OBJECTIVE: To compare the diagnostic accuracy of supraspinatus muscle outlet X-ray film, oblique sagittal multislice helical CT (MSCT), and oblique sagittal MRI in the diagnosis of subacromial impingement syndrome (SIS). METHODS: A retrospective analysis was conducted on the imaging data of 106 patients diagnosed with SIS between January 2023 and December 2024. The cohort consisted of 32 males and 74 females, with ages ranging from 43 to 70 years (mean, 60.19 years). All patients underwent supraspinatus muscle outlet X-ray film, MSCT, and MRI scans, with MSCT further subjected to three-dimensional reconstruction. Two experienced radiologists independently evaluated the acromion morphology in each imaging modality using the Bigliani classification system. Inter-observer reliability was assessed via Kappa statistics. The CT three-dimensional reconstructions were used as the "gold standard". The overall consistency, Kappa values, sensitivity, and specificity of the three imaging modalities were calculated. Receiver operating characteristic (ROC) curves were plotted, and the area under the curve (AUC) was computed. RESULTS: The inter-observer reliability for supraspinatus muscle outlet X-ray film, oblique sagittal MSCT, and oblique sagittal MRI was moderate, with Kappa values of 0.62, 0.63, and 0.55, respectively. When compared to the CT three-dimensional reconstructions as the "gold standard", the overall consistency was 88.7% (94/106), 62.3% (66/106), and 58.5% (62/106), respectively. The supraspinatus muscle outlet X-ray film showed excellent consistency (Kappa=0.77), whereas the consistency of MSCT and MRI was lower (Kappa=0.34 and 0.29, respectively). In terms of diagnostic sensitivity and specificity, the supraspinatus muscle outlet X-ray film outperformed oblique sagittal MSCT and oblique sagittal MRI in distinguishing various acromion types. ROC analysis demonstrated that the AUC for the supraspinatus muscle outlet X-ray film was consistently higher than for oblique sagittal MSCT and oblique sagittal MRI, with the highest diagnostic performance observed for type Ⅲ hooked acromion (AUC=0.939). CONCLUSION Supraspinatus muscle outlet X-ray film provides the highest diagnostic accuracy for acromion classification in SIS patients, particularly in identifying type Ⅲ hooked acromion, which is strongly associated with SIS. Given its superior sensitivity and consistency, it should be considered the primary screening tool. MSCT and MRI serve as valuable supplementary modalities for complex cases and preoperative evaluation.
Humans ; Middle Aged ; Male ; Female ; Shoulder Impingement Syndrome/diagnostic imaging* ; Magnetic Resonance Imaging/methods* ; Retrospective Studies ; Aged ; Adult ; Imaging, Three-Dimensional ; Sensitivity and Specificity ; Tomography, Spiral Computed/methods* ; Multidetector Computed Tomography/methods* ; Reproducibility of Results

PURPOSE: To analyze the diagnostic efficacy of computed tomography angiography compared to digital cerebral angiography for the diagnosis of traumatic aneurysms (TAs) associated with combat-related penetrating head injuries and propose the most suitable angiography protocol in this clinical context. METHODS: A retrospective analysis was conducted on patients admitted to the neurosurgical clinic for penetrating traumatic brain injuries between February, 2022 and July, 2024, for whom both cerebral multidetector computed tomography angiography (MCTA) and digital cerebral angiography (DCA) were available. The inclusion were patients (1) with penetrating head injuries, (2) with missile trajectory traverses through the Sylvian or great longitudinal fissure, (3) basal cisterns with/or major subarachnoid hemorrhage. The sensitivity, specificity, positive predictive value, and negative predictive value of MCTA were calculated. DCA was considered as the gold standard of diagnosis. The sensitivity, specificity, positive predictive value, and negative predictive value of MCTA were calculated. Descriptive statistics and nonparametric statistics were used to analyze the study results and their differences, respectively. RESULTS: A total of 40 patients with 45 TAs were included in the study. Of these, 26 patients (65.0%) were found to have aneurysms on MCTA. The median diameter of the aneurysms diagnosed by MCTA was 4.9 (3.6, 4.8) mm (range of 2.5 - 10.4 mm). However, the mean diameter of TAs not detected by MCTA but diagnosed by DCA was (3.0 ± 1.3) mm (range of 1.3 - 4.9 mm). MCTA demonstrated sensitivity and specificity of 35.5% and 99.5%, respectively, with positive and negative predictive values of 92.3% and 90.7%. CONCLUSIONS A low sensitivity of MCTA for the diagnosis of TAs associated with combat-related penetrating head injuries was reported. When MCTA is inconclusive in the setting of radiologic predictors of cerebral artery injury, DSA may be required.
Humans ; Male ; Retrospective Studies ; Adult ; Multidetector Computed Tomography/methods* ; Intracranial Aneurysm/etiology* ; Computed Tomography Angiography/methods* ; Female ; Head Injuries, Penetrating/diagnostic imaging* ; Middle Aged ; Cerebral Angiography/methods* ; Predictive Value of Tests ; Sensitivity and Specificity ; Young Adult

Transcatheter aortic valve replacement (TAVR) has emerged as a viable treatment option for patients with severe aortic stenosis regardless of its surgical risk stratification (Otto et al., 2021). Aortic angulation is usually measured as the angle between the horizontal and the aortic annulus planes based on preproced‍ural multidetector computed tomography (MDCT) (Al-Lamee et al., 2011). Extremely horizontal aorta, defined as an aortic angulation greater than 70°, is an unfavorable anatomic structure that poses particular technical challenges for TAVR. Abramowitz et al. (2016) have proved that an extremely horizontal aorta increased the risk of procedural complications, such as lower device success rates, more moderate or even severe perivalvular leakage (PVL), and the need for second valve implantation. Because of the long stent frame, inflexibility, and non-steerability, it is challenging to pass the delivery system of self-expanding valves (SEVs) through an extremely horizontal aorta. As a result, patients with an extremely horizontal aorta have always been excluded from the clinical trials of TAVR, and transfemoral (TF)-TAVR with SEV is considered as an "off-label" use of TAVR (Adams et al., 2014; Kaneko et al., 2020). Herein, we present a technically difficult case, in which a patient with an extremely horizontal aorta underwent TF-TAVR with SEV by applying a unique apical-to-femoral rail strategy.
Aorta ; Humans ; Lower Extremity ; Multidetector Computed Tomography ; Transcatheter Aortic Valve Replacement

computed tomography (3rd-DSCT) allows dynamic myocardial CT perfusion imaging (dynamic CTP) with a 10.5-cm z-axis coverage. Although the increased radiation exposure associated with the 50% wider scan range compared to second-generation DSCT (2nd-DSCT) may be suppressed by using a tube voltage of 70 kV, it remains unclear whether image quality and the ability to quantify myocardial blood flow (MBF) can be maintained under these conditions. This study aimed to compare the image quality, estimated MBF, and radiation dose of dynamic CTP between 2nd-DSCT and 3rd-DSCT and to evaluate whether a 10.5-cm coverage is suitable for dynamic CTP.MATERIALS AND METHODS: We retrospectively analyzed 107 patients who underwent dynamic CTP using 2nd-DSCT at 80 kV (n = 54) or 3rd-DSCT at 70 kV (n = 53). Image quality, estimated MBF, radiation dose, and coverage of left ventricular (LV) myocardium were compared.RESULTS: No significant differences were observed between 3rd-DSCT and 2nd-DSCT in contrast-to-noise ratio (37.4 ± 11.4 vs. 35.5 ± 11.2, p = 0.396). Effective radiation dose was lower with 3rd-DSCT (3.97 ± 0.92 mSv with a conversion factor of 0.017 mSv/mGy·cm) compared to 2nd-DSCT (5.49 ± 1.36 mSv, p < 0.001). Incomplete coverage was more frequent with 2nd-DSCT than with 3rd-DSCT (1.9% [1/53] vs. 56% [30/54], p < 0.001). In propensity score-matched cohorts, MBF was comparable between 3rd-DSCT and 2nd-DSCT in non-ischemic (146.2 ± 26.5 vs. 157.5 ± 34.9 mL/min/100 g, p = 0.137) as well as ischemic myocardium (92.7 ± 21.1 vs. 90.9 ± 29.7 mL/min/100 g, p = 0.876).CONCLUSION: The radiation increase inherent to the widened z-axis coverage in 3rd-DSCT can be balanced by using a tube voltage of 70 kV without compromising image quality or MBF quantification. In dynamic CTP, a z-axis coverage of 10.5 cm is sufficient to achieve complete coverage of the LV myocardium in most patients.]]>
Cardiac Imaging Techniques ; Cohort Studies ; Cytidine Triphosphate ; Humans ; Image Enhancement ; Multidetector Computed Tomography ; Myocardial Perfusion Imaging ; Myocardium ; Perfusion Imaging ; Radiation Dosage ; Radiation Exposure ; Retrospective Studies

CT enterography and magnetic resonance (MR) enterography are widely used imaging modalities used to examine the small bowel. These radiologic tests are distinguished from routine abdominopelvic CT and MRI by the oral ingestion of a large amount of neutral contrast to distend the small bowel before scanning. For achievement of high quality, diagnostic images and proper technique are required. Conducted protocols still vary in patient preparation, enteric contrast, and CT and MRI acquisition sequences, resulting in heterogeneous diagnostic accuracy. The purpose of this article is to review the processes and techniques that optimize CT/MR enterography for patients with suspected Crohn's disease or other small bowel diseases.
Crohn Disease ; Diagnostic Imaging ; Eating ; Humans ; Intestine, Small ; Magnetic Resonance Imaging ; Multidetector Computed Tomography

OBJECTIVE: To characterize the changes in right ventricular (RV) volume, volume load, and function measured with cardiac computed tomography (CT) over the entire time course of tetralogy of Fallot (TOF). MATERIALS AND METHODS: In 374 patients with TOF, the ventricular volume, ventricular function, and RV volume load were measured with cardiac CT preoperatively (stage 1), after palliative operation (stage 2), after total surgical repair (stage 3), or after pulmonary valve replacement (PVR) (stage 4). The CT-measured variables were compared among the four stages. After total surgical repair, the postoperative duration (POD) and the CT-measured variables were correlated with each other. In addition, the demographic and CT-measured variables in the early postoperative groups were compared with those in the late postoperative and the preoperative group. RESULTS: Significantly different CT-based measures were found between stages 1 and 3 (indexed RV end-diastolic volume [EDV], 63.6 ± 15.2 mL/m2 vs. 147.0 ± 38.5 mL/m2 and indexed stroke volume (SV) difference, 7.7 ± 10.3 mL/m2 vs. 32.2 ± 16.4 mL/m2; p < 0.001), and between stages 2 and 3 (indexed RV EDV, 72.4 ± 19.7 mL/m2 vs. 147.0 ± 38.5 mL/m2 and indexed SV difference, 5.7 ± 13.1 mL/m2 vs. 32.2 ± 16.4 mL/m2; p < 0.001). After PVR, the effect of RV volume load (i.e., indexed SV difference) was reduced from 32.2 mL/m2 to 1.7 mL/m2. Positive (0.2 to 0.8) or negative (−0.2 to −0.4) correlations were found among the CT-based measures except between the RV ejection fraction (EF) and the RV volume load parameters. With increasing POD, an early rapid increase was followed by a slow increase and a plateau in the indexed ventricular volumes and the RV volume load parameters. Compared with the preoperative data, larger ventricular volumes and lower EFs were observed in the early postoperative period. CONCLUSION: Cardiac CT can be used to characterize RV volume, volume load, and function over the entire time course of TOF.
Humans ; Multidetector Computed Tomography ; Postoperative Period ; Pulmonary Valve ; Pulmonary Valve Insufficiency ; Stroke Volume ; Tetralogy of Fallot ; Ventricular Function

OBJECTIVE: To retrospectively investigate whether tumor size assessment on multiplanar reconstruction (MPR) CT images better reflects pathologic T-stage than evaluation on axial images and evaluate the additional value of measurement in three-dimensional (3D) space. MATERIALS AND METHODS: From 1661 patients who had undergone surgical resection for primary lung cancer between June 2013 and November 2016, 210 patients (145 men; mean age, 64.4 years) were randomly selected and 30 were assigned to each pathologic T-stage. Two readers independently measured the maximal lesion diameters on MPR CT. The longest diameters on 3D were obtained using volume segmentation. T-stages determined on CT images were compared with pathologic T-stages (overall and subgroup—Group 1, T1a/b; Group 2, T1c or higher), with differences in accuracy evaluated using McNemar's test. Agreement between readers was evaluated with intraclass correlation coefficients (ICC). RESULTS: The diagnostic accuracy of MPR measurements for determining T-stage was significantly higher than that of axial measurement alone for both reader 1 (74.3% [156/210] vs. 63.8% [134/210]; p = 0.001) and reader 2 (68.1% [143/210] vs. 61.9% [130/210]; p = 0.049). In the subgroup analysis, diagnostic accuracy with MPR diameter was significantly higher than that with axial diameter in only Group 2 (p < 0.05). Inter-reader agreements for the ICCs on axial and MPR measurements were 0.98 and 0.98. The longest diameter on 3D images showed a significantly lower performance than MPR, with an accuracy of 54.8% (115/210) (p < 0.05). CONCLUSION: Size measurement on MPR CT better reflected the pathological T-stage, specifically for T1c or higher stage lung cancer. Measurements in a 3D plane showed no added value.
Humans ; Lung Neoplasms ; Lung ; Male ; Multidetector Computed Tomography ; Neoplasm Staging ; Retrospective Studies

OBJECTIVE: To investigate the accuracy of model-based iterative reconstruction (MIR) for volume measurement of part-solid nodules (PSNs) and solid nodules (SNs) in comparison with filtered back projection (FBP) or hybrid iterative reconstruction (HIR) at various radiation dose settings. MATERIALS AND METHODS: CT scanning was performed for eight different diameters of PSNs and SNs placed in the phantom at five radiation dose levels (120 kVp/100 mAs, 120 kVp/50 mAs, 120 kVp/20 mAs, 120 kVp/10 mAs, and 80 kVp/10 mAs). Each CT scan was reconstructed using FBP, HIR, or MIR with three different image definitions (body routine level 1 [IMR-R1], body soft tissue level 1 [IMR-ST1], and sharp plus level 1 [IMR-SP1]; Philips Healthcare). The SN and PSN volumes including each solid/ground-glass opacity portion were measured semi-automatically, after which absolute percentage measurement errors (APEs) of the measured volumes were calculated. Image noise was calculated to assess the image quality. RESULTS: Across all nodules and dose settings, the APEs were significantly lower in MIR than in FBP and HIR (all p < 0.01). The APEs of the smallest inner solid portion of the PSNs (3 mm) and SNs (3 mm) were the lowest when MIR (IMR-R1 and IMR-ST1) was used for reconstruction for all radiation dose settings. (IMR-R1 and IMR-ST1 at 120 kVp/100 mAs, 1.06 ± 1.36 and 8.75 ± 3.96, p < 0.001; at 120 kVp/50 mAs, 1.95 ± 1.56 and 5.61 ± 0.85, p = 0.002; at 120 kVp/20 mAs, 2.88 ± 3.68 and 5.75 ± 1.95, p = 0.001; at 120 kVp/10 mAs, 5.57 ± 6.26 and 6.32 ± 2.91, p = 0.091; at 80 kVp/10 mAs, 5.84 ± 1.96 and 6.90 ± 3.31, p = 0.632). Image noise was significantly lower in MIR than in FBP and HIR for all radiation dose settings (120 kVp/100 mAs, 3.22 ± 0.66; 120 kVp/50 mAs, 4.19 ± 1.37; 120 kVp/20 mAs, 5.49 ± 1.16; 120 kVp/10 mAs, 6.88 ± 1.91; 80 kVp/10 mAs, 12.49 ± 6.14; all p < 0.001). CONCLUSION: MIR was the most accurate algorithm for volume measurements of both PSNs and SNs in comparison with FBP and HIR at low-dose as well as standard-dose settings. Specifically, MIR was effective in the volume measurement of the smallest PSNs and SNs.
Hominidae ; Humans ; Lung Neoplasms ; Multidetector Computed Tomography ; Noise ; Phantoms, Imaging ; Radiation Dosage ; Thorax ; Tomography, X-Ray Computed

Unenhanced echocardiography (UE), commonly used in veterinary practice, is limited by left ventricular (LV) foreshortening and observer dependency. Contrast echocardiography (CE) was used to compare two-dimensional (2D) LV measurements made using UE and 256-row multi-detector computed tomography (MDCT) as a reference standard. Seven healthy beagle dogs were evaluated in this study. Measurements obtained using CE, including LV wall thickness, internal diameter, and longitudinal and transverse length, were significantly greater than those obtained using UE. Measurements of LV internal dimension in diastole (LVIDd) and systole (LVIDs) were significantly larger with CE compared UE. Regardless of the cardiac cycle, LV longitudinal (LVLd and LVLs) and transverse diameter (LVTDd and LVTDs) measurements were significantly different with CE and approximated values from MDCT. Among automatically calculated parameters, LV end-systolic volume and the relative wall thickness were significantly different between UE and CE. In CE, the correlation coefficients of 4 major parameters (r = 0.87 in LVIDd; 0.91 in LVIDs; 0.87 in LVLd; and 0.81 in LVLs) showed higher values compared to the UE (r = 0.68 in LVIDd, 0.71 in LVIDs, 0.69 in LVLd, and 0.35 in LVLs). Inter-observer agreement was highest for MDCT and higher for CE than UE. In conclusion, CE is more accurate and reproducible than UE in assessing 2D LV measurements and can overcome the limitations of UE including LV foreshortening and high observer dependency.
Animals ; Diastole ; Dogs ; Echocardiography ; Multidetector Computed Tomography ; Systole

OBJECTIVE: The aim of our study was to develop and validate a convolutional neural network (CNN) architecture to convert CT images reconstructed with one kernel to images with different reconstruction kernels without using a sinogram. MATERIALS AND METHODS: This retrospective study was approved by the Institutional Review Board. Ten chest CT scans were performed and reconstructed with the B10f, B30f, B50f, and B70f kernels. The dataset was divided into six, two, and two examinations for training, validation, and testing, respectively. We constructed a CNN architecture consisting of six convolutional layers, each with a 3 × 3 kernel with 64 filter banks. Quantitative performance was evaluated using root mean square error (RMSE) values. To validate clinical use, image conversion was conducted on 30 additional chest CT scans reconstructed with the B30f and B50f kernels. The influence of image conversion on emphysema quantification was assessed with Bland–Altman plots. RESULTS: Our scheme rapidly generated conversion results at the rate of 0.065 s/slice. Substantial reduction in RMSE was observed in the converted images in comparison with the original images with different kernels (mean reduction, 65.7%; range, 29.5–82.2%). The mean emphysema indices for B30f, B50f, converted B30f, and converted B50f were 5.4 ± 7.2%, 15.3 ± 7.2%, 5.9 ± 7.3%, and 16.8 ± 7.5%, respectively. The 95% limits of agreement between B30f and other kernels (B50f and converted B30f) ranged from −14.1% to −2.6% (mean, −8.3%) and −2.3% to 0.7% (mean, −0.8%), respectively. CONCLUSION: CNN-based CT kernel conversion shows adequate performance with high accuracy and speed, indicating its potential clinical use.
Dataset ; Emphysema ; Ethics Committees, Research ; Image Processing, Computer-Assisted ; Machine Learning ; Multidetector Computed Tomography ; Retrospective Studies ; Tomography, X-Ray Computed