Peritumoral perfusion and proton spectroscopic MR imaging in the differentiation of gliomas and solitary metastases

Purpose: To asses the value of peritumoural perfusion-weighted and proton spectroscopic MR imaging in preoperative grading of gliomas and in differentiating between primary gliomas and solitary metastases. Methods and Materials: Ten low-grade gliomas, eight high-grade gliomas, and ten metastases were prospectively evaluated with MR imaging, dynamic susceptibility contrast-enhanced perfusion imaging, and single-voxel proton MR spectroscopy before surgical resection or stereotactic biopsy. Maximal rCBV values and maximal Cho/Cr ratios were calculated from peritumoural region surrounding the tumour. Tumour grade presumed with these values was compared to histopathologic grading. Differences in the study parameters between groups were assessed using the Mann-Whitney test. A Receiver Operating Characteristic analysis was performed to determine cutoff values. Results: A clear rCBV cutoff value of 1.88 was detected for differentiating low-grade gliomas from high-grade gliomas (sensitivity 100%, specificity 90%, area under the ROC curve .994, p< 0.0001). A clear rCBV cutoff value of 1.20 was detected for differentiation of metastases from gliomas (sensitivity 100%, specificity 90%, area under the ROC curve .972, p< 0.0001). The differences in the Cho/Cr ratios in the peritumoural regions of high-grade gliomas and of solitary metastasis were statistically significant (p<.001) but a clear cutoff value was not found. Conclusion: Our preliminary data support that peritumoural perfusion-weighted imaging can assist in preoperative differentiation between a glioma and a solitary metastasis, along with separating high-grade gliomas from low-grade gliomas

Multiple sclerosis: High prevalence of the ‘central vein’ sign in white matter lesions on susceptibility-weighted images

Purpose: The aim of this study was to determine the occurrence and distribution of the ‘central vein’ sign in white matter lesions on susceptibility-weighted magnetic resonance images in patients with multiple sclerosis (MS) and cerebral small vessel disease (CSVD). Materials and methods: T2-weighted and fluid-attenuated inversion recovery magnetic resonance images of 19 MS patients and 19 patients affected by CSVD were analysed for the presence and localisation of focal hyperintense white matter lesions. Lesions were subdivided into periventricular or non-periventricular (juxtacortical, subcortical, deep white matter and cerebellar) distributed. The number and localisation of lesions presenting with the central vein sign were recorded and compared between MS and CSVD lesions. Results: A total of 313 MS patients and 75 CSVD lesions were identified on T2-weighted and fluid-attenuated inversion recovery magnetic resonance images. The central vein sign was found in 128 MS lesions (40.9%), and the majority of them (71/128, 55.5%) had a periventricular distribution. The central vein sign was found in 22 out of 75 (29.3%) CSVD lesions, and periventricular distribution was seen in six out of 22 (27.2%) CSVD lesions. The difference in the proportion of white matter hyperintense lesions that presented with the central vein sign on susceptibility-weighted images in patients with MS and CSVD was statistically different, and a significantly higher number of MS patients presented with lesions with the central vein sign compared to CSVD patients. Conclusion: The presence of the central vein sign on susceptibility-weighted images for MS lesions improves the understanding of the periventricular distribution of MS lesions and could contribute as adjunctive diagnostic criteria for MS disease

Focal confluent fibrosis in cirrhotic liver: natural history studied with serial CT.

OBJECTIVE: The objective of this study was to assess the long-term natural history of focal confluent fibrosis in cirrhotic liver with CT. MATERIALS AND METHODS: Two radiologists retrospectively reviewed in consensus 118 liver CT examinations in 26 patients (19 men, seven women; age range, 32-68 years; mean age, 50 years) performed over approximately 6 years. Helical CT scans were obtained before and 30-35 and 65-70 seconds after injection of 125-150 mL of contrast medium at a rate of 4-5 mL/s. Proof of cirrhosis was based on liver transplantation (n = 6), biopsy (n = 9), or imaging findings (n = 11). The number, location, and attenuation of fibrotic lesions and presence of trapped vessels were evaluated. Variation of hepatic retraction associated with the development of focal confluent fibrosis lesions was assessed using the ellipsoid volume formula and an arbitrary retraction index. RESULTS: Each radiologist identified 41 focal confluent fibrosis lesions. All lesions were identified by both radiologists. Twelve patients (46%) had a single lesion, 13 (50%) had two lesions, and one (4%) had three lesions. Thirty-four (83%) of 41 lesions were located in segment IV, VII, or VIII. Thirty-two lesions (78%) were hypoattenuating on unenhanced images, 25 lesions (61%) were hypoattenuating on hepatic arterial phase images, and 20 lesions (49%) were isoattenuating on portal venous phase images. Seven lesions (17%) were or became hyperattenuating at follow-up on portal venous phase images. Trapped vessels were found in six lesions (15%). The retraction index showed a significant increase over time (r = 0.423, p < or = 0.0001). CONCLUSION: The degree of capsule retraction associated with focal confluent fibrosis evolves with time and relates to the natural evolution of cirrhosis

Magnetic resonance imaging in the assessment of brain involvement in alcoholic and nonalcoholic Wernicke's encephalopathy

To present the typical and atypical magnetic resonance (MR) imaging findings of alcoholic and non-alcoholic Wernicke's encephalopathy

Assessment of cerebral microbleeds by susceptibility-weighted imaging at 3T in patients with end-stage organ failure

Purpose: Cerebral microbleeds (CMBs) are small rounded lesions representing cerebral hemosiderin deposits surrounded by macrophages that results from previous microhemorrhages. The aim of this study was to review the distribution of cerebral microbleeds in patients with end-stage organ failure and their association with specific end-stage organ failure risk factors. Materials and methods: Between August 2015 and June 2017, we evaluated 15 patients, 9 males, and 6 females, (mean age 65.5 years). Patients population was subdivided into three groups according to the organ failure: (a) chronic kidney failure (n = 8), (b) restrictive cardiomyopathy undergoing heart transplantation (n = 1), and (c) end-stage liver failure undergoing liver transplantation (n = 6). The MR exams were performed on a 3T MR unit and the SWI sequence was used for the detection of CMBs. CMBs were subdivided in supratentorial lobar distributed, supratentorial non-lobar distributed, and infratentorial distributed. Results: A total of 91 microbleeds were observed in 15 patients. Fifty-nine CMBs lesions (64.8%) had supratentorial lobar distribution, 17 CMBs lesions (18.8%) had supratentorial non-lobar distribution and the remaining 15 CMBs lesions (16.4%) were infratentorial distributed. An overall predominance of supratentorial multiple lobar localizations was found in all types of end-stage organ failure. The presence of CMBs was significantly correlated with age, hypertension, and specific end-stage organ failure risk factors (p &lt; 0.001). Conclusions: CMBs are mostly founded in supratentorial lobar localization in end-stage organ failure. The improved detection of CMBs with SWI sequences may contribute to a more accurate identification of patients with cerebral risk factors to prevent complications during or after the organ transplantation

Evolution of indeterminate hepatocellular nodules at Gd-EOB-DPTA-enhanced MRI in cirrhotic patients

To retrospectively analyze the evolution of indeterminate hepatocellular nodules in cirrhotic patients on serial Gd-EOB-DPTA-enhanced MRI, and to identify predictors of HCC development

Glioma Grading: The Role of Combined Perfusion MR Imaging and Single-Voxel MR Spectroscopy Compared to Conventional MR Imaging

Abstract Body: Purpose To assess the contribution of combined perfusion MR imaging (MRI) and single-voxel MR spectroscopy (MRS) in grading primary gliomas compared with conventional MRI. Materials & Methods Thirty-two patients with primary cerebral glioma underwent conventional MRI, dynamic contrast-enhanced T2*-weighted perfusion MRI and single-voxel proton MRS. Gliomas were graded as low or high based on conventional MRI. The rCBV measurements were obtained from regions of maximum perfusion normalized between tumor and healthy tissue. Metabolite ratios ( [Cho]/[Cr], [Cho]/[NAA], [NAA]/[Cr]) were measured with TE: 34 ms. Tumor grade determined with the three methods then was compared with that from histopathologic grading. Logistic regression and ROC analyses were performed to determine which parameters best increased diagnostic accuracy (sensitivity, specificity, positive and negative predictive values) Results Statistically significant differences were found for rCBV tumor/normal tissue ratio, and NAA/Cr ratio in tumor and Cho/Cr ratio in tumor between low- and high-grade tumors. The best performing single parameter for glioma grading was normalized rCBV value. Combined rCBV tumor/normal tissue ratio and NAA/Cr tumor ratio increased overall accuracy in glioma grading. Receiver operating characteristic curves demonstrated a rCBV tumor/normal tissue ratio of >1.16 and NAA/Cr tumor ratio of <0.44 has the higher probability for a neoplasm to be a high-grade glioma. Conclusion The rCBV measurements and metabolite ratios both individually and in combination can increase the accuracy when compared with conventional MRI alone in determining glioma grade. The best performing parameter was found to be the rCBV measurements. Threshold values can provide a means for guiding treatment and predicting postoperative patient outcome

Brain-core temperature of patients before and after orthotopic liver transplantation assessed by DWI thermometry

To assess brain-core temperature of end-stage liver disease patients undergoing orthotopic liver transplantation (OLT) using a temperature measurement technique based on the apparent diffusion coefficient of the cerebrospinal fluid in the lateral ventricles

Seizure in isolated brain cryptococcoma: Case report and review of the literature

Background: Central nervous system (CNS) cryptococcosis is an invasive fungal infection predominantly seen among immunosuppressed patients causing meningitis or meningoencephalitis. Rarely, cryptococcosis can affect immunologically competent hosts with the formation of localized CNS granulomatous reaction, known as cryptococcoma. Common symptoms of CNS cryptococcoma are headaches, consciousness or mental changes, focal deficits, and cranial nerve dysfunction. Rarely, seizures are the only presenting symptom. Case description: We report the case of an immunocompetent patient with a solitary CNS cryptococcoma presenting with a long history of non-responsive generalized seizure who has been successfully operated. Conclusion: CNS cryptococcoma is a rare entity, and in immunocompetent patients, its diagnosis can be challenging. The pathophysiology of lesion-related seizure is discussed along with a review of the pertinent literature