[MR cholangiopancreatography]

MR cholangiopancreatography (MRCP) is a new technique allowing noninvasive investigation of the bile ducts and pancreatic duct. Due to the extremely intense signal of water on T2-weighting, MR sequences can be obtained only demonstrating liquids. The bile and pancreatic ducts can therefore be studied spontaneously even in the case of major cholestasis. The contraindications of MR cholangiography are exclusively those of MR. MRCP can visualize the level of a bile duct obstruction and often the nature of this obstruction (stone, tumour). Complementary axial T1- and T2-weighted sequences can also visualize the parenchyma around the ducts. MR cholangiography therefore appears to be a technique of the future for noninvasive investigation of the bile ducts.

Comparing contrast-enhanced breath-hold MR angiography and conventional angiography in the evaluation of mesenteric circulation

OBJECTIVE

Our aim was to compare the results of gadolinium-enhanced breath-hold MR angiography with those of conventional angiography for the study of mesenteric circulation.

SUBJECTS AND METHODS

MR angiography and digital subtraction angiography were prospectively performed in 33 patients referred for hepatic, pancreatic, or mesenteric disease. MR angiography was performed with four three-dimensional acquisitions at 0, 30, 60, and 90 sec after injection of 0.1 mmol/kg of gadolinium. Selective conventional angiography was used as the standard of reference.

RESULTS

A pure arterial angiogram (one on which veins could not be visualized) was obtained in 27 patients during the second or third acquisition. By subtracting the arterial phase from an arteriovenous phase (third or fourth acquisition) we obtained a pure venous angiogram (one on which arteries could not be visualized) in 28 patients. Agreement was good or excellent for the hepatic artery (kappa = 0.78), the superior mesenteric artery (kappa = 0.65), the splenic artery (kappa = 0.70), the portal vein (kappa = 1.0), the superior mesenteric vein (kappa = 0.88), and the splenic vein (kappa = 0.75). Agreement was poor, and vessels were better shown by conventional angiography, for the intrahepatic arteries (kappa = 0.006) and the branches of the superior mesenteric artery (kappa = 0.14). MR angiography and conventional angiography revealed 29 and 27 portosystemic collaterals, respectively.

CONCLUSION

Dynamic breath-hold contrast-enhanced MR angiography compared favorably with conventional angiography in preoperative assessment of the proximal mesenteric arteries and in the evaluation of portal hypertension; however, conventional angiography is still necessary to evaluate distal arteries.

Biliary leaks: treatment by means of percutaneous transhepatic biliary drainage

PURPOSE

To evaluate the efficacy of percutaneous transhepatic biliary drainage in the treatment of biliary leaks.

MATERIALS AND METHODS

Sixteen patients with a biliary leak involving either the common bile duct (n = 12), the biliary confluence (n = 2), or a hepaticojejunal anastomosis (n = 2) were treated by means of percutaneous transhepatic biliary drainage. The biliary leak was due to severe acute necrotizing pancreatitis in six patients, while 10 patients had postoperative leak. Percutaneous transhepatic biliary drainage was performed with a 12-F catheter, with two series of side holes positioned on both sides of the extravasation to divert bile flow away from the defect.

RESULTS

In 13 patients, the biliary leak healed after drainage (mean duration, 78 days). In four of these patients, a slight residual narrowing of the bile duct was treated by means of either balloon dilation (n = 2) or balloon dilation followed by insertion of a metallic stent (n = 2). All 13 patients remained cured (mean follow-up, 38 months). Two patients with severe acute necrotizing pancreatitis died of complications unrelated to the biliary leak. Vascular complications occurred in two patients, one of whom died after surgical drainage of a subcapsular hematoma.

CONCLUSION

Biliary leaks can be treated successfully by means of percutaneous transhepatic biliary drainage. The procedure is particularly useful when surgical or endoscopic management has failed.

Treatment of hepatocellular carcinoma by transcatheter arterial chemoembolization: comparison of planned periodic chemoembolization and chemoembolization based on tumor response

OBJECTIVE

The purpose of our study was to assess the efficacy of transcatheter arterial chemoembolization in the treatment of hepatocellular carcinoma using two different infusion schedules.

MATERIALS AND METHODS

Chemoembolization with lipiodol-mediated injection of doxorubicin was performed in 160 patients. In the first group of 80 patients, conventional chemoembolization was initially planned to be repeated at least three times at 2-month intervals. In the second group of 80 patients, chemoembolization was used selectively and repeated only when necessary on the basis of follow-up CT or MR imaging. According to the Okuda classification, 72 patients were stage 1, 33 belonging to group 1 (subgroup 1, Okuda 1) and 39 belonging to group 2 (subgroup 2, Okuda 1). Eighty-eight patients were stage 2, 47 belonging to group 1 (subgroup 1, Okuda 2) and 41 belonging to group 2 (subgroup 2, Okuda 2).

RESULTS

Complications of transcatheter arterial chemoembolization occurred in 19 patients from group 1 and six patients from group 2 (p < .001). The mean time between the first and the third courses was significantly different between group 1 (4 months) and group 2 (14 months) (p < .001). The 1-year, 2-year, and 3-year survival rates were significantly different between subgroup 1, Okuda 1, (58%, 28%, 11%) and subgroup 2, Okuda 1 (89%, 68%, 39%) (p <. 001), and between subgroup 1, Okuda 2 (19%, 0%, 0%), and subgroup 2, Okuda 2 (48%, 31%, 15%) (p < .001).

CONCLUSION

The efficacy and tolerability of chemoembolization increase when it is used selectively and repeated only when necessary. Such technical considerations might explain some of the discrepancies of the results of chemoembolization in published data.

MR cholangiography in primary sclerosing cholangitis

OBJECTIVE

The purpose of this study was to evaluate the ability of MR cholangiography to reveal the characteristics of biliary abnormalities found in primary sclerosing cholangitis.

CONCLUSION

Our results suggest that MR cholangiography could be useful in the diagnosis of primary sclerosing cholangitis. Slightly dilated peripheral bile ducts unconnected to the central ducts in several hepatic segments are a characteristic MR sign of primary sclerosing cholangitis. However, other studies are necessary to establish the usefulness of MR cholangiography in relation to other imaging techniques for evaluating primary sclerosing cholangitis.

Congenital hepatic fibrosis: findings at MR cholangiopancreatography

OBJECTIVE

This study describes the MR imaging features of congenital hepatic fibrosis in four children who were examined with MR cholangiopancreatography.

CONCLUSION

MR cholangiopancreatography effectively reveals biliary cysts, dilatation of intrahepatic bile ducts, and polycystic kidney disease, findings often associated with congenital hepatic fibrosis. This diagnosis should be suspected when these biliary and renal abnormalities are associated with hepatosplenomegaly in a patient with normal liver function.

Hepatic iron overload: diagnosis and quantification with MR imaging

OBJECTIVE

The aim of this study was to assess the sensitivity of MR imaging in the diagnosis of liver hemochromatosis and its ability to quantify hepatic iron concentration (HIC).

SUBJECTS AND METHODS

MR images were prospectively obtained in 58 patients suspected to have hemochromatosis. We used a scanner with a 0.5-T magnet and two sequences: gradient-echo T1-weighted (400/12 [TR/TE], 90 degrees flip angle) and gradient-echo T2*-weighted (700/30, 30 degrees flip angle) sequences. Measurement of the liver-to-muscle signal-intensity ratio was compared with the HIC value measured at biopsy for each patient.

RESULTS

Both MR sequences showed significant correlation between decreased signal-intensity ratios and increased HIC (r = -.87 for T1-weighted sequences and r = -.74 for T2*-weighted sequences). The sensitivity and specificity of the T2*-weighted sequence (signal-intensity ratio < 0.8) to detect iron overload (HIC > 36 mumol/g) were 91% and 88%, respectively. The best correlation was obtained with T2*-weighted sequences, when patients had an HIC less than 100 mumol/g (r = -.71); with T1-weighted sequences, the best correlation was obtained when patients had an HIC of 100-324 mumol/g (r = -.67). We found a significant correlation between the HIC revealed on MR images, calculated from both sequences, and that measured at biopsy when patients had an HIC of less than 300 mumol/g (r = -.93, p < .01).

CONCLUSION

MR imaging shows promise in differentiating normal from abnormal hepatic iron concentration and in grossly quantifying moderate degrees of hepatic iron overload.

[Factors of image quality in spiral x-ray computed tomography]

In helical CT, there are 4 mains factors of quality: The in-plane spatial resolution that is the same in conventional CT; The spatial resolution on the Z axis, which is the slice thickness. The increase factor of the slice thickness between a conventional and a helical CT depends on the pitch and the reconstruction algorithm. The value of the increase factor can be easily calculated; The signal to noise ratio which depends on the collimation, the mA, the KV and the reconstruction algorithm. The signal to noise ratio is not depending on the table speed; The reconstruction interval which can be less than the slice thickness. Then the contrast of small lesion is improved and stair-step artifacts are reduced in 3D reformations.

Arterial complications of pancreatitis: diagnostic and therapeutic aspects in 104 cases

PURPOSE

A retrospective study of 104 cases of arterial lesions related to pancreatitis was undertaken to examine the diagnostic and therapeutic benefits of arteriography compared with ultrasonography (US) and computed tomography (CT).

PATIENTS AND METHODS

Data were acquired from responses to a questionnaire. Eighty-seven patients were men, 17 were women (age range, 21-80 years; mean, 48 years). These lesions were usually revealed by hemorrhage (70 cases), pain (69 cases), or both (46 cases).

RESULTS

Arteriography was immediately positive in 90 of 93 patients in whom it was performed, but US and CT may also permit incidental discovery of silent lesions (17 cases). These lesions are often single (90%) and related to an arterial rupture in a pseudocyst (60%) or a pseudoaneurysm (48%). They involved the splenic (42%), the gastroduodenal (22%), and the small pancreatic arteries (25%). Of 32 cases in which embolization was performed, immediate success was achieved in all cases but bleeding recurred in 12 cases (37%). Treatment in 25 patients was a definitive success (78%), and five patients died of hemorrhage (16%).

CONCLUSION

Arteriography remains essential for diagnosis of arterial lesions, and embolization may be indicated as a stabilizing preoperative procedure and also for immediately stopping hemorrhage.

Percutaneous transhepatic embolization of gastroesophageal varices: results in 400 patients

During a 7-year period, bleeding esophageal varices were treated by means of percutaneous transhepatic embolization in 400 cirrhotic patients, including 258 patients with Child's class C cirrhosis (65%) and 142 patients with Child's class B cirrhosis (35%). Embolization was performed either with bucrylate or with absolute ethanol and stainless-steel coils. Variceal hemorrhage was controlled in 245 (83%) of the 297 patients in whom percutaneous transhepatic embolization was performed as an emergency treatment. The 10-day survival rate in the series was 76%, with 97 deaths occurring shortly after the procedure as a result of recurrent bleeding or liver failure. The actuarial rate of recurrent bleeding was 55% at 6 months (38% Child's class B, 70% Child's class C) and 81% at 2 years (71% Child's class B, 90% Child's class C). One-half the cases of recurrent bleeding were easily controlled by medical treatment; 56% of these patients were still alive at 6 months (79% Child's class B, 42% Child's class C), 48% were alive at 1 year, and 26% were alive at 5 years. Results indicated that the survival rate was significantly higher (p less than .01) in Child's class B patients than in Child's class C patients during the 5-year follow-up period. The overall technical failure and complication rates were 9% and 7%, respectively, but these rates declined progressively as we gained more experience with the procedure. In this large series, transhepatic embolization was a safe, easy-to-perform, and effective treatment for the control of variceal bleeding and was somewhat more efficacious than previously reported.

[Palliative treatment of neoplastic jaundice by a percutaneous transhepatic endoprosthesis. Apropos of 73 cases]

Seventy three patients with malignant obstruction of the extrahepatic bile ducts were submitted to palliative drainage through percutaneous transhepatic endoprosthesis (P.T.E.). Complications occurred within the first month following the procedure in 13 patients (18%) and 8 of them died (10%). Cholangitis was the main complication resulting, from dysfunction of the endoprosthesis due to an incorrect placement of the stent in most cases. On the other hand, not any significant vascular complication such as previously reported following P.T.E., was encountered in our series. Late complications are mainly due to endoprosthesis obstruction (5 cases) or dislodgement (2 cases). The mortality rate within the first month following P.T.E. is 19%, resulting from either a complication of the procedure (11%) or the underlying disease (8%). The mean survival of these 73 patients, is 4, 7 months. When considering only the 59 patients who are alive one month following the procedure, the mean survival (post-operative deaths excluded) is 6 months. According to our experience P.T.E. remains a valuable palliative procedure when other endoscopic or surgical methods either have failed or cannot be resorted to provided a correct placement of the stent allowing for a good bile drainage can be achieved. Thus P.T.E. is able to provide in many cases the same long-term survival as palliative surgery, allowing the patients to resume their normal daily activity.

[Colonic complications of pancreatitis. A report on 39 cases (author's transl)]

Colonic complications of pancreatitis are not infrequent occurrences, as illustrated by the fact that the authors have personally treated 39 such cases. Lesions are found in the colon at sites which correspond perfectly to diffusion of pancreatic necrotic lesions along mesenteric pathways as described by Meyers. They occur mainly in the left colic flexure (17 cases) and transverse colon (10 cases) but may affect the ascending (6 cases) and descending (4 cases) colon by diffusion of the pancreatitis into the anterior extrarenal space. These topographical characteristics, associated with the extrinsic and inflammatory nature of the lesions, produce a very specific and typical radiological syndrome which should assist diagnosis.

[Extension of infiltrating cancer of the stomach into the transverse colon (author's transl)]

The extension of infiltrating stomach cancer through the gastrocolic ligament into the transverse colon appears to be relatively common. The radiological appearance is characteristic, with more or less widespread, but shallow, extrinsic prints with irregular contours typical of malignant tumours. Its gastric origin is strongly suggested by its position of the superior border of the transverse colon. The authors report 6 observations in which the value of this very characteristic radiological abnormality of the colon to diagnose primary stomach cancer was confirmed. Radiological appearances are not very specific in primary stomach cancer and interpretation is often difficult; endoscopy or even biopsies are often inconclusive.

[Spontaneous sub-capsular haematoma of the liver compressing the hepatic veins. Angiographic diagnosis (author's transl)]

Apart from special types encountered in neonates and during pregnancy, spontaneous sub-capsular haematoma (SCH) of the liver is a rare condition which is usually not recognized before operation. The diagnostic value of arteriography is emphasized by this case of SCH in a 29 year old man which presented spontaneously with the appearance of a large mass in the right hypochondrium with fever and pain. Angiographic changes identical to those seen with a traumatic SCH were found and, in this case, were accompanied by a local reversal in intra-hepatic portal flow related to a tumoural Budd-Chiari phenomenon (compression of the hepatic veins by the haematoma). Despite histological study of the liver, no tumoural, vascular, infective or parasitic aetiology could be found to explain this apparently idiopathic spontaneous SCH.

[Angiographic diagnosis of lesions of Winslow's lobe of the pancreas (author's transl)]

Winslow's lobe, the postero-inferior lobe of the head of the pancreas, gives rise to special angiographic appearances owing to its posterior position in relation to the axis of the superior mesenteric artery. It displaces the superior mesenteric artery laterally and forwards, and may also obstruct the vein. In 12 cases of pancreatitis, these signs were usually due to a pseudo-cyst of this lobe of the pancreas, the angiographic discovery of which provided greater accuracy in diagnosis. In 4 cases of carcinoma of the pancreas, there was also irregular stenosis of the first few jejunal arteries, the diagnostic interest of which is important.