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Torsten Beck

Publications and source records attributed to Torsten Beck.

11 recordsLinked to original sources
PubMed2006

Coronary artery bypass grafts: assessment of graft patency and native coronary artery lesions using 16-slice MDCT.

The objective of this study was to evaluate the accuracy of electrocardiography (ECG)-gated 16-slice multidetector-row computed tomography (MDCT) in detection of stenosis of bypass grafts and native coronary arteries in patients who have undergone coronary artery bypass grafting (CABG). ECG-gated contrast-enhanced MDCT using 12 x 0.75-mm collimation was performed in 20 patients with recurrent angina 4.75 years after undergoing CABG. A total of 50 grafts, 16 arterial and 34 venous, were examined. All graft and coronary segments were evaluated for stenosis in comparison with conventional coronary angiography (CCA). Among the 80 arterial graft segments, 62 could be assessed (77.5%). Sensitivity, specificity, and positive and negative predictive values for stenosis were 96.2%, 97.2%, 96.2%, and 97.2%, respectively. In a total of 180 venous graft segments, 167 could be assessed. Sensitivity, specificity, and positive and negative predictive values for stenosis were 98.5%, 93.9%, 91.8%, and 98.9%, respectively. MDCT could assess 179 of 260 native coronary artery segments (68.8%). Sensitivity, specificity, and positive and negative predictive values for stenosis were 92.1%, 76.9%, 87.5%, and 84.7%, respectively. Sixteen-slice MDCT provides excellent image quality and diagnostic accuracy in detection of graft and coronary artery lesions in patients with suspected graft dysfunction.

Angina Pectoris↗
PubMed2006

Non-invasive evaluation of coronary artery bypass grafts using 16-row multi-slice computed tomography with 188 ms temporal resolution.

BACKGROUND: Cardiac multi-slice computed tomography (MSCT) scanners permit visualization of the coronary arteries and coronary artery bypass grafts. The latest MSCT generation with true 16-detector slices (Sensation 16 Speed 4 D, Siemens, Forchheim, Germany) provides improved temporal and spatial resolution, as well as significantly reduced scan time. To assess, whether this technical improvement has also an impact on image quality and accuracy of MSCT diagnosis in patients with previous coronary artery bypass graft (CABG) surgery the following study was conducted. METHODS AND MATERIAL: Thirteen consecutive patients (pts) (10 male, 3 female, mean age 62 +/- 6.4 [55-73] years, heart rate 68 +/- 11 [52-88] bpm) and a total number of 43 coronary bypass grafts (11 arterial, 32 venous grafts) were examined by MSCT (gantry rotation time 375 ms). In addition to the analysis of coronary bypass grafts, 13 coronary segments (sgts) were evaluated in each patient (n = 169 sgts). MSCT results were compared with coronary angiography. RESULTS: Forty-one of 43 bypass grafts (95%) were analyzable by MSCT. In conventional angiography 16 of 43 (37%) grafts were occluded. Sixteen of them were correctly diagnosed by MSCT (sensitivity 100%). One graft showed a 50% anastomosis stenosis which was also detected. Twenty-five of 27 grafts without severe lesion showed no significant stenosis in MSCT (specificity 93%, positive predictive value (PPV) 89%, negative predictive value (NPV) 100%). Ninety of 108 (83%) high-grade stenosis (>70%) of the native coronary vessels were correctly detected (sensitivity 83%, PPV 78%). From the 61 sgts without high grade stenosis 36 were correctly classified (specificity 59%, NPV 67%). If sgts number 8, 9 and 10, which are normally not target for revascularization, are excluded sensitivity rises to 89%, specificity to 71%, PPV to 87% and NPV to 75%. The correct clinical diagnosis (absence or presence of a high grade stenosis of at least one bypass graft) was achieved in all patients. CONCLUSIONS: True 16-slice MSCT with faster gantry rotation time allows detection of lesions in coronary artery bypass grafts with high sensitivity and specificity. The evaluation of native vessels in pts with known CAD remains a diagnostic challenge. However, the correct clinical diagnosis was achieved in all pts. MSCT is a non-invasive tool to assess coronary artery bypass grafts.

Aged↗
PubMed2005

Usefulness of noninvasive MSCT coronary angiography as first-line imaging technique in patients with chest pain: initial clinical experience.

PURPOSE: Comparative studies with invasive coronary angiography (ICA) indicated a good sensitivity and specificity in the noninvasive detection of coronary artery disease (CAD) using Multi-slice spiral computed tomography coronary angiography (MS-CTA). The aim was to investigate the usefulness of MS-CTA as first-line imaging technique in patients (pts) with known or suspected CAD and low to intermediate probability of a severe coronary lesion. We report on our initial clinical experience using MS-CTA without compelled ICA. MATERIAL AND METHODS: One hundred thirty six patients with chest pain underwent MS-CTA on an outpatient basis (age 60+/-10, suspicion of CAD: n=95, suspicion of restenosis: n=24, after CABG: n=17). Based on the MS-CTA results, a recommendation concerning further diagnostics and therapy was given to each pt. A telephone interview was performed after 455+/-166 days to evaluate the further clinical course. RESULTS: Per pt, 8.2+/-2.7 coronary segments could be evaluated. Based on the MSCT results, the presence of flow-limiting stenoses was excluded in n=77 (57%) pts (group I). An additional ICA was recommended in n=59 (43%) pts (group II). An ICA had been performed in meantime in 27/136 (20%) pts, and could be avoided in the majority of pts. Nevertheless, 58/136 (42%) pts reported on improved clinical symptoms and 42/136 (31%) pts of improved quality of life. CONCLUSIONS: MS-CTA was found to be useful to evaluate the need and to reduce the total number of ICA in pts with unclear chest pain. It appears to be the first noninvasive modality, which might be used on a clinical routine basis in selected groups of pts.

Aged↗
PubMed2005

Diagnostic accuracy of noninvasive coronary imaging using 16-detector slice spiral computed tomography with 188 ms temporal resolution.

OBJECTIVES: The aim of our study was to evaluate the diagnostic accuracy of 16-multi-detector spiral computed tomography (MDCT) with 188 ms temporal resolution. BACKGROUND: Because of rapid technical innovations, MDCT coronary imaging has significantly improved in the last five years. Recent results indicate a high diagnostic accuracy, especially in patients with clinical suspicion of coronary artery disease (CAD). METHODS: A total of 72 consecutive patients (30 women, 42 men, age 64 +/- 10 years) scheduled for invasive coronary angiography (ICA) because of suspected CAD were additionally studied by MDCT (Sensation 16 Speed 4D, Siemens, Forchheim, Germany). Thirty-seven of 72 patients (51%) received an additional beta-blockade before MDCT because of heart rates >65 beats/min. The MDCT scans were analyzed regarding the presence of coronary artery lesions. Results were compared with ICA. RESULTS: All 72 scans showed diagnostic image quality (heart rate: 64.1 +/- 9.2 beats/min, calcium mass: 86 +/- 156 mg). Thirteen coronary segments were evaluated in each patient. Sixty-two of 936 (6.6%) segments showed a nondiagnostic image quality. All segments were included in the analysis. A total of 117 relevant lesions (diameter stenosis >50%) were detected using ICA, and 96 of 117 (82%) were detected by MDCT. Sensitivity, specificity, and positive and negative predictive values for the whole study group were as follows: 82%, 98%, 87%, and 97%, respectively. The correct clinical diagnosis of presence or absence of significant CAD was obtained in 65 of 72 (90%) patients. All stenoses were detected by MDCT in 52 of 72 (72%) patients. CONCLUSIONS: Our results indicate a high diagnostic accuracy of 16-slice MDCT with improved temporal resolution.

Adult↗
PubMed2005

Technology insight: possible applications of multislice computed tomography in clinical cardiology.

With the introduction of four-slice scanners in 1999, multislice CT (MSCT) technology became available for investigative examination of the heart. Since then, MSCT technology has undergone rapid technical progress; temporal and spatial resolutions have been especially improved. The improved diagnostic image quality has led to more possible uses of MSCT being defined. At present, issues such as visualization of coronary artery bypass grafts, detection of stenoses of native coronary arteries, description of coronary anomalies, and calcium scoring, can be investigated reasonably well. Other features, such as plaque imaging and visualization of intracoronary stents, need further evaluation. A large number of factors, however, such as heart rate, atrial fibrillation, breathing artefacts and severe calcification, still influence image quality and reduce validity. In this article we provide a summary of current fields of application of cardiac MSCT. The word 'indication' is consciously avoided because official guidelines for the use of MSCT in heart examination have not yet been issued. Hopefully, prospective multicenter trials will be performed soon, providing more data with which to establish guidelines for both cardiologist and radiologist.

Cardiology↗
PubMed2004

[Noninvasive detection of coronary stenosis using 16-slice detector computed tomography in carefully selected patients].

BACKGROUND AND PURPOSE: Due to technical improvements, multislice spiral computed tomography (MSCT) has become available for the noninvasive visualization of human coronary arteries. The current scanner generation provides 16 detector slices. The aim of the present study was to evaluate the influence of a careful patient selection on the diagnostic accuracy of noninvasive angiography. PATIENTS AND METHODS: Out of a study population of 60 patients, 36 with mild coronary calcifications (Agatston score < 500) were selected for the present retrospective analysis. In addition to conventional coronary angiography (CCA), all patients underwent a noninvasive MSCT examination of the coronary arteries. All coronary segments were assessed with respect to image quality and presence of severe lesions with a diameter stenosis >or = 50%. The MSCT examinations were performed using a Sensation 16 scanner (Siemens Medical Systems, Forchheim, Germany). RESULTS: The Agatston score of the study population was 83.3 +/- 125.4 (0-491.3), calcium mass 14.7 +/- 21.4 (0-83) mg CaHA (calcium hydroxyapatite). Diagnostic image quality could be obtained in 391/455 coronary segments (86%). 26 lesions > or = 50% could be detected by MSCT, CCA confirmed the presence of 21 lesions. No false-negative results were obtained (sensitivity: 100%, specificity: 99%, positive predictive value: 0.81, negative predictive value: 1.0). CONCLUSION: The new MSCT generation with 16 detector slices permits a noninvasive visualization of the coronary arteries with good image quality. It could be shown that a careful patient selection is of major importance for the diagnostic accuracy of MSCT imaging. It appears to be useful to perform a stepwise imaging, starting with a native scan to rule out severe calcifications. Prospective multicenter trials with larger patient numbers are required to confirm these initial results.

Calcinosis↗
PubMed2004

Noninvasive detection of coronary lesions using 16-detector multislice spiral computed tomography technology: initial clinical results.

OBJECTIVES: The aim of our study was to evaluate the feasibility of detecting coronary artery lesions using a new computed tomography (CT) scanner with 16 detectors and faster gantry rotation. BACKGROUND: Computed tomography angiography of the coronaries permits assessment of the coronaries; however, image quality is still impaired by motion artifacts and calcifications. METHODS: Sixty patients scheduled for conventional coronary angiography (CCA) were additionally studied by multislice spiral computed tomography (MSCT). Calcium scores and a contrast-enhanced visualization of the coronaries were performed and analyzed regarding evaluability, presence of coronary artery lesions, and correct clinical diagnosis. RESULTS: Calcium scoring was successful in all patients; 58 of 60 patients had a diagnostic contrast-enhanced scan. Mean calcium score was 506 +/- 743 Agatston score equivalent (ASE); 13 of 58 (22%) patients had an ASE >or=1,000, 46 of 58 (78%) patients <1,000. In 763 coronary segments, CCA detected a total of 75 lesions >or=50%. The MSCT correctly assessed 54 of these. Twenty-one lesions were missed or incorrectly underestimated. Sensitivity was 72%, specificity 97%. When restricting analysis to patients with an ASE <1,000, 40 significant lesions >or=50% were seen on CCA, and MSCT correctly detected 39 lesions (sensitivity 98%, specificity 98%). Regardless of any threshold, the correct clinical diagnosis could be obtained in 58 of 60 (97%) of all patients. CONCLUSIONS: In individuals with low-to-moderate amounts of coronary artery calcium, 16-detector CT coronary angiography has high sensitivity and specificity for the diagnosis of significant coronary artery stenosis.

Adult↗
PubMedDate not supplied

Coronary vessel visualization using true 16-row multi-slice computed tomography technology.

BACKGROUND: Multi-slice computed tomography (MSCT) scanners with retrospective ECG-gating permit visualization of the coronary arteries. Limited spatial and temporal resolution as well as breathing artefacts due to the scan time can cause poor distal vessel segment and side branch visualization. The latest MSCT generation with true 16-detector slices (Sensation 16), Siemens, Forchheim, Germany) provides furthermore improved temporal and spatial resolution, as well as significantly reduced scan time. To assess, whether this technical improvement has also an impact on image quality we conducted the following study. METHODS AND MATERIAL: Sixty-two consecutive patients (33 male, 29 female, mean age 63+/-8 [47-79] years, heart rate after beta-blockade 63+/-7 [45-86] bpm) with suspicion of coronary artery disease (CAD) were examined by cardiac MSCT. Parameter settings were: 0.75 mm collimation, 2.8mm table feed/rotation, caudocranial scan direction, 80 cc contrast media biphasic injection protocol, gantry rotation time 375 ms, temporal resolution 188 ms). Thirteen coronary segments (sgts) were evaluated in each patient (total number: 806 sgts). Image quality of each segment was determined as: excellent--free of motion artefacts, good--mild motion artefacts, relevant artefacts--still diagnostic value, severe calcification and insufficient image quality--not visualized segment. RESULTS: 301/806 (37%) sgts showed excellent and 294/806 (36%) sgts good image quality. Relevant artefacts were seen in 107/806 (13%) sgts, calcifications in 41/806 (5%) sgts. 63/806 (8%) sgts could not be visualized (34 of them (54%) either segment 9 or 10). Diagnostic image quality was achieved in 702/806 (87%) sgts. CONCLUSIONS: Due to true 16-slice technology and faster gantry rotation time MSCT image quality could be improved and allows a visualization of the entire coronary tree. Larger, randomized, catheter-controlled studies have to be conducted to determine, whether this improved visualization also translates into better diagnostic accuracy.

Aged↗
PubMedDate not supplied

Image quality and diagnostic accuracy of 16-slice multidetector spiral computed tomography for the detection of coronary artery disease in elderly patients.

OBJECTIVES: To determine the image quality and diagnostic accuracy of cardiac multislice spiral computed tomography (MSCT) in elderly patients (>65 years old) in comparison to younger patients, this retrospective analysis was performed. METHODS: The catheter-controlled MSCT results from patients older than 65 years of age were compared with the results of younger patients in a cohort of 117 patients with regard to sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and image quality. Fifty-three patients were older than 65 years of age (group 1: 31 men, age range: 72.2 +/- 4.1 years, number of risk factors: 2.6 +/- 1.3, Agatston score: 866 +/- 1090) and 64 were younger (group 2: 45 men, age range: 57.4 +/- 6.1 years, number of risk factors: 2.6 +/- 1.0, Agatston score: 765 +/- 1013). All patients were examined by MSCT (Sensation 16 Speed 4 D; Siemens, Forchheim, Germany, with a gantry rotation time of 375 milliseconds) and invasive coronary angiography. The MSCT results were compared blinded with the results of the coronary angiography with regard to the presence or absence of significant stenosis (>50%) in a 13-segment model. Image quality was assessed on a qualitative scale between 1 (very good) and 5 (insufficient image quality) for each segment. RESULTS: Sensitivity, specificity, PPV, and NPP were not different statistically in both groups (group 1: 0.80/0.96/0.89/0.93 and group 2: 0.89/0.98/0.93/0.97). Three patients (all <65 years old) had to be excluded from analysis because of technical problems. Image quality was significantly better in group 2. Gender, body mass index, number of risk factors, and mean heart rate were not significantly different in either group. CONCLUSIONS: Age has an impact on MSCT image quality but did not hamper diagnostic accuracy. Thus, MSCT is a noninvasive method to detect or rule out coronary artery disease independently of age. These retrospective data have to be confirmed in larger prospective trials.

Age Factors↗