The usefulness of percutaneous ethanol injection therapy under guidance with carbon dioxide contrast enhanced ultrasound sonography

We evaluated the usefulness of percutaneous ethanol injection therapy (PEIT) under Carbon dioxide (CO2) contrast enhanced ultrasound sonography (CEUS) guidance during digital subtraction angiography (DSA) in 21 cases of hepatocellular carcinoma (HCC) with 28 nodules that could not be detected by plain (non-contrast enhanced) US (PUS). In all cases of HCC that could not be visualized by PUS, PEIT could be performed successfully under CEUS guidance. Tumor size was below 10 mm in most cases, in 2 cases tumor size was more than 20 mm. Tumor location was roughly divided into 5 areas: just below the diaphragm and it's vicinity, liver surface, edge of the liver, around the portal and hepatic vein, and around the inferior vena cave. The detection rate of the nodules that could not be visualized with PUS was 35.7% for CT and 32.1% for DSA. PEIT was performed 1-9 times for each lesion, 3.32 times on an average. The effectiveness of PEIT was judged by CT. All cases were confirmed as LDA. We concluded that the range of indication of PEIT can be expanded by this method.     

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.     

MR imaging of small hepatocellular carcinoma (< or = 20 mm)--correlation with vascularity and histological features

We have evaluated the efficacy of magnetic resonance (MR) imaging for detecting hepatocellular carcinoma less than 20 mm in diameter (sHCC). This study involved 72 cases of sHCC tumors which were also investigated by angiography and histology. These cases were retrospectively examined for correlations between tumor stain (vascularity) on angiography, histological features (fat deposition, clear cells and the grade of differentiation) and the findings on T1 and T2 weighted MR imaging. The sHCC detection rate by MR imaging was 73.6% (53 cases) and by angiography was 59.7% (43 cases). Thirty-five cases were detected both the MR imaging and by angiography. The main MR imaging patterns were hypo to isointense on T1 weighted images (T1WI) and hyperintense on T2 weighted images (T2WI) in 22 cases, and hyperintense on both T1WI and T2WI in 7. In 18 cases which were not demonstrated by tumor staining on angiography, the main MR imaging patterns were hyperintense on T1WI and isointense on T2WI in 14. The histological features included fat deposition in 22 cases, 20 cases of which were hyperintense on T1WI, and 10 of these 20 were hyperintense on both T1WI and T2WI. Fat deposition was marked in 9. According to the grade of differentiation, 23 of the 26 cases with well differentiated HCC tumors were hyperintense on T1WI, and 21 of the 27 cases with moderately to poorly differentiated HCC were hypo to isointense on T1WI and hyperintense on T2WI. sHCC was visualized by MR imaging, reflecting vascularity, fat deposition and the grade of differentiation. In particular, MR imaging is useful for a differential diagnosis between the well differentiated HCC and the moderately to poorly differentiated HCC, and useful for the diagnosis of an early HCC.     

Usefulness of CO2 US angiography in treating hepatocellular carcinoma

We evaluated the usefulness of CO2 US angiography in the detectability of and the effectiveness of TAE and/or PEIT for hepatocellular carcinoma (HCC). Twenty-three patients with HCC underwent CO2 angiography during the interventional procedure to treat HCC after examination of CT and conventional US. CO2 US angiography was observed on the US monitor by injecting CO2 microbubbles through a catheter placed in the hepatic artery. Contrast materials for CO2 US angiography were 3 ml of CO2 microbubbles prepared by vigorously mixing 3 ml of normal saline with 3 ml of 20% Intralipid, 3 ml of 20% albumin or 3 ml of the patient's own blood. In all patients, CO2 US angiography revealed equal or superior tumor detectability as compared with CT, conventional US and angiography. For demonstrating the inner structure of HCC, the image of CO2 microbubbles mixed with Intralipid was better than that of CO2 microbubbles mixed with albumin. In 9 of 23 patients, CO2 US angiography depicted nodules that had not been seen in the other images. TAE was performed in 21 patients with HCC who showed hypervascularity. In one patient in whom it was difficult to clearly depict the small lesion of HCC by conventional angiography and US, PEIT was successful under CO2 US angiography. The detectability of HCC was higher in CO2 US angiography than in CT, conventional US or angiography. The distribution of blood supply to HCC was observed easily by CO2 US angiography. In TAE of HCC, CO2 US angiography was useful to determine the dose of embolization materials without having to perform repeated angiography. It was possible to perform PEIT easily for non-detectable tumors without CO2 US angiography. CO2 US angiography was useful to evaluate the stage of HCC and to perform TAE and PEIT.     

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.     

Relative characteristics of MR angiography and competing vascular imaging modalities

This article reviews the general characteristics of several vascular imaging modalities with the purpose of identifying the distinguishing features of magnetic resonance (MR) angiography. Brief discussions of conventional x-ray film angiography, intravenous and intraarterial digital subtraction angiography (DSA), duplex and color Doppler flow ultrasound (US), computed tomographic (CT) angiography, transesophageal and intravascular US, angioscopy, and MR angiography are presented. The advantages and disadvantages of each are discussed. The general attributes and image quality features of MR angiography, intraarterial DSA, CT angiography, and US are compared. It is concluded that no single imaging modality will presently suffice for all purposes. Because of its noninvasiveness, rapidly improving image quality, and ability to directly provide velocity information, MR angiography is likely to play a role in an increasing number of clinical applications.     

Visualization of tumor vessels in hepatocellular carcinoma. Power Doppler compared with color Doppler and angiography

PURPOSE: To assess the visualization of tumor vessels in hepatocellular carcinoma (HCC) by power Doppler sonography. MATERIAL AND METHODS: We examined 40 patients with 47 HCC lesions by means of power Doppler sonography and compared its visualization of tumor vessels with those of color Doppler and angiography. RESULTS: In 38 (81%) of the 47 lesions, power Doppler sonography improved the visualization of tumor vessels compared with color Doppler sonography; in the remaining lesions no significant difference was noted. In lesions located within 7 cm in depth, there was no significant difference between power Doppler sonography and angiography. In 10 (83%) out of 12 small (< or = 2 cm in diameter) lesions and in 11 (85%) out of 13 hypovascular lesions, power Doppler sonography performed considerably better than angiography. In deeper-seated lesions, however, angiography was significantly superior to power Doppler sonography. CONCLUSION: Power Doppler sonography is more sensitive in detecting the fine tumor vessels in most HCCs than color Doppler sonography. In addition, power Doppler sonography can replace angiography in evaluating tumor vascularity in HCCs except in lesions that are deep-seated or located near the heart. In these lesions, angiography can complement power Doppler sonography in demonstrating tumor vessels.     

Non-invasive vascular imaging of peripheral vessels

The purpose of this review is to describe recent advances in non-invasive vascular imaging techniques and to discuss their current clinical applications for imaging of peripheral vessels. Principles for applying ultrasound, CT angiography (CTA), and magnetic resonance angiography (MRA) for non-invasive imaging of peripheral arteries and veins are presented. Clinical applications are reviewed for different vascular diseases, therapy planning, and follow-up studies. Conventional Doppler and color duplex sonography are the most cost-effective procedures to detect or rule out peripheral arterial occlusive disease (PAOD) and to provide specific recommendations for therapy. In the near future, contrast-enhanced MRA (CE MRA) with additional axial two-dimensional time-of-flight studies to search for non-anatomic runoff will replace diagnostic intra-arterial digital subtraction angiography (DSA) for planning of reconstructive surgery with acquisition slabs displaying projections similar to intra-arterial DSA. Color duplex sonography should also be the first non-invasive technique applied for the detection of peripheral aneurysms. Preoperative or preinterventional therapy planning of aneurysms may be performed by CTA or CE MRA. Compression ultrasound is the imaging procedure of choice in deep venous thrombosis (DVT). In the preoperative assessment of venous incompetence, color duplex sonography is the imaging technique which is sufficient in most cases.     

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The blood supply of hepatocellular carcinoma (HCC) is primarily arterial. Recent studies reported differences of vascular, especially arterial, supply among low- and high-grade dysplastic nodules and HCC. We assessed arterialization using monoclonal antibody specific for smooth muscle actin as well as simultaneous changes in sinusoidal capillarization in cirrhotic nodules, dysplastic nodules, and HCC. We immunohistochemically stained 56 cirrhotic nodules, 20 low-grade dysplastic nodules, 27 high-grade dysplastic nodules, and 20 HCCs for alpha smooth muscle actin (to identify unpaired arteries (i.e., arteries not accompanied by bile ducts) and CD34 (indicating sinusoidal capillarization). Distribution and number of unpaired arteries and distribution of sinusoidal capillarization were graded semiquantitatively. Unpaired arteries were rare in cirrhotic nodules, significantly more common in dysplastic nodules of both types (p < 0.00001), and most common in HCC. Sinusoidal capillarization was least common in cirrhotic nodules, significantly more common in dysplastic nodules (p < 0.0035), and most common in HCC. No topographic relationship between unpaired arteries and sinusoidal capillarization was identified. These findings showed that (1) distributions of sinusoidal capillarization and unpaired arteries in dysplastic nodules are intermediate between those in cirrhotic nodules and HCC, supporting dysplastic nodules as premalignant lesions; (2) unpaired arteries are histologically useful for distinguishing dysplastic nodules from large cirrhotic nodules; and (3) areas of sinusoidal capillarization within dysplastic nodules are unrelated to location of arterialization.     

Tumour-to-normal uptake ratio of 90Y microspheres in hepatic cancer assessed with 99Tcm macroaggregated albumin

The selective delivery of a high dose of radiation to malignant hepatic tumours by infusion of non-biodegradable yttrium-90 (90Y) microspheres via the hepatic artery while sparing the non-tumorous liver parenchyma depends on the tumour-to-normal uptake ratio (T/N) of the therapeutic radiopharmaceutical. Using intrahepatic arterial technetium-99m macroaggregated albumin (99Tcm-MAA), the effect of tumour type, tumour vascularity assessed by hepatic angiography (HAG), tumour size and the degree of extrahepatic shunting on the T/N was investigated in 377 patients with hepatocellular carcinoma (HCC) and 25 patients with colorectal liver metastases. HCC was shown to have a wider range of T/N (0.2-26.5) compared with liver metastases (2.3-7.2). HCC with vascularity grade 1 on HAG had significantly lower T/N but there was no significant difference in HCC with higher vascularity grades. This confirmed that vascularity on HAG does not predict T/N. Overall there was no correlation between T/N and tumour size. Large tumours (> 20 cm) had a significantly lower T/N, probably due to necrosis in the tumour centres. A decrease in mean T/N with increasing percentages of lung shunting was observed in HCC. Determination of T/N by simulation with 99Tcm-MAA is recommended before internal radiation therapy with 90Y microspheres.     

Experience with computed tomographic angiography for the detection of intracranial aneurysms in the setting of acute subarachnoid hemorrhage

OBJECTIVE: To objectively compare computed tomographic angiography (CTA) with selective digital subtraction angiography (DSA) in the detection and anatomic definition of intracranial aneurysms, particularly in the setting of acute subarachnoid hemorrhage (SAH). METHODS: In a blinded prospective study, 40 patients with known or suspected intracranial saccular aneurysms underwent both CTA and DSA, including 32 consecutive patients with SAH in whom CTA was performed after CT images were obtained diagnostic for SAH. The CT angiograms were interpreted for presence, location, and size of the aneurysms, and anatomic features, such as the number of aneurysms lobes, aneurysm neck size (< or = 4 mm), and the number of adjacent arterial branches were suggested. The images obtained with CTA were then compared with the images obtained with DSA, with the later images serving as controls. RESULTS: DSA revealed 43 aneurysms in 30 patients and ruled out intracranial aneurysms in the remaining 10 patients. For aneurysm presence alone, the sensitivity and specificity for CTA was 86 and 90%, respectively. For the presence of an aneurysms, six CT angiogram showed false negative results and one CT angiogram showed a false positive result. False negative results were usually caused by technical problems with the image, tiny aneurysm domes (< 3 mm), and unusual aneurysm locations (i.e., intracavernous carotid or posterior inferior cerebellar artery aneurysms). The results obtained with CTA were, compared with the results obtained with DSA, more than 95% accurate in determining dome and neck size of aneurysm, aneurysm lobularity, and the presence and number of adjacent arterial branches. In addition, CTA provided a three-dimensional representation of the aneurysmal lesion, which was considered useful for surgical planning. CONCLUSION: CTA is useful for rapid and relatively noninvasive detection of aneurysms in common locations, and the anatomic information provided in images showing positive results is at least equivalent to that provided by DSA. In cases of SAH in which the nonaugmented CT and CTA results indicate a clear source of bleeding and provide adequate anatomic detail, we think it is possible to forego DSA before urgent early aneurysm surgery. In all other cases, DSA is indicated.     

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.     

Nonsteroidal anti-inflammatory drugs and cognitive function: do they have a beneficial or deleterious effect?

AIMS/BACKGROUND: A recent advancement in Doppler ultrasonography (US) is power Doppler for detecting low-velocity blood flow at the microvascular level with angle independence. The present study was performed to characterize the factors contributing to the power Doppler signals of hepatocellular carcinoma (HCC). METHOD: Correlation of Doppler signals of HCC in 114 patients with 178 HCC nodules was analyzed in relation to the findings of CT and angiography, tumor characteristics (size, echo pattern, and histological differentiation of tumor), viral markers and severity of liver disease. RESULTS: The sensitivity of power Doppler US was superior to that of CT and angiography (each p<0.05; McNemar's test). The detection rate of power Doppler signal was significantly higher in tumors with diameter > or =2 cm (vs <2 cm in diameter), and with low/mixed echo pattern (vs high echo appearance), and with moderately/poorly differentiated HCC (vs well-differentiated HCC). Univariate analysis revealed that echo pattern, tumor size and histological differentiation of HCC in addition to CT and angiographic findings were significant. Multivariate analysis showed that tumor size and differentiation were significant. CONCLUSION: These results indicate that tumor characteristics play an important role in power Doppler signals and that these could be assessed by the presence or absence of power Doppler signals.     

Diagnostic imaging and interventional therapy of hepatocellular carcinoma

Diagnostic imaging has many important roles in the management of patients with hepatocellular carcinoma (HCC). In diagnosis, lipiodol CT (LCT) has been shown to be the most sensitive imaging modality (90-97%) for all sizes of lesions; all other modalities have high sensitivities for lesions 1-3 cm but low sensitivities for lesions < 1 cm (ultrasound 33-37%, conventional CT 20-42% and digital subtraction angiography 40-55%). All imaging modalities understage HCC. Once again LCT is the most accurate method of evaluating the extent of tumour, but even this method does not identify all satellite nodules. Ultrasound has been proposed as a screening method, but this cannot be justified on the basis of its results or cost benefit analysis. Both CT and dynamic MRI play useful roles in evaluating the efficacy and follow-up of patients undergoing chemoembolization (TACE) and percutaneous ethanol injection (PEI). Although surgery remains the best treatment of HCC, it is unsuitable in most of the cases which would be better treated with interventional therapy. This article presents a review of the literature regarding the use of TACE, PEI or a combination of both procedures in the treatment of HCC. A multicentric study has shown that patients with monofocal lesions less than 5 cm in diameter are better treated with PEI, which is therefore a good alternative to the surgical treatment; patients with multifocal lesions (maximum of three lesions) show a better survival with TACE. Combined treatment with TACE and PEI proves to be effective in patients with large HCC.     

Percutaneous ethanol injection in the treatment of hepatocellular carcinoma. A multicenter survey of evaluation practices and complication rates

BACKGROUND: Percutaneous ethanol injection (PEI) has become a widely used procedure in the treatment of hepatocellular carcinoma (HCC). However, the criteria for selecting patients are not standardized, and little information is available about the complications of the procedure. METHODS: A questionnaire was sent to 11 experienced Italian centers. It investigated: the size and the number of HCC nodules suitable for treatment and the Child-Pugh risk class of the associated cirrhosis; the performance of the procedure; the number and characteristics of the patients treated; and, finally, any complications. RESULTS: Most of the centers performed PEI in single HCC nodules less than 5 cm in diameter or in multiple nodules if fewer than three, the larger being less than 3 cm. Patients in Child-Pugh's classes A, B, and C with single nodules were generally considered for PEI. A prothrombin time of less than 40% and a platelet count of less than 40,000/mm3 contraindicated PEI in most of the centers. PEI was generally performed on outpatients, using Chiba or spinal needles. One thousand and sixty-six patients (8118 sessions) were enrolled; 74% had a single HCC nodule and 26% multiple nodules. All except four had cirrhosis; 53% were in Child class A, 38% in class B, and 9% in class C. The mean number of sessions needed to destroy an HCC nodule was 6.7 (range, 2-14), with a mean alcohol injection volume of 5.0 ml per session (range, 2-20 ml). One death (0.09%) and 34 complications (3.2%) were reported. Among the complications we call attention to the hemorrhagic ones (eight cases) and tumoral seeding (seven cases). Severe pain experienced during the maneuver led to discontinuation of the procedure in 3.7% of the patients; 13.5% of the patients required analgesics and 24% had fever after PEI. CONCLUSIONS: Some procedural aspects of PEI treatment differ among the various centers a standardization is advisable. In the present survey PEI is a low-risk technique.     

Pulmonary embolism in patients with intermediate probability lung scans: diagnosis with Doppler venous US and D-dimer measurement

PURPOSE: To test the usefulness of lower limb Doppler venous compression ultrasound (US) and serum D-dimer measurements in diagnosis of pulmonary embolism in patients in whom ventilation-perfusion (V-P) scans indicate intermediate probability of pulmonary embolism. MATERIALS AND METHODS: V-P scanning, pulmonary angiography, US, and D-dimer measurements were performed in 36 patients without known deep venous thrombosis but with intermediate probability of having a pulmonary embolism. RESULTS: Pulmonary angiography demonstrated pulmonary embolism in 15 (41%) of 36 patients. US demonstrated deep venous thrombosis in only two patients, both with pulmonary embolism. Sensitivity of US was only 13%, but specificity was 100%. Five (14%) of the 36 patients had normal (< 220 micrograms/L) D-dimer levels; none of the five had pulmonary embolism. Sensitivity and specificity of D-dimer values were 100% and 16%, respectively, with a negative predictive value of 100%. CONCLUSION: Combined D-dimer measurement and US were helpful in correctly diagnosing pulmonary embolism in only seven (20%) of 36 patients. Pulmonary angiography is still required to diagnose pulmonary embolism in the majority of patients.     

The diagnosis of the early stage of hepatocellular carcinoma by US-angiography with intraarterial Albunex (sonicated serum albumin) infusion

Contrast-enhanced ultrasonography (arterial infusion) has been clinically established as a qualitative diagnosis imaging tool for hepatocellular carcinoma (HCC). Contrast-enhanced ultrasonography (CEUS) was performed after of Albunex (sonicated serum albumin) or Carbon Dioxide (CO2) microbubble by hand, into the hepatic artery as a diagnostic modality for the early HCC. Here, we discussed the diagnosis of the early HCC by CEUS using Albunex as a contrast medium. Briefly, a diagnosis of the early HCC was made CEUS examination of the hemodynamics of the arteries showed a hypovascular pattern. And tumor size was under 20 mm in diameter, the histopathologic examination was essential to reach a final diagnosis, well-differentiated HCC.     

Role of 99mTc-labeled RBC SPECT in the diagnosis of hepatic hemangioma--comparison with US, CT and angiography

The roles of planar imaging and SPECT with 99mTc-labeled RBC, US, Dynamic CT and angiography in the diagnosis of hepatic hemangioma were evaluated. The study group consisted of 18 patients with a total of 40 hemangiomas and 13 patients with a total of 21 non-hemangiomas. Among these patients, 5 patients with a total of 8 hemangiomas and 10 patients with a total of 14 non-hemangiomas were diagnosed by operation and biopsy. In all 40 hemangiomas, sensitivity for planar imaging was 35%, SPECT 50%, US 53%, Dynamic CT 82% and angiography 81%, respectively. When the tumor size was greater than 2.2 cm by SPECT and 2.8 cm by planar imaging, their sensitivity for both methods was 100%. Specificity for planar imaging was 100%, SPECT 95%, US 81%, Dynamic CT 100% and angiography 83%, respectively. One patient with hepatocellular carcinoma diagnosed by angiography showed increased uptake on SPECT. Because of the highest accuracy for SPECT in hemangioma greater than 2.0 cm, SPECT should be considered to be the method of choice for noninvasive diagnosis of hemangioma.     

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.     

Maximum intensity projection images in the detection of simulated pulmonary nodules by spiral CT

This study was undertaken to investigate the use of maximum intensity projection (MIP) images in the detection of pulmonary nodules by spiral CT (SCT). 40 pulmonary nodules of high density were created by endobronchial deployment of 2 and 4 mm beads in the peripheral airways of five anesthetized dogs. Standard SCT was performed with 5 mm collimation, pitch 2 and reconstruction of contiguous slices. MIP images were generated from overlapped slabs of seven consecutive 3 mm slices, reconstructed at 2 mm intervals and acquired at pitch 2. Scans were reviewed by six radiologists. The data were modelled using ordinal logistic regression for repeated measures, and the Wald chi 2 statistic used to test if there was a difference in nodule detection and reader confidence level between the two techniques. MIP imaging increased the odds of nodule detection by 2.18 (p = 0.0002). Reader confidence level for nodule detection was significantly higher with MIP images (p < 0.00001). MIP images improve the detection rate for small high density pulmonary nodules and increase reader confidence level, when compared with standard SCT.