Published papers

Kawasaki disease (KD) is a common pediatric vasculitis syndrome involving medium-and small-sized arteries that is especially preva-lent in early childhood (ie, age 6 months to 5 years). The diagnosis of KD is made on the basis of clinical features, such as fever, char-acteristic mucocutaneous changes, and nonsuppurative cervical lymphadenopathy. However, early diagnosis is often challenging because many children with KD present with atypical symptoms. The most serious complication of KD is coronary artery aneurysm caused by coronary arteritis. Prompt intravenous immunoglobu-lin therapy reduces the risk of cardiac morbidity. In addition, the systemic extension of KD-related vasculitis during the acute phase causes a variety of multisystem manifestations, including encepha-lopathy, stroke, retropharyngeal edema, pericarditis, myocarditis, KD shock syndrome, pulmonary lesions, intestinal pseudo-obstruc-tion, gallbladder hydrops, arthritis, and myositis. These complications tend to be more common in affected children with atypical presentation. Radiologists can play an important role in the timely identification of diverse KD-associated morbidities and thus may contribute to the early diagnosis of atypical KD.

Purpose: To investigate the site-specific pattern of disease recurrence and/or metastasis and the associated patient outcomes after radical nephroureterectomy (RNU) in upper tract urothelial carcinoma (UTUC). Methods: A total of 733 patients with UTUC from a retrospective multi-institutional cohort were included, with a median follow-up of 34 months. Associated patient outcomes were analyzed by multivariate analysis. To evaluate the influence of primary tumor location, we divided it into four areas: renal pelvis, and upper, middle, and lower ureter. Results: A total of 218 patients experienced disease recurrence, with the majority of relapses occurring within the first 3 years. Cumulative incidence rates of first disease recurrence at 1 and 3 years were 18.9 and 29.8 %, respectively. Of these patients, 38.5 % developed distant recurrence; 17.4 % experienced both local and distant recurrences; and 44.0 % developed isolated local recurrence. The predominant sites of distant metastasis were lung, liver, and bone. Multivariate analysis revealed that the prevalence of local recurrence and lung metastasis was significantly associated, with primary tumor location being independent of other clinicopathological variables. Lower/middle ureter tumors had a higher rate of local recurrence in the pelvic cavity, and renal pelvic tumors had a higher prevalence of distant relapse in the lungs. Similar results were obtained when rerunning the data set by excluding patients who received adjuvant chemotherapy (n = 131). Conclusions: This multi-institutional study provided a detailed picture of metastatic behavior after RNU, and primary tumor locations were associated with unique patterns of metastatic spread in UTUC patients. © 2013 Society of Surgical Oncology.

Objectives: The aim of this study was to assess the effectiveness of a model-based iterative reconstruction (MBIR) in improving image quality and diagnostic performance of ultralow-dose computed tomography (ULDCT) of the lung. Materials and Methods: The institutional review board approved this study, and all patients provided written informed consent. Fifty-two patients underwent low-dose computed tomography (LDCT) (screening-dose, 50 mAs) and ULDCT (4 mAs) of the lung simultaneously. The LDCT images were reconstructed with filtered back projection (LDCT-FBP images) and ULDCT images were reconstructed with both MBIR (ULDCT-MBIR images) and FBP (ULDCT-FBP images). On all the 156 image series, objective image noise was measured in the thoracic aorta, and 2 blinded radiologists independently assessed subjective image quality. Another 2 blinded radiologists independently evaluated the ULDCT-MBIR and ULDCT-FBP images for the presence of noncalcified and calcified pulmonary nodules; LDCT-FBP images served as the reference. Paired t test, Wilcoxon signed rank sum test, and free-response receiver-operating characteristic analysis were used for statistical analysis of the data. Results: Compared with LDCT-FBP and ULDCT-FBP, ULDCT-MBIR had significantly reduced objective noise (both P <; 0.001). Subjective noise on the ULDCT-MBIR images was comparable with that on the LDCT-FBP images but lower than that on the ULDCT-FBP images (P <; 0.001). Artifacts on ULDCT-MBIR images were more numerous than those on the LDCT-FBP images (P = 0.007) but fewer than those on the ULDCT-FBP images (P <; 0.001). Compared with the LDCT-FBP images, ULDCT-MBIR and ULDCT-FBP images showed reduced image sharpness (both P <; 0.001). All the ULDCT-MBIR images showed a blotchy pixelated appearance; however, the performance of ULDCT-MBIR was significantly superior to that of ULDCT-FBP for the detection of noncalcified pulmonary nodules (P = 0.002). The average true-positive fractions for significantly sized noncalcified nodules (≈4 mm) and small noncalcified nodules (<4 mm) on the ULDCT-MBIR images were 0.944 and 0.884, respectively, when LDCT-FBP images were used as reference. All of the calcified nodules were detected by both the observers on both the ULDCT-MBIR and ULDCT-FBP images. Conclusion: As compared with FBP, MBIR enables significant reduction of the image noise and artifacts and also better detection of noncalcified pulmonary nodules on ULDCT of the lung. Compared with LDCT-FBP images, ULDCT-MBIR images showed significantly reduced objective noise and comparable subjective image noise. Almost all of the noncalcified nodules and all of the calcified nodules could be detected on the ULDCT-MBIR images, when LDCT-FBP images were used as the reference. © 2012 by Lippincott Williams & Wilkins.

Traumatic lymphorrhea is a rare but potentially life-threatening complication. Postoperative lymphorrhea is the leading cause of traumatic lymphorrhea and can arise anywhere within the lymphatic system. Leaks arising from the aortoiliac region to the thoracic duct (TD) and from hepatic lymphatics can be identified with intranodal lymphangiography and transhepatic lymphangiography, respectively. Therefore, an appropriate lymphangiography technique is essential for identifying the sources of leaks. Chylothorax resulting from damage to the TD can be serious because the TD transports large amounts of lymphatic fluid from the gastrointestinal, hepatic, and aortoiliac regions. Percutaneous TD embolization-comprising access to the TD followed by embolization-has recently become a minimally invasive alternative to surgical TD ligation for high-output chylothorax. The selection of access routes to the TD depends on its anatomy. If the TD cannot be approached by such means, other options include TD needle interruption or drainage of lymphatic fluid adjacent to the leakage point followed by sclerotherapy. Most cases of abdominal lymphorrhea arise from the aorta-iliac lymphatic system, and lymphangiography alone or computed tomography-guided sclerotherapy might be useful. Rarely, leakage may arise from hepatic lymphatics due to a damaged gastroduodenal ligament and can be visualized and embolized transhepatically. This article comprehensively reviews clinically relevant anatomic TD variations, lymphangiography techniques and criteria for their selection, and treatment strategies for lymphorrhea. ©RSNA, 2016.

Background-Epicardial fat may play a role in the pathogenesis of coronary artery disease (CAD). We explored the relationship of epicardial fat volume (EFV) with the presence and severity of CAD or myocardial perfusion abnormalities in a diverse, symptomatic patient population. Methods and Results-Patients (n=380) with known or suspected CAD who underwent 320-detector row computed tomographic angiography, nuclear stress perfusion imaging, and clinically driven invasive coronary angiography for the CORE320 international study were included. EFV was defined as adipose tissue within the pericardial borders as assessed by computed tomography using semiautomatic software. We used linear and logistic regression models to assess the relationship of EFV with coronary calcium score, stenosis severity by quantitative coronary angiography, and myocardial perfusion abnormalities by single photon emission computed tomography (SPECT). Median EFV among patients (median age, 62.6 years) was 102 cm3 (interquartile range: 53). A coronary calcium score of ≥1 was present in 83% of patients. Fifty-nine percent of patients had ≥1 coronary artery stenosis of ≥50% by quantitative coronary angiography, and 49% had abnormal myocardial perfusion results by SPECT. There were no significant associations between EFV and coronary artery calcium scanning, presence severity of ≥50% stenosis by quantitative coronary angiography, or abnormal myocardial perfusion by SPECT. Conclusions-In a diverse population of symptomatic patients referred for invasive coronary angiography, we did not find associations of EFV with the presence and severity of CAD or with myocardial perfusion abnormalities. The clinical significance of quantifying EFV remains uncertain but may relate to the pathophysiology of acute coronary events rather than the presence of atherosclerotic disease.

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. Preoperative prediction of molecular information of lower-grade gliomas (LrGGs) helps to determine the overall treatment strategy as well as the initial surgical strategy. This study aimed to detect magnetic resonance imaging (MRI) texture parameters to predict the molecular signature of LrGGs using a commercially available software and routine MR images. Forty-three patients treated at Keio University Hospital who had World Health Organization grade II or III gliomas were included. All patients having preoperative T1- and T2-weighted, fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted (DW) images were also included. Texture analyses of T2, FLAIR, and apparent diffusion coefficient (ADC) histograms were performed using a commercially available software. Texture parameters including kurtosis, skewness, and entropy were investigated to determine any correlation with the presence or absence of isocitrate dehydrogenase (IDH) mutations, 1p/19q codeletion, and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation. ADC skewness and T2 skewness were significantly associated with 1p/19q codeletion status. ADC skewness of ≥ 0.25 predicted 1p/19q codeletion with a sensitivity and specificity of 80% and 65.2%, respectively (AUC = 0.728). T2 skewness of ≥ − 0.11 predicted 1p/19q codeletion with a sensitivity and specificity of 80% and 91.3%, respectively, (AUC = 0.866). None of the texture parameters were associated with IDH mutation and MGMT promoter methylation. MRI texture analysis using a commercially available software demonstrated that T2 skewness could predict 1p/19q codeletion with high sensitivity and specificity, suggesting a clinical utility.

Few studies had been published regarding imaging findings of skin adnexal tumors. We experienced two giant cases of them with a characteristic mushroom-like growth pattern. MRI showed a circumscribed mushroom-like shaped mass extruding from the subcutaneous tissue with microcystic lesions. Although differentiation between benignancy and malignancy may be difficult by radiological examinations, MRI may be helpful to identify its origin and differentiate soft tissue tumors with skin adnexal tumors in having these imaging findings.

Objective: Dermal backflow (DBF) and reduced lymphatic visualization are common findings of lymphedema on various imaging modalities. However, there is a lack of knowledge about how these findings vary with the anatomic location and severity of lymphedema, and previous reports using indocyanine green lymphography or lymphoscintigraphy show variable results. Magnetic resonance lymphangiography (MRL) is expected to clarify this clinical question due to its superior ability for lymphatic visualization. This retrospective study aimed to investigate the following: (1) Are there any characteristic patterns for DBF and lymphatics' visualization, depending on the anatomic location within lower limbs and severity of lymphedema? (2) Is it possible to classify the severity of lymphedema based on MRL findings? Methods: Two radiologists performed consensus readings of MRL of 56 patients (112 limbs) with lower-limb lymphedema. The frequency of visualized DBF and lymphatics was analyzed in six regions in each lower limb. The results were compared with the International Society of Lymphology clinical stages and etiology of lymphedema. Characteristic findings were categorized and compared with the clinical stage and duration of lymphedema. Results: DBF and lymphatics were observed more frequently in the distal regions than the proximal regions of lower limbs. DBF appeared more frequently as the clinical stage increased, reaching statistical significance (P < 10−3) between stages 0 or I and II. DBF above the knee joint was rarely observed (0.48%) in early stages (0 and I) but appeared more frequently (13.5%, P < 10−5) in stage II. Lymphatics appeared less frequently as the stage progressed, with significant differences (P <.05) between stages I and II and between II and III. The frequency of lymphatics above the knee joint decreased significantly (P <.05) between stages I and II and between II and III as the stage progressed, reaching 0% in stage III. An MRL staging was proposed and showed significant positive correlations with the clinical stage (r = 0.79, P <.01) and the duration of lymphedema (r = 0.57, P <.01). Conclusions: MRL-specific patterns of DBF and lymphatics that depended on the site within the lower limb and clinical stage were shown. The DBF pattern differed from those observed in previous studies with other imaging techniques. The proposed MRL staging based on these characteristic findings allows new stratification of patients with lymphedema. Combined with its excellent ability to visualize lymphatic anatomy, MRL could enable a more detailed understanding of individual patient's pathology, useful for determining the most appropriate treatment.

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Purpose: Although involvement of the osseous component with an anterior condylar dural arteriovenous fistula (AC-DAVF) has been frequently described, osseous venous structures in which AC-DAVFs develop have not been fully elucidated. We investigated osseous venous structures adjacent to the hypoglossal canal in normal controls and patients with AC-DAVFs. Methods: The study included 50 individuals with unruptured aneurysms as normal controls and seven patients with AC-DAVFs. Osseous venous structures adjacent to the hypoglossal canal in normal controls were analyzed using computed tomography (CT) digital subtraction venography. In patients with AC-DAVFs, the fistulous pouches, draining veins, and surrounding venous structures were examined using cone beam CT. Results: In 46.0% of laterals in normal controls, osseous venous structures were visualized within the jugular tubercle superomedially to the hypoglossal canal. We named these structures the jugular tubercle venous complex (JTVC). The JTVC was always continuous with the anterior condylar vein and was sometimes connected to surrounding venous channels. We detected nine fistulous pouches in the seven patients with AC-DAVFs. The fistulous pouches were in the JTVC (33.3%), anterior condylar vein (33.3%), and other venous channels within the exoccipital region (33.3%). Conclusion: Although the JTVC is a venous structure frequently found in normal people, it had not been investigated until now. The venous channel between the anterior condylar vein and JTVC is a common origin site for AC-DAVFs, and it was associated with 66.6% of the AC-DAVF cases in the current study.

Background. Few studies have described the clinical courses and outcomes in the bladder after treatment of intravesical recurrence after radical nephroureterectomy (RNU) in patients with primary upper tract urothelial carcinoma (UTUC). We investigated the indicators for predicting subsequent bladder outcomes after treatment of intravesical recurrence after RNU. Methods. A total of 241 patients with primary UTUC (pTa-4N0M0) who experienced intravesical recurrence after RNU were included. Of these patients, 101 (41.9 %) underwent Bacillus Calmette-Guérin treatments, whereas 49 (20.3 %) underwent intravesical chemotherapy. The median follow-up period after initial transurethral resection of the bladder tumor was 33 months. Relationships with bladder outcomes were analyzed by using multivariable analysis. Results. Ninety-six patients experienced intravesical recurrence, and bladder progression was observed in 13. Cumulative incidence rates of intravesical recurrence at 1 and 5 years after treatment of the first intravesical recurrence were 31.0 and 48.4 %, whereas those of bladder progression at 1 and 5 years thereafter were 2.4 and 8.0 %. Multivariate analysis showed that the number of recurrent tumors and pT1 tumors at the time of the first intravesical relapse were independent risk factors for subsequent intravesical recurrence. With respect to bladder progression, multivariate analysis showed that pT1 tumors, the appearance of concomitant carcinoma-in situ at the time of the first intravesical relapse, and the absence of the Bacillus Calmette-Guérin treatment were independent risk factors. Conclusions. This retrospective study presents a detailed picture of further bladder outcomes after intravesical recurrence after RNU in primary UTUC patients. The results may assist physicians to develop a more rational protocol in bladder surveillance. © 2014 Society of Surgical Oncology.

The purpose of this study was to evaluate improvement of measurement accuracy of in-stent lumen using coronary stent phantoms on new High-Definition CT (HDCT) compared with conventional 64 detector-row CT (MDCT). To estimate the spatial resolution, a high-resolution insert of CATPHAN (The Phantom Laboratory, NY, USA) was scanned by both HDCT (DiscoveryCT750HD) andMDCT(LightSpeed VCT). Also, we developed six types of stent phantom, which have 2.5- and 3.0-mm-diameter with three different types of stents (Velocity: Johnson & Johnson, Driver: Medtronic, Multilink-Rx: Guidant). A 50% stenotic segment made of acrylic resin was built at the center inside the stent. Those coronary vessel phantoms were made of acrylic resin and filled with diluted Iodine (350 HUin 120 kVp), and each stent was fixed inside of those vessels. Those phantoms in water-filled tank were scanned on both HDCT and MDCT. The luminal diameter obtained using digital calipers at five different points and the mean luminal diameter (MLD) were calculated. The underestimate ratio (UR) and ΔUR was defined as follows: UR = [True diameter of stent - MLD]/True diameter of stent; ΔUR = [MLD at HDCT - MLD at MDCT]/True diameter of stent. The spatial resolution was estimated to be 0.71 mm on MDCT and 0.50 mm on HDCT. At the non-stenotic segments, the ΔURs were 11.6% (Velocity), 16.4% (Driver) and 7.2%(Multilink) for the 2.5-mmstents, and 14.0% (Velocity), 16.3% (Driver) and 13.3% (Multi-link) for the 3.0-mm stents. At the stenotic segment, the ΔURs were 23.2% (Velocity), 8.0% (Driver) and 13.6% (Multilink) for the 2.5-mm stents, and 20.0% (Velocity), 14.7% (Driver) and 15.3% (Multilink) for the 3.0-mm stents. Superior spatial resolution of HDCT could be promising for more accurate measurement of in-stent diameter. © Springer Science+Business Media, B.V. 2011.

Background: The relationship between the epicardial fat volume measured by 64-slice multidetector computed tomography (MDCT) and the extension and severity of coronary atherosclerosis was investigated. Methods and Results: Both MDCT and conventional coronary angiography (CAG) were performed in 71 consecutive patients who presented with effort angina. The volume of epicardial adipose tissue (EAT) was measured by MDCT. The severity of coronary atherosclerosis was assessed by evaluating the extension of coronary plaques in 790 segments using MDCT data, and the percentage diameter stenosis in 995 segments using CAG data. The estimated volume of EAT indexed by body surface area was defined as VEAT. Increased VEAT was associated with advanced age, male sex, degree of metabolic alterations, a history of acute coronary syndrome (ACS) and the presence of total occlusions, and showed positive correlation with the stenosis score (r=0.28, P=0.02) and the atheromatosis score (r=0.67, P<0.0001) of the coronary arteries. Multiple logistic regression analysis revealed an increased VEAT (≥50 cm3/m2) to be the strongest independent determinant of the presence of total occlusions (odds ratio 4.64, P=0.02). Conclusions: VEAT correlates with the degree of metabolic alterations and coronary atheromatosis. Excessive accumulation of EAT might contribute to the development of ACS and coronary total occlusions.

PURPOSE: Apical wall thickening with an "ace-of-spades" configuration is a unique sign of apical hypertrophic cardiomyopathy (AHCM). We investigated spade-shaped FDG uptake around the left ventricular apex (SSUA) incidentally found in routine oncological FDG PET. METHODS: Cases showing SSUA were selected based on retrospective review. The pattern or intensity of SSUA was compared with the results of electrocardiogram (ECG), echocardiography, and stress myocardial perfusion SPECT. The diagnosis of ACHM was based on the presence of giant negative T wave in ECG, thickness of spade-shaped hypertrophy in the apex in echocardiography, and increased tracer uptake in the apex in rest SPECT. RESULTS: Among the 34 patients in 36 PET scans showing SSUA, SSUA was weak in 17 and intense in 17. There were isolated SSUA (n = 29) and SSUA with diffuse or other focal left ventricular uptake (n = 5). Three patients with the latter uptake pattern turned out to have coexistence of AHCM and asymmetric septal hypertrophy. Of the 16 SSUA-positive patients who underwent echocardiography, 13 (81%) were diagnosed as AHCM and the remaining 3 were regarded as borderline AHCM (apical wall thickness, 14-15 mm). There were 16 patients with SSUA who also underwent PET scans after the study period among which 11 (69%) had persistent SSUA in the follow-up PET. In the remaining 5, follow-up PET scans showed diffuse left ventricular uptake and SSUA was barely visible. The intensity of SSUA was significantly or marginally associated with giant negative T wave (p < 0.01), apical asynergy (p = 0.08), and impaired coronary flow reserve (p < 0.05). There were no other factors correlated with the pattern or intensity of SSUA. CONCLUSION: SSUA incidentally found in oncological FDG PET appeared to be associated with AHCM, especially in ischemic conditions. The moderate repeatability of SSUA was probably due to obscurity by physiological uptake.

BACKGROUND AND OBJECTIVES: Pulmonary Mycobacterium avium complex (pMAC) disease manifests as various types of lesions, such as infiltrates, nodules, cavities, and bronchiectasis. However, the important determinants for clinical parameters in lung involvement are poorly understood. The objective of this study was to obtain quantitative parameters by 3-dimensional CT, and investigate the relationship between these parameters and the pulmonary function tests (PFTs) and health-related quality of life. MATERIAL AND METHODS: Quantitative analysis using CT was performed in 67 pMAC patients. The relationship between new quantitative parameters for evaluating lung involvement using 3-dimensional CT and PFTs or St George's Respiratory Questionnaire (SGRQ) was evaluated. RESULTS: The ratio of infiltration to total lung volume showed significant correlation with the PFT results, especially the percent-predicted forced vital capacity (%FVC; ρ = -0.52), residual volume (ρ = -0.51), and total lung capacity (ρ = -0.59). The cavity volume was strongly correlated with the %FVC (ρ = -0.78) in the cavity group, while the ratio of infiltration to total lung volume was strongly correlated with the %FVC (ρ = -0.53) in the non-cavity group. The ratio of infiltration to total lung volume was significantly correlated with all SGRQ parameters (ρ = 0.41-0.52) in the non-cavity group. CONCLUSIONS: Infiltration was an important parameter for the PFTs and SGRQ in pMAC patients according to the 3-dimensional CT analysis. Moreover, cavity volume was an important parameter of the PFTs in the cavity group. Therefore, infiltration and cavity volume are key features for the management of pMAC disease.

The aim of this study was to evaluate the clinical significance of visceral fat accumulation as a prognostic factor in patients with metastatic renal cell carcinoma (mRCC) treated with systemic therapies. A total of 114 patients were retrospectively reviewed. All patients received systemic therapy for mRCC at Keio University hospital in Japan. The intra-abdominal visceral fat area was determined by computed tomography at the umbilical level. The visceral fat accumulation was defined as ≥100 cm2. The mean visceral fat area was 107.4 ± 62.8 cm2. In the whole cohort, the median follow-up was 29 months. According to the Memorial Sloan Kettering Cancer Center (MSKCC) classification, 27.2% patients were favorable risk, 53.5% were intermediate risk, and 19.3% were poor risk. Visceral fat accumulation correlated with improved progression-free (P = 0.0070) and overall survival (P = 0.0001). On multivariate analysis, visceral fat accumulation (P = 0.0290) and MSKCC classification (P = 0.0085) were independent indices to predict progression-free survival in first-line treatment. In addition, visceral fat accumulation (P = 0.0007) and MSKCC classification (P = 0.0005) independently predicted overall survival. Prognostic grouping using visceral fat accumulation was identified as an independent prognostic marker in patients with mRCC. The addition of visceral fat accumulation improved the prognostic value of MSKCC classification alone in predicting overall survival in patients treated with systemic therapy for mRCC.

Complications after transcatheter aortic valve implantation (TAVI) remain an important issue. This study aimed to evaluate the impact of systematic postprocedural multidetector computed tomography (MDCT) to detect subclinical complications after TAVI. From October 2013 to August 2015, a total of 135 patients who underwent transfemoral TAVI (n = 116) or transapical TAVI (n = 19) with Sapien XT and MDCT preprocedure and postprocedure were enrolled. Postprocedural MDCT findings were compared with the preprocedural MDCT findings. Cardiovascular complications were observed in 25.9% of patients, including 6 cases (4.5%) with major complications. Of those, clinically apparent major complications were reported in 2 cases including rupture of the sinus of Valsalva and iliac rupture. The complications in the remaining 4 cases (3.0%) included aortic dissection, aortic intramural hematoma, and left ventricular apical pseudoaneurysm, which were totally asymptomatic and only detected by MDCT. The apical pseudoaneurysm required surgical repair. Minor complications were observed in 21.5% of patients, 50% of which were subclinical. Only 1 case with femoral pseudoaneurysm required an additional procedure. Noncardiovascular findings were detected in 27.4% of patients; the most frequent were pleural effusions and atelectasis, which were predominantly observed in those treated through a transapical approach. Contrast-induced acute kidney injury after postprocedural MDCT was reported in 1 patient whose clinical course was complicated by sepsis. In conclusion, postprocedural MDCT was useful in detecting important subclinical complications that may affect the clinical course without deterioration of renal function.