Current noninvasive imaging techniques for diagnosis of deep venous thrombosis (DVT) of extremities are limited in their ability to demonstrate central vein involvement and to distinguish acute from chronic changes. The utility of spin-echo magnetic resonance (MR) imaging for DVT was evaluated in 100 patients suspected of having either upper- (n = 25) or lower-extremity (n = 75) DVT. Ninety-seven patients were imaged successfully. In a subset of 36 patients, prospective comparison of MR imaging with contrast venography revealed a sensitivity of 90%, specificity of 100%, and Kappa level of agreement of .752 (P less than .0001). MR imaging showed more central extent of thrombus than did venography in all five patients with upper-extremity DVT and in 13 of 25 patients (52%) with lower-extremity DVT. Although all patients in the study were evaluated for acute symptoms, 13 of 59 (22%) MR imaging studies positive for DVT demonstrated chronic disease. MR images demonstrated ancillary abnormalities in 18 of 41 (44%) patients who did not have DVT. Thus, MR imaging has a role as the definitive examination when the results of initial screening studies are unsatisfactory, or as a first-line examination if (a) there is suspicion of upper-extremity or pelvic vein thrombosis, (b) there is a history of prior DVT that necessitates distinction of acute from chronic changes, or (c) other tests are unavailable.
Arterial collaterals in the hilus of the liver may develop in a variety of clinical situations including neoplasm, atherosclerosis, operative ligation and other vascular stenoses, and cirrhosis. They are normally present but are not demonstrated angiographically unless they are functioning as collaterals. Hilar collaterals are an important factor in maintaining liver viability following accidental or purposeful hepatic arterial ligation. The authors base their discussion on personal experience with 16 cases. INDEX TERMS: Liver, blood supply. Arteries, hepatic Radiology 94: 575-579, March 1970 T H E POSSIBILITIES for the development of collateral blood flow to an occluded hepatic artery depend primarily on the site of the occlusion (3). If the celiac or common hepatic artery is occluded, several potential routes exist for collateral circulation (1,4). The main pathway is through the pancreaticoduodenal arcades and the gastroduodenal artery. With proper hepatic artery occlusion, these major collateral channels cannot be utilized, and the liver becomes dependent upon small collaterals in the hepatic ligaments and around the common bile duct. If the occlusion is located in the right or left hepatic arteries or their branches, collateral vessels may develop between these arteries in the hilus of the liver. These hilar communications between hepatic arteries are an important but poorly recognized entity. We are, therefore, presenting 16 patients in whom such collaterals were demonstrated at angiography. METHODS AND MATERIALSThe 16 patients underwent celiac and superior mesenteric angiography for a variety of reasons. The angiograms were obtained by the percutaneous femoral technique, using thin-walled, red Kifa catheters (LD./O.D. = 1.4/2.2). Renografin 76 per cent (Squibb) was injected into the celiac and superior mesenteric arteries at a rate of 12 ml/sec. for three seconds, and serial films were obtained at 2 per second for five seconds, 1 per second for five seconds, and 1 every other second for ten seconds. The angiograms were evaluated to determine (a) the direction of the blood flow through the collateral vessels and (b) the cause for the development of the collateral flow. In addition, the relevant visceral vascular anatomy and its contribution to the pattern of development of collateral flow were assessed. RESULTSHilar collaterals developed subsequent to vascular stenosis in 7 patients, to operative ligation in 5, to tumor in 2, and to cirrhosis in 2. The vascular stenoses were secondary to atherosclerosis in 4 patients, but in 3 younger patients they were probably caused by diaphragmatic crus or were congenital. The operative stenoses were seen in 3 patients following liver resection
Technical advances and operator experience have resulted in a rapid and marked streamlining of the percutaneous approach to renal calculi. The development of nephrostomy tract balloon dilators, improved grasping instruments and the use of assisted local anesthesia have been integral in reducing the morbidity and cost of the procedure. We report our initial favorable experience in the use of percutaneous stone removal on an outpatient basis. All 5 patients underwent an uncomplicated 1-stage stone removal. Cost for outpatient percutaneous stone removal was substantially less than for surgery or extracorporeal shock wave lithotripsy.
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