Kiyoshi Ohkuma

Evaluation of liver fibrosis by transient elastography using acoustic radiation force impulse: comparison with Fibroscan ®

BackgroundAccurate evaluation of liver fibrosis in patients with chronic liver damage is required to determine the appropriate treatment. Various approaches, including laboratory tests and transient elastography, have been used to evaluate liver fibrosis. Recently, transient elastography with acoustic radiation force impulse (ARFI) has been developed and applied with conventional ultrasonography. The aim of this study was to evaluate the clinical utility of transient elastography with ARFI and to compare the results with this method and those of the Fibroscan® procedure.MethodsOne hundred and thirty-one patients with liver damage, who underwent liver biopsy at our department, were enrolled prospectively in this study. Elastography with ARFI (applied with ACUSON S2000®), and Fibroscan® was performed at the same time as liver biopsy. These measurements were compared with histological findings in liver biopsy specimens, and measurement accuracy was evaluated by receiver-operating characteristic analysis.ResultsElastography values with both procedures were significantly correlated with the stages of liver fibrosis and there was little difference in the results obtained using the 2 procedures. The accuracy of differential diagnosis between no fibrosis at F0 and more than F1 stage was insufficient with ARFI, but this procedure was sufficient for diagnosing advanced fibrosis. The accuracy of ARFI was almost equivalent to that of the Fibroscan® method. Moreover, both ARFI and Fibroscan® values increased in proportion to the severity of hepatic inflammation when fibrosis stage is low, but not in proportion to the severity of steatosis.ConclusionsTransient elastography with ARFI is simple, non-invasive and useful for diagnosing the stage of fibrosis in chronic liver disease. The utility of ARFI was almost equivalent to that of the Fibroscan® method.

Acoustic radiation force impulse imaging for assessing graft fibrosis after pediatric living donor liver transplantation: a pilot study.

Graft fibrosis is a common finding during protocol biopsy examinations after pediatric liver transplantation. We evaluated the clinical utility of liver stiffness measurements by acoustic radiation force impulse (ARFI) imaging, a novel ultrasound‐based elastography method, for assessing graft fibrosis after pediatric living donor liver transplantation (LDLT). We performed 73 liver stiffness measurements by ARFI imaging in 65 pediatric LDLT recipients through the upper midline of the abdomen (midline value) and the right intercostal space (intercostal value) around the time of protocol biopsy examinations. Fifty‐nine of these liver stiffness measurements could be compared with histopathological findings. Graft fibrosis was assessed according to the degrees of portal and pericellular fibrosis. Significant fibrosis, which was defined as F2 or worse portal fibrosis and/or moderate or worse pericellular fibrosis, was observed in 14 examinations, which had significantly higher midline (P = 0.005) and intercostal values (P < 0.001) than the others. Liver stiffness measurements by ARFI imaging significantly increased with increases in the portal and pericellular fibrosis grades. For the diagnosis of significant fibrosis, the areas under the receiver operating characteristic curve (AUROCs) were 0.760 (P = 0.005) and 0.849 (P < 0.001) for the midline and intercostal values, respectively. The optimal cutoff values were 1.30 and 1.39 m/second for midline and intercostal values, respectively. Slight but significant elevations were noted in the results of biochemical liver tests: serum levels of γ‐glutamyltransferase showed the highest AUROC (0.809, P = 0.001) with an optimal cutoff value of 20 IU/L. In conclusion, liver stiffness measurements by ARFI imaging had good accuracy for diagnosing graft fibrosis after pediatric LDLT. The pericellular pattern of fibrosis was frequently observed after pediatric LDLT, and moderate pericellular fibrosis was detectable by ARFI imaging. Liver Transpl 19:1202–1213, 2013.

Diagnosing native liver fibrosis and esophageal varices using liver and spleen stiffness measurements in biliary atresia: a pilot study

BackgroundBiliary atresia commonly leads to liver fibrosis and cirrhotic complications, including esophageal varices.ObjectiveTo evaluate liver and spleen stiffness measurements using acoustic radiation force impulse (ARFI) imaging for diagnosing grade of liver fibrosis and predicting the presence of esophageal varices in patients treated for biliary atresia.Materials and methodsARFI imaging of the spleen and native liver was performed in 28 patients with biliary atresia. We studied the relation between ARFI imaging values and liver histology findings (n=22), upper gastrointestinal endoscopy findings (n=16) and several noninvasive test results. Diagnostic accuracy was assessed using receiver operating characteristic curve analyses.ResultsLiver stiffness measurements exhibited a significant difference among the different grades of liver fibrosis (P=0.009), and showed higher values in patients with high-risk esophageal varices than in the other patients (P=0.04). The areas under the receiver operating characteristic curves of liver stiffness measurements for liver fibrosis grades  ≥ F2, ≥F3 and = F4 were 0.83, 0.93 and 0.94, respectively. Patients with high-risk esophageal varices were preferentially diagnosed by the combined liver and spleen stiffness measurements (area under the curve, 0.92).ConclusionLiver and spleen stiffness measurements using ARFI imaging are potential noninvasive markers for liver fibrosis and esophageal varices in patients treated for biliary atresia.

Bone SPECT/CT Localizes Increased Bone Metabolism and Subsequent Bone Resorption in Reflex Sympathetic Dystrophy

A 64-year-old man with lung cancer with a history of revascularization of the occluded right femoral artery underwent bone scintigraphy, which showed intense uptake in the distal side of the right leg. The additional SPECT/CT clarified that the uptake was predominantly increased in the epiphyses of the right ankle and foot with possible osteopenia. One month later, follow-up SPECT/CT showed the manifestation of periosteal resorption in the hypermetabolic sites with slight decrease in bone metabolism. Radiological correlation between bone metabolism and subsequent bone resorption in addition to clinical symptoms in this patient suggested the diagnosis of reflex sympathetic dystrophy.

Cerebral blood flow after hybrid distal hemiarch repair

OBJECTIVES Aortic arch disease can be treated with hybrid repair (extra-anatomic bypass plus placement of aortic endoprostheses), but there is controversy about whether a bypass from one relatively small vessel will provide adequate blood flow to the entire brachiocephalic system. We, therefore, compared flow volumes before and after hybrid repair. METHODS We reviewed the records of 16 patients who underwent a hybrid distal hemiarch repair between October 2010 and May 2012. The procedure consisted of debranching of the left subclavian and left common carotid arteries, creation of a bypass to these vessels from the right subclavian artery by using a T-shaped synthetic graft, and placement of a stent graft. Preoperative and postoperative measurements of blood flow volume in the carotid and vertebral arteries and of regional cerebral blood flow were performed in ~70% of the patients. RESULTS Perioperative complications were one new-onset, fatal acute aortic dissection and two minor strokes. No major endoleaks occurred. Postoperatively, mean flow volumes in the right and left common carotid arteries, right and left internal carotid arteries, and right and left vertebral arteries were 423 and 393, 271 and 189, and 87 and 80 ml/min, respectively. Regional cerebral blood flow in the territories of the anterior, middle and posterior cerebral arteries was not significantly different from preoperative levels, as assessed both with and without administration of acetazolamide. CONCLUSIONS Hybrid distal hemiarch repair preserved regional cerebral blood flow and vasoreactivity, although flow in the common and internal carotid arteries was right-side dominant postoperatively.

Examination of efficacy of SHU 508A for color Doppler sonography of peripheral vascular diseases and soft tissue tumors in the pelvis and extremity

Color Doppler sonography has been used clinically in the diagnosis of arterial occlusive diseases in the pelvis and extremity and of deep venous thrombosis in the lower extremities as well as for follow-up examination after bypass operation [1]. However, this method has certain limitations: it is difficult to delineate color display for intrapelvic vessels or vessels running in parallel with the probe, and only a poor color display is obtained for peripheral, small and low velocity flow vessels. Those limitations might be improved with use of contrast agents.

Carotid Plaque Score and Risk of Cardiovascular Mortality in the Oldest Old: Results from the TOOTH Study

Aim: Accumulating evidence suggests that predictability of traditional cardiovascular risk factors declines with advancing age. We investigated whether carotid plaque scores (CPSs) were associated with cardiovascular disease (CVD) death in the oldest old, and whether asymmetrical dimethylarginine (ADMA), a marker of endothelial dysfunction, moderated the association between the CPS and CVD death. Methods: We conducted a prospective cohort study of Japanese subjects aged ≥ 85 years without CVD at baseline. We followed this cohort for 6 years to investigate the association of CPS with CVD death via multivariable Cox proportional hazard analysis. We divided participants into three groups according to CPS (no, 0 points; low, 1.2–4.9 points; high, ≥5.0 points). The predictive value of CPS for estimating CVD death risk over CVD risk factors, including ADMA, was examined using C-statistics. Results: We analyzed 347 participants (151 men, 196 women; mean age, 87.6 years), of which 135 (38.9%) had no carotid plaque at baseline, and 48 (13.8%) had high CPS. Of the total, 29 (8.4%) participants experienced CVD-related death during the study period. Multivariable analysis revealed a significant association of high CPS with CVD-related mortality relative to no CPS (hazard ratio, 3.90; 95% confidence interval: 1.47–10.39). ADMA was not associated with CVD death, but the significant association between CPS and CVD death was observed only in lower ADMA level. The addition of CPS to other risk factors improved the predictability of CVD death (p = 0.032). Conclusions: High CPS correlated significantly with a higher CVD death risk in the oldest old with low cardiovascular risk. Ultrasound carotid plaque evaluation might facilitate risk evaluations of CVD death in the very old.

Visualization of tumor vessels in renal tumors. Comparison between power Doppler ultrasonography and angiography.

Purpose: To compare the ability of power Doppler ultrasonography (PDUS) with that of renal angiography for assessment of renal tumor vessels. Material and Methods: We performed PDUS and angiography in 52 histologically proven renal parenchymal tumors (50 renal cell carcinomas (RCCs) and 2 oncocytomas), and compared vascularity on PDUS and angiography. The vascularity of PDUS was graded as follows: grade 0 - no recognizable tumor vessel; grade 1 - hypovascular to surrounding renal interlobar arteries; grade 2 - hyper- or isovascular to surrounding renal interlobar arteries. Results: With PDUS, 41 tumors were grade 2 and 11 were grade 1. With angiography, 44 lesions had iso/hypervascular pattern, 6 hypovascular pattern, and 2 were judged to be avascular. Among 44 iso/hypervascular tumors, 41 were grade 2, and 3 were grade 1. These latter 3 were located deeper than 7 cm. Six hypovascular tumors and 2 avascular tumors were grade 1. The 2 avascular tumors were small and hypovascular. The κ-level of agreement was 0.81. Conclusion: There was very good agreement betweeen PDUS and angiography in visualizing renal tumor vessels. PDUS appears appropriate for assessing renal tumor vascularity as compared to angiography in small and hypovascular lesions, but deep location reduced the detectability of tumor vessels with PDUS.

Small Solid Renal Lesions: Usefulness of Power Doppler US

PURPOSE To evaluate whether the vascular pattern at power Doppler ultrasonography (US) improves diagnostic accuracy in small solid renal lesions over that at gray-scale US. MATERIALS AND METHODS Gray-scale and power Doppler US were performed prospectively in 64 small (1.5-3.0-cm-diameter) solid renal lesions (26 renal cell carcinomas [RCCs], 34 angiomyolipomas, two oncocytomas, two pseudotumors). At gray-scale US, echogenicity and homogeneity of the lesion, an anechoic rim, intratumoral cysts, shadowing, or a central scar were sought. At power Doppler US, the vascular distribution was divided into four patterns. RESULTS Findings at gray-scale US included an anechoic rim or intratumoral cysts in 20 of 26 RCCs (77%) and the two oncocytomas. Shadowing was seen in seven of 34 angiomyolipomas (21%). Echogenicity, homogeneity, and a central scar were not pathognomonic. At power Doppler US, pattern 3 (peripheral) or 4 (mixed penetrating and peripheral) was seen in all RCCs, seven of 34 angiomyolipomas, and the two oncocytomas. Pattern 1 (intratumoral focal) or 2 (penetrating) was seen in 27 angiomyolipomas. Pattern 1 or 2 was characteristic of angiomyolipoma. The rate of correct diagnosis was significantly increased with combined US (78%) as compared to that with gray-scale (42%) or power Doppler (45%) US alone. CONCLUSION The vascular distribution at power Doppler US could add important information to gray-scale US findings for differential diagnosis of small solid renal lesions.