胃がんリスク評価におけるABC分類とX線所見の関連性について

PURPOSE:To investigate the correlation between ABC risk assessment and radiological findings of gastric mucosa and to propose an improved method for gastric cancer screening. MATERIALS AND METHODS:We evaluated 318 participants with Helicobacter pylori (Hp) antibody titers, serum pepsinogen (PG) and upper GI radiography and then classified them into three groups: A, double-negative; B, Hp-positive, PG-negative; C, PG-positive. Group A was subclassified as: A-1, Hp antibody titer <3.0 U/ml; A-2, Hp antibody titer ≥3.0 U/ml. Results for group A and non-A (B or C) participants and radiological findings of gastric mucosa (fold and area gastricae) were analyzed retrospectively. RESULTS:Radiological findings differed significantly between the 207 A-1 and 98 non-A group. Odds ratios were 17.72 for fold distribution, 10.63 for fold thickness, 6.10 for fold characteristics, and 10.62 for area gastricae. Presence of ≥2 risk factors offered 90.3 % sensitivity, 94.7 % specificity, and 93.3 % accuracy. Nine (69.2 %) of the 13 A-2 group participants and 11 (5.3 %) A-1 group participants had a risk for gastric cancer according to radiological findings. CONCLUSION:A good correlation exists between ABC classifications and radiological findings for gastric cancer risk, but some discrepant cases exist. We recommend both methods as screening for gastric cancer.博士（医学）・乙第1370号・平成27年11月27日© Japan Radiological Society 2015© Springer-Verlag Berlin Heidelberg 2015The final publication is available at Springer via http://dx.doi.org/10.1007/s11604-015-0469-

乳房ソナゾイド造影超音波における背景乳腺の造影効果についての検討

Purpose: The objective of this study was to retrospectively evaluate the association between background parenchymal enhancement (BPE) on contrast-enhanced ultrasound (CEUS) with Sonazoid® and patient characteristics. Additionally, background parenchymal tissues with the high-contrast effect were pathologically observed compared to those showing the low-contrast effect. Methods: A total of 65 patients who underwent breast CEUS with Sonazoid® between January 2010 and November 2013 were enrolled. Regions of interest (ROIs) were put on the tumor and on the background parenchymal tissue. The dB values during the nonenhanced time and at peak contrast enhancement were measured based on the time intensity curve (TIC) drawn by the ROI. The differences in the dB values of pre- and post-enhanced time were obtained separately for ROIs on the tumor and ROIs on the parenchymal tissue. The patient characteristics studied were age, menstrual status, mammographic density, BPE on magnetic resonance imaging (MRI), and pathological diagnoses of breast tumors. Results: There was a weak negative correlation between BPE on CEUS and age. As for the contrast effect of parenchymal tissue, there was a significant difference between the menstruating and menopausal groups. There was no significant difference among the levels of mammographic density, and among the degrees of contrast effect on MRI. BPE on CEUS was the same between those with a malignant tumor and those with a benign tumor in each menstrual status. The parenchymal tissue with the low-contrast effect showed pathological atrophy. Conclusion: The degree of BPE on CEUS appeared related to age, menstruating or menopausal, and atrophy of breast tissue. BPE on CEUS was the same between those with a malignant tumor and those with a benign tumor in each menstrual status.博士（医学）・乙第1508号・令和3年3月15日© Springer Nature Singapore Pte Ltd. 2020.© The Japan Society of Ultrasonics in Medicine 2020.This is a post-peer-review, pre-copyedit version of an article published in Journal of medical ultrasonics. The final authenticated version is available online at: https://doi.org/10.1007/s10396-020-01052-4

機能的腎体積測定による術後分腎機能評価の検討

PURPOSE:The change in functional renal volume (FRV) has an absolute influence on renal function after nephrectomy (Nx) or nephron-sparing surgery (NSS). In this study, we prospectively examined whether the postoperative renal function following Nx and NSS could be accurately predicted and assessed the reproducibility of our newly developed 3-D image reconstruction system (Kashihara) to measure the FRV. METHODS:We enrolled 98 patients who underwent Nx and 41 patients who underwent NSS from April 2006 to September 2009 to predict postoperative FRV and renal function. FRV was measured before and after (1 month and 1 year) renal surgery. The postoperative estimated glomerular filtration rate (eGFR) was predicted from the preoperative eGFR calculated from the serum creatinine (sCr) level and the ratio of the postoperative/preoperative FRV. To assess the reproducibility and accuracy of our newly developed 3-dimensional (3-D) image reconstruction system, FRV was measured by five examiners using images obtained by CT (five cases) and MRI (five cases). RESULTS:Significant correlation was found both for FRV and for renal function between the predictive values and the actually measured values at 1 month and 1 year after surgery, not only in the Nx group, but also in the NSS group. The accuracy and reproducibility could be confirmed both with CT and MRI studies. CONCLUSIONS:The postoperative FRV and renal function could be predicted preoperatively using a 3-D image reconstructive system, preoperative routine diagnostic imaging, and preoperative sCr level.博士（医学）・乙第1369号・平成27年11月27日© Springer-Verlag Berlin Heidelberg 2015The final publication is available at Springer via http://dx.doi.org/10.1007/s00345-014-1470-

超常磁性体酸化鉄造影MRIを用いた大動脈ステントグラフ治療後のエドリークの検出 : 造影CTとの比較検討

OBJECTIVE: Contrast-enhanced computed tomography (CE-CT) has been commonly used for follow-up imaging after endovascular aneurysm repair (EVAR), but it is difficult to use on patients with renal insufficiency. Superparamagnetic iron oxide (SPIO) particles, contrast medium for magnetic resonance imaging (MRI) that has been widely used for detection of the liver tumor, rarely affects renal function. The present study examined SPIO-enhanced dynamic MRI as a potential alternative to CE-CT for detection of endoleaks after EVAR. METHODS: Institutional review board approval was obtained for this prospective study. Twenty-three consecutive patients with normal renal function were evaluated using both CE-CT and SPIO-enhanced MRI within 2 weeks after EVAR. The median interval between the two modalities was 2 days. SPIO-enhanced MRI was performed at 1.5 T with T1-weighted, SPIO-enhanced dynamic, and postcontrast T1-weighted gradient echo sequences. The CE-CT protocol consisted of triple scans. Two experienced, blinded observers evaluated all images. Consensus reading of CE-CT and SPIO-MRI was defined as the reference standard. Interobserver, intraobserver, and intermodality agreement for endoleak detection was assessed by κ statistics. RESULTS: A total of 11 type II endoleaks originating from either the lumbar or inferior mesenteric artery were detected. Eight were able to be detected by CE-CT (8/11:73%) and 10 (10/11:91%) by SPIO-enhanced MRI. Interobserver (κ = 0.91; 95% CI, 0.74-1.00) and intraobserver agreement for MRI (κ = 1.00) were excellent. Intermodality agreement for endoleak detection was moderate (κ = 0.63; 95% CI, 0.32-0.94; and κ = 0.62; 95% CI, 0.29-0.95 for observers A and B, respectively). CONCLUSIONS: SPIO-enhanced MRI could represent a useful alternative to CE-CT, as it offers excellent interobserver, intraobserver agreement, and could detect more endoleaks than CE-CT.博士（医学）・乙第1379号・平成28年7月8日Copyright © 2013 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved

遺残胎盤組織：診断と臨床的取り扱いにおけるMRI所見の役割

OBJECTIVE:To assess the role of MRI in diagnosis and predicting clinical outcome in women with retained placental tissue. PATIENTS AND METHODS:Eleven patients with pathologically proven RPT were retrospectively studied. All underwent MRI. The following MRI parameters of RPT were studied: size, signal intensity on T1- and T2-weighted images, enhancement pattern on dynamic study, extent of attachment to the uterine myometrium, and myometrial thickness at the attachment site. Clinical reports were reviewed and MRI findings were compared with respect to outcome. RESULTS:RPT diameter varied from 30 to 102 mm. On T2-weighted images, 10 cases showed high intensity, while on T1-weighted images, seven cases showed high intensity. Nine cases were hypervascular. The myometrium was thinner at the attachment side than at the opposite side. All five cases in which RPT was delivered spontaneously showed an attachment area of less than a semicircle, hence broad attachment appears to impede detachment and necessitate additional therapy. After uterine arterial embolization, two patients showed complete infarction of RPT on enhanced MRI. CONCLUSION:MRI is useful for diagnosis and follow-up of RPT. The evaluation of extent of RPT attachment to the myometrium and vascularity on MRI can help the clinical assessment.博士（医学）・乙第1351号・平成26年12月3日© Springer Verlag. The definitive version is available at " http://dx.doi.org/10.1007/s00261-010-9604-x

下部直腸癌におけるMRIを用いた歯状線浸潤の診断精度

Purpose: To retrospectively assess the accuracy of magnetic resonance imaging (MRI) in predicting dentate line invasion in low rectal cancer. Materials and methods: Eighty-one patients with primary rectal cancer were assessed by dynamic contrast-enhanced MRI. The location of the dentate line was assessed on MRI in 27 patients with upper-mid rectal cancer. Two observers independently evaluated the distance between the distal tumor edge and the MRI-defined dentate line in 54 patients with low rectal cancer, and the imaging and histological findings were compared. Results: The MRI-defined dentate line was 24.0 ± 3.8 mm above the anal verge in patients with upper-mid rectal cancer. The dentate line invasion status agreed with the histological findings in 49/54 (91%) patients (κ = 0.72 [95% CI 0.50-0.95]) for observer 1, and in 51/54 (94%) patients (κ = 0.83 [0.65-1.00]) for observer 2 in patients with low rectal cancer. Interobserver agreement was good (κ = 0.83 [0.65-1.00]). The MRI-derived distance between the distal tumor edge and the dentate line had significant correlation with the histological distance (r = 0.86 for reader 1 and 0.75 for observer 2). Conclusion: MRI demonstrates high accuracy in predicting dentate line invasion in low rectal cancer.博士（医学）・甲第748号・令和2年6月30日© Japan Radiological Society 2020© 2020 Springer Nature Switzerland AG. Part of Springer Nature.This is a post-peer-review, pre-copyedit version of an article published in Japanese journal of radiology. The final authenticated version is available online at: http://dx.doi.org/10.1007/s11604-020-00933-5

肝癌に対する経動脈的治療におけるマイクロカテーテル挿入可能ポー トの開発

PURPOSE: To develop an implantable port in which a microcatheter can be inserted for a combination therapy of repeated transarterial chemoembolization (TACE) and hepatic arterial infusion chemotherapy (HAIC) for advanced liver cancer. MATERIALS AND METHODS: The design of a currently used implantable port was modified. A funnel part was constructed in the port. The septum was punctured by a 20-gauge indwelling needle, and 2.0-Fr non-tapered microcatheter was inserted into the port. In the in vitro studies, the advance of a microcatheter out of the funnel part was evaluated via seven different septum puncture sites. A 5-Fr indwelling catheter connected to the port was placed in a vascular model, and a microcatheter catheterization was evaluated. In an in vivo study, the port-catheter system was implanted in the hepatic artery in a pig. A microcatheter was percutaneously inserted through the port into the hepatic arterial branches, and embolization was performed. RESULTS: In the in vitro studies, the microcatheter was smoothly advanced out of the port and catheterizations into the hepatic arteries were successful via all septum puncture sites. In the in vivo study, repeated selective embolization through the port was successfully conducted on 7, 14 and 21 days after the implantation. CONCLUSION: The developed implantable port can be used for repeated catheter insertion into the hepatic artery. The combination of repeated TACE and HAIC could be possible using this device.博士（医学）・甲第710号・令和元年6月26日© Springer Science+Business Media, LLC, part of Springer Nature and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) 2018This is a post-peer-review, pre-copyedit version of an article published in Cardiovascular and interventional radiology. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00270-018-2111-0

膜乳化デバイスによるエマルションを用いたウサギVX2肝腫瘍モデノレへの肝動脈化学塞栓術における抗腫瘍効果、薬物動態の検討

Purpose: To evaluate the phamacokinetics of epirubicin in conventional transarterial chemoembolization using a developed pumping emulsification device with a microporous glass membrane in VX2 rabbits. Materials and methods: Epirubicin solution (10 mg/mL) was mixed with ethiodized oil (1:2 ratio) using the device or 3-way stopcock. Forty-eight rabbits with VX2 liver tumor implanted 2 weeks prior to transarterial chemoembolization were divided into 2 groups: a device group (n = 24) and a 3-way-stopcock group (n = 24). Next, 0.5 mL of emulsion was injected into the hepatic artery, followed by embolization using 100-300-μm microspheres. The serum epirubicin concentrations (immediately after, 5 minutes after, and 10 minutes after) and the tumor epirubicin concentrations (20 minutes after and 48 hours after) were measured after transarterial chemoembolization. Histopathologic evaluation was performed with a fluorescence microscope. Results: The area under the curve and maximum concentrations of epirubicin in plasma were 0.45 ± 0.18 μg min/mL and 0.13 ± 0.06 μg/mL, respectively, in the device group and 0.71 ± 0.45 μg min/mL and 0.22 ± 0.17 μg/mL, respectively, in the 3-way-stopcock group (P = .013 and P = .021, respectively). The mean epirubicin concentrations in VX2 tumors at 48 hours in the device group and the 3-way-stopcock group were 13.7 ± 6.71 and 7.72 ± 3.26 μg/g tissue, respectively (P = .013). The tumor necrosis ratios at 48 hours were 62 ± 11% in the device group and 51 ± 13% in the 3-way-stopcock group (P = .039). Conclusions: Conventional transarterial chemoembolization using the pumping emulsification device significantly improved the pharmacokinetics of epirubicin compared to the current standard technique using a 3-way stopcock.博士（医学）・乙第1443号・令和元年12月5日Copyright © 2019 SIR. Published by Elsevier Inc. All rights reserved

ラット肝腫瘍モデルにおける化学療法の早期効果判定に有用なダイナミック造影超音波のパラメータについて

Objectives: The objective of the study is to determine a parameter on the time-intensity curve (TIC) of dynamic contrast-enhanced ultrasonography (DCE-US) that best correlates with tumor growth and to evaluate whether the parameter could correlate with the early response to irinotecan in a rat liver tumor model. Material and Methods: Twenty rats with tumors were evaluated (control: Saline, n = 6; treatment: Irinotecan, n = 14) regarding four parameters from TIC: Peak intensity (PI), k value, slope (PI × k), and time to peak (TTP). Relative changes in maximum tumor diameter between day 0 and 10, and parameters in the first 3 days were evaluated. The Mann-Whitney U-test was used to compare differences in tumor size and other parameters. Pearson’s correlation coefficients (r) between tumor size and parameters in the control group were calculated. In the treatment group, relative changes of parameters in the first 3 days were compared between responder and non-responder (<20% and ≥20% increase in size on day 10, respectively). Results: PI, k value, PI × k, and TTP significantly correlated with tumor growth (r = 0.513, 0.911, 0.665, and 0.741, respectively). The mean RC in k value among responders (n = 6) was significantly lower than non-responders (n = 8) (mean k value, 4.96 vs. 72.5; P = 0.003). Conclusion: Parameters of DCE-US could be a useful parameter for identifying early response to irinotecan.博士（医学）・甲第879号・令和5年3月15

下部直腸癌における側方リンパ節転移に関して、造影MRI で描出される中直腸動脈の転移予測因子に関する検討

Purpose: Lateral lymph node (LLN) metastasis is one of the leading causes of local recurrence in patients with lower rectal cancer. Unfortunately, no diagnostic biomarkers are currently available that can predict LLN metastasis preoperatively. Accordingly, we investigated the relationship between the middle rectal artery (MRA) identified by contrast-enhanced magnetic resonance imaging (ceMRI) and LLN metastases. Methods: Data from 102 patients with lower rectal cancer who underwent surgery, and were evaluated by preoperative ceMRI, between 2008 and 2016 were reviewed retrospectively. Two expert radiologists evaluated the MRA findings. The diagnostic performance of MRA for LLN metastasis was evaluated by a multivariate analysis with conventional clinicopathological factors. Results: The MRA was detected in 67 patients (65.7%), including 32 (31.4%) with bilateral MRA and 35 (34.3%) with unilateral MRA. The tumor size, presence of the MRA, and clinical LLN status were significantly correlated with LLN metastasis. A multivariate analysis demonstrated that the presence of MRA (P = 0.045) and clinical LLN status (P = 0.001) were independent predictive factors for LLN metastasis. Furthermore, the sensitivity and negative predictive value of MRA for LLN metastasis were 95% and 97.1%, respectively. Conclusion: We successfully demonstrated that MRAs could be clearly detected by ceMRI, and the presence of MRA robustly predicted LLN metastasis in patients with lower rectal cancer, highlighting its clinical significance in the selection of more appropriate treatment strategies. Trial registration: Trial registration number: retrospectively registered 2126 Trial registration date of registration: August 23, 2019.博士（医学）・乙第1512号・令和3年12月21日© 2021. The Author(s). Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/