Ultrasonography fusion imaging system increases the chance of radiofrequency ablation for hepatocellular carcinoma with poor conspicuity on conventional ultrasonography.

OBJECTIVES: To investigate the usefulness of the ultrasonography (US) fusion imaging system for radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). METHODS: Since the US fusion imaging system became available in 2010, we have conducted RFA with this system in all cases. The characteristics of 75 patients with 120 HCCs and 89 patients with 123 HCCs who underwent RFA before the introduction of this system (period A) and after it (period B), respectively, were retrospectively compared. RESULTS: Significant difference in the characteristics of the patients and HCCs between the two periods was found only in the proportion of HCCs with poor conspicuity on grayscale US treated with RFA (1.7%, 2/120 for period A vs. 15.4%, 19/123 for period B, p < 0.01). Among the 19 HCCs with poor conspicuity on grayscale US for period B, 5 and 9 HCCs were identified on grayscale US and contrast-enhanced US, respectively, by the use of the US fusion imaging system, whereas the 5 remaining undetectable HCCs were treated by using the system in conjunction with reference images displayed side-by-side with grayscale US. CONCLUSION: Since the introduction of the US fusion imaging system, it has become possible to perform RFA for HCCs with poor conspicuity on grayscale US.

Utility of computed tomography fusion imaging for the evaluation of the ablative margin of radiofrequency ablation for hepatocellular carcinoma and the correlation to local tumor progression.

AIM: To demonstrate the usefulness of the computed tomography (CT) fusion imaging for the evaluation of treatment effect of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). METHODS: Eighty-five patients with 94 HCC with complete ablation judged on conventional side-by-side interpretation of pre-RFA and post-RFA CT at the time of RFA were included in this retrospective study. CT data was retrospectively used to create fusion images of pre-RFA and post-RFA CT using automatic rigid registration and manual correction referring to intrahepatic structures and hepatic contours around a tumor. Clinical factors including a minimal ablative margin (MAM) measured on fusion images were examined to prove risk factors for local tumor progression (LTP). RESULTS: LTP was observed in 13 (13.8%) tumors with a median follow up of 21.0 months (range, 2-75). The mean MAM on the fusion image was 1.4 ± 3.1 mm and 23 tumors (24.5%) were judged to be protruding from the ablation zone. Multivariate analysis revealed that protruding from the ablation zone was the only significant factor for LTP (hazard ratio, 7.09; 95% confidential interval, 2.26-22.3; P < 0.001). CONCLUSION: Some HCC were assessed as incomplete ablation on the CT fusion images, although considered completely ablated on side-by-side images at the time of treatment, and incomplete ablation was revealed to be the only independent risk factor for LTP. The CT fusion imaging enables quantitative and accurate evaluation of treatment effect of RFA.

Hypervascular hepatocellular carcinomas: detection with gadoxetate disodium-enhanced MR imaging and multiphasic multidetector CT.

OBJECTIVES: To retrospectively compare the accuracy of detection of hypervascular hepatocellular carcinoma (HCC) by multiphasic multidetector CT and by gadoxetate disodium-enhanced MR imaging. METHODS: After ethical approval, we analysed a total of 73 hypervascular HCC lesions from 31 patients suspected of having HCC, who underwent both gadoxetate disodium-enhanced MR imaging and multiphasic multidetector CT. Five blinded observers independently reviewed CT images, as well as dynamic MR images alone and combined with hepatobiliary phase MR images. Diagnostic accuracy (Az values), sensitivities and positive predictive values were compared by using the Scheffe post hoc test. RESULTS: The mean Az value for dynamic and hepatobiliary phase MR combined (0.81) or dynamic MR images alone (0.78) was significantly higher than that for CT images (0.67, P < 0.001, 0.005, respectively). The mean sensitivity of the combined MR images (0.67) was significantly higher than that of dynamic MR alone (0.52, P < 0.05) or CT images (0.44, P < 0.05). The mean positive predictive values were 0.96, 0.95 and 0.94, for CT, dynamic MR alone and combined MR images, respectively. CONCLUSIONS: Compared with multiphasic multidetector CT, gadoxetate disodium-enhanced MR imaging combining dynamic and hepatobiliary phase images results in significantly improved sensitivity and diagnostic accuracy for detection of hypervascular HCC. KEY POINTS: Gadoxetate disodium is a new liver-specific MR imaging contrast agent. Gadoxetate disodium-enhanced MRI helps the assessment of patients with liver disease. It showed high diagnostic accuracy for the detection of hepatocellular carcinoma.

Sonazoid-enhanced ultrasonography for the diagnosis of an intrapancreatic accessory spleen: a case report.

We report a case of an intrapancreatic accessory spleen in 59-year-old man, in which contrast-enhanced sonography (US) using Sonazoid, a second-generation contrast agent, was useful for the diagnosis. Sonazoid-enhanced US could prove both hypervascularity and the existence of reticuloendothelial cell systems in the mass, which is the key to the diagnosis of an accessory spleen. Sonazoid-enhanced US might become a standard imaging technique for the diagnosis of an accessory spleen.

Comparison of enhancement patterns of histologically confirmed hepatocellular carcinoma between gadoxetate- and ferucarbotran-enhanced magnetic resonance imaging.

PURPOSE: To compare enhancenent patterns of hepatocellular carcinoma (HCC) and dysplastic nodule (DN) between gadoxetate- and ferucarbotran-enhanced MRI. MATERIALS AND METHODS: Patients recruited from ultrasound surveillance for HCC in chronic liver diseases were enrolled in this prospective study approved by institutional review board. Thirty-six patients with 37 histologically proven HCC, including 22 well-differentiated HCCs (wHCC), 15 moderately to poorly differentiated HCCs (mpHCCs), and 4 DNs, underwent gadoxetate-enhanced and ferucarbotran-enhanced MRI. We compared hepatobiliary phase image of gadoxetate-enhanced MRI with ferucarbotran-enhanced MR image regarding signal intensity of HCC and DN relative to surrounding liver parenchyma. We calculated contrast ratios between tumor and liver on pre-enhancement, hepatobiliary phase of gadoxetate-enhanced MRI and ferucarbotran-enhanced MRI. RESULTS: On ferucarbotran-enhanced MRI, all mpHCCs showed hyper-intensity, while 14 wHCCs (14/22;63%) showed iso-intensity. On hepatobiliary phase of gadoxetate-enhanced MRI, 13 mpHCCs (13/15;86%) and 20 wHCCs (20/22;91%) showed hypo-intensity. Two DNs and the other two showed iso- and hypo-intensity, respectively, on gadoxetate-enhanced MRI, whereas all DNs revealed iso-intensity on ferucarbotran-enhanced MRI. Gadoxetate-postcontrast ratio was significantly lower than ferucarbotran-postcontrast ratio in wHCC (P = 0.015). CONCLUSION: The uptake function of hepatocytes that are targeted by gadoxetate is more sensitive than that of Kupffer cells targeted by ferucarbotran in stepwise hepatocarcinogenesis.

Gd-EOB-DTPA-enhanced magnetic resonance images of hepatocellular carcinoma: correlation with histological grading and portal blood flow.

OBJECTIVE: To retrospectively investigate enhancement patterns of hepatocellular carcinoma (HCC) and dysplastic nodule (DN) in the hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA)-enhanced MRI in relation to histological grading and portal blood flow. METHODS: Sixty-nine consecutive patients with 83 histologically proven HCCs and DNs were studied. To assess Gd-EOB-DTPA uptake, we calculated the EOB enhancement ratio, which is the ratio of the relative intensity of tumorous lesion to surrounding nontumorous area on hepatobiliary phase images (post-contrast EOB ratio) to that on unenhanced images (pre-contrast EOB ratio). Portal blood flow was evaluated by CT during arterial portography. RESULTS: Post-contrast EOB ratios significantly decreased as the degree of differentiation declined in DNs (1.00 ± 0.14) and well, moderately and poorly differentiated HCCs (0.79 ± 0.19, 0.60 ± 0.27, 0.49 ± 0.10 respectively). Gd-EOB-DTPA uptake, assessed by EOB enhancement ratios, deceased slightly in DNs and still more in HCCs, while there was no statistical difference in the decrease between different histological grades of HCC. Reductions in portal blood flow were observed less frequently than decreases in Gd-EOB-DTPA uptake in DNs and well-differentiated HCCs. CONCLUSIONS: Reduced Gd-EOB-DTPA uptake might be an early event of hepatocarcinogenesis, preceding portal blood flow reduction. The hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI may help estimate histological grading, although difficulties exist in differentiating HCCs from DNs.

Prospective Comparison of Gd-EOB-DTPA-Enhanced MRI with Dynamic CT for Detecting Recurrence of HCC after Radiofrequency Ablation.

BACKGROUND: We prospectively compared the efficacy of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) with that of dynamic multidetector computed tomography (MDCT) for detection of recurrent hypervascular hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA). METHODS: Institutional review board approval and written informed consent were obtained for this multicenter study. Ninety-seven HCC patients treated with curative RFA underwent both Gd-EOB-DTPA-enhanced MRI and dynamic MDCT every 3-4 months. HCC diagnosis was made based on the typical enhancement pattern of HCC on MRI and/or CT by on-site consensus reading. Two blinded observers independently assessed image datasets to compare diagnostic accuracy, sensitivity, specificity, and the areas under the receiver operating characteristic curve (AUROC). RESULTS: Recurrence was observed in 48 of 97 patients. Among these, 22 were diagnosed by both Gd-EOB-DTPA-enhanced MRI and MDCT; the remainder were diagnosed by only one of these 2 modalities. Recurrence was diagnosed in more patients by Gd-EOB-DTPA-enhanced MRI than by MDCT (44 vs. 26 patients, p < 0.001). Patient-based analysis revealed that the accuracy, sensitivity, and AUROC of Gd-EOB-DTPA-enhanced MRI were significantly higher than those of MDCT for both observers (p < 0.005). The AUROC of Gd-EOB-DTPA- enhanced MRI and MDCT was 0.95 and 0.76 for observer 1 and 0.90 and 0.74 for observer 2, respectively. The κ values for MRI and MDCT were 0.83 and 0.70, respectively. CONCLUSIONS: Compared with dynamic MDCT, Gd-EOB-DTPA-enhanced MRI had higher diagnostic accuracy and sensitivity for detection of recurrent hypervascular HCC and may be a better tool for following patients after RFA.

Pulmonary tumor thrombotic microangiopathy caused by prostate carcinoma.

Pulmonary tumor thrombotic microangiopathy (PTTM) is a fatal malignancy-related condition that involves rapidly progressing hypoxia and pulmonary hypertension. We report a case of PTTM caused by prostate carcinoma, which was diagnosed before autopsy in an 81-year-old man. Computed tomography showed diffuse ground-glass opacities, consolidation, and small nodules in the peripheral regions of the lung. Autopsy showed adenocarcinoma cells embolizing small pulmonary arteries with fibrocellular intimal proliferation, which was consistent with PTTM caused by prostate carcinoma.

Feasibility of Extracted-Overlay Fusion Imaging for Intraoperative Treatment Evaluation of Radiofrequency Ablation for Hepatocellular Carcinoma.

BACKGROUND AND AIMS: Extracted-overlay fusion imaging is a novel computed tomography/magnetic resonance-ultrasonography (CT/MR-US) imaging technique in which a target tumor with a virtual ablative margin is extracted from CT/MR volume data and synchronously overlaid on US images. We investigated the applicability of the technique to intraoperative evaluation of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). METHODS: This retrospective study analyzed 85 HCCs treated with RFA using extracted-overlay fusion imaging for guidance and evaluation. To perform RFA, an electrode was inserted targeting the tumor and a virtual 5-mm ablative margin overlaid on the US image. Following ablation, contrast-enhanced US (CEUS) was performed to assess the ablative margin, and the minimal ablative margins were categorized into three groups: (I) margin <0 mm (protrusion), (II) margin 0 to <5 mm, and (III) margin ≥5 mm. Margin assessment was based on the positional relationship between the overlaid tumor plus margin and the perfusion defect of the ablation zone. Tumors in group I underwent repeat ablation until they were in groups II or III. The final classifications were compared with those obtained by retrospectively created fusion images of pre- and post-RFA CT or MR imaging (CT-CT/MR-MR fusion imaging). RESULTS: Treatment evaluation was impossible using CEUS in six HCCs because the tumors were located far below the body surface. Of the remaining 79 HCCs, the categorizations of minimal ablative margins between CEUS extracted-overlay fusion imaging and CT-CT/MR-MR fusion imaging were in agreement for 72 tumors (91.1%) (Cohen's quadratic-weighted kappa coefficient 0.66, good agreement, p<0.01). CONCLUSIONS: Extracted-overlay fusion imaging combined with CEUS is feasible for the evaluation of RFA and enables intraoperative treatment evaluation without the need to perform contrast-enhanced CT.

Double phase CT during hepatic arteriography for diagnosis of hepatocellular carcinoma.

RATIONALE AND OBJECTIVES: The purpose of this study is to assess the diagnostic impact of double phase computed tomography during hepatic arteriography for hepatocellular carcinoma. MATERIALS AND METHODS: 118 hepatocellular carcinomas in 73 cirrhotic patients who underwent double phase computed tomography during hepatic arteriography were enrolled in this study. Double phase computed tomography during hepatic arteriography consisted of computed tomography images obtained at 5-10 s (first phase) and 40-50 s (second phase) after the initiation of an intraarterial administration of 40-60 ml of contrast medium through the hepatic artery. Diagnostic accuracy of the first phase computed tomography during hepatic arteriography alone and double phase computed tomography during hepatic arteriography images for hepatocellular carcinoma were separately analyzed by three blinded readers independently. Alternative-free response receiver operating characteristic curves were constructed to compare each set of computed tomography during hepatic arteriography images. RESULTS: The detection sensitivity of the double phase CTHA for HCC (mean, 83.1%) was significantly higher than that of the first phase CTHA alone (mean, 73.4%) (P < 0.01). Moreover, the positive predictive value of the double phase CTHA (mean, 93.7%) was higher than that of the first phase CTHA alone (87.4%). The area under the AFROC curve (Az value) of the double phase CTHA (mean, 0.88) was significantly higher than that of the first phase CTHA alone (mean, 0.77) (P < 0.05). CONCLUSIONS: Double phase computed tomography during hepatic arteriography can improve the diagnostic accuracy of hepatocellular carcinoma.

[A case of pseudo aneurysm of common hepatic artery related to hepatic arterial infusion chemotherapy].

A 87-year-old male underwent the extended hepatic left lobectomy and the partial hepatectomy (S7, S8) for liver hepatic metastasis from the rectal cancer in March 2003. The reserver was implanted by the GDA-coil method from the right femoral artery, and WHF was enforced 10 times. Epigastric and back pain appeared from January 2004. The pain became strong gradually. MRI and CT scan were examined after hospitalization. These imaging tests showed the pseudo aneurysm of common hepatic artery. Therefore, an emergency angiography was performed, and pseudo aneurysm of the common hepatic artery was embolized with 36 metallic coils. After the embolization, the pain had disappeared suddenly. The patient was discharged the 7th day after embolization. Hepatic arterial infusion chemotherapy is considered safe with respect to blood and non blood toxicity, which was compared with systemic chemotherapy. However, there were also complications like this case, and caution is required.

Detection of malignant hepatic tumors with ferumoxide-enhanced MR imaging: usefulness of multishot and single-shot fast spin echo sequences.

The purpose of our study was to assess whether respiratory-triggered multishot fast spin echo (MS-FSE) and breath-hold half-Fourier single-shot fast spin echo (SS-FSE) images, in addition to breath-hold T(2)*-weighted gradient recalled echo (GRE) images, increase observer performance in the detection of malignant hepatic tumors with ferumoxide-enhanced magnetic resonance (MR) imaging. Ferumoxide-enhanced MR images obtained from 48 patients with 83 malignant hepatic tumors were retrospectively reviewed by three independent off-site readers. In the first image review, GRE images alone were reviewed. Then, MS-FSE images were added for the first combination review. Finally, SS-FSE images were added for the second combination review. Observer performances were tested by McNemar's test and receiver-operating-characteristic analysis for the clustered data. Sensitivity for hepatocellular carcinomas, metastases, and malignant hepatic tumors overall was significantly (p < 0.05) higher with GRE and MS-FSE combined and GRE, MS-FSE and SS-FSE combined than with GRE alone. For metastases, the Az value was significantly (p < 0.05) higher with GRE and MS-FSE combined, and GRE, MS-FSE and SS-FSE combined than with GRE alone. We confirmed the incremental value of ferumoxide-enhanced MR imaging by obtaining MS-FSE and SS-FSE images in addition to GRE images in the detection of malignant hepatic tumors.

[Long-term outcome of advanced hepatocellular carcinoma that received transarterial hepatic chemotherapy].

Nineteen patients with far advanced hepatocellular carcinoma received transarterial hepatic chemotherapy. Twelve patients were Child-Pugh A, 2 were B, and 2 were C. Seventeen patients had portal vein thrombus, and 2 patients had extra-hepatic metastasis. Among the 19 patients, 13 received low-dose CDDP and 5-FU, and 5-FU with interferon was performed in 2. Lipiodol chemotherapy with epirubicin and MMC was performed after first-line chemotherapy, following the evaluation of the progressive disease. The 1- and 3-year survival rates in all cases were 42.5% and 18.2%, respectively. Of the 18 patients evaluated for response, 1 showed complete response, 2 showed partial responses, 8 had stable disease, and 7 progressed. Median survival time of CR, PR and SD patients was 14.2 months. A multivariate analysis identified CLIP score and therapeutic effect as independent predictors for mortality. It is concluded that transarterial hepatic chemotherapy was very useful for far advanced hepatocellular carcinoma.

[A case of spinal infarction related to hepatic arterial infusion chemotherapy].

A 65-year-old male underwent iliocecal excision and hepatic posterior segmentectomy for cecum cancer and synchronous liver hepatic metastasis in September and October 2001, respectively. A reservoir was implanted by the GDA-coil method from the right femoral artery in November, and WHF (5-FU 1,000 mg/m2) was administered 8 times. Because of the remnant liver recurrence, WHF was restarted in April 2002. Left leg paralysis appeared suddenly after the 3rd administration. Heparin and urokinase were administrated continuously after hospitalization. Also, liver function tests showed a worsening condition. The bile duct necrosis in the liver was examined with abdominal CT scan. The anti-coagulation therapy was changed to an oral drug on the 7th day after hospitalization. The liver function tests normalized gradually. Although the rehabilitation for leg paralysis performed during hospitalization was continued after discharge from the hospital, the patient is unable to walk and uses a wheelchair. Hepatic arterial infusion chemotherapy is considered safe for blood and non-blood toxicity compared with systemic chemotherapy. However, there are also complications as in this case, where QOL is reduced remarkably, and caution is required.

Images of Sonazoid-enhanced ultrasonography in multistep hepatocarcinogenesis: comparison with Gd-EOB-DTPA-enhanced MRI.

BACKGROUND: Little is known about the difference in enhancement patterns of hepatocellular carcinoma (HCC) during multistep hepatocarcinogenesis between the post-vascular phase of Sonazoid-enhanced ultrasonography (SEUS) and hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine (Gd-EOB-DTPA)-enhanced MRI, as well as uptakes of Sonazoid and Gd-EOB-DTPA by HCC. METHODS: Seventy patients with 73 histologically proven HCCs (33 hypovascular well-differentiated HCCs and 40 progressed HCCs) and 9 dysplastic nodules (DNs) were enrolled. Enhancement patterns of the lesions on the post-vascular phase of SEUS and hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI were evaluated. Uptakes of Sonazoid and Gd-EOB-DTPA were assessed by Sonazoid enhancement index and EOB enhancement ratio in relation to immunohistochemistry of CD68 and organic anion transporting polypeptide 8 (OATP8), respectively. RESULTS: On the post-vascular phase of SEUS, none of the 9 DNs and 3 of 33 hypovascular well-differentiated HCCs (9 %) were hypoechoic, whereas 3 of 9 DNs (33 %) and 31 of 33 hypovascular well-differentiated HCCs (94 %) showed hypointensity on the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI. Of 31 progressed HCCs, 95 and 93 % were hypoechoic and hypointense on the post-vascular phase of SEUS and hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI, respectively. Sonazoid enhancement indexes decreased in progressed HCCs, correlating with lower Kupffer cell numbers (P < 0.001). EOB enhancement ratios decreased in hypovascular well-differentiated and progressed HCCs, as OATP8 expression declined (P < 0.001). CONCLUSIONS: In stepwise hepatocarcinogenesis, uptake of Sonazoid starts decreasing later than that of Gd-EOB-DTPA. Although signal reductions on the post-vascular phase of SEUS or hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI suggest HCC, hypoechoic appearance on the post-vascular phase of SEUS might be HCC-specific, particularly progressed HCC.

Computed radiography-based mammography with 50-microm pixel size: intra-individual comparison with film-screen mammography for diagnosis of breast cancers.

RATIONALE AND OBJECTIVES: The aim of this study was to evaluate the breast cancer diagnostic capability of "dual-side readout" computed radiography-based mammography (DRCRM) with a 50-microm pixel size compared to that of conventional film-screen mammography (FSM). MATERIALS AND METHODS: Thirty patients who were scheduled for surgical treatment for breast cancer and 10 normal volunteers were enrolled. All 30 patients underwent surgical treatment, and breast cancer was proved histopathologically. Twenty-eight patients had 35 invasive carcinomas, and the remaining two had ductal carcinomas in situ. Each of the 40 women underwent both DRCRM and FSM (with double exposure and the same view, without removing compression). Three observers retrospectively interpreted the mammograms independently and evaluated and rated masses and class categories. The accuracy of the detection of masses was evaluated with alternative free-response receiver-operating characteristic analysis. Sensitivity for the detection of masses and of cancers was also evaluated. RESULTS: The mean areas under the alternative free-response receiver-operating characteristic curves in the detection of the masses were 0.88 for DRCRM and 0.91 for FSM (P = .08). The corresponding values for mean sensitivity for the detection of masses were 0.74 and 0.77 (P = .48) and those for the detection of cancers 0.79 and 0.84 (P = .20). CONCLUSION: No significant differences were observed between DRCRM and FSM for diagnosis of breast cancers.

New measurement of hepatic blood flow by xenon CT system: an animal study with PGE1.

BACKGROUND: A new Xenon computed tomography (CT) system was developed to measure both hepatic arterial and portal venous tissue blood flow (HATBF/PVTBF) non-invasively. Despite its clinical trial, the effect of prostaglandin E1 (PGE1) on hepatic hemodynamics is not well investigated. In a rabbit model, we evaluated the accuracy of this system by comparing it with the electromagnetic blood flowmeter (EMBF), the pharmacological effect of PGE1 on the fractional hepatic hemodynamics. MATERIALS AND METHODS: Seven NZW-rabbits were used. Serial abdominal CT scan was obtained every min before and during the 4 min inhalation of the Xenon gas, followed by 5 min administration of oxygen air. From these images, HATBF and PVTBF were separately calculated with a special new imaging system. We also used EMBF during laparotomy, and directly measured the hepatic arterial and portal venous flow with or without PGE1 administration. RESULTS: Xenon CT showed HATBF of 18.4 +/- 4.5 (ml/min/100 g) and PVTBF of 69.4 +/- 15.0, was almost identical with those of EMBF (19.8 +/- 5.7 and 67.2 +/- 19.1, respectively). After PGE1 administration, Xenon CT showed 22.9 +/- 4.6 and 76.5 +/- 20.5, while those with EMBF were 21.0 +/- 6.5 and 84.7 +/- 21.6, respectively. There were significant correlations (P < 0.01) in total HTBF, HATBF, and PVTBF between results of Xenon CT and EMBF. CONCLUSIONS: Xenon CT with a newly developed imaging system enables us to measure the fractional hepatic tissue blood flow in rabbits, differentially and accurately. Venous administration of PGE1 increased total hepatic blood flow, mainly affecting the portal blood flow.

Is half-dose contrast-enhanced three-dimensional MR angiography sufficient for the abdominal aorta and pelvis?

PURPOSE: To evaluate the usefulness of half-dose contrast-enhanced magnetic resonance (MR) angiography for depicting the abdominal aorta and its major branches. MATERIALS AND METHODS: A total of 72 consecutive patients were randomly assigned to one of four groups that underwent MR angiography after receiving different concentrations (original or diluted to 50%) and total amounts (single or half-dose) of gadolinium chelate injected at different rates (1 or 0.5 mL/second). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the abdominal aorta and of the common and external iliac arteries were calculated, and two blinded readers rated the respective image qualities. RESULTS: The SNR and CNR of the abdominal aorta and the common iliac artery in the 0.5 mL/second groups were statistically significantly lower than those in the 1 mL/second groups. The differences in overall image quality across the four groups were not statistically significant. CONCLUSION: Half-dose MR angiography using diluted contrast medium injected at a rate of 1 mL/second depicted the abdominal aorta and its branches as clearly as using a full single dose.

Percutaneous microwave tumor coagulation for hepatocellular carcinomas with interruption of segmental hepatic blood flow.

PURPOSE: To assess the effect of hepatic artery occlusion with or without hepatic venous outflow interruption on coagulation diameter during percutaneous microwave coagulation therapy (PMCT) for hepatocellular carcinoma (HCC) by a prospective and randomized trial. MATERIALS AND METHODS: Thirty-one patients with 36 HCCs (10-38 mm in diameter) were randomly separated into two treatment groups as follows: group 1 (14 tumors in 14 patients) was treated with PMCT in conjunction with both segmental hepatic artery embolization with gelatin sponge particles and temporary interruption of hepatic venous flow by means of a 6-F balloon catheter to reduce the portal venous flow; group 2 (22 tumors in 17 patients) was treated with PMCT with segmental hepatic artery embolization only. PMCT under ultrasound (US) guidance was performed with 2,450 MHz of microwave frequency at 40-60 W and a needle applicator 1.6 mm in diameter. The coagulated area was measured at the maximum diameter perpendicular to the needle tract on enhanced computed tomography (CT) performed immediately after PMCT. The local effect of the treatment was evaluated by follow-up enhanced CT (6-33 mo). RESULTS: Patients in group 1 had a significantly larger coagulation area (mean +/-SD = 42.9 mm +/- 8.3), with coagulation times of 5.3 min +/- 1.4, than patients in group 2 (32.6 mm +/- 8.0), with coagulation times of 4.2 min +/- 1.3 (P <.05). Follow-up enhanced CT showed no local enhancement of the tumor, indicating complete necrosis and no local recurrence, except for four tumors. There were no major complications after PMCT except liver abscess that developed after PMCT in one patient with pneumobilia. CONCLUSIONS: PMCT with combined hepatic arterial embolization and temporary hepatic venous flow interruption can coagulate significantly larger volumes of tumor than PMCT with only hepatic arterial embolization.