Manabu Watanabe

To perform energy-dispersive x-ray computed tomography (EDCT), we constructed a computer program to amplify the digital values of raw radiograms. The CT scanner consists of an x-ray generator with a 0.1-mm-focus tube, a turntable, a flat panel detector (FPD), and a personal computer (PC). An object on the turntable is irradiated by the x-ray generator, 1.3-magnified 720 radiograms are taken by the FPD, and tomograms are reconstructed using the PC. Utilizing the digital amplifier, the object projections obtained using low-energy photons disappeared with increasing amplification factor at a constant maximum value, and the effective energy increased according to increases in the amplification factor by beam hardening. Using the beam-hardening CT (BHCT) scanner, high-contrast tomography for various objects was performed by controlling effective energy. In particular, fine blood vessels were observed by K-edge CT using iodine media.

Contrast-enhanced ultrasonography (CEUS) is useful for evaluation of the hemodynamics of hepatic tumors and surrounding he-patic parenchyma in real time. CEUS with intravenous contrast administration is well established for evaluation of hepatocellular carcinoma (HCC). On the other hand, intra-arterial (transcatheter) CEUS (IAUS) is an emerging technique that allows more selective evaluation of the arterial supply to the tumor. IAUS was performed by administration of Sonazoid® through the microcatheter and imaging of the area of the target lesion with a dedicated, contrast-specific technique. Sonazoid® (0.5 ml diluted with 49.5 ml of distilled water) was used as the contrast medium in IAUS. The diluted Sonazoid® was introduced into the feeding artery by in-termittent injection of 0.3-1.0 ml through a microcatheter placed in the artery and flushing with saline at the same flow rate. We report the three cases in which IAUS was useful in transarterial chemoembolization (TACE) for HCC. Two cases were performed TACE for hepatic metastasis. In any cases, plain computed tomography (CT) after TACE showed accumulation of Lipiodol® only in the metastases. One case was suspected having HCC rupture and urgent abdominal angiography was performed. IAUS was performed frequently to reduce the amount of iodinated contrast agent as much as possible because of renal failure. Concomitant use of IAUS enabled reduction of the amount of contrast agent.

The aim of this study was to assess the usefulness of contrast-enhanced ultrasound (CEUS) for predicting the therapeutic efficacy of transarterial chemoembolization with drug-eluting beads (DEB-TACE) for hepatocellular carcinoma (HCC). Thirty-two patients with HCC who underwent DEB-TACE were enrolled in this study. Enhancement patterns of vascular phase images on CEUS were compared before and within 3 days after DEB-TACE, and the patterns after DEB-TACE were classified as follows: Pattern A, no enhancement; Pattern B, peripheral ring enhancement; Pattern C, partial enhancement within or peripheral to tumors, and Pattern D, reduced or unchanged enhancement in the whole tumor. Enhancement patterns in all lesions and contrast-enhanced computed tomography (CECT) findings after DEB-TACE were compared statistically. The treatment response of DEB-TACE was evaluated using the Modified Response Evaluation Criteria in Solid Tumors (mRECIST) by CECT. The enhancement patterns on CEUS performed within 3 days after DEB-TACE were defined as Pattern A in 17 cases, B in 7, C in 13, and D in 2. The complete response rates at one month after treatment were 94.1% (16/17 lesions) for Pattern A, 85.7% (6/7) for B, 15.4% (2/13) for C, and 50% (1/2) for D. The response rates were significantly higher for lesions with Pattern A compared to those with Pattern C at one month (p = 0.009) and 12 months (p < 0.001) after treatment, and significantly higher for lesions with Pattern B compared to those with Pattern C at 12 months after treatment (p = 0.031). Comparisons between other patterns showed no significant differences. CEUS immediately after DEB-TACE may allow early assessment of therapeutic efficacy, with findings of no enhancement or peripheral ring enhancement suggesting a positive outcome.

To assess the usefulness of intra-arterial contrast-enhanced ultrasonography (IAUS) during transarterial chemoembolization (TACE) with drug-eluting beads (DEB) for hepatocellular carcinoma (HCC). Thirty two patients with 39 HCC underwent DEB-TACE guided with IAUS, and examined by contrast-enhanced ultrasonography (CEUS) or dynamic CT after DEB-TACE were enrolled in this study. CEUS findings before DEB-TACE and IAUS findings were compared. Treatments judged to be complete and incomplete for lesions were appropriate and insufficient, respectively. Findings on CEUS and/or dynamic CT performed 1, 3 and 6 mo after DEB-TACE were evaluated using mRECIST (CR/PR/SD/PD). The treatments were complete and incomplete in 26 and 13 lesions, respectively. On imaging evaluation using CEUS and/or dynamic CT one month after treatment, 25 and 1 lesions were judged to be CR and PR, respectively, and at 6 mo after treatment, the results were CR, PR, SD and PD for 24, 1, 0 and 1 of these lesions, respectively, in the 26 completely treated lesions. Of the 13 lesions in which treatment was incomplete, the results on imaging at one month after treatment were CR, PR, SD and PD for 0, 6, 4 and 3 lesions, respectively. The overall CR rate at 6 mo after treatment was 61.5% (24/39). A combination of DEB-TACE with IAUS can improve the therapeutic effects in patients with HCC.

膵頭十二指腸術（pancreaticoduodenectomy;PD）は高度侵襲を伴う術式であり，未だ術後合併症発生率，在院死亡率が高率な術式である．今回，われわれはPD術前に消化管ステントを留置した2例を経験したので報告する．症例1は76歳の男性．十二指腸浸潤を伴う切除可能境界膵鉤部癌と診断した．十二指腸狭窄により経口摂取が困難であったため，術前に内視鏡的十二指腸ステントを留置した．留置後1カ月目にPDを施行し，術後第23病日に退院となった．症例2は68歳の男性．十二指腸，肝浸潤を伴う閉塞性上行結腸癌と診断した．経口摂取が困難であったため，術前に内視鏡的大腸ステント留置を行った．留置後16日目に結腸右半切除術・PD・肝部分切除術を施行し，術後第25病日に退院した．高度侵襲手術であるPDを必要とする症例に対して，術前の消化管ステント留置は考慮すべき治療戦略の一つと考えられた．

Purpose: To compare contrast‐enhanced ultrasonography (CEUS) using Sonazoid with Gd‐EOB‐DTPA‐enhanced MRI (EOB‐MRI) in the diagnosis of liver metastases in patients with colorectal cancer.Methods: A total of 69 patients diagnosed with or suspected of having liver metastasis were enrolled. These hepatic lesions were diagnosed by histopathological examination after surgical resection or based on follow‐up using various imaging modalities. The diagnostic accuracies of CEUS and EOB‐MRI were compared.Results: One hundred thirty‐three lesions were detected. Of these lesions, 109 were diagnosed as liver metastases. Of the 133 lesions, 90.2% were detected on CEUS, and 98.5% on EOB‐MRI. One hundred nine lesions were diagnosed as liver metastasis. The areas under the receiver operating characteristic curve for diagnosis were 0.906 and 0.851 on CEUS and EOB‐MRI, respectively (p = 0.41). Sensitivity, specificity, positive predictive value (PPV), negative predictive value, and overall accuracy were 90.8%, 84.5%, 97.1%, 67.1%, and 90.2%, respectively, for CEUS, and 95.4%, 70.8%, 93.7%, 77.3%, and 91%, respectively, for EOB‐MRI.Conclusions: CEUS has a higher specificity and PPV for the diagnosis of liver metastasis than EOB‐MRI. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:138–144, 2017

The present study aimed to determine the usefulness of contrast-enhanced ultrasonography (CEUS) with Sonazoid in evaluating the therapeutic response to sorafenib for hepatocellular carcinoma (HCC). In total, 26 patients with advanced HCC who received sorafenib and were followed up by CEUS were enrolled in the present study. CEUS was performed prior to and within 2‑4 weeks of treatment, and the images of the target lesion in the post‑vascular phase with a re‑injection method were analyzed. The presence (+) or absence (‑) of intratumoral necrosis and the intratumoral vascular architecture on micro‑flow imaging (MFI) were compared prior to and subsequent to treatment. Target lesions that exhibited non‑enhancement after re‑injection were considered to indicate intratumoral necrosis. The intratumoral vascular architecture was classified into three groups, as follows: Vd, the intratumoral vessels visually narrowed or decreased; Vnc, the vessels remained unchanged; and Vi, the vessels were thickened or increased. Survival curves were estimated using the Kaplan‑Meier method and compared using the log rank test between the intratumoral necrosis (+) and (‑) groups, and among the Vd, Vnc and Vi groups. P<0.05 was considered to indicate a statistically significant difference. The number of patients in the intratumoral necrosis (+) and (‑) groups was 8 and 18 patients, respectively, and the median survival time (MST) was 7.2 months [95% confidence interval (CI), 2.2‑12.2] and 9.5 months (95% CI, 5.1‑13.8), respectively (P=0.44). The MFI findings were observed in 11 patients in the Vd group, 10 patients in the Vnc group and 5 patients in the Vi group. The MSTs in the Vd, Vnc and Vi groups were 15.6 months (95% CI, 5.0‑23.3), 11.0 months (95% CI, 3.5‑17.6) and 3.6 months (95% CI: 1.2‑6.0), respectively. The P‑value for the differences between the Vd and Vnc groups, Vd and Vi groups, and Vnc and Vi groups were 0.78, 0.016 and 0.047, respectively, which indicated that the survival time decreased significantly in the Vi group. Evaluation of intratumoral vascular architecture using MFI demonstrates promise for assessing the therapeutic response to sorafenib in patients with HCC.

We aimed to determine the usefulness of arrival time parametric imaging (AtPI) using contrast-enhanced ultrasonography (CEUS)with Sonazoid in the evaluation of early response to sorafenib for hepatocellular carcinoma (HCC). Thirteen ad- vanced HCC patients with low a / -fetoprotein (AFP) level (≤35 ng/mL) who received sorafenib for at least 4 weeks were enrolled in this study. CEUS was performed before and after treatment (2 weeks), and the images of the target lesion in the arterial phase were analyzed by AtPI. In the color mapping images obtained by AtPI, the mean arrival time of the contrast agent in the target lesion from the starting point (mean time: MT) was calculated. In each patient, differences between MT before and MT 2 weeks after treatment were compared. MT (+) and MT(-) groups were designated as such if the difference was 0 or greater(blood flow velocity of the lesion was reduced)and less than 0 sec(blood flow velocity of the lesion was increased), respectively. The overall survival was evaluated between the 2 groups. In the MT (+) group (7 patients) and MT (-) group (6 patients), the median survival times were 307 and 208 days, respectively, which was statistically significant. We suggest AtPI is useful for evaluating early response to sorafenib in advanced HCC patients with low AFP level.

The CyberKnife® is expected to be a novel local treatment for hepatocellular carcinoma (HCC), however, a long-term follow-up using dynamic computed tomography and magnetic resonance imaging is required to determine the effect of treatment in a number of the affected patients. Therefore, there is a requirement to evaluate procedures for early determination of the effect of CyberKnife treatment. The present study aimed to evaluate the changes in the hemodynamics of the tumors and the hepatic parenchyma surrounding the tumor prior to and following CyberKnife treatment for HCC. A total of 4 HCC patients were enrolled in this study. These patients underwent CyberKnife treatment and were evaluated by image analysis prior to and following treatment using contrast-enhanced ultrasonography (CEUS) with Sonazoid. CEUS was performed prior to treatment, at 2 and 4 weeks post-treatment, and every 4 weeks thereafter for as long as possible. The dynamics of the enhancement of the tumor and the hepatic parenchyma surrounding the tumor in the vascular phase, and the presence or absence of a hypoechoic area in the hepatic parenchyma surrounding the tumor in the post-vascular phase were assessed. Results showed that: i) In the patient with earlier changes, hemodynamic changes were evident in the tumor at 4 weeks and in the hepatic parenchyma surrounding the tumor at 2 weeks post-treatment, respectively; ii) the tumor showed hypoenhancement in all patients; and iii) with regard to findings in the hepatic parenchyma surrounding the tumor, strong hyperenhancement appeared in the vascular phase initially, followed by a hypoechoic area in the post-vascular phase. Evaluation of the hemodynamics of tumors and hepatic parenchyma surrounding the tumor using CEUS with Sonazoid may be therapeutically applicable, as it is less invasive than dynamic computed tomography (CT) and provides an early evaluation of the effectiveness of CyberKnife treatment.