ABSTRACT
Objective To investigate the CT and MRI features and morphology classification of intraductal papillary mucinous neoplasm of the bile duct (IPMN-B).Methods A total of 18 patients with IPMN-B proved by pathology were retrospectively analyzed.Out of 18 patients,16 patients underwent enhanced and non-enhanced CT,13 underwent contrast enhanced MR,and 11 out of 13 underwent both CT and MRI.IPMN-B was classified into 4 types:typical IPMN-B,cystic-forming IPMN-B,non-tumor IPMN-B and invasive IPMN-B,according to imaging findings and gross pathological findings.Results Typical IPMN-B (9 cases):tumors were distributed along the bile ducts,both upstream and downstream bile ducts were obviously dilated.Cystic-forming IPMN-B (5 cases):single or multiple tumors were found in aneurysmal dilatation of bile ducts.Non-tumor 1PMN-B (2 cases):no mass was found in the widely dilated bile ducts with smooth bile duct wall.Invasive IPMN-B (2 cases):tumors protruded into the dilated bile ducts causing jagged wall of bile duct,with accompanied abnormal density or signal intensity outside the bile ducts.Bile duct dilatations were shown in all 18 cases,and tumors were shown in 16 cases.In 2 cases no mass was displayed in widely dilated bile ducts.CT density of the tumor was lower than that of liver parenchyma,and higher than that of the bile and intraductal mucin.Signal intensity of the tumor was higher than that of stones,and lower than that of bile and intraductal mucin at MR T2WI.All tumors showed high intensity on DWI.Tumors showed mild to moderate enhancement after injection of contrast agent,CT density or signal intensity of the tumors were lower than that of the liver parenchyma during all three phases of contrast-enhanced CT or MRI.Conclusion IPMN-B has some specific CT and MR imaging features,which are helpful for the diagnosis and classification of IPMN-B.
ABSTRACT
Objective To investigate whether perfusion-weighted imaging (PWI) can be used to evaluate blood perfusion of patients with leukoaraiosis (LA), its relationship to clinical features, and the therapy effect of LA. Methods The 44 patients with LA were recruited in the study. All the subjects were examined with both conventional and dynamic susceptibility contrast-enhanced perfusion MR imaging, 13 of them repeated the examinations after the treatment. The shapes and sizes of the biggest lesions in each patient were confirmed by conventional MR imaging, then the values of relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF) and relative mean transit time (rMTT) in each lesion were calculated respectively. Furtherly, a Pearson's correlation analysis was performed to show whether these values were correlated with mini-mental state examination (MMSE)scores or activities of daily living (ADL) scores. Results The 44 lesions of all the subjects showed significant decreases in rCBV (0. 797 ± 0. 160) and rCBF (0. 779± 0. 164) but increase in rMTT (1. 029±0. 073). There were positive correlations between rCBV and MMSE (r = 0. 524, P =0. 000), between rCBV and ADL (r=0. 621, P=0. 000), between rCBF and MMSE (r=0. 555, P=0. 000), and between rCBF and ADL (r= 0. 690, P= 0. 000), and negative correlations between rMTTand MMSE (r=-0.307, P=0.043), and between rMTT and ADL (r=-0.434, P=0. 003). The blood perfusion was enhanced in 10 out of 13 patients who received the repeated examinations after the treatment, most of whom showed the improvement of clinical symptoms.Conclusions Perfusion MR imaging can assess hemodynamic alterations in LA, which could reflect the clinical symptoms. Moreover, the changes of blood perfusions can be used to evaluate and monitor the therapy effect of LA.