular fibrocartilage. The clinically meaningful ulnar-sided peripheral tears are otherwise hard to diagnose. The diagnostic performance of MR imaging for interosseous ligament tears varies considerably. The sensitivity for scapholunate ligament tears is consistently better than for lunotriquetral ligament tears. Gadolinium-enhanced MR imaging is considered to be the best technique for detecting established avascularity of bone, but the assessment of the MR results remains challenging. Most cases of ulnar impaction syndrome have characteristic focal signal intensity changes in the ulnar aspect of the lunate. Avascular necrosis of the lunate (Kienboeck's disease) is characterized by signal changes starting in the proximal radial aspect of the lunate. MR imaging is extremely sensitive for occult fractures. Questions arise if occult posttraumatic bone lesions seen on MR images only necessarily require the same treatment as fractures evident on plain films or computed tomography (CT) images. MR imaging and ultrasound are equally effective for detecting occult carpal ganglia. Carpe bossu (carpal boss) is a bony protuberance of a carpometacarpal joint II and III which may be associated with pain. (orig.)

Role of MR imaging in chronic wrist pain

International Nuclear Information System (INIS)

Zanetti, Marco; Saupe, Nadja; Nagy, Ladislav

2007-01-01

Magnetic resonance (MR) imaging for chronic wrist pain is challenging. Correct assessment of the triangular fibrocartilage, hyaline cartilage, ligaments, and tendons has become mandatory for comprehensive decision making in wrist surgery. The MR technique, potential and limits of MR imaging in patients with chronic wrist pain will be discussed. MR arthrography with injection of gadolinium-containing contrast material into the distal radioulnar joint is suggested for evaluation of the triangular fibrocartilage. The clinically meaningful ulnar-sided peripheral tears are otherwise hard to diagnose. The diagnostic performance of MR imaging for interosseous ligament tears varies considerably. The sensitivity for scapholunate ligament tears is consistently better than for lunotriquetral ligament tears. Gadolinium-enhanced MR imaging is considered to be the best technique for detecting established avascularity of bone, but the assessment of the MR results remains challenging. Most cases of ulnar impaction syndrome have characteristic focal signal intensity changes in the ulnar aspect of the lunate. Avascular necrosis of the lunate (Kienboeck's disease) is characterized by signal changes starting in the proximal radial aspect of the lunate. MR imaging is extremely sensitive for occult fractures. Questions arise if occult posttraumatic bone lesions seen on MR images only necessarily require the same treatment as fractures evident on plain films or computed tomography (CT) images. MR imaging and ultrasound are equally effective for detecting occult carpal ganglia. Carpe bossu (carpal boss) is a bony protuberance of a carpometacarpal joint II and III which may be associated with pain. (orig.)

MR imaging of sacral and perisacral lesions

International Nuclear Information System (INIS)

Wetzel, L.H.; Levine, E.; Murphey, M.D.

1987-01-01

This exhibit demonstrates the utility of MR imaging in evaluating sacral and perisacral lesions. Thirty-two lesions were studied using a superconducting 1.0-T MR imager. Eleven primary and 13 metastatic tumors, four congenital lesions, and four arachnoid cysts were evaluated. MR did not usually enable a more specific histologic diagnosis than other imaging techniques. However, extraosseous and proximal spinal extent of tumors was well defined without use of oral or intravenous contrast material. MR imaging is an excellent noninvasive technique for evaluating most sacral and perisacral lesions and is particularly helpful when precise tumor extent must be determined for treatment planning

MR imaging of the brain in neurofibromatosis

International Nuclear Information System (INIS)

Kuhn, J.P.; Cohen, M.L.; Duffner, P.K.; Seidel, F.; Harwood-Nash, D.

1986-01-01

Fifteen children and young adults with neurofibromatosis underwent CT and MR imaging (0.5-T superconducting magnet). Seven had optic gliomas and five had other intracranial neoplasms. Before thin-section MR imaging became available, CT was superior for demonstrating the optic nerves, although MR imaging better delineated tumor spread to the optic chiasm and tract. MR imaging was superior for demonstrating other gliomatous lesions associated with neurofibromatosis. Most lesions had long T1 and T2 values and were best seen on T2-weighted images. MR imaging revealed small areas of increased signal intensity on T2-weighted images in nearly half the patients. These lesions were not apparent on CT and were usually located in the globus pallidus, but were seen in many areas of the brain, commonly in the white matter, and in the brain steam and the cerebellar peduncles. Their exact etiology is unknown. Their imaging characteristics are somewhat different from those of gray matter. They may represent hamartomas or areas of glial scarring. Differentiation from a small glioma is presently not possible on a single examination

MR imaging evaluation of diabetic foot

International Nuclear Information System (INIS)

Beltran, J.; Campanini, D.S.; McCalla, M.; Knight, C.T.

1988-01-01

Fourteen diabetic patients with suspected foot infection and/or neuropathic joint were evaluated with MR imaging to identify the presence and extent of infection and also to exclude coexistent infection in the neuropathic joint. Osteomyelitis (n = 8), abscess (n = 7), septic arthritis (n = 4), tenosynovitis (n = 4), and neuropathic joint (n = 5) were diagnosed with MR imaging. Osteomyelitis and/or abscess were excluded by MR findings in 13 instances. Most patients with infection had one more than one site of involvement. Clinical or surgical confirmation of the MR diagnoses was obtained in all but nine of the infection sites or cases of neuropathic joint. Only one false-negative diagnosis of osteomyelitis was made in this series. It is concluded that MR imaging provided accurate information regarding the presence and extent of infection and that this information was decisive in patient management

MR imaging of cerebral abnormalities in utero.

Science.gov (United States)

Thickman, D; Mintz, M; Mennuti, M; Kressel, H Y

1984-12-01

In view of the lack of ionizing radiation, ability to image in a variety of planes, and high contrast resolution, magnetic resonance (MR) imaging may have a role in obstetrical management. Three fetuses with severe cerebral abnormalities were studied by MR in utero. The findings were correlated with ultrasound examinations and with autopsy results. Ventricular dilatation and progression of hydrocephalus were detected by MR. Although fetal motion may affect image quality, diagnostically useful images were obtained with imaging times of 2.5 min.

Reflex sympathetic dystrophy syndrome: MR imaging study

International Nuclear Information System (INIS)

Masciocchi, C.; Fascetti, E.; Bonanni, G.; Calvisi, V.; Buoni, C.; Passariello, R.

1987-01-01

Reflex sympathetic dystrophy syndrome (RSDS) is characterized by pain, swelling, and limitation of motion. The etiology and pathophysiology mechanism have not yet been identified. We considered eight patients with clinical signs of RSDS, in five cases located at the knee joint and in three cases in the hip. In all cases conventional radiography and radionuclide bone scanning were performed before MR imaging. Conventional radiography was negative in three cases while scintigraphy demonstrated the lesion in all patients. MR imaging showed an area of low intensity signal on T1-weighted scans and an increased signal intensity on T2-weighted images. This area is located at the bone marrow and its regular and homogeneous. This specific finding on MR images is due to reflect edema by hyperemia of the bone marrow. The MR imaging diagnosis was confirmed on clinical and radiological follow-up. MR imaging can have a role in the differential diagnosis when other studies are nondiagnostic or nonspecific for RSDS

Zusammenarbeit, Sichtbarkeit, Einbindung und Effizienz : Fallstudie zur Verwendung interaktiver Whiteboards an einem Gymnasium in Deutschland

OpenAIRE

Passey, Donald

2017-01-01

Dieser Bericht bietet einen Überblick über die Ergebnisse einer einjährigen Studie, die an einer deutschen Schule (Gymnasium) in einer Stadt in Nordrhein-Westfalen (NRW) durchgeführt wurde. Während ein Forschungsschwerpunkt auf dem Thema „Zusammenarbeit“ lag, erforderte auch die Planung und Durchführung der Studie gemeinsame Anstrengungen: Die Schule hatte ihren Anteil an der Implementation interaktiver Whiteboards; SMART Technologies stellte Ausrüstung und technische Unterstützung zur Verfüg...

MR imaging and spinal cord injury

International Nuclear Information System (INIS)

Azar-Kia, B.; Fine, M.; Naheedy, M.; Elias, D.

1987-01-01

MR imaging has significantly improved diagnostic capability of spinal cord injuries. Other available diagnostic modalities such as plain films, myelography, CT, and post-CT myelography have failed to consistently show the secific evidence of spinal cord injuries and their true extent. The authors are presenting our experiences with MR imaging in spinal column injury. They have found MR imaging to be the procedure of choice for prognostic evaluation of spinal cord trauma. They are showing examples of recent and old spinal cord injury such as hematomyelia, myelomalacia, transection, spinal cord edema, and cavitation

MR imaging and histopathology of cartilage tumors

Energy Technology Data Exchange (ETDEWEB)

Mizutani, Hirokazu; Ohba, Satoru; Ohtsuka, Takanobu; Matui, Norio; Nakamura, Takaaki (Nagoya City Univ. (Japan). Faculty of Medicine)

1994-05-01

The MR imaging-pathologic correlation of cartilaginous bone tumors and the value of intravenously administered Gd-DTPA enhanced MR imaging was studied. The MR studies were retrospectively reviewed. Thirty-seven cases were examined with 0.5 T and 1.0 T scanner and all cases were pathologically proved. We discussed the following MR findings: signal intensities of tumors, Gd-DTPA features, morphological findings, and associated findings. Hyaline cartilage tumors showed low signal intensity on T[sub 1]-weighted images and very high signal intensity on T[sub 2]-weighted images. Lobulated marginal enhancements were recognized in chondrosarcomas. This may be an important finding to suspect chondrosarcoma. (author).

Sacrococcygeal chordoma: MR imaging in 30 patients

Energy Technology Data Exchange (ETDEWEB)

Sung, Mi Sook; Chung, Myung Hee [Catholic University of Korea, Holy Family Hospital, Department of Radiology, Pucheon (Korea); Lee, Gyung Kyu; Kang, Heung Sik [Seoul National University Hospital, Department of Radiology, Seoul (Korea); Kwon, Soon Tae [Chungnam University Hospital, Department of Radiology, Taejun (Korea); Park, Jin Gyoon [Chunnam University Hospital, Department of Radiology, Kwangju (Korea); Suh, Jin Suk [Yonsei University, Severans Hospital, Department of Radiology, Seoul (Korea); Cho, Gil Ho [Yeungnam University Hospital, Department of Radiology, Taegu (Korea); Lee, Sung Moon [Kaemyung University Hospital, Department of Radiology, Taeku (Korea); Resnick, Donald [VA Medical Center, Department of Radiology, San Diego, CA (United States)

2005-02-01

To evaluate MR imaging of sacrococcygeal chordoma. Thirty patients (age range 22-80 years) underwent MR imaging for the diagnosis and preoperative evaluation of sacrococcygeal chordomas. Eight patients had follow-up MR examination after treatment. The MR images were performed with T1- and T2-weighted imaging, and gadolinium (Gd)-enhanced imaging. The MR images were analyzed for the signal intensity, enhancing pattern, tumor size, growth pattern of the soft tissue component, and tumor extension. T1-weighted images showed low signal masses with foci of high signal intensity in 73% of cases. Tumors enhanced in a variety of patterns after the administration of Gd. Soft tissue masses extending anteriorly were seen in all cases with posterior extension in 77% of cases. The posterior masses involved the surrounding muscles and extended toward the greater sciatic notch, appearing with pseudopodia (87%). Sacroiliac joints were involved in 23% of cases. Four lesions showed intraspinal extension and involvement of the posterior spinal muscles above the level of bony involvement. In 6 patients recurrent tumors were found at or around the surgical margin of the tumor 6 months to 5 years after resection of the sacral tumor. In two of the patients, nodular metastases to the pelvic bones and femur were found 1-4 years after initial examination. In conclusion, MR imaging is useful in the diagnosis and preoperative assessment of sacrococcygeal chordoma. Characteristic findings included sacral mass with heterogeneously high signal intensity with crisscrossing septa on long-repetition-time imaging, well-encapsulated pseudopodia-like or lobulated appearance, and gluteal muscle infiltration. Follow-up MR imaging is helpful to assess for recurrent or metastatic lesions of chordomas. (orig.)

Evaluation of fetal anomalies with MR imaging

International Nuclear Information System (INIS)

Benson, R.C.; Platt, L.D.; Colletti, P.M.; Raval, J.K.; Boswell, W.D. Jr.; Halls, J.M.

1987-01-01

Twenty pregnant women underwent MR imaging (0.5 T) after US disclosed a significant fetal anomaly. The ability of MR imaging to depict the abnormalities was assessed. Of 20 abnormalities, 17 were visualized with MR imaging. Abnormalities included conjoined twins, omphalocele, gastroschisis, hydrocephalus, hydronephrosis, fetal ascites, facial teratoma, anencephaly, bladder outlet obstruction, thanatophoric dwarfism, cystic, hygroma, and fetal ovarian cyst. Thirteen of 14 abnormalities in third-trimester fetuses were visualized, as were four of six abnormalities in second-trimester fetuses. Associated polyhydramnios or oligohydramnios was evident in six of six cases. Anomalies were best delineated with T1-weighted sequences. The study suggests that MR imaging is potentially useful as a complementary imaging modality in the evaluation of fetal anomalies

Fast high-resolution MR imaging using the snapshot-FLASH MR sequence

International Nuclear Information System (INIS)

Matthaei, D.; Haase, A.; Henrich, D.; Duhmke, E.

1990-01-01

Snapshot, fast low-angle short (FLASH) MR imaging using an accelerated FLASH-MR sequence provides MR images with measuring times far below 1 second. The short TE of this sequence prevents susceptibility artifacts in gradient-echo imaging. In this paper variations of the sequence are shown that provide high resolution images with T1-weighted IR, T2-weighted SE, and chemical shift (CHESS) contrast sequences. METHODS AND MATERIALS: A whole-body 2-T system (Bruker-Medizintechnik) were used in combination with a 60-cm gradient system (providing gradient strength of 5 mT/m) to study healthy volunteers. The measuring time for a 256 x 256 image matrix was 800 msec. This sequence has been used in combination with T1-weighted IR, T2-weighted SE, and CHESS variations

MR imaging of pleural and peritoneal effusion

International Nuclear Information System (INIS)

Shiono, Takahiro; Yoshikawa, Kohki; Takenaka, Eiichi; Hisamatsu, Katsuji

1993-01-01

The purpose of this study was to assess the efficacy of MR imaging in predicting the quality of ascites and pleural effusion. MR examinations of 20 patients with different benign or malignant diseases accompanied with ascites or pleural effusion were retrospectively studied. Results were compared with histopathological findings. On T 1 - and T 2 -weighted images, the MR intensity of the effusion depended mainly on the concentration of protein, whereas on gradient echo images, it depended mainly on the concentration of blood. MR examination was useful in non-invasively differentiating exudative or hemorrhagic effusion from serous effusion. Knowledge or inference of the quality of effusion can direct MR interpretation and may improve diagnostic accuracy. (author)

Mr imaging and mr spectroscopy of brain metastases by mr perfusion

International Nuclear Information System (INIS)

Weber, Marc-Andre; Lichy, M.P.; Thilmann, C.; Guenther, M.; Bachert, P.; Delorme, S.; Schad, L.R.; Debus, J.; Schlemmer, H.P.; Maudsley, A.A.

2003-01-01

In follow-up examinations of irradiated brain metastases conventional contrast-enhanced morphological MR imaging is often unable to distinguish between transient radiation effects, radionecrosis, and tumor recurrence. To evaluate changes of relative cerebral blood flow (rCBF) in irradiated brain metastases arterial spin-labeling techniques (ASL) were applied and compared to the outcome of 1 H MR spectroscopy and spectroscopic imaging ( 1 H MRS, SI). Patients and methods In 2 patients follow-up examinations of irradiated brain metastases were performed on a 1.5-T tomograph (average single dose: 20 Gy/80% isodose). Relative CBF values of gray matter (GM), white matter (WM), and metastases (Met) were measured by means of the ASL techniques ITS-FAIR and Q2TIPS. 1 H MRS was performed with PRESS 1500/135. In both patients with initially hyperperfused metastases (Met/GM >1) the reduction of rCBF after stereotactic radiosurgery indicated response to treatment - even if the contrast-enhancing region increased - while increasing rCBF values indicated tumor progression. The findings were confirmed by 1 H MRS, SI and subsequent follow-up. The ASL techniques ITS-FAIR and Q2TIPS are able to monitor changes of rCBF in irradiated brain metastases. The two cases imply a possible role for ASL-MR perfusion imaging and 1 H MR spectroscopy in differentiating radiation effects from tumor progression. (orig.) [de

MR plaque imaging of the carotid artery

International Nuclear Information System (INIS)

Watanabe, Yuji; Nagayama, Masako

2010-01-01

Atherosclerotic carotid plaque represents a major cause of cerebral ischemia. The detection of vulnerable plaque is important for preventing future cardiovascular events. The key factors in advanced plaque that are most likely to lead to patient complications are the condition of the fibrous cap, the size of the necrotic core and hemorrhage, and the extent of inflammatory activity within the plaque. Magnetic resonance (MR) imaging has excellent soft tissue contrast and can allow for a more accurate and objective estimation of carotid wall morphology and plaque composition. Recent advances in MR imaging techniques have permitted serial monitoring of atherosclerotic disease evolution and the identification of intraplaque risk factors for accelerated progression. The purpose of this review article is to review the current state of techniques of carotid wall MR imaging and the characterization of plaque components and surface morphology with MR imaging, and to describe the clinical practice of carotid wall MR imaging for the determination of treatment plan. (orig.)

Dynamic MR imaging in Tolosa-Hunt syndrome

Energy Technology Data Exchange (ETDEWEB)

Haque, Tabassum Laz; Miki, Yukio; Kashii, Satoshi; Yamamoto, Akira; Kanagaki, Mitsunori; Takahashi, Takahiro; Fushimi, Yasutaka; Asato, Reinin; Murase, Nagako; Shibasaki, Hiroshi; Konishi, Junji

2004-09-01

Objective: To evaluate the cavernous sinuses with dynamic magnetic resonance (MR) imaging in patients with Tolosa-Hunt syndrome (THS). Methods: The sellar and parasellar regions of five patients with THS and 12 control subjects were examined with dynamic MR (1.5 T) imaging in the coronal plane. Dynamic images were obtained with spin-echo (SE) sequences in three patients, and with fast spin-echo (FSE) sequences in two patients and control subjects. Conventional MR images of the cranium including sellar and parasellar regions were also obtained on T1-weighted pre- and post-contrast SE, and T2-weighted FSE sequences in the coronal plane. Results: MR images revealed affected cavernous sinus with bulged convex lateral wall in three patients and concave lateral wall in two patients. In all control subjects, cavernous sinuses were observed with concave lateral wall. The signal intensity on T1- and T2-weighted images and contrast enhancement on post-contrast images of the affected cavernous sinuses in patients were similar to those of the unaffected cavernous sinuses in patients and control subjects. The dynamic images in all patients disclosed small areas adjacent to the cranial nerve filling-defects within the enhanced venous spaces of the affected cavernous sinus, which showed slow and gradual enhancement from the early to the late dynamic images. No such gradually enhancing area was observed in control subjects except one. The follow-up dynamic MR images after corticosteroid therapy revealed complete resolution of the gradually enhancing areas in the previously affected cavernous sinus. Conclusion: Dynamic MR imaging may facilitate the diagnosis of THS.

Dynamic MR imaging in Tolosa-Hunt syndrome

International Nuclear Information System (INIS)

Haque, Tabassum Laz; Miki, Yukio; Kashii, Satoshi; Yamamoto, Akira; Kanagaki, Mitsunori; Takahashi, Takahiro; Fushimi, Yasutaka; Asato, Reinin; Murase, Nagako; Shibasaki, Hiroshi; Konishi, Junji

2004-01-01

Objective: To evaluate the cavernous sinuses with dynamic magnetic resonance (MR) imaging in patients with Tolosa-Hunt syndrome (THS). Methods: The sellar and parasellar regions of five patients with THS and 12 control subjects were examined with dynamic MR (1.5 T) imaging in the coronal plane. Dynamic images were obtained with spin-echo (SE) sequences in three patients, and with fast spin-echo (FSE) sequences in two patients and control subjects. Conventional MR images of the cranium including sellar and parasellar regions were also obtained on T1-weighted pre- and post-contrast SE, and T2-weighted FSE sequences in the coronal plane. Results: MR images revealed affected cavernous sinus with bulged convex lateral wall in three patients and concave lateral wall in two patients. In all control subjects, cavernous sinuses were observed with concave lateral wall. The signal intensity on T1- and T2-weighted images and contrast enhancement on post-contrast images of the affected cavernous sinuses in patients were similar to those of the unaffected cavernous sinuses in patients and control subjects. The dynamic images in all patients disclosed small areas adjacent to the cranial nerve filling-defects within the enhanced venous spaces of the affected cavernous sinus, which showed slow and gradual enhancement from the early to the late dynamic images. No such gradually enhancing area was observed in control subjects except one. The follow-up dynamic MR images after corticosteroid therapy revealed complete resolution of the gradually enhancing areas in the previously affected cavernous sinus. Conclusion: Dynamic MR imaging may facilitate the diagnosis of THS

Cardiac MR imaging: Comparison with echocardiography and dynamic CT

International Nuclear Information System (INIS)

Colletti, P.M.; Norris, S.; Raval, J.; Boswell, W.; Lee, K.; Ralls, P.; Haywood, J.; Halls, J.

1986-01-01

The authors compared gated cardiac MR imaging with two-dimensional and Doppler echocardiography and dynamic CT. Gated cardiac MR imaging (VISTA unit, 0.5 T) was performed in 55 patients with a variety of conditions. Accuracy of diagnosis was compared. CT showed arterial, valvular, and pericardial calcifications not seen on MR imaging. Many lesions were seen as well on CT as on MR imaging. Two-dimensional echocardiography was superior in demonstrating wall motion and valvular disease. MR imaging was superior in demonstrating myocardial structures

Intravascular (catheter) MR imaging

International Nuclear Information System (INIS)

Cohen, A.M.; Hurst, G.C.; Katz, D.E.; Dverk, J.L.; Wiesen, E.J.; Czerski, L.W.; Malaya, R.; Bellon, E.M.

1989-01-01

Intravascular MR probes allow excellent spatial resolution and have the potential to detect arterial wall microstructure. Ultrasonic intravascular probes suggest that detailed morphologic information can assist clinical decision making. Catheter MR probes of 2--7 mm outside diameter (OD) were built of copper wire, Teflon, and parts from standard commercial catheters. The probes were connected to the surface coil receiver input of our Picker VISTA 2055HP 1.5-T imaging system. The extant (linear) body coil was used for transmit. Phantoms were constructed of coaxial glass MR tubes, filled with doped water. Watanabe rabbit aorta and human autopsy iliac artery specimens were examined within 4 hours of excision or stored by freezing. In vivo iliac arteries in dogs under general anesthesia were imaged, with percutaneous placement of the probe. Results are presented

Usefulness of perfusion MR imaging in hyperacute ischemic stroke

International Nuclear Information System (INIS)

Park, Ji Hoon; Kim, Jae Hyoung; Shin, Tae Min; Lee, Eun Ja; Chung, Sung Hoon; Choi, Nack Cheon; Lim, Byeong Hoon; Kim, In One

1998-01-01

Perfusion MR imaging is a new technique for the assessment of acute ischemic stroke. The aim of this study was to evaluate the usefulness of this imaging in hyperacute ischemic stroke in comparison with conventional CT and MR imaging. Eight patients presenting the symptoms of acute ischemic stroke due to middle cerebral artery occlusion were included in this study. Within 2 hours of initial CT scan and 6 hours after the onset of stroke, perfusion MR imaging was performed in all patients using a single-section dynamic contrast-enhanced T2*-weighted imager in conjunction with conventional routine MR imaging and MR angiography. Cerebral blood volume (CBV) maps were then obtained from dynamic MR imaging data by using numerical integration techniques. The findings of CBV maps were compared with those of initial and follow-up CT or MR images. The findings of CBV maps were obviously abnormal in all patients, as compared with normal or focal subtle abnormal findings seen on initial CT and MR images. CBV in the occluded arterial territory was lower in all eight patients;two had focal regions of increased CBV within the affected territory, indicating reperfusion hyperemia. In all patients, regions of abnormal CBV were eventually converted to infarctions on follow-up images. Perfusion MR imaging was useful for the evaluation of hemodynamic change occurring during cerebral perfusion in hyperacute ischemic stroke, and prediction of the final extent of infarction. These results suggest that pertusion MR imaging can play an important role in the diagnosis and management of hyperacute ischemic stroke.=20

MR imaging of brachial plexus

International Nuclear Information System (INIS)

Carriero, A.; Ciccotosto, C.; Dragani, M.; Manes, L.; Bonomo, L.

1991-01-01

The brachial plexus is a difficult region to evaluate with radiological techniques. MR imaging has great potentials for the depiction of the various anatomical structures of the branchial plexus - i.e., spinal ganglion, ventral nerve rami root exit of the neural foramina, trunks an cordes. Moreover, MR imaging, thanks to its direct multiplanarity, to its excellent soft-tissue contrast, and to its lack of motion artifacts, allows good evaluation of pathologic conditions in the branchial plexus, especially traumas and cancers. On the contrary CT, in spite of its high spatial resolution and good contrast, cannot demonstrate the anatomical structures of the brachial plexus. US detects superficials structures, and conventional radiographs depict only indirect changes in the adjacent lung apex and skeletal structures. From November 1989 to May 1990, 20 normal volunteers (15 males and 5 females; average age: 35 years) were studied with MR imaging. Multisection technique was employed with a dedicated coil and a primary coil. The anatomical structures of the brachial plexus were clearly demonstrated by T1-weighted sequences on the sagittal and axial planes. T2-weighted pulse sequences on the coronal plane were useful for the anatomical definition of the brachial plexus and for eventual tissue characterization. The correct representation of the anatomical structures of the brachial plexus allowed by MR imaging with author's standard technique makes MR imaging the most appropriate exam for the diagnosis of pathologic conditions in the brachial plexus, although its use must be suggested by specific clinical questions

MR imaging of acoustic neurinoma

International Nuclear Information System (INIS)

Miyamachi, Keikichi; Aida, Toshimitsu; Abe, Hiroshi; Nomura, Mikio; Saitou, Hisatoshi.

1988-01-01

Fifteen cases of acoustic neurinomas were studied by the use of a 0.15 T magnetic resonance (MR) imager. Three of the patients were male, and twelve were female. The patients' ages ranged from 23 to 67 years. The tumors were measured by means of MR images; the maximum was 37.5 mm across, and the minimum, 10 mm. The MR images of the acoustic neurinomas were hypointense on the T 1 -weighted images except in one case (isointense), while all cases were hyperintense on the T 2 -weighted images. MRI was much better than contrastenhanced CT for internal auditory canal (IAC) tumors (78 % versus 36 %), especially by means of coronal oblique image on T 2 -weighted images. In addition, MRI was more useful in demonstrating a VII - VIII neurocomplex on the non-affected side than was CT (57 % versus 10 %), but it did not demonstrate a VII - VIII neurocomplex on the affected side when a 0.15 T MR imager was used. It is very effective to separate the tumor from the tentorium cerebelli when it is necessary to differentiate an acoustic neurinoma from a meningioma at the cerebellopontine angle. A coronal or coronal oblique image offers information for use in separating the tentorium cerebelli. In small IAC tumors, the increased protein content of the cerebro-spinal fluid in an obstructed IAC and the bound-water effect in small collections of fluid may shorten the relaxation times of the trapped intracanalicular fluid, producing difficulty in the ability to diagnosis small tumors. To reveal cystic components, it was found to be effective to use Gd-DTPA or short-TR short-TE spin-echo images. (author)

Brain MR imaging in systemic lupus erythematous

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Park, Hyun Ae; Chang, Kee Hyun; Han, Moon Hee; Lee, Kyung Hwon; Kim, Sung Kwon; Lee, Jung Sang [Seoul National University College of Medicine, Seoul (Korea, Republic of); Cha, Sang Hoon [Chungbuk National University College of Medicine, Chungju (Korea, Republic of)

1992-09-15

To present MR imaging findings of intracranial lesions in systemic lupus erythematosus(SLE), a retrospective study was performed on MR images of 33 SLE patients with neurologic symptoms and signs. MR imaging was performed on either a 0.5 T (21 patients) or 2.0 T unit (12 patients), using T1-weighted, proton-density-weighted, and T2-weighted spin echo sequences in all patients. In seven patients, post-contrast T1-weighted images were also obtained after administration of gadopentetate dimeglumine. The main MR findings consisted of focal lesions suggesting ischemia/infarct (15 patients), diffuse brain atrophy (8), and findings associated with infection (4). The MR findings were normal in 11 patients (33%). The focal lesions suggesting ischemia/infarcts presumably secondary to vasculitis were distributed in the cortex or subcortical white matter (7 patients), deep periventricular white matter (3), or in both areas (5). Most of the focal lesions were multiple and small in size. The findings associated with infection were variable and included communicating hydrocephalus, meningeal enhancement, granuloma, etc. MR findings of SLE were non-specific and therefore clinical correlation is needed when evaluating SLE in MR.

Classification of bones from MR images in torso PET-MR imaging using a statistical shape model

International Nuclear Information System (INIS)

Reza Ay, Mohammad; Akbarzadeh, Afshin; Ahmadian, Alireza; Zaidi, Habib

2014-01-01

There have been exclusive features for hybrid PET/MRI systems in comparison with its PET/CT counterpart in terms of reduction of radiation exposure, improved soft-tissue contrast and truly simultaneous and multi-parametric imaging capabilities. However, quantitative imaging on PET/MR is challenged by attenuation of annihilation photons through their pathway. The correction for photon attenuation requires the availability of patient-specific attenuation map, which accounts for the spatial distribution of attenuation coefficients of biological tissues. However, the lack of information on electron density in the MR signal poses an inherent difficulty to the derivation of the attenuation map from MR images. In other words, the MR signal correlates with proton densities and tissue relaxation properties, rather than with electron density and, as such, it is not directly related to attenuation coefficients. In order to derive the attenuation map from MR images at 511 keV, various strategies have been proposed and implemented on prototype and commercial PET/MR systems. Segmentation-based methods generate an attenuation map by classification of T1-weighted or high resolution Dixon MR sequences followed by assignment of predefined attenuation coefficients to various tissue types. Intensity-based segmentation approaches fail to include bones in the attenuation map since the segmentation of bones from conventional MR sequences is a difficult task. Most MR-guided attenuation correction techniques ignore bones owing to the inherent difficulties associated with bone segmentation unless specialized MR sequences such as ultra-short echo (UTE) sequence are utilized. In this work, we introduce a new technique based on statistical shape modeling to segment bones and generate a four-class attenuation map. Our segmentation approach requires a torso bone shape model based on principle component analysis (PCA). A CT-based training set including clearly segmented bones of the torso region

Early evaluation of irradiated parotid glands with intravoxel incoherent motion MR imaging: correlation with dynamic contrast-enhanced MR imaging

International Nuclear Information System (INIS)

Zhou, Nan; Chu, Chen; Dou, Xin; Li, Ming; Liu, Song; Zhu, Lijing; Liu, Baorui; Guo, Tingting; Chen, Weibo; He, Jian; Yan, Jing; Zhou, Zhengyang; Yang, Xiaofeng; Liu, Tian

2016-01-01

Radiation-induced parotid damage is one of the most common complications in patients with nasopharyngeal carcinoma (NPC) undergoing radiotherapy (RT). Intravoxel incoherent motion (IVIM) magnetic resonance (MR) imaging has been reported for evaluating irradiated parotid damage. However, the changes of IVIM perfusion-related parameters in irradiated parotid glands have not been confirmed by conventional perfusion measurements obtained from dynamic contrast-enhanced (DCE) MR imaging. The purposes of this study were to monitor radiation-induced parotid damage using IVIM and DCE MR imaging and to investigate the correlations between changes of these MR parameters. Eighteen NPC patients underwent bilateral parotid T1-weighted, IVIM and DCE MR imaging pre-RT (2 weeks before RT) and post-RT (4 weeks after RT). Parotid volume; IVIM MR parameters, including apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f); and DCE MR parameters, including maximum relative enhancement (MRE), time to peak (TTP), Wash in Rate, and the degree of xerostomia were recorded. Correlations of parotid MR parameters with mean radiation dose, atrophy rate and xerostomia degree, as well as the relationships between IVIM and DCE MR parameters, were investigated. From pre-RT to post-RT, all of the IVIM and DCE MR parameters increased significantly (p < 0.001 for ADC, D, f, MRE, Wash in Rate; p = 0.024 for D*; p = 0.037 for TTP). Change rates of ADC, f and MRE were negatively correlated with atrophy rate significantly (all p < 0.05). Significant correlations were observed between the change rates of D* and MRE (r = 0.371, p = 0.026) and between the change rates of D* and TTP (r = 0.396, p = 0.017). The intra- and interobserver reproducibility of IVIM and DCE MR parameters was good to excellent (intraclass correlation coefficient, 0.633–0.983). Early radiation-induced changes of parotid glands could be evaluated by IVIM and

Changes of renal blood flow after ESWL: assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index.

Science.gov (United States)

Abd Ellah, Mohamed; Kremser, Christian; Pallwein, Leo; Aigner, Friedrich; Schocke, Michael; Peschel, Reinhard; Pedross, Florian; Pinggera, Germar-Michael; Wolf, Christian; Alsharkawy, Mostafa A M; Jaschke, Werner; Frauscher, Ferdinand

2010-10-01

The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12h before and 12h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI (pESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

Pseudodynamic MR imaging of temporomandibular joint disorders

International Nuclear Information System (INIS)

Nakasato, Tatsuhiko; Ehara, Shigeru

1992-01-01

Magnetic resonance (MR) imaging of the temporomandibular joint (TMJ) has now been established as a procedure of choice in the evaluation of TMJ disorders. In this study, we evaluated the dynamics of TMJ motion on MR imaging, which resembles arthrography. Sixty-eight TMJs in 38 symptomatic patients and one healthy volunteer were examined using pseudodynamic images with gradient echo sequences using a 0.5 Tesla MR unit and 8 cm circular planar surface coil. For depiction of each compartment of the meniscus, the optimum sequence was 200/15/2 (TR/TE/excitations) with 50 deg or 60 deg flip angle in gradient refocused acquisition in steady-state (GRASS) sequences. Three contiguous slices on sagittal MR images were routinely obtained at 14-18 different phases of the opening cycle and displayed in closed-loop cine fashion. Internal derangement was observed in 57% of 68 joints. The most common type was anterior meniscal displacement without reduction. Sideway and rotational displacements, observed in 10% each, were noted on both sagittal multislice images and axial reference images. As a pseudodynamic MR technique, jaw movement specifically designed to check bite procedure to adjust splints is useful for detecting the exact time of meniscal redisplacement on the second click. After conservative therapy for arthrosis, pseudodynamic MR provided information on changes in the meniscus and condylar relationship. Pseudodynamic MR with multiple phases is suitable for evaluating subtle motion abnormality of the meniscus and for post-therapeutic monitoring. (author)

Pseudodynamic MR imaging of temporomandibular joint disorders

Energy Technology Data Exchange (ETDEWEB)

Nakasato, Tatsuhiko; Ehara, Shigeru (Iwate Medical Coll., Morioka (Japan). School of Medicine)

1992-09-01

Magnetic resonance (MR) imaging of the temporomandibular joint (TMJ) has now been established as a procedure of choice in the evaluation of TMJ disorders. In this study, we evaluated the dynamics of TMJ motion on MR imaging, which resembles arthrography. Sixty-eight TMJs in 38 symptomatic patients and one healthy volunteer were examined using pseudodynamic images with gradient echo sequences using a 0.5 Tesla MR unit and 8 cm circular planar surface coil. For depiction of each compartment of the meniscus, the optimum sequence was 200/15/2 (TR/TE/excitations) with 50 deg or 60 deg flip angle in gradient refocused acquisition in steady-state (GRASS) sequences. Three contiguous slices on sagittal MR images were routinely obtained at 14-18 different phases of the opening cycle and displayed in closed-loop cine fashion. Internal derangement was observed in 57% of 68 joints. The most common type was anterior meniscal displacement without reduction. Sideway and rotational displacements, observed in 10% each, were noted on both sagittal multislice images and axial reference images. As a pseudodynamic MR technique, jaw movement specifically designed to check bite procedure to adjust splints is useful for detecting the exact time of meniscal redisplacement on the second click. After conservative therapy for arthrosis, pseudodynamic MR provided information on changes in the meniscus and condylar relationship. Pseudodynamic MR with multiple phases is suitable for evaluating subtle motion abnormality of the meniscus and for post-therapeutic monitoring. (author).

Clinical PET/MR Imaging in Oncology

DEFF Research Database (Denmark)

Kjær, Andreas; Torigian, Drew A.

2016-01-01

. The question, therefore, arises regarding what the future clinical applications of PET/MR imaging will be. In this article, the authors discuss ways in which PET/MR imaging may be used in future applications that justify the added cost, predominantly focusing on oncologic applications. The authors suggest...

Clinical software for MR imaging system, 4

International Nuclear Information System (INIS)

Shimizu, Koji; Kasai, Akira; Okamura, Shoichi

1992-01-01

Magnetic resonance imaging continues to elicit new application software through the recent technological advances of MR equipment. This paper describes several applications of our newly developed clinical software. The fast SE sequence (RISE) has proved to reduce routine examination time and to improve image quality, and ultra-fast FE sequence (SMASH) was found to extend the diagnostic capabilities in the field of cardiac study. Diffusion/perfusion imaging achieved in our MR system showed significant promise for providing novel information regarding tissue characterization. Furthermore, Image quality and practicalities of MR angiography have been improved by advanced imaging sequences and sophisticated post-processing software. (author)

MR imaging of the female urethra

International Nuclear Information System (INIS)

Hricak, H.; Secaf, E.; Buckley, D.; Brown, J.J.; McAninch, J.W.; Tanagho, E.A.

1990-01-01

This paper evaluates the appearance of the female urethra on noncontrast and contrast-enhanced MR images and to evaluate the potential of MR imaging in the diagnosis of various urethral conditions and the staging of urethral tumors. Sixty-four patients (mean age, 54.6 years) were studied. Normal urethra was assessed in 36 patients, and urethral pathology (including urethral diverticula, inflammatory granuloma, and primary and metastatic neoplasms) in 28. MR imaging was performed on a 1.5-T magnet (General Electric Signa). T1-weighted (500/20) and T2-weighted (2,500/80) images were obtained, with a section thickness of 5 mm (20% gap), a 192 x 256 matrix, and two excitations. In 27 patients, T1-weighted images were repeated after intravenous injection of 0.1 mmol/kg of Gd-DTPA

High-field-strength MR imaging of endometriosis

International Nuclear Information System (INIS)

Zawin, M.; McCarthy, S.M.; Comite, F.

1987-01-01

Twelve women with proven endometriosis were evaluated with MR imaging, utilizing a 1.5-T system. Axial and sagittal T1, proton density, and T2-weighted images were acquired. Laparoscopies were performed within a 1-month interval of the study in all cases. MR imaging accurately identified seven endometriomas but missed lesions in two cases. Areas with endometriotic implants were accurately localized five cases. The authors conclude that MR imaging is extremely useful in identifying sites of endometriosis and, therefore, promises to obviate repeated laparoscopies to monitor patients' response to therapy

Gd-DTPA administered MR imaging of intracranial mass lesions

International Nuclear Information System (INIS)

Mihara, Futoshi; Hirakata, Ryosuke; Hasuo, Kanehiro; Yasumori, Kotaro; Yoshida, Kisaku; Kuroiwa, Toshiro; Masuda, Kouji; Fukui, Masashi

1989-01-01

Magnetic resonance (MR) images of 13 intracranial mass lesions taken with the intravenous administration of gadolinium-DTPA were evaluated in comparison with precontrast computed tomography (CT), postcontrast CT, and precontrast MR. In the MR images taken with Gd-DTPA, tumor delineation improved in eight of 13 cases (62%) in comparison with precontrast MR images, and in seven of 13 cases (54%) in comparison with the overall evaluation of precontrast CT, postcontrast CT, and precontrast MR images. Tumor demarcation was unchanged in the remaining cases; no deterioration was observed with Gd-DTPA administration. MR imaging with Gd-DTPA should be performed to better evaluate the extent of intracranial mass lesions and to provide additional information. (author)

MR imaging of chondramalacia patella

International Nuclear Information System (INIS)

Yulish, B.S.; Montanez, J.; Mulopulos, G.P.; Goodfellow, D.; Dollinger, B.; Bryan, P.J.; Modic, M.T.

1986-01-01

Because of its inherent soft-tissue contrast, MR imaging can distinguish hyaline articular cartilage, fibrocartilage, and cortical and medullary bone, and thus seems a method ideally suited to examine the posterior patellar hyaline articular cartilage. The authors studied the knees of people with suspected chondromalacia patella using MR imagine and compared our findings to normal knees and, where available, results of surgery. They find that we can distinguish swollen cartilage, irregular cartilage, absent cartilage, and bony patellar defects. Joint fluid and meniscal injuries could also be identified. MR imaging is a useful method for evaluation of chondromalacia patella and may reduce the need for arthroscopy and arthrography for diagnosis

A typical MR imaging of multiple sclerosis

International Nuclear Information System (INIS)

Katagiri, Shinako; Kan, Shinichi; Ikeda, Toshiaki; Nishiyama, Syougo; Nishimaki, Hiroshi; Matsubayashi, Takashi; Hata, Takashi

1995-01-01

MR imaging is very useful in detecting the intracranial lesion of multiple sclerosis (MS). We present six patients of MS with atypical MR imaging findings. Six patients aged 27-56 years (mean 36 years), and sexuality of six patients were 2 men and 4 females. Three patient's clinical course had episodes of optic neuritis. The plaque's size of the predominant lesion of the patients ranged from 3.0 to 9.0 cm in diameter. The plaques were oval, elliptically and other shaped. At acute stage, MR imaging detected perfocal edema and focal mass effect in three cases of our study. Two out of six cases showed multiple irregularly enhancing lesion with Gadolinium-DTPA. Plaques of all cases did not disappear completely in final MR imaging study. (author)

High-resolution axial MR imaging of tibial stress injuries

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Mammoto Takeo

2012-05-01

Full Text Available Abstract Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries.

High-resolution axial MR imaging of tibial stress injuries

Science.gov (United States)

2012-01-01

Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries. PMID:22574840

MR imaging of articular cartilage; Gelenkknorpel in der MR-Tomographie

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Schaefer, F.K.W.; Muhle, C.; Heller, M.; Brossmann, J. [Kiel Univ. (Germany). Klinik fuer Diagnostische Radiologie

2001-04-01

MR imaging has evolved to the best non-invasive method for the evaluation of articular cartilage. MR imaging helps to understand the structure and physiology of cartilage, and to diagnose cartilage lesions. Numerous studies have shown high accuracy and reliability concerning detection of cartilage lesions and early changes in both structure and biochemistry. High contrast-to-noise ratio and high spatial resolution are essential for analysis of articular cartilage. Fat-suppressed 3D-T{sub 1} weighted gradient echo and T{sub 2}-weighted fast spin echo sequences with or without fat suppression are recommended for clinical routine. In this article the anatomy and pathology of hyaline articular cartilage and the complex imaging characteristics of hyaline cartilage will be discussed. (orig.) [German] Die MR-Tomographie hat sich zur besten nichtinvasiven bildgebenden Methode fuer die Untersuchung von Gelenkknorpel entwickelt. Die MR-Tomographie liefert einen Beitrag zum Verstaendnis der Knorpelstruktur und der Physiologie sowie zur Diagnostik von Knorpelschaeden. Zahlreiche MR-Studien konnten eine hohe Genauigkeit und Zuverlaessigkeit bei der Detektion chondraler Laesionen sowie frueher Veraenderungen struktureller und biochemischer Natur zeigen. Neben einem hohen Kontrast/Rausch-Verhaeltnis ist fuer die Gelenkknorpelanalyse eine hohe raeumliche Aufloesung erforderlich. Im klinischen Routinebetrieb empfehlen sich fuer die Erkennung von Knorpellaesionen besonders fettunterdrueckte 3D-T{sub 1}-gewichtete Gradientenecho- und T{sub 2}-gewichtete Fastspinecho-Sequenzen mit oder ohne Fettunterdrueckung. Die vorliegende Arbeit geht auf die Anatomie und Pathologie des hyalinen Gelenkknorpels ein und diskutiert das komplexe MR-Signalverhalten. (orig.)

A wavelet multiscale denoising algorithm for magnetic resonance (MR) images

International Nuclear Information System (INIS)

Yang, Xiaofeng; Fei, Baowei

2011-01-01

Based on the Radon transform, a wavelet multiscale denoising method is proposed for MR images. The approach explicitly accounts for the Rician nature of MR data. Based on noise statistics we apply the Radon transform to the original MR images and use the Gaussian noise model to process the MR sinogram image. A translation invariant wavelet transform is employed to decompose the MR 'sinogram' into multiscales in order to effectively denoise the images. Based on the nature of Rician noise we estimate noise variance in different scales. For the final denoised sinogram we apply the inverse Radon transform in order to reconstruct the original MR images. Phantom, simulation brain MR images, and human brain MR images were used to validate our method. The experiment results show the superiority of the proposed scheme over the traditional methods. Our method can reduce Rician noise while preserving the key image details and features. The wavelet denoising method can have wide applications in MRI as well as other imaging modalities

3D dynamic pituitary MR imaging with CAIPIRINHA: Initial experience and comparison with 2D dynamic MR imaging

Energy Technology Data Exchange (ETDEWEB)

Fushimi, Yasutaka, E-mail: yfushimi@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8507 (Japan); Okada, Tomohisa; Kanagaki, Mitsunori; Yamamoto, Akira; Kanda, Yumiko; Sakamoto, Ryo [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8507 (Japan); Hojo, Masato; Takahashi, Jun C.; Miyamoto, Susumu [Department of Neurosurgery, Kyoto University Graduate School of Medicine, Kyoto 606-8507 (Japan); Togashi, Kaori [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, Kyoto 606-8507 (Japan)

2014-10-15

Objectives: To evaluate the validity of 3D dynamic pituitary MR imaging with controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA), with special emphasis on demarcation of pituitary posterior lobe and stalk. Methods: Participants comprised 32 patients who underwent dynamic pituitary MR imaging due to pituitary or parasellar lesions. 3D dynamic MR with CAIPIRINHA was performed at 3 T with 20-s-interval, precontrast, 1st to 5th dynamic images. Normalized values and enhanced ratios (dynamic postcontrast image values divided by precontrast ones) were compared between 3D and 2D dynamic MR imaging for patients with visual identification of posterior lobe and stalk. Results: In 3D, stalk was identified in 29 patients and unidentified in 3, and posterior lobe was identified in 28 and unidentified in 4. In 2D, stalk was identified in 26 patients and unidentified in 6 patients, and posterior lobe was identified in 15 and unidentified in 17. Normalized values of pituitary posterior lobe and stalk were higher in 3D than 2D (P < 0.001). No significant difference in enhancement ratio was seen between 3D and 2D. Conclusions: 3D dynamic pituitary MR provided better identification and higher normalized values of pituitary posterior lobe and stalk than 2D.

MR imaging of neonatal cerebral infarction

International Nuclear Information System (INIS)

McArdle, C.B.; Mehta, S.D.; Kulkarni, M.V.; Keeney, S.A.; Hayden, C.K.; Adcock, E.W. III.

1987-01-01

Twenty-six neonatal infarcts were imaged with 0.6 T and 1.5-T magnets and correlated with US and/or CT. Periventricular leukomalacia (PVL) was seen in six cases: lobar infarction, ten cases; global infarction, six cases; and basal ganglia infarction, four cases. MR imaging was superior to US and CT in detecting hemorrhagic PVL and basal ganglia infarcts. MR demonstrates lobar infarcts better than US and CT because of a wider field of view, specificty, and improved gray and white matter differentiation. US underestimates the extent of brain destruction in global infarcts. These results indicate that MR is the single best imaging modality for detecting ischemic brain injury

Modified-BRISQUE as no reference image quality assessment for structural MR images.

Science.gov (United States)

Chow, Li Sze; Rajagopal, Heshalini

2017-11-01

An effective and practical Image Quality Assessment (IQA) model is needed to assess the image quality produced from any new hardware or software in MRI. A highly competitive No Reference - IQA (NR - IQA) model called Blind/Referenceless Image Spatial Quality Evaluator (BRISQUE) initially designed for natural images were modified to evaluate structural MR images. The BRISQUE model measures the image quality by using the locally normalized luminance coefficients, which were used to calculate the image features. The modified-BRISQUE model trained a new regression model using MR image features and Difference Mean Opinion Score (DMOS) from 775 MR images. Two types of benchmarks: objective and subjective assessments were used as performance evaluators for both original and modified-BRISQUE models. There was a high correlation between the modified-BRISQUE with both benchmarks, and they were higher than those for the original BRISQUE. There was a significant percentage improvement in their correlation values. The modified-BRISQUE was statistically better than the original BRISQUE. The modified-BRISQUE model can accurately measure the image quality of MR images. It is a practical NR-IQA model for MR images without using reference images. Copyright © 2017 Elsevier Inc. All rights reserved.

Utility of MR imaging in pediatric spinal cord injury

International Nuclear Information System (INIS)

Felsberg, G.J.; Tien, R.D.; Osumi, A.K.; Cardenas, C.A.

1995-01-01

We evaluated the utility of MR imaging in pediatric patients with acute and subacute spinal cord injuries. MR imaging of 22 pediatric patients with suspected traumatic spinal cord injuries was reviewed. MR findings were correlated with physical examination and compared to available radiographs and CT examinations performed at time of presentation. Twelve patients had abnormalities on MR imaging. Seven had spinal cord contusions; five contusions were hemorrhagic. Five of seven patients with cord contusion had normal radiographs and CT exams. Six patients with normal radiographs and CT examinations had abnormal MR studies revealing cord contusion, ligamentous injury, disc herniation, and epidural hematoma. MR is useful in initial evaluation of pediatric patients with spinal cord injuries and in prognosis of future neurologic function. In the setting of spinal cord symptomatology and negative radiographic studies, MR imaging should be performed. Surgically correctable causes of cord compression demonstrated by MR imaging include disc herniation, epidural hematoma, and retropulsed fracture fragments. The entity of spinal cord injury without radiographic abnormality is a diagnosis of exclusion which should only be made after radiologic investigation with radiographs, high-resolution thin-section CT, and MR imaging. (orig.)

MR imaging of acute transverse myelitis (myelopathy)

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Isoda, Haruo [Hamamatsu Univ., Shizuoka (Japan). School of Medicine; Ramsey, R.G.

1998-05-01

The purpose of our study was to review the MR characteristics of acute transverse myelitis (ATM) retrospectively and to review the literature. The subjects were 26 patients (two males, 24 females). MR examinations were carried out using a 1.5 Tesla scanner. MR imaging in eight of 16 lesions in nine subjects with preexisting MS showed multiple areas of increased signal intensity on T{sub 2}-weighted sagittal images, and 11 lesions had no cord swelling. Twelve of 16 lesions showed heterogeneous enhancement. MR imaging in 10 of 13 lesions in 12 subjects with preexisting HTLV-1 infection, mycoplasma pneumonia infection, hepatitis B vaccinations, and uncertain etiologies revealed fusiform increased signal intensity areas on T{sub 2}-weighted sagittal images and cord swelling. Seven of 11 lesions in the patients who underwent injection of contrast medium showed heterogeneous enhancement, whereas others showed no enhancement. MR examination is recommended for the evaluation of ATM. (author)

A study of artefacts in simultaneous PET and MR imaging using a prototype MR compatible PET scanner

International Nuclear Information System (INIS)

Slates, R.B.; Farahani, K.; Marsden, P.K.; Taylor, J.; Summers, P.E.; Williams, S.; Beech, J.

1999-01-01

We have assessed the possibility of artefacts that can arise in attempting to perform simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) using a small prototype MR compatible PET scanner (McPET). In these experiments, we examine MR images for any major artefacts or loss in image quality due to inhomogeneities in the magnetic field, radiofrequency interference or susceptibility effects caused by operation of the PET system inside the MR scanner. In addition, possible artefacts in the PET images caused by the static and time-varying magnetic fields or radiofrequency interference from the MR system were investigated. Biological tissue and a T 2 -weighted spin echo sequence were used to examine susceptibility artefacts due to components of the McPET scanner (scintillator, optical fibres) situated in the MR field of view. A range of commonly used MR pulse sequences was studied while acquiring PET data to look for possible artefacts in either the PET or MR images. Other than a small loss in signal-to-noise using gradient echo sequences, there was no significant interaction between the two imaging systems. Simultaneous PET and MR imaging of simple phantoms was also carried out in different MR systems with field strengths ranging from 0.2 to 4.7 T. The results of these studies demonstrate that it is possible to acquire PET and MR images simultaneously, without any significant artefacts or loss in image quality, using our prototype MR compatible PET scanner. (author)

Pulmonary functional MR imaging for COPD

International Nuclear Information System (INIS)

Ohno, Yoshiharu

2008-01-01

Chronic obstructive pulmonary disease (COPD) is a slowly progressive disease characterized by airflow limitation, cough, sputum production, and, at later stages, dyspnea. COPD is currently the fourth-leading cause of mortality and the twelfth-leading cause of disability, and by the year 2020 it is expected to be the third-leading cause of death and the fifth-leading cause of disability worldwide. The diagnosis of COPD largely relies on a history of exposure to noxious stimuli and abnormal lung function test results. Since the pathology of COPD varies and the molecular mechanisms are only slightly understood, the diagnosis and stage assessment of COPD have relied on the results of pulmonary function test. In addition, CT and nuclear medicine study are utilized for assessment of regional morphological and functional abnormalities. Recently, pulmonary functional MR imaging is suggested as a new technique for assessment of regional physiopathologic information in various pulmonary diseases including COPD, pulmonary thromboembolism, lung cancer and interstitial lung diseases. This review article covers the brief description of theory and clinical application of contrast-enhanced perfusion MR imaging; hyperpolarized noble gas MR imaging and oxygen-enhanced MR imaging in COPD subjects. We believe that further basic studies as well as clinical applications of this new technique will define the real significance of pulmonary functional MR imaging for the future of pulmonary functional imaging and its usefulness for diagnosis and patients' management in COPD. (author)

Hyperparathyroidism: comparison of MR imaging with radionuclide scanning

International Nuclear Information System (INIS)

Peck, W.W.; Higgins, C.B.; Fisher, M.R.; Ling, M.; Okerlund, M.D.; Clark, O.H.

1987-01-01

Twenty-three patients with hyperparathyroidism were evaluated preoperatively with magnetic resonance (MR) imaging. Twenty patients also underwent thallium-201/technetium-99m scintigraphy. Of 22 patients with primary hyperparathyroidism, 12 had persistent or recurrent disease. One had secondary hyperparathyroidism due to end-stage renal disease. MR imaging allowed accurate localization of abnormal parathyroid glands in 64% evaluated prospectively and 82% evaluated retrospectively. Scintigraphy allowed localization of 60% evaluated prospectively and 70% retrospectively. The two imaging modalities together allowed detection of 68% evaluated prospectively and 91% retrospectively. MR imaging allowed detection of two of five mediastinal adenomas evaluated prospectively and four of five retrospectively. In patients who underwent both imaging studies, MR was more successful in those with previous neck surgery (73% evaluated prospectively and 91% retrospectively) than in those with no prior surgery (57% prospectively and 71% retrospectively). Scintigraphy allowed accurate localization in 64% evaluated prospectively and 64% retrospectively in patients with previous surgery versus 57% prospectively and 86% retrospectively in patients with no prior neck surgery. Four false-positive results were obtained with MR imaging and three with scintigraphy. MR imaging was useful for parathyroid localization in patients with hyperparathyroidism, particularly in patients requiring additional surgery

MR image-guided portal verification for brain treatment field

International Nuclear Information System (INIS)

Yin, F.-F.; Gao, Q.H.; Xie, H.; Nelson, D.F.; Yu, Y.; Kwok, W.E.; Totterman, S.; Schell, M.C.; Rubin, P.

1996-01-01

Purpose/Objective: Although MR images have been extensively used for the treatment planning of radiation therapy of cancers, especially for brain cancers, they are not effectively used for the portal verification due to lack of bone/air information in MR images and geometric distortions. Typically, MR images are utilized through correlation with CT images, and this procedure is usually very labor and time consuming. For many brain cancer patients to be treated using conventional external beam radiation, MR images with proper distortion correction provide sufficient information for treatment planning and dose calculation, and a projection images may be generated for each specific treatment port and to be used as a reference image for treatment verification. The question is how to transfer anatomical features in MR images to the projection image as landmarks which could be correlated automatically to those in the portal image. The goal of this study is to generate digitally reconstructed projection images from MR brain images with some important anatomical features (brain contour, skull and gross tumor) as well as their relative locations to be used as references for the development of computerized portal verification scheme. Materials/Methods: Compared to conventional digital reconstructed radiograph from CT images, generation of digitally reconstructed projection images from MR images is heavily involved with pixel manipulation of MR images to correlate information from two types of images (MR, portal x-ray images) which are produced based on totally different imaging principles. Initially a wavelet based multi-resolution adaptive thresholding method is used to segment the skull slice-by-slice in MR brain axial images, and identified skull pixels are re-assigned to relatively higher intensities so that projection images will have comparable grey-level information as that in typical brain portal images. Both T1- and T2-weighted images are utilized to eliminate fat

Staging of pancreatic ductal adenocarcinoma using dynamic MR imaging

International Nuclear Information System (INIS)

Murakami, Kouji; Nawano, Shigeru; Moriyama, Noriyuki; Sekiguchi, Ryuzou; Satake, Mituo; Iwata, Ryouko; Hayashi, Takayuki; Nemoto, Kazuhisa.

1997-01-01

Single breath-hold gradient echo images were obtained before and immediately after bolus intravenous administration of Gd-DTPA (dynamic MR imaging) in the study of the pancreas. Of 37 patients with pathologically proved pancreatic ductal adenocarcinoma, seventeen patients who underwent both dynamic MR imaging studies and curative surgery were included in this study. Correlations between histologic findings in the resected specimens and MR images were analyzed as to tumor extension and staging according to the General Rules for the Study of Pancreatic Cancer (4th Edition) published by the Japan Pancreas Society. In comparison with conventional MR images, dynamic MR imaging improved the detectability of pancreatic carcinoma and delineation of the vasculature by clarifying the margin of the tumor and the vessels. Nonenhanced T1-weighted imaging is the best sequence to estimate peripancreatic tumor extension, because the contrast between the tumor and peripancreatic fat deteriorates with the use of contrast material. There is a tendency to overestimate vascular invasion on MR images, the reason for which is considered to be the contractive nature of fibrotic change induced by pancreatic carcinoma. The diagnostic efficacy of lymph node metastasis remains insufficient on MR images because some cases show no enlargement of lymph nodes in spite of the existence of pathological metastasis. Our results suggest that dynamic MR imaging has the advantage of improving the conspicuity of the tumor and the vasculature. (author)

Radial MR images of the knee

International Nuclear Information System (INIS)

Hewes, R.C.; Miller, T.R.

1988-01-01

To profile optimally each portion of the meniscus, the authors use the multiangle, multisection feature of a General Electric SIGNA 1.5-T imager to produce radial images centered on each meniscus. A total of 12-15 sections are imaged at 10 0 -15 0 intervals of each meniscus, yielding perpendicular images of the entire meniscus, comparable with the arthrographic tangential views. The authors review their technique and demonstrate correlation cases between the radial gradient recalled acquisition in a steady state sequences, sagittal and coronal MR images, and arthrograms. Radial images should be a routine part of knee MR imaging

Body diffusion-weighted MR imaging of uterine endometrial cancer: Is it helpful in the detection of cancer in nonenhanced MR imaging?

International Nuclear Information System (INIS)

Inada, Yuki; Matsuki, Mitsuru; Nakai, Go; Tatsugami, Fuminari; Tanikake, Masato; Narabayashi, Isamu; Yamada, Takashi; Tsuji, Motomu

2009-01-01

Objective: In this study, the authors discussed the feasibility and value of diffusion-weighted (DW) MR imaging in the detection of uterine endometrial cancer in addition to conventional nonenhanced MR images. Methods and materials: DW images of endometrial cancer in 23 patients were examined by using a 1.5-T MR scanner. This study investigated whether or not DW images offer additional incremental value to conventional nonenhanced MR imaging in comparison with histopathological results. Moreover, the apparent diffusion coefficient (ADC) values were measured in the regions of interest within the endometrial cancer and compared with those of normal endometrium and myometrium in 31 volunteers, leiomyoma in 14 patients and adenomyosis in 10 patients. The Wilcoxon rank sum test was used, with a p -3 mm 2 /s, which was significantly lower than those of the normal endometrium, myometrium, leiomyoma and adenomyosis (p < 0.05). Conclusion: DW imaging can be helpful in the detection of uterine endometrial cancer in nonenhanced MR imaging.

Fundamentals of quantitative dynamic contrast-enhanced MR imaging.

Science.gov (United States)

Paldino, Michael J; Barboriak, Daniel P

2009-05-01

Quantitative analysis of dynamic contrast-enhanced MR imaging (DCE-MR imaging) has the power to provide information regarding physiologic characteristics of the microvasculature and is, therefore, of great potential value to the practice of oncology. In particular, these techniques could have a significant impact on the development of novel anticancer therapies as a promising biomarker of drug activity. Standardization of DCE-MR imaging acquisition and analysis to provide more reproducible measures of tumor vessel physiology is of crucial importance to realize this potential. The purpose of this article is to review the pathophysiologic basis and technical aspects of DCE-MR imaging techniques.

Cine MR imaging of internal derangements of the knee

International Nuclear Information System (INIS)

Niitsu, M.; Anno, I.; Ishikawa, N.; Akisada, M.; Fukubayashi, T.

1990-01-01

This paper assesses internal derangements of the knee joint by a new method of cine MR imaging. Cine MR imaging, involving cine acquisition of kinematic sagittal images during knee movement, was used to evaluate 51 symptomatic patients and 19 healthy subjects. Cine MR images of cruciate ligament fears showed disappearance of low-intensity bundles during knee movement, periodic appearance of joint fluid in the area of the ligament, and irregular tibial movement. Cine MR images of meniscal tears showed independent movement of meniscal fragments and periodic tear opening and closing. Twenty-seven of the 28 anterior cruciate ligament (ACL) tears confirmed arthroscopically were correctly identified with cine MR imaging, with a sensitivity of 96% and a specificity of 92%

Dynamic MR imaging in the musculoskeletal system

International Nuclear Information System (INIS)

Hedlund, L.; Vogler, J.; Utz, J.A.; Herfkens, R.J.; Martinez, S.; Urbaniak, J.; Evans, A.

1986-01-01

Many joint disorders are related to movement, and lack of dynamic imaging has thus far been a limitation of MR imaging. A recently developed dynamic MR imaging technique utilizing a gradient refocused echo (TE = 12 msec, TR = 21 msec) coupled to a physiologic trigger allows dynamic images of the moving joint to be obtained. Controlled joint articulation is produced using an air-driven nonmagnetic device. Imaging of the wrist by this technique demonstrated the dynamic motion of the carpal rows. The method displays cartilage with more sensitivity than does conventional MR imaging; thus, ligamentous and triangular cartilage alignment could be evaluated during motion. In the wrist, potential applications include imaging of carpal instability syndromes, ligamentous interruption, and tears of the triangular cartilage

Pancreatic adenocarcinoma: combination of MR imaging, MR angiography and MR cholangiopancreatography for the diagnosis and assessment of resectability

International Nuclear Information System (INIS)

Catalano, C.; Pavone, P.; Laghi, A.; Panebianco, V.; Scipioni, A.; Fanelli, F.; Brillo, R.; Passariello, R.

1998-01-01

The purpose of this study was to determine the possibility of integrating MR cholangiopancreatography (MRCP) and MR angiography (MRA) to conventional MR images in the diagnosis and assessment of resectability of pancreatic adenocarcinoma. Twenty-three patients with pancreatic adenocarcinoma were prospectively examined with MR. Conventional MR images were acquired in all patients. Three-dimensional MRCP and MRA images were acquired in all patients with suspected biliary and vascular involvement. Acquisition time was less than 45 min in all cases. Images were independently evaluated by two radiologists, with final reading decided by consensus among readers. Diagnosis was confirmed with surgery in 16 patients and with percutaneous biopsy in 7. Concordance among readers was high with a kappa value of 0.83. Pancreatic adenocarcinoma was observed in all patients. Correct assessment of unresectability due to vascular involvement was found in 22 of 23 patients. Biliary obstruction was evident in 13 patients, involving the biliary and pancreatic ducts in 9 and the biliary ducts only in 4. Technical advances permit extensive use of MRI in the evaluation of abdominal pathologies. The combination of MR imaging, MRCP, and MRA can provide sufficient information for the diagnosis and assessment of resectability of pancreatic adenocarcinoma, which otherwise would require three different exams. (orig.)

MR imaging of pineal cysts

International Nuclear Information System (INIS)

Ahn, Yong Sik; Yu, Hyeon; Kim, Wan Tae; Bae, Jin Woo; Moon, Hee Jung; Shin, Hyun Ja

1999-01-01

To evaluate the incidence and characteristic findings of pineal cyst incidentally detected on magnetic resonance (MR) imaging. Brain MR images obtained in 2432 patients were retrospectively reviewed to determine the incidence and MR findings of pineal cysts, which were evaluated according to their size, shape, location, signal intensity, interval change, contrast enhancement and mass effect on adjacent structures. Cysts were encountered in 107(4.4 %) of 2432 patients evaluated. their size ranged from 1 X 1 X 1 to 15 X 8 X 9 (mean, 5.97 X 3.82 X 4.82)mm. All were spherical (n=53) or oval (n=54) in shape. Their margin was smooth and they were homogeneous in nature. On T1-weighted images, the cysts were seen to be hyperintense (n=57) or isointense (n=50) to cerebrospinal fluid, but less so than brain parenchyma. T2-weighted images showed them to be isointense (n=51)or hyperintense (n=56) to cerebrospinal fluid. The cysts were centrally located in 65 cases and eccentrically in 42. Compression of the superior colliculi of the tectum was demonstrated in 17 cases (15.9 %). NO patients presented clinical symptoms or signs related to either pineal or tectal lesions. Peripheral enhancement around the cyst after Gd-DTPA injection was demonstrated in 51 cases(100 %). Follow-up examinations in 19 cases demonstrated no interval change. The incidence of pineal cysts was 4.4 %. The MR characteristics of simple pineal cysts include: (1) an oval or spherical shape, (2) a smooth outer margin and homogeneous nature, (3) isosignal or slightly high signal intensity to cerebrospinal fluid on whole pulse sequences, (4) ring enhancement after contrast injection, (5) an absence of interval change, as seen during follow up MR study. These MR appearances of pineal cysts might be helpful for differentiating them from pineal tumors

A typical MR imaging of multiple sclerosis

Energy Technology Data Exchange (ETDEWEB)

Katagiri, Shinako; Kan, Shinichi; Ikeda, Toshiaki; Nishiyama, Syougo; Nishimaki, Hiroshi; Matsubayashi, Takashi; Hata, Takashi [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine

1995-06-01

MR imaging is very useful in detecting the intracranial lesion of multiple sclerosis (MS). We present six patients of MS with atypical MR imaging findings. Six patients aged 27-56 years (mean 36 years), and sexuality of six patients were 2 men and 4 females. Three patient`s clinical course had episodes of optic neuritis. The plaque`s size of the predominant lesion of the patients ranged from 3.0 to 9.0 cm in diameter. The plaques were oval, elliptically and other shaped. At acute stage, MR imaging detected perfocal edema and focal mass effect in three cases of our study. Two out of six cases showed multiple irregularly enhancing lesion with Gadolinium-DTPA. Plaques of all cases did not disappear completely in final MR imaging study. (author).

MR imaging of abnormal synovial processes

International Nuclear Information System (INIS)

Quinn, S.F.; Sanchez, R.; Murray, W.T.; Silbiger, M.L.; Ogden, J.; Cochran, C.

1987-01-01

MR imaging can directly image abnormal synovium. The authors reviewed over 50 cases with abnormal synovial processes. The abnormalities include Baker cysts, semimembranous bursitis, chronic shoulder bursitis, peroneal tendon ganglion cyst, periarticular abscesses, thickened synovium from rheumatoid and septic arthritis, and synovial hypertrophy secondary to Legg-Calve-Perthes disease. MR imaging has proved invaluable in identifying abnormal synovium, defining the extent and, to a limited degree, characterizing its makeup

MR imaging of phenylketonuria

International Nuclear Information System (INIS)

Hong, Hyun Sook; Kim, Dae Ho; Lee, Hae Kyung; Kwon, Kui Hyang; Choi, Deuk Lin; Lee, Dong Hwan

1997-01-01

The purpose of this study was to evaluate MR findings among patients with phenyl-ketonuria(PKU). Eleven patients with biochemically documented PKU underwent MR imaging;In nine, the typical classic form was seen, and two were atypical. We evaluated signal intensity, the distribution of abnormal signal intensity, the extent of brain atrophy, and possible clinical correlation between IQ scores of the patients and abnormal signal intensity. Varying degrees of symmetrical high signal intensity were noted on T2-weighted sequences in the parietal white matter of six patients;the periventricular deep white matter was most seriously affected, but there was no evidence of brain atrophy. In one advanced case, high signal intensity of both the parietal and frontal lobes was seen on T2-weighted images, and brain atrophy and gyriform enhancement on contrast enhanced T1-weighted images. In five patients, findings were normal. No abnormality was found in the basal ganglia, brain stem or cerebellum. There was no correlation between IQ level and sevrity of high signal intensity. Although MR findings were nonspecific, PKU patients showed symmetrical high signal intensity, predominantly in the peritrigonal region. In the advanced case, the lesion, as seen on T2-weighted images, extended to the periventricular and subcortical white matter.=20

MR imaging of phenylketonuria

Energy Technology Data Exchange (ETDEWEB)

Hong, Hyun Sook; Kim, Dae Ho; Lee, Hae Kyung; Kwon, Kui Hyang; Choi, Deuk Lin; Lee, Dong Hwan [Soonchunhyang Univ. College of Medicine, Seoul (Korea, Republic of)

1997-09-01

The purpose of this study was to evaluate MR findings among patients with phenyl-ketonuria(PKU). Eleven patients with biochemically documented PKU underwent MR imaging;In nine, the typical classic form was seen, and two were atypical. We evaluated signal intensity, the distribution of abnormal signal intensity, the extent of brain atrophy, and possible clinical correlation between IQ scores of the patients and abnormal signal intensity. Varying degrees of symmetrical high signal intensity were noted on T2-weighted sequences in the parietal white matter of six patients;the periventricular deep white matter was most seriously affected, but there was no evidence of brain atrophy. In one advanced case, high signal intensity of both the parietal and frontal lobes was seen on T2-weighted images, and brain atrophy and gyriform enhancement on contrast enhanced T1-weighted images. In five patients, findings were normal. No abnormality was found in the basal ganglia, brain stem or cerebellum. There was no correlation between IQ level and sevrity of high signal intensity. Although MR findings were nonspecific, PKU patients showed symmetrical high signal intensity, predominantly in the peritrigonal region. In the advanced case, the lesion, as seen on T2-weighted images, extended to the periventricular and subcortical white matter.=20.

Evaluation of pelvic floor anatomy with MR imaging

International Nuclear Information System (INIS)

Sato, Y.; Pringle, K.C.; Bergman, R.A.; Yuh, W.T.C.; Smith, W.C.; Franken, E.A. Jr.; Schreiber, A.E.

1987-01-01

MR imaging allows direct diagnostic imaging of the anorectal sphincter. This report reviews the normal anatomy of the musculature of the pelvic floor as demonstrated by MR imaging with emphasis on its relationship to the rectum and anal canal correlating with cadaver dissection. Anatomic landmarks routinely depicted by MR imaging include the levator ani, striated muscle complex, superficial transverse perineal muscle, and the urogenital diaphragm. The following abnormalities of the sphincteric musculature were also studied: hindgut duplication, hypoplasia, both abnormal and normal placement of the rectum after surgical procedures for anorectal anomalies, rectal inflammation, and displacement of the musculature by mass lesions. MR imaging plays an important role for the preoperative and postoperative evaluation of pelvic floor pathology

MR imaging of lipoma and liposarcoma

International Nuclear Information System (INIS)

Einarsdottir, H.; Soederlund, V.; Larson, O.; Jenner, G.; Bauer, H.C.F.

1999-01-01

Purpose: To evaluate whether lipoma, atypical lipomatous tumors, and liposarcomas can be differentiated by MR images. Material and Methods: The MR images of 59 lipomatous lesions and liposarcomas were retrospectively reviewed. Apart from size, surgical site, location and margins, the percentage of fat of the tumor volume was assessed as none, 1-75%, 75-95%, or 95-100%. Results: None of the 18 liposarcomas contained fat that could be recognized by MR imaging. The 3 atypical lipomatous tumors all contained fat but less than 75% of the tumor volume. In 32 of 38 ordinary lipomas, the percentage of fat was 95-100%, and in 4 less than 95% of the tumor volume. Two lipomas did not contain fat that could be recognized by MR imaging. Conclusion: A lesion which predominantly has a fat signal is, in all probability, an ordinary lipoma. Lesions with less fat, but still mostly fatty, may either be lipoma or atypical lipomatous tumor. In this group, the discrimination between these two entities cannot be based upon imaging features. In the absence of a fat signal, liposarcoma or lipoma cannot be differentiated from other soft tissue tumors. (orig.)

Knowledge-based interpretation of cranial MR images

International Nuclear Information System (INIS)

Kuhn, M.H.; Menhardt, W.; Schmidt, K.H.

1987-01-01

A computerized system is described that can be used to evaluate an MR tomogram automatically to support clinical identification of anatomic and pathologic structures and to aid in planning MR measurements. Knowledge from three domains is used for the interpretation of an MR image: nosologic knowledge, knowledge of MR imaging parameters, and anatomic and morphologic knowledge. Nosologic information is used to generate hypotheses about possible pathologies and their locations, based on the signs and symptoms of the patient. With this information, a sequence of interpretation modules, each able to detect substructures in already detected structures with the aid of techniques from image processing, pattern recognition, and artificial intelligence, is generated and executed

Basics concepts and clinical applications of oxygen-enhanced MR imaging

International Nuclear Information System (INIS)

Ohno, Yoshiharu; Hatabu, Hiroto

2007-01-01

Oxygen-enhanced MR imaging is a new technique, and its physiological significance has not yet been fully elucidated. This review article covers (1) the theory of oxygen enhancement and its relationship with respiratory physiology; (2) design for oxygen-enhanced MR imaging sequencing; (3) a basic study of oxygen-enhanced MR imaging in animal models and humans; (4) a clinical study of oxygen-enhanced MR imaging; and (5) a comparison of advantages and disadvantages of this technique with those of hyperpolarized noble gas MR ventilation imaging. Oxygen-enhanced MR imaging provides not only the ventilation-related, but also respiration-related information. Oxygen-enhanced MR imaging has the potential to replace nuclear medicine studies for the identification of regional pulmonary function, and many investigators are now attempting to adapt this technique for routine clinical studies. We believe that further basic studies as well as clinical applications of this new technique will define the real significance of oxygen-enhanced MR imaging for the future of pulmonary functional imaging and its usefulness for diagnostic radiology and pulmonary medicine

Double oblique MR images of the shoulder. Comparison with conventional images

International Nuclear Information System (INIS)

Sasaki, Taisuke; Saito, Yoko; Yodono, Hiraku; Miura, Hiroyuki; Shinohara, Atsushi; Abe, Shuichiro

1998-01-01

Because the scapula is not only slanted on transverse sections but also inclines on sagittal sections, we now perform shoulder MR imaging using double oblique images (DOI), which are planes perpendicular or parallel to the long axis of the scapula obtained with oblique sagittal scout imaging. The purpose of this study was to evaluate the usefulness of double oblique shoulder MR imaging. MR images of shoulders with operatively or arthroscopically proven lesions (20 cases) that had been examined on both conventional images (CI) and DOI were retrospectively reviewed. DOI were compared with CI not only in terms of diagnostic performance but also in their ability to identify the details of shoulder anatomy. All MR studies were done with a shoulder coil on a high-field (1.5 T) unit. Although the accuracy of DOI in diagnosing shoulder disorders such as rotator cuff tear and labrum injury was not as good as that of CI, DOI were better for identifying or discriminating muscles and tendons of the rotator cuff, labralbicipital junction and anterior band of the inferior gleno-humeral ligament, and for recognizing the correct position of the glenoid labrum. MR double oblique imaging of the shoulder provides more detailed information about shoulder anatomy and disorders than conventional imaging. (author)

Detection and staging of chondromalacia patellae: relative efficacies of conventional MR imaging, MR arthrography, and CT arthrography.

Science.gov (United States)

Gagliardi, J A; Chung, E M; Chandnani, V P; Kesling, K L; Christensen, K P; Null, R N; Radvany, M G; Hansen, M F

1994-09-01

Chondromalacia patellae is a condition characterized by softening, fraying, and ulceration of patellar articular cartilage. We compare the sensitivity, specificity, and accuracy of conventional MR imaging, MR arthrography, and CT arthrography in detecting and staging this abnormality. Twenty-seven patients with pain in the anterior part of the knee were prospectively examined with MR imaging, including T1-weighted (650/16), proton density-weighted (2000/20), T2-weighted (2000/80), and spoiled two-dimensional gradient-recalled acquisition in the steady state (SPGR/)/35 degrees (51/10) with fat saturation pulse sequences. All were also examined with T1-weighted MR imaging after intraarticular injection of dilute gadopentetate dimeglumine and with double-contrast CT arthrography. Each imaging technique was evaluated independently by two observers, who reached a consensus interpretation. The signal characteristics of cartilage on MR images and contour abnormalities noted with all imaging techniques were evaluated and graded according to a modification of the classification of Shahriaree. Twenty-six of the 54 facets examined had chondromalacia shown by arthroscopy, which was used as the standard of reference. The sensitivity, specificity, and accuracy of each imaging technique in the diagnosis of each stage of chondromalacia patellae were determined and compared by using the McNemar two-tailed analysis. Arthroscopy showed that 28 facets were normal. Grade 1 chondromalacia patellae was diagnosed only with MR and CT arthrography in two (29%) of seven facets. Intermediate (grade 2 or 3) chondromalacia patellae was detected in two (13%) of 15 facets with T1-weighted and SPGR MR imaging, in three (20%) of 15 facets with proton density-weighted MR imaging, in seven (47%) of 15 facets with T2-weighted MR imaging, in 11 (73%) of 15 facets with CT arthrography, and in 12 (80%) of 15 facets with MR arthrography. Grade 4 was detected in three (75%) of four facets with T1-, proton

MR imaging of knee arthritides

International Nuclear Information System (INIS)

Stoller, D.W.; Genant, H.K.

1987-01-01

T1- and T2-weighted MR images were obtained in five patients with hemophilia, 19 patients with juvenile rheumatoid arthritis, two patients with adult rheumatoid arthritis, four patients with pigmented villonodular synovitis (PVNS), and one patient with lyme arthritis, synovial osteochondromatosis, and Glanzman thrombocytopenia. Pannus formation in synovial hypertrophy imaged low to intermediate in signal intensity on T1- and T2-weighted images. Hemosiderin deposits in PVNS and hemophilia maintained low signal intensity regardless of the pulsing sequence. Early articular erosions and synovitis with irregularity of Hoffa infrapatellar fat pad were detected at an earlier stage and more accurately by MR

MR imaging evaluation of subdural hematomas in child abuse

International Nuclear Information System (INIS)

Hay, T.C.; Rumack, C.M.; Horgan, J.G.; Hyden, P.; Krugman, R.

1988-01-01

MR imaging is the most accurate modality for determining the presence, number, and aging of subdural hematomas. Based on seven patients studied with CT and MR imaging, MR imaging should be the gold standard in child abuse evaluations. Since the history of child abuse is often ambiguous, MR imaging can assist in dating when the injury occurred. MR imaging in two perpendicular planes is needed, with one plane having both T1- and T2-weighted sequences. Chronic subdural hematomas on CT often have the same density as cerebrospinal fluid and may be misdiagnosed as atrophy or unrecognized. Therefore, the child may be returned into a dangerous situation and subjected to recurrent episodes of battering

CT and MR imaging findings of sinonasal angiomatous polyps

Energy Technology Data Exchange (ETDEWEB)

Zou, Jing [Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong (China); Man, Fengyuan [Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing (China); Deng, Kai [Department of Radiology, Qingdao No. 4 People' s Hospital, Qingdao, Shandong (China); Zheng, Yuanyuan [Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong (China); Hao, Dapeng, E-mail: haodp_2009@163.com [Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong (China); Xu, Wenjian, E-mail: cjr.xuwenjian@vip.163.com [Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong (China)

2014-03-15

Objective: To characterize the CT and MR imaging findings of patients with sinonasal angiomatous polyps (SAPs) and evaluate their respective clinical value in the diagnosis of SAP. Methods: CT and MR imaging findings of 15 patients with pathologically proven SAP were examined. Assessed image features included location, size, margin, attenuation, and change of the bony walls of the sinonasal cavity on CT, and signal intensity and enhancement pattern on MR. Results: On CT, the SAP was mostly isoattenuated with patches of slight hyperattenuation. Most lesions caused changes in the adjacent bone, including expansile remodeling (n = 8), defect or destruction (n = 7), and hyperostosis (n = 6). All lesions examined by MR showed heterogeneous isointense signal intensity on T1-weighted images and mixed obvious hyperintense and hypointense signal intensity with linear hypointense septum internally (n = 10), and hypointense peripheral rim on T2-weighted images (n = 10). Postcontrast MR images demonstrated areas of heterogeneous and marked enhancement with an unenhanced hypointense rim and septa (n = 7). Conclusions: CT and MR imaging have respective advantages in the diagnosis of SAP. Combined application of CT and MR examinations is necessary for patients with suspected SAP.

CT and MR imaging findings of sinonasal angiomatous polyps

International Nuclear Information System (INIS)

Zou, Jing; Man, Fengyuan; Deng, Kai; Zheng, Yuanyuan; Hao, Dapeng; Xu, Wenjian

2014-01-01

Objective: To characterize the CT and MR imaging findings of patients with sinonasal angiomatous polyps (SAPs) and evaluate their respective clinical value in the diagnosis of SAP. Methods: CT and MR imaging findings of 15 patients with pathologically proven SAP were examined. Assessed image features included location, size, margin, attenuation, and change of the bony walls of the sinonasal cavity on CT, and signal intensity and enhancement pattern on MR. Results: On CT, the SAP was mostly isoattenuated with patches of slight hyperattenuation. Most lesions caused changes in the adjacent bone, including expansile remodeling (n = 8), defect or destruction (n = 7), and hyperostosis (n = 6). All lesions examined by MR showed heterogeneous isointense signal intensity on T1-weighted images and mixed obvious hyperintense and hypointense signal intensity with linear hypointense septum internally (n = 10), and hypointense peripheral rim on T2-weighted images (n = 10). Postcontrast MR images demonstrated areas of heterogeneous and marked enhancement with an unenhanced hypointense rim and septa (n = 7). Conclusions: CT and MR imaging have respective advantages in the diagnosis of SAP. Combined application of CT and MR examinations is necessary for patients with suspected SAP

MR imaging exploration of the pituitary region

International Nuclear Information System (INIS)

Braun, M.; Roland, J.; Moret, C.; Picard, L.

1992-01-01

MR Imaging has become the procedure of choice for the exploration of the pituitary region. MR contrast resolution is far better than the finest CT examination, especially concerning the microadenomas and the neurohypophysis. The present paper concerns, at first the major principles of magnetic resonance imaging, its application for the study of the pituitary region including the use of contrast agent (Gadolinium). Lastly, MR anatomy and physiological variations are presented

Imaging Human Brain Perfusion with Inhaled Hyperpolarized 129Xe MR Imaging.

Science.gov (United States)

Rao, Madhwesha R; Stewart, Neil J; Griffiths, Paul D; Norquay, Graham; Wild, Jim M

2018-02-01

Purpose To evaluate the feasibility of directly imaging perfusion of human brain tissue by using magnetic resonance (MR) imaging with inhaled hyperpolarized xenon 129 ( 129 Xe). Materials and Methods In vivo imaging with 129 Xe was performed in three healthy participants. The combination of a high-yield spin-exchange optical pumping 129 Xe polarizer, custom-built radiofrequency coils, and an optimized gradient-echo MR imaging protocol was used to achieve signal sensitivity sufficient to directly image hyperpolarized 129 Xe dissolved in the human brain. Conventional T1-weighted proton (hydrogen 1 [ 1 H]) images and perfusion images by using arterial spin labeling were obtained for comparison. Results Images of 129 Xe uptake were obtained with a signal-to-noise ratio of 31 ± 9 and demonstrated structural similarities to the gray matter distribution on conventional T1-weighted 1 H images and to perfusion images from arterial spin labeling. Conclusion Hyperpolarized 129 Xe MR imaging is an injection-free means of imaging the perfusion of cerebral tissue. The proposed method images the uptake of inhaled xenon gas to the extravascular brain tissue compartment across the intact blood-brain barrier. This level of sensitivity is not readily available with contemporary MR imaging methods. © RSNA, 2017.

High-field MR imaging of spinal cord vascular lesions

International Nuclear Information System (INIS)

Blas, C.; Halimi, P.; Sigal, R.; Doyon, D.; Hurth, M.

1986-01-01

MR imaging (1.5T) was performed in 20 patients with spinal cord vascular malformations and hemangioblastomas. MR imaging findings were correlated with data obtained by other imaging modalities (myelography, CT and selective angiography). A diagnosis of vascular legions was suspected or established in 15 patients. Seven had a history of embolization or surgery prior to MR imaging. Six of seven hemangioblastomas were detected on MR imaging. The diagnosis was incorrect in one case because of the small size of the hemangioblastoma nodule, although the cystic part of the lesion was correctly identified. In three cases, the diagnosis was made first on MR imaging and then confirmed on angiography and surgery. Eleven vascular malformations were studied. Malformative thrombosis was found in four of the 11, as suggested by high-intensity signals on T1- and T2-weighted images

Urinary bladder cancer: role of MR imaging.

Science.gov (United States)

Verma, Sadhna; Rajesh, Arumugam; Prasad, Srinivasa R; Gaitonde, Krishnanath; Lall, Chandana G; Mouraviev, Vladimir; Aeron, Gunjan; Bracken, Robert B; Sandrasegaran, Kumaresan

2012-01-01

Urinary bladder cancer is a heterogeneous disease with a variety of pathologic features, cytogenetic characteristics, and natural histories. It is the fourth most common cancer in males and the tenth most common cancer in females. Urinary bladder cancer has a high recurrence rate, necessitating long-term surveillance after initial therapy. Early detection is important, since up to 47% of bladder cancer-related deaths may have been avoided. Conventional computed tomography (CT) and magnetic resonance (MR) imaging are only moderately accurate in the diagnosis and local staging of bladder cancer, with cystoscopy and pathologic staging remaining the standards of reference. However, the role of newer MR imaging sequences (eg, diffusion-weighted imaging) in the diagnosis and local staging of bladder cancer is still evolving. Substantial advances in MR imaging technology have made multiparametric MR imaging a feasible and reasonably accurate technique for the local staging of bladder cancer to optimize treatment. In addition, whole-body CT is the primary imaging technique for the detection of metastases in bladder cancer patients, especially those with disease that invades muscle. © RSNA, 2012.

Ultrasound and MR imaging of diabetic mastopathy

International Nuclear Information System (INIS)

Wong, K.T.; Tse, G.M.K.; Yang, W.T.

2002-01-01

AIM: To review the imaging findings of diabetic mastopathy, and document the colour flow ultrasound and MR imaging features in this benign condition. MATERIALS AND METHODS: Diabetic mastopathy was clinically and histologically diagnosed in eight lesions in six women. All six women underwent conventional mammography and high frequency grey-scale ultrasound. Colour flow ultrasound was performed additionally in six lesions in four women and MR imaging in four lesions in three women before biopsy. The imaging findings were reviewed and correlated with final histological diagnosis. RESULTS: Mammography showed regional asymmetric increased opacity with ill-defined margins in all lesions. A heterogeneously hypoechoic mass with ill-defined margins was identified on high frequency grey-scale ultrasound in all lesions. Marked posterior acoustic shadowing was present in seven of eight (88%) lesions. Six lesions interrogated with colour flow ultrasound showed absence of Doppler signal. MR imaging in three women revealed non-specific stromal enhancement. CONCLUSION: Diabetic mastopathy shows absence of Doppler signal on colour flow ultrasound and non-specific stromal enhancement on MR imaging. Wong K.T. et al. (2002)

Imaging of melorheostosis : emphasis on MR imaging findings

Energy Technology Data Exchange (ETDEWEB)

Lee, Chang Hyon; Lee, Sang Kwon; Kim, Jong Yeol; Shin, Tae Bum; Kim, Young Whan; Pak, Hyo Yong; Kim, Yong Joo; Kang, Duk Sik [College of Medicine, Kyungpook National University, Taegu (Korea, Republic of); Lee, Yeong Hwan [College of Medicine, Catholic University of Taegu-Hyosung, Taegu (Korea, Republic of); Byun, Kyung Hwan [Kumi CHA General Hospital, College of Medicine, Pochon CHA University, Kumi (Korea, Republic of)

2000-02-01

To evaluate the usefulness of various radiographic imaging modalities in the diagnosis and characterization of melorheostosis. We retrospectively evaluated the plain film (n=3D8), computed tomographic (CT) imaging (n=3D5) and magnetic resonance (MR) imaging (n=3D5) findings of eight patients with melorheostosis diagnosed by bone biopsy (n=3D4) and characteristic radiographic findings (n=3D8). MR images were obtained with a 1.5-T scanner focused on the region of maximal radiographic abnormality. Pulse sequences include T1-weighted SE. T2-weighted fast SE (n=3D5) and postcontrast imaging (n=3D4). In order to define subtle enhancement of the lesions, subtraction MR images were obtained in one case. Imaging findings were analyzed with particular emphasis on the distribution lesions along the sclerotome, differential radiographic findings between diaphyseal and metaepiphyseal lesions of the long bones, as seen on plain radiographs, and the density and signal characteristics of hyperostotic lesions, as seen on CT and MR images. Characteristic distribution along the sclerotome was identified in five of eight cases mainly along C6 and 7 (n=3D2) and L3, 4 and 5 (n=3D3) sclerotomes. In diaphyseal melorherostosis (8/8), a characteristic finding, i.e., a wax flowing down from the candle, was identified on plain radiographs. In all three patients with metaepiphyseal melorheostosis (3/8), multiple round or oval hyperostotic lesions were seen in the epipysis and metaphysis of the long bones. On CT, the marrow cavity was partly obliterated by hyperostotic lesions in all five patients with endosteal hyperostosis. Among these, central ground glass opacity with a sclerotic rim was seen in three patients. Periosteal hyperostosis was seen in two of five cases, being visualized as irregular excrescence in the periosteal region and surrounding soft tissue. Individual hyperostosis was visualized as hypointense on T1-weighted images and as a hyperintense center with a surrounding

Dedicated extremity MR imaging of the foot and ankle

International Nuclear Information System (INIS)

Hottya, G.A.; Peterfy, C.G.; Uffmann, M.; Haeckl, F.O.; LeHir, P.; Redei, J.; Gindele, A.U.; Dion, E.; Genant, H.K.

2000-01-01

The purpose of this review is to provide illustrative examples of diseases of the foot and ankle when imaged with a low-field MR imaging system. A retrospective review of 268 foot and ankle examinations, performed in our institution within the past 3 years with a 0.2-T (Artoscan Esaote, Genoa, Italy) dedicated extremity MR system was done. Additionally, illustrative comparison with conventional radiography and high-field MR imaging is presented in patients in whom these examinations were also performed. Although motion artifact limited the value of a few studies, in the majority of examinations low-field MR imaging provided diagnostic image quality for the full spectrum of disorders affecting the foot and ankle and seemed to be a feasible alternative to high-field MR imaging in establishing an accurate diagnosis. (orig.)

MR imaging of colorectal carcinomas using an MR endoscopic coil

International Nuclear Information System (INIS)

Murano, Akihiko; Kido, Choichiro; Sasaki, Fumio; Nakamura, Tsuneya; Kobayashi, Semi; Katoh, Tomoyuki; Hirai, Takashi

1994-01-01

Diagnosis of the depth of wall invasion by rectal carcinoma using MR endoscopy was performed in ten resected specimens, including five rectal carcinomas, three colon carcinomas, two normal gastric wall. In addition, the gastric wall of a pig was examined. MR imaging was done with a 1.5-T Signa Advantage (GE Medical System) system, with the surface coil of the MR endoscope acting as the receiver coil. Five layers could be distinguished in the bowel wall: mucosa, submucosa and muscularis propria divided into circular muscle, longitudinal muscle and intervening connective tissue. Tumors had almost the same signal intensity as muscle. The MR images of colon carcinomas, rectal carcinomas, and extrinsically metastatic involvement of the sigmoid colon by rectal carcinoma all correlated well with the pathological findings. The normal structure of the gastric wall was similar to that of the colon. 3D-fast Spoiled Grass (SPGR) sequence has a fairly short scanning time. Thus, the possibility of precise clinical diagnosis by this method was suggested. (author)

First MR images obtained during megavoltage photon irradiation from a prototype integrated linac-MR system

International Nuclear Information System (INIS)

Fallone, B. G.; Murray, B.; Rathee, S.; Stanescu, T.; Steciw, S.; Vidakovic, S.; Blosser, E.; Tymofichuk, D.

2009-01-01

The authors report the first magnetic resonance (MR) images produced by their prototype MR system integrated with a radiation therapy source. The prototype consists of a 6 MV linac mounted onto the open end of a biplanar 0.2 T permanent MR system which has 27.9 cm pole-to-pole opening with flat gradients (40 mT/m) running under a TMX NRC console. The distance from the magnet isocenter to the linac target is 80 cm. The authors' design has resolved the mutual interferences between the two devices such that the MR magnetic field does not interfere with the trajectory of the electron in the linac waveguide, and the radiofrequency (RF) signals from each system do not interfere with the operation of the other system. Magnetic and RF shielding calculations were performed and confirmed with appropriate measurements. The prototype is currently on a fixed gantry; however, in the very near future, the linac and MR magnet will rotate in unison such that the linac is always aimed through the opening in the biplanar magnet. MR imaging was found to be fully operational during linac irradiation and proven by imaging a phantom with conventional gradient echo sequences. Except for small changes in SNR, MR images produced during irradiation were visually and quantitatively very similar to those taken with the linac turned off. This prototype system provides proof of concept that the design has decreased the mutual interferences sufficiently to allow the development of real-time MR-guided radiotherapy. Low field-strength systems (0.2-0.5 T) have been used clinically as diagnostic tools. The task of the linac-MR system is, however, to provide MR guidance to the radiotherapy beam. Therefore, the 0.2 T field strength would provide adequate image quality for this purpose and, with the addition of fast imaging techniques, has the potential to provide 4D soft-tissue visualization not presently available in image-guided radiotherapy systems. The authors' initial design incorporates a

Quality evaluation of no-reference MR images using multidirectional filters and image statistics.

Science.gov (United States)

Jang, Jinseong; Bang, Kihun; Jang, Hanbyol; Hwang, Dosik

2018-09-01

This study aimed to develop a fully automatic, no-reference image-quality assessment (IQA) method for MR images. New quality-aware features were obtained by applying multidirectional filters to MR images and examining the feature statistics. A histogram of these features was then fitted to a generalized Gaussian distribution function for which the shape parameters yielded different values depending on the type of distortion in the MR image. Standard feature statistics were established through a training process based on high-quality MR images without distortion. Subsequently, the feature statistics of a test MR image were calculated and compared with the standards. The quality score was calculated as the difference between the shape parameters of the test image and the undistorted standard images. The proposed IQA method showed a >0.99 correlation with the conventional full-reference assessment methods; accordingly, this proposed method yielded the best performance among no-reference IQA methods for images containing six types of synthetic, MR-specific distortions. In addition, for authentically distorted images, the proposed method yielded the highest correlation with subjective assessments by human observers, thus demonstrating its superior performance over other no-reference IQAs. Our proposed IQA was designed to consider MR-specific features and outperformed other no-reference IQAs designed mainly for photographic images. Magn Reson Med 80:914-924, 2018. © 2018 International Society for Magnetic Resonance in Medicine. © 2018 International Society for Magnetic Resonance in Medicine.

Chondromalacia patellae: fat-suppressed MR imaging.

Science.gov (United States)

Rose, P M; Demlow, T A; Szumowski, J; Quinn, S F

1994-11-01

To evaluate the accuracy of fat-suppressed magnetic resonance (MR) imaging in diagnosing chondromalacia patellae. Seventy-one patients underwent fat-suppressed MR imaging and arthroscopy of the patellofemoral compartment. Findings were classified as early or advanced chondromalacia or as normal and were correlated with arthroscopic findings. Early and advanced stages of chondromalacia patellae were reliably detected, with positive predictive values of 85% and 92%, respectively. Specificity in early stages was 94% and in late stages was 98%. However, the overall accuracies did not differ substantially from those reported in studies that did not use fat-suppressed imaging. Axial, fat-suppressed MR imaging accurately depicts changes caused by chondromalacia patellae. Early stages can be seen as intrasubstance changes of increased signal intensity. Results of this study suggest a high degree of specificity in excluding both early and advanced changes.

MR imaging findings of hypertrophic olivary degeneration

Energy Technology Data Exchange (ETDEWEB)

Kim, Do Joong; Jeon, Pyung; Kim, Dong Ik [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

1997-06-01

To describe the magnetic resonance (MR) imaging findings of hypertrophic olivary degeneration (HOD) MR images of seven patients with HOD were retrospectively reviewed. Two were women and five were men, and they were aged between 48 and 65 (mean 58) years. Imaging examinations were performed with a 1.5-T unit, and the findings were used to evaluate the size and signal intensity of olivary lesions. The time interval from hemorrhagic ictus to MR imaging was between two and 30 months. Follow-up examinations were performed in two patients. All four patients with hemorrhages involving the central tegmental tract in the pons or midbrain showed ipsilateral HOD. Among these four, bilateral HOD was seen in one patient with hemorrhage involving the bilateral central tegmental tract, and in another with tegmental hemorrhage extending to the ipsilateral superior cerebellar peduncle. One patient with cerebellar hemorrhage involving the dentate nucleus had contralateral HOD. Two patients with multiple hemorrhages involving both the pons and cerebellum showed bilateral HOD. Axial MR images showed mild enlargement of the involved olivary mucleus, with high signal intensity on both proton density and T2 weighted images. There was no apparent enhancement on postcontrast T1-weighted images. MR imaging can clearly distinguish secondary olivary degeneration from underlying pathology involving the central tegmental tract in the pons or midbrain and cerebellum. These olivary abnormalities should not, however, be mistaken for primary medullary lesions.

MR imaging findings of hypertrophic olivary degeneration

International Nuclear Information System (INIS)

Kim, Do Joong; Jeon, Pyung; Kim, Dong Ik

1997-01-01

To describe the magnetic resonance (MR) imaging findings of hypertrophic olivary degeneration (HOD) MR images of seven patients with HOD were retrospectively reviewed. Two were women and five were men, and they were aged between 48 and 65 (mean 58) years. Imaging examinations were performed with a 1.5-T unit, and the findings were used to evaluate the size and signal intensity of olivary lesions. The time interval from hemorrhagic ictus to MR imaging was between two and 30 months. Follow-up examinations were performed in two patients. All four patients with hemorrhages involving the central tegmental tract in the pons or midbrain showed ipsilateral HOD. Among these four, bilateral HOD was seen in one patient with hemorrhage involving the bilateral central tegmental tract, and in another with tegmental hemorrhage extending to the ipsilateral superior cerebellar peduncle. One patient with cerebellar hemorrhage involving the dentate nucleus had contralateral HOD. Two patients with multiple hemorrhages involving both the pons and cerebellum showed bilateral HOD. Axial MR images showed mild enlargement of the involved olivary mucleus, with high signal intensity on both proton density and T2 weighted images. There was no apparent enhancement on postcontrast T1-weighted images. MR imaging can clearly distinguish secondary olivary degeneration from underlying pathology involving the central tegmental tract in the pons or midbrain and cerebellum. These olivary abnormalities should not, however, be mistaken for primary medullary lesions

MR imaging of muscle injuries; MRT von Muskelverletzungen

Energy Technology Data Exchange (ETDEWEB)

Woertler, Klaus [Technische Univ. Muenchen, Klinikum rechts der Isar (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie

2014-12-15

Injuries to skeletal muscle are very common particularly in athletes. Besides ultrasound, MR imaging represents the most valuable imaging modality for diagnosis and grading of muscle lesions. This article reviews the examination technique and diagnostic criteria of acute and chronic lesions of skeletal muscle at MR imaging. In addition to the morphology of direct and indirect muscle injuries, MR findings in myositis ossificans and compartment syndrome are discussed as well.

MR imaging of syringoperitoneal and syringosubarachnoid shunts

International Nuclear Information System (INIS)

Hasso, A.N.; Kucharczyk, W.; Mall, J.C.; Colombo, N.; Newton, T.H.; Norman, D.

1986-01-01

The authors utilized MR imaging for the evaluation of syringohydromelic shunt procedures in 16 patients. Four characteristic MR imaging findings were seen: ''tethering'' of the spinal cord posteriorly at the site of laminectomy and placement of the shunt tube distortion of the usual elliptical shape of the spinal cord at the site of the shunt, a ''snake-eyes'' appearance of the cord on transverse images which corresponded to the position of the shunt within or next to a collapsed syringohydromelic cavity, and a generous amount of subachnoid space surrounding the collapsed portion of the cavity. Occasionally the shunt could not be visualized on sagittal images but could be seen on transverse images. In the majority of cases, the MR imaging findings were sufficiently characteristic to warrant accurate diagnosis

MR imaging of acute hemorrhagic brain infarction

International Nuclear Information System (INIS)

Uchino, Akira; Ohnari, Norihiro; Ohno, Masato

1989-01-01

Six patients with acute hemorrhagic brain infarct were imaged using spin-echo (SE) pulse sequences on a 1.5 Tesla MR scanner. Including two patients with repeated MR imaging, a total of eight examinations, all performed within 15 days after stroke, were analyzed retrospectively. Four patients revealed massive hemorrhages in the basal ganglia or cerebellum and three cases demonstrated multiple linear hemorrhages in the cerebral cortex. On T1-weighted images, hemorrhages were either mildly or definitely hyperintense relative to gray matter, while varied from mildly hypointense to hyperintense on T2-weighted images. T1-weighted images were superior to T2-weighted images in detection of hemorrhgage. CT failed to detect hemorrhage in two of five cases: indicative of MR superiority to CT in the diagnosis of acute hemorrhagic infarcts. (author)

MR imaging of chronic alcoholism

Energy Technology Data Exchange (ETDEWEB)

Hayakawa, K.; Kumagai, H.; Suzuki, Y.; Furusawa, N.; Haga, T.; Hoshi, T.; Fujiwara, Y.; Yamaguchi, K. (Kyoto City Hospital (Japan). Dept. of Radiology Consultant Radiologists of Wakamiya Hospital (Japan) Wakamiya Hospital (Japan). Depts. of Psychiatry and Radiology Yamagata Univ. School of Medicine (Japan). Dept. of Radiology)

1992-05-01

We evaluated the brain lesions of patients with chronic alcoholism in comparison with age-and sex-matched controls by MR imaging. T1-weighted sagittal and axial images and T2-weighted axial images were obtained with a 0.5 T superconducting MR unit. Various brain measurements were then performed, and the presence of regions of abnormal signal intensity was also compared between the two groups. The brain measurements revealed significant cerebral atrophy as well as significant cerebellar atrophy in the alcoholic group. These changes were more prominent in patients in their fifties and sixties than in those aged in the thirties and forties. Focal hypointense lesions were observed in 20.6% of the alcoholics and in 5% of the controls, while focal hyperintense lesions were observed in 61.8% of the alcoholics and in 20% of the controls. The severity of the MR findings correlated well with the age of the patients. These observations suggest that alcohol is an important promotor of brain aging. (orig.).

MR imaging of medullary compression due to vertebral metastases

International Nuclear Information System (INIS)

Dooms, G.C.; Mathurin, P.; Maldague, B.; Cornelis, G.; Malghem, J.; Demeure, R.

1987-01-01

A prospective study was performed to assess the value of MR imaging for demonstrating medullary compression due to vertebral metastases in cancer patients clinically suspected of presenting with that complication. Twenty-five consecutive unselected patients were studied, and the MR imaging findings were confirmed by myelography, CT, and/or surgical and autopsy findings for each patient. The MR examinations were performed with a superconducting magnet (Philips Gyroscan S15) operating at 0.5-T. MR imaging demonstrated the metastases (single or multiple) mainly on T1- weighted images (TR = 0.45 sec and TE = 20 msec). Soft-tissue tumoral mass and/or deformity of a vertebral body secondary to metastasis, compressing the spinal cord, was equally demonstrated on T1- and heavily T2-weighted images (TR = 1.65 sec and TE = 100 msec). In the sagittal plane, MR imaging demonstrated the exact level of the compression (one or multiple levels) and its full extent. In conclusion, MR is the first imaging modality for studying cancer patients with clinically suspected medullary compression and obviates the need for more invasive procedures

Motion correction in simultaneous PET/MR brain imaging using sparsely sampled MR navigators

DEFF Research Database (Denmark)

Keller, Sune H; Hansen, Casper; Hansen, Christian

2015-01-01

BACKGROUND: We present a study performing motion correction (MC) of PET using MR navigators sampled between other protocolled MR sequences during simultaneous PET/MR brain scanning with the purpose of evaluating its clinical feasibility and the potential improvement of image quality. FINDINGS......: Twenty-nine human subjects had a 30-min [(11)C]-PiB PET scan with simultaneous MR including 3D navigators sampled at six time points, which were used to correct the PET image for rigid head motion. Five subjects with motion greater than 4 mm were reconstructed into six frames (one for each navigator...

Diffusion-weighted MR imaging in biopsy-proven Creutzfeldt-Jakob disease

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyo Cheol; Chang, Kee Hyun; Song In Chan; Lee, Sang Hyun; Kwon, Bae Ju; Han, Moon Hee; Kim, Sang Yun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

2001-12-01

To compare conventional and diffusion-weighted MR imaging in terms of their depiction of the abnormalities occurring in Creutzfeldt-Jakob disease. We retrospectively analyzed the findings of conventional (T2-weighted and fluid-attenuated inversion recovery) and diffusion-weighted MR imaging in four patients with biopsy-proven Creutzfeldt-Jakob disease. The signal intensity of the lesion was classified by visual assessment as markedly high, slightly high, or isointense, relative to normal brain parenchyma. Both conventional and diffusion-weighted MR images demonstrated bilateral high signal intensity in the basal ganglia in all four patients. Cortical lesions were observed on diffusion-weighted MR images in all four, and on fluidattenuated inversion recovery MR images in one, but in no patient on T2-weighted images. Conventional MR images showed slightly high signal intensity in all lesions, while diffusion-weighted images showed markedly high signal intensity in most. Diffusion-weighted MR imaging is more sensitive than its conventional counterpart in the depiction of Creutzfeldt-Jakob disease, and permits better detection of the lesion in both the cerebral cortices and basal ganglia.

Diffusion-weighted MR imaging in biopsy-proven Creutzfeldt-Jakob disease

International Nuclear Information System (INIS)

Kim, Hyo Cheol; Chang, Kee Hyun; Song In Chan; Lee, Sang Hyun; Kwon, Bae Ju; Han, Moon Hee; Kim, Sang Yun

2001-01-01

To compare conventional and diffusion-weighted MR imaging in terms of their depiction of the abnormalities occurring in Creutzfeldt-Jakob disease. We retrospectively analyzed the findings of conventional (T2-weighted and fluid-attenuated inversion recovery) and diffusion-weighted MR imaging in four patients with biopsy-proven Creutzfeldt-Jakob disease. The signal intensity of the lesion was classified by visual assessment as markedly high, slightly high, or isointense, relative to normal brain parenchyma. Both conventional and diffusion-weighted MR images demonstrated bilateral high signal intensity in the basal ganglia in all four patients. Cortical lesions were observed on diffusion-weighted MR images in all four, and on fluidattenuated inversion recovery MR images in one, but in no patient on T2-weighted images. Conventional MR images showed slightly high signal intensity in all lesions, while diffusion-weighted images showed markedly high signal intensity in most. Diffusion-weighted MR imaging is more sensitive than its conventional counterpart in the depiction of Creutzfeldt-Jakob disease, and permits better detection of the lesion in both the cerebral cortices and basal ganglia

Correlation of angiography and MR imaging in cerebral vasculitis

International Nuclear Information System (INIS)

Cloft, H.J.; Phillips, C.D.; Dix, J.E.; McNulty, B.C.; Kallmes, D.F.; Zagardo, M.T.

1999-01-01

Purpose: MR imaging and cerebral angiography were correlated in patients with primary angiitis of the central nervous system (PACNS) to assess the relative roles of these imaging modalities in the diagnosis. Material and Methods: In 9 patients, MR imaging and angiography were compared with regard to the relative involvement of each major vascular territory. Vascular territories assessed were the anterior, middle, and posterior cerebral arteries, and the posterior fossa. Results: All patients had angiographic findings consistent with vasculitis in multiple vascular territories. MR findings ranged from normal to diffusely abnormal. One patient had a completely normal MR investigation. Of 50 territories affected by vasculitis on angiography, 17 (34%) were normal on MR. Conclusion: Relative to cerebral angiography, MR imaging is a poor indicator of the presence or absence of PACNS. Angiography is indicated when clinical suspicion of PACNS is strong, regardless of the findings on MR. (orig.)

Appearance of abdominal wall endometriosis on MR imaging

International Nuclear Information System (INIS)

Busard, Milou P.H.; Kuijk, Cees van; Waesberghe, Jan Hein T.M. van; Mijatovic, Velja; Hompes, Peter G.A.

2010-01-01

Abdominal wall endometriosis (AWE) is defined as endometrial tissue that is superficial to the peritoneum. AWE is often difficult to diagnose, mimicking a broad spectrum of diseases. The aim of this study was to describe the appearance of AWE on magnetic resonance (MR) imaging. We present ten patients with AWE (12 lesions) in which MR imaging was used for diagnosis. MR imaging included T2-weighted imaging and T1-weighted imaging with fat suppression. To assess the value of diffusion-weighted imaging (DWI) in endometriosis, four patients underwent additional DWI. The apparent diffusion coefficient (ADC) was calculated using b values of 50, 400, 800 and 1,200 s/mm 2 . In most cases, the lesion was located ventral or dorsal to the aponeurosis of the rectus oblique muscle (n=6) or in the rectus abdominis (n = 5). MR of AWE lesions showed isointense or slightly hyperintense signal compared with muscle on T2-weighted images and showed isointense or slightly hyperintense signal compared with muscle on T1-weighted images with foci of high signal intensity, indicative of haemorrhage. The mean ADC value of AWE was 0.93 x 10 -3 /mm 2 /s. MR imaging seems to be useful in determining the location and depth of infiltration in surrounding tissue preoperatively. (orig.)

MR imaging of the knee

International Nuclear Information System (INIS)

Djukic, S.; Melnikoff, S.; Genant, H.K.

1990-01-01

Artificial neural networks (ANNs) have been shown to be useful in the area of pattern recognition for medical imaging. This paper investigates whether an ANN system can accurately classify meniscal tears on MR images of the knee. Thirty-five patients were selected for either definite meniscal tear (grade III) or normal meniscus (grade O) on MR images. The images were digitized using a high-resolution image scanner (Truvel) and then archived on disk. A two-dimensional fast Fourier transform of the image was computed, and a 15-band wedge-ring filter was applied to the output. The results were used as input to a three-layer back-propagation network. After successfully training the ANN on a portion of the data base (16 cases) with an accuracy error of less than 1%, the remainder of the data was applied

Heuristically improved Bayesian segmentation of brain MR images ...

African Journals Online (AJOL)

Heuristically improved Bayesian segmentation of brain MR images. ... or even the most prevalent task in medical image processing is image segmentation. Among them, brain MR images suffer ... show that our algorithm performs well in comparison with the one implemented in SPM. It can be concluded that incorporating ...

High-field MR imaging of the tendons

International Nuclear Information System (INIS)

Beltran, J.; Burk, J.M.; Herman, L.J.; Mosure, J.C.

1987-01-01

MR imaging was used to investigate normal anatomy and pathologic conditions of the tendons. Tendons of experimental animals, cadaver joints, normal volunteers, and patients with suspected tendon pathology were studied. Tendon anatomy is easily identified because of the hypointensity of the tendons contrasting with the hyperintendensity of the surrounding fat. Pathologic conditions including posttraumatic and postsurgical tendon rupture, peritendinous scarring, tendinitis, and tenosynovitis are well seen with MR imaging. A detailed study of normal and abnormal tendon anatomy of the finger, wrist, shoulder, knee, and ankle is displayed, including MR images, gross specimens, and line drawings

Troubleshooting arterial-phase MR images of gadoxetate disodium-enhanced liver

Energy Technology Data Exchange (ETDEWEB)

Huh, Ji Mi; Kim, So Yeon; Lee, Seung Soo; Kim, Kyoung Won [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Yeh, Benjamin M.; Wang, Z. Jane [Dept. of Radiologyand Biomedical Imaging, University of California San Francisco, San Francisco (United States); Wu, En Haw [Dept. of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University College of Medicine, Taoyuan (China); Zhao, Li Qin [Beijing Friendship Hospital, Capital Medical University, Beijing (China); Chang, Wei Chou [Tri-Service General Hospital and National Defense Medical Center, Taipei (China)

2015-12-15

Gadoxetate disodium is a widely used magnetic resonance (MR) contrast agent for liver MR imaging, and it provides both dynamic and hepatobiliary phase images. However, acquiring optimal arterial phase images at liver MR using gadoxetate disodium is more challenging than using conventional extracellular MR contrast agent because of the small volume administered, the gadolinium content of the agent, and the common occurrence of transient severe motion. In this article, we identify the challenges in obtaining high-quality arterial-phase images of gadoxetate disodium-enhanced liver MR imaging and present strategies for optimizing arterial-phase imaging based on the thorough review of recent research in this field.

Troubleshooting arterial-phase MR images of gadoxetate disodium-enhanced liver

International Nuclear Information System (INIS)

Huh, Ji Mi; Kim, So Yeon; Lee, Seung Soo; Kim, Kyoung Won; Yeh, Benjamin M.; Wang, Z. Jane; Wu, En Haw; Zhao, Li Qin; Chang, Wei Chou

2015-01-01

Gadoxetate disodium is a widely used magnetic resonance (MR) contrast agent for liver MR imaging, and it provides both dynamic and hepatobiliary phase images. However, acquiring optimal arterial phase images at liver MR using gadoxetate disodium is more challenging than using conventional extracellular MR contrast agent because of the small volume administered, the gadolinium content of the agent, and the common occurrence of transient severe motion. In this article, we identify the challenges in obtaining high-quality arterial-phase images of gadoxetate disodium-enhanced liver MR imaging and present strategies for optimizing arterial-phase imaging based on the thorough review of recent research in this field

Recent developments of MR imaging system and future trends

International Nuclear Information System (INIS)

Fujieda, Kunimi

1996-01-01

Because MR imaging technique has no limitation of slice direction, uses none of mechanically moving components and can employ electronic scanning method for data acquisition, the most advanced electronics and CPU techniques have been applied to develop MR imaging systems. Along with pursuance of better equipment performance as clinical diagnostic equipment, cost reduction, improvement of operability and safety, easy siting, comfortable examination and economical operation cost by remarkable reduction of running cost have become important factors in development of MR imaging system. From this viewpoint, MR imaging systems incorporating an open gantry with a relatively low field strength and of vertical field system have been developed recently and they are being accepted as clinically useful equipment. The vertical field, open gantry system has an optimum structure capable of performing interventional imaging, thus clinical application of the system have been actively attempted. Thanks to recent development of various MRI techniques, image quality quite acceptable for routine clinical diagnosis can now be obtained by using the systems with permanent magnet and resistive magnet. Thus, it is considered that evaluation of not only equipment performance but also the total performances of the MR imaging system as described above will become important. The MR imaging technique has a possibility to substitute itself for other conventional imaging modalities because the technique can visualize physiological and metabolic functions in addition to morphological imaging. It is expected that application of MR imaging modality will be further expanded by continuous investigation of applicable clinical fields and development of imaging technologies. (J.P.N.)

Pediatric hemiplegic migraine: susceptibility weighted and MR perfusion imaging abnormality

Energy Technology Data Exchange (ETDEWEB)

Altinok, Deniz; Agarwal, Ajay [Children' s Hospital of Michigan, Department of Radiology, Detroit, MI (United States); Ascadi, Gyula; Luat, Aimee; Tapos, Daniela [Children' s Hospital of Michigan, Department of Neurology, Detroit, MI (United States)

2010-12-15

We report on an 11-year-old girl suffering from a typical attack of hemiplegic migraine with characteristic abnormalities in perfusion MR and susceptibility-weighted MR imaging findings. The imaging abnormalities were resolved 48 h after the attack. Susceptibility-weighted MR imaging findings correlated well with the MR perfusion, thus it can be used along with conventional MRI for evaluation of children with complex migraine attacks. Susceptibility-weighted MR imaging might have a diagnostic role in assessing the vascular events in hemiplegic migraine. (orig.)

Pediatric hemiplegic migraine: susceptibility weighted and MR perfusion imaging abnormality

International Nuclear Information System (INIS)

Altinok, Deniz; Agarwal, Ajay; Ascadi, Gyula; Luat, Aimee; Tapos, Daniela

2010-01-01

We report on an 11-year-old girl suffering from a typical attack of hemiplegic migraine with characteristic abnormalities in perfusion MR and susceptibility-weighted MR imaging findings. The imaging abnormalities were resolved 48 h after the attack. Susceptibility-weighted MR imaging findings correlated well with the MR perfusion, thus it can be used along with conventional MRI for evaluation of children with complex migraine attacks. Susceptibility-weighted MR imaging might have a diagnostic role in assessing the vascular events in hemiplegic migraine. (orig.)

Subtraction and dynamic MR images of breast cancer

Energy Technology Data Exchange (ETDEWEB)

Murakami, Yoshitaka; Aoki, Manabu; Harada, Junta (Jikei Univ., Tokyo (Japan). School of Medicine)

1993-04-01

The purpose of this study was to evaluate the diagnostic effectiveness of subtraction and dynamic MR imaging in patients with breast masses. In 23 breast cancers and six fibroadenomas, spin echo T1 images were obtained at 0.2 Tesla before and every minute after intravenous injection of Gd-DTPA (0.1 or 0.2 mmol/kg). Subtraction images were obtained sequentially on the CRT monitor. All breast masses were enhanced after gadolinium and stood out as bright lesions on subtraction images. The tumor margin and its extension were more precisely evaluated on subtraction MR images than on conventional postcontrast MR images. Breast cancer showed a characteristic time-intensity curve with an early peak, in contrast to fibroadenoma, which showed a gradual increase in signal intensity. Subtraction MR imaging is a simple method for the evaluation of breast masses, and further, the time-intensity curve obtained by dynamic study is helpful in the differential diagnosis of lesions. (author).

Fibrolipomatous hamartoma: pathognomonic on MR imaging

International Nuclear Information System (INIS)

Marom, E.M.; Helms, C.A.

1999-01-01

Purpose. To assess the MR imaging characteristics, presenting symptoms, age and nerve distribution of fibrolipomatous hamartoma. Design. A computer search was performed of the term fibrolipomatous hamartoma through the musculoskeletal section MR imaging results at our institution from June 7, 1996 to January 21, 1998 followed by a search of the terms lipomatous hamartoma, median nerve, surrounding fat, increased fatty signal, coaxial, and neuroma. MR images and medical files were retrospectively reviewed by two experienced musculoskeletal radiologists for imaging characteristics, nerve and age distribution as well as for history of trauma. In addition three consultation cases from outside institutions were added for determination of image characteristics. Results. Ten fibrolipomatous hamartomas were identified: eight in the median nerve, one in the ulnar nerve and one in the sciatic nerve. Mean age was 32.3 years (range 4-75 years, SD 21 years). Imaging characteristics were serpiginous low-intensity structures representing thickened nerve fascicles, surrounded by evenly distributed fat, high signal intensity on T1-weighted sequences and low signal intensity on T2-weighted sequences. The amount of fat varied; however, distribution in eight cases (80%) was predominantly between nerve fibers rather than surrounding them peripherally. All had a coaxial-cable-like appearance on axial planes and a spaghetti-like appearance on coronal planes that was not seen in any other type of median nerve abnormality imaged during the study period. Conclusion. The MR imaging characteristics of fibrolipomatous hamartoma are pathognomonic, obviating the need for biopsy for diagnosis. (orig.)

MR imaging of the ankle: Normal variants

International Nuclear Information System (INIS)

Noto, A.M.; Cheung, Y.; Rosenberg, Z.S.; Norman, A.; Leeds, N.E.

1987-01-01

Thirty asymptomatic ankles were studied with high-resolution surface coil MR imaging. The thirty ankles were reviewed for identification or normal structures. The MR appearance of the deltoid and posterior to talo-fibular ligaments, peroneous brevis and longus tendons, and posterior aspect of the tibial-talar joint demonstrated several normal variants not previously described. These should not be misinterpreted as pathologic processes. The specific findings included (1) cortical irregularity of the posterior tibial-talar joint in 27 of 30 cases which should not be mistaken for osteonecrois; (2) normal posterior talo-fibular ligament with irregular and frayed inhomogeneity, which represents a normal variant in seven of ten cases; and (3) fluid in the shared peroneal tendons sheath which may be confused for a longitudinal tendon tear in three of 30 cases. Ankle imaging with the use of MR is still a relatively new procedure. Further investigation is needed to better define normal anatomy as well as normal variants. The authors described several structures that normally present with variable MR imaging appearances. This is clinically significant in order to maintain a high sensitivity and specificity in MR imaging interpretation

Utility of MR imaging in cat-scratch neuroretinitis

International Nuclear Information System (INIS)

Reddy, Arun K.; Morriss, Michael C.; Lowe, Lisa H.; Ostrow, Greg I.; Stass-Isern, Merrill; Olitsky, Scott E.

2007-01-01

About 80% of cat-scratch disease (CSD) infections occur in children, and CSD neuroretinitis (optic neuropathy with retinal exudates in a ''macular star'' pattern) mostly occurs in children and young adults. A recent study suggested that CSD optic neuropathy has specific features on MR imaging. However, MR imaging findings in CSD neuroretinitis are not well described in the pediatric literature. We present a patient with CSD neuroretinitis in whom these specific MR imaging features preceded the macular star, a funduscopic finding strongly suggestive of neuroretinitis. This case demonstrates how knowledge of these features is important in the appropriate diagnostic work-up of optic neuropathy. MR imaging also incidentally revealed neuritis of another cranial nerve in the auditory canal - a rare manifestation of CSD. (orig.)

MR imaging and CT findings after liver transplantation

International Nuclear Information System (INIS)

Langer, M.; Langer, R.; Scholz, A.; Zwicker, C.; Astinet, F.

1990-01-01

The aim of the paper is to evaluate MR imaging and dynamic CT as noninvasive procedures to image signs of graft failure after an orthotopic liver transplantation (OLT). Thirty MR studies and 50 dynamic CT examinations were performed within 20 days after OLT. MR examinations were performed with a 0.5-T Siemens Magnetom. CT scans were obtained by using a Siemens Somatom Plus. In all patients, MR images demonstrated a perivascular rim of intermediate signal intensity on T1-weighted and increased signal intensity on T2-weighted images in the hilum of the liver; in 20/26, this was seen in peripheral areas also. In all patients, a perivascular area of low attenuation was diagnosed at angio-CT

Brain MR image segmentation using NAMS in pseudo-color.

Science.gov (United States)

Li, Hua; Chen, Chuanbo; Fang, Shaohong; Zhao, Shengrong

2017-12-01

Image segmentation plays a crucial role in various biomedical applications. In general, the segmentation of brain Magnetic Resonance (MR) images is mainly used to represent the image with several homogeneous regions instead of pixels for surgical analyzing and planning. This paper proposes a new approach for segmenting MR brain images by using pseudo-color based segmentation with Non-symmetry and Anti-packing Model with Squares (NAMS). First of all, the NAMS model is presented. The model can represent the image with sub-patterns to keep the image content and largely reduce the data redundancy. Second, the key idea is proposed that convert the original gray-scale brain MR image into a pseudo-colored image and then segment the pseudo-colored image with NAMS model. The pseudo-colored image can enhance the color contrast in different tissues in brain MR images, which can improve the precision of segmentation as well as directly visual perceptional distinction. Experimental results indicate that compared with other brain MR image segmentation methods, the proposed NAMS based pseudo-color segmentation method performs more excellent in not only segmenting precisely but also saving storage.

Interventional MR imaging: state of the art and future perspectives

International Nuclear Information System (INIS)

Kahn, T.; Moedder, U.

1998-01-01

The concept of MR guidance of invasive diagnostic and minimally invasive therapeutic procedures is based on the excellent morphologic and functional properties of MR imaging. Prerequisites are adequate patient monitoring and adherence to safety guidelines. Fast and ultrafast sequences, temperature quantification, visualization of intravascular devices, thermal stability of contrast media and thermosensitive contrast media are discussed. The spectrum of clinical applications includes biopsies, thermal ablation modalities, vascular applications, MR endoscopy and intraoperative MR imaging. The development of interventional MR imaging is still in its infancy. In the future, MR imaging may play an important role in interventional radiology and minimally invasive therapy. (orig.) [de

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

MR imaging of amyotrophic lateral sclerosis

Energy Technology Data Exchange (ETDEWEB)

Oba, Hiroshi; Monzawa, Shuichi (Yamanashi Medical College, Nakakoma (Japan). Hospital); Araki, Tsutomu (and others)

1992-04-01

Magnetic resonance imaging (MR imaging) provides a sensitive method for mapping the normal and pathological distribution of iron in the brain. High field strength MR imaging (1.5 T) was used to evaluate eight patients with amyotrophic lateral sclerosis (ALS) and 49 neurological normal control patients. All eight ALS patients showed decreased signal intensity in the motor cortex on T2-weighted images, while only one of the normal control patients showed this finding. The results suggested that the decreased signal intensity in the motor cortex in ALS was caused by the deposition of iron in this area. (author).

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

MR imaging of the parotid gland

International Nuclear Information System (INIS)

Vogl, T.; Dresel, S.; Lissner, J.; Grevers, G.; Riederer, A.

1989-01-01

In this study MR imaging combined with Gd-DTPA as a new effective diagnostic tool is compared with plain MR imaging. Seventy-two patients with lesions of the parotid gland were examined. In the author's patient group, they found 25 malignant tumors, 19 benign lesions, 20 Sjogren syndromes, and eight inflamed parotid glands. Axial and coronal images were acquired with long (TR = 1,600 msec, TE = 25/90 msec) and short (TR = 500 msec, TE = 25 msec) spin-echo sequences before and after Gd-DTPA

Normal anatomy and MR findings of fetal main organs at MR imaging

International Nuclear Information System (INIS)

Xia Liming; Zou Mingli; Feng Dingyi; Hu Junwu; Qi Jianpin; Wang Chengyuan

2005-01-01

Objective: To investigate normal anatomy and MR findings of fetal main organs. Methods: Forty-seven fetus underwented fast MR imaging, SSFSE sequence was used, the normal anatomy and MR findings of fetal main organs was observed in different gestational age. The organs included: brain, lungs, heart, liver, spleen, gastrointestinal tract, urinary collecting systems, bladder, bones, spine, and subcutaneous fat. Results: Results of MR in 47 fetus showed that the main organs had developed by 20-week-old fetus, about 20 weeks gestation, cerebral cortical surface was smooth, no cortical gyri and sulci, then cortical gyri and sulci developed slowly. The lungs, trachea, bronchus, gastrointestinal tract, renal collecting system and bladder showed high signal intensity; the heart, great vessels, liver, spleen, bones and muscles appeared hypointense; the kidneys appeared isointense, the spine had developed and subcutaneous fat was seen in 20-week-old fetus, the subcutaneous fat increased with fetus maturating. Conclusion: Normal anatomy and MR findings of fetal main organs were clearly showed by fast MR imaging, and they are different from the newborns. (authors)

Role of endorectal MR imaging and MR spectroscopic imaging in defining treatable intraprostatic tumor foci in prostate cancer: Quantitative analysis of imaging contour compared to whole-mount histopathology

International Nuclear Information System (INIS)

Anwar, Mekhail; Westphalen, Antonio C.; Jung, Adam J.; Noworolski, Susan M.; Simko, Jeffry P.; Kurhanewicz, John; Roach, Mack; Carroll, Peter R.; Coakley, Fergus V.

2014-01-01

Purpose: To investigate the role of endorectal MR imaging and MR spectroscopic imaging in defining the contour of treatable intraprostatic tumor foci in prostate cancer, since targeted therapy requires accurate target volume definition. Materials and methods: We retrospectively identified 20 patients with prostate cancer who underwent endorectal MR imaging and MR spectroscopic imaging prior to radical prostatectomy and subsequent creation of detailed histopathological tumor maps from whole-mount step sections. Two experienced radiologists independently reviewed all MR images and electronically contoured all suspected treatable (⩾0.5 cm 3 ) tumor foci. Deformable co-registration in MATLAB was used to calculate the margin of error between imaging and histopathological contours at both capsular and non-capsular surfaces and the treatment margin required to ensure at least 95% tumor coverage. Results: Histopathology showed 17 treatable tumor foci in 16 patients, of which 8 were correctly identified by both readers and an additional 2 were correctly identified by reader 2. For all correctly identified lesions, both readers accurately identified that tumor contacted the prostatic capsule, with no error in contour identification. On the non-capsular border, the median distance between the imaging and histopathological contour was 1.4 mm (range, 0–12). Expanding the contour by 5 mm at the non-capsular margin included 95% of tumor volume not initially covered within the MR contour. Conclusions: Endorectal MR imaging and MR spectroscopic imaging can be used to accurately contour treatable intraprostatic tumor foci; adequate tumor coverage is achieved by expanding the treatment contour at the non-capsular margin by 5 mm

Pre- and postoperative MR imaging of craniopharyngiomas

Energy Technology Data Exchange (ETDEWEB)

Hald, J.K. [Rijkshospitalet, Oslo (Norway). Dept. of Radiology; Eldevik, O.P. [Rijkshospitalet, Oslo (Norway). Dept. of Neurosurgery; Quint, D.J. [Rijkshospitalet, Oslo (Norway). Dept. of Neurosurgery; Chandler, W.F. [Univ. of Michigan Hospital, Ann Arbor, MI (United States). Dept. of Radiology; Kollevold, T. [Univ. of Michigan Hospital, Ann Arbor, MI (United States). Dept. of Neurosurgery

1996-09-01

Purpose: To compare the pre- and postoperative MR appearance of craniopharyngiomas with respect to lesion size, tumour morphology and identification of surrounding normal structures. Material and Methods: MR images obtained prior to and following craniopharyngioma resection were evaluated retrospectively in 10 patients. Tumour signal charcteristics, size and extension with particular reference to the optic chiasm, the pituitary gland, the pituitary stalk and the third ventricle were evaluated. Results: Following surgery, tumour volume was reduced in all patients. In 6 patients there was further tumour volume reduction between the first and second postoperative images. Two of these patients received radiation therapy between the 2 postoperative studies, while 4 had no adjuvant treatment to the surgical intervention. There was improved visualization of the optic chiasm, in 3, the pituitary stalk in one, and the third ventricle in 9 of the 10 patients. The pituitary gland was identified preoperatively only in one patient, postoperatively only in another, pre- and postoperatively in 5, and neither pre- nor postoperatively in 3 patients. In 3 patients MR imaging 0-7 days postoperatively identified tumour remnants not seen at the end of the surgical procedure. The signal intensities of solid and cystic tumour components were stable from pre- to the first postoperative MR images. Optic tract increased signal prior to surgery was gone 28 days postoperatively in one patient, but persisted on the left side for 197 days after surgery in another. Conclusion: Postoperative MR imaging of craniopharyngiomas demonstrated tumour volume reduction and tumour remnants not seen at surgery. Early postoperative MR imaging of craniopharyngiomas may overestimate the size of residual tumour. Improved visualization of peritumoral structures may be achieved. (orig.).

Appearance of abdominal wall endometriosis on MR imaging

Energy Technology Data Exchange (ETDEWEB)

Busard, Milou P.H.; Kuijk, Cees van; Waesberghe, Jan Hein T.M. van [VU Medical Center, Department of Radiology, Endometriosis Center VUMC, Amsterdam (Netherlands); Mijatovic, Velja; Hompes, Peter G.A. [VU Medical Center, Department of Gynecology, Endometriosis Center, Amsterdam (Netherlands)

2010-05-15

Abdominal wall endometriosis (AWE) is defined as endometrial tissue that is superficial to the peritoneum. AWE is often difficult to diagnose, mimicking a broad spectrum of diseases. The aim of this study was to describe the appearance of AWE on magnetic resonance (MR) imaging. We present ten patients with AWE (12 lesions) in which MR imaging was used for diagnosis. MR imaging included T2-weighted imaging and T1-weighted imaging with fat suppression. To assess the value of diffusion-weighted imaging (DWI) in endometriosis, four patients underwent additional DWI. The apparent diffusion coefficient (ADC) was calculated using b values of 50, 400, 800 and 1,200 s/mm{sup 2}. In most cases, the lesion was located ventral or dorsal to the aponeurosis of the rectus oblique muscle (n=6) or in the rectus abdominis (n = 5). MR of AWE lesions showed isointense or slightly hyperintense signal compared with muscle on T2-weighted images and showed isointense or slightly hyperintense signal compared with muscle on T1-weighted images with foci of high signal intensity, indicative of haemorrhage. The mean ADC value of AWE was 0.93 x 10{sup -3}/mm{sup 2}/s. MR imaging seems to be useful in determining the location and depth of infiltration in surrounding tissue preoperatively. (orig.)

MR imaging findings in patients with mesial temporal sclerosis

International Nuclear Information System (INIS)

Zimmerman, R.A.; Sperling, M.; Bilaniuk, L.T.; O'Connor, M.; Hackney, D.B.; Grossman, R.I.; Goldberg, H.I.; Gonatas, N.

1987-01-01

Eleven patients (aged 19-37) with temporal lobe epilepsy were evaluated by 1.5-T MR imaging. The MR imaging followed a negative CT examination. All patients underwent ictal and interictal, depth electrode EEG recording, carotid arteriography with amytol test, neuropsychological testing, subsequent unilateral temporal lobectomy, and pathologic correlation. MR images were retrospectively reviewed and correlated. MR images in ten patients showed a small temporal lobe on the abnormal side. Abnormal signal intensity was not found within the temporal lobe despite the use of coronal and axial long TR (2,500 msec) and short and long TE(30 and 80 msec) studies

MR imaging features of hemispherical spondylosclerosis

Energy Technology Data Exchange (ETDEWEB)

Vicentini, Joao R.T.; Martinez-Salazar, Edgar L.; Chang, Connie Y.; Bredella, Miriam A.; Rosenthal, Daniel I.; Torriani, Martin [Massachusetts General Hospital and Harvard Medical School, Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States)

2017-10-15

Hemispherical spondylosclerosis (HS) is a rare degenerative entity characterized by dome-shaped sclerosis of a single vertebral body that may pose a diagnostic dilemma. The goal of this study was to describe the MR imaging features of HS. We identified spine radiographs and CT examinations of subjects with HS who also had MR imaging for correlation. Two musculoskeletal radiologists independently assessed sclerosis characteristics, presence of endplate erosions, marrow signal intensity, and disk degeneration (Pfirrmann scale). We identified 11 subjects (six males, five females, mean 48 ± 10 years) with radiographic/CT findings of HS. The most commonly affected vertebral body was L4 (6/11; 55%). On MR imaging, variable signal intensity was noted, being most commonly low on T1 (8/11, 73%) and high on fat-suppressed T2-weighted (8/11, 73%) images. In two subjects, diffuse post-contrast enhancement was seen in the lesion. Moderate disk degeneration and endplate bone erosions adjacent to sclerosis were present in all subjects. Erosions of the opposite endplate were present in two subjects (2/11, 18%). CT data from nine subjects showed the mean attenuation value of HS was 472 ± 96 HU. HS appearance on MR imaging is variable and may not correlate with the degree of sclerosis seen on radiographs or CT. Disk degenerative changes and asymmetric endplate erosions are consistent markers of HS. (orig.)

MR imaging of symptomatic osteochondromas with pathological correlation

International Nuclear Information System (INIS)

Mehta, M.; Knapp, T.; White, L.M.; Wunder, J.S.; Bell, R.S.

1998-01-01

Objective. To demonstrate the value of MR imaging in the diagnosis and differentiation of the various symptomatic complications of osteochondromas, providing pathological correlation with emphasis on the usefulness of MR imaging as a single imaging modality in these patients. Design. We retrospectively reviewed all MR examinations of clinically symptomatic osteochondromas (30 patients) performed at our institution between March 1990 and October 1997. Patients. Thirty patients had clinically symptomatic osteochondromas during the study period. Twenty patients were male and 10 were female. There were five cases of multiple osteochondromatosis. Pathological correlation was available in 24 patients. Results and conclusion. Symptomatic complications included fracture (7%), osseous deformity limiting range of motion (23%), vascular injury (7%), neurological compromise (10%), bursa formation (27%) and malignant transformation (27%). MR imaging was able to diagnose or suggest the etiology for the clinical symptomatology in all cases, demonstrating that it is an ideal imaging modality in the diagnostic evaluation of symptomatic complications of osteochondromas and often avoids the need for further imaging. (orig.)

Sequential contrast-enhanced MR imaging of the penis.

Science.gov (United States)

Kaneko, K; De Mouy, E H; Lee, B E

1994-04-01

To determine the enhancement patterns of the penis at magnetic resonance (MR) imaging. Sequential contrast material-enhanced MR images of the penis in a flaccid state were obtained in 16 volunteers (12 with normal penile function and four with erectile dysfunction). Subjects with normal erectile function showed gradual and centrifugal enhancement of the corpora cavernosa, while those with erectile dysfunction showed poor enhancement with abnormal progression. Sequential contrast-enhanced MR imaging provides additional morphologic information for the evaluation of erectile dysfunction.

Zeitungssuche interaktiv: Der neue ZDB-Webkatalog

Directory of Open Access Journals (Sweden)

Jessica Hubrich

2014-12-01

Full Text Available Die Zeitschriftendatenbank (ZDB bietet als weltweit größte Datenbank für fortlaufende Sammelwerke umfangreiche Informationen zu mehr als 60000 Zeitungen, die in deutschen und österreichischen Bibliotheken vorgehalten werden. Im Rahmen eines von der Deutschen Forschungsgemeinschaft (DFG geförderten Projekts soll ein neuer ZDB-Webkatalog entstehen, der bessere Unterstützung für eine Vielzahl von Recherchen bietet als der aktuelle ZDB-OPAC und mittels interaktiver Visualisierungen komplexe Zusammenhänge zwischen verschiedenen Zeitungen sichtbar werden lässt. Dieser Beitrag informiert über das Projekt zur ZDB-Weiterentwicklung und gibt Einblicke in einige zentrale Funktionalitäten des zukünftigen ZDB-Webkatalogs, auf die sich Wissenschaftler/innen, Bibliothekar/innen und Endnutzer/innen 2015 freuen können. The German Union Catalogue of Serials (Zeitschriftendatenbank, ZDB is the world’s largest dedicated database for serials of all kinds. It contains extensive information about more than 60.000 newspapers being held in about 4.400 German and Austrian libraries. In a project funded by the German Research Foundation, a new ZDB web catalogue is being created which will provide better support for a wider range of newspaper search functions than the current ZDB OPAC. Interactive graphic representations allow for intuitive and clear visualisations of complex interconnections between different newspapers. The paper describes the ZDB project and highlights some significant features of the forthcoming ZDB web catalogue which will be available in 2015.

MR imaging in Peyronie's disease

International Nuclear Information System (INIS)

Shin, Young Yoel; Lee, Jeong Min; Lee, Sang Yong; Kim, Chong Soo; Park, Jong Kwan

1999-01-01

To evaluate the characteristics of magnetic resonance (MR) images in Peyronie's disease and to assess the usefulness of post-erection penile MRI. We retrospectively reviewed the MR images of seven patients in whom Peyronie's disease was clinically suspected. All seven underwent pre-and post-erectile MRI. After the acquisition of erectile MRI, three patients also underwent contrast-enhanced MRI. We compared image quality and the rate of detection of penile plaque between pre-erectile and post-erectile images. In three patients who underwent contrast-enhanced MRI, we assessed correlation between the contrast enhancement pattern, as seen on MRI, of the plaque and corpus cavernosa and clinical inflammatory signs such as painful erection. In the seven patients, all post-erectile MRI images showed localized thickening and irregularities of the tunica albuginea and the septum penis, suggesting penile plaque. On pre-erectile MRI, however, plaque was detected in five cases. In six of seven cases, plaque as seen on T2-weighted images (T2WI) showed low signal intensity similar to that of the tunica albuginea, and as seen on T1-weighted images (T1W1), a signal intensity of signal intensity similar to or similar to or slightly higher than that of the tunica albuginea. In one case, plaque showed high signal intensity on both T1WI and T2WI. On T1WI, the corpus cavernosa showed homogeneous medium-signal intensity on all pre- and post-erectile MR images. On pre-erectile T2WI, the corpus cavernosa of six patients showed heterogeneous high signal intensity, whereas on post-erectile T2WI the corpus cavernosa of all patients showed homogeneous high signal intensity. Due to the enlarged penis and homogeneous signal intensity of the corpus cavernosa, the image quality of post-erectile images was superior to that of pre-erectile images. The images of two of three patients who underwent contrast enhanced MRI showed strong enhancement of the plaque and adjacent corpus cavernosa, while in

Wrist and finger joint MR imaging in rheumatoid arthritis

DEFF Research Database (Denmark)

Klarlund, Mette; Østergaard, Mikkel; Gideon, P

1999-01-01

PURPOSE: To elaborate the best MR imaging protocol for studies in rheumatoid arthritis (RA) and to evaluate the sensitivity and interobserver agreement with respect to detection of bone erosions (MR and radiography) and grading of synovial membrane hypertrophy (MR imaging only). MATERIAL...

MR imaging of oropharynx and oral cavity

International Nuclear Information System (INIS)

Vogl, T.; Markl, A.F.; Bruning, R.; Greves, G.; Kang, K.; Lissner, J.A.

1988-01-01

The effect of intravenously administered Gd-DTPA on signal intensity, in the oropharynx and oral cavity was analyzed, in comparison with plain imaging the examinations were carried out on 150 patients, with a 1.5-T magnetic resonance (MR) imaging unit. During and after the application of Gd-DTPA, flash images with a repetition time of 30, an echo time of 12 msec, and a 20 0 flip angle were acquired over a period of 7 minutes. In 89 patients, malignant tumors were discovered, located primarily in the oropharynx and oral cavity. Plain MR imaging was equal to or better than computed tomograph in all patients except five. Marked contrast enhancement was observed in carcinomas, sarcomas, and inflammation. The enhancement of signal intensity versus time allowed a better differentiation of histologic features. MR imaging contributes substantially to the imaging of the oropharynx and oral cavity by improved soft-tissue contrast and the capacity for multiplanar imaging

Atlas of PET/MR imaging in oncology

International Nuclear Information System (INIS)

Ratib, Osman; Schwaiger, Markus; Beyer, Thomas

2013-01-01

Numerous illustrated clinical cases in different oncology domains. Includes digital interactive software matching the cases in the book. Interactive version based on the latest web standard, HTML5, ensuring the widest compatibility. Edited by three international opinion leaders/imaging experts in the field. This new project on PET/MR imaging in oncology includes digital interactive software matching the cases in the book. The interactive version of the atlas is based on the latest web standard, HTML5, ensuring compatibility with any computer operating system as well as a dedicated version for Apple iPad and iPhone. The book opens with an introduction to the principles of hybrid imaging that pays particular attention to PET/MR imaging and standard PET/MR acquisition protocols. A wide range of illustrated clinical case reports are then presented. Each case study includes a short clinical history, findings, and teaching points, followed by illustrations, legends, and comments. The multimedia version of the book includes dynamic movies that allow the reader to browse through series of rotating 3D images (MIP or volume rendered), display blending between PET and MR, and dynamic visualization of 3D image volumes. The movies can be played either continuously or sequentially for better exploration of sets of images. The editors of this state-of-the-art publication are key opinion leaders in the field of multimodality imaging. Professor Osman Ratib (Geneva) and Professor Markus Schwaiger (Munich) were the first in Europe to initiate the clinical adoption of PET/MR imaging. Professor Thomas Beyer (Zurich) is an internationally renowned pioneering physicist in the field of hybrid imaging. Individual clinical cases presented in this book are co-authored by leading international radiologists and nuclear physicians experts in the use of PET and MRI.

Atlas of PET/MR imaging in oncology

Energy Technology Data Exchange (ETDEWEB)

Ratib, Osman [University Hospital of Geneva (Switzerland). Nuclear Medicine Division; Schwaiger, Markus [Technische Univ. Muenchen (Germany). Nuklearmedizinische Klinik und Poliklinik; Beyer, Thomas (eds.) [General Hospital Vienna (Austria). Center for Medical Physics and Biomedical Engineering

2013-08-01

Numerous illustrated clinical cases in different oncology domains. Includes digital interactive software matching the cases in the book. Interactive version based on the latest web standard, HTML5, ensuring the widest compatibility. Edited by three international opinion leaders/imaging experts in the field. This new project on PET/MR imaging in oncology includes digital interactive software matching the cases in the book. The interactive version of the atlas is based on the latest web standard, HTML5, ensuring compatibility with any computer operating system as well as a dedicated version for Apple iPad and iPhone. The book opens with an introduction to the principles of hybrid imaging that pays particular attention to PET/MR imaging and standard PET/MR acquisition protocols. A wide range of illustrated clinical case reports are then presented. Each case study includes a short clinical history, findings, and teaching points, followed by illustrations, legends, and comments. The multimedia version of the book includes dynamic movies that allow the reader to browse through series of rotating 3D images (MIP or volume rendered), display blending between PET and MR, and dynamic visualization of 3D image volumes. The movies can be played either continuously or sequentially for better exploration of sets of images. The editors of this state-of-the-art publication are key opinion leaders in the field of multimodality imaging. Professor Osman Ratib (Geneva) and Professor Markus Schwaiger (Munich) were the first in Europe to initiate the clinical adoption of PET/MR imaging. Professor Thomas Beyer (Zurich) is an internationally renowned pioneering physicist in the field of hybrid imaging. Individual clinical cases presented in this book are co-authored by leading international radiologists and nuclear physicians experts in the use of PET and MRI.

Brain water mapping with MR imaging

International Nuclear Information System (INIS)

Laine, F.J.; Fatouros, P.P.; Kraft, K.A.

1990-01-01

This paper reports on a recently developed MR imaging technique to determine the spatial distribution of brain water to healthy volunteers. A noninvasive MR imaging technique to obtain absolute measurements of brain water has been developed and validated with phantom and animal studies. Patient confirmation was obtained from independent gravimetric measurements of brain tissue samples harvested by biopsy. This approach entails the production of accurate T1 maps from multiple inversion recovery images of a selected anatomic section and their subsequent conversion into an absolute water image by means of a previously determined calibration curve. Twenty healthy volunteers were studied and their water distribution was determined in a standard section. The following brain water values means and SD grams of water per gram of tissue) were obtained for selected brain regions; white matter, 68.9% ± 1.0; corpus callosum, 67.4% ± 1.1; thalamus, 75.3% ± 1.4; and caudate nucleus, 80.3% ± 1.4. MR imaging water mapping is a valid means of determining water content in a variety of brain tissues

Predictive value of MR imaging-dependent and non-MR imaging-dependent parameters for recurrence of laryngeal cancer after radiation therapy

NARCIS (Netherlands)

Castelijns, J. A.; van den Brekel, M. W.; Smit, E. M.; Tobi, H.; van Wagtendonk, F. W.; Golding, R. P.; Venema, H. W.; van Schaik, C.; Snow, G. B.

1995-01-01

To determine the predictive value of several clinical and radiologic parameters for recurrence of laryngeal cancer. Eighty previously untreated patients underwent magnetic resonance (MR) imaging before radiation therapy with curative intent. Tumor volume was calculated from T1-weighted MR images.

Utility of MR imaging in cat-scratch neuroretinitis

Energy Technology Data Exchange (ETDEWEB)

Reddy, Arun K. [University of Missouri-Kansas City, School of Medicine, Kansas City, MO (United States); Morriss, Michael C.; Lowe, Lisa H. [University of Missouri-Kansas City, Department of Radiology, The Children' s Mercy Hospital and Clinics, Kansas City, MO (United States); Ostrow, Greg I.; Stass-Isern, Merrill; Olitsky, Scott E. [University of Missouri-Kansas City, Department of Ophthalmology, Children' s Mercy Hospital and Clinics, Kansas City, MO (United States)

2007-08-15

About 80% of cat-scratch disease (CSD) infections occur in children, and CSD neuroretinitis (optic neuropathy with retinal exudates in a ''macular star'' pattern) mostly occurs in children and young adults. A recent study suggested that CSD optic neuropathy has specific features on MR imaging. However, MR imaging findings in CSD neuroretinitis are not well described in the pediatric literature. We present a patient with CSD neuroretinitis in whom these specific MR imaging features preceded the macular star, a funduscopic finding strongly suggestive of neuroretinitis. This case demonstrates how knowledge of these features is important in the appropriate diagnostic work-up of optic neuropathy. MR imaging also incidentally revealed neuritis of another cranial nerve in the auditory canal - a rare manifestation of CSD. (orig.)

Significance of MR imaging in congenital heart disease

International Nuclear Information System (INIS)

Mayr, H.; Globits, S.; Frank, H.; Glogar, D.; Nouhold, A.; Imhof, H.

1989-01-01

To determine the diagnostic impact of MR imaging in congenital heart disease, the authors used a 0.5- or 1.5-T magnet to examine 85 patients. Multisection spin-echo images were obtained in three planes. Diagnoses included atrial septal defect, trilogy and tetralogy of Fallot, ventricular septal defect, transposition (seven), single ventricle, and other complex disorders. Compared with other noninvasive techniques, MR imaging allowed a much better visualization of anatomic structures and the relationship of great vessels to shunt lesions in complex congenital heart disease. In 53 (63%) of 85 patients, MR imaging made a major contribution to establishing or modifying diagnoses

Traumatic spinal cord injury in MR imaging

International Nuclear Information System (INIS)

Bronarski, J.; Wozniak, E.

1993-01-01

Spinal cord injuries in tetraplegics were briefly discussed on the basis of MR imaging. It was found that severe cervical spine trauma usually results in concussion - the complete transection of the cord is rare. A case of 19 years old male with total cord transection confirmed by MR imaging is described. (author)

Athletic pubalgia and the "sports hernia": MR imaging findings.

Science.gov (United States)

Zoga, Adam C; Kavanagh, Eoin C; Omar, Imran M; Morrison, William B; Koulouris, George; Lopez, Hector; Chaabra, Avneesh; Domesek, John; Meyers, William C

2008-06-01

To retrospectively determine the sensitivity and specificity of magnetic resonance (MR) imaging findings in patients with clinical athletic pubalgia, with either surgical or physical examination findings as the reference standard. Institutional review board approval was granted for this HIPAA-compliant study, and informed consent was waived. MR imaging studies in 141 patients (134 male patients, seven female patients; mean age, 30.1 years; range, 17-71 years) who had been referred to a subspecialist because of groin pain were reviewed for findings including hernia, pubic bone marrow edema, secondary cleft sign, and rectus abdominis and adductor tendon injury. MR imaging findings were compared with surgical findings for 102 patients, physical examination findings for all 141 patients, and MR imaging findings in an asymptomatic control group of 25 men (mean age, 29.8 years; range, 18-39 years). Sensitivity and specificity of MR imaging for rectus abdominis and adductor tendon injury were determined by using a chi(2) analysis, and significance of the findings was analyzed with an unpaired Student t test. Disease patterns seen at MR imaging were compared with those reported in the surgical and sports medicine literature. One hundred thirty-eight (98%) of 141 patients had findings at MR imaging that could cause groin pain. Compared with surgery, MR imaging had a sensitivity and specificity, respectively, of 68% and 100% for rectus abdominis tendon injury and 86% and 89% for adductor tendon injury. Injury in each of these structures was significantly more common in the patient group than in the control group (P pubalgia, including rectus abdominis insertional injury, thigh adductor injury, and articular diseases at the pubic symphysis (osteitis pubis). (c) RSNA, 2008.

Neurocysticercosis: Correlative pathomorphology and MR imaging

International Nuclear Information System (INIS)

Lotz, J.; Hewlett, R.; Alheit, B.; Tygerberg Hospital, Stellenbosch; Bowen, R.

1988-01-01

CT and MR images of 32 patients with neurocysticercosis were correlated with pathomorphology. Gross morphological features of cystic larvae, complex arachnoid cysts, granulomatous abscesses, basal meningitis and mineralised nodules correlated closely with the images obtained, especially on MR, where resolution permitted visualisation of larval protoscolices. Our material indicates three forms of the natural history of neurocysticercosis related chiefly to anatomic location, and provides details of the evolution of large, complex arachnoid cysts. (orig.)

Neurocysticercosis: Correlative pathomorphology and MR imaging

Energy Technology Data Exchange (ETDEWEB)

Lotz, J.; Hewlett, R.; Alheit, B.; Bowen, R.

1988-02-01

CT and MR images of 32 patients with neurocysticercosis were correlated with pathomorphology. Gross morphological features of cystic larvae, complex arachnoid cysts, granulomatous abscesses, basal meningitis and mineralised nodules correlated closely with the images obtained, especially on MR, where resolution permitted visualisation of larval protoscolices. Our material indicates three forms of the natural history of neurocysticercosis related chiefly to anatomic location, and provides details of the evolution of large, complex arachnoid cysts.

MR imaging manifestations of skin tumors

Energy Technology Data Exchange (ETDEWEB)

Kim, Jeong-hyon; Kim, Jee Young [The Catholic University of Korea, Department of Diagnostic Radiology, St. Vincent' s Hospital, Suwon, Gyeonggi-do (Korea); Chun, Kyung Ah [The Catholic University of Korea, Department of Diagnostic Radiology, Uijeongbu St. Mary Hospital, Uijeongbu, Gyeonggi-do (Korea); Jee, Won-Hee [The Catholic University of Korea, Department of Diagnostic Radiology, Kangnam St. Mary' s Hospital, Seoul (Korea); Sung, Mi-Sook [The Catholic University of Korea, Department of Diagnostic Radiology, Holy family Hospital, Bucheon, Gyeonggi-do (Korea)

2008-11-15

In this study, we evaluated MR imaging findings of skin tumors and categorized them into four types: (1) discrete mass lesions of the dermis and epidermis, (2) mass lesions of the subcutis with or without abutment to the skin, (3) diffuse or localized skin thickening without a true mass, and (4) a skin mass with bone destruction. The categorization of MR images may be useful in the differential diagnosis of skin tumors. (orig.)

MR imaging appearance of discoid menisci of the knee

International Nuclear Information System (INIS)

Silverman, J.; Mink, J.H.; Deutsch, A.L.

1988-01-01

Although discoid menisci of the knee have been recognized with magnetic resonance (MR) imaging, there are no MR criteria for their diagnosis. In this paper the authors define a discord meniscus as three or more 5-mm-thick interleaved sagittal sections that demonstrate continuity of the meniscus between the anterior and posterior horns. High-resolution coronal images allow more graphic depiction of the abnormally wide meniscus. They present a total of 29 cases imaged with MR. In approximately one-third of their cases, the measurable height difference between the discoid meniscus and the adjacent meniscus was at least 2 mm. Surgical correlation revealed only two discrepancies between MR imaging and arthrography

MR imaging of the pulmonary vasculature - an update

Energy Technology Data Exchange (ETDEWEB)

Pedersen, Mark R.; Fisher, Mark T. [University of Iowa, Department of Radiology, Carver College of Medicine, Iowa City, Iowa (United States); Beek, Edwin J.R. van [University of Iowa, Department of Radiology, Carver College of Medicine, Iowa City, Iowa (United States); University of Iowa Hospitals and Clinics, JPP 3895, Department of Radiology, Iowa City, Iowa (United States)

2006-06-15

Although the advent of multi-detector row computed tomography (CT) angiography has been at the heart of improving the diagnostic management of pulmonary vascular disease, MR technology has also moved forward. This review outlines the current state of affairs of MR techniques for the assessment of pulmonary vascular diseases such as pulmonary hypertension, pulmonary arteritis and arteriovenous malformations. It highlights the main areas of MR angiography and MR perfusion imaging and discusses novel methods, such as non-contrast enhanced direct thrombus imaging, and will discuss its merits in the context of other diagnostic modalities. (orig.)

Brain imaging with synthetic MR in children: clinical quality assessment

Energy Technology Data Exchange (ETDEWEB)

Betts, Aaron M.; Serai, Suraj [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Leach, James L.; Jones, Blaise V. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); University of Cincinnati College of Medicine, Cincinnati, OH (United States); Zhang, Bin [Cincinnati Children' s Hospital Medical Center, Biostatistics and Epidemiology, Cincinnati, OH (United States)

2016-10-15

Synthetic magnetic resonance imaging is a quantitative imaging technique that measures inherent T1-relaxation, T2-relaxation, and proton density. These inherent tissue properties allow synthesis of various imaging sequences from a single acquisition. Clinical use of synthetic MR imaging has been described in adult populations. However, use of synthetic MR imaging has not been previously reported in children. The purpose of this study is to report our assessment of diagnostic image quality using synthetic MR imaging in children. Synthetic MR acquisition was obtained in a sample of children undergoing brain MR imaging. Image quality assessments were performed on conventional and synthetic T1-weighted, T2-weighted, and FLAIR images. Standardized linear measurements were performed on conventional and synthetic T2 images. Estimates of patient age based upon myelination patterns were also performed. Conventional and synthetic MR images were evaluated on 30 children. Using a 4-point assessment scale, conventional imaging performed better than synthetic imaging for T1-weighted, T2-weighted, and FLAIR images. When the assessment was simplified to a dichotomized scale, the conventional and synthetic T1-weighted and T2-weighted images performed similarly. However, the superiority of conventional FLAIR images persisted in the dichotomized assessment. There were no statistically significant differences between linear measurements made on T2-weighted images. Estimates of patient age based upon pattern of myelination were also similar between conventional and synthetic techniques. Synthetic MR imaging may be acceptable for clinical use in children. However, users should be aware of current limitations that could impact clinical utility in the software version used in this study. (orig.)

Cine MR imaging in valvular heart disease

Energy Technology Data Exchange (ETDEWEB)

Nishimura, Tsunehiko; Yamada, Naoaki; Itoh, Akira; Miyatake, Kunio

1989-01-01

Cine MR Imaging was carried out using FLASH (fast low angle shot) which employes TE of 16 msec and TR of 30/similar to/40 msec. Regurgitant jet was visible as discrete area of low signal intensity extending from the incompetent valve into the respective cardiac chamber. In 20 patients with mitral regurgitation, the correlation of the length and area of mitral jet by cine MR and color doppler mapping was 0.74 and 0.71, respectively. Cine MR imaging is a promising modality for detection and quantification of valvular heart disease.

Carcinoma of the cervix: Staging with MR imaging

International Nuclear Information System (INIS)

Waggenspack, G.A.; Amparo, E.G.; Fagan, C.J.; Hannigan, E.V.

1986-01-01

Forty MR imaging examinations in 38 patients with newly diagnosed or recurrent squamous cell carcinoma of the cervix were retrospectively evaluated and compared with clinical and surgical findings for staging. There was poor correlation between loss of fat planes and extension of tumor into the rectum or bladder, and it was impossible to differentiate bladder edema from direct invasion. MR imaging underestimated parametrial and pelvic sidewall extension when compared with physical exam under anesthesia. MR imaging was useful in the direct demonstration of a cervical mass and in detecting enlarged pelvic nodes

Robust generative asymmetric GMM for brain MR image segmentation.

Science.gov (United States)

Ji, Zexuan; Xia, Yong; Zheng, Yuhui

2017-11-01

Accurate segmentation of brain tissues from magnetic resonance (MR) images based on the unsupervised statistical models such as Gaussian mixture model (GMM) has been widely studied during last decades. However, most GMM based segmentation methods suffer from limited accuracy due to the influences of noise and intensity inhomogeneity in brain MR images. To further improve the accuracy for brain MR image segmentation, this paper presents a Robust Generative Asymmetric GMM (RGAGMM) for simultaneous brain MR image segmentation and intensity inhomogeneity correction. First, we develop an asymmetric distribution to fit the data shapes, and thus construct a spatial constrained asymmetric model. Then, we incorporate two pseudo-likelihood quantities and bias field estimation into the model's log-likelihood, aiming to exploit the neighboring priors of within-cluster and between-cluster and to alleviate the impact of intensity inhomogeneity, respectively. Finally, an expectation maximization algorithm is derived to iteratively maximize the approximation of the data log-likelihood function to overcome the intensity inhomogeneity in the image and segment the brain MR images simultaneously. To demonstrate the performances of the proposed algorithm, we first applied the proposed algorithm to a synthetic brain MR image to show the intermediate illustrations and the estimated distribution of the proposed algorithm. The next group of experiments is carried out in clinical 3T-weighted brain MR images which contain quite serious intensity inhomogeneity and noise. Then we quantitatively compare our algorithm to state-of-the-art segmentation approaches by using Dice coefficient (DC) on benchmark images obtained from IBSR and BrainWeb with different level of noise and intensity inhomogeneity. The comparison results on various brain MR images demonstrate the superior performances of the proposed algorithm in dealing with the noise and intensity inhomogeneity. In this paper, the RGAGMM

MR imaging of articular cartilage

International Nuclear Information System (INIS)

Schaefer, F.K.W.; Muhle, C.; Heller, M.; Brossmann, J.

2001-01-01

MR imaging has evolved to the best non-invasive method for the evaluation of articular cartilage. MR imaging helps to understand the structure and physiology of cartilage, and to diagnose cartilage lesions. Numerous studies have shown high accuracy and reliability concerning detection of cartilage lesions and early changes in both structure and biochemistry. High contrast-to-noise ratio and high spatial resolution are essential for analysis of articular cartilage. Fat-suppressed 3D-T 1 weighted gradient echo and T 2 -weighted fast spin echo sequences with or without fat suppression are recommended for clinical routine. In this article the anatomy and pathology of hyaline articular cartilage and the complex imaging characteristics of hyaline cartilage will be discussed. (orig.) [de

MR imaging for diagnostic evaluation of encephalopathy in the newborn.

Science.gov (United States)

Shroff, Manohar M; Soares-Fernandes, João P; Whyte, Hilary; Raybaud, Charles

2010-05-01

Magnetic resonance (MR) imaging is used with increasing frequency to evaluate the neonatal brain because it can provide important diagnostic and prognostic information that is needed for optimal treatment and appropriate counseling. Special care must be taken in preparing encephalopathic neonates for an MR study, transporting them from the intensive care unit, monitoring their vital signs, and optimizing MR sequences and protocols. Moreover, to accurately interpret the findings, specific knowledge is needed about the normal MR imaging appearances of the physiologic processes of myelination, cell migration, and sulcation, as well as patterns of injury, in the neonatal brain at various stages of gestational development. Hypoxic-ischemic injury, the most common cause of neonatal encephalopathy, has characteristic appearances that depend on the severity and duration of the insult as well as the stage of brain development. Diffusion-weighted MR imaging and MR spectroscopy depict abnormalities earlier than do conventional MR imaging sequences. However, diffusion-weighted imaging, if performed in the first 24 hours after the insult, might lead to underestimation of the extent of injury. When the MR findings are atypical, the differential diagnosis of neonatal encephalopathy also should include congenital and metabolic disorders and infectious diseases. Despite recent advances in the MR imaging-based characterization of these conditions, the clinical history must be borne in mind to achieve an accurate diagnosis.

Measurement of skeletal muscle area: Comparison of CT and MR imaging

Energy Technology Data Exchange (ETDEWEB)

Sinelnikov, Andrey, E-mail: sinelnikovas@upmc.edu [Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Qu, Chuanxing [Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Fetzer, David T. [Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX (United States); Pelletier, Jean-Sébastien [Department of Surgery, Jewish General Hospital, McGill University, Montreal, Quebec (Canada); Dunn, Michael A. [Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Tsung, Allan [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Furlan, Alessandro [Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA (United States)

2016-10-15

Objective: To investigate the intra- and inter-observer agreement and correlation between CT and MR measurements of skeletal muscle area (SMA) in the abdomen. Methods: CT and MR images from twelve patients were analyzed by two blinded observers using segmentation software (MITK-3M3, Mint Medical and Slice-O-Matic, Tomovision) to quantify SMA. MR images included T1w “in-phase”, T1w “out-of-phase”, and T2w sequences. Inter- and intra-observer agreement was assessed using the intraclass correlation coefficient (ICC). Pearson correlation coefficient (r) was used to correlate measurements obtained on MR with CT. CT and MR measurements were compared with Bland-Altman plots. Results: Intra- and inter-observer agreement for SMA was high for CT and MR. For MR, the measurements on T2w images showed the highest inter-observer agreement (ICC = 0.96). CT SMA correlated closely with MR, with T2w images showing the highest correlation (r = 0.98; P < 0.01). Bland-Altman plots showed a 1.7%–3.9% bias between CT and MR measurements, lowest for T2w images. Conclusions: MR SMA measurements are reproducible and correlate closely with CT. The T2w sequence is recommended to quantify SMA on MR images.

Principles of Simultaneous PET/MR Imaging.

Science.gov (United States)

Catana, Ciprian

2017-05-01

Combined PET/MR imaging scanners capable of acquiring simultaneously the complementary information provided by the 2 imaging modalities are now available for human use. After addressing the hardware challenges for integrating the 2 imaging modalities, most of the efforts in the field have focused on developing MR-based attenuation correction methods for neurologic and whole-body applications, implementing approaches for improving one modality by using the data provided by the other and exploring research and clinical applications that could benefit from the synergistic use of the multimodal data. Copyright © 2017 Elsevier Inc. All rights reserved.

External Snapping Hip Syndrome: Emphasis on the MR Imaging

International Nuclear Information System (INIS)

Choi, Jung Eun; Lee, Bae Young; Sung, Mi Sook; Lee, Ki Haeng; Yoo, Won Jong; Lim, Hyun Wook; Chung, Myung Hee; Park, Jeong Mi; Kim, Jee Young

2010-01-01

The aim of this study is to evaluate the MR imaging features of patients with external snapping hip syndrome. We retrospectively reviewed 63 hip MR images. The images were analyzed according to the thickness and contour of the iliotibial band and the gluteus maximus, the presence of bone marrow edema, bursitis, joint effusion and other associated findings. The MR imaging of 22 hips with snapping hip syndrome depicted the causes of external snapping hip syndrome in twenty cases (90%). The MR imaging features of the snapping hip included thickening of the iliotibial band in twelve cases (55%) and/or thickening of the anterior band of the gluteus maximus in nineteen (86%), and a wavy contour of the iliotibial band or the anterior band of the gluteus maximus in ten cases (45%). These findings show a significant p value (<0.01). The majority of patients with snapping hip syndrome revealed thickening of the iliotibial band, thickening of the anterior band of the gluteus maximus and wavy contour of the those structures on MR imaging

External Snapping Hip Syndrome: Emphasis on the MR Imaging

Energy Technology Data Exchange (ETDEWEB)

Choi, Jung Eun; Lee, Bae Young [Catholic University St. Paul' s Hospital, Seoul (Korea, Republic of); Sung, Mi Sook; Lee, Ki Haeng; Yoo, Won Jong; Lim, Hyun Wook; Chung, Myung Hee [Catholic University Bucheon St. Mary' s Hospital, Bucheon (Korea, Republic of); Park, Jeong Mi [Catholic University St. Mary' s Hospital, Seoul (Korea, Republic of); Kim, Jee Young [Catholic University St. Vincent' s Hospital, Suwon (Korea, Republic of)

2010-02-15

The aim of this study is to evaluate the MR imaging features of patients with external snapping hip syndrome. We retrospectively reviewed 63 hip MR images. The images were analyzed according to the thickness and contour of the iliotibial band and the gluteus maximus, the presence of bone marrow edema, bursitis, joint effusion and other associated findings. The MR imaging of 22 hips with snapping hip syndrome depicted the causes of external snapping hip syndrome in twenty cases (90%). The MR imaging features of the snapping hip included thickening of the iliotibial band in twelve cases (55%) and/or thickening of the anterior band of the gluteus maximus in nineteen (86%), and a wavy contour of the iliotibial band or the anterior band of the gluteus maximus in ten cases (45%). These findings show a significant p value (<0.01). The majority of patients with snapping hip syndrome revealed thickening of the iliotibial band, thickening of the anterior band of the gluteus maximus and wavy contour of the those structures on MR imaging.

MR imaging of the triangular fibrocartilage of the wrist

International Nuclear Information System (INIS)

Golimbu, C.N.; Firooznia, H.; Rafii, M.; Melone, C.; Leber, C.

1988-01-01

Magnetic resonance (MR) imaging of the wrist was performed in 25 patients who had pain or localized soft-tissue swelling in the ulnar side of the wrist. T1-weighted coronal images were obtained in all patients. In addition, coronal or axial images with T2-weighted or fast-field-echo sequences were obtained in 16 of these patients. MR imaging demonstrated tears of the triangular fibrocartilage of the wrist in 13 patients. Twelve of these tears were confirmed at surgery. In one patient, the triangular fibrocartilage was found at surgery to be stretched and folded on itself but not torn. This represents the one false-positive MR image in this group of patients. In 12 patients, the symptoms could be explained by a diversity of MR abnormalities, such as aseptic necrosis of carpal bones, subluxation of distal radioulnar joint, and synovitis of the tendon sheaths. MR imaging offers the advantage of investigating the triangular fibrocartilage of the wrist in a noninvasive manner; it may be used as a screening method in patients considered for surgery

Body diffusion-weighted MR imaging of uterine endometrial cancer: Is it helpful in the detection of cancer in nonenhanced MR imaging?

Energy Technology Data Exchange (ETDEWEB)

Inada, Yuki [Department of Radiology, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki City, Osaka 569-8686 (Japan)], E-mail: rad068@poh.osaka-med.ac.jp; Matsuki, Mitsuru; Nakai, Go; Tatsugami, Fuminari; Tanikake, Masato; Narabayashi, Isamu [Department of Radiology, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki City, Osaka 569-8686 (Japan); Yamada, Takashi; Tsuji, Motomu [Department of Pathology, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki City, Osaka 569-8686 (Japan)

2009-04-15

Objective: In this study, the authors discussed the feasibility and value of diffusion-weighted (DW) MR imaging in the detection of uterine endometrial cancer in addition to conventional nonenhanced MR images. Methods and materials: DW images of endometrial cancer in 23 patients were examined by using a 1.5-T MR scanner. This study investigated whether or not DW images offer additional incremental value to conventional nonenhanced MR imaging in comparison with histopathological results. Moreover, the apparent diffusion coefficient (ADC) values were measured in the regions of interest within the endometrial cancer and compared with those of normal endometrium and myometrium in 31 volunteers, leiomyoma in 14 patients and adenomyosis in 10 patients. The Wilcoxon rank sum test was used, with a p < 0.05 considered statistically significant. Results: In 19 of 23 patients, endometrial cancers were detected only on T2-weighted images. In the remaining 4 patients, of whom two had coexisting leiomyoma, no cancer was detected on T2-weighted images. This corresponds to an 83% detection sensitivity for the carcinomas. When DW images and fused DW images/T2-weighted images were used in addition to the T2-weighted images, cancers were identified in 3 of the remaining 4 patients in addition to the 19 patients (overall detection sensitivity of 96%). The mean ADC value of endometrial cancer (n = 22) was (0.97 {+-} 0.19) x 10{sup -3} mm{sup 2}/s, which was significantly lower than those of the normal endometrium, myometrium, leiomyoma and adenomyosis (p < 0.05). Conclusion: DW imaging can be helpful in the detection of uterine endometrial cancer in nonenhanced MR imaging.

The history of MR imaging as seen through the pages of radiology.

Science.gov (United States)

Edelman, Robert R

2014-11-01

The first reports in Radiology pertaining to magnetic resonance (MR) imaging were published in 1980, 7 years after Paul Lauterbur pioneered the first MR images and 9 years after the first human computed tomographic images were obtained. Historical advances in the research and clinical applications of MR imaging very much parallel the remarkable advances in MR imaging technology. These advances can be roughly classified into hardware (eg, magnets, gradients, radiofrequency [RF] coils, RF transmitter and receiver, MR imaging-compatible biopsy devices) and imaging techniques (eg, pulse sequences, parallel imaging, and so forth). Image quality has been dramatically improved with the introduction of high-field-strength superconducting magnets, digital RF systems, and phased-array coils. Hybrid systems, such as MR/positron emission tomography (PET), combine the superb anatomic and functional imaging capabilities of MR imaging with the unsurpassed capability of PET to demonstrate tissue metabolism. Supported by the improvements in hardware, advances in pulse sequence design and image reconstruction techniques have spurred dramatic improvements in imaging speed and the capability for studying tissue function. In this historical review, the history of MR imaging technology and developing research and clinical applications, as seen through the pages of Radiology, will be considered.

MR imaging of the breast with Gd-DTPA enhancement

International Nuclear Information System (INIS)

Hachiya, Junichi; Seki, Tsuneaki; Okada, Minoru; Nitatori, Toshiaki; Korenaga, Tateo; Furuya, Yoshiro

1991-01-01

The accuracy of MR imaging with Gd-DTPA enhancement was compared with mammography and ultrasonography in 52 patients with clinically palpable benign and malignant breast masses (36 carcinomas, 2 malignant phyllodes tumors, 7 fibroadenomas, 7 cysts). On dynamic MR imaging, carcinomas and fibroadenomas were discriminated by their different dynamic enhancement profiles. In carcinomas, signal intensity increased rapidly, reaching a peak or plateau within 2 min after the injection of contrast medium. In fibroadenomas, signal intensity showed a much slower continuous increase without ceasing until about 8 min after injection. Malignant phyllodes tumors showed a dynamic enhancement profile identical to that of benign fibroadenomas. MR imaging correctly identified 84% of malignant tumors, 86% of fibroadenomas, and 100% of cysts, and was substantially more accurate in tissue characterization than mammography. The results of ultrasonography were highly similar to those of MR imaging. However, no single modality was infallible, and the three modalities were complementary rather than competitive. Considering the high cost and long examination time of MR imaging, mammography supplemented by ultrasonography seems to be the method of choice in the diagnosis of breast lesions. Nevertheless, MR imaging can add important information when the results of mammography and ultrasonography are insufficient or contradictory. (author)

Combined PET/MR imaging in neurology

DEFF Research Database (Denmark)

Andersen, Flemming Littrup; Ladefoged, Claes Nøhr; Beyer, Thomas

2014-01-01

AIM: Combined PET/MR systems have now become available for clinical use. Given the lack of integrated standard transmission (TX) sources in these systems, attenuation and scatter correction (AC) must be performed using the available MR-images. Since bone tissue cannot easily be accounted for duri...

MR imaging of the hip

International Nuclear Information System (INIS)

Kramer, J.

2006-01-01

Full text: MRI has been shown to gain increasing importance in recent years in the evaluation of disorders of the hip and pelvis. Nowadays, conventional or fast spin echo (T1, Turbo (Fast) T2 (or PD)) MR imaging sequences are used most commonly to examine the hip and pelvis. Three dimensional (3D) gradient echo (GE) imaging allows acquisition of very thin (1 mm) sections. MR imaging with fat suppression technique (STIR, TIRM, FAT SAT T2) represent an effective screening technique for the assessment of fluid, hemorrhage, pus, or tumor in the marrow, joint or soft tissues. These techniques increase the sensitivity for the detection of a variety of pathologic processes. Fat suppression MR imaging, when combined with intravenous (or intraarticular) administration of a gadolinium compound, also is effective and often is employed when evaluating neoplastic or infectious diseases (intravenous injection), abnormalities of articular cartilage or labrum, or possible intraarticular osteocartilaginous bodies (intraarticular injection). A lesion of the acetabular labrum based is one cause of chronic hip pain in patients with developmental dysplasia of the hips, as well as in patients with a history of hip trauma or femoroacetabular impingement. MR imaging and, in particular, MR arthrography, however, have been shown to be highly accurate in the detection of subtle intraarticular abnormalities such as labral lesion. Conventional MR imaging has shown poor accuracy in detecting labral lesions, due to its inability to depict small tears and the difficulty in determining if intralabral signal abnormalities extend to the surface of the labrum. MR arthrography, however has been shown to overcome these difficulties and to have excellent accuracy in detecting labral pathology. As labral abnormalities are believed to be a precursor of osteoarthritis, orthopedic surgeons believe that surgical intervention will be influenced substantially by the type, extension and location of labral

MR imaging of the shoulder

International Nuclear Information System (INIS)

Heuck, A.; Appel, M.; Kaiser, E.; Luttke, G.; Lukas, P.

1990-01-01

This paper evaluates the occurrence, frequency, and significance of increased signal intensity (SI) in the rotator cuff (RC) of normal volunteers suggestive of pathologic findings such as partial tears and tendinitis. Shoulders of 30 volunteers without evidence of prior shoulder disease or trauma were studied. MR imaging at 1.5 T included T1-weighted, proton-density, and T2-weighted spin-echo (SE) and T2*-weighted gradient-echo sequences in axial, oblique coronal, and sagittal planes. Shoulders of 30 cadavers were dissected and studied for correlation with MR findings, five of them after MR examination

Do carotid MR surface coils affect PET quantification in PET/MR imaging?

International Nuclear Information System (INIS)

Willemink, Martin J; Eldib, Mootaz; Leiner, Tim; Fayad, Zahi A; Mani, Venkatesh

2015-01-01

To evaluate the effect of surface coils for carotid MR imaging on PET quantification in a clinical simultaneous whole-body PET/MR scanner. A cylindrical phantom was filled with a homogeneous 2L water-FDG mixture at a starting dose of 301.2MBq. Clinical PET/MR and PET/CT systems were used to acquire PET-data without a coil (reference standard) and with two carotid MRI coils (Siemens Special Purpose 8-Channel and Machnet 4-Channel Phased Array). PET-signal attenuation was evaluated with Osirix using 51 (PET/MR) and 37 (PET/CT) circular ROIs. Mean and maximum standardized uptake values (SUVs) were quantified for each ROI. Furthermore, SUVs of PET/MR and PET/CT were compared. For validation, a patient was scanned with an injected dose of 407.7MBq on both a PET/CT and a PET/MR system without a coil and with both coils. PET/MR underestimations were -2.2% (Siemens) and -7.8% (Machnet) for SUVmean, and -1.2% (Siemens) and -3.3% (Machnet) for SUVmax, respectively. For PET/CT, underestimations were -1.3% (Siemens) and -1.4% (Machnet) for SUVmean and -0.5% (both Siemens and Machnet) for SUVmax, respectively using no coil data as reference. Except for PET/CT SUVmax values all differences were significant. SUVs differed significantly between PET/MR and PET/CT with SUVmean values of 0.51-0.55 for PET/MR and 0.68-0.69 for PET/CT, respectively. The patient examination showed that median SUVmean values measured in the carotid arteries decreased from 0.97 without a coil to 0.96 (Siemens) and 0.88 (Machnet). Carotid surface coils do affect attenuation correction in both PET/MR and PET/CT imaging. Furthermore, SUVs differed significantly between PET/MR and PET/CT.

MR images of rupture and leakage of breast implants

International Nuclear Information System (INIS)

Fang Ling; Liu Pengcheng; Huang Rong; Hu Huaxin; Chen Zaizhong; Du Duanming; Liu Hanqiao; Feng Fei

2002-01-01

Objective: To investigate the diagnostic value of magnetic resonance imaging in detecting rupture and leakage of breast implants. Methods: Seventeen cases with breast implants were imaged by MR scanner. 1 normal silicone breast implant outside the body was scanned by MR as an consultative standard. MR images of silicone implants and polypropylene acyl amine implants were classified and analyzed. Results: In 7 cases, 12 single lumen silicone implants were intact, among them 8 were silicone gel-filled implants, 4 were physiological saline-filled implants. 2 physiological saline-filled implants ruptured, among them 1 belonged to intracapsular silicone implant rupture with subsided silicone gel capsule which presented as long T 1 signal and short T 2 signal on MR images; The other belonged to extracapsular silicone implant rapture with physiological saline granule outside breast on MR images. 20 breast implants in 10 cases were injected by polypropylene acyl amine, among them 2 breast implants were intact, 16 breast implants ruptured completely with pieces and nodes of long T 1 signal and long T 2 signal on MR images, 14 of 16 also presented polypropylene acyl amine granule outside breast; 2 breast implants splited inside with linguine sign. Conclusion: The magnetic resonance imaging can make clear the type and the seat of breast implants, the type of rupture of breast implants, and the distribution of leakage material. Therefore magnetic resonance imaging can be an effective guidance for clinical operation and can be an consultative standard for follow-up

Avascular necrosis of the femoral head; Staging by MR imaging

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Kokubo, Takashi; Takatori, Yoshio; Ninomiya, Setsuo; Sasaki, Yasuhito [Tokyo Univ. (Japan). Faculty of Medicine

1993-03-01

Magnetic resonance (MR) images and conventional radiographs were compared in 142 hips with avascular necrosis, and a staging system for the disease based on MR imaging was developed. MR images were classified into three patterns: a band of low signal intensity (class I); an area of low signal intensity with internal spot(s) of high signal (class II); and an area of low signal intensity without internal spots of high signal (class III). Most MR class I lesions were in radiographic stage I (normal) or II (sclerotic or cystic changes without collapse). Most MR class II lesions were in radiographic stage III (segmental collapse), and most MR class III lesions were in stage III or IV (secondary degenerative changes). The MR image classification was closely correlated with radiographic staging (p<0.01, using [chi] square test). We considered that this classification closely reflected the different stages of the disease according to the histopathology of the bone marrow. (author).

Ultrafast MR Imaging in Pediatric Neuroradiology

International Nuclear Information System (INIS)

Singh, R.K.; Smith, J.T.; Wilkinson, I.D.; Griffiths, P.D.

2003-01-01

Purpose: To compare the diagnostic information obtained from ultrafast MR imaging with standard MR imaging techniques in pediatric neuroradiology. The goal was to judge whether ultrafast methods can be used to replace standard methods and reduce the need for sedation or general anesthesia as a result of the considerably shorter scan times. Material and Methods: Our prospective study involved 125 patients. Routine clinical imaging was performed along with two ultrafast methods. Single shot fast spin echo (SSFSE) was used to give T2-weighted images and an echo planar imaging (EPI) sequence to provide a T1-weighted images. The ultrafast images were presented to an experienced neuro radiologist who was also given the information present on the initial referral card. These reports based on the ultrafast images were then compared with the formal radiologic report made solely on the basis of the standard imaging. Results: The overall sensitivity and specificity for ultrafast imaging when compared to the reference standard were 78% and 98% with positive and negative predictive values of 98% and 76%. Pathologies characterized by small areas of subtle T2 prolongation were difficult or impossible to see on the ultrafast images but otherwise they provided reliable information. Conclusions: This paper demonstrates that ultrafast MR imaging can diagnose many pediatric intracranial abnormalities as well as standard methods. Anatomic resolution limits its capacity to define subtle developmental anomalies and contrast resolution limitations of the ultrafast methods reduce the detection of pathology characterized by subtle T2 prolongation

Craniopharyngioma identification by CT and MR imaging at 1.5 T

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Hald, J.K. [Dept. of Radiology, Rikshospitalet, Oslo Univ. (Norway)]|[Dept. of Radiology, Univ. of Michigan Hospitals, Ann Arbor, MI (United States); Eldevik, O.P. [Dept. of Radiology, Rikshospitalet, Oslo Univ. (Norway)]|[Dept. of Radiology, Univ. of Michigan Hospitals, Ann Arbor, MI (United States); Skalpe, I.O. [Dept. of Radiology, Rikshospitalet, Oslo Univ. (Norway)]|[Dept. of Radiology, Univ. of Michigan Hospitals, Ann Arbor, MI (United States)

1995-03-01

To compare the detectability of craniopharyngiomas by CT and MR imaging, preoperative CT and MR studies obtained within 16 days of each other were evaluated retrospectively in 9 patients. MR imaging demonstrated cystic and solid tumor components in all 9 tumors, and enhancement in the 7 tumors that were studied after contrast medium injection. MR imaging demonstrated a signal void consistent with calcification in 4 patients. Combining unenhanced and contrast medium-enhanced studies, CT also identified all the tumors. CT demonstrated cysts in 7 lesions, calcification in 7 and enhancement in 6 of the 7 lesions that received i.v. contrast medium. Calcification was better seen by CT than MR imaging, while MR imaging identified cystic tumor components not seen on CT. The contrast medium enhancement pattern was the same with the 2 modalities. MR imaging of the sellar region, including at least one contrast medium-enhanced sequence, should be sufficient in most instances to establish a preoperative diagnosis of craniopharyngioma. (orig.).

Simultaneous PET and MR imaging

International Nuclear Information System (INIS)

Yiping Shao; Cherry, Simon R.; Meadors, Ken; Siegel, Stefan; Silverman, Robert W.; Farahani, Keyvan; Marsden, Paul K.

1997-01-01

We have developed a prototype PET detector which is compatible with a clinical MRI system to provide simultaneous PET and MR imaging. This single-slice PET system consists of 48 2x2x10mm 3 LSO crystals in a 38 mm diameter ring configuration that can be placed inside the receiver coil of the MRI system, coupled to three multi-channel photomultipliers housed outside the main magnetic field via 4 m long and 2 mm diameter optical fibres. The PET system exhibits 2 mm spatial resolution, 41% energy resolution at 511 keV and 20 ns timing resolution. Simultaneous PET and MR phantom images were successfully acquired. (author)

The role of MR imaging in scaphoid disorders

International Nuclear Information System (INIS)

Karantanas, Apostolos; Dailiana, Zoe; Malizos, Konstantinos

2007-01-01

The scaphoid bone of the wrist is one of the most commonly fractured bones in the body. Due to its importance in the biomechanics and functionality of the wrist, it is important to depict and characterize the type of injury. Plain radiographs and scintigraphy may fail to disclose the type and severity of the injury. In patients with normal initial plain radiographs, MR imaging can discriminate occult fractures from bone bruises and may also demonstrate ligamentous disruption. MR imaging can also discriminate the proximal pole viability versus avascular necrosis secondary to previous fracture, which is important for treatment planning. Treatment of non-united fractures with vascularized grafts can be evaluated with contrast-enhanced MR imaging. Idiopathic osteonecrosis or Preiser's disease was originally described after trauma. The non-traumatic disorders of the scaphoid include post-traumatic osteoarthritis, inflammatory bone marrow edema in patients with rheumatoid arthritis, and osteomyelitis. MR imaging is helpful in all the above disorders to demonstrate early bone marrow edema, cartilage degeneration and associated subchondral marrow changes. The most commonly found tumors in the scaphoid are usually benign and include enchondroma, osteoblastoma and osteoid osteoma. MR imaging is not mandatory for the initial diagnosis, which should be based on plain X-ray findings. (orig.)

The role of MR imaging in scaphoid disorders

Energy Technology Data Exchange (ETDEWEB)

Karantanas, Apostolos [University of Crete, Department of Radiology, Medical School, Heraklion (Greece); University Hospital, Department of Radiology, Stavrakia, Heraklion (Greece); Dailiana, Zoe; Malizos, Konstantinos [University of Thessaly, Department of Orthopedic Surgery, School of Health Sciences, Larissa (Greece)

2007-11-15

The scaphoid bone of the wrist is one of the most commonly fractured bones in the body. Due to its importance in the biomechanics and functionality of the wrist, it is important to depict and characterize the type of injury. Plain radiographs and scintigraphy may fail to disclose the type and severity of the injury. In patients with normal initial plain radiographs, MR imaging can discriminate occult fractures from bone bruises and may also demonstrate ligamentous disruption. MR imaging can also discriminate the proximal pole viability versus avascular necrosis secondary to previous fracture, which is important for treatment planning. Treatment of non-united fractures with vascularized grafts can be evaluated with contrast-enhanced MR imaging. Idiopathic osteonecrosis or Preiser's disease was originally described after trauma. The non-traumatic disorders of the scaphoid include post-traumatic osteoarthritis, inflammatory bone marrow edema in patients with rheumatoid arthritis, and osteomyelitis. MR imaging is helpful in all the above disorders to demonstrate early bone marrow edema, cartilage degeneration and associated subchondral marrow changes. The most commonly found tumors in the scaphoid are usually benign and include enchondroma, osteoblastoma and osteoid osteoma. MR imaging is not mandatory for the initial diagnosis, which should be based on plain X-ray findings. (orig.)

Dynamic MR imaging of hepatoma treated by transcatheter arterial embolization therapy

International Nuclear Information System (INIS)

Yamashita, Y.; Yoshimatsu, S.; Sumi, M.; Harada, M.; Takahashi, M.

1993-01-01

The effect of transcatheter arterial chemo-embolization theory (TACE) for hepatoma was evaluated with dynamic MR imaging with Gd-DTPA in 37 patients (44 tumors). TACE was performed using Lipiodol/cis-platinum and gelatin sponge (or microspheres) as an embolic material. All patients were examined with dynamic CT and MR imaging before and after treatment. On conventional spin echo images, changes of signal intensity after treatment varied regardless of presence of Lipiodol. Dynamic MR imaging revealed changes of tumor vascularity before and after treatment. On histologic correlation, areas of persistent tumor enhancement on dynamic MR imaging corresponded to areas of viable tumor cells while areas of nonenhancement corresponded to areas of necrosis. Dynamic MR imaging was superior in contrast resolution and was not influenced by the presence of Lipiodol compared with dynamic CT, and therefore residual viable tumors were better defined by dynamic MR imaging. (orig.)

Plantar tendons of the foot: MR imaging and US.

Science.gov (United States)

Donovan, Andrea; Rosenberg, Zehava Sadka; Bencardino, Jenny T; Velez, Zoraida Restrepo; Blonder, David B; Ciavarra, Gina A; Adler, Ronald Steven

2013-01-01

Tendon disorders along the plantar aspect of the foot may lead to significant symptoms but are often clinically misdiagnosed. Familiarity with the normal anatomy of the plantar tendons and its appearance at magnetic resonance (MR) imaging and ultrasonography (US) is essential for recognizing plantar tendon disorders. At MR imaging, the course of the plantar tendons is optimally visualized with dedicated imaging of the midfoot and forefoot. This imaging should include short-axis images obtained perpendicular to the long axis of the metatarsal shafts, which allows true cross-sectional evaluation of the plantar tendons. Normal plantar tendons appear as low-signal-intensity structures with all MR sequences. At US, accurate evaluation of the tendons requires that the ultrasound beam be perpendicular to the tendon. The normal tendon appears as a compact linear band of echogenic tissue that contains a fine, mixed hypoechoic and hyperechoic internal fibrillar pattern. Tendon injuries can be grouped into six major categories: tendinosis, peritendinosis, tenosynovitis, entrapment, rupture, and instability (subluxation or dislocation) and can be well assessed with both MR imaging and US. The radiologist plays an important role in the diagnosis of plantar tendon disorders, and recognizing their imaging appearances at MR imaging and US is essential.

High-field MR imaging of spinal cord multiple sclerosis

International Nuclear Information System (INIS)

De La Paz, R.L.; Floris, R.; Norman, D.; Enzmann, D.R.

1987-01-01

Fifty-one high-field MR imaging studies (1.5 T, General Electric Signa) of the spinal cord were performed in 42 patients (27 female, 15 male; mean age, 40 years) with clinically definitive (n = 34) or probable (n = 8) multiple sclerosis and suspected spinal cord lesions. MR imaging showed focal spinal cord abnormalities in 38 (75%) of 51 studies. T2-weighted images were abnormal (showing foci of high signal intensity) in 38 studies, T1-weighted images were abnormal (showing areas of low signal intensity or mass effect) in 16 (42%) of 38, and GRASS images were abnormal (showing foci of high signal intensity) in 9 (82%) of 11 cases. Brain MR imaging showed periventricular lesions typical of multiple sclerosis in 34 (81%) of 42 studies. Spinal cord studies were positive in eight cases with normal brain MR images, and brain studies were positive in 13 instances of normal spinal cord MR images. Four lesions were at the cervicomedullary junction, 44 in the cervical spinal cord, and three in the thoracic cord. Mass effect in cord lesions, simulating neoplasm, was seen in seven patients during the acute symptomatic phase. Serial studies in three patients with decreasing symptoms showed a reduction after 3-4 weeks and resolution of the mass effect after 2-6 months

Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging.

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Mark A Lum

Full Text Available To evaluate the ability of IA MR perfusion to characterize meningioma blood supply.Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA and intravenous (IV T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA dural, internal carotid artery (ICA dural, or pial. MR perfusion data regions of interest (ROIs were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM, relative cerebral blood flow (rCBF, relative cerebral blood volume (rCBV, and mean transit time (MTT. Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling.18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11, ICA dural (n = 4, or pial (n = 3. FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion.

Evaluation of ambiguous genitalia with MR imaging

International Nuclear Information System (INIS)

Secaf, E.; Nuruddin, R.; Hricak, H.; Conte, F.A.

1989-01-01

To assess the potential of MR imaging in the evaluation of patients with ambiguous genitalia. Twenty-three consecutive patients with ambiguous genitalia at birth or phenotypic anomalies at puberty were included in this study. MR imaging was performed on a 1.5-T unit using T1- (600/30) and T2- (2,500/70) weighted sequences. In patients aged 5 years or less, 3-mm contiguous sagittal and transaxial sections were obtained. The same imaging planes at 5-mm intervals were obtained in older patients. MR findings were compared to those of surgery (n = 14) or biochemical assays (n = 9). Diagnoses included true hermaphroditism (n = 2), pseudohermaphroditism (n = 6), Turner syndrome (n = 2), testicular feminization (n = 2), adrenogenital syndrome (n = 3), vaginal agenesis (n = 3), cloacal abnormality (n = 2), microphallus (n = 2), and double phallus (n = 1. MR imaging correctly identified the presence or absence of the vagina (n = 10) and uterus (n = 9), thus helping in the diagnosis and management of patients with ambiguous genitalia. Demonstration of development of corpora cavernosa, corpora spongiosa, undescended testis, or partial vaginal agenesis assisted in the surgical approach

Evaluation of the cervical neural foramina with MR imaging

International Nuclear Information System (INIS)

Czervionke, L.F.; Daniels, D.L.; Ho, P.S.P.; Yu, S.; Williams, A.L.; Haughton, V.M.

1987-01-01

Accurately diagnosing the causes of cervical radiculopathy with MR imaging requires better understanding of the anatomic relationships in the cervical neural foramina. The cervical foramina were studied in three ways: (1) In cadavers, the paravertebral veins were injected with paramagnetic contrast material. Cryomicrotome sections were then correlated with MR images. (2) In patients, the cervical foramina were studied with MR imaging with intravenous Gd-DTPA. (3) Normal volunteers were scanned using spin-echo and gradient-echo techniques. The nerve root sheaths, ganglia, vessels, and bone margins of the cervical foramina can be well demonstrated by MR imaging. Intravenous Gd-DTPA enhances some normal structures in the foramen. The authors report on optimal pulse sequences for evaluating the cervical neural foramina

Mutiple sclerosios of the spinal cord: MR imaging findings

International Nuclear Information System (INIS)

Kim, Young Hoon; Chang, Kee Hyun; Kim, Sam Soo; Park, Byung Kwan; Seong, Chang Kyu; Han, Moon Hee; Cho, Yong Jin; Jeon, Beom Seok

1998-01-01

To evaluate the MR appearance of multiple sclerosis in the spinal cord. Between January 1990 and December 1996, we retrospectively analyzed 27 spinal MR images of 18 patients in whom-on the basis of Poser's diagnostic critera-multiple sclerosis of the spinal cord had been diagnosed. Eleven patients were men and seven were women, and they were aged between 18 and 58(mean, 37) years. Using T1-weighted sagittal(n=3D27), T2-weighted axial(n=3D26) and sagittal(n=3D27), and contrast enhanced T1-weighted(n=3D14) images, lesions were analyzed for multiplicity, location, length, cross-sectional area and location, cord size, and enhancement pattern. Brain MR images(n=3D15) were also evaluated. In 14 of 18 patients, a solitary lesion was seen on initial MR imaging. Four of the 14 had double lesions, and on follow-up MR imaging at 2-5 months, five were seen to have double lesions. Eleven lesions were found in the cervical cord, and 12 in the thoracic cord, two were in the cervicothoracic and two in the thoracolumbar region. The length of 12 lesions was less than two vertebral heights, while 15 extended for more than two vertebral heights. Six lesions occupied less than 50% of the cross-sectional area of the cord and the other 20 occupied more than 50% of this area. Cord size was enlarged in 17 cases, unchanged in eight, and atrophic in two. Eight lesions in 14 patients who underwent enhanced MR imaging showed focal contrast enhancement; there was patchy enhacement in two, nodular enhancement in two, and linear enhancement in four. Among 15 MR images of the brain, high-signal intensity lesions, compatible with multiple sclerosis, were demonstrated in seven cases. Multiple sclerosis plaques in the spinal cord frequently extend for more than two vertebral body heights of either the cervical or thoracic level, occupy more than 50% of the cross-sectional area and manifest as enlarged cord. But the MR imaging findings, however, are nonspecific. Abnormalities were seen in

Prospective evaluation of contrast-enhanced MR imaging after uncomplicated lumbar discography

International Nuclear Information System (INIS)

Carrino, John A.; Swathwood, Todd C.; Morrison, William B.; Glover, J.M.

2007-01-01

Postdiscography infection is an uncommon complication. Magnetic resonance (MR) imaging is often the modality of choice for evaluating spinal infection. Discography entails disc access and fluid injection that could alter the baseline MR imaging appearance of the spine and be confounded for infection. Our purpose was to describe the MR imaging findings of the lumbar spine subsequent to uncomplicated discography and to determine if this may mimic infection. In a prospective cohort study of eight adults (age 22-64 years, mean 45 years) with 22 intradiscal injections, all subjects underwent routine unenhanced and contrast-enhanced MR imaging during the 2-3 week interval postdiscography. A subset of four returned for additional MR imaging during the 4-8 week interval postdiscography. MR images were reviewed for intradiscal, endplate, marrow, and epidural findings and then compared with prediscography examinations. Infection was excluded by clinical documentation. Postdiscography MR imaging showed that almost all levels were similar to baseline prediscography examinations. No levels developed new vertebral marrow edema, fluid-like intradiscal signal, endplate irregularity, or epidural abnormality. Two subjects simulated potential discitis, but these findings were unchanged from prediscography and were related to prior surgery. Uncomplicated lumbar spine discography does not cause MR imaging changes that simulate discitis. (orig.)

Prospective evaluation of contrast-enhanced MR imaging after uncomplicated lumbar discography

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Carrino, John A. [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Outpatient Center, Baltimore, MD (United States); Swathwood, Todd C. [Blue Ridge Orthopedic Associates, Seneca (United States); Morrison, William B. [Thomas Jefferson University Hospital, Department of Radiology, Philadelphia, PA (United States); Glover, J.M. [Northern Arizona Orthopaedics, Flagstaff, AZ (United States)

2007-04-15

Postdiscography infection is an uncommon complication. Magnetic resonance (MR) imaging is often the modality of choice for evaluating spinal infection. Discography entails disc access and fluid injection that could alter the baseline MR imaging appearance of the spine and be confounded for infection. Our purpose was to describe the MR imaging findings of the lumbar spine subsequent to uncomplicated discography and to determine if this may mimic infection. In a prospective cohort study of eight adults (age 22-64 years, mean 45 years) with 22 intradiscal injections, all subjects underwent routine unenhanced and contrast-enhanced MR imaging during the 2-3 week interval postdiscography. A subset of four returned for additional MR imaging during the 4-8 week interval postdiscography. MR images were reviewed for intradiscal, endplate, marrow, and epidural findings and then compared with prediscography examinations. Infection was excluded by clinical documentation. Postdiscography MR imaging showed that almost all levels were similar to baseline prediscography examinations. No levels developed new vertebral marrow edema, fluid-like intradiscal signal, endplate irregularity, or epidural abnormality. Two subjects simulated potential discitis, but these findings were unchanged from prediscography and were related to prior surgery. Uncomplicated lumbar spine discography does not cause MR imaging changes that simulate discitis. (orig.)

MR imaging of kidneys: functional evaluation using F-15 perfusion imaging

International Nuclear Information System (INIS)

Grattan-Smith, J. Damien; Jones, Richard A.; Little, Stephen; Perez-Bayfield, Marcos R.; Broecker, Bruce; Smith, Edwin A.; Scherz, Hal C.; Kirsch, Andrew J.

2003-01-01

Children with hydronephrosis are typically investigated by a combination of diuretic renal scintigraphy, ultrasound, and voiding cystourethrography. Unfortunately, there is no gold standard to assess obstruction. The purpose of our study was to evaluate the utility of dynamic contrast enhanced MR urography in the investigation of children with hydronephrosis to define urinary tract anatomy, to calculate differential renal function and to assess urinary tract obstruction. Dynamic contrast-enhanced MR imaging was performed in 40 children with unilateral hydronephrosis. There were 14 girls and 26 boys with an age range of 1 month to 14 years (mean 1.4 years). The information from traditional imaging modalities was compared to the information obtained from the single MR study. The anatomic imaging with MR urography was superior to other modalities. The split renal function was estimated with MR urography by calculating the volume of enhancing renal parenchyma and was comparable to renal scintigraphy (r=0.98). By using surgery versus non-surgery as the decision point, with MR urography the sensitivity was 100%, specificity 71%, positive predictive value 86%, negative predictive value 100%, and diagnostic efficiency 90%. For renal scintigraphy the sensitivity was 96%, the specificity 56%, positive predictive value 76%, negative predictive value 90%, and diagnostic efficiency 79%. Dynamic contrast-enhanced MR urography provides superior anatomic and functional information when compared with ultrasound and diuretic renal scintigraphy. The information is gathered in a single study that does not use ionizing radiation. It is likely that MR urography will replace renal scintigraphy in the evaluation of hydronephrosis in children. (orig.)

MR imaging of kidneys: functional evaluation using F-15 perfusion imaging

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Grattan-Smith, J. Damien; Jones, Richard A.; Little, Stephen [Department of Pediatric Radiology, Children' s Healthcare of Atlanta, Emory University School of Medicine, 1001 Johnson Ferry Road, GA 30342, Atlanta (United States); Perez-Bayfield, Marcos R.; Broecker, Bruce; Smith, Edwin A.; Scherz, Hal C.; Kirsch, Andrew J. [Department of Pediatric Urology, Children' s Healthcare of Atlanta, Emory University School of Medicine, GA 30342, Atlanta (United States)

2003-05-01

Children with hydronephrosis are typically investigated by a combination of diuretic renal scintigraphy, ultrasound, and voiding cystourethrography. Unfortunately, there is no gold standard to assess obstruction. The purpose of our study was to evaluate the utility of dynamic contrast enhanced MR urography in the investigation of children with hydronephrosis to define urinary tract anatomy, to calculate differential renal function and to assess urinary tract obstruction. Dynamic contrast-enhanced MR imaging was performed in 40 children with unilateral hydronephrosis. There were 14 girls and 26 boys with an age range of 1 month to 14 years (mean 1.4 years). The information from traditional imaging modalities was compared to the information obtained from the single MR study. The anatomic imaging with MR urography was superior to other modalities. The split renal function was estimated with MR urography by calculating the volume of enhancing renal parenchyma and was comparable to renal scintigraphy (r=0.98). By using surgery versus non-surgery as the decision point, with MR urography the sensitivity was 100%, specificity 71%, positive predictive value 86%, negative predictive value 100%, and diagnostic efficiency 90%. For renal scintigraphy the sensitivity was 96%, the specificity 56%, positive predictive value 76%, negative predictive value 90%, and diagnostic efficiency 79%. Dynamic contrast-enhanced MR urography provides superior anatomic and functional information when compared with ultrasound and diuretic renal scintigraphy. The information is gathered in a single study that does not use ionizing radiation. It is likely that MR urography will replace renal scintigraphy in the evaluation of hydronephrosis in children. (orig.)

Complications of anterior cruciate ligament reconstruction: MR imaging

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Papakonstantinou, Olympia; Chung, Christine B.; Chanchairujira, Kullanuch; Resnick, Donald L. [Department of Radiology, Veterans Affairs Medical Center, University of California, 3350 La Jolla Village Dr., San Diego, CA 92161 (United States)

2003-05-01

Arthroscopic reconstruction of the anterior cruciate ligament (ACL) using autografts or allografts is being performed with increasing frequency, particularly in young athletes. Although the procedure is generally well tolerated, with good success rates, early and late complications have been documented. As clinical manifestations of graft complications are often non-specific and plain radiographs cannot directly visualize the graft and the adjacent soft tissues, MR imaging has a definite role in the diagnosis of complications after ACL reconstruction and may direct subsequent therapeutic management. Our purpose is to review the normal MR imaging of the ACL graft and present the MR imaging findings of a wide spectrum of complications after ACL reconstruction, such as graft impingement, graft rupture, cystic degeneration of the graft, postoperative infection of the knee, diffuse and localized (i.e., cyclops lesion) arthrofibrosis, and associated donor site abnormalities. Awareness of the MR imaging findings of complications as well as the normal appearances of the normal ACL graft is essential for correct interpretation. (orig.)

Complications of anterior cruciate ligament reconstruction: MR imaging

International Nuclear Information System (INIS)

Papakonstantinou, Olympia; Chung, Christine B.; Chanchairujira, Kullanuch; Resnick, Donald L.

2003-01-01

Arthroscopic reconstruction of the anterior cruciate ligament (ACL) using autografts or allografts is being performed with increasing frequency, particularly in young athletes. Although the procedure is generally well tolerated, with good success rates, early and late complications have been documented. As clinical manifestations of graft complications are often non-specific and plain radiographs cannot directly visualize the graft and the adjacent soft tissues, MR imaging has a definite role in the diagnosis of complications after ACL reconstruction and may direct subsequent therapeutic management. Our purpose is to review the normal MR imaging of the ACL graft and present the MR imaging findings of a wide spectrum of complications after ACL reconstruction, such as graft impingement, graft rupture, cystic degeneration of the graft, postoperative infection of the knee, diffuse and localized (i.e., cyclops lesion) arthrofibrosis, and associated donor site abnormalities. Awareness of the MR imaging findings of complications as well as the normal appearances of the normal ACL graft is essential for correct interpretation. (orig.)

MR imaging of rectus femoris origin injuries

International Nuclear Information System (INIS)

Ouellette, Hugue; Thomas, Bijoy J.; Nelson, Erik; Torriani, Martin

2006-01-01

To describe the MR imaging findings of acute and chronic rectus femoris origin (RFO) injuries. A retrospective review of pelvic and hip MR imaging procedures was performed over a 4-year period for detection of cases with injuries to the RFO. Subjects were classified as having either acute or chronic symptoms. MR imaging studies, radiographs, CT scans, radiology reports, medical records, and operative notes were reviewed. Imaging analysis was directed to assess injuries affecting the direct and indirect heads of the RFO. Concurrent osseous, cartilaginous and musculotendinous injuries were tabulated. The incidence of RFO injuries on MR imaging was 0.5% (17/3160). With the exception of one case of anterior inferior iliac spine apophysis avulsion and partial tear of the direct head of RFO, all subjects had indirect head of RFO injuries (acute injury 8/9, chronic injury 8/8). Partial tear of the direct head of RFO was less frequently seen (acute injury 3/9, chronic injury 2/8). Partial tears of the conjoint tendon were least frequent (acute 1/9, chronic 2/8). No full-thickness tears of the RFO were noted. Associated labral tears were seen in only one case, with no other concomitant abnormality of the articular cartilage or surrounding soft tissues. All RFO injuries were treated non-operatively. Injuries of the RFO are uncommon on MR examinations of pelvis/hips and may occur in a sequence progressing from indirect head injury to involvement of direct head and conjoint tendon in more severe cases. (orig.)

MR imaging of the spine in children

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Duthoy, M.J.; Lund, G.

1988-08-01

MR imaging was reviewed in 66 pediatric spinal cord patients with diagnoses of posterior fossa tumor, primary spinal cord tumor, metastatic disease, neuroectodermal disorder, congenital malformation, trauma, and demyelinating, neurodegenerative, or metabolic disorders. MR proved to be useful in delineating the extent of posterior fossa and cord tumor including metastasis to the cord. MR was of limited value in demyelinating and metabolic disorders. Arnold Chiari malformations, syringomyelia, tethered cord and meningoceles were all easily evaluated using MR.

MR imaging of cerebral palsy

International Nuclear Information System (INIS)

Saginoya, Toshiyuki; Yamaguchi, Keiichiro; Kuniyoshi, Kazuhide

1996-01-01

We evaluated 35 patients with cerebral palsy on the basis of MR imaging findings in the brain. The types of palsy were spastic quadriplegia (n=11), spastic diplegia (n=9), spastic hemiplegia (n=2), double hemiplegia (n=1), athetosis (n=10) and mixed (n=2). Of all patients, 28 (80%) generated abnormal findings. In spastic quadriplegia, although eight cases revealed severe brain damage, two cases showed no abnormal findings in the brain. One of the three had cervical cord compression caused by atlanto-axial subluxation. In spastic diplegia, the findings were divided according to whether the patient was born at term or preterm. If the patient had been born prematurely, the findings showed periventricular leukomalacia and abnormally high intensity in the posterior limbs of the internal capsule on T2-weighted images. MR imaging in spastic hemiplegia revealed cerebral infarction. In the athetoid type, half of all cases showed either no abnormal findings or slight widening of the lateral ventricle. Three cases showed abnormal signals of the basal ganglia. The reason why athetoid-type palsy did not show severe abnormality is unknown. We believe that MR imaging is a useful diagnostic modality to detect damage in the brain in cerebral palsy and plays an important role in the differentiation of cerebral palsy from the spastic palsy disease. (author)

MR imaging of cerebral palsy

Energy Technology Data Exchange (ETDEWEB)

Saginoya, Toshiyuki [Urasoe General Hospital, Okinawa (Japan); Yamaguchi, Keiichiro; Kuniyoshi, Kazuhide [and others

1996-06-01

We evaluated 35 patients with cerebral palsy on the basis of MR imaging findings in the brain. The types of palsy were spastic quadriplegia (n=11), spastic diplegia (n=9), spastic hemiplegia (n=2), double hemiplegia (n=1), athetosis (n=10) and mixed (n=2). Of all patients, 28 (80%) generated abnormal findings. In spastic quadriplegia, although eight cases revealed severe brain damage, two cases showed no abnormal findings in the brain. One of the three had cervical cord compression caused by atlanto-axial subluxation. In spastic diplegia, the findings were divided according to whether the patient was born at term or preterm. If the patient had been born prematurely, the findings showed periventricular leukomalacia and abnormally high intensity in the posterior limbs of the internal capsule on T2-weighted images. MR imaging in spastic hemiplegia revealed cerebral infarction. In the athetoid type, half of all cases showed either no abnormal findings or slight widening of the lateral ventricle. Three cases showed abnormal signals of the basal ganglia. The reason why athetoid-type palsy did not show severe abnormality is unknown. We believe that MR imaging is a useful diagnostic modality to detect damage in the brain in cerebral palsy and plays an important role in the differentiation of cerebral palsy from the spastic palsy disease. (author)

Optimizing MR imaging-guided navigation for focused ultrasound interventions in the brain

Science.gov (United States)

Werner, B.; Martin, E.; Bauer, R.; O'Gorman, R.

2017-03-01

MR imaging during transcranial MR imaging-guided Focused Ultrasound surgery (tcMRIgFUS) is challenging due to the complex ultrasound transducer setup and the water bolus used for acoustic coupling. Achievable image quality in the tcMRIgFUS setup using the standard body coil is significantly inferior to current neuroradiologic standards. As a consequence, MR image guidance for precise navigation in functional neurosurgical interventions using tcMRIgFUS is basically limited to the acquisition of MR coordinates of salient landmarks such as the anterior and posterior commissure for aligning a stereotactic atlas. Here, we show how improved MR image quality provided by a custom built MR coil and optimized MR imaging sequences can support imaging-guided navigation for functional tcMRIgFUS neurosurgery by visualizing anatomical landmarks that can be integrated into the navigation process to accommodate for patient specific anatomy.

Leukoencephalopathy following CNS prophylaxis therapy in pediatric leukemia : MR imaging findings

International Nuclear Information System (INIS)

Kim, Jong Sub; Lee, Sang Kwon; Kim, Tae Hun; Kim, Yong Joo; Kang, Duck Sik; Kwon, Soon Hak; Lee, Keon Soo

2001-01-01

To evaluate the MR imaging findings and the usefulness of MR imaging in the diagnosis and follow-up leukoencephalopathy following CNS prophylaxis therapy in pediatric leukemia. We retrospectively evaluated the MR imaging findings of eight children with white matter abnormalities on MR out of seventeen acute leukemic patients with various neuropsychiatric symptoms who received intrathecal methotrexate administration, with or without cranial irradiation. In all cases, initial MR was performed within a week of the onset of neuropsychiatric symptoms. Follow-up MR was performed one to sixteen months after initial study, and the MR imaging findings were compared with the initial findings. The initial MR imaging findings were classified into three categories : focal or multifocal white matter abnormalities (3/8), and diffuse white matter abnormalities without enhancement (3/8), and diffuse white matter abnormalities with enhancement (2/8). At follow-up MR, diffuse or focal atrophic changes were noted in all children. White matter abnormalities improved in two out of three patients with focal or multifocal white matter abnormalities. In five with diffuse white matter abnormalities, the extent of these showed no significant change, but contrast enhancement was markedly reduced in two children in whom diffuse white matter abnormalities with enhancement had been demonstrated. In pediatric leukemia, the MR imaging findings of leukoencephalopathy following CNS prophylaxis therapy are variable, but are specific with the clinical history of neuropsychiatric symptoms after intrathecal methotrexate administration, with or without cranial irradiation. The MR imaging is valuable in the diagnosis and follow-up of leukoencephalopathy following CNS prophylaxis therapy in pediatric leukemia

MR imaging of pontine infarction within 2 weeks after ictus

Energy Technology Data Exchange (ETDEWEB)

Uchino, Akira; Hata, Hirofumi; Ohno, Masato (Kyushu Rosai Hospital, Fukuoka (Japan))

1991-08-01

Magnetic resonance (MR) images of 10 patients with pontine infarction were reviewed. A total of 17 examinations were performed on a 1.5 Tesla high-field scanner (GE) within two weeks after ictus. The infarcted area was detected by MR as early as 20 hours after stroke in one case. However, MR images obtained in two cases three and nine hours after onset were unremarkable. It is therefore suggested that follow-up study should be performed when initial MR images within 20 hours postictus are normal. T{sub 1}-weighted images at four, nine and twelve days after ictus were interpreted as normal. In two of these three examinations, the infarcted areas were clearly demonstrated as hyperintense lesions on T{sub 2}-weighted images. In the other examination, however, an area of mildly increased signal intensity was seen on T{sub 2}-weighted images. This case suggests that the fogging effect is also observed on MR imaging and that a small pontine infarction may be overlooked during the subacute stage. Basilar artery occlusion was detected as an absence-of-flow void in three of the ten patients. In conclusion, MR imaging proved to be a relatively useful diagnostic modality for evaluating acute and subacute pontine infarction. (author).

MR image-guided portal verification for brain treatment field

International Nuclear Information System (INIS)

Yin Fangfang; Gao Qinghuai; Xie Huchen; Nelson, Diana F.; Yu Yan; Kwok, W. Edmund; Totterman, Saara; Schell, Michael C.; Rubin, Philip

1998-01-01

Purpose: To investigate a method for the generation of digitally reconstructed radiographs directly from MR images (DRR-MRI) to guide a computerized portal verification procedure. Methods and Materials: Several major steps were developed to perform an MR image-guided portal verification procedure. Initially, a wavelet-based multiresolution adaptive thresholding method was used to segment the skin slice-by-slice in MR brain axial images. Some selected anatomical structures, such as target volume and critical organs, were then manually identified and were reassigned to relatively higher intensities. Interslice information was interpolated with a directional method to achieve comparable display resolution in three dimensions. Next, a ray-tracing method was used to generate a DRR-MRI image at the planned treatment position, and the ray tracing was simply performed on summation of voxels along the ray. The skin and its relative positions were also projected to the DRR-MRI and were used to guide the search of similar features in the portal image. A Canny edge detector was used to enhance the brain contour in both portal and simulation images. The skin in the brain portal image was then extracted using a knowledge-based searching technique. Finally, a Chamfer matching technique was used to correlate features between DRR-MRI and portal image. Results: The MR image-guided portal verification method was evaluated using a brain phantom case and a clinical patient case. Both DRR-CT and DRR-MRI were generated using CT and MR phantom images with the same beam orientation and then compared. The matching result indicated that the maximum deviation of internal structures was less than 1 mm. The segmented results for brain MR slice images indicated that a wavelet-based image segmentation technique provided a reasonable estimation for the brain skin. For the clinical patient case with a given portal field, the MR image-guided verification method provided an excellent match between

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

MR imaging in sports-related glenohumeral instability

International Nuclear Information System (INIS)

Woertler, Klaus; Waldt, Simone

2006-01-01

Sports-related shoulder pain and injuries represent a common problem. In this context, glenohumeral instability is currently believed to play a central role either as a recognized or as an unrecognized condition. Shoulder instabilities can roughly be divided into traumatic, atraumatic, and microtraumatic glenohumeral instabilities. In athletes, atraumatic and microtraumatic instabilities can lead to secondary impingement syndromes and chronic damage to intraarticular structures. Magnetic resonance (MR) arthrography is superior to conventional MR imaging in the diagnosis of labro-ligamentous injuries, intrinsic impingement, and SLAP (superior labral anteroposterior) lesions, and thus represents the most informative imaging modality in the overall assessment of glenohumeral instability. This article reviews the imaging criteria for the detection and classification of instability-related injuries in athletes with special emphasis on the influence of MR findings on therapeutic decisions. (orig.)

MR imaging assisted radiation therapy planning of brain tumors

International Nuclear Information System (INIS)

Just, M.; Roesler, H.P.; Higer, H.P.; Kutzner, J.; Thelen, M.

1990-01-01

This paper reports on the improvement of the accuracy of treatment portals in radiation therapy of brain tumors with use of MR imaging. After proper processing, the parasagittal MR image showing the largest tumor size and the midline sagittal image were superimposed. With common anatomic landmarks of midline tomogram and lateral simulation radiograph, commensurate reference grids were laid over both images in identical positions. Tumor coordinates were then transferred from the synthesized MR image to the lateral radiograph. Rectangular fields or individual shielding blocks encompassing the tumor could be drawn directly. This new method was used in 17 patients, and results were compared with CT-assisted results

Cine MR imaging of valvular heart disease

International Nuclear Information System (INIS)

Underwood, S.R.; Firmin, D.N.; Mohiaddin, R.H.; Klipstein, R.H.; Bogren, H.G.; Rees, R.S.O.; Longmore, D.B.

1987-01-01

Cine MR imaging shows details of cardiac valve motion and the turbulence caused by regurgitation and stenosis. In 30 patients, the area of turbulence proximal to regurgitant valves correlated well with the regurgitant fraction measured from right and left ventricular stroke volumes. Turbulence distal to stenotic valves did not correlate with the pressure gradient because abnormal valves that were not stenosed produced turbulence. Valve motion and the presence of thrombus were easier to assess than in conventional images. Cine MR imaging provides an important addition to conventional imaging in valvular regurgitation, but pressure gradients cannot be assessed in valvular stenosis

MR imaging in following follicular and endometrial development during the menstrual cycle

International Nuclear Information System (INIS)

Janus, C.L.; Gendal, E.S.; Wiczyk, H.; Rabinowitz, J.G.; Laufer, N.

1987-01-01

The authors assessed the usefulness of MR imaging in monitoring follicular and endometrial development during the menstrual cycle. MR images, sonograms, and hormonal levels of estradiol (E2) and progesterone (P) obtained from five ovulatory volunteers were evaluated in approximately days 4, 8, 12, 16, 20, and 24 of the cycle. MR imaging surpassed US in demonstrating endometrial and myometrial changes. Follicular growth and development seen on MR images correlated well with US appearance and hormonal levels, with MR imaging demonstrating more secondary smaller follicles than US. Information about the normal cycle obtained with MR imaging is described and may have practical implications for women in infertility programs undergoing stimulated cycles and in vitro fertilization

Towards integration of PET/MR hybrid imaging into radiation therapy treatment planning

International Nuclear Information System (INIS)

Paulus, Daniel H.; Thorwath, Daniela; Schmidt, Holger; Quick, Harald H.

2014-01-01

Purpose: Multimodality imaging has become an important adjunct of state-of-the-art radiation therapy (RT) treatment planning. Recently, simultaneous PET/MR hybrid imaging has become clinically available and may also contribute to target volume delineation and biological individualization in RT planning. For integration of PET/MR hybrid imaging into RT treatment planning, compatible dedicated RT devices are required for accurate patient positioning. In this study, prototype RT positioning devices intended for PET/MR hybrid imaging are introduced and tested toward PET/MR compatibility and image quality. Methods: A prototype flat RT table overlay and two radiofrequency (RF) coil holders that each fix one flexible body matrix RF coil for RT head/neck imaging have been evaluated within this study. MR image quality with the RT head setup was compared to the actual PET/MR setup with a dedicated head RF coil. PET photon attenuation and CT-based attenuation correction (AC) of the hardware components has been quantitatively evaluated by phantom scans. Clinical application of the new RT setup in PET/MR imaging was evaluated in anin vivo study. Results: The RT table overlay and RF coil holders are fully PET/MR compatible. MR phantom and volunteer imaging with the RT head setup revealed high image quality, comparable to images acquired with the dedicated PET/MR head RF coil, albeit with 25% reduced SNR. Repositioning accuracy of the RF coil holders was below 1 mm. PET photon attenuation of the RT table overlay was calculated to be 3.8% and 13.8% for the RF coil holders. With CT-based AC of the devices, the underestimation error was reduced to 0.6% and 0.8%, respectively. Comparable results were found within the patient study. Conclusions: The newly designed RT devices for hybrid PET/MR imaging are PET and MR compatible. The mechanically rigid design and the reproducible positioning allow for straightforward CT-based AC. The systematic evaluation within this study provides the

Discoid meniscus of the knee: MR imaging

International Nuclear Information System (INIS)

Kim, Sung Moon; Kang, Heung Sik; Ahn, Joong Mo; Seong, Sang Cheol

1992-01-01

To evaluate the role of magnetic resonance (MR) imaging in the diagnosis of the discoid meniscus, the authors reviewed 31 cases of discoid menisci diagnosed by MR imaging among which 16 cases received arthroscopy. Using knee surface coil, sagittal T1, T2 and proton density images and coronal T1 weighted images were obtained with 18 cm FOV and 4 mm/ 1 mm thickness/gap. A discoid meniscus was considered if three or more contiguous sagittal images demonstrated continuity of the meniscus between the anterior and posterior horns or the diameter of the mid-portion of the meniscus exceeded 15 mm on the coronal image. The authors also observed the associated abnormalities including tears of meniscus and ligament, meniscal cyst, and osteochondral defects. All discoid menisci were lateral menisci and torn discoid lateral menisci were present in 26 cases (83%). In two cases, tears of the contralateral medial meniscus were present. The tears of anterior and posterior cruciate ligaments, meniscal cyst, and osteochondral defects were present in 4, 2, 4, and 5 cases respectively. All collateral ligaments were intact. In conclusion MR imaging was useful for the detection of discoid meniscus and associated abnormalities

MR imaging of the normal pancreas

International Nuclear Information System (INIS)

Itoh, Hisao; Takahashi, Norio; Uchida, Yoshie; Nakayama, Gen; Bito, Kaoru; Haba, Hirotsugu; Kawamura, Masashi; Kataoka, Masaaki; Hamamoto, Ken.

1989-01-01

To evaluate current 1.5-T MR imaging with respiratory ordered phase encoding (ROPE) technique in the identification of pancreatic contour and main pancreatic duct, 100 normal subjects examined with spin echo technique including transaxial scans of T 1 -WI,T 2 -WI, and proton density (PD)-WI were reviewed. The results of MR imaging were then compared with computed tomography (CT). Pancreatic contour was divided into 3 parts; head, body, and tail. T 1 -WI was the best pulse sequence in describing pancreas and the rates of specific identification of head, body, and tail were 69%, 97%, and 92%, respectively. While these rates were 62%, 90%, and 92% with plain CT and 69%, 94%, and 94% with contrast-enhanced CT, respectively. A combination of MR imaging and CT yielded better rates of identification. The main pancreatic duct was visible in 44% as a low intensity line on T 1 -WI and in 16% on plain CT. Dorsal to pancreas, all of the major vessels were seen in every patients. Ventrally, retroperitoneal fat was important, however, it was not a limiting factor. When respiratory compensation using ROPE functioned well, it was possible to differentiate bowel from pancreas in patients with sparse fat because signal intensity of the pancreas tended to be higher than that of gastrointestinal wall and its contents on T 1 -WI. Current MR imaging seemed to be a complementary method with CT in the identification of the pancreas. (author)

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)

MR imaging

International Nuclear Information System (INIS)

Barbaric, Z.L.; Sukov, R.M.; Boechat, I.M.

1988-01-01

MR images were obtained from six patients with surgically proved hemorrhagic renal cysts and three with adult polycystic renal disease that contained many hemorrhagic cysts. Their appearance was compared with that of 30 simple renal cysts. Simple cysts were hypointense on T1-weighted spin-echo sequences and hyperintense to the kidney on T2-weighted sequences. On the same sequences, hemorrhagic cysts showed three patterns: (1) hyperintense-hyperintense, (2) isointense-hyperintense, and (3) hypointense-hypointense. The fluid-fluid interphase was identified in a number of hemorrhagic cysts on T2-weighted images. Three hemorrhagic cysts contained renal carcinoma. Hemorrhagic cysts may be impossible to differentiate from solid renal tumors except for layering

Clinical blood pool MR Imaging

Energy Technology Data Exchange (ETDEWEB)

Leiner, Tim [Maastrich University Medical Center (Netherlands). Dept. of Radiology; Goyen, Martin [University Medical Center Hamburg-Eppendorf (Germany); Rohrer, Mathias [Bayer Schering Pharma AG, Berlin (Germany). European Business Unit Diagnostic Imaging; Schoenberg, Stefan O. (eds.) [University Hospital Mannheim Medical Faculty Mannheim - Heidelberg Univ. (Germany). Dept. of Clinical Radiology and Nuclear Medicine

2008-07-01

Clinical Blood Pool MR Imaging - This excellent treatise on Vasovist {sup registered} created by a team of exceptional faculty who are pioneers in MR Angiography covers the basic techniques, safety, efficacy, image processing and pharmaco-economic details to successfully implement a new level of MRA image quality with this new contrast agent. Martin Prince, Cornell University, New York The editors and authors have made groundbreaking contributions towards establishing MR angiography in various investigative settings, rendering it more precise and applying it for diverse indications. The work presented here is founded upon the extensive experience of the editors, as well as the broad range of experience from other scientific working groups. Maximilian Reiser, Ludwig Maximilian University, Munich Vasovist {sup registered} (Gadofosveset), worldwide the first blood pool agent, has only recently become available for clinical use, but has already gained wide acceptance as a tool to improve magnetic resonance angiography. This book presents the first in-depth introduction to the basic physicochemical aspects of the agent, the application of Vasovist {sup registered} in clinical MRA, as well as potential clinical applications beyond MRA and patient management-related aspects. The first part of the book explains basic and technical properties of the agent and the differences of Vasovist {sup registered} compared to currently available extracellular agents. The second part contains detailed chapters on safety and efficacy. In the third part the focus is on MR angiographic applications, and in the fourth part of the book potential clinical fields beyond MRA are explored. All clinical chapters feature ready-to-use clinical protocols and a series of take home messages that concisely summarize the current role of blood pool imaging for each specific indication. (orig.)

Adult tibial intercondylar eminence fracture: evaluation with MR imaging

International Nuclear Information System (INIS)

Toye, Leon R.; Cummings, Dean P.; Armendariz, Gus

2002-01-01

Tibial intercondylar eminence (TIE) fractures are well described in the pediatric orthopedic literature. Adult TIEs are much less common, and limited literature exists on the subject. Adult knee hyperextension injuries commonly result in anterior cruciate ligament (ACL) injury; however, with significant trauma, a TIE enters the differential diagnosis. Identification and classification of TIE fractures typically has been provided by radiography. The incidence of concomitant injuries with magnetic resonance (MR) imaging in patients with adult TIE fractures has not been determined. We present a case of an adult type III TIE fracture seen on radiography that only with further MR imaging revealed a concomitant lateral tibial plateau fracture. Utilization of MR imaging altered the surgeon's course of treatment and postoperative care. Radiographic and MR images and a review of the literature are provided. (orig.)

MR imaging of marrow heterotopia in the hemoglobinopathies

International Nuclear Information System (INIS)

Trakadas, S.; Papavasiliou, C.; Gouliamos, A.D.; Vlahos, L.

1987-01-01

The MR imaging findings of marrow heterotopia in the costovertebral angles in patients with various hemoglobinopathies are presented. There was good correlation between the MR imaging findings and the appearance of the masses on conventional radiography or CT. The masses were of low signal intensity, similar to the signal intensity of the adjacent marrow of the thoracic spine, and surrounded by a high-intensity rim attributed to a layer of fat surrounding the masses. The latter finding is thought to be characteristic of marrow heterotopia masses. MR imaging may also reveal potential intrusion of marrow heterotopia into the spinal canal, thus eliminating the need for myelography

Brain MR imaging of systemic lupus erythematodes

International Nuclear Information System (INIS)

Kobayashi, Satoshi; Suzuki, Masayuki; Ueda, Fumiaki; Arai, Kazunori; Kobayashi, Takeshi; Kadoya, Masumi; Matsui, Osamu; Takashima, Tsutomu

1996-01-01

Brain MR imaging of 13 patients with systemic lupus erythematodus (SLE) were reviewed. Two major findings was obtained. One was deep white matter hyperintensity (DWMH) and periventricular hyperintensity (PVH), the other was cerebral infarction. In comparison with the same age group, relatively severe brain atrophy was also observed. It was thought that these findings were induced from the vasculitis caused by SLE. However, the influence of the steroid therapy could not be excluded. No definite correlation between MR findings and clinical symptoms were seen. In conclusion, when we interpret brain MR imaging of the patients with SLE, special attention should be paid to their age. (author)

MR imaging of diffuse thyroid disorders

International Nuclear Information System (INIS)

Inoue, Masaaki; Fujii, Koichi; Ohnishi, Takuya; Higashikawa, Motoki; Araki, Yutaka; Hamada, Tatsumi; Ishida, Osamu

1996-01-01

Magnetic resonance imaging was performed in 38 diffuse goiters, including 30 chronic thyroiditis and 8 Basedow disease. MR findings were analyzed as to degree of swelling, margin, internal structures including homogeneity and low intensity bands. With regard to signal intensity, thyroid-muscle-signal intensity ratios on T1 and T2-weighted images were measured in 19 normal thyroid glands, 30 chronic thyroiditis and 8 Basedow disease. Additionally thyroid-muscle-signal intensity ratios were compared between 19 hypothyroid glands and 11 euthyroid glands in chronic thyroiditis. Chronic thyroiditis tended to show lobulated margins, inhomogeneous intensity, and low intensity bands connecting with vessels or not. Basedow disease tended to display smooth margins, inhomogeneous intensity and low intensity bands connecting with vessels. Thyroid-muscle-signal intensity ratios of Basedow disease and chronic thyroiditis were significantly higher than those of normal thyroid gland at all sequences. In chronic thyroiditis thyroid-muscle-signal intensity ratios of euthyroid glands were significantly higher than those of hypothyroid glands. MR imaging could reflect pathologic features of diffuse goiters. Moreover, MR imaging is potentially contributory to speculate about thyroid function and degree of serious condition in diffuse thyroid disorders. (author)

Magnetic resonance (MR) imaging in hydrocephalus

International Nuclear Information System (INIS)

Tamaki, Norihiko; Nagashima, Tatsuya; Shirakuni, Takayuki; Masumura, Michio; Matsumoto, Satoshi

1985-01-01

The correlation between the findings on MR images and CT findings, clinical symptoms, and the results of various specific investigations was determined. MR imaging was more sensitive in demonstrating the pathology of the periventricular tissue in hydrocephalus than was CT scanning, although the overall correlation between MR and CT findings was good. The authors classified the periventricular high-signal intensities (PVHI) of MR images into 4 types according to the extension and grade of the PVHI. Type 0 has no PVHI. Type I has a band of the PVHI around the wall of the lateral ventricles, including the corpus callosum and the septum pellucidum. In Type III, PVHI extended half of the width of the periventricular white matter, while in Type IV PVHI occupied the entire white matter. CT scans showed periventricular lucency (PVL) only in the periventricular white matter, especially surrounding the anterior horn, but the PVHI was visible not only in wider areas of the entire periventricular white matter, but also in the corpus callosum and the septum pellucidum. The PVHI seen in case of hydrocephalus due to posterior fossa tumors was characterized by PVHI of Type I; the PVHI disappeared after CSF shunting in all cases. There was no PVHI in the cases of marked hydrocephalus due to aqueductal stenosis, which appeared to be compensated for a long period. In the cases of normal-pressure hydrocephalus, there were various types of PVHI. There was no correlation between the types of PVHI and the grade of ventriculomegaly. There was, however, a close correlation between the types of PVHI on MR images and the clinical symptoms, and the cerebral blood flow in cases of normal-pressure hydrocephalus. In some patients with normal-pressure hydrocephalus, the PVHI improved and the cerebral blood flow increased after cerebrospinal fluid shunting. (J.P.N.)

MR imaging of the knee

International Nuclear Information System (INIS)

Teresi, L.M.; Davis, S.J.; Ziemba, M.R.; Bradley, W.G. Jr.

1990-01-01

This paper describes the two-tone meniscus, a sign of meniscal tear on MR imaging. MR images obtained at 0.3 and 1.5 T with 3-mm-thick sections were compared with arthroscopic findings for 86 patients studied over a 2-year period. Menisci described as two-tone menisci had two geographic regions of slightly different signal intensity: a region of subtle increased signal extending to at least one articular surface, which did not have linear or globular configuration, effacing a region of normal meniscal signal. The higher-signal-intensity region shows signal intensity greater than normal meniscus but less than grade 2 or 3 changes, hyalin cartilage, or joint fluid

MR imaging findings of trigger thumb

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Chang, Eric Y.; Chen, Karen C.; Chung, Christine B. [VA San Diego Healthcare System, Radiology Service, San Diego, CA (United States); University of California, San Diego Medical Center, Department of Radiology, San Diego, CA (United States)

2015-08-15

Trigger finger (or trigger thumb), also known as sclerosing tenosynovitis, is a common clinical diagnosis that rarely presents for imaging. Because of this selection bias, many radiologists may not be familiar with the process. Furthermore, patients who do present for imaging frequently have misleading examination indications. To our knowledge, magnetic resonance (MR) imaging findings of trigger thumb have not been previously reported in the literature. In this article, we review the entity of trigger thumb, the anatomy involved, and associated imaging findings, which include flexor pollicis longus tendinosis with a distinct nodule, A1 pulley thickening, and tenosynovitis. In addition, in some cases, an abnormal Av pulley is apparent. In the rare cases of trigger finger that present for MR imaging, accurate diagnosis by the radiologist can allow initiation of treatment and avoid further unnecessary workup. (orig.)

MR imaging findings of trigger thumb

International Nuclear Information System (INIS)

Chang, Eric Y.; Chen, Karen C.; Chung, Christine B.

2015-01-01

Trigger finger (or trigger thumb), also known as sclerosing tenosynovitis, is a common clinical diagnosis that rarely presents for imaging. Because of this selection bias, many radiologists may not be familiar with the process. Furthermore, patients who do present for imaging frequently have misleading examination indications. To our knowledge, magnetic resonance (MR) imaging findings of trigger thumb have not been previously reported in the literature. In this article, we review the entity of trigger thumb, the anatomy involved, and associated imaging findings, which include flexor pollicis longus tendinosis with a distinct nodule, A1 pulley thickening, and tenosynovitis. In addition, in some cases, an abnormal Av pulley is apparent. In the rare cases of trigger finger that present for MR imaging, accurate diagnosis by the radiologist can allow initiation of treatment and avoid further unnecessary workup. (orig.)

Spinal infection: Evaluation with MR imaging and intraoperative spinal US

International Nuclear Information System (INIS)

Donovan Post, M.J.; Montalvo, B.M.; Quencer, R.M.; Katz, B.H.; Green, B.A.; Elsmont, F.

1987-01-01

MR spine images and/or intraoperative US scans in 15 patients were reviewed retrospectively and correlated with clinical and pathologic data to determine the diagnostic value of these modalities in spinal infection. In osteomyelitis and retrospinal abscess MR imaging was definitive; in myelitis it was positive but nonspecific. In epidural abscess concomitant with meningitis, myelography with CT and intraoperative US were superior to MR imaging. Intraoperative US could be used to distinguish these processes and to monitor surgical decompression. The authors recommend that MR imaging be performed at the screening examination in cases of spinal infection, accompanied by intraoperative US in all surgical cases

Serial MR imaging and 1H-MR spectroscopy in monozygotic twins with Tay-Sachs disease.

Science.gov (United States)

Imamura, A; Miyajima, H; Ito, R; Orii, K O

2008-10-01

Four-year-old monozygotic female twins with early onset Tay-Sachs disease are described. The sisters showed similar slowly progressive clinical symptoms and deterioration, however the younger sister also demonstrated intractable myoclonus in the right leg. The serial MR images and (1)H-MR spectroscopy of the brain were obtained in both twins. MR images showed high intensity on T (2)-weighted image in the bilateral white matter, however there were no signal changes in the basal ganglia and thalamus during any of the phases. The ratio of N-acetylaspartate (NAA)/creatine (Cr) was decreased in the both white matter lesions and the corpus striatum, and that of myoinositol (mI)/Cr was increased in the damaged white matter on MR spectroscopy. The elevation of the lactate peak was clearly demonstrated in the left basal ganglia of the younger sister; however it was not shown in cerebral lesions of the elder sister. Changes in metabolites on MR spectroscopy were closely linked to the respective clinical features of each twin. Follow-up examination by (1)H-MR spectroscopy is useful for the evaluation of neuronal changes in children with Tay-Sachs disease.

Functional MR imaging of the cervical spine in patients with rheumatoid arthritis

International Nuclear Information System (INIS)

Allmann, K.H.; Uhl, M.; Uhrmeister, P.; Neumann, K.; Langer, M.; Kempis, J. von

1998-01-01

Purpose: To evaluate functional MR imaging in patients with rheumatoid arthritis (RA) involving the cervical spine. Material and Methods: We used a device that allows MR examination to be made of the cervical spine in infinitely variable degrees of flexion and extension. Dynamic functional MR imaging was performed on 25 patients with RA. Results: Functional MR imaging was able to show the degree of vertebral instability of the occipito-atlantal or atlanto-axial level as well as the subaxial level. By performing functional MR imaging, we were able to demonstrate the extent of synovial tissue around the dens, and the impingement and displacement of the spinal cord during flexion and extension. The basilar impression, the cord impingement into the foramen magnum, the cord compression, the slipping of vertebrae, and the angulation of the cord were all much more evident in functional than in static MR imaging. Conclusion: Functional MR imaging provided additional information in patients with RA, and is valuable in patients who have a normal MR study in the neutral position and yet have signs of a neurological deficit. Functional MR imaging is important in the planning of stabilizing operations of the cervical spine. (orig.)

MR imaging of ''sterilized'' lymphoma

International Nuclear Information System (INIS)

Zerhouni, E.A.; Fishman, E.K.; Jones, R.; Siegelman, S.S.; Soulen, R.L.

1986-01-01

Residual masses are commonly observed after effective therapy in patients with lymphoma. These masses may be sterile but their presence poses a management problem, inasmuch as there is no adequate means of distinguishing sterile from active masses. The potential role of MR imaging in this context was evaluated by studying a group of 15 patients with stable, residual, presumably inactive masses (as determined from CT) and comparing the MR imaging findings in patients with newly diagnosed, untreated or recently treated lymphoma. All patients underwent an MR imaging examination consisting of one short repetition time (TR), short echo time (TE) (T1-weighted) sequence and one long TR, long TE(T2-weighted) sequence. The signal intensity of the masses was compared with that of fat in each patient, for each sequence. In selected patients, sequential examinations showed a progressive evolution toward the inactive pattern over a period of several weeks. Active and inactive disease are well depicted on T1-weighted sequences but are not distinguishable from each other. On T2-weighted sequences active disease is poorly demonstrated because the lesions are isointense with fat, whereas inactive masses remain clearly identifiable because they are of much lower signal intensity than fat

MR arthrography gadolinium versus standard MR imaging in rotator cuff pathology

International Nuclear Information System (INIS)

Hodler, J.; Brahme, S.K.; Karzel, R.; Cervilla, V.; Snyder, S.; Schweitzer, M.; Flannigan, B.; Resnick, D.

1990-01-01

This paper compares the accuracy of MR imaging with and without intraarticular gadolinium in the diagnosis of rotator cuff pathology, using arthroscopy as the gold standard. The authors examined 36 patients, first with T2-weighted sequences and then with T1-weighted sequences after the injection of 15-20 mL of diluted gadolinium. The images were read blindly by three radiologists experienced in musculoskeletal MR imaging. The results were compared with those of arthroscopy. In 16 of 19 arthroscopically intact rotator cuffs, both sequences demonstrated no evidence of rotator cuff tear. The remaining three cases were interpreted as partial or full-thickness tears. Of 12 partial tears, T1-weighted images with intraarticular gadolinium demonstrated a partial tear in five, degeneration in four, a full thickness tear in two, and a normal rotator cuff in one

MR imaging evaluation of plica synoviallis mediopatellaris of the knee joint

Energy Technology Data Exchange (ETDEWEB)

Nakanishi, Katsuyuki; Inoue, Masahiro; Murakami, Takamichi (Osaka Univ. (Japan). Faculty of Medicine) (and others)

1992-12-01

To evaluate the diagnostic ability of MR imaging for plica synoviallis mediopatellaris (PSM), we retrospectively reviewed the MR imaging findings of patellofemoral space in 20 knee joints of 11 patients. In all 20 knee joints, arthroscopy and MR imaging were available. MR imaging was performed with a 1.5 Tesla Magnetom (Siemens) using a round surface coil. Pulse sequences were SE (TR 600 ms/TE 26 ms), SE (TR 200 ms/TE 26,70 ms) and FLASH (TR 450 ms/TE 15 ms/FA 90deg). In six of the 20 knees with PSM proved by arthroscopy, a low intensity band was shown above the medial condyle of the femur on both T1- and T2-weighted MR images, and on FLASH images this band was shown as intermediate intensity. In the other 14 knees with no PSM observed by arthroscopy, the low intensity band was not shown on MR imaging. In all 20 knees, a similar low intensity band was shown about 1 cm cranial to the medial condyle of the femur. This should not be diagnosed as PSM. The low intensity band seen on T1- and T2-weighted MR images and its anatomical relation to the medial condyle are important in diagnosing PSM. (author).

MR imaging evaluation of plica synoviallis mediopatellaris of the knee joint

International Nuclear Information System (INIS)

Nakanishi, Katsuyuki; Inoue, Masahiro; Murakami, Takamichi

1992-01-01

To evaluate the diagnostic ability of MR imaging for plica synoviallis mediopatellaris (PSM), we retrospectively reviewed the MR imaging findings of patellofemoral space in 20 knee joints of 11 patients. In all 20 knee joints, arthroscopy and MR imaging were available. MR imaging was performed with a 1.5 Tesla Magnetom (Siemens) using a round surface coil. Pulse sequences were SE (TR 600 ms/TE 26 ms), SE (TR 200 ms/TE 26,70 ms) and FLASH (TR 450 ms/TE 15 ms/FA 90deg). In six of the 20 knees with PSM proved by arthroscopy, a low intensity band was shown above the medial condyle of the femur on both T1- and T2-weighted MR images, and on FLASH images this band was shown as intermediate intensity. In the other 14 knees with no PSM observed by arthroscopy, the low intensity band was not shown on MR imaging. In all 20 knees, a similar low intensity band was shown about 1 cm cranial to the medial condyle of the femur. This should not be diagnosed as PSM. The low intensity band seen on T1- and T2-weighted MR images and its anatomical relation to the medial condyle are important in diagnosing PSM. (author)

PET/MR in oncology: an introduction with focus on MR and future perspectives for hybrid imaging

Science.gov (United States)

Balyasnikova, Svetlana; Löfgren, Johan; de Nijs, Robin; Zamogilnaya, Yanna; Højgaard, Liselotte; Fischer, Barbara M

2012-01-01

After more than 20 years of research, a fully integrated PET/MR scanner was launched in 2010 enabling simultaneous acquisition of PET and MR imaging. Currently, no clinical indication for combined PET/MR has been established, however the expectations are high. In this paper we will discuss some of the challenges inherent in this new technology, but focus on potential applications for simultaneous PET/MR in the field of oncology. Methods and tracers for use with the PET technology will be familiar to most readers of this journal; thus this paper aims to provide a short and basic introduction to a number of different MRI techniques, such as DWI-MR (diffusion weighted imaging MR), DCE-MR (dynamic contrast enhanced MR), MRS (MR spectroscopy) and MR for attenuation correction of PET. All MR techniques presented in this paper have shown promising results in the treatment of patients with solid tumors and could be applied together with PET increasing the amount of information about the tissues of interest. The potential clinical benefit of applying PET/MR in staging, radiotherapy planning and treatment evaluation in oncology, as well as the research perspectives for the use of PET/MR in the development of new tracers and drugs will be discussed. PMID:23145362

Hemorrhage in pituitary adenoma: correlation of MR imaging with operative findings

Energy Technology Data Exchange (ETDEWEB)

Kurihara, N.; Takahashi, S.; Higano, S.; Mugikura, S.; Singh, L.N.; Furuta, S.; Tamura, H.; Ishibashi, T.; Maruoka, S.; Yamada, S. [Department of Radiology, Tohoku University School of Medicine, Sendai (Japan); Ikeda, H. [Department of Neurosurgery, Tohoku University School of Medicine, Sendai (Japan)

1998-07-01

The aim of this study was to correlate MR imaging and operative findings of hemorrhage in pituitary macroadenomas. We retrospectively reviewed MR images of 113 surgically proven pituitary adenomas. All patients were examined on a 1.5-T MR system. The intensity of intratumoral cystic cavities was correlated with operative findings. In 15 patients with pituitary apoplexy, we determined relationship between interval of MR examination after apoplectic event and MR signal intensity. In 8 patients with repeated preoperative MR examination, we evaluated sequential changes of intratumoral hemorrhage. There were 54 cavities at surgery: 52 were hemorrhagic and 2 were nonhemorrhagic. Twenty-nine of 52 hemorrhagic cysts demonstrated high/low signal (H/L) fluid-fluid levels on T2-weighted image (T2WI). In 19 of them, two components could be separately seen at operation: the supernatant high-intensity area represented xanthochromic fluid, and the dependent low-intensity area represented liquefied hematoma. The H/L fluid-fluid level was observed predominantly in hematomas on MR images obtained after longer intervals. In patients with repeated MR examination, follow-up MR imaging revealed additional hemorrhage or new formation of fluid-fluid levels. It was surprising that 12 of 14 cysts preoperatively judged as nonhemorrhagic in fact contained hemorrhagic components. The preoperative MR images are well correlated to the operative findings in hemorrhagic pituitary macroadenomas. It proved that 52 of 54 cystic cavities had hemorrhagic component. (orig.) With 8 figs., 3 tabs., 17 refs.

Hemorrhage in pituitary adenoma: correlation of MR imaging with operative findings

International Nuclear Information System (INIS)

Kurihara, N.; Takahashi, S.; Higano, S.; Mugikura, S.; Singh, L.N.; Furuta, S.; Tamura, H.; Ishibashi, T.; Maruoka, S.; Yamada, S.; Ikeda, H.

1998-01-01

The aim of this study was to correlate MR imaging and operative findings of hemorrhage in pituitary macroadenomas. We retrospectively reviewed MR images of 113 surgically proven pituitary adenomas. All patients were examined on a 1.5-T MR system. The intensity of intratumoral cystic cavities was correlated with operative findings. In 15 patients with pituitary apoplexy, we determined relationship between interval of MR examination after apoplectic event and MR signal intensity. In 8 patients with repeated preoperative MR examination, we evaluated sequential changes of intratumoral hemorrhage. There were 54 cavities at surgery: 52 were hemorrhagic and 2 were nonhemorrhagic. Twenty-nine of 52 hemorrhagic cysts demonstrated high/low signal (H/L) fluid-fluid levels on T2-weighted image (T2WI). In 19 of them, two components could be separately seen at operation: the supernatant high-intensity area represented xanthochromic fluid, and the dependent low-intensity area represented liquefied hematoma. The H/L fluid-fluid level was observed predominantly in hematomas on MR images obtained after longer intervals. In patients with repeated MR examination, follow-up MR imaging revealed additional hemorrhage or new formation of fluid-fluid levels. It was surprising that 12 of 14 cysts preoperatively judged as nonhemorrhagic in fact contained hemorrhagic components. The preoperative MR images are well correlated to the operative findings in hemorrhagic pituitary macroadenomas. It proved that 52 of 54 cystic cavities had hemorrhagic component. (orig.)

MR imaging of bone marrow disorders

International Nuclear Information System (INIS)

Yoshida, H.; Mano, I.; Yashiro, N.; Asai, S.; Lio, M.

1986-01-01

The author performed MR imaging in 89 patients with bone marrow disorders (29 with aplastic anemia, 20 with leukemia, 9 with postirradiation changes, 8 with hemosiderosis, 6 with primary bone tumors and metastases, and 17 with bone marrow disorders of other etiologies). They selected the thoracic and lumbar vertebral marrow as a target and used both T1-weighted spin-echo images and calculated T1 images. T1 was prolonged in bone marrow hyperplasia but shortened in hypoplasia. Bone marrow T1 values proved to depend on the number of fat cells (pathologic correlation). In aplastic anemia scattered islands of low signal intensity were seen within a background of high signal intensity in some typical cases. MR imaging patterns were used for staging aplastic anemia. T1 was prolonged in leukemia cells

MR imaging of degenerative disc disease

International Nuclear Information System (INIS)

Farshad-Amacker, Nadja A.; Farshad, Mazda; Winklehner, Anna; Andreisek, Gustav

2015-01-01

Highlights: • This systematic literature review summarizes the current knowledge on MR imaging in degenerative disc disease. • Different classification systems for segmental spine degeneration are summarized. • It outlines the diagnostic limitations of MR imaging. - Abstract: Magnet resonance imaging (MRI) is the most commonly used imaging modality for diagnosis of degenerative disc disease (DDD). Lack of precise observations and documentation of aspects within the complex entity of DDD might partially be the cause of poor correlation of radiographic findings to clinical symptoms. This literature review summarizes the current knowledge on MRI in DDD and outlines the diagnostic limitations. The review further sensitizes the reader toward awareness of potentially untended aspects of DDD and the interaction of DDD and endplate changes. A summary of the available classifications for DDD is provided

MR imaging of degenerative disc disease

Energy Technology Data Exchange (ETDEWEB)

Farshad-Amacker, Nadja A., E-mail: nadja.farshad@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, Zurich (Switzerland); Farshad, Mazda [Department of Orthopaedic Surgery, Balgrist University Hospital, Zurich (Switzerland); Winklehner, Anna; Andreisek, Gustav [Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, Zurich (Switzerland)

2015-09-15

Highlights: • This systematic literature review summarizes the current knowledge on MR imaging in degenerative disc disease. • Different classification systems for segmental spine degeneration are summarized. • It outlines the diagnostic limitations of MR imaging. - Abstract: Magnet resonance imaging (MRI) is the most commonly used imaging modality for diagnosis of degenerative disc disease (DDD). Lack of precise observations and documentation of aspects within the complex entity of DDD might partially be the cause of poor correlation of radiographic findings to clinical symptoms. This literature review summarizes the current knowledge on MRI in DDD and outlines the diagnostic limitations. The review further sensitizes the reader toward awareness of potentially untended aspects of DDD and the interaction of DDD and endplate changes. A summary of the available classifications for DDD is provided.

Transport, monitoring, and successful brain MR imaging in unsedated neonates

International Nuclear Information System (INIS)

Mathur, Amit M.; Neil, Jeffrey J.; McKinstry, Robert C.; Inder, Terrie E.

2008-01-01

Neonatal cerebral MR imaging is a sensitive technique for evaluating brain injury in the term and preterm infant. In term encephalopathic infants, MR imaging reliably detects not only the pattern of brain injury but might also provide clues about the timing of injury. In premature infants, MR imaging has surpassed US in the detection of white matter injury, a common lesion in this population. Concerns remain about the safety and transport of sedated neonates for MR examination to radiology suites, which are usually located at a distance from neonatal intensive care units. We present our own institutional experience and guidelines used to optimize the performance of cerebral MR examinations in neonates without sedation or anesthesia. (orig.)

MR imaging of acute viral hepatitis

International Nuclear Information System (INIS)

Sakai, Toyohiko; Itoh, Hisao; Takahashi, Norio; Kitada, Masahisa; Saito, Masayuki; Ohshiro, Kennwa; Ishimori, Masatoshi; Ishii, Yasushi.

1991-01-01

Twenty-three MR studies of 19 patients with acute viral hepatitis were reviewed. The findings of MR imaging including peripotal high intensity (PHI) on T 2 -weighted images and gallbladder wall thickening (GBWT) were compared with the level of serum GOT level and clinical phase which was determined by the interval between the peak of serum GOT level and MR study. PHI was found in 15 out of 23 studies (65%) and GBWT in 7 out of 22 studies (32%). The incidence of these findings were correlated well with the severity of serum GOT level and clinical phase. PHI became less prominent gradually as during the clinical recovery. While GBWT was found in the earlier phase and disappeared immediately. PHI seems to correspond to edema and infiltration of inflammatory cells in the periportal area of the liver. (author)

MR imaging of acute viral hepatitis

Energy Technology Data Exchange (ETDEWEB)

Sakai, Toyohiko; Itoh, Hisao; Takahashi, Norio; Kitada, Masahisa; Saito, Masayuki; Ohshiro, Kennwa; Ishimori, Masatoshi [Matsunami General Hospital, Kasamatsu, Gifu (Japan); Ishii, Yasushi

1991-02-01

Twenty-three MR studies of 19 patients with acute viral hepatitis were reviewed. The findings of MR imaging including peripotal high intensity (PHI) on T{sub 2}-weighted images and gallbladder wall thickening (GBWT) were compared with the level of serum GOT level and clinical phase which was determined by the interval between the peak of serum GOT level and MR study. PHI was found in 15 out of 23 studies (65%) and GBWT in 7 out of 22 studies (32%). The incidence of these findings were correlated well with the severity of serum GOT level and clinical phase. PHI became less prominent gradually as during the clinical recovery. While GBWT was found in the earlier phase and disappeared immediately. PHI seems to correspond to edema and infiltration of inflammatory cells in the periportal area of the liver. (author).

MR imaging of transient synovitis: differentiation from septic arthritis

International Nuclear Information System (INIS)

Yang, W.J.; Im, S.A.; Lim, G.Y.; Chun, H.J.; Jung, N.Y.; Sung, M.S.; Choi, B.G.

2006-01-01

Transient synovitis is the most common cause of acute hip pain in children. However, MR imaging findings in transient synovitis and the role of MR imaging in differentiating transient synovitis from septic arthritis have not been fully reported. To describe the MR findings of transient synovitis and to determine whether the MR characteristics can differentiate this disease entity from septic arthritis. Clinical findings and MR images of 49 patients with transient synovitis (male/female 36/13, mean age 6.1 years) and 18 patients with septic arthritis (male/female 10/8, mean age 4.9 years) were retrospectively reviewed. MR findings of transient synovitis were symptomatic joint effusion, synovial enhancement, contralateral joint effusion, synovial thickening, and signal intensity (SI) alterations and enhancement in surrounding soft tissue. Among these, SI alterations and enhancement in bone marrow and soft tissue, contralateral joint effusion, and synovial thickening were statistically significant MR findings in differentiating transient synovitis from septic arthritis. The statistically significant MR findings in transient synovitis are contralateral (asymptomatic) joint effusions and the absence of SI abnormalities of the bone marrow. It is less common to have SI alterations and contrast enhancement of the soft tissues. The statistically significant MR findings in septic arthritis are SI alterations of the bone marrow, and SI alterations and contrast enhancement of the soft tissue. Ipsilateral effusion and synovial thickening and enhancement are present in both diseases

MR imaging of adult glomerulocystic kidney disease

International Nuclear Information System (INIS)

Egashira, K.; Nakata, H.; Hashimoto, O.; Kaizu, K.; University of Occupational and Environmental Health School of Medicine, Kitakyushu

1991-01-01

A 59-year-old man with hypertension and severe renal dysfunction was diagnosed as having adult glomerulocystic kidney disease. MR imaging of the kidney showed a diffuse reduction of the intensity of the renal cortex with a loss of normal cortico-medullary differentiation of T1-weighted images. Numerous small cortical cysts were also demonstrated. These MR findings complemented the results of the biopsy and were useful for making a definitive diagnosis. (orig.)

MR imaging evaluation of congenital malformation of the spine

International Nuclear Information System (INIS)

Byrd, S.E.; Radkowski, M.A.; McLone, D.G.; Storrs, B.B.

1988-01-01

One hundred fifty children with congenital malformations of the spine were studied with MR imaging, US, and water-soluble myelography with CT. The malformations encountered included myelomeningoceles and Chiari II malformations, diastematomyelia, hydromyelia, arachnoid cyst, dermal sinus and dermoid, spinal lipomas and teratomas, tight filum terminale, anterior sacral meningoceles, lipomyelomeningoceles, myelocystocele, and severe scoliosis. MR imaging was the most effective modality in delineating these abnormalities. At times, real-time US and water-soluble CT myelography were required as adjuncts to MR imaging in delineating subtle spinal cord tethering, arachnoid cyst, diastematomyelia, and severe scoliosis

MR imaging of hemangiomas in oral cavity

International Nuclear Information System (INIS)

Toyoda, Keiko; Kobayashi, Masao; Tada, Shimpei.

1995-01-01

Eleven patients with hemangioma in the oral cavity were studied by MR imaging using spin-echo T 1 - and fast SE T 2 -weighted sequences. The hemangioma was iso-intense to muscles on T 1 -weighted images, and markedly hyperintense on T 2 -weighted images. The lesions were lobulated in margin. Four lesions showed internal spotty and/or curvilinear structures of low signal intensity. After administration of Gd-DTPA, three of seven lesions showed uniform contrast enhancement, three lesions showed partial or marginal enhancement, and remaining one lesion did not show enhancement effect. We conclude that MR imaging of oral hemangiomas is useful in delineating extent of the lesion. (author)

MR imaging in female pelvic organs prolapse

International Nuclear Information System (INIS)

Capiel, Carlos A. h; Bouzas, Carlos A.

2003-01-01

Pelvic floor weakness and consequent organ prolapse may result in a variety of symptoms, including pain, urinary or fecal incontinence and constipation. Diagnosis is made primary on the basis of findings at physical pelvic examination. Imaging is useful in patients in whom findings at physical examination are equivocal. Different imaging techniques (fluoroscopy, ultrasonography), can be useful in evaluating pelvic organs prolapse. MR imaging is a new noninvasive technique that provides a multiplanar global evaluation of the pelvic contents and demonstrates pelvic organs prolapse. Reference points are the pubococcygeal line and puborectalis muscle sling. This pictorial assay illustrates different grades of cystourethrocele, recto-sigmoidocele and hysteroptosis (uterine prolapse) on MR imaging. (author)

MR imaging features of foot involvement in ankylosing spondylitis

Energy Technology Data Exchange (ETDEWEB)

Erdem, C. Zuhal E-mail: sunarerdem@yahoo.com; Sarikaya, Selda; Erdem, L. Oktay; Ozdolap, Senay; Gundogdu, Sadi

2005-01-01

Objective: To determine alterations of the soft tissue, tendon, cartilage, joint space, and bone of the foot using magnetic resonance (MR) imaging in ankylosing spondylitis (AS) patients. Materials and Method: Clinical and MR examination of the foot was performed in 23 AS patients (46 feet). Ten asymptomatic volunteers (20 feet) were studied on MR imaging, as a control group. MR imaging protocol included; T1-weighted spin-echo, T2-weighted fast-field echo (FFE) and fat-suppressed short tau inversion recovery (STIR) sequences in sagittal, sagittal oblique, and coronal planes using a head coil. Specifically, we examined: bone erosions, tendinitis (acute and chronic), para-articular enthesophyte, joint effusion, plantar fasciitis, joint space narrowing, soft tissue edema, bone marrow edema, enthesopathy in the Achilles tendon and plantar fascia attachment, subchondral signal intensity abnormalities (edema and sclerosis), tenosynovitis, retrocalcaneal bursitis, subchondral cysts, subchondral fissures, and bony ankylosis. Midfoot, hindfoot, and ankle were included in examined anatomic regions. Results: Clinical signs and symptoms (pain and swelling) due to foot involvement were present in 3 (13%) of the patients while frequency of involvement was 21 (91%) with MR imaging assessment. The MR imaging findings were bone erosions (65%), Achilles tendinitis (acute and chronic) (61%), para-articular enthesophyte (48%), joint effusion (43%), plantar fasciitis (40%), joint space narrowing (40%), subchondral sclerosis (35%), soft tissue edema (30%), bone marrow edema (30%), enthesopathy of the Achilles attachment (30%), subchondral edema (26%), enthesopathy in the plantar fascia attachment (22%), retrocalcaneal bursitis (22%), subchondral cysts (17%), subchondral fissures (17%), tendinitis and enthesopathy of the plantar ligament (13%), and bony ankylosis (9%). The most common involved anatomical region was the hindfoot (83%) following by midfoot (69% ) and ankle (22

MR imaging features of foot involvement in ankylosing spondylitis

International Nuclear Information System (INIS)

Erdem, C. Zuhal; Sarikaya, Selda; Erdem, L. Oktay; Ozdolap, Senay; Gundogdu, Sadi

2005-01-01

Objective: To determine alterations of the soft tissue, tendon, cartilage, joint space, and bone of the foot using magnetic resonance (MR) imaging in ankylosing spondylitis (AS) patients. Materials and Method: Clinical and MR examination of the foot was performed in 23 AS patients (46 feet). Ten asymptomatic volunteers (20 feet) were studied on MR imaging, as a control group. MR imaging protocol included; T1-weighted spin-echo, T2-weighted fast-field echo (FFE) and fat-suppressed short tau inversion recovery (STIR) sequences in sagittal, sagittal oblique, and coronal planes using a head coil. Specifically, we examined: bone erosions, tendinitis (acute and chronic), para-articular enthesophyte, joint effusion, plantar fasciitis, joint space narrowing, soft tissue edema, bone marrow edema, enthesopathy in the Achilles tendon and plantar fascia attachment, subchondral signal intensity abnormalities (edema and sclerosis), tenosynovitis, retrocalcaneal bursitis, subchondral cysts, subchondral fissures, and bony ankylosis. Midfoot, hindfoot, and ankle were included in examined anatomic regions. Results: Clinical signs and symptoms (pain and swelling) due to foot involvement were present in 3 (13%) of the patients while frequency of involvement was 21 (91%) with MR imaging assessment. The MR imaging findings were bone erosions (65%), Achilles tendinitis (acute and chronic) (61%), para-articular enthesophyte (48%), joint effusion (43%), plantar fasciitis (40%), joint space narrowing (40%), subchondral sclerosis (35%), soft tissue edema (30%), bone marrow edema (30%), enthesopathy of the Achilles attachment (30%), subchondral edema (26%), enthesopathy in the plantar fascia attachment (22%), retrocalcaneal bursitis (22%), subchondral cysts (17%), subchondral fissures (17%), tendinitis and enthesopathy of the plantar ligament (13%), and bony ankylosis (9%). The most common involved anatomical region was the hindfoot (83%) following by midfoot (69% ) and ankle (22

Trends in utilization: has extremity MR imaging replaced diagnostic arthroscopy?

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Glynn, Nicole; Morrison, William B.; Parker, Laurence; Schweitzer, Mark E.; Carrino, John A.

2004-01-01

To examine the relative change in utilization of magnetic resonance (MR) imaging of the extremities versus diagnostic and therapeutic arthroscopy. Using the 1993, 1996, and 1999 nationwide Medicare Part B databases, utilization rates (per 100,000) were determined for upper and lower extremity MR imaging, diagnostic arthroscopy and therapeutic arthroscopy using CPT-4 codes. Utilization of extremity MR imaging was compared with that of diagnostic and therapeutic arthroscopy in 10 geographic regions of the United States and tracked over time. Combined lower and upper extremity MR imaging utilization per 100,000 increased from 393 to 1,056 in 1999 (+168.7%). Utilization of diagnostic arthroscopy of the extremities decreased from 18 in 1993 to 8 in 1999 (-55.6%); therapeutic arthroscopy rates increased from 461 in 1993 to 636 in 1999 (+40.0%). Specifically, from 1993 to 1999, utilization of lower extremity MR imaging increased from 270 to 661 (+144.8%). Utilization of diagnostic arthroscopy of the knee over the same time period decreased from 11 to 5 (-54.5%); therapeutic arthroscopy increased from 394 to 501 (+27.2%). Similarly, utilization rates for upper extremity MR imaging increased from 123 to 395 (+221.1%). Utilization of diagnostic arthroscopy of the shoulder over the same time period decreased from 7 to 2 (-71.4%); therapeutic arthroscopy increased from 44 to 104 (+136.4%). No specific geographic trends were ascertained. The utilization of MR imaging of the extremities has markedly increased from 1993 to 1999. During the same time period the utilization of diagnostic arthroscopy has decreased and that of therapeutic arthroscopy has increased. These findings support the hypothesis that there is increased reliance of clinical practitioners on the diagnostic information provided by MR imaging in preoperative clinical decision-making. (orig.)

CT and MR imaging characteristics of infantile hepatic hemangioendothelioma

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Feng Shiting; Chan Tao; Ching, A.S.C.; Sun Canhui; Guo Huanyi; Fan Miao; Meng Quanfei; Li Ziping

2010-01-01

Aim: This study aims to analyze computed tomography (CT) and magnetic resonance (MR) imaging features of infantile hepatic hemangioendotheliomas before and after treatment. Materials and methods: CT and MR examinations of seven infants with biopsy proven hepatic hemangioendotheliomas were retrospectively analyzed. The distribution, number, size, imaging appearance, enhancement pattern and post-treatment changes of the tumors were evaluated. Results: A total of 153 hepatic hemangioendotheliomas were detected on CT (111) and MR (42) imaging. In six infants, 109/111 (98.2%) tumors were hypodense and 2/111 (1.8%) lesions contained calcification on unenhanced CT. On MR imaging, all 42 lesions in one infant were heterogeneously T1-hypointense and T2-hyperintense compared to the normal liver parenchyma. Contrast-enhanced CT and MRI showed peripheral rim (51.6%), uniform (48.4%), fibrillary (33.3%), and nodular (28.8%) contrast enhancement in the hepatic arterial phase. Homogeneous (100%), rim (98.2%) and mixed enhancement patterns were noted in tumors 2.0 cm and 1.0-2.0 cm in diameter respectively in the hepatic arterial phase. In three patients who underwent steroid therapy, follow-up CT examination demonstrated tumor size reduction and increased intra-tumoral calcification in two patients. Conclusion: Infantile hepatic hemangioendotheliomas show some typical imaging features and size-dependent pattern of contrast enhancement on CT and MR imaging, which allow accurate imaging diagnosis and post-treatment evaluation.

MR imaging of the parotid gland following sialography

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Nakano, Y.; Nishimura, K.; Togashi, K.; Itoh, K.; Fujisawa, I.; Itoh, H.; Abe, M.; Torizuka, K.; Naito, Y.

1986-01-01

MR imaging was performed after sialography (using 76% Renografin) in eight patients with parotid tumor. MR imaging was performed at 1.5 T and using 16-cm-diameter surface coil and a pulse sequence of 600/25 msec. The ductal system and periductal interstitial space consistently appeared as a linear low-intensity band. MR images of two rabbits that had received parotid gland injections of 76% Renografin confirmed that the low-intensity signal arose from the edema fluid in the periductal interstitial space of the gland. Since the facial nerve follows a course immediately lateral to the major duct, an appreciation of the course of the facial nerve may allow more precise presurgical planning

Kallman syndrome versus idiopathic hypogonadotropic hypogonadism at MR imaging

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Vogl, T.J.; Stemmler, J.; Bergman, C.; Balzer, J.O.; Felix, R. [Free Univ. of Berlin (Germany); Heye, B.; Schopohl, J.; Danek, A. [Univ. of Munich (Germany)

1994-04-01

To identify morphologic differences between Kallman syndrome (KS) and idiopathic hypogonadotropic hypogonadism (IHH) and establish a role for magnetic resonance (MR) imaging in these disorders. Twenty-eight patients were compared with 10 eugonal male volunteers. Eighteen patients had KS (hypogonadotropic hypogonadism with anosmia) and 10 had IHH. All participants underwent hormone analysis, a sniff-bottle smell test, and gadolinium-enhanced MR imaging. Changes in the hypothalamic-hypophyseal region and the rhinencephalon were evaluated. MR imaging revealed intracranial morphologic changes in all patients on plain T1-weighted sections. Seventeen patients with KS demonstrated aplasia of an olfactory bulb; one olfactory sulcus was absent in six, rudimentary in four, and normal in eight. Olfactory bulbs were present in all 10 IHH patients and three showed one slightly hypoplastic bulb. Ten patients with KS and three with IHH showed an enlarged paranasal sinus system. Further MR findings were similar. MR imaging demonstrates abnormalities of the rhinencephalon present in KS patients and occasionally absent in IHH patients. 18 refs., 10 figs., 1 tab.

MR imaging of cranial nerve schwannomas

International Nuclear Information System (INIS)

Shapiro, M.; Peyster, R.; Cross, R.R.; Charles, J.; Murtagh, R.; Shapiro, R.; Chyatte, D.

1988-01-01

One of the major advantages of magnetic resonance (MR) imaging over other imaging modalities is direct visualization of the cranial nerves. This is best accomplished with thin-section, contiguous T1-weighted images. They report a series of 75 cranial nerve neuromas, including 47 of the eighth nerve and a mixture of schwannomas involving all other cranial nerves (excluding the fourth). All tumors demonstrated at least some area of increased signal (equal to or greater than that of cerebrospinal fluid) on T2-weighted images. This fact enabled them to differentiate schwannomas from neoplasms (lymphoma, meningioma, sarcoma) that may be isointense on T2-weighted pulse sequences. Many of the lesions had areas of low signal intermixed with predominantly high signal (on T2-weighted images). The pathologic evaluation of these areas of decreased signal revealed predominant fibrosis. In addition, some of the neuromas had a cystic component. Gadolinium-enhanced MR imaging may permit detection when the nerve is still normal in size

MR imaging in cervical hyperextension injuries

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Davis, S.J.; Teresi, L.M.; Bradley, W.G. Jr.; Ziemba, M.R.

1990-01-01

This paper reports on cervical hyperextension injuries that are common and often show minimal radiographic abnormalities, even with severe or unstable lesions. MR images and clinical records of 14 patients scanned within 4 months of hyperextension cervical injuries were reviewed. Clinical, radiographic, and MR findings were correlated. Nine patients had acceleration hyperextension whiplash injuries, four with acute cervical disk herniations developing radiculopathy after several weeks. Five patients injured by direct frontal head trauma presented with myelopathy and had MR evidence of cord injury, and four had acute disk herniation

Hyperthermia system working in combination with an MR imaging unit

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LeBihan, D.J.; Delannoy, J.; Levin, R.L.; Hoult, D.I.

1988-01-01

The authors propose a hyperthermia device to be used for temperature monitoring. It consists of a modified miniannular phased array (MAPA) radio-frequency applicator designed for limb tumor treatment that works in combination with a whole-body MR imaging unit operating at 21 MHz. Highly accurate (0.5 0 c/0.8 cm 2 ) temperature images are obtained noninvasively throughout the heated volume from MR images of molecular diffusion, the relation of which with temperature is well known. The MAPA, electrically modified to be compatible with MR imagers, can be centered inside the MR head coil. The combined system was tested on a phantom in which the temperature distribution was confirmed by miniature thermocouples

Comparison of MR imaging and CT in neuroendrocrine disorders in children

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Garreh, M.K.; Ball, W.S.; Brody, A.S.; Dolan, L.; Burton, E.M.

1989-01-01

MR imaging has been shown to be superior in imaging the adult hypothalamicpituitary axis. The authors have reviewed the CT and MR findings in children with known abnormalities, including hamartoma of the tuber cinereum, craniopharyngiomas,. pituitary adenoma, Rathke cleft cyst, incomplete pituitary stalk, and septo-optic dysplasia. Clinical correlation and typical CT and MR features were analyzed. In four cases, abnormalities were not visualized on CT. The authors conclude that because of its unique sensitivity and excellent anatomic resolution, MR imaging is the modality of choice in the imaging of neuroendocrine disorders in children

Brain Perfusion SPECT Imaging in Sturge - Weber Syndrome : Comparison with MR Imaging

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Ryu, Jin Sook; Choi, Yun Young; Moon, Dae Hyuk; Yang, Seoung Oh; Ko, Tae Sung; Yoo, Shi Joon; Lee, Hee Kyung

1996-01-01

The purpose of this study was evaluate the characteristic perfusion changes in patients with Sturge-Weber syndrome by comparison of the findings of brain MR images and perfusion SPECT images. 99m Tc-HMPAO or 99m Tc-ECD interictal brain SPECTs were performed on 5 pediatric patients with Struge-Weber syndrome within 2 weeks after MR imaging. Brain SPECTs of three patients without calcification showed diminished perfusion in the affected area on MR image. A 3 month-old patient without brain atrophy or calcification demonstrated paradoxical hyperperfusion in the affected hemisphere, and follow-up perfusion SPECT revealed decreased perfusion in the same area. The other patient with advanced calcified lesion and atrophy on MR image showed diffusely decreased perfusion in the affected hemisphere, but a focal area of increased perfusion was also noted in the ipsilateral temporal lobe on SPECT. In conclusion, brain perfusion of the affected area of Sturge-Weber syndrome patients was usually diminished, but early or advanced patients may show paradoxical diffuse or focal hyperperfusion in the affected hemisphere. Further studies are needed for better understanding of these perfusion changes and pathophysiology of Struge-Weber syndrome.

Cancer Metabolism and Tumor Heterogeneity: Imaging Perspectives Using MR Imaging and Spectroscopy

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Gigin Lin

2017-01-01

Full Text Available Cancer cells reprogram their metabolism to maintain viability via genetic mutations and epigenetic alterations, expressing overall dynamic heterogeneity. The complex relaxation mechanisms of nuclear spins provide unique and convertible tissue contrasts, making magnetic resonance imaging (MRI and magnetic resonance spectroscopy (MRS pertinent imaging tools in both clinics and research. In this review, we summarized MR methods that visualize tumor characteristics and its metabolic phenotypes on an anatomical, microvascular, microstructural, microenvironmental, and metabolomics scale. The review will progress from the utilities of basic spin-relaxation contrasts in cancer imaging to more advanced imaging methods that measure tumor-distinctive parameters such as perfusion, water diffusion, magnetic susceptibility, oxygenation, acidosis, redox state, and cell death. Analytical methods to assess tumor heterogeneity are also reviewed in brief. Although the clinical utility of tumor heterogeneity from imaging is debatable, the quantification of tumor heterogeneity using functional and metabolic MR images with development of robust analytical methods and improved MR methods may offer more critical roles of tumor heterogeneity data in clinics. MRI/MRS can also provide insightful information on pharmacometabolomics, biomarker discovery, disease diagnosis and prognosis, and treatment response. With these future directions in mind, we anticipate the widespread utilization of these MR-based techniques in studying in vivo cancer biology to better address significant clinical needs.

Fuzzy object models for newborn brain MR image segmentation

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Kobashi, Syoji; Udupa, Jayaram K.

2013-03-01

Newborn brain MR image segmentation is a challenging problem because of variety of size, shape and MR signal although it is the fundamental study for quantitative radiology in brain MR images. Because of the large difference between the adult brain and the newborn brain, it is difficult to directly apply the conventional methods for the newborn brain. Inspired by the original fuzzy object model introduced by Udupa et al. at SPIE Medical Imaging 2011, called fuzzy shape object model (FSOM) here, this paper introduces fuzzy intensity object model (FIOM), and proposes a new image segmentation method which combines the FSOM and FIOM into fuzzy connected (FC) image segmentation. The fuzzy object models are built from training datasets in which the cerebral parenchyma is delineated by experts. After registering FSOM with the evaluating image, the proposed method roughly recognizes the cerebral parenchyma region based on a prior knowledge of location, shape, and the MR signal given by the registered FSOM and FIOM. Then, FC image segmentation delineates the cerebral parenchyma using the fuzzy object models. The proposed method has been evaluated using 9 newborn brain MR images using the leave-one-out strategy. The revised age was between -1 and 2 months. Quantitative evaluation using false positive volume fraction (FPVF) and false negative volume fraction (FNVF) has been conducted. Using the evaluation data, a FPVF of 0.75% and FNVF of 3.75% were achieved. More data collection and testing are underway.

MR Imaging Features of Fibrocystic Change of the Breast

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Chen, Jeon-Hor; Liu, Hui; Baek, Hyeon-Man; Nalcioglu, Orhan; Su, Min-Ying

2008-01-01

Purpose Studies specifically reporting MR imaging of fibrocystic change (FCC) of the breast are very few and its MR imaging features are not clearly known. The purpose of this study was to analyze the MR imaging features of FCC of the breast. Materials and Methods Thirty one patients of pathologically proved FCC of the breast were retrospectively reviewed. The MRI study was performed using a 1.5 T MR scanner with standard bilateral breast coil. The imaging protocol consisted of pre-contrast T1W imaging and dynamic contrast-enhanced axial T1W imaging. The MRI features were interpreted based on the morphologic and enhancement kinetic descriptors defined on ACR BIRADS-MRI lexicon. Results FCC of the breast had a wide spectrum of morphologic and kinetic features on MRI. Two types of FCC were found, including a more diffuse type of non-mass lesion (12/31, 39%) showing benign enhancement kinetic pattern with medium wash-in in early phase (9/10, 90%) and a focal mass type lesion (11/31, 35%) with enhancement kinetic usually showing rapid up-slope mimicking a breast cancer (8/11, 73%). Conclusion MRI is able to elaborate the diverse imaging features of fibrocystic change of the breast. Our result showed that FCC presenting as focal mass type lesion were usually over-diagnosed as malignancy. Understanding MR imaging of FCC is important to determine which cohort of patients should be followed up alone or receive aggressive management. PMID:18436406

Influence of MR imaging in radiation therapy of chest lymphoma

International Nuclear Information System (INIS)

Carlsen, S.E.; Hoppe, R.; Bergin, C.J.

1991-01-01

This paper evaluates the influence of MR detection of additional sites of chest lymphoma on radiation therapy. Chest MR images and CT scans of 56 patients with new or recurrent mediastinal lymphoma obtained within 1 month of each other were retrospectively reviewed. MR images included T1- and T2-weighted SE and STIR sequences. Images were assessed for pleural and extrapleural disease. Radiation portals of patients with pleural or chest wall disease were reevaluated and compared with portals originally designed with CT. MR imaging demonstrated chest wall disease in 15 patients (21 sites). Ten patients also had pleural disease (13 sites). CT identified chest wall disease in four of these patients (five sites) and pleural disease in three patients (five sites). Seven of the 15 patients with chest wall disease were treated with radiation therapy alone. Two of the seven patients had significant modification of radiation portals based on MR findings. Retrospectively, therapy would have been altered in an additional two patients in whom pleural disease was identified at MR. The increased sensitivity of MR in detecting chest wall or pleural disease has important implications for treatment planning in chest wall lymphoma

Comparative evaluation of the porta hepatis/hepatoduodenal ligament with CT and MR imaging

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Silverman, P.M.; Feuerstein, I.M.; Zeman, R.K.; Jaffe, M.H.; Garra, B.S.

1988-01-01

CT and MR imaging were compared in a retrospective evaluation of 16 patients with abnormalities, predominantly neoplasms, of the porta hepatis/hepatoduodenal ligament. Masses on CT were of decreased density compared with that of liver and were seen in contrast to surrounding periportal fat. On MR images, T1-weighted images demonstrated findings similar to those of CT. T2-weighted images clearly depicted intrahepatic lesions but less distinctly depicted lesions surrounded by fat. Short inversion recovery (STIR) images better demonstrated tumor relative to fat. CT was better than all MR imaging sequences in one of 16 cases, whereas at least one MR imaging sequence was better than CT in six of 16. In nine cases, CT was equivalent to the best MR imaging sequence. In five of six cases where MR imaging was better than CT, STIR sequences were most favorable. In conclusion, MR imaging provided a valuable technique for assessing abnormalities of the porta hepatis/hepatoduodenal ligament

Simultaneous acquisition of multislice PET and MR images: initial results with a MR-compatible PET scanner.

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Catana, Ciprian; Wu, Yibao; Judenhofer, Martin S; Qi, Jinyi; Pichler, Bernd J; Cherry, Simon R

2006-12-01

PET and MRI are powerful imaging techniques that are largely complementary in the information they provide. We have designed and built a MR-compatible PET scanner based on avalanche photodiode technology that allows simultaneous acquisition of PET and MR images in small animals. The PET scanner insert uses magnetic field-insensitive, position-sensitive avalanche photodiode (PSAPD) detectors coupled, via short lengths of optical fibers, to arrays of lutetium oxyorthosilicate (LSO) scintillator crystals. The optical fibers are used to minimize electromagnetic interference between the radiofrequency and gradient coils and the PET detector system. The PET detector module components and the complete PET insert assembly are described. PET data were acquired with and without MR sequences running, and detector flood histograms were compared with the ones generated from the data acquired outside the magnet. A uniform MR phantom was also imaged to assess the effect of the PET detector on the MR data acquisition. Simultaneous PET and MRI studies of a mouse were performed ex vivo. PSAPDs can be successfully used to read out large numbers of scintillator crystals coupled through optical fibers with acceptable performance in terms of energy and timing resolution and crystal identification. The PSAPD-LSO detector performs well in the 7-T magnet, and no visible artifacts are detected in the MR images using standard pulse sequences. The first images from the complete system have been successfully acquired and reconstructed, demonstrating that simultaneous PET and MRI studies are feasible and opening up interesting possibilities for dual-modality molecular imaging studies.

MR imaging of edematous limbs in lymphatic and nonlymphatic edema

International Nuclear Information System (INIS)

Fujii, K.

1994-01-01

To evaluate the role of MR imaging in the diagnosis of edema, various types of edema were examined with MR imaging. MR imaging of edematous limbs was performed on 60 patients (lymphatic edema 48, nonlymphatic edema 12) using. T1-and T2-weighted spin-echo and shot inversion time inversion recovery sequences. Thickness and signal intensity of the cutis, subcutis and subfascia were evaluated in the images. In all 48 cases with lymphatic edema, trabecular structures suggesting dilated collateral lymphatic vessels were observed in the swollen subcutis. Two cases with nephrotic syndrome showed similar findings. In 6 cases with venous edema, fatty intensity was found in the subfascia. In the remaining 4 cases, the subcutis exhibited only water intensity. MR imaging is a potential contributor to the diagnosis of various edematous diseases. (orig./MG)

MR imaging of the prostate

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Asbach, P.; Haas, M.; Hamm, B.

2015-01-01

Prostate cancer is the most common form of cancer in men in Germany; however, there is a distinct difference between incidence and mortality. The detection of prostate cancer is based on clinical and laboratory testing using serum prostate-specific antigen (PSA) levels and transrectal ultrasound with randomized biopsy. Multiparametric MR imaging of the prostate can provide valuable diagnostic information for detection of prostate cancer, especially after negative results of a biopsy prior to repeat biopsy. In addition the use of MR ultrasound fusion-guided biopsy has gained in diagnostic importance and has increased the prostate cancer detection rate. The prostate imaging reporting and data system (PI-RADS) classification has standardized the reporting of prostate MRI which has positively influenced the acceptance by urologists. (orig.) [de

MR imaging of muscle diseases

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Kaiser, W.A.; Zeitler, E.; Schalke, B.C.G.

1986-01-01

Because of high soft-tissue contrast, MR imaging is especially suitable for the investigation of muscle diseases. Between March 1984 and March 1986, 76 patients with different types of muscle diseases were examined using a 1-T superconductive magnet (Siemens Magnetom). Studied were 14 patients with progressive muscular dystrophy (including carriers), 32 patients with myositis, four patients with myotonic dystrophy, six patients with spinal muscular atrophy, and 20 patients with other muscle diseases, including metabolic disorders. MR imaging showed typical signal patterns in affected muscle groups. These patterns can be used in the differential diagnosis, in biopsy planning, or in evaluation of response to therapy. The T1/T2 ratio especially seems to indicate very early stages of muscle disease

MR imaging of the pediatric central nervous system utilization review

International Nuclear Information System (INIS)

Barnes, P.D.; Prince, J.R.; Galloway, D.C.; Ross-Duggan, J.; Lester, P.D.; Yamanashi, W.S.

1986-01-01

MR has been done in over 500 pediatric and adolescent patients (ages 5 days to 20 years) with central nervous system (CNS) disease (brain, n = 331; spine, n = 218), including high-field and special coil application in 362 cases. T1-weighted, multiplanar MR imaging provides superior anatomic delineation of organogenetic CNS malformations, while multiparameter (T1, T2, p) MR is usually necessary for more complete characterization of histogenetic malformations, as well as acquired conditions. MR imaging is a desirable method for the initial and definitive evaluation of many cranial and spinal conditions of childhood (more-invasive procedures were obviated in 164 patients). CT or other modalities may be added when MR imaging does not satisfy the clinical query

Diffusion-weighted MR imaging of the brain. 2. ed.

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Moritani, Toshio; Ekholm, Sven; Westesson, Per-Lennart

2009-01-01

This practical-minded text helps the radiologist and the clinician understand diffusion-weighted MR imaging. The book's 15 chapters range from basic principles to interpretation of diffusion-weighted MR imaging and specific disease. In this second edition, diffusion tensor imaging (fractional anisotropy, color map and fiber tractography) is covered and a new chapter, on ''Diffusion-Weighted Imaging of Scalp and Skull Lesions,'' is included. The volume is updated by newly added cases accompanied by radiological and pathological images along with the most recent references. It is aimed at all those who are involved in neuroimaging, including: residents, fellows, staff, as well as neurologists and neurosurgeons. Diffusion-weighted MR imaging is widely accepted as a means to identify acute infarction but also to differentiate many other pathologic conditions. Understanding diffusion-weighted imaging is important for radiologists, neurologists, neurosurgeons as well as radiology technologists. (orig.)

Human fetal anatomy: MR imaging.

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Weinreb, J C; Lowe, T; Cohen, J M; Kutler, M

1985-12-01

Twenty-four pregnant women carrying 26 fetuses (two sets of twins) were imaged with magnetic resonance (MR) imaging at 0.35 T following sonographic evaluation. Each study was retrospectively evaluated to determine which of 33 normal fetal structures were visible on the images and which imaging parameters were most useful for depicting fetal anatomy. Fetal motion degraded fetal images in all but two cases, both with oligohydramnios and in the third trimester of gestation. Nevertheless, many fetal structures were identifiable, particularly in the third trimester. Visualization of fetal anatomy improved with intravenous maternal sedation in five cases. Relatively T1-weighted images occasionally offered the advantage of less image degradation owing to fetal motion and improved contrast between different fetal structures. More T2 weighting was believed to be advantageous in one case for outlining the fetal head and in one case for delineation of the brain. In many cases, structures were similarly identifiable (though with different signal intensities) regardless of the parameters selected. The authors conclude that MR imaging of many fetal structures is currently unsatisfactory and is probably of limited value, particularly in the first and second trimesters. However, the relative frequency and detail with which the fetal head and liver can be depicted indicate that these may be areas for further investigation, and the potential utility of imaging fetal fat warrants further investigation.

Hypervascular hepatocellular carcinomas: detection with gadoxetate disodium-enhanced MR imaging and multiphasic multidetector CT

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Onishi, Hiromitsu; Kim, Tonsok; Hori, Masatoshi; Nakaya, Yasuhiro; Tsuboyama, Takahiro; Nakamoto, Atsushi; Tatsumi, Mitsuaki; Tomiyama, Noriyuki [Osaka University Graduate School of Medicine, Department of Radiology, Suita, Osaka (Japan); Imai, Yasuharu [Ikeda Municipal Hospital, Department of Gastroenterology, Ikeda, Osaka (Japan); Nagano, Hiroaki [Osaka University Graduate School of Medicine, Department of Surgery, Suita, Osaka (Japan); Kumano, Seishi; Okada, Masahiro; Murakami, Takamichi [Kinki University School of Medicine, Department of Radiology, Osakasayama, Osaka (Japan); Takamura, Manabu [Ikeda Municipal Hospital, Department of Radiology, Ikeda, Osaka (Japan); Wakasa, Kenichi [Osaka City University Graduate School of Medicine, Department of Diagnostic Pathology, Osaka, Osaka (Japan)

2012-04-15

To retrospectively compare the accuracy of detection of hypervascular hepatocellular carcinoma (HCC) by multiphasic multidetector CT and by gadoxetate disodium-enhanced MR imaging. After ethical approval, we analysed a total of 73 hypervascular HCC lesions from 31 patients suspected of having HCC, who underwent both gadoxetate disodium-enhanced MR imaging and multiphasic multidetector CT. Five blinded observers independently reviewed CT images, as well as dynamic MR images alone and combined with hepatobiliary phase MR images. Diagnostic accuracy (Az values), sensitivities and positive predictive values were compared by using the Scheffe post hoc test. The mean Az value for dynamic and hepatobiliary phase MR combined (0.81) or dynamic MR images alone (0.78) was significantly higher than that for CT images (0.67, P < 0.001, 0.005, respectively). The mean sensitivity of the combined MR images (0.67) was significantly higher than that of dynamic MR alone (0.52, P < 0.05) or CT images (0.44, P < 0.05). The mean positive predictive values were 0.96, 0.95 and 0.94, for CT, dynamic MR alone and combined MR images, respectively. Compared with multiphasic multidetector CT, gadoxetate disodium-enhanced MR imaging combining dynamic and hepatobiliary phase images results in significantly improved sensitivity and diagnostic accuracy for detection of hypervascular HCC. (orig.)

Fast MR imaging for evaluating the pancreaticobiliary system

International Nuclear Information System (INIS)

Takehara, Yasuo

1999-01-01

Due to physiological movement clinical MR applications for abdominal organs got off to a very slow start compared to MR imaging of other organs. However, with recent cutting-edge hardware technologies such as high performance gradient systems and phased-array capability, as well as software innovations including short TR fast spoiled gradient recalled acquisition in the steady state (GRASS), snapshot imaging such as single shot fast spin echo sequence (SSFSE) and echo planar imaging (EPI), scan times have been further reduced to make breath-hold imaging clinically viable and to enable semi-fluoroscopic, kinematic imaging recognition. The elimination of physiological motion has contributed to the significant improvement in image quality, or more specifically, the physiological motion that had long been problematic has been turned into a source of physiological information about pancreaticobiliary pathologies. In this article, the author reviewed the current status of fast MR technologies for examining pancreaticobiliary pathologies, stressing the functional and physiological aspects of the corresponding anatomy. The technologies included secretin MRCP, which became a powerful tool when combined with kinematic imaging

MR imaging of the hip in avascular necrosis: Radiologic-pathologic correlation

International Nuclear Information System (INIS)

Kang, H.S.; Lee, S.H.; Lee, Y.S.; Cho, Z.H.; Han, M.C.; Kim, C.W.

1987-01-01

MR imaging is the most sensitive modality for diagnosing avascular necrosis (AVN), but there is no established explanation for the change of signal intensity of the osteonecrotic segment. Ten surgically removed femoral heads with AVN underwent MR imaging at 2.0 T. A combination of high gradient strength (0.1 m T/cm) and small radio frequency coil (8 cm in diameter) was used to obtain images with effective thickness of 2.0 mm and pixel dimensions as small as 200 μm. MR images were correlated with high-resolution CT and histologic findings. This paper illustrates how MR images the histologic findings of AVN

Contrast enhancement pattern in MR imaging of acute cerebral infarction

International Nuclear Information System (INIS)

Kim, Jong Deok; Cho, Mee Young; Lee, Chae Guk; Song, Dong Hoon

1994-01-01

To present the enhancement pattern of acute cerebral or cerebellar cortical infarctions aged 1-3 days on MR. Contrast-enhanced MR images of 26 patients with acute cerebral or cerebellar ischemic events were retrospectively reviewed. MR was performed within 3 days after ictus. Contrast enhancement in the area of infarction was observed in 61.5% (16/26) on MR. Of these 50% (13/26) showed non-parenchymal enhancement (NPE) representing either vascular or leptomeningeal enhancement, 7.7% (2/26) showed parenchymal enhancement (PE), and 2.8% (1/26) showed both NPE and PE. The earliest enhancement was seen in images obtained 12 hours after the onset of symptoms and appeared as NPE. One patient showed NPE without apparent high signal intensity at the corresponding area on T2-weighted images. In 38.5% (10/26), there was no enhancement. Contrast-enhanced MR imaging may be needed in acute ischemic infarction, because NPE may be seen as the earliest MR finding of acute cortical infraction aged 1-3 days