BACKGROUND & AIMS: :Calcinosis is a typical feature of systemic sclerosis (SSc) and can be found in many different tissues including the superficial soft tissues, periarticular structures, muscles, and tendons. It can also provoke erosive changes on bones. Investigation is conducted most often with plain radiographs. However, when a more detailed assessment is necessary, multidetector computed tomography (MDCT) is helpful owing to its multiplanar reformat (MPR) ability. The purpose of this review is to provide an overview of the various appearances of calcinosis in SSc patients as visualized at MDCT.

背景与目标： : 钙质沉着症是系统性硬化症 (SSc) 的典型特征，可在许多不同的组织中发现，包括浅表软组织，关节周围结构，肌肉和肌腱。它还会引起骨骼的侵蚀变化。调查最常使用x线平片进行。但是，当需要更详细的评估时，多探测器计算机断层扫描 (MDCT) 由于其多平面重新格式化 (MPR) 能力而很有帮助。这篇综述的目的是概述在MDCT中可见的SSc患者中钙化沉病的各种表现。

BACKGROUND & AIMS: OBJECTIVE:The purpose of this study was to evaluate the performance of MRI and a combination of MDCT arthrography and MR arthrography in the diagnosis of tears and cartilage abnormalities of the wrist ligaments. SUBJECTS AND METHODS:The feasibility of combining MDCT arthrography and MR arthrography and performing them with an optimized contrast solution was evaluated in vitro and in vivo. Forty-five consecutively enrolled subjects with suspected wrist ligament tears underwent MRI and a combined MDCT and MR arthrographic procedure. Two observers reviewed the images for evidence of tears and cartilage abnormalities of the scapholunate and lunotriquetral ligaments and triangular fibrocartilaginous complex. Interobserver agreement was determined with kappa statistics, and the diagnostic accuracy of each technique was calculated. RESULTS:A 1:1 solution of 2.5 mmol/L tetraazacyclododecanetetraacetic acid (DOTA)-gadolinium and 300 mg I/mL iopamidol provided adequate contrast enhancement for both in vitro and in vivo MDCT arthrographic and MR arthrographic images. Interobserver agreement was substantial for MRI (kappa = 0.61) and MR arthrography (kappa = 0.71) and almost perfect for MDCT arthrography (kappa = 0.93). The sensitivity and specificity of MRI, MDCT arthrography, and MR arthrography for tears of the scapholunate ligament were 59% and 70%, 95% and 96%, and 68% and 87% for the first observer and 77% and 83%, 95% and 100%, and 77% and 87% for the second observer. For tears of the lunotriquetral ligament, these values were 30% and 94%, 100% and 94%, and 60% and 97% for the first observer and 50% and 97%, 90% and 100%, and 50% and 94% for the second observer. The three techniques appeared equivalent for complete tears of the scapholunate and lunotriquetral ligaments, but partial tears were significantly better visualized with MDCT arthrography. The sensitivity and specificity of MRI, MDCT arthrography, and MR arthrography for triangular fibrocartilaginous complex tears were 27% and 100%, 100% and 100%, and 82% and 100% for the first observer and 45% and 100%, 100% and 100%, and 82% and 100% for the second observer. For cartilage abnormalities, these values were 30% and 100%, 100% and 100%, and 30% and 100% for the first observer and 10% and 100%, 100% and 100%, and 40% and 100% for the second observer. CONCLUSION:MDCT arthrography appears more accurate than MRI and MR arthrography, particularly for discerning partial tears of the scapholunate and lunotriquetral ligaments that do not necessitate surgical therapy.

背景与目标：

BACKGROUND & AIMS: PURPOSE:The aim of the study was to compare the influence of different reconstruction algorithms on quantitative emphysema analysis in patients with severe emphysema. MATERIAL AND METHODS:Twenty-five patients suffering from severe emphysema were included in the study. All patients underwent inspiratory MDCT (Aquilion-16, slice thickness 1/0.8mm). The raw data were reconstructed using six different algorithms: bone kernel with beam hardening correction (BHC), soft tissue kernel with BHC; standard soft tissue kernel, smooth soft tissue kernel (internal reference standard), standard lung kernel, and high-convolution kernel. The only difference between image data sets was the algorithm employed to reconstruct the raw data, no additional radiation was required. CT data were analysed using self-written emphysema detection and quantification software providing lung volume, emphysema volume (EV), emphysema index (EI) and mean lung density (MLD). RESULTS:The use of kernels with BHC led to a significant decrease in MLD (5%) and EI (61-79%) in comparison with kernels without BHC. The absolute difference (from smooth soft tissue kernel) in MLD ranged from -0.6 to -6.1 HU and were significant different for all kernels. The EV showed absolute differences between -0.05 and -0.4 L and was significantly different for all kernels. The EI showed absolute differences between -0.8 and -5.1 and was significantly different for all kernels. CONCLUSION:The use of kernels with BHC led to a significant decrease in MLD and EI. The absolute differences between different kernels without BHC were small but they were larger than the known interscan variation in patients. Thus, for follow-up examinations the same reconstruction algorithm has to be used and use of BHC has to be avoided.

背景与目标：

BACKGROUND & AIMS: CONCLUSION:Three-dimensional multi-detector computed tomography (3D MDCT) analysis of the upper airway suggested that the lengthening of the upper airway in the absence of volumetric change may independently contribute to the severity of obstructive sleep apnea syndrome (OSAS) in adults. OBJECTIVES:We sought to investigate the relationships among the length and volume of the upper airway to the severity of OSAS. METHODS:A total of 73 subjects underwent 3D MDCT scanning and standard polysomnography. We measured the upper airway length (UAL), which was defined as the vertical distance from the hard palate to the hyoid in the mid-sagittal plane. We also used the height-adjusted UAL for analyses. Upper airway volume was measured using a 3D reconstruction of the cross-sectional area from the hard palate to the hyoid. RESULTS:The adjusted UAL showed a significant positive correlation with the apnea hypopnea index (AHI, r = 0.523, p < 0.000) and was a significant variable for predicting the AHI of OSAS patients in multiple stepwise regression analysis. Although the severe OSAS group had a greater adjusted UAL compared with that of other groups (p = 0.001), the volume of the upper airway did not show differences among groups.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:Determination of left ventricular (LV) volumes and global function parameters from MDCT data sets is usually based on short-axis reformations from primarily reconstructed axial images, which prolong postprocessing time. The aim of this study was to evaluate the feasibility of LV volumetry and global LV function assessment from axial images in comparison with short-axis image reformations. SUBJECTS AND METHODS:This study consisted of 20 patients with either coronary artery disease or dilated cardiomyopathy. We evaluated MDCT results using cine MRI as the reference technique. RESULTS:LV end-diastolic volume (LVEDV) and end-systolic volume (LVESV) were significantly overestimated by the axial MDCT approach in comparison with volume measurements from short-axis CT image reformations. The mean LV ejection fraction (LVEF) was not significantly different (41.2% vs 42.7%). Short-axis and axial MDCT determination of LVEF revealed a systematic underestimation by a mean +/- SD of -2.1% +/- 3.6% versus -3.6% +/- 8.2%, respectively, when compared with LVEF values based on cine MRI. The interobserver variability for volume and function measurements from axial images (LVEDV = 8.5%, LVESV = 10.8%, LVEF = 9.6%) was slightly higher than those measurements from short-axis reformations (LVEDV = 7.2%, LVESV = 9.5%, LVEF = 8.7%). The mean total evaluation time was significantly shorter using axial images (14.1 +/- 3.9 min) compared with short-axis reformations (16.9 +/- 5.2 min) (p < 0.05). CONCLUSION:Determination of LV volumes and assessment of global LV function from axial MDCT image reformations is feasible and time efficient. This approach might be a clinically useful alternative to established short-axis-based measurements in patients with normal or near-normal LV function. A progressive underestimation of LVEF with increasing LV volumes may limit the clinical applicability of the axial approach in patients with dilated cardiomyopathy.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:The purposes of this study were to determine the reproducibility of quantitative colorectal cancer perfusion measurements using dynamic contrast-enhanced MDCT, and to compare this with measurements from skeletal muscle. SUBJECTS AND METHODS:Ten patients (mean age, 67 years; six men, four women) with histologically proven colorectal cancer were examined prospectively using 4-MDCT. Perfusion studies (cine mode; 4 x 5 mm collimation; 1 acquisition/s; 65 seconds total) were performed through the tumor epicenter after IV bolus contrast administration (iopamidol 340, 100 mL; 5 mL/s) and repeated within 48 hours. Quantitative values for blood volume, blood flow, mean transit time, and permeability were determined using commercial software. Two regions of interest were studied on the axial image: one within the tumor and another within the left gluteal muscle. Measurement reproducibility was assessed using Bland-Altman statistics. RESULTS:For the tumor, the mean difference (95% limits of agreement) was -0.04 mL/100 g tissue (-2.50, 2.42); 8.80 (-50.5, 68.0) mL/100 g tissue/min; -0.99 (-8.19, 6.20) seconds; and 1.20 (-5.42, 7.83) mL/100 g tissue/min for blood volume, blood flow, mean transit time, and permeability, respectively. For muscle, the mean difference (95% limits of agreement) was 0.02 (-1.40, 1.43), 6.60 (-11.2, 24.3), -3.76 (-16.87, 9.35), and 1.30 (-4.68, 7.28), respectively. CONCLUSION:Quantitative perfusion measurements are reproducible. Measurements from tumor are less variable than from skeletal muscle.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:High reproducibility on coronary artery calcium (CAC) scoring is a key requirement in monitoring the progression of coronary atherosclerosis. Retrospective ECG-gated helical CT has been shown to be superior to prospective gating helical CT in the reproducibility of CAC measurements. However, it brings with it a high level of radiation exposure. The purpose of this study was to compare low- and standard-dose protocols in the variability of CAC scores and in image quality, thereby assessing the feasibility of low-dose retrospective ECG-gated helical CT in CAC measurements. SUBJECTS AND METHODS:Eighty-six patients with CAC were scanned using a tube current setting of 100 mA once and then a tube current setting equivalent to the patient's body weight twice. CAC scores (Agatston and volume) and interscan variability were evaluated. The mean and SD of the CT attenuation values in regions of interest in the aorta were measured, and the value (mean + 2 x SD) was obtained. RESULTS:A high correlation of log(10) (Agatston score + 1) was observed between sequential helical CT scans (r = 0.998). The variability in CAC measurements ranged from 11% to 12% for both the Agatston and volume scores. With the tube current equivalent to body weight, the value (mean + 2 x SD) did not exceed a CT attenuation value of 130 H. CONCLUSION:Low-dose retrospective ECG-gated helical CT-yielding low variability and achieving the level of image quality needed to measure CAC-can be used to monitor patients with coronary atherosclerosis.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:This article illustrates the MDCT postmortem imaging features that have the potential to enhance forensic investigation and conventional autopsy. CONCLUSION:MDCT may guide, direct, or limit forensic autopsy in projectile injury cases, thereby eliminating the need for a complete invasive autopsy.

背景与目标：

BACKGROUND & AIMS: :Scimitar syndrome with bilateral abnormal venous drainage and horseshoe lung is extremely rare. These rare complex anomalies were diagnosed in a 5-year-old boy by 64-slice multidetector CT (MDCT). This technique provides high-quality visualization of vascular, bronchial and parenchymal structures in a single session, such that no further invasive techniques are required. One obvious disadvantage of MDCT is the radiation exposure, especially in paediatric patients. The use of a single phase of contrast material administration reduces radiation exposure. The workstation platforms of MDCT systems allow multiplanar 2-D and 3-D postprocessing. As a result, various complex pathologies, such as that discussed here, can be diagnosed following a single imaging session with a certain precision.

背景与目标： : 双侧静脉引流和马蹄肺异常的弯刀综合征极为罕见。这些罕见的复杂异常是通过64层多探测器CT (MDCT) 在5岁男孩中诊断出来的。该技术可在一次会议中提供高质量的血管，支气管和实质结构可视化，因此不需要进一步的侵入性技术。MDCT的一个明显缺点是辐射暴露，尤其是在儿科患者中。使用单相造影剂给药可减少辐射暴露。MDCT系统的工作站平台允许多平面2-D和3-D后处理。结果，可以在单个成像会话之后以一定的精度诊断出各种复杂的病理，例如这里讨论的病理。

BACKGROUND & AIMS: :The double contrast barium enema of the colon continues to be a diffused conventional radiological technique and allows for the diagnosis of neoplastic and inflammatory pathology. After the '70s, a massive initiative is undertaken to simplify, perfect and encode the method of the double contrast barium enema: Altaras from Germany, Miller from USA and Cittadini from Italy are responsible for the perfection of this technique in the last 30 years. The tailored patient preparation, a perfect technique of execution and a precise radiological documentation are essentials steps to obtain a reliable examination. The main limit of double contrast enema is that it considers the pathology only from the mucosal surface. In neoplastic pathology evaluation the main limit is the "T" parameter staging, but more limited are the "N" and "M" parameters evaluation. Today the double contrast technique continues to be a refined, sensitive and specific diagnostic method, moreover, diagnostic results cannot compete with the new CT multislice techniques (CT-enteroclysis and virtual colonoscopy) which can examine both the lumen and the wall of the colon. The double contrast is a cheap and simple examination but in the next future is predictably a progressive substitution of conventional radiology from new multislice techniques, because the cross sectional imaging is more frequently able to detect causes of the symptoms whether resulting both from colonic or non colonic origin.

背景与目标： : 结肠双对比钡灌肠继续是一种扩散的常规放射学技术，可诊断肿瘤和炎症病理。在70年代之后，我们采取了一项大规模的举措来简化，完善和编码双对比钡灌肠的方法: 来自德国的Altaras，来自美国的Miller和来自意大利的Cittadini在过去30年中负责这项技术的完善。量身定制的患者准备，完美的执行技术和精确的放射学文件是获得可靠检查的基本步骤。双重对比灌肠的主要限制是它仅从粘膜表面考虑病理。在肿瘤病理学评估中，主要限制是 “T” 参数分期，但更有限的是 “N” 和 “M” 参数评估。如今，双重对比技术仍然是一种精致，敏感和特异性的诊断方法，而且，诊断结果无法与可以检查管腔和壁的新CT多层技术 (CT-肠溶和虚拟结肠镜检查) 竞争。结肠。双重对比是一种廉价且简单的检查，但在未来的将来，可以预见的是传统放射学从新的多层技术的逐步替代，因为横截面成像更经常能够检测症状的原因，无论是结肠还是非结肠起源。

BACKGROUND & AIMS: :To determine the CT findings and assess their diagnostic performance in differentiating early perforated appendicitis from nonperforated appendicitis, and to compare therapeutic approaches and clinical outcomes between two types of appendicitis. Our retrospective study was approved by our institutional review board and informed consent was waived. From July 2012 to July 2013, 339 patients [mean age 40.8 years; age range 19-80 years; 183 male (mean age 40.5 years; age range 19-79 years) and 156 female (mean age 41.2 years; age range 19-80 years)] who underwent appendectomy with preoperative CT examination for suspected acute appendicitis were included, with exclusion of 37 patients with specific CT findings for advanced perforated appendicitis. And they were categorized into nonperforated and early perforated appendicitis groups according to surgical and pathologic reports. The following CT findings were evaluated by two radiologists blinded to pathologic and surgical findings: transverse diameter of the appendix, thickness of the appendiceal wall, the depth of intraluminal appendiceal fluid, appendiceal wall enhancement, presence or absence of focal defect in the appendiceal wall, intraluminal appendiceal air, appendicolith/fecalith, periappendiceal changes, cecal wall thickening, and free fluid. The type of surgical procedures, performance of surgical drainage, and the length of hospital stay were recorded. Univariate and multivariate logistic regression analysis were used to determine the CT findings for differentiating early perforated appendicitis from nonperforated appendicitis, a total of 75 (22%) of the 339 patients was diagnosed with early perforated appendicitis. Focal wall defect [adjusted odds ratio (aOR), 23.40; p < 0.001], circumferential periappendiceal changes (aOR, 5.63; p < 0.001), appendicoliths/fecaliths (aOR, 2.47; p = 0.015), and transverse diameter of the appendix (aOR, 1.22; p = 0.003) were independently differentiating variables for early perforated appendicitis. The transverse diameter of the appendix (≥11 mm) had the highest sensitivity (62.7%) and focal wall defect in the appendiceal wall showed the highest specificity (98.8%). The prevalence of surgical drainage was higher (p = 0.001) and the mean hospital stay was approximately one day longer (p < 0.001) in the early perforated group than nonperforated group. CT can be helpful in differentiating early perforated appendicitis from nonperforated appendicitis, although the sensitivity of the evaluated findings was somewhat limited.

背景与目标： : 确定CT表现并评估其在区分早期穿孔性阑尾炎和非穿孔性阑尾炎方面的诊断性能，并比较两种类型阑尾炎的治疗方法和临床结果。我们的回顾性研究获得了我们的机构审查委员会的批准，并且放弃了知情同意。从2012年7月到2013年7月，339名患者 [平均年龄40.8岁; 年龄范围19-80岁; 183名男性 (平均年龄40.5岁; 年龄范围19-79岁) 和156名女性 (平均年龄41.2岁; 年龄范围19-80岁)] 包括因疑似急性阑尾炎接受阑尾切除术并进行术前ct检查的患者，其中排除了37例具有特定CT表现的晚期穿孔阑尾炎患者。根据手术和病理报告，将其分为未穿孔和早期穿孔阑尾炎组。由两名对病理和手术结果视而不见的放射科医生评估了以下CT表现: 阑尾的横向直径，阑尾壁的厚度，腔内阑尾液的深度，阑尾壁的增强，阑尾壁中是否存在局灶性缺损，腔内阑尾空气，阑尾/粪便，阑尾周围改变，盲肠壁增厚，游离液体。记录手术类型，手术引流性能和住院时间。采用单因素和多因素logistic回归分析来确定CT表现，以区分早期穿孔性阑尾炎和非穿孔性阑尾炎，总共339例患者中有75例 (22% 例) 被诊断为早期穿孔性阑尾炎。局灶性壁缺损 [调整比值比 (aOR)，23.40; p <0.001]，周缘阑尾周围变化 (aOR，5.63; p <0.001)，阑尾石料/粪便 (aOR，2.47; p = 0.015) 和阑尾横径 (aOR，1.22; p = 0.003) 是早期穿孔性阑尾炎的独立差异变量。阑尾的横向直径 (≥ 11毫米) 具有最高的敏感性 (62.7%)，阑尾壁的局部壁缺损显示出最高的特异性 (98.8%)。与未穿孔组相比，早期穿孔组手术引流的发生率更高 (p = 0.001)，平均住院时间长约一天 (p <0.001)。尽管评估结果的敏感性有些有限，但CT有助于区分早期穿孔性阑尾炎和非穿孔性阑尾炎。

BACKGROUND & AIMS: OBJECTIVE:Imaging of the vast array of pathologic processes occurring in the small bowel has been facilitated by recent advances, including the use of MDCT scanners that acquire isotropic data and neutral oral contrast agents that improve small-bowel distention. CONCLUSION:This review shows how a systematic pattern approach can be used to narrow the differential diagnosis when an abnormal small-bowel loop is detected on MDCT.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:The purposes of this pictorial essay are to show MDCT findings of renal trauma and describe the indications and protocol for MDCT. CONCLUSION:CT is indicated when patients have gross hematuria, hypotension, lumbar spinal injury, and fractures of lower ribs or the transverse process. The CT examination must be designed specifically for urinary tract evaluation, and MDCT is especially useful for this purpose. Injury to the kidney is graded I to V according to degree of laceration and amount of hematoma.

背景与目标：

BACKGROUND & AIMS: :The goal of this study was to investigate the impact of computing parameters and the location of volumes of interest (VOI) on the calculation of 3D noise power spectrum (NPS) in order to determine an optimal set of computing parameters and propose a robust method for evaluating the noise properties of imaging systems. Noise stationarity in noise volumes acquired with a water phantom on a 128-MDCT and a 320-MDCT scanner were analyzed in the spatial domain in order to define locally stationary VOIs. The influence of the computing parameters in the 3D NPS measurement: the sampling distances bx,y,z and the VOI lengths Lx,y,z, the number of VOIs NVOI and the structured noise were investigated to minimize measurement errors. The effect of the VOI locations on the NPS was also investigated. Results showed that the noise (standard deviation) varies more in the r-direction (phantom radius) than z-direction plane. A 25 × 25 × 40 mm(3) VOI associated with DFOV = 200 mm (Lx,y,z = 64, bx,y = 0.391 mm with 512 × 512 matrix) and a first-order detrending method to reduce structured noise led to an accurate NPS estimation. NPS estimated from off centered small VOIs had a directional dependency contrary to NPS obtained from large VOIs located in the center of the volume or from small VOIs located on a concentric circle. This showed that the VOI size and location play a major role in the determination of NPS when images are not stationary. This study emphasizes the need for consistent measurement methods to assess and compare image quality in CT.

背景与目标： : 本研究的目的是研究计算参数和感兴趣体积 (VOI) 的位置对3D噪声功率谱 (NPS) 计算的影响，以便确定一组最佳的计算参数，并提出一种可靠的方法评估成像系统的噪声特性。在空间域中分析了在128-MDCT和320-MDCT扫描仪上使用水体模获得的噪声体积中的噪声平稳性，以定义局部固定的VOIs。研究了3D NPS测量中计算参数的影响: 采样距离bx，y，z和VOI长度Lx，y，z，VOIs NVOI的数量和结构化噪声，以最大程度地减少测量误差。还研究了VOI位置对NPS的影响。结果表明，噪声 (标准偏差) 在r方向 (幻影半径) 上的变化大于z方向平面。与DFOV = 200毫米 (Lx，y，z = 64，bx，y = 0.391毫米，具有512 × 512矩阵) 相关联的25 × 40毫米 (3) VOI和减少结构化噪声的一阶去趋势方法导致了准确的NPS估计。从偏心小voi估算的NPS具有方向依赖性，这与从位于体积中心的大voi或位于同心圆上的小voi获得的NPS相反。这表明，当图像不静止时，VOI的大小和位置在确定np中起主要作用。这项研究强调需要一致的测量方法来评估和比较CT中的图像质量。

BACKGROUND & AIMS: PURPOSE:To investigate whether electrocardiogram (ECG)-gated single- and dual-heartbeat computed tomography coronary angiography (CTCA) with automatic exposure control (AEC) yields images with uniform image noise at reduced radiation doses. MATERIALS AND METHODS:Using an anthropomorphic chest CT phantom we performed prospectively ECG-gated single- and dual-heartbeat CTCA on a second-generation 320-multidetector CT volume scanner. The exposure phase window was set at 75%, 70-80%, 40-80%, and 0-100% and the heart rate at 60 or 80 or corr80 bpm; images were reconstructed with filtered back projection (FBP) or iterative reconstruction (IR, adaptive iterative dose reduction 3D). We applied AEC and set the image noise level to 20 or 25 HU. For each technique we determined the image noise and the radiation dose to the phantom center. RESULTS:With half-scan reconstruction at 60 bpm, a 70-80% phase window- and a 20-HU standard deviation (SD) setting, the imagenoise level and -variation along the z axis manifested similar curves with FBP and IR. With half-scan reconstruction, the radiation dose to the phantom center with 70-80% phase window was 18.89 and 12.34 mGy for FBP and 4.61 and 3.10 mGy for IR at an SD setting SD of 20 and 25 HU, respectively. At 80 bpm with two-segment reconstruction the dose was approximately twice that of 60 bpm at both SD settings. However, increasing radiation dose at corr80 bpm was suppressed to 1.39 times compared to 60 bpm. CONCLUSION:AEC at ECG-gated single- and dual-heartbeat CTCA controls the image noise at different radiation dose.

背景与目标：