Accuracy Of Multidetector Computed Tomography Research Articles

Preoperative evaluation of the longitudinal spread of extrahepatic bile duct cancer using multidetector computed tomography

The aim of this study was to compare the diagnostic accuracy of multidetector computed tomography (MDCT) and direct cholangiography in evaluating the longitudinal spread of extrahepatic bile duct cancer. Images obtained from a 16-detector row scanner (MDCT) and from direct cholangiography (via either endoscopic naso-biliary drainage or percutaneous transhepatic biliary drainage) of 47 patients with histopathologically proven extrahepatic bile duct cancer were retrospectively interpreted. Differences between measures of longitudinal tumor spread determined by each modality and measures of macroscopic spread in resected specimens were assessed and compared. Assessments carried out using MDCT differed significantly less from the macroscopic measurements than those made using direct cholangiography (P < 0.0001). Provided the diagnosis was defined as being accurate, based on a diagnostic difference of within +/-5 mm, the diagnostic accuracy of MDCT (96%) was significantly higher than that of direct cholangiography (70%) (P = 0.028). Preoperative evaluation with direct cholangiography resulted in a 30% underestimation of the incidence. MDCT is superior to direct cholangiography for evaluating the preoperative longitudinal extent of bile duct cancer. Consequently, the utility of MDCT for preoperative evaluation of extrahepatic bile duct cancer warrants further examination.

Noninvasive coronary angiography with 64-channel multidetector computed tomography in patients with acute coronary syndrome

Advances in computer tomography (CT) imaging technology in recent years have facilitated the possibility of noninvasive coronary angiography. To compare the diagnostic accuracy of 64-channel multidetector computed tomography (MDCT) with conventional invasive coronary angiography (ICA) for the detection of significant coronary stenosis in patients with acute coronary syndrome (ACS). MDCT was performed in 60 patients classified with non-ST-elevation infarction (NSTEMI) or unstable angina and scheduled for ICA within 3 days. The diagnostic accuracy of MDCT was evaluated using quantitative coronary angiography (QCA) as the gold standard. 48 out of 60 patients had interpretable scans by both MDCT and ICA. On a segment-based analysis, 488 out of 665 segments with a diameter of > or =1.5 mm, as defined by QCA, were interpretable by MDCT. Sensitivity was 78%, specificity 87%, positive predictive value 47%, and negative predictive value 97% in detecting and excluding significant coronary stenosis, as defined with MDCT. On a per patient-based analysis, sensitivity was 89%, specificity 50%, positive predictive value 84%, and negative predictive value 60%. Limited diagnostic accuracy restricts the usefulness of coronary MDCT in patient groups with a high pretest probability of disease, such as in acute coronary syndrome.

The importance of the extent of pelvic-lymph-node dissection in the diagnosis of lymph-node metastases in prostate cancer

In the September issue of The Lancet Oncology, Heesakkers and colleagues1 reported on the accuracy of MR lymphoangiography using a new lymph-node specific MR-contrast agent, ferumoxtran-10, for the detection of lymph-node invasion (LNI) in a cohort of 375 patients with intermediate to high-risk prostate cancer, undergoing radical prostatectomy and pelvic-lymph-node dissection (PLND). The researchers compared the LNI diagnostic accuracy of MR lymphoangiography with the accuracy of multidetector CT, both of which were done preoperatively.

Multi-detector CT diagnosis and preoperative evaluation of hilar cholangiocarcinoma

Objective To determine the value of multi-detector CT (MDCT) in the preoperative evaluation of hilar cholangioearcinoma. Methods Thirty-one cases of hilar cholangiocarcinoma proved by histopathology were analyzed retrospectively. The MDCT scan was studied in order to observe the size, location, enhancement pattern of the lesions, extent of tumor involvement and indirect signs (such as the dilation of intrahepatic ducts and the changes of the liver and the gallbladder). Finally,the resectability of hilar cholangiocarcinoma was evaluated. Results The coincidence rate of MDCT reached 93.5% in the diagnosis of hilar cholangiocarcinoma. Most cases (77.4%) were judged cor-rectly in the location of obstruction by comparison with surgicohistopathology. The overall accuracy of MDCT in the estimation of TNM stages was 71.0%, while that of stage Ⅰ 100%. Conclusion MDCT can demonstrate the hilar cholangiocarcinoma and assess the extent of tumor involvement. It is helpful in the preoperative diagnosis and the treatment planning. Key words: Bile duct neoplasms; Tomography, X-ray computed

Combined coronary and late-enhanced multidetector-computed tomography for delineation of the etiology of left ventricular dysfunction: comparison with coronary angiography and contrast-enhanced cardiac magnetic resonance imaging

AimsTo evaluate whether comprehensive evaluation of coronary anatomy and delayed enhancement (DE) by multidetector-computed tomography (MDCT) would allow determination of etiology of left ventricular dysfunction (LVD) as compared with coronary angiography (CA) and DE-magnetic resonance (CMR).Methods and resultsSeventy-one consecutive patients (50 males, 59 ± 16 years) with LVD (ejection fraction: 26 ± 11%) of unknown etiology underwent MDCT, LGE (late Gd-DTPA-enhanced)-CMR and CA. Patients were classified into four groups according to coronary artery disease (CAD) by CA and LGE-CMR patterns. Patients (n = 24) with CAD and transmural or sub-endocardial DE by CMR were considered having definite ischaemic LVD (group 1). Patients (n = 36) without CAD by CA and with no/atypical LGE-CMR were considered non-ischaemic LVD (group 2). Further we identified four patients with transmural DE but no CAD (group 3) and seven patients with CAD but no DE (group 4). On per-patient basis, combined coronary and DE-MDCT had excellent agreement (κ = 0.89; P < 0.001) with CA/LGE-CMR to classify patients into the same four groups. Sensitivity, specificity and accuracy of MDCT were 97, 92 and 94%, respectively for detecting patients with definite (group 1) or likely (groups 3 and 4) ischaemic LVD.ConclusionCombined coronary and DE-MDCT can accurately differentiate ischaemic vs. non-ischaemic etiology of LVD.

Correlation of Multidetector CT Findings with Splenic Arteriography and Surgery: Prospective Study in 392 Patients

To determine the accuracy of contrast-enhanced multidetector CT (MDCT) in demonstrating splenic vascular injury based on results of splenic angiography and operation. This institutional review board-approved study included 392 hemodynamically stable blunt trauma patients whose admission MDCTs demonstrated splenic injury. Images were assessed for parenchymal injury grade, hemoperitoneum volume, and evidence of bleeding and nonbleeding splenic vascular injury. Splenic arteriography was performed for high splenic injury grade and splenic vascular injury. Medical records were reviewed to determine arteriographic interpretation, surgery indications and findings, outcomes, and demographics. Sensitivity, specificity, predictive values, and accuracy of MDCT in detecting vascular injury were calculated based on results of arteriography and operation. Splenic vascular injury was seen in 22% of patients (86 of 392) on MDCT. Presence of a vascular injury correlated with the CT-based parenchymal splenic injury grade (p < 0.0001). Active splenic bleeding was associated with subsequent clinical deterioration (p < 0.0001). Overall, MDCT had a sensitivity of 76% (76 of 100); specificity of 90% (95 of 106); negative and positive predictive values of 80% (95 of 119) and 87% (76 of 87), respectively; and accuracy of 83% (171 of 206) in detecting vascular injury compared with reference standards. The success rate of nonoperative management was 96%. MDCT provides valuable information to direct initial clinical management of patients with blunt splenic trauma by demonstrating both active bleeding and nonbleeding vascular injuries. Not all vascular injuries are detected on MDCT, and splenic angiography is still indicated for high-grade parenchymal injury.

Comparative evaluation of multidetector CT and MR imaging in the differentiation of adnexal masses

The purpose was to compare the accuracy of multidetector CT (MDCT) on a 16-row CT scanner and magnetic resonance (MR) imaging in the characterization of ovarian masses. Preoperative CT examination of the abdomen and MR imaging of the pelvis was performed in 67 women, with clinically or sonographically detected adnexal masses. The CT examinations were performed on a 16-row CT scanner, and the protocol included scanning of the abdomen during the portal phase, using a detector collimation of 16 x 0.75 mm and a pitch of 1.2. We used a 1.5-T magnet unit to perform T1, T2 and fat-suppressed T1-weighted sequences, before and after intravenous administration of gadolinium chelate compounds. The accuracy of multidetector CT and MR imaging in the differentiation between benign and malignant ovarian masses was evaluated, using histopathologic results as the standard of reference. The sensitivity, specificity and accuracy of MDCT in the characterization of ovarian masses were 90.5%, 93.7% and 92.9%, respectively, and that of MR imaging 95.2%, 98.4% and 97.6%, respectively. Although MRI performed slightly better, this did not reach statistical significance. In conclusion, both MDCT on a 16-row CT scanner and MR imaging demonstrated satisfactory results in the characterization of ovarian masses.

Local staging of endometrial carcinoma: role of multidetector CT

The purpose was to evaluate the accuracy of multidetector CT (MDCT) on a 16-row CT scanner in local staging of endometrial carcinoma and more specifically in the assessment of the depth of myometrial invasion and presence of cervical infiltration. This prospective study includes 21 women with newly diagnosed endometrial carcinoma. All CT examinations were performed on a 16-row CT scanner, and the protocol included scanning of the abdomen after intravenous administration of iodinated contrast material, during the portal phase, using a detector collimation of 16 x 0.75 mm and a pitch of 1.2. Sagittal, parasagittal and oblique reformatted images were evaluated for the depth of myometrial invasion, whether superficial or deep, and the presence of cervical infiltration. Imaging findings were correlated with the histopathologic results. The sensitivity, specificity and accuracy of MDCT in evaluating myometrial invasion were 100%, 80% and 95%, respectively, and for assessing cervical infiltration were 78%, 83% and 81%, respectively. In conclusion, MDCT on a 16-row CT scanner proved accurate in local staging of endometrial carcinoma.

Diagnostic Accuracy of Arterial Phase 64‐Slice Multidetector CT Angiography for Left Atrial Appendage Thrombus in Patients Undergoing Atrial Fibrillation Ablation

Multidetector CT (MDCT) is used prior to atrial fibrillation ablation (AFA) to anatomically guide ablation procedures. Whether 64-slice MDCT also can be used to diagnose left atrial thrombus is not known. We sought to determine the accuracy and interobserver variability of MDCT in the evaluation of left atrial thrombus prior to AFA. We enrolled 50 patients scheduled for AFA who underwent 64-slice MDCT scan and transesophageal echocardiography prior to the procedure. Three experienced observers reviewed all the MDCT images for the presence of a left atrial thrombus, and two different readers interpreted the transesophageal echocardiograms (TEE), which were used as the gold standard. All observers were blinded to clinical data and each other. Interobserver variability between the three MDCT readers was poor (highest kappa statistic 0.43, P = 0.001). Diagnostic accuracy was highly variable, with sensitivities ranging from 100% to 50% and specificities ranging from 85% to 44%. TEE reader agreement was 98%. MDCT demonstrates high interobserver variability and has only modest diagnostic accuracy for the detection of left atrial thrombus in patients undergoing AFA procedure. Potential factors affecting the accuracy of MDCT include image quality and the difficulty of distinguishing clot from pectinate muscle. MDCT likely is not the optimal method to detect left atrial thrombus using current techniques and standards of interpretation.

Abstract 3084: Accuracy of Multidetector CT in Assessing the Degree of Stenosis Caused by Calcified Coronary Artery Plaques

Purpose: Because of beam hardening and blooming artifacts, it is difficult to determine the degree of stenosis caused by calcified CAPs at CCTA. Our goal was to determine how accurate CCTA is in evaluating these lesions. Method &amp; Materials: Thirty-one patients who had 1 or more calcified CAPs at CCTA underwent cardiac catheterization (cath). CCTAs were reviewed by 2 experienced radiologists blinded as to cath results. CCTAs were performed on 40- and 64-detector row CTs (Philips Medical Systems, Cleveland, OH) and post-processed using Philips Brilliance workstations. The size of the calcified CAPs was graded subjectively as small, moderate, or large. Using post-processing techniques such as segmentation and tracking, we attempted to determine whether the calcified lesions were obstructive (&gt;50% diameter narrowing) or nonobstructive (&lt;50% diameter narrowing). Concordance with cath was then determined. Results: Calcified CAPS were graded as small at 61 locations, moderate at 22 locations, and large at 43 locations. With small calcified CAPs, CCTA and cath were concordant in 58/61 (95%). CCTA overestimated the degree of stenosis in 2 and underestimated it in 1. With moderate-sized calcified CAPs, CCTA and cath were concordant in 20/22 (91%). CCTA overestimated the degree of stenosis in the other 2. With large calcified CAPs, CCTA and cath were concordant in 29/43 (67%). In all the other 14, CCTA overestimated the degree of stenosis. In detecting obstructive lesions caused by the large calcified CAPs, CCTA sens=100%, spec=44%, PPV=56%, NPV=100%, accuracy=67%. Conclusion: CCTA accurately predicts the presence of obstructive disease in &gt;90% of small and moderate-sized calcified CAPs. With large calcified CAPs, CTA correctly predicts presence of obstructive disease about 2/3 of the time. When errors occur, they are virtually always due to overestimation of the degree of stenosis.

Left atrial appendage filling defects identified by multidetector computed tomography in patients undergoing radiofrequency pulmonary vein antral isolation: A comparison with transesophageal echocardiography

Patients referred for radiofrequency pulmonary vein antral isolation undergo contrast-enhanced multidetector computed tomography (MDCT) to assess pulmonary vein and left atrial anatomy as well as transesophageal echocardiography (TEE) to detect intraatrial thrombus. We sought to determine the accuracy of MDCT to qualitatively and quantitatively detect severe spontaneous echo contrast (SEC) or thrombus by TEE in the left atrial appendage (LAA). Two hundred twenty-three consecutive MDCT and TEE studies performed within 7 days of each other were retrospectively identified. The LAA was evaluated by MDCT for filling defects and by TEE for thrombus or SEC. Severe SEC or thrombus on TEE was considered positive. In patients with preserved ejection fraction, the Hounsfield unit (HU) density of a 1-cm2 region of interest was measured in the LAA and ascending aorta (AA) of the same slice to calculate an LAA/AA HU ratio. Visually identified filling defects in LAA by MDCT correspond to severe SEC and thrombus with a sensitivity, specificity, positive predictive value, and negative predictive value of 93%, 85%, 31%, and 99%, respectively. Multidetector CT missed severe SEC detected by TEE in one examination; all thrombi, however, were correctly identified. There is a significant inverse association between mean LAA/AA HU ratios with increasing grades of SEC or thrombus (P < .001). Using an LAA/AA HU ratio cutoff of 0.25, the positive predictive value and specificity increased to 75% and 96%, respectively, while preserving a high negative predictive value (96%). Multidetector CT can qualitatively and quantitatively identify and distinguish severe LAA SEC/thrombus from lesser grades of SEC.

Interobserver Variability of 64-Slice Computed Tomography for the Quantification of Non-Calcified Coronary Atherosclerotic Plaque

Multidetector CT (MDCT) is a reliable tool to assess and quantify calcified plaque in coronary arteries. Only very limited information is available concerning the accuracy of MDCT for evaluating non-calcified plaque. We determined the interobserver variability for measuring non-calcified plaque volumes in the three main coronary arteries using 64-slice computed tomography. We retrospectively evaluated data sets of 41 patients who received a 64-slice CT scan (Sensation 64, Siemens Forchheim, Germany, 330 msec rotation, 0.6 mm collimation, 60 ml contrast agent i. v. at 5 ml/sec) due to suspected stable coronary artery disease. The patients showed presence of non-calcified plaque in the proximal part of at least one main coronary artery. The image quality was defined on the basis of a 4-point rating scale. Two independent and blinded investigators measured the plaque volume of the non-calcified plaque by manually tracing plaque areas in contiguous cross-sectional reconstructions rendered along the vessel centerline using a slice thickness of 1 mm and an increment of 0.5 mm. The interobserver variability was evaluated and the influence of plaque volume and image quality on interobserver variability was determined. The mean volume of non-calcified plaque was 157 +/- 85 mm (3), 76 +/- 43 mm (3) and 133 +/- 80 mm (3) for the LAD, LCX and RCA, respectively (LAD vs. LCX: p < 0.01; LAD vs. RCA: p = 0.33; LCX vs. RCA: p < 0.01). There was a mean absolute difference in plaque volume between the two observers of 23 +/- 15 mm (3), of 20 +/- 9 mm (3) and of 38 +/- 21 mm (3), which corresponds to a mean interobserver variability of 17 +/- 10 %, 29 +/- 13 % and 32 +/- 13 % for the LAD, LCX and RCA, respectively (LAD vs. LCX: p < 0.01; LAD vs. RCA: p < 0.01; LCX vs. RCA: p = 0.87). A significant inverse correlation between interobserver variability and the extent of the plaque volume (r = - 0.48; p = 0.01) was found. Interobserver variability was dependent on image quality: The highest image quality was observed in the LAD (2.4 +/- 0.5), while the image quality in the LCX (2.1 +/- 0.7) and the RCA (2.0 +/- 0.6) was lower. Interobserver variability for the quantification of non-calcified plaque volumes in 64-slice MDCT is substantial. Interobserver variability in the LAD was significantly lower than in the LCX and the RCA. This might be due to a larger mean plaque volume and better image quality in the LAD than in other coronary arteries.

Accuracy of Nonstenotic Coronary Atherosclerosis Assessment by Multi-Detector Computed Tomography

The ability to evaluate coronary stenosis using multi-detector computed tomography (MDCT) has been well discussed. In contrast, several studies demonstrated that the plaque burden measured by intravascular ultrasound (IVUS) has a relationship to the risk of cardiovascular events. the accuracy of MDCT was studied to determine plaque and vessel size compared with IVUS. Fifty-six proximal lesions (American College of Cardiology/American Heart Association classification: segment 1, 5, 6) from 33 patients were assessed using MDCT and IVUS. The plaque and vessel area were measured from the cross-sectional image using both MDCT and IVUS. Eight coronary artery lesions with motion artifacts and heavily calcified plaques were excluded from the analysis. The vessel and lumen size evaluated using MDCT were closely correlated with those evaluated by IVUS (R(2)=0.614, 0.750 respectively). Furthermore, there was a strong correlation between percentage plaque area assessed by MDCT and IVUS (R(2)=0.824). MDCT can noninvasively quantify coronary atherosclerotic plaque with good correlation compared with IVUS in patients with atherosclerosis.

Biliary Ductal Involvement of Hilar Cholangiocarcinoma

To compare the diagnostic accuracy of multidetector computed tomography (MDCT) and magnetic resonance cholangiography (MRC) in evaluating the extent of biliary involvement of hilar cholangiocarcinoma. Images of 16-detector MDCT, MRC, and direct cholangiography of 33 patients with pathologically proven hilar cholangiocarcinoma were retrospectively interpreted independently by 2 radiologists according to the Bismuth classification. In the operated 14 patients, the diagnostic accuracies of MDCT and MRC were calculated according to surgical and pathological records. In nonoperated 19 patients, the agreement of MDCT and MRC with direct cholangiography was calculated. In the operated patients, the diagnostic accuracy of MDCT was 64.3%, and that of MRC was 71.4%, without statistical difference (P = 0.93). In nonoperated patients, the agreement of MDCT with direct cholangiography was 73.7%, and that of MRC was 94.7%, without statistical difference (P = 0.58). In evaluating the biliary ductal extension of hilar cholangiocarcinoma, MDCT and MRC showed similar accuracies and agreements.

Measurement of Coronary Artery Bifurcation Angles by Multidetector Computed Tomography

Optimal stent deployment in coronary artery bifurcations requires information about the angle between main vessel and side branch. We evaluated the accuracy and interobserver variability of bifurcation angle measurements by contrast-enhanced 16-slice multidetector computed tomography (MDCT) in comparison with invasive angiography and examined the average angles of 4 main coronary bifurcations. To determine the accuracy of MDCT for measurement of bifurcation angles, we scanned a coronary artery phantom containing 6 bifurcations (2-mm metal rods with angles between 25 degrees and 90 degrees ) using MDCT, and angles determined in the MDCT data set were compared with the true values. To assess interobserver variability of angle measurements in comparison to invasive angiography, the angles of 3 bifurcation sites (left anterior descending and left circumflex coronary artery [LAD/LCX], LAD and first diagonal branch [LAD/Diag 1], and posterior descending coronary artery and right posterolateral branch [PDA/Rpld]) were determined in 15 patients both in 16-detector row MDCT data sets and invasive coronary angiograms by 2 independent observers each. To assess the natural distribution of the 4 main coronary artery bifurcation angles (LAD and LCX, LAD and Diag 1, LCX and OM1, PDA and Rpld), the average angles of these bifurcations were determined in 16-slice MDCT data sets acquired for coronary artery visalization in a group of 100 consecutive patients with suspected coronary artery disease. The phantom study revealed a mean difference between measured and true angles of 0.7 +/- 0.5 degrees . In the comparison MDCT versus invasive angiography, the 45 angles were significantly lager in MDCT (mean: 66 +/- 20 degrees vs. 56 +/- 24 degrees , P = 0.027). Interobserver variability was significantly lower in MDCT (r = 0.91) than invasive angiography (r = 0.62). Analysis of the natural distribution of bifurcation angles by MDCT revealed average values of 80 +/- 27 degrees (LAD/LCX), 46 +/- 19 degrees (LAD/Diag1), 48 +/- 24 degrees (LCX/OM1), and 53 +/- 27 degrees (PDA/Rpld), respectively. MDCT allows assessment of coronary bifurcation angles with high accuracy, which may be of future potential for planning interventional treatment.

The Diagnostic Accuracy of 64-Slice Computed Tomography Coronary Angiography Compared With Stress Nuclear Imaging in Emergency Department Low-Risk Chest Pain Patients

We compared the accuracy of multidetector computed tomography (CT) coronary angiography with stress nuclear imaging for the detection of an acute coronary syndrome or 30-day major adverse cardiac events in low-risk chest pain patients. This was a prospective study of the diagnostic accuracy of myocardial perfusion imaging and multidetector CT in low-risk chest pain patients. The target condition was an acute coronary syndrome (confirmed >70% coronary stenosis on coronary artery catheterization) or major adverse cardiac events within 30 days. Patients were low risk by Reilly/Goldman criteria and had negative serial ECGs and cardiac markers. All had both rest/stress sestamibi nuclear imaging and multidetector CT. Patients with abnormal stress nuclear imaging results (reversible perfusion defects) or multidetector CT results (stenosis >50% or calcium score >400) were considered for cardiac catheterization, and those with discordant results had a greater than 30-day reevaluation (including ECG) by a cardiologist. All were followed up for evidence of major adverse cardiac events within 30 days by review of hospital records and structured telephone interview. Primary outcomes were the accuracy of multidetector CT and myocardial perfusion imaging for the detection of an acute coronary syndrome and 30-day major adverse cardiac events. Of the 92 patients, 7 (8%) were excluded because of uninterpretable multidetector CT scans. Of the remaining 85 study patients (49+/-11 years, 53% men), 7 (8%) were found to have the target condition, with all having significant coronary stenosis (88%+/-9%) and none having myocardial infarction or major adverse cardiac events during 30 days. Stress nuclear imaging results were negative in 72 (85%) patients, and multidetector CT results were negative in 73 (86%) patients. The sensitivity of stress nuclear imaging was 71% (95% confidence interval [CI] 36% to 92%), and multidetector CT was 86% (95% CI 49% to 97%), and the specificity was 90% (95% CI 81% to 95%) and 92% (95% CI 84% to 96%), respectively. The negative predictive value of stress nuclear imaging and multidetector CT was 97% (95% CI 90% to 99%) and 99% (95% CI 93% to 100%), respectively, and the positive predictive value was 38% (95% CI 18% to 64%) and 50% (95% CI 25% to 75%), respectively. The accuracy of multidetector CT is at least as good as that of stress nuclear imaging for the detection and exclusion of an acute coronary syndrome in low-risk chest pain patients.

Multidetector computed tomography assessment on tumor size and nodal status in patients with locally advanced breast cancer before and after neoadjuvant chemotherapy

Aims To evaluate the utility of multidetector computed tomography (MCT) in assessing tumor size and nodal status in patients with advanced breast cancers before and after the neoadjuvant chemotherapy. Methods Twenty-eight proven locally advanced breast cancer patients with 30 tumors were enrolled in this study. MCT was used to assess tumor size and axillary lymph nodes before and after the neoadjuvant chemotherapy. The correlation between tumor size on MCT and gross tumor size was tested. Results The MCT measurements documented complete response in 3, partial response in 18, non-response in 8 and progressed in 1. The mean tumor diameters on pathology and post-chemotherapy MCT were 3.6 cm (S.D. = ±2.9 cm) and 3.1 cm (S.D. = ±2.6 cm), respectively. The Pearson correlation coefficient was 0.76 ( p < 0.001). The sensitivity, specificity, positive predictive valve, negative predictive valve and accuracy of MCT in diagnosing the axillary lymph node metastases after pre-operative neoadjuvant chemotherapy were counted, respectively, to 72%, 40%, 85.7%, 22.2% and 66.7%. All the 5 downstaged axillary nodal statuses from node-positive to node-negative on MCT had micrometastases. Conclusion MCT can be used to evaluate tumor size and nodal status in patients with advanced breast cancer. As there is a baseline MCT before chemotherapy for comparison, we are potentially aware of the possibility of false negative nodal micrometastases on the post-chemotherapy MCT.

Accuracy of 16-slice multi-detector CT to quantify the degree of coronary artery stenosis: Assessment of cross-sectional and longitudinal vessel reconstructions

Background Sixteen-slice multi-detector computed tomography (MDCT) permits reliable noninvasive detection of significant coronary stenosis based on qualitative visual assessment. The purpose of this study was to determine the accuracy of MDCT to quantify the degree of coronary stenosis as compared to quantitative coronary angiography (QCA) using two different reconstruction methods. Methods We studied 69 coronary artery lesions from 38 consecutive patients that underwent 16-slice MDCT as a part of research study, which enrolled consecutive subjects scheduled for clinically indicated invasive coronary angiography. Nine coronary artery lesions with motion artifacts, heavily calcified plaques or stents were excluded from the analysis. The degree of stenosis was calculated by two independent readers non-blinded to the location of the stenosis, but blinded to the results of the QCA. MDCT luminal diameters were measured in cross-sectional multi-planar reformatted (CS-MPR) images created perpendicular to the centerline of the vessel and in 5 mm thin-slab maximum intensity projections (MIP) parallel to the long axis of the vessel. Both MDCT methods were compared against QCA. Results The mean degree of stenosis as measured by MDCT was closely correlated to QCA for both methods (CS-MPR versus QCA: 61 ± 23% versus 64 ± 29%; r 2 = 0.83, p < 0.001and MIP versus QCA: 64 ± 22% versus 64 ± 29%; r 2 = 0.84, p < 0.001for MIP. Bland–Altman analysis demonstrated a negative bias of the degree of stenosis of −2.8 ± 12% using CS-MPR and a minimally positive bias of 0.6 ± 12% for MIP. In stratified analysis for lesion severity (mild, 0–40%; moderate, 41–70% or severe, >70%) the agreement between both CS-MPR and MIP was high when compared to QCA ( κ = 0.74 and 0.71, respectively). Conclusion Multi-detector spiral CT permits accurate quantitative assessment of the degree of coronary stenosis in selected data sets of sufficient quality using both cross-sectional and longitudinal vessel reconstructions.

Usefulness of Multidetector Computed Tomography for the Initial Assessment of Blunt Abdominal Trauma Patients

The prompt detection and accurate localization of abdominal injuries are difficult. Some diagnostic modalities, including laboratory tests, ultrasound, and diagnostic peritoneal lavage (DPL) were used to evaluate patients with blunt abdominal trauma, with various advantages and pitfalls. We aimed to evaluate the risk and benefit of using multidetector computed tomography (MDCT) as an initial assessment tool for proper diagnosis and treatment planning of patients with blunt abdominal trauma. Two hundred fifty-two patients with blunt abdominal trauma were prospectively enrolled. Multidetector computed tomography was performed during resuscitation. The risk and benefit of using MDCT in the diagnosis and planning of treatment were analyzed. The time required for a MDCT examination averaged 10.2 minutes. Of the studies done, 224 revealed abdominal injuries. Of those, 34 were performed in patients with unstable hemodynamic status without adverse effect. Prompt diagnosis and proper treatment were given according to the MDCT findings. A total of 43 (17.1%) MDCTs showed contrast extravasation. Active bleeding was confirmed in all and treated with transarterial embolization (30) or surgery (13). Another 58 patients sustained bowel, mesenteric, or pancreatic injuries (BMPI) necessitating laparotomy. The sensitivity, specificity, and accuracy of MDCT in identifying patients with active bleeding or BMPI were all 100%. Multidetector computed tomography was useful as a second line initial assessment tool to identify injuries and determine treatment planning in blunt abdominal trauma patients. No increased risk was found if the facility is readily available, the protocol is well designed, and the patient is well prepared.

Detection of coronary artery stenoses using multi-detector CT with 16×0.75 collimation and 375 ms rotation

Insufficient spatial and temporal resolutions have limited image quality and accuracy of multi-detector CT (MDCT) for coronary artery visualization and detection of stenoses. We assessed the accuracy of a new 16-slice scanner with 370 ms rotation and 0.75 mm collimation for detection of coronary stenoses using an analysis approach based on coronary artery segments. Fifty consecutive patients scheduled for diagnostic coronary angiography in stable clinical condition and sinus rhythm were enrolled. All patients with a heart rate > 60 b.p.m. received 100 mg atenolol p.o. and up to four doses of 5 mg metoprolol i.v. before the scan. MDCT was performed using 16 x 0.75 mm collimation, 120 kV, and ECG-gated tube current modulation. Ninety millilitres of contrast agent was injected intravenously. MDCT images were visually analysed using the 16-segment coronary artery model of the American Heart Association and compared with invasive, quantitative coronary angiography in a blinded fashion. A significant stenosis was assumed if the diameter reduction was > or = 50%. Mean heart rate was 58 b.p.m. during MDCT. After exclusion of two patients with not fully evaluable data sets, MDCT correctly identified at least one coronary stenosis in all 25 patients with significant coronary lesions in angiography and correctly demonstrated the absence of stenoses in 19/23 patients (sensitivity 100%, specificity 83%). Sensitivity and specificity for all 50 patients were 93 and 83%, respectively. On a per-segment basis, nine coronary segments distal of total occlusions and 128 coronary segments with a reference diameter < 1.5 mm were excluded from the analysis. Twenty-eight of the included 663 segments (4%) were unevaluable due to calcification or motion artefact. In the remaining 635 segments, 50/53 stenoses were detected by MDCT (sensitivity 94%, specificity 96%, negative predictive value 99%, positive predictive value 69%). Increasing temporal and spatial resolutions of MDCT lead to improved evaluation and diagnostic accuracy for detection of coronary stenoses.