Published papers

OBJECTIVES: This study sought to clarify the incidence and predictors of hypoattenuated leaflet thickening (HALT) and mid-term outcomes after transcatheter aortic valve replacement. BACKGROUND: HALT detected on multidetector computed tomography (MDCT) scanning raised concerns about possible subclinical leaflet thrombosis. METHODS: We studied 70 of 100 consecutive patients from a single-center registry who underwent implantation with the Edwards SAPIEN-XT device. MDCT results, echocardiographic data, and laboratory findings obtained at the 6-month and 1-year follow-ups were analyzed. RESULTS: Of 70 patients, MDCT scans revealed HALT in 1 patient (1.4%) at discharge, 7 (10.0%) at 6 months, and 10 (14.3%) at 1 year post-transcatheter aortic valve replacement cumulatively. The degree of leaflet immobility correlated with the HALT area on 4-dimensional MDCT (r = 0.68) on the basis of data from 10 patients. HALT was associated with male sex (70% vs. 25%; p = 0.008) and larger sinus of Valsalva (31.0 ± 2.0 mm vs. 28.6 ± 2.6 mm; p = 0.005). HALT was found in 3 of 49 patients with a 23-mm bioprosthesis and in 7 of 21 patients with a 26-mm bioprosthesis (6.1% vs. 33.3%; p = 0.006). D-dimer levels were significantly increased in the HALT group at the 6-month (2.3 μg/ml [interquartile range (IQR): 2.1 to 6.1 μg/ml] vs. 1.1 μg/ml [IQR: 0.8 to 2.2 μg/ml]; p = 0.002) and 1-year (2.7 μg/ml [IQR: 1.7 to 4.8 μg/ml] vs. 1.2 μg/ml [IQR: 0.9 to 2.1 μg/ml]; p = 0.006) follow-ups, despite no differences at discharge. The pressure gradient was decreased in the HALT group at the 1-year follow-up (8.3 ± 0.8 mm Hg vs. 11.1 ± 4.9 mm Hg; p = 0.005). After detecting HALT, additional anticoagulation therapy was not administered. Clinical outcomes, including all-cause mortality (0% vs. 1.7%; p = 1.00) and stroke (0% vs. 0%; p = 1.00), were similar between the groups. CONCLUSIONS: HALT with reduced leaflet motion was not rare but usually subclinical. Valve hemodynamics and mid-term outcomes were uneventful even without additional anticoagulant therapy in our limited number of cases. Male sex, larger sinus and bioprosthesis size, and elevated D-dimer levels during follow-up were associated with this phenomenon. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

BACKGROUND: Underfilling or overfilling of balloon-expandable transcatheter heart valves (THVs) during transcatheter aortic valve implantation (TAVI) is commonly used to improve conformity to small or calcified annuli in order to avoid serious complications. However, little is known about this technique. This study assessed the effects of underfilling and overfilling of THVs. METHODS AND RESULTS: Data from 213 consecutive TAVI patients treated with balloon-expandable THVs in 4 Japanese centers between October 2013 and December 2014 were prospectively analyzed; 23-mm and 26-mm THVs were implanted in 96 cases (56 underfilling, 22 nominal filling, and 18 overfilling) and 38 cases (23 underfilling and 15 nominal filling), respectively. Pre/postprocedural multidetector computed tomography (MDCT) and echocardiographic data were compared. MDCT revealed that the minimum area of the underfilled 23-mm THVs was significantly decreased compared to that of nominal filled and overfilled THVs (308.3 SD 26.1 vs. 333.9 SD 14.7 vs. 347.8 SD 21.3mm(2), respectively, p<0.0001); analogous results were demonstrated for underfilled 26-mm THVs compared to nominal filled THVs (386.2 SD 34.6 vs. 423.6 SD 17.3mm(2), respectively, p=0.0004). The postprocedural transvalvular gradient of underfilled 23-mm THVs was significantly higher than that of nominal filled and overfilled THVs, while there were no differences for 26-mm THVs. CONCLUSIONS: Underfilling or overfilling of THVs is safe and feasible, conforming to the original annulus and covering a continuous range of annular sizes with limited THV size options. However, care should be taken when underfilling 23-mm THVs due to the potential for increased transvalvular gradient.

Background: Previous studies showed the prognostic impact of preoperative levels of neutrophil-to-lymphocyte ratio (NLR), plasma fibrinogen, and serum C-reactive protein (CRP) in surgically treated upper tract urothelial carcinoma; however, few papers have discussed the proper use of these indices. Objective: To investigate whether combinations of these three markers, as a cumulative marker score (CMS), improve the accuracy of prognostic models following radical nephroureterectomy (RNU). Design, setting, and participants: A total of 394 patients from multiple institutions were included. Median follow-up was 30 mo. Intervention: All patients underwent RNU without neoadjuvant chemotherapy. Outcome measurements and statistical analysis: Associated outcomes were assessed using multivariate analysis. The CMS was defined as the number of elevated levels of preoperative NLR, plasma fibrinogen, and serum CRP. Results and limitations: Multivariate analyses revealed that an increasing CMS was independently associated with high rates of disease recurrence, cancer-specific mortality, and all-cause mortality following RNU. Addition of the CMS to a model that included standard clinicopathologic predictors significantly improved predictive accuracy by 2.7% for disease recurrence, 3.9% for cancer-specific mortality, and 4.0% for all-cause mortality, which were the highest among other prognostic models using each marker alone or combinations of two. The study is limited by its retrospective nature. Conclusions: Although the use of each inflammatory marker alone may be as predictive as clinicopathologic indices for prognosis, combinations like CMS can provide more accurate prognostic models following RNU. Patient summary: Elevation of blood-based inflammatory markers may be useful for predicting prognosis because of their low cost and accessibility. Among blood-based indices, we examined the efficacy of preoperative neutrophil-to-lymphocyte ratio, plasma fibrinogen, and serum C-reactive protein levels. Although use of each marker alone provides additional prognostic information, the combination of all three markers would be more predictive than any single marker or combinations of two.

© 2019, The Author(s). Background: A cerebrospinal fluid (CSF)-mask algorithm has been developed to reduce the adverse influence of CSF-low-counts on the diagnostic utility of the specific binding ratio (SBR) index calculated with Southampton method. We assessed the effect of the CSF-mask algorithm on the diagnostic performance of the SBR index for parkinsonian syndromes (PS), including Parkinson’s disease, and the influence of cerebral ventricle dilatation on the CSF-mask algorithm. Methods: We enrolled 163 and 158 patients with and without PS, respectively. Both the conventional SBR (non-CSF-mask) and SBR corrected with the CSF-mask algorithm (CSF-mask) were calculated from 123I-Ioflupane single-photon emission computed tomography (SPECT) images of these patients. We compared the diagnostic performance of the corresponding indices and evaluated whether the effect of the CSF-mask algorithm varied according to the extent of ventricle dilatation, as assessed with the Evans index (EI). A receiver-operating characteristics (ROC) analysis was used for statistical analyses. Results: ROC analyses demonstrated that the CSF-mask algorithm performed better than the non-CSF-mask (no correction, area under the curve [AUC] = 0.917 [95% confidence interval (CI) 0.887–0.947] vs. 0.895 [95% CI 0.861–0.929], p < 0.001; attenuation correction, AUC = 0.930 [95% CI 0.902–0.957] vs. 0.903 [95% CI 0.870–0.936], p < 0.001). When not corrected for attenuation, no significant difference in the AUC was observed in the low EI group between the non-CSF-mask and CSF-mask algorithms (0.927 [95% CI 0.877–0.978] vs. 0.942 [95% CI 0.898–0.986], p = 0.11); in the middle and high EI groups, the CSF-mask algorithm performed better than the non-CSF-mask algorithm (middle EI group, AUC = 0.894 [95% CI 0.825–0.963] vs. 0.872 [95% CI 0.798–0.947], p < 0.05; high EI group, AUC = 0.931 [95% CI 0.883–0.978] vs. 0.900 [95% CI 0.840–0.961], p < 0.01). When corrected for attenuation, significant differences in the AUC were observed in all three EI groups (low EI group, AUC = 0.961 [95% CI 0.924–0.998] vs. 0.942 [95% CI 0.895–0.988], p < 0.05; middle EI group, AUC = 0.905 [95% CI 0.843–0.968] vs. 0.872 [95% CI 0.800–0.944], p < 0.005; high EI group, AUC = 0.954 [95% CI 0.917–0.991] vs. 0.917 [95% CI 0.862–0.973], p < 0.005). Conclusion: The CSF-mask algorithm improved the performance of the SBR index in informing the diagnosis of PS, especially in cases with ventricle dilatation.

© 2020 The Authors. Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press Transplantation of human-induced pluripotent stem cell-derived neural stem/progenitor cells (hiPSC-NS/PCs) is a promising treatment for a variety of neuropathological conditions. Although previous reports have indicated the effectiveness of hiPSC-NS/PCs transplantation into the injured spinal cord of rodents and nonhuman primates, long-term observation of hiPSC-NS/PCs post-transplantation suggested some “unsafe” differentiation-resistant properties, resulting in disordered overgrowth. These findings suggest that, even if “safe” NS/PCs are transplanted into the human central nervous system (CNS), the dynamics of cellular differentiation of stem cells should be noninvasively tracked to ensure safety. Positron emission tomography (PET) provides molecular-functional information and helps to detect specific disease conditions. The current study was conducted to visualize Nestin (an NS/PC marker)-positive undifferentiated neural cells in the CNS of immune-deficient (nonobese diabetic-severe combined immune-deficient) mice after hiPSC-NS/PCs transplantation with PET, using 18 kDa translocator protein (TSPO) ligands as labels. TSPO was recently found to be expressed in rodent NS/PCs, and its expression decreased with the progression of neuronal differentiation. We hypothesized that TSPO would also be present in hiPSC-NS/PCs and expressed strongly in residual immature neural cells after transplantation. The results showed high levels of TSPO expression in immature hiPSC-NS/PCs-derived cells, and decreased TSPO expression as neural differentiation progressed in vitro. Furthermore, PET with [18F] FEDAC (a TSPO radioligand) was able to visualize the remnant undifferentiated hiPSC-NS/PCs-derived cells consisting of TSPO and Nestin+ cells in vivo. These findings suggest that PET with [18F] FEDAC could play a key role in the safe clinical application of CNS repair in regenerative medicine.

Purpose: To assess the effects of deep learning image reconstruction (DLIR) and hybrid iterative reconstruction (HIR) on the image quality of virtual monochromatic spectral (VMS) images and to investigate the dose reduction potential of the VMS and conventional 120 kVp images. Methods: A cylindrical phantom simulating an adult abdomen was used. The contrast was set to 60 (medium) and 300 (high) Hounsfield units. CT acquisitions were performed at three dose levels: 12, 9, and 6 mGy. Images were reconstructed via filtered back projection (FBP), DLIR, and HIR. The noise power spectrum (NPS) and task transfer function (TTF) were measured, and the system performance (SP) function was calculated (TTF2/NPS). Results: The noise magnitudes at low spatial frequencies with DLIR and HIR were lower than that with FBP by 45.6% and 24.4%, respectively. Compared to the FBP results, the TTF values at 50% with DLIR at medium and high contrast changed by –13.2% and +25.3% with the VMS images and –2.0% and +9.3% with the 120 kVp images, respectively. In the VMS and 120 kVp images, compared to the SP values of 12 mGy FBP images, SP values of 6 mGy DLIR images decreased at medium contrast and increased at high contrast. Conclusions: DLIR achieved better noise reduction than HIR. The spatial resolution of VMS-DLIR varied significantly depending on the contrast. The image quality of VMS-DLIR and 120 kVp-DLIR potentially decrease in medium contrast tasks and increase in high contrast tasks with 50% dose reduction.

Background: The semiquantitative Clinical Frailty Scale (CFS) is a simple tool to assess patients’ frailty and has been shown to correlate with mortality in elderly patients even when evaluated by nongeriatricians. The aim of the current study was to determine the prognostic value of CFS in patients who underwent transcatheter aortic valve replacement. Methods: We utilized the OCEAN (Optimized Catheter Valvular Intervention) Japanese multicenter registry to review data of 1215 patients who underwent transcatheter aortic valve replacement. Patients were categorized into 5 groups based on the CFS stages: CFS 1-3, CFS 4, CFS 5, CFS 6, and CFS ≥7. We subsequently evaluated the relationship between CFS grading and other indicators of frailty, including body mass index, serum albumin, gait speed, and mean hand grip. We also assessed differences in baseline characteristics, procedural outcomes, and early and midterm mortality among the 5 groups. Results: Patient distribution into the 5 CFS groups was as follows: 38.0% (CFS 1-3), 32.9% (CFS4), 15.1% (CFS 5), 10.0% (CFS 6), and 4.0% (CFS ≥7). The CFS grade showed significant correlation with body mass index (Spearman’s ρ=−0.077, P =0.007), albumin (ρ=−0.22, P <0.001), gait speed (ρ=−0.28, P <0.001), and grip strength (ρ=−0.26, P <0.001). Cumulative 1-year mortality increased with increasing CFS stage (7.2%, 8.6%. 15.7%, 16.9%, 44.1%, P <0.001). In a Cox regression multivariate analysis, the CFS (per 1 category increase) was an independent predictive factor of increased late cumulative mortality risk (hazard ratio, 1.28; 95% confidence interval, 1.10–1.49; P <0.001). Conclusions: In addition to reflecting the degree of frailty, the CFS was a useful marker for predicting late mortality in an elderly transcatheter aortic valve replacement cohort.

Background: Dual-energy CT technology enables acquisition of virtual unenhanced (VUE) images from contrast-enhanced scans. Objective: To assess the feasibility of coronary artery calcium (CAC) scoring on VUE images derived from fast kVp-switching dual-energy coronary CT angiography. Methods: Twenty-seven patients underwent true noncontrast CAC-scoring CT followed by routine single-energy (120-kVp) and fast kVp-switching dual-energy coronary CT angiography, in a random acquisition order on the same day. We calculated the CAC scores on true noncontrast and VUE images. The image noises and the signal-to-noise and contrast-to-noise ratios of the aorta and coronary arteries were measured on both the single-energy coronary CT angiography images and dual-energy coronary CT angiography images (70 keV virtual monochromatic spectral images). The Pearson correlation coefficient test and paired t test were used for statistical analysis. Results: Excellent correlation was observed between the CAC scores on the true noncontrast and those on the VUE images (. r = 0.88; P <001). Compared with single-energy coronary CT angiography, dual-energy coronary CT angiography showed significantly reduced image noise and increased signal-to-noise and contrast-to-noise ratios in all regions (all P <001). The effective dose of dual-energy coronary CT angiography (4.3 ± 0.3 mSv) was significantly lower than that of true noncontrast CAC-scoring CT plus single-energy coronary CT angiography (5.4 ± 0.7 mSv; P <0001). Conclusions: Excellent correlation was observed between the CAC scores on the VUE images and true noncontrast images. Thus, fast kVp-switching dual-energy coronary CT angiography could allow prediction of the true CAC scores, potentially reducing the total radiation exposure and image acquisition time by obviating the need for true noncontrast CAC-scoring CT.

A type II endoleak (T2EL) is the most common endoleak after endovascular aneurysm repair (EVAR), and a persistent T2EL has been occasionally associated with aneurysmal enlargement. Typical findings of a T2EL consist of an endoleak cavity with inflow and outflow arteries of aortic branch vessels. However, an atypical T2EL, in which hypertrophied vasa vasorum and enlargement of a thrombosed aneurysm are observed, has no endoleak cavity. We have seen three cases of continuous aortic aneurysmal growth after EVAR caused by atypical T2ELs without endoleak cavities through developed vasa vasorum. In this report, the imaging findings of selective angiography and dynamic computed tomography of these cases are reviewed.

Objective: In a previous study, we described the relationship between operating time and obesity, particularly visceral obesity, in laparoscopic surgery. Operating time in laparoscopic surgery is affected by the experience and technique of the surgeon. Here, we investigated whether a difference in the surgeon's experience affects the operating time for laparoscopic radical nephrectomy in patients with visceral obesity. Methods: From January 2006 to February 2012, 167 laparoscopic radical nephrectomies were performed at our institution. Visceral fat areawas measured at the level of the umbilicus using computed tomography. A visceral fat area ≥ 100 cm2 was used as the definition of visceral obesity. All laparoscopic radical nephrectomies were performed by six surgeons. Two of the six surgeons perform 50 cases or more laparoscopic surgeries every year and they were defined as the expert group. We analyzed the relationships between clinical findings, methods, surgeon experience, body mass index or visceral fat area and operating time. Results: The expert and non-expert surgeons performed 77 and 90 laparoscopic radical nephrectomies, respectively, and the median operating timewas 167.0 ± 44.0 and 227.5 ± 60.6 min. Twenty-five patients underwent laparoendoscopic single-site nephrectomy by the expert surgeons. For all surgeons, visceral obesity was a significant factor for prolonged operating time. Multivariate analysis showed that visceral obesity and clinical T stage were independent risk factors for prolonged operating time for the non-expert surgeons [P = 0.004, hazard ratio (HR):5.15, P = 0.037, HR:10.41]. However, for the expert surgeons, clinical T stage was the only independent risk factor for prolonged operating time (P = 0.039, HR:4.33). Conclusion: Visceral obesity was a factor of prolonged operating time in laparoscopic radical nephrectomy. The non-expert surgeons were particularly affected by visceral obesity.

© 2019 The Author(s). Background: Although T1rho and T2 map magnetic resonance imaging (MRI) have been perceived as useful diagnostic modalities for cartilage degeneration, no studies have assessed whether these two sequences are useful for monitoring ACL graft maturation after ACL reconstruction. The present study examined whether the two sequences reflect graft function and maturation after ACL reconstruction. Methods: Twenty consecutive patients who consented to undergo MRI at 3, 6, and 12 months after double-bundle ACL reconstruction were enrolled. MRI was performed using T1 rho and T2 map sequences in a single session. Temporal changes in T1rho and T2 values of a purely tendinous portion of graft were assessed at each time point. Correlations were analyzed between T1rho or T2 map values and clinical results, including anteroposterior laxity at 2 and 4 years postoperatively, pivot shift test results at 4 years, and graft tension on second-look arthroscopy. Separate analyses were performed for the anteromedial bundle (AMB) and posterolateral bundle (PLB). Results: T1rho sequence was able to visualize the tendinous portions of AMB and PLB more clearly than T2 map sequence even on gray-scale images. Mean T1rho and T2 map values gradually decreased during the first operative year, but the trend was more prominent and consistent for T1rho values than for T2 map values. Correlation analysis revealed that T1rho and T2 map values at 1 year correlated significantly with anteroposterior laxity at 2 and 4 years. This trend was found in both AMB and PLB. Both T1rho and T2 map values failed to exhibit a statistical correlation with arthroscopic findings of graft tension. Conclusions: The present study was the first trial to assess the feasibility of T1rho and T2 map sequences to objectively monitor the course of graft maturation after ACL reconstruction. Both sequences successfully detected purely tendinous portions of graft, and mean values gradually decreased during the first year postoperatively. Both values at 1 year correlated significantly with anteroposterior laxity of the knee joint at 4 years, indicating that the values reflected graft fate.

© 2019 Wolters Kluwer Health, Inc. All rights reserved. An 84-year-old man with parkinsonism was referred for 123 I-MIBG scintigraphy. Abnormal uptake in the right upper abdomen was incidentally seen in planar image, and SPECT revealed focal uptake in the medial segment (S4) of the liver. Subsequent triple-phase contrast-enhanced CT showed no evidence of hepatic tumors, although in the arterial phase, there were an enhanced region corresponding to the uptake area and the enhanced vein of Sappey that flowed into S4. In this case, the focal 123 I-MIBG uptake would be attributable to hemodynamic change in the liver.

© 2019 Journal of Visualized Experiments. Four-dimensional computed tomography (4DCT) provides a series of volume data and visualizes joint motions. However, numerical analysis of 4DCT data remains difficult because segmentation in all volumetric frames is time-consuming. We aimed to analyze joint kinematics using a sequential 3D-3D registration technique to provide the kinematics of the moving bone with respect to the fixed bone semiautomatically using 4DCT DICOM data and existing software. Surface data of the source bones are reconstructed from 3DCT. The trimmed surface data are respectively matched with surface data from the first frame in 4DCT. These trimmed surfaces are sequentially matched until the last frame. These processes provide positional information for target bones in all frames of the 4DCT. Once the coordinate systems of the target bones are decided, translation and rotation angles between any two bones can be calculated. This 4DCT analysis offers advantages in kinematic analyses of complex structures such as carpal or tarsal bones. However, fast or large-scale motions cannot be traced because of motion artifacts.

Purpose: To assess the clinical importance in the feature change in giant cell tumors of the bone (GCTB) after denosumab treatment, detected by MRI.Methods: In 12 patients, MRI and CT of GCTB obtained before and after the treatment retrospectively compared. The tumor size, the signal intensity (SI) ratio between the solid part of the GCTB and muscle, cystic part size, gadolinium enhancement and apparent diffusion coefficient (ADC) value were measured on MRI. The bone formation in the tumor was observed on CT and X-ray.Results: The mean number of denosumab injections was 19 ± 10. The follow-up period was up to 2 years. One case showed partial remission, while the other 11 cases were stable. A mean SI ratio on T2-weighted image statistically significantly decreased from 3.9 to 1.9 after the treatment. A cystic component in the tumor was observed in five cases before the treatment, and the diameter of the cystic part decreased after the treatment in 80% of cases (4/5). All the tumors showed contrast enhancement on T1-weighted image pre- and post-treatment (11/11). The averaged ADC values were 1.52 × 10−3 mm2/s before and 1.44 × 10−3 mm2/s after the treatment (P = 0.63). Bone formation in the tumor was observed in 58% of cases (7/12).Conclusion: The decrease of SI ratio on T2-weighted image, shrinkage of cystic part and bone formation should be regarded as the effectiveness of denosumab treatment despite of no substantial change in the tumor size.

© 2019 Journal of Shoulder and Elbow Surgery Board of Trustees Background: Although glenohumeral instability is common, the mechanism of instability remains unclear. The purpose of this study was to quantitatively evaluate humeral head translation during active external rotation with abduction in patients with glenohumeral instability by use of 4-dimensional computed tomography scans. Methods: Ten patients with unilateral glenohumeral instability with a positive fulcrum test were prospectively included in this study. Sequential computed tomography of bilateral shoulders during active external rotation at 90° of shoulder abduction was performed for 6 seconds at 5 frames per second. The 3-dimensional positions of the humeral head center in the anteroposterior, superoinferior, and mediolateral directions were calculated at 0°, 20°, 40°, 60°, and maximum shoulder abduction–external rotation from the starting position. Translation of the humeral head center from the starting position was evaluated using Dunnett multiple-comparison tests, and the differences between the affected and intact shoulders were assessed using Wilcoxon signed rank tests. Results: The humeral head center translated posteriorly, inferiorly, and medially during glenohumeral external rotation with the shoulder in the abducted position on the intact side. However, the affected humeral head showed significantly less posterior translation (P = .028), greater inferior translation (P = .047), and less medial translation (P = .037) than the contralateral side. Conclusions: This study indicated that dysfunction of the anterior band of the inferior glenohumeral ligament causes decreased posterior, increased inferior, and decreased medial translation of the humeral head during active shoulder abduction–external rotation.

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. This study aimed to validate the hypothesis that the ratio of cerebral blood flow (CBF) at rest in the lenticular nucleus (LN) territory to that in the middle cerebral artery (MCA) territory is higher in symptomatic Moyamoya disease (MMD) patients than in asymptomatic MMD patients. This was a retrospective observational study of adult patients with documented MMD who underwent single-photon emission computed tomography (SPECT) and had been examined at the Department of Neurosurgery of Keio University Hospital during a 10-year period (2006–2016). The diagnosis was made on the basis of typical imaging findings. We classified unoperated MMD patients into three groups: class I, no evidence of stenosis or occlusion hemispheres and without symptoms in unilateral MMD patients; class II, hemispheres with stenosis or occlusion but without ischemic symptoms; and class III, hemispheres with evidence of stenosis or occlusion associated with ischemic symptoms. Hemodynamic stress distribution (hdSD) was defined as the ratio of CBF in one LN to the CBF in the peripheral MCA; this was obtained by SPECT at rest. We compared the values of CBF and hdSD among the groups. A total of 173 adult patients were diagnosed with MMD from January 1, 2006, to January 1, 2016. Among them, 85 MMD patients underwent SPECT studies. After excluding inappropriate cases, 144 hemispheres were included in our analysis. hdSD was significantly higher (p < 0.001) in hemispheres with ischemic symptoms (class III, mean hdSD = 1.1; 36 sides) than in those without symptoms (class II, mean hdSD = 1.03; 82 sides). However, CBF at rest in the MCA or LN was not significantly associated with ischemic symptoms. The optimal threshold for hdSD to have ischemic symptoms was 1.040 (area under the curve; 74% sensitivity 91.7% and specificity 54.9%). We used SPECT to investigate cerebral blood from MMD patients and found that high hdSD values were predictive of ischemic symptom development in these patients.

© 2019, The Author(s). Background: We sought to assess the machine learning-based combined diagnostic accuracy of three types of quantitative indices obtained using dopamine transporter single-photon emission computed tomography (DAT SPECT)—specific binding ratio (SBR), putamen-to-caudate ratio (PCR)/fractal dimension (FD), and asymmetry index (AI)—for parkinsonian syndrome (PS). We also aimed to compare the effect of two different types of volume of interest (VOI) settings from commercially available software packages DaTQUANT (Q) and DaTView (V) on diagnostic accuracy. Methods: Seventy-one patients with PS and 40 without PS (NPS) were enrolled. Using SPECT images obtained from these patients, three quantitative indices were calculated at two different VOI settings each. SBR-Q, PCR-Q, and AI-Q were derived using the VOI settings from DaTQUANT, whereas SBR-V, FD-V, and AI-V were derived using those from DaTView. We compared the diagnostic value of these six indices for PS. We incorporated a support vector machine (SVM) classifier for assessing the combined accuracy of the three indices (SVM-Q: combination of SBR-Q, PCR-Q, and AI-Q; SVM-V: combination of SBR-V, FD-V, and AI-V). A Mann-Whitney U test and receiver-operating characteristics (ROC) analysis were used for statistical analyses. Results: ROC analyses demonstrated that the areas under the curve (AUC) for SBR-Q, PCR-Q, AI-Q, SBR-V, FD-V, and AI-V were 0.978, 0.837, 0.802, 0.906, 0.972, and 0.829, respectively. On comparing the corresponding quantitative indices between the two types of VOI settings, SBR-Q performed better than SBR-V (p = 0.006), whereas FD-V performed better than PCR-Q (p = 0.0003). No significant difference was observed between AI-Q and AI-V (p = 0.56). The AUCs for SVM-Q and SVM-V were 0.988 and 0.994, respectively; the two different VOI settings displayed no significant differences in terms of diagnostic accuracy (p = 0.48). Conclusion: The combination of the three indices obtained using the SVM classifier improved the diagnostic performance for PS; this performance did not differ based on the VOI settings and software used.

症例は40歳代女性で、10年前、左卵巣癌ステージIa(粘液性腺癌G1)に対し左付属器切除術が行われた。下腹部痛で受診し、卵巣腫大を指摘され、産婦人科へ紹介受診となった。経腟超音波で内部に嚢胞成分を伴う卵巣充実性腫瘍を認め、術前に精査のため造影FDG-PET/CTを施行した。右卵巣に16cm大の嚢胞成分を伴う腫瘤を認め、SUVmax:3.15とFDG軽度集積亢進を認めた。卵巣原発もしくは転移性卵巣癌のも考えられたが、PETのMIP像で積極的に原発巣を疑うような明瞭なFDG異常蓄積は指摘できなかった。しかし、造影CTでは胃のび漫性壁肥厚を認め、腹腔動脈近傍から左胃動脈周囲に不整な軟部影形成を認めた。転移性卵巣癌の可能性が考えられ、MRIを施行したところ、骨盤内に嚢胞成分を有し、T2強調像で全体に高信号を呈する腫瘍性病変を認めた。脂肪抑制造影T1強調像では腫瘍内部に緩徐な造影効果を認めた。症状、画像から卵巣茎捻転とそれに伴う卵巣広範性浮腫が疑われ、緊急で腹式単純子宮全摘+右付属器切除術を施行した。部分的な腺管形成傾向も認め、多臓器からの腺癌の転移と診断した。上部消化管内視鏡検査で胃に潰瘍性病変や粘膜上皮の肥厚が確認され、生検で粘液を含む印環細胞癌およびそれに伴う転移性卵巣癌(Krukenberg腫瘍)と診断し、化学療法のため消化器内科に転科となった。