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Sebastian Leschka

Publications and source records attributed to Sebastian Leschka.

At least 19 recordsLinked to original sources
PubMed2007

Accuracy of 64-slice CT angiography for the detection of functionally relevant coronary stenoses as assessed with myocardial perfusion SPECT.

PURPOSE: CT angiography (CTA) offers a valuable alternative for the diagnosis of CAD but its value in the detection of functionally relevant coronary stenoses remains uncertain. We prospectively compared the accuracy of 64-slice CTA with that of myocardial perfusion imaging (MPI) using (99m)Tc-tetrofosmin-SPECT as the gold standard for the detection of functionally relevant coronary artery disease (CAD). METHODS: MPI and 64-slice CT were performed in 100 consecutive patients. CTA lesions were analysed quantitatively and area stenoses > or =50% and > or =75% were compared with the MPI findings. RESULTS: In 23 patients, MPI perfusion defects were found (12 reversible, 13 fixed). A total of 399 coronary arteries and 1,386 segments was analysed. Eighty-four segments (6.1%) in 23 coronary arteries (5.8%) of nine patients (9.0%) were excluded owing to insufficient image quality. In the remaining 1,302 segments, quantitative CTA revealed stenoses > or =50% in 57 of 376 coronary arteries (15.2%) and stenoses > or =75% in 32 (8.5%) coronary arteries. Using a cut-off at > or =75% area stenosis, CTA yielded the following sensitivity, specificity, negative (NPV) and positive predictive value (PPV), and accuracy for the detection of any (fixed and reversible) MPI defect: by patient, 75%, 90%, 93%, 68% and 87%, respectively; by artery, 76%, 95%, 99%, 50% and 94%, respectively. CONCLUSION: Sixty-four-slice CTA is a reliable tool to rule out functionally relevant CAD in a non-selected population with an intermediate pretest likelihood of disease. However, an abnormal CTA is a poor predictor of ischaemia.

Adult↗
PubMed2007

Coronary artery stent geometry and in-stent contrast attenuation with 64-slice computed tomography.

We aimed at assessing stent geometry and in-stent contrast attenuation with 64-slice CT in patients with various coronary stents. Twenty-nine patients (mean age 60 +/- 11 years; 24 men) with 50 stents underwent CT within 2 weeks after stent placement. Mean in-stent luminal diameter and reference vessel diameter proximal and distal to the stent were assessed with CT, and compared to quantitative coronary angiography (QCA). Stent length was also compared to the manufacturer's values. Images were reconstructed using a medium-smooth (B30f) and sharp (B46f) kernel. All 50 stents could be visualized with CT. Mean in-stent luminal diameter was systematically underestimated with CT compared to QCA (1.60 +/- 0.39 mm versus 2.49 +/- 0.45 mm; P < 0.0001), resulting in a modest correlation of QCA versus CT (r = 0.49; P < 0.0001). Stent length as given by the manufacturer was 18.2 +/- 6.2 mm, correlating well with CT (18.5 +/- 5.7 mm; r = 0.95; P < 0.0001) and QCA (17.4 +/- 5.6 mm; r = 0.87; P < 0.0001). Proximal and distal reference vessel diameters were similar with CT and QCA (P = 0.06 and P = 0.03). B46f kernel images showed higher image noise (P < 0.05) and lower in-stent CT attenuation values (P < 0.001) than images reconstructed with the B30f kernel. 64-slice CT allows measurement of coronary artery in-stent density, and significantly underestimates the true in-stent diameter compared to QCA.

Adult↗
PubMed2006

In-vivo flow simulation in coronary arteries based on computed tomography datasets: feasibility and initial results.

The purpose of this paper was to non-invasively assess hemodynamic parameters such as mass flow, wall shear stress (WSS), and wall pressure with computational fluid dynamics (CFD) in coronary arteries using patient-specific data from computed tomography (CT) angiography. Five patients (two without atherosclerosis, three with atherosclerosis) underwent retrospectively electrocardiogram (ECG) gated 16-detector row CT using ECG-pulsing and geometric models of coronary arteries were reconstructed for CFD analysis. Blood flow was considered laminar, incompressible, Newtonian, and pulsatile. The mass flow, WSS, and wall pressure were quantified and flow patterns were visualized. The wall pressure continuously decreased towards distal segments and showed pressure drops in stenotic segments. In coronary segments without atherosclerotic wall changes, WSS remained low, even during phases of high flow velocity, whereas in atherosclerotic vessels, the WSS was elevated already at low flow velocities. Stenoses and post-stenotic dilatations led to flow acceleration and rapid deceleration, respectively, including a distortion of flow. Areas of high WSS and high flow velocities were found adjacent to plaques, with values correlating with the degree of stenosis. CFD provided detailed mass flow measurements. CFD analysis is feasible in normal and atherosclerotic coronary arteries and provides the rationale for further investigation of the links between hemodynamic parameters and the significance of coronary stenoses.

Aged↗
PubMed2006

Accuracy of dual-source CT coronary angiography: First experience in a high pre-test probability population without heart rate control.

The aim of this study was to assess the diagnostic accuracy of dual-source computed tomography (DSCT) for evaluation of coronary artery disease (CAD) in a population with extensive coronary calcifications without heart rate control. Thirty patients (24 male, 6 female, mean age 63.1+/-11.3 years) with a high pre-test probability of CAD underwent DSCT coronary angiography and invasive coronary angiography (ICA) within 14+/-9 days. No beta-blockers were administered prior to the scan. Two readers independently assessed image quality of all coronary segments with a diameter > or =1.5 mm using a four-point score (1: excellent to 4: not assessable) and qualitatively assessed significant stenoses as narrowing of the luminal diameter >50%. Causes of false-positive (FP) and false-negative (FN) ratings were assigned to calcifications or motion artifacts. ICA was considered the standard of reference. Mean body mass index was 28.3+/-3.9 kg/m2 (range 22.4-36.3 kg/m2), mean heart rate during CT was 70.3+/-14.2 bpm (range 47-102 bpm), and mean Agatston score was 821+/-904 (range 0-3,110). Image quality was diagnostic (scores 1-3) in 98.6% (414/420) of segments (mean image quality score 1.68+/-0.75); six segments in three patients were considered not assessable (1.4%). DSCT correctly identified 54 of 56 significant coronary stenoses. Severe calcifications accounted for false ratings in nine segments (eight FP/one FN) and motion artifacts in two segments (one FP/one FN). Overall sensitivity, specificity, positive and negative predictive value for evaluating CAD were 96.4, 97.5, 85.7, and 99.4%, respectively. First experience indicates that DSCT coronary angiography provides high diagnostic accuracy for assessment of CAD in a high pre-test probability population with extensive coronary calcifications and without heart rate control.

Adult↗
PubMed2006

Noninvasive coronary angiography with 64-section CT: effect of average heart rate and heart rate variability on image quality.

PURPOSE: To evaluate prospectively the effect of average heart rate and heart rate variability on image quality at 64-section computed tomographic (CT) coronary angiography. MATERIALS AND METHODS: The study protocol had local ethics committee approval; written informed consent was obtained. There were 125 patients (45 women, 80 men; mean age, 59.9 years +/- 12.9 [standard deviation]; 79 receiving beta-blockers) who underwent 64-section CT coronary angiography with retrospective electrocardiographic gating. Data sets were reconstructed in 5% steps from 20% to 80% of R-R interval. Heart rate variability was calculated as 1 standard deviation from mean rate during scanning. Two observers rated image quality of each coronary segment at least 1.5-mm diameter (1 = no motion artifacts, 5 = not evaluative). Repeated analysis of variance measurements were performed to evaluate quantitative parameters. Pearson correlation analysis was performed to compare image quality in each patient with average heart rate and heart rate variability. RESULTS: Average heart rate was 63.3 beats per minute +/- 13.1, with variability of 3.2 beats per minute +/- 2.1. Diagnostic image quality (score < or = 3) was attained in 1821 of 1836 segments at the best reconstruction interval. There was no correlation between mean heart rate and image quality for all segments of the right coronary and left anterior descending arteries, but there was a significant correlation for left circumflex artery (r = 0.33, P < .05). Heart rate variability was correlated with image quality overall (r = 0.75, P < .001) and for each coronary artery. Heart rate was less variable and image quality was better (P < .05) in patients receiving beta-blockers. Best image quality was obtained in diastole with heart rate less than 80 beats per minute and in systole with faster heart rate. CONCLUSION: Coronary angiography with 64-section CT provides diagnostic image quality within a wide range of heart rates. Reducing average heart rate and heart rate variability is beneficial for reducing artifacts.

Adult↗
PubMed2006

Immunomodulation by interleukin-4 suppresses matrix metalloproteinases and improves cardiac function in murine myocarditis.

Immune response is critically involved in determining the course of viral myocarditis and immunomodulation. Different cytokines may have either deleterious or protective effects. Following acute Coxsackievirus B3 infection, intramyocardial inflammation is associated with altered myocardial matrix metalloproteinase (MMP) expression and left ventricular dysfunction. In this study, we evaluated the effect of exogenous interleukin-4 treatment on myocardial inflammation, MMPs and left ventricular function in Coxsackievirus B3-induced acute murine myocarditis. Eight-week-old inbred male BALB/c (H-2d) mice (The Jackson Laboratory, Bar Harbor, Maine, USA) were used. Myocardial inflammation was measured by immunohistochemical detection of CD3(+)-, CD8a(+)-T-lymphocytes, and CD11b+ macrophages. In situ hybridization was used to detect enteroviral genome in the myocardium. Semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) was employed to detect cytokine and MMP mRNA. MMP activity was quantified by zymography analysis. Detection of myocytolysis was performed by Luxol fast blue staining. In the early acute phase, in comparison to infected mice without treatment, interleukin-4 administration (200 ng daily) reduced intramyocardial inflammation (CD3+ lymphocytes: 55.3+/-7.0 vs. 72.1+/-13.7 cells/mm2, P < 0.05; CD8a+ lymphocytes: 31.7+/-3.6 vs. 64.2+/-7.7 cells/mm2, P < 0.05; CD11b+ macrophages: 5.1+/-2.3 vs. 13.2+/-2.5 cells/mm2, P < 0.05). It also down-regulated interleukin-2 (IL) (1.7-fold, P < 0.001) but increased transforming growth factor-beta1 (TGF) (1.5-fold, P < 0.001) and IL-4 (1.4-fold, P < 0.001). IL-4 suppressed MMP-2/-3/-9 transcription and activity. These biochemical alterations were accompanied by a significant improvement of left ventricular function as assessed by Milar tip catheter (left ventricular endsystolic pressure, 1.3-fold, P < 0.01; dP/dt max, 1.5-fold, P < 0.01). Immunomodulation by exogenous IL-4 treatment may lead to an anti-inflammatory effect with the inhibition of Th1 cell phenotypic response, which may further mediate the down-regulation of MMPs. A significant suppression of MMPs may mainly contribute to an improvement of left ventricular dysfunction in acute murine CVB3-induced myocarditis.

Animals↗
PubMed2006

Use of coronary calcium score scans from stand-alone multislice computed tomography for attenuation correction of myocardial perfusion SPECT.

PURPOSE: To evaluate the use of CT attenuation maps, generated from coronary calcium scoring (CCS) scans at in- and expiration with a 64-slice CT scanner, for attenuation correction (AC) of myocardial perfusion SPECT images. METHODS: Thirty-two consecutive patients underwent( 99m)Tc-tetrofosmin gated adenosine stress/rest SPECT scan on an Infinia Hawkeye SPECT-CT device (GE Medical Systems) followed by CCS and CT angiography on a 64-slice CT. AC of the iteratively reconstructed images was performed with AC maps obtained: (a) from the "Hawkeye" low-resolution X-ray CT facility attached to the Infinia camera (IRAC); (b) from the CCS scan acquired on a 64-slice CT scanner during maximal inspiration (AC(INSP)) and (c) during normal expiration (AC(EXP)). Automatically determined uptake values of stress scans (QPS, Cedars Medical Sinai) from AC(INSP) and AC(EXP) were compared with IRAC. Agatston score (AS) values using AC(INSP)versus AC(EXP) were also compared. RESULTS: AC(INSP) and AC(EXP) resulted in identical findings versus IRAC by visual analysis. A good correlation for uptake values between IRAC and AC(INSP) was found (apex, r=0.92; anterior, r=0.85; septal, r=0.91; lateral, r=0.86; inferior, r=0.90; all p<0.0001). The correlation was even closer between IRAC and AC(EXP) (apex, r=0.97; anterior, r=0.91; septal, r=0.94; lateral, r=0.92; inferior, r=0.97; all p<0.0001). The mean AS during inspiration (319+/-737) and expiration(317+/-778) was comparable (p=NS). CONCLUSION: Attenuation maps from CCS allow accurate AC of SPECT MPI images. AC(EXP) proved superior to AC(INSP), suggesting that in hybrid scans CCS may be performed during normal expiration to allow its additional use for AC of SPECT MPI.

Adult↗
PubMed2006

Functional growth in tissue-engineered living, vascular grafts: follow-up at 100 weeks in a large animal model.

BACKGROUND: Living autologous vascular grafts with the capacity for regeneration and growth may overcome the limitations of contemporary artificial prostheses. Particularly in congenital cardiovascular surgery, there is an unmet medical need for growing replacement materials. Here we investigate growth capacity of tissue-engineered living pulmonary arteries in a growing lamb model. METHODS AND RESULTS: Vascular grafts fabricated from biodegradable scaffolds (ID 18+/-l mm) were sequentially seeded with vascular cells. The seeded constructs were grown in vitro for 21 days using biomimetic conditions. Thereafter, these tissue-engineered vascular grafts (TEVGs) were surgically implanted as main pulmonary artery replacements in 14 lambs using cardiopulmonary bypass and followed up for < or = 100 weeks. The animals more than doubled their body weight during the 2-year period. The TEVG showed good functional performance demonstrated by regular echocardiography at 20, 50, 80, and 100 weeks and computed tomography-angiography. In particular, there was no evidence of thrombus, calcification, stenosis, suture dehiscence, or aneurysm. There was a significant increase in diameter by 30% and length by 45%. Histology showed tissue formation reminiscent of native artery. Biochemical analysis revealed cellularity and proteoglycans and increased collagen contents in all of the groups, analogous to those of native vessels. The mechanical profiles of the TEVG showed stronger but less elastic tissue properties than native pulmonary arteries. CONCLUSIONS: This study provides evidence of growth in living, functional pulmonary arteries engineered from vascular cells in a full growth animal model.

Absorbable Implants↗
PubMed2006

Coronary artery imaging with 64-slice computed tomography from cardiac surgical perspective.

INTRODUCTION: 64-Slice computed tomography (CT) has been introduced with high expectations. This study illustrates the value of 64-slice CT for the diagnosis of significant coronary artery stenoses when images are analysed by cardiovascular surgeons. METHODS: Fifty patients (39 males, 11 females) underwent invasive coronary angiography and 64-slice CT. In these patients, 40 had coronary artery disease and 10 patients had valvular disease. Evaluation of right coronary artery (RCA), left main (LM), left anterior descending artery (LAD), diagonal branch 1 (D1), circumflex branch (CX), and 1st marginal branch was performed by two cardiovascular surgeons. All vessels with a diameter >/=1.5 mm were analysed and a lumen restriction of >50% was considered a significant stenosis. CT image quality was classified as excellent, reduced but still diagnostic, and not assessable. Invasive coronary angiography was taken as gold standard for calculations of diagnostic accuracy. RESULTS: Mean heart rate during CT scan was 65+/-11 beats per minute (bpm). Image quality of 92% (506/550) of all segments was rated as excellent, 5% (27/550) were rated as being of reduced quality but still diagnostic, and 3% (17/550) were considered not assessable. The sensitivity for diagnosing a significant stenosis with CT when including all reliably evaluated segments was 93% (106/114), specificity was 97% (381/392), positive predictive value was 91% (106/117), and negative predictive value was 98% (381/389). CONCLUSION: 64-Slice CT provides a high diagnostic accuracy in assessing significant coronary artery stenosis. Nevertheless, still exist some disadvantages such as strong vessel wall calcifications reducing the reliability for image interpretation. At the moment, 64-slice CT should be used as a complementary imaging modality to invasive coronary angiography.

Aged↗
PubMed2006

Aortic stenosis: comparative evaluation of 16-detector row CT and echocardiography.

PURPOSE: To prospectively evaluate whether planimetric measurements of aortic valve area (AVA) with 16-detector row computed tomography (CT) allow classification of aortic stenosis (AS). MATERIALS AND METHODS: The study had institutional review board approval; patients gave informed consent. Twenty patients (11 men, nine women; mean age, 63 years) with AS and 20 patients (10 men, 10 women; mean age, 65 years) without underwent transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and retrospectively electrocardiographically gated 16-detector row CT. Twenty CT data sets were reconstructed in 5% steps of R-R interval; data analysis was performed with four-dimensional software. Maximum AVA in systole planimetrically measured with CT (AVA(CT)) was compared with AVA planimetrically measured with TEE (AVA(TEE)), AVA calculated with the continuity equation and TTE (AVA(TTE)), and transvalvular pressure gradients determined with the Bernoulli equation and TTE. Correlations among AVA(CT), AVA(TTE), AVA(TEE), and transvalvular pressure gradients were tested with bivariate regression analysis; agreement between methods was assessed with the Bland-Altman method. RESULTS: In patients without AS, mean AVA(CT) was 3.56 cm2 +/- 0.66 and mean AVA(TEE) was 3.43 cm2 +/- 0.69. In patients with AS, mean AVA(CT) was 0.89 cm2 +/- 0.35; mean AVA(TEE), 0.86 cm2 +/- 0.35; and mean AVA(TTE), 0.83 cm2 +/- 0.33. Mean transvalvular pressure gradient was 51 mm Hg +/- 22. Significant correlations were present between AVA(CT) and AVA(TEE) (r = 0.99, P < .001), AVA(CT) and AVA(TTE) (r = 0.95, P < .001), and AVA(CT) and transvalvular pressure gradients (r = -0.74, P < .01). Mean differences were -0.08 cm2 (limits of agreement: -0.32, 0.16) for AVA(CT) versus AVA(TEE) and 0.06 cm2 (limits of agreement: -0.15, 0.26) for AVA(CT) versus AVA(TTE). CONCLUSION: Planimetric measurements of AVA with retrospectively electrocardiographically gated 16-detector row CT allow classification of AS that is similar to that achieved with measurements by using echocardiographic methods.

Aged↗
PubMed2006

Optimal image reconstruction intervals for non-invasive coronary angiography with 64-slice CT.

The reconstruction intervals providing best image quality for non-invasive coronary angiography with 64-slice computed tomography (CT) were evaluated. Contrast-enhanced, retrospectively electrocardiography (ECG)-gated 64-slice CT coronary angiography was performed in 80 patients (47 male, 33 female; mean age 62.1+/-10.6 years). Thirteen data sets were reconstructed in 5% increments from 20 to 80% of the R-R interval. Depending on the average heart rate during scanning, patients were grouped as < 65 bpm (n = 49) and > or = 65 bpm (n = 31). Two blinded and independent readers assessed the image quality of each coronary segment with a diameter > or = 1.5 mm using the following scores: 1, no motion artifacts; 2, minor artifacts; 3, moderate artifacts; 4, severe artifacts; and 5, not evaluative. The average heart rate was 63.3 +/- 13.1 bpm (range 38-102). Acceptable image quality (scores 1-3) was achieved in 99.1% of all coronary segments (1,162/1,172; mean image quality score 1.55 +/- 0.77) in the best reconstruction interval. Best image quality was found at 60% and 65% of the R-R interval for all patients and for each heart rate subgroup, whereas motion artifacts occurred significantly more often (P < 0.01) at other reconstruction intervals. At heart rates < 65 bpm, acceptable image quality was found in all coronary segments at 60%. At heart rates > or = 65 bpm, the whole coronary artery tree could be visualized with acceptable image quality in 87% (27/31) of the patients at 60%, while ten segments in four patients were rated as non-diagnostic (scores 4-5) at any reconstruction interval. In conclusion, 64-slice CT coronary angiography provides best overall image quality in mid-diastole. At heart rates < 65 bpm, diagnostic image quality of all coronary segments can be obtained at a single reconstruction interval of 60%.

Adult↗
PubMed2006

Influence of cardiac hemodynamic parameters on coronary artery opacification with 64-slice computed tomography.

The purpose of this study was to evaluate the influence of ejection fraction (EF), stroke volume (SV), heart rate, and cardiac output (CO) on coronary artery opacification with 64-slice computed tomography (CT). Sixty patients underwent, retrospectively, electrocardiography-gated 64-slice CT coronary angiography. Left ventricular EF, SV, and CO were calculated with semi-automated software. Attenuation values were measured and contrast-to-noise ratios (CNRs) were calculated in the proximal right coronary artery (RCA) and left main artery (LMA). Mean EF during scanning was 61.5+/-12.4%, SV was 63.2+/-15.6 ml, heart rate was 62.5+/-11.8 beats per minute (bpm), and CO was 3.88+/-1.06 l/min. There was no significant correlation between the EF and heart rate and the attenuation and CNR in either coronary artery. A significant negative correlation was found in both arteries between SV and attenuation (RCA r=-0.26, P<0.05; LMA r=-0.34, P<0.01) and between SV and CNR (RCA r=-0.26, P<0.05; LMA r=-0.26, P<0.05). Similarly, a significant negative correlation was found between the CO and attenuation (RCA r=-0.42, P<0.05; LMA r=-0.56, P<0.001) and between the CO and CNR (RCA r=-0.39, P<0.05; LMA r=-0.44, P<0.001). The actual hemodynamic status of the patient influences the coronary artery opacification with 64-slice CT, in that vessel opacification decreases as SV and CO increase.

Adult↗
PubMed2006

Thick maximum intensity projections for the assessment of left ventricular function with 64-slice computed tomography.

OBJECTIVE: The objective of this study was to assess the accuracy of thick maximum intensity projections (MIP) from computed tomography (CT) data sets mimicking projection images from biplane ventriculography for evaluation of left ventricular (LV) parameters. MATERIALS AND METHODS: Fifty-eight patients underwent 64-slice CT. Multiphase images were reconstructed in 10% steps of the RR interval. MIP images (70-mm thickness) of the contrast-enhanced LV in fixed 30 degrees right anterior oblique (RAO)/60 degrees left anterior oblique (LAO) and in adapted short-/long-axis planes were reconstructed. LV parameters were calculated using the area-length method formula. Three-dimensional assessment with semiautomated software served as reference standard. RESULTS: Use of thick MIP reconstructions had a high intermethod reliability (86-94%) compared with the 3-dimensional approach. Smaller measurement errors were found for thick MIP reconstructions in adapted short-/long-axis planes. A significant projection error (3.0%, P < 0.001) of thick MIP reconstructions was found using fixed 30 degrees RAO/60 degrees LAO compared with adapted short-/long-axis reconstructions. CONCLUSION: Thick MIP reconstructions with adapted short-/long-axis planes allow an accurate assessment of LV parameters compared with the established 3-dimensional method.

Adult↗
PubMed2006

Comparison of 64-slice CT with gated SPECT for evaluation of left ventricular function.

UNLABELLED: Precise and reliable assessment of left ventricular (LV) function and dimensions is prognostically important in cardiac patients. As the integration of SPECT and multislice CT into hybrid scanners will promote the combined use of both techniques in the same patient, a comparison of the 2 methods is pertinent. We aimed at comparing LV dimensions, muscle mass, and function obtained by electrocardiographically gated 64-slice CT versus gated-SPECT. METHODS: Sixty patients (mean age, 64 +/- 8 y) referred for evaluation of coronary artery disease underwent 99mTc-tetrofosmin gated SPECT and 64-slice CT within 4 +/- 2 d. LV ejection fraction (LVEF), end-systolic volume (ESV), and end-diastolic volume (EDV) from CT were compared with SPECT. Additionally, LV muscle mass and quantitative regional wall motion were assessed in 20 patients with both methods. RESULTS: CT was in good agreement with SPECT for quantification of LVEF (r = 0.825), EDV (r = 0.898), and ESV (r = 0.956; all P < 0.0001). LVEF was 59% +/- 13% measured by SPECT and slightly higher but not significantly different by CT (60% +/- 12%; mean difference compared with SPECT, 1.1% +/- 1.7%; P = not significant). A systematic overestimation using CT for EDV (147 +/- 60 mL vs. 113 +/- 52 mL; mean difference, 33.5 +/- 23.1 mL) and ESV (63 +/- 55 mL vs. 53 +/- 49 mL; mean difference, 9.3 +/- 15.9 mL; P < 0.0001) was found compared with SPECT. A good correlation for muscle mass was found between the 2 methods (r = 0.868; P < 0.005). However, muscle mass calculated by SPECT was significantly lower compared with CT (127 +/- 24 g vs. 148 +/- 37 g; mean difference, 23.0 +/- 12.2 g; P < 0.001). The correlation for regional wall motion between the 2 methods was moderate (r = 0.648; P < 0.0001). CONCLUSION: LVEF and LV functional parameters as determined by 64-slice CT agree over a wide range of clinically relevant values with gated SPECT. However, interchangeable use of the 2 techniques should be avoided for LV volumes, muscle mass, and regional wall motion because of variances inherent to the different techniques.

Adult↗
PubMed2005

Mitral regurgitation: quantification with 16-detector row CT--initial experience.

PURPOSE: To prospectively determine if retrospectively electrocardiographic (ECG)-gated multi-detector row computed tomography (CT) with a 16-detector row CT scanner can depict mitral regurgitation and enable quantification of the severity of the disease. MATERIALS AND METHODS: The study had institutional review board approval, and patients gave informed consent. Nineteen patients with mitral regurgitation (10 men, nine women; mean age, 66 years +/- 9 [standard deviation]; range, 41-83 years) and 25 patients without mitral regurgitation (14 men, 11 women; mean age, 68 years +/- 9; range, 43-83 years) as determined with transesophageal color Doppler echocardiography and ventriculography underwent retrospectively ECG-gated 16-detector row CT. Twenty CT data sets covering the entire mitral valve apparatus were reconstructed in 5% steps of the R-R interval for each patient, and data analysis was performed with four-dimensional software. Using planimetry, two readers measured in consensus the area of the regurgitant orifice during systole. These measurements were compared with semiquantitative data from transesophageal echocardiography and ventriculography by using Spearman rank order correlation coefficients. RESULTS: In the 25 patients without mitral regurgitation, no regurgitant orifice during systole could be detected with multi-detector row CT. In the 19 patients with mitral regurgitation, a regurgitant orifice could be visualized in all cases. The mean regurgitant orifice area at CT-45 mm(2) +/- 34 (range, 10-148 mm(2))-correlated significantly with the results at transesophageal echocardiography (r = 0.807, P < .001) and ventriculography (r = 0.922, P < .001). CONCLUSION: Planimetric measurements of the regurgitant orifice area at retrospectively ECG-gated 16-detector row CT enable quantification of mitral regurgitation.

Adult↗
PubMed2005

Multi-detector computed tomography of acute abdomen.

Acute abdominal pain is one of the most common causes for referrals to the emergency department. The sudden onset of severe abdominal pain characterising the "acute abdomen" requires rapid and accurate identification of a potentially life-threatening abdominal pathology to provide a timely referral to the appropriate physician. While the physical examination and laboratory investigations are often non-specific, computed tomography (CT) has evolved as the first-line imaging modality in patients with an acute abdomen. Because the new multi-detector CT (MDCT) scanner generations provide increased speed, greater volume coverage and thinner slices, the acceptance of CT for abdominal imaging has increased rapidly. The goal of this article is to discuss the role of MDCT in the diagnostic work-up of acute abdominal pain.

Abdomen, Acute↗
PubMed2005

Accuracy of MSCT coronary angiography with 64-slice technology: first experience.

AIMS: The aim of our study was to investigate the accuracy of 64-slice computed tomography (CT) for assessing haemodynamically significant stenoses of coronary arteries. METHODS AND RESULTS: CT angiography was performed in 67 patients (50 male, 17 female; mean age 60.1+/-10.5 years) with suspected coronary artery disease and compared with invasive coronary angiography. All vessels > or =1.5 mm were considered for the assessment of significant coronary artery stenosis (diameter reduction >50%). Forty-seven patients were identified as having significant coronary stenoses on invasive angiography with 18% (176/1005) affected segments. None of the coronary segments needed to be excluded from analysis. CT correctly identified all 20 patients having no significant stenosis on invasive angiography. Overall sensitivity for classifying stenoses was 94%, specificity was 97%, positive predictive value was 87%, and negative predictive value was 99%. CONCLUSION: Sixty-four-slice CT provides a high diagnostic accuracy in assessing coronary artery stenoses.

Adult↗