Multidetector Row Research Articles

Is Routine Thromboprophylaxis Needed in Korean Patients Undergoing Unicompartmental Knee Arthroplasty?

This study was undertaken to determine the prevalence and the natural course of venous thromboembolism (VTE) without thromboprophylaxis to ascertain whether routine thromboprophylaxis is necessary following unicompartmental knee arthroplasty (UKA) in Korean patients. The medical records and multidetector row computed tomography (MDCT) imaging of the consecutive 77 UKAs in 70 patients were reviewed. In all patients, MDCTs were undertaken preoperatively and at 1-week after surgery, and VTE symptoms were evaluated. At postoperative 6-months, follow-up MDCTs were undertaken in all patients in whom VTEs were newly detected after surgery. VTE lesions were newly detected in 18 (26%) of the 70 patients. However, none of the patients complained of VTE-related symptoms and MDCT demonstrated that all VTEs were small and involved limited portion without lower leg edema or pleuroparenchymal complication. At the 6-month follow up MDCT, all types of VTEs were shown to be completely resolved, regardless of their location. All of the VTE lesions maintained an asymptomatic status for 6-month after surgery. VTE following UKA in Korean patients who do not receive thromboprophylaxis seems to occur frequently, but all of the VTEs are clinically insignificant and all VTEs are spontaneously regressed. Routine thromboprophylaxis or thrombolytic treatment in Korean patients undergoing UKA may not be necessary.

1B42 最大努力呼気4DCTが明らかにした肺気腫の縦隔内気道虚脱

Functional disorder of the pulmonary emphysema has been believed due to dynamic compression of small airways. However, its direct evidences have never been shown. We hypnotized that overinflated lungs compressed the intra-mediastinal airway (IMA, intra-thoracic trachea, main bronchi, and right lobar bronchi) in emphysema at the beginning of forced expiration and would let IMA collapse due to fluid dynamical effect. We evaluated the morphological change of IMA during maximum forced expiration by 4D-CT, and investigated its relationship to the value of FEV_<1.0>. Five emphysema patients and a normal subject underwent 4D-CT by multi-detector row CT during maximum forced expiration over six seconds at supine posture. Voxel size was 0.7 mm x 0.7 mm x 1.0 mm with the range of 16 cm, and time interval was 0.5 sec. Volumes of intra-thoracic trachea and bilateral main bronchi are measured for each frame. The IMA of all emphysema patients were extremely narrowed just after the beginning of forced expiration and slightly recovered later. The membranous part of IMA was invaginated inside. There was no apparent shape change in the normal subject. The relative volume after two seconds was highly correlated to FEV_<1.0>. These 4D-CT images have revealed that low values of FEV_<1.0> in emphysema patients are caused by dynamic collapse of IMA. Pneumodynamics should be urgently reconstructed based on dynamic imaging.

Association Between Tegmen Tympani Status and Superior Semicircular Canal Pattern.

Detecting and quantifying the possible association between tegmen tympani (TT) status and superior semicircular canal (SSC) pattern. Observational study. Study conducted in three tertiary Spanish hospitals. Nonselected consecutive patients of all ages (607 temporal bones). Thin-section multidetector row computed axial tomography (CAT scan) of the temporal bones. Thickness of SSC bone coverture adjacent to the middle fossa, and TT status as a dichotomous variable: dehiscence (TTD) or integrity (TTI). The observed SSC patterns were dehiscence (3.79%), papyraceous or thin (11.20%), normal (76.77%), thick (4.94%), and pneumatized (3.29%). The observed TT statuses were TTD (10.87%) and TTI (89.13%). TTD was associated with SSCD and papyraceous patterns, and TTI percentages were higher in normal and thick patterns (χ2 = 11.102; p = 0.001). The TTD probability was estimated as a function of SSC pattern and age by a multivariate binary logistics regression model (χ2 = 45.939; p < 0.001). SSC pattern was significantly associated with TT status. Age influenced this association. The risk for TTD increased by 4.1% per each year of increasing age, did not differ significantly for normal and thick patterns, and increased 12 times and 20 times for papyraceous and SSCD patterns, respectively.

Individually adapted kilovoltage for oncologic chest CT: Levels of radiation dose in clinical practice

Purpose: The main purpose of this study was to verify the adequacy of dose levels of irradiation in oncologic chest CT obtained in our daily practice with the recommendations of the existing referral guidelines. The secondary objective was to evaluate the effect on radiation dose of individual adjustment of kilovoltage in thoracic multidetector row computed tomography (MDCT) images acquired with single and dual-source technology. The impact of lowering the kilovoltage in the diagnostic quality of these studies was also evaluated. Methods: Ninety-seven patients were included in the study. CT examinations were performed using two different equipments: a conventional CT scanner (SOMATOM Emotion 6), and a dual-source computed tomography (DSCT) system (SOMATOM Force), (Siemens Medical System, Forchheim, Germany), with the following parameters. Emotion 6: collimation 6 × 1.0, slice thickness 1.25 mm, 110/130 kV, 48-107 mAs. FORCE: collimation 64 × 0.6, slice thickness 1 mm, 100-150 kV, 65-300 mAs. Dose levels of the CT scans were recorded digitally. The levels of DLP (Dose Length Product) obtained, as well as the existing noise in the acquired images, was evaluated. Results: The average DLP of the protocols was as follows. Emotion 6, 130 kV: 336.3 mGy (5.72 mSv). Emotion 6, 110 kV: 209 mGy (3.55 mSv). FORCE, 150 kV: 183.3 mGy (3.11 mSv). FORCE, 100 kV: 49.4 mGy (0.84 mSv). The values of effective dose were obtained using the conversion factor described by the European Guidelines for Computed Tomography for chest CT (0.017 mSv/mGy/cm). The levels of noise did not rise significantly in the lower kV group. Conclusions: The average values of DLP obtained in our daily practice meet the recommendations of the existing referral guidelines. Lower values can be achieved through individual adjustment of kilovoltage and using CT scanners with dual-source technology, maintaining the diagnostic quality of these studies.

Quantitative Features of Liver Lesions, Lung Nodules, and Renal Stones at Multi-Detector Row CT Examinations: Dependency on Radiation Dose and Reconstruction Algorithm.

To determine if radiation dose and reconstruction algorithm affect the computer-based extraction and analysis of quantitative imaging features in lung nodules, liver lesions, and renal stones at multi-detector row computed tomography (CT). Retrospective analysis of data from a prospective, multicenter, HIPAA-compliant, institutional review board-approved clinical trial was performed by extracting 23 quantitative imaging features (size, shape, attenuation, edge sharpness, pixel value distribution, and texture) of lesions on multi-detector row CT images of 20 adult patients (14 men, six women; mean age, 63 years; range, 38-72 years) referred for known or suspected focal liver lesions, lung nodules, or kidney stones. Data were acquired between September 2011 and April 2012. All multi-detector row CT scans were performed at two different radiation dose levels; images were reconstructed with filtered back projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction (MBIR) algorithms. A linear mixed-effects model was used to assess the effect of radiation dose and reconstruction algorithm on extracted features. Among the 23 imaging features assessed, radiation dose had a significant effect on five, three, and four of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Adaptive statistical iterative reconstruction had a significant effect on three, one, and one of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). MBIR reconstruction had a significant effect on nine, 11, and 15 of the features for liver lesions, lung nodules, and renal stones, respectively (P < .002 for all comparisons). Of note, the measured size of lung nodules and renal stones with MBIR was significantly different than those for the other two algorithms (P < .002 for all comparisons). Although lesion texture was significantly affected by the reconstruction algorithm used (average of 3.33 features affected by MBIR throughout lesion types; P < .002, for all comparisons), no significant effect of the radiation dose setting was observed for all but one of the texture features (P = .002-.998). Radiation dose settings and reconstruction algorithms affect the extraction and analysis of quantitative imaging features in lesions at multi-detector row CT.

MDCT features of hepatocellular carcinoma (HCC) in non-cirrhotic liver.

To describe the multidetector row computed tomography (MDCT) imaging features of HCC that develops in patients who are free from underlying liver cirrhosis and to determine if the MDCT presentation of this specific tumor differs from that of the more common HCC that develops in patients with liver cirrhosis using a retrospective case-control study. The MDCT examinations of 38 patients with HCC in non-cirrhotic liver (group 1) were quantitatively and qualitatively analyzed and compared to those obtained in 38 patients with HCC in cirrhotic liver (group 2) matched for age and gender. Quantitative and qualitative characteristics of HCC of both groups were compared using univariate analysis. HCCs were significantly larger in group 1 (81.5mm±55.5) than in group 2 (44.5mm±39.1 SD; P=0.0015). In group 1, HCCs were more frequently single tumors (87%) than in group 2 (37%) (P<0.0001), encapsulated (92% vs. 47% respectively; P<0.0001), had more frequently fatty component (24% vs. 8%, respectively; P=0.0279) and internal hemorrhage (29% vs. 3%, respectively; P=0.0033). No significant differences were found between the two groups for location, hyperenhancement of HCC during the arterial phase, washout during the portal phase, endoluminal portal involvement by HCC, endoportal cruoric thrombus, invasion of adjacent organs and underlying liver steatosis. HCC in non-cirrhotic liver are larger than those observed in cirrhotic liver and more frequently present as a single encapsulated tumor. They have the same patterns of enhancement than HCC that develops in cirrhotic liver.

MDCT Linear and Volumetric Analysis of Adrenal Glands: Normative Data and Multiparametric Assessment.

To study linear and volumetric adrenal measurements, their reproducibility, and correlations between total adrenal volume (TAV) and adrenal micronodularity, age, gender, body mass index (BMI), visceral (VAAT) and subcutaneous adipose tissue volume (SAAT), presence of diabetes, chronic alcoholic abuse and chronic inflammatory disease (CID). We included 154 patients (M/F, 65/89; mean age, 57years) undergoing abdominal multidetector row computed tomography (MDCT). Two radiologists prospectively independently performed adrenal linear and volumetric measurements with semi-automatic software. Inter-observer reliability was studied using inter-observer correlation coefficient (ICC). Relationships between TAV and associated factors were studied using bivariate and multivariable analysis. Mean TAV was 8.4 ± 2.7cm(3) (3.3-18.7cm(3)). ICC was excellent for TAV (0.97; 95% CI: 0.96-0.98) and moderate to good for linear measurements. TAV was significantly greater in men (p < 0.0001), alcoholics (p = 0.04), diabetics (p = 0.0003) and those with micronodular glands (p = 0.001). TAV was lower in CID patients (p = 0.0001). TAV correlated positively with VAAT (r = 0.53, p < 0.0001), BMI (r = 0.42, p < 0.0001), SAAT (r = 0.29, p = 0.0003) and age (r = 0.23, p = 0.005). Multivariable analysis revealed gender, micronodularity, diabetes, age and BMI as independent factors influencing TAV. Adrenal gland MDCT-based volumetric measurements are more reproducible than linear measurements. Gender, micronodularity, age, BMI and diabetes independently influence TAV. • Volumetric measurements are more reproducible than linear measurements for adrenal glands. • Inter-observer reproducibility of adrenal gland volume is excellent using semiautomatic software. • Gender, age, BMI, and diabetes independently influence total adrenal gland volume. • Adrenal micronodularity is associated with increased total adrenal gland volume.

Role of Multidetector Computed Tomography in the Diagnosis of Colorectal Perforations

Colonic perforations can be classified into perforations that occur at the site of a localized pathologic process and cecal perforations that occur secondary to distal colonic obstructions. Rectal perforations may result from foreign bodies inserted into the rectum; moreover, deep rectal biopsies, polypectomy, improper cleansing enema, or thermometer placement may also lead to rectal perforation. Correct identification of the cause and site of the perforation is crucial for appropriate management and surgical planning. Multidetector row computed tomography has a pivot role in planning the type of operative treatment, the prognosis, and in assessing those patients who have clinical symptoms of peritonitis but no radiographic signs of perforation.

Acute Perforated Diverticulitis: Assessment With Multidetector Computed Tomography

Colonic diverticulitis is a common condition in the western population. Complicated diverticulitis is defined as the presence of extraluminal air or abscess, peritonitis, colon occlusion, or fistulas. Multidetector row computed tomography (MDCT) is the modality of choice for the diagnosis and the staging of diverticulitis and its complications, which enables performing an accurate differential diagnosis and addressing the patients to a correct management. MDCT is accurate in diagnosing the site of perforation in approximately 85% of cases, by the detection of direct signs (focal bowel wall discontinuity, extraluminal gas, and extraluminal enteric contrast) and indirect signs, which are represented by segmental bowel wall thickening, abnormal bowel wall enhancement, perivisceral fat stranding of fluid, and abscess. MDCT is accurate in the differentiation from complicated colon diverticulitis and colon cancer, often with a similar imaging. The computed tomography-guided classification is recommended to discriminate patients with mild diverticulitis, generally treated with antibiotics, from those with severe diverticulitis with a large abscess, which may be drained with a percutaneous approach.

Prevalence and characteristics of coronary artery anomalies in an adult population undergoing multidetector-row computed tomography for the evaluation of coronary artery disease.

BackgroundCongenital coronary anomalies are uncommon with an incidence ranging from 0.17 % in autopsy cases to 1.2 % in angiographically evaluated cases. The recent development of ECG–gated multi–detector row computed tomography (MDCT) coronary angiography allows accurate and noninvasive depiction of coronary artery anomalies.MethodsThis retrospective study included 2572 patients who underwent coronary 64-slice MDCT coronary angiography from January 2008 to March 2012. Coronary angiographic scans were obtained with injection of 80 ml nonionic contrast medium. Retrospective gating technique was used to synchronize data reconstruction with the ECG signal. Maximum intensity projection, multi-planar reformatted, and volume rendering images were derived from axial scans.ResultsOf the 2572 patients, sixty (2.33 %) were diagnosed with coronary artery anomalies (CAAs), with a mean age of 53.6 ± 11.8 years (range 29–80 years). High take-off of the RCA was seen in 16 patients (0.62 %), of the left main coronary artery (LMCA) in 2 patients (0.08 %) and both of them in 2 patients (0.08 %). Separate origin of the left anterior descending artery (LAD) and left circumflex artery (LCx) from left sinus of Valsalva (LSV) was found in 15 patients (an incidence of 0.58 %). In 9 patients (0.35 %) the right coronary artery (RCA) arose from the opposite sinus of Valsalva with a separate ostium. In 6 patients (0.23 %) an abnormal origin of LCX from the right sinus of Valsalva (RSV) was found with a further posterior course within the atrioventricular groove. A single coronary artery was seen in 3 patients (0.12 %). It originated from the right sinus of Valsalva in one patient and from LSV in two patients. In two other patients (0.08 %) the left coronary trunk originated from the RSV with separate ostium from the RCA. LCA originating from the pulmonary artery was found in one patient (0.04 %). A coronary artery fistula, which is a termination anomaly, was detected in 4 patients (0.15 %).DiscussionAlthough these anomalies, which are remarkably different from the normal structure, exist as early as birth, they are incidentally encountered during selective angiography or at autopsy. The incidence in reported angiographic series ranges from 0.6 % to 1.3 %. Variations in the frequency of primary congenital coronary anomalies may possibly have a genetic background. The largest angiographic series of 126595 patients, by Yamanaka and Hobbs, reported a 1.3 % incidence of anomalous coronary artery.ConclusionThe results of this study support the use MDCT coronary angiography as a safe and effective noninvasive imaging modality for defining CAAs in an appropriate clinical setting, providing detailed three-dimensional anatomic information that may be difficult to obtain with invasive angiography.

Imaging of IPMN of the pancreas: evaluation of malignant potential and resectability

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is defined as a tumor growing in the main duct or branch duct of the pancreas, with differentiated papillary features and production of atypical mucin, as well as segmental or diffuse dilation of the main pancreatic duct (MPD), cystic dilation of the secondary branches, or both. Histologically they exhibit a wide spectrum of dysplastic changes from low and moderate grade dysplasia to high grade dysplasia (in situ carcinoma) to eventually, invasive carcinoma. The international consensus guidelines 2012 for the management of IPMNs and mucinous cystic neoplasms of the pancreas have been issued. The new international consensus guidelines recommend multidetector row CT or MR imaging with MR cholangiopancreatography (CP) in the evaluation of pancreatic cysts larger than 1 cm to check for high-risk stigmata or worrisome features. In cysts that show high-risk stigmata, surgical management is recommended. In this lecture, I would like to discuss the diagnostic performance of magnetic resonance imaging (MRI) with MR cholangiopancreatography (MRCP) and diffusion weighted imaging, and MDCT in determining the malignant potential and surgical resectability of pancreas IPMNs using pathologic and surgical analyses as reference standards. In addition, I would like to discuss interobserver agreement of each diagnostic criterion on CT and MRI for evaluation of the malignant potential of IPMNs.

Utility of multidetector row computed tomography and virtual bronchoscopy in evaluation of hemoptysis due to lung cancer

BackgroundWe aimed to evaluate the usefulness of multidetector row computed tomography (MDCT), with angiography, as well as its generated virtual bronchoscopy (VB) in the evaluation of patients with hemoptysis due to lung cancer. MethodsA prospective study was carried out on 24 patients diagnosed as primary lung cancer and presented with hemoptysis, from May 2011 to August 2014. They underwent MDCT using a 16-detector row scanner with bronchial and pulmonary angiographic techniques. MDCT-generated VB was carried out and compared to findings obtained by fiberoptic bronchoscopy (FOB). ResultsMDCT identified the cause of hemoptysis and its angiography detected the site and vascular source of bleeding in 96% of patients. Virtual bronchoscopy had sensitivity, specificity, and accuracy of 91%, 50%, and 87.5%, respectively. While FOB detected 11, 19, 3 and 2 endoluminal lesions, obstructive lesions, external compressions, and mucosal abnormalities; VB detected 7, 25, 11, and 0 lesions, respectively. ConclusionMDCT angiography is a useful and non invasive method that allows a rapid and detailed identification of abnormal vasculature responsible for hemoptysis in patients with lung cancer. MDCT-generated virtual bronchoscopy is an accurate, and non invasive method for evaluating obstructions, endoluminal masses, and external compressions in patients with hemoptysis due to lung cancer.

Utility of multidetector row computed tomography in the management of hemoptysis: An experience from Upper Egypt

BackgroundWe aimed to report our experience with the use of multidetector row computed tomography (MDCT), with angiography in the evaluation of patients with hemoptysis. MethodsA prospective study was carried out on 52 patients suffering from hemoptysis, from May 2011 to August 2014. They underwent MDCT using a 16-detector row scanner with bronchial and pulmonary angiographic techniques. ResultsMDCT identified the cause of hemoptysis in 92% of patients. MDCT angiography was able to detect the site and vascular source of bleeding in 85% of patients. A total of 92 bronchial arteries were detected in 65% of patients; 29 of these arteries (31%) were abnormally dilated. ConclusionOur results confirm that MDCT angiography is a useful method to identify and depict the bronchial arteries and to predict the presence of nonbronchial systemic vessels that supply a parenchymal lesion. MDCT angiography allows a rapid and detailed identification of abnormal vasculature and provides a precise road map which can be used to guide therapeutic arterial embolization.

FDG PET and Split-Bolus Multi-Detector Row CT Fusion Imaging in Oncologic Patients: Preliminary Results.

To assess the incremental value of split-bolus multidetector computed tomography (CT) combined with fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for follow-up of oncologic patients. The institutional ethics committee approved the use of this protocol. Thirty-eight oncologic patients who underwent FDG PET/unenhanced multidetector CT and split-bolus multidetector CT for restaging were investigated retrospectively. The split-bolus CT protocol included imaging during the hepatic arterial and portal venous phases in one scan. Software was used for fusion of the independently acquired FDG PET and split-bolus CT data, and fused datasets were compared with FDG PET/unenhanced CT data. The standard of reference for diagnosis of lesions in all patients was a combination of histologic results (if available), clinical results (medical history, physical examination, and laboratory test results), and the results of follow-up imaging (conventional CT, magnetic resonance imaging, and/or ultrasonography) for at least 6 months. Descriptive statistics were used. Fifty-nine true-positive lesions were identified with fused FDG PET/split-bolus CT; 41 were concordant and detected with both split-bolus CT and PET/unenhanced CT, 16 with split-bolus CT only, and two with PET/unenhanced CT. Two different false-positive lesions were identified with PET/unenhanced CT and PET/split-bolus CT. Furthermore, in 20 of 38 (53%) patients, FDG PET/split-bolus CT allowed detection of important additional findings (n = 40) not detected at FDG PET/unenhanced CT. Both the tumor-related findings (n = 13, 32.5%) and the non-tumor-related findings (n = 27, 67.5%) were important to the clinical treatment of these patients. Fused FDG PET/split-bolus multidetector CT provides additional information compared with FDG PET/unenhanced multidetector CT in oncologic patients.

Utility of 64-row MDCT in assessment of neonates with congenital EA and distal TEF

IntroductionEsophageal atresia (EA), with or without trachea-esophageal fistula (TEF), is one of the most challenging congenital anomalies in neonates, due to its high morbidity and mortality. The anatomy of the EA should be clearly known before surgery because the surgical approach of congenital EA with distal TEF depends on the correct evaluation of the trachea–bronchial tree and the distance between the proximal pouch and distal fistula. AimTo evaluate the application of multiple planar reformatting (MPR) and three-dimensional (3D) transparency lung volume rendering (TL-VR) with virtual tracheo-bronchoscopy by 64-row multidetector computed tomography (MDCT) in neonates with congenital EA and distal TEF. MethodsTwenty-three neonates (10 boys and 13 girls) born with EA and distal TEF were enrolled in this study. All patients were preoperatively examined by 64 multidetector non-enhanced CT examinations with multiplanar reformatting, 3D volume rendering TLVR and virtual endoscopy. The MDCT findings were correlated with operative findings in 19 cases. ResultsMDCT could detect the proximal esophageal pouches, gap distance in all patients. The gap distances ranged from 7mm to 38mm (mean 18mm). The gap distances by MDCT were the same of surgical findings in 14 cases and less than surgical findings by 1–2mm in 5 cases. No statistically significant difference was detected between the two measurements, P=0.908. The site of the fistula was seen by the axial images in 23 patients, followed by sagittal MPR and 3D TL-VR (20 patients), coronal MPR images in 18 patients while the virtual tracheo-bronchoscopy showed the site of the fistula in 16 patients. The most common site of distal fistula in this study was main trachea in 10 of 23 neonates (43.5%). ConclusionPreoperative MDCT scan with MPVR, 3D TL-VR of 64-row MDCT which is a noninvasive technique could provide more accurate information about the assessment of the origin of the fistula, the distal esophageal pouches and inter-pouch distance in neonates with EA and distal TEF.

Spectrum of hepatofugal collateral pathways in portal hypertension: an illustrated radiological review.

The purpose of this article is to describe the various portosystemic collateral pathways pertinent to portal hypertension on multi-detector row computed tomography (MDCT) and their clinical relevance, with special emphasis on the uncommon ones. The knowledge and understanding of the various patterns of portosystemic collateral channels has important implications both for the clinician and the interventionist. MDCT with its advanced post processing capabilities can exquisitely demonstrate these vascular pathways to help in therapeutic decision making.Teaching points• Portosystemic collaterals are an important cause of bleeding and hepatic encephalopathy.• Radiologists should be familiar with the imaging findings to effectively identify them.• Pre-operative knowledge of portosystemic collaterals is essential to avoid inadvertent vascular injury.

High pitch CT in triple rule-out studies: Radiation dose and image quality compared to multidetector CT

ObjectiveTo compare the image quality and radiation dose from high pitch dual source CT (128-DSCT) vs. those from retrospective acquisition with 64-row multidetector CT (64-MDCT) in triple rule-out studies. Material and methodsWe retrospectively studied 60 patients with acute chest pain: 30 with a retrospective EKG acquisition with 64-MDCT and 30 with high pitch 128-DSCT. We quantitatively analyzed the image quality by calculating the vascular density, muscular density (DM), noise, vascular density/noise ratio (VDNR), and contrast/noise ratio (CNR). We qualitatively evaluated the artifacts in the vena cava, aorta, and coronary arteries. We estimated the effective dose (ED) of radiation by means of the dose-length product. ResultsThere were no significant differences between 128-DSCT and 64-MDCT in the vascular density. The VDNR and CNR were higher on 128-DSCT than on 64-MDCT in the aorta (VDNR: 28.9±11.7 vs. 20±5.5; CNR: 24.4±10.9 vs. 16.8±5.4; P<.01), in the pulmonary arteries (VDNR: 25.5±10 vs. 20.6±6.5; CNR: 24.5±5.4 vs. 17.4±6.4; P<.01), and in the coronary arteries (VDNR: 25.9±8.2 vs. 18.9±4.9; CNR: 24.9±8.2 vs. 15.6±4.6; P<.01). There were fewer artifacts in the coronary arteries on 128-DSCT than on 64-MDCT (3 vs. 34 nondiagnostic segments; P<.001), and the ED in 128-DSCT was lower than in 64-MDCT (13.77±4 vs. 2.77±0.6mSv; P<.001). ConclusionIn triple rule-out studies, high pitch 128-DSCT delivers a lower dose of radiation and provides better image quality than retrospective acquisition with 64-MDCT.

Unusual formation and distribution of the superficial palmar arch – A case report

Celiacomesenteric trunk is a very rare vascular anomaly with a reported incidence of 0.54 %–3.4 % and represents the common trunk of origin of celiac and superior mesenteric arteries. The aim of the present study is to evaluate variations of the celiacomesenteric trunk by multidetector row computed tomography.We have retrospectively reviewed contrast enhanced computed tomographic scans of 682 patients and found celiacomesenteric trunk and its variants in 19 cases, 9 males and 10 females.The classical celiacomesenteric trunk, dividing into celiac and superior mesenteric arteries, was observed in 3 cases only. Hepatosplenomesenteric trunk with independent origin of left gastric artery from aorta was noted in 3 cases. In one case hepatomesenteric trunk with independent origin of splenic and left gastric arteries was noted. Nine cases exhibited hepatomesenteric and gastrosplenic trunks. Only in one case, the hepatosplenic and gastromesenteric trunks were seen. Two cases exhibited incomplete type of hepatomesenteric trunk not classified before. The most common celiacomesenteric trunk variant observed in this study is the hepatomesenteric trunk.Any pathology involving this single celiacomesenteric trunk can lead to catastrophic consequences jeopardizing the vascular supply of major abdominal organs. Thorough knowledge of these anatomical variants is of paramount importance to laparoscopic surgeons, interventional radiologists and clinicians alike for proper preprocedural planning to prevent any inadvertent injury to the variant arterial trunks.

Automated contrast medium monitoring system for computed tomography – Intra-institutional audit

The aim of this study was to analyze the usage and the data recorded by a RIS-PACS-connected contrast medium (CM) monitoring system (Certegra®, Bayer Healthcare, Leverkusen, Germany) over 19 months of CT activity. The system used was connected to two dual syringe power injectors (each associated with a 16-row and a high definition 64-row multidetector CT scanner, respectively), allowing to manage contrast medium injection parameters and to send and retrieve CT study-related information via RIS/PACS for any scheduled contrast-enhanced CT examination. The system can handle up to 64 variables and can be accessed via touchscreen by CT operators as well as via a web interface by registered users with three different hierarchy levels. Data related to CM injection parameters (i.e. iodine concentration, volume and flow rate of CM, iodine delivery rate and iodine dose, CM injection pressure, and volume and flow rate of saline), patient weight and height, and type of CT study over a testing period spanning from 1 June 2013 to 10 January 2015 were retrieved from the system. Technical alerts occurred for each injection event (such as system disarm due to technical failure, disarm due to operator's stop, incomplete filling of patient data fields, or excessively high injection pressure), as well as interoperability issues related to data sending and receiving to/from the RIS/PACS were also recorded. During the testing period, the CM monitoring system generated a total of 8609 reports, of which 7629 relative to successful injection events (88.6%). 331 alerts were generated, of which 40 resulted in injection interruption and 291 in CM flow rate limitation due to excessively high injection pressure (>325psi). Average CM volume and flow rate were 93.73±17.58mL and 3.53±0.89mL/s, and contrast injection pressure ranged between 5 and 167psi. A statistically significant correlation was found between iodine concentration and peak IDR (rs=0.2744, p<0.0001), as well as between iodine concentration and iodine dose (rs=0.3862, p<0.0001) for all CT studies. Automated contrast management systems can provide a full report of contrast use with the possibility to systematically compare different contrast injection protocols, minimize errors, and optimize organ-specific contrast enhancement for any given patient and clinical application. This can be useful to improve and harmonize the quality and consistency of contrast CT procedures within the same radiological department and across the hospital, as well as to monitor potential adverse events and overall costs.

Characterization of trabecular bone plate-rod microarchitecture using multirow detector CT and the tensor scale: Algorithms, validation, and applications to pilot human studies.

Osteoporosis is a common bone disease associated with increased risk of low-trauma fractures leading to substantial morbidity, mortality, and financial costs. Clinically, osteoporosis is defined by low bone mineral density (BMD); however, increasing evidence suggests that trabecular bone (TB) microarchitectural quality is an important determinant of bone strength and fracture risk. A tensor scale based algorithm for in vivo characterization of TB plate-rod microarchitecture at the distal tibia using multirow detector CT (MD-CT) imaging is presented and its performance and applications are examined. The tensor scale characterizes individual TB on the continuum between a perfect plate and a perfect rod and computes their orientation using optimal ellipsoidal representation of local structures. The accuracy of the method was evaluated using computer-generated phantom images at a resolution and signal-to-noise ratio achievable in vivo. The robustness of the method was examined in terms of stability across a wide range of voxel sizes, repeat scan reproducibility, and correlation between TB measures derived by imaging human ankle specimens under ex vivo and in vivo conditions. Finally, the application of the method was evaluated in pilot human studies involving healthy young-adult volunteers (age: 19 to 21 yr; 51 females and 46 males) and patients treated with selective serotonin reuptake inhibitors (SSRIs) (age: 19 to 21 yr; six males and six females). An error of (3.2% ± 2.0%) (mean ± SD), computed as deviation from known measures of TB plate-width, was observed for computer-generated phantoms. An intraclass correlation coefficient of 0.95 was observed for tensor scale TB measures in repeat MD-CT scans where the measures were averaged over a small volume of interest of 1.05 mm diameter with limited smoothing effects. The method was found to be highly stable at different voxel sizes with an error of (2.29% ± 1.56%) at an in vivo voxel size as compared to the original ex vivo voxel size. Tensor scale measures derived from imaging under in vivo and ex vivo conditions with significantly different modulation transfer function, i.e., difference in "true resolution," showed strong linear correlation (r = 0.92). The study of healthy volunteers shows that, after adjustment for height and weight, males have a 14% higher mean TB plate-width as compared to females (p < 0.05). SSRI-treated patients have 12.5% lower mean TB plate-width (p = 0.052) as compared to age-similar and sex-, height-, and weight-matched healthy controls. In contrast, the observed group difference in dual-energy x-ray absorptiometry (DXA)-derived hip BMD was 10.5% between males and females and only 5.04% between healthy controls and patients on SSRIs. Tensor scale analysis of MD-CT images yields accurate and reproducible characterization of TB plate-rod microarchitecture that may be more sensitive than DXA-derived BMD to sex differences and to the skeletal changes associated with medical conditions or their treatments.