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.     

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.     

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.     

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.     

Age-related changes of the insular cortex and lateral ventricles: conventional MRI volumetric measures

RATIONALE AND OBJECTIVES: The authors correlate computed tomography (CT) findings in biphasic spiral technique with histopathology in patients with hepatocellular carcinoma (HCC) who had undergone liver resection (LR) or orthotopic liver transplantation (OLT). METHODS: Preoperative biphasic spiral CT findings in 33 consecutive patients (23 men, 10 women, aged 43-74 years; LR group: n = 17; OLT group; n = 16) with liver cirrhosis and HCC were reviewed retrospectively by consensus of two radiologists and correlated with pathology from liver specimens. RESULTS: Of the 16 patients in the OLT group with 1 to 5 confirmed HCC lesions (total lesions: 29; mean lesion diameter: 2 cm; range: 0.6-5.0 cm), CT before OLT depicted 22 lesions in 15 patients (sensitivity for lesions with a diameter of 0.5-1.0 cm, 20%; for lesions 1.1-2.0 cm, 82%; and for lesions 2.1-3.0 cm and > 3.0 cm, 86% and 100%, respectively). Among the 17 patients in the LR group (total lesions: 21; mean lesion diameter: 5.4 cm; range: 1.0-11.0 cm), CT detected 18 lesions. Lesion-by-lesion sensitivity, as correlated with pathology, was calculated at 76% and 86% in the OLT and LR groups, respectively (overall sensitivity, 80%). The diameter of CT detected lesions, compared with liver specimens, corresponded in 90% of lesions (maximum deviation, 15%). Characteristic CT findings of HCC included unenhanced hypoattenuating focal liver lesions (32 lesions), with hyperattenuation (38 lesions) in the arterial phase of contrast material administration. CONCLUSIONS: Biphasic spiral CT for preoperative HCC detection correlated with pathology in 80%, thus proving this technique to represent a sensitive imaging modality for pretherapeutic evaluation of HCC.     

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.     

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.     

Aberrant gastric venous drainage into the medial segment: demonstration by color Doppler sonography

BACKGROUND: Aberrant gastric venous drainage (AGVD) into the posterior edge of the medial segment of the liver (segment IV) is the main cause of pseudolesion on computed tomography (CT) during arterial portography. We estimated the prevalence of AGVD into the medial segment of the liver with color and power Doppler ultrasound (US). METHODS: Screening gray-scale and color Doppler and power Doppler US were performed in 100 consecutive patients. AGVD was defined as a venous structure that ascended parallel to the main portal vein and drained independently into segment IV. RESULTS: AGVDs were observed in eight of 100 patients (8%) with color and power Doppler US. Power Doppler US depicted these veins more clearly than did color Doppler US. Gray-scale US did not show any AGVDs. Two of eight patients with AGVDs detected by color Doppler US underwent celiac arteriography and CT during arterial portography (CTAP). In these two patients, celiac arteriography directly demonstrated AGVDs draining into segment IV, which revealed nontumorous perfusion defects (pseudolesions) on CTAP. CONCLUSION: Color and power Doppler US are useful imaging methods for demonstrating AGVDs.     

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.     

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.     

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)     

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.     

CT combined with arterial portography. A sensitive method for evaluation of liver tumors

During the period 1994-95, 22 patients were examined with CT during arterial portography for evaluation of hepatic tumours. The majority, 20 patients, had metastases from colon cancer. All patients were candidates for liver resection. In the series of patients described here, this process detected additional lesions in four more of the patients than found with any other imaging techniques. This supports that CT during arterial portography is the most sensitive method for detecting small malignant hepatic tumours, and for localizing them in relation to liver segments and major vascular structures. Optimal results are obtained in the absence of diffuse parenchymal disease and portal hypertension. Non-tumourous perfusion defects limit the accuracy of this technique, but such defects have characteristic locations and appearance. In difficult cases the technique should be correlated with ultrasonography and MR.     

Triphasic spiral computerized tomography of the liver: vascular models of non-cystic focal lesions

PURPOSE: The purpose of this study was to investigate if Triphasic Spiral CT (arterial, portal and equilibrium phases) can improve the characterization of noncystic focal lesions. MATERIAL AND METHODS: Sixty-six patients with suspected focal liver disease underwent Triphasic Spiral CT. After the injection of 120-140 ml contrast material at 3 ml/s the liver was imaged in the arterial (scanning delay: 20-27 s), portal (scanning delay: 45-80 s) and equilibrium (scanning delay: 5-8 min) phases. The enhancement of each lesion was evaluated in each phase and the lesions were grouped by enhancement pattern (11 patterns in all). The reference standards in our 66 patients were surgery (12), biopsy (43), MRI (9), follow-up (9), somatostatin receptor scintigraphy (6). RESULTS: One hundred and twenty-six liver lesions were detected in 66 patients, four of 11 enhancement patterns (hypo/hyper/hyper, hyper/iso/iso, hyper/hyper/iso, hyper/hyper/hyper) were always referrable to benign disease (hemangioma, focal nodular hyperplasia-FNH-adenoma). Four of 11 enhancement patterns (iso/hypo/hypo, iso/iso/hypo, hyper/hypo/hypo, hyper/hyper/hypo) were always referrable to malignant disease (hepatocellular carcinoma-HCC-metastases). The other two patterns (hypo/hypo/hypo, hypo/hypo/hyper) were seen in both benign and malignant diseases. CONCLUSIONS: Triphasic Spiral CT improves the characterization of HCC, FNH, adenoma and hemangioma. The arterial and the equilibrium phases add no information to the yield of the portal venous phase in metastases, except for those from pancreas neuroendocrine tumors in the arterial phase. In our experience, patients with unclassified lesions at US or conventional CT, suspected HCC and metastases from pancreas neuroendocrine tumors should be submitted to Triphasic CT of the liver. This technique however does not appear to be indicated in the study of liver metastases from hypovascular tumors, while it improves the detection of FNH and adenoma.     

Attention-deficit hyperactivity disorder: a category or a continuum? Genetic analysis of a large-scale twin study

The improvement of preoperative imaging techniques gets hepatic surgery easier making it more safer and effective. The authors describe the most common hepatic pathologies, benign and malignant, pointing out for each one the principal diagnostic appearances achievable with, the several techniques and, collating these last between them, they optimize the diagnostic-curative pathways for several pathologies. Beyond allowing the diagnosis of the lesion's nature, an important role of the imaging modalities is also to evaluate the resectability of single lesion, weighing up its exact location and the impact on the vascular system esteeming, finally, the volume of remnant liver in case of larger resections. The intra- and extrahepatic, preoperative staging, of the varied hepatic lesions, primitive and secondary, performed comparing the most modern diagnostics techniques, results to be dramatically important arterial portography during, CT (CTAP), contrast-enhanced helical CT, MR imaging. For each patient it's possible to plan the most adequate treatment to his pathology.     

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.     

Nontumorous arterioportal shunt mimicking hypervascular tumor in cirrhotic liver: two-phase spiral CT findings

PURPOSE: To determine the two-phase (hepatic arterial phase [HAP] and portal venous phase [PVP]) spiral computed tomographic (CT) findings of a nontumorous arterioportal shunt in the cirrhotic liver that can mimic a hypervascular tumor. MATERIALS AND METHODS: For 14 months, 803 patients with known or suspected hepatocellular carcinoma were referred for initial or repeated transcatheter arterial chemoembolization (TACE). Twenty-nine hyperattenuating lesions on HAP CT images obtained in 25 patients (23 men, two women; age range, 39-70 years) were regarded as nontumorous arterioportal shunts and were included in this study. The diagnosis of nontumorous arterioportal shunt was established by four radiologists who reviewed the two-phase spiral CT images and hepatic angiograms. RESULTS: The longest dimension of the lesion was 1.0-7.9 cm (mean dimension, 2.9 cm). The morphology at HAP CT was wedge-shaped in 25 (86%), geographic (ie, focal area with irregular outline) in two (7%), and nodular in two (7%) lesions. All lesions were homogeneous in attenuation. Hyperattenuating linear branching structures that represented early opacification of portal veins were demonstrated during the HAP in nine (31%) lesions. PVP CT images showed these lesions as isoattenuating (n = 20 [69%]) or slightly hyperattenuating (n = 9 [31%]). Iodized oil CT images showed faint or no accumulation of iodized oil in all lesions. CONCLUSION: In cirrhotic liver, nontumorous arterioportal shunts can be a cause of pseudolesions that mimic hypervascular tumors at two-phase spiral CT. Lesions that have the typical wedge-shaped and homogeneous appearance with or without internal linear branching structures during the HAP and that are isoattenuating or slightly hyperattenuating during the PVP can suggest this unusual condition.     

Does CTAP prior to hepatic resection improve patient survival rates?

The purpose of our study was to compare survival rates of colon carcinoma patients who had undergone attempted curative hepatic resection based on liver staging by computed tomographic angiography (CTA) or portography (CTAP) with previously reported survival rates of patients who underwent similar surgery without preoperative CTAP evaluations. A total of 404 CTAP studies performed at three institutions were reviewed. Of this group, 197 had colon carcinoma. Sixty-nine of the colon patients went to surgery. Actuarial adjusted yearly survival rates were calculated for the prior CTAP colon group and compared to historical controls. The control survival data were taken from reports published prior to the CTAP era. Our study demonstrated no difference in the 1-year survival data between the groups. However, the CTAP patients had greater survival in years 2-4. This greater survival may be multifactorial but in part due to better surgical selection caused by CTAP.     

Controlled prospective study of positron emission tomography using the glucose analogue [18f]fluorodeoxyglucose in the evaluation of pulmonary nodules

BACKGROUND: Positron emission tomography (PET) is a new imaging technique which, by measuring focal metabolic activities, can make a qualitative statement (benign or malignant) about a tumour. PET has been described in many studies to provide a high diagnostic accuracy for the evaluation of pulmonary coin lesions. However, these studies were not always supported by histological confirmation of the results. In a controlled prospective study, it was investigated whether the diagnostic accuracy of PET is sufficiently high to allow omission of diagnostic thoracotomy or thoracoscopy in the case of a negative finding. METHODS: A PET scan was carried out before operation using [18F]fluorodeoxyglucose (FDG) in 50 patients with pulmonary coin lesions (diameter 30 mm or less). All of these lesions were completely removed thoracoscopically or by a formal thoracotomy and were examined histologically. Using the histology results, the diagnostic accuracy of the PET procedure with regard to a benign or malignant diagnosis was evaluated and compared with that of computed tomography (CT). Results From a total of 54 coin lesions (four of the 50 patients had two lesions) there were 31 malignant (19 primary bronchial carcinomas, 12 metastases) and 23 benign diagnoses. With the PET procedure 28 of 31 malignant and 19 of 23 benign lesions were classified correctly (sensitivity 90 per cent, specificity 83 per cent). False negatives included two bronchial carcinomas and one metastasis. CT had a sensitivity of 100 per cent and specificity of 52 per cent. CONCLUSION: FDG PET cannot generally be considered as a replacement for diagnostic thoracoscopy or thoracotomy at the present time. However, by combining FDG PET with radiological follow-up, clinical applications may evolve in patients at low risk for a malignant tumour or at high risk for surgical complications.