Diffusion-weighted MRI of maple syrup urine disease encephalopathy

Energy Technology Data Exchange (ETDEWEB)

Cavalleri, F.; Mavilla, L. [Servizio di Neuroradiologia, Azienda Ospedaliera Policlinico, Modena (Italy); Berardi, A.; Ferrari, F. [Servizio di Neonatologia, Azienda Ospedaliera Policlinico, Modena (Italy); Burlina, A.B. [Dipartimento di Pediatria, Azienda Ospedaliera, Universita di Padova, Padua (Italy)

2002-06-01

We report the case of a newborn child with maple syrup urine disease (MSUD), diagnosed at 10 days of life. Diffusion-weighted echoplanar MRI showed marked hyperintensity of the cerebellar white matter, the brainstem, the cerebral peduncles, the thalami, the dorsal limb of the internal capsule and the centrum semiovale, while conventional dual-echo sequence evidenced only a weak diffuse T2 hyperintensity in the cerebellar white matter and in the dorsal brainstem. The apparent diffusion coefficient (ADC) of these regions was markedly (>80%) decreased. Therefore, in agreement with current hypotheses on MSUD pathogenesis, MSUD oedema proves to be a cytotoxic oedema. Diffusion-weighted MRI may be a valuable tool, more sensitive than conventional spin-echo techniques, to assess the extent and progression of cytotoxicity in MSUD, as well as the effectiveness of the therapeutic interventions. (orig.)

Diffusion-weighted MRI of maple syrup urine disease encephalopathy

International Nuclear Information System (INIS)

Cavalleri, F.; Mavilla, L.; Berardi, A.; Ferrari, F.; Burlina, A.B.

2002-01-01

We report the case of a newborn child with maple syrup urine disease (MSUD), diagnosed at 10 days of life. Diffusion-weighted echoplanar MRI showed marked hyperintensity of the cerebellar white matter, the brainstem, the cerebral peduncles, the thalami, the dorsal limb of the internal capsule and the centrum semiovale, while conventional dual-echo sequence evidenced only a weak diffuse T2 hyperintensity in the cerebellar white matter and in the dorsal brainstem. The apparent diffusion coefficient (ADC) of these regions was markedly (>80%) decreased. Therefore, in agreement with current hypotheses on MSUD pathogenesis, MSUD oedema proves to be a cytotoxic oedema. Diffusion-weighted MRI may be a valuable tool, more sensitive than conventional spin-echo techniques, to assess the extent and progression of cytotoxicity in MSUD, as well as the effectiveness of the therapeutic interventions. (orig.)

Diffusion-weighted imaging findings on MRI as the sole radiographic findings in a child with proven herpes simplex encephalitis

Energy Technology Data Exchange (ETDEWEB)

Obeid, Makram; Franklin, Jeremy; Shrestha, Shraddha; Johnson, Lara; Hurst, Daniel [Texas Tech University Health Sciences Center, Department of Pediatrics, Lubbock, TX (United States); Quattromani, Frank [Texas Tech University Health Sciences Center, Department of Radiology, Lubbock, TX (United States)

2007-11-15

We present a case of herpes simplex encephalitis in an 8-year-old girl, in whom hyperintensity was detected on diffusion-weighted imaging (DWI) while conventional MRI sequences were normal 1 week after the onset of neurological symptoms. This case is rare in that a child beyond the neonatal period with focal herpes simplex encephalitis had an abnormal DWI sequence as the only MRI finding. (orig.)

Heroin-induced leukoencephalopathy: characterization using MRI, diffusion-weighted imaging, and MR spectroscopy

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Offiah, C. [Department of Neuroradiology, St Bartholomew' s and the London Hospitals NHS Trust, London (United Kingdom); Hall, E. [Department of Neuroradiology, St Bartholomew' s and the London Hospitals NHS Trust, London (United Kingdom)], E-mail: curtis.offiah@bartsandthelondon.nhs.uk

2008-02-15

Aim: To describe the magnetic resonance imaging (MRI) characteristics of heroin-induced leukoencephalopathy or 'chasing the dragon syndrome' and, in particular, the diffusion-weighted imaging (DWI) and MR spectroscopy (MRS) features. Material and methods: Six patients with a clinical or histopathological diagnosis of heroin-induced leukoencephalopathy were identified and MRI examinations, including DWI and single-voxel MRS, reviewed. Results: Cerebellar white matter was involved in all six cases demonstrating similar symmetrical distribution with sparing of the dentate nuclei. Brain stem signal change was evident in five of the six patients imaged. Supratentorial brain parenchymal involvement, as well as brain stem involvement, correlated anatomically with corticospinal tract distribution. None of the areas of signal abnormality were restricted on DWI. Of those patients subjected to MRS, the areas of parenchymal damage demonstrated reduced N-acetylaspartate, reduced choline, and elevated lactate. Conclusion: Heroin-induced leukoencephalopathy results in characteristic and highly specific signal abnormalities on MRI, which can greatly aid diagnosis. DWI and MRS findings can be explained by known reported neuropathological descriptions in this condition and can be used to support a proposed mechanism for the benefit of current recommended drug treatment regimes.

Diffusion-weighted MRI in acute posterior ischemic optic neuropathy

International Nuclear Information System (INIS)

Srinivasan, Sivasubramanian; Moorthy, Srikant; Sreekumar, KP; Kulkarni, Chinmay

2012-01-01

Blindness following surgery, especially cardiac surgery, has been reported sporadically, the most common cause being ischemic optic neuropathy. The role of MRI in the diagnosis of this condition is not well established. We present a case of postoperative posterior ischemic optic neuropathy that was diagnosed on diffusion-weighted MRI

Atypical abdominal paediatric lymphangiomatosis: diagnosis aided by diffusion-weighted MRI

International Nuclear Information System (INIS)

Humphries, Paul D.; Olsen, Oeystein E.; Wynne, Catherine S.; Sebire, Neil J.

2006-01-01

We report a 4-year-old child with a mesenteric mass, which on ultrasound, CT and conventional MRI appeared solid, raising lymphoma as a possible diagnosis. Diffusion weighted MRI (DW-MRI), however, suggested a low-cellularity lesion, making lymphoma less likely. Biopsy confirmed lymphangioma. DW-MRI may be a useful adjunct to conventional imaging, even in the abdomen. (orig.)

The contribution of MRI to the diagnosis of diffuse meningeal lesions

International Nuclear Information System (INIS)

Kreuzberg, B.; Kastner, J.; Ferda, J.

2004-01-01

We analysed MRI findings in patients in whom a diffuse abnormality of the meninges was revealed by MRI. We looked at T1 and T2-weighted spin-echo or fast spin-echo images and contrast-enhanced T1-weighted images. There were 15 patients with abnormalities on MRI, clinically suspected in ten. Four had meningoencephalitis, one meningeal and subcortical sarcoidosis nodules, four meningeal malignancies - one disseminated oligodendroglioma, one with meningeal infiltration around an adenocarcinoma, three meningeal infiltration by a haematological malignancy, and one a chronic subdural haematoma without a history of injury. We excluded patients with primary meningeal tumours and typical injury-related meningeal bleeding. The relatively small number of patients is due to both the infrequency of diffuse meningeal disease and to the low frequency of suspected meningeal pathology as an indication for MRI. The latter's diagnostic contribution is greatest in infectious disease and neoplastic infiltration, and less obvious in haematological malignancies. Contrast-enhanced T1-weighted images are most useful. (orig.)

Imaging of postthalamic visual fiber tracts by anisotropic diffusion weighted MRI and diffusion tensor imaging: principles and applications

International Nuclear Information System (INIS)

Reinges, Marcus H.T.; Schoth, Felix; Coenen, Volker A.; Krings, Timo

2004-01-01

Diffusion weighted MRI offers the possibility to study the course of the cerebral white matter tracts. In the present manuscript, the basics, the technique and the limitations of diffusion tensor imaging and anisotropic diffusion weighted MRI are presented and their applications in various neurological and neurosurgical diseases are discussed with special emphasis on the visual system. A special focus is laid on the combination of fiber tract imaging, anatomical imaging and functional MRI for presurgical planning and intraoperative neuronavigation of lesions near the visual system

MRI in seven cases of tacrolimus (FK-506) encephalopathy: utility of FLAIR and diffusion-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Furukawa, M. [Dept. of Radiology, Yamaguchi University School of Medicine, Ube (Japan); Dept. of Radiology, Hokkaido University School of Medicine, Sapporo (Japan); Terae, S.; Chu, B.C.; Kaneko, K.; Kamada, H.; Miyasaka, K. [Dept. of Radiology, Hokkaido University School of Medicine, Sapporo (Japan)

2001-08-01

We assessed the utility of fluid-attenuated inversion-recovery (FLAIR) and diffusion-weighted (DWI) images in investigation of tacrolimus (FK-506) encephalopathy, and to see whether we could predict its cause from clinical and imaging data. In seven patients with presumed FK-506 toxicity the areas involved on MRI were similar to those in cyclosporin A (CsA) toxicity. The abnormal signal was most evident on FLAIR in all cases. In three of four patients who underwent DWI, no diffusion abnormalities were detected; in the remaining patient, increased diffusion was seen in the deep white matter bilaterally on the apparent diffusion coefficient map, consistent with the findings on T2-weighted spin-echo and FLAIR images. Five of the six patients for whom we had clinical data showed sudden changes in electrolyte or fluid equilibrium due to diarrhoea, a polyuria or oliguria one day before or on the day of onset of the central nervous system disturbances. We speculate that FK-506 encephalopathy is triggered by the disturbance of the electrolyte and/or fluid equilibrium, given a certain serum level of FK-506. (orig.)

MRI in seven cases of tacrolimus (FK-506) encephalopathy: utility of FLAIR and diffusion-weighted imaging

International Nuclear Information System (INIS)

Furukawa, M.; Terae, S.; Chu, B.C.; Kaneko, K.; Kamada, H.; Miyasaka, K.

2001-01-01

We assessed the utility of fluid-attenuated inversion-recovery (FLAIR) and diffusion-weighted (DWI) images in investigation of tacrolimus (FK-506) encephalopathy, and to see whether we could predict its cause from clinical and imaging data. In seven patients with presumed FK-506 toxicity the areas involved on MRI were similar to those in cyclosporin A (CsA) toxicity. The abnormal signal was most evident on FLAIR in all cases. In three of four patients who underwent DWI, no diffusion abnormalities were detected; in the remaining patient, increased diffusion was seen in the deep white matter bilaterally on the apparent diffusion coefficient map, consistent with the findings on T2-weighted spin-echo and FLAIR images. Five of the six patients for whom we had clinical data showed sudden changes in electrolyte or fluid equilibrium due to diarrhoea, a polyuria or oliguria one day before or on the day of onset of the central nervous system disturbances. We speculate that FK-506 encephalopathy is triggered by the disturbance of the electrolyte and/or fluid equilibrium, given a certain serum level of FK-506. (orig.)

Evolution of Diffusion-Weighted Magnetic Resonance Imaging Signal Abnormality in Sporadic Creutzfeldt-Jakob Disease, With Histopathological Correlation.

Science.gov (United States)

Eisenmenger, Laura; Porter, Marie-Claire; Carswell, Christopher J; Thompson, Andrew; Mead, Simon; Rudge, Peter; Collinge, John; Brandner, Sebastian; Jäger, Hans R; Hyare, Harpreet

2016-01-01

Prion diseases represent the archetype of brain diseases caused by protein misfolding, with the most common subtype being sporadic Creutzfeldt-Jakob disease (sCJD), a rapidly progressive dementia. Diffusion-weighted imaging (DWI) has emerged as the most sensitive magnetic resonance imaging (MRI) sequence for the diagnosis of sCJD, but few studies have assessed the evolution of MRI signal as the disease progresses. To assess the natural history of the MRI signal abnormalities on DWI in sCJD to improve our understanding of the pathogenesis and to investigate the potential of DWI as a biomarker of disease progression, with histopathological correlation. Gray matter involvement on DWI was assessed among 37 patients with sCJD in 26 cortical and 5 subcortical subdivisions per hemisphere using a semiquantitative scoring system of 0 to 2 at baseline and follow-up. A total brain score was calculated as the summed scores in the individual regions. In 7 patients, serial mean diffusivity measurements were obtained. Age at baseline MRI, disease duration, atrophy, codon 129 methionine valine polymorphism, Medical Research Council Rating Scale score, and histopathological findings were documented. The study setting was the National Prion Clinic, London, England. All participants had a probable or definite diagnosis of sCJD and had at least 2 MRI studies performed during the course of their illness. The study dates were October 1, 2008 to April 1, 2012. The dates of our analysis were January 19 to April 20, 2012. Correlation of regional and total brain scores with disease duration. Among the 37 patients with sCJD in this study there was a significant increase in the number of regions demonstrating signal abnormality during the study period, with 59 of 62 regions showing increased signal intensity (SI) at follow-up, most substantially in the caudate and putamen (P disease duration (r = 0.47, P = .003 at baseline and r = 0.35, P = .03 at follow-up), and the left

Diffusion-weighted MRI in acute cerebral stroke

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Takayama, Hideichi; Kobayashi, Masahito; Suga, Sadao; Kawase, Takeshi; Nagasawa, Masakazu; Sadanaga, Humiko; Okamura, Miyuki; Kanai, Yoshihiro; Mihara, Ban [Mihara Memorial Hospital, Isezaki, Gunma (Japan)

1999-03-01

Diffusion-weighted MRI has been demonstrated to be valuable in the assessment of cerebral stroke. Recent advance in MR systems of hardware with larger maximum gradient amplitude and faster imaging strategies, such as EPI, has made it possible to acquire whole brain diffusion-weighted imaging (DWI) in less that one minute. The purposes of this study are to evaluate clinical usefulness of DWI and to clarify pitfalls in the diagnosis of acute cerebral stroke. Seventeen patients with 18 ischemic lesions were studied. DWI were taken with 1.5 Tesla MRI (Magnetom Vision, Siemens, Germany) using EPI sequence. Fifteen lesions out of them (3 in cerebral cortex, 9 in basal ganglia/deep white matter and 3 in cerebellum) were studied serially at various times up to 147 days. Acute cerebral infarction was seen clearly as an area of hyperintensity with DWI and as hypointensity in apparent diffusion coefficient (ADC) maps which are indicative of decreased diffusion. DWI detected areas of hyperintense acute infarcts, as early as 2.5 hours after onset, which were not visualized on T{sub 2}-weighted image (T2WI). The lesion of cerebral infarction became isointense in ADC maps at 14-28 days after onset, whereas with DWI it became isointense at about 2 months. Because ADC changed earlier than DWI, ADC maps were useful for differentiate acute from nonacute lesion in cases of recurrent stroke within a short period. In a patient with transient global amnesia for 7 hours, DWI did not show any lesion at 8 hours. In terms of cerebral hemorrhage, lesions were seen as area of hyperintensity in DWI at 3 days and were not distinguishable from that of infarct. Despite limitations in the diagnosis of transient ischemia and cerebral hemorrhage, DWI is a useful technique for early detection of cerebral infarction, especially within the first 6 hours after stroke onset. (author)

Diffusion-weighted MRI in acute cerebral stroke

International Nuclear Information System (INIS)

Takayama, Hideichi; Kobayashi, Masahito; Suga, Sadao; Kawase, Takeshi; Nagasawa, Masakazu; Sadanaga, Humiko; Okamura, Miyuki; Kanai, Yoshihiro; Mihara, Ban

1999-01-01

Diffusion-weighted MRI has been demonstrated to be valuable in the assessment of cerebral stroke. Recent advance in MR systems of hardware with larger maximum gradient amplitude and faster imaging strategies, such as EPI, has made it possible to acquire whole brain diffusion-weighted imaging (DWI) in less that one minute. The purposes of this study are to evaluate clinical usefulness of DWI and to clarify pitfalls in the diagnosis of acute cerebral stroke. Seventeen patients with 18 ischemic lesions were studied. DWI were taken with 1.5 Tesla MRI (Magnetom Vision, Siemens, Germany) using EPI sequence. Fifteen lesions out of them (3 in cerebral cortex, 9 in basal ganglia/deep white matter and 3 in cerebellum) were studied serially at various times up to 147 days. Acute cerebral infarction was seen clearly as an area of hyperintensity with DWI and as hypointensity in apparent diffusion coefficient (ADC) maps which are indicative of decreased diffusion. DWI detected areas of hyperintense acute infarcts, as early as 2.5 hours after onset, which were not visualized on T 2 -weighted image (T2WI). The lesion of cerebral infarction became isointense in ADC maps at 14-28 days after onset, whereas with DWI it became isointense at about 2 months. Because ADC changed earlier than DWI, ADC maps were useful for differentiate acute from nonacute lesion in cases of recurrent stroke within a short period. In a patient with transient global amnesia for 7 hours, DWI did not show any lesion at 8 hours. In terms of cerebral hemorrhage, lesions were seen as area of hyperintensity in DWI at 3 days and were not distinguishable from that of infarct. Despite limitations in the diagnosis of transient ischemia and cerebral hemorrhage, DWI is a useful technique for early detection of cerebral infarction, especially within the first 6 hours after stroke onset. (author)

Patterns in early diffusion-weighted MRI in children with haemolytic uraemic syndrome and CNS involvement

Energy Technology Data Exchange (ETDEWEB)

Donnerstag, Frank; Ding, Xiaoqi; Bueltmann, Eva; Zajaczek, Jan; Lanfermann, Heinrich [Hannover Medical School, Institute of Diagnostic and Therapeutic Neuroradiology, Hannover (Germany); Pape, Lars; Das, Anibh Martin; Ehrich, Jochen; Hartmann, Hans [Hannover Medical School, Clinic for Pediatric Kidney, Liver and Metabolic Diseases, Hannover (Germany); Luecke, Thomas [Hannover Medical School, Clinic for Pediatric Kidney, Liver and Metabolic Diseases, Hannover (Germany); University of Bochum, Department of Neuropediatrics, Pediatric Hospital, Bochum (Germany); Hoy, Ludwig [Hannover Medical School, Institute of Biometrics, Hannover (Germany)

2012-03-15

Diffusion-weighted imaging (DWI) in children with diarrhoea associated haemolytic uraemic syndrome (D+HUS) and cerebral involvement was evaluated retrospectively. DWI within 24 h of onset of neurological symptoms. The apparent diffusion coefficient (ADC) was measured in grey/white matter and correlated with clinical and laboratory findings. DWI was abnormal in all. Abnormal ADC was detected in the supratentorial white matter (6/12) and cortex (1/12), the basal ganglia (5/12), the thalami (4/12), and the cerebellum (1/12). ADC was reduced in 5/12, increased in 4/12, and both in 3/12. Mean serum sodium was lower in patients with DWI abnormalities affecting the white matter (6/12), than in those with basal ganglia/thalamic involvement (6/12). Neurological outcome was normal in 4/11 and abnormal in 7/11, and 1 patient died, outcome did not correlate to either localisation or type of DWI abnormality. In D+HUS with neurological symptoms, early DWI may reveal abnormal ADC not only in the basal ganglia/thalami, but also in the white matter/cortex. Besides thrombotic microangiopathy, toxic effects of shiga toxin, azotaemia and hyponatraemia / hypoosmolality may be involved in cerebral involvement in children with D+HUS. Findings on early MRI seem not to predict clinical course or outcome. (orig.)

Patterns in early diffusion-weighted MRI in children with haemolytic uraemic syndrome and CNS involvement

International Nuclear Information System (INIS)

Donnerstag, Frank; Ding, Xiaoqi; Bueltmann, Eva; Zajaczek, Jan; Lanfermann, Heinrich; Pape, Lars; Das, Anibh Martin; Ehrich, Jochen; Hartmann, Hans; Luecke, Thomas; Hoy, Ludwig

2012-01-01

Diffusion-weighted imaging (DWI) in children with diarrhoea associated haemolytic uraemic syndrome (D+HUS) and cerebral involvement was evaluated retrospectively. DWI within 24 h of onset of neurological symptoms. The apparent diffusion coefficient (ADC) was measured in grey/white matter and correlated with clinical and laboratory findings. DWI was abnormal in all. Abnormal ADC was detected in the supratentorial white matter (6/12) and cortex (1/12), the basal ganglia (5/12), the thalami (4/12), and the cerebellum (1/12). ADC was reduced in 5/12, increased in 4/12, and both in 3/12. Mean serum sodium was lower in patients with DWI abnormalities affecting the white matter (6/12), than in those with basal ganglia/thalamic involvement (6/12). Neurological outcome was normal in 4/11 and abnormal in 7/11, and 1 patient died, outcome did not correlate to either localisation or type of DWI abnormality. In D+HUS with neurological symptoms, early DWI may reveal abnormal ADC not only in the basal ganglia/thalami, but also in the white matter/cortex. Besides thrombotic microangiopathy, toxic effects of shiga toxin, azotaemia and hyponatraemia / hypoosmolality may be involved in cerebral involvement in children with D+HUS. Findings on early MRI seem not to predict clinical course or outcome. (orig.)

Transient detection of early wallerian degeneration on diffusion-weighted MRI after an acute cerebrovascular accident

International Nuclear Information System (INIS)

Uchino, A.; Sawada, A.; Takase, Y.; Egashira, R.; Kudo, S.

2004-01-01

We report three patients with a cerebrovascular accident studied serially by MRI, including diffusion-weighted imaging (DWI). In case 1, DWI 1 day after the onset of left frontoparietal cortical infarcts showed no abnormal signal in the left corticospinal tract. DWI 12 days after onset showed high signal in the corticospinal tract, interpreted as early wallerian degeneration. This had disappeared by 22 days after onset. In case 2, DWI obtained 7 days after the onset of a right internal capsule lacunar infarct showed high signal from the right corticospinal tract in the brainstem, which was less marked 15 days after onset. In case 3, MRI on postnatal day 7 showed a cerebral haemorrhage in the right corona radiata and high signal from the right corticospinal tract on DWI. The latter disappeared by day 23. DWI shows early wallerian degeneration; transient signal abnormalities within 2 weeks of stroke should not be mistaken for new ischaemic lesions. (orig.)

Transient detection of early wallerian degeneration on diffusion-weighted MRI after an acute cerebrovascular accident

Energy Technology Data Exchange (ETDEWEB)

Uchino, A.; Sawada, A.; Takase, Y.; Egashira, R.; Kudo, S. [Department of Radiology, Saga Medical School, 5-1-1 Nabeshima, Saga, 849-8501 (Japan)

2004-03-01

We report three patients with a cerebrovascular accident studied serially by MRI, including diffusion-weighted imaging (DWI). In case 1, DWI 1 day after the onset of left frontoparietal cortical infarcts showed no abnormal signal in the left corticospinal tract. DWI 12 days after onset showed high signal in the corticospinal tract, interpreted as early wallerian degeneration. This had disappeared by 22 days after onset. In case 2, DWI obtained 7 days after the onset of a right internal capsule lacunar infarct showed high signal from the right corticospinal tract in the brainstem, which was less marked 15 days after onset. In case 3, MRI on postnatal day 7 showed a cerebral haemorrhage in the right corona radiata and high signal from the right corticospinal tract on DWI. The latter disappeared by day 23. DWI shows early wallerian degeneration; transient signal abnormalities within 2 weeks of stroke should not be mistaken for new ischaemic lesions. (orig.)

Diffusion and perfusion MRI for the localisation of epileptogenic foci in drug-resistant epilepsy

International Nuclear Information System (INIS)

Heiniger, P.; El-Koussy, M.; Kiefer, C.; Oswald, H.; Schroth, G.; Schindler, K.; Donati, F.; Loevblad, K.O.; Wissmeyer, M.; Mariani, L.; Weder, B.

2002-01-01

Drug-resistant epilepsy is an important clinical challenge, both diagnostically and therapeutically. More and more surgical options are being considered, but precise presurgical assessment is necessary. We prospectively studied eight patients with drug-resistant epilepsy, who underwent clinical examination, single photon emission computed tomography (SPECT) and interictal MRI, including diffusion- and perfusion-weighted echoplanar sequences. Lesions suspected on SPECT of being epileptogenic showed mild hypoperfusion, while the diffusion-weighted MRI (DWI) revealed increased apparent diffusion coefficients relative to the other side. However, these abnormalities were not visible on the corresponding maps. We showed that DWI and perfusion-weighted MRI could be used confirm the characteristics and site of an epileptogenic area in patients with drug-resistant epilepsy. (orig.)

Prospective comparison of T2w-MRI and dynamic-contrast-enhanced MRI, 3D-MR spectroscopic imaging or diffusion-weighted MRI in repeat TRUS-guided biopsies

Energy Technology Data Exchange (ETDEWEB)

Portalez, Daniel [Clinique Pasteur, 45, Department of Radiology, Toulouse (France); Rollin, Gautier; Mouly, Patrick; Jonca, Frederic; Malavaud, Bernard [Hopital de Rangueil, Department of Urology, Toulouse Cedex 9 (France); Leandri, Pierre [Clinique Saint Jean, 20, Department of Urology, Toulouse (France); Elman, Benjamin [Clinique Pasteur, 45, Department of Urology, Toulouse (France)

2010-12-15

To compare T2-weighted MRI and functional MRI techniques in guiding repeat prostate biopsies. Sixty-eight patients with a history of negative biopsies, negative digital rectal examination and elevated PSA were imaged before repeat biopsies. Dichotomous criteria were used with visual validation of T2-weighted MRI, dynamic contrast-enhanced MRI and literature-derived cut-offs for 3D-spectroscopy MRI (choline-creatine-to-citrate ratio >0.86) and diffusion-weighted imaging (ADC x 10{sup 3} mm{sup 2}/s < 1.24). For each segment and MRI technique, results were rendered as being suspicious/non-suspicious for malignancy. Sextant biopsies, transition zone biopsies and at least two additional biopsies of suspicious areas were taken. In the peripheral zones, 105/408 segments and in the transition zones 19/136 segments were suspicious according to at least one MRI technique. A total of 28/68 (41.2%) patients were found to have cancer. Diffusion-weighted imaging exhibited the highest positive predictive value (0.52) compared with T2-weighted MRI (0.29), dynamic contrast-enhanced MRI (0.33) and 3D-spectroscopy MRI (0.25). Logistic regression showed the probability of cancer in a segment increasing 12-fold when T2-weighted and diffusion-weighted imaging MRI were both suspicious (63.4%) compared with both being non-suspicious (5.2%). The proposed system of analysis and reporting could prove clinically relevant in the decision whether to repeat targeted biopsies. (orig.)

Conventional and Diffusion-Weighted MRI in the Evaluation of Methanol Poisoning. A case report

International Nuclear Information System (INIS)

Server, A.; Nakstad, P.Hj.; Dullerud, R.; Haakonsen, M.; Hovda, K.E.; Jacobsen, D.

2003-01-01

Cerebral lesions were studied in 2 methanol-poisoned patients using conventional magnetic resonance imaging (MRI). In 1 patient, diffusion-weighted MRI (DWI) was also performed. In this patient, conventional MRI showed symmetrical, bilateral increased signal in the lentiform nuclei, involving predominantly putamina, but also extending into the corona radiata, centrum semiovale and subcortical white matter. DWI showed decreased diffusion, which most probably reflects cytotoxic edema. In the other patient, fluid attenuated-inversion recovery (FLAIR) and T2-weighted images showed hyperintensity in the putamina, characteristic of post-necrotic changes

Diffusion-weighted MRI in cervical cancer

International Nuclear Information System (INIS)

McVeigh, Patrick Z.; Haider, Masoom A.; Syed, Aejaz M.; Milosevic, Michael; Fyles, Anthony

2008-01-01

The purpose was to investigate the potential value of apparent diffusion coefficient (ADC) measurement with MRI in the assessment of cervix cancer. Diffusion-weighted MRI was performed in 47 patients with cervical carcinoma undergoing chemoradiation therapy and 26 normal controls on a 1.5-T system with a b-value of 600 s/mm 2 . FIGO stage, tumor volume, nodal status, interstitial fluid pressure (IFP) and oxygen measurements were recorded. Response was defined as no visible tumor 3-6 months following completion of therapy. The average median ADC (mADC) of cervical carcinomas (1.09±0.20 x 10 -3 mm 2 /s) was significantly lower than normal cervix (2.09±0.46 x 10 -3 mm 2 /s) (P -3 mm 2 /s) compared to T2b (1.21 x 10 -3 mm 2 /s) and T3/T4 (1.10 x 10 -3 mm 2 /s) (P<0.001). In patients with squamous carcinomas the 90th percentile of ADC values was lower in responders than non-responders (P<0.05). Median ADC in cervix carcinoma is significantly lower compared to normal cervix. ADC may have predictive value in squamous tumors, but further long-term study will determine the ultimate clinical utility. (orig.)

Diffusion-weighted MRI of the prostate; Diffusionsgewichtete MRT der Prostata

Energy Technology Data Exchange (ETDEWEB)

Mueller-Lisse, U.G.; Scherr, M.K. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany); Mueller-Lisse, U.L. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Klinik und Poliklinik fuer Urologie, Muenchen (Germany); Zamecnik, P.; Schlemmer, H.P.W. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung fuer Radiologische Diagnostik, Heidelberg (Germany)

2011-03-15

Diffusion-weighted magnetic resonance imaging (DWI) can complement MRI of the prostate in the detection and localization of prostate cancer, particularly after previous negative biopsy. A total of 13 original reports and 2 reviews published in 2010 demonstrate that prostate cancer can be detected by DWI due to its increased cell density and decreased diffusiveness, either qualitatively in DWI images or quantitatively by means of the apparent diffusion coefficient (ADC). In the prostate, the ADC is influenced by the strength of diffusion weighting, localization (peripheral or transitional zone), presence of prostatitis or hemorrhage and density and differentiation of prostate cancer cells. Mean differences between healthy tissue of the peripheral zone and prostate cancer appear to be smaller for ADC than for the (choline + creatine)/citrate ratio in MR spectroscopy. Test quality parameters vary greatly between different studies but appear to be slightly better for combined MRI and DWI than for MRI of the prostate alone. Clinical validation of DWI of the prostate requires both increased technical conformity and increased numbers of patients in clinical studies. (orig.) [German] Die diffusionsgewichtete MRT (''diffusion-weighted imaging'', DWI) kann die MRT der Prostata bei der Erkennung und Lokalisation von Prostatakarzinomen besonders nach vorangehender, negativer Stanzbiopsie ergaenzen. In 13 klinischen Original- und 2 Uebersichtsarbeiten des Jahres 2010 zeigt sich, dass die DWI Prostatakarzinome an Einschraenkungen der freien Teilchenbeweglichkeit bei erhoehter Zelldichte qualitativ im Bild oder quantitativ an Hand des ''apparent diffusion coefficient'' (ADC) nachweist. Den ADC in der Prostata beeinflussen Staerke der Diffusionsgewichtung, Lokalisation (periphere Zone, Transitionalzone), Vorliegen von Prostatitis oder Einblutung sowie Streudichte und Differenzierung von Prostatakarzinomzellen. Unterschiede zwischen gesundem

Diffusion-weighted MRI in Crohn's disease: Current status and recommendations

OpenAIRE

Dohan, A.; Taylor, S.; Hoeffel, C.; Barret, M.; Allez, M.; Dautry, R.; Zappa, M.; Savoye-Collet, C.; Dray, X.; Boudiaf, M.; Reinhold, C.; Soyer, P.

2016-01-01

Over the past years, technological improvements and refinements in magnetic resonance imaging (MRI) hardware have made high-quality diffusion-weighted imaging (DWI) routinely possible for the bowel. DWI is promising for the detection and characterization of lesions in Crohn's disease (CD) and has been advocated as an alternative to intravenous gadolinium-based contrast agents. Furthermore, quantification using the apparent diffusion coefficient may have value as a biomarker of CD activity and...

Diffusion weighted MRI by spatiotemporal encoding: Analytical description and in vivo validations

Science.gov (United States)

Solomon, Eddy; Shemesh, Noam; Frydman, Lucio

2013-07-01

Diffusion-weighted (DW) MRI is a powerful modality for studying microstructure in normal and pathological tissues. The accuracy derived from DW MRI depends on the acquisition of quality images, and on a precise assessment of the b-values involved. Conventional DW MRI tends to be of limited use in regions suffering from large magnetic field or chemical shift heterogeneities, which severely distort the MR images. In this study we propose novel sequences based on SPatio-temporal ENcoding (SPEN), which overcome such shortcomings owing to SPEN's inherent robustness to offsets. SPEN, however, relies on the simultaneous application of gradients and radiofrequency-swept pulses, which may impart different diffusion weightings along the spatial axes. These will be further complicated in DW measurements by the diffusion-sensitizing gradients, and will in general lead to complex, spatially-dependent b-values. This study presents a formalism for analyzing these diffusion-weighted SPEN (dSPEN) data, which takes into account the concomitant effects of adiabatic pulses, of the imaging as well as diffusion gradients, and of the cross-terms between them. These analytical b-values derivations are subject to experimental validations in phantom systems and ex vivo spinal cords. Excellent agreement is found between the theoretical predictions and these dSPEN experiments. The ensuing methodology is then demonstrated by in vivo mapping of diffusion in human breast - organs where conventional k-space DW acquisition methods are challenged by both field and chemical shift heterogeneities. These studies demonstrate the increased robustness of dSPEN vis-à-vis comparable DW echo planar imaging, and demonstrate the value of this new methodology for medium- or high-field diffusion measurements in heterogeneous systems.

Diffusion-weighted MRI of myelination in the rat brain following treatment with gonadal hormones

International Nuclear Information System (INIS)

Prayer, D.; Roberts, T.; Barkovich, A.J.; Prayer, L.; Kucharczyk, J.; Moseley, M.; Arieff, A.

1997-01-01

Previous studies have demonstrated the ability of high-resolution diffusion-weighted MRI to show maturation of white-matter structures in the developing rat brain. The purpose of this study was to investigate the influence of gonadal steroid hormones on the rate of this development. Starting from their second postnatal day, 16 rat-pups of either sex were repeatedly treated with subcutaneous implants containing 17-beta estradiol or delta-androstene 3,17 dione, respectively. Serial T1-, T2- and diffusion-weighted MRI was performed weekly for 8 weeks using a 4.7 T unit. Maturation of anterior optic pathways and hemisphere commissures was assessed. Diffusion-weighted images were processed to produce ''anisotropy index maps'', previously shown to be sensitive to white-matter maturation. Compared with untreated rat-pups, estrogen-treated animals showed accelerated, and testosterone-treated animals delayed maturation on anisotropy index maps and histological sections. In all animals, maturational changes appeared earlie on anisotropy index maps than on other MRI sequences or on myelin-sensitive stained sections. Diffusion-weighted imaging, and the construction of spatial maps sensitive to diffusion anisotropy, seem to be the most sensitive approach for the detection of maturational white-matter changes, and thus may hold potential for early diagnosis of temporary delay or permanent disturbances of white-matter development. (orig.). With 6 figs., 1 tab

Diffusion-weighted MRI of myelination in the rat brain following treatment with gonadal hormones

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Prayer, D. [Department of Radiology, Section of Neuroradiology, University of Vienna (Austria); Roberts, T. [Department of Radiology, Section of Neuroradiology, University of California at San Francisco (UCSF), CA (United States); Barkovich, A.J. [Department of Radiology, Section of Neuroradiology, University of California at San Francisco (UCSF), CA (United States); Prayer, L. [Department of Radiology, Section of Neuroradiology, University of Vienna (Austria); Kucharczyk, J. [Department of Radiology, Section of Neuroradiology, University of California at San Francisco (UCSF), CA (United States); Moseley, M. [Department of Radiology, Section of Neuroradiology, University of California at San Francisco (UCSF), CA (United States); Arieff, A. [Department of Medicine, Geriatrics Section, Veteran`s Affairs Medical Center and University of California at San Francisco (UCSF), CA (United States)

1997-05-01

Previous studies have demonstrated the ability of high-resolution diffusion-weighted MRI to show maturation of white-matter structures in the developing rat brain. The purpose of this study was to investigate the influence of gonadal steroid hormones on the rate of this development. Starting from their second postnatal day, 16 rat-pups of either sex were repeatedly treated with subcutaneous implants containing 17-beta estradiol or delta-androstene 3,17 dione, respectively. Serial T1-, T2- and diffusion-weighted MRI was performed weekly for 8 weeks using a 4.7 T unit. Maturation of anterior optic pathways and hemisphere commissures was assessed. Diffusion-weighted images were processed to produce ``anisotropy index maps``, previously shown to be sensitive to white-matter maturation. Compared with untreated rat-pups, estrogen-treated animals showed accelerated, and testosterone-treated animals delayed maturation on anisotropy index maps and histological sections. In all animals, maturational changes appeared earlie on anisotropy index maps than on other MRI sequences or on myelin-sensitive stained sections. Diffusion-weighted imaging, and the construction of spatial maps sensitive to diffusion anisotropy, seem to be the most sensitive approach for the detection of maturational white-matter changes, and thus may hold potential for early diagnosis of temporary delay or permanent disturbances of white-matter development. (orig.). With 6 figs., 1 tab.

Optimising diffusion weighted MRI for imaging metastatic and myeloma bone disease and assessing reproducibility

International Nuclear Information System (INIS)

Messiou, C.; Collins, D.J.; Morgan, V.A.; DeSouza, N.M.

2011-01-01

To establish normal bone marrow values of apparent diffusion coefficient (ADC) over an age range, compare them with metastatic and myelomatous involvement, to establish reproducibility and to optimise b values. The ADCs of bone marrow in 7 volunteers (mean age 29.7 years), 34 volunteers (mean age 63.3 years) and 43 patients with metastatic and myelomatous involvement (mean age 65.5 years) were measured. In 9 volunteers diffusion weighted MRI was repeated within 7 days. b values were derived to optimise contrast between normal and pathological marrow. The mean ADC of bone marrow in younger volunteers was significantly higher than that of older volunteers. The coefficient of reproducibility was 14.8%. The ADC mean of metastatic and myeloma bone disease was 1054+/-456 x 10 -6 mm 2 s -1 . An ADC threshold of 655 x 10 -6 mm 2 s -1 separated normal and abnormal marrow with a sensitivity and specificity of 90% and 93% respectively. Contrast between normal and abnormal marrow was optimal at b = 1389 smm -2 . The reproducibility of ADC measurements in bone is equivalent to published data for soft tissue with a high sensitivity and specificity for separating abnormal from age matched normal bone marrow. A b value of around 1,400 smm -2 is optimal for imaging bone marrow. (orig.)

Optimising diffusion weighted MRI for imaging metastatic and myeloma bone disease and assessing reproducibility

Energy Technology Data Exchange (ETDEWEB)

Messiou, C. [Institute of Cancer Research and Royal Marsden, NHS Foundation Trust, Cancer Research UK Clinical Magnetic Resonance Research Group, Surrey (United Kingdom); Institute of Cancer Research and Royal Marsden, NHS Foundation Trust, MRI Department, Surrey (United Kingdom); Collins, D.J.; Morgan, V.A.; DeSouza, N.M. [Institute of Cancer Research and Royal Marsden, NHS Foundation Trust, Cancer Research UK Clinical Magnetic Resonance Research Group, Surrey (United Kingdom)

2011-08-15

To establish normal bone marrow values of apparent diffusion coefficient (ADC) over an age range, compare them with metastatic and myelomatous involvement, to establish reproducibility and to optimise b values. The ADCs of bone marrow in 7 volunteers (mean age 29.7 years), 34 volunteers (mean age 63.3 years) and 43 patients with metastatic and myelomatous involvement (mean age 65.5 years) were measured. In 9 volunteers diffusion weighted MRI was repeated within 7 days. b values were derived to optimise contrast between normal and pathological marrow. The mean ADC of bone marrow in younger volunteers was significantly higher than that of older volunteers. The coefficient of reproducibility was 14.8%. The ADC mean of metastatic and myeloma bone disease was 1054+/-456 x 10{sup -6} mm{sup 2}s{sup -1}. An ADC threshold of 655 x 10{sup -6} mm{sup 2}s{sup -1} separated normal and abnormal marrow with a sensitivity and specificity of 90% and 93% respectively. Contrast between normal and abnormal marrow was optimal at b = 1389 smm{sup -2}. The reproducibility of ADC measurements in bone is equivalent to published data for soft tissue with a high sensitivity and specificity for separating abnormal from age matched normal bone marrow. A b value of around 1,400 smm{sup -2} is optimal for imaging bone marrow. (orig.)

Abnormalities on diffusion-weighted magnetic resonance imaging in patients with transient ischemic attack

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Nakamura, Tomomi; Shibagaki, Yasuro [Ushiku Aiwa General Hospital, Ibaraki (Japan); Uchiyama, Shinichiro; Iwata, Makoto [Tokyo Women' s Medical Coll. (Japan)

2003-03-01

We studied abnormalities on diffusion-weighted magnetic resonance imaging (DWI) in patients with transient ischemic attack (TIA). Out of 18 consecutive TIA patients, 9 patients had relevant focal abnormalities on DWI. Among TIA patients, six patients were associated with atrial fibrillation (Af), and all of these patients had focal abnormalities on DWI as well. TIA patients with Af had significantly more frequent focal abnormalities on DWI than those without Af (p=0.009; Fisher's exact probability test). In addition, the duration of TIA symptoms was not related to the presence of focal abnormalities on DWI. These results indicate that embolic mechanism may cause focal abnormalities on DWI. DWI was more sensitive to detect responsible ischemic lesions in these patients than T2-weighted image or fluid-attenuated inversion recovery image. (author)

Abnormalities on diffusion-weighted magnetic resonance imaging in patients with transient ischemic attack

International Nuclear Information System (INIS)

Nakamura, Tomomi; Shibagaki, Yasuro; Uchiyama, Shinichiro; Iwata, Makoto

2003-01-01

We studied abnormalities on diffusion-weighted magnetic resonance imaging (DWI) in patients with transient ischemic attack (TIA). Out of 18 consecutive TIA patients, 9 patients had relevant focal abnormalities on DWI. Among TIA patients, six patients were associated with atrial fibrillation (Af), and all of these patients had focal abnormalities on DWI as well. TIA patients with Af had significantly more frequent focal abnormalities on DWI than those without Af (p=0.009; Fisher's exact probability test). In addition, the duration of TIA symptoms was not related to the presence of focal abnormalities on DWI. These results indicate that embolic mechanism may cause focal abnormalities on DWI. DWI was more sensitive to detect responsible ischemic lesions in these patients than T2-weighted image or fluid-attenuated inversion recovery image. (author)

Diffusion-weighted MRI of adult male pelvic cancers

International Nuclear Information System (INIS)

Lim, K.S.; Tan, C.H.

2012-01-01

Magnetic resonance imaging (MRI), with its superior soft-tissue delineation, plays a pivotal role in the staging and surveillance of cancers affecting adult males, in particular, rectal, urinary bladder, and prostate cancers. There has been much recent interest in the complementary roles of diffusion-weighted imaging (DWI) for imaging of pelvic cancers. DWI measures the diffusivity of water molecules in biological tissue. Cancer, with its high cellular density and nuclear:cytoplasmic ratio, and extracellular disorganization, typically shows significant restricted diffusivity compared with surrounding normal tissue. In theory, diffusivity of water molecules may vary according to degree of tumour aggressiveness and changes in cell density and extracellular fluid content after treatment. Information regarding these variations may be used to study the histological grades of cancers and their response to treatment. In this article, we present the currently available evidence on the potential roles of DWI for the assessment of pelvic cancers in men, and demonstrate with imaging examples how this knowledge may be applied to daily clinical practice.

Role of diffusion-weighted MRI in differentiation of hepatic abscesses from non-infected fluid collections.

Science.gov (United States)

Schmid-Tannwald, C; Schmid-Tannwald, C M; Morelli, J N; Neumann, R; Reiser, M F; Nikolaou, K; Rist, C

2014-07-01

To evaluate the role of diffusion-weighted magnetic resonance imaging (DW-MRI) in the differentiation of hepatic abscesses from non-infected fluid collections. In this retrospective study, 22 hepatic abscesses and 27 non-infected hepatic fluid collections were examined in 27 patients who underwent abdominal MRI including DW-MRI. Two independent observers reviewed T2-weighted + DW-MRI and T2-weighted + contrast-enhanced T1-weighted (CET1W) images in two sessions. Detection rates and confidence levels were calculated and compared using McNemar's and Wilcoxon's signed rank tests, respectively. Apparent diffusion coefficient (ADC) values of abscesses and non-infected fluid collections were compared using the t-test. Receiver operating characteristic (ROC) curves were constructed. There was no statistically significant difference in the accuracy of detecting abscesses using T2-weighted + DW-MRI (both observers: 21/22, 95.5%) versus T2-weighted + CET1W images (observer 1: 21/22, 95.5%; observer 2: 22/22, 100%; p collections (0.83 ± 0.24 versus 2.25 ± 0.61 × 10(-3) mm(2)/s; p collections at a threshold ADC value of 1.36 × 10(-3) mm(2)/s. DW-MRI allows qualitative and quantitative differentiation of abscesses from non-infected fluid collections in the liver. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Diffusion weighted MRI in intrahepatic bile duct adenoma arising from the cirrhotic liver

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An, Chansik [Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Park, Sumi; Choi, Yoon Jung [National Health Insurance Corporation Ilsan Hospital, Goyang (Korea, Republic of)

2013-10-15

A 64-year-old male patient with liver cirrhosis underwent a CT study for hepatocellular carcinoma surveillance, which demonstrated a 1.4-cm hypervascular subcapsular tumor in the liver. On gadoxetic acid-enhanced MRI, the tumor showed brisk arterial enhancement and persistent hyperenhancement in the portal phase, but hypointensity in the hepatobiliary phase. On diffusion-weighted MRI, the tumor showed an apparent diffusion coefficient twofold greater than that of the background liver parenchyma, which suggested that the lesion was benign. The histologic diagnosis was intrahepatic bile duct adenoma with alcoholic liver cirrhosis.

Diffusion-weighted MRI in intrahepatic bile duct adenoma arising from the cirrhotic liver.

Science.gov (United States)

An, Chansik; Park, Sumi; Choi, Yoon Jung

2013-01-01

A 64-year-old male patient with liver cirrhosis underwent a CT study for hepatocellular carcinoma surveillance, which demonstrated a 1.4-cm hypervascular subcapsular tumor in the liver. On gadoxetic acid-enhanced MRI, the tumor showed brisk arterial enhancement and persistent hyperenhancement in the portal phase, but hypointensity in the hepatobiliary phase. On diffusion-weighted MRI, the tumor showed an apparent diffusion coefficient twofold greater than that of the background liver parenchyma, which suggested that the lesion was benign. The histologic diagnosis was intrahepatic bile duct adenoma with alcoholic liver cirrhosis.

Correlation of human papillomavirus status with apparent diffusion coefficient of diffusion-weighted MRI in head and neck squamous cell carcinomas.

Science.gov (United States)

Driessen, Juliette P; van Bemmel, Alexander J M; van Kempen, Pauline M W; Janssen, Luuk M; Terhaard, Chris H J; Pameijer, Frank A; Willems, Stefan M; Stegeman, Inge; Grolman, Wilko; Philippens, Marielle E P

2016-04-01

Identification of prognostic patient characteristics in head and neck squamous cell carcinoma (HNSCC) is of great importance. Human papillomavirus (HPV)-positive HNSCCs have favorable response to (chemo)radiotherapy. Apparent diffusion coefficient, derived from diffusion-weighted MRI, has also shown to predict treatment response. The purpose of this study was to evaluate the correlation between HPV status and apparent diffusion coefficient. Seventy-three patients with histologically proven HNSCC were retrospectively analyzed. Mean pretreatment apparent diffusion coefficient was calculated by delineation of total tumor volume on diffusion-weighted MRI. HPV status was analyzed and correlated to apparent diffusion coefficient. Six HNSCCs were HPV-positive. HPV-positive HNSCC showed significantly lower apparent diffusion coefficient compared to HPV-negative. This correlation was independent of other patient characteristics. In HNSCC, positive HPV status correlates with low mean apparent diffusion coefficient. The favorable prognostic value of low pretreatment apparent diffusion coefficient might be partially attributed to patients with a positive HPV status. © 2015 Wiley Periodicals, Inc. Head Neck 38: E613-E618, 2016. © 2015 Wiley Periodicals, Inc.

Diffusion-weighted MRI of the liver—Interpretative pearls and pitfalls

International Nuclear Information System (INIS)

Culverwell, A.D.; Sheridan, M.B.; Guthrie, J.A.; Scarsbrook, A.F.

2013-01-01

Diffusion-weighted magnetic resonance imaging (DW MRI) is an established technique in neuroradiology and more recently has emerged as a useful adjunct to various oncological applications of MRI. It has an expanding role in the evaluation of liver lesions, offers higher detection rates for small lesions, and can increase confidence in differentiating between benign and malignant lesions. Other applications include assessment of tumour response to therapy, differentiating tumour from bland thrombus, and assessment of liver fibrosis. DW sequences can be performed on most modern MRI machines with relative ease, in a short time period and without the need for contrast medium. DW MRI can be of value in the detection and characterization of hepatic lesions but there are pitfalls, which can potentially cause interpretative difficulty. This article will review the rationale for DW MRI in liver imaging, demonstrate the clinical utility of the technique in a spectrum of hepatic diseases, and illustrate key interpretative pearls and pitfalls

CT and MRI findings of Creutzfeldt-Jakob disease in the early stage. The usefulness of diffusion-weighted images

International Nuclear Information System (INIS)

Ukisu, Ryutaro; Kushihashi, Tamio; Gokan, Takehiko

2001-01-01

To detect subtle CT and MRI features of Creutzfeldt-Jacob disease (CJD) in the early stage is important to prevent a human-to-human transmission. This study included 10 patients of CJD who underwent CT and/or MRI in its early stage. CT, T1- and T2-weighted MRI, DWI, and FLAIR images were obtained in 10, 6, 4, and 2 patients respectively. On DWI, abnormal hyperintensities were observed in both cerebral cortex, and in basal ganglia in all patients. On FLAIR images, abnormal hyperintensies were observed in one patient. Detection of abnormal intensities may be possible in the early stage of CJD using MRI, particularly with DWI. (author)

CT and MRI findings of Creutzfeldt-Jakob disease in the early stage. The usefulness of diffusion-weighted images

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Ukisu, Ryutaro; Kushihashi, Tamio; Gokan, Takehiko [Showa Univ., Tokyo (Japan). School of Medicine] [and others

2001-02-01

To detect subtle CT and MRI features of Creutzfeldt-Jacob disease (CJD) in the early stage is important to prevent a human-to-human transmission. This study included 10 patients of CJD who underwent CT and/or MRI in its early stage. CT, T1- and T2-weighted MRI, DWI, and FLAIR images were obtained in 10, 6, 4, and 2 patients respectively. On DWI, abnormal hyperintensities were observed in both cerebral cortex, and in basal ganglia in all patients. On FLAIR images, abnormal hyperintensies were observed in one patient. Detection of abnormal intensities may be possible in the early stage of CJD using MRI, particularly with DWI. (author)

Rapid resolution of diffusion weighted MRI abnormality in a patient with a stuttering stroke

Science.gov (United States)

Peters, Jurriaan M; MacLean, Ainsley V; Young, Geoffrey S

2010-01-01

We report the unusually rapid and spontaneous normalisation of low diffusivity that accompanied resolution of acute neurological deficits in a stroke patient who underwent two magnetic resonance imaging examinations within 24 h of symptom onset. Diffusion weighted imaging obtained within hours of onset of left sided weakness demonstrated a focal right capsular area of low diffusivity that resolved within 24 h, coinciding with resolution of the patient’s symptoms. PMID:22315635

Comparison of diffusion-weighted fMRI and BOLD fMRI responses in a verbal working memory task

International Nuclear Information System (INIS)

Aso, Toshihiko; Urayama, Shin-ichi; Fukuyama, Hidenao; Le Bihan, Denis

2013-01-01

Diffusion-weighted functional MRI (DfMRI) has been reported to have a different response pattern in the visual cortex than that of BOLD-fMRI. Especially, the DfMRI signal shows a constantly faster response at both onset and offset of the stimulus, suggesting that the DfMRI signal might be more directly linked to neuronal events than the hemodynamic response. However, because the DfMRI response also contains a residual sensitivity to BOLD this hypothesis has been challenged. Using a verbal working memory task we show that the DfMRI time-course features are preserved outside visual cortices, but also less liable to between-subject/between-regional variation than the BOLD response. The overall findings not only support the feasibility of DfMRI as an approach for functional brain imaging, but also strengthen the uniqueness of the DfMRI signal origin. (authors)

Report of diffusion-weighted MRI in two cases with different cerebral hydatid disease

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Kitis, O.; Calli, C.; Yunten, N. [Ege Univ., Izmir (Turkey). Dept. of Radiology

2004-02-01

To present MRI findings in two cases of cerebral hydatid disease with an emphasis on diffusion-weighted imaging (DWI) findings of Echinococcus granulosus (EG) versus Echinococcus alveolaris (EA). EG lesions were isointense with cerebrospinal fluid in all sequences including DWI. On DWI, EA lesions remained hypointense on b = 1000 s/mm2 diffusion-weighted images. Apparent diffusion coefficient (ADC) values of EG and EA lesions were completely different from each other, 2.88 {+-} 0.24 x 10{sup -3} s/mm{sup 2} and 1.33 {+-} 0.15 x 10{sup -3} s/mm{sup 2}, respectively. The ADC values could not be used to discriminate from other differential diagnoses.

Report of diffusion-weighted MRI in two cases with different cerebral hydatid disease

International Nuclear Information System (INIS)

Kitis, O.; Calli, C.; Yunten, N.

2004-01-01

To present MRI findings in two cases of cerebral hydatid disease with an emphasis on diffusion-weighted imaging (DWI) findings of Echinococcus granulosus (EG) versus Echinococcus alveolaris (EA). EG lesions were isointense with cerebrospinal fluid in all sequences including DWI. On DWI, EA lesions remained hypointense on b = 1000 s/mm2 diffusion-weighted images. Apparent diffusion coefficient (ADC) values of EG and EA lesions were completely different from each other, 2.88 ± 0.24 x 10 -3 s/mm 2 and 1.33 ± 0.15 x 10 -3 s/mm 2 , respectively. The ADC values could not be used to discriminate from other differential diagnoses

Detection of hyperacute parenchymal hemorrhage of the brain using echo-planar T2{sup *}-weighted and diffusion-weighted MRI

Energy Technology Data Exchange (ETDEWEB)

Wiesmann, M. [Dept. of Radiology, Medizinische Universitaet zu Luebeck (Germany); Mayer, T.E.; Yousry, I.; Brueckmann, H. [Dept. of Neuroradiology, Klinikum Grosshadern, Ludwig-Maximilians-Universitaet, Muenchen (Germany); Hamann, G.F. [Dept. of Neurology, Klinikum Grosshadern, Ludwig-Maximilians-Universitaet, Muenchen (Germany)

2001-05-01

We investigated the usefulness of echo-planar imaging (EPI) as well as T2{sup *}-weighted and diffusion-weighted MRI (DWI) to identify hyperacute hemorrhage (within 24 h after ictus) in the brain. Seven patients were examined 3.5 to 24 h after onset of symptoms using a whole-body 1.5-T MR system. Two diffusion-weighted sequences were run to obtain isotropic and anisotropic diffusion images. Apparent diffusion coefficients (ADC) were calculated from the isotropic diffusion images. All DWI images as well as the T2*-weighted EPI images showed the hematomas as either discrete, deeply hypointense homogeneous lesions, or as lesions of mixed signal intensity containing hypointense areas. We conclude that even in the early phase after hemorrhage, sufficient amounts of paramagnetic deoxyhemoglobin are present in intracerebral hemorrhages to cause hypointensity on EPI T2{sup *}-weighted and DWI images; thus, use of ultrafast EPI allows identification of intracerebral hemorrhage. (orig.)

Serial diffusion-weighted imaging in MELAS

International Nuclear Information System (INIS)

Ohshita, T.; Oka, M.; Imon, Y.; Watanabe, C.; Katayama, S.; Yamaguchi, S.; Kajima, T.; Mimori, Y.; Nakamura, S.

2000-01-01

Clinical features of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) resemble those of cerebral infarcts, but the pathogenesis of infarct-like lesions is not fully understood. To characterise these infarct-like lesions, we studied two patients with MELAS using diffusion-weighted (DWI) MRI before and after stroke-like episodes and measured the apparent diffusion coefficient (ADC) in the new infarct-like lesions. These gave high signal on DWI and had much higher ADC than normal-appearing regions. The ADC remained high even 30 days after a stroke-like episode then decreased in lesions, with or without abnormality as shown by conventional MRI. We speculate that early elevation of ADC in the acute or subacute phase reflects vasogenic rather than cytotoxic edema. The ADC of the lesions, which disappeared almost completely with clinical improvement, returned to normal levels, which may reflect tissue recovery without severe damage. To our knowledge, this is the first study of DWI in MELAS. (orig.)

Benign and malignant skull-involved lesions: discriminative value of conventional CT and MRI combined with diffusion-weighted MRI.

Science.gov (United States)

Tu, Zhanhai; Xiao, Zebin; Zheng, Yingyan; Huang, Hongjie; Yang, Libin; Cao, Dairong

2018-01-01

Background Little is known about the value of computed tomography (CT) and magnetic resonance imaging (MRI) combined with diffusion-weighted imaging (DWI) in distinguishing malignant from benign skull-involved lesions. Purpose To evaluate the discriminative value of DWI combined with conventional CT and MRI for differentiating between benign and malignant skull-involved lesions. Material and Methods CT and MRI findings of 58 patients with pathologically proven skull-involved lesions (43 benign and 15 malignant) were retrospectively reviewed. Conventional CT and MRI characteristics and apparent diffusion coefficient (ADC) value of the two groups were evaluated and compared. Multivariate logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the differential performance of each parameter separately and together. Results The presence of cortical defects or break-through and ill-defined margins were associated with malignant skull-involved lesions (both P benign and malignant skull-involved lesions. Conclusion The combination of CT, MRI, and DWI can help to differentiate malignant from benign skull-involved lesions. CT + MRI + DWI offers optimal sensitivity, while DWI offers optimal specificity.

Diffusion-weighted imaging and dynamic contrast-enhanced MRI of experimental breast cancer bone metastases – A correlation study with histology

Energy Technology Data Exchange (ETDEWEB)

Merz, Maximilian [Department of Medical Physics in Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Department of Hematology, Oncology and Rheumatology, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg (Germany); Seyler, Lisa; Bretschi, Maren; Semmler, Wolfhard [Department of Medical Physics in Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Bäuerle, Tobias, E-mail: tobias.baeuerle@uk-erlangen.de [Department of Medical Physics in Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Institute of Radiology, University Medical Center Erlangen, Palmsanlage 5, 90154 Erlangen (Germany)

2015-04-15

Purpose: To validate imaging parameters from diffusion-weighted imaging and dynamic contrast-enhanced MRI with immunohistology and to non-invasively assess microstructure of experimental breast cancer bone metastases. Materials and methods: Animals bearing breast cancer bone metastases were imaged in a clinical 1.5 T MRI scanner. HASTE sequences were performed to calculate apparent diffusion coefficients. Saturation recovery turbo FLASH sequences were conducted while infusing 0.1 mmol/l Gd–DTPA for dynamic contrast-enhanced MRI to quantify parameters amplitude A and exchange rate constant k{sub ep}. After imaging, bone metastases were analyzed immunohistologically. Results: We found correlations of the apparent diffusion coefficients from diffusion-weighted imaging with tumor cellularity as assessed with cell nuclei staining. Histological vessel maturity was correlated negatively with parameters A and k{sub ep} from dynamic contrast-enhanced MRI. Tumor size correlated inversely with cell density and vessel permeability as well as positively with mean vessel calibers. Parameters from the rim of bone metastases differed significantly from values of the center. Conclusion: In vivo diffusion-weighted imaging and dynamic contrast-enhanced MRI in experimental bone metastases provide information about tumor cellularity and vascularity and correlate well with immunohistology.

Diffusion-weighted MRI and quantitative biophysical modeling of hippocampal neurite loss in chronic stress.

Directory of Open Access Journals (Sweden)

Peter Vestergaard-Poulsen

Full Text Available Chronic stress has detrimental effects on physiology, learning and memory and is involved in the development of anxiety and depressive disorders. Besides changes in synaptic formation and neurogenesis, chronic stress also induces dendritic remodeling in the hippocampus, amygdala and the prefrontal cortex. Investigations of dendritic remodeling during development and treatment of stress are currently limited by the invasive nature of histological and stereological methods. Here we show that high field diffusion-weighted MRI combined with quantitative biophysical modeling of the hippocampal dendritic loss in 21 day restraint stressed rats highly correlates with former histological findings. Our study strongly indicates that diffusion-weighted MRI is sensitive to regional dendritic loss and thus a promising candidate for non-invasive studies of dendritic plasticity in chronic stress and stress-related disorders.

Relationship between pretreatment FDG-PET and diffusion-weighted MRI biomarkers in diffuse large B-cell lymphoma

Science.gov (United States)

de Jong, Antoinette; Kwee, Thomas C; de Klerk, John MH; Adam, Judit A; de Keizer, Bart; Fijnheer, Rob; Kersten, Marie José; Ludwig, Inge; Jauw, Yvonne WS; Zijlstra, Josée M; den Bos, Indra C Pieters - Van; Stoker, Jaap; Hoekstra, Otto S; Nievelstein, Rutger AJ

2014-01-01

The purpose of this study was to determine the correlation between the 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) standardized uptake value (SUV) and the diffusion-weighted magnetic resonance imaging (MRI) apparent diffusion coefficient (ADC) in newly diagnosed diffuse large B-cell lymphoma (DLBCL). Pretreatment FDG-PET and diffusion-weighted MRI of 21 patients with histologically proven DLBCL were prospectively analyzed. In each patient, maximum, mean and peak standardized uptake value (SUV) was measured in the lesion with visually highest FDG uptake and in the largest lesion. Mean ADC (ADCmean, calculated with b-values of 0 and 1000 s/mm2) was measured in the same lesions. Correlations between FDG-PET metrics (SUVmax, SUVmean, SUVpeak) and ADCmean were assessed using Pearson’s correlation coefficients. In the lesions with visually highest FDG uptake, no significant correlations were found between the SUVmax, SUVmean, SUVpeak and the ADCmean (P=0.498, P=0.609 and P=0.595, respectively). In the largest lesions, there were no significant correlations either between the SUVmax, SUVmean, SUVpeak and the ADCmean (P=0.992, P=0.843 and P=0.894, respectively). The results of this study indicate that the glycolytic rate as measured by FDG-PET and changes in water compartmentalization and water diffusion as measured by the ADC are independent biological phenomena in newly diagnosed DLBCL. Further studies are warranted to assess the complementary roles of these different imaging biomarkers in the evaluation and follow-up of DLBCL. PMID:24795837

Whole-body MRI, dynamic contrast-enhanced MRI, and diffusion-weighted imaging for the staging of multiple myeloma

Energy Technology Data Exchange (ETDEWEB)

Dutoit, Julie C.; Verstraete, Koenraad L. [Ghent University Hospital, Department of Radiology, Ghent (Belgium)

2017-06-15

Magnetic resonance imaging (MRI) is the most sensitive imaging technique for the detection of bone marrow infiltration, and has therefore recently been included in the new diagnostic myeloma criteria, as proposed by the International Myeloma Working Group. Nevertheless, conventional MRI only provides anatomical information and is therefore only of limited use in the response assessment of patients with multiple myeloma. The additional information from functional MRI techniques, such as diffusion-weighted imaging and dynamic contrast-enhanced MRI, can improve the detection rate of bone marrow infiltration and the assessment of response. This can further enhance the sensitivity and specificity of MRI in the staging of multiple myeloma patients. This article provides an overview of the technical aspects of conventional and functional MRI techniques with practical recommendations. It reviews the diagnostic performance, prognostic value, and role in therapy assessment in multiple myeloma and its precursor stages. (orig.)

Focal Pancreatitis Mimicking Pancreatic Mass: Magnetic Resonance Imaging (MRI)/Magnetic Resonance Cholangiopancreatography (MRCP) Findings Including Diffusion-Weighted MRI

International Nuclear Information System (INIS)

Momtahen, A.J.; Balci, N.C.; Alkaade, S.; Akduman, E.I.; Burton, F.R.

2008-01-01

Background: Focal pancreatitis (FP) is a confined inflammation that mimics a pancreatic mass. Its imaging diagnosis is important to avoid unnecessary procedures. Purpose: To describe the spectrum of magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) and diffusion-weighted MRI (DWI) findings of focal pancreatitis mimicking pancreatic masses. Material and Methods: Findings of MRI/MRCP including DWI with a b value of 0 and 600 s/mm2 in 14 patients with pancreatic masses on MRI were retrospectively reviewed and compared to normal pancreas in 14 patients as a control group. Results: FP revealed hypointense signal intensity (SI) (3/14), hypo- to isointense SI (7/14), or isointense SI (4/14) on T1-weighted images, and hypointense SI (1/14), isointense SI (5/14), iso- to hyperintense SI (7/14), or hyperintense SI (1/14) on T2-weighted images compared to remaining pancreas (RP). MRCP images revealed dilatation of the common bile duct (CBD) and main pancreatic duct (MPD) (5/14), dilatation of the MPD only (3/14), dilatation of the CBD only (3/14), and normal MPD and CBD (3/14). Both FP and RP revealed three types of time-signal intensity curves: 1) rapid rise to a peak, with a rapid decline (FP=2, RP=4), 2) slow rise to a peak, followed by a slow decline (FP=5, RP=4), and 3) slower rise to a peak, with a slow decline or plateau (FP=7, RP=6). Mean apparent diffusion coefficient (ADC) values for FP and RP were 2.09±0.18 and 2.03±0.2x10 -3 mm 2 /s, respectively. ADC values of FP and RP revealed no significant difference. Conclusion: The spectrum of imaging findings of focal pancreatitis on MRI/MRCP including DWI was described. Findings of FP were not distinctive as compared to the remaining pancreas

Diffusion-Weighted MRI for the Assessment of Liver Fibrosis: Principles and Applications

Directory of Open Access Journals (Sweden)

Stefano Palmucci

2015-01-01

Full Text Available The importance of an early identification of hepatic fibrosis has been emphasized, in order to start therapy and obtain fibrosis regression. Biopsy is the gold-standard method for the assessment of liver fibrosis in chronic liver diseases, but it is limited by complications, interobserver variability, and sampling errors. Several noninvasive methods have been recently introduced into clinical routine, in order to detect liver fibrosis early. One of the most diffuse approaches is represented by diffusion-weighted liver MRI. In this review, the main technical principles are briefly reported in order to explain the rationale for clinical applications. In addition, roles of apparent diffusion coefficient, intravoxel incoherent motion, and relative apparent diffusion coefficient are also reported, showing their advantages and limits.

Assessment of the link between quantitative biexponential diffusion-weighted imaging and contrast-enhanced MRI in the liver

NARCIS (Netherlands)

Dijkstra, Hildebrand; Oudkerk, Matthijs; Kappert, Peter; Sijens, Paul E.

Purpose: To investigate if intravoxel incoherent motion (IVIM) modeled diffusion-weighted imaging (DWI) can be linked to contrast-enhanced (CE-)MRI in liver parenchyma and liver lesions. Methods: Twenty-five patients underwent IVIM-DWI followed by multiphase CE-MRI using Gd-EOB-DTPA (n = 20) or

Selection for biopsy of kidney transplant patients by diffusion-weighted MRI

Energy Technology Data Exchange (ETDEWEB)

Steiger, Philipp; Barbieri, Sebastiano; Ith, Michael; Thoeny, Harriet C. [Inselspital, Bern University Hospital, University of Bern, Inselspital, Department of Radiology, Neuroradiology, and Nuclear Medicine, Institute of Diagnostic, Pediatric, and Interventional Radiology, Bern (Switzerland); Kruse, Anja [Inselspital, Bern University Hospital, University of Bern, Inselspital, Department of Nephrology and Hypertension, Bern (Switzerland)

2017-10-15

To assess retrospectively whether diffusion-weighted magnetic resonance imaging (DW-MRI) allows physicians to determine the severity of histopathologic findings in biopsies of renal allograft patients with deteriorating renal function. Forty consecutive kidney transplant patients underwent DW-MRI and biopsy. Patients were assigned to one group with severe and to another group with normal or mild histopathologic findings. These two groups were compared based on a qualitative DW-MRI assessment (homo-/heterogeneity) and the combination of qualitative and quantitative DW-MRI parameters (ADC, and intravoxel incoherent motion, IVIM, parameters: D, f, D*). Sensitivity, specificity, and accuracy were determined for each parameter. Biopsy findings were severe in 25 patients and normal or mild in 15 patients. Qualitative DW-MRI led to a sensitivity of 44.0% and a specificity of 93.3%. Combined qualitative and quantitative DW-MRI led to an accuracy of 80% for both the minimal ADC (ADCmin) and the minimal perfusion fraction (fmin) with a sensitivity of 84.0% and 92.0% and a specificity of 73.3% and 60.0%, respectively. Combined qualitative and quantitative DW-MRI might allow physicians to determine the severity of histopathologic findings in biopsies of a high number of kidney transplant patients. (orig.)

Diffusion Weighted MRI as a predictive tool for effect of radiotherapy in locally advanced cervical cancer

DEFF Research Database (Denmark)

Haack, Søren; Tanderup, Kari; Fokdal, Lars

Diffusion weighted MRI has shown great potential in diagnostic cancer imaging and may also have value for monitoring tumor response during radiotherapy. Patients with advanced cervical cancer are treated with external beam radiotherapy followed by brachytherapy. This study evaluates the value of DW......-MRI for predicting outcome of patients with advanced cervical cancer at time of brachytherapy. Volume of hyper-intensity on highly diffusion sensitive images and resulting ADC value for treatment responders and non-responders is compared. The change of ADC and volume of hyper-intensity over time of BT is also...

Diffusion-weighted MRI of lymphoma: prognostic utility and implications for PET/MRI?

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Punwani, Shonit; Taylor, Stuart A.; Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom); University College London Hospital, Department of Radiology, London (United Kingdom); Saad, Ziauddin Z.; Groves, Ashley [University College London Hospital, Institute of Nuclear Medicine, London (United Kingdom); Bainbridge, Alan [University College London Hospital, Department of Medical Physics and Bioengineering, London (United Kingdom); Daw, Stephen; Shankar, Ananth [University College London Hospital, Department of Paediatrics, London (United Kingdom); Humphries, Paul D. [University College London Hospital, Department of Radiology, London (United Kingdom); Great Ormond Street Hospital, Department of Radiology, London (United Kingdom)

2013-03-15

With the recent introduction of PET/MRI, we investigated whether diffusion-weighted imaging (DWI) can complement PET for predicting local treatment response in Hodgkin lymphoma. This retrospective study included 39 patients selected from a hospital database with a histological diagnosis of Hodgkin lymphoma undergoing whole-body MRI (supplemented by DWI) and PET/CT before and after two cycles of vincristine, etoposide, prednisolone and doxorubicin (OEPA). The pretreatment volume, MRI apparent diffusion coefficient (ADC) and PET maximum standardized uptake value (SUV{sub max}) of the largest nodal mass were determined quantitatively for evaluation of the local response following two cycles of OEPA. Quantitative pretreatment imaging biomarkers (disease volume, ADC, SUV{sub max}) were compared between sites with an adequate and those with an inadequate response using Fisher's exact test and Mann Whitney statistics. Multivariate models predictive of an inadequate response based on demographic/clinical features, pretreatment disease volume and SUV{sub max} without (model 1) and with (model 2) the addition of ADC were derived and crossvalidated. The ROC area under curve (AUC) was calculated for both models using the full dataset (training) and the crossvalidation (test) data. Sites with an adequate response had a significantly lower median pretreatment ADC (1.0 x 10{sup -3}mm{sup 2}s{sup -1}) than those with an inadequate response (1.26 x 10{sup -3}mm{sup 2}s{sup -1}; p < 0.01). There were no significant differences in patient demographic/clinical parameters, pretreatment SUV{sub max} or pretreatment nodal volume between sites with inadequate and adequate response. The ROC-AUCs for prediction of an inadequate response for the training and test data for model 1 were 0.90 and 0.53, and for model 2 were 0.84 and 0.71, respectively. DWI complements PET for prediction of site-specific interim response to chemotherapy. (orig.)

Utility of diffusion-weighted MR imaging in the diagnosis of placenta accreta spectrum abnormality.

Science.gov (United States)

Sannananja, Bhagya; Ellermeier, Anna; Hippe, Daniel S; Winter, Thomas C; Kang, Stella K; Lee, Susanna I; Kilgore, Mark R; Dighe, Manjiri K

2018-04-17

The aim of this study was to evaluate the utility of added DWI sequences as an adjunct to traditional MR imaging in the evaluation of abnormal placentation in patients with suspicion for placenta accreta spectrum abnormality or morbidly adherent placenta (MAP). The study was approved by local ethics committee. The subjects included pregnant women with prenatal MRI performed between July 2013 to July 2015. All imaging was performed on a Philips 1.5T MR scanner using pelvic phased-array coil. Only T2-weighted and diffusion-weighted imaging (DWI) series were compiled for review. Two randomized imaging sets were created: set 1 included T2-weighted series only (T2W); set 2 included T2W with DWI series together (T2W + DWI). Three radiologists, blinded to history and pathology, reviewed the imaging, with 2 weeks of time between the two image sets. Sensitivity, specificity, and overall accuracy for MAP were calculated and compared between T2W only and T2W + DWI reads. Associations between imaging findings and invasion on pathology were tested using the Chi-squared test. Confidence scores, inter-reader agreement, and systematic differences were documented. A total of 17 pregnant women were included in the study. 8 cases were pathologically diagnosed with MAP. There were no significant differences in the diagnostic accuracy between T2W and T2W + DWI in the diagnosis of MAP in terms of overall accuracy (62.7% for T2W vs. 68.6% for T2W + DWI, p = 0.68), sensitivity (70.8% for T2W vs. 95.8% for T2W + DWI, p = 0.12), and specificity (55.6% for T2W vs. 44.4% for T2W + DWI, p = 0.49). There was no significant difference in the diagnostic confidence between the review of T2W images alone and the T2W + DWI review (mean 7.3 ± 1.8 for T2W vs. 7.5 ± 1.8 for T2W + DWI, p = 0.37). With the current imaging technique, addition of DWI sequence to the traditional T2W images cannot be shown to significantly increase the accuracy or

Diffusion-weighted MRI of kidneys in healthy volunteers and living kidney donors

International Nuclear Information System (INIS)

Sulkowska, K.; Palczewski, P.; Duda-Zysk, A.; Szeszkowski, W.; Wojcik, D.; Kownacka-Piotrowska, D.; Gołebiowski, M.

2015-01-01

Aim: To establish the normal apparent diffusion coefficient (ADC) values in healthy kidneys, comparing them with the literature, and assessing the correlation between ADC values, creatinine blood level, and glomerular filtration rate (GFR). Materials and methods: Twenty-four healthy volunteers and 26 living kidney donors were examined on a 1.5 T magnetic resonance imaging (MRI) unit. Two diffusion-weighted imaging (DWI) sequences were included in the study protocol (protocol 1 with 16 b-values, protocol 2 with 10 b-values) before the examination blood and urine samples were collected. The GFR was calculated using Cockcroft & Gault and MDRD (Modification of Diet In Renal Disease) formulas and the ADC values were measured separately for the cortex and medulla of each kidney by two independent observers. All statistical analyses were performed using the STATISTICA (version 10.0) software package. Data were analysed using an unpaired t-test; p<0.05 indicated a statistically significant difference. Results: The average ADC value for protocol 1 for the cortex was 2.26×10 −3  mm 2 /s, for the medulla 2.21×10 −3  mm 2 /s. In protocol 2, the respective values were 2.13×10 −3  mm 2 /s and 2.06×10 −3  mm 2 /s. Neither statistically significant interobserver differences nor correlation between ADC values, GFR, and creatinine serum level were observed. Conclusion: The reference ADC values were established. The measurements show high interobserver consistency. The differences in ADC values reported in the literature suggest dependence on the equipment and methodology and point to the necessity of obtaining ADC norms for each MRI unit. -- Highlights: •Magnetic resonance diffusion-weighted imaging of kidneys. •Apparent diffusion coefficient in healthy individuals. •Monoexponential model of diffusion

Perfusion MRI abnormalities in the absence of diffusion changes in a case of moyamoya-like syndrome in neurofibromatosis type 1

International Nuclear Information System (INIS)

El-Koussy, Marwan; Kiefer, Claus; Schroth, Gerhard; Loevblad, Karl-Olof; Steinlin, Maja

2002-01-01

We report on a 12-year-old boy with neurofibromatosis type 1 who suffered a transient ischemic attack. Angiography revealed occlusion of intracranial arteries, moyamoya vessels and leptomeningeal collaterals. The conventional T2-weighted and the diffusion-weighted MRI images demonstrated no pathology. Dynamic first-pass postgadolinium T2* perfusion-weighted MRI depicted altered hemodynamics in the vascular territory of the left middle cerebral artery, which defined this region as ischemic tissue at risk. The patient suffered a repeat transient ischemic attack5 days later. (orig.)

Whole body MRI, including diffusion-weighted imaging in follow-up of patients with testicular cancer.

Science.gov (United States)

Mosavi, Firas; Laurell, Anna; Ahlström, Håkan

2015-11-01

Whole body (WB) magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI) has become increasingly utilized in cancer imaging, yet the clinical utility of these techniques in follow-up of testicular cancer patients has not been evaluated. The purpose of this study was to evaluate the feasibility of WB MRI with continuous table movement (CTM) technique, including multistep DWI in follow-up of patients with testicular cancer. WB MRI including DWI was performed in follow-up of 71 consecutive patients (median age, 37 years; range 19-84) with histologically confirmed testicular cancer. WB MRI protocol included axial T1-Dixon and T2-BLADE sequences using CTM technique. Furthermore, multi-step DWI was performed using b-value 50 and 1000 s/mm(2). One criterion for feasibility was patient tolerance and satisfactory image quality. Another criterion was the accuracy in detection of any pathological mass, compared to standard of reference. Signal intensity in DWI was used for evaluation of residual mass activity. Clinical, laboratory and imaging follow-up were applied as standard of reference for the evaluation of WB MRI. WB MRI was tolerated in nearly all patients (69/71 patients, 97%) and the image quality was satisfactory. Metal artifacts deteriorated the image quality in six patients, but it did not influence the overall results. No case of clinical relapse was observed during the follow-up time. There was a good agreement between conventional WB MRI and standard of reference in all patients. Three patients showed residual masses and DWI signal was not restricted in these patients. Furthermore, DWI showed abnormally high signal intensity in a normal-sized retroperitoneal lymph node indicating metastasis. The subsequent (18)F-FDG PET/CT could verify the finding. WB MRI with CTM technique including multi-step DWI is feasible in follow-up of patients with testicular cancer. DWI may contribute to important added-value data to conventional MRI sequences

Diffusion-weighted imaging (DWI) in musculoskeletal MRI: a critical review

Energy Technology Data Exchange (ETDEWEB)

Khoo, Michael M.Y.; Tyler, Philippa A.; Saifuddin, Asif [Royal National Orthopaedic Hospital, Department of Radiology, Stanmore, Middlesex (United Kingdom); Padhani, Anwar R. [Mount Vernon Cancer Centre, Paul Strickland Scanner Centre, Northwood (United Kingdom)

2011-06-15

Magnetic resonance imaging (MRI) is the mainstay of diagnosis, staging and follow-up of much musculoskeletal pathology. Diffusion-weighted magnetic resonance imaging (DWI) is a recent addition to the MR sequences conventionally employed. DWI provides qualitative and quantitative functional information concerning the microscopic movements of water at the cellular level. A number of musculoskeletal disorders have been evaluated by DWI, including vertebral fractures, bone marrow infection, bone marrow malignancy, primary bone and soft tissue tumours; post-treatment follow-up has also been assessed. Differentiation between benign and malignant vertebral fractures by DWI and monitoring of therapy response have shown excellent results. However, in other pathologies, such as primary soft tissue tumours, DWI data have been inconclusive in some cases, contributing little additional information beyond that gained from conventional MR sequences. The aim of this article is to critically review the current literature on the contribution of DWI to musculoskeletal MRI. (orig.)

Associations among q-space MRI, diffusion-weighted MRI and histopathological parameters in meningiomas

Energy Technology Data Exchange (ETDEWEB)

Fatima, Zareen; Motosugi, Utaroh; Ishigame, Keiichi; Araki, Tsutomu [University of Yamanashi, Department of Radiology, Chuo-shi, Yamanashi (Japan); Waqar, Ahmed Bilal [University of Yamanashi, Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, Chuo-shi, Yamanashi (Japan); Hori, Masaaki [Juntendo University, Department of Radiology, School of Medicine, Tokyo (Japan); Oishi, Naoki; Katoh, Ryohei [University of Yamanashi, Department of Pathology, Chuo-shi, Yamanashi (Japan); Onodera, Toshiyuki; Yagi, Kazuo [Tokyo Metropolitan University, Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo (Japan)

2013-08-15

The purposes of this MR-based study were to calculate q-space imaging (QSI)-derived mean displacement (MDP) in meningiomas, to evaluate the correlation of MDP values with apparent diffusion coefficient (ADC) and to investigate the relationships among these diffusion parameters, tumour cell count (TCC) and MIB-1 labelling index (LI). MRI, including QSI and conventional diffusion-weighted imaging (DWI), was performed in 44 meningioma patients (52 lesions). ADC and MDP maps were acquired from post-processing of the data. Quantitative analyses of these maps were performed by applying regions of interest. Pearson correlation coefficients were calculated for ADC and MDP in all lesions and for ADC and TCC, MDP and TCC, ADC and MIB-1 LI, and MDP and MIB-1 LI in 17 patients who underwent subsequent surgery. ADC and MDP values were found to have a strong correlation: r = 0.78 (P = <0.0001). Both ADC and MDP values had a significant negative association with TCC: r = -0.53 (p = 0.02) and -0.48 (P = 0.04), respectively. MIB-1 LI was not, however, found to have a significant association with these diffusion parameters. In meningiomas, both ADC and MDP may be representative of cell density. (orig.)

Associations among q-space MRI, diffusion-weighted MRI and histopathological parameters in meningiomas

International Nuclear Information System (INIS)

Fatima, Zareen; Motosugi, Utaroh; Ishigame, Keiichi; Araki, Tsutomu; Waqar, Ahmed Bilal; Hori, Masaaki; Oishi, Naoki; Katoh, Ryohei; Onodera, Toshiyuki; Yagi, Kazuo

2013-01-01

The purposes of this MR-based study were to calculate q-space imaging (QSI)-derived mean displacement (MDP) in meningiomas, to evaluate the correlation of MDP values with apparent diffusion coefficient (ADC) and to investigate the relationships among these diffusion parameters, tumour cell count (TCC) and MIB-1 labelling index (LI). MRI, including QSI and conventional diffusion-weighted imaging (DWI), was performed in 44 meningioma patients (52 lesions). ADC and MDP maps were acquired from post-processing of the data. Quantitative analyses of these maps were performed by applying regions of interest. Pearson correlation coefficients were calculated for ADC and MDP in all lesions and for ADC and TCC, MDP and TCC, ADC and MIB-1 LI, and MDP and MIB-1 LI in 17 patients who underwent subsequent surgery. ADC and MDP values were found to have a strong correlation: r = 0.78 (P = <0.0001). Both ADC and MDP values had a significant negative association with TCC: r = -0.53 (p = 0.02) and -0.48 (P = 0.04), respectively. MIB-1 LI was not, however, found to have a significant association with these diffusion parameters. In meningiomas, both ADC and MDP may be representative of cell density. (orig.)

Assessment of renal fibrosis in chronic kidney disease using diffusion-weighted MRI

International Nuclear Information System (INIS)

Zhao, J.; Wang, Z.J.; Liu, M.; Zhu, J.; Zhang, X.; Zhang, T.; Li, S.; Li, Y.

2014-01-01

Aim: To assess the performance of diffusion-weighted magnetic resonance imaging (MRI) for the assessment of renal fibrosis in chronic kidney disease (CKD), with histopathology as a reference standard. Materials and methods: Forty patients with CKD and 30 healthy volunteers were recruited for the study. All participants underwent diffusion-weighted MRI. Renal biopsy was performed in 25 patients with CKD. Mean renal medullary and cortical apparent diffusion coefficient (ADC) values were compared between CKD patients and the healthy volunteers. Pearson's correlation coefficient was calculated to investigate the relationship between ADC values, serum creatinine (SCr), estimated glomerular filtration rate (eGFR), 24 h urinary protein (24h-UPRO), and renal histopathological scores. Results: Cortical and medullary ADC values in the CKD group were significantly lower compared to those in the healthy controls. In the CKD group, a significant negative correlation was found between cortical ADC values and SCr/24h-UPRO, and significant positive correlation was found between cortical ADC and eGFR. There was also a significant negative correlation between medullary ADC values and SCr. Both cortical and medullary ADC values were significantly correlated with histopathological fibrosis score. Conclusion: Renal ADC values strongly correlate with histological measures of fibrosis, and have the potential to enhance the non-invasive monitoring of chronic kidney disease. - Highlights: • Renal ADC values in the CKD patients were lower than those in controls. • Renal ADC values were strongly correlated with histological fibrosis score. • Renal ADC values have the potential to enhance the noninvasive monitoring of CKD

Readout-segmented multi-shot diffusion-weighted MRI of the knee joint in patients with juvenile idiopathic arthritis.

Science.gov (United States)

Sauer, Alexander; Li, Mengxia; Holl-Wieden, Annette; Pabst, Thomas; Neubauer, Henning

2017-10-12

Diffusion-weighted MRI has been proposed as a new technique for imaging synovitis without intravenous contrast application. We investigated diagnostic utility of multi-shot readout-segmented diffusion-weighted MRI (multi-shot DWI) for synovial imaging of the knee joint in patients with juvenile idiopathic arthritis (JIA). Thirty-two consecutive patients with confirmed or suspected JIA (21 girls, median age 13 years) underwent routine 1.5 T MRI with contrast-enhanced T1w imaging (contrast-enhanced MRI) and with multi-shot DWI (RESOLVE, b-values 0-50 and 800 s/mm 2 ). Contrast-enhanced MRI, representing the diagnostic standard, and diffusion-weighted images at b = 800 s/mm 2 were separately rated by three independent blinded readers at different levels of expertise for the presence and the degree of synovitis on a modified 5-item Likert scale along with the level of subjective diagnostic confidence. Fourteen (44%) patients had active synovitis and joint effusion, nine (28%) patients showed mild synovial enhancement not qualifying for arthritis and another nine (28%) patients had no synovial signal alterations on contrast-enhanced imaging. Ratings by the 1st reader on contrast-enhanced MRI and on DWI showed substantial agreement (κ = 0.74). Inter-observer-agreement was high for diagnosing, or ruling out, active arthritis of the knee joint on contrast-enhanced MRI and on DWI, showing full agreement between 1st and 2nd reader and disagreement in one case (3%) between 1st and 3rd reader. In contrast, ratings in cases of absent vs. little synovial inflammation were markedly inconsistent on DWI. Diagnostic confidence was lower on DWI, compared to contrast-enhanced imaging. Multi-shot DWI of the knee joint is feasible in routine imaging and reliably diagnoses, or rules out, active arthritis of the knee joint in paediatric patients without the need of gadolinium-based i.v. contrast injection. Possibly due to "T2w shine-through" artifacts, DWI does not reliably

Differentiation of prostate cancer lesions with high and with low Gleason score by diffusion-weighted MRI

Energy Technology Data Exchange (ETDEWEB)

Barbieri, Sebastiano; Broennimann, Michael; Vermathen, Peter; Thoeny, Harriet C. [Inselspital University Hospital, Institute of Diagnostic, Pediatric, and Interventional Radiology, Bern (Switzerland); Boxler, Silvan [Inselspital, Inselspital University Hospital, Department of Urology, Bern (Switzerland)

2017-04-15

To differentiate prostate cancer lesions with high and with low Gleason score by diffusion-weighted-MRI (DW-MRI). This prospective study was approved by the responsible ethics committee. DW-MRI of 84 consenting prostate and/or bladder cancer patients scheduled for radical prostatectomy were acquired and used to compute apparent diffusion coefficient (ADC), intravoxel incoherent motion (IVIM: the pure diffusion coefficient D{sub t}, the pseudo-diffusion fraction F{sub p} and the pseudo-diffusion coefficient D{sub p}), and high b value (as acquired and Hessian filtered) parameters within the index lesion. These parameters (separately and combined in a logistic regression model) were used to differentiate lesions depending on whether whole-prostate histopathological analysis after prostatectomy determined a high (≥7) or low (6) Gleason score. Mean ADC and D{sub t} differed significantly (p of independent two-sample t test < 0.01) between high- and low-grade lesions. The highest classification accuracy was achieved by the mean ADC (AUC 0.74) and D{sub t} (AUC 0.70). A logistic regression model based on mean ADC, mean F{sub p} and mean high b value image led to an AUC of 0.74 following leave-one-out cross-validation. Classification by IVIM parameters was not superior to classification by ADC. DW-MRI parameters correlated with Gleason score but did not provide sufficient information to classify individual patients. (orig.)

Comparison of conventional and diffusion-weighted MRI and proton MR spectroscopy in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like events

Energy Technology Data Exchange (ETDEWEB)

Abe, K.; Hikita, T.; Sakoda, S. [Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, 565-0871, Osaka (Japan); Yoshimura, H.; Tanaka, H.; Fujita, N. [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, 565-0871, Osaka (Japan)

2004-02-01

The mechanism of neurological disturbances in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is controversial. We studied 12 patients with MELAS using conventional and diffusion weighted MRI (DWI) and MR spectroscopy (MRS), to look at the physiopathology of the stroke-like events. Although conventional MRI showed lesions in all patients, DWI was more sensitive. One patient did not show high signal on DWI 48 h after a from stroke-like episode, but MRS demonstrated a lactate peak in left occipital lobe; 2 weeks after the attack, high signal was demonstrated on the right frontal lobe where MRS had shown a lactate peak. Our findings suggest a possible predictive ability of {sup 1}H-MRS, in showing early MELAS lesions and supports the hypothesis that mitochondrial metabolic dysfunction may precedes abnormalities on DWI. (orig.)

Comparison of conventional and diffusion-weighted MRI and proton MR spectroscopy in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like events

International Nuclear Information System (INIS)

Abe, K.; Hikita, T.; Sakoda, S.; Yoshimura, H.; Tanaka, H.; Fujita, N.

2004-01-01

The mechanism of neurological disturbances in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is controversial. We studied 12 patients with MELAS using conventional and diffusion weighted MRI (DWI) and MR spectroscopy (MRS), to look at the physiopathology of the stroke-like events. Although conventional MRI showed lesions in all patients, DWI was more sensitive. One patient did not show high signal on DWI 48 h after a from stroke-like episode, but MRS demonstrated a lactate peak in left occipital lobe; 2 weeks after the attack, high signal was demonstrated on the right frontal lobe where MRS had shown a lactate peak. Our findings suggest a possible predictive ability of 1 H-MRS, in showing early MELAS lesions and supports the hypothesis that mitochondrial metabolic dysfunction may precedes abnormalities on DWI. (orig.)

Detection of electroporation-induced membrane permeabilization states in the brain using diffusion-weighted MRI

DEFF Research Database (Denmark)

Mahmood, Faisal; Hansen, Rasmus H; Agerholm-Larsen, Birgit

2015-01-01

BACKGROUND: Tissue permeabilization by electroporation (EP) is a promising technique to treat certain cancers. Non-invasive methods for verification of induced permeabilization are important, especially in deep-seated cancers. In this study we evaluated diffusion-weighted magnetic resonance imaging...... (NP), transient membrane permeabilization (TMP), and permanent membrane permeabilization (PMP), respectively. DW-MRI was acquired 5 minutes, 2 hours, 24 hours and 48 hours after EP. Histology was performed for validation of the permeabilization states. Tissue content of water, Na+, K+, Ca2...... minutes after EP, compared to NP. Kurtosis was also significantly higher at 24 hours (pstates, supporting the DW-MRI findings. We conclude that DW-MRI is capable of detecting EP...

Diffusion-weighted imaging in the diagnosis of enterovirus 71 encephalitis

International Nuclear Information System (INIS)

Lian, Zhou-yang; Huang, Biao; Liang, Chang-hong; He, Shaoru; Guo, Yuxiong

2012-01-01

Background. In the early phase of viral encephalitis, conventional MRI may appear normal. Diffusion-weighted imaging (DWI) is a sensitive tool for detecting early changes in cellular function in the central nervous system. Purpose. To investigate the usefulness of DWI in the diagnosis of enterovirus 71 (EV71) encephalitis, and to determine whether DWI is superior to conventional MR sequences. Material and Methods. MRI scans in 26 patients were retrospectively evaluated for distribution of lesions on T1-weighted images (T1WI), T2-weighted images (T2WI), fluid-attenuated inversion recovery (FLAIR), and DWI. Contrast-to-noise ratios (CNRs) were calculated for all regions on each sequence and differences in the four MRI sequences were assessed using CNRs. Apparent diffusion coefficient (ADC) values were measured for all regions to look for true restriction of diffusion. Results. Fifteen out of 26 cases showed positive findings on MR imaging. The brain stem was involved in 11 patients, cortex and subcortical white matter in four patients. DWI was more sensitive in detecting the abnormalities (89.7%) compared to T2WI (48.7%), FLAIR (41.0%), and T1WI (35.9%), and the positive ratio of DWI was significantly higher compared to other sequences. Furthermore, no significant difference was found between T2WI and FLAIR (P 0.649). The corresponding mean CNRs were 8.73 ± 2.57, 83.59 ± 29.28, 24.22 ± 6.22, and 132.27 ± 78.32 on T1WI, T2WI, FLAIR, and DWI, respectively. The absolute values of CNRs of lesions on DWI were significantly greater than those on other sequences. Conclusion. DWI appears to be more sensitive in detecting EV71 encephalitis than conventional MRI sequences. This capability may improve the accuracy in diagnosing EV71 encephalitis, especially at the early stage

Diffusion-weighted imaging in the diagnosis of enterovirus 71 encephalitis

Energy Technology Data Exchange (ETDEWEB)

Lian, Zhou-yang; Huang, Biao; Liang, Chang-hong (Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China)), Email: cjr.huangbiao@vip.163.com; He, Shaoru; Guo, Yuxiong (Department of Pediatrics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong (China))

2012-03-15

Background. In the early phase of viral encephalitis, conventional MRI may appear normal. Diffusion-weighted imaging (DWI) is a sensitive tool for detecting early changes in cellular function in the central nervous system. Purpose. To investigate the usefulness of DWI in the diagnosis of enterovirus 71 (EV71) encephalitis, and to determine whether DWI is superior to conventional MR sequences. Material and Methods. MRI scans in 26 patients were retrospectively evaluated for distribution of lesions on T1-weighted images (T1WI), T2-weighted images (T2WI), fluid-attenuated inversion recovery (FLAIR), and DWI. Contrast-to-noise ratios (CNRs) were calculated for all regions on each sequence and differences in the four MRI sequences were assessed using CNRs. Apparent diffusion coefficient (ADC) values were measured for all regions to look for true restriction of diffusion. Results. Fifteen out of 26 cases showed positive findings on MR imaging. The brain stem was involved in 11 patients, cortex and subcortical white matter in four patients. DWI was more sensitive in detecting the abnormalities (89.7%) compared to T2WI (48.7%), FLAIR (41.0%), and T1WI (35.9%), and the positive ratio of DWI was significantly higher compared to other sequences. Furthermore, no significant difference was found between T2WI and FLAIR (P 0.649). The corresponding mean CNRs were 8.73 +- 2.57, 83.59 +- 29.28, 24.22 +- 6.22, and 132.27 +- 78.32 on T1WI, T2WI, FLAIR, and DWI, respectively. The absolute values of CNRs of lesions on DWI were significantly greater than those on other sequences. Conclusion. DWI appears to be more sensitive in detecting EV71 encephalitis than conventional MRI sequences. This capability may improve the accuracy in diagnosing EV71 encephalitis, especially at the early stage

Diffusion-weighted (DW) MRI in lung cancers. ADC test-retest repeatability

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Weller, Alex; Papoutsaki, Marianthi Vasiliki; Blackledge, Matthew; DeSouza, Nandita M. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK Cancer Imaging Centre, Surrey (United Kingdom); Waterton, John C. [University of Manchester, Manchester (United Kingdom); Chiti, Arturo [Humanitas University, Milan (Italy); Stroobants, Sigrid [Universiteit Antwerpen, Antwerpen (Belgium); Kuijer, Joost [Vrije Universiteit Medisch Centrum, Amsterdam (Netherlands); Morgan, Veronica [Royal Marsden NHS Foundation Trust, Department of Medicine, London (United Kingdom)

2017-11-15

To determine the test-retest repeatability of Apparent Diffusion Coefficient (ADC) measurements across institutions and MRI vendors, plus investigate the effect of post-processing methodology on measurement precision. Thirty malignant lung lesions >2 cm in size (23 patients) were scanned on two occasions, using echo-planar-Diffusion-Weighted (DW)-MRI to derive whole-tumour ADC (b = 100, 500 and 800 s/mm{sup -2}). Scanning was performed at 4 institutions (3 MRI vendors). Whole-tumour volumes-of-interest were copied from first visit onto second visit images and from one post-processing platform to an open-source platform, to assess ADC repeatability and cross-platform reproducibility. Whole-tumour ADC values ranged from 0.66-1.94x10{sup -3} mm{sup 2}s{sup -1} (mean = 1.14). Within-patient coefficient-of-variation (wCV) was 7.1% (95% CI 5.7-9.6%), limits-of-agreement (LoA) -18.0 to 21.9%. Lesions >3 cm had improved repeatability: wCV 3.9% (95% CI 2.9-5.9%); and LoA -10.2 to 11.4%. Variability for lesions <3 cm was 2.46 times higher. ADC reproducibility across different post-processing platforms was excellent: Pearson's R{sup 2} = 0.99; CoV 2.8% (95% CI 2.3-3.4%); and LoA -7.4 to 8.0%. A free-breathing DW-MRI protocol for imaging malignant lung tumours achieved satisfactory within-patient repeatability and was robust to changes in post-processing software, justifying its use in multi-centre trials. For response evaluation in individual patients, a change in ADC >21.9% will reflect treatment-related change. (orig.)

Diffusion-weighted MRI of malignant versus benign portal vein thrombosis

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Ahn, Jhii Hyun; Yu, Jeong Sik; Cho, Eun Suk; Chung, Jae Joon; Kim, Joo Hee; Kim, Ki Whang [Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul(Korea, Republic of)

2016-07-15

To validate the diffusion-weighted MRI (DWI) for differentiation of benign from malignant portal vein thrombosis. The Institutional Review Board approved this retrospective study and waived informed consent. A total of 59 consecutive patients (52 men and 7 women, aged 40-85 years) with grossly defined portal vein thrombus (PVT) on hepatic MRI were retrospectively analyzed. Among them, liver cirrhosis was found in 45 patients, and hepatocellular carcinoma in 47 patients. DWI was performed using b values of 50 and 800 sec/mm2 at 1.5-T unit. A thrombus was considered malignant if it enhanced on dynamic CT or MRI; otherwise, it was considered bland. There were 18 bland thrombi and 49 malignant thrombi in 59 patients, including 8 patients with simultaneous benign and malignant PVT. Mean apparent diffusion coefficients (ADCs) of benign and malignant PVTs were compared by using Mann-Whitney U test. Diagnostic accuracy was evaluated using receiver operating characteristic (ROC) curve analysis. The mean ADC ± standard deviation of bland and malignant PVT were 1.00 ± 0.39 × 10(-3) mm{sup 2}/sec and 0.92 ± 0.25 × 10(-3) mm{sup 2}/sec, respectively; without significant difference (p = 0.799). The area under ROC curve for ADC was 0.520. An ADC value of > 1.35 × 10(-3) mm{sup 2}/sec predicted bland PVT with a specificity of 94.6% (95% confidence interval [CI]: 84.9-98.9%) and a sensitivity of 22.2% (95% CI: 6.4-47.6%), respectively. Due to the wide range and considerable overlap of the ADCs, DWI cannot differentiate the benign from malignant thrombi efficiently.

Diffusion-weighted MRI of malignant versus benign portal vein thrombosis

International Nuclear Information System (INIS)

Ahn, Jhii Hyun; Yu, Jeong Sik; Cho, Eun Suk; Chung, Jae Joon; Kim, Joo Hee; Kim, Ki Whang

2016-01-01

To validate the diffusion-weighted MRI (DWI) for differentiation of benign from malignant portal vein thrombosis. The Institutional Review Board approved this retrospective study and waived informed consent. A total of 59 consecutive patients (52 men and 7 women, aged 40-85 years) with grossly defined portal vein thrombus (PVT) on hepatic MRI were retrospectively analyzed. Among them, liver cirrhosis was found in 45 patients, and hepatocellular carcinoma in 47 patients. DWI was performed using b values of 50 and 800 sec/mm2 at 1.5-T unit. A thrombus was considered malignant if it enhanced on dynamic CT or MRI; otherwise, it was considered bland. There were 18 bland thrombi and 49 malignant thrombi in 59 patients, including 8 patients with simultaneous benign and malignant PVT. Mean apparent diffusion coefficients (ADCs) of benign and malignant PVTs were compared by using Mann-Whitney U test. Diagnostic accuracy was evaluated using receiver operating characteristic (ROC) curve analysis. The mean ADC ± standard deviation of bland and malignant PVT were 1.00 ± 0.39 × 10(-3) mm 2 /sec and 0.92 ± 0.25 × 10(-3) mm 2 /sec, respectively; without significant difference (p = 0.799). The area under ROC curve for ADC was 0.520. An ADC value of > 1.35 × 10(-3) mm 2 /sec predicted bland PVT with a specificity of 94.6% (95% confidence interval [CI]: 84.9-98.9%) and a sensitivity of 22.2% (95% CI: 6.4-47.6%), respectively. Due to the wide range and considerable overlap of the ADCs, DWI cannot differentiate the benign from malignant thrombi efficiently

Diffusion-Weighted MRI of Malignant versus Benign Portal Vein Thrombosis

International Nuclear Information System (INIS)

Ahn, Jhii-Hyun; Yu, Jeong-Sik; Cho, Eun-Suk; Chung, Jae-Joon; Kim, Joo Hee; Kim, Ki Whang

2016-01-01

To validate the diffusion-weighted MRI (DWI) for differentiation of benign from malignant portal vein thrombosis. The Institutional Review Board approved this retrospective study and waived informed consent. A total of 59 consecutive patients (52 men and 7 women, aged 40–85 years) with grossly defined portal vein thrombus (PVT) on hepatic MRI were retrospectively analyzed. Among them, liver cirrhosis was found in 45 patients, and hepatocellular carcinoma in 47 patients. DWI was performed using b values of 50 and 800 sec/mm 2 at 1.5-T unit. A thrombus was considered malignant if it enhanced on dynamic CT or MRI; otherwise, it was considered bland. There were 18 bland thrombi and 49 malignant thrombi in 59 patients, including 8 patients with simultaneous benign and malignant PVT. Mean apparent diffusion coefficients (ADCs) of benign and malignant PVTs were compared by using Mann-Whitney U test. Diagnostic accuracy was evaluated using receiver operating characteristic (ROC) curve analysis. The mean ADC ± standard deviation of bland and malignant PVT were 1.00 ± 0.39 × 10 -3 mm 2 /sec and 0.92 ± 0.25 × 10 -3 mm 2 /sec, respectively; without significant difference (p = 0.799). The area under ROC curve for ADC was 0.520. An ADC value of > 1.35 × 10 -3 mm 2 /sec predicted bland PVT with a specificity of 94.6% (95% confidence interval [CI]: 84.9–98.9%) and a sensitivity of 22.2% (95% CI: 6.4–47.6%), respectively. Due to the wide range and considerable overlap of the ADCs, DWI cannot differentiate the benign from malignant thrombi efficiently

Normal diffusion-weighted imaging in cerebral air embolism complicating angiography

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Sayama, T.; Inamura, T.; Fukui, M. [Dept. of Neurosurgery, Kyushu University Hospital, Fukuoka (Japan); Mitani, M.; Yagi, H. [Dept. of Neurosurgery, Yagi Hospital, Fukuoka (Japan)

2000-03-01

We report a case of cerebral air embolism resulting from accidental air infection during cerebral angiography. A 60-year-old man was accidentally injected with air via the left subclavian artery. Angiography demonstrated air within the basilar artery. The patient showed signs of posterior circulation ischaemia (confusion, blindness, gaze palsy and hemiparesis). However, MRI, including diffusion-weighted imaging, showed no abnormality 4 h later. The patient was treated with hyperbaric oxygen within 5 h of the embolism. All symptoms and signs resolved completely within a week. (orig.)

A biomimetic tumor tissue phantom for validating diffusion-weighted MRI measurements.

Science.gov (United States)

McHugh, Damien J; Zhou, Feng-Lei; Wimpenny, Ian; Poologasundarampillai, Gowsihan; Naish, Josephine H; Hubbard Cristinacce, Penny L; Parker, Geoffrey J M

2018-07-01

To develop a biomimetic tumor tissue phantom which more closely reflects water diffusion in biological tissue than previously used phantoms, and to evaluate the stability of the phantom and its potential as a tool for validating diffusion-weighted (DW) MRI measurements. Coaxial-electrospraying was used to generate micron-sized hollow polymer spheres, which mimic cells. The bulk structure was immersed in water, providing a DW-MRI phantom whose apparent diffusion coefficient (ADC) and microstructural properties were evaluated over a period of 10 months. Independent characterization of the phantom's microstructure was performed using scanning electron microscopy (SEM). The repeatability of the construction process was investigated by generating a second phantom, which underwent high resolution synchrotron-CT as well as SEM and MR scans. ADC values were stable (coefficients of variation (CoVs) < 5%), and varied with diffusion time, with average values of 1.44 ± 0.03 µm 2 /ms (Δ = 12 ms) and 1.20 ± 0.05 µm 2 /ms (Δ = 45 ms). Microstructural parameters showed greater variability (CoVs up to 13%), with evidence of bias in sphere size estimates. Similar trends were observed in the second phantom. A novel biomimetic phantom has been developed and shown to be stable over 10 months. It is envisaged that such phantoms will be used for further investigation of microstructural models relevant to characterizing tumor tissue, and may also find application in evaluating acquisition protocols and comparing DW-MRI-derived biomarkers obtained from different scanners at different sites. Magn Reson Med 80:147-158, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is

Modifications of pancreatic diffusion MRI by tissue characteristics: what are we weighting for?

Science.gov (United States)

Nissan, Noam

2017-08-01

Diffusion-weighted imaging holds the potential to improve the diagnosis and biological characterization of pancreatic disease, and in particular pancreatic cancer, which exhibits decreased values of the apparent diffusion coefficient (ADC). Yet, variable and overlapping ADC values have been reported for the healthy and the pathological pancreas, including for cancer and other benign conditions. This controversy reflects the complexity of probing the water-diffusion process in the pancreas, which is dependent upon multiple biological factors within this organ's unique physiological environment. In recent years, extensive studies have investigated the correlation between tissue properties including cellularity, vascularity, fibrosis, secretion and microstructure and pancreatic diffusivity. Understanding how the various physiological and pathological features and the underlying functional processes affect the diffusion measurement may serve to optimize the method for improved diagnostic gain. Therefore, the aim of the present review article is to elucidate the relationship between pancreatic tissue characteristics and diffusion MRI measurement. Copyright © 2017 John Wiley & Sons, Ltd.

Evaluation of conventional, dynamic contrast enhanced and diffusion weighted MRI for quantitative Crohn's disease assessment with histopathology of surgical specimens

NARCIS (Netherlands)

Tielbeek, Jeroen A. W.; Ziech, Manon L. W.; Li, Zhang; Lavini, Cristina; Bipat, Shandra; Bemelman, Willem A.; Roelofs, Joris J. T. H.; Ponsioen, Cyriel Y.; Vos, Frans M.; Stoker, Jaap

2014-01-01

To prospectively compare conventional MRI sequences, dynamic contrast enhanced (DCE) MRI and diffusion weighted imaging (DWI) with histopathology of surgical specimens in Crohn's disease. 3-T MR enterography was performed in consecutive Crohn's disease patients scheduled for surgery within 4 weeks.

Value of diffusion-weighted MR imaging in the diagnosis of Creutzfeldt-Jakob disease

International Nuclear Information System (INIS)

Xu Quangang; Wu Weiping; Huang Dehui; Zhang Jiatang; Lang Senyang; Pu Chuanqiang

2005-01-01

Objective: To assess the diagnosis value of diffusion- weighted imaging (DWI) in Creutzfeldt-Jakob disease (CJD). Methods: 8 cases of sporadic CJD who underwent MRI were reported. 4 cases were definite, 3 cases were probable and 1 case was possible. The sensitivity of DWI and conventional MRI were compared. Results: T 1 WI and T 2 WI revealed no abnormal signals except nonspecific diffuse brain atrophy in 4 cases, whereas DWI detected hyperintense abnormalities in all cases. 2 cases showed linear lesions only in the cerebral cortex, and 6 cases showed lesions in both the cerebral cortex and the striatum. The lesions were symmetric in 5 cases, but were asymmetric in the other 3 cases. Although fluid- attenuated inversion recovery (FLAIR) imaging also showed cortical hyperintensity in 1 case, the high signal changes were more evident and extensive on DWI. Conclusions: The hyperintense changes in the cerebral cortices and/or striata on DWI are considered characteristic of CJD. DWI is more sensitive than conventional MRI in depicting lesions of CJD and may be an essential tool for the early diagnosis of this disease. (authors)

Is it possible to model the risk of malignancy of focal abnormalities found at prostate multiparametric MRI?

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Rouviere, Olivier [Hopital Edouard Herriot, Hospices Civils de Lyon, Department of Urinary and Vascular Radiology, Lyon (France); Universite de Lyon, Lyon (France); Universite Lyon 1, faculte de medecine Lyon Est, Lyon (France); Inserm, U556, Lyon (France); Pavillon P Radio, Hopital Edouard Herriot, Department of Urinary and Vascular Radiology, Lyon Cedex 03 (France); Papillard, Matthieu; Girouin, Nicolas; Boutier, Romain [Hopital Edouard Herriot, Hospices Civils de Lyon, Department of Urinary and Vascular Radiology, Lyon (France); Universite de Lyon, Lyon (France); Universite Lyon 1, faculte de medecine Lyon Est, Lyon (France); Rabilloud, Muriel; Riche, Benjamin [Hospices Civils de Lyon, Department of Biostatistics, Lyon (France); Universite Lyon 1, UMR CNRS 5558, Laboratoire Biostatistiques-Sante, Pierre-Benite (France); Mege-Lechevallier, Florence [Hopital Edouard Herriot, Hospices Civils de Lyon, Department of Pathology, Lyon (France); Colombel, Marc [Hopital Edouard Herriot, Hospices Civils de Lyon, Department of Urology, Lyon (France); Gelet, Albert [Hopital Edouard Herriot, Hospices Civils de Lyon, Department of Urology, Lyon (France); Inserm, U556, Lyon (France)

2012-05-15

To evaluate whether focal abnormalities (FAs) depicted by prostate MRI could be characterised using simple semiological features. 134 patients who underwent T2-weighted, diffusion-weighted and dynamic contrast-enhanced MRI at 1.5 T before prostate biopsy were prospectively included. FAs visible at MRI were characterised by their shape, the degree of signal abnormality (0 = normal to 3 = markedly abnormal) on individual MR sequences, and a subjective score (SS{sub 1} = probably benign to SS{sub 3} = probably malignant). FAs were then biopsied under US guidance. 56/233 FAs were positive at biopsy. The subjective score significantly predicted biopsy results (P < 0.01). As compared to SS{sub 1} FAs, the odds ratios (OR) of malignancy of SS{sub 2} and SS{sub 3} FAs were 9.9 (1.8-55.9) and 163.8 (11.5-2331). Unlike FAs' shape, a simple combination of MR signal abnormalities (into ''low-risk'', ''intermediate'' and ''high-risk'' groups) significantly predicted biopsy results (P < 0.008). As compared to ''low risk'' FAs, the OR of malignancy of ''intermediate'' and ''high-risk'' FAs were 4.5 (1.1-18.4) and 52.7 (6.8-407) in the overall population and 5.4 (1.1-27.2) and 118.2 (6.1-2301) in PZ. A simple combination of signal abnormalities of individual MR sequences can significantly stratify the risk of malignancy of FAs, holding promise of a more standardised interpretation of MRI by readers with varying experience. (orig.)

Usefulness of diffusion-weighted MRI in differentiating benign from malignant musculoskeletal tumors

International Nuclear Information System (INIS)

Nagata, Shuji; Uchida, Masafumi; Hayabuchi, Naofumi

2005-01-01

The purpose of this study was to evaluate the usefulness of diffusion-weighted MRI in distinguishing different components and in differentiating benign from malignant musculoskeletal tumors. Fifty-seven patients with musculoskeletal tumors underwent MR at our institution from October 1999 to April 2002. We evaluated 57 tumors (9 bone tumors and 48 soft tissue tumors). All tumors were classified into 8 groups (myxomatous, fibrous, cystic, cartilaginous, fatty components, hematomas, other benign tumors, and other malignant tumors). MR examinations were performed with a 1.5-Tesla system. Diffusion-weighted single-shot echo planer imaging (EPI) images were obtained in all patients. Apparent diffusion coefficients (ADCs) were calculated by using b factors of 0 and 1,000 sec/mm 2 . ADC values of myxomatous, cystic, and cartilaginous components were significantly higher than those of other tumors. In cartilaginous tumors, malignant tumor ADC values (2.33±0.44) were higher than those of benign tumors (2.13±0.13). However, there was no significant difference between benign and malignant tumors. Except for high-intensity components on T1-weighted imaging and low or homogeneously very high intensity components on T2-weighted imaging, there was a significant difference in ADC between malignant (1.35±0.40) and benign (1.97±0.50) tumors. Within the limited number of cases, there was a significant difference in ADC between malignant and benign tumors. (author)

Comparison of non-Gaussian and Gaussian diffusion models of diffusion weighted imaging of rectal cancer at 3.0 T MRI.

Science.gov (United States)

Zhang, Guangwen; Wang, Shuangshuang; Wen, Didi; Zhang, Jing; Wei, Xiaocheng; Ma, Wanling; Zhao, Weiwei; Wang, Mian; Wu, Guosheng; Zhang, Jinsong

2016-12-09

Water molecular diffusion in vivo tissue is much more complicated. We aimed to compare non-Gaussian diffusion models of diffusion-weighted imaging (DWI) including intra-voxel incoherent motion (IVIM), stretched-exponential model (SEM) and Gaussian diffusion model at 3.0 T MRI in patients with rectal cancer, and to determine the optimal model for investigating the water diffusion properties and characterization of rectal carcinoma. Fifty-nine consecutive patients with pathologically confirmed rectal adenocarcinoma underwent DWI with 16 b-values at a 3.0 T MRI system. DWI signals were fitted to the mono-exponential and non-Gaussian diffusion models (IVIM-mono, IVIM-bi and SEM) on primary tumor and adjacent normal rectal tissue. Parameters of standard apparent diffusion coefficient (ADC), slow- and fast-ADC, fraction of fast ADC (f), α value and distributed diffusion coefficient (DDC) were generated and compared between the tumor and normal tissues. The SEM exhibited the best fitting results of actual DWI signal in rectal cancer and the normal rectal wall (R 2  = 0.998, 0.999 respectively). The DDC achieved relatively high area under the curve (AUC = 0.980) in differentiating tumor from normal rectal wall. Non-Gaussian diffusion models could assess tissue properties more accurately than the ADC derived Gaussian diffusion model. SEM may be used as a potential optimal model for characterization of rectal cancer.

Clinical usefulness of diffusion-weighted MRI in various stages of ischemic stroke

International Nuclear Information System (INIS)

Song, So Youne; Cho, Woo Ho; Kim, Soung Hee; Kim, Jung Sook; Kim, Young Hoon; Kim, Myung Gyu; Hur, Gham

2002-01-01

Diffusion-weighted MRI (DWI) is well known to be sensitive in the detection of hyperacute infarct, but has not been systematically investigated in patients with acute or subacute infarct. We evaluated the usefulness of diffusion-weighted MRI in assessing the various stages of brain infarct. Fifty-five consecutive patients with symptoms of brain infarct underwent fast spinecho T2-weighted MRI (T2WI) and DWI. Using only a brief clinical history, two radiologists first attempted to detect the lesion using T2W1, which was then compared with DWI. The usefulness of the latter was then evaluated in terms of the following criteria: 1) Its abilility to detect a lesion not seen at T2WI(detection); 2) localization of the responsible ischemic focus among multiple high-signal intensities seen at T2WI (localization); 3) conspicuity of a lesion which was subtle at T2WI (conspicuity); 4) detection of multiple lesions (multiplicity). DWI was useful in 44 of 55 patients (80%), including 9 of 9 (100%) with hyperacute infarct (<6 hours), 20 of 27 (74%) with acute infarct (<48 hours), and 15 of 19 (79%) with subacute infarct (<2 weeks). Among the nine patients at the hyperacute stage, DWI was useful for detection of the lesion in six (67%), for localization, 4 (44%) in one (11%), for conspicuity in four (44%), and for multiplicity in five (56%); at the acute stage (20 patients), for detection in three (15%), for localization in ten (50%), for conspicuity in eight (40%), and for moltiplicity in five (25%); and at the subacute stage (15 patients), for detection in three (20%), for localization in nine (60%), for conspicuity in two (13%), and for multiplicity in three (20%). DWI is very sensitive for the diagnosis of hyperacute infarct. In the assessment of this, it is useful during the acute or subacute period for the detection of small lesions, the localization of ongoing lesions among multiple high signal intensities seen at T2WI, and the determination of lesion conspicuity

Diffusion-weighted MRI - a new parameter for advanced rectal carcinoma?

International Nuclear Information System (INIS)

Hein, P.A.; Lukas, P.; DeVries, A.F.; Pfeiffer, K.-P.

2003-01-01

Purpose: To evaluate the predictive value of apparent diffusion coefficient (ADC) on therapy outcome of combined chemoradiation in patients with primary carcinoma of the rectum. Materials and Method: Prior to standardized, combined, neoadjuvant chemoradiation, 16 patients with primary carcinoma of the rectum (cT3) were examined with magnetic resonance imaging (MRI). Diffusion weighted spin echo echo-planar images (SE-EPI) and contrast-enhanced T 1 -weighted spin echo (SE) images at 1.5 Tesla were obtained. The mean ADC of the tumor region was calculated and correlated with the therapy outcome substantiated by postsurgical histopathologic staging. Results: Tumor downstaging (pT0-2) occurred in 9 patients (therapy responders) and no down-staging (pT3) in 7 patients (therapy non-responders). The mean ADC measured 0.476±0.114 x 10 -3 mm 2 /s in the responder group and 0.703±0.085 x 10 -3 mm 2 /s in the non-responder group. Comparison of the mean ADC between the groups reached statistical significance (p=0.001). Conclusion: The mean ADC might be a new quantitative parameter to predict therapy outcome of combined preoperative chemoradiation in patients with primary carcinoma of the rectum. (orig.) [de

D-BRAIN : Anatomically accurate simulated diffusion MRI brain data

NARCIS (Netherlands)

Perrone, Daniele; Jeurissen, Ben; Aelterman, Jan; Roine, Timo; Sijbers, Jan; Pizurica, Aleksandra; Leemans, Alexander; Philips, Wilfried

2016-01-01

Diffusion Weighted (DW) MRI allows for the non-invasive study of water diffusion inside living tissues. As such, it is useful for the investigation of human brain white matter (WM) connectivity in vivo through fiber tractography (FT) algorithms. Many DW-MRI tailored restoration techniques and FT

IgG4-related kidney disease: MRI findings with emphasis on the usefulness of diffusion-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Kim, Bohyun; Kim, Jin Hee, E-mail: kimjhrad@amc.seoul.kr; Byun, Jae Ho; Kim, Hyoung Jung; Lee, Seung Soo; Kim, So Yeon; Lee, Moon-Gyu

2014-07-15

Objectives: To investigate the imaging findings of immunoglobulin G4 (IgG4)-related kidney disease (IgG4-KD) on magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) and to evaluate the usefulness of DWI in lesion detection. Methods: This retrospective cohort study included 31 patients with IgG4-KD who underwent MRI covering both kidneys. Two radiologists reviewed in consensus the MR images to determine the distribution pattern (location, laterality, and multiplicity) and the visually assessed signal intensity (hypointense, isointense or hyperintense) of the renal lesions compared to the normal renal parenchyma on each sequence. Per-patient sensitivity for detecting IgG4-KD and the number of detectable lesions were compared in T2-weighted images, DWI, and dynamic contrast-enhanced images. Results: IgG4-KD typically manifested as bilateral (83.9%), multiple (93.5%), and renal parenchymal (87.1%) nodules appearing isointense (93.5%) on T1-weighted images, hypointense (77.4%) on T2-weighted images, hyperintense (100%) on DWI (b = 1000), and hypointense (83.3%) in the arterial phase and with a progressive enhancement pattern on dynamic contrast-enhanced images. The sensitivity of DWI for detecting IgG4-KD was significantly higher than that of T2-weighted images (100% vs. 77.4%, P = 0.034). The median number of detectable lesions was significantly greater in DWI (n = 9) than in T2-weighted images (n = 2) and dynamic contrast-enhanced images (n = 5) (P ≤ 0.008). Conclusions: The characteristic MRI findings of IgG4-KD were bilateral, multiple, renal parenchymal nodules with T2 hypointensity, diffusion restriction, and a progressive enhancement pattern. As DWI was useful in the detection of IgG4-KD, adding DWI to conventional MRI for patients suspected of having IgG4-KD may enhance the diagnosis.

IgG4-related kidney disease: MRI findings with emphasis on the usefulness of diffusion-weighted imaging

International Nuclear Information System (INIS)

Kim, Bohyun; Kim, Jin Hee; Byun, Jae Ho; Kim, Hyoung Jung; Lee, Seung Soo; Kim, So Yeon; Lee, Moon-Gyu

2014-01-01

Objectives: To investigate the imaging findings of immunoglobulin G4 (IgG4)-related kidney disease (IgG4-KD) on magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) and to evaluate the usefulness of DWI in lesion detection. Methods: This retrospective cohort study included 31 patients with IgG4-KD who underwent MRI covering both kidneys. Two radiologists reviewed in consensus the MR images to determine the distribution pattern (location, laterality, and multiplicity) and the visually assessed signal intensity (hypointense, isointense or hyperintense) of the renal lesions compared to the normal renal parenchyma on each sequence. Per-patient sensitivity for detecting IgG4-KD and the number of detectable lesions were compared in T2-weighted images, DWI, and dynamic contrast-enhanced images. Results: IgG4-KD typically manifested as bilateral (83.9%), multiple (93.5%), and renal parenchymal (87.1%) nodules appearing isointense (93.5%) on T1-weighted images, hypointense (77.4%) on T2-weighted images, hyperintense (100%) on DWI (b = 1000), and hypointense (83.3%) in the arterial phase and with a progressive enhancement pattern on dynamic contrast-enhanced images. The sensitivity of DWI for detecting IgG4-KD was significantly higher than that of T2-weighted images (100% vs. 77.4%, P = 0.034). The median number of detectable lesions was significantly greater in DWI (n = 9) than in T2-weighted images (n = 2) and dynamic contrast-enhanced images (n = 5) (P ≤ 0.008). Conclusions: The characteristic MRI findings of IgG4-KD were bilateral, multiple, renal parenchymal nodules with T2 hypointensity, diffusion restriction, and a progressive enhancement pattern. As DWI was useful in the detection of IgG4-KD, adding DWI to conventional MRI for patients suspected of having IgG4-KD may enhance the diagnosis

Diffusion-Weighted MRI of Malignant versus Benign Portal Vein Thrombosis

Energy Technology Data Exchange (ETDEWEB)

Ahn, Jhii-Hyun; Yu, Jeong-Sik; Cho, Eun-Suk; Chung, Jae-Joon; Kim, Joo Hee; Kim, Ki Whang [Department of Radiology, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul 06273 (Korea, Republic of)

2016-11-01

To validate the diffusion-weighted MRI (DWI) for differentiation of benign from malignant portal vein thrombosis. The Institutional Review Board approved this retrospective study and waived informed consent. A total of 59 consecutive patients (52 men and 7 women, aged 40–85 years) with grossly defined portal vein thrombus (PVT) on hepatic MRI were retrospectively analyzed. Among them, liver cirrhosis was found in 45 patients, and hepatocellular carcinoma in 47 patients. DWI was performed using b values of 50 and 800 sec/mm{sup 2} at 1.5-T unit. A thrombus was considered malignant if it enhanced on dynamic CT or MRI; otherwise, it was considered bland. There were 18 bland thrombi and 49 malignant thrombi in 59 patients, including 8 patients with simultaneous benign and malignant PVT. Mean apparent diffusion coefficients (ADCs) of benign and malignant PVTs were compared by using Mann-Whitney U test. Diagnostic accuracy was evaluated using receiver operating characteristic (ROC) curve analysis. The mean ADC ± standard deviation of bland and malignant PVT were 1.00 ± 0.39 × 10{sup -3} mm{sup 2}/sec and 0.92 ± 0.25 × 10{sup -3} mm{sup 2}/sec, respectively; without significant difference (p = 0.799). The area under ROC curve for ADC was 0.520. An ADC value of > 1.35 × 10{sup -3} mm{sup 2}/sec predicted bland PVT with a specificity of 94.6% (95% confidence interval [CI]: 84.9–98.9%) and a sensitivity of 22.2% (95% CI: 6.4–47.6%), respectively. Due to the wide range and considerable overlap of the ADCs, DWI cannot differentiate the benign from malignant thrombi efficiently.

Possibilities opened up by MRI in the diagnosis of hand and wrist abnormalities

International Nuclear Information System (INIS)

Heuck, A.; Steinbach, L.; Stoller, D.; Genant, H.

1989-01-01

MRI studies of 63 patients with various abnormalities of the hand and wrist were analyzed. Studies were performed on scanners with a field strength of 0.35, 0.5, or 1.5 T. Imaging parameters included T1- and T2-weighted sequences in the coronal and transverse planes and contiguous slices 3-5 mm thick. In 37 patients with post-traumatic disorders, MRI revealed carpal avascular necrosis, tendon abnormalities and, in some cases, abnormalities of interosseous ligaments and the triangular fibrocartilage. In 15 patients with such inflammatory diseases as arthritis, tenosynovitis and carpal tunnel syndrome and in 11 patients with tumors, MRI provided clear delineation of osseous and soft tissue abnormalities. The current role of MRI in the diagnosis of hand and wrist abnormalities is discussed on the basis of these results. (orig.) [de

Possibilities opened up by MRI in the diagnosis of hand and wrist abnormalities

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Heuck, A; Steinbach, L; Stoller, D; Genant, H; Neumann, C

1989-02-01

MRI studies of 63 patients with various abnormalities of the hand and wrist were analyzed. Studies were performed on scanners with a field strength of 0.35, 0.5, or 1.5 T. Imaging parameters included T1- and T2-weighted sequences in the coronal and transverse planes and contiguous slices 3-5 mm thick. In 37 patients with post-traumatic disorders, MRI revealed carpal avascular necrosis, tendon abnormalities and, in some cases, abnormalities of interosseous ligaments and the triangular fibrocartilage. In 15 patients with such inflammatory diseases as arthritis, tenosynovitis and carpal tunnel syndrome and in 11 patients with tumors, MRI provided clear delineation of osseous and soft tissue abnormalities. The current role of MRI in the diagnosis of hand and wrist abnormalities is discussed on the basis of these results.

Seizure-induced brain lesions: A wide spectrum of variably reversible MRI abnormalities

International Nuclear Information System (INIS)

Cianfoni, A.; Caulo, M.; Cerase, A.; Della Marca, G.; Falcone, C.; Di Lella, G.M.; Gaudino, S.; Edwards, J.; Colosimo, C.

2013-01-01

Introduction MRI abnormalities in the postictal period might represent the effect of the seizure activity, rather than its structural cause. Material and Methods Retrospective review of clinical and neuroimaging charts of 26 patients diagnosed with seizure-related MR-signal changes. All patients underwent brain-MRI (1.5-Tesla, standard pre- and post-contrast brain imaging, including DWI-ADC in 19/26) within 7 days from a seizure and at least one follow-up MRI, showing partial or complete reversibility of the MR-signal changes. Extensive clinical work-up and follow-up, ranging from 3 months to 5 years, ruled out infection or other possible causes of brain damage. Seizure-induced brain-MRI abnormalities remained a diagnosis of exclusion. Site, characteristics and reversibility of MRI changes, and association with characteristics of seizures were determined. Results MRI showed unilateral (13/26) and bilateral abnormalities, with high (24/26) and low (2/26) T2-signal, leptomeningeal contrast-enhancement (2/26), restricted diffusion (9/19). Location of abnormality was cortical/subcortical, basal ganglia, white matter, corpus callosum, cerebellum. Hippocampus was involved in 10/26 patients. Reversibility of MRI changes was complete in 15, and with residual gliosis or focal atrophy in 11 patients. Reversibility was noted between 15 and 150 days (average, 62 days). Partial simple and complex seizures were associated with hippocampal involvement (p = 0.015), status epilepticus with incomplete reversibility of MRI abnormalities (p = 0.041). Conclusions Seizure or epileptic status can induce transient, variably reversible MRI brain abnormalities. Partial seizures are frequently associated with hippocampal involvement and status epilepticus with incompletely reversible lesions. These seizure-induced MRI abnormalities pose a broad differential diagnosis; increased awareness may reduce the risk of misdiagnosis and unnecessary intervention

Seizure-induced brain lesions: A wide spectrum of variably reversible MRI abnormalities

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Cianfoni, A., E-mail: acianfoni@hotmail.com [Neuroradiology, Neurocenter of Italian Switzerland–Ospedale regionale Lugano, Via Tesserete 46, Lugano, 6900, CH (Switzerland); Caulo, M., E-mail: caulo@unich.it [Department of Neuroscience and Imaging, University of Chieti, Via dei Vestini 33, 6610 Chieti. Italy (Italy); Cerase, A., E-mail: alfonsocerase@gmail.com [Unit of Neuroimaging and Neurointervention NINT, Department of Neurological and Sensorineural Sciences, Azienda Ospedaliera Universitaria Senese, Policlinico “Santa Maria alle Scotte”, V.le Bracci 16, Siena (Italy); Della Marca, G., E-mail: dellamarca@rm.unicatt.it [Neurology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Falcone, C., E-mail: carlo_falc@libero.it [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Di Lella, G.M., E-mail: gdilella@rm.unicatt.it [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Gaudino, S., E-mail: sgaudino@sirm.org [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy); Edwards, J., E-mail: edwardjc@musc.edu [Neuroscience Dept., Medical University of South Carolina, 96J Lucas st, 29425, Charleston, SC (United States); Colosimo, C., E-mail: colosimo@rm.unicatt.it [Radiology Dept., Catholic University of Rome, L.go F Vito 1, 00100, Rome (Italy)

2013-11-01

Introduction MRI abnormalities in the postictal period might represent the effect of the seizure activity, rather than its structural cause. Material and Methods Retrospective review of clinical and neuroimaging charts of 26 patients diagnosed with seizure-related MR-signal changes. All patients underwent brain-MRI (1.5-Tesla, standard pre- and post-contrast brain imaging, including DWI-ADC in 19/26) within 7 days from a seizure and at least one follow-up MRI, showing partial or complete reversibility of the MR-signal changes. Extensive clinical work-up and follow-up, ranging from 3 months to 5 years, ruled out infection or other possible causes of brain damage. Seizure-induced brain-MRI abnormalities remained a diagnosis of exclusion. Site, characteristics and reversibility of MRI changes, and association with characteristics of seizures were determined. Results MRI showed unilateral (13/26) and bilateral abnormalities, with high (24/26) and low (2/26) T2-signal, leptomeningeal contrast-enhancement (2/26), restricted diffusion (9/19). Location of abnormality was cortical/subcortical, basal ganglia, white matter, corpus callosum, cerebellum. Hippocampus was involved in 10/26 patients. Reversibility of MRI changes was complete in 15, and with residual gliosis or focal atrophy in 11 patients. Reversibility was noted between 15 and 150 days (average, 62 days). Partial simple and complex seizures were associated with hippocampal involvement (p = 0.015), status epilepticus with incomplete reversibility of MRI abnormalities (p = 0.041). Conclusions Seizure or epileptic status can induce transient, variably reversible MRI brain abnormalities. Partial seizures are frequently associated with hippocampal involvement and status epilepticus with incompletely reversible lesions. These seizure-induced MRI abnormalities pose a broad differential diagnosis; increased awareness may reduce the risk of misdiagnosis and unnecessary intervention.

MRI-only lesions: application of diffusion-weighted imaging obviates unnecessary MR-guided breast biopsies

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Spick, Claudio; Pinker-Domenig, Katja; Helbich, Thomas H.; Baltzer, Pascal A. [Medical University of Vienna (AKH), General Hospital Vienna, Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Wien (Austria); Rudas, Margaretha [Medical University of Vienna (AKH), Clinical Institute of Pathology, Wien (Austria)

2014-06-15

To assess if the application of diffusion-weighted imaging (DWI) obviates unnecessary MR-guided biopsies in suspicious breast lesions visible only on contrast-enhanced MRI (CE-MRI). This institutional review board (IRB)-approved, retrospective, single-centre study included 101 patients (mean age, 49.5; SD 13.9 years) who underwent additional DWI at 1.5 T prior to MRI-guided biopsy of 104 lesions classified as suspicious for malignancy and visible on CE-MRI only. An experienced radiologist, blinded to histopathologic and follow-up results, measured apparent diffusion coefficient (ADC) values obtained from DWI. Diagnostic accuracy was investigated using receiver operating characteristics (ROC) analysis. Histopathology revealed 20 malignant and 84 benign lesions. Lesions were masses in 61 (15 malignant, 24.6 %) and non-masses in 43 cases (five malignant, 11.6 %). Mean ADC values were 1.53 ± 0.38 x 10{sup -3} mm{sup 2}/s in benign lesions and 1.06 ± 0.27 x 10{sup -3} mm{sup 2}/s in malignant lesions. ROC analysis revealed exclusively benign lesions if ADC values were greater than 1.58 x 10{sup -3} mm{sup 2}/s. As a consequence, 29 false-positive biopsies (34.5 %) could have been avoided without any false-negative findings. Both in mass and in non-mass lesions, rule-in and rule-out criteria were identified using flexible ADC thresholds based on ROC analysis. Additional application of DWI in breast lesions visible only on MRI can avoid false-positive, MR-guided biopsies. Thus, DWI should be an integral part of breast MRI protocols. (orig.)

Neonatal physiological correlates of near-term brain development on MRI and DTI in very-low-birth-weight preterm infants.

Science.gov (United States)

Rose, Jessica; Vassar, Rachel; Cahill-Rowley, Katelyn; Stecher Guzman, Ximena; Hintz, Susan R; Stevenson, David K; Barnea-Goraly, Naama

2014-01-01

Structural brain abnormalities identified at near-term age have been recognized as potential predictors of neurodevelopment in children born preterm. The aim of this study was to examine the relationship between neonatal physiological risk factors and early brain structure in very-low-birth-weight (VLBW) preterm infants using structural MRI and diffusion tensor imaging (DTI) at near-term age. Structural brain MRI, diffusion-weighted scans, and neonatal physiological risk factors were analyzed in a cross-sectional sample of 102 VLBW preterm infants (BW ≤ 1500 g, gestational age (GA) ≤ 32 weeks), who were admitted to the Lucile Packard Children's Hospital, Stanford NICU and recruited to participate prior to routine near-term brain MRI conducted at 36.6 ± 1.8 weeks postmenstrual age (PMA) from 2010 to 2011; 66/102 also underwent a diffusion-weighted scan. Brain abnormalities were assessed qualitatively on structural MRI, and white matter (WM) microstructure was analyzed quantitatively on DTI in six subcortical regions defined by DiffeoMap neonatal brain atlas. Specific regions of interest included the genu and splenium of the corpus callosum, anterior and posterior limbs of the internal capsule, the thalamus, and the globus pallidus. Regional fractional anisotropy (FA) and mean diffusivity (MD) were calculated using DTI data and examined in relation to neonatal physiological risk factors including gestational age (GA), bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), retinopathy of prematurity (ROP), and sepsis, as well as serum levels of C-reactive protein (CRP), glucose, albumin, and total bilirubin. Brain abnormalities were observed on structural MRI in 38/102 infants including 35% of females and 40% of males. Infants with brain abnormalities observed on MRI had higher incidence of BPD (42% vs. 25%) and sepsis (21% vs. 6%) and higher mean and peak serum CRP levels, respectively, (0.64 vs. 0.34 mg/dL, p = .008; 1.57 vs. 0.67�

Brain Abnormalities in Congenital Fibrosis of the Extraocular Muscles Type 1: A Multimodal MRI Imaging Study.

Science.gov (United States)

Miao, Wen; Man, Fengyuan; Wu, Shaoqin; Lv, Bin; Wang, Zhenchang; Xian, Junfang; Sabel, Bernhard A; He, Huiguang; Jiao, Yonghong

2015-01-01

To explore the possible brain structural and functional alterations in congenital fibrosis of extraocular muscles type 1 (CFEOM1) patients using multimodal MRI imaging. T1-weighted, diffusion tensor images and functional MRI data were obtained from 9 KIF21A positive patients and 19 age- and gender-matched healthy controls. Voxel based morphometry and tract based spatial statistics were applied to the T1-weighted and diffusion tensor images, respectively. Amplitude of low frequency fluctuations and regional homogeneity were used to process the functional MRI data. We then compared these multimodal characteristics between CFEOM1 patients and healthy controls. Compared with healthy controls, CFEOM1 patients demonstrated increased grey matter volume in bilateral frontal orbital cortex and in the right temporal pole. No diffusion indices changes were detected, indicating unaffected white matter microstructure. In addition, from resting state functional MRI data, trend of amplitude of low-frequency fluctuations increases were noted in the right inferior parietal lobe and in the right frontal cortex, and a trend of ReHo increase (pleft precentral gyrus, left orbital frontal cortex, temporal pole and cingulate gyrus. CFEOM1 patients had structural and functional changes in grey matter, but the white matter was unaffected. These alterations in the brain may be due to the abnormality of extraocular muscles and their innervating nerves. Future studies should consider the possible correlations between brain morphological/functional findings and clinical data, especially pertaining to eye movements, to obtain more precise answers about the role of brain area changes and their functional consequence in CFEOM1.

Brain Abnormalities in Congenital Fibrosis of the Extraocular Muscles Type 1: A Multimodal MRI Imaging Study

Science.gov (United States)

Wu, Shaoqin; Lv, Bin; Wang, Zhenchang; Xian, Junfang; Sabel, Bernhard A.; He, Huiguang; Jiao, Yonghong

2015-01-01

Purpose To explore the possible brain structural and functional alterations in congenital fibrosis of extraocular muscles type 1 (CFEOM1) patients using multimodal MRI imaging. Methods T1-weighted, diffusion tensor images and functional MRI data were obtained from 9 KIF21A positive patients and 19 age- and gender- matched healthy controls. Voxel based morphometry and tract based spatial statistics were applied to the T1-weighted and diffusion tensor images, respectively. Amplitude of low frequency fluctuations and regional homogeneity were used to process the functional MRI data. We then compared these multimodal characteristics between CFEOM1 patients and healthy controls. Results Compared with healthy controls, CFEOM1 patients demonstrated increased grey matter volume in bilateral frontal orbital cortex and in the right temporal pole. No diffusion indices changes were detected, indicating unaffected white matter microstructure. In addition, from resting state functional MRI data, trend of amplitude of low-frequency fluctuations increases were noted in the right inferior parietal lobe and in the right frontal cortex, and a trend of ReHo increase (pleft precentral gyrus, left orbital frontal cortex, temporal pole and cingulate gyrus. Conclusions CFEOM1 patients had structural and functional changes in grey matter, but the white matter was unaffected. These alterations in the brain may be due to the abnormality of extraocular muscles and their innervating nerves. Future studies should consider the possible correlations between brain morphological/functional findings and clinical data, especially pertaining to eye movements, to obtain more precise answers about the role of brain area changes and their functional consequence in CFEOM1. PMID:26186732

Diffuse axonal injury: detection of changes in anisotropy of water diffusion by diffusion-weighted imaging

International Nuclear Information System (INIS)

Chan, J.H.M.; Tsui, E.Y.K.; Yuen, M.K.; Peh, W.C.G.; Fong, D.; Fok, K.F.; Leung, K.M.; Fung, K.K.L.

2003-01-01

Myelinated axons of white matter demonstrate prominent directional differences in water diffusion. We performed diffusion-weighted imaging on ten patients with head injury to explore the feasibility of using water diffusion anisotropy for quantitating diffuse axonal injury. We showed significant decrease in diffusion anisotropy indices in areas with or without signal abnormality on T2 and T2*-weighted images. We conclude that the water diffusion anisotropy index a potentially useful, sensitive and quantitative way of diagnosing and assessing patients with diffuse axonal injury. (orig.)

Diffusion-weighted MR imaging in leukodystrophies

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Patay, Zoltan [King Faisal Specialist Hospital and Research Centre, Department of Radiology, Riyadh (Saudi Arabia)

2005-11-01

Leukodystrophies are genetically determined metabolic diseases, in which the underlying biochemical abnormality interferes with the normal build-up and/or maintenance of myelin, which leads to hypo- (or arrested) myelination, or dysmyelination with resultant demyelination. Although conventional magnetic resonance imaging has significantly contributed to recent progress in the diagnostic work-up of these diseases, diffusion-weighted imaging has the potential to further improve our understanding of underlying pathological processes and their dynamics through the assessment of normal and abnormal diffusion properties of cerebral white matter. Evaluation of conventional diffusion-weighted and ADC map images allows the detection of major diffusion abnormalities and the identification of various edema types, of which the so-called myelin edema is particularly relevant to leukodystrophies. Depending on the nature of histopathological changes, stage and progression gradient of diseases, various diffusion-weighted imaging patterns may be seen in leukodystrophies. Absent or low-grade myelin edema is found in mucopolysaccharidoses, GM gangliosidoses, Zellweger disease, adrenomyeloneuropathy, L-2-hydroxyglutaric aciduria, non-ketotic hyperglycinemia, classical phenylketonuria, Van der Knaap disease and the vanishing white matter, medium grade myelin edema in metachromatic leukodystrophy, X-linked adrenoleukodystrophy and HMG coenzyme lyase deficiency and high grade edema in Krabbe disease, Canavan disease, hyperhomocystinemias, maple syrup urine disease and leukodystrophy with brainstem and spinal cord involvement and high lactate. (orig.)

Diffusion-weighted MR imaging in leukodystrophies

International Nuclear Information System (INIS)

Patay, Zoltan

2005-01-01

Leukodystrophies are genetically determined metabolic diseases, in which the underlying biochemical abnormality interferes with the normal build-up and/or maintenance of myelin, which leads to hypo- (or arrested) myelination, or dysmyelination with resultant demyelination. Although conventional magnetic resonance imaging has significantly contributed to recent progress in the diagnostic work-up of these diseases, diffusion-weighted imaging has the potential to further improve our understanding of underlying pathological processes and their dynamics through the assessment of normal and abnormal diffusion properties of cerebral white matter. Evaluation of conventional diffusion-weighted and ADC map images allows the detection of major diffusion abnormalities and the identification of various edema types, of which the so-called myelin edema is particularly relevant to leukodystrophies. Depending on the nature of histopathological changes, stage and progression gradient of diseases, various diffusion-weighted imaging patterns may be seen in leukodystrophies. Absent or low-grade myelin edema is found in mucopolysaccharidoses, GM gangliosidoses, Zellweger disease, adrenomyeloneuropathy, L-2-hydroxyglutaric aciduria, non-ketotic hyperglycinemia, classical phenylketonuria, Van der Knaap disease and the vanishing white matter, medium grade myelin edema in metachromatic leukodystrophy, X-linked adrenoleukodystrophy and HMG coenzyme lyase deficiency and high grade edema in Krabbe disease, Canavan disease, hyperhomocystinemias, maple syrup urine disease and leukodystrophy with brainstem and spinal cord involvement and high lactate. (orig.)

MRI of Neurosyphilis Presenting as Mesiotemporal Abnormalities: a Case Report

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Jeong, Yu Mi; Hwang, Hee Young; Kim, Hyung Sik [Gachon University, Gil Medical Center, Incheon (Korea, Republic of)

2009-06-15

The high signal intensities in bilateral mesiotemporal lobes on T2-weighted images are typical findings of herpes encephalitis or paraneoplastic limbic encephalitis. We report a case of neurosyphilis with mesiotemporal involvement on MRI. Positive antibodies in the cerebrospinal fluid confirmed the diagnosis. The results suggest that neurosyphilis should be considered when MRI results indicate mesiotemporal abnormalities.

A variational image-based approach to the correction of susceptibility artifacts in the alignment of diffusion weighted and structural MRI.

Science.gov (United States)

Tao, Ran; Fletcher, P Thomas; Gerber, Samuel; Whitaker, Ross T

2009-01-01

This paper presents a method for correcting the geometric and greyscale distortions in diffusion-weighted MRI that result from inhomogeneities in the static magnetic field. These inhomogeneities may due to imperfections in the magnet or to spatial variations in the magnetic susceptibility of the object being imaged--so called susceptibility artifacts. Echo-planar imaging (EPI), used in virtually all diffusion weighted acquisition protocols, assumes a homogeneous static field, which generally does not hold for head MRI. The resulting distortions are significant, sometimes more than ten millimeters. These artifacts impede accurate alignment of diffusion images with structural MRI, and are generally considered an obstacle to the joint analysis of connectivity and structure in head MRI. In principle, susceptibility artifacts can be corrected by acquiring (and applying) a field map. However, as shown in the literature and demonstrated in this paper, field map corrections of susceptibility artifacts are not entirely accurate and reliable, and thus field maps do not produce reliable alignment of EPIs with corresponding structural images. This paper presents a new, image-based method for correcting susceptibility artifacts. The method relies on a variational formulation of the match between an EPI baseline image and a corresponding T2-weighted structural image but also specifically accounts for the physics of susceptibility artifacts. We derive a set of partial differential equations associated with the optimization, describe the numerical methods for solving these equations, and present results that demonstrate the effectiveness of the proposed method compared with field-map correction.

Added value of diffusion-weighted MRI in detection of cervical cancer recurrence: comparison with morphologic and dynamic contrast-enhanced MRI sequences.

Science.gov (United States)

Lucas, Rita; Lopes Dias, João; Cunha, Teresa Margarida

2015-01-01

We aimed to evaluate the added value of diffusion-weighted imaging (DWI) to standard magnetic resonance imaging (MRI) for detecting post-treatment cervical cancer recurrence. The detection accuracy of T2-weighted (T2W) images was compared with that of T2W MRI combined with either dynamic contrast-enhanced (DCE) MRI or DWI. Thirty-eight women with clinically suspected uterine cervical cancer recurrence more than six months after treatment completion were examined with 1.5 Tesla MRI including T2W, DCE, and DWI sequences. Disease was confirmed histologically and correlated with MRI findings. The diagnostic performance of T2W imaging and its combination with either DCE or DWI were analyzed. Sensitivity, positive predictive value, and accuracy were calculated. Thirty-six women had histologically proven recurrence. The accuracy for recurrence detection was 80% with T2W/DCE MRI and 92.1% with T2W/DWI. The addition of DCE sequences did not significantly improve the diagnostic ability of T2W imaging, and this sequence combination misclassified two patients as falsely positive and seven as falsely negative. The T2W/DWI combination revealed a positive predictive value of 100% and only three false negatives. The addition of DWI to T2W sequences considerably improved the diagnostic ability of MRI. Our results support the inclusion of DWI in the initial MRI protocol for the detection of cervical cancer recurrence, leaving DCE sequences as an option for uncertain cases.

Pediatric hemiplegic migraine: susceptibility weighted and MR perfusion imaging abnormality

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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.)

Can MRI diffusion-weighted imaging identify postoperative residual/recurrent soft-tissue sarcomas?

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Mai Maher ElDaly

2018-01-01

Full Text Available Purpose: The aim of this study was to evaluate contrast-enhanced magnetic resonance imaging (CE-MRI and quantitative diffusion-weighted imaging (DWI with apparent diffusion coefficient (ADC mapping in the detection of recurrent/residual postoperative soft tissue sarcomas. Materials and Methods: This study included 36 patients; 27 patients had postoperative recurrent/residual soft tissue sarcomas and 9 patients had postoperative and treatment-related changes (inflammation/fibrosis. The DWI was obtained with 3 b values including 0, 400, and 800 s/mm2. Calculation of the ADC value of the lesion was done via placing the region of interest (ROI to include the largest area of the lesion. ADC values were compared to histopathology. Results: Our results showed that including CE-MRI improved the diagnostic accuracy and sensitivity in recurrence detection compared to conventional non-enhanced sequences. However, it showed low specificity (55.56% with a high false-positive rate that may lead to an unnecessary biopsy of a mass such as region of postoperative scar tissue. Conclusion: The joint use of gadolinium-enhanced MRI and quantitative DWI with ADC mapping offer added value in the detection of recurrent/residual postoperative soft tissue sarcoma. This combined use increased both the diagnostic sensitivity and specificity with a cut-off average ADC value for detecting nonmyxoid recurrent/residual lesions ≤1.3 × 10−3 mm2/s (100% specificity and 90.48% sensitivity. Our results showed limited value of DWI with ADC mapping in assessing myxoid sarcomatous tumor recurrences.

Respiratory syncytial virus-related encephalitis: magnetic resonance imaging findings with diffusion-weighted study

International Nuclear Information System (INIS)

Park, Arim; Suh, Sang-il; Seol, Hae-Young; Son, Gyu-Ri; Lee, Nam-Joon; Lee, Young Hen; Seo, Hyung Suk; Eun, Baik-Lin

2014-01-01

Respiratory syncytial virus (RSV) is a common pathogen causing acute respiratory infection in children. Herein, we describe the incidence and clinical and magnetic resonance imaging (MRI) findings of RSV-related encephalitis, a major neurological complication of RSV infection. We retrospectively reviewed the medical records and imaging findings of the patients over the past 7 years who are admitted to our medical center and are tested positive for RSV-RNA by reverse transcriptase PCR. In total, 3,856 patients were diagnosed with RSV bronchiolitis, and 28 of them underwent brain MRI for the evaluation of neurologic symptoms; 8 of these 28 patients had positive imaging findings. Five of these 8 patients were excluded because of non-RSV-related pathologies, such as subdural hemorrhage, brain volume loss due to status epilepticus, periventricular leukomalacia, preexisting ventriculomegaly, and hypoxic brain injury. The incidence of RSV-related encephalitis was as follows: 3/3,856 (0.08 %) of the patients are positive for RSV RNA, 3/28 (10.7 %) of the patient underwent brain MRI for neurological symptom, and 3/8 (37.5 %) of patients revealed abnormal MR findings. The imaging findings were suggestive of patterns of rhombenmesencephalitis, encephalitis with acute disseminated encephalomyelitis, and limbic encephalitis. They demonstrated no diffusion abnormality on diffusion-weighted image and symptom improvement on the follow-up study. Encephalitis with RSV bronchiolitis occurs rarely. However, on brain MRI performed upon suspicion of neurologic involvement, RSV encephalitis is not infrequently observed among the abnormal MR findings and may mimic other viral and limbic encephalitis. Physicians should be aware of this entity to ensure proper diagnosis and neurologic care of RSV-positive patients. (orig.)

Respiratory syncytial virus-related encephalitis: magnetic resonance imaging findings with diffusion-weighted study

Energy Technology Data Exchange (ETDEWEB)

Park, Arim; Suh, Sang-il; Seol, Hae-Young [Korea University College of Medicine, Department of Radiology, Korea University Guro Hospital, Seoul (Korea, Republic of); Son, Gyu-Ri; Lee, Nam-Joon [Korea University College of Medicine, Department of Radiology, Korea University Anam Hospital, Seoul (Korea, Republic of); Lee, Young Hen; Seo, Hyung Suk [Korea University College of Medicine, Department of Radiology, Korea University Ansan Hospital, Gyeonggi-do (Korea, Republic of); Eun, Baik-Lin [Korea University College of Medicine, Department of Pediatrics, Korea University Guro Hospital, Seoul (Korea, Republic of)

2014-02-15

Respiratory syncytial virus (RSV) is a common pathogen causing acute respiratory infection in children. Herein, we describe the incidence and clinical and magnetic resonance imaging (MRI) findings of RSV-related encephalitis, a major neurological complication of RSV infection. We retrospectively reviewed the medical records and imaging findings of the patients over the past 7 years who are admitted to our medical center and are tested positive for RSV-RNA by reverse transcriptase PCR. In total, 3,856 patients were diagnosed with RSV bronchiolitis, and 28 of them underwent brain MRI for the evaluation of neurologic symptoms; 8 of these 28 patients had positive imaging findings. Five of these 8 patients were excluded because of non-RSV-related pathologies, such as subdural hemorrhage, brain volume loss due to status epilepticus, periventricular leukomalacia, preexisting ventriculomegaly, and hypoxic brain injury. The incidence of RSV-related encephalitis was as follows: 3/3,856 (0.08 %) of the patients are positive for RSV RNA, 3/28 (10.7 %) of the patient underwent brain MRI for neurological symptom, and 3/8 (37.5 %) of patients revealed abnormal MR findings. The imaging findings were suggestive of patterns of rhombenmesencephalitis, encephalitis with acute disseminated encephalomyelitis, and limbic encephalitis. They demonstrated no diffusion abnormality on diffusion-weighted image and symptom improvement on the follow-up study. Encephalitis with RSV bronchiolitis occurs rarely. However, on brain MRI performed upon suspicion of neurologic involvement, RSV encephalitis is not infrequently observed among the abnormal MR findings and may mimic other viral and limbic encephalitis. Physicians should be aware of this entity to ensure proper diagnosis and neurologic care of RSV-positive patients. (orig.)

Tuberous sclerosis: diffusion MRI findings in the brain

International Nuclear Information System (INIS)

Sener, R.N.

2002-01-01

Diffusion MRI has mainly been used for detection of acute ischemia, and for distinction of cytotoxic and vasogenic edema. We applied diffusion MRI in patients with tuberous sclerosis in order to evaluate diffusion imaging characteristics of parenchymal changes. Five children with known tuberous sclerosis were included in this study. The MRI examinations were performed on a 1.5-T MR unit. Diffusion MRI was obtained using the echo-planar imaging sequence. Apparent diffusion coefficient (ADC) values from the abnormal brain parenchyma were calculated directly from automatically generated ADC maps. Seven normal children were available for comparison. In this control group the mean ADC value of the normal white matter was 0.84±0.12 x 10 -3 mm 2 /s. In tuberous sclerosis patients the mean ADC value of the white matter hamartomas (n=20) was apparently high (1.52±0.24 x 10 -3 mm 2 /s) compared with that of normal white matter. The ADC value of calcified hamartomas was ''zero''. The ADC value within a giant cell tumor was 0.89 x 10 -3 mm 2 /s, similar to that of normal cerebral white matter. The ADC maps were superior to b=1000 s/mm 2 (true diffusion) images with respect to lesion evaluation, and they provided mathematical information on tissue integrity. With respect to detection of the exact numbers and sizes of the parenchymal hamartomas fluid-attenuated inversion recovery images were superior to ADC maps. It is believed that diffusion MRI can be useful in evaluation of various parenchymal changes associated with tuberous sclerosis. Further studies on tuberous sclerosis, and on various brain lesions, would provide increasing data on this relatively new MRI sequence. (orig.)

Brain Abnormalities in Congenital Fibrosis of the Extraocular Muscles Type 1: A Multimodal MRI Imaging Study.

Directory of Open Access Journals (Sweden)

Wen Miao

Full Text Available To explore the possible brain structural and functional alterations in congenital fibrosis of extraocular muscles type 1 (CFEOM1 patients using multimodal MRI imaging.T1-weighted, diffusion tensor images and functional MRI data were obtained from 9 KIF21A positive patients and 19 age- and gender-matched healthy controls. Voxel based morphometry and tract based spatial statistics were applied to the T1-weighted and diffusion tensor images, respectively. Amplitude of low frequency fluctuations and regional homogeneity were used to process the functional MRI data. We then compared these multimodal characteristics between CFEOM1 patients and healthy controls.Compared with healthy controls, CFEOM1 patients demonstrated increased grey matter volume in bilateral frontal orbital cortex and in the right temporal pole. No diffusion indices changes were detected, indicating unaffected white matter microstructure. In addition, from resting state functional MRI data, trend of amplitude of low-frequency fluctuations increases were noted in the right inferior parietal lobe and in the right frontal cortex, and a trend of ReHo increase (p<0.001 uncorrected in the left precentral gyrus, left orbital frontal cortex, temporal pole and cingulate gyrus.CFEOM1 patients had structural and functional changes in grey matter, but the white matter was unaffected. These alterations in the brain may be due to the abnormality of extraocular muscles and their innervating nerves. Future studies should consider the possible correlations between brain morphological/functional findings and clinical data, especially pertaining to eye movements, to obtain more precise answers about the role of brain area changes and their functional consequence in CFEOM1.

Novel Diffusion-Weighted MRI for High-Grade Prostate Cancer Detection

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2017-10-01

technical difficulty with comparison of radical prostatectomy histology with imaging, we have also introduced a method to evaluate the accuracy of our...MatLab code for co-registration of digital radical prostatectomy histology to T2 weighted MRI images of alpha and DDC maps to T2 weighted MRI was...HPA 479 ( Evaluation of Clinical Interventions), with a grade of A. He completed BHIS 509 (Informatics for the Clinical Investigator) with a grade

Evaluation of malignant and benign renal lesions using diffusion-weighted MRI with multiple b values

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Erbay, Gurcan; Koc, Zafer; Karadeli, Elif; Kuzgunbay, Baris; Goren, M. Resit; Bal, Nebil

2012-01-01

Background: Limited data are available regarding the use of diffusion-weighted (DW) magnetic resonance imaging (MRI) with multiple b values for characterization of renal lesions. Purpose: To demonstrate and compare the diagnostic performance of DW-MRI with multiple b values for renal lesion characterization. Material and Methods: Sixty-three lesions (36 malignant, 27 benign) in 60 consecutive patients (48 men, 12 women; age 60 ± 12.5 years) with solid/cystic renal lesion diagnosed after MRI were included prospectively. Single-shot echo-planar DW abdominal MRI (1.5T) was obtained using seven b values with eight apparent diffusion coefficient (ADC) maps. Contrast-to-noise ratios (CNRs), signal intensities, lesion ADCs, and lesion/normal parenchyma ADC ratios were analyzed. Receiver-operating characteristic analysis was performed. Results: The mean signal intensities of malignant lesions (at b0, 50, and 200 s/mm 2 ) were significantly lower than those of benign lesions (P 2 . ADC with all b values could better distinguish between benign and malignant lesions. A 1.35 x 10 -3 mm 2 /s threshold ADC value permitted this distinction with 85.2% sensitivity and 65.6% specificity. The lesion/normal parenchyma ADC ratio was more effective than the lesion ADC. Conclusion: In addition to the ADC value, the signal intensity curve on DW images using multiple b values could be helpful for differentiation of malignant and benign renal lesions

Comparison of gadolinium-EOB-DTPA-enhanced and diffusion-weighted liver MRI for detection of small hepatic metastases.

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Shimada, Kotaro; Isoda, Hiroyoshi; Hirokawa, Yuusuke; Arizono, Shigeki; Shibata, Toshiya; Togashi, Kaori

2010-11-01

To compare the accuracy of gadolinium ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI with that of diffusion-weighted MRI (DWI) in the detection of small hepatic metastases (2 cm or smaller). Forty-five patients underwent abdominal MRI at 3 T, including T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), heavily T2WI (HASTE), DWI with a b-value of 500 s/mm(2) and contrast-enhanced MRI with Gd-EOB-DTPA. Two groups were assigned and compared: group A (T1WI, T2WI, HASTE and contrast-enhanced study with Gd-EOB-DTPA), and group B (T1WI, T2WI, HASTE and DWI). Two observers independently interpreted the images obtained in a random order. For all hepatic metastases, the diagnostic performance using each imaging set was evaluated by receiver-operating characteristic (ROC) curve analysis. A total of 51 hepatic metastases were confirmed. The area under the ROC curve (Az) of group A was larger than that of group B, and the difference in the mean Az values between the two image sets was statistically significant, whereas, there were three metastases that lay near thin vessels or among multiple cysts and were better visualised in group B than in group A. Gd-EOB-DTPA-enhanced MRI showed higher accuracy in the detection of small metastases than DWI.

Current and future diagnostic tools for traumatic brain injury: CT, conventional MRI, and diffusion tensor imaging.

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Brody, David L; Mac Donald, Christine L; Shimony, Joshua S

2015-01-01

Brain imaging plays a key role in the assessment of traumatic brain injury. In this review, we present our perspectives on the use of computed tomography (CT), conventional magnetic resonance imaging (MRI), and newer advanced modalities such as diffusion tensor imaging. Specifically, we address assessment for immediately life-threatening intracranial lesions (noncontrast head CT), assessment of progression of intracranial lesions (noncontrast head CT), documenting intracranial abnormalities for medicolegal reasons (conventional MRI with blood-sensitive sequences), presurgical planning for post-traumatic epilepsy (high spatial resolution conventional MRI), early prognostic decision making (conventional MRI with diffusion-weighted imaging), prognostic assessment for rehabilitative planning (conventional MRI and possibly diffusion tensor imaging in the future), stratification of subjects and pharmacodynamic tracking of targeted therapies in clinical trials (specific MRI sequences or positron emission tomography (PET) ligands, e.g., diffusion tensor imaging for traumatic axonal injury). We would like to emphasize that all of these methods, especially the newer research approaches, require careful radiologic-pathologic validation for optimal interpretation. We have taken this approach in a mouse model of pericontusional traumatic axonal injury. We found that the extent of reduction in the diffusion tensor imaging parameter relative anisotropy directly correlated with the number of amyloid precursor protein (APP)-stained axonal varicosities (r(2)=0.81, p<0.0001, n=20 injured mice). Interestingly, however, the least severe contusional injuries did not result in APP-stained axonal varicosities, but did cause reduction in relative anisotropy. Clearly, both the imaging assessments and the pathologic assessments will require iterative refinement. © 2015 Elsevier B.V. All rights reserved.

Characteristic signal changes in the pontine base on T2- and multishot diffusion-weighted images in spinocerebellar ataxia type 1

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Adachi, M.; Kawanami, T.; Ohshima, H.; Hosoya, T.

2006-01-01

The aim of the present study was to demonstrate characteristic signal changes of the pontine base on T2-weighted images of patients with SCA 1, and to elucidate the relationship between abnormal high-intensities of the pontine base on T2-weighted images and the findings on multishot diffusion-weighted images. We assessed abnormal signals of the pontine base on T2-weighted images from 50 controls and six patients with SCA 1 diagnosed by genetic analysis. At the same time, we evaluated the degeneration of the transverse pontine fibers in the pontine base by multishot diffusion-weighted imaging. A midline high-intensity was seen in the pontine base on T2-weighted images in two of the 50 controls and five of the six patients with SCA 1. The midline high-intensity had a sensitivity of 83.3% for patients and a specificity of 96.0% for controls. Multishot diffusion-weighted imaging demonstrated the degeneration - the amorphous-pattern signal - of the transverse pontine fibers in four (66.7%) of the six patients. In the other two patients, the zebra-pattern signal was seen in the pontine base. The midline high-intensity on T2-weighted images appears to be one of characteristic MRI findings of SCA 1. Multishot diffusion-weighted imaging suggested that the midline high-intensity should reflect the degeneration of the transverse pontine fibers. (orig.)

Diffusion tensor MR imaging in neurofibromatosis type 1: expanding the knowledge of microstructural brain abnormalities

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Ferraz-Filho, Jose R.L.; Muniz, Marcos P.; Souza, Antonio S.; Rocha, Antonio J. da; Goloni-Bertollo, Eny M.; Pavarino-Bertelli, Erika C.

2012-01-01

Neurofibromatosis type 1 (NF1) is a hereditary disease with a dominant autosomal pattern. In children and adolescents, it is frequently associated with the appearance of T2-weighted hyperintensities in the brain's white matter. MRI with diffusion tensor imaging (DTI) is used to detect white matter abnormalities by measuring fractional anisotropy (FA). This study employed DTI to evaluate the relationship between FA patterns and the findings of T2 sequences, with the aim of improving our understanding of anatomical changes and microstructural brain abnormalities in individuals with NF1. Forty-four individuals with NF1 and 20 control subjects were evaluated. The comparative analysis of FA between NF1 and control groups was based on four predetermined anatomical regions of the brain hemispheres (basal ganglia, cerebellum, pons, thalamus) and related the presence or absence of T2-weighted hyperintensities in the brain, which are called unidentified bright objects (UBOs). The FA values between the groups demonstrated statistically significant differences (P ≤ 0.05) for the cerebellum and thalamus in patients with NF1, independent of the occurrence of UBOs. Diffusion tensor MR imaging confirms the influence of UBOs in the decrease of FA values in this series of patients with NF1. Additionally, this technique allows the characterization of microstructural abnormalities even in some brain regions that appear normal in conventional MR sequences. (orig.)

Separation of type and grade in cervical tumours using non-mono-exponential models of diffusion-weighted MRI

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Winfield, Jessica M.; Collins, David J.; Morgan, Veronica A.; DeSouza, Nandita M.; Orton, Matthew R.; Ind, Thomas E.J.; Attygalle, Ayoma; Hazell, Steve

2017-01-01

Assessment of empirical diffusion-weighted MRI (DW-MRI) models in cervical tumours to investigate whether fitted parameters distinguish between types and grades of tumours. Forty-two patients (24 squamous cell carcinomas, 14 well/moderately differentiated, 10 poorly differentiated; 15 adenocarcinomas, 13 well/moderately differentiated, two poorly differentiated; three rare types) were imaged at 3 T using nine b-values (0 to 800 s mm -2 ). Mono-exponential, stretched exponential, kurtosis, statistical, and bi-exponential models were fitted. Model preference was assessed using Bayesian Information Criterion analysis. Differences in fitted parameters between tumour types/grades and correlation between fitted parameters were assessed using two-way analysis of variance and Pearson's linear correlation coefficient, respectively. Non-mono-exponential models were preferred by 83 % of tumours with bi-exponential and stretched exponential models preferred by the largest numbers of tumours. Apparent diffusion coefficient (ADC) and diffusion coefficients from non-mono-exponential models were significantly lower in poorly differentiated tumours than well/moderately differentiated tumours. α (stretched exponential), K (kurtosis), f and D* (bi-exponential) were significantly different between tumour types. Strong correlation was observed between ADC and diffusion coefficients from other models. Non-mono-exponential models were preferred to the mono-exponential model in DW-MRI data from cervical tumours. Parameters of non-mono-exponential models showed significant differences between types and grades of tumours. (orig.)

Separation of type and grade in cervical tumours using non-mono-exponential models of diffusion-weighted MRI

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Winfield, Jessica M.; Collins, David J.; Morgan, Veronica A.; DeSouza, Nandita M. [The Royal Marsden NHS Foundation Trust, MRI Unit, Sutton, Surrey (United Kingdom); The Institute of Cancer Research, Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy and Imaging, London (United Kingdom); Orton, Matthew R. [The Institute of Cancer Research, Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy and Imaging, London (United Kingdom); Ind, Thomas E.J. [The Royal Marsden NHS Foundation Trust, Gynaecology Unit, London (United Kingdom); Attygalle, Ayoma; Hazell, Steve [The Royal Marsden NHS Foundation Trust, Department of Histopathology, London (United Kingdom)

2017-02-15

Assessment of empirical diffusion-weighted MRI (DW-MRI) models in cervical tumours to investigate whether fitted parameters distinguish between types and grades of tumours. Forty-two patients (24 squamous cell carcinomas, 14 well/moderately differentiated, 10 poorly differentiated; 15 adenocarcinomas, 13 well/moderately differentiated, two poorly differentiated; three rare types) were imaged at 3 T using nine b-values (0 to 800 s mm{sup -2}). Mono-exponential, stretched exponential, kurtosis, statistical, and bi-exponential models were fitted. Model preference was assessed using Bayesian Information Criterion analysis. Differences in fitted parameters between tumour types/grades and correlation between fitted parameters were assessed using two-way analysis of variance and Pearson's linear correlation coefficient, respectively. Non-mono-exponential models were preferred by 83 % of tumours with bi-exponential and stretched exponential models preferred by the largest numbers of tumours. Apparent diffusion coefficient (ADC) and diffusion coefficients from non-mono-exponential models were significantly lower in poorly differentiated tumours than well/moderately differentiated tumours. α (stretched exponential), K (kurtosis), f and D* (bi-exponential) were significantly different between tumour types. Strong correlation was observed between ADC and diffusion coefficients from other models. Non-mono-exponential models were preferred to the mono-exponential model in DW-MRI data from cervical tumours. Parameters of non-mono-exponential models showed significant differences between types and grades of tumours. (orig.)

Diffusion, confusion and functional MRI

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Le Bihan, Denis

2012-01-01

Diffusion MRI has been introduced in 1985 and has had a very successful life on its own. While it has become a standard for imaging stroke and white matter disorders, the borders between diffusion MRI and the general field of fMRI have always remained fuzzy. First, diffusion MRI has been used to obtain images of brain function, based on the idea that diffusion MRI could also be made sensitive to blood flow, through the intra-voxel incoherent motion (IVIM) concept. Second, the IVIM concept helped better understand the contribution from different vasculature components to the BOLD fMRI signal. Third, it has been shown recently that a genuine fMRI signal can be obtained with diffusion MRI. This 'DfMRI' signal is notably different from the BOLD fMRI signal, especially for its much faster response to brain activation both at onset and offset, which points out to structural changes in the neural tissues, perhaps such as cell swelling, occurring in activated neural tissue. This short article reviews the major steps which have paved the way for this exciting development, underlying how technical progress with MRI equipment has each time been instrumental to expand the horizon of diffusion MRI toward the field of fMRI. (authors)

Correlation of diffusion-weighted MRI and gross anatomy of rat kidneys

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Chen Rongfeng; Wu Xiaomei; Chen Xiaoyan; Deng Yu; Li Xinchun; He Jianxun; Li Huiming

2011-01-01

Objective: To investigate the feasibility and accuracy of diffusion-weighted MRI in differentiating the cortico-medullary layers of rat kidneys. Methods: Twelve rats underwent MRI using a 1.5 Tesla system including DWI of various b-values, T1WI and T 2 WI sequences. The MR characteristics and thickness of renal cortico-medullary layers compared to those of the gross anatomical layers. Results: On the longitudinal anatomical sections of the kidneys, four parenchymal layers of cortex (CO), the outer (OS) and inner (IS) stripes of the outer medulla (OM), the inner medulla (IM) and renal pelvis could be clearly recognized. The numbers of layers visible on MRI varied with different pulse sequences. Single layers of cortex and medulla were visible on T 1 WI. CO, OM and IM were delineated on T 2 WI. CO, OS, IS and IM were clearly identified on DWI and ADC maps. DWI was significantly superior to T 1 WI and T 2 WI for displaying the renal parenchymal layers (P 0.05) from the measurements on DWI (CO: 1.39±0.15 mm, OS: 1.01±0.17 mm, IS: 1.11±0.19 mm, IM: 1.06±0.10 mm). Different b-values of DWI did not show significant difference in depiction of the parenchyma (P>0.05). Conclusion: Four parenchymal layers shown on DWI correlated well with gross anatomical structure and may be used in imaging study of rat kidneys. (authors)

Incremental value of diffusion weighted and dynamic contrast enhanced MRI in the detection of locally recurrent prostate cancer after radiation treatment: preliminary results

International Nuclear Information System (INIS)

Akin, Oguz; Vargas, Hebert Alberto; Hricak, Hedvig; Gultekin, David H.; Zheng, Junting; Moskowitz, Chaya; Pei, Xin; Sperling, Dahlia; Zelefsky, Michael J.; Schwartz, Lawrence H.

2011-01-01

To assess the incremental value of diffusion-weighted (DW-MRI) and dynamic contrast-enhanced MRI (DCE-MRI) to T2-weighted MRI (T2WI) in detecting locally recurrent prostate cancer after radiotherapy. Twenty-four patients (median age, 70 years) with a history of radiotherapy-treated prostate cancer underwent multi-parametric MRI (MP-MRI) and transrectal prostate biopsy. Two readers independently scored the likelihood of cancer on a 1-5 scale, using T2WI alone and then adding DW-MRI and DCE-MRI. Areas under receiver operating characteristic curves (AUCs) were estimated at the patient and prostate-side levels. The apparent diffusion coefficient (ADC) from DW-MRI and the K trans , k ep , v e , AUGC90 and AUGC180 from DCE-MRI were recorded. Biopsy was positive in 16/24 (67%) and negative in 8/24 (33%) patients. AUCs for readers 1 and 2 increased from 0.64 and 0.53 to 0.95 and 0.86 with MP-MRI, at the patient level, and from 0.73 and 0.66 to 0.90 and 0.79 with MP-MRI, at the prostate-side level (p values -3 mm 2 /s)], median K trans [1.07 vs. 0.34 (1/min)], and k ep [2.06 vs 1.0 (1/min)] (p values < 0.05). MP-MRI was significantly more accurate than T2WI alone in detecting locally recurrent prostate cancer after radiotherapy. (orig.)

Persistent lesion hyperintensity on brain diffusion-weighted MRI is an early sign of intravascular lymphoma.

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Kageyama, Takashi; Yamanaka, Haruo; Nakamura, Fumihiko; Suenaga, Toshihiko

2017-06-08

A 63-year-old man presented with right-sided hemianopia and unsteady gait. Brain MRI revealed multiple hyperintense infarct-like lesions on diffusion-weighted images (DWI). Hyperintensity persisted in some of these lesions even after 6 weeks, although his symptoms were ameliorated then. The patient developed episodic dizziness and a transient event of apraxia at 18 weeks after the first episode. Brain MRI revealed additional hyperintense lesions on DWI, which persisted even after 7 weeks. Eventually, the patient manifested cauda equina syndrome 39 weeks after the first episode. Brain MRI showed the presence of new lesions in addition to the persistent hyperintense lesions on DWI over 21 weeks in the right frontal lobe. Based on laboratory findings and the pathological assessment of bone marrow and random skin biopsies, the patient was diagnosed with intravascular lymphoma (IVL). Persistent hyperintense lesions on DWI of brain MRI may precede the clinical exacerbation of IVL. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

D-BRAIN : Anatomically accurate simulated diffusion MRI brain data

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Perrone, Daniele; Jeurissen, Ben; Aelterman, Jan; Roine, Timo; Sijbers, Jan; Pizurica, Aleksandra; Leemans, Alexander; Philips, Wilfried

2016-01-01

Diffusion Weighted (DW) MRI allows for the non-invasive study of water diffusion inside living tissues. As such, it is useful for the investigation of human brain white matter (WM) connectivity in vivo through fiber tractography (FT) algorithms. Many DW-MRI tailored restoration techniques and FT algorithms have been developed. However, it is not clear how accurately these methods reproduce the WM bundle characteristics in real-world conditions, such as in the presence of noise, partial volume...

TU-F-CAMPUS-J-02: Evaluation of Textural Feature Extraction for Radiotherapy Response Assessment of Early Stage Breast Cancer Patients Using Diffusion Weighted MRI and Dynamic Contrast Enhanced MRI

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Xie, Y; Wang, C; Horton, J; Chang, Z [Duke University Medical Center, Durham, NC (United States)

2015-06-15

Purpose: To investigate the feasibility of using classic textural feature extraction in radiotherapy response assessment, we studied a unique cohort of early stage breast cancer patients with paired pre - and post-radiation Diffusion Weighted MRI (DWI-MRI) and Dynamic Contrast Enhanced MRI (DCE-MRI). Methods: 15 female patients from our prospective phase I trial evaluating preoperative radiotherapy were included in this retrospective study. Each patient received a single-fraction radiation treatment, and DWI and DCE scans were conducted before and after the radiotherapy. DWI scans were acquired using a spin-echo EPI sequence with diffusion weighting factors of b = 0 and b = 500 mm{sup 2} /s, and the apparent diffusion coefficient (ADC) maps were calculated. DCE-MRI scans were acquired using a T{sub 1}-weighted 3D SPGR sequence with a temporal resolution of about 1 minute. The contrast agent (CA) was intravenously injected with a 0.1 mmol/kg bodyweight dose at 2 ml/s. Two parameters, volume transfer constant (K{sup trans} ) and k{sub ep} were analyzed using the two-compartment Tofts kinetic model. For DCE parametric maps and ADC maps, 33 textural features were generated from the clinical target volume (CTV) in a 3D fashion using the classic gray level co-occurrence matrix (GLCOM) and gray level run length matrix (GLRLM). Wilcoxon signed-rank test was used to determine the significance of each texture feature’s change after the radiotherapy. The significance was set to 0.05 with Bonferroni correction. Results: For ADC maps calculated from DWI-MRI, 24 out of 33 CTV features changed significantly after the radiotherapy. For DCE-MRI pharmacokinetic parameters, all 33 CTV features of K{sup trans} and 33 features of k{sub ep} changed significantly. Conclusion: Initial results indicate that those significantly changed classic texture features are sensitive to radiation-induced changes and can be used for assessment of radiotherapy response in breast cancer.

A neurotological study of patients with pontine hyperintense lesions on T2 weighted MRI

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Seo, Toru; Tominaga, Satoru; Yukimasa, Akiko; Oku, Masaya; Sakagami, Masafumi [Hyogo Coll. of Medicine, Nishinomiya (Japan)

2002-03-01

Pontine hyperintense lesions seen on T2-weighted MRI were thought to be related to disequilibrium. Some of these lesions have a low signal on T1-weighted imaging, while others have an iso-signal. The purpose of this study was to clarify the relationship between neurological findings and pontine lesions detected by MRI. The subjects were 11 patients (6 males, 5 females; age range: 30 to 83 years [mean: 64.1 years]) with pontine hyperintense lesions identified on T2-weighted MRI. We compared the clinical signs and the MRI findings. Six of the patients had low-intensity areas on T1-weighted images, and the other 5 had iso-intensity areas. Six patients complained of vertigo, and 5 complained of dizziness. Eight complained of positionaly evoked disequilibrium. Positional nystagmus was seen in 4 patients. In 9 patients, abnormalities were found on the ENG test, including the saccadic eye movement test, ETT, and OKP. Numbness on the lips occurred in 2 patients, and cerebellar signs were present in 4. None of the patients had facial paralysis. Disequilibrium originating in the central nervous system was suggested in 10 patients. Clinical examinations revealed similar findings in patients with a low signal on T1-weighted MRI and those with an iso-signal. Our results indicate that pontine lesions identified by T2-weighted MRI cause vertigo or dizziness, and, in most cases, these lesions cause abnormal neurological or neurological abnormalities. (author)

A neurotological study of patients with pontine hyperintense lesions on T2 weighted MRI

International Nuclear Information System (INIS)

Seo, Toru; Tominaga, Satoru; Yukimasa, Akiko; Oku, Masaya; Sakagami, Masafumi

2002-01-01

Pontine hyperintense lesions seen on T2-weighted MRI were thought to be related to disequilibrium. Some of these lesions have a low signal on T1-weighted imaging, while others have an iso-signal. The purpose of this study was to clarify the relationship between neurological findings and pontine lesions detected by MRI. The subjects were 11 patients (6 males, 5 females; age range: 30 to 83 years [mean: 64.1 years]) with pontine hyperintense lesions identified on T2-weighted MRI. We compared the clinical signs and the MRI findings. Six of the patients had low-intensity areas on T1-weighted images, and the other 5 had iso-intensity areas. Six patients complained of vertigo, and 5 complained of dizziness. Eight complained of positionaly evoked disequilibrium. Positional nystagmus was seen in 4 patients. In 9 patients, abnormalities were found on the ENG test, including the saccadic eye movement test, ETT, and OKP. Numbness on the lips occurred in 2 patients, and cerebellar signs were present in 4. None of the patients had facial paralysis. Disequilibrium originating in the central nervous system was suggested in 10 patients. Clinical examinations revealed similar findings in patients with a low signal on T1-weighted MRI and those with an iso-signal. Our results indicate that pontine lesions identified by T2-weighted MRI cause vertigo or dizziness, and, in most cases, these lesions cause abnormal neurological or neurological abnormalities. (author)

Abnormal findings of magnetic resonance imaging (MRI) in patients with systemic lupus erythematosus involving the brain

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Ishikawa, Akira; Okada, Jun; Kondo, Hirobumi (Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine); Kashiwazaki, Sadao

1992-06-01

To elucidate the clinical significance of MRI on central nervous system systemic lupus erythematosus (CNS-SLE), MRI and CT scans were performed in 35 patients with SLE, of 18 patients who had CNS manifestations at the time of MRI examinations. The investigations were also carried out in 17 patients without CNS-SLE. The rate of detection of abnormal findings on MRI in patients with CNS-SLE was 77.2% (14/18), which was high, as compared with the rate of those on CT scans (50%: 9/18). Especially, all of 4 patients with seizure and 3 patients with encephalopathy showed abnormal MRI findings, although respectively 50% and 33.3% of them had abnormal CT scan findings. MRI findings were classified into 4 groups below: (1) Large focal are as increased signal intensity at T2 weighted image. These were observed in 2 of 4 patients with seizure and 1 of 3 patients with encephalopathy, which were completely resolved after treatment. (2) Patchy subcortical foci of increased signal intensity at T2 weighted image. These were observed in 11 of 18 CNS-SLE and 7 of 17 without CNS-SLE, which were not detected by CT scan. (3) All of six patients with cerebral infarctions showed high signal intensity areas at T2 weighted image and low signal intensity areas at T1 weighted image. (4) Normal findings were observed in 4 of 18 CNS-SLE (22.2%). We concluded that MRI is useful for the evaluation of CNS-SLE and provides more information than CT scan. (author).

Abnormal findings of magnetic resonance imaging (MRI) in patients with systemic lupus erythematosus involving the brain

International Nuclear Information System (INIS)

Ishikawa, Akira; Okada, Jun; Kondo, Hirobumi; Kashiwazaki, Sadao.

1992-01-01

To elucidate the clinical significance of MRI on central nervous system systemic lupus erythematosus (CNS-SLE), MRI and CT scans were performed in 35 patients with SLE, of 18 patients who had CNS manifestations at the time of MRI examinations. The investigations were also carried out in 17 patients without CNS-SLE. The rate of detection of abnormal findings on MRI in patients with CNS-SLE was 77.2% (14/18), which was high, as compared with the rate of those on CT scans (50%: 9/18). Especially, all of 4 patients with seizure and 3 patients with encephalopathy showed abnormal MRI findings, although respectively 50% and 33.3% of them had abnormal CT scan findings. MRI findings were classified into 4 groups below: 1) Large focal are as increased signal intensity at T2 weighted image. These were observed in 2 of 4 patients with seizure and 1 of 3 patients with encephalopathy, which were completely resolved after treatment. 2) Patchy subcortical foci of increased signal intensity at T2 weighted image. These were observed in 11 of 18 CNS-SLE and 7 of 17 without CNS-SLE, which were not detected by CT scan. 3) All of six patients with cerebral infarctions showed high signal intensity areas at T2 weighted image and low signal intensity areas at T1 weighted image. 4) Normal findings were observed in 4 of 18 CNS-SLE (22.2%). We concluded that MRI is useful for the evaluation of CNS-SLE and provides more information than CT scan. (author)

Diffusion abnormality maps in demyelinating disease: Correlations with clinical scores

International Nuclear Information System (INIS)

Onu, Mihaela; Roceanu, Adina; Sboto-Frankenstein, Uta; Bendic, Robert; Tarta, Eugen; Preoteasa, Florentin; Bajenaru, Ovidiu

2012-01-01

Background and purpose: Magnetic resonance imaging (MRI) has been explored as a noninvasive tool to assess pathology in multiple sclerosis (MS) patients. However, the correlation between classical MRI measures and physical disability is modest in MS. The diffusion tensor imaging (DTI) MRI technique holds particular promise in this regard. The present study shows brain regions where FA and individual diffusivities abnormalities are present and check their correlations with physical disability clinical scores. Methods: Eight patients and 12 matched healthy controls were recruited. The Multiple Sclerosis Functional Composite was administered. For MR-DTI acquisitions, a Genesis Signa 1.5T MR system, an EP/SE scanning sequence, 25 gradient directions were used. Results: Tract Based Spatial Statistics (TBSS) group comparisons showed reduced FA and increased individual diffusivities in several brain regions in patients. Significant correlations were found between FA and: EDSS, 9-HPT(NON)DOM and 25FW score; between λ 2 and: P100 (r and l), 9-HPT(NON)DOM and 25FW; between λ 3 and: 9-HPT(NON)DOM and 25FW score. Conclusions: Fractional anisotropy and individual radial diffusivities proved to be important markers of motor disabilities in MS patients when the disease duration mean and the disability scores values range are relatively high.

Telomere length and advanced diffusion MRI as biomarkers for repetitive mild traumatic brain injury in adolescent rats

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David K. Wright

Full Text Available Mild traumatic brain injuries (mTBI are of worldwide concern in adolescents of both sexes, and repeated mTBI (RmTBI may have serious long-term neurological consequences. As such, the study of RmTBI and discovery of objective biomarkers that can help guide medical decisions is an important undertaking. Diffusion-weighted MRI (DWI, which provides markers of axonal injury, and telomere length (TL are two clinically relevant biomarkers that have been implicated in a number of neurological conditions, and may also be affected by RmTBI. Therefore, this study utilized the lateral impact injury model of RmTBI to investigate changes in diffusion MRI and TL, and how these changes relate to each other. Adolescent male and female rats received either three mTBIs or three sham injuries. The first injury was given on postnatal day 30 (P30, with the repeated injuries separated by four days each. Seven days after the final injury, a sample of ear tissue was collected for TL analysis. Rats were then euthanized and whole brains were collected and fixated for MRI analyses that included diffusion and high-resolution structural sequences. Compared to the sham-injured group, RmTBI rats had significantly shorter TL at seven days post-injury. Analysis of advanced DWI measures found that RmTBI rats had abnormalities in the corpus callosum and cortex at seven days post-injury. Notably, many of the DWI changes were correlated with TL. These findings demonstrate that TL and DWI measurements are changed by RmTBI and may represent clinically applicable biomarkers for this. Keywords: Biomarker, Concussion, Track weighted imaging, Animal model, Diffusion tensor imaging, MRI

The usefulness of MRI for the diagnosis of abnormal pregnancies

International Nuclear Information System (INIS)

Amano, Yasuo

1994-01-01

The clinical usefulness of MRI for the diagnosis of abnormal pregnancies was evaluated. Pelvic MRI was carried out on 29 cases suspected of abnormal pregnancy by ultrasonography and clinical examinations. The abnormal pregnancies were classified into three categories: (1) maternal abnormalities, (2) fetal abnormalities and (3) placental abnormalities. MRI was of great value for the diagnosis of maternal abnormalities, particularly in cases of coexistent pelvic tumor. MRI allowed diagnosis of uterine leiomyomas and dermoid cyst through its excellent tissue characterization and broad range of vision. MRI was useful in making diagnoses of fetal central nervous anomalies and fetal death, since the lack of fetal movement and the lesions were clear enough to be detected by MRI. However, anomalies in the fetal trunk or extremities could only be demonstrated, but not diagnosed, by MRI owing to its inferior spatial and time resolution. MRI showed placenta accreta and placental hematoma. Although accurate diagnosis was difficult because of their rarity, MRI revealed the hemorrhagic component of the lesions, which was not shown by ultrasonography. The author believes MRI has potential usefulness in making diagnoses of placental abnormalities through its tissue characterization. MRI was superior to ultrasonography in the soft tissue characterization, field of view, while MRI was inferior in time and spatial resolution. In summary, MRI hould be used in case of abnormal pregnancies such as pelvic tumors, fetal nervous anomalies and placental hemorrhagic lesions. MRI will become useful for the diagnosis of other abnormalities as its spatial resolution and fast scan technology advances. (author)

The usefulness of MRI for the diagnosis of abnormal pregnancies

Energy Technology Data Exchange (ETDEWEB)

Amano, Yasuo (Nippon Medical School, Tokyo (Japan))

1994-02-01

The clinical usefulness of MRI for the diagnosis of abnormal pregnancies was evaluated. Pelvic MRI was carried out on 29 cases suspected of abnormal pregnancy by ultrasonography and clinical examinations. The abnormal pregnancies were classified into three categories: (1) maternal abnormalities, (2) fetal abnormalities and (3) placental abnormalities. MRI was of great value for the diagnosis of maternal abnormalities, particularly in cases of coexistent pelvic tumor. MRI allowed diagnosis of uterine leiomyomas and dermoid cyst through its excellent tissue characterization and broad range of vision. MRI was useful in making diagnoses of fetal central nervous anomalies and fetal death, since the lack of fetal movement and the lesions were clear enough to be detected by MRI. However, anomalies in the fetal trunk or extremities could only be demonstrated, but not diagnosed, by MRI owing to its inferior spatial and time resolution. MRI showed placenta accreta and placental hematoma. Although accurate diagnosis was difficult because of their rarity, MRI revealed the hemorrhagic component of the lesions, which was not shown by ultrasonography. The author believes MRI has potential usefulness in making diagnoses of placental abnormalities through its tissue characterization. MRI was superior to ultrasonography in the soft tissue characterization, field of view, while MRI was inferior in time and spatial resolution. In summary, MRI hould be used in case of abnormal pregnancies such as pelvic tumors, fetal nervous anomalies and placental hemorrhagic lesions. MRI will become useful for the diagnosis of other abnormalities as its spatial resolution and fast scan technology advances. (author).

Differentiation between benign and malignant breast lesions using quantitative diffusion-weighted sequence on 3 T MRI

International Nuclear Information System (INIS)

Tan, S.L.L.; Rahmat, K.; Rozalli, F.I.; Mohd-Shah, M.N.; Aziz, Y.F.A.; Yip, C.H.; Vijayananthan, A.; Ng, K.H.

2014-01-01

Aim: To investigate the capability and diagnostic accuracy of diffusion-weighted imaging (DWI) in differentiating benign from malignant breast lesions using 3 T magnetic resonance imaging (MRI). Materials and methods: Women with suspicious or indeterminate breast lesions detected at MRI, mammogram and/or ultrasound were recruited for dynamic contrast-enhanced (DCE)-MRI and DWI prior to their biopsy. Image fusion of DCE-MRI with apparent diffusion coefficient (ADC) map was utilized to select the region of interest (ROI) for ADC calculation in the area that showed the most avid enhancement. DWI was performed using two sets of b-values at 500 and 1000 s/mm 2 , respectively. Results: Fifty women were recruited and the final analysis comprised 44 breast lesions, 31 of which were malignant and 13 were benign. Significant results were obtained between ADC values of benign and malignant lesions (p −3 mm 2 /s for b = 500 s/mm 2 and 1.22 × 10 −3 mm 2 /s for b = 1000 s/mm 2 , respectively. The sensitivity of DCE-MRI alone was 100% with a specificity of 66.7%. When DCE-MRI was combined with b = 1000 s/mm 2 , the specificity rose to 100%, while only mildly affecting sensitivity (90.6%). No significant correlation was found between ADC values and prognostic factors, such as lymph node metastasis, tumour size, oestrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status, and tumour grades. Conclusion: The present study provides consistent evidence to support DWI as a diagnostic tool for breast lesion characterization. A combination of DCE-MRI with DWI is suggested to improve the sensitivity and specificity of lesion characterization

Diffusion-weighted MRI characteristics of the cerebral metastasis to brain boundary predicts patient outcomes

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Zakaria, Rasheed; Das, Kumar; Radon, Mark; Bhojak, Maneesh; Rudland, Philip R; Sluming, Vanessa; Jenkinson, Michael D

2014-01-01

Diffusion-weighted MRI (DWI) has been used in neurosurgical practice mainly to distinguish cerebral metastases from abscess and glioma. There is evidence from other solid organ cancers and metastases that DWI may be used as a biomarker of prognosis and treatment response. We therefore investigated DWI characteristics of cerebral metastases and their peritumoral region recorded pre-operatively and related these to patient outcomes. Retrospective analysis of 76 cases operated upon at a single institution with DWI performed pre-operatively at 1.5T. Maps of apparent diffusion coefficient (ADC) were generated using standard protocols. Readings were taken from the tumor, peritumoral region and across the brain-tumor interface. Patient outcomes were overall survival and time to local recurrence. A minimum ADC greater than 919.4 × 10 -6 mm 2 /s within a metastasis predicted longer overall survival regardless of adjuvant therapies. This was not simply due to differences between the types of primary cancer because the effect was observed even in a subgroup of 36 patients with the same primary, non-small cell lung cancer. The change in diffusion across the tumor border and into peritumoral brain was measured by the “ADC transition coefficient” or ATC and this was more strongly predictive than ADC readings alone. Metastases with a sharp change in diffusion across their border (ATC >0.279) showed shorter overall survival compared to those with a more diffuse edge. The ATC was the only imaging measurement which independently predicted overall survival in multivariate analysis (hazard ratio 0.54, 95% CI 0.3 – 0.97, p = 0.04). DWI demonstrates changes in the tumor, across the tumor edge and in the peritumoral region which may not be visible on conventional MRI and this may be useful in predicting patient outcomes for operated cerebral metastases

Study on diffusion anisotropy of cerebral ischemia using diffusion weighted echo-planar MRI

International Nuclear Information System (INIS)

Kajima, Toshio

1997-01-01

Focal cerebral ischemia was produced by occlusion of the intracranial main cerebral artery with a silicone cylinder in Wistar rats. Diffusion-weighted echo-planar images (DW-EPls) using the motion-probing gradient (MPG) method were acquired at 1-3 hours and 24-48 hours after occlusion. Apparent diffusion coefficients (ADCs) were calculated from these images in ischemic lesions and in normal unoccluded regions. Results were as follows. Ischemic lesions could be detected on the DW-EPIs at 1 hour after occlusion. The ADC of water in the brain tissue was smaller than that of free water as a result of restricted diffusion. Anisotropic diffusion that probably can be attributed to the myelin sheath was observed in the normal white matter. In the ischemic lesions, the ADC decreased rapidly within 1-3 hours after occlusion and then decreased gradually after 24-48 hours. In the ischemic white matter, diffusion anisotropy disappeared at 24-48 hours after occlusion. Diffusion-weighted imaging may have applications in the examination of pathophysiological mechanisms in cerebral ischemia by means of evaluation of ADC and diffusion anisotropy. (author)

The importance of correcting for signal drift in diffusion MRI

OpenAIRE

Vos, Sjoerd B; Tax, Chantal M W; Luijten, Peter R; Ourselin, Sebastien; Leemans, Alexander; Froeling, Martijn

2017-01-01

PURPOSE: To investigate previously unreported effects of signal drift as a result of temporal scanner instability on diffusion MRI data analysis and to propose a method to correct this signal drift. METHODS: We investigated the signal magnitude of non-diffusion-weighted EPI volumes in a series of diffusion-weighted imaging experiments to determine whether signal magnitude changes over time. Different scan protocols and scanners from multiple vendors were used to verify this on phantom data, a...

Sequential cranial ultrasound and cerebellar diffusion weighted imaging contribute to the early prognosis of neurodevelopmental outcome in preterm infants.

Directory of Open Access Journals (Sweden)

Margaretha J Brouwer

Full Text Available OBJECTIVE: To evaluate the contribution of sequential cranial ultrasound (cUS and term-equivalent age magnetic resonance imaging (TEA-MRI including diffusion weighted imaging (DWI to the early prognosis of neurodevelopmental outcome in a cohort of very preterm infants (gestational age [GA] <31 weeks. STUDY DESIGN: In total, 93 preterm infants (median [range] GA in weeks: 28.3 [25.0-30.9] were enrolled in this prospective cohort study and underwent early and term cUS as well as TEA-MRI including DWI. Early cUS abnormalities were classified as normal, mild, moderate or severe. Term cUS was evaluated for ex-vacuo ventriculomegaly (VM and enlargement of the extracerebral cerebrospinal fluid (eCSF space. Abnormalities on T1- and T2-weighted TEA-MRI were scored according to Kidokoro et al. Using DWI at TEA, apparent diffusion coefficients (ADCs were measured in four white matter regions bilaterally and both cerebellar hemispheres. Neurodevelopmental outcome was assessed at two years' corrected age (CA using the Bayley Scales of Infant and Toddler Development, third edition. Linear regression analysis was conducted to explore the correlation between the different neuroimaging modalities and outcome. RESULTS: Moderate/severe abnormalities on early cUS, ex-vacuo VM and enlargement of the eCSF space on term cUS and increased cerebellar ADC values on term DWI were independently associated with worse motor outcome (p<.05. Ex-vacuo VM on term cUS was also related to worse cognitive performance at two years' CA (p<.01. CONCLUSION: These data support the clinical value of sequential cUS and recommend repeating cUS at TEA. In particular, assessment of moderate/severe early cUS abnormalities and ex-vacuo VM on term cUS provides important prognostic information. Cerebellar ADC values may further aid in the prognostication of gross motor function.

Focal status epilepticus: follow-up by perfusion- and diffusion MRI

International Nuclear Information System (INIS)

El-Koussy, M.; Loevblad, K.O.; Kiefer, C.; Schroth, G.; Mathis, J.; Stepper, F.

2002-01-01

Diffusion-weighted MRI demonstrated bright right temporoparietal cortex, right hippocampus, and left cerebellum in a 63-year-old female suffering a focal convulsive status epilepticus. Hyperperfusion was noted in the right temporoparietal region. Two days later, a tendency to normalization of most of the diffusion and perfusion changes was noted, apart from the right hippocampus which became brighter on diffusion- and T2-weighted images. On the tenth day the apparent diffusion coefficient was slightly elevated, getting brighter on T2-weighted images with suspected mild post-contrast enhancement. We postulate that the discharging right hippocampus suffered cytotoxic edema, which later progressed to cell damage. (orig.)

Focal status epilepticus: follow-up by perfusion- and diffusion MRI

Energy Technology Data Exchange (ETDEWEB)

El-Koussy, M; Loevblad, K O; Kiefer, C; Schroth, G [Department of Neuroradiology, University of Bern, Inselspital (Switzerland); Mathis, J; Stepper, F [Department of Neurology, University of Bern, Inselspital (Switzerland)

2002-03-01

Diffusion-weighted MRI demonstrated bright right temporoparietal cortex, right hippocampus, and left cerebellum in a 63-year-old female suffering a focal convulsive status epilepticus. Hyperperfusion was noted in the right temporoparietal region. Two days later, a tendency to normalization of most of the diffusion and perfusion changes was noted, apart from the right hippocampus which became brighter on diffusion- and T2-weighted images. On the tenth day the apparent diffusion coefficient was slightly elevated, getting brighter on T2-weighted images with suspected mild post-contrast enhancement. We postulate that the discharging right hippocampus suffered cytotoxic edema, which later progressed to cell damage. (orig.)

Support vector machine for breast cancer classification using diffusion-weighted MRI histogram features: Preliminary study.

Science.gov (United States)

Vidić, Igor; Egnell, Liv; Jerome, Neil P; Teruel, Jose R; Sjøbakk, Torill E; Østlie, Agnes; Fjøsne, Hans E; Bathen, Tone F; Goa, Pål Erik

2018-05-01

Diffusion-weighted MRI (DWI) is currently one of the fastest developing MRI-based techniques in oncology. Histogram properties from model fitting of DWI are useful features for differentiation of lesions, and classification can potentially be improved by machine learning. To evaluate classification of malignant and benign tumors and breast cancer subtypes using support vector machine (SVM). Prospective. Fifty-one patients with benign (n = 23) and malignant (n = 28) breast tumors (26 ER+, whereof six were HER2+). Patients were imaged with DW-MRI (3T) using twice refocused spin-echo echo-planar imaging with echo time / repetition time (TR/TE) = 9000/86 msec, 90 × 90 matrix size, 2 × 2 mm in-plane resolution, 2.5 mm slice thickness, and 13 b-values. Apparent diffusion coefficient (ADC), relative enhanced diffusivity (RED), and the intravoxel incoherent motion (IVIM) parameters diffusivity (D), pseudo-diffusivity (D*), and perfusion fraction (f) were calculated. The histogram properties (median, mean, standard deviation, skewness, kurtosis) were used as features in SVM (10-fold cross-validation) for differentiation of lesions and subtyping. Accuracies of the SVM classifications were calculated to find the combination of features with highest prediction accuracy. Mann-Whitney tests were performed for univariate comparisons. For benign versus malignant tumors, univariate analysis found 11 histogram properties to be significant differentiators. Using SVM, the highest accuracy (0.96) was achieved from a single feature (mean of RED), or from three feature combinations of IVIM or ADC. Combining features from all models gave perfect classification. No single feature predicted HER2 status of ER + tumors (univariate or SVM), although high accuracy (0.90) was achieved with SVM combining several features. Importantly, these features had to include higher-order statistics (kurtosis and skewness), indicating the importance to account for heterogeneity. Our

MRI characterization of brown adipose tissue in obese and normal-weight children

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Deng, Jie; Rigsby, Cynthia K.; Shore, Richard M. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, 225 E. Chicago Ave., Box 9, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Schoeneman, Samantha E. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, 225 E. Chicago Ave., Box 9, Chicago, IL (United States); Zhang, Huiyuan [John H. Stroger, Jr. Hospital of Cook County, Collaborative Research Unit, Chicago, IL (United States); Kwon, Soyang [Ann and Robert H. Lurie Children' s Hospital of Chicago, Stanley Manne Children' s Research Institute, Chicago, IL (United States); Northwestern University, Department of Pediatrics, Feinberg School of Medicine, Chicago, IL (United States); Josefson, Jami L. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Division of Endocrinology, Chicago, IL (United States); Northwestern University, Department of Pediatrics, Feinberg School of Medicine, Chicago, IL (United States)

2015-10-15

Brown adipose tissue (BAT) is identified in mammals as an adaptive thermogenic organ for modulation of energy expenditure and heat generation. Human BAT may be primarily composed of brown-in-white (BRITE) adipocytes and stimulation of BRITE may serve as a potential target for obesity interventions. Current imaging studies of BAT detection and characterization have been mainly limited to PET/CT. MRI is an emerging application for BAT characterization in healthy children. To exploit Dixon and diffusion-weighted MRI methods to characterize cervical-supraclavicular BAT/BRITE properties in normal-weight and obese children while accounting for pubertal status. Twenty-eight healthy children (9-15 years old) with a normal or obese body mass index participated. MRI exams were performed to characterize supraclavicular adipose tissues by measuring tissue fat percentage, T2*, tissue water mobility, and microvasculature properties. We used multivariate linear regression models to compare tissue properties between normal-weight and obese groups while accounting for pubertal status. MRI measurements of BAT/BRITE tissues in obese children showed higher fat percentage (P < 0.0001), higher T2* (P < 0.0001), and lower diffusion coefficient (P = 0.015) compared with normal-weight children. Pubertal status was a significant covariate for the T2* measurement, with higher T2* (P = 0.0087) in pubertal children compared to prepubertal children. Perfusion measurements varied by pubertal status. Compared to normal-weight children, obese prepubertal children had lower perfusion fraction (P = 0.003) and pseudo-perfusion coefficient (P = 0.048); however, obese pubertal children had higher perfusion fraction (P = 0.02) and pseudo-perfusion coefficient (P = 0.028). This study utilized chemical-shift Dixon MRI and diffusion-weighted MRI methods to characterize supraclavicular BAT/BRITE tissue properties. The multi-parametric evaluation revealed evidence of morphological differences in brown

MRI characterization of brown adipose tissue in obese and normal-weight children

International Nuclear Information System (INIS)

Deng, Jie; Rigsby, Cynthia K.; Shore, Richard M.; Schoeneman, Samantha E.; Zhang, Huiyuan; Kwon, Soyang; Josefson, Jami L.

2015-01-01

Brown adipose tissue (BAT) is identified in mammals as an adaptive thermogenic organ for modulation of energy expenditure and heat generation. Human BAT may be primarily composed of brown-in-white (BRITE) adipocytes and stimulation of BRITE may serve as a potential target for obesity interventions. Current imaging studies of BAT detection and characterization have been mainly limited to PET/CT. MRI is an emerging application for BAT characterization in healthy children. To exploit Dixon and diffusion-weighted MRI methods to characterize cervical-supraclavicular BAT/BRITE properties in normal-weight and obese children while accounting for pubertal status. Twenty-eight healthy children (9-15 years old) with a normal or obese body mass index participated. MRI exams were performed to characterize supraclavicular adipose tissues by measuring tissue fat percentage, T2*, tissue water mobility, and microvasculature properties. We used multivariate linear regression models to compare tissue properties between normal-weight and obese groups while accounting for pubertal status. MRI measurements of BAT/BRITE tissues in obese children showed higher fat percentage (P < 0.0001), higher T2* (P < 0.0001), and lower diffusion coefficient (P = 0.015) compared with normal-weight children. Pubertal status was a significant covariate for the T2* measurement, with higher T2* (P = 0.0087) in pubertal children compared to prepubertal children. Perfusion measurements varied by pubertal status. Compared to normal-weight children, obese prepubertal children had lower perfusion fraction (P = 0.003) and pseudo-perfusion coefficient (P = 0.048); however, obese pubertal children had higher perfusion fraction (P = 0.02) and pseudo-perfusion coefficient (P = 0.028). This study utilized chemical-shift Dixon MRI and diffusion-weighted MRI methods to characterize supraclavicular BAT/BRITE tissue properties. The multi-parametric evaluation revealed evidence of morphological differences in brown

Incremental value of diffusion weighted and dynamic contrast enhanced MRI in the detection of locally recurrent prostate cancer after radiation treatment: preliminary results

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Akin, Oguz; Vargas, Hebert Alberto; Hricak, Hedvig [Memorial Sloan-Kettering Cancer Center, Department of Radiology, New York, NY (United States); Gultekin, David H. [Memorial Sloan-Kettering Cancer Center, Medical Physics, New York, NY (United States); Zheng, Junting; Moskowitz, Chaya [Memorial Sloan-Kettering Cancer Center, Epidemiology and Biostatistics, New York, NY (United States); Pei, Xin; Sperling, Dahlia; Zelefsky, Michael J. [Memorial Sloan-Kettering Cancer Center, Radiation Oncology, New York, NY (United States); Schwartz, Lawrence H. [Columbia University College of Physicians and Surgeons, Radiology, New York, NY (United States)

2011-09-15

To assess the incremental value of diffusion-weighted (DW-MRI) and dynamic contrast-enhanced MRI (DCE-MRI) to T2-weighted MRI (T2WI) in detecting locally recurrent prostate cancer after radiotherapy. Twenty-four patients (median age, 70 years) with a history of radiotherapy-treated prostate cancer underwent multi-parametric MRI (MP-MRI) and transrectal prostate biopsy. Two readers independently scored the likelihood of cancer on a 1-5 scale, using T2WI alone and then adding DW-MRI and DCE-MRI. Areas under receiver operating characteristic curves (AUCs) were estimated at the patient and prostate-side levels. The apparent diffusion coefficient (ADC) from DW-MRI and the K{sup trans}, k{sub ep}, v{sub e}, AUGC90 and AUGC180 from DCE-MRI were recorded. Biopsy was positive in 16/24 (67%) and negative in 8/24 (33%) patients. AUCs for readers 1 and 2 increased from 0.64 and 0.53 to 0.95 and 0.86 with MP-MRI, at the patient level, and from 0.73 and 0.66 to 0.90 and 0.79 with MP-MRI, at the prostate-side level (p values < 0.05). Biopsy-positive and biopsy-negative prostate sides differed significantly in median ADC [1.44 vs. 1.68 (x 10{sup -3} mm{sup 2}/s)], median K{sup trans} [1.07 vs. 0.34 (1/min)], and k{sub ep} [2.06 vs 1.0 (1/min)] (p values < 0.05). MP-MRI was significantly more accurate than T2WI alone in detecting locally recurrent prostate cancer after radiotherapy. (orig.)

Diffusion-weighted imaging in acute demyelinating myelopathy

International Nuclear Information System (INIS)

Zecca, Chiara; Cereda, Carlo; Tschuor, Silvia; Staedler, Claudio; Nadarajah, Navarajah; Bassetti, Claudio L.; Gobbi, Claudio; Wetzel, Stephan; Santini, Francesco

2012-01-01

Diffusion-weighted imaging (DWI) has become a reference MRI technique for the evaluation of neurological disorders. Few publications have investigated the application of DWI for inflammatory demyelinating lesions. The purpose of the study was to describe diffusion-weighted imaging characteristics of acute, spinal demyelinating lesions. Six consecutive patients (two males, four females; aged 28-64 years) with acute spinal cord demyelinating lesions were studied in a prospective case series design from June 2009 to October 2010. We performed magnetic resonance imaging studies from 2 to 14 days from symptom onset on the patients with relapsing remitting multiple sclerosis (n = 3) or clinically isolated syndrome (n = 3). Main outcome measures were diffusion-weighted imaging and apparent diffusion coefficient pattern (ADC) of acute spinal cord demyelinating lesions. All spinal lesions showed a restricted diffusion pattern (DWI+/ADC-) with a 24% median ADC signal decrease. A good correlation between clinical presentation and lesion site was observed. Acute demyelinating spinal cord lesions show a uniform restricted diffusion pattern. Clinicians and neuro-radiologists should be aware that this pattern is not necessarily confirmatory for an ischaemic aetiology. (orig.)

Diffusion-weighted imaging in acute demyelinating myelopathy

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Zecca, Chiara; Cereda, Carlo; Tschuor, Silvia; Staedler, Claudio; Nadarajah, Navarajah; Bassetti, Claudio L.; Gobbi, Claudio [Ospedale Regionale di Lugano, Servizio di Neurologia e Neuroradiologia, Neurocenter of Southern Switzerland, Lugano (Switzerland); Wetzel, Stephan [Swiss Neuro Institute (SNI), Abteilung fuer Neuroradiologie, Hirslanden Klinik Zuerich, Zuerich (Switzerland); Santini, Francesco [University of Basel Hospital, Division of Radiological Physics, Basel (Switzerland)

2012-06-15

Diffusion-weighted imaging (DWI) has become a reference MRI technique for the evaluation of neurological disorders. Few publications have investigated the application of DWI for inflammatory demyelinating lesions. The purpose of the study was to describe diffusion-weighted imaging characteristics of acute, spinal demyelinating lesions. Six consecutive patients (two males, four females; aged 28-64 years) with acute spinal cord demyelinating lesions were studied in a prospective case series design from June 2009 to October 2010. We performed magnetic resonance imaging studies from 2 to 14 days from symptom onset on the patients with relapsing remitting multiple sclerosis (n = 3) or clinically isolated syndrome (n = 3). Main outcome measures were diffusion-weighted imaging and apparent diffusion coefficient pattern (ADC) of acute spinal cord demyelinating lesions. All spinal lesions showed a restricted diffusion pattern (DWI+/ADC-) with a 24% median ADC signal decrease. A good correlation between clinical presentation and lesion site was observed. Acute demyelinating spinal cord lesions show a uniform restricted diffusion pattern. Clinicians and neuro-radiologists should be aware that this pattern is not necessarily confirmatory for an ischaemic aetiology. (orig.)

Dynamic Contrast Magnetic Resonance Imaging (DCE-MRI) and Diffusion Weighted MR Imaging (DWI) for Differentiation between Benign and Malignant Salivary Gland Tumors

OpenAIRE

Assili, S.; Fathi Kazerooni, A.; Aghaghazvini, L.; Saligheh Rad, H.R.; Pirayesh Islamian, J.

2015-01-01

Background: Salivary gland tumors form nearly 3% of head and neck tumors. Due to their large histological variety and vicinity to facial nerves, pre-operative diagnosis and differentiation of benign and malignant parotid tumors are a major challenge for radiologists. Objective: The majority of these tumors are benign; however, sometimes they tend to transform into a malignant form. Functional MRI techniques, namely dynamic contrast enhanced (DCE-) MRI and diffusion-weighted ...

T2-weighted MRI-derived textural features reflect prostate cancer aggressiveness: preliminary results

NARCIS (Netherlands)

Nketiah, G.; Elschot, M.; Kim, E.; Teruel, J.R.; Scheenen, T.W.J.; Bathen, T.F.; Selnaes, K.M.

2017-01-01

PURPOSE: To evaluate the diagnostic relevance of T2-weighted (T2W) MRI-derived textural features relative to quantitative physiological parameters derived from diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI in Gleason score (GS) 3+4 and 4+3 prostate cancers. MATERIALS AND METHODS:

Corroboration of in utero MRI using post-mortem MRI and autopsy in foetuses with CNS abnormalities

International Nuclear Information System (INIS)

Whitby, E.H.; Variend, S.; Rutter, S.; Paley, M.N.J.; Wilkinson, I.D.; Davies, N.P.; Sparey, C.; Griffiths, P.D.

2004-01-01

AIMS: To corroborate the findings of in utero magnetic resonance imaging (MRI) with autopsy and post-mortem MRI in cases of known or suspected central nervous system (CNS) abnormalities on ultrasound and to compare the diagnostic accuracy of ante-natal ultrasound and in utero MRI. METHODS: Twelve pregnant women, whose foetuses had suspected central nervous system abnormalities underwent in utero MRI. The foetuses were imaged using MRi before autopsy. The data were used to evaluate the diagnostic accuracy of in utero MRI when compared with a reference standard of autopsy and post-mortem MRI in 10 cases and post-mortem MRI alone in two cases. RESULTS: The diagnostic accuracy of antenatal ultrasound and in utero MRI in correctly characterizing brain and spine abnormalities were 42 and 100%, respectively. CONCLUSION: In utero MRI provides a useful adjuvant to antenatal ultrasound when assessing CNS abnormalities by providing more accurate anatomical information. Post-mortem MRI assists the diagnosis of macroscopic structural abnormalities

Child dermoid cyst mimicking a craniopharyngioma: the benefit of MRI T2-weighted diffusion sequence.

Science.gov (United States)

Amelot, Aymeric; Borha, Alin; Calmon, Raphael; Barbet, Patrick; Puget, Stephanie

2018-02-01

Brain dermoid cysts are very rare lesions. Although benign, these cysts may be associated with devastating complications due to mass effect or meningitis. The discovery of completely asymptomatic dermoid cysts in the pediatric population is exceedingly rare. Despite the advances in imaging modalities, it sometimes remains difficult to exclude the differential diagnosis of craniopharyngioma. We describe a 12-year-old boy addressed for suspicion of craniopharyngioma diagnosed by decreased visual acuity, bitemporal hemianopia and a CT scan showing a large hypodense suprasellar lesion with intralesional calcifications. Despite the unusual localization and size of this lesion, the absence of dermal sinus commonly found, and before visualizing a hyperintense mass on MRI-diffusion, the diagnosis of craniopharyngioma was ruled out in favor of a dermoid cyst. Radical excision was performed. In the suprasellar area, craniopharyngioma and dermoid cyst may have very similar radiological aspects: low density masses on CT scan and a hyperintense signal on T1-weighted MRI sequences with a variable signal on T2-weighted sequences. Hitherto, only two cases in literature have described suprasellar dermoid cyst. Their initial diagnosis was facilitated by the presence of a dermal sinus.

Anatomical and diffusion MRI of deep gray matter in pediatric spina bifida

Directory of Open Access Journals (Sweden)

Ashley L. Ware

2014-01-01

Full Text Available Individuals with spina bifida myelomeningocele (SBM exhibit brain abnormalities in cortical thickness, white matter integrity, and cerebellar structure. Little is known about deep gray matter macro- and microstructure in this population. The current study utilized volumetric and diffusion-weighted MRI techniques to examine gray matter volume and microstructure in several subcortical structures: basal ganglia nuclei, thalamus, hippocampus, and amygdala. Sixty-six children and adolescents (ages 8–18; M = 12.0, SD = 2.73 with SBM and typically developing (TD controls underwent T1- and diffusion-weighted neuroimaging. Microstructural results indicated that hippocampal volume was disproportionately reduced, whereas the putamen volume was enlarged in the group with SBM. Microstructural analyses indicated increased mean diffusivity (MD and fractional anisotropy (FA in the gray matter of most examined structures (i.e., thalamus, caudate, hippocampus, with the putamen exhibiting a unique pattern of decreased MD and increased FA. These results provide further support that SBM differentially disrupts brain regions whereby some structures are volumetrically normal whereas others are reduced or enlarged. In the hippocampus, volumetric reduction coupled with increased MD may imply reduced cellular density and aberrant organization. Alternatively, the enlarged volume and significantly reduced MD in the putamen suggest increased density.

MRI of paraventricular white matter lesions in amyotrophic lateral sclerosis. Analysis by diffusion-weighted images

International Nuclear Information System (INIS)

Segawa, Fuminori; Kinoshita, Masao; Kishibayashi, Jun; Kamada, Kazuhiko; Sunohara, Nobuhiko.

1994-01-01

Magnetic resonance images in some cases of amyotrophic lateral sclerosis (ALS) revealed abnormal signals in both the paraventriculer white matter and in the posterior limbs of the internal capsule. We examined T 2 - and diffusion-weighted MR images of these lesions in 18 cases of ALS. There were symmetrical high-signal areas in the posterior limbs of the internal capsule in all of the cases. The high-signal areas in the internal capsule corresponded to the pyramidal tracts in the anatomical atlas by Talairach. In 5 of the cases of ALS, T 2 -weighted MR images showed discrete paraventricular white matter lesions as well. The mean age of the ALS patients with paraventricular white matter lesions was higher than that of the ALS patients without such lesions. Proton densities calculated from the conventional MR images were higher in both the capsular and paraventricular lesions. The diffusion coefficients perpendicular to the pyramidal tract in the internal capsular lesions were within the normal range, where as the diffusion coefficients in the paraventricular lesions were increased in all directions. Thus, diffusion anisotropy was lost in the paraventricular lesions. These findings are similar to those observed in the white matter lesions of cerebro-vascular origin. As a result, the pathology of the paraventricular lesions in ALS was confirmed to be different from that of the internal capsular lesions. (author)

MRI of paraventricular white matter lesions in amyotrophic lateral sclerosis. Analysis by diffusion-weighted images

Energy Technology Data Exchange (ETDEWEB)

Segawa, Fuminori; Kinoshita, Masao (Toho Univ., Tokyo (Japan). Ohashi Hospital); Kishibayashi, Jun; Kamada, Kazuhiko; Sunohara, Nobuhiko

1994-09-01

Magnetic resonance images in some cases of amyotrophic lateral sclerosis (ALS) revealed abnormal signals in both the paraventriculer white matter and in the posterior limbs of the internal capsule. We examined T[sub 2]- and diffusion-weighted MR images of these lesions in 18 cases of ALS. There were symmetrical high-signal areas in the posterior limbs of the internal capsule in all of the cases. The high-signal areas in the internal capsule corresponded to the pyramidal tracts in the anatomical atlas by Talairach. In 5 of the cases of ALS, T[sub 2]-weighted MR images showed discrete paraventricular white matter lesions as well. The mean age of the ALS patients with paraventricular white matter lesions was higher than that of the ALS patients without such lesions. Proton densities calculated from the conventional MR images were higher in both the capsular and paraventricular lesions. The diffusion coefficients perpendicular to the pyramidal tract in the internal capsular lesions were within the normal range, where as the diffusion coefficients in the paraventricular lesions were increased in all directions. Thus, diffusion anisotropy was lost in the paraventricular lesions. These findings are similar to those observed in the white matter lesions of cerebro-vascular origin. As a result, the pathology of the paraventricular lesions in ALS was confirmed to be different from that of the internal capsular lesions. (author).

Use of diffusion-weighted imaging (DWI) in PET/MRI for head and neck cancer evaluation

International Nuclear Information System (INIS)

Queiroz, Marcelo A.; Schulthess, Gustav von; Huellner, Martin; Kuhn, Felix; Veit-Haibach, Patrick; Huber, Gerhardt; Meerwein, Christian; Kollias, Spyros

2014-01-01

The purpose of this study was to analyze whether diffusion-weighted imaging (DWI) adds significant information to positron emission tomography/magnetic resonance imaging (PET/MRI) on lesion detection and characterization in head and neck cancers. Seventy patients with different head and neck cancers were enrolled in this prospective study. All patients underwent sequential contrast-enhanced (ce) PET/computed tomography (CT) and cePET/MRI using a tri-modality PET/CT-MR setup either for staging or re-staging. First, the DWI alone was evaluated, followed by the PET/MRI with conventional sequences, and in a third step, the PET/MRI with DWI was evaluated. McNemar's test was used to evaluate differences in the accuracy of PET/MRI with and without DWI compared to the standard of reference. One hundred eighty-eight (188) lesions were found, and of those, 118 (62.8 %) were malignant and 70 (37.2 %) were benign. PET/MRI without DWI had a higher accuracy in detecting malignant lesions than DWI alone (86.8 % vs. 60.6 %, p < 0.001). PET/MRI combined with DWI detected 120 concurrent lesions (89 malignant and 31 benign), PET/MRI alone identified 48 additional lesions (20 malignant and 28 benign), and DWI alone detected 20 different lesions (nine malignant and 11 benign). However, lesions detected on DWI did not change overall staging. SUV maximum and mean were significantly higher in malignant lesions than in benign lesions. DWI parameters between malignant and benign lesions were not statistically different. The use of DWI as part of PET/MRI to evaluate head and neck cancers does not provide remarkable information. Thus, the use of DWI might not be needed in clinical PET/MRI protocols for the staging or restaging of head and neck cancers. (orig.)

Diffusion-weighted MR imaging in the early diagnosis of periventricular leukomalacia

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Bozzao, Alessandro; Di Paolo, Ambrogio; Simonetti, Alessandra; Mazzoleni, Clarissa; Fasoli, Fabrizio; Floris, Roberto; Fantozzi, Luigi Maria

2003-01-01

Diffusion-weighted imaging (DWI) has been shown to be highly sensitive in detecting acute cerebral infarction, but its use in detecting hypoxic-ischemic encephalopathy (HIE) in neonates is still controversial. Moreover, few reports concern pre-term infants with possible periventricular leukomalacia (PVL). We examined the ability of this technique to detect cerebral changes in the acute phase of PVL. Fifteen MR examinations were performed in 11 pre-term infants (mean age 3.4 days, range 2-6 days). Conventional DWI sequences, apparent diffusion coefficient (ADC) maps, and US obtained in the acute phase were compared. All the neonates underwent US follow-up up to 4 months after delivery; those with suspected PVL also underwent MRI follow-up for up to 2 months. Qualitative and quantitative evaluations were performed to assess the presence of DW changes compatible with PVL. Diffusion-weighted MRI showed signal hyperintensity associated with decreased ADC values in 3 subjects (27%). In these patients conventional MRI sequences were interpreted as normal and US (performed at the same time) as doubtful in 2 and compatible with PVL in 1 subject. The MRI and US follow-up confirmed severe damage in all these patients. In 1 neonate hemorrhages involving the germinative matrix were identified. In 8 neonates MRI was considered normal. In these subjects US follow-up (up to 4 months) confirmed no signs of PVL. Diffusion-weighted imaging may have a higher correlation with later evidence of PVL than does conventional MR imaging and US when performed in the acute phase of the disease. (orig.)

Comparison of abdominal MRI with diffusion-weighted imaging to {sup 68}Ga-DOTATATE PET/CT in detection of neuroendocrine tumors of the pancreas

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Schmid-Tannwald, Christine; Schmid-Tannwald, Christoph M.; Neumann, Ralph; Nikolaou, Konstantin; Schramm, Nicolai; Reiser, Maximilian F.; Rist, Carsten [Ludwig Maximilians University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Morelli, John N. [Scott and White Hospital Temple, Department of Radiology, Temple, TX (United States); Haug, Alexander R.; Jansen, Nathalie [Ludwig Maximilians University Hospital Munich, Department of Nuclear Medicine, Munich (Germany)

2013-06-15

The aim of the study was to evaluate contrast-enhanced MRI, diffusion-weighted MRI (DW MRI), and {sup 68}Ga-DOTATATE positron emission tomography (PET)/CT in the detection of intermediate to well-differentiated neuroendocrine tumors (NET) of the pancreas. Eighteen patients with pathologically proven pancreatic NET who underwent MRI including DW MRI and PET/CT within 6 weeks of each other were included in this retrospective study. Two radiologists evaluated T2-weighted (T2w), T2w + DW MRI, T2w + contrast-enhanced T1-weighted (CE T1w) MR images, and PET/CT for NET detection. The sensitivity and level of diagnostic confidence were compared among modalities using McNemar's test and a Wilcoxon signed rank test. Apparent diffusion coefficients (ADC) of pancreatic NETs and normal pancreatic tissue were compared with Student's t test. Of the NETs, 8/23 (34.8 %) and 9/23 (39.1 %) were detected on T2w images by observers 1 and 2, respectively. Detection rates improved significantly by combining T2w images with DW MRI (observer 1: 14/23 = 61 %; observer 2: 15/23 = 65.2 %; p < 0.05) or CE T1w images (observer 1: 14/23 = 61 %; observer 2: 15/23 = 65.2 %; p < 0.05). Detection rates of pancreatic NET with PET/CT (both observers: 23/23 = 100 %) were statistically significantly higher than with MRI (p < 0.05). The mean ADC value of NET (1.02 {+-} 0.26 x 10{sup -3} mm{sup 2}/s) was statistically significantly lower than that of normal pancreatic tissue (1.48 {+-} 0.39 x 10{sup -3} mm{sup 2}/s). DW MRI is a valuable adjunct to T2w imaging and comparable to CE T1w imaging in pancreatic NET detection, quantitatively differentiating between NET and normal pancreatic tissue with ADC measurements. {sup 68}Ga-DOTATATE PET/CT is more sensitive than MRI in the detection of pancreatic NET. (orig.)

Meningoencephalitis caused by Streptococcus pneumoniae: a diagnostic and therapeutic challenge. Diagnosis with diffusion-weighted MRI leading to treatment with corticosteroids

International Nuclear Information System (INIS)

Jorens, Philippe G.; Demey, Hendrik E.; Parizel, Paul M.; Smets, Katrien; Jadoul, Kris; Verbeek, M.M.; Wevers, R.A.; Cras, Patrick

2005-01-01

Streptococcus pneumoniae is a common cause of bacterial meningitis but only rarely causes other infections such as brain abscess, encephalitis, encephalomyelitis or meningoencephalitis. We report on three adult patients with meningoencephalitis caused by S. pneumoniae. In all three, CT and MRI revealed widespread brain lesions, suggesting extensive parenchymal injury. Diffusion-weighted MRI showed lesions with restricted diffusion, reflecting local areas of ischaemia with cytotoxic oedema secondary to an immunologically mediated necrotising vasculitis and thrombosis. High levels of markers of neuronal, glial and myelin damage were found in the cerebrospinal fluid. According to the literature, brain parenchyma lesions in adults with pneumococcal meningoencephalitis are often associated with death or severe neurological deficit. Our patients were treated with pulse doses of glucocorticoids: this resulted in dramatic clinical improvement and an excellent final neurological recovery. (orig.)

Meningoencephalitis caused by Streptococcus pneumoniae: a diagnostic and therapeutic challenge. Diagnosis with diffusion-weighted MRI leading to treatment with corticosteroids

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Jorens, Philippe G.; Demey, Hendrik E. [University Hospital of Antwerp, UZA, Department of Intensive Care Medicine, Edegem (Belgium); Parizel, Paul M. [University of Antwerp, Department of Radiology, Edegem (Belgium); Smets, Katrien [University of Antwerp, Department of Neurology, Edegem (Belgium); General Hospital AZ Middelares, Department of Neurology, Sint-Niklaas (Belgium); Jadoul, Kris [General Hospital AZ Middelares, Department of Neurology, Sint-Niklaas (Belgium); Verbeek, M.M.; Wevers, R.A. [University Hospital of Nijmegen, Laboratory of Paediatrics and Neurology, Nijmegen (Netherlands); Cras, Patrick [University of Antwerp, Department of Neurology, Edegem (Belgium)

2005-10-01

Streptococcus pneumoniae is a common cause of bacterial meningitis but only rarely causes other infections such as brain abscess, encephalitis, encephalomyelitis or meningoencephalitis. We report on three adult patients with meningoencephalitis caused by S. pneumoniae. In all three, CT and MRI revealed widespread brain lesions, suggesting extensive parenchymal injury. Diffusion-weighted MRI showed lesions with restricted diffusion, reflecting local areas of ischaemia with cytotoxic oedema secondary to an immunologically mediated necrotising vasculitis and thrombosis. High levels of markers of neuronal, glial and myelin damage were found in the cerebrospinal fluid. According to the literature, brain parenchyma lesions in adults with pneumococcal meningoencephalitis are often associated with death or severe neurological deficit. Our patients were treated with pulse doses of glucocorticoids: this resulted in dramatic clinical improvement and an excellent final neurological recovery. (orig.)

Diffusion-weighted MRI of denervated muscle: a clinical and experimental study

International Nuclear Information System (INIS)

Holl, Nathalie; Bierry, Guillaume; Moser, Thomas; Dietemann, Jean-Louis; Kremer, Stephane; Echaniz-Laguna, Andoni; Mohr, Michel; Loeffler, Jean-Philippe

2008-01-01

The aim of this study was to investigate skeletal muscle denervation using diffusion-weighted magnetic resonance imaging (DWMRI). Sciatic nerve axotomy was performed in a group of nine New Zealand White rabbits, and electromyographic (EMG), pathological, and DWMRI studies were conducted on ipsilateral hamstring muscles 1 and 8 days after axotomy. In addition, DWMRI studies were carried out on leg muscles of ten patients with acute and subacute lumbosacral radiculopathy. High intensity signals on short tau inversion recovery (STIR) magnetic resonance imaging and an increased apparent diffusion coefficient (ADC) were observed in denervated muscles of the animals 1 and 8 days after axotomy as well as in denervated muscles of the patients with radiculopathy. In the clinical study, ADC was 1.26±0.18 x 10 -9 m 2 /s in normal muscle and increased to 1.56±0.23 x 10 -9 m 2 /s in denervated muscles (p =0.0016). In animals, EMG and muscle pathological studies were normal 1 day after axotomy, and the muscles demonstrated spontaneous activity on EMG and neurogenic atrophy on histological studies 7 days later. This DWMRI study demonstrates that enlargement of extracellular fluid space in muscle denervation is an early phenomenon occurring several days before the appearance of EMG and histological abnormalities. (orig.)

Detection of hepatocellular carcinoma in gadoxetic acid-enhanced MRI and diffusion-weighted MRI with respect to the severity of liver cirrhosis

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Kim, Ah Yeong; Kim, Young Kon; Lee, Min Woo; Park, Min Jung; Hwang, Jiyoung; Lee, Mi Hee; Lee, Jae Won

2012-01-01

Background As gadoxetic acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) have been widely used for the evaluation of hepatocellular carcinoma (HCC), it is clinically relevant to determine the diagnostic efficacy of gadoxetic acid-enhanced MRI and DWI for detection of HCCs with respect to the severity of liver cirrhosis. Purpose To compare the diagnostic accuracy and sensitivity of gadoxetic acid-enhanced MRI and DWI for detection of HCCs with respect to the severity of liver cirrhosis. Material and Methods A total of 189 patients with 240 HCCs (≤3.0 cm) (Child-Pugh A, 81 patients with 90 HCCs; Child-Pugh B, 65 patients with 85 HCCs; Child-Pugh C, 43 patients with 65 HCCs) underwent DWI and gadoxetic acid-enhanced MRI at 3.0 T. A gadoxetic acid set (dynamic and hepatobiliary phase plus T2-weighted image) and DWI set (DWI plus unenhanced MRIs) for each Child-Pugh class were analyzed independently by two observers for detecting HCCs using receiver-operating characteristic analysis. The diagnostic accuracy and sensitivity were calculated. Results There was a trend toward decreased diagnostic accuracy for gadoxetic acid and DWI set with respect to the severity of cirrhosis (Child-Pugh A [mean 0.974, 0.961], B [mean 0.904, 0.863], C [mean 0.779, 0.760]). For both observers, the sensitivities of both image sets were highest in Child-Pugh class A (mean 95.6%, 93.9%), followed by class B (mean 83.0%, 77.1%), and class C (mean 60.6%, 60.0%) (P < 0.05). Conclusion In HCC detection, the diagnostic accuracy and sensitivity for gadoxetic acid-enhanced MRI and DWI were highest in Child-Pugh class A, followed by Child-Pugh class B, and Child-Pugh class C, indicating a tendency toward decreased diagnostic capability with the severity of cirrhosis

Effectiveness of 3 T PROPELLER DUO diffusion-weighted MRI in differentiating sinonasal lymphomas and carcinomas

International Nuclear Information System (INIS)

Wang, X.; Zhang, Z.; Chen, Q.; Li, J.; Xian, J.

2014-01-01

Aim: To evaluate the value of 3 T Periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) DUO diffusion-weighted MRI (DW-MRI) in differentiating sinonasal lymphomas from carcinomas. Materials and methods: PROPELLER DUO DW-MRI was performed in 23 patients with sinonasal lymphomas and 28 patients with carcinomas histologically confirmed at 3 T MRI. Apparent diffusion coefficients (ADCs) were obtained with two different b-values (b = 0 and 700 s/mm 2 , b = 0 and 1000 s/mm 2 ) and two different regions of interest (ROIs) sampling strategies [whole section (WS), partial section (PS)], respectively. Difference in ADCs between sinonasal lymphomas and carcinomas was evaluated using the independent samples t-test or Mann–Whitney U-test. The utility of ADC thresholds for discriminating between them was evaluated by receiver operating characteristic analysis. Results: ADCs of sinonasal lymphomas (WS ADC b0,700 , 0.838 × 10 −3  mm 2 /s) were significantly (p < 0.001) lower than those of carcinomas (WS ADC b0,700 , 1.396 × 10 −3  mm 2 /s). Using a WS ADC b0,700 value of 1.040 × 10 −3  mm 2 /s as the threshold value effectively differentiated sinonasal lymphomas from carcinomas with 100% sensitivity, 82.1% specificity, and 82.1% positive and 100% negative predictive values and 90.2% accuracy (b = 0, 700 s/mm 2 ). There was no significant difference in diagnostic ability between different b-values settings (p > 0.05) and different sampling strategies of ROIs (p > 0.05), respectively. Additionally, there was significant differences in the ADCs between diffuse large B-cell lymphomas and natural killer (NK)/T-cell lymphomas (p < 0.05). Conclusion: PROPELLER DUO DW-MRI can effectively differentiate sinonasal lymphomas from carcinomas. - Highlights: • ADCs of sinonasal lymphomas were lower than those of carcinomas. • ADCs might effectively differentiate sinonasal lymphomas from carcinomas. • Diffuse large B

Basic principles of diffusion-weighted imaging

International Nuclear Information System (INIS)

Bammer, Roland.

2003-01-01

In diffusion-weighted MRI (DWI), image contrast is determined by the random microscopic motion of water protons. During the last years, DWI has become an important modality in the diagnostic work-up of acute ischemia in the CNS. There are also a few promising reports about the application of DWI to other regions in the human body, such as the vertebral column or the abdomen. This manuscript provides an introduction into the basics of DWI and Diffusion Tensor imaging. The potential of various MR sequences in concert with diffusion preparation are discussed with respect to acquisition speed, spatial resolution, and sensitivity to bulk physiologic motion. More advanced diffusion measurement techniques, such as high angular resolution diffusion imaging, are also addressed

Diffusion-weighted magnetic resonance imaging of the abdomen

International Nuclear Information System (INIS)

Schmid-Tannwald, C.; Reiser, M.F.; Zech, C.J.

2011-01-01

Diffusion-weighted magnetic resonance imaging (DW-MRI) provides qualitative and quantitative information of tissue cellularity and the integrity of cellular membranes. Since DW-MRI can be performed without ionizing radiation exposure and contrast media application, DW-MRI is a particularly attractive tool for patients with allergies for gadolinium-based contrast agents or renal failure. Recent technical developments have made DW-MRI a robust and feasible technique for abdominal imaging. DW-MRI provides information on the detection and characterization of focal liver lesions and can also visualize treatment effects and early changes in chronic liver disease. In addition DW-MRI is a promising tool for the detection of inflammatory changes in patients with Crohn's disease. (orig.) [de

Reversible MRI abnormalities in an unusual paediatric presentation of Wernicke's encephalopathy

International Nuclear Information System (INIS)

Sparacia, G.; Banco, A.; Lagalla, R.

1999-01-01

Background. We report an unusual paediatric presentation of acute Wernicke's encephalopathy in a 12-year-old boy affected by chronic gastrointestinal disease. MRI demonstrated, in addition to the typical diencephalic and mesencephalic signal abnormalities on T2-weighted images, enhancement of the mammillary bodies and the floor of the hypothalamus. Materials and methods. Following parenteral administration of thiamine for 4 days, the patient recovered from his neurological deficits and on follow-up enhanced MRI 1 month later, no signal abnormalities were found nor was there diencephalic or mesencephalic atrophy, as is usual in the chronic phase of the disease. Results. MRI provides crucial information in the diagnosis of Wernicke's encephalopathy, either in the acute or chronic phases of the disease. Conclusion. Our report provides an additional clue for recognition of the acute phase of the disease; enhancement of the floor of the hypothalamus has not previously been described despite its recorded involvement at autopsy. (orig.)

Diffusion-weighted MRI of the Prostate: Advantages of Zoomed EPI with Parallel-transmit-accelerated 2D-selective Excitation Imaging

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Thierfelder, Kolja M.; Scherr, Michael K.; Weiss, Jakob; Mueller-Lisse, Ullrich G.; Theisen, Daniel [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Notohamiprodjo, Mike; Nikolaou, Konstantin [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); University Hospital Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Dietrich, Olaf [Ludwig-Maximilians-University Hospital Munich, Josef Lissner Laboratory for Biomedical Imaging, Institute for Clinical Radiology, Munich (Germany); Pfeuffer, Josef [Siemens Healthcare, Application Development, Erlangen (Germany)

2014-12-15

The purpose of our study was to evaluate the use of 2D-selective, parallel-transmit excitation magnetic resonance imaging (MRI) for diffusion-weighted echo-planar imaging (pTX-EPI) of the prostate, and to compare it to conventional, single-shot EPI (c-EPI). The MRI examinations of 35 patients were evaluated in this prospective study. PTX-EPI was performed with a TX-acceleration factor of 1.7 and a field of view (FOV) of 150 x 90 mm{sup 2}, whereas c-EPI used a full FOV of 380 x 297 mm{sup 2}. Two readers evaluated three different aspects of image quality on 5-point Likert scales. To quantify distortion artefacts, maximum diameters and prostate volume were determined for both techniques and compared to T2-weighted imaging. The zoomed pTX-EPI was superior to c-EPI with respect to overall image quality (3.39 ± 0.62 vs 2.45 ± 0.67) and anatomic differentiability (3.29 ± 0.65 vs 2.41 ± 0.65), each with p < 0.0001. Artefacts were significantly less severe in pTX-EPI (0.93 ± 0.73 vs 1.49 ± 1.08), p < 0.001. The quantitative analysis yielded a higher agreement of pTX-EPI with T2-weighted imaging than c-EPI with respect to coronal (ICCs: 0.95 vs 0.93) and sagittal (0.86 vs 0.73) diameters as well as prostate volume (0.94 vs 0.92). Apparent diffusion coefficient (ADC) values did not differ significantly between the two techniques (p > 0.05). Zoomed pTX-EPI leads to substantial improvements in diffusion-weighted imaging (DWI) of the prostate with respect to different aspects of image quality and severity of artefacts. (orig.)

Diffusion MRI findings in phenylketonuria

International Nuclear Information System (INIS)

Sener, R.N.

2003-01-01

Two patients with phenylketonuria were studied who were under dietary control since infancy, and who were mentally normal. Diffusion MRI was obtained using a spin-echo, echo-planar sequence with a gradient strength of 30 mT/m at 1.5 T. A trace sequence (TR=5700 ms, and TE=139 ms) was used, acquired in 22 s. Heavily diffusion-weighted (b=1000 mm 2 /s) images, and the apparent diffusion coefficient (ADC) values from automatically generated ADC maps were studied. There were two different patterns in these two patients, restricted and increased diffusion patterns. Restricted diffusion pattern consisted of high-signal on b=1000 s/mm 2 images with low ADC values ranging from 0.46 to 0.57 x 10 -3 mm 2 /s. Increased diffusion pattern consisted of normal b=1000 s/mm 2 images with high ADC values ranging from 1.37 to 1.63 x 10 -3 mm 2 /s. It is likely that these values reflected presence of two different histopathological changes in phenylketonuria or reflected different stages of the same disease. (orig.)

Combined diffusion-weighted, blood oxygen level-dependent, and dynamic contrast-enhanced MRI for characterization and differentiation of renal cell carcinoma.

Science.gov (United States)

Notohamiprodjo, Mike; Staehler, Michael; Steiner, Nicole; Schwab, Felix; Sourbron, Steven P; Michaely, Henrik J; Helck, Andreas D; Reiser, Maximilian F; Nikolaou, Konstantin

2013-06-01

To investigate a multiparametric magnetic resonance imaging (MRI) approach comprising diffusion-weighted imaging (DWI), blood oxygen-dependent (BOLD), and dynamic contrast-enhanced (DCE) MRI for characterization and differentiation of primary renal cell carcinoma (RCC). Fourteen patients with clear-cell carcinoma and four patients with papillary RCC were examined with DWI, BOLD MRI, and DCE MRI at 1.5T. The apparent diffusion coefficient (ADC) was calculated with a monoexponential decay. The spin-dephasing rate R2* was derived from parametric R2* maps. DCE-MRI was analyzed using a two-compartment exchange model allowing separation of perfusion (plasma flow [FP] and plasma volume [VP]), permeability (permeability surface area product [PS]), and extravascular extracellular volume (VE). Statistical analysis was performed with Wilcoxon signed-rank test, Pearson's correlation coefficient, and receiver operating characteristic curve analysis. Clear-cell RCC showed higher ADC and lower R2* compared to papillary subtypes, but differences were not significant. FP of clear-cell subtypes was significantly higher than in papillary RCC. Perfusion parameters showed moderate but significant inverse correlation with R2*. VE showed moderate inverse correlation with ADC. Fp and Vp showed best sensitivity for histological differentiation. Multiparametric MRI comprising DWI, BOLD, and DCE MRI is feasible for assessment of primary RCC. BOLD moderately correlates to DCE MRI-derived perfusion. ADC shows moderate correlation to the extracellular volume, but does not correlate to tumor oxygenation or perfusion. In this preliminary study DCE-MRI appeared superior to BOLD and DWI for histological differentiation. Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.

The Gini coefficient: a methodological pilot study to assess fetal brain development employing postmortem diffusion MRI

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Viehweger, Adrian; Sorge, Ina; Hirsch, Wolfgang; Riffert, Till; Dhital, Bibek; Knoesche, Thomas R.; Anwander, Alfred; Stepan, Holger

2014-01-01

Diffusion-weighted imaging (DWI) is important in the assessment of fetal brain development. However, it is clinically challenging and time-consuming to prepare neuromorphological examinations to assess real brain age and to detect abnormalities. To demonstrate that the Gini coefficient can be a simple, intuitive parameter for modelling fetal brain development. Postmortem fetal specimens(n = 28) were evaluated by diffusion-weighted imaging (DWI) on a 3-T MRI scanner using 60 directions, 0.7-mm isotropic voxels and b-values of 0, 150, 1,600 s/mm 2 . Constrained spherical deconvolution (CSD) was used as the local diffusion model. Fractional anisotropy (FA), apparent diffusion coefficient (ADC) and complexity (CX) maps were generated. CX was defined as a novel diffusion metric. On the basis of those three parameters, the Gini coefficient was calculated. Study of fetal brain development in postmortem specimens was feasible using DWI. The Gini coefficient could be calculated for the combination of the three diffusion parameters. This multidimensional Gini coefficient correlated well with age (Adjusted R 2 = 0.59) between the ages of 17 and 26 gestational weeks. We propose a new method that uses an economics concept, the Gini coefficient, to describe the whole brain with one simple and intuitive measure, which can be used to assess the brain's developmental state. (orig.)

Hippocampal sclerosis and status epilepticus: cause or consequence? A MRI study

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Kuster, Gustavo Wruck; Braga-Neto, Pedro; Santos-Neto, Denizart; Santana, Maria Teresa Garcia; Barsottini, Orlando Graziani; Maia Junior, Antonio Carlos Martins

2007-01-01

Background: Transient imaging abnormalities, including changes on diffusion-weighted imaging (DWI), may be seen in status epilepticus. These abnormalities can be followed by hippocampal sclerosis. Case Report: We report a 15-year-old lady with focal non convulsive status epilepticus (NCSE) and focal slowing on EEG. DWI exhibited abnormal hyperintense signals in bilateral temporal and insular cortices. After 3 weeks, MRI performed a localized hippocampal atrophy. Conclusion: The MRI findings indicated vasogenic and cytotoxic edema during seizure activity and subsequent loss of brain parenchyma. (author)

Diffusion-weighted MRI for detecting prostate tumour in men at increased genetic risk

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Souza, Nandita M. de; Morgan, Veronica A.; Bancroft, Elizabeth; Sohaib, S. Aslam; Giles, Sharon L.; Kote-Jarai, Zsofia; Castro, Elena; Hazell, Steven; Jafar, Maysam; Eeles, Rosalind

2014-01-01

•Endorectal T2W + DW-MRI is potentially useful for prostate cancer screening.•MRI is specific for detecting prostate cancer in men with increased genetic risk.•Detection of prostate cancer in men at genetically low risk with MRI is limited. Endorectal T2W + DW-MRI is potentially useful for prostate cancer screening. MRI is specific for detecting prostate cancer in men with increased genetic risk. Detection of prostate cancer in men at genetically low risk with MRI is limited. Diffusion-weighted (DW)-MRI is invaluable in detecting prostate cancer. We determined its sensitivity and specificity and established interobserver agreement for detecting tumour in men with a family history of prostate cancer stratified by genetic risk. 51 men with a family history of prostate cancer underwent T2-W + DW-endorectal MRI at 3.0 T. Presence of tumour was noted at right and left apex, mid and basal prostate sextants by 2 independent observers, 1 experienced and the other inexperienced in endorectal MRI. Sensitivity and specificity against a 10-core sampling technique (lateral and medial cores at each level considered together) in men with >2× population risk based on 71 SNP analysis versus those with lower genetic risk scores was established. Interobserver agreement was determined at a subject level. Biopsies indicated cancer in 28 sextants in 13/51 men; 32 of 51 men had twice the population risk (>0.25) based on 71 SNP profiling. Sensitivity/specificity per-subject for patients was 90.0%/86.4% (high-risk) vs. 66.7%/100% (low-risk, observer 1) and 60.0%/86.3% (high-risk) vs. 33.3%/93.8% (low-risk, observer 2) with moderate overall inter-observer agreement (kappa = 0.42). Regional sensitivities/specificities for high-risk vs. low-risk for observer 1 apex 72.2%/100% [33.3%/100%], mid 100%/93.1% [100%/97.3%], base 16.7%/98.3% [0%/100%] and for observer 2 apex 36.4%/98.1% [0%/100%], mid 28.6%/96.5% [100%/100%], base 20%/100% [0%/97.3%] were poorer as they failed to detect

Use of diffusion-weighted MRI to modify radiosurgery planning in brain metastases may reduce local recurrence.

Science.gov (United States)

Zakaria, Rasheed; Pomschar, Andreas; Jenkinson, Michael D; Tonn, Jörg-Christian; Belka, Claus; Ertl-Wagner, Birgit; Niyazi, Maximilian

2017-02-01

Stereotactic radiosurgery (SRS) is an effective and well tolerated treatment for selected brain metastases; however, local recurrence still occurs. We investigated the use of diffusion weighted MRI (DWI) as an adjunct for SRS treatment planning in brain metastases. Seventeen consecutive patients undergoing complete surgical resection of a solitary brain metastasis underwent image analysis retrospectively. SRS treatment plans were generated based on standard 3D post-contrast T1-weighted sequences at 1.5T and then separately using apparent diffusion coefficient (ADC) maps in a blinded fashion. Control scans immediately post operation confirmed complete tumour resection. Treatment plans were compared to one another and with volume of local recurrence at progression quantitatively and qualitatively by calculating the conformity index (CI), the overlapping volume as a proportion of the total combined volume, where 1 = identical plans and 0 = no conformation whatsoever. Gross tumour volumes (GTVs) using ADC and post-contrast T1-weighted sequences were quantitatively the same (related samples Wilcoxon signed rank test = -0.45, p = 0.653) but showed differing conformations (CI 0.53, p recurrence than the standard plan (median 3.53 cm 3 vs. 3.84 cm 3 , p = 0.002). ADC maps may be a useful tool in addition to the standard post-contrast T1-weighted sequence used for SRS planning.

Diffusion-weighted imaging in relation to morphology on dynamic contrast enhancement MRI: the diagnostic value of characterizing non-puerperal mastitis.

Science.gov (United States)

Zhang, Lina; Hu, Jiani; Guys, Nicholas; Meng, Jinli; Chu, Jianguo; Zhang, Weisheng; Liu, Ailian; Wang, Shaowu; Song, Qingwei

2018-03-01

To demonstrate the value of diffusion-weighted imaging (DWI) in the characterisation of mastitis lesions. Sixty-one non-puerperal patients with pathologically confirmed single benign mastitis lesions underwent preoperative examinations with conventional MRI and axial DWI. Patients were categorised into three groups: (1) periductal mastitis (PDM), (2) granulomatous lobular mastitis (GLM), and (3) infectious abscess (IAB). Apparent diffusion coefficient (ADC) values of each lesion were recorded. A one-way ANOVA with logistic analysis was performed to compare ADC values and other parameters. Discriminative abilities of DWI modalities were compared using the area under the receiver operating characteristic curve (AUC). P mastitis subtypes. • Mastitis subtypes exhibit different characteristics on DWI and DCE MRI. • ADC values are helpful in isolating PDM from other mastitis lesions. • Distribution of non-mass enhancement also has value in comparing mastitis subtypes.

Diffusion-weighted imaging in acute bacterial meningitis in infancy

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Jan, W.; Zimmerman, R.A.; Bilaniuk, L.T.; Hunter, J.V.; Simon, E.M.; Haselgrove, J. [Department of Radiology, Children' s Hospital of Philadelphia, 34th Street and Civic Center Boulevard, PA 19104, Philadelphia (United States)

2003-09-01

Bacterial meningitis is frequently fatal or leads to severe neurological impairment. Complications such as vasculitis, resulting in infarcts, should be anticipated and dealt with promptly. Our aim was to demonstrate the complications of meningitis by diffusion weighted imaging (DWI) in patients who deteriorated despite therapy. We studied 13 infants between the ages of 1 day and 32 months who presented with symptoms ranging from fever and vomiting to seizures, encephalopathy and coma due to bacterial meningitis, performing MRI, including DWI, 2-5 days after presentation. Multiple infarcts were found on DWI in 12 of the 13, most commonly in the frontal lobes (in 10). Global involvement was seen in four children, three of whom died; the fourth had a very poor outcome. In one case abnormalities on DWI were due to subdural empyemas. We diagnosed vasculitis in three of five patients studied with MRA. We think DWI an important part of an MRI study in infants with meningitis. Small cortical or deep white-matter infarcts due to septic vasculitis can lead to tissue damage not easily recognized on routine imaging and DWI can be used to confirm that extra-axial collections represent empyemas. (orig.)

Diffusion-weighted imaging in acute bacterial meningitis in infancy

International Nuclear Information System (INIS)

Jan, W.; Zimmerman, R.A.; Bilaniuk, L.T.; Hunter, J.V.; Simon, E.M.; Haselgrove, J.

2003-01-01

Bacterial meningitis is frequently fatal or leads to severe neurological impairment. Complications such as vasculitis, resulting in infarcts, should be anticipated and dealt with promptly. Our aim was to demonstrate the complications of meningitis by diffusion weighted imaging (DWI) in patients who deteriorated despite therapy. We studied 13 infants between the ages of 1 day and 32 months who presented with symptoms ranging from fever and vomiting to seizures, encephalopathy and coma due to bacterial meningitis, performing MRI, including DWI, 2-5 days after presentation. Multiple infarcts were found on DWI in 12 of the 13, most commonly in the frontal lobes (in 10). Global involvement was seen in four children, three of whom died; the fourth had a very poor outcome. In one case abnormalities on DWI were due to subdural empyemas. We diagnosed vasculitis in three of five patients studied with MRA. We think DWI an important part of an MRI study in infants with meningitis. Small cortical or deep white-matter infarcts due to septic vasculitis can lead to tissue damage not easily recognized on routine imaging and DWI can be used to confirm that extra-axial collections represent empyemas. (orig.)

Differentiation of benign and malignant lesions of the tongue by using diffusion-weighted MRI at 3.0 T.

Science.gov (United States)

Li, S; Cheng, J; Zhang, Y; Zhang, Z

2015-01-01

Diffusion-weighted MRI (DWI) has been introduced in head and neck lesions and adds important information to the findings obtained through conventional MRI. The purpose of this study was to assess the role of DWI in differentiating benign and malignant lesions of the tongue at 3.0-T field strength imaging. 78 patients with 78 lingual lesions underwent conventional MRI and DWI with b-values of 0 and 1000 s mm(-2) before therapy. The apparent diffusion coefficient (ADC) maps were reconstructed, and the ADC values of the lingual lesions were calculated and compared between benign and malignant lesions of the tongue. The mean ADC values of the malignant tumours, benign solid lesions and cystic lesions were (1.08±0.16)×10(-3), (1.68±0.33)×10(-3) and (2.21±0.35)×10(-3) mm2 s(-1), respectively. The mean ADC values of malignant tumours were significantly lower (pbenign and malignant lesions are significantly different at 3.0-T imaging. DWI can be applied as a complementary tool in the differentiation of benign and malignant lesions of the tongue.

Cognition and brain abnormalities on MRI in pituitary patients

International Nuclear Information System (INIS)

Brummelman, Pauline; Sattler, Margriet G.A.; Meiners, Linda C.; Berg, Gerrit van den; Klauw, Melanie M. van der; Elderson, Martin F.; Dullaart, Robin P.F.; Koerts, Janneke; Werumeus Buning, Jorien; Tucha, Oliver; Wolffenbuttel, Bruce H.R.; Bergh, Alfons C.M. van den; Beek, André P. van

2015-01-01

Highlights: • Cognitive impairments are frequently observed in treated NFA patients. • NFA patients with cognitive impairments do not show brain abnormalities on MRI more frequently than patients without cognitive impairments. • The absence of brain abnormalities on brain MRI does not exclude impairments of cognition. - Abstract: Purpose: The extent to which cognitive dysfunction is related to specific brain abnormalities in patients treated for pituitary macroadenoma is unclear. Therefore, we compared brain abnormalities seen on Magnetic Resonance Imaging (MRI) in patients treated for nonfunctioning pituitary macroadenoma (NFA) with or without impairments in cognitive functioning. Methods: In this cross-sectional design, a cohort of 43 NFA patients was studied at the University Medical Center Groningen. White matter lesions (WMLs), cerebral atrophy, (silent) brain infarcts and abnormalities of the temporal lobes and hippocampi were assessed on pre-treatment and post-treatment MRI scans. Post-treatment cognitive examinations were performed using a verbal memory and executive functioning test. We compared our patient cohort with large reference populations representative of the Dutch population. Results: One or more impairments on both cognitive tests were frequently observed in treated NFA patients. No treatment effects were found with regard to the comparison between patients with and without impairments in executive functioning. Interestingly, in patients with one or more impairments on verbal memory function, treatment with radiotherapy had been given more frequently (74% in the impaired group versus 40% in the unimpaired group, P = 0.025). Patients with or without any brain abnormality on MRI did not differ in verbal memory or executive functioning. Conclusions: Brain abnormalities on MRI are not observed more frequently in treated NFA patients with impairments compared to NFA patients without impairments in verbal memory or executive functioning

Cognition and brain abnormalities on MRI in pituitary patients

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Brummelman, Pauline [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Sattler, Margriet G.A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen (Netherlands); Department of Radiation Oncology, Netherlands Cancer Institute – Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Meiners, Linda C. [Department of Radiology, University of Groningen, University Medical Center Groningen (Netherlands); Berg, Gerrit van den; Klauw, Melanie M. van der [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Elderson, Martin F. [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); LifeLines Cohort Study and Biobank, University of Groningen, University Medical Center Groningen (Netherlands); Dullaart, Robin P.F. [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Koerts, Janneke [Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen (Netherlands); Werumeus Buning, Jorien, E-mail: j.werumeus.buning@umcg.nl [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); Tucha, Oliver [Department of Clinical and Developmental Neuropsychology, University of Groningen, Groningen (Netherlands); Wolffenbuttel, Bruce H.R. [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands); LifeLines Cohort Study and Biobank, University of Groningen, University Medical Center Groningen (Netherlands); Bergh, Alfons C.M. van den [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen (Netherlands); Beek, André P. van, E-mail: a.p.van.beek@umcg.nl [Department of Endocrinology, University of Groningen, University Medical Center Groningen (Netherlands)

2015-02-15

Highlights: • Cognitive impairments are frequently observed in treated NFA patients. • NFA patients with cognitive impairments do not show brain abnormalities on MRI more frequently than patients without cognitive impairments. • The absence of brain abnormalities on brain MRI does not exclude impairments of cognition. - Abstract: Purpose: The extent to which cognitive dysfunction is related to specific brain abnormalities in patients treated for pituitary macroadenoma is unclear. Therefore, we compared brain abnormalities seen on Magnetic Resonance Imaging (MRI) in patients treated for nonfunctioning pituitary macroadenoma (NFA) with or without impairments in cognitive functioning. Methods: In this cross-sectional design, a cohort of 43 NFA patients was studied at the University Medical Center Groningen. White matter lesions (WMLs), cerebral atrophy, (silent) brain infarcts and abnormalities of the temporal lobes and hippocampi were assessed on pre-treatment and post-treatment MRI scans. Post-treatment cognitive examinations were performed using a verbal memory and executive functioning test. We compared our patient cohort with large reference populations representative of the Dutch population. Results: One or more impairments on both cognitive tests were frequently observed in treated NFA patients. No treatment effects were found with regard to the comparison between patients with and without impairments in executive functioning. Interestingly, in patients with one or more impairments on verbal memory function, treatment with radiotherapy had been given more frequently (74% in the impaired group versus 40% in the unimpaired group, P = 0.025). Patients with or without any brain abnormality on MRI did not differ in verbal memory or executive functioning. Conclusions: Brain abnormalities on MRI are not observed more frequently in treated NFA patients with impairments compared to NFA patients without impairments in verbal memory or executive functioning

Diffusion-weighted MRI in the diagnosis of intracranial hematomas

OpenAIRE

Şanlı, Davut; Ünal, Özkan; Bora, Aydın; Beyazal, Mehmet; Yavuz, Alpaslan; Avcu, Serhat

2013-01-01

Abstract. To determinate the diagnostic value of diffusion-weighted MR imaging (DWI) in intracerebral hematomas, epidural hematomas, subdural hematomas, and subarachnoid hemorrhage, and to assess the contribution of diffusion signal characteristics in the differentiation of hematoma stages. In this prospective study, consecutive 67 patients (range: 3-89 years), 35 (18 men 17 women) with intracerebral hematoma, 18 (10 men 8 women) with subdural hematoma, 2 (1 man 1 woman) with epidural hematom...

Dynamic Contrast Magnetic Resonance Imaging (DCE-MRI and Diffusion Weighted MR Imaging (DWI for Differentiation between Benign and Malignant Salivary Gland Tumors

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Assili S

2012-12-01

Full Text Available Background: Salivary gland tumors form nearly 3% of head and neck tumors. Due to their large histological variety and vicinity to facial nerves, pre-operative diagnosis and differentiation of benign and malignant parotid tumors are a major challenge for radiologists. Objective: The majority of these tumors are benign; however, sometimes they tend to transform into a malignant form. Functional MRI techniques, namely dynamic contrast enhanced (DCE- MRI and diffusion-weighted MRI (DWI can indicate the characteristics of tumor tissue. Methods: DCE-MRI analysis is based on the parameters of time intensity curve (TIC before and after contrast agent injection. This method has the potential to identify the angiogenesis of tumors. DWI analysis is performed according to diffusion of water molecules in a tissue for determination of the cellularity of tumors. Conclusion: According to the literature, these methods cannot be used individually to differentiate benign from malignant salivary gland tumors. An effective approach could be to combine the aforementioned methods to increase the accuracy of discrimination between different tumor types. The main objective of this study is to explore the application of DCE-MRI and DWI for assessment of salivary gland tumor types.

Dynamic Contrast Magnetic Resonance Imaging (DCE-MRI) and Diffusion Weighted MR Imaging (DWI) for Differentiation between Benign and Malignant Salivary Gland Tumors.

Science.gov (United States)

Assili, S; Fathi Kazerooni, A; Aghaghazvini, L; Saligheh Rad, H R; Pirayesh Islamian, J

2015-12-01

Salivary gland tumors form nearly 3% of head and neck tumors. Due to their large histological variety and vicinity to facial nerves, pre-operative diagnosis and differentiation of benign and malignant parotid tumors are a major challenge for radiologists. The majority of these tumors are benign; however, sometimes they tend to transform into a malignant form. Functional MRI techniques, namely dynamic contrast enhanced (DCE-) MRI and diffusion-weighted MRI (DWI) can indicate the characteristics of tumor tissue. DCE-MRI analysis is based on the parameters of time intensity curve (TIC) before and after contrast agent injection. This method has the potential to identify the angiogenesis of tumors. DWI analysis is performed according to diffusion of water molecules in a tissue for determination of the cellularity of tumors. According to the literature, these methods cannot be used individually to differentiate benign from malignant salivary gland tumors. An effective approach could be to combine the aforementioned methods to increase the accuracy of discrimination between different tumor types. The main objective of this study is to explore the application of DCE-MRI and DWI for assessment of salivary gland tumor types.

Dynamic Contrast Magnetic Resonance Imaging (DCE-MRI) and Diffusion Weighted MR Imaging (DWI) for Differentiation between Benign and Malignant Salivary Gland Tumors

Science.gov (United States)

Assili, S.; Fathi Kazerooni, A.; Aghaghazvini, L.; Saligheh Rad, H.R.; Pirayesh Islamian, J.

2015-01-01

Background Salivary gland tumors form nearly 3% of head and neck tumors. Due to their large histological variety and vicinity to facial nerves, pre-operative diagnosis and differentiation of benign and malignant parotid tumors are a major challenge for radiologists. Objective The majority of these tumors are benign; however, sometimes they tend to transform into a malignant form. Functional MRI techniques, namely dynamic contrast enhanced (DCE-) MRI and diffusion-weighted MRI (DWI) can indicate the characteristics of tumor tissue. Methods DCE-MRI analysis is based on the parameters of time intensity curve (TIC) before and after contrast agent injection. This method has the potential to identify the angiogenesis of tumors. DWI analysis is performed according to diffusion of water molecules in a tissue for determination of the cellularity of tumors. Conclusion According to the literature, these methods cannot be used individually to differentiate benign from malignant salivary gland tumors. An effective approach could be to combine the aforementioned methods to increase the accuracy of discrimination between different tumor types. The main objective of this study is to explore the application of DCE-MRI and DWI for assessment of salivary gland tumor types. PMID:26688794

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

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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

Characterization of ductal carcinoma in situ on diffusion weighted breast MRI

International Nuclear Information System (INIS)

Rahbar, Habib; Partridge, Savannah C.; Eby, Peter R.; DeMartini, Wendy B.; Gutierrez, Robert L.; Peacock, Sue; Lehman, Constance D.

2011-01-01

To characterize ductal carcinoma in situ (DCIS) and its subtypes on diffusion-weighted imaging (DWI). We retrospectively reviewed 74 pure DCIS lesions in 69 women who underwent DWI at 1.5 T (b = 0 and 600 s/mm 2 ). Each lesion was characterized by qualitative DWI intensity, quantitative DWI lesion-to-normal contrast-to-noise ratio (CNR), and quantitative apparent diffusion coefficient (ADC). The detection rate was calculated with predetermined thresholds for each parameter. The effects of lesion size, grade, morphology, and necrosis were assessed. Ninety-six percent (71/74) of DCIS lesions demonstrated greater qualitative DWI intensity than normal breast tissue. Quantitatively, DCIS lesions demonstrated on average 56% greater signal than normal tissue (mean CNR = 1.83 ± 2.7) and lower ADC values (1.50 ± 0.28 x 10 -3 mm 2 /s) than normal tissue (2.01 ± 0.37 x 10 -3 mm 2 /s, p -3 mm 2 /s). Non-high-grade DCIS exhibited greater qualitative DWI intensity (p = 0.02) and quantitative CNR (p = 0.01) than high-grade DCIS but no difference in ADC (p = 0.40). Lesion size, morphology, and necrosis did not affect qualitative or quantitative DWI parameters of DCIS lesions (p > 0.05). DCIS lesions have higher DWI signal intensity and lower ADC values than normal breast tissue. DWI warrants further investigation as a potential non-contrast MRI tool for early breast cancer detection. (orig.)

The role of diffusion-weighted MRI (DWI) in the differentiation of benign from malignant skeletal lesions of the pelvis

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Douis, Hassan, E-mail: douis.hassan@hotmail.co.uk [Department of Radiology, University Hospital Birmingham NHS Foundation Trust, Birmingham, B15 2GW (United Kingdom); Department of Radiology, Royal Orthopaedic Hospital NHS Foundation Trust, Birmingham, B31 2AP (United Kingdom); Davies, Mark A. [Department of Radiology, Royal Orthopaedic Hospital NHS Foundation Trust, Birmingham, B31 2AP (United Kingdom); Sian, Parmjit [Department of Spinal Surgical Oncology, Royal Orthopaedic Hospital NHS Foundation Trust, Birmingham, B31 2AP (United Kingdom)

2016-12-15

Purpose: To evaluate the utility of Diffusion-weighted MRI in the differentiation of benign from malignant skeletal lesions of the pelvis. Materials and methods: In this retrospective study 33 patients with indeterminate skeletal lesions of the pelvis were evaluated with DWI. Minimum, mean, maximum ADC-values of the skeletal lesions were measured followed by qualitative assessment of DWI. All patients underwent histological confirmation using CT-guided biopsy or surgical resection. The histology of the skeletal lesions was correlated with the findings on DWI. Results: There were 13 malignant lesions and 20 benign lesions. The mean, minimum and maximum ADC values (×10–6mm2/s) for benign skeletal lesions was higher than the mean ADC-values for malignant lesions (1422.2 vs 1263.7; 780.4 vs 771.8; 1969.6 vs 1676.8 respectively). These differences were however not statistically significant (P-values = 0.29; 0.94; 0.149 respectively). The sensitivity, specificity, positive predictive value and negative predictive value for qualitative assessment of Diffusion-weighted MRI in the differentiation of benign from malignant skeletal lesions were: 53.9%, 85%, 70%, 73.9% respectively. Qualitative assessment of DWI (restricted diffusion versus non-restricted diffusion) allowed differentiation of benign from malignant skeletal lesions (P-value = 0.0259). Conclusions: Qualitative assessment of DWI may aid in the differentiation of benign skeletal lesions from malignant skeletal lesions of the pelvis. Although DWI has a low sensitivity in the distinction of the two disease entities, it may be a useful adjunct due to its relatively high specificity. This is of particular importance in lymphoma where biopsy may only show chronic inflammatory cells and hence may be false negative.

The role of diffusion-weighted MRI (DWI) in the differentiation of benign from malignant skeletal lesions of the pelvis

International Nuclear Information System (INIS)

Douis, Hassan; Davies, Mark A.; Sian, Parmjit

2016-01-01

Purpose: To evaluate the utility of Diffusion-weighted MRI in the differentiation of benign from malignant skeletal lesions of the pelvis. Materials and methods: In this retrospective study 33 patients with indeterminate skeletal lesions of the pelvis were evaluated with DWI. Minimum, mean, maximum ADC-values of the skeletal lesions were measured followed by qualitative assessment of DWI. All patients underwent histological confirmation using CT-guided biopsy or surgical resection. The histology of the skeletal lesions was correlated with the findings on DWI. Results: There were 13 malignant lesions and 20 benign lesions. The mean, minimum and maximum ADC values (×10–6mm2/s) for benign skeletal lesions was higher than the mean ADC-values for malignant lesions (1422.2 vs 1263.7; 780.4 vs 771.8; 1969.6 vs 1676.8 respectively). These differences were however not statistically significant (P-values = 0.29; 0.94; 0.149 respectively). The sensitivity, specificity, positive predictive value and negative predictive value for qualitative assessment of Diffusion-weighted MRI in the differentiation of benign from malignant skeletal lesions were: 53.9%, 85%, 70%, 73.9% respectively. Qualitative assessment of DWI (restricted diffusion versus non-restricted diffusion) allowed differentiation of benign from malignant skeletal lesions (P-value = 0.0259). Conclusions: Qualitative assessment of DWI may aid in the differentiation of benign skeletal lesions from malignant skeletal lesions of the pelvis. Although DWI has a low sensitivity in the distinction of the two disease entities, it may be a useful adjunct due to its relatively high specificity. This is of particular importance in lymphoma where biopsy may only show chronic inflammatory cells and hence may be false negative.

Pretreatment Diffusion-Weighted MRI Can Predict the Response to Neoadjuvant Chemotherapy in Patients with Nasopharyngeal Carcinoma

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Guo-Yi Zhang

2015-01-01

Full Text Available Purpose. To explore the potential of diffusion-weighted (DW magnetic resonance imaging (MRI using apparent diffusion coefficient (ADC for predicting the response to neoadjuvant chemotherapy in nasopharyngeal carcinoma (NPC. Methods and Materials. Ninety-two consecutive patients with NPC who underwent three cycles of neoadjuvant chemotherapy were retrospectively analyzed. DW and anatomical MRI were performed before and after neoadjuvant chemotherapy prior to radiotherapy. Pretreatment ADCs and percentage increases in ADC after chemotherapy were calculated for the primary lesions and metastatic adenopathies. Receiver operating characteristic curve analysis was used to select optimal pretreatment ADCs. Results. Pretreatment mean ADCs were significantly lower for responders than for nonresponders (primary lesions, P=0.012; metastatic adenopathies, P=0.013. Mean percentage increases in ADC were higher for responders than for nonresponders (primary lesions, P=0.008; metastatic adenopathies, P<0.001. The optimal pretreatment primary lesion and metastatic adenopathy ADCs for differentiating responders from nonresponders were 0.897 × 10−3 mm2/sec and 1.031 × 10−3 mm2/sec, respectively. Conclusions. NPC patients with low pretreatment ADCs tend to respond better to neoadjuvant chemotherapy. Pretreatment ADCs could be used as a new pretreatment imaging biomarker of response to neoadjuvant chemotherapy.

Diffusion-weighted echo-planar MRI of lacunar infarcts

International Nuclear Information System (INIS)

Noguchi, K.; Nagayoshi, T.; Watanabe, N.; Kanazawa, T.; Toyoshima, S.; Morijiri, M.; Shojaku, H.; Shimizu, M.; Seto, H.

1998-01-01

We studied 35 patients with lacunar infarcts, using diffusion-weighted echo-planar imaging (DW-EPI) at 1.5 T. The relative apparent diffusion coefficient ratio (ADCR) of each lesion was calculated and lesion conspicuity on DW-EPI was compared to that on images aquired with fast fluid-attenuated inversion recovery and T2-weighted fast spin-echo sequences. Acute small infarcts (within 3 days) were identified with DW-EPI as an area of decreased ADCR (range 0.33-0.87; mean 0.67) and high signal, subacute small infarcts (4-30 days) as a high-signal or isointense areas of decreased or nearly normal ADCR (0.54-0.98; 0.73), and chronic small infarcts (> 30 days) as low- or high-signal areas of nearly normal or increased ADCR (0.97-1.92; 1.32). In three patients, small infarcts of the brain stem in the hyperacute phase (within 6 h) were seen only with DW-EPI. In five patients, fresh small infarcts adjacent to multiple old infarcts could be distinguished only with DW-EPI. (orig.)

Morphostructural MRI Abnormalities Related to Neuropsychiatric Disorders Associated to Multiple Sclerosis

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Simona Bonavita

2013-01-01

Full Text Available Multiple Sclerosis associated neuropsychiatric disorders include major depression (MD, obsessive-compulsive disorder (OCD, bipolar affective disorder, euphoria, pseudobulbar affect, psychosis, and personality change. Magnetic Resonance Imaging (MRI studies focused mainly on identifying morphostructural correlates of MD; only a few anecdotal cases on OCD associated to MS (OCD-MS, euphoria, pseudobulbar affect, psychosis, personality change, and one research article on MRI abnormalities in OCD-MS have been published. Therefore, in the present review we will report mainly on neuroimaging abnormalities found in MS patients with MD and OCD. All together, the studies on MD associated to MS suggest that, in this disease, depression is linked to a damage involving mainly frontotemporal regions either with discrete lesions (with those visible in T1 weighted images playing a more significant role or subtle normal appearing white matter abnormalities. Hippocampal atrophy, as well, seems to be involved in MS related depression. It is conceivable that grey matter pathology (i.e., global and regional atrophy, cortical lesions, which occurs early in the course of disease, may involve several areas including the dorsolateral prefrontal cortex, the orbitofrontal cortex, and the anterior cingulate cortex whose disruption is currently thought to explain late-life depression. Further MRI studies are necessary to better elucidate OCD pathogenesis in MS.

Diffusion MRI findings in phenylketonuria

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Sener, R.N. [Dept. of Radiology, Ege Univ. Hospital, Izmir (Turkey)

2003-12-01

Two patients with phenylketonuria were studied who were under dietary control since infancy, and who were mentally normal. Diffusion MRI was obtained using a spin-echo, echo-planar sequence with a gradient strength of 30 mT/m at 1.5 T. A trace sequence (TR=5700 ms, and TE=139 ms) was used, acquired in 22 s. Heavily diffusion-weighted (b=1000 mm{sup 2}/s) images, and the apparent diffusion coefficient (ADC) values from automatically generated ADC maps were studied. There were two different patterns in these two patients, restricted and increased diffusion patterns. Restricted diffusion pattern consisted of high-signal on b=1000 s/mm{sup 2} images with low ADC values ranging from 0.46 to 0.57 x 10{sup -3} mm{sup 2}/s. Increased diffusion pattern consisted of normal b=1000 s/mm{sup 2} images with high ADC values ranging from 1.37 to 1.63 x 10{sup -3} mm{sup 2}/s. It is likely that these values reflected presence of two different histopathological changes in phenylketonuria or reflected different stages of the same disease. (orig.)

Diffusion weighted imaging in prostate cancer

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Tan, Cher Heng [The University of Texas, M D Anderson Cancer Center, Department of Diagnostic Radiology, Division of Diagnostic Imaging, Houston, TX (United States); Tan Tock Seng Hospital, Department of Diagnostic Radiology, Singapore (Singapore); Wang, Jihong [The University of Texas, M D Anderson Cancer Center, Department of Imaging Physics, Division of Diagnostic Imaging, Houston, TX (United States); Kundra, Vikas [The University of Texas, M D Anderson Cancer Center, Department of Diagnostic Radiology, Division of Diagnostic Imaging, Houston, TX (United States); The University of Texas, M D Anderson Cancer Center, Department of Experimental Diagnostic Imaging, Division of Diagnostic Imaging, Houston, TX (United States)

2011-03-15

Diffusion-weighted imaging has generated substantial interest in the hope that it can be developed into a robust technique to improve the accuracy of MRI for the evaluation of prostate cancer. This technique has the advantages of short acquisition times, no need for intravenous administration of contrast medium, and the ability to study diffusion of water molecules that indirectly reflects tissue cellularity. In this article, we review the existing literature on the utility of DWI in tumour detection, localisation, treatment response, limitations of the technique, how it compares with other imaging techniques, technical considerations and future directions. (orig.)

The Gini coefficient: a methodological pilot study to assess fetal brain development employing postmortem diffusion MRI

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Viehweger, Adrian; Sorge, Ina; Hirsch, Wolfgang [University Hospital Leipzig, Department of Pediatric Radiology, Leipzig (Germany); Riffert, Till; Dhital, Bibek; Knoesche, Thomas R.; Anwander, Alfred [Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig (Germany); Stepan, Holger [University Leipzig, Department of Obstetrics, Leipzig (Germany)

2014-10-15

Diffusion-weighted imaging (DWI) is important in the assessment of fetal brain development. However, it is clinically challenging and time-consuming to prepare neuromorphological examinations to assess real brain age and to detect abnormalities. To demonstrate that the Gini coefficient can be a simple, intuitive parameter for modelling fetal brain development. Postmortem fetal specimens(n = 28) were evaluated by diffusion-weighted imaging (DWI) on a 3-T MRI scanner using 60 directions, 0.7-mm isotropic voxels and b-values of 0, 150, 1,600 s/mm{sup 2}. Constrained spherical deconvolution (CSD) was used as the local diffusion model. Fractional anisotropy (FA), apparent diffusion coefficient (ADC) and complexity (CX) maps were generated. CX was defined as a novel diffusion metric. On the basis of those three parameters, the Gini coefficient was calculated. Study of fetal brain development in postmortem specimens was feasible using DWI. The Gini coefficient could be calculated for the combination of the three diffusion parameters. This multidimensional Gini coefficient correlated well with age (Adjusted R{sup 2} = 0.59) between the ages of 17 and 26 gestational weeks. We propose a new method that uses an economics concept, the Gini coefficient, to describe the whole brain with one simple and intuitive measure, which can be used to assess the brain's developmental state. (orig.)

MRI of sporadic Creutzfeldt-Jakob disease

International Nuclear Information System (INIS)

Kong, A.; Vliet, A. Van der.

2008-01-01

Full text: The key MRI findings in five cases of sporadic Creutzfeldt-Jakob disease (CJD) are illustrated with four 'definite' and one 'probable' according to World Health Organization criteria. Close attention to fluid-attenuation inversion recovery and diffusion-weighted imaging sequences are important for diagnosis, noting especially restricted diffusion in cortical and deep grey matter. Our study and those of others show predominant cortical, caudate and thalamic involvement. This pattern is highly sensitive and specific for the diagnosis. Fluid-attenuation inversion recovery and diffusion-weighted imaging signal abnormality becomes progressively more extensive and bilateral as disease progresses, but may become less pronounced in end-stage disease because of atrophy.

Fetal MRI; Fetales MRT

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Blondin, D. [Inst. fuer Diagn. Radiologie, Uniklinikum Duesseldorf (Germany); Turowski, B. [Inst. fuer Diagn. Radiologie, Neuroradiologie, Uniklinikum Duesseldorf (Germany); Schaper, J. [Inst. fuer Diagn. Radiologie, Kinderradiologie, Uniklinikum Duesseldorf (Germany)

2007-02-15

Ultrasonography is the method of choice for prenatal malformation screening, but it does not always provide sufficient information for correct diagnosis or adequate abnormality evaluation. Fetal MRI is increasingly being used to complete sonographic findings. It was initially used for evaluation of cerebral abnormalities but is increasingly being applied to other fetal areas. In vivo investigation of fetal brain maturation has been enhanced by MRI. An adequate analysis of fetal chest and abdomen can be achieved with fast T2-, T1-weighted and diffusion-weighted imaging (DWI). The advantages include the great field of view and the excellent soft tissue contrast. This allows correct diagnosis of congenital diaphragmatic hernia and evaluation of the consequences on pulmonary growth. Other pulmonary malformations, such as cystic adenomatoid malformation, sequestration and brochogenic cysts, can also be easily identified. Renal position can be quickly determined using DWI sequences and renal agenesia can be easily diagnosed with only one sequence. Prenatal MRI is virtually as effective as postnatal examination, dispenses with transport of a potentially very ill newborn, and provides logistic advantages. Therefore, prenatal MRI is useful for adequate postnatal treatment of newborns with malformations. (orig.)

Value of MRI of the brain in patients with systemic lupus erythematosus and neurologic disturbance

International Nuclear Information System (INIS)

Jennings, J.E.; Sundgren, P.C.; Maly, P.; Attwood, J.; McCune, J.

2004-01-01

Our objective was to review the frequency and pattern of signal abnormalities seen on conventional MRI in patients with suspected neuropsychiatric systemic lupus erythematosus (NP-SLE). We reviewed 116 MRI examinations of the brain performed on 85 patients with SLE, (81 women, four men, aged 21-78 years, mean 40.6 years) presenting with neurological disturbances. MRI was normal or nearly normal in 34%. In 60% high-signal lesions were observed on T2-weighted images, frequently in the frontal and parietal subcortical white matter. Infarct-like lesions involving gray and white matter were demonstrated in 21 of cases. Areas of restricted diffusion were seen in 12 of the 67 patients who underwent diffusion-weighted imaging. Other abnormalities included loss of brain volume, hemorrhage, meningeal enhancement, and bilateral high signal in occipital white-matter. The MRI findings alone did not allow us to distinguish between thromboembolic and inflammatory events in many patients. Some patients with normal MRI improved clinically while on immunosuppressive therapy. More sensitive and/or specific imaging methods, such as spectroscopy and perfusion-weighted imaging, should be investigated in these subgroups of patients with suspected NP-SLE. (orig.)

Preoperative prediction of sentinel lymph node metastasis in breast cancer based on radiomics of T2-weighted fat-suppression and diffusion-weighted MRI

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Dong, Yuhao; Mo, Xiaokai [Guangdong General Hospital/Guangdong Academy of Medical Sciences, Department of Radiology, Guangzhou, Guangdong Province (China); Shantou University Medical College, Graduate College, Shantou, Guangdong (China); Feng, Qianjin; Yang, Wei; Lu, Zixiao; Deng, Chunyan [Southern Medical University, The Guangdong Provincial Key Laboratory of Medical Image Processing, School of Biomedical Engineering, Guangzhou, Guangdong (China); Zhang, Lu; Lian, Zhouyang; Liu, Jing; Luo, Xiaoning; Pei, Shufang; Huang, Wenhui; Liang, Changhong; Zhang, Bin; Zhang, Shuixing [Guangdong General Hospital/Guangdong Academy of Medical Sciences, Department of Radiology, Guangzhou, Guangdong Province (China)

2018-02-15

To predict sentinel lymph node (SLN) metastasis in breast cancer patients using radiomics based on T{sub 2}-weighted fat suppression (T{sub 2}-FS) and diffusion-weighted MRI (DWI). We enrolled 146 patients with histologically proven breast cancer. All underwent pretreatment T{sub 2}-FS and DWI MRI scan. In all, 10,962 texture and four non-texture features were extracted for each patient. The 0.623 + bootstrap method and the area under the curve (AUC) were used to select the features. We constructed ten logistic regression models (orders of 1-10) based on different combination of image features using stepwise forward method. For T{sub 2}-FS, model 10 with ten features yielded the highest AUC of 0.847 in the training set and 0.770 in the validation set. For DWI, model 8 with eight features reached the highest AUC of 0.847 in the training set and 0.787 in the validation set. For joint T{sub 2}-FS and DWI, model 10 with ten features yielded an AUC of 0.863 in the training set and 0.805 in the validation set. Full utilisation of breast cancer-specific textural features extracted from anatomical and functional MRI images improves the performance of radiomics in predicting SLN metastasis, providing a non-invasive approach in clinical practice. (orig.)

Renal and perirenal space involvement in acute pancreatitis: An MRI study

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Li, Xing Hui, E-mail: lixinghui1005@126.com [Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000 (China); Zhang, Xiao Ming, E-mail: cjr.zhxm@vip.163.com [Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000 (China); Ji, Yi Fan, E-mail: 526504036@qq.com [Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000 (China); Jing, Zong Lin, E-mail: jzl325@163.com [Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000 (China); Huang, Xiao Hua, E-mail: nc_hxh1966@yahoo.com.cn [Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000 (China); Yang, Lin, E-mail: linyangmd@163.com [Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000 (China); Zhai, Zhao Hua, E-mail: zhaizhaohuada@163.com [Sichuan Key Laboratory of Medical Imaging, Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000 (China)

2012-08-15

Objectives: To study the prevalence and characteristics of renal and perirenal space involvement and its relation to the severity of acute pancreatitis (AP) using MRI. Methods: 115 patients with AP who underwent MRI with the clinical kidney function test were retrospectively analyzed in this study. MRI sequences included conventional and diffusion weighted imaging (DWI) sequences. The renal and perirenal space involvement in AP was noted on MRI. The renal apparent diffusion coefficient (ADC) on DWI was measured for each kidney. The severity of AP on MRI was graded using MR severity index (MRSI). The relationships among the renal and perirenal space involvement on MRI, the renal ADC, MRSI and the results of the kidney function test were analyzed. Results: In the 115 patients with AP, the renal and perirenal space abnormalities detected included renal parenchymal abnormalities (0.8%), abnormalities of the renal collecting system (2.6%), renal vascular abnormalities (1.7%), thickened renal fascia (99%), perirenal stranding (62%) and perirenal fluid collection (40%). The prevalence of perirenal space abnormalities was correlated with the severity of AP based on MRSI (P < 0.05). The renal ADC values were lower in patients with abnormal kidney function than in those without kidney injury (P < 0.05). The prevalence of kidney function abnormalities was 9.4%, 32% and 100% in mild, moderate, and severe AP cases, respectively (P = 0.00). Conclusion: Perirenal space involvement is much more than renal parenchymal involvement in AP. The prevalence of perirenal space involvement in AP on MRI has a positive correlation with the severity of AP according to MRSI.

Renal and perirenal space involvement in acute pancreatitis: An MRI study

International Nuclear Information System (INIS)

Li, Xing Hui; Zhang, Xiao Ming; Ji, Yi Fan; Jing, Zong Lin; Huang, Xiao Hua; Yang, Lin; Zhai, Zhao Hua

2012-01-01

Objectives: To study the prevalence and characteristics of renal and perirenal space involvement and its relation to the severity of acute pancreatitis (AP) using MRI. Methods: 115 patients with AP who underwent MRI with the clinical kidney function test were retrospectively analyzed in this study. MRI sequences included conventional and diffusion weighted imaging (DWI) sequences. The renal and perirenal space involvement in AP was noted on MRI. The renal apparent diffusion coefficient (ADC) on DWI was measured for each kidney. The severity of AP on MRI was graded using MR severity index (MRSI). The relationships among the renal and perirenal space involvement on MRI, the renal ADC, MRSI and the results of the kidney function test were analyzed. Results: In the 115 patients with AP, the renal and perirenal space abnormalities detected included renal parenchymal abnormalities (0.8%), abnormalities of the renal collecting system (2.6%), renal vascular abnormalities (1.7%), thickened renal fascia (99%), perirenal stranding (62%) and perirenal fluid collection (40%). The prevalence of perirenal space abnormalities was correlated with the severity of AP based on MRSI (P < 0.05). The renal ADC values were lower in patients with abnormal kidney function than in those without kidney injury (P < 0.05). The prevalence of kidney function abnormalities was 9.4%, 32% and 100% in mild, moderate, and severe AP cases, respectively (P = 0.00). Conclusion: Perirenal space involvement is much more than renal parenchymal involvement in AP. The prevalence of perirenal space involvement in AP on MRI has a positive correlation with the severity of AP according to MRSI.

Contribution of the diffusion-weighted MRI in the diagnosis and follow-up of encephalopathy caused by maple syrup urine disease in a full-term newborn

International Nuclear Information System (INIS)

Ferraz-Filho, Jose Roberto Lopes; Floriano, Valdeci Helio; Quirici, Marcelo Bianco; Souza, Antonio Soares; Albuquerque, Regina Pires de

2009-01-01

The purpose of this case report is to show conventional MRI and diffusion-weighted imaging (DWI) findings of the different evolutionary phases in MSUD (Maple syrup urine disease) of a newborn that evolved with brain white matter lesions (author)

Nonrigid Registration of Prostate Diffusion-Weighted MRI

Directory of Open Access Journals (Sweden)

Lei Hao

2017-01-01

Full Text Available Motion and deformation are common in prostate diffusion-weighted magnetic resonance imaging (DWI during acquisition. These misalignments lead to errors in estimating an apparent diffusion coefficient (ADC map fitted with DWI. To address this problem, we propose an image registration algorithm to align the prostate DWI and improve ADC map. First, we apply affine transformation to DWI to correct intraslice motions. Then, nonrigid registration based on free-form deformation (FFD is used to compensate for intraimage deformations. To evaluate the influence of the proposed algorithm on ADC values, we perform statistical experiments in three schemes: no processing of the DWI, with the affine transform approach, and with FFD. The experimental results show that our proposed algorithm can correct the misalignment of prostate DWI and decrease the artifacts of ROI in the ADC maps. These ADC maps thus obtain sharper contours of lesions, which are helpful for improving the diagnosis and clinical staging of prostate cancer.

Neonatal brain structure on MRI and diffusion tensor imaging, sex, and neurodevelopment in very-low-birthweight preterm children.

Science.gov (United States)

Rose, Jessica; Butler, Erin E; Lamont, Lauren E; Barnes, Patrick D; Atlas, Scott W; Stevenson, David K

2009-07-01

The neurological basis of an increased incidence of cerebral palsy (CP) in preterm males is unknown. This study examined neonatal brain structure on magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) at term-equivalent age, sex, and neurodevelopment at 1 year 6 months on the basis of the Amiel-Tison neurological examination, Gross Motor Function Classification System, and Bayley Scales of Infant Development in 78 very-low-birthweight preterm children (41 males, 37 females; mean gestational age 27.6 wks, SD 2.5; mean birthweight 1021 g, SD 339). Brain abnormalities on MRI and DTI were not different between males and females except in the splenium of the corpus callosum, where males had lower DTI fractional anisotropy (p=0.025) and a higher apparent diffusion coefficient (p=0.013), indicating delayed splenium development. In the 26 infants who were at higher risk on the basis of DTI, males had more abnormalities on MRI (p=0.034) and had lower fractional anisotropy and a higher apparent diffusion coefficient in the splenium (p=0.049; p=0.025) and right posterior limb of the internal capsule (PLIC; p=0.003; p=0.033). Abnormal neurodevelopment was more common in males (n=9) than in females (n=2; p=0.036). Children with abnormal neurodevelopment had more abnormalities on MRI (p=0.014) and reduced splenium and right PLIC fractional anisotropy (p=0.001; p=0.035). In children with abnormal neurodevelopment, right PLIC fractional anisotropy was lower than left (p=0.035), whereas in those with normal neurodevelopment right PLIC fractional anisotropy was higher than left (p=0.001). Right PLIC fractional anisotropy correlated to neurodevelopment (rho=0.371, p=0.002). Logistic regression predicted neurodevelopment with 94% accuracy; only right PLIC fractional anisotropy was a significant logistic coefficient. Results indicate that the higher incidence of abnormal neurodevelopment in preterm males relates to greater incidence and severity of brain abnormalities

Magnetic resonance imaging of epidermoid, including diffusion weighted images and an atypical case

International Nuclear Information System (INIS)

Takahashi, Shoki; Higano, Shuichi; Kurihara, Noriko

1994-01-01

In order to study the role of magnetic resonance imaging (MRI) in diagnosing intracranial epidermoid, we evaluated the MRI findings on five cases with such tumor, all of which were surgically verified. In addition to standard spin-echo (SE) images obtained in all cases, diffusion-weighted images were acquired in two patients. In four patients, the tumor revealed to be almost isointense relative to cerebrospinal fluid (CSF) on both T 1 -and T 2 -weighted images, while it tended to show slightly hyperintense to CSF on proton-density-weighted images; thus, based on the signal intensity on standard SE images the distinction between epidermoid and arachnoid cyst may be difficult. Furthermore, the presence of the tumor which has a tendency to grow in and along the subarachnoid space causing relatively minimal mass effect may be overlooked. Diffusion-weighted images were shown to have advantages in such cases by demonstrating the tumor unequivocally as a mass of high signal, and differentiating it from arachnoid cysts. In the remaining patient, its appearance was atypical, showing bright signal on both T 1 -and T 2 -weighted images. In conclusion free of bone artifacts, multiplanar MRI with additional diffusion-weighted images provides a clear demonstration of epidermoid, and its differentiation from arachnoid cyst, thus obviating the need for CT cisternography. (author)

Liver Imaging Reporting and Data System on CT and gadoxetic acid-enhanced MRI with diffusion-weighted imaging

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Cha, Dong Ik; Jang, Kyung Mi; Kim, Seong Hyun; Kang, Tae Wook; Song, Kyoung Doo [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of)

2017-10-15

To assess major imaging features of Liver Imaging Reporting and Data System (LI-RADS) on contrast-enhanced CT and gadoxetic acid-enhanced MRI and to estimate whether the combination of signal intensity favouring HCC on hepatobiliary phase (HBP) and diffusion-weighted images (DWI) can act as a major feature in LI-RADS. Four hundred twenty one patients with 445 observations were included. Major features of LI-RADS on CT and MRI as well as HBP and DWI features were assessed. Diagnostic performances of LR-5 according to LI-RADS v2014 and modified LI-RADS which incorporate combination of HBP and DWI were assessed. Pairwise comparisons of the receiver operating characteristic (ROC) curves were performed. For HCCs, capsule appearance had the highest rate of discordance between CT and MRI (32.7%), followed by washout appearance (22.2%). Specificity (75%) of LR-5 of LI-RADS v2014 was lower than that (77.1-79.2%) of modified LI-RADS. Area under the ROC curve of modified LI-RADS (0.755-0.775) was not significantly different from that of LI-RADS v 2014 (0.709) (p > 0.05). There were substantial discordances between CT and MRI for capsule and washout appearances in hepatic observations, and combination of gadoxetic acid-enhanced MRI and DWI might be able to be incorporated as a major feature of LI-RADS. (orig.)

Diffusion-weighted magnetic resonance imaging (MRI) in acute brain stem infarction

International Nuclear Information System (INIS)

Narisawa, Aya; Shamoto, Hiroshi; Shimizu, Hiroaki; Tominaga, Teiji; Yoshimoto, Takashi

2001-01-01

Diffusion-weighted magnetic resonance imaging (DWI) provides one of the earliest demonstrations of ischemic lesions. However some lesions may be missed in the acute stage due to technical limitation of DWI. We therefore conducted the study to clarify the sensitivity of DWI to acute brain stem infarctions. Twenty-eight patients with the final diagnosis of brain stem infarction (midbrain 2, pons 9, medulla oblongata 17) who had been examined by DWI within 24 hours of onset were retrospectively analyzed for how sensitively the initial DWI demonstrated the final ischemic lesion. Only obvious (distinguishable with DWI alone without referring clinical symptoms and other informations) hyperintensity on DWI was regarded to show an ischemic lesion. Sixteen (57.1%) out of 28 patients had brain stem infarctions demonstrated by initial DWI. In the remaining 12 cases, no obvious ischemic lesion was evident on initial DWI. Subsequent MRI studies obtained 127 hours, on average after the onset showed infarction in the medulla oblongate in 11 cases and in the pons in one case. Negative findings of DWI in the acute stage does not exclude possibility of the brain stem infarction, in particularly medulla oblongata infarction. (author)

Superselective intra-arterial fibrinolysis for acute cerebral ischemic infarct : usefulness of diffusion weighted MR imaging

International Nuclear Information System (INIS)

Byun, Woo Mok; Lee, Se Jin; Kim, Yong Sun; Han, Gun Soo; Bae, Won Kyong

1999-01-01

To evaluate the efficacy of superselective intra-arterial fibrinolysis for acute cerebral stroke and the usefulness of pre-and postfibrinolysis diffusion-weighted MRI (DWI). In 41 patients with acute ischemic stroke whose treatment involved intra-arterial fibrinolysis, the occlusion site, degree of recanalization, and clinical results were compared. In 12 patients, diffusion weighted MRI was performed before fibrinolysis, and eight of these also underwent diffusion-weighted MRI after fibrinolysis. Using diffusion-weighted MRI, neurological outcomes were compared with signal intensity ratio (SIR, or the average signal intensity within the region of interest divided by that in the contralateral, nonischemic, homologous region). Twenty patients showed complete recanalization, nine partial recanalization, and in twelve there was no recanalization. Fourteen patients (34%) improved neurologically. No relationship existed between occlusion sites, degree of recanalization, and clinical outcome. Among 12 patients who underwent DWI before fibrinolysis, complete recanalization was noted in eight. Neurological improvement was seen in four patients with low SIR( 1.7), neurological outcome was poor despite complete recanalization. Although superselective intra-arterial fibrinolysis for acute cerebral stroke is a good therapeutic method for recanalization, the clinical outcome can be disappointing. We therefore suggest that in cases of acute cerebral ischemic infaret, SIR-as seen on DWI-might be useful for predicting the benefits of recanalization. In such cases, further investigation of the use of DWI prior to fibrinolysis is therefore needed

Is diffusion-weighted MRI sufficient for follow-up of neuroendocrine tumour liver metastases?

International Nuclear Information System (INIS)

Lavelle, L.P.; O'Neill, A.C.; McMahon, C.J.; Cantwell, C.P.; Heffernan, E.J.; Malone, D.E.; Daly, L.; Skehan, S.J.

2016-01-01

Aim: To assess if diffusion-weighted imaging (DWI) alone could be used for follow-up of neuroendocrine hepatic metastases. Material and methods: This was a retrospective study, approved by the institutional review board. Twenty-two patients with neuroendocrine liver metastases who had undergone more than one liver magnetic resonance imaging (MRI) examination, (including DWI and using hepatocyte-specific contrast medium) were evaluated. Up to five metastases were measured at baseline and at each subsequent examination. The reference standard measurement was performed on the hepatocyte phase by one reader. Three independent readers separately measured the same lesions on DWI sequences alone, blinded to other sequences, and recorded the presence of any new lesions. Results: The longest diameters of 317 liver metastases (91 on 22 baseline examinations and a further 226 measurements on follow-up) were measured on the reference standard by one reader and on three b-values by three other readers. The mean difference between DWI measurements and the reference standard measurement was between 0.01–0.08 cm over the nine reader/b-value combinations. Based on the width of the Bland and Altman interval containing approximately 95% of the differences between the reader observation and the mean of reference standard and DWI measurement, the narrowest interval over the nine reader/b-value combinations was −0.6 to +0.7 cm and the widest was −0.9 to 1 cm. In the evaluation of overall response using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria, the weighted kappa statistic was between 0.49 and 0.86, indicating moderate-to-good agreement between the reference standard and DWI. Conclusion: The visualisation and measurement of hepatic metastases using DWI alone are within acceptable limits for clinical use, allowing the use of this rapid technique to restage hepatic disease in patients with neuroendocrine metastases. - Highlights: • DWI showed excellent

Additional value of diffusion-weighted imaging to evaluate multifocal and multicentric breast cancer detected using pre-operative breast MRI

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Song, Sung Eun; Park, Eun Kyung; Cho, Kyu Ran; Cho, Sung Bum [Korea University Anam Hospital, Korea University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seo, Bo Kyoung [Korea University Ansan Hospital, Korea University College of Medicine, Department of Radiology, Ansan (Korea, Republic of); Woo, Ok Hee [Korea University Guro Hospital, Korea University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Jung, Seung Pil [Korea University Anam Hospital, Korea University College of Medicine, Department of Surgery, Seoul (Korea, Republic of)

2017-11-15

To investigate whether diffusion-weighted imaging (DWI) aids pre-operative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to evaluate additional lesions in breast cancer patients. DCE-MRI and DWI were performed on 131 lesions, with available histopathological results. The apparent diffusion coefficient (ADC) of each lesion was measured, and the cut-off value for differentiation between malignant and benign lesions was calculated. A protocol combining the ADC cut-off value with DCE-MRI was validated in a cohort of 107 lesions in 77 patients. When an ADC cut-off value of 1.11 x 10{sup -3} mm{sup 2}/s from the development cohort was applied to the additional lesions in the validation cohort, the specificity increased from 18.9% to 67.6% (P < 0.001), and the diagnostic accuracy increased from 61.7% to 82.2% (P = 0.05), without significant loss of sensitivity (98.6% vs. 90.0%, P = 0.07). The negative predictive values of lesions in the same quadrant had decreased, as had those of lesions ≥1 cm in diameter. The ADC cut-off value in the validation cohort was 1.05 x 10{sup -3} mm{sup 2}/s. Additional implementation of DWI for breast lesions in pre-operative MRI can help to obviate unnecessary biopsies by increasing specificity. However, to avoid missing cancers, clinicians should closely monitor lesions located in the same quadrant or lesions ≥1 cm. (orig.)

False-negative diffusion-weighted imaging findings in acute stroke

International Nuclear Information System (INIS)

Ishikawa, Tatsuya; Yuasa, Naoki; Otomo, Takashi; Shiramizu, Hideki; Matsuda, Hiroshi; Kitagawa, Yasuhisa; Takagi, Shigeharu

2006-01-01

The utility of DWI (diffusion-weighted imaging) has been established in acute ischemic stroke. However, some patients with acute stroke show no abnormal signals on DWI, despite the presence of infarction (false-negative DWI). We analyzed the relationship between false-negative DWI and the clinical manifestations of acute ischemic stroke in 151 DWI-positive (89%) and 19 false-negative DWI (11%) patients. We performed MRI within 24 hours after onset at our hospital. Non-specific clinical manifestations, including vertigo and nausea, were frequently observed in false-negative DWI patients. As regards the vascular territory, false-negative DWI was noted in 15.3% of 59 patients with infarctions within the territory of the vertebrobasilar artery. Concerning the duration from onset to initial imaging, 73.7% of the patients with false-negative DWI findings underwent MRI examination within 6 hours after onset. Of the patients with false-negative DWI, 84.2% had lacunar infarction (χ 2 =16.4, P<0.001). In conclusion, false negative DWI is more frequently observed in lacunar infarction than in atherothrombotic infarction or cardiogenic embolism. It is important to examine carefully the neurological changes occurring in patients who present with acute stroke, but have negative DWI findings. (author)

Cerebral perfusion abnormalities in therapy-resistant epilepsy in childhood: comparison between EEG, MRI and 99Tcm-ECD brain SPET.

Science.gov (United States)

Vattimo, A; Burroni, L; Bertelli, P; Volterrani, D; Vella, A

1996-01-01

We performed 99Tcm-ethyl cysteinate dimer (ECD) interictal single photon emission tomography (SPET) in 26 children with severe therapy-resistant epilepsy. All the children underwent a detailed clinical examination, an electroencephalogram (EEG) investigation and brain magnetic resonance imaging (MRI). In 21 of the 26 children, SPET demonstrated brain blood flow abnormalities, in 13 cases in the same territories that showed EEG alterations. MRI showed structural lesions in 6 of the 26 children, while SPET imaging confirmed these abnormalities in only 5 children. The lesion not detected on SPET was shown to be 3 mm thick on MRI. Five symptomatic patients had normal SPET. In one of these patients, the EEG findings were normal and MRI revealed a small calcific nodule (4 mm thick); in the others, the EEG showed non-focal but diffuse abnormalities. These data confirm that brain SPET is sensitive in detecting and localizing hypoperfused areas that could be associated with epileptic foci in this group of patients, even when the MRI image is normal.

Assessment of early renal allograft dysfunction with blood oxygenation level-dependent MRI and diffusion-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Park, Sung Yoon [Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Chan Kyo, E-mail: chankyokim@skku.edu [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Park, Byung Kwan [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Sung Ju; Lee, Sanghoon [Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Huh, Wooseong [Department of Nephrology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2014-12-15

Highlights: • R2* and ADC in renal allografts are moderately correlated with eGFR. • R2* and ADC are lower in early allograft dysfunction than normal allograft function. • No significant difference between AR and ATN was found in both R2* and ADC. - Abstract: Purpose: To investigate blood oxygenation level-dependent (BOLD) MRI and diffusion-weighted imaging (DWI) at 3 T for assessment of early renal allograft dysfunction. Materials and methods: 34 patients with a renal allograft (early dysfunction, 24; normal, 10) were prospectively enrolled. BOLD MRI and DWI were performed at 3 T. R2* and apparent diffusion coefficient (ADC) values were measured in cortex and medulla of the allografts. Correlation between R2* or ADC values and estimated glomerular filtration rate (eGFR) was investigated. R2* or ADC values were compared among acute rejection (AR), acute tubular necrosis (ATN) and normal function. Results: In all renal allografts, cortical or medullary R2* and ADC values were moderately correlated with eGFR (P < 0.05). Early dysfunction group showed lower R2* and ADC values than normal function group (P < 0.05). AR or ATN had lower R2* values than normal allografts (P < 0.05), and ARs had lower cortical ADC values than normal allografts (P < 0.05). No significant difference of R2* or ADC values was found between AR and ATN (P > 0.05). Conclusion: BOLD MRI and DWI at 3 T may demonstrate early functional state of renal allografts, but may be limited in characterizing a cause of early renal allograft dysfunction. Further studies are needed.

Differentiation of prostate cancer lesions in the Transition Zone by diffusion-weighted MRI

Directory of Open Access Journals (Sweden)

Jie Bao

Full Text Available Objective: To differentiate prostate cancer lesions in transition zone by diffusion-weighted-MRI (DW-MRI. Methods: Data from a total of 63 patients who underwent preoperative DWI (b of 0–1000 s/mm2 were prospectively collected and processed by a monoexponential (DWI model and compared with a biexponential (IVIM model for quantitation of apparent diffusion coefficients (ADCs, perfusion fraction f, diffusivity D and pseudo-diffusivity D*. Histogram analyses were performed by outlining entire-tumor regions of interest (ROIs. These parameters (separately and combined in a logistic regression model were used to differentiate lesions depending on histopathological analysis of Magnetic Resonance/transrectal Ultrasound (MR/TRUS fusion-guided biopsy. The diagnostic ability of differentiate the PCa from BHP in TZ was analyzed by ROC regression. Histogram analysis of quantitative parameters and Gleason score were assessed with Spearman correlation. Results: Thirty (30 foci cases of PCa in PZ and 33 (36 foci cases of BPH were confirmed by pathology. Mean ADC, median ADC, 10th percentile ADC, 90th percentile ADC, kurtosis and skewness of ADC and mean D values, median D and 90th percentile D differed significantly between PCa and BHP in TZ. The highest classification accuracy was achieved by the mean ADC (0.841 and mean D (0.809. A logistic regression model based on mean ADC and mean D led to an AUC of 0.873, however, the difference is not significant. There were 7 Gleason 6 areas, 9 Gleason 7 areas, 8 Gleason 8 areas, 5 Gleason 9 areas and 2 Gleason 10 areas detected from the 31 prostate cancer areas, the mean Gleason value was(7.5 ± 1.2. The mean ADC and mean D had correlation with Gleason score(r = −0.522 and r = −0.407 respectively, P < 0.05. Conclusion: The diagnosis efficiency of IVIM parameters was not superior to ADC in the diagnosis of PCa in TZ. Moreover, the combination of mean ADC and mean D did not

Role of diffusion-weighted echo-planar MRI in distinguishing between brain abscess and tumour: a preliminary report

International Nuclear Information System (INIS)

Noguchi, K.; Watanabe, N.; Nagayoshi, T.; Kanazawa, T.; Toyoshima, S.; Shimizu, M.; Seto, H.

1999-01-01

Our purpose was to evaluate diffusion-weighted (DW) echo-planar MRI in differentiating between brain abscess and tumour. We examined two patients with surgically confirmed pyogenic brain abscess and 18 with metastatic brain tumours or high-grade glioma, using a 1.5 T system. The apparent diffusion coefficient (ADC) of each necrotic or solid contrast-enhancing lesion was measured with two different b values (20 and 1200 s/mm 2 ). All capsule-stage brain abscesses (4 lesions) and zones of cerebritis (2 lesions) were identified on high-b-value DWI as markedly high-signal areas of decreased ADC (range, 0.58-0.70 [(10-3 mm 2 /s; mean, 0.63)]). All cystic or necrotic portions of brain tumours (14 lesions) were identified on high-b-value DWI as low-signal areas of increased ADC (range, 2.20-3.20 [(10-3 mm 2 /s; mean, 2.70)]). Solid, contrast-enhancing portions of brain tumours (19 lesions) were identified on high-b-value DWI as high-signal areas of sightly decreased or increased ADC (range, 0.77-1.29 [(10-3 mm 2 /s; mean, 0.94)]). Our preliminary results indicate that DW echo-planar MRI be used for distinguishing between brain abscess and tumour. (orig.) (orig.)

Diffusion-Weighted MRI in Creutzfeldt-Jakob Disease: Focus on the Cerebral Cortex and Chronologic Change

International Nuclear Information System (INIS)

Lee, Jeong Eun; Song, Chang Joon; Lee, In Ho; Yu, In Kyu; Choi, See Sung

2010-01-01

To evaluate high cortical signal intensity and chronologic changes for diffusion-weighted MR imaging (DWI) in sporadic Creutzfeldt-Jakob disease. We retrospectively analyzed the DWI results of 16 patients with probable CJD (according to WHO criteria) and evaluated the distribution, extent and bilaterality of the lesions in the cortex, basal ganglia and thalamus. We also reviewed the chronologic changes of the lesions by evaluating the followup MR examination results in 8 of 16 patients. Cortical abnormalities were present in 15 (94%) of 16 patients. Isolated cortical involvement was present in 6 patients (40%), while the combined involvement of the cortex and basal ganglia was present in 9 patients (60%). The distribution of the lesions was bilateral in 12 patients and predominantly on the right side in 8 patients. Upon follow-up MR imaging, the cortical lesions showed progress in terms of extent and signal intensity. Basal ganglia abnormalities were present in 9 of 15 patients. Moreover, 4 of 6 patients who had no abnormal signal intensity in the basal ganglia on the initial MR imaging results, showed abnormally high signal intensity upon follow-up MR imaging. The characteristically high cortical signal intensities on DWI in an elderly patient with rapidly progressive dementia should point to the diagnosis of early phase CJD and might be useful for the differential diagnosis

Diffusion-Weighted MRI in Creutzfeldt-Jakob Disease: Focus on the Cerebral Cortex and Chronologic Change

Energy Technology Data Exchange (ETDEWEB)

Lee, Jeong Eun; Song, Chang Joon; Lee, In Ho [Chungnam National University, Daejeon (Korea, Republic of); Yu, In Kyu [Eulji University Hospital, Seoul (Korea, Republic of); Choi, See Sung [Wonkwang University Hospital, Iksan (Korea, Republic of)

2010-08-15

To evaluate high cortical signal intensity and chronologic changes for diffusion-weighted MR imaging (DWI) in sporadic Creutzfeldt-Jakob disease. We retrospectively analyzed the DWI results of 16 patients with probable CJD (according to WHO criteria) and evaluated the distribution, extent and bilaterality of the lesions in the cortex, basal ganglia and thalamus. We also reviewed the chronologic changes of the lesions by evaluating the followup MR examination results in 8 of 16 patients. Cortical abnormalities were present in 15 (94%) of 16 patients. Isolated cortical involvement was present in 6 patients (40%), while the combined involvement of the cortex and basal ganglia was present in 9 patients (60%). The distribution of the lesions was bilateral in 12 patients and predominantly on the right side in 8 patients. Upon follow-up MR imaging, the cortical lesions showed progress in terms of extent and signal intensity. Basal ganglia abnormalities were present in 9 of 15 patients. Moreover, 4 of 6 patients who had no abnormal signal intensity in the basal ganglia on the initial MR imaging results, showed abnormally high signal intensity upon follow-up MR imaging. The characteristically high cortical signal intensities on DWI in an elderly patient with rapidly progressive dementia should point to the diagnosis of early phase CJD and might be useful for the differential diagnosis.

Tensor Based Representation and Analysis of Diffusion-Weighted Magnetic Resonance Images

Science.gov (United States)

Barmpoutis, Angelos

2009-01-01

Cartesian tensor bases have been widely used to model spherical functions. In medical imaging, tensors of various orders can approximate the diffusivity function at each voxel of a diffusion-weighted MRI data set. This approximation produces tensor-valued datasets that contain information about the underlying local structure of the scanned tissue.…

The role of diffusion weighted magnetic resonance imaging in ...

African Journals Online (AJOL)

Aim of the work: To demonstrate the role of Diffusion Weighted Imaging and ADC maps in assessing normal progression of the infantile brain myelination. Patients and methods: The present work included 30 infants with normal MRI study of the brain, normal psychomotor development and normal neurological examination.

Short-term evolution of spinal cord damage in multiple sclerosis: a diffusion tensor MRI study

International Nuclear Information System (INIS)

Theaudin, M.; Denier, C.; Adams, D.; Saliou, G.; Ducot, B.; Deiva, K.; Ducreux, D.

2012-01-01

The potential of diffusion tensor imaging (DTI) to detect spinal cord abnormalities in patients with multiple sclerosis has already been demonstrated. The objective of this study was to apply DTI techniques to multiple sclerosis patients with a recently diagnosed spinal cord lesion, in order to demonstrate a correlation between variations of DTI parameters and clinical outcome, and to try to identify DTI parameters predictive of outcome. A prospective single-centre study of patients with spinal cord relapse treated by intravenous steroid therapy was made. Patients were assessed clinically and by conventional MRI with DTI sequences at baseline and at 3 months. Sixteen patients were recruited. At 3 months, 12 patients were clinically improved. All but one patient had lower fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values than normal subjects in either inflammatory lesions or normal-appearing spinal cord. Patients who improved at 3 months presented a significant reduction in the radial diffusivity (p = 0.05) in lesions during the follow-up period. They also had a significant reduction in the mean ADC (p = 0.002), axial diffusivity (p = 0.02), radial diffusivity (p = 0.02) and a significant increase in FA values (p = 0.02) in normal-appearing spinal cord. Patients in whom the American Spinal Injury Association sensory score improved at 3 months showed a significantly higher FA (p = 0.009) and lower radial diffusivity (p = 0.04) in inflammatory lesion at baseline compared to patients with no improvement. DTI MRI detects more extensive abnormalities than conventional T2 MRI. A less marked decrease in FA value and more marked decreased in radial diffusivity inside the inflammatory lesion were associated with better outcome. (orig.)

Short-term evolution of spinal cord damage in multiple sclerosis: a diffusion tensor MRI study

Energy Technology Data Exchange (ETDEWEB)

Theaudin, M.; Denier, C.; Adams, D. [AP-HP, CHU Bicetre, Service de Neurologie Adultes, Le Kremlin-Bicetre (France); INSERM, UMR788, Faculte de Medecine Paris Sud, Le Kremlin-Bicetre (France); Saliou, G. [AP-HP, CHU Bicetre, Service de Neuroradiologie, Le Kremlin-Bicetre (France); Ducot, B. [INSERM, U1018, CESP Centre for Research in Epidemiology and Population Health, Faculte de Medecine Paris Sud, Le Kremlin-Bicetre (France); Deiva, K. [Service de Neuropediatrie, Le Kremlin-Bicetre (France); Ducreux, D. [INSERM, UMR788, Faculte de Medecine Paris Sud, Le Kremlin-Bicetre (France); AP-HP, CHU Bicetre, Service de Neuroradiologie, Le Kremlin-Bicetre (France)

2012-10-15

The potential of diffusion tensor imaging (DTI) to detect spinal cord abnormalities in patients with multiple sclerosis has already been demonstrated. The objective of this study was to apply DTI techniques to multiple sclerosis patients with a recently diagnosed spinal cord lesion, in order to demonstrate a correlation between variations of DTI parameters and clinical outcome, and to try to identify DTI parameters predictive of outcome. A prospective single-centre study of patients with spinal cord relapse treated by intravenous steroid therapy was made. Patients were assessed clinically and by conventional MRI with DTI sequences at baseline and at 3 months. Sixteen patients were recruited. At 3 months, 12 patients were clinically improved. All but one patient had lower fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values than normal subjects in either inflammatory lesions or normal-appearing spinal cord. Patients who improved at 3 months presented a significant reduction in the radial diffusivity (p = 0.05) in lesions during the follow-up period. They also had a significant reduction in the mean ADC (p = 0.002), axial diffusivity (p = 0.02), radial diffusivity (p = 0.02) and a significant increase in FA values (p = 0.02) in normal-appearing spinal cord. Patients in whom the American Spinal Injury Association sensory score improved at 3 months showed a significantly higher FA (p = 0.009) and lower radial diffusivity (p = 0.04) in inflammatory lesion at baseline compared to patients with no improvement. DTI MRI detects more extensive abnormalities than conventional T2 MRI. A less marked decrease in FA value and more marked decreased in radial diffusivity inside the inflammatory lesion were associated with better outcome. (orig.)

Histological grade of differentiation of hepatocellular carcinoma: comparison of the efficacy of diffusion-weighted MRI with T2-weighted imaging and angiography-assisted CT

International Nuclear Information System (INIS)

Saito, Kazuhiro; Nishio, Ryota; Saguchi, Toru; Akata, Soichi; Tokuuye, Koichi; Moriyasu, Fuminori; Sugimoto, Katsutoshi

2012-01-01

The purpose of this study is to determine the usefulness of diffusion-weighted imaging (DWI) for evaluating the histological grade of differentiation of hepatocellular carcinoma (HCC) compared with T2-weighted imaging (T2WI) and tumour haemodynamics. We retrospectively evaluated 32 patients with 42 pathologically confirmed HCC nodules. These patients underwent MRI, CT during arterial portography and CT hepatic arteriography. We evaluated the relationship between the histological grade of differentiation and the apparent diffusion coefficient (ADC) values, conspicuity of tumour on DWI, DWI and T2WI contrast-to-noise (C/N) ratios and tumour haemodynamics. There was no correlation between the histological grade of differentiation and the ADC values. The DWI C/N ratio was significantly different among all histological grades, but the T2WI C/N ratio was not. Tumour conspicuity on DWI correlated well with the histological grade of differentiation, but tumour haemodynamics only partially correlated with the histological grade of differentiation. DWI was useful for evaluating the histological grade of differentiation of HCC.

Computational Diffusion MRI : MICCAI Workshop

CERN Document Server

Grussu, Francesco; Ning, Lipeng; Tax, Chantal; Veraart, Jelle

2018-01-01

This volume presents the latest developments in the highly active and rapidly growing field of diffusion MRI. The reader will find numerous contributions covering a broad range of topics, from the mathematical foundations of the diffusion process and signal generation, to new computational methods and estimation techniques for the in-vivo recovery of microstructural and connectivity features, as well as frontline applications in neuroscience research and clinical practice. These proceedings contain the papers presented at the 2017 MICCAI Workshop on Computational Diffusion MRI (CDMRI’17) held in Québec, Canada on September 10, 2017, sharing new perspectives on the most recent research challenges for those currently working in the field, but also offering a valuable starting point for anyone interested in learning computational techniques in diffusion MRI. This book includes rigorous mathematical derivations, a large number of rich, full-colour visualisations and clinically relevant results. As such, it wil...

Diffusion-weighted MRI of the prostate at 3.0 T: comparison of endorectal coil (ERC) MRI and phased-array coil (PAC) MRI-The impact of SNR on ADC measurement.

Science.gov (United States)

Mazaheri, Yousef; Vargas, H Alberto; Nyman, Gregory; Shukla-Dave, Amita; Akin, Oguz; Hricak, Hedvig

2013-10-01

To compare ADC values measured from diffusion-weighted MR (DW-MR) images of the prostate obtained with both endorectal and phased-array coils (ERC+PAC) to those from DW-MRI images obtained with an eight-channel torso phased-array coil (PAC) at 3.0 T. The institutional review board issued a waiver of informed consent for this HIPAA-compliant study. Twenty-five patients with biopsy-proven prostate cancer underwent standard 3-T MRI using 2 different coil arrangements (ERC+PAC and PAC only) in the same session. DW-MRI at five b-values (0, 600, 1000, 1200, and 1500 s/mm(2)) were acquired using both coil arrangements. On b=0 images, signal-to-noise ratios (SNRs) were measured as the ratio of the mean signal from PZ and TZ ROIs to the standard deviation from the mean signal in an artifact-free ROI in the rectum. Matching regions-of-interest (ROIs) were identified in the peripheral zone and transition zone on ERC-MRI and PAC-MRI. For each ROI, mean ADC values for all zero and non-zero b-value combinations were computed. Mean SNR with ERC-MRI at PZ (66.33 ± 27.07) and TZ (32.69 ± 12.52) was 9.27 and 5.52 times higher than with PAC-MRI ((7.32 ± 2.30) and (6.13 ± 1.56), respectively) (PERC-MRI (PERC. To address these requirements, clinical MR systems should have image processing capabilities which incorporate the noise distribution. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Early Conventional MRI for Prediction of Neurodevelopmental Impairment in Extremely-Low-Birth-Weight Infants.

Science.gov (United States)

Slaughter, Laurel A; Bonfante-Mejia, Eliana; Hintz, Susan R; Dvorchik, Igor; Parikh, Nehal A

2016-01-01

Extremely-low-birth-weight (ELBW; ≤1,000 g) infants are at high risk for neurodevelopmental impairments. Conventional brain MRI at term-equivalent age is increasingly used for prediction of outcomes. However, optimal prediction models remain to be determined, especially for cognitive outcomes. The aim was to evaluate the accuracy of a data-driven MRI scoring system to predict neurodevelopmental impairments. 122 ELBW infants had a brain MRI performed at term-equivalent age. Conventional MRI findings were scored with a standardized algorithm and tested using a multivariable regression model to predict neurodevelopmental impairment, defined as one or more of the following at 18-24 months' corrected age: cerebral palsy, bilateral blindness, bilateral deafness requiring amplification, and/or cognitive/language delay. Results were compared with a commonly cited scoring system. In multivariable analyses, only moderate-to-severe gyral maturational delay was a significant predictor of overall neurodevelopmental impairment (OR: 12.6, 95% CI: 2.6, 62.0; p neurodevelopmental impairment/death. Diffuse cystic abnormality was a significant predictor of cerebral palsy (OR: 33.6, 95% CI: 4.9, 229.7; p neurodevelopmental impairment. In our cohort, conventional MRI at term-equivalent age exhibited high specificity in predicting neurodevelopmental outcomes. However, sensitivity was suboptimal, suggesting additional clinical factors and biomarkers are needed to enable accurate prognostication. © 2016 S. Karger AG, Basel.

Incidence of postangiographic silent brain infarction detected by diffusion-weighted MR imaging

International Nuclear Information System (INIS)

Mori, Harushi; Hayashi, Naoto; Aoki, Shigeki

2002-01-01

We surveyed to assess for the incidence of clinically silent brain infarction after cerebral catheter angiography. Diffusion-weighted images were performed shortly after 33 cerebral catheter angiographies. We found totally 11 abnormally high intensity spots in 5 of 33 patients on diffusion-weighted images and, therefore, the incidence was calculated as 15.2%. This incidence is higher than has been estimated based on the incidence of neurological deficits (about 0.5%) after cerebral angiography. Diffusion-weighted MR imaging is suitable to monitor the safety of angiographic procedures and material. (author)

IDH mutant and 1p/19q co-deleted oligodendrogliomas: tumor grade stratification using diffusion-, susceptibility-, and perfusion-weighted MRI

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Lin, Yu; Xing, Zhen; She, Dejun; Yang, Xiefeng; Zheng, Yingyan; Xiao, Zebin; Cao, Dairong [First Affiliated Hospital of Fujian Medical University, Department of Radiology, Fuzhou, Fujian (China); Wang, Xingfu [First Affiliated Hospital of Fujian Medical University, Department of Pathology, Fuzhou (China)

2017-06-15

Currently, isocitrate dehydrogenase (IDH) mutation and 1p/19q co-deletion are proven diagnostic biomarkers for both grade II and III oligodendrogliomas (ODs). Non-invasive diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI), and dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI) are widely used to provide physiological information (cellularity, hemorrhage, calcifications, and angiogenesis) of neoplastic histology and tumor grade. However, it is unclear whether DWI, SWI, and DSC-PWI are able to stratify grades of IDH-mutant and 1p/19q co-deleted ODs. We retrospectively reviewed the conventional MRI (cMRI), DWI, SWI, and DSC-PWI obtained on 33 patients with IDH-mutated and 1p/19q co-deleted ODs. Features of cMRI, normalized ADC (nADC), intratumoral susceptibility signals (ITSSs), normalized maxim CBV (nCBV), and normalized maximum CBF (nCBF) were compared between low-grade ODs (LGOs) and high-grade ODs (HGOs). Receiver operating characteristic curve and logistic regression were applied to determine diagnostic performances. HGOs tended to present with prominent edema and enhancement. nADC, ITSSs, nCBV, and nCBF were significantly different between groups (all P < 0.05). The combination of SWI and DSC-PWI for grading resulted in sensitivity and specificity of 100.00 and 93.33%, respectively. IDH-mutant and 1p/19q co-deleted ODs can be stratified by grades using cMRI and advanced magnetic resonance imaging techniques including DWI, SWI, and DSC-PWI. Combined ITSSs with nCBV appear to be a promising option for grading molecularly defined ODs in clinical practice. (orig.)

Whole-Body MRI Virtual Autopsy Using Diffusion-weighted Imaging With Background Suppression (DWIBS) at 3 T in a Child Succumbing to Chordoma.

Science.gov (United States)

Andronikou, Savvas; Kemp, Marnie L; Meiring, Michelle

2017-03-01

We report the use of diffusion-weighted imaging with background suppression (DWIBS) in pediatric virtual magnetic resonance imaging (MRI) autopsy of a child who succumbed to chordoma. A 10-year-old girl who succumbed to relapse of a chordoma underwent whole-body virtual MRI autopsy 12 hours postmortem with short Tau inversion recovery (STIR) and DWIBS on 3 T, which demonstrated the primary mass, local and cardiac invasion, and metastatic disease to the thorax, abdomen, head/neck, and musculoskeletal system. Postmortem virtual MRI autopsy including DWIBS successfully demonstrated the transthoracic spread of chordoma and invasion of the heart, resulting in blood-borne metastases. Motion and respiratory artifact were not factors during virtual autopsy using DWIBS on 3 T, making ideal use of this technology.

Less Confusion in Diffusion MRI

NARCIS (Netherlands)

Tax, CMW

2016-01-01

With its unique ability to investigate tissue architecture and microstructure in vivo, diffusion MRI (dMRI) has gained tremendous interest and the society has been continuously triggered to develop novel dMRI image analysis approaches. With the overwhelming amount of strategies currently available

Diffusion-weighted magnetic resonance imaging in autoimmune pancreatitis

International Nuclear Information System (INIS)

Taniguchi, Takao; Kobayashi, Hisato; Nishikawa, Koji; Iida, Etsushi; Michigami, Yoshihiro; Morimoto, Emiko; Yamashita, Rikiya; Miyagi, Ken; Okamoto, Motozumi

2009-01-01

The aim of this study was to investigate the usefulness of diffusion-weighted magnetic resonance imaging (DWI MRI) for the diagnosis and evaluation of autoimmune pancreatitis (AIP). A total of 4 consecutive patients with AIP, 5 patients with chronic alcoholic pancreatitis (CP), and 13 patients without pancreatic disease (controls) were studied. DWI was performed in the axial plane with spin-echo echo-planar imaging single-shot sequence. Apparent diffusion coefficients (ADCs) were measured in circular regions of interest in the pancreas. In AIP patients, abdominal MRI was performed before, and 2-4 weeks after steroid treatment. Follow-up study was performed chronologically for up to 11 months in two patients. The correlation between ADCs of the pancreas and the immunoglobulin G4 (IgG4) index (serum IgG4 value/serum IgG4 value before steroid treatment) was evaluated. In the AIP patients, DWI of the pancreas showed high signal intensity, and the ADCs of the pancreas (mean±standard deviation (SD): 0.97±0.18 x 10 -3 mm 2 /s) were significantly lower than those in patients with CP (1.45±0.10 x 10 -3 mm 2 /s) or the controls (1.45±0.16 x 10 -3 mm 2 /s) (Mann-Whitney U-test, P s =-0.80, P<0.05). Autoimmune pancreatitis showed high signal intensity on DWI, which improved after steroid treatment. ADCs reflected disease activity. Thus, diffusion-weighted MRI might be useful for diagnosing AIP, determining the affected area, and evaluating the effect of treatment. (author)

Functional and structural abnormalities associated with empathy in patients with schizophrenia: An fMRI and VBM study

OpenAIRE

Singh, Sadhana; Modi, Shilpi; Goyal, Satnam; Kaur, Prabhjot; Singh, Namita; Bhatia, Triptish; Deshpande, Smita N; Khushu, Subash

2015-01-01

Empathy deficit is a core feature of schizophrenia which may lead to social dysfunction. The present study was carried out to investigate functional and structural abnormalities associated with empathy in patients with schizophrenia using functional magnetic resonance imaging (fMRI) and voxel-based morphometry (VBM). A sample of 14 schizophrenia patients and 14 healthy control subjects matched for age, sex and education were examined with structural high-resolution T1-weighted MRI; fMRI image...

Study of cervical cord injury without radiological abnormality using MRI at injury

International Nuclear Information System (INIS)

Park, Jin-Soo; Ei, Terumi; Uchida, Yoko; Kodai, Yujiro; Yasumatsu, Hideo; Yoshino, Kazutaka; Hirakawa, Takashi.

1994-01-01

This study was undertaken, using MRI at the time of injury, to examine cervical cord injury without radiological abnormality. The subjects were 30 patients (24 men and 6 women) seen during the 4-year period 1989-1993, who ranged in age from 31 to 83 years (an average age of 62.8 years). Of these patients, 10 had a slightly irregular alignment of the vertebral body on plain X-rays. These 10 patients were examined using MRI early after sustaining trauma (within 24 hours in 9 and 48 hours in one). As a result, spinal cord was seen as isointensity on T1-weighted images and hyperintensity on T2-weighted images, corresponding to irregular alignment. These findings suggest that reduction of a dislocation may transiently occur due to patient transfer or natural elasticity, as plain X-rays indicated no evidence of bone abnormalities. Thus injuries like dislocations may have occurred at the time of trauma, and structural changes of the vertebral body may be responsible for the occurrence of cervical spinal cord. Spinal cord injuries, even if not evidenced on plain X-rays, should not be categorized as non-osseous injuries. (N.K.)

Fetal MRI: An approach to practice: A review

Directory of Open Access Journals (Sweden)

Sahar N. Saleem

2014-09-01

Full Text Available MRI has been increasingly used for detailed visualization of the fetus in utero as well as pregnancy structures. Yet, the familiarity of radiologists and clinicians with fetal MRI is still limited. This article provides a practical approach to fetal MR imaging. Fetal MRI is an interactive scanning of the moving fetus owed to the use of fast sequences. Single-shot fast spin-echo (SSFSE T2-weighted imaging is a standard sequence. T1-weighted sequences are primarily used to demonstrate fat, calcification and hemorrhage. Balanced steady-state free-precession (SSFP, are beneficial in demonstrating fetal structures as the heart and vessels. Diffusion weighted imaging (DWI, MR spectroscopy (MRS, and diffusion tensor imaging (DTI have potential applications in fetal imaging. Knowing the developing fetal MR anatomy is essential to detect abnormalities. MR evaluation of the developing fetal brain should include recognition of the multilayered-appearance of the cerebral parenchyma, knowledge of the timing of sulci appearance, myelination and changes in ventricular size. With advanced gestation, fetal organs as lungs and kidneys show significant changes in volume and T2-signal. Through a systematic approach, the normal anatomy of the developing fetus is shown to contrast with a wide spectrum of fetal disorders. The abnormalities displayed are graded in severity from simple common lesions to more complex rare cases. Complete fetal MRI is fulfilled by careful evaluation of the placenta, umbilical cord and amniotic cavity. Accurate interpretation of fetal MRI can provide valuable information that helps prenatal counseling, facilitate management decisions, guide therapy, and support research studies.

Analysis of the utility of diffusion-weighted MRI and apparent diffusion coefficient values in distinguishing central nervous system toxoplasmosis from lymphoma

International Nuclear Information System (INIS)

Schroeder, Paul C.; Donovan Post, M. Judith; Bruce-Gregorios, Jocelyn; Oschatz, Elizabeth; Stadler, Alfred; Thurnher, Majda M.

2006-01-01

Toxoplasmosis and lymphoma are common lesions of the central nervous system in patients with AIDS. It is often difficult to distinguish between these lesions both clinically and radiographically. Previous research has demonstrated restricted diffusion within cerebral lymphomas and bacterial abscesses. However, little work has been done to evaluate the diffusion characteristics of toxoplasmosis lesions. This study was designed to explore further the utility of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps and values in making the distinction between toxoplasmosis and lymphoma. The magnetic resonance imaging (MRI) studies of 36 patients, including 22 with toxoplasmosis (all of whom had AIDS) and 14 with lymphoma (8 of whom had AIDS), at two institutions were reviewed retrospectively. The characteristics of the lesions on DWI were evaluated, and the ADC ratios of the lesions were calculated and compared. There was significant overlap of the ADC ratios of toxoplasma and lymphoma, most notably in the intermediate (1.0-1.6) range. There was variability in ADC ratios even among different lesions in the same patient. In only a minority of the lymphoma patients were the ADC ratios low enough to suggest the correct diagnosis. Our study showed that toxoplasmosis exhibits a wide spectrum of diffusion characteristics with ADC ratios which have significant overlap with those of lymphoma. Therefore, in the majority of patients, ADC ratios are not definitive in making the distinction between toxoplasmosis and lymphoma. (orig.)

Analysis of the utility of diffusion-weighted MRI and apparent diffusion coefficient values in distinguishing central nervous system toxoplasmosis from lymphoma

Energy Technology Data Exchange (ETDEWEB)

Schroeder, Paul C.; Donovan Post, M. Judith; Bruce-Gregorios, Jocelyn [University of Miami, Jackson Memorial Hospital, Miami, FL (United States); Oschatz, Elizabeth; Stadler, Alfred; Thurnher, Majda M. [Medical University of Vienna, Department of Radiology Neuroradiology Section, Vienna (Austria)

2006-10-15

Toxoplasmosis and lymphoma are common lesions of the central nervous system in patients with AIDS. It is often difficult to distinguish between these lesions both clinically and radiographically. Previous research has demonstrated restricted diffusion within cerebral lymphomas and bacterial abscesses. However, little work has been done to evaluate the diffusion characteristics of toxoplasmosis lesions. This study was designed to explore further the utility of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps and values in making the distinction between toxoplasmosis and lymphoma. The magnetic resonance imaging (MRI) studies of 36 patients, including 22 with toxoplasmosis (all of whom had AIDS) and 14 with lymphoma (8 of whom had AIDS), at two institutions were reviewed retrospectively. The characteristics of the lesions on DWI were evaluated, and the ADC ratios of the lesions were calculated and compared. There was significant overlap of the ADC ratios of toxoplasma and lymphoma, most notably in the intermediate (1.0-1.6) range. There was variability in ADC ratios even among different lesions in the same patient. In only a minority of the lymphoma patients were the ADC ratios low enough to suggest the correct diagnosis. Our study showed that toxoplasmosis exhibits a wide spectrum of diffusion characteristics with ADC ratios which have significant overlap with those of lymphoma. Therefore, in the majority of patients, ADC ratios are not definitive in making the distinction between toxoplasmosis and lymphoma. (orig.)

2015 MICCAI Workshop on Computational Diffusion MRI

CERN Document Server

Ghosh, Aurobrata; Kaden, Enrico; Rathi, Yogesh; Reisert, Marco

2016-01-01

These Proceedings of the 2015 MICCAI Workshop “Computational Diffusion MRI” offer a snapshot of the current state of the art on a broad range of topics within the highly active and growing field of diffusion MRI. The topics vary from fundamental theoretical work on mathematical modeling, to the development and evaluation of robust algorithms, new computational methods applied to diffusion magnetic resonance imaging data, and applications in neuroscientific studies and clinical practice. Over the last decade interest in diffusion MRI has exploded. The technique provides unique insights into the microstructure of living tissue and enables in-vivo connectivity mapping of the brain. Computational techniques are key to the continued success and development of diffusion MRI and to its widespread transfer into clinical practice. New processing methods are essential for addressing issues at each stage of the diffusion MRI pipeline: acquisition, reconstruction, modeling and model fitting, image processing, fiber t...

Comparing brain white matter on sequential cranial ultrasound and MRI in very preterm infants

Energy Technology Data Exchange (ETDEWEB)

Leijser, Lara M.; Veen, Sylvia; Boer, Inge P. de; Walther, Frans J.; Wezel-Meijler, Gerda van [Leiden University Medical Center, Department of Pediatrics, Division of Neonatology, Albinusdreef 2, P.O. Box 9600, Leiden (Netherlands); Liauw, Lishya [Leiden University Medical Center, Department of Radiology, Division of Neuroradiology, Albinusdreef 2, P.O. Box 9600, Leiden (Netherlands)

2008-09-15

Periventricular white matter (WM) echodensities, frequently seen in preterm infants, can be associated with suboptimal neurodevelopment. Major WM injury is well detected on cranial ultrasound (cUS). cUS seems less sensitive for diffuse or more subtle WM injury. Our aim was to assess the value of cUS and magnetic resonance imaging (MRI) for evaluating WM changes and the predictive value of cUS and/or MRI findings for neurodevelopmental outcome in very preterm infants with normal to severely abnormal WM on sequential high-quality cUS. Very preterm infants (<32 weeks) who had sequential cUS and one MRI within the first three postnatal months were included. Periventricular WM on cUS and MRI was compared and correlated with neurodevelopmental outcome at 2 years corrected age. Forty preterm infants were studied; outcome data were available in 32. WM changes on sequential cUS were predictive of WM changes on MRI. Severely abnormal WM on cUS/MRI was predictive of adverse outcome, and normal-mildly abnormal WM of favorable outcome. Moderately abnormal WM on cUS/MRI was associated with variable outcome. Additional MRI slightly increased the predictive value of cUS in severe WM changes. Sequential cUS in preterm infants is reliable for detecting WM changes and predicting favorable and severely abnormal outcome. Conventional and diffusion-weighted MRI sequences before term equivalent age in very preterm infants, suggested on cUS to have mild to moderately abnormal WM, do not seem to be warranted. (orig.)

Comparing brain white matter on sequential cranial ultrasound and MRI in very preterm infants

International Nuclear Information System (INIS)

Leijser, Lara M.; Veen, Sylvia; Boer, Inge P. de; Walther, Frans J.; Wezel-Meijler, Gerda van; Liauw, Lishya

2008-01-01

Periventricular white matter (WM) echodensities, frequently seen in preterm infants, can be associated with suboptimal neurodevelopment. Major WM injury is well detected on cranial ultrasound (cUS). cUS seems less sensitive for diffuse or more subtle WM injury. Our aim was to assess the value of cUS and magnetic resonance imaging (MRI) for evaluating WM changes and the predictive value of cUS and/or MRI findings for neurodevelopmental outcome in very preterm infants with normal to severely abnormal WM on sequential high-quality cUS. Very preterm infants (<32 weeks) who had sequential cUS and one MRI within the first three postnatal months were included. Periventricular WM on cUS and MRI was compared and correlated with neurodevelopmental outcome at 2 years corrected age. Forty preterm infants were studied; outcome data were available in 32. WM changes on sequential cUS were predictive of WM changes on MRI. Severely abnormal WM on cUS/MRI was predictive of adverse outcome, and normal-mildly abnormal WM of favorable outcome. Moderately abnormal WM on cUS/MRI was associated with variable outcome. Additional MRI slightly increased the predictive value of cUS in severe WM changes. Sequential cUS in preterm infants is reliable for detecting WM changes and predicting favorable and severely abnormal outcome. Conventional and diffusion-weighted MRI sequences before term equivalent age in very preterm infants, suggested on cUS to have mild to moderately abnormal WM, do not seem to be warranted. (orig.)

Diffusion weighted MR imaging in the diagnosis of multiple sclerosis

International Nuclear Information System (INIS)

Hagen, T.; Schweigerer-Schroeter, G.; Wellnitz, J.; Wuerstle, T.

2000-01-01

Magnetic resonance (MR) imaging is one of the best methods in diagnosis of multiple sclerosis, particularly in disclosure of active demyelinating lesions. Aim of this study was to compare diffusion weighted imaging and contrast enhancement in the detection of active lesions. A MR study with a contrast enhanced T1-weighted pulse sequence with magnetization transfer presaturation and a diffusion weighted echoplanar pulse sequence (b=1000 s/mm 2 ) was performed in 17 patients (11 women, 6 men) with multiple sclerosis. 29 of 239 lesions showed an increased signal intensity in diffusion weighted imaging, 24 lesions a contrast enhancement, but only 16 lesions were visible in both pulse sequences. In patients with short clinical symptomatology significant more lesions could be detected with diffusion-weighted pulse sequence in comparison to patients with long standing symptomatology showing more lesions with contrast enhancement. Hence it is likely, that both pulse sequences detect different histopathologic changes. The early detection of demyelinating lesions in diffusion weighted imaging is attributed to the extracellular edema, however the contrast enhancement is caused by a blood brain barrier abnormality. It can be expected that diffusion weighted imaging will have a high impact on imaging of multiple sclerosis not only in therapeutic trials, but also in clinical routine. (orig.) [de

Transient Splenial Lesion of Corpus Callosum Associated with Antiepileptic Drug: Conventional and Diffusion-weighted Magnetic Resonance Images

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Hakyemez, B.; Erdogan, C.; Yildirim, N.; Gokalp, G.; Parlak, M. [Uludag Univ. Medical School, Bursa (Turkey). Dept. of Radiology

2005-11-01

Transient focal lesions of splenium of corpus callosum can be seen as a component of many central nervous system diseases, including antiepileptic drug toxicity. The conventional magnetic resonance (MR) findings of the disease are characteristic and include ovoid lesions with high signal intensity at T2-weighted MRI. Limited information exists about the diffusion-weighted MRI characteristics of these lesions vanishing completely after a period of time. We examined the conventional, FLAIR, and diffusion-weighted MR images of a patient complaining of depressive mood and anxiety disorder after 1 year receiving antiepileptic medication.

Comparison of CT and diffusion-weighted MRI in acute ischemic stroke

International Nuclear Information System (INIS)

Moriwaki, Hiroshi; Okazaki, Shuhei; Yamada, Naoaki; Naritomi, Hiroaki

2006-01-01

Non-contrast CT and diffusion-weighted MRI (DWI) are widely used for assessing patients with acute ischemic stroke including candidates for thrombolytic therapy. Early CT signs, still a gold standard as the diagnostic measure for thrombolysis, are quite subtle and strongly depend on image quality. We evaluated 76 patients (47 male, mean age 71.0 yrs) with ischemic stroke of the anterior cerebral circulation who underwent CT and DWI within 6 hours of onset. The scans were examined separately by two neurologists in a blinded fashion with knowledge of the affected hemisphere. Detection of acute ischemic changes were significantly higher on DWI (72/76, 95%) compared with that on CT (50/76, 66%) (P<0.0001), especially in cases with subcortical lesions (P<0.001). Detection of the lesion with more than 33% of MCA involvement, which should exclude from the thrombolitic therapy, was somewhat higher for DWI (26/26, 100%) compared with CT (22/26, 85%). DWI is more sensitive than CT in the identification of acute ischemic stroke and can visualize major ischemia more easily than CT. Additional studies are required to determine whether these advantages of DWI are clinically relevant in the management of patients with acute stroke. (author)

Diffusion-weighted MR imaging in transient ischaemic attacks

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Lamy, C.; Calvet, D.; Domigo, V.; Mas, J. [de l' Hopital Sainte-Anne, Service de Neurologie, Paris Cedex 14 (France); Oppenheim, C.; Naggara, O.; Meder, J.F. [Hoepital Sainte-Anne, Departement d' Imagere Morphologique et Fonchonnille, Paris (France)

2006-05-15

The purpose of this study was to determine frequency and the characteristics of diffusion-weighted imaging (DWI) abnormalities in patients with transient ischaemic attack (TIA). We analysed data of 98 consecutive patients (mean age: 60.6{+-}15.4 years, 56 men) admitted between January 2003 and April 2004 for TIA. Age, gender, symptom type and duration, delay from onset to magnetic resonance imaging (MRI), probable or possible TIA and cause of TIA were compared in patients with (DWI+) and without (DWI-) lesions on DWI. Volume and apparent diffusion coefficient (ADC) values of DWI lesions were computed. DWI revealed ischaemic lesions in 34 patients (34.7%). Lesions were small (mean volume: 1.9 cm{sup 3}{+-}3.3), and ADC was moderately decreased (mean ADC ratio: 79.5%). The diagnosis of TIA was considered as probable in all DWI+ patients. A multiple logistic regression model demonstrated that TIA duration greater than or equal to 60 min (OR, 7.6; 95% CI, 2.3-25.7), aphasia (OR, 9.2; 95% CI, 2.7-31.4) and motor deficit (OR, 5.1; 95% CI, 1.5-17.8) were independent predictors of DWI lesions. Prolonged TIA duration, aphasia and motor deficits are associated with DWI lesions. More than half of TIA patients with symptoms lasting more than 60 min have DWI lesions. (orig.)

Diffusion-weighted MR imaging in transient ischaemic attacks

International Nuclear Information System (INIS)

Lamy, C.; Calvet, D.; Domigo, V.; Mas, J.; Oppenheim, C.; Naggara, O.; Meder, J.F.

2006-01-01

The purpose of this study was to determine frequency and the characteristics of diffusion-weighted imaging (DWI) abnormalities in patients with transient ischaemic attack (TIA). We analysed data of 98 consecutive patients (mean age: 60.6±15.4 years, 56 men) admitted between January 2003 and April 2004 for TIA. Age, gender, symptom type and duration, delay from onset to magnetic resonance imaging (MRI), probable or possible TIA and cause of TIA were compared in patients with (DWI+) and without (DWI-) lesions on DWI. Volume and apparent diffusion coefficient (ADC) values of DWI lesions were computed. DWI revealed ischaemic lesions in 34 patients (34.7%). Lesions were small (mean volume: 1.9 cm 3 ±3.3), and ADC was moderately decreased (mean ADC ratio: 79.5%). The diagnosis of TIA was considered as probable in all DWI+ patients. A multiple logistic regression model demonstrated that TIA duration greater than or equal to 60 min (OR, 7.6; 95% CI, 2.3-25.7), aphasia (OR, 9.2; 95% CI, 2.7-31.4) and motor deficit (OR, 5.1; 95% CI, 1.5-17.8) were independent predictors of DWI lesions. Prolonged TIA duration, aphasia and motor deficits are associated with DWI lesions. More than half of TIA patients with symptoms lasting more than 60 min have DWI lesions. (orig.)

Transient ischemic attacks and presence of an acute brain lesion in diffusion-weighted MRI: study of 50 patients

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Sabeti M

2012-10-01

Full Text Available Background: Finding an acute brain lesion by diffusion-weighted (DW MRI upon an episode of transient ischemic attack (TIA is a predictor of imminent stroke in the near future. Therefore, exploring risk factors associated with lesions in DW-MRI of the brain is important in adopting an approach to TIA management. In the current study, we tried to determine the risk factors associated with lesions in DW-MRI of the brain in patients experiencing TIA episodes.Methods: Fifty patients with TIA were recruited consecutively in Sina Hospital, Tehran, Iran, over a 6-month period between July 2008 and January 2009. All of the patients underwent a complete neurological examination and laboratory tests. Brain DW-MRIs were performed for all the patients within 72 hours of a TIA episode.Results: DW-MRI revealed an acute lesion in 16% of the participants. There was a significant correlation between presence of an acute lesion in DW-MRI and TIA duration, history of diabetes mellitus and presence of unilateral facial palsy (P=0.0003, P=0.02 and P=0.008, respectively. Other variables such as age, hypertension, hyperlipidemia, past history of TIA, headache, vertigo, and sensory or visual disturbances had no significant relation with the presence of an acute lesion in DW-MRI.Conclusion: Duration of TIA, presence of diabetes mellitus and unilateral facial palsy are risk factors for an acute lesion in DW-MRI, meaning that patients with such risk factors are at risk for stroke in the near future.

Relationship between cortex and pulvinar abnormalities on diffusion-weighted imaging in status epilepticus.

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Nakae, Yoshiharu; Kudo, Yosuke; Yamamoto, Ryoo; Dobashi, Yuichi; Kawabata, Yuichi; Ikeda, Shingo; Yokoyama, Mutsumi; Higashiyama, Yuichi; Doi, Hiroshi; Johkura, Ken; Tanaka, Fumiaki

2016-01-01

The aim of this study was to analyze the pattern of magnetic resonance diffusion-weighted imaging (DWI) findings in status epilepticus in terms of clinical characteristics. Participants comprised 106 patients with status epilepticus who were admitted to our hospital and underwent DWI. Forty-five patients (42.5 %) showed abnormal findings on DWI and were divided into two groups, comprising 26 patients (24.5 %) with cortex lesions alone and 19 patients (17.9 %) with cortex and pulvinar lesions in the same hemisphere. A long duration of status epilepticus (>120 min) tended to be more prevalent among patients with cortex and pulvinar lesions (57.9 %) than among patients with cortex lesions alone (30.8 %) by univariate and multivariate analyses. Todd's palsy tended to be more frequent in patients with abnormalities on DWI (24/45, 53.3 %) than in patients with normal DWI (21/61, 34.4 %). Six of the 26 patients with cortex lesions alone (23.1 %) had taken anti-epileptic drugs before the attack compared to none of the 19 patients with both cortex and pulvinar lesions. The trend toward a longer duration of status epilepticus in patients with both cortex and pulvinar lesions favors a spreading pattern of seizure discharge from cortex to pulvinar via cortico-pulvinar pathways, and anti-epileptic drugs might, to some extent, prevent spreading of seizure discharge from cortex to pulvinar. In addition, existence of high-intensity areas on DWI at the onset of epilepsy may be a predictive factor for the occurrence of Todd's palsy.

A time-efficient acquisition protocol for multipurpose diffusion-weighted microstructural imaging at 7 Tesla.

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Sepehrband, Farshid; O'Brien, Kieran; Barth, Markus

2017-12-01

Several diffusion-weighted MRI techniques have been developed and validated during the past 2 decades. While offering various neuroanatomical inferences, these techniques differ in their proposed optimal acquisition design, preventing clinicians and researchers benefiting from all potential inference methods, particularly when limited time is available. This study reports an optimal design that enables for a time-efficient diffusion-weighted MRI acquisition scheme at 7 Tesla. The primary audience of this article is the typical end user, interested in diffusion-weighted microstructural imaging at 7 Tesla. We tested b-values in the range of 700 to 3000 s/mm 2 with different number of angular diffusion-encoding samples, against a data-driven "gold standard." The suggested design is a protocol with b-values of 1000 and 2500 s/mm 2 , with 25 and 50 samples, uniformly distributed over two shells. We also report a range of protocols in which the results of fitting microstructural models to the diffusion-weighted data had high correlation with the gold standard. We estimated minimum acquisition requirements that enable diffusion tensor imaging, higher angular resolution diffusion-weighted imaging, neurite orientation dispersion, and density imaging and white matter tract integrity across whole brain with isotropic resolution of 1.8 mm in less than 11 min. Magn Reson Med 78:2170-2184, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Multi-institutional validation of a novel textural analysis tool for preoperative stratification of suspected thyroid tumors on diffusion-weighted MRI.

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Brown, Anna M; Nagala, Sidhartha; McLean, Mary A; Lu, Yonggang; Scoffings, Daniel; Apte, Aditya; Gonen, Mithat; Stambuk, Hilda E; Shaha, Ashok R; Tuttle, R Michael; Deasy, Joseph O; Priest, Andrew N; Jani, Piyush; Shukla-Dave, Amita; Griffiths, John

2016-04-01

Ultrasound-guided fine needle aspirate cytology fails to diagnose many malignant thyroid nodules; consequently, patients may undergo diagnostic lobectomy. This study assessed whether textural analysis (TA) could noninvasively stratify thyroid nodules accurately using diffusion-weighted MRI (DW-MRI). This multi-institutional study examined 3T DW-MRI images obtained with spin echo echo planar imaging sequences. The training data set included 26 patients from Cambridge, United Kingdom, and the test data set included 18 thyroid cancer patients from Memorial Sloan Kettering Cancer Center (New York, New York, USA). Apparent diffusion coefficients (ADCs) were compared over regions of interest (ROIs) defined on thyroid nodules. TA, linear discriminant analysis (LDA), and feature reduction were performed using the 21 MaZda-generated texture parameters that best distinguished benign and malignant ROIs. Training data set mean ADC values were significantly different for benign and malignant nodules (P = 0.02) with a sensitivity and specificity of 70% and 63%, respectively, and a receiver operator characteristic (ROC) area under the curve (AUC) of 0.73. The LDA model of the top 21 textural features correctly classified 89/94 DW-MRI ROIs with 92% sensitivity, 96% specificity, and an AUC of 0.97. This algorithm correctly classified 16/18 (89%) patients in the independently obtained test set of thyroid DW-MRI scans. TA classifies thyroid nodules with high sensitivity and specificity on multi-institutional DW-MRI data sets. This method requires further validation in a larger prospective study. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

Non-echoplanar diffusion-weighted MRI in children and adolescents with cholesteatoma: reliability and pitfalls in comparison to middle ear surgery

International Nuclear Information System (INIS)

Kalle, Thekla von; Amrhein, Peter; Koitschev, Assen

2015-01-01

Currently, there is only limited and contradictory evidence of the role of diffusion-weighted MRI (DW-MRI) in the management of children with cholesteatoma. To provide surgically controlled data that may allow to replace second-look surgery by non-echoplanar DW-MRI in children. Fifty-five children and adolescents with a median age of 8.6 years (2.2-17.7 years) underwent 61 preoperative half-Fourier acquisition single-shot turbo spin-echo (HASTE) DW-MRI of their petrous bone. Surgical interventions followed within 24 h (79%), within 5 months (20%) or at 18 months (1 case). Surgery detected a cholesteatoma or retraction pocket in 41 of 61 cases (67%). In 49 cases (80%), the MR result was confirmed by surgical findings. Two MR findings were false-positive and 10 false-negative (including cholesteatomas <4 mm). HASTE DW-MRI alone had a sensitivity of 76% and a specificity of 90%. The positive predictive value was 94%, the negative predictive value 64%. In combination with preoperative otoscopy, sensitivity was 90% and negative predictive value 82%. DW-MRI correctly detected the majority of lesions but could not reliably exclude small cholesteatomas and empty retraction pockets. We would therefore not generally recommend MR as a substitute for second-look surgery. (orig.)

Non-echoplanar diffusion-weighted MRI in children and adolescents with cholesteatoma: reliability and pitfalls in comparison to middle ear surgery

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Kalle, Thekla von [Olgahospital Klinikum Stuttgart, Pediatric Radiology, Radiologisches Institut, Stuttgart (Germany); Amrhein, Peter; Koitschev, Assen [Olgahospital Klinikum Stuttgart, Division of Pediatric Otorhinolaryngology and Otology, Department of Otorhinolaryngology, Stuttgart (Germany)

2015-07-15

Currently, there is only limited and contradictory evidence of the role of diffusion-weighted MRI (DW-MRI) in the management of children with cholesteatoma. To provide surgically controlled data that may allow to replace second-look surgery by non-echoplanar DW-MRI in children. Fifty-five children and adolescents with a median age of 8.6 years (2.2-17.7 years) underwent 61 preoperative half-Fourier acquisition single-shot turbo spin-echo (HASTE) DW-MRI of their petrous bone. Surgical interventions followed within 24 h (79%), within 5 months (20%) or at 18 months (1 case). Surgery detected a cholesteatoma or retraction pocket in 41 of 61 cases (67%). In 49 cases (80%), the MR result was confirmed by surgical findings. Two MR findings were false-positive and 10 false-negative (including cholesteatomas <4 mm). HASTE DW-MRI alone had a sensitivity of 76% and a specificity of 90%. The positive predictive value was 94%, the negative predictive value 64%. In combination with preoperative otoscopy, sensitivity was 90% and negative predictive value 82%. DW-MRI correctly detected the majority of lesions but could not reliably exclude small cholesteatomas and empty retraction pockets. We would therefore not generally recommend MR as a substitute for second-look surgery. (orig.)

Diffusion-weighted MR imaging findings in carbon monoxide poisoning

International Nuclear Information System (INIS)

Teksam, M.; Casey, S.O.; Michel, E.; Liu, H.; Truwit, C.L.

2002-01-01

Diffusion-weighted MR imaging (DWI) of two patients with carbon monoxide (CO) poisoning demonstrated white matter and cortical hyperintensities. In one patient, the changes on the FLAIR sequence were more subtle than those on DWI. The DWI abnormality in this patient represented true restriction. In the second patient, repeated exposure to CO caused restricted diffusion. DWI may be helpful for earlier identification of the changes of acute CO poisoning. (orig.)

Cerebral Effects of Targeted Temperature Management Methods Assessed by Diffusion-Weighted Magnetic Resonance Imaging

DEFF Research Database (Denmark)

Grejs, Anders Morten; Gjedsted, Jakob; Pedersen, Michael

2016-01-01

The aim of this randomized porcine study was to compare surface targeted temperature management (TTM) to endovascular TTM evaluated by cerebral diffusion-weighted magnetic resonance imaging (MRI): apparent diffusion coefficient (ADC), and by intracerebral/intramuscular microdialysis. It is well k...

Diffusion-weighted imaging in transient global amnesia exposes the CA1 region of the hippocampus

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Lee, Ho Yun; Kim, Jae Hyoung; Weon, Young-Cheol; Youn, Sung Won; Kim, Sung Hyun [Seoul National University Bundang Hospital, Department of Radiology, Seoul National University College of Medicine, Seongnam-si (Korea); Lee, Jung Seok; Kim, Sang Yun [Seoul National University Bundang Hospital, Department of Neurology, Seoul National University College of Medicine, Seongnam-si (Korea)

2007-06-15

Transient global amnesia (TGA) is characterized by a sudden onset of anterograde amnesia without alteration of consciousness or personal identity. Interestingly, recent studies have reported a high frequency of small high-signal abnormalities in the hippocampus with diffusion-weighted (DW) imaging, and ischemia has been proposed as an etiology of TGA. We hypothesized that TGA lesions occur preferentially in the CA1 region of the hippocampus, known to be susceptible to ischemia. Over a 30-month period 34 patients with TGA underwent MRI including DW imaging within 4 days of symptom onset. Patients with high-signal abnormalities in the hippocampus on the initial DW images underwent subsequent DW and T2-weighted imaging in the coronal plane to identify the precise lesion locations. Fourteen patients had small (1-3 mm) high-signal abnormalities in the hippocampus unilaterally on DW images. One of these patients had two lesions in one hippocampus and therefore in total 15 lesions were identified: four in the hippocampal head, and 11 in the body. Eleven lesions in ten patients with available coronal images were clearly demonstrated on both coronal DW and T2-weighted images and were localized to the lateral portion of the hippocampus, corresponding to the CA1 region. Lesions associated with TGA were localized exclusively to the lateral portion of the hippocampus corresponding to the CA1 region. This finding supports the ischemic etiology of TGA; however, the pathophysiological mechanism involved requires further study. (orig.)

Diffusion-weighted imaging in transient global amnesia exposes the CA1 region of the hippocampus

International Nuclear Information System (INIS)

Lee, Ho Yun; Kim, Jae Hyoung; Weon, Young-Cheol; Youn, Sung Won; Kim, Sung Hyun; Lee, Jung Seok; Kim, Sang Yun

2007-01-01

Transient global amnesia (TGA) is characterized by a sudden onset of anterograde amnesia without alteration of consciousness or personal identity. Interestingly, recent studies have reported a high frequency of small high-signal abnormalities in the hippocampus with diffusion-weighted (DW) imaging, and ischemia has been proposed as an etiology of TGA. We hypothesized that TGA lesions occur preferentially in the CA1 region of the hippocampus, known to be susceptible to ischemia. Over a 30-month period 34 patients with TGA underwent MRI including DW imaging within 4 days of symptom onset. Patients with high-signal abnormalities in the hippocampus on the initial DW images underwent subsequent DW and T2-weighted imaging in the coronal plane to identify the precise lesion locations. Fourteen patients had small (1-3 mm) high-signal abnormalities in the hippocampus unilaterally on DW images. One of these patients had two lesions in one hippocampus and therefore in total 15 lesions were identified: four in the hippocampal head, and 11 in the body. Eleven lesions in ten patients with available coronal images were clearly demonstrated on both coronal DW and T2-weighted images and were localized to the lateral portion of the hippocampus, corresponding to the CA1 region. Lesions associated with TGA were localized exclusively to the lateral portion of the hippocampus corresponding to the CA1 region. This finding supports the ischemic etiology of TGA; however, the pathophysiological mechanism involved requires further study. (orig.)

Individual white matter fractional anisotropy analysis on patients with MRI negative partial epilepsy.

Science.gov (United States)

Duning, Thomas; Kellinghaus, Christoph; Mohammadi, Siawoosh; Schiffbauer, Hagen; Keller, Simon; Ringelstein, E Bernd; Knecht, Stefan; Deppe, Michael

2010-02-01

Conventional structural MRI fails to identify a cerebral lesion in 25% of patients with cryptogenic partial epilepsy (CPE). Diffusion tensor imaging is an MRI technique sensitive to microstructural abnormalities of cerebral white matter (WM) by quantification of fractional anisotropy (FA). The objectives of the present study were to identify focal FA abnormalities in patients with CPE who were deemed MRI negative during routine presurgical evaluation. Diffusion tensor imaging at 3 T was performed in 12 patients with CPE and normal conventional MRI and in 67 age matched healthy volunteers. WM integrity was compared between groups on the basis of automated voxel-wise statistics of FA maps using an analysis of covariance. Volumetric measurements from high resolution T1-weighted images were also performed. Significant FA reductions in WM regions encompassing diffuse areas of the brain were observed when all patients as a group were compared with controls. On an individual basis, voxel based analyses revealed widespread symmetrical FA reduction in CPE patients. Furthermore, asymmetrical temporal lobe FA reduction was consistently ipsilateral to the electroclinical focus. No significant correlations were found between FA alterations and clinical data. There were no differences in brain volumes of CPE patients compared with controls. Despite normal conventional MRI, WM integrity abnormalities in CPE patients extend far beyond the epileptogenic zone. Given that unilateral temporal lobe FA abnormalities were consistently observed ipsilateral to the seizure focus, analysis of temporal FA may provide an informative in vivo investigation into the localisation of the epileptogenic zone in MRI negative patients.

Continuous diffusion signal, EAP and ODF estimation via Compressive Sensing in diffusion MRI.

Science.gov (United States)

Merlet, Sylvain L; Deriche, Rachid

2013-07-01

In this paper, we exploit the ability of Compressed Sensing (CS) to recover the whole 3D Diffusion MRI (dMRI) signal from a limited number of samples while efficiently recovering important diffusion features such as the Ensemble Average Propagator (EAP) and the Orientation Distribution Function (ODF). Some attempts to use CS in estimating diffusion signals have been done recently. However, this was mainly an experimental insight of CS capabilities in dMRI and the CS theory has not been fully exploited. In this work, we also propose to study the impact of the sparsity, the incoherence and the RIP property on the reconstruction of diffusion signals. We show that an efficient use of the CS theory enables to drastically reduce the number of measurements commonly used in dMRI acquisitions. Only 20-30 measurements, optimally spread on several b-value shells, are shown to be necessary, which is less than previous attempts to recover the diffusion signal using CS. This opens an attractive perspective to measure the diffusion signals in white matter within a reduced acquisition time and shows that CS holds great promise and opens new and exciting perspectives in diffusion MRI (dMRI). Copyright © 2013 Elsevier B.V. All rights reserved.

Cerebral Fat Embolism: Diffusion-weighted Magnetic Resonance Imaging Findings

International Nuclear Information System (INIS)

Ryu, C.W.

2005-01-01

PURPOSE: To demonstrate the diffusion-weighted (DWI) magnetic resonance imaging (MRI) findings, and the follow-up MRI findings, of cerebral fat embolism in the acute stage. MATERIAL AND METHODS: The initial DWI and clinical findings of six patients with cerebral fat embolism were retrospectively evaluated. The finding of DWI with a b-value of 1000 s/mm 2 (b=1000) was compared with that of DWI with a b-value of 0 s/mm 2 (b=0). In three patients who underwent follow-up MRI, the interval change of the lesion on T2-weighted images was investigated. RESULTS: The characteristic DWI finding of cerebral fat embolism in the acute stage was multiple, hyperintense, dot-like lesions disseminated in the brain. These lesions were distributed dominantly in the bilateral border-zone areas. Some lesions had an ancillary location including the cortex, deep white matter, basal ganglia, and cerebellum. The lesions were more intense and numerous in DWI (b=1000) than in DWI (b=0). The findings on the follow-up T2-weighted images were multiple confluent hyperintense lesions in the white matter with progression since the initial MRI. CONCLUSION: DWI could be a sensitive tool for detecting cerebral fat embolism in the acute phase. It is recommended that DWI be included in the initial evaluation of cerebral fat embolism with MRI

Rocky Mountain spotted fever: 'starry sky' appearance with diffusion-weighted imaging in a child.

Science.gov (United States)

Crapp, Seth; Harrar, Dana; Strother, Megan; Wushensky, Curtis; Pruthi, Sumit

2012-04-01

We present a case of Rocky Mountain spotted fever encephalitis in a child imaged utilizing diffusion-weighted MRI. Although the imaging and clinical manifestations of this entity have been previously described, a review of the literature did not reveal any such cases reported in children utilizing diffusion-weighted imaging. The imaging findings and clinical history are presented as well as a brief review of this disease.

Tumor disease and associated congenital abnormalities on prenatal MRI.

Science.gov (United States)

Nemec, Stefan F; Horcher, Ernst; Kasprian, Gregor; Brugger, Peter C; Bettelheim, Dieter; Amann, Gabriele; Nemec, Ursula; Rotmensch, Siegfried; Rimoin, David L; Graham, John M; Prayer, Daniela

2012-02-01

Fetal tumors can have a devastating effect on the fetus, and may occur in association with congenital malformations. In view of the increasing role of fetal magnetic resonance imaging (MRI) as an adjunct to prenatal ultrasonography (US), we sought to demonstrate the visualization of fetal tumors, with regard to congenital abnormalities, on MRI. This retrospective study included 18 fetuses with tumors depicted on fetal MRI after suspicious US findings. An MRI standard protocol was used to diagnose tumors judged as benign or malignant. All organ systems were assessed for tumor-related complications and other congenital malformations. Available US results and histopathology were compared with MRI. There were 13/18 (72.2%) benign and 5/18 (27.8%) malignant tumors diagnosed: a cerebral primitive neuroectodermal tumor in 1/18, head-neck teratomas in 4/18; ventricular rhabdomyomas in 4/18; a cardiac teratoma in 1/18; a hepatoblastoma in 1/18; neuroblastomas in 2/18; a cystic hemorrhagic adrenal hyperplasia in 1/18; a pelvic leiomyoma in 1/18; sacrococcygeal teratomas in 3/18. Tumor-related complications were present in 13/18 (72.2%) cases; other congenital abnormalities in 3/18 (16.7%). MRI diagnosis and histology were concordant in 8/11 (72.7%) cases. In 6/12 (50%) cases, US and MRI diagnoses were concordant, and, in 6/12 (50%) cases, additional MRI findings changed the US diagnosis. Our MRI results demonstrate the visualization of fetal tumors, with frequently encountered tumor-related complications, and other exceptional congenital abnormalities, which may provide important information for perinatal management. Compared to prenatal US, MRI may add important findings in certain cases. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Tumor disease and associated congenital abnormalities on prenatal MRI

International Nuclear Information System (INIS)

Nemec, Stefan F.; Horcher, Ernst; Kasprian, Gregor; Brugger, Peter C.; Bettelheim, Dieter; Amann, Gabriele; Nemec, Ursula; Rotmensch, Siegfried; Rimoin, David L.; Graham, John M. Jr.; Prayer, Daniela

2012-01-01

Objective: Fetal tumors can have a devastating effect on the fetus, and may occur in association with congenital malformations. In view of the increasing role of fetal magnetic resonance imaging (MRI) as an adjunct to prenatal ultrasonography (US), we sought to demonstrate the visualization of fetal tumors, with regard to congenital abnormalities, on MRI. Materials and methods: This retrospective study included 18 fetuses with tumors depicted on fetal MRI after suspicious US findings. An MRI standard protocol was used to diagnose tumors judged as benign or malignant. All organ systems were assessed for tumor-related complications and other congenital malformations. Available US results and histopathology were compared with MRI. Results: There were 13/18 (72.2%) benign and 5/18 (27.8%) malignant tumors diagnosed: a cerebral primitive neuroectodermal tumor in 1/18, head–neck teratomas in 4/18; ventricular rhabdomyomas in 4/18; a cardiac teratoma in 1/18; a hepatoblastoma in 1/18; neuroblastomas in 2/18; a cystic hemorrhagic adrenal hyperplasia in 1/18; a pelvic leiomyoma in 1/18; sacrococcygeal teratomas in 3/18. Tumor-related complications were present in 13/18 (72.2%) cases; other congenital abnormalities in 3/18 (16.7%). MRI diagnosis and histology were concordant in 8/11 (72.7%) cases. In 6/12 (50%) cases, US and MRI diagnoses were concordant, and, in 6/12 (50%) cases, additional MRI findings changed the US diagnosis. Conclusion: Our MRI results demonstrate the visualization of fetal tumors, with frequently encountered tumor-related complications, and other exceptional congenital abnormalities, which may provide important information for perinatal management. Compared to prenatal US, MRI may add important findings in certain cases.

Diffusion-weighted imaging features in spinal cord infarction

International Nuclear Information System (INIS)

Zhang Jingsong; Huan Yi; Sun Lijun; Chang Yingjuan; Zhao Haitao; Yang Chunmin; Zhang Guangyun

2005-01-01

Objective: To analyze the diffusion-weighted MR imaging findings in ischemic spinal cord lesions and discuss the value of diffusion-weighted MR imaging in differentiating diagnosis with inflammatory diseases and tumors. Methods: Six patients (2 male, 4 female) with typical sudden onset of neurological deficits caused by spinal cord ischemia were evaluated. There were no definite etiologies in all patients. DW imaging was performed within 1 to 30 days after the initial neurological symptoms using a Philips Gyroscan 1.5 TMR system. Four patients had other scans including contrast-enhanced MR imaging (CE-MRI) and/or FLAIR scans. Two of them followed up with MR images in three months. All six patients were imaged using a multi-shot, navigator-corrected, echo-planar pulse sequence, and ADC values were calculated in sagittal-oriented plane. Results: MR abnormalities were demonstrated on sagittal T 2 -weighted images with 'patch-like' or 'strip-like' hyperintensities (6/6) and cord enlargement (5/6). Axial T 2 -weighted images showed bilateral (6/6) hyperintensities. In one patient only the posterior spinal artery (PSA) territory was involved. Spinal cord was mainly affected at the cervical (2/6) and thoracolumbar (4/6) region, two of them included the conus medullaris (T10-L1). DW images showed high signals in all infarct lesions, degree of intensity depended on scanning time from ill-onset and progress of illness and whether companied with hemorrhage. In this group, except one case with closely normal ADC value due to one month course of illness, the five others ADC values of lesions calculated from ADC maps arranged from 0.23 x 10 -3 mm 2 /s to 0.47 x 10 -3 mm 2 /s [average value (0.37 ± 0.10) x 10 -3 mm 2 /s], markedly lower than normal parts [ average value (0.89 ± 0.08) x 10 -3 mm 2 /s]. There were marked difference between lesions and normal regions (t=4.71, P 2 W images. Meanwhile, lesions could be displayed much better in DW images than in T 2 W images because

Comparison of endorectal coil and nonendorectal coil T2W and diffusion-weighted MRI at 3 Tesla for localizing prostate cancer: correlation with whole-mount histopathology.

Science.gov (United States)

Turkbey, Baris; Merino, Maria J; Gallardo, Elma Carvajal; Shah, Vijay; Aras, Omer; Bernardo, Marcelino; Mena, Esther; Daar, Dagane; Rastinehad, Ardeshir R; Linehan, W Marston; Wood, Bradford J; Pinto, Peter A; Choyke, Peter L

2014-06-01

To compare utility of T2-weighted (T2W) MRI and diffusion-weighted MRI (DWI-MRI) obtained with and without an endorectal coil at 3 Tesla (T) for localizing prostate cancer. This Institutional Review Board-approved study included 20 patients (median prostate-specific antigen, 8.4 ng/mL). Patients underwent consecutive prostate MRIs at 3T, first with a surface coil alone, then with combination of surface, endorectal coils (dual coil) followed by robotic assisted radical prostatectomy. Lesions were mapped at time of acquisition on dual-coil T2W, DWI-MRI. To avoid bias, 6 months later nonendorectal coil T2W, DWI-MRI were mapped. Both MRI evaluations were performed by two readers blinded to pathology with differences resolved by consensus. A lesion-based correlation with whole-mount histopathology was performed. At histopathology 51 cancer foci were present ranging in size from 2 to 60 mm. The sensitivity of the endorectal dual-coil, nonendorectal coil MRIs were 0.76, 0.45, respectively. PPVs for endorectal dual-coil, nonendorectal coil MRI were 0.80, 0.64, respectively. Mean size of detected lesions with nonendorectal coil MRI were larger than those detected by dual-coil MRI (22 mm versus 17.4 mm). Dual-coil prostate MRI detected more cancer foci than nonendorectal coil MRI. While nonendorectal coil MRI is an attractive alternative, physicians performing prostate MRI should be aware of its limitations. Copyright © 2013 Wiley Periodicals, Inc.

MRI appearance of surgically proven abnormal accessory anterior-inferior tibiofibular ligament (Bassett's ligament)

International Nuclear Information System (INIS)

Subhas, Naveen; Vinson, Emily N.; Cothran, R.L.; Helms, Clyde A.; Santangelo, James R.; Nunley, James A.

2008-01-01

A thickened accessory anterior-inferior tibiofibular ligament (Bassett's ligament) of the ankle can be a cause of ankle impingement. Its imaging appearance is not well described. The purpose of this study was to determine if the ligament could be identified on magnetic resonance imaging (MRI), to determine associated abnormalities, and to determine if MRI could be used to differentiate normal from abnormal. Eighteen patients with a preoperative ankle MRI and an abnormal Bassett's ligament reported at surgery were found retrospectively. A separate cohort of 18 patients was selected as a control population. The presence of Bassett's ligament and its thickness were noted. The integrity and appearance of the lateral ankle ligaments, talar dome cartilage, and anterolateral gutter were also noted. In 34 of the 36 cases (94%), Bassett's ligament was identified on MRI. The ligament was seen in all three imaging planes and most frequently in the axial plane. The mean thickness of the ligament in the surgically abnormal cases was 2.37 mm, compared with 1.87 mm in the control with a p value = 0.015 (t test). Nine of the 18 abnormal cases (50%) had talar dome cartilage lesions as a result of contact with the ligament at surgery, with only 3 cases of high-grade defects seen on MRI. Fourteen of the 18 abnormal cases (78%) had of synovitis or scarring in the lateral gutter at surgery, with only 5 cases with scarring seen on MRI. The anterior-inferior tibiofibular ligament was abnormal or torn in 8 of the 18 abnormal cases (44%) by MRI and confirmed in only 3 cases at surgery. Bassett's ligament can be routinely identified on MRI and was significantly thicker in patients who had it resected at surgery. An abnormal Bassett's ligament is often present in the setting of a normal anterior-inferior tibiofibular ligament. The cartilage abnormalities and synovitis associated with an abnormal Bassett's ligament are poorly detected by conventional MRI. (orig.)

Diffusion abnormalities of the uncinate fasciculus in Alzheimer's disease: diffusion tensor tract-specific analysis using a new method to measure the core of the tract

International Nuclear Information System (INIS)

Yasmin, Hasina; Nakata, Yasuhiro; Abe, Osamu; Masutani, Yoshitaka; Ohtomo, Kuni; Aoki, Shigeki; Sato, Noriko; Nemoto, Kiyotaka; Arima, Kunimasa; Furuta, Nobuo; Uno, Masatake; Hirai, Shigeo

2008-01-01

Our aim was to determine diffusion abnormalities in the uncinate fasciculus (UF) in Alzheimer's disease (AD) by diffusion tensor tractography (DTT) using a new method for measuring the core of the tract. We studied 19 patients with AD and 19 age-matched control subjects who underwent MRI using diffusion tensor imaging (DTI). DTT of the UF was generated. The mean diffusivity (MD) and fractional anisotropy (FA) of the core of the tract were measured after voxelized tract shape processing. Student's t-test was used to compare results between patients with AD and controls. Intraobserver correlation tests were also performed. FA was significantly lower (P 0.93 for measured FA and r > 0.92 for measured MD. Our results suggest that FA reflects progression of AD-related histopathological changes in the UF of the white matter and may represent a useful biological index in monitoring AD. Diffusion tensor tract-specific analysis with voxelized tract shape processing to measure the core of the tract may be a sensitive tool for evaluation of diffusion abnormalities of white matter tracts in AD. (orig.)

Diffusion weighted imaging of female pelvic cancers: Concepts and clinical applications

International Nuclear Information System (INIS)

Punwani, Shonit

2011-01-01

Early applications of diffusion weighted magnetic resonance imaging (DWI) were limited to neuroimaging, concentrating either on stroke or brain tumours. With recent advances in MRI hardware and software DWI is now increasingly being investigated for cancer assessment throughout the body. Clinical applications of DWI relating to female pelvic cancers have largely concentrated on detection, localisation and staging of disease. More recently investigators have started to evaluate the ability of DWI for determining tumour histology and even predicting the outcome of chemoradiation treatment. This article reviews the physical concepts of MR diffusion weighting, illustrates the biophysical basis of diffusion contrast and reports the clinical applications of DWI for cervical, endometrial, ovarian, rectal and bladder tumours.

Gadoxetic acid-enhanced MRI and diffusion-weighted imaging for the detection of colorectal liver metastases after neoadjuvant chemotherapy

International Nuclear Information System (INIS)

Yu, Mi Hye; Lee, Jeong Min; Han, Joon Koo; Choi, Byung-Ihn; Hur, Bo Yun; Kim, Tae-You; Jeong, Seung-Yong; Yi, Nam-Joon; Suh, Kyung-Suk

2015-01-01

To investigate the diagnostic performance of gadoxetic acid-enhanced MRI including diffusion-weighted imaging (DWI) for the detection of colorectal liver metastases (CRLMs) after neoadjuvant chemotherapy (NAC). Our study population comprised 77 patients with 140 CRLMs who underwent gadoxetic acid-enhanced MRI within 1 month prior to surgery: group A (without NAC, n = 38) and group B (with NAC, n = 39). Two radiologists independently assessed all MR images and graded their diagnostic confidence for CRLM on a 5-point scale. Diagnostic accuracy, sensitivity and positive predictive values (PPV) were calculated and compared between the two groups. Diagnostic accuracy of gadoxetic acid-enhanced MRI in group B was slightly lower than in group A, but a statistically significant difference was not observed (observer 1: A z , 0.926 in group A, 0.905 in group B; observer 2: A z , 0.944 in group A, 0.885 in group B; p > 0.05). Sensitivity and PPV of group B were comparable to those of group A (observer 1: sensitivity = 93.5 % vs. 93.6 %, PPV = 95.1 % vs. 86.9 %; observer 2: sensitivity = 96.8 % vs. 91.0 %; PPV = 90.0 % vs. 89.7 %; all p > 0.05). Gadoxetic acid-enhanced MRI including DWI provided good diagnostic performance with high sensitivity (>90 %) for the detection of CRLMs, regardless of the influence of NAC. (orig.)

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging of bone marrow in healthy individuals

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Hillengass, Jens (Dept. of Radiology, German Cancer Research Center, Heidelberg (Germany); Dept. of Hematology, Oncology and Rheumatology, Univ. of Heidelberg (Germany)), e-mail: j.hillengass@dkfz.de; Stieltjes, Bram (Dept. of Radiology, German Cancer Research Center, Heidelberg (Germany)); Baeuerle, Tobias (Dept. of Medical Physics in Radiology, German Cancer Research Center, Heidelberg (Germany)) (and others)

2011-04-15

Background: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) displays microcirculation and permeability by application of contrast-media and diffusion-weighted imaging (DWI) is a tool for quantification of cellularity in the investigated area. Recently published examples cover breast cancer, CNS tumors, head and neck cancer, gastrointestinal cancer, prostate cancer as well as hematologic malignancies. Purpose: To investigated the influence of age, sex, and localization of the investigated region on findings of DCE-MRI and DWI. Material and Methods: DCE-MRI-parameters amplitude A and exchange rate constant kep as well as the DWI-parameter ADC of the bone marrow of the lumbar vertebral column of 30 healthy individuals covering the typical range of age of tumor patients were evaluated. ADC was calculated using b=0 and a maximal b value of either 400 or 750 s/mm2. Results: Amplitude A of DCE-MRI decreased with age (P = 0.01) and amplitude A, exchange rate constant kep as well as ADC based on b = 400 s/mm2 and b = 750 s/mm2, respectively, decreased significantly from the first to the fifth lumbar vertebra with P = 0.02, P = 0.05, P = 0.003, and P = 0.002, respectively. Conclusion: Quantitative parameters of functional imaging techniques in bone marrow are influenced by the age of the examined individual and the anatomical location of the investigated region

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging of bone marrow in healthy individuals

International Nuclear Information System (INIS)

Hillengass, Jens; Stieltjes, Bram; Baeuerle, Tobias

2011-01-01

Background: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) displays microcirculation and permeability by application of contrast-media and diffusion-weighted imaging (DWI) is a tool for quantification of cellularity in the investigated area. Recently published examples cover breast cancer, CNS tumors, head and neck cancer, gastrointestinal cancer, prostate cancer as well as hematologic malignancies. Purpose: To investigated the influence of age, sex, and localization of the investigated region on findings of DCE-MRI and DWI. Material and Methods: DCE-MRI-parameters amplitude A and exchange rate constant kep as well as the DWI-parameter ADC of the bone marrow of the lumbar vertebral column of 30 healthy individuals covering the typical range of age of tumor patients were evaluated. ADC was calculated using b=0 and a maximal b value of either 400 or 750 s/mm2. Results: Amplitude A of DCE-MRI decreased with age (P = 0.01) and amplitude A, exchange rate constant kep as well as ADC based on b = 400 s/mm 2 and b = 750 s/mm 2 , respectively, decreased significantly from the first to the fifth lumbar vertebra with P = 0.02, P = 0.05, P = 0.003, and P = 0.002, respectively. Conclusion: Quantitative parameters of functional imaging techniques in bone marrow are influenced by the age of the examined individual and the anatomical location of the investigated region

Utility of diffusion-weighted imaging in the presurgical diagnosis of an infected urachal cyst

International Nuclear Information System (INIS)

Chouhan, Manil; Cuckow, Peter; Humphries, Paul D.

2011-01-01

Urachal cysts are one of a spectrum of urachal abnormalities that occur following failure of regression of the allantois and presumptive bladder between 4 weeks and 6 weeks of gestation. Infection is the most common complication of this rare congenital anomaly. The nonspecific presentation may mimic other pathological processes, underlining their clinical and radiological significance. Imaging investigations typically include US and CT, both of which are limited in their ability to characterize lesions. We report the case of a 5-year-old presenting with macroscopic haematuria in whom diffusion-weighted MRI (DWI) suggested the diagnosis of an infected urachal cyst, which was confirmed surgically. We discuss the radiological findings in multiple imaging modalities and present the application of DWI in this context as a means of improving the radiological diagnostic yield. (orig.)

A follow-up study by CT and MRI in 3 cases of Japanese encephalitis

International Nuclear Information System (INIS)

Shoji, H.; Murakami, T.; Murai, I.; Kida, H.; Sato, Y.; Kojima, K.; Abe, T.; Okudera, T.

1990-01-01

A follow-up study by CT and MRI in 3 cases of Japanese encephalitis (JE) was performed. Neurologically dementia, forced laughing, tetraplegia and parkinsonism were observed as sequelae. In the CT and MR scans about 3 years after the onset of JE, low-density areas (LDAs) or abnormal signal intensities had remained in the thalamus and basal ganglia. The abnormalities were also found in the brain stem. When the main lesions shown by CT and MRI were compared with those of the acute stage, T2-weighted MRI clearly revealed multiple small areas with high signal intensities, although the ones at the acute stage had showed diffuse abnormal signals. These findings may be useful in helping to identity a long time after the onset. (orig.)

T2-weighted MRI-derived textural features reflect prostate cancer aggressiveness: preliminary results

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Nketiah, Gabriel; Elschot, Mattijs; Kim, Eugene; Teruel, Jose R. [NTNU, Norwegian University of Science and Technology, Department of Circulation and Medical Imaging, Faculty of Medicine, Trondheim (Norway); Scheenen, Tom W. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Bathen, Tone F.; Selnaes, Kirsten M. [NTNU, Norwegian University of Science and Technology, Department of Circulation and Medical Imaging, Faculty of Medicine, Trondheim (Norway); St. Olavs Hospital, Trondheim University Hospital, Trondheim (Norway)

2017-07-15

To evaluate the diagnostic relevance of T2-weighted (T2W) MRI-derived textural features relative to quantitative physiological parameters derived from diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI in Gleason score (GS) 3+4 and 4+3 prostate cancers. 3T multiparametric-MRI was performed on 23 prostate cancer patients prior to prostatectomy. Textural features [angular second moment (ASM), contrast, correlation, entropy], apparent diffusion coefficient (ADC), and DCE pharmacokinetic parameters (K{sup trans} and V{sub e}) were calculated from index tumours delineated on the T2W, DW, and DCE images, respectively. The association between the textural features and prostatectomy GS and the MRI-derived parameters, and the utility of the parameters in differentiating between GS 3+4 and 4+3 prostate cancers were assessed statistically. ASM and entropy correlated significantly (p < 0.05) with both GS and median ADC. Contrast correlated moderately with median ADC. The textural features correlated insignificantly with K{sup trans} and V{sub e}. GS 4+3 cancers had significantly lower ASM and higher entropy than 3+4 cancers, but insignificant differences in median ADC, K{sup trans}, and V{sub e}. The combined texture-MRI parameters yielded higher classification accuracy (91%) than the individual parameter sets. T2W MRI-derived textural features could serve as potential diagnostic markers, sensitive to the pathological differences in prostate cancers. (orig.)

Q-ball imaging models: comparison between high and low angular resolution diffusion-weighted MRI protocols for investigation of brain white matter integrity

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Caiazzo, Giuseppina; Trojsi, Francesca; Cirillo, Mario; Tedeschi, Gioacchino [MRI Research Center SUN-FISM-Neurological Institute for Diagnosis and Care ' ' Hermitage Capodimonte' ' , Naples (Italy); Second University of Naples, Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Naples (Italy); Esposito, Fabrizio [University of Salerno, Department of Medicine and Surgery, Baronissi (Salerno) (Italy); Maastricht University, Department of Cognitive Neuroscience, Maastricht (Netherlands)

2016-02-15

Q-ball imaging (QBI) is one of the typical data models for quantifying white matter (WM) anisotropy in diffusion-weighted MRI (DwMRI) studies. Brain and spinal investigation by high angular resolution DwMRI (high angular resolution imaging (HARDI)) protocols exhibits higher angular resolution in diffusion imaging compared to low angular resolution models, although with longer acquisition times. We aimed to assess the difference between QBI-derived anisotropy values from high and low angular resolution DwMRI protocols and their potential advantages or shortcomings in neuroradiology. Brain DwMRI data sets were acquired in seven healthy volunteers using both HARDI (b = 3000 s/mm{sup 2}, 54 gradient directions) and low angular resolution (b = 1000 s/mm{sup 2}, 32 gradient directions) acquisition schemes. For both sequences, tract of interest tractography and generalized fractional anisotropy (GFA) measures were extracted by using QBI model and were compared between the two data sets. QBI tractography and voxel-wise analyses showed that some WM tracts, such as corpus callosum, inferior longitudinal, and uncinate fasciculi, were reconstructed as one-dominant-direction fiber bundles with both acquisition schemes. In these WM tracts, mean percent different difference in GFA between the two data sets was less than 5 %. Contrariwise, multidirectional fiber bundles, such as corticospinal tract and superior longitudinal fasciculus, were more accurately depicted by HARDI acquisition scheme. Our results suggest that the design of optimal DwMRI acquisition protocols for clinical investigation of WM anisotropy by QBI models should consider the specific brain target regions to be explored, inducing researchers to a trade-off choice between angular resolution and acquisition time. (orig.)

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

International Nuclear Information System (INIS)

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

1998-01-01

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

Diffusion properties of conventional and calcium-sensitive MRI contrast agents in the rat cerebral cortex.

Science.gov (United States)

Hagberg, Gisela E; Mamedov, Ilgar; Power, Anthony; Beyerlein, Michael; Merkle, Hellmut; Kiselev, Valerij G; Dhingra, Kirti; Kubìček, Vojtĕch; Angelovski, Goran; Logothetis, Nikos K

2014-01-01

Calcium-sensitive MRI contrast agents can only yield quantitative results if the agent concentration in the tissue is known. The agent concentration could be determined by diffusion modeling, if relevant parameters were available. We have established an MRI-based method capable of determining diffusion properties of conventional and calcium-sensitive agents. Simulations and experiments demonstrate that the method is applicable both for conventional contrast agents with a fixed relaxivity value and for calcium-sensitive contrast agents. The full pharmacokinetic time-course of gadolinium concentration estimates was observed by MRI before, during and after intracerebral administration of the agent, and the effective diffusion coefficient D* was determined by voxel-wise fitting of the solution to the diffusion equation. The method yielded whole brain coverage with a high spatial and temporal sampling. The use of two types of MRI sequences for sampling of the diffusion time courses was investigated: Look-Locker-based quantitative T(1) mapping, and T(1) -weighted MRI. The observation times of the proposed MRI method is long (up to 20 h) and consequently the diffusion distances covered are also long (2-4 mm). Despite this difference, the D* values in vivo were in agreement with previous findings using optical measurement techniques, based on observation times of a few minutes. The effective diffusion coefficient determined for the calcium-sensitive contrast agents may be used to determine local tissue concentrations and to design infusion protocols that maintain the agent concentration at a steady state, thereby enabling quantitative sensing of the local calcium concentration. Copyright © 2014 John Wiley & Sons, Ltd.

T2-weighted MRI-derived textural features reflect prostate cancer aggressiveness: preliminary results.

Science.gov (United States)

Nketiah, Gabriel; Elschot, Mattijs; Kim, Eugene; Teruel, Jose R; Scheenen, Tom W; Bathen, Tone F; Selnæs, Kirsten M

2017-07-01

To evaluate the diagnostic relevance of T2-weighted (T2W) MRI-derived textural features relative to quantitative physiological parameters derived from diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI in Gleason score (GS) 3+4 and 4+3 prostate cancers. 3T multiparametric-MRI was performed on 23 prostate cancer patients prior to prostatectomy. Textural features [angular second moment (ASM), contrast, correlation, entropy], apparent diffusion coefficient (ADC), and DCE pharmacokinetic parameters (K trans and V e ) were calculated from index tumours delineated on the T2W, DW, and DCE images, respectively. The association between the textural features and prostatectomy GS and the MRI-derived parameters, and the utility of the parameters in differentiating between GS 3+4 and 4+3 prostate cancers were assessed statistically. ASM and entropy correlated significantly (p textural features correlated insignificantly with K trans and V e . GS 4+3 cancers had significantly lower ASM and higher entropy than 3+4 cancers, but insignificant differences in median ADC, K trans , and V e . The combined texture-MRI parameters yielded higher classification accuracy (91%) than the individual parameter sets. T2W MRI-derived textural features could serve as potential diagnostic markers, sensitive to the pathological differences in prostate cancers. • T2W MRI-derived textural features correlate significantly with Gleason score and ADC. • T2W MRI-derived textural features differentiate Gleason score 3+4 from 4+3 cancers. • T2W image textural features could augment tumour characterization.

Diffusion-weighted MR imaging of neuro-Behcet's disease: a case report

International Nuclear Information System (INIS)

Hiwatashi, Akio; Moritani, Toshio; Kinoshita, Toshibumi; Westesson, Per-Lennart; Garber, Todd

2003-01-01

We present a serial study of diffusion-weighted imaging (DWI) in a patient with neuro-Behcet's disease. Initial T2-weighted magnetic resonance images showed a hyperintense lesion in the brain stem. The lesion was slightly hyperintense on DWI and the apparent diffusion coefficient (ADC) was slightly increased. Ten months later, DWI showed an improvement in the abnormal signal intensity and the region of increased ADC had increased in size, especially on the left side. DWI is useful for differentiating an acute exacerbation of neuro-Behcet's disease from acute infarction. (orig.)

Hippocampal sclerosis and status epilepticus: cause or consequence? A MRI study; Esclerose hipocampal e status epilepticus: causa ou consequencia? Um estudo de RM

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Kuster, Gustavo Wruck; Braga-Neto, Pedro; Santos-Neto, Denizart; Santana, Maria Teresa Garcia; Barsottini, Orlando Graziani [Universidade Federal de Sao Paulo (UNIFESP-EPM), Sao Paulo, SP (Brazil). Dept. of Neurology. Div. of General Neurology; Maia Junior, Antonio Carlos Martins [Fleury Institute, Sao Paulo, SP (Brazil). Magnetic Resonance Imaging Unit

2007-12-15

Background: Transient imaging abnormalities, including changes on diffusion-weighted imaging (DWI), may be seen in status epilepticus. These abnormalities can be followed by hippocampal sclerosis. Case Report: We report a 15-year-old lady with focal non convulsive status epilepticus (NCSE) and focal slowing on EEG. DWI exhibited abnormal hyperintense signals in bilateral temporal and insular cortices. After 3 weeks, MRI performed a localized hippocampal atrophy. Conclusion: The MRI findings indicated vasogenic and cytotoxic edema during seizure activity and subsequent loss of brain parenchyma. (author)

MRI of a family with focal abnormalities of gyration

International Nuclear Information System (INIS)

Muntaner, L.; Perez-Ferron, J.J.; Herrera, M.; Rosell, J.; Taboada, D.; Climent, S.

1997-01-01

Focal abnormalities of gyration (FAG) are developmental disorders that may occur in isolated patients or, as in the case being reported, as part of a familial disorder. Analysis of individuals in a family spanning three generations was carried out using MRI. Abnormalities, present in all members of generations II and III, included focal cortical dysplasia (three patients), focal cortical infolding (two patients) and schizencephaly (one patient); associated minor anomalies, such as white matter abnormalities, were seen in the remaining three members of generations II and III. MRI recognition of FAG in the family being reported proved useful in defining their phenotypical expression and providing proper counselling for individual family members. (orig.). With 6 figs

Diffusion-weighted magnetic resonance imaging with apparent diffusion coefficient (ADC) determination in normal and pathological fetal kidneys.

Science.gov (United States)

Chaumoitre, K; Colavolpe, N; Shojai, R; Sarran, A; D' Ercole, C; Panuel, M

2007-01-01

To assess the use of diffusion-weighted magnetic resonance imaging (DW-MRI) in the evaluation of the fetal kidney and to estimate age-dependent changes in the apparent diffusion coefficient (ADC) of normal and pathological fetal kidneys. DW-MRI was performed on a 1.5-T machine at 23-38 gestational weeks in 51 pregnant women in whom the fetal kidneys were normal and in 10 whose fetuses had renal pathology (three with suspected nephropathy, three with renal tract dilatation, one with unilateral renal venous thrombosis, and three with twin-twin transfusion syndrome (TTTS)). The ADC was measured in an approximately 1-cm2 region of interest within the renal parenchyma. ADC values in normal renal parenchyma ranged from 1.1 to 1.8 10(-3) mm2 s-1. There was no significant age-dependent change in the ADC of normal kidneys. In cases of nephropathy, the ADC value was not always pathological but an ADC map could show abnormal findings. In cases of dilatation, the ADC value was difficult to determine when the dilatation was huge. In cases of TTTS, the ADC of the donor twin was higher than that of the recipient twin and the difference seemed to be related to the severity of the syndrome. Evaluation of the ADC for fetal kidneys is feasible. Fetal measurement of the ADC value and ADC maps may be useful tools with which to explore the fetal kidney when used in conjunction with current methods. DW-MR images, ADC value and ADC map seem to be useful in cases of suspected nephropathy (hyperechoic kidneys), dilated kidney and vascular pathology (renal venous thrombosis, TTTS). Copyright (c) 2006 ISUOG.

Variability of non-Gaussian diffusion MRI and intravoxel incoherent motion (IVIM) measurements in the breast.

Science.gov (United States)

Iima, Mami; Kataoka, Masako; Kanao, Shotaro; Kawai, Makiko; Onishi, Natsuko; Koyasu, Sho; Murata, Katsutoshi; Ohashi, Akane; Sakaguchi, Rena; Togashi, Kaori

2018-01-01

We prospectively examined the variability of non-Gaussian diffusion magnetic resonance imaging (MRI) and intravoxel incoherent motion (IVIM) measurements with different numbers of b-values and excitations in normal breast tissue and breast lesions. Thirteen volunteers and fourteen patients with breast lesions (seven malignant, eight benign; one patient had bilateral lesions) were recruited in this prospective study (approved by the Internal Review Board). Diffusion-weighted MRI was performed with 16 b-values (0-2500 s/mm2 with one number of excitations [NEX]) and five b-values (0-2500 s/mm2, 3 NEX), using a 3T breast MRI. Intravoxel incoherent motion (flowing blood volume fraction [fIVIM] and pseudodiffusion coefficient [D*]) and non-Gaussian diffusion (theoretical apparent diffusion coefficient [ADC] at b value of 0 sec/mm2 [ADC0] and kurtosis [K]) parameters were estimated from IVIM and Kurtosis models using 16 b-values, and synthetic apparent diffusion coefficient (sADC) values were obtained from two key b-values. The variabilities between and within subjects and between different diffusion acquisition methods were estimated. There were no statistical differences in ADC0, K, or sADC values between the different b-values or NEX. A good agreement of diffusion parameters was observed between 16 b-values (one NEX), five b-values (one NEX), and five b-values (three NEX) in normal breast tissue or breast lesions. Insufficient agreement was observed for IVIM parameters. There were no statistical differences in the non-Gaussian diffusion MRI estimated values obtained from a different number of b-values or excitations in normal breast tissue or breast lesions. These data suggest that a limited MRI protocol using a few b-values might be relevant in a clinical setting for the estimation of non-Gaussian diffusion MRI parameters in normal breast tissue and breast lesions.

Feasibility of a RARE-based sequence for quantitative diffusion-weighted MRI of the spine

International Nuclear Information System (INIS)

Raya, J.G.; Dietrich, O.; Sommer, J.; Reiser, M.F.; Baur-Melnyk, A.; Birkenmaier, C.

2007-01-01

The feasibility of a diffusion-weighted single-shot fast-spin-echo sequence for the diagnostic work-up of bone marrow diseases was assessed. Twenty healthy controls and 16 patients with various bone marrow pathologies of the spine (bone marrow edema, tumor and inflammation) were examined with a diffusion-weighted single-shot sequence based on a modified rapid acquisition with relaxation enhancement (mRARE) technique; four diffusion weightings (b-values: 50, 250, 500 and 750 s/mm 2 ) in three orthogonal orientations were applied. Apparent diffusion coefficients (ADCs) were determined in the bone marrow and in the intervertebral discs of healthy volunteers and in diseased bone marrow. Ten of the 20 volunteers were repeatedly scanned within 30 min to examine short-time reproducibility. Spatial reproducibility was assessed by measuring ADCs in two different slices including the same lesion in 12 patients. The ADCs of the lesions exhibited significantly higher values, (1.27 ± 0.32) x 10 -3 mm 2 /s, compared with healthy bone marrow, (0.21 ± 0.10) x 10 -3 mm 2 /s. Short-time and spatial reproducibility had a mean coefficient of variation of 2.1% and 6.4%, respectively. The diffusion-weighted mRARE sequence provides a reliable tool for determining quantitative ADCs in vertebral bone marrow with adequate image quality. (orig.)

Independent value of image fusion in unenhanced breast MRI using diffusion-weighted and morphological T2-weighted images for lesion characterization in patients with recently detected BI-RADS 4/5 X-ray mammography findings

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Bickelhaupt, Sebastian; Tesdorff, Jana; Delorme, Stefan; Schlemmer, Heinz-Peter [German Cancer Research Center (dkfz), Department of Radiology, Heidelberg (Germany); Laun, Frederik Bernd; Kuder, Tristan Anselm [German Cancer Research Center (dkfz), Medical Physics in Radiology, Heidelberg (Germany); Lederer, Wolfgang; Teiner, Susanne [Radiological Practice at the ATOS Clinic Heidelberg, Heidelberg (Germany); Maier-Hein, Klaus [German Cancer Research Center (dkfz), Junior Group Medical Image Computing, Heidelberg (Germany); Daniel, Heidi [Radiology Center Mannheim (RZM), Mannheim (Germany); Stieber, Anne [University Hospital Heidelberg, Department of Clinical and Interventional Radiology, Heidelberg (Germany)

2017-02-15

The aim of this study was to evaluate the accuracy and applicability of solitarily reading fused image series of T2-weighted and high-b-value diffusion-weighted sequences for lesion characterization as compared to sequential or combined image analysis of these unenhanced sequences and to contrast- enhanced breast MRI. This IRB-approved study included 50 female participants with suspicious breast lesions detected in screening X-ray mammograms, all of which provided written informed consent. Prior to biopsy, all women underwent MRI including diffusion-weighted imaging (DWIBS, b = 1500s/mm{sup 2}). Images were analyzed as follows: prospective image fusion of DWIBS and T2-weighted images (FU), side-by-side analysis of DWIBS and T2-weighted series (CO), combination of the first two methods (CO+FU), and full contrast-enhanced diagnostic protocol (FDP). Diagnostic indices, confidence, and image quality of the protocols were compared by two blinded readers. Reading the CO+FU (accuracy 0.92; NPV 96.1 %; PPV 87.6 %) and the CO series (0.90; 96.1 %; 83.7 %) provided a diagnostic performance similar to the FDP (0.95; 96.1 %; 91.3 %; p > 0.05). FU reading alone significantly reduced the diagnostic accuracy (0.82; 93.3 %; 73.4 %; p = 0.023). MR evaluation of suspicious BI-RADS 4 and 5 lesions detected on mammography by using a non-contrast-enhanced T2-weighted and DWIBS sequence protocol is most accurate if MR images were read using the CO+FU protocol. (orig.)

Diffusion-weighted imaging as part of hybrid PET/MRI protocols for whole-body cancer staging: Does it benefit lesion detection?

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Buchbender, Christian, E-mail: christian.buchbender@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Hartung-Knemeyer, Verena, E-mail: verena.hartung@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Nuclear Medicine, Hufelandstr. 55, D-45147 Essen (Germany); Beiderwellen, Karsten, E-mail: karsten.beiderwellen@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Heusch, Philipp, E-mail: philipp.heusch@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Kühl, Hilmar, E-mail: hilmar.kuehl@uni-due.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Lauenstein, Thomas C., E-mail: thomas.lauenstein@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Forsting, Michael, E-mail: michael.forsting@uk-essen.de [Univ Duisburg-Essen, Medical Faculty, Department of Diagnostic and Interventional Radiology and Neuroradiology, Hufelandstr. 55, D-45147 Essen (Germany); Antoch, Gerald, E-mail: antoch@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Heusner, Till A., E-mail: heusner@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany)

2013-05-15

Purpose: Positron emission tomography/magnetic resonance imaging (PET/MRI) requires efficient scan protocols for whole-body cancer staging. The aim of this study was to evaluate if the application of diffusion-weighted MR imaging (DWI) results in a diagnostic benefit for lesion detection in oncologic patients if added to a whole-body [18F]-fluorodesoxyglucose ([18F]-FDG) PET/MRI protocol. Methods: 25 consecutive oncologic patients (16 men, 9 women; age 57 ± 12 years) prospectively underwent whole-body [18F]-FDG-PET/MRI including DWI on a hybrid PET/MRI scanner. A team of two readers assessed [18F]-FDG PET/MRI without DWI for primary tumors and metastases. In a second session, now considering DWI, readers reassessed [18F]-FDG PET/MRI accordingly. Additionally, the lesion-to-background contrast on [18F]-FDG PET and DWI was rated qualitatively (0, invisible; 1, low; 2, intermediate; 3, high). Wilcoxon's signed-rank test was performed to test for differences in the lesion-to-background contrast. Results: 49 lesions were detected in 16 patients (5 primaries, 44 metastases). All 49 lesions were concordantly detected by [18F]-FDG PET/MRI alone and [18F]-FDG PET/MRI with DWI. The lesion-to-background contrast on DWI compared to [18F]-FDG PET was rated lower in 22 (44.9%) of 49 detected lesions resulting in a significantly higher lesion-to-background contrast on [18F]-FDG PET compared to DWI (P = 0.001). Conclusions: DWI as part of whole-body [18F]-FDG PET/MRI does not benefit lesion detection. Given the necessity to optimize imaging protocols with regard to patient comfort and efficacy, DWI has to be questioned as a standard tool for whole-body staging in oncologic PET/MRI.

MRI abnormalities and related risk factors of the brain in patients with neuromyelitis optica

International Nuclear Information System (INIS)

Xiao Hui; Ma Lin; Lou Xin; Cai Youquan; Wang Yulin; Wang Yan; Wu Lei; Wu Weiping

2011-01-01

Objective: To investigate the MRI features of the brain in patients with neuromyelitis optica (NMO), and to evaluate the correlation between the brain abnormalities and related risk factors. Methods: Fifty-four patients with definite NMO according to 2006 Wingerchuk diagnosis criteria were enrolled in this study. MRI scanning of the brain was performed in these patients. Distribution and signal features of all the lesions were analyzed. A Logistic regression analysis was used to evaluate the risk factors of brain abnormalities. Results: Twenty-four NMO patients (44.4%) showed unremarkable findings and thirty (55.6%) showed abnormalities on brain MRI. Multiple and non-specific small lesions in the subcortical white matter and grey-white matter junction were the most frequent abnormalities on brain MRI (13/30, 43.3%). Typical lesion locations included corpus callosum, subependyma of ventricles, hypothalamus and brain stem. The lesions showed punctate, patchy and linear abnormal signals. Post-contrast MRI showed no abnormal enhancement in 16 cases. Logistic regression analysis showed that coexisting autoimmune disease or infection. history had correlations with abnormalities of the brain on MRI (OR=3.519, P<0.05). Conclusions: There was a high incidence of brain abnormalities in NMO. Subependymal white matter, corpus callosum, hypothalamus and brain stem were often involved in NMO. NMO patients with coexisting autoimmune disease and infection history had higher risk of brain abnormalities. (authors)

Cerebral MRI findings in very-low-birth-weight and small-for-gestational-age children at 15 years of age

International Nuclear Information System (INIS)

Skranes, Jon S.; Brubakk, Ann-Mari; Martinussen, Marit; Smevik, Olaug; Myhr, Gunnar; Indredavik, Marit; Vik, Torstein

2005-01-01

A high prevalence of abnormal cerebral MRI findings has been reported in low-birth-weight children. To compare MRI findings in very-low-birth-weight (VLBW) and term small-for-gestational-age (SGA) children with controls in early adolescence. Cerebral MRI was used to examine 55 VLBW, 54 SGA and 66 controls at 15 years of age. The MR images were qualitatively assessed, and size of ventricles, white-matter and grey-matter abnormalities were reported. The VLBW teenagers had a higher prevalence of various MRI abnormalities than SGA children and controls. Dilation of the ventricular system, especially of the occipital horns, was found in 82% of the VLBW group, in 19% of the SGA group and in 21% of controls. White-matter reduction was found in 53% of the VLBW, in 6% of the SGA and in 2% of controls. Corpus callosum thinning was found in 47% of the VLBW, in 2% of the SGA and in 6% of controls. Periventricular gliosis was found in 29% of the VLBW, in 4% of the SGA and in 8% of controls. Cerebral MRI pathology in white matter is a common finding in VLBW teenagers. The findings may indicate minor perinatal PVL with resulting loss of white-matter tissue and ventricular dilation. (orig.)

New MRI technologies. Diffusion MRI and its application to functional neuroimaging and analyses of white matter integrity

International Nuclear Information System (INIS)

Kobayashi, Tetsuo

2010-01-01

Described is the technological aspect of MRI, MR diffusion-weighted imaging (MR-DWI), principles of its measurement and application for imaging the cerebral function and for aiding the quantitative diagnosis of brain diseases. The author explains the principle of MR imaging process; diffusion properties of water molecules, MR-DWI based on them and DW-fMRI of the brain; MR-diffusion tensor imaging (MR-DTI), its analysis and color acquisition, and tracking of white matter nerve fibers; analysis of white matter lesions by the tracking; and the new tracking method at the chiasm of nerve fascicles. The usual fMRI reflects the blood oxygen level depending (BOLD) signals whereas recently attracted DW-fMRI, the volume changes of nerve cells concomitant to nerve activation accompanying apparent changes of water diffusion coefficients in and out of cells which occur faster than BOLD signs, resulting in higher resolution of time and space. However, DWI requires the higher intensity of static magnetic field like 3T. MR-DTI acquires the anisotropic diffusion of water molecules using MR-DWI technique with application of 6 or more motion probing gradients, thus makes it possible to track the running directions of nerve fibers and capillary vessels, and is proposed to be a useful mean of specific fiber tracking in the white matter when displayed by 3 different colors exhibiting the directions like the right/left (x axis, red), anterior/posterior (y, green) and upper/lower (z, blue) sides of head. Recently, MR-DWI and MR-DTI have been found usable for pathogenic studies of brain diseases such as dementia. Tensor anisotropy is apparently lowered at the chiasm of nerve fascicles, the cause of tracking error, for which authors have developed a new method using the similarity of directional vector, not of tensor, before and behind the chiasm. As exemplified, MRI technology is further advancing even at present. (T.T.)

Regularized spherical polar fourier diffusion MRI with optimal dictionary learning.

Science.gov (United States)

Cheng, Jian; Jiang, Tianzi; Deriche, Rachid; Shen, Dinggang; Yap, Pew-Thian

2013-01-01

Compressed Sensing (CS) takes advantage of signal sparsity or compressibility and allows superb signal reconstruction from relatively few measurements. Based on CS theory, a suitable dictionary for sparse representation of the signal is required. In diffusion MRI (dMRI), CS methods proposed for reconstruction of diffusion-weighted signal and the Ensemble Average Propagator (EAP) utilize two kinds of Dictionary Learning (DL) methods: 1) Discrete Representation DL (DR-DL), and 2) Continuous Representation DL (CR-DL). DR-DL is susceptible to numerical inaccuracy owing to interpolation and regridding errors in a discretized q-space. In this paper, we propose a novel CR-DL approach, called Dictionary Learning - Spherical Polar Fourier Imaging (DL-SPFI) for effective compressed-sensing reconstruction of the q-space diffusion-weighted signal and the EAP. In DL-SPFI, a dictionary that sparsifies the signal is learned from the space of continuous Gaussian diffusion signals. The learned dictionary is then adaptively applied to different voxels using a weighted LASSO framework for robust signal reconstruction. Compared with the start-of-the-art CR-DL and DR-DL methods proposed by Merlet et al. and Bilgic et al., respectively, our work offers the following advantages. First, the learned dictionary is proved to be optimal for Gaussian diffusion signals. Second, to our knowledge, this is the first work to learn a voxel-adaptive dictionary. The importance of the adaptive dictionary in EAP reconstruction will be demonstrated theoretically and empirically. Third, optimization in DL-SPFI is only performed in a small subspace resided by the SPF coefficients, as opposed to the q-space approach utilized by Merlet et al. We experimentally evaluated DL-SPFI with respect to L1-norm regularized SPFI (L1-SPFI), which uses the original SPF basis, and the DR-DL method proposed by Bilgic et al. The experiment results on synthetic and real data indicate that the learned dictionary produces

Diffusion-weighted imaging in relation to morphology on dynamic contrast enhancement MRI. The diagnostic value of characterizing non-puerperal mastitis

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Zhang, Lina; Chu, Jianguo; Zhang, Weisheng; Liu, Ailian; Song, Qingwei [First Affiliated Hospital of Dalian Medical University, Department of Radiology, Dalian, Liaoning (China); Hu, Jiani; Guys, Nicholas [Wayne State University, Department of Radiology, Detroit, MI (United States); Meng, Jinli [Chengban Branch of West China Hospital, Department of Radiology, Chengdu, Sichuan (China); Wang, Shaowu [Second Affiliated Hospital of Dalian Medical University, Department of Radiology, Dalian, Liaoning (China)

2018-03-15

To demonstrate the value of diffusion-weighted imaging (DWI) in the characterisation of mastitis lesions. Sixty-one non-puerperal patients with pathologically confirmed single benign mastitis lesions underwent preoperative examinations with conventional MRI and axial DWI. Patients were categorised into three groups: (1) periductal mastitis (PDM), (2) granulomatous lobular mastitis (GLM), and (3) infectious abscess (IAB). Apparent diffusion coefficient (ADC) values of each lesion were recorded. A one-way ANOVA with logistic analysis was performed to compare ADC values and other parameters. Discriminative abilities of DWI modalities were compared using the area under the receiver operating characteristic curve (AUC). P < 0.05 was considered statistically significant. ADC values differed significantly among the three groups (P = 0.003) as well as between PDM and IAB and between PDM and GLM. The distribution of non-mass enhancement on dynamic contrast-enhanced (DCE) MRI differed significantly among the three groups (P = 0.03) but not between any two groups specifically. There were no differences in lesion location, patient age, T{sub 2}WI or DWI signal intensity, enhancement type, non-mass internal enhancement, or mass enhancement characteristics among the three groups. ADC values and the distribution of non-mass enhancement are valuable in classifying mastitis subtypes. (orig.)

Cerebral MRI of very low birth weight children at 6 years of age compared with the findings at 1 year

International Nuclear Information System (INIS)

Skranes, J.S.; Nilsen, G.; Smevik, O.; Vik, T.; Brubakk, A.M.

1998-01-01

Background. We have previously reported the results of cerebral MRI examinations in an unselected year cohort of very low birth weight (VLBW) infants at one year of corrected age. Twenty-one (78 %) of 27 infants had abnormal myelination, mainly in the central occipital white matter (COWM) and in the centrum semiovale (CS), seen on T2-weighted images. Twelve infants had irregular and dilated lateral ventricles. We speculated whether these findings indicated perinatal periventricular leukomalacia (PVL). Only two infants had completely normal MRI at age 1 year. Objective. To determine whether the abnormal myelination seen at 1 year of age, was still present, either as delayed myelination or as gliosis caused by perinatal PVL. Materials and methods. In the present study, we report the results of follow-up cerebral MRI in 20 of these infants at 6 years of age. Results. Most of the children with MRI deviations at 1 year still had abnormalities at 6 years. Abnormal myelination in the central occipital white matter combined with abnormalities in the CS or with ventricular dilatation at age 1 year, presented as gliosis in 12 of 13 children at 6 years of age. Abnormalities solely in the COWM at age 1 year had normalised in two of five children and persisted as delayed myelination in three at age 6 years. Gliotic changes in periventricular white matter were found in 12 of 20 children (60 %). Areas most affected were the CS (11 children) and the COWM (9 children). Delayed myelination in COWM was found in six children (30 %), combined with gliosis in CS in three children. Twelve infants had ventricular dilatation both at 1 and 6 years of age. Conclusions. The MRI correlates of PVL, i. e. gliosis and ventricular dilatation, are common findings on cerebral MRI at 6 years of age in VLBW infants. (orig.)

Is there a role for conventional MRI and MR diffusion-weighted imaging for distinction of skull base chordoma and chondrosarcoma?

Science.gov (United States)

Müller, Uta; Kubik-Huch, Rahel A; Ares, Carmen; Hug, Eugen B; Löw, Roland; Valavanis, Antonios; Ahlhelm, Frank J

2016-02-01

Chordoma and chondrosarcoma are locally invasive skull base tumors with similar clinical symptoms and anatomic imaging features as reported in the literature. To determine differentiation of chordoma and chondrosarcoma of the skull base with conventional magnetic resonance imaging (cMRI) and diffusion-weighted MR imaging (DWI) in comparison to histopathological diagnosis. This retrospective study comprised 96 (chordoma, n = 64; chondrosarcoma, n = 32) patients with skull base tumors referred to the Paul Scherrer Institute (PSI) for proton therapy. cMRI signal intensities of all tumors were investigated. In addition, median apparent diffusion coefficient (ADC) values were measured in a subgroup of 19 patients (chordoma, n = 11; chondrosarcoma, n = 8). The majority 81.2% (26/32) of chondrosarcomas displayed an off-midline growth pattern, 18.8% (6/32) showed clival invasion, 18.8% (6/32) were located more centrally. Only 4.7% (3/64) of chordomas revealed a lateral clival origin. Using cMRI no significant differences in MR signal intensities were observed in contrast to significantly different ADC values (subgroup of 19/96 patients examined by DWI), with the highest mean value of 2017.2 × 10(-6 )mm(2)/s (SD, 139.9( )mm(2)/s) for chondrosarcoma and significantly lower value of 1263.5 × 10(-6 )mm(2)/s (SD, 100.2 × 10(-6 )mm(2)/s) for chordoma (P = 0.001/median test). An off-midline growth pattern can differentiate chondrosarcoma from chordoma on cMRI in a majority of patients. Additional DWI is a promising tool for the differentiation of these skull base tumors. © The Foundation Acta Radiologica 2015.

Diffusion weighted imaging (DWI) in the abdomen

International Nuclear Information System (INIS)

Collaku, A.

2013-01-01

Full text: Introduction: The use of diffusion weighted images when performing abdomen MRI has been increased during the last years; achieving high quality images for a short period of time remains still a challenge. Learning points: We present a literature review together with our experience in optimizing the DW imaging in the abdomen, focused on creating high density ADC maps and handling the uncooperative patients. Discussion: The factors that influence the image quality are discussed as well. Conclusion: The factors that influence the image quality are discussed as well

Acute hyperammonemic encephalopathy with features on diffusion-weighted images: Report of two cases

International Nuclear Information System (INIS)

Kim, Ja Young; Yu, In Kyu

2015-01-01

Acute hyperammonemic encephalopathy is a rare toxic encephalopathy caused by accumulated plasma ammonia. A few literatures are reported about MRI findings of acute hyperammonemic encephalopathy. It is different from the well-known chronic hepatic encephalopathy. The clinical symptom and MRI findings of acute hyperammonemic encephalopathy can be reversible with proper treatment. Acute hepatic encephalopathy involves the cingulate cortex, diffuse cerebral cortices, insula, bilateral thalami on diffusion-weighted imaging (DWI), and fluid-attenuated inversion-recovery. Acute hepatic encephalopathy might mimic hypoxic-ischemic encephalopathy because of their similar predominant involving sites. We experienced 2 cases of acute hyperammonemic encephalopathy consecutively. They showed restricted diffusion at the cingulate cortex, cerebral cortices, insula, and bilateral dorsomedial thalami on DWI. One patient underwent acute fulminant hepatitis A, the other patient with underlying chronic liver disease had acute liver failure due to hepatotoxicity of tuberculosis medication. In this report, we presented the characteristic features of DWI in acute hyperammonemic encephalopathy. In addition, we reviewed articles on MRI findings of acute hyperammonemic encephalopathy.

Acute hyperammonemic encephalopathy with features on diffusion-weighted images: Report of two cases

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Kim, Ja Young; Yu, In Kyu [Dept. of Radiology, Eulji University Hospital, Daejeon (Korea, Republic of)

2015-02-15

Acute hyperammonemic encephalopathy is a rare toxic encephalopathy caused by accumulated plasma ammonia. A few literatures are reported about MRI findings of acute hyperammonemic encephalopathy. It is different from the well-known chronic hepatic encephalopathy. The clinical symptom and MRI findings of acute hyperammonemic encephalopathy can be reversible with proper treatment. Acute hepatic encephalopathy involves the cingulate cortex, diffuse cerebral cortices, insula, bilateral thalami on diffusion-weighted imaging (DWI), and fluid-attenuated inversion-recovery. Acute hepatic encephalopathy might mimic hypoxic-ischemic encephalopathy because of their similar predominant involving sites. We experienced 2 cases of acute hyperammonemic encephalopathy consecutively. They showed restricted diffusion at the cingulate cortex, cerebral cortices, insula, and bilateral dorsomedial thalami on DWI. One patient underwent acute fulminant hepatitis A, the other patient with underlying chronic liver disease had acute liver failure due to hepatotoxicity of tuberculosis medication. In this report, we presented the characteristic features of DWI in acute hyperammonemic encephalopathy. In addition, we reviewed articles on MRI findings of acute hyperammonemic encephalopathy.

Diffusion-Weighted Magnetic Resonance Imaging in Renal Lesion Characterization

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Elif Karadeli

2012-03-01

Conclusion: The technique has the advantage that it is non-invasive without need for gadolinium administration, takes about 2 minute. This method provides qualitative and quantitative infomation on tissue characterization. DA-MRI and ADC values are important for characterization of renal lesions. Especially, utility of diffusion-weighted magnetic resonance imaging in the patients with risk for nephrogenic systemic fibrosis (NSF could be beneficial. [Cukurova Med J 2012; 37(1: 27-36

Diffusion tensor smoothing through weighted Karcher means

Science.gov (United States)

Carmichael, Owen; Chen, Jun; Paul, Debashis; Peng, Jie

2014-01-01

Diffusion tensor magnetic resonance imaging (MRI) quantifies the spatial distribution of water Diffusion at each voxel on a regular grid of locations in a biological specimen by Diffusion tensors– 3 × 3 positive definite matrices. Removal of noise from DTI is an important problem due to the high scientific relevance of DTI and relatively low signal to noise ratio it provides. Leading approaches to this problem amount to estimation of weighted Karcher means of Diffusion tensors within spatial neighborhoods, under various metrics imposed on the space of tensors. However, it is unclear how the behavior of these estimators varies with the magnitude of DTI sensor noise (the noise resulting from the thermal e!ects of MRI scanning) as well as the geometric structure of the underlying Diffusion tensor neighborhoods. In this paper, we combine theoretical analysis, empirical analysis of simulated DTI data, and empirical analysis of real DTI scans to compare the noise removal performance of three kernel-based DTI smoothers that are based on Euclidean, log-Euclidean, and affine-invariant metrics. The results suggest, contrary to conventional wisdom, that imposing a simplistic Euclidean metric may in fact provide comparable or superior noise removal, especially in relatively unstructured regions and/or in the presence of moderate to high levels of sensor noise. On the contrary, log-Euclidean and affine-invariant metrics may lead to better noise removal in highly structured anatomical regions, especially when the sensor noise is of low magnitude. These findings emphasize the importance of considering the interplay of sensor noise magnitude and tensor field geometric structure when assessing Diffusion tensor smoothing options. They also point to the necessity for continued development of smoothing methods that perform well across a large range of scenarios. PMID:25419264

Brain microstructure mapping using quantitative and diffusion MRI

International Nuclear Information System (INIS)

Lebois, Alice

2014-01-01

This thesis is focused on the human brain microstructure mapping using quantitative and diffusion MRI. The T1/T2 quantitative imaging relies on sequences dedicated to the mapping of T1 and T2 relaxation times. Their variations within the tissue are linked to the presence of different water compartments defined by a specific organization of the tissue at the cell scale. Measuring these parameters can help, therefore, to better characterize the brain microstructure. The dMRI, on the other hand, explores the brownian motion of water molecules in the brain tissue, where the water molecules' movement is constrained by natural barriers, such as cell membranes. Thus, the information on their displacement carried by the dMRI signal gives access to the underlying cyto-architecture. Combination of these two modalities is, therefore, a promising way to probe the brain tissue microstructure. The main goal of the present thesis is to set up the methodology to study the microstructure of the white matter of the human brain in vivo. The first part includes the acquisition of a unique MRI database of 79 healthy subjects (the Archi/CONNECT), which includes anatomical high resolution data, relaxometry data, diffusion-weighted data at high spatio-angular resolution and functional data. This database has allowed us to build the first atlas of the anatomical connectivity of the healthy brain through the automatic segmentation of the major white matter bundles, providing an appropriate anatomical reference for the white matter to study individually the quantitative parameters along each fascicle, characterizing its microstructure organization. Emphasis was placed on the construction of the first atlas of the T1/T2 profiles along the major white matter pathways. The profiles of the T1 and T2 relaxation times were then correlated to the quantitative profiles computed from the diffusion MRI data (fractional anisotropy, radial and longitudinal diffusivities, apparent diffusion coefficient

Implementing diffusion-weighted MRI for body imaging in prospective multicentre trials. Current considerations and future perspectives

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DeSouza, N.M.; Winfield, J.M.; Weller, A.; Papoutsaki, M.V.; Doran, S.J.; Collins, D.J. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK Cancer Imaging Centre, Surrey (United Kingdom); Waterton, J.C.; Jackson, A. [University of Manchester, Manchester Academic Health Sciences Institute, Manchester (United Kingdom); Fournier, L. [Universite Paris Descartes Sorbonne Paris Cite, Assistance Publique-Hopitaux de Paris, Hopital Europeen Georges Pompidou, Radiology Department, Paris (France); Sullivan, D. [Duke Comprehensive Cancer Institute, Durham, NC (United States); Chenevert, T. [University of Michigan Health System, Department of Radiology, Ann Arbor, MI (United States); Boss, M. [National Institute of Standards and Technology (NIST), Applied Physics Division, Boulder, CO (United States); Trattnig, S. [Medical University of Vienna, Department of Biomedical Imaging and Image Guided Therapy, Vienna (Austria); Liu, Y. [European Organisation for Research and Treatment of Cancer, Brussels (Belgium)

2018-03-15

For body imaging, diffusion-weighted MRI may be used for tumour detection, staging, prognostic information, assessing response and follow-up. Disease detection and staging involve qualitative, subjective assessment of images, whereas for prognosis, progression or response, quantitative evaluation of the apparent diffusion coefficient (ADC) is required. Validation and qualification of ADC in multicentre trials involves examination of i) technical performance to determine biomarker bias and reproducibility and ii) biological performance to interrogate a specific aspect of biology or to forecast outcome. Unfortunately, the variety of acquisition and analysis methodologies employed at different centres make ADC values non-comparable between them. This invalidates implementation in multicentre trials and limits utility of ADC as a biomarker. This article reviews the factors contributing to ADC variability in terms of data acquisition and analysis. Hardware and software considerations are discussed when implementing standardised protocols across multi-vendor platforms together with methods for quality assurance and quality control. Processes of data collection, archiving, curation, analysis, central reading and handling incidental findings are considered in the conduct of multicentre trials. Data protection and good clinical practice are essential prerequisites. Developing international consensus of procedures is critical to successful validation if ADC is to become a useful biomarker in oncology. (orig.)

Upper abdominal gadoxetic acid-enhanced and diffusion-weighted MRI for the detection of gastric cancer: Comparison with two-dimensional multidetector row CT

International Nuclear Information System (INIS)

Jang, K.M.; Kim, S.H.; Lee, S.J.; Lee, M.W.; Choi, D.; Kim, K.M.

2014-01-01

Aim: To evaluate the diagnostic performance of abdominal magnetic resonance imaging (MRI) for the detection of gastric cancer in comparison with that of two-dimensional (2D) multidetector row computed tomography (CT). Materials and methods: The study included 189 patients with 170 surgically confirmed gastric cancers and 19 patients without gastric cancer, all of whom underwent gadoxetic acid-enhanced MRI with diffusion-weighted (DW) imaging, and multidetector contrast-enhanced abdominal CT imaging. Two observers independently analysed three sets of images (CT set, conventional MRI set, and combined conventional and DW MRI set). A five-point scale for likelihood of gastric cancer was used. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were evaluated. Quantitative [apparent diffusion coefficient (ADC) analyses with Mann–Whitney U-test were conducted for gastric cancers and the nearby normal gastric wall. Results: The diagnostic accuracy and sensitivity for detection of gastric cancer were significantly higher on combined conventional and DW MRI set (77.8–78.3%; 75.3–75.9%) than the CT imaging set (67.7–71.4%; 64.1–68.2%) or the conventional MRI set (72–73%; 68.8–70%; p < 0.01). In particular, for gastric cancers with pT2 and pT3, the combined conventional and DW MRI set (91.6–92.6%) yielded significantly higher sensitivity for detection of gastric cancer than did the CT imaging set (76.8–81.1%) by both observers (p < 0.01). The mean ADC of gastric cancer lesions (1 ± 0.23 × 10 −3 mm 2 /s) differed significantly from that of normal gastric wall (1.77 ± 0.25 × 10 −3  mm 2 /s; p < 0.01). Conclusion: Abdominal MRI with DW imaging was more sensitive for the detection of gastric cancer than 2D-multidetector row CT or conventional MRI alone. - Highlights: • The sensitivity for detection of gastric cancer is high on abdominal MR imaging. • DW imaging is helpful for

Comparative study of diffusion weighted imaging and dynamic contrast enhanced MRI for the detection of small breast cancers

International Nuclear Information System (INIS)

Tang Jianhua; Yan Fuhua; Zhou Meiling; Ye Fang; Xu Pengju

2008-01-01

Objective: To compare the sensitivity of diffusion weighted imaging (DWI) with dynamic contrast enhanced (DCE) MRI for the detection of small breast cancers and to evaluate the clinical value of DWI. Methods: Forty-eight patients with benign (n=25) and malignant (n=45) small breast lesions (≤2 cm) proved by pathology underwent DWI and DCE MRI. The DCE MRI was performed using FLASH sequence and the time-signal intensity curve was drawn. The DWI was performed using GRAPPA- EPI sequence with different b values (800, 1000 s/mm 2 ) and the ADC values of lesions were measured. The sensitivity and specificity of DWI for the detection of small breast cancers were compared with DCE MRI. Results: Forty of 45 small breast cancers and 19 of 25 small benign breast lesions were correctly diagnosed using DCE MRI. The sensitivity and positive predictive value of TIC were 88.9% (40/45) and 87.0% (40/46). With b values of 800 s/mm 2 and 1000 s/mm 2 , the average ADC values of small breast cancers were (1.153±0.192) x 10 -3 and (1.079±0.186) x 10 -3 mm 2 /s, while those of benign ones were (1.473±0.252) x 10 -3 and (1.419 ± 0.255) x 10 -3 mm 2 /s, respectively. There was no significant difference for the ADC values with different b values in the same group (P>0.05), while there was a significant difference between the malignant and the benign lesions (P 2 . Both the sensitivity and positive predictive value of diagnosis were 86.7% (39/45). The abilities of DWI and DCE MRI for the diagnosis of small breast cancers were the same. The sensitivity (93.3%) and positive predictive value (91.3%) were improved with the combination of DCE MRI and DWI. Conclusion: DWI has a high sensitivity for the detection of small breast cancers, the ADC value can provide valuable information in the differential diagnosis. (authors)

Analysis and visualization methods for interpretation of diffusion MRI data

NARCIS (Netherlands)

Vos, S.B.

2013-01-01

Diffusion MRI is an imaging technique that is very sensitive to microstructural changes in tissue. Diffusion tensor MRI, the most commonly used method, can estimate the magnitude and anisotropy of diffusion. These tensor-based diffusion parameters have been shown to change in many neuropathological

Acute diffusion abnormalities in the hippocampus of children with new-onset seizures: the development of mesial temporal sclerosis

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Farina, L. [Department of Neuroradiology, Istituto Nazionale Neurologico C. Besta, Milan (Italy); Department of Pediatrics, Division of Neurology, The Children' s Hospital of Philadelphia, 34th Street and Civic Center Boulevard, PA 19104, Philadelphia (United States); Bergqvist, C.; Zimmerman, R.A.; Haselgrove, J.; Hunter, J.V.; Bilaniuk, L.T. [Department of Pediatrics, Division of Neurology, The Children' s Hospital of Philadelphia, 34th Street and Civic Center Boulevard, PA 19104, Philadelphia (United States); Department of Radiology, The Children' s Hospital of Philadelphia, 34th Street and Civic Center Boulevard, PA 19104, Philadelphia (United States)

2004-04-01

We studied the role of early diffusion-weighted imaging DWI in the investigation of children with new-onset prolonged seizures which eventually result in unilateral hippocampal sclerosis (HS). We carried out MRI on five children aged 17 months to 7 years including conventional and diffusion-weighted sequences. We calculated apparent diffusion coefficients (ADC) for the affected and the normal opposite hippocampus. Follow-up examinations were performed, including DWI and ADC measurements in four. We studied four children within 3 days of the onset of prolonged psychomotor seizures and showed increased signal on T2-weighted images, and DWI, indicating restricted diffusion, throughout the affected hippocampus. The ADC were reduced by a mean of 14.4% in the head and by 15% in the body of the hippocampus. In one child examined 15 days after the onset of seizures, the ADC were the same on both sides. All five patients showed hippocampal atrophy on follow-up 2-18 months later. In the four patients in whom ADC were obtained on follow-up, they were increased by 19% in the head and 17% in the body. DWI may represent a useful adjunct to conventional MRI for identifying acute injury to the hippocampus which results in sclerosis. (orig.)

Posterior fossa abnormalities in high-risk term infants: comparison of ultrasound and MRI

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Steggerda, S.J.; Smits-Wintjens, V.E.H.J.; Verbon, P.; Walther, F.J. [Leiden University Medical Centre, Department of Neonatology, Leiden (Netherlands); Bruine, F.T. de [Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands); Wezel-Meijler, G. van [Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands); Isala Hospital, Department of Neonatology, Zwolle (Netherlands)

2015-09-15

We aimed to assess the characteristics of posterior fossa (PF) abnormalities in a cohort of high-risk term neonates, as well as the diagnostic performance of cranial ultrasound (CUS) with additional mastoid fontanelle (MF) views for the detection of these abnormalities, with magnetic resonance imaging (MRI) being the reference standard. In this retrospective study, 113 term neonates with CUS and subsequent MRI were included. Sensitivity, specificity, and predictive values of routine CUS and CUS with MF views were calculated. Posterior fossa abnormalities were diagnosed on CUS in 46 of 113 infants. MRI confirmed these findings in 43 and showed additional abnormalities in 32 infants. The sensitivity and specificity of anterior fontanelle views for major PF abnormalities as seen on MRI were 16 % and 99 %. Adding MF views increased the sensitivity of US to 82 %. The sensitivity and specificity of MF views for the detection of any (major or minor) PF abnormality were 57 % and 95 %. Especially acute hypoxic-ischemic injury and small subdural and punctate cerebellar haemorrhage remained undetected by CUS. PF abnormalities are frequent in high-risk term infants. MF-CUS enables early diagnosis of major PF abnormalities. We therefore advocate to perform MF-CUS in high-risk term neonates. (orig.)

Posterior fossa abnormalities in high-risk term infants: comparison of ultrasound and MRI

International Nuclear Information System (INIS)

Steggerda, S.J.; Smits-Wintjens, V.E.H.J.; Verbon, P.; Walther, F.J.; Bruine, F.T. de; Wezel-Meijler, G. van

2015-01-01

We aimed to assess the characteristics of posterior fossa (PF) abnormalities in a cohort of high-risk term neonates, as well as the diagnostic performance of cranial ultrasound (CUS) with additional mastoid fontanelle (MF) views for the detection of these abnormalities, with magnetic resonance imaging (MRI) being the reference standard. In this retrospective study, 113 term neonates with CUS and subsequent MRI were included. Sensitivity, specificity, and predictive values of routine CUS and CUS with MF views were calculated. Posterior fossa abnormalities were diagnosed on CUS in 46 of 113 infants. MRI confirmed these findings in 43 and showed additional abnormalities in 32 infants. The sensitivity and specificity of anterior fontanelle views for major PF abnormalities as seen on MRI were 16 % and 99 %. Adding MF views increased the sensitivity of US to 82 %. The sensitivity and specificity of MF views for the detection of any (major or minor) PF abnormality were 57 % and 95 %. Especially acute hypoxic-ischemic injury and small subdural and punctate cerebellar haemorrhage remained undetected by CUS. PF abnormalities are frequent in high-risk term infants. MF-CUS enables early diagnosis of major PF abnormalities. We therefore advocate to perform MF-CUS in high-risk term neonates. (orig.)

Evaluation of short-term response of high intensity focused ultrasound ablation for primary hepatic carcinoma: Utility of contrast-enhanced MRI and diffusion-weighted imaging

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Zhang Yuanyuan; Zhao Jiannong [Department of Radiology, Second Affiliated Hospital, Chongqing Medical University, No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010 (China); Guo Dajing, E-mail: guodaj@163.com [Department of Radiology, Second Affiliated Hospital, Chongqing Medical University, No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010 (China); Zhong Weijia [Department of Radiology, Second Affiliated Hospital, Chongqing Medical University, No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010 (China); Ran Lifen [Clinical Center for Tumor Therapy, Second Affiliated Hospital, Chongqing Medical University, No. 74 Linjiang Rd, Yuzhong District, Chongqing 400010 (China)

2011-09-15

Objective: To explore the significance of contrast-enhanced MRI (CE-MRI) and diffusion-weighted imaging (DWI) in evaluating the short-term response of high intensity focused ultrasound (HIFU) ablation for primary hepatic carcinoma (PHC). Methods: Thirty-nine lesions in the livers of 27 patients were performed HIFU ablation. Conventional MRI sequences, CE-MRI and DWI were performed 1 week before HIFU and 1 week, 3 months after the therapy, respectively. The short-term responses of HIFU for all lesions were evaluated with MRI. Results: 28 of the 39 lesions (28/39, 71.8%) showed complete necrosis with no enhancement 1 week and 3 months after HIFU. The apparent diffusion coefficient (ADC) values 1 week and 3 months after HIFU were significantly higher than those 1 week before treatment (p < 0.05). The tumor recurrence was detected in 7 of the 39 lesions (7/39, 17.9%) which had no significant enhancement 1 week after HIFU. On the 3 months follow-up, focal nodules were found on the inner aspects of the treated areas. The ADC values had no significant difference between 1 week before and after treatment (p > 0.05), however, they were significantly higher 3 months after HIFU (p < 0.05). The tumor residuals were detected in 4 of the 39 lesions (4/39, 10.3%) showing enhancement 1 week after treatment and increased size 3 months after HIFU. The ADC values had no significant difference among 1 week before HIFU, 1 week and 3 months after treatment (p > 0.05). Conclusion: CE-MRI and DWI can be employed to evaluate the short-term response of HIFU ablation for PHC and to guide the patient management.

Role of MRI and added value of diffusion-weighted and gadolinium-enhanced MRI for the diagnosis of local recurrence from rectal cancer.

Science.gov (United States)

Molinelli, Valeria; Angeretti, Maria Gloria; Duka, Ejona; Tarallo, Nicola; Bracchi, Elena; Novario, Raffaele; Fugazzola, Carlo

2018-03-14

To evaluate whether the addition of gadolinium-enhanced MRI and diffusion-weighted imaging (DWI) improves T2 sequence performance for the diagnosis of local recurrence (LR) from rectal cancer and to assess which approach is better at formulating this diagnosis among readers with different experience. Forty-three patients with suspected LR underwent pelvic MRI with T2 weighted (T2) sequences, gadolinium fat-suppressed T1 weighted sequences (post-contrast T1), and DWI sequences. Three readers (expert: G, intermediate: E, resident: V) scored the likelihood of LR on T2, T2 + post-contrast T1, T2 + DWI, and T2 + post-contrast T1 + DWI. In total, 18/43 patients had LR; on T2 images, the expert reader achieved an area under the ROC curve (AUC) of 0.916, sensitivity of 88.9%, and specificity of 76%; the intermediate reader achieved values of 0.890, 88.9%, and 48%, respectively, and the resident achieved values of 0.852, 88.9%, and 48%, respectively. DWI significantly improved the AUC value for the expert radiologist by up to 0.999 (p = 0.04), while post-contrast T1 significantly improved the AUC for the resident by up to 0.950 (p = 0.04). For the intermediate reader, both the T2 + DWI AUC and T2 + post-contrast T1 AUC were better than the T2 AUC (0.976 and 0.980, respectively), but with no statistically significant difference. No statistically significant difference was achieved by any of the three readers by comparing either the T2 + DWI AUCs to the T2 + post-contrast T1 AUCs or the AUCs of the two pairs of sequences to those of the combined three sequences. Furthermore, using the T2 sequences alone, all of the readers achieved a fair number of "equivocal" cases: they decreased with the addition of either DWI or post-contrast T1 sequences and, for the two less experienced readers, they decreased even more with the three combined sequences. Both DWI and T1 post-contrast MRI increased diagnostic performance for LR diagnosis compared to T2; however, no

Diffusion microscopist simulator - The development and application of a Monte Carlo simulation system for diffusion MRI

International Nuclear Information System (INIS)

Yeh, C.H.

2011-09-01

Diffusion magnetic resonance imaging (dMRI) has made a significant breakthrough in neurological disorders and brain research thanks to its exquisite sensitivity to tissue cyto-architecture. However, as the water diffusion process in neuronal tissues is a complex biophysical phenomena at molecular scale, it is difficult to infer tissue microscopic characteristics on a voxel scale from dMRI data. The major methodological contribution of this thesis is the development of an integrated and generic Monte Carlo simulation framework, 'Diffusion Microscopist Simulator' (DMS), which has the capacity to create 3D biological tissue models of various shapes and properties, as well as to synthesize dMRI data for a large variety of MRI methods, pulse sequence design and parameters. DMS aims at bridging the gap between the elementary diffusion processes occurring at a micrometric scale and the resulting diffusion signal measured at millimetric scale, providing better insights into the features observed in dMRI, as well as offering ground-truth information for optimization and validation of dMRI acquisition protocols for different applications. We have verified the performance and validity of DMS through various benchmark experiments, and applied to address particular research topics in dMRI. Based on DMS, there are two major application contributions in this thesis. First, we use DMS to investigate the impact of finite diffusion gradient pulse duration (delta) on fibre orientation estimation in dMRI. We propose that current practice of using long delta, which is enforced by the hardware limitation of clinical MRI scanners, is actually beneficial for mapping fibre orientations, even though it violates the underlying assumption made in q-space theory. Second, we employ DMS to investigate the feasibility of estimating axon radius using a clinical MRI system. The results suggest that the algorithm for mapping the direct microstructures is applicable to dMRI data acquired from

Modern MRI tools for the characterization of acute demyelinating lesions: value of chemical shift and diffusion-weighted imaging

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Kueker, W.; Mehnert, F.; Mader, I.; Naegele, T.; Ruff, J.; Gaertner, S.

2004-01-01

Acute demyelinating lesions occur in various inflammatory disorders of the CNS. Apart from multiple sclerosis, most cases can be attributed to an overshooting immunological response to infectious agents called acute disseminated encephalomyelitis (ADEM). ADEM, which is mostly characterized by a monophasic course, has a multiphasic variant (MDEM). The early application of corticosteroids has been shown to be beneficial for the outcome; thus, an early diagnosis is highly desirable. Furthermore, the differential diagnosis ruling out neoplastic disorders may be difficult using conventional MRI alone. The potential diagnostic value of advanced MR techniques such as chemical shift imaging (CSI) and diffusion-weighted imaging (DWI) was investigated in a patient with MDEM, who had a new lesion in continuity with the initial disease manifestation. CSI was performed at 1.5 T with a long echo time of 135 ms for the evaluation of N-acetyl-aspartate (NAA) and choline (Cho) and with short TE of 30 ms for macromolecules (mm) and myo-Inositol (mI). DWI was performed using a single-shot isotropic EPI sequence. Whereas acute and chronic areas of demyelination were neither distinguishable on T2- nor on contrast-enhanced T1-weigted images, CSI and DWI revealed different metabolite concentrations and diffusion characteristics within the composite lesion, clearly separating acute from chronic areas of demyelination. In conclusion, the addition of CSI and DWI may add to the diagnostic power of MRI in the setting of demyelinating disorders by identifying areas of acute and chronic demyelination, even in the absence of contrast enhancement. (orig.)

Case report of a young stroke patient showing interim normalization of the MRI diffusion-weighted imaging lesion

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Ostwaldt, Ann-Christin; Usnich, Tatiana; Nolte, Christian H.; Villringer, Kersten; Fiebach, Jochen B.

2015-01-01

In acute ischemic stroke, diffusion weighted imaging (DWI) shows hyperintensities and is considered to indicate irreversibly damaged tissue. We present the case of a young stroke patient with unusual variability in the development of signal intensities within the same vessel territory. A 35-year-old patient presented with symptoms of global aphasia and hypesthesia of the left hand. MRI demonstrated a scattered lesion in the MCA territory. After rtPA therapy the patient received further MRI examination, three times on day 1, and once on day 2, 3, 5 and 43. The posterior part of the lesion showed the usual pattern with increasing DWI hyperintensity and decreased ADC, as well as delayed FLAIR positivity. However, the anterior part of the lesion, which was clearly visible in the first examination completely normalized on the first day and only reappeared on day 2. This was accompanied by a normalization of the ADC as well as an even further delayed FLAIR positivity. We showed that interim normalization of DWI and ADC in the acute phase can not only be found in rodent models of stroke, but also in humans. We propose that DWI lesion development might be more variable during the first 24 h after stroke than previously assumed

Cerebral malaria: susceptibility weighted MRI

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Vinit Baliyan

2015-03-01

Full Text Available Cerebral malaria is one of the fatal complications of Plasmodium falciparum infection. Pathogenesis involves cerebral microangiopathy related to microvascular plugging by infected red blood cells. Conventional imaging with MRI and CT do not reveal anything specific in case of cerebral malaria. Susceptibility weighted imaging, a recent advance in the MRI, is very sensitive to microbleeds related to microangiopathy. Histopathological studies in cerebral malaria have revealed microbleeds in brain parenchyma secondary to microangiopathy. Susceptibility weighted imaging, being exquisitely sensitive to microbleeds may provide additional information and improve the diagnostic accuracy of MRI in cerebral malaria.

Predicting postnatal renal function of prenatally detected posterior urethral valves using fetal diffusion-weighted magnetic resonance imaging with apparent diffusion coefficient determination.

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Faure, Alice; Panait, Nicoleta; Panuel, Michel; Alessandrini, Pierre; D'Ercole, Claude; Chaumoitre, Kathia; Merrot, Thierry

2017-07-01

The objective of this study was to evaluate the accuracy of fetal diffusion-weighted magnetic resonance imaging with apparent diffusion coefficient (ADC) determination to predict postnatal renal function (nadir creatinine at 1 year and eGFR) of men with posterior urethral valves (PUV). Between 2003 and 2014, 11 MRI were performed on fetuses (between 28 and 32 weeks) in whom second trimester sonography suggested severe bilateral urinary tract anomalies, suspected of PUV. The ADC of the 11 fetuses ranged from 1.3 to 2.86 mm 2  s -1 (median = 1.79 mm 2  s -1 , normal range for fetal kidney: 1.1-1.8). Two pregnancies with ADC > 2.6 mm 2  s -1 were interrupted; the autopsy confirmed PUV and Potter syndrome. For the remaining nine babies, the follow-up was 5.4 years (0.8-10). Four children with abnormal ADC (1.8-2.3) had chronic kidney disease. The remaining five cases with normal nadir creatinine and eGFR had normal ADC. One case with unilateral elevated ADC had a poor ipsilateral renal function on dimercaptosuccinic acid scan. Here, it seems that diffusion-weighted magnetic resonance imaging with ADC determination could be useful in accurately evaluating fetal kidneys in PUV and predicting renal function. It may be an additional, non-invasive method when biologic and sonographic findings are inconclusive, especially in the case of oligohydramnios. Further studies are needed to confirm our data. © 2017 John Wiley & Sons, Ltd. © 2017 John Wiley & Sons, Ltd.

Transient MRI abnormalities associated with partial status epilepticus: a case report

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Amato, Carmelo; Elia, Maurizio; Musumeci, Sebastiano A; Bisceglie, Pierluigi; Moschini, Massimo

2001-04-01

We report the case of an 18-year-old woman who presented a long-lasting cluster of partial seizures, and MRI cortical abnormalities localized in the left parietal lobe. The MRI changes correlated with the site of the epileptogenic focus, and disappeared within 2 weeks. The recognition of these reversible MRI abnormalities, which are presumably due to a temporary alteration of blood-brain barrier in the epileptogenic zone with subsequent edema, and are not associated with any underlying organic conditions, is extremely useful in the medical management of the patient and allows to avoid other invasive diagnostic procedures.

Transient MRI abnormalities associated with partial status epilepticus: a case report

International Nuclear Information System (INIS)

Amato, Carmelo; Elia, Maurizio; Musumeci, Sebastiano A.; Bisceglie, Pierluigi; Moschini, Massimo

2001-01-01

We report the case of an 18-year-old woman who presented a long-lasting cluster of partial seizures, and MRI cortical abnormalities localized in the left parietal lobe. The MRI changes correlated with the site of the epileptogenic focus, and disappeared within 2 weeks. The recognition of these reversible MRI abnormalities, which are presumably due to a temporary alteration of blood-brain barrier in the epileptogenic zone with subsequent edema, and are not associated with any underlying organic conditions, is extremely useful in the medical management of the patient and allows to avoid other invasive diagnostic procedures

Redefining the target early during treatment. Can we visualize regional differences within the target volume using sequential diffusion weighted MRI?

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Lambrecht, Maarten; Van Herck, Hans; De Keyzer, Frederik; Vandecaveye, Vincent; Slagmolen, Pieter; Suetens, Paul; Hermans, Robert; Nuyts, Sandra

2014-01-01

Purpose: In head and neck cancer, diffusion weighted MRI (DWI) can predict response early during treatment. Treatment-induced changes and DWI-specific artifacts hinder an accurate registration between apparent diffusion coefficient (ADC) maps. The aim of the study was to develop a registration tool which calculates and visualizes regional changes in ADC. Methods: Twenty patients with stage IV HNC treated with primary radiotherapy received an MRI including DWI before and early during treatment. Markers were manually placed at anatomical landmarks on the different modalities at both time points. A registration method, consisting of a fully automatic rigid and nonrigid registration and two semi-automatic thin-plate spline (TPS) warps was developed and applied to the image sets. After each registration step the mean registration errors were calculated and ΔADC was compared between good and poor responders. Results: Adding the TPS warps significantly reduced the registration error (in mm, 6.3 ± 6.2 vs 3.2 ± 3.3 mm, p < 0.001). After the marker based registration the median ΔADC in poor responders was significantly lower than in good responders (7% vs. 21%; p < 0.001). Conclusions: This registration method allowed for a significant reduction of the mean registration error. Furthermore the voxel-wise calculation of the ΔADC early during radiotherapy allowed for a visualization of the regional differences of ΔADC within the tumor

Diffusion-weighted imaging in patients with progressive multifocal leukoencephalopathy

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Cosottini, M. [University of Pisa, Department of Neuroscience, Pisa (Italy); Service of Neuroradiology AO, Pisa (Italy); Tavarelli, C.; De Cori, S.; Bartolozzi, C. [University of Pisa, Department of Radiology, Pisa (Italy); Del Bono, L.; Doria, G. [Unit of Infectious Diseases AO, Pisa (Italy); Giannelli, M. [Unit of Medical Physics, Pisa (Italy); Michelassi, M.C. [Service of Neuroradiology AO, Pisa (Italy); Murri, L. [University of Pisa, Department of Neuroscience, Pisa (Italy)

2008-05-15

Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease of the central nervous system due to JC polyoma virus infection of oligodendrocytes. PML develops in patients with impaired T-cell function as occurs in HIV, malignancy or immunosuppressive drugs users. Until now no imaging methods have been reported to correlate with clinical status. Diffusion-weighted imaging (DWI) is a robust MRI tool in investigating white matter architecture and diseases. The aim of our work was to assess diffusion abnormalities in focal white matter lesions in patients with PML and to correlate the lesion load measured with conventional MRI and DWI to clinical variables. We evaluated eight patients with a biopsy or laboratory-supported diagnosis of PML. All patients underwent MRI including conventional sequences (fluid attenuated inversion recovery-FLAIR) and DWI. Mean diffusivity (MD) maps were used to quantify diffusion on white matter lesions. Global lesion load was calculated by manually tracing lesions on FLAIR images, while total, central core and peripheral lesion loads were calculated by manually tracing lesions on DWI images. Lesion load obtained with the conventional or DWI-based methods were correlated with clinical variables such as disease duration, disease severity and survival. White matter focal lesions are characterized by a central core with low signal on DWI images and high MD (1.853 x 10{sup -3} mm2/s), surrounded by a rim of high signal intensity on DWI and lower MD (1.1 x 10{sup -3} mm2/s). The MD value of normal-appearing white matter is higher although not statistically significant (0.783 x 10{sup -3} mm2/s) with respect to control subjects (0.750 x 10{sup -3} mm2/s). Inter-rater correlations of global lesion load between FLAIR (3.96%) and DWI (3.43%) was excellent (ICC =0.87). Global lesion load on FLAIR and DWI correlates with disease duration and severity (respectively, p = 0.037, p = 0.0272 with Karnofsky scale and p = 0.0338 with

Seminal vesicle invasion in prostate cancer: prediction with combined T2-weighted and diffusion-weighted MR imaging

International Nuclear Information System (INIS)

Ren, Jing; Huan, Yi; Ge, YaLi; Chang, YingJuan; Yin, Hong; Sun, LiJun; Wang, He

2009-01-01

The aim of this study was to evaluate the usefulness of diffusion-weighted imaging (DWI) in detecting seminal vesicle invasion (SVI). A total of 283 patients underwent conventional MRI and DWI before prostate cancer surgery. The apparent diffusion coefficient (ADC) values of all PCa foci, SVI and seminal vesicle were measured. T2 images alone and then T2 images combined with DWI were scored for the likelihood of SVI. The area under the receiver operating characteristic curve (AUC) was used to assess accuracy. Statistical significance was inferred at P<0.05. On pathological analysis, 39 patients had SVI. The ADC values of SVI were significantly lower than those of SV. The AUC for T2-weighted imaging plus DW imaging (0.897) was significantly larger (P<0.05) than that for T2-weighted imaging alone (0.779). T2 images combined with DWI shows significantly higher accuracy than T2-weighted imaging alone in the detection of SVI. (orig.)

Functional imaging of submandibular glands: diffusion-weighted echo-planar MRI before and after stimulation

International Nuclear Information System (INIS)

Arndt, C.; Cramer, M.C.; Weiss, F.; Kaul, M.G.; Adam, G.; Habermann, C.R.; Graessner, J.; Petersen, K.; Reitmeier, F.; Jaehne, M.

2006-01-01

Purpose: To investigate the feasibility of diffusion-weighted (DWI) echo-planar imaging (EPI) to depict the submandibular glands and to measure different functional conditions. Materials and Methods: Twenty-seven healthy volunteers were examined. Diffusion weighted sequence was performed prior to stimulation. Exactly 30 seconds after a commercially available lemon juice was given orally, the diffusion weighted sequence was repeated. All examinations were performed by using a 1.5-T superconducting system with a 30 mT/m maximum gradient capability and maximum slew rate of 125 mT/m/sec (Magnetom Symphony, Siemens, Erlangen, Germany). The lower part of the circularly polarized (CP) head coil and a standard two-element CP neck array coil were used. The flexibility of the neck array coil allowed positioning the N1 element (upper part of the coil) right next to the submandibular gland. The axial diffusion-weighted EPI (echo planar imaging) sequence was performed using a matrix of 119 x 128, a field of view of 250 x 250 mm (pixel size 2.1 x 1.95 mm), a section thickness of 5 mm with an interslice gap of 1 mm. The b factors used were 0 sec/mm 2 , 500 sec/mm 2 and 1000 sec/mm 2 . Apparent diffusion coefficient (ADC) maps were digitally transferred to MRIcro (Chris Rorden, University of Nottingham, Great Britain). After detecting the submandibular glands a region of interest (ROI) was placed manually exactly within the boarder of both submandibular glands, excluding the external carotid artery on ADC maps. These procedures were performed on all ADC slices the submandibular glands could be differentiated in before and after oral stimulation. For statistical comparison of results, a student's t-test was performed with an overall two-tailed significance level of p=0.05. Results: The visualization of the submandibular glands using the diffusion-weighted EPI sequence was possible in all of the 27 volunteers. Prior to oral stimulation an ADC of 1.31 x 10 -3 mm 2 /sec (95% CI, 1

Distortion-free diffusion MRI using an MRI-guided Tri-Cobalt 60 radiotherapy system: Sequence verification and preliminary clinical experience.

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Gao, Yu; Han, Fei; Zhou, Ziwu; Cao, Minsong; Kaprealian, Tania; Kamrava, Mitchell; Wang, Chenyang; Neylon, John; Low, Daniel A; Yang, Yingli; Hu, Peng

2017-10-01

Monitoring tumor response during the course of treatment and adaptively modifying treatment plan based on tumor biological feedback may represent a new paradigm for radiotherapy. Diffusion MRI has shown great promises in assessing and predicting tumor response to radiotherapy. However, the conventional diffusion-weighted single-shot echo-planar-imaging (DW-ssEPI) technique suffers from limited resolution, severe distortion, and possibly inaccurate ADC at low field strength. The purpose of this work was to develop a reliable, accurate and distortion-free diffusion MRI technique that is practicable for longitudinal tumor response evaluation and adaptive radiotherapy on a 0.35 T MRI-guided radiotherapy system. A diffusion-prepared turbo spin echo readout (DP-TSE) sequence was developed and compared with the conventional diffusion-weighted single-shot echo-planar-imaging sequence on a 0.35 T MRI-guided radiotherapy system (ViewRay). A spatial integrity phantom was used to quantitate and compare the geometric accuracy of the two diffusion sequences for three orthogonal orientations. The apparent diffusion coefficient (ADC) accuracy was evaluated on a diffusion phantom under both 0 °C and room temperature to cover a diffusivity range between 0.40 × 10 -3 and 2.10 × 10 -3 mm 2 /s. Ten room temperature measurements repeated on five different days were conducted to assess the ADC reproducibility of DP-TSE. Two glioblastoma (GBM) and six sarcoma patients were included to examine the in vivo feasibility. The target registration error (TRE) was calculated to quantitate the geometric accuracy where structural CT or MR images were co-registered to the diffusion images as references. ADC maps from DP-TSE and DW-ssEPI were calculated and compared. A tube phantom was placed next to patients not treated on ViewRay, and ADCs of this reference tube were also compared. The proposed DP-TSE passed the spatial integrity test (< 1 mm within 100 mm radius and < 2 mm within 175 mm radius

Diffusion-Weighted Magnetic Resonance Imaging as a Cancer Biomarker: Consensus and Recommendations

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Anwar R. Padhani

2009-02-01

Full Text Available On May 3, 2008, a National Cancer Institute (NCI-sponsored open consensus conference was held in Toronto, Ontario, Canada, during the 2008 International Society for Magnetic Resonance in Medicine Meeting. Approximately 100 experts and stakeholders summarized the current understanding of diffusion-weighted magnetic resonance imaging (DW-MRI and reached consensus on the use of DW-MRI as a cancer imaging biomarker. DW-MRI should be tested as an imaging biomarker in the context of well-defined clinical trials, by adding DW-MRI to existing NCI-sponsored trials, particularly those with tissue sampling or survival indicators. Where possible, DW-MRI measurements should be compared with histologic indices including cellularity and tissue response. There is a need for tissue equivalent diffusivity phantoms; meanwhile, simple fluid-filled phantoms should be used. Monoexponential assessments of apparent diffusion coefficient values should use two b values (> 100 and between 500 and 1000 mm2/sec depending on the application. Free breathing with multiple acquisitions is superior to complex gating techniques. Baseline patient reproducibility studies should be part of study designs. Both region of interest and histogram analysis of apparent diffusion coefficient measurements should be obtained. Standards for measurement, analysis, and display are needed. Annotated data from validation studies (along with outcome measures should be made publicly available. Magnetic resonance imaging vendors should be engaged in this process. The NCI should establish a task force of experts (physicists, radiologists, and oncologists to plan, organize technical aspects, and conduct pilot trials. The American College of Radiology Imaging Network infrastructure may be suitable for these purposes. There is an extraordinary opportunity for DW-MRI to evolve into a clinically valuable imaging tool, potentially important for drug development.

Comparison of X-ray, CT and MRI in detection of abnormal sacroiliac joint changes in patients with early stage of ankylosing spondylitis

International Nuclear Information System (INIS)

Huang Zhenguo; Zhang Xuezhe; Hong Wen; Wang Guochun; Zhou Huiqiong; Lu Xin; Wang Wu

2011-01-01

Objective: To compare X-ray, CT, and MRI in detection of abnormal sacroiliac joint changes in patients with early stage of ankylosing spondylitis (AS). Methods: Fifty-three patients with clinical suspected early stage of AS underwent X-ray and MRI scan. MR scan sequences for the sacroiliac joints consisted of T 1 -weighted, T 2 -weighted, short time inversion recovery (STIR) and three dimensional balance turbo field echo with water selective excitation (3D-BTFE-WATS) in all patients. In 24 of the patients, fat-saturated contrast-enhanced T 1 -weighted was used. Twenty-five of 53 patients underwent CT scan. The Chi-square test was used to analyse the uniformity of bone erosions detected by X-ray, CT, and MRI. Results: Of the 106 sacroiliac joints in 53 patients, 16 sacroiliac joints with bone erosions were detected by X-ray and 63 sacroiliac joints by MRI. Of the 50 sacroiliac joints in 25 patients, 26 sacroiliac joints with bone erosions were found by CT. With regard to the detection of bone erosions, there was no difference between Cf and MRI (χ 2 =0.16, P>0.05) and there was significant difference between CT and X-ray or MRI and X-ray (χ 2 =14.44 and 17.36, P<0.05). 3D-BTFE-WATS was better than other sequences in detection of bone erosions. Acute inflammatory changes were determined by MRI, which included subchondral bone marrow edema in 32 patients, synovitis in 35 patients, fat depositions in 16 patients, enthesitis in 15 patients, capsulitis in 9 patients, and cartilaginous disruption in 31 patients. Conclusions: MRI can detect acute inflammatory changes that can not display by X-ray and CT. Compared with radiography and CT, MRI is more useful in detection of abnormal sacroiliac joint changes in patients with early stage of AS. (authors)

Diffusion-Weighted MRI Assessment of Adjacent Disc Degeneration After Thoracolumbar Vertebral Fractures

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Noriega, David C., E-mail: dcnoriega1970@gmail.com [Valladolid University Hospital, Spine Department (Spain); Marcia, Stefano, E-mail: stemarcia@gmail.com [SS. Trinità Hospital ASL 8 Cagliari, Department of Radiology (Italy); Ardura, Francisco, E-mail: fardura@ono.com [Valladolid University Hospital, Spine Department (Spain); Lite, Israel Sanchez, E-mail: israelslite@hotmail.com [Valladolid University Hospital, Radiology Department (Spain); Marras, Mariangela, E-mail: mariangela.marrasmd@gmail.com [Azienda Ospedaliero Brotzu (A.O.B.), Department of Radiology (Italy); Saba, Luca, E-mail: lucasaba@tiscali.it [Azienda Ospedaliero Universitaria (A.O.U.), Department of Radiology (Italy)

2016-09-15

ObjectiveThe purpose of this study was to assess, by the mean apparent diffusion coefficient (ADC), if a relationship exists between disc ADC and MR findings of adjacent disc degeneration after thoracolumbar fractures treated by anatomic reduction using vertebral augmentation (VAP).Materials and MethodsTwenty non-consecutive patients (mean age 50.7 years; range 45–56) treated because of vertebral fractures, were included in this study. There were 10 A3.1 and 10 A1.2 fractures (AO classification). Surgical treatment using VAP was applied in 14 cases, and conservative in 6 patients. MRI T2-weighted images and mapping of apparent diffusion coefficient (ADC) of the intervertebral disc adjacent to the fractured segment were performed after a mean follow-up of 32 months. A total of 60 discs, 3 per patient, were analysed: infra-adjacent, supra-adjacent and a control disc one level above the supra-adjacent.ResultsNo differences between patients surgically treated and those following a conservative protocol regarding the average ADC values obtained in the 20 control discs analysed were found. Considering all discs, average ADC in the supra-adjacent level was lower than in the infra-adjacent (1.35 ± 0.12 vs. 1.53 ± 0.06; p < 0.001). Average ADC values of the discs used as a control were similar to those of the infra-adjacent level (1.54 ± 0.06). Compared to surgically treated patients, discs at the supra-adjacent fracture level showed statistically significant lower values in cases treated conservatively (p < 0.001). The variation in the delay of surgery had no influence on the average values of ADC at any of the measured levels.ConclusionsADC measurements of the supra-adjacent discs after a mean follow-up of 32 months following thoracolumbar fractures, showed that restoration of the vertebral collapse by minimally invasive VAP prevents posttraumatic disc degeneration.

Diffusion-weighted imaging: basic concepts and application in cerebral stroke and head trauma

International Nuclear Information System (INIS)

Huisman, Thierry A.G.M.

2003-01-01

Diffusion-weighted imaging (DWI) of the brain represents a new imaging technique that extends imaging from depiction of neuroanatomy to the level of function and physiology. DWI measures a fundamentally different physiological parameter compared with conventional MRI. Image contrast is related to differences in the diffusion rate of water molecules rather than to changes in total tissue water. DWI can reveal pathology in cases where conventional MRI remains unremarkable. DWI has proven to be highly sensitive in the early detection of acute cerebral ischemia and seems promising in the evaluation of traumatic brain injury. DWI can differentiate between lesions with decreased and increased diffusion. In addition, full-tensor DWI can evaluate the microscopic architecture of the brain, in particular white matter tracts, by measuring the degree and spatial distribution of anisotropic diffusion within the brain. This article reviews the basic concepts of DWI and its application in cerebral ischemia and traumatic brain injury. (orig.)

Diffusion-weighted imaging: basic concepts and application in cerebral stroke and head trauma

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Huisman, Thierry A.G.M. [Department of Radiology, Neuroradiology Section and MGH-NMR Center, Massachusetts General Hospital and Harvard Medical School, MA 02129, Boston (United States); Department of Radiology, University Children' s Hospital Zurich, Steinwiesstrasse 75, 8032, Zurich (Switzerland)

2003-10-01

Diffusion-weighted imaging (DWI) of the brain represents a new imaging technique that extends imaging from depiction of neuroanatomy to the level of function and physiology. DWI measures a fundamentally different physiological parameter compared with conventional MRI. Image contrast is related to differences in the diffusion rate of water molecules rather than to changes in total tissue water. DWI can reveal pathology in cases where conventional MRI remains unremarkable. DWI has proven to be highly sensitive in the early detection of acute cerebral ischemia and seems promising in the evaluation of traumatic brain injury. DWI can differentiate between lesions with decreased and increased diffusion. In addition, full-tensor DWI can evaluate the microscopic architecture of the brain, in particular white matter tracts, by measuring the degree and spatial distribution of anisotropic diffusion within the brain. This article reviews the basic concepts of DWI and its application in cerebral ischemia and traumatic brain injury. (orig.)

Iron accumulation in deep cortical layers accounts for MRI signal abnormalities in ALS: correlating 7 tesla MRI and pathology.

Directory of Open Access Journals (Sweden)

Justin Y Kwan

Full Text Available Amyotrophic lateral sclerosis (ALS is a progressive neurodegenerative disorder characterized by cortical and spinal motor neuron dysfunction. Routine magnetic resonance imaging (MRI studies have previously shown hypointense signal in the motor cortex on T(2-weighted images in some ALS patients, however, the cause of this finding is unknown. To investigate the utility of this MR signal change as a marker of cortical motor neuron degeneration, signal abnormalities on 3T and 7T MR images of the brain were compared, and pathology was obtained in two ALS patients to determine the origin of the motor cortex hypointensity. Nineteen patients with clinically probable or definite ALS by El Escorial criteria and 19 healthy controls underwent 3T MRI. A 7T MRI scan was carried out on five ALS patients who had motor cortex hypointensity on the 3T FLAIR sequence and on three healthy controls. Postmortem 7T MRI of the brain was performed in one ALS patient and histological studies of the brains and spinal cords were obtained post-mortem in two patients. The motor cortex hypointensity on 3T FLAIR images was present in greater frequency in ALS patients. Increased hypointensity correlated with greater severity of upper motor neuron impairment. Analysis of 7T T(2(*-weighted gradient echo imaging localized the signal alteration to the deeper layers of the motor cortex in both ALS patients. Pathological studies showed increased iron accumulation in microglial cells in areas corresponding to the location of the signal changes on the 3T and 7T MRI of the motor cortex. These findings indicate that the motor cortex hypointensity on 3T MRI FLAIR images in ALS is due to increased iron accumulation by microglia.

TU-AB-BRA-07: Distortion-Free 3D Diffusion MRI On An MRI-Guided Radiotherapy System for Longitudinal Tumor Response Assessment

International Nuclear Information System (INIS)

Gao, Y; Yang, Y; Rangwala, N; Cao, M; Low, D; Hu, P

2016-01-01

Purpose: To develop a reliable, 3D distortion-free diffusion MRI technique for longitudinal tumor response assessment and MRI-guided adaptive radiotherapy(RT). Methods: A diffusion prepared 3D turbo spin echo readout (DP-TSE) sequence was developed and compared with the conventional diffusion-weighted single-shot echo-planar-imaging (DW-ssEPI) sequence in a commercially available diffusion phantom, and one head-and-neck and one brain cancer patient on an MRI-guided RT system (ViewRay). In phantom study, the geometric fidelity was quantified as the ratio between the left-right (RL) and anterior-posterior (AP) dimension. Ten slices were measured on DP-TSE, DW-ssEPI and standard TSE images where the later was used as the geometric reference. ADC accuracy was verified at both 0°C (reference ADC available) and room temperature with a range of diffusivity between 0.35 and 2.0*10"−"3mm"2/s. The ADC reproducibility was assessed based on 8 room-temperature measurements on 6 different days. In the pilot single-slice in-vivo study, CT images were used as the geometric reference, and ADC maps from both diffusion sequences were compared. Results: Distortion and susceptive-related artifact were severe in DW-ssEPI, with significantly lower RL/AP ratio (0.9579±0.0163) than DP-TSE (0.9990±0.0031) and TSE (0.9995±0.0031). ADCs from the two diffusion sequences both matched well with the vendor-provided values at 0°C; however DW-ssEPI fails to provide accurate ADC for high diffusivity vials at room temperature due to high noise level (10 times higher than DP-TSE). The DP-TSE sequence had excellent ADC reproducibility with <4% ADC variation among 8 separate measurements. In patient study, DP-TSE exhibited substantially improved geometric reliability. ROI analysis in ADC maps generated from DP-TSE and DW-ssEPI showed <5% difference where high b-value images were excluded from the latter approach due to excessive noise level. Conclusion: A diffusion MRI sequence with excellent

TU-AB-BRA-07: Distortion-Free 3D Diffusion MRI On An MRI-Guided Radiotherapy System for Longitudinal Tumor Response Assessment

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Gao, Y; Yang, Y; Rangwala, N; Cao, M; Low, D; Hu, P [UCLA School of Medicine, Los Angeles, CA (United States)

2016-06-15

Purpose: To develop a reliable, 3D distortion-free diffusion MRI technique for longitudinal tumor response assessment and MRI-guided adaptive radiotherapy(RT). Methods: A diffusion prepared 3D turbo spin echo readout (DP-TSE) sequence was developed and compared with the conventional diffusion-weighted single-shot echo-planar-imaging (DW-ssEPI) sequence in a commercially available diffusion phantom, and one head-and-neck and one brain cancer patient on an MRI-guided RT system (ViewRay). In phantom study, the geometric fidelity was quantified as the ratio between the left-right (RL) and anterior-posterior (AP) dimension. Ten slices were measured on DP-TSE, DW-ssEPI and standard TSE images where the later was used as the geometric reference. ADC accuracy was verified at both 0°C (reference ADC available) and room temperature with a range of diffusivity between 0.35 and 2.0*10{sup −3}mm{sup 2}/s. The ADC reproducibility was assessed based on 8 room-temperature measurements on 6 different days. In the pilot single-slice in-vivo study, CT images were used as the geometric reference, and ADC maps from both diffusion sequences were compared. Results: Distortion and susceptive-related artifact were severe in DW-ssEPI, with significantly lower RL/AP ratio (0.9579±0.0163) than DP-TSE (0.9990±0.0031) and TSE (0.9995±0.0031). ADCs from the two diffusion sequences both matched well with the vendor-provided values at 0°C; however DW-ssEPI fails to provide accurate ADC for high diffusivity vials at room temperature due to high noise level (10 times higher than DP-TSE). The DP-TSE sequence had excellent ADC reproducibility with <4% ADC variation among 8 separate measurements. In patient study, DP-TSE exhibited substantially improved geometric reliability. ROI analysis in ADC maps generated from DP-TSE and DW-ssEPI showed <5% difference where high b-value images were excluded from the latter approach due to excessive noise level. Conclusion: A diffusion MRI sequence with

Initial experience of functional imaging of upper urinary tract neoplasm by diffusion-weighted magnetic resonance imaging

International Nuclear Information System (INIS)

Yoshida, Soichiro; Masuda, Hitoshi; Saito, Kazutaka; Kawakami, Satoru; Kihara, Kazunori; Ishii, Chikako

2008-01-01

Diffusion-weighted (DW) magnetic resonance imaging (MRI) provides functional information widely used in the diagnosis of acute cerebral stroke. We reported our initial experience of this imaging technique of upper urinary tract (UUT) urothelial carcinoma (UC). Diffusion-weighted magnetic resonance imaging was carried out in 10 consecutive patients with suspected UUT UC. With conventional imaging, seven were diagnosed as having renal pelvic tumors and two were highly suspected of having UUT UC. These nine patients were diagnosed histopathologically as having renal pelvic UC by subsequent operation. The last patient was confirmed as experiencing benign stenosis. DW MRI was obtained with a 1.5-T MR imager without a breath-holding sequence. The apparent diffusion coefficient (ADC) values of renal parenchyma, dilated collecting system, and tumor were calculated. The differences were analyzed using Wilcoxon t-test. On DW MRI, all nine tumors showed hyperintensity with negligible urinary intensity. Two cases of highly suspected UUT UC with unclear conventional MRI had high signal intensity and contrast. The case of benign stenosis had negative DW MRI. The median (range) ADC value of the tumor (0.803 [0.412-0.958] x 10 -3 mm 2 /s) was significantly lower than those of the dilated collecting system (2.19 [1.42-2.40] x 10 -3 ) and renal parenchyma (1.28 [0.922-1.45] x 10 -3 , respectively (P<0.01 and P<0.01). This is the first report on the application of DW MRI for a series of UUT UC. With this technique, a clear demonstration of UUT UC could be obtained. Moreover, this imaging technique is potentially useful to identify small lesions if they have a low diffusion coefficient. (author)

Familial Mediterranean fever mimicking septic arthritis: distinguishing with diffusion weighted imaging

International Nuclear Information System (INIS)

Oner, Ali Yusuf; Ucar, Murat; Akpek, Sergin; Tokgoz, Nil

2007-01-01

FMF arthritis is generally monoarticular in origin. The affected joint is hot, tender, red and mimics septic arthritis. Conventional imaging findings, including magnetic resonance imaging (MRI) and ultrasound, do not help differentiate between these two entities. The final diagnosis depends on culture of the synovial fluid, and therefore initiation of proper drug therapy can be delayed. Diffusion weighted imaging (DWI), with its ability to detect altered water-proton mobility, might play an important role as a fast and non-invasive problem-solving tool in this setting. We here present MRI and DWI findings of a case of FMF arthritis mimicking septic arthritis. (orig.)

Evaluation of renal allograft function early after transplantation with diffusion-weighted MR imaging

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Eisenberger, Ute; Frey, Felix J. [University Hospital of Bern, Department of Nephrology and Hypertension, Bern (Switzerland); Thoeny, Harriet C. [University Hospital of Bern, Department of Radiology, Neuroradiology and Nuclear Medicine, Bern (Switzerland); Binser, Tobias; Boesch, Chris [University Hospital of Bern, Department of Clinical Research, Bern (Switzerland); Gugger, Mathias [University Hospital of Bern, Department of Pathology, Bern (Switzerland); Vermathen, Peter [University Hospital of Bern, Department of Clinical Research, Bern (Switzerland); University Bern, Department of Clinical Research/AMSM, Pavillon 52, Inselspital, P.O. Box 35, Bern (Switzerland)

2010-06-15

To determine the inter-patient variability of apparent diffusion coefficients (ADC) and concurrent micro-circulation contributions from diffusion-weighted MR imaging (DW-MRI) in renal allografts early after transplantation, and to obtain initial information on whether these measures are altered in histologically proven acute allograft rejection (AR). DW-MRI was performed in 15 renal allograft recipients 5-19 days after transplantation. Four patients presented with AR and one with acute tubular necrosis (ATN). Total ADC (ADC{sub T}) was determined, which includes diffusion and micro-circulation contributions. Furthermore, diffusion and micro-circulation contributions were separated, yielding the ''perfusion fraction'' (F{sub P}), and ''perfusion-free'' diffusion (ADC{sub D}). Diffusion parameters in the ten allografts with stable function early after transplantation demonstrated low variabilities. Values for ADC{sub T} and ADC{sub D} were (x 10{sup -5} mm{sup 2}/s) 228 {+-} 14 and 203 {+-} 9, respectively, in cortex and 226 {+-} 16 and 199 {+-} 9, respectively, in medulla. F{sub P} values were 18 {+-} 5% in cortex and 19 {+-} 5% in medulla. F{sub P} values were strongly reduced to less than 12% in cortex and medulla of renal transplants with AR and ATN. F{sub P} values correlated with creatinine clearance. DW-MRI allows reliable determination of diffusion and micro-circulation contributions in renal allografts shortly after transplantation; deviations in AR indicate potential clinical utility of this method to non-invasively monitor derangements in renal allografts. (orig.)

Evaluation of renal allograft function early after transplantation with diffusion-weighted MR imaging

International Nuclear Information System (INIS)

Eisenberger, Ute; Frey, Felix J.; Thoeny, Harriet C.; Binser, Tobias; Boesch, Chris; Gugger, Mathias; Vermathen, Peter

2010-01-01

To determine the inter-patient variability of apparent diffusion coefficients (ADC) and concurrent micro-circulation contributions from diffusion-weighted MR imaging (DW-MRI) in renal allografts early after transplantation, and to obtain initial information on whether these measures are altered in histologically proven acute allograft rejection (AR). DW-MRI was performed in 15 renal allograft recipients 5-19 days after transplantation. Four patients presented with AR and one with acute tubular necrosis (ATN). Total ADC (ADC T ) was determined, which includes diffusion and micro-circulation contributions. Furthermore, diffusion and micro-circulation contributions were separated, yielding the ''perfusion fraction'' (F P ), and ''perfusion-free'' diffusion (ADC D ). Diffusion parameters in the ten allografts with stable function early after transplantation demonstrated low variabilities. Values for ADC T and ADC D were (x 10 -5 mm 2 /s) 228 ± 14 and 203 ± 9, respectively, in cortex and 226 ± 16 and 199 ± 9, respectively, in medulla. F P values were 18 ± 5% in cortex and 19 ± 5% in medulla. F P values were strongly reduced to less than 12% in cortex and medulla of renal transplants with AR and ATN. F P values correlated with creatinine clearance. DW-MRI allows reliable determination of diffusion and micro-circulation contributions in renal allografts shortly after transplantation; deviations in AR indicate potential clinical utility of this method to non-invasively monitor derangements in renal allografts. (orig.)

Human cerebral cortices: signal variation on diffusion-weighted MR imaging

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Asao, Chiaki [Kumamoto Regional Medical Center, Department of Radiology, Kumamoto (Japan); National Hospital Organization Kumamoto Medical Center, Department of Radiology, Kumamoto (Japan); Hirai, Toshinori; Yamashita, Yasuyuki [Kumamoto University Graduate School of Medical Sciences, Department of Diagnostic Radiology, Kumamoto (Japan); Yoshimatsu, Shunji [National Hospital Organization Kumamoto Medical Center, Department of Radiology, Kumamoto (Japan); Matsukawa, Tetsuya; Imuta, Masanori [Kumamoto Regional Medical Center, Department of Radiology, Kumamoto (Japan); Sagara, Katsuro [Kumamoto Regional Medical Center, Department of Internal Medicine, Kumamoto (Japan)

2008-03-15

We have often encountered high signal intensity (SI) of the cingulate gyrus and insula during diffusion-weighted magnetic resonance imaging (DW-MRI) on neurologically healthy adults. To date, cortical signal heterogeneity on DW images has not been investigated systematically. The purpose of our study was to determine whether there is regional signal variation in the brain cortices of neurologically healthy adults on DW-MR images. The SI of the cerebral cortices on DW-MR images at 1.5 T was evaluated in 50 neurologically healthy subjects (34 men, 16 women; age range 33-84 years; mean age 57.6 years). The cortical SI in the cingulate gyrus, insula, and temporal, occipital, and parietal lobes was graded relative to the SI of the frontal lobe. Contrast-to-noise ratios (CNRs) on DW-MR images were compared for each cortical area. Diffusion changes were analyzed by visually assessment of the differences in appearance among the cortices on apparent diffusion coefficient (ADC) maps. Increased SI was frequently seen in the cingulate gyrus and insula regardless of patient age. There were no significant gender- or laterality-related differences. The CNR was significantly higher in the cingulate gyrus and insula than in the other cortices (p <.01), and significant differences existed among the cortical regions (p <.001). There were no apparent ADC differences among the cortices on ADC maps. Regional signal variation of the brain cortices was observed on DW-MR images of healthy subjects, and the cingulate gyrus and insula frequently manifested high SI. These findings may help in the recognition of cortical signal abnormalities as visualized on DW-MR images. (orig.)

Human cerebral cortices: signal variation on diffusion-weighted MR imaging

International Nuclear Information System (INIS)

Asao, Chiaki; Hirai, Toshinori; Yamashita, Yasuyuki; Yoshimatsu, Shunji; Matsukawa, Tetsuya; Imuta, Masanori; Sagara, Katsuro

2008-01-01

We have often encountered high signal intensity (SI) of the cingulate gyrus and insula during diffusion-weighted magnetic resonance imaging (DW-MRI) on neurologically healthy adults. To date, cortical signal heterogeneity on DW images has not been investigated systematically. The purpose of our study was to determine whether there is regional signal variation in the brain cortices of neurologically healthy adults on DW-MR images. The SI of the cerebral cortices on DW-MR images at 1.5 T was evaluated in 50 neurologically healthy subjects (34 men, 16 women; age range 33-84 years; mean age 57.6 years). The cortical SI in the cingulate gyrus, insula, and temporal, occipital, and parietal lobes was graded relative to the SI of the frontal lobe. Contrast-to-noise ratios (CNRs) on DW-MR images were compared for each cortical area. Diffusion changes were analyzed by visually assessment of the differences in appearance among the cortices on apparent diffusion coefficient (ADC) maps. Increased SI was frequently seen in the cingulate gyrus and insula regardless of patient age. There were no significant gender- or laterality-related differences. The CNR was significantly higher in the cingulate gyrus and insula than in the other cortices (p <.01), and significant differences existed among the cortical regions (p <.001). There were no apparent ADC differences among the cortices on ADC maps. Regional signal variation of the brain cortices was observed on DW-MR images of healthy subjects, and the cingulate gyrus and insula frequently manifested high SI. These findings may help in the recognition of cortical signal abnormalities as visualized on DW-MR images. (orig.)

DTIPrep: Quality Control of Diffusion-Weighted Images

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Ipek eOguz

2014-01-01

Full Text Available In the last decade, diffusion MRI (dMRI studies of the human and animal brain have been used to investigate a multitude of pathologies and drug-related effects in neuroscience research. Study after study identifies white matter (WM degeneration as a crucial biomarker for all these diseases. The tool of choice for studying WM is dMRI. However, dMRI has inherently low signal-to-noise ratio and its acquisition requires a relatively long scan time; in fact, the high loads required occasionally stress scanner hardware past the point of physical failure. As a result, many types of artifacts implicate the quality of diffusion imagery. Using these complex scans containing artifacts without quality control (QC can result in considerable error and bias in the subsequent analysis, negatively affecting the results of research studies using them. However, dMRI QC remains an under-recognized issue in the dMRI community as there are no user-friendly tools commonly available to comprehensively address the issue of dMRI QC. As a result, current dMRI studies often perform a poor job at dMRI QC.Thorough QC of diffusion MRI will reduce measurement noise and improve reproducibility, and sensitivity in neuroimaging studies; this will allow researchers to more fully exploit the power of the dMRI technique and will ultimately advance neuroscience. Therefore, in this manuscript, we present our open-source software, DTIPrep, as a unified, user friendly platform for thorough quality control of dMRI data. These include artifacts caused by eddy-currents, head motion, bed vibration and pulsation, venetian blind artifacts, as well as slice-wise and gradient-wise intensity inconsistencies. This paper summarizes a basic set of features of DTIPrep described earlier and focuses on newly added capabilities related to directional artifacts and bias analysis.

Sequential Magnetic Resonance Imaging Finding of Intramedullary Spinal Cord Abscess including Diffusion Weighted Image: a Case Report

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Roh, Jae Eun; Lee, Seung Young; Cha, Sang Hoon; Cho, Bum Sang; Jeon, Min Hee; Kang, Min Ho [Chungbuk National University College of Medicine, Cheongju (Korea, Republic of)

2011-04-15

Intramedullary spinal cord abscess (ISCA) is a rare infection of the central nervous system. We describe the magnetic resonance imaging (MRI) findings, including the diffusion-weighted imaging (DWI) findings, of ISCA in a 78-year-old man. The initial conventional MRI of the thoracic spine demonstrated a subtle enhancing nodule accompanied by significant edema. On the follow-up MRI after seven days, the nodule appeared as a ring-enhancing nodule. The non-enhancing central portion of the nodule appeared hyperintense on DWI with a decreased apparent diffusion coefficient (ADC) value on the ADC map. We performed myelotomy and surgical drainage, and thick, yellowish pus was drained

Improved longitudinal length accuracy of gross tumor volume delineation with diffusion weighted magnetic resonance imaging for esophageal squamous cell carcinoma

International Nuclear Information System (INIS)

Hou, Dong-Liang; Shi, Gao-Feng; Gao, Xian-Shu; Asaumi, Junichi; Li, Xue-Ying; Liu, Hui; Yao, Chen; Chang, Joe Y

2013-01-01

To analyze the longitudinal length accuracy of gross tumor volume (GTV) delineation with diffusion weighted magnetic resonance imaging for esophageal squamous cell carcinoma (SCC). Forty-two patients from December 2011 to June 2012 with esophageal SCC who underwent radical surgery were analyzed. Routine computed tomography (CT) scan, T2-weighted MRI and diffusion weighted magnetic resonance imaging (DWI) were employed before surgery. Diffusion-sensitive gradient b-values were taken at 400, 600, and 800 s/mm 2 . Gross tumor volumes (GTV) were delineated using CT, T2-weighted MRI and DWI on different b-value images. GTV longitude length measured using the imaging modalities listed above was compared with pathologic lesion length to determine the most accurate imaging modality. CMS Xio radiotherapy planning system was used to fuse DWI scans and CT images to investigate the possibility of delineating GTV on fused images. The differences between the GTV length according to CT, T2-weighted MRI and pathology were 3.63 ± 12.06 mm and 3.46 ± 11.41 mm, respectively. When the diffusion-sensitive gradient b-value was 400, 600, and 800 s/mm 2 , the differences between the GTV length using DWI and pathology were 0.73 ± 6.09 mm, -0.54 ± 6.03 mm and −1.58 ± 5.71 mm, respectively. DWI scans and CT images were fused accurately using the radiotherapy planning system. GTV margins were depicted clearly on fused images. DWI displays esophageal SCC lengths most precisely when compared with CT or regular MRI. DWI scans fused with CT images can be used to improve accuracy to delineate GTV in esophageal SCC

Is there a role for diffusion-weighted MRI (DWI) in the diagnosis of central cartilage tumors?

International Nuclear Information System (INIS)

Douis, H.; Jeys, L.; Grimer, R.; Vaiyapuri, S.; Davies, A.M.

2015-01-01

To assess if diffusion-weighted MRI (DWI) can differentiate between central enchondromas and chondrosarcomas (CS) and if DWI can distinguish low-grade chondroid lesions from high-grade CS. Fifty-two patients with central cartilage tumors were included. Patients underwent conventional MRI and DWI with ADC mapping. The slice on MRI with the most aggressive imaging feature was identified. The corresponding mean and minimum ADC maps of the tumor at this position were measured. There were 24 enchondromas, five atypical cartilaginous lesions, 15 grade 1, three grade 2, two grade 3, and three dedifferentiated CS. Mean ADC values (x 10 -6 mm 2 /s) for enchondromas, atypical cartilaginous tumors, grade 1 CS, grade 2, CS, grade 3 CS and dedifferentiated CS were 1,896, 2,048, 2,152, 2,170, 2,076, and 1,261, respectively. Minimum ADC values (x 10 -6 mm 2 /s) for enchondromas, atypical cartilaginous tumors, grade 1 CS, grade 2, CS, grade 3 CS and dedifferentiated CS were 1,820, 1,752, 2,010, 1,829, 1,752, and 767, respectively. ANOVA test demonstrated a statistically significant difference in mean and minimum ADC values in all groups. Post hoc analysis revealed this was due to difference in mean and minimum ADC values in dedifferentiated CS. The mean ADC value in low-grade chondroid lesions was 2,001, while the ADC value for high-grade CS were 2,132. The minimum ADC value for low-grade chondroid lesions was 1,896, while the minimum ADC for high-grade CS was 1,837. The difference in minimum and mean ADC values was not statistically significant. DWI cannot differentiate between enchondromas and CS and DWI does not aid in the distinction of low-grade chondroid tumors from high-grade CS. (orig.)

In Vivo Evaluation of the Visual Pathway in Streptozotocin-Induced Diabetes by Diffusion Tensor MRI and Contrast Enhanced MRI.

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Swarupa Kancherla

Full Text Available Visual function has been shown to deteriorate prior to the onset of retinopathy in some diabetic patients and experimental animal models. This suggests the involvement of the brain's visual system in the early stages of diabetes. In this study, we tested this hypothesis by examining the integrity of the visual pathway in a diabetic rat model using in vivo multi-modal magnetic resonance imaging (MRI. Ten-week-old Sprague-Dawley rats were divided into an experimental diabetic group by intraperitoneal injection of 65 mg/kg streptozotocin in 0.01 M citric acid, and a sham control group by intraperitoneal injection of citric acid only. One month later, diffusion tensor MRI (DTI was performed to examine the white matter integrity in the brain, followed by chromium-enhanced MRI of retinal integrity and manganese-enhanced MRI of anterograde manganese transport along the visual pathway. Prior to MRI experiments, the streptozotocin-induced diabetic rats showed significantly smaller weight gain and higher blood glucose level than the control rats. DTI revealed significantly lower fractional anisotropy and higher radial diffusivity in the prechiasmatic optic nerve of the diabetic rats compared to the control rats. No apparent difference was observed in the axial diffusivity of the optic nerve, the chromium enhancement in the retina, or the manganese enhancement in the lateral geniculate nucleus and superior colliculus between groups. Our results suggest that streptozotocin-induced diabetes leads to early injury in the optic nerve when no substantial change in retinal integrity or anterograde transport along the visual pathways was observed in MRI using contrast agent enhancement. DTI may be a useful tool for detecting and monitoring early pathophysiological changes in the visual system of experimental diabetes non-invasively.

Advances in MRI diagnosis of prostate cancer

International Nuclear Information System (INIS)

Zhang Longmin; Liu Ailian

2014-01-01

Prostate cancer is the second most common cancer in the world, and the incidence of prostate cancer in China shows an upward trend. MRI has high soft tissue resolution and multi-dimensional imaging advantages, and it can better show the anatomy of the prostate and adjacent tissue structures. With the development of MR technique, it plays a more and more important role in prostate cancer diagnosis. This review starts from the imaging performance of routine MRI sequence of prostate cancer, and a variety of functional MRI applications in the diagnosis and differential diagnosis of prostate cancer are described in detail, such as MR perfusion-weighted imaging, MR spectroscopy, MR diffusion-weighted imaging, MR diffusion tensor imaging, intravoxel incoherent motion diffusion-weighted imaging, MR susceptibility-weighted imaging. Meanwhile this review introduces that functional MRI has more advantages and can provide more image information than routine MRI sequence. According to a series of semi-quantitative and quantitative data, functional MRI can further provide the blood perfusion of prostate cancer, water molecule diffusion and microcirculation state, metabolism and biochemical composition change information. (authors)

USE OF DIFFUSION-WEIGHTED MAGNETIC RESONANCE IMAGING FOR REVEALING HYPOXIC-ISCHEMIC BRAIN LESIONS IN NEONATES

Directory of Open Access Journals (Sweden)

E. V. Shimchenko

2014-01-01

Full Text Available The article presents advantages of use of diffusion-weighted magnetic resonance imaging (DW MRI for revealing hypoxic-ischemic brain lesions in neonates. The trial included 97 neonates with perinatal brain lesion who had been undergoing treatment at a resuscitation department or neonatal pathology department in the first month of life. The article shows high information value of diffusion-weighted images (DWI for diagnostics of hypoxic-ischemic lesions in comparison with regular standard modes. In the event of no structural brain lesions of neonates, pronounced increase in signal characteristics revealed by DWI indicated considerable pathophysiological alterations. Subsequently, children developed structural alterations in the form of cystic encephalomalacia with expansion of cerebrospinal fluid spaces manifested with pronounced neurological deficit. DW MRI has been offered as a method of prognosticating further neurological development of children on early stages. 

Diagnostic reliability of 3.0-T MRI for detecting osseous abnormalities of the temporomandibular joint.

Science.gov (United States)

Sawada, Kunihiko; Amemiya, Toshihiko; Hirai, Shigenori; Hayashi, Yusuke; Suzuki, Toshihiro; Honda, Masahiko; Sisounthone, Johnny; Matsumoto, Kunihito; Honda, Kazuya

2018-01-01

We compared the diagnostic reliability of 3.0-T magnetic resonance imaging (MRI) for detection of osseous abnormalities of the temporomandibular joint (TMJ) with that of the gold standard, cone-beam computed tomography (CBCT). Fifty-six TMJs were imaged with CBCT and MRI, and images of condyles and fossae were independently assessed for the presence of osseous abnormalities. The accuracy, sensitivity, and specificity of 3.0-T MRI were 0.88, 1.0, and 0.73, respectively, in condyle evaluation and 0.91, 0.75, and 0.95 in fossa evaluation. The McNemar test showed no significant difference (P > 0.05) between MRI and CBCT in the evaluation of osseous abnormalities in condyles and fossae. The present results indicate that 3.0-T MRI is equal to CBCT in the diagnostic evaluation of osseous abnormalities of the mandibular condyle.

Diffusion-weighted MRI for uveal melanoma liver metastasis detection

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Wagner, Mathilde; Petras, Slavomir; Servois, Vincent [Institut Curie, Department of Radiology and Nuclear Medicine, Paris (France); Mariani, Pascale; Cassoux, Nathalie [Institut Curie, Department of Surgery, Paris (France); Bidard, Francois Clement; Rodrigues, Manuel Jorge; Piperno-Neumann, Sophie [Institut Curie, Department of Medical Oncology, Paris (France); Farkhondeh, Fereshteh [Institut Curie, Department of Pathology, Paris (France)

2015-08-15

We aimed to assess the sensitivity of diffusion-weighted (DW) magnetic resonance (MR) imaging for the detection of pathologically confirmed uveal melanoma liver metastases (UMLM). Twenty patients who underwent complete surgical resection of their UMLM (N = 83) were included. Pre-surgery liver MR imaging included T2-weighted, T1-weighted, DW and dynamic-gadolinium-enhanced MR sequences. Two radiologists independently reviewed three sets of images (DW / morphologic-dynamic / combined) for each patient using intraoperative and pathological findings as a standard of reference. The sensitivities of the morphologic-dynamic and DW images for UMLM detection were 63 % and 59 %, respectively, for reader 1 (R1) and 64 % and 53 %, for reader 2 (R2). Sensitivity of the combined set was higher than sensitivity in the two other sets (R1:69 %, R2:67 %), but was only significantly different than the sensitivity of the DW images (McNemar test). For the three sets and the two readers, the sensitivity for UMLM smaller than 5 mm (37-46 %) was significantly lower than that for UMLM larger than 5 mm (67-90 %). The sensitivity for UMLM located in the subcapsular area (41-54 %) was significantly lower than that for intraparenchymal UMLM (68-86 %) (Chi-square test). Our study shows that the addition of DW imaging to morphologic-dynamic images does not significantly increase MR sensitivities for UMLM detection. (orig.)

Reversible Restricted Diffusion in the Corpus Callosum in Various Pediatric Diseases

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Kim, Won Kyung; Hong, Hyun Sook; Lee, A Leum; Cha, Jang Gyu; Lee, Hae Kyung [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Bae, Won Kyung [Dept. of Radiology, Soonchunhyang University Cheonan Hospital, Soonchunhyang University College of Medicine, Cheonan (Korea, Republic of)

2012-04-15

To evaluate the reversible restricted diffusion in the corpus callosum in pediatric patients with clinical findings, and to discuss the possible pathogenesis of these lesions. Between 2007 and 2011, seven children with reversible signal abnormalities in the corpus callosum were identified and retrospectively reviewed. Diseases and conditions associated with lesions included: trauma (n = 3), neonatal seizure (n = 1), clinically suspected mild encephalopathy (n = 1), multiple sclerosis (n = 1), and seizure with subdural hygroma (n = 1). The callosal lesions were located in the splenium and the genu (n = 2), the splenium and the body (n = 1), and the splenium only (n 4). The shape of the lesions was round-to-ovoid (n = 4) or linear (n = 3). Follow-up MRI scans showed completely resolved (n = 6) or persistent (n = 1) signal abnormalities on diffusion-weighted imaging as well as apparent diffusion coefficient mapping. Clinical outcomes were good in six of the patents but poor in the seventh. Reversible restricted diffusion in the corpus callosum can develop in various diseases. Knowledge of the MRI findings and associated diseases might be helpful in predicting patients' conditions and clinical outcomes.

Influence of MRI abnormality in skull base bone on prognosis of nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Jin-Cheng, Lu; Qing, Wei; Yi-Qin, Zhang; Feng, Li

2004-01-01

Purpose. To evaluate the influence of skull base bone (SBB) abnormality showed by MRI on prognosis of nasopharyngeal carcinoma (NPC). Patients and methods. From March 1993 to December 1998, 122 NPC patients received prime radiotherapy treatment. All of them were proved pathologically and checked by magnetic resonance imaging (MRI). Every patient received radiation through conjoint facio-cervical field and conventional dose-fractionation schedules. The total dose to the primary tumor was 60 5 Gy (median, 70 Gy). The Kaplan Meier method, the Log-rank test and the Cox regression model were used to evaluate the significance of prognostic factors on NPC patient survival. Results. The overall median survival period was 50 (6 2) months, and the 1, 3 and 5 year-survival rates were, respectively, 99.2%, 87.9%, and 73.3%. The 1, 3, and 5 year-survival rates of abnormality and normality of the SBB on MRI were 98.9%, 87.2%, 71.9%, and 100.0%, 89.8%, 77.0%, respectively (P 0.4233). Gender, age, head pain, SBB abnormality, cranial nerve palsy, cervical lymphadenopathy and primary tumor extent were analyzed with the Cox regression model and SBB abnormality on MRI did not prove to have statistical significance (P = 0.6934). According to the analysis of regrouping, patients with SBB abnormalities ≥ sites have a worse prognosis (P = 0.0427). Then. the above seven factors are analyzed by Cox regression model and the result had statistical significance (P = 0.0385). Conclusion. The SBB abnormality on MRI is of no obvious influence on prognosis of NPC. However, when SBB abnormality sites were ≥ 2, there is obvious statistical significance on the prognosis. (author)

Increasing the Accuracy of Volume and ADC Delineation for Heterogeneous Tumor on Diffusion-Weighted MRI: Correlation with PET/CT

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Gong, Nan-Jie [Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong (China); Wong, Chun-Sing, E-mail: drcswong@gmail.com [Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong (China); Chu, Yiu-Ching [Department of Radiology, Kwong Wah Hospital, Hong Kong (China); Guo, Hua [Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing (China); Huang, Bingsheng [Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong (China); Chan, Queenie [Philips Healthcare, Hong Kong (China)

2013-10-01

Purpose: To improve the accuracy of volume and apparent diffusion coefficient (ADC) measurements in diffusion-weighted magnetic resonance imaging (MRI), we proposed a method based on thresholding both the b0 images and the ADC maps. Methods and Materials: In 21 heterogeneous lesions from patients with metastatic gastrointestinal stromal tumors (GIST), gross lesion were manually contoured, and corresponding volumes and ADCs were denoted as gross tumor volume (GTV) and gross ADC (ADC{sub g}), respectively. Using a k-means clustering algorithm, the probable high-cellularity tumor tissues were selected based on b0 images and ADC maps. ADC and volume of the tissues selected using the proposed method were denoted as thresholded ADC (ADC{sub thr}) and high-cellularity tumor volume (HCTV), respectively. The metabolic tumor volume (MTV) in positron emission tomography (PET)/computed tomography (CT) was measured using 40% maximum standard uptake value (SUV{sub max}) as the lower threshold, and corresponding mean SUV (SUV{sub mean}) was also measured. Results: HCTV had excellent concordance with MTV according to Pearson's correlation (r=0.984, P<.001) and linear regression (slope = 1.085, intercept = −4.731). In contrast, GTV overestimated the volume and differed significantly from MTV (P=.005). ADC{sub thr} correlated significantly and strongly with SUV{sub mean} (r=−0.807, P<.001) and SUV{sub max} (r=−0.843, P<.001); both were stronger than those of ADC{sub g}. Conclusions: The proposed lesion-adaptive semiautomatic method can help segment high-cellularity tissues that match hypermetabolic tissues in PET/CT and enables more accurate volume and ADC delineation on diffusion-weighted MR images of GIST.

Differential diagnosis of benign and malignant breast masses using diffusion-weighted magnetic resonance imaging.

Science.gov (United States)

Min, Qinghua; Shao, Kangwei; Zhai, Lulan; Liu, Wei; Zhu, Caisong; Yuan, Lixin; Yang, Jun

2015-02-07

Diffusion-weighted magnetic resonance imaging (DW-MRI) is different from conventional diagnostic methods and has the potential to delineate the microscopic anatomy of a target tissue or organ. The purpose of our study was to evaluate the value of DW-MRI in the diagnosis of benign and malignant breast masses, which would help the clinical surgeon to decide the scope and pattern of operation. A total of 52 female patients with palpable solid breast masses received breast MRI scans using routine sequences, dynamic contrast-enhanced imaging, and diffusion-weighted echo-planar imaging at b values of 400, 600, and 800 s/mm(2), respectively. Two regions of interest (ROIs) were plotted, with a smaller ROI for the highest signal and a larger ROI for the overall lesion. Apparent diffusion coefficient (ADC) values were calculated at three different b values for all detectable lesions and from two different ROIs. The sensitivity, specificity, positive predictive value, and positive likelihood ratio of DW-MRI were determined for comparison with histological results. A total of 49 (49/52, 94.2%) lesions were detected using DW-MRI, including 20 benign lesions (two lesions detected in the same patient) and 29 malignant lesions. Benign lesion had a higher mean ADC value than their malignant counterparts, regardless of b value. According to the receiver operating characteristic (ROC) curve, the smaller-range ROI was more effective in differentiation between benign and malignant lesions. The area under the ROC curve was the largest at a b value of 800 s/mm(2). With a threshold ADC value at 1.23 × 10(-3) mm(2)/s, DW-MRI achieved a sensitivity of 82.8%, specificity of 90.0%, positive predictive value of 92.3%, and positive likelihood ratio of 8.3 for differentiating benign and malignant lesions. DW-MRI is an accurate diagnostic tool for differentiation between benign and malignant breast lesions, with an optimal b value of 800 s/mm(2). A smaller-range ROI focusing on the

Diffusion tensor and diffusion weighted imaging. Pictorial mathematics

Energy Technology Data Exchange (ETDEWEB)

Nakada, Tsutomu [California Univ., Davis, CA (United States)

1995-06-01

A new imaging algorithm for the treatment of a second order apparent diffusion tensor, D{sub app}{sup {xi}} is described. The method calls for only mathematics of images (pictorial mathematics) without necessity of eigenvalues/eigenvectors estimation. Nevertheless, it is capable of extracting properties of D{sub app}{sup {xi}} invariant to observation axes. While trace image is an example of images weighted by invariance of the tensor matrix, three dimensional anisotropy (3DAC) contrast represents the imaging method making use to anisotropic direction of tensor ellipsoid producing color coded contrast of exceptionally high anatomic resolution. Contrary to intuition, the processes require only a simple algorithm directly applicable to clinical magnetic resonance imaging (MRI). As a contrast method which precisely represents physical characteristics of a target tissue, invariant D{sub app}{sup {xi}} images produced by pictorial mathematics possess significant potential for a number of biological and clinical applications. (author).

Acute vertebral fracture: differentiation of malignant and benign causes by diffusion weighted magnetic resonance imaging

International Nuclear Information System (INIS)

Mubarak, F.; Akhtar, W.

2011-01-01

Objective: To evaluate the sensitivity, specificity and accuracy of diffusion weighted (DWI) magnetic resonance imaging (MRI) in the diagnosis and differentiation between benign (osteoporotic/infectious) and malignant vertebral compression fractures in comparison with histology findings and clinical follow up. Methods: The study was conducted at the Radiology Department, Aga Khan University Hospital (AKUH) Karachi. It was a one year cross-sectional study from 01/01/2009 to 01/01/2010. Forty patients with sixty three vertebral compression fractures were included. Diffusion-weighted sequences and apparent diffusion coefficient (ADC) images on a 1.5 T MR scanner were obtained in all patients to identify the vertebral compression fracture along with benign and malignant causes. Imaging findings were compared with histopathologic results and clinical follow-up. Results: Diffusion-weighted MR imaging found to have, 92% sensitivity, 90% specificity and accuracy of 85% in differentiation of benign and malignant vertebral compression fracture while PPV and NPV were 78 % and 90% respectively. Conclusion: Diffusion weighted magnetic resonance imaging offers a safe, accurate and non invasive modality to differentiate between the benign and malignant vertebral compression fracture. (author)

MRI shows thickening and altered diffusion in the median and ulnar nerves in multifocal motor neuropathy

Energy Technology Data Exchange (ETDEWEB)

Haakma, Wieke [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Aarhus University, Department of Forensic Medicine and Comparative Medicine Lab, Aarhus (Denmark); Jongbloed, Bas A.; Goedee, H.S.; Berg, Leonard H. van den; Pol, W.L. van der [University Medical Center Utrecht, Brain Centre Rudolf Magnus, Department of Neurology and Neurosurgery, Utrecht (Netherlands); Froeling, Martijn; Bos, Clemens; Hendrikse, Jeroen [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Leemans, Alexander [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands)

2017-05-15

To study disease mechanisms in multifocal motor neuropathy (MMN) with magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) of the median and ulnar nerves. We enrolled ten MMN patients, ten patients with amyotrophic lateral sclerosis (ALS) and ten healthy controls (HCs). Patients underwent MRI (in a prone position) and nerve conduction studies. DTI and fat-suppressed T2-weighted scans of the forearms were performed on a 3.0T MRI scanner. Fibre tractography of the median and ulnar nerves was performed to extract diffusion parameters: fractional anisotropy (FA), mean (MD), axial (AD) and radial (RD) diffusivity. Cross-sectional areas (CSA) were measured on T2-weighted scans. Forty-five out of 60 arms were included in the analysis. AD was significantly lower in MMN patients (2.20 ± 0.12 x 10{sup -3} mm{sup 2}/s) compared to ALS patients (2.31 ± 0.17 x 10{sup -3} mm{sup 2}/s; p < 0.05) and HCs (2.31± 0.17 x 10{sup -3} mm{sup 2}/s; p < 0.05). Segmental analysis showed significant restriction of AD, RD and MD (p < 0.005) in the proximal third of the nerves. CSA was significantly larger in MMN patients compared to ALS patients and HCs (p < 0.01). Thickening of nerves is compatible with changes in the myelin sheath structure, whereas lowered AD values suggest axonal dysfunction. These findings suggest that myelin and axons are diffusely involved in MMN pathogenesis. (orig.)

[Diffusion weighted imaging and perfusion weighted imaging in the differential diagnosis of benign and malignant renal masses on 3.0 T MRI].

Science.gov (United States)

Xu, Xiaowen; Wang, Peijun; Ma, Liang; Shao, Zhihong; Zhang, Min

2015-01-20

To explore the value of diffusion weighted imaging (DWI) and perfusion weighted imaging (PWI) in identifying benign and malignant renal masses and differentiating the histological types of renal masses. Fifteen healthy volunteers and 46 patients with renal masses proven by pathology, including clear cell carcinomas (n = 18), papillary carcinomas (n = 8), chromophobe carcinomas (n = 7) and angiomyolipomas (n = 13), were examined with DWI and PWI scan at 3.0 T MRI. ANOVA was employed to compare the values of transfer constant (K(trans)), rate constant of backflux (Kep) and extra-vascular extra-cellular space fractional volume (Ve) proceeded by PWI and the value of ADC resulted from DWI between normal kidney and different histological types of renal masses. Receiver operating characteristics (ROC) curve was used to analyze and compare the diagnostic value of the methods of PWI and DWI in differentiating benign and malignant renal masses. The ADC value of normal renal parenchyma was (2.10 ± 0.24) × 10⁻³ mm²/s, which was statistically higher than benign and malignant renal masses (P 0.05).Values of K(trans), Kep and Ve between normal renal parenchyma and different histological types of renal masses had statistical differences.Values of K(trans) and Ve in three histological types of malignant renal masses were statistically higher than those of benign renal masses.Kep value of clear cell carcinoma was significantly higher than that of benign renal masses (P benign and malignant renal masses. The K(trans) of benign and malignant renal masses had the largest AUC (AUC = 0.937) at a threshold of 0.38/min. And there were a sensitivity of 87.9% and a specificity of 85.7%. The AUC of ADC was 0.823, sensitivity 72.7% and specificity 92.9%. The ADC threshold for differentiating benign from malignant masses was 1.40 × 10⁻³ mm²/s; AUC of Ve 0.803, sensitivity 78.8% and specificity 71.4%, a threshold of 0.29/min; Kep showed lower diagnostic value. 3.0 T MRI DWI and PWI

Characterization of the collagen component of cartilage repair tissue of the talus with quantitative MRI: comparison of T2 relaxation time measurements with a diffusion-weighted double-echo steady-state sequence (dwDESS)

International Nuclear Information System (INIS)

Kretzschmar, M.; Hainc, N.; Studler, U.; Bieri, O.; Miska, M.; Wiewiorski, M.; Valderrabano, V.

2015-01-01

The purpose of this study was to characterize the collagen component of repair tissue (RT) of the talus after autologous matrix-induced chondrogenesis (AMIC) using quantitative T2 and diffusion-weighted imaging. Mean T2 values and diffusion coefficients of AMIC-RT and normal cartilage of the talus of 25 patients with posttraumatic osteochondral lesions and AMIC repair were compared in a cross-sectional design using partially spoiled steady-state free precession (pSSFP) for T2 quantification, and diffusion-weighted double-echo steady-state (dwDESS) for diffusion measurement. RT and cartilage were graded with modified Noyes and MOCART scores on morphological sequences. An association between follow-up interval and quantitative MRI measures was assessed using multivariate regression, after stratifying the cohort according to time interval between surgery and MRI. Mean T2 of the AMIC-RT and cartilage were 43.1 ms and 39.1 ms, respectively (p = 0.26). Mean diffusivity of the RT (1.76 μm 2 /ms) was significantly higher compared to normal cartilage (1.46 μm 2 /ms) (p = 0.0092). No correlation was found between morphological and quantitative parameters. RT diffusivity was lowest in the subgroup with follow-up >28 months (p = 0.027). Compared to T2-mapping, dwDESS demonstrated greater sensitivity in detecting differences in the collagen matrix between AMIC-RT and cartilage. Decreased diffusivity in patients with longer follow-up times may indicate an increased matrix organization of RT. (orig.)

Characterization of the collagen component of cartilage repair tissue of the talus with quantitative MRI: comparison of T2 relaxation time measurements with a diffusion-weighted double-echo steady-state sequence (dwDESS)

Energy Technology Data Exchange (ETDEWEB)

Kretzschmar, M.; Hainc, N.; Studler, U. [University Hospital Basel, Department of Radiology, Basel (Switzerland); Bieri, O. [University Hospital Basel, Division of Radiological Physics, Basel (Switzerland); Miska, M. [University Hospital, Department of Orthopedics, Heidelberg (Germany); Wiewiorski, M.; Valderrabano, V. [University Hospital Basel, Department of Orthopedic Surgery, Basel (Switzerland)

2015-04-01

The purpose of this study was to characterize the collagen component of repair tissue (RT) of the talus after autologous matrix-induced chondrogenesis (AMIC) using quantitative T2 and diffusion-weighted imaging. Mean T2 values and diffusion coefficients of AMIC-RT and normal cartilage of the talus of 25 patients with posttraumatic osteochondral lesions and AMIC repair were compared in a cross-sectional design using partially spoiled steady-state free precession (pSSFP) for T2 quantification, and diffusion-weighted double-echo steady-state (dwDESS) for diffusion measurement. RT and cartilage were graded with modified Noyes and MOCART scores on morphological sequences. An association between follow-up interval and quantitative MRI measures was assessed using multivariate regression, after stratifying the cohort according to time interval between surgery and MRI. Mean T2 of the AMIC-RT and cartilage were 43.1 ms and 39.1 ms, respectively (p = 0.26). Mean diffusivity of the RT (1.76 μm{sup 2}/ms) was significantly higher compared to normal cartilage (1.46 μm{sup 2}/ms) (p = 0.0092). No correlation was found between morphological and quantitative parameters. RT diffusivity was lowest in the subgroup with follow-up >28 months (p = 0.027). Compared to T2-mapping, dwDESS demonstrated greater sensitivity in detecting differences in the collagen matrix between AMIC-RT and cartilage. Decreased diffusivity in patients with longer follow-up times may indicate an increased matrix organization of RT. (orig.)

Anisotropy in "isotropic diffusion" measurements due to nongaussian diffusion

DEFF Research Database (Denmark)

Jespersen, Sune Nørhøj; Olesen, Jonas Lynge; Ianuş, Andrada

2017-01-01

Designing novel diffusion-weighted NMR and MRI pulse sequences aiming to probe tissue microstructure with techniques extending beyond the conventional Stejskal-Tanner family is currently of broad interest. One such technique, multidimensional diffusion MRI, has been recently proposed to afford...... model-free decomposition of diffusion signal kurtosis into terms originating from either ensemble variance of isotropic diffusivity or microscopic diffusion anisotropy. This ability rests on the assumption that diffusion can be described as a sum of multiple Gaussian compartments, but this is often...

Diffusion-weighted magnetic resonance imaging - a new instrument in the diagnosis of Creutzfeldt-Jacob's disease

International Nuclear Information System (INIS)

Romi, Fredrik; Smivoll, Alf Inge; Moerk, Sverre; Tysnes, Ole-Bjoern

2000-01-01

Creutzfeldt-Jacob's disease (CID) is characterised by rapidly progressive dementia, ataxia, myoclonus and several other neurological deficits. It generally affects older adults and occurs in sporadic, genetic and iatrogenic forms. Death occurs usually within one year after onset of the disease. The diagnosis is based on clinical criteria, neuro physiological and radiological findings and confirmed by post mortal histopathology. During the last two years several cases of CID have been reported with diffusion-weighted magnetic resonance imaging (MR) abnormalities represented by increased signal intensity indicating reduced diffusion in basal ganglia and/or cortex cerebric. These abnormalities seem to be characteristic of CID. We report a case of CID in a 54 year old woman who developed vertigo, nystagmus, ataxia, myoclonus and dementia over a period of eight months. Diffusion-weighted magnetic resonance imaging showed increased signal intensity in corpus striatum and gyrus conguli. The diagnosis was post mortally confirmed with histopathology. (Author) 7 figs., 15 refs

Cumulant expansions for measuring water exchange using diffusion MRI

Science.gov (United States)

Ning, Lipeng; Nilsson, Markus; Lasič, Samo; Westin, Carl-Fredrik; Rathi, Yogesh

2018-02-01

The rate of water exchange across cell membranes is a parameter of biological interest and can be measured by diffusion magnetic resonance imaging (dMRI). In this work, we investigate a stochastic model for the diffusion-and-exchange of water molecules. This model provides a general solution for the temporal evolution of dMRI signal using any type of gradient waveform, thereby generalizing the signal expressions for the Kärger model. Moreover, we also derive a general nth order cumulant expansion of the dMRI signal accounting for water exchange, which has not been explored in earlier studies. Based on this analytical expression, we compute the cumulant expansion for dMRI signals for the special case of single diffusion encoding (SDE) and double diffusion encoding (DDE) sequences. Our results provide a theoretical guideline on optimizing experimental parameters for SDE and DDE sequences, respectively. Moreover, we show that DDE signals are more sensitive to water exchange at short-time scale but provide less attenuation at long-time scale than SDE signals. Our theoretical analysis is also validated using Monte Carlo simulations on synthetic structures.

MRI findings of juvenile psoriatic arthritis

International Nuclear Information System (INIS)

Lee, Edward Y.; Kleinman, Paul K.; Sundel, Robert P.; Kim, Susan; Zurakowski, David

2008-01-01

The aim of this study was to describe the magnetic resonance imaging (MRI) features of juvenile psoriatic arthritis (JpsA) in children in order to facilitate early diagnosis and proper management. Two pediatric radiologists retrospectively reviewed in consensus a total of 37 abnormal MRI examinations from 31 pediatric patients (nine boys, 22 girls; age range 1-17 years; mean age 9.4 years) who had a definite diagnosis of JpsA and underwent MRI. Each MRI was evaluated for synovium abnormality (thickening and enhancement), joint effusion (small, moderate, and large), bone marrow abnormality (edema, enhancement, and location of abnormality), soft tissue abnormality (edema, enhancement, atrophy, and fatty infiltration), tendon abnormality (thickening, edema, tendon sheath fluid, and enhancement), and articular abnormality (joint space narrowing and erosion). The distribution of abnormal MRI findings among the six categories for the 37 MRI examinations was evaluated. The number of abnormal MRI findings for each MRI examination was assessed. Age at MRI examination and all six categories of abnormal MRI findings according to gender were evaluated. There were a total 96 abnormal MRI findings noted on 37 abnormal MRI examinations from 31 pediatric patients. The 37 abnormal MRI examinations included MRI of the hand (n=8), knee (n = 8), ankle (n = 5), pelvis (n = 5), temporomandibular joint (n = 4), wrist (n = 3), foot (n = 2), elbow (n = 1), and shoulder (n = 1). Twenty-eight diffuse synovial thickening and/or enhancement were the most common MRI abnormality (29.2%). Joint effusion comprised 22 abnormal MRI findings (22.9%). There were 16 abnormal MRI bone marrow edema and/or enhancement findings (16.7%), and in seven (7.3%) the edema involved non-articular sites. Soft tissue abnormality manifested as edema and/or enhancement constituted 14 abnormal MRI findings (14.5%). There were ten MRI abnormalities (10.4%) involving tendons. Articular abnormality seen as joint space

MRI findings of juvenile psoriatic arthritis

Energy Technology Data Exchange (ETDEWEB)

Lee, Edward Y.; Kleinman, Paul K. [Harvard Medical School, Department of Radiology, Boston, MA (United States); Children' s Hospital Boston, MA (United States); Sundel, Robert P.; Kim, Susan [Harvard Medical School, Rheumatology Program, Division of Immunology and the Department of Pediatrics, Boston, MA (United States); Children' s Hospital Boston, MA (United States); Zurakowski, David [Harvard Medical School, Department of Radiology, Boston, MA (United States); Harvard Medical School, Department of Orthopaedic Surgery, Boston, MA (United States); Children' s Hospital Boston, MA (United States)

2008-11-15

The aim of this study was to describe the magnetic resonance imaging (MRI) features of juvenile psoriatic arthritis (JpsA) in children in order to facilitate early diagnosis and proper management. Two pediatric radiologists retrospectively reviewed in consensus a total of 37 abnormal MRI examinations from 31 pediatric patients (nine boys, 22 girls; age range 1-17 years; mean age 9.4 years) who had a definite diagnosis of JpsA and underwent MRI. Each MRI was evaluated for synovium abnormality (thickening and enhancement), joint effusion (small, moderate, and large), bone marrow abnormality (edema, enhancement, and location of abnormality), soft tissue abnormality (edema, enhancement, atrophy, and fatty infiltration), tendon abnormality (thickening, edema, tendon sheath fluid, and enhancement), and articular abnormality (joint space narrowing and erosion). The distribution of abnormal MRI findings among the six categories for the 37 MRI examinations was evaluated. The number of abnormal MRI findings for each MRI examination was assessed. Age at MRI examination and all six categories of abnormal MRI findings according to gender were evaluated. There were a total 96 abnormal MRI findings noted on 37 abnormal MRI examinations from 31 pediatric patients. The 37 abnormal MRI examinations included MRI of the hand (n=8), knee (n = 8), ankle (n = 5), pelvis (n = 5), temporomandibular joint (n = 4), wrist (n = 3), foot (n = 2), elbow (n = 1), and shoulder (n = 1). Twenty-eight diffuse synovial thickening and/or enhancement were the most common MRI abnormality (29.2%). Joint effusion comprised 22 abnormal MRI findings (22.9%). There were 16 abnormal MRI bone marrow edema and/or enhancement findings (16.7%), and in seven (7.3%) the edema involved non-articular sites. Soft tissue abnormality manifested as edema and/or enhancement constituted 14 abnormal MRI findings (14.5%). There were ten MRI abnormalities (10.4%) involving tendons. Articular abnormality seen as joint space

Hypomelanosis of Ito and brain abnormalities: MRI findings and literature review

International Nuclear Information System (INIS)

Steiner, J.; Adamsbaum, C.; Desguerres, I.; Lalande, G.; Raynaud, F.; Ponsot, G.; Kalifa, G.

1996-01-01

We report the results of a 14-year retrospective study of brain MRI abnormalities in 12 pediatric patients presenting with hypomelanosis of Ito (HI). Miscellaneous brain abnormalities were found: one patient had a medulloblastoma, three had cortical malformations, and five demonstrated ''minor'' abnormalities such as dilated Virchow-Robin spaces or brain atrophy. We emphasize the polymorphism of brain abnormalities associated with HI. (orig.). With 5 figs., 1 tab

MRI abnormalities of sacroiliac joints in early spondylarthropathy

DEFF Research Database (Denmark)

Puhakka, K B; Jurik, A G; Schiøttz-Christensen, Berit

2004-01-01

OBJECTIVE: To describe changes in chronic and acute magnetic resonance imaging (MRI) abnormalities of the sacroiliac joints (SIJs) in early spondylarthropathy (SpA), and to associate these findings with computed tomography (CT), X-ray, and clinical findings during a 1-year follow-up. METHODS...

Whole body MRI in children; Ganzkoerper-MRT bei Kindern

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Schaefer, Juergen F.; Tsiflikas, Ilias [Tuebingen Univ. (Germany). Bereich Kinderradiologie

2014-09-15

In pediatric patients whole body MRI has a relevant impact on both, diagnostic work-up and treatment. Using adapted sequence protocols comprehensive imaging without radiation exposure is possible avoiding additional examinations in many cases. Especially in bone marrow the differentiation between normal and abnormal finding can be difficult, therefore the knowledge of normal maturing of organs is important. Whole body diffusion weighted imaging particularly in neuroblastomas or sarcomas improves the low specificity of conventional MR-protocols. Technical prerequisites, examination protocol and strategies, image interpretation, indications and clinical relevance as well as advantages and disadvantages of whole body MRI will be discussed on the basis of application-oriented cases and the literature.

Diffusion-weighted imaging of brain metastases: their potential to be misinterpreted as focal ischaemic lesions

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Geijer, B. [Department of Radiology, University Hospital, Lund (Sweden); Holtaas, S. [Department of Diagnostic Imaging, King Fahd Hospital, Riyadh (Saudi Arabia)

2002-07-01

Small focal ischaemic brain lesions are said to be easy to identify in the acute stage and to differentiate from older lesions using diffusion-weighted imaging (DWI). Brain metastases are common and the aim of this study was to evaluate the risk of misinterpretation as ischaemic lesions in a standard MRI protocol for clinical stroke. Of 26 patients investigated with MRI for possible metastases, 12 did have metastatic brain lesions, including most of the common tumours. On a 1.5 tesla imager, we obtained DWI, plus T2- and T1-weighted images, the latter before and after triple-dose contrast medium. Well-circumscribed brain lesions with a decreased apparent diffusion coefficient and a slightly or moderately increased signal on T2-weighted images were found in patients with metastases from a small-cell bronchial carcinoma and a pulmonary adenocarcinoma. The same features were also found in metastases from a breast carcinoma but the lesions were surrounded by oedema. With a standard DWI protocol, the features of common brain metastases may overlap with those of small acute and subacute ischaemic lesions. (orig.)

Diffusion-weighted magnetic resonance imaging in carotid angioplasty and stenting with balloon embolic protection devices

International Nuclear Information System (INIS)

Asakura, Fumio; Kawaguchi, Kenji; Sakaida, Hiroshi; Toma, Naoki; Matsushima, Satoshi; Kuraishi, Keita; Tanemura, Hiroshi; Miura, Yoichi; Taki, Waro; Maeda, Masayuki

2006-01-01

We compared the results of two procedures to protect against distal embolism caused by embolic debris from carotid angioplasty with stent deployment (CAS) using diffusion-weighted magnetic resonance imaging (MRI). The study group comprised 39 men and 3 women (42 and 3 CAS procedures, respectively) with severe carotid stenosis (average age 70.0±6.6 years). During 20 CAS procedures the internal carotid artery was protected with a single balloon. A PercuSurge GuardWire was used for temporary occlusion. During 25 CAS procedures the internal and external carotid arteries were simultaneously temporarily occluded with a PercuSurge GuardWire and a Sentry balloon catheter, respectively. Diffusion-weighted MRI was performed 1 to 3 days after CAS. Data from 26 patients undergoing conventional angiography for diagnosis of cerebral ischemic disease, cerebral aneurysm or brain tumors were included as controls. Diffusion-weighted MRI after conventional diagnostic angiography showed ischemic spots in 3 of the 26 controls (11.5%). Ischemic spots were observed during 11 of 20 CAS procedures with the internal carotid artery protected with a single balloon (55.0%), and were observed during 9 of 25 CAS procedures with both the internal and external carotid arteries protected (36.0%). This difference was significant (P=0.0068). Ischemic lesions appeared not only ipsilateral to the carotid stenosis but also in the contralateral carotid artery (31.9%) and vertebrobasilar territory (25.3%). Better protection was obtained with simultaneous double occlusion of both the internal and external carotid artery than with single protection of the internal carotid artery during CAS. (orig.)

Inter-Observer Agreement on Diffusion-Weighted Magnetic Resonance Imaging Interpretation for Diagnosis of Acute Ischemic Stroke Among Emergency Physicians

Directory of Open Access Journals (Sweden)

Deniz ORAY

2015-06-01

Full Text Available SUMMARY: Objectives: Diffusion-weighted magnetic resonance imaging (DW-MRI is a highly sensitive tool for the detection of early ischemic stroke and is excellent at detecting small and early infarcts. Nevertheless, conflict may arise and judgments may differ among different interpreters. Inter-observer variability shows the systematic difference among different observers and is expressed as the kappa (Κ coefficient. In this study, we aimed to determinate the inter-observer variability among emergency physicians in the use of DW-MRI for the diagnosis of acute ischemic stroke. Methods: Cranial DW-MRI images of 50 patients were interpreted in this retrospective observational cross-sectional study. Patients who were submitted to DW-MRI imaging for a suspected acute ischemic stroke were included in the study, unless the scans were ordered by any of the reviewers or they were absent in the system. The scans were blindly and randomly interpreted by four emergency physicians. Inter-observer agreement between reviewers was evaluated using Fleiss’ Κ statistics. Results: The mean kappa value for high signal on diffusion-weighted images (DWI and for reduction on apparent diffusion coefficient (ADC were substantial (k=0.67 and moderate (k=0.60 respectively. The correlation for detection of the presence of ischemia and location was substantial (k: 0.67. There were 18 false-positive and 4 false-negative evaluations of DWI, 15 false positive and 8 false-negative evaluations of ADC. Conclusions: Our data suggest that DW-MRI is reliable in screening for ischemic stroke when interpreted by emergency physicians in the emergency department. The levels of stroke identification and variability show that emergency physicians may have an acceptable level of agreement. Key words: Emergency department, diffusion weighted magnetic resonance imaging, inter-observer agreement, ischemic stroke

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

Directory of Open Access Journals (Sweden)

Jayalakshmi Sita

2006-01-01

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

CADrx for GBM Brain Tumors: Predicting Treatment Response from Changes in Diffusion-Weighted MRI

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Matthew S. Brown

2009-11-01

Full Text Available The goal of this study was to develop a computer-aided therapeutic response (CADrx system for early prediction of drug treatment response for glioblastoma multiforme (GBM brain tumors with diffusion weighted (DW MR images. In conventional Macdonald assessment, tumor response is assessed nine weeks or more post-treatment. However, we will investigate the ability of DW-MRI to assess response earlier, at five weeks post treatment. The apparent diffusion coefficient (ADC map, calculated from DW images, has been shown to reveal changes in the tumor’s microenvironment preceding morphologic tumor changes. ADC values in treated brain tumors could theoretically both increase due to the cell kill (and thus reduced cell density and decrease due to inhibition of edema. In this study, we investigated the effectiveness of features that quantify changes from pre- and post-treatment tumor ADC histograms to detect treatment response. There are three parts to this study: first, tumor regions were segmented on T1w contrast enhanced images by Otsu’s thresholding method, and mapped from T1w images onto ADC images by a 3D region of interest (ROI mapping tool using DICOM header information; second, ADC histograms of the tumor region were extracted from both pre- and five weeks post-treatment scans, and fitted by a two-component Gaussian mixture model (GMM. The GMM features as well as standard histogram-based features were extracted. Finally, supervised machine learning techniques were applied for classification of responders or non-responders. The approach was evaluated with a dataset of 85 patients with GBM under chemotherapy, in which 39 responded and 46 did not, based on tumor volume reduction. We compared adaBoost, random forest and support vector machine classification algorithms, using ten-fold cross validation, resulting in the best accuracy of 69.41% and the corresponding area under the curve (Az of 0.70.

SU-E-P-33: Critical Role of T2-Weighted Imaging Combined with Diffusion-Weighted Imaging of MRI in Diagnosis of Loco-Regional Recurrent Esophageal Cancer After Radical Surgery

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Deng, G; Qiao, L [Department of Oncology, Shandong University School of Medicine, Jinan, Shandong (China); Liang, N; Xie, J; Zhang, J [Department of Radiation Oncology, Qianfoshan Hospital Affiliated to Shandon, Jinan, Shandong (China); Luo, H; Zhang, J [Division of Oncology, Department of Graduate, Weifang Medical College, Weifang, Shandong (China)

2015-06-15

Purpose: We perform this study to investigate the diagnostic efficacy of T2-weighted MRI (T2WI) and diffusion-weighted MRI (DWI) in confirming local relapses of esophageal cancer in patients highly suspected of recurrence after eradicating surgery. Methods: Forty-two postoperative esophageal cancer patients with clinical suspicions of cancer recurrence underwent 3.0T MRI applying axial, coronal, sagittal T2WI and axial DWI sequences. Two experienced radiologists (R1 and R2) both used two methods (T2WI, T2WI+DWI) to observe the images, and graded the patients ranging from 1 to 5 to represent severity of the disease based on visual signal intensity (patients equal to or more than grade 3 was confirmed as recurrent disease) Results: 27/42patients were verified of recurrent disease by pathologic findings and/or imaging findings during follow-up. The sensitivity, specificity and accuracy of R1 applying T2WI+DWI are 96%, 87% and 93% versus 81%, 80% and 77% on T2WI, these figures by R2 were 96%, 93% and 95% versus 89%, 93% and 90%. The receiver operating curve (ROC) analyses suggest that both of the two readers can obtain better accuracy when adding DWI to T2WI compared with T2WI alone. Kappa test between R1 and R2 indicates excellent inter-observer agreement on T2WI+DWI. Conclusion: Standard T2WI in combination DWI can achieve better accuracy than T2WI alone in diagnosing local recurrence of esophageal cancer, and improve consistency between different readers.

Diffusion-Weighted MRI in the Assessment of Early Treatment Response in Patients with Squamous-Cell Carcinoma of the Head and Neck: Comparison with Morphological and PET/CT Findings.

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Eduardo Bruno Lobato Martins

Full Text Available To evaluate changes in apparent diffusion coefficients (ADC as measured by magnetic resonance imaging (MRI before and after the treatment of primary tumors and cervical metastases in patients with squamous-cell carcinoma (SCC of the head and neck, and to compare these values to the results of widely used morphological criteria and [18F]-FDG PET/CT findings.This was a longitudinal, prospective, single-center nonrandomized trial involving patients with head and neck SCC treated with chemotherapy alone or in combination with radiotherapy. Imaging examinations ([18F]-FDG PET/CT and diffusion-weighted MRI were performed on the same day, up to one day prior to the beginning of the first treatment cycle, and on the 14th day of the first chemotherapy cycle. Treatment response was evaluated based on the Response Evaluation Criteria in Solid Tumors (RECIST and World Health Organization (WHO morphological criteria, as well as PET Response Criteria in Solid Tumors (PERCIST metabolic criteria.Seventy-five lesions were examined in 23 patients. Pre- and post-treatment comparisons of data pertaining to all target lesions revealed reductions in tumor size and SUV, as well as increases in ADC values, all of which were statistically significant. The increase in ADC following treatment was significantly higher in patients classified as complete responders by both morphological criteria than that observed in any of the other patient groups of response. Patients with a complete metabolic response also showed greater increases in ADC values as compared to the remaining groups.The assessment of tumor response based on diffusion-weighted MRI showed an increase in the ADC of cervical lesions following treatment, which was corroborated by morphological and metabolic findings. Associations between changes in ADC values and treatment response categories using morphologic criteria and [18F]-FDG PET/CT were only identified in complete responders.

Preliminary experience with fetal MRI for evaluation of intracranial abnormalities

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Penev, L.; Georgieva-Kosarova, G.

2015-01-01

Full text: Modern MRI technologies allow the preparation of a multi-planar images as well as images showing the movement of the fetus for less than 1 sec. the methodology is particularly useful as a rendering intracranial lesions (at ventriculomegaly, lesions in the posterior cranial fossa, corpus callosum abnormalities, myelination, migration and sulcation) and in the body lesions of the fetus (diaphragmatic hernia, congenital cystic abnormalities, renal cystic lesions spinal anomalies) and the abdomen of the mother. We set a goal to prove the usefulness of MRI research in prenatal diagnosis of congenital malformations of the central nervous system. For a period of 24 months in City Clinic Hospital Sofia were studied 12 pregnant women and 13 fetuses in which there was doubt about intracranial fetal malformations. All studies were conducted as a supplementary diagnostic technique after ultrasound in the third trimester of pregnancy when the fetus is large enough and organogenesis is completed. MRI is held superconductive 3.0t magnet using single-shot fast-spin echo and half-Fourier acquisition turbo spin echo (HASTE) with a duration of under one minute scan, MRI study therefore does not require preparation of the mother. Does not require use of contrast. None reported harm to the fetus and the mother. Although ultrasound due to its low price and its wide accessibility as well as of its non-invasiveness and low time in some cases results were insufficient to determine condition and course of pregnancy. We believe that the MRI examination in the case of ambiguous results of the ultrasound has an important role to refine abnormalities prenatal and postnatal treatment planning

Complete Fourier Direct Magnetic Resonance Imaging (CFD-MRI for Diffusion MRI

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Alpay eÖzcan

2013-04-01

Full Text Available The foundation for an accurate and unifying Fourier based theory of diffusion weighted magnetic resonance imaging (DW-MRI is constructed by carefully re-examining the first principles of DW-MRI signal formation and deriving its mathematical model from scratch. The derivations are specifically obtained for DW-MRI signal by including all of its elements (e.g., imaging gradients using complex values. Particle methods are utilized in contrast to conventional partial differential equations approach. The signal is shown to be the Fourier transform of the joint distribution of number of the magnetic moments (at a given location at the initial time and magnetic moment displacement integrals. In effect, the k-space is augmented by three more dimensions, corresponding to the frequency variables dual to displacement integral vectors. The joint distribution function is recovered by applying the Fourier transform to the complete high-dimensional data set. In the process, to obtain a physically meaningful real valued distribution function, phase corrections are applied for the re-establishment of Hermitian symmetry in the signal. Consequently, the method is fully unconstrained and directly presents the distribution of displacement integrals without any assumptions such as symmetry or Markovian property. The joint distribution function is visualized with isosurfaces, which describe the displacement integrals, overlaid on the distribution map of the number of magnetic moments with low mobility. The model provides an accurate description of the molecular motion measurements via DW-MRI. The improvement of the characterization of tissue microstructure leads to a better localization, detection and assessment of biological properties such as white matter integrity. The results are demonstrated on the experimental data obtained from an ex-vivo baboon brain.

Role of diffusion weighted imaging in musculoskeletal infections: Current perspectives

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Kumar, Yogesh; Khaleel, Mohammad; Boothe, Ethan; Awdeh, Haitham; Wadhwa, Vibhor; Chhabra, Avneesh

2017-01-01

Accurate diagnosis and prompt therapy of musculoskeletal infections are important prognostic factors. In most cases, clinical history, examination and laboratory findings help one make the diagnosis, and routine magnetic resonance imaging (MRI) is useful to identify the extent of the disease process. However, in many situations, a routine MRI may not be specific enough especially if the patient cannot receive contrast intravenously, thereby delaying the appropriate treatment. Diffusion-weighted imaging (DWI) can help in many such situations by providing additional information, accurate characterization and defining the extent of the disease, so that prompt treatment can be initiated. In this article, we illustrate the imaging findings of the spectrum of musculoskeletal infections, emphasizing the role of DWI in this domain. (orig.)

Role of diffusion weighted imaging in musculoskeletal infections: Current perspectives