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Purpose: The thoracic spine is considered a rigid region because it is restricted by the rib cage. Previously, we reported functional alignments and range of motion (ROM) at all segmental levels. The purpose of this study was to investigate dynamic changes of the dural sac and spinal cord in the thoracic spine using a multidetector-row computed tomography (MDCT).Methods: Fifty patients with cervical or lumbar spinal disease were prospectively enrolled. After preoperative myelography, MDCT was performed at maximum passive flexion and extension. The anteroposterior diameter and cross-sectional area of the dural sac and spinal cord in the axial plane were measured using Scion imaging software. We also evaluated the correlation between the change ratio of the cross-sectional area and segmental kyphotic angle and ROM.Results: In flexion, the anteroposterior diameter of the dural sac was larger than in extension. The cross-sectional area in the upper and middle regions was smaller, but was larger in the lower region. The anteroposterior diameter and cross-sectional area of the spinal cord in the upper and middle regions were smaller than in extension, but these values were nearly the same in both flexion and extension in the lower region. Change ratios of the cross-sectional area were correlated with segmental kyphotic angle rather than ROM.Conclusions: The thoracic spine showed some dynamic changes of the dural sac and spinal cord in the axial plane within functional motion. Segmental kyphotic angle, rather than segmental ROM, was the more important factor affecting dimensions of the dural sac and spinal cord. [ABSTRACT FROM AUTHOR]

Adrenal myelolipoma is an unusual, benign and biochemically inactive tumor that is composed of mature adipose and hematopoietic tissue. It is usually diagnosed accidentally and nowadays much more frequently because of widespread use of ultrasonography, computed tomography (CT) and magnetic resonance imaging. Adrenal myelolipoma is usually unilateral and asymptomatic, though known to be associated with obesity, hypertension, endocrinological disorders and some malignancies. We report herein two cases of right-sided giant adrenal myelolipoma diagnosed by multidetector-row CT. One patient was symptomatic because of a large mass in the right upper abdomen, which on imaging with CT was seen to be right adrenal myelolipoma. Another patient had a large left side Bochdalek hernia and right adrenal myelolipoma was incidentally discovered on CT.

Objectives: The purpose of this study was to clarify the difference in diagnostic accuracy for alveolar bone defects of the mandibular molar region between cone-beam computed tomography (CBCT) and multidetector-row CT (MDCT) by receiver-operating characteristic (ROC) analysis. Methods: Artificial alveolar bone defects in a dry human mandible were scanned with a CBCT system (CB MercuRay; Hitachi Medical Corporation) and an MDCT scanner (Aquilion 16-slice; Toshiba Medical Systems Corporation). The field of view (FOV) for the CT images was 5, 10, and 15 cm. Five radiologists observed the obtained DICOM CT images using OsiriX version 3.8.1 (OsiriX Foundation) on an iMac computer (Apple Computer Inc.), and rated the confidence levels for detecting the bone defects using a continuously distributed test. The areas under the ROC curves (Az values) were then calculated with ROCKIT 1.1B (Charles E Metz, The University of Chicago). The significance of differences in the Az values between CBCT and MDCT was tested by the Steel-Dwass method with a significance level of 5 %. Results: The overall differences in the Az values between CBCT and MDCT were not significant. However, in the images with 15-cm FOV, the Az value for CBCT was significantly lower than that for MDCT. Conclusions: The diagnostic accuracy for alveolar bone defects was comprehensively equal between CBCT and MDCT. In CBCT, a large FOV can be avoided to reduce the radiation exposure dose, because enlargement of the FOV does not improve the diagnostic accuracy. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to determine the optimal cut-off value of lymph node size for diagnosing metastasis in gastric cancer with multidetector-row computed tomography (MDCT) after categorizing perigastric lymph nodes into three regions. Methods: The study included 90 gastric cancer patients who underwent gastrectomy. The long-axis diameter (LAD) and short-axis diameter (SAD) of all visualized lymph nodes were measured with transverse MDCT images. The locations of lymph nodes were categorized into three regions: lesser curvature, greater curvature, and suprapancreatic. The diagnostic value of lymph node metastasis was assessed with receiver operating characteristic (ROC) analysis. Results: The area under the curve was larger for SAD than LAD in all groups. The optimal cut-off values of SAD were determined as follows: overall, 9 mm; differentiated type, 9 mm; undifferentiated type, 8 mm; lesser curvature region, 7 mm; greater curvature region, 6 mm; and suprapancreatic region, 9 mm. The diagnostic accuracies for lymph node metastasis using individual cut-off values were 71.1 % based on histological type and 76.6 % based on region of lymph node location. Conclusions: The diagnostic accuracy of lymph node metastasis in gastric cancer was improved by using individual cut-off values for each lymph node region. Key points: • Multidetector-row computed tomography is widely used to predict pathological nodal status. • An optimal cut-off value of lymph node size has not been determined. • Cut-off values were assessed according to histology and nodal location. • The optimal cut-off values differed based on histology and nodal location. • Diagnostic accuracy was improved by using individual cut-off values for each region. [ABSTRACT FROM AUTHOR]

Study design: Imaging study of thoracic spine. Objective: The purpose of this study was to investigate dynamic alignment and range of motion (ROM) at all segmental levels of thoracic spine. Summary of background data: Thoracic spine is considered to have restricted ROM because of restriction by the rib cage. However, angular movements of thoracic spine can induce thoracic compressive myelopathy in some patients. Although few previous studies have reported segmental ROM with regard to sagittal plane, these were based on cadaver specimens. No study has reported normal functional ROM of thoracic spine. Methods: Fifty patients with cervical or lumbar spinal disease but neither thoracic spinal disease nor compression fracture were enrolled prospectively in this study (34 males, 16 females; mean age 55.4 ± 14.7 years; range 27-81 years). After preoperative myelography, multidetector-row computed tomography scanning was performed at passive maximum flexion and extension position. Total and segmental thoracic kyphotic angles were measured and ROM calculated. Results: Total kyphotic angle (T1/L1) was 40.2° ± 11.4° and 8.5° ± 12.8° in flexion and extension, respectively ( P < 0.0001). The apex of the kyphotic angle was at T6/7 in flexion. Total ROM (T1/L1) was 31.7° ± 11.3°. Segmental ROM decreased from T1/2 to T4/5 but increased gradually from T4/5 to T12/L1. Maximum ROM was at T12/L1 (4.2° ± 2.1°) and minimum at T4/5 (0.9° ± 3.0°). Conclusions: Thoracic spine showed ROM in sagittal plane, despite being considered a stable region. These findings offer useful information in the diagnosis and selection of surgical intervention in thoracic spinal disease. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To clarify the optimal iodine dose of contrast material for 3-dimensional multidetector-row CT angiography (3D-MDCTA) of the venous vasculature of the liver using volume rendering technique. Materials and methods: This study included 103 patients who were randomly assigned to 5 contrast-enhanced MDCT protocol groups with different body-weight-tailored doses of contrast material: 500, 600, 630, 650, and 700mgI/kg body weight. The arterial, portal, and hepatic parenchymal phases were obtained to evaluate enhancement values of the aorta, portal vein, and hepatic vein. Visualization of the portal and hepatic veins on the volume-rendering images of 3D-MDCTA was evaluated using a 5-point grade. Dunnett''s test was used to compare the mean enhancement value and mean grades of image quality (700mgI/kg dose group was control). Results: The mean enhancement values of portal and hepatic vein in the group with 500 and 600mgI/kg were significantly lower than those of the control group. During visual assessment, a significantly lower mean grades were observed in 500mgI/kg groups for the portal vein, and 500 and 600mgI/kg groups for hepatic vein. There were no significant intergroup differences in mean enhancement values and visual assessment among the groups using 630mgI/kg or more. Conclusion: Iodine doses of 630mgI/kg was recommended for 3D-MDCTA. [Copyright &y& Elsevier]

Copyright of La Radiologia Medica is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: To review the role of imaging in the diagnosis of recurrent disease in previously treated non-small cell lung cancer (NSCLC) and discuss the imaging pitfalls. Methods: A comprehensive review of published literature on CT and PET imaging of NSCLC recurrence was performed. Diagnostic and prognostic values are discussed. Representative imaging examples are illustrated. Results: Up to 30% of NSCLC recurrences present as loco-regional, involving treated hemithorax and ipsilateral lymph nodes, while 70% present as metachronous distant metastases. CT and PET-CT play an important role in the early detection of recurrence; indications for imaging vary depending on pathological features. Conclusion: Imaging plays a central role in the identification of recurrence and may predict prognosis. Key Points: [ABSTRACT FROM AUTHOR]

Intraventricular arteriovenous malformation (AVM) is a rare congenital vascular disorder that is often associated with primary intraventricular hemorrhage (IVH) and a rapid clinical course. Acute imaging diagnosis requires depiction of both the location of hemorrhage and vascular nidus for emergent management. In this report, a 17-year-old teenager developed primary IVH with presentation of consciousness change during a video game. Multidetector-row computed tomographic angiography (CTA) demonstrated an AVM in the right lateral ventricle and its angioarchitectural relationship to the surrounding intracranial structures. Although selective angiography is essential both in planning treatment for cerebral AVMs and in establishing the final diagnosis, CTA can be an important first-line imaging modality to quickly confirm the diagnosis and hence initiate prompt management. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to compare diffusion-weighted magnetic resonance imaging (DWI) and multidetector-row computed tomography (MDCT) for detection of primary pancreatic cancer by reviewing images of patients at high risk for pancreatic cancer with main pancreatic duct (MPD) dilatation shown by magnetic resonance cholangiopancreatography (MRCP). Methods: From October 2007 to September 2009, 83 patients who had undergone both DWI and MDCT with MPD dilatation were identified and were reviewed by four readers (2 radiologists and 2 gastroenterology fellows). Diagnostic performance in pancreatic cancer detection was evaluated with 95% confidence intervals. Statistically significant differences in the detection of pancreatic cancer between DWI and MDCT were compared by receiver operating characteristics and the confidence of the diagnosis by the paired t test. Results: Thirty-two of 83 patients were diagnosed with primary pancreatic cancer by histological evaluation of 15 surgical and 2 endoscopic ultrasound-guided fine needle aspiration samples, and by the clinical course for 15 lesions. Overall average accuracies of pancreatic cancer detection by the four readers were 84% with DWI and 86% with MDCT. Conclusion: Performance of DWI and MDCT was equivocal for detection of pancreatic cancer in a high-risk population with MPD dilatation. The combination of MRCP and DWI for detection of pancreatic cancer allowed identification of a high-risk population and tumor detection with a single imaging modality with no need for contrast medium. [ABSTRACT FROM AUTHOR]

Abstract: Background/Purpose: The aim of this study was to investigate the diagnostic potential of computed tomography cholangiography (CTC) and magnetic resonance cholangiopancreatography (MRCP) in children with pancreaticobiliary maljunction (PBM). Methods: Fifty-three children with PBM were consecutively treated between 1997 and 2009. Among them, the patients who underwent CTC and/or MRCP preoperatively were enrolled in this study. Computed tomography cholangiography was examined after infusion of meglumine iodoxamate with subsequent 3-dimensional rendering. The visualization of the biliary and pancreatic duct systems was evaluated and compared with that visualized with MRCP. The findings of direct cholangiography were used as the standard of reference. Results: Of the 53 cases with PBM, 17 cases were examined by CTC, 10 cases by MRCP, and 17 with both. The extrahepatic bile tract was visualized in 32 (94.1%) of 34 patients in CTC and in all 27 patients in MRCP. The intrahepatic bile duct was more frequently demonstrated by MRCP than by CTC (96.3% vs 70.6%, P = .02). Pancreaticobiliary maljunction was noted in 13 (38.2%) of 34 with CTC and in 12 (44.4%) of 27 with MRCP. The minimum age for visualization of PBM was at 10 months in CTC and at 1 year and 11 months in MRCP, respectively. The main pancreatic duct was more frequently visualized by MRCP than by CTC (81.5% vs 8.8%, P < .001). Conclusions: Magnetic resonance cholangiopancreatography provides superior visualization of the intrahepatic duct and the pancreatic system when compared with CTC. However, it is still challenging to perform a good-quality examination in young infant. The great advantage of CTC is its ability to produce high-quality images without respiratory artifacts and that it allows accurate assessment of the presence of PBM equivalent to MRCP. [Copyright &y& Elsevier]

Aim: The purpose of this study is to determine the value of diffusion-weighted MR imaging (DWI) in the detection of liver metastases in patients with pancreatic tumors when compared to multidetector-row CT (MDCT). Methods: DWI and MDCT were performed in 31 consecutive patients with newly diagnosed, potentially resectable pancreatic tumors. CT images were obtained in the arterial and the portal venous phase. For DWI, a respiratory-triggered single-shot echo-planar imaging sequence (b values: 0, 300, and 600 s/mm(2)) was acquired. Images were analyzed in consensus by two radiologists blinded to the clinical data. Imaging results were correlated with intraoperative surgical and ultrasound findings as well as with results of histopathologic analysis and imaging follow-up. Results: Sensitivity and specificity in detecting liver metastases were 53.3% and 77.8% for MDCT and 86.7% and 97.5% for DWI, respectively. In our study population DWI would have changed the therapeutic management in 4 out of 31 patients (12.9%) when compared to MDCT. Conclusion: In the present pilot study, DWI performed significantly better than MDCT in the detection of liver metastases in patients with pancreatic tumors. Therefore, DWI may help to optimize therapeutic management in those patients in the future. [ABSTRACT FROM AUTHOR]

Abstract: Patients with ulcerative colitis are at increased risk for venous thrombosis. We report herein the case of a 28-year-old woman who developed multiple intraabdominal venous thrombosis, including partial Budd–Chiari syndrome in association with intracranial venous thrombosis and pulmonary embolism during the relapse of a known ulcerative colitis. Multidetector-row computed tomography (MDCT) allowed depiction of multiple intraabdominal sites of thrombosis including right and medial hepatic veins, left portal vein, splenic vein and left ovarian vein and demonstrated complete resolution of the multiple thrombi after anticoagulant therapy. The association of partial Budd–Chiari syndrome with other thrombi involving portal, splenic and ovarian veins in association with ulcerative colitis, has, to our knowledge never been reported yet. In addition, the potential role of MDCT in the detection of possible multiple thrombosis in patients with ulcerative colitis has never been emphasized. [ABSTRACT FROM AUTHOR]

Copyright of Der Gastroenterologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of La Radiologia Medica is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The airway can become obstructed as a result of compression by an elongated aortic arch. In this study we evaluated tracheal compression using multidetector-row CT in patients with congenital heart disease and an elongated aortic arch. The trachea was measured at the level of the aortic arch in 205 children and young adults and then the severity of tracheal compression was determined by measuring the tracheal diameter ratio (short axis diameter/long axis diameter). Patients were divided as follows: group I (normal aortic arch; n=166), group II (transversely running aortic arch; n=22), and group III (elongated aortic arch; n=17). From the viewpoint of the relationship of the great arteries, group II had D-malposition, and group III had L-malposition. Age, height, weight and body surface area were significantly correlated with the short and long axis diameter in group I. There was a negative correlation between tracheal diameter ratio and the physical size parameters. The tracheal diameter ratio in group III was 0.50±0.13, which was significantly lower than in groups I and II ( P<0.01 and 0.05, respectively). Even apparently asymptomatic patients with an elongated aortic arch can have tracheal compression. An elongated aortic arch may be a useful predictor of tracheal compression. [ABSTRACT FROM AUTHOR]

There are only few basic papers treating of the imaging features and anatomic variations of the normal greater omentum (GO). The goal of our study was to exploit the new major capabilities of 64-row MDCT—in terms of spatial resolution and crucial improvements in the quality of 2D and 3D reformatted images—to extensively review the in vivo anatomy, landmarks and variations of the normal GO a large cohort of patients. The abdominal 64-row MDCT of a series of 111 patients (51 females and 60 males) were scrupulously retrospectively analysed to individually characterize the morphologic and anatomic features of the GO through multiplanar reconstructions, various methods of measure and selective volume rendering views. The GO was clearly identified, localized and characterized in all patients. The good delineation of the GO vessels, which predominantly have a vertical course, was the key of this analysis. Several individual and sex related anatomic variations were found. In females the left hemi-GO was found being statistically significantly longer than the right ( P = 0.0053) but also longer than the male left hemi-GO ( P < 0.0001). On the contrary, no statistically significant variation was found between the length of the left and right hemi-GO in males and between the length of the right hemi-GO in males and females. The average length of the entire GO also appeared sex-related being very statistically significantly longer in females than in males ( P = 0.0002). In males the mean thickness of the GO (mtGO) was paralleling the increasing of the maximal thickness of the subcutaneous fat (mtSF). In females it remained rather independent from the increasing of the mtSF and, as a consequence, in obese and very obese females the increasing volume of the abdomen is caused preponderantly by the increasing amount of SF. In most males and females the mtGO followed the increasing of the amount of intraabdominal fat. Finally the projection of a less or more important portion of the GO into the pre-hepatic sub-phrenic space was an almost exclusive male feature found in 32% of males versus only 2% in females. Abdominal 64-row MDCT is able to perfectly delineate the anatomy and landmarks of the normal GO. Our study reveals several sex related anatomical variations. Knowledge of these anatomic variations may be helpful for a better understanding and diagnosis of various pathologic processes involving the GO including vascular, inflammatory and neoplastic diseases but also for surgical therapy planning including reconstructive surgery. [ABSTRACT FROM AUTHOR]

Mitral-aortic intervalvular fibrosa aneurysm is a rare disease whose aetiology remains a matter of debate. Here we present the youngest reported patient with the disease, a 6-month-old boy, without a history of infection, which supports a congenital origin as initially proposed. Multidetector-row CT (MDCT) surpassed echocardiography in delineating the intracardiac anatomical details with high spatial resolution, confirming the important problem-solving role of MDCT in the diagnosis of congenital heart disease. [ABSTRACT FROM AUTHOR]

We evaluated the difference in computed tomography (CT) attenuation values of the intracranial arterial and venous systems among the various contrast injection protocols (higher iodine delivery rate or higher concentration of the agent) on the source images of intracranial three-dimensional CT angiography (3D-CTA) using a multidetector-row CT (MDCT) scanner. We used 100 ml of iopamidol 300 at an injection rate of 3.0 ml/s, 100 ml of iopamidol 300 at an injection rate of 3.7 ml/s, and 80 ml of iopamidol 370 at an injection rate of 3.0 ml/s. There were 10 patients in each group. Attenuation values of the bilateral internal carotid arteries (ICAs), basilar artery trunk, bilateral cavernous sinuses (CSs), and Galenic vein were measured quantitatively on the axial CT angiographic source images obtained by four-channel MDCT. Injection of the high-concentration contrast with a higher iodine-delivery rate achieved good arteriovenous contrast at the cavernous portion. With the same rate of iodine delivery, injection of the intermediate concentrate agent increased the CT value of not only the ICAs but also the CSs. High-concentration contrast could increase ICA attenuation without intracavernous attenuation gain during the “first-pass” phase. [ABSTRACT FROM AUTHOR]

Pulmonary embolism (PE) is a life-threatening condition. Multidetector CT pulmonary angiography is currently the imaging method of choice for the detection of PE. The aim of this pictorial essay is to review the appearances of PE on multidetector CT pulmonary angiography, including signs that differentiate acute and chronic PE and markers of severity. The features of a non-diagnostic study and pitfalls leading to a false-positive or false-negative study are presented. [ABSTRACT FROM AUTHOR]

Our aim was to investigate the diagnostic reliability of multidetector-row computed tomography (MDCT) for preoperative assessment of local tumoral spread in hilar cholangiocarcinoma. Thirteen of 30 consecutive patients with hilar cholangiocarcinoma who underwent surgery, excluding 17 patients who underwent biliary drainage or preoperative portal embolization, were retrospectively evaluated. Using MDCT systems of 4 detector rows or 16 detector rows, plain and dynamic contrast-enhanced images of three phases were obtained. Extent of tumor spread and lymph node metastasis were assessed with MDCT and compared with histopathological findings. The Bismuth-Corlette classification of hilar cholangiocarcinoma with MDCT were type I, 1 patient; type IIIa, 3 patients; type IIIb, 4 patients; and type IV, 5 patients; those with histopathological findings were type I, 1 patient; type IIIa, 2 patients; type IIIb, 4 patients; and type IV, 6 patients. One patient diagnosed as type IIIa with MDCT was pathologically diagnosed as type IV. Accuracy of MDCT in tumoral spread was 92.3%, although that of lymph node metastasis was 54%. MDCT is likely to play an important role in evaluation of focal lesion spread especially in intrapancreatic tumor invasion, although a greater number of cohort cases are necessary to clearly define its role. [ABSTRACT FROM AUTHOR]

Neonatal congenital heart disease is a most difficult area of diagnostic radiology because of the small patient body size and fast resting heart rate. Recently, the spatial and temporal resolution of multidetector-row CT (MDCT) has evolved so that neonatal congenital heart disease can be precisely diagnosed. We describe the role of MDCT in neonatal congenital heart disease and offer tips for the scanning procedure to familiarize radiologists with this developing field. [ABSTRACT FROM AUTHOR]

This study was performed for evaluation of high- and low-contrast resolution in multidetector-row CT (MDCT) with 16 detector rows. For evaluating high-contrast resolution, a phantom was scanned ten times at 100 mA s with 24 patterns of scan parameters under several X-ray beam widths, X-ray tube voltages, X-ray tube rotation times, and helical pitches. Three radiological technologists observed the images visually. For evaluating low-contrast resolution, a phantom was scanned ten times at 100 mA s with the 24 patterns of scan parameters, which were the same as for high-contrast resolution. The images were examined based on receiver operating characteristic (ROC) curves. The high-contrast resolution deteriorated in the off-center locations when helical pitches of 1.375:1 or 1.75:1 were used. High helical pitch (>0.9375:1) and low tube voltage had significant effects on the low-contrast resolution. However, a wide X-ray beam width and short X-ray tube rotation time had no definite influence. Therefore, a helical pitch of 0.5625:1 should be used when the contrast resolutions are really important, and a wide X-ray beam width and short X-ray tube rotation time can improve the temporal resolution without deterioration of contrast resolution. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the decreasing of cardiac motion artifact and whether the extent of ground-glass attenuation of idiopathic pulmonary fibrosis (IPF) was accurately assessed by electrocardiography (ECG)-triggered high-resolution computed tomography (HRCT) by 0.5-s/rotation multidetector-row CT (MDCT). ECG-triggered HRCT were scanned at the end-diastolic phase by a MDCT scanner with the following scan parameters; axial four-slice mode, 0.5 mm collimation, 0.5-s/rotation, 120 kVp, 200 mA/rotation, high-frequency algorithm, and half reconstruction. In 42 patients with IPF, both conventional HRCT (ECG gating(−), full reconstruction) and ECG-triggered HRCT were performed at the same levels (10-mm intervals) with the above scan parameters. The correlation between percent diffusion of carbon monoxide of the lung (%DLCO) and the mean extent of ground-glass attenuation on both conventional HRCT and ECG-triggered HRCT was evaluated with the Spearman rank correlation coefficient test. The correlation between %DLCO and the mean extent of ground-glass attenuation on ECG-triggered HRCT (observer A: r = −0.790, P < 0.0001; observer B: r = −0.710, P < 0.0001) was superior to that on conventional HRCT (observer A: r = −0.395, P < 0.05; observer B: r = −0.577, P = 0.002) for both observers. ECG-triggered HRCT by 0.5 s/rotation MDCT can reduce the cardiac motion artifact and is useful for evaluating the extent of ground-glass attenuation of IPF. [ABSTRACT FROM AUTHOR]

The aim of this study was to improve the contrast-to-noise ratio on noncontrast head computed tomography (CT) images, which are crucial for assessing patients with acute ischemic stroke. We applied a technique combining volume helical scanning with a three-dimensional (3D) denoising filter. We scanned phantoms for low-contrast resolutions and helical/cone-beam artifacts as well as stroke patients using a 16-row multidetector-row CT (MDCT) unit. Volume helical scans with 1-mm collimation and nonhelical scans with 8-mm thickness were performed. From the 1-mm thick volume data, 8-mm thick contiguous images were generated before and after applying a 3D denoising filter. On images stacked from volume data, the contrast-to-noise ratio was significantly improved by the 3D denoising filter and was nearly the same as that on nonhelical images. On stacked volume images, artifacts due to the cone beam and the helical scan were increased with larger helical pitches, but bone-related streak artifacts in the posterior fossa and underneath the calvarium were reduced when compared with nonhelical images. Volume helical scan with a 3D denoising filter effectively improves image quality in noncontrast head MDCT images. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the diagnostic efficacy of curved planar reformations along the duct (long-axis CPR) and series of reformations perpendicular to the duct (short-axis MPR) in evaluating T-factors of pancreaticobiliary malignancy. Materials and Methods: Twenty-five patients with surgically proven pancreaticobiliary malignancy (12 bile duct cancers and 13 pancreas cancers) were evaluated. A dynamic study was performed with multidetector-row CT with four detectors, and reconstructed with 1mm thickness and intervals. Tracing the center of the duct system on axial images, long-axis CPR images and serial short-axis MPR images were obtained. Two radiologists interpreted the T factor of the diseases three times: session (1), axial images only; session (2), axial, coronal and sagittal multiplanar reformation images; and session (3), axial, long-axis CPR, and short-axis MPR images. Receiver operating characteristic curves were analyzed. Results: In evaluations of bile duct cancer, Az values of (3) (0.95, 0.92) were higher than those of (1) (0.89, 0.88) and (2) (0.92, 0.89), with some significant differences. In evaluations of pancreas cancer, Az values of all interpretations were almost equal. Conclusion: Long-axis CPR and short-axis MPR images were suggested to be useful as additional images to the original axial images in evaluating the local extension of bile duct carcinomas. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To prospectively evaluate the diagnostic performance of 64-section multidetector computed tomography (MDCT) to detect significant coronary artery stenosis using conventional coronary angiography (CCA) as the reference standard. Materials and methods: Institutional Review Board approval and informed consent were obtained. In this prospective study, 80 patients (61 male, 19 female, mean age 56) were examined. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated. McNemar test was used to search for the significant difference between 64-section MDCT angiography and CCA to detect stenosis. Also, kappa index (κ) for the agreement between MDCT angiography and CCA was calculated. Results: The sensitivity, specificity, positive (PPV) and negative predictive values (NPV) for detecting significant stenosis were 96%, 98%, 91%, 99%, respectively. The sensitivity, specificity, PPV and NPV for classification of patients with or without CAD were 100% for all. McNemar test demostrated no significant difference between 64-section MDCT angiography and CCA. Also, kappa index (κ) indicated excellent agreement. Conclusion: Sixty-four section MDCT angiography is an effective diagnostic tool for the detection of significant coronary artery stenosis. Especially, the potential to differentiate patients with and without CAD may provide MDCT an important role in the prevention of unnecessary invasive diagnostic procedures. [Copyright &y& Elsevier]

Acute thoracic aortic syndromes encompass a spectrum of emergencies presenting with acute chest pain and marked by a high risk of aortic rupture and sudden death. These include nontraumatic disease entities of the thoracic aorta, namely, dissection, intramural haematoma, penetrating atherosclerotic ulcer and aneurysm rupture. In clinical practice, the most frequent imaging procedure used in the diagnostic assessment of these diseases is computed tomography (CT), which, thanks to recent technological developments [multidetector-row computed tomography (MDCT)], affords important diagnostic possibilities and very interesting future perspectives. This paper on the use of MDCT in the evaluation of acute thoracic nontraumatic aortic syndromes illustrates the examination technique and the key imaging findings related to each disease. Moreover, the role of MDCT for planning specific treatment is also highlighted. [ABSTRACT FROM AUTHOR]

Image quality, visible lumen and patency of lower limb stents was assessed by multidetector-row computed tomography (MDCT) angiography using various reconstruction parameters and the results compared with conventional angiography. Fourteen patients (25 stents) were evaluated. From MDCT datasets, axial and coronal oblique reformations were reconstructed using differing reconstruction parameters (slice thickness, kernel, views). Artifacts and image quality were assessed using a five-degree scale (1=excellent, 5=poor). Visible stent diameter was measured. Stenosis severity was compared with calibrated catheter angiography. The image quality of medium and sharp image kernels were good/fair (1.9-2.4), while smooth kernel provided only acceptable/poor image quality (3.9-4.4). Coronal oblique images were rated superior to assess in-stent lumen rather than axial. Using medium and sharp kernels, the visible stent lumen was significantly greater than using smooth kernel (P<0.001). thirteen out of fourteen patients (24/25 stents) were correctly classified as patent. In one patient, in-stent stenosis (> or =50%) was falsely diagnosed using CT angiography (CTA) with smooth kernel and was, therefore, rated as false positive. Coronal oblique views, as well as medium and sharp kernels, have shown the best results regarding image quality to assess stent patency in the lower limb. Therefore, MDCT could be a valuable non-invasive modality for stent imaging in the peripheral vasculature. [ABSTRACT FROM AUTHOR]

Background: Video-assisted thoracoscopic (VATS) thymectomy has been applied as a surgical option for autoimmune myasthenia gravis. Prior identification and fine division of the thymic veins are critical to the prevention of unexpected severe bleeding that may require conversion to open surgery. Until recently, such bleeding could be avoided only by meticulous dissection of thymic fat tissue away from the left brachiocephalic vein (LBV). With recent advances in computed tomography (CT), multidetector-row computed tomography (MDCT) can readily be obtained and provides three-dimensional (3D) images. This study explored its value for preoperative identification of the thymic veins draining into the LBV, and thus for prevention of injury to these veins during endoscopic thymectomy.Methods: Five patients with myasthenia gravis, thymoma, or both underwent enhanced MDCT preoperatively. The thymic veins draining into the LBV were visualized using both horizontal and sagittal/coronal CT images. Then 3D images were reconstructed to enable operators to simulate endoscopic views. During each VATS extended thymectomy, the numbers and branching patterns of the thymic veins were compared with the preoperative MDCT images.Results: The thymic veins draining into the LBV were clearly identified with MDCT in all five patients examined. Reconstructed 3D images clearly located their courses in the thymic/fat tissue and their entry routes into the LBV, thus simulating the actual intraoperative endoscopic views. All tributaries divided during surgery were identified preoperatively with MDCT.Conclusions: Location of thymic veins with MDCT can provide precise preoperative information about thymic venous anatomy. This easy and less invasive examination has the potential to make VATS thymectomy easier and safer. [ABSTRACT FROM AUTHOR]

We present a performance evaluation of a recently introduced dual-source computed tomography (DSCT) system equipped with two X-ray tubes and two corresponding detectors, mounted onto the rotating gantry with an angular offset of 90 degrees . We introduce the system concept and derive its consequences and potential benefits for electrocardiograph [corrected] (ECG)-controlled cardiac CT and for general radiology applications. We evaluate both temporal and spatial resolution by means of phantom scans. We present first patient scans to illustrate the performance of DSCT for ECG-gated cardiac imaging, and we demonstrate first results using a dual-energy acquisition mode. Using ECG-gated single-segment reconstruction, the DSCT system provides 83 ms temporal resolution independent of the patient's heart rate for coronary CT angiography (CTA) and evaluation of basic functional parameters. With dual-segment reconstruction, the mean temporal resolution is 60 ms (minimum temporal resolution 42 ms) for advanced functional evaluation. The z-flying focal spot technique implemented in the evaluated DSCT system allows 0.4 mm cylinders to be resolved at all heart rates. First clinical experience shows a considerably increased robustness for the imaging of patients with high heart rates. As a potential application of the dual-energy acquisition mode, the automatic separation of bones and iodine-filled vessels is demonstrated. [ABSTRACT FROM AUTHOR]

The accuracy of 16-row multidetector CT in the visualization of different peripheral artery stents and in the appraisal of in-stent stenosis was assessed. Nine different stent types (nitinol and stainless steel) with three diameters (6, 8 and 10 mm) were used; altogether 27 stents were analyzed in a barrel-shaped vascular model. Low-grade (<40%) and high-grade (>60%) in-stent stenoses were simulated by polyurethane sticks (70 HU) of differing diameters (2-6 mm). Imaging was performed with 16x0.75-mm detector collimation, 130 mAs, 120 kV, 12-mm table feed/rotation, 1.0-mm slice thickness and 0.5-mm increment. The stent diameter, strut thickness, in-stent attenuation values, degree and degree of in-stent stenosis were evaluated. Nitinol stents showed significantly (P<10-6) less stent lumen narrowing, artificial strut thickening and overestimation of the degree of in-stent stenoses than stainless steel stents. In-stent attenuation values and artificial strut thickening were significantly (P<10-6) lower in 10- and 8-mm stents than in 6-mm stents. Stent lumen narrowing was significantly less in 10-mm stents than in 8-mm (P<10-4) or 6-mm (P<10-6) stents. In-stent stenoses were significantly overestimated, irrespective of the stent diameter. In 6-mm stents overestimation was significantly higher than in 8-mm (P<0.01) or 10-mm stents (P<10-6). Under in-vitro conditions 16-row MDCT allowed an accurate identification of in-stent stenosis, but significantly overestimated the effective degree of the stenosis. [ABSTRACT FROM AUTHOR]

Coronary calcium mass percentiles can be derived from electron beam CT as well as from multidetector-row CT of all manufacturers. Coronary calcium mass may serve as a more individualized substitute for age for cardiac risk stratification. The aim was to investigate the potential impact of CT coronary calcium mass quantification on cardiac risk stratification using an adjusted Framingham score. Standardized coronary calcium mass was determined by multidetector-row CT in a total of 1,473 patients (1,038 male, 435 female). The impact on risk stratification of replacing the traditional Framingham age point score by a point score based on calcium mass relative to age was tested. Any coronary calcium found in males in the age group of 20-34 years and females in the age group of 20-59 years results in an increase of the Framingham score by 9 and 4-7 points, respectively. Only in males 65 years of age and older, none or minimal amounts of coronary calcium decrease the Framingham score by three points. The coronary calcium mass and age-related scoring system may have impact on the reassignment of patients with an intermediate Framingham risk to a lower or higher risk group. [ABSTRACT FROM AUTHOR]

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The purpose of this study was to establish the technique of multiplanar reconstruction (MPR) with multidetector-row (MDR) computed tomography (CT) guided needle biopsy for the diagnosis to access very difficult lesions. The CT guided percutaneous biopsy are well-established methods to obtain cytological and histological material such as the peripheral tumors in lung cancer. Occasionally, the conventional CT cannot permit planning a trajectory to avoid passage through bones, avoidance of bullae, fissures or vessels. In addition, some lesions are situated in less favorable locations such as those in the costophrenic recess or close to the mediastinum. Rarely can we diagnose them. MPR with MDR-CT has recently become widely available with applications for thoracic lesions. MPR images have been used to evaluate the location of small peripheral lung nodules to the relation of bullaes, vessels, and costophrenic recess. To diagnose these lesions, the usefulness of MPR were evaluated for an planning of an oblique approach of CT guided needle biopsy. MPR images were reconstructed as a line from the needle entry point to the target lesion. The first oblique image applied as the direction of posterior–anterior and cranio-caudal axis, and the second oblique image applied as the direction of posterior–anterior and left–right.Eleven out of 151 patients were required MPR technique to allow possible access to target, because of avoidance of bone and fissures in the needle pass or located in the costophrenic recess, between April 2001 and December 2002. The 5/11 patients were at the upper site (segment 1, 2 and 6) behind the scapula and ribs, 3/11 patients were at the lower lobe (segment 10) in the costophrenic recess, and 3/11 were middle lobe or segment 3 covered by the ribs and fissures. All the lesions except one were histologically diagnosed. Five patients were adenocarcinoma, and the other five patients were benign tumors. Pneumothorax occurred in one patient before we obtained the specimens. MPR guided needle biopsy with oblique approach was thought to be useful for diagnosis of very difficult thoracic lesions and would obviate an unnecessary surgical thoracoscopy. [Copyright &y& Elsevier]

The aim of this article is to critically assess the role of multidetector-row CT (MDCT) in the field of cardiothoracic surgery. In the beginning, a short overview is given about technical aspects such as scan protocols, optimal image reconstruction, image reformation techniques, data evaluation, and data presentation. This is followed by sections about possible indications for cardiothoracic surgery and future prospects for this technology. For the cardiac surgeon, the main benefit of MDCT lies in the combination of large scan-volume coverage, high spatial resolution, proper identification of calcifications, and the simultaneous registration of other thoracic structures. Preoperative applications may include the assessment of cardiac valves, noninvasive evaluation of large thoracic vessels, staging of cardiac tumors, and planning of minimally invasive surgical procedures. After surgery, MDCT examinations particularly facilitate an early identification of severe postoperative complications. MDCT may also be used to assess coronary artery bypass graft patency and to identify transplant-related complications in heart transplant recipients at an early stage. New technological developments such as 64-row MDCT or flat panel computed tomography will further increase the field of possible indications. [ABSTRACT FROM AUTHOR]

This article critically evaluates the role of multidetector-row CT before and after cardiosurgical procedures. In addition, technical aspects, such as scan protocols, optimal image reconstruction intervals, image reformation techniques, and data evaluation, are presented and briefly discussed. [ABSTRACT FROM AUTHOR]

In the past 2 years mechanical multidetector-row CT (MDCT) systems with simultaneous acquisition of four slices and halfsecond scanner rotation have become widely available. Data acquisition with these scanners allows for considerably faster coverage of the heart volume compared with single-slice scanning. This increased scan speed can be used for retrospective gating together with 1 -mm collimated slice widths and allows coverage of the entire cardiac volume in one breath hold. Initial results from studies in correlation with intracoronary ultrasound suggest that MDTC technology not only offers the possibility to visualize intracoronary stenoses noninvasively but also to differentiate plaque morphology. This is especially the case with the next generation of 16-row multidetector CT. An increased number of simultaneously acquired slices and sub-millimeter collimation for cardiac applications allows true isotropic scanning with high temporal resolution. Contrastenhanced MDTC is a promising noninvasive technique for the detection, visualization, and characterization of stenotic artery disease. It could act as a gate keeper prior to cardiac catherization and finally replace conventional diagnostic modalities. [ABSTRACT FROM AUTHOR]

Multidetector-row CT (MDCT) scanners have been recently introduced into clinical practice. Major attributes that are improved are the z-axis coverage speed and the longitudinal resolution. These improvements translate into rapid hepatic imaging and allow new imaging protocols. Thin sections can now be used on a routine basis in single-breath-hold technique. This results in improved lesion detection and the nearly isotropic image acquisition provides high-resolution multiplanar reformations. Furthermore, the ability to scan through the entire liver in 10 s or less allows acquisition of two separate sets of CT images of the liver within the time generally regarded as the hepatic arterial dominant phase in monoslice CT; thus, MDCT may demonstrate three clear separate distinct hepatic circulatory phases with a triple-pass technique. Multidetector-row CT with the improvements in morphological and functional information compared with single-slice CT enables a comprehensive approach to hepatic imaging within a single examination. [ABSTRACT FROM AUTHOR]

Copyright of Der Radiologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Radiologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Der Radiologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rapid advancements in multidetector-row computed tomography scanner technology over the last decade have significantly improved the diagnostic performance of coronary computed tomography angiography (CTA), enabling it to potentially become the preferred imaging modality used in the rapid assessment of chest pain patients in the emergency department. There is a growing body of evidence suggesting coronary CTA can rule out coronary artery stenosis quickly and accurately, thereby reducing the number of hospitalizations and healthcare costs, without compromising quality of care. CT-STAT is the first multicenter trial to demonstrate the power of coronary CTA to streamline patient care in the acute setting and radically transform current treatment algorithms. INSET: Key issues. [ABSTRACT FROM AUTHOR]

Intracranial localization is a rare manifestation of hydatid cyst disease (Echinococcosis). It comprises only 2% of cases of Echinococcosis infection even in endemic areas and is predominantly seen in children. Clinical manifestations resulting from raised intracranial tension are nonspecific. Imaging with computed tomography (CT) may suggest the diagnosis preoperatively with reasonable accuracy. Multidetector-row CT (MDCT) with its high resolution multiplanar reformations can demonstrate the relationship of the cyst with adjacent brain structures and thus help in planning surgery. This has a practical utility in places where magnetic resonance imaging is not available. We describe a case of cerebral hydatid cyst in a 13-year-old boy who was diagnosed with MDCT, which helped in planning its surgical removal. [ABSTRACT FROM AUTHOR]