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Background Localized pleural adhesion (LPA) evaluation in the apical region is difficult even with four-dimensional ultra-low-dose computed tomography (4D-ULDCT) in the supine position due to smaller pleural movements. Purpose To assess usability of 4D-ULDCT in the lateral decubitus (LD) position for LPA detection in the apical region. Material and Methods Forty-seven patients underwent 4D-ULDCT of a single respiration cycle with 16-cm coverage of body axis in supine and LD positions with the affected lung uppermost. Intraoperative thoracoscopic findings confirmed LPA presence. A pleural point and a corresponding point on costal outer edge were placed in identical axial planes at end-inspiration. Pleuro-chest wall distance between two points (PCD) was calculated at each respiratory phase. In the affected lung, average change in amount of PCD (PCDACA) was compared between patients with and without LPA in total and two sub-groups (non-COPD and COPD, non-emphysematous and emphysematous patients) in supine and non-dependent (ND) LD positions. Receiver operating characteristic (ROC) curve analysis was performed to determine optimal thresholds in PCDACA for differentiating patients with LPA from those without. Results In COPD/emphysematous patients and total population, PCDACA with LPA was smaller than in those without in the supine and NDLD positions for overall, lateral, and dorsal regions. For the lateral region in COPD patients, area under ROC curve (AUC) increased from supine (0.64) to NDLD position (0.81). For the dorsal region in emphysematous patients, AUC increased from supine (0.76) to NDLD position (0.96). Conclusion 4D-ULDCT in LD position may be useful for LPA detection in apical regions for COPD and/or emphysematous patients.

We aimed to reveal specific findings of gastrointestinal stromal tumors (GISTs) in the small intestine on contrast-enhanced computed tomography (CT) by comparing GISTs with non-GISTs. We enrolled 28 patients with 39 GISTs and 20 patients with 22 non-GISTs who underwent enterectomy with a preoperative diagnosis of small intestinal tumor. All lesions were diagnosed by histopathological examination. Two radiologists independently evaluated internal homogeneity, growth pattern, calcification, intratumoral hemorrhage, degeneration, ulceration, and lymphadenopathy and measured the maximum diameter of the tumor and contrast-enhanced CT (CECT) value of the solid portion as well as the diameter and CT value of the feeding artery and drainage vein on CECT in the arterial and venous phases. Intratumoral hemorrhage was seen in 15.4% and 25.6% of GISTs and in 0% and 0% of non-GISTs (p = 0.079 and 0.010), with good interobserver agreement (κ = 0.715). The drainage vein diameter correlated well with the maximum diameter of the tumor (r = 0.744, p

Purpose To assess the usefulness of software analysis using dynamic-ventilation CT for localized pleural adhesion (LPA). Materials and methods Fifty-one patients scheduled to undergo surgery underwent both dynamic-ventilation CT and static chest CT as preoperative assessments. Five observers independently evaluated the presence and severity of LPA on a three-point scale (non, mild, and severe LPA) for 9 pleural regions (upper, middle, and lower pleural aspects on ventral, lateral, and dorsal areas) on the chest CT by three different methods by observing images from: static high-resolution CT (static image); dynamic-ventilation CT (movie image), and dynamic-ventilation CT while referring to the adhesion map (movie image with color map), which was created using research software to visualize movement differences between the lung surface and chest wall. The presence and severity of LPA was confirmed by intraoperative thoracoscopic findings. Parameters of diagnostic accuracy for LPA presence and severity were assessed among the three methods using Wilcoxon signed rank test in total and for each of the three pleural aspects. Results Mild and severe LPA were confirmed in 14 and 8 patients. Movie image with color map had higher sensitivity (56.9 ± 10.7 %) and negative predictive value (NPV) (91.4 ± 1.7 %) in LPA detection than both movie image and static image. Additionally, for severe LPA, detection sensitivity was the highest with movie image with color map (82.5 ± 6.1 %), followed by movie image (58.8 ± 17.0 %) and static image (38.8 ± 13.9 %). For LPA severity, movie image with color map was similar to movie image and superior to static image in accuracy as well as underestimation and overestimation, with a mean value of 80.2 %. Conclusion Software-assisted dynamic-ventilation CT may be a useful novel imaging approach to improve the detection performance of LPA.

Background It is still unclear which image reconstruction algorithm is appropriate for peripheral bronchial luminal conspicuity (PBLC) on dynamic-ventilation computed tomography (DVCT). Purpose To assess the influence of radiation doses and temporal resolution (TR) on the association between movement velocity (MV) and PBLC on DVCT. Material and Methods An ex vivo porcine lung phantom with simulated respiratory movement was scanned by 320-row CT at 240 mA and 10 mA. Peak and dip CT density and luminal area adjusted by values at end-inspiration (CTDpeak and CTDdip, luminal area ratio [LAR]) for PBLC and MVs were measured and visual scores (VS) were obtained at 12 measurement points on 13 frame images obtained at half and full reconstructions (TR 340 and 190 ms) during expiration. Size-specific dose estimate (SSDE) was applied to presume radiation dose. VS, CTDpeak, CTDdip, LAR, and their cross-correlation coefficients with MV (CCC) were compared among four methods with combinations of two reconstruction algorithms and two doses. Results The dose at 10 mA was presumed as 26 mA by SSDE for standard proportion adults. VS, CTDdip, CTDpeak, and LAR with half reconstruction at 10 mA (2.52 ± 0.59, 1.016 ± 0.221, 0.948 ± 0.103, and 0.990 ± 0.527) were similar to those at 240 mA except for VS, and different from those with full reconstruction at both doses (2.24 ± 0.85, 0.830 ± 0.209, 0.986 ± 0.065, and 1.012 ± 0.438 at 240 mA) ( P dip with half reconstruction (–0.024 ± 0.552) at 10 mA was higher compared with full reconstruction (–0.503 ± 0.291) ( P Conclusion PBLC with half reconstruction at 10 mA was comparable to that at 240 mA and better than those with full reconstruction on DVCT.

Rationale and Objectives The objectives of this study were to compare the visibility and quantification of subsolid nodules (SSNs) on computed tomography (CT) using adaptive iterative dose reduction using three-dimensional processing between 7 and 42 mAs and to assess the association of size-specific dose estimate (SSDE) with relative measured value change between 7 and 84 mAs (RMVC7–84) and relative measured value change between 42 and 84 mAs (RMVC42–84). Materials and Methods As a Japanese multicenter research project (Area-detector Computed Tomography for the Investigation of Thoracic Diseases [ACTIve] study), 50 subjects underwent chest CT with 120 kV, 0.35 second per location and three tube currents: 240 mA (84 mAs), 120 mA (42 mAs), and 20 mA (7 mAs). Axial CT images were reconstructed using adaptive iterative dose reduction using three-dimensional processing. SSN visibility was assessed with three grades (1, obscure, to 3, definitely visible) using CT at 84 mAs as reference standard and compared between 7 and 42 mAs using t test. Dimension, mean CT density, and particular SSDE to the nodular center of 71 SSNs and volume of 58 SSNs (diameter >5 mm) were measured. Measured values (MVs) were compared using Wilcoxon signed-rank tests among CTs at three doses. Pearson correlation analyses were performed to assess the association of SSDE with RMVC7–84: 100 × (MV at 7 mAs − MV at 84 mAs)/MV at 84 mAs and RMVC42–84. Results SSN visibilities were similar between 7 and 42 mAs (2.76 ± 0.45 vs 2.78 ± 0.40) (P = .67). For larger SSNs (>8 mm), MVs were similar among CTs at three doses (P > .05). For smaller SSNs ( Conclusions Comparable quantification was demonstrated irrespective of doses for larger SSNs. For smaller SSNs, nodular exaggerating effect associated with decreased SSDE on CT at 7 mAs compared to 84 mAs could result in comparable visibilities to CT at 42 mAs.

We aimed to estimate the usefulness of transcatheter arterial embolization (TAE) in patients with postoperative abdominal hemorrhage and to evaluate the effects of pancreatic fistula on clinical outcomes and angiographic findings. We enrolled 22 patients (20 males and 2 females; mean age 63 years; range 25–86 years), who underwent transarterial angiography for postoperative hemorrhage after abdominal surgery. This group corresponded to 28 procedures. Technical and clinical success rates were calculated, and clinical findings and outcomes were compared between patients with and without a pancreatic fistula. Pre-interventional CT was performed in all patients before first angiography, and the location of the bleeding was identified in all but one patient. Active arterial bleeding, identified by extravasation of contrast agent (n = 12), pseudoaneurysm formation (n = 12), and arterial wall irregularity (n = 2) were detected in 28 angiographic procedures, and embolization was performed in 26 instances. Various embolization techniques such as isolation, packing, embolization, and stentgraft implantation were performed. The technical and clinical success rates were 96% (25/26 procedures) and 82% (18/22 patients), respectively. In hemodynamically unstable patients (shock index: heart rate/systolic blood pressure > 1), a 92% (12/13 cases) technical success rate was achieved. There were no significant differences in any evaluated parameters between patients with and without pancreatic fistula. TAE is a safe and effective for treating postoperative hemorrhage even in patients with hemodynamic instability and pancreatic fistula. Additionally, pre-interventional CT is useful for effective, consecutive interventions.

Purpose To assess the feasibility of Four-Dimensional Ultra-Low-Dose Computed Tomography (4D-ULDCT) for distinguishing pleural aspects with localized pleural adhesion (LPA) from those without. Methods Twenty-seven patients underwent 4D-ULDCT during a single respiration with a 16 cm-coverage of the body axis. The presence and severity of LPA was confirmed by their intraoperative thoracoscopic findings. A point on the pleura and a corresponding point on the outer edge of the costal bone were placed in identical axial planes at end-inspiration. The distance of the two points (PCD), traced by automatic tracking functions respectively, was calculated at each respiratory phase. The maximal and average change amounts in PCD (PCDMCA and PCDACA) were compared among 110 measurement points (MPs) without LPA, 16 MPs with mild LPA and 10 MPs with severe LPA in upper lung field cranial to the bronchial bifurcation (ULF), and 150 MPs without LPA, 17 MPs with mild LPA and 9 MPs with severe LPA in lower lung field caudal to the bronchial bifurcation (LLF) using the Mann-Whitney U test. Results In the LLF, PCDACA as well as PCDMCA demonstrated a significant difference among non-LPA, mild LPA and severe LPA (18.1 ± 9.2, 12.3 ± 6.2 and 5.0 ± 3.3 mm) (p Conclusions Four D-ULDCT could be a useful non-invasive preoperative assessment modality for the detection of the presence or severity of LPA.

Yukihiro Nagatani,1 Masayuki Hashimoto,2 Norihisa Nitta,1 Yasuhiko Oshio,2 Tsuneo Yamashiro,3 Shigetaka Sato,1 Shinsuke Tsukagoshi,4 Hiroshi Moriya,5 Tatsuya Kimoto,6 Tomoyuki Igarashi,2 Noritoshi Ushio,1 Akinaga Sonoda,1 Hideji Otani,1 Jun Hanaoka,2 Kiyoshi Murata1On behalf of investigators of the ACTIve Study Group1Department of Radiology, Shiga University of Medical Science, Otsu, Shiga 520-2192, Japan; 2Department of Surgery, Division of General Thoracic Surgery, Shiga University of Medical Science, Otsu, Shiga 520-2192, Japan; 3Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara, Okinawa 903-0215, Japan; 4CT System Division, Canon Medical Systems, Otawara, Tochigi 324-8550, Japan; 5Department of Radiology, Ohara General Hospital, Fukushima, Fukushima 960-8611, Japan; 6Healthcare IT Development Center, Canon Medical Systems, Otawara, Tochigi 324-8550, JapanPurpose: The purpose of this study was to measure changes in lung density and airway dimension in smokers in the lateral position using four-dimensional dynamic-ventilation computed tomography (CT) during free breathing and to evaluate their correlations with spirometric values.Materials and methods: Preoperative pleural adhesion assessments included dynamic-ventilation CT of 42 smokers (including 22 patients with COPD) in the lateral position, with the unoperated lung beneath (dependent lung). The scanned lungs’ mean lung density (MLD) and the bilateral main bronchi’s luminal areas (Ai) were measured automatically (13–18 continuous image frames, 0.35 seconds/frame). Calculations included cross-correlation coefficients (CCCs) between the MLD and Ai time curves, and correlations between the quantitative measurements and spirometric values were evaluated by using Spearman’s rank coefficient.Results: The ΔMLD1.05 (from the peak inspiration frame to the third expiratory frame, 1.05 seconds later) in the nondependent lung negatively correlated with FEV1/FVC (r=-0.417, P

The objectives of this study were to compare the visibility and quantification of subsolid nodules (SSNs) on computed tomography (CT) using adaptive iterative dose reduction using three-dimensional processing between 7 and 42 mAs and to assess the association of size-specific dose estimate (SSDE) with relative measured value change between 7 and 84 mAs (RMVCAs a Japanese multicenter research project (Area-detector Computed Tomography for the Investigation of Thoracic Diseases [ACTIve] study), 50 subjects underwent chest CT with 120 kV, 0.35 second per location and three tube currents: 240 mA (84 mAs), 120 mA (42 mAs), and 20 mA (7 mAs). Axial CT images were reconstructed using adaptive iterative dose reduction using three-dimensional processing. SSN visibility was assessed with three grades (1, obscure, to 3, definitely visible) using CT at 84 mAs as reference standard and compared between 7 and 42 mAs using t test. Dimension, mean CT density, and particular SSDE to the nodular center of 71 SSNs and volume of 58 SSNs (diameter5 mm) were measured. Measured values (MVs) were compared using Wilcoxon signed-rank tests among CTs at three doses. Pearson correlation analyses were performed to assess the association of SSDE with RMVCSSN visibilities were similar between 7 and 42 mAs (2.76 ± 0.45 vs 2.78 ± 0.40) (P = .67). For larger SSNs (8 mm), MVs were similar among CTs at three doses (P .05). For smaller SSNs (8 mm), dimensions and volumes on CT at 7 mAs were larger and the mean CT density was smaller than 42 and 84 mAs, and SSDE had mild negative correlations with RMVCComparable quantification was demonstrated irrespective of doses for larger SSNs. For smaller SSNs, nodular exaggerating effect associated with decreased SSDE on CT at 7 mAs compared to 84 mAs could result in comparable visibilities to CT at 42 mAs.