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Objective ToinvestigatethevalueofDWIhyperintensityinvenoussinusindiagnosisandrecanalizationpredictionof cerebralvenoussinusthrombosis(CVST).Methods Clinicaland MRIdataof19patientswithCVST wereanalyzedretrospectively. BasedonDWIsignalcharacteristicsoftheCVST,thepatientsweredividedintoasthehyperintensegroupandthenon-hyperintense group.TheintervaltimebetweenthefirstMRIexaminationandtheonset,andtherecanalizationratewithin1 monthand3 months werecomparedbetweenthetwogroups.Results Therewere76 CVSTinthe19patients,withhyperintensein16venoussinus (21%)andin11patients(57.9%).Theintervaltimewaslongerinthehypertensegroupthanthenon-hypertensegroupbutnosta-tisticalsignificance[(12.81±11.10)daysversus(5.70±7.82)days,P=0.165].17patientsunderwentthesecond MRIexamination in1month,andtherecanalizationrateoftheobstructedsinuswaslowerinthehypertensegroupthanthenon-hypertensegroupwith nostatisticalsignificance(P=0.130).14patientsunderwenttheMRIexaminationafter3 months,andtherecanalizationrateofthe obstructedsinuswaslowerinthehypertensegroupthanthenon-hypertensegroupwithstatisticalsignificance(P=0.047).Conclu-sion ThehypertenseonDWIhashighsensitivityforthedetectionofsubacuteCVST.Thepresenceofhypertenseinoccludedsinus onDWIhasthepredictivevalueforvesselrecanalization.
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Objective To investigate the atypical MRI manifestations in patients with primary central nervous system lymphoma(PCNSL). Methods The clinical and MRI manifestations of 17 patients with pathologically confirmed atypical PCNSL in the First Affiliated Hospital of Henan University of Science and Technology (from May 2011 to Dec 2016) and Nanfang Hospital (from Sep 2003 to May 2009) were analyzed retrospectively in this study. Both conventional and contrast-enhanced MR images were acquired for each patient. The MRI manifestations including the number, location, size, shape, signal intensity, enhancement patterns of lesions were evaluated by two senior radiologists.Results Of the 17 cases,8 were solitary and 9 were multiple.Two types of atypical MR findings were found:(1)Atypical location:For the 9 patients showed atypical location,7 patients had solitary masses which were located in the brainstem(n=3), the supratentorial superficial parts(n=2), the cerebellum(n=1)and the sella(n=1). Two patients had multiple lesions, showing multiple subependymal nodules and no abnormalities in the brain parenchyma. Six of the 7 solitary lesions and the 2 multiple cases showed isointense or hypointense on T1-weighted scans and isointense or hyperintense on T2-weighted scans as well as significant homogenous enhancement on contrast-enhanced T1-weighted scans.(2)Atypical signal features:Ten cases were found with atypical signal features including:①Patchy lesions were observed in 6 patients( one patient with single lesion, and five patients with multiple lesions),appearing as hyperintense spots on T2-weighted image and subtle hypointense on T1-Weighted image. Corresponding contrast-enhanced T1-weighted MR image showed multiple patchy/linear enhancement. ②Two cases showed diffuse supratentorial periventricular and infra-tentorial white matter T2hyperintensity and absence of contrast enhancement. ③Nodular lesions with inhomogeneous internal signals were found in 2 cases with calcification(n=1) and cystic necrosis (n=1, ring-like enhancement).Conclusions The atypical imaging manifestations of PCNSL could lead to misdiagnosis or delay in the diagnosis.It is important to understand its atypical imaging features and combine with clinical manifestations to improve the accuracy of differential diagnosis of intracranial lesions.
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Objective To investigate the utility value of monoexponential and biexponential DWI in the differential diagnosis between benign and malignant liver neoplasms.Methods Seventy three patients with pathologically or clinically confirmed liver mass,were analyzed retrospectively and categorized into benign and malignant groups between January 2013 and October 2013.Malignant group included 46 patients with 53 lesions,while 27 patients in benign group had 35 lesions.All patients underwent MR examinations on 3.0T system (GE 750).Conventional MR T1WI,T2WI,DWI(b=0,800 s/mm2) (to obtain ADC with monoexponential modeling),multi-b value DWI(b=0,20 50,100,200,400,600,800 and 1 200 s/mm2) (to obtain Slow-ADC,Fast-ADC,f with biexponential modeling) and dynamic enhancement were performed.The ADC,Slow-ADC,Fast-ADC and f mean values of benign and malignant liver neoplasms were measured and analyzed by using independent samples t test.Diagnostic efficacy of these parameters in malignant group was evaluated by using receiver operating characteristic curve,with histopathologic findings as the gold standard.Results ADC,Slow-ADC,Fast-ADC and f of malignant group were lower than those of benign group [ADC:(1.79±0.35)× 10-3 mm2/s vs (1.16±0.36) × 10-3 mm2/s; Slow-ADC:(1.67±0.25) × 10-3 mm2/s vs(0.94±0.22)×10-3mm2/s; Fast-ADC(72.40±23.70)×10-3mm2/s vs(34.62±17.43)×10-3mm2/s; and f:(33.59± 11.77)％ vs (22.28±8.97)％ in benign and malignant groups,respectively).Significant inter-group difference was observed in ADC,Fast-ADC,Slow-ADC and f (t=0.89,14.77,8.96 and 5.47,respectively and P＜0.05).The areas under the ROC curve (AUC) of ADC,Slow-ADC,Fast-ADC and fwere 0.938,0.974,0.895 and 0.789,respectively.The sensitivity and specificity of ADC,Slow-ADC,Fast-ADC and fwere 90.6％ (48/53),96.2％ (51/53),90.6％ (48/53) and 90.6％ (48/53) and 85.7％ (30/35),91.4％ (32/35),82.9％ (29/35) and 57.1％ (20/35)respectively for differentiating benign from malignant hepatic lesions.Conclusion ADC obtained with mono-exponential modeling and Fast-ADC,Slow-ADC,f obtained with biexponential modeling are useful parameters in distinguishing benign and malignant hepatic lesions,among which slow-ADC demonstrates the highest diagnostic efficacy.
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Objective To analyze MRI and MRCP appearances of duodenal papilla adenocarcinoma with low biliary obstruction,in order to improve the diagnosis of this lesion.Methods The clinical data of 29 patients with duodenal papilla adenocarcinoma con-firmed by pathology were retrospectively analyzed.All cases were scanned by un-enhanced MR and MRCP,and the lesion shape,sig-nal characteristics and biliary obstruction of the lesion were analyzed.Results A soft tissue mass or nodule in the duodenal papilla region was showed in 29 cases.On non-enhanced T1 WI,1 9 lesions demonstrated slightly hypointense ,10 lesions were isointensity. On T2 WI,21 lesions were slightly hyperintense,8 lesions were isointensity.On DWI(b=800 s/mm2 ),the lesions were hyperintense or slightly hyperintense.On MRCP,the narrow at the distant end of the common bile duct was showed;20 lesions showed the expan-sion of intra-hepatic bile duct and common bile duct,and showed “soft rattan sign”,7 lesions showed the expansion of the bile duct inside and outside the liver and the pancreatic duct,and “double duct sign”could be seen.2 cases showed the expansion of the com-mon bile duct.Conclusion The combination of non-enhanced MR and MRCP can show duodenal papilla adenocarcinoma with low biliary obstruction .Definite MRI diagnosis of duodenal papilla adenocarcinoma is important for treatment.
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Purpose To explore the methods of selectively visualizing hepatic portal vein by using three-dimensional fast imaging employing steady state acquisition combined with in-flow inversion recovery labeling pulse at 3.0 Tesla. Materials and Methods Ten healthy volunteers were examined under different TI (1200, 1400, 1600, 1800 ms), and the vessel-to-liver contrast ratio of the main portal vein, right portal vein, and left portal vein were measured. Results Non-contrast-enhanced MRA images of portal vein were obtained successfully in all ten volunteers. The signal intensity of peripheral portal branches gradually increased when TI increased from 1200 ms to 1600 ms, and the highest vessel-to-liver contrast ratio occurred when TI was 1400 ms. Conclusion Non-contrast enhanced magnetic resonance angiography of the hepatic portal vein can be successfully achieved at 3.0T high field MRI. A fixed TI of 1400 ms is preferable.