MR imaging of Kienbock's Disease

PURPOSE: To evaluate the MRI appearance of Kienbock's disease and correlate this with radiographic findings. MATERIALS AND METHODS: Thirteen clinically confirmed cases of 12 patients with kienbock's disease wereretrospectively reviewed. The significance of signal intensity and pattern of Kienbock's disease on MR images was evaluated and the findings on MR images were compared with radiographic stages classified by Lichtman. Enhanced MR images were abtained in four cases. RESULTS: Lichtman's stage I accounted for one case; stage II, two; stage III, eight; stage IV, two. On T1-weighted MR images, the lunate showed focal low signal intensity in the stage I caseand in one of the two stage II case. Eleven wrists demonstrated a generalized loss of lunate signal. On T2-weighted images, the stage I case showed focal high signal intensity. In stage II, one showed focal low signal intensity and the other exhibited generalized low signal intensity with a high spot area. In stage III, five ofeight cases showed generalized low signal intensity, and one demonstrated high signal intensity. Two showed a high spot area within the generalized low signal intensity. In stage IV, one showed generalized low signal intensity and the other exhibited high signal intensity. No enhancement was seen in the three lesions with focal orgeneralized low signal intensity both on T1 and T2-weighted images. Conversely, one lesion with low signalintensity on T1-weighted imaes and high signal intensity on T2-weighted images showed contrast enhancement. CONCLUSION: Low signal intensity of the lunate on T1-weighted images is a consistent findings of Kienbock's disease. However, further studies such as follow-up MRIs, or pathologic correlation studies and MR contrast enhancement studies will be necessary to evaluate the sighificance of high signal intensity on T2-weighted images.

Non-obstructive Biliary Dilatation After Gastrectomy for Gastric Carcinoma

PURPOSE: To evaluate the incidence,. degree, and clinical significance of non-obstructive intrahepatic bile duct di'latation encountered on follow up CT after gastrectomy for gastric carcinoma. MATERIALS AND METHODS: We retrospectively analyzed follow-up abdominal CT of 65 patients who had undergone gastrectomy with truncal vagotomy and subtotal gastrectomy for gastric carcinoma. We classified those patients who showed intrahepatic duct dilatation into non-obstructive or obstructive groups depending on the presence or absence of the lesions obstructing the duct. We also evaluated the incidence, degree and pattern, and appearance time of non-obstructive type of duct dilatation. RESULTS: Non-obstructive and obstructive biliary dilatations were present in 8 cases(12.3%) and 9 cases(13. 8%), respectively. The degree of non-obstructive group was mild in 6 cases(75%) and moderate in 2 cases (25%) who had taken cholecystectomy during the follow up period, and patterns were proportional dilatation of the central and peripheral intrahepatic ducts. It appeared on follow up CT obtained 6 to 12 months after operation in 7 cases and 3.5 months in one case. No statistical significance was noted between the type of surgery and the incidence of non-obstructive dilatation(p>0.05). CONCLUSION: Mild dilatation of the central intrahepatic ducts without evidence of mechanical biliary obstruction can be seen on follow-up CT obtained more than 6 months after gastrectomy for gastric carcinoma, and the incidence is about 12%. We think that this finding is non-obstructive and clinical evaluation is unnecessary.