A new prenylated flavone from Artocarpus champeden inhibits the K(+)-dependent amino acid transport in Bombyx mori midgut

OBJECTIVE: The purpose of our study was to assess the frequency and imaging characteristics of nonpathologic portal perfusion defects in subcapsular liver parenchyma adjacent to the right ribs as seen on CT hepatic arteriography combined with helical CT during arterial portography (CTAP). MATERIALS AND METHODS: From January 1994 to June 1997, helical CTAP and CT hepatic arteriography were performed in 94 patients with suspected malignant hepatic tumors. The patient group comprised 66 men and 28 women ranging from 37 to 83 years old (mean, 64 years old). Three radiologists retrospectively reviewed the images obtained by CTAP to evaluate portal perfusion defects adjacent to the right ribs for location, shape, size, and correlation with findings seen on CT hepatic arteriography. RESULTS: We identified 16 nonpathologic portal perfusion defects adjacent to the right eighth (n = 1), ninth (n = 12), and tenth (n = 3) ribs in 12 (13%) of 94 patients. The shapes of the 16 defects were circular (n = 1), oval (n = 7), wedge (n = 3), and irregular (n = 5). The defects were 10-30 mm in diameter (mean, 16.9 mm). In four (25%) of 16 locations, CT hepatic arteriography showed poorly identified, homogeneous, irregularly shaped areas of contrast enhancement corresponding to the defects seen on CTAP. The portal perfusion defects were proven to be nonpathologic on definitive surgery in four patients and on follow-up radiography in eight patients. CONCLUSION: Helical CTAP may show nonpathologic portal perfusion defects adjacent to the right ribs. Most defects did not appear circular but rather were oval, irregular, or wedge-shaped. CT hepatic arteriography infrequently showed corresponding findings. Radiologists should recognize this potential pitfall when interpreting images obtained by helical CTAP.     

Antioxidant status and dialysis: plasma and saliva antioxidant activity in patients with fluctuating urate levels

PURPOSE: The aim of this study was to clarify the clinical usefulness of combined CT during arterial portography (CTAP), and CT arteriography (CTA), for the diagnosis of hepatocellular carcinoma. MATERIALS AND METHODS: CTAP and CTA were performed in 58 patients with a combined 144 hepatocellular carcinoma (HCC) lesions. Arterial vascular access was obtained through bilateral punctures of the femoral artery with selective placement of catheters in the hepatic artery and superior mesenteric artery. CT scans were performed first during injection of contrast media into the superior mesenteric artery, followed by repeated imaging of the liver during injection of contrast media into the hepatic artery. Delayed CT (DCT) was also obtained 5 min after CTA. RESULTS: The detection rates for all 144 lesions were 73.6% with conventional contrast enhanced CT, 90.3% with CTAP, 95.8% with CTA, 87.5% with DCT, and 98.6% with combined CTAP and CTA. Of early HCC lesions (n = 18), 88.9%, 33.3%, 77.8%, 100%, and 88.9% were detected by conventional contrast enhanced CT, CTAP, CTA, DCT, and combined CTAP and CTA, respectively. Of classical HCC lesions (n = 126), 71.4%, 98.4%, 98.4%, 85.7%, and 100% were detected by conventional contrast enhanced CT, CTAP, CTA, DCT, and combined CTAP and CTA, respectively. CONCLUSION: Combining CTAP and CTA improved the radiologist's ability to detect lesions with confidence and to differentiate perfusion abnormalities of HCCs.     

Same-day computed tomography during arterial portography and delayed high-dose iodine computed tomography: an efficient approach to imaging potentially resectable liver tumours

Preoperative imaging in patients with potentially resectable liver tumours has traditionally been performed in specialized hepatobiliary centres. To assess the feasibility and value of establishing a same-day, pre-resectional hepatic imaging service, computed tomography during arterial portography (CTAP) and delayed high-dose iodine computed tomography (DICT) were used to examine patients considered suitable for curative hepatic resection. The study group comprised 27 patients (14 from hospitals not affiliated with a university and 13 from two university-affiliated hospitals) for whom pre-referral imaging showed tumour distribution amenable to resection. Among the patients from centres not affiliated with a university, seven had undergone ultrasonography (US) and equilibrium-phase CT, four had undergone US and unenhanced CT, two had undergone equilibrium-phase CT only and one had undergone bolus dynamic incremented CT (BDCT) only. For 12 of the patients coming from the university-affiliated centres, the pre-referral imaging had consisted of US and BDCT; the other had undergone US only. After CTAP and DICT, 20 (74%) of the 27 patients were reclassified as having unresectable disease: 7 (54%) of the 13 patients who had undergone BDCT before CTAP and DICT and 12 (92%) of the 13 patients who had undergone unenhanced or equilibrium-phase CT, as well as the patient who had undergone US only. By averting laparotomy in 20 of the patients, CTAP and DICT resulted in short-term health care savings of about $160,000. These findings suggest that BDCT was underused in the hospitals not affiliated with university centres.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of a pharmaceutical care model on diabetes management

PURPOSE: To determine the value of spiral CT during arterial portography (SCTAP) in detecting and localising focal liver lesions we compared the SCTAP findings to those gained by conventional CT during arterial portography (CTAP). MATERIAL AND METHODS: We evaluated a total of CT scans of 128 patients with 162 malignant lesions of the liver. 45 patients underwent SCTAP and 83 patients CTAP. Results of radiological studies were compared with surgical and pathological findings. RESULTS: The overall sensitivity of SCTAP was 93% with a sensitivity of 80% for lesions of less than 1 cm diameter. For CTAP the overall sensitivity was 88%, but the sensitivity for lesions smaller than 1 cm was only 53%. Although with SCTAP examination of hepatic vasculature and liver parenchyma was continuous, we found no advantage in the localisation of lesions to the liver segments compared to CTAP, and the sensitivity of localisation did not correlate with the size of lesions. CONCLUSION: In our study SCTAP turned out to be a reliable radiological method in the preoperative detection of focal liver lesions, with a high overall sensitivity. SCTAP showed improved sensitivity in the detection of small malignant lesions (< 1 cm) in comparison to CTAP.     

Veins of Retzius at CT during arterial portography: anatomy and clinical importance

PURPOSE: To classify the veins of Retzius demonstrated at computed tomography (CT) during arterial portography (CTAP) on the basis of anatomic location and to evaluate the relationship between the frequency of CT visualization and associated disease. MATERIALS AND METHODS: The authors reviewed axial CTAP scans from 130 patients. Patients were classified into one of two groups: patients with liver cirrhosis (group 1 [n = 81]) and patients without liver cirrhosis (group 2 [n = 49]). RESULTS: The pathways of the veins of Retzius were classified as follows: (a) The ileocolic vein drained into the inferior vena cava (IVC) or the right renal vein through the right gonadal vein (n = 61); (b) the pancreaticoduodenal vein drained into the IVC (n = 8); (c) the proximal branches of the superior mesenteric vein drained into the left gonadal vein (n = 6); and (d) the ileocolic vein drained directly into the IVC (n = 5). The veins of Retzius were demonstrated in 41 (51%) of the 81 patients in group 1 and 26 (53%) of the 49 patients in group 2. There was no statistically significant difference between the two groups. CONCLUSION: The veins of Retzius were demonstrated at CTAP in approximately 50% of patients with and 50% of patients without liver cirrhosis.     

Unicornuate uterus: imaging appearance, associated anomalies, and clinical implications

OBJECTIVE: The study is a prospective comparison of helical CT with nonhelical CT arterial portography (CTAP) in the detection of liver metastases from colorectal carcinoma, using surgical and histologic findings as the gold standard. SUBJECTS AND METHODS: Thirty-five patients with colorectal carcinoma and suspected liver metastases were prospectively examined with helical CT and CTAP before surgery. In nine cases, surgery was not performed. In the remaining 26 patients, imaging results were correlated with surgical and pathologic findings. Three radiologists prospectively assessed metastatic involvement with both techniques. The results were compared with pathologic and surgical findings on a lesion-by-lesion basis. In a second phase, three radiologists not directly concerned in the design of the study independently assessed metastatic involvement of the liver as revealed on helical CT and CTAP on a segment-by-segment basis with a five-level scale of confidence. Results were analyzed by receiver operating characteristic methods. RESULTS: The results of the histologic study disclosed 50 metastatic lesions. Helical CT had a sensitivity of 76% (38/50) and a positive predictive value of 90%. CTAP had a sensitivity of 74% (37/50) and positive predictive value of 69%. Receiver operating characteristic analysis revealed a greater area under the curve (Az index), 0.96, for helical CT than for CTAP (0.86). Differences were statistically significant (p < .001). CONCLUSION: Helical CT is superior to nonhelical CTAP in the detection of hepatic metastases from colorectal carcinoma.     

Detection of hepatocellular carcinoma in patients with cirrhosis: MR imaging versus angiographically assisted helical CT

OBJECTIVE: The purpose of our study was to compare the combination of conventional spin-echo, phase-shift gradient-recalled echo (GRE), and triple-phasic dynamic GRE MR imaging with the combination of helical CT hepatic arteriography (CTA) and CT performed during arterial portography (CTAP) in the preoperative detection of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Thirty-seven patients with cirrhosis underwent MR imaging and angiographically assisted CT imaging. Paired T1- and T2-weighted spin-echo images, paired in-phase and out-of-phase GRE images, triple-phasic dynamic GRE images, the combined MR images, and the paired CTA and CTAP images were retrospectively and independently reviewed by three radiologists. Image review was done on a segment-by-segment basis. Of the 280 liver segments, 58 segments contained 79 HCCs that were 0.5-8.0 cm (mean, 2.0 cm) in diameter. The diagnostic value of each pair of images was rated by means of receiver operating characteristic curve analysis. RESULTS: The diagnostic accuracy of combined CTA and CTAP (mean area under the receiver operating characteristic curve [Az] = 0.94) was significantly better than that of spin-echo (Az = 0.86, p < .0001), phase-shift GRE (Az = 0.83, p < .0001), dynamic GRE (Az = 0.85, p < .0001), and all combined (Az = 0.91, p < .001) MR imaging. The relative sensitivity of combined CTA and CTAP (89%) was also significantly (p < .0005) better than that of the combined MR imaging (75%). CONCLUSION: Angiographically assisted helical CT imaging was superior to MR imaging combined with conventional spin-echo, phase-shift GRE, and triple-phasic dynamic GRE techniques in the detection of HCC in patients with cirrhosis. The noninvasive dedicated combined MR imaging could not obviate invasive angiographically assisted CT imaging. Combined CTA and CTAP is recommended, especially in the preoperative examination of patients with HCC.     

Interrelationship between beta-amyloid deposition and complement-activated oligodendroglia

PURPOSE: To assess the reliability of the size-overestimation ratio obtained from spiral CT arterial portography (CTAP) and spiral equilibrium-phase CT (EPCT) in distinguishing malignant focal hepatic lesions from benign ones. METHODS: The CTAP images and EPCT images obtained five minutes after CTAP in 39 patients with focal hepatic lesions were retrospectively analyzed. Fifty-eight lesions (hepatocellular carcinoma [HCC], 33; metastasis, 10; liver cyst, 10; cavernous hemangioma, 2; adenomatous hyperplasia [AH], 2; focal nodular hyperplasia [FNH], 1) had their sizes measured on CTAP and EPCT images using the calipers on the CT console. RESULTS: The size-overestimation ratios (CTAP/EPCT) were 1.24+/-0.15 in HCC, 1.28+/-0.26 in metastasis, 1.02+/-0.23 in liver cyst, 0.98+/-0.34 in cavernous hemangioma, 0.94+/-0.39 in AH, and 1.00 in FNH. Mean size-overestimation ratios for benign- and malignant-lesion groups were 1.00+/-0.37 and 1.25+/-0.18, respectively (p < 0.0001). When a cutoff level was set at 1.05, sensitivity and specificity for malignancy were 91% and 93%, respectively. CONCLUSIONS: In comparison with EPCT, CTAP significantly overestimates the size of malignant hepatic tumors. This phenomenon may be an indicator of hepatic malignancy.     

Imaging of large early and early advanced hepatocellular carcinomas of more than 5 cm in diameter: report of two cases

In an attempt to clarify the imaging characteristics of large early and early advanced hepatocellular carcinoma (HCC), we present two such cases which were greater than 5 cm in diameter. One case had four early HCCs and the other had early advanced HCC which was followed for five years and nine months. Multiphasic CT, CT arteriography (CTA), CT arterial portography (CTAP), and MR imaging were performed. Early HCC was shown as a low density mass by multiphasic contrast CT, CTAP and as a hyperintense mass on a T1-weighted image (WI) and isointense on T2WI. Early advanced HCC was demonstrated as a hypodense mass with hyperenhancing interior nodules on CTA, and isodense with hypodense internal foci on CTAP. One follow-up case showed a multi-step progression from early to early advanced HCC, and finally to overtly advanced HCC. Despite the unusually large size of these two tumors, the findings of multiphasic CT, CTA, CTAP, and MR imaging were consistent with those seen in common-sized (less than 2 cm) early and early advanced HCCs. Multi-step progression of hepatocarcinogenesis was observed in one case.     

Prediction of surgical resectability in patients with hepatic colorectal metastases

OBJECTIVE: To evaluate the efficacy of two distinct imaging techniques to predict, before operation, unresectability compared with standard computed tomographic scan (CT). SUMMARY BACKGROUND: Accurate preoperative identification of the number, size, and location of hepatic lesions is crucial in planning hepatic resection for colorectal hepatic metastases. Although infusion-enhanced CT is the standard, its limitations are the imaging of relatively isodense and/or small (< 1 cm) lesions. The increased sensitivity of CT arterial portography (CTAP) may be offset by false-positive results caused by benign lesions and flow artifacts. METHODS: Fifty-eight selected patients considered to be eligible for resection by standard CT had laparotomy. Before operation and in addition to CT, all patients had CT arterial portography and hepatic artery perfusion scintigraphy (HAPS) using radiolabeled macroaggregated albumin. Early studies showed an increased sensitivity for detecting small lesions using the invasive CTAP. Similarly, the HAPS study has detected malignant lesions not observed by standard CT. RESULTS: Of 58 patients having laparotomy, 40 were resectable by either lobectomy (22) or trisegmentectomy (1) and the rest by single or multiple wedge resections. Eighteen patients could not be resected because of combined intra- and extrahepatic disease or the number and location of metastases. Standard CT detected 64% of all lesions (12% of lesions less than 1 cm). Unresectability was accurately predicted by CTAP and HAPS in 16 (88%) and 15 (83%), respectively, of the 18 patients considered ineligible for resection at laparotomy. Of the 40 patients who had resection for possible cure, CTAP and HAPS falsely predicted unresectability in 6 of 40 patients (15%) and in 10 of 40 patients (25%), respectively. The positive predictive value for unresectability of CTAP and HAPS was 73% and 60%, respectively. False-positive lesions after CTAP included hemangiomas, cysts, granulomas, and flow artifacts. False-positive HAPS lesions included patients in whom no tumor was found at surgery but with some identified by intraoperative ultrasound, blind biopsy, and blind resection. CONCLUSIONS: False-positive results by HAPS and CTAP may limit the ability of these tests to accurately predict unresectability before operation and may deny patients the chance for surgical resection. The HAPS study does, however, detect small lesions not seen by CT or CTAP. Standard CT, although less sensitive, followed by surgery and intraoperative ultrasound, does not necessarily preclude patients who could be resected.     

Sodium butyrate induces NIH3T3 cells to senescence-like state and enhances promoter activity of p21WAF/CIP1 in p53-independent manner

PURPOSE: To evaluate the diagnostic efficacy of computed tomography (CT) after hepatic intraarterial injection of iodized oil in patients with hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Forty patients who underwent CT with iodized oil before orthotopic liver transplantation (OLT) were evaluated prospectively. All patients underwent digital subtraction angiography and injection of iodized oil during chemoembolization. CT during arterial portography (CTAP) was performed in 34 patients. The number of neoplastic nodules was assessed in explanted livers and compared with the radiologic results. RESULTS: Sixty-six HCC nodules were present in the explanted livers. CT with iodized oil enabled correct diagnosis in 38 of 66 lesions (58%), and the results were false-positive in two lesions (3%). Digital subtraction angiography had a sensitivity of 67% (44 of 66 nodules) and CTAP had a sensitivity of 85% (45 of 53 nodules). Four (6%) false-positive diagnoses were made at digital subtraction angiography and three (6%) at CTAP. The diagnostic efficacy of CT with iodized oil was significantly related to lesion diameter greater than 2 cm (P < .0001) and hypervascularity (P < .0001). CONCLUSION: CT with iodized oil failed to provide any substantial information in the pre-OLT staging of HCC: It was inaccurate for small HCC nodules (<2 cm) and intrahepatic metastases. Its sensitivity matched that of digital subtraction angiography and was statistically significantly inferior to that of CTAP.     

Use of intravenous contrast material in transcranial sonography

RATIONALE AND OBJECTIVES: The appearance of the intracranial vasculature was compared on power and color Doppler ultrasound (US) scans obtained with and without a microbubble contrast agent. MATERIALS AND METHODS: Nine patients (three men, six women) aged 42-70 years (mean age, 53 years) participated in the study. Seven patients underwent both color Doppler US and power Doppler US before and after intravenous administration of contrast agent, and two underwent only color Doppler US. All patients had previously undergone cerebral angiography. RESULTS: Before contrast material was administered, power Doppler US was more sensitive than color Doppler US in the detection of intracranial vessels (P < .05); neither technique depicted the entire circle of Willis in eight of nine patients. Postcontrast power Doppler US depicted more vascular segments than postcontrast color Doppler US (P < .01) or precontrast power Doppler US (P < .01). Use of intravenous contrast material enabled the entire circle of Willis to be evaluated from a single temporal bone acoustic window with both power Doppler US and color Doppler US in all patients. Contrast-enhanced power Doppler US depicted vessels not shown by enhanced color Doppler US. CONCLUSION: Contrast-enhanced power Doppler US depicted more vessels, better demonstrated specific vascular segments, and provided better vascular definition of the intracranial vasculature than contrast-enhanced color Doppler US or unenhanced power Doppler US.     

Serum LDH value as a predictor of clinical outcome in acute myelogenous leukaemia of the elderly

PURPOSE: To determine whether the diagnostic quality of computed tomography (CT) during arterial portography (CTAP) performed via the splenic artery (SA) is better than that performed via the superior mesenteric artery (SMA). MATERIALS AND METHODS: The authors evaluated CTAP images obtained in 98 patients from 1991 to 1994; 47 examinations were performed via the SA and 51 were performed via the SMA. Images were reviewed, by consensus, by three radiologists blinded to catheter location. Hepatic enhancement was quantitatively assessed in 53 patients (31 in the SA group, 22 in the SMA group). RESULTS: The numbers of low-attenuation non-tumor-related perfusion defects (19 in the SA group, 17 in the SMA group), high-attenuation non-tumor-related perfusion defects (six in the SA group, six in the SMA group), diffuse mottled perfusion abnormalities (six in the SA group, five in the SMA group), and portal venous flow defects (20 in the SA group, 20 in the SMA group) were similar in both groups (P > .05). Peak hepatic enhancement was similar in both groups (SMA group = 111 HU; SA group = 112 HU) (P > .05). CONCLUSION: There is no difference in quality between CTAP performed via the SA versus CTAP performed via the SMA.     

Doppler-duplex ultrasonography in the diagnosis of cavernous portal vein

Prehepatic portal hypertension caused by cavernous transformation of the portal vein has been more and more considered as a multiorgan disease with circulatory changes in numerous organs related to systemic and splanchnic vascular network [1]. Honeycomb-like, spongy, cavernous portal vein is a rare clinical and pathoanatomical entity which usually results from portal vein thrombosis. Recanalization and neovascularization processes lead to cavernomatous transformation of the portal vein lumen and formation of periportal collateral hepatopetal venous varices (Petren's veins) [5, 6]. Recently, with Doppler ultrasonography and angiography cavernous portal vein has been identified as the cause of prehepatic portal hypertension. Usage of color Doppler and duplex Doppler ultrasonography has greatly contributed to diagnostic efficiency, while therapeutically, the disease remains a serious and controversial problem. METHODS: At the Institute of Digestive Diseases, Clinical Centre of Serbia, 8 patients with cavernous portal vein were studied in the period 1995-1997. Real-time duplex and color Doppler ultrasonography (Toshiba-SSA 100A with sector duplex probe 3.75 MHz, and 9 ATL with color Doppler convex duplex probe 3.5 MHz) were used. Indirect (arterial) portography was used for imaging of lienoportal system in the venous phase of angiography as follows: catheterization (Seldinger's technique) of the coeliac trunk or lienal artery, and catheterization of the superior mesenteric artery. Indirect portography was performed by injection of 60-80 ml of the contrast medium by an automatic pump, at 10-14 ml/sec, i.e. 8-10 ml/sec by the digital technique [7]. Peroral fiberendoscopy was performed in all patients by Olympus GIF-XQ 10 endoscope. RESULTS: In our study the conventional ultrasonographic examination failed to provide an appropriate image of the normal portal vein. In hepatoduodenal ligament multiple tubular and round structures were seen, revealing an atypical honeycomb or spongycavernous shape of the venous lumen (Figs. 1 and 2). Doppler ultrasonography of the lumen of these venous collateral structures revealed a continuous, hypokinetic flow, mid-rate 7.4 cm/sec, which was always hepatopetally directed (to the liver). Color Doppler ultrasonography detected extensive portosystemic collateralls in all patients, and varices in the gallbladder wall in 1 patient. The results of indirect portography correlated well with Doppler ultrasonographic findings. In all patients hepatopetal flow was found (Figs. 3 and 4). The aetiology was diverse: idiopathic, liver cirrhosis, haematological diseases, Crohn's disease and Marfan's syndrome. Two patients had IV degree varices in the distal third of the oesophagus, and 4 patients had II/III degree varices. Patients with posthepatic liver cirrhosis and Crohn's disease had no varices in the distal third of the oesophagus and gastric fornix. DISCUSSION: Since Pick (1909) described this malformation as the hepatopetal collateral, the haemodynamic concept of this entity has not been changed. Doppler ultrasonography and angiography confirm that the blood flow in cavernomas is hepatopetal, i.e. compensated and functional. Cavernous transformation of the portal vein is clinically manifested by bleeding from oesophagogastric varices. Haemathemesis is the most alarming complication and may be the first clinical sign. The haemorrhage is usually recurrent and profuse, but in most cases it is tolerated well owing to preserved hepatic function in patients without liver cirrhosis [19]. Portosystemic collateral circulation may take place via retroperitoneal and other spontaneous venous shunts, not involving the left gastric vein or vv. gastricae breves, when oesophagogastric varices are absent (our patient with Crohn's disease and posthepatitic B cirrhosis). Splenomegaly with hypersplenism is always present with cavernous transformation of the portal vein, and usually precedes the occurrence of gastrointestinal hae     

Endogenous benzodiazepine-like compounds and diazepam binding inhibitor in serum of patients with liver cirrhosis with and without overt encephalopathy

PURPOSE: The purpose of our work was to determine the usefulness of double-phase helical CT during arterial portography (CTAP) for the detection of hypervascular hepatocellular carcinoma (HCC). METHOD: Eighty-four patients with 176 hypervascular HCC nodules underwent double-phase CTAP. Hypervascular HCCs were diagnosed by iodized oil CT after transcatheter arterial chemoembolization (TACE). The first-phase images were obtained 30 s after the initiation of injection of a nonionic iodinated contrast medium into the superior mesenteric artery or splenic artery, and the second-phase images were obtained after 70 s. These images were interpreted separately for detection of HCC. RESULTS: The double-phase CTAP detected two nodules and six nodules that were missed by the first- and second-phase images, respectively. The sensitivity for hypervascular HCC nodules was 89% for the first phase, 91% for the second phase, and 93% for the first phase and second phase combined. The double-phase CTAP showed significantly superior sensitivity to the first-phase CTAP for detecting HCC nodules (p < 0.05). However, there was no statistically significant difference between the sensitivities of the double-phase CTAP and the second-phase CTAP. The positive predictive values of the double-phase images were inferior to those of either the first-phase or the second-phase images alone. CONCLUSION: Double-phase helical CTAP was found to be no better than second-phase CTAP alone for the detection of hypervascular HCC nodules.     

Segmented areas of increased attenuation in the liver caused by right adrenal tumors: CT features

OBJECTIVE: Our goal was to describe attenuation differences bordered by a straight line in the right hepatic lobe on enhanced CT in patients with right adrenal tumors and to discuss the cause of this appearance. MATERIALS AND METHODS: Three patients showing attenuation differences bordered by a straight line were discovered in the CT files of 26 cases of right adrenal tumor over 3 cm in diameter. All CT scans were examined by incremental dynamic study. RESULTS: Two patients had large zone of hyperattenuation in the right lobe bordered with a straight line intersecting both anterior branches of the right portal vein and the inferior vena cava (IVC). A third patient and one of the two patients mentioned already had zones of relative hyper- and hypoattenuation in the medial portion of the posterior hepatic segment, respectively. All three patients had large right adrenal tumors, which severely compressed the right hepatic vein near its confluence with the IVC and/or the IVC in or below its intrahepatic portion. The distribution of attenuation differences was similar to the hyperattenuation at CT arteriography or perfusion defect at CT arterial portography under temporary balloon occlusion of the right hepatic vein and inferior right hepatic vein, respectively. CONCLUSION: Straight-bordered attenuation differences within the right hepatic lobe at dynamic CT can be caused by compression of the right hepatic vein by large right adrenal tumors.     

Dynamic computed tomography and duplex ultrasonography: adjuncts to arterial portography

The applications and limitations of contrast enhanced computed tomography (CT) in defining the extrahepatic portal system is discussed in the context of three separate cases in which the CT examination was used as an adjunct to an incomplete arterial portogram examination. Dynamic CT may be useful when excessive contrast dilution precludes the visualization of major venous structures during arterial portography. Real-time/pulsed Doppler ultrasonography is another complementary test but more limited in application than dynamic CT. Patency and flow direction in the proximal splenic vein, portal vein, and hepatic vein can be defined by the ultrasonic technique.     

Diagnostic imaging in deep vein thrombosis of the limbs

The clinically suspected deep vein thrombosis (DVT) should always be confirmed by instrumental procedures. In fact, about 70% of patients with clinically suspected DVT are shown to be negative on instrumental investigations. Phlebography is still the gold standard in the diagnosis of peripheral DVT. Main phlebographic findings are: persistent filling defect; abrupt interruption of contrast in a vein; lack of opacification in all or some deep veins; flow diversion with opacification of collateral branches. At present, peripheral phlebography is performed when the other noninvasive exams (Color Doppler US and Duplex Doppler) are doubtful, technically limited or when thrombosis of innominate veins or superior vena cava, is suspected. Real-time US enables direct visualization of the limb proximal veins. The venous wall, the venous valves, the thrombus and its development, the anatomic variants, the perivenous structures which may impact on the normal physiology of venous return, are depicted. However, the distal veins of the leg and arm and deep veins (the iliac veins, the superficial femoral vein in the adductor canal) are not accurately visualized. The US findings in DVT include: the presence of echoes within the vascular lumen; the veins in axial scans are not compressible. Pulsed Doppler and duplex Doppler combine the morphologic and functional study. Injury caused by DVT at the valvular level (postphlebitic syndrome) is visualized. Primary deep vein thrombosis caused by valvular disorders (valvular aplasia) is identified. Inadequate superficial and perforating veins to be treated with surgery are mapped. Color Doppler US depicts directly superficial and deep limb veins combining the morphologic with the functional assessment represented by the visualization of the map of flow velocity and direction. Recently, a new diagnostic procedure, the color Doppler Energy (CDE) or Power Doppler has been introduced. Together with mean flow velocity and spectral variance, the signal energy or power is also analyzed. The CDE is independent of the US incidence angle, it does not shows the flow direction, detects particularly slow flows, early canalization of thrombi and non occlusive thrombosis. Color Doppler diagnosis of thrombosis is prompt because an area with absence of color is visualized. Collateral vessels and flow direction within them, is well depicted. Beside the site and extension of thrombosis, color Doppler US is able to directly visualize the distal end of the thrombus, which when floating is at high risk for embolism. CT allows an adequate study of the iliocaval axis and is useful if phlebography or color Doppler US are not diagnostic. Iliocaval thrombosis represents a not infrequent finding during abdominal CT. The thrombus appears as a hypodense mass encircled by the hyperdense rim of contrast medium.     

Detection of hypervascular hepatocellular carcinoma by using spiral volumetric CT: comparison of US and MR imaging

BACKGROUND: Most hepatocellular carcinomas (HCCs) are hypervascular and arise in the liver with chronicity. Spiral volumetric CT (SVCT) is a new rapid-scan technique that offers whole-liver scanning during the arterial-dominant phase. The main aim of the present study is to evaluate the detectability of hypervascular HCC with SVCT as compared with ultrasonography (US) and magnetic resonance (MR) imaging. METHODS: Forty-three hypervascular HCCs in 512 patients with chronic liver disease were examined with US, precontrast SVCT, postcontrast SVCT during the arterial-dominant phase (CT-ADP) and during the equivalent-phase (CT-EP) noncontrast MR imaging and angiography including SVCT during arteriography and arterial portography. Angiographic and follow-up findings were used as the gold standard if the lesion was not confirmed histologically. RESULTS: The sensitivity was 61% with precontrast CT, 84% with CT-ADP, 58% with CT-EP, 70% with US, 72% with MR, and 95% with the combination of these five modalities. Five HCCs (12%) were detected with only CT-ADP. The vascularity of HCC was correctly evaluated as hypervascular in 38 nodules (88%) with the combination of precontrast CT and CT-ADP. CONCLUSIONS: We suggest that the combination of precontrast SVCT and CT-ADP is an essential modality to screen for HCC in patients with chronic liver disease. CT-EP did not contribute to the detection of hypervascular HCC.     

Microwave hepatic tumor coagulation therapy during stoppage of hepatic blood flow using balloon catheters

The usefulness of microwave hepatic tumor coagulation therapy (MTC) with stoppage of hepatic blood flow using a balloon catheter was assessed. By placing a 5-French balloon catheter in a hepatic artery and 6-French balloon catheter in a hepatic vein, hepatic arterial and portal venous flow of the liver segment including the tumor was interrupted. The effects of balloon occlusion were evaluated by CT during arterial portography. MTC with stoppage of hepatic flow was performed for two patients with metastatic liver tumor 2 cm in diameter. Enhanced CT obtained after MTC showed no enhancement of the tumor, indicating complete necrosis. There were no complications and the two patients were discharged within 4 days after MTC. MTC with stoppage of hepatic blood flow is effective for treatment of hepatic metastatic tumor.