Multisegment and halfscan reconstruction of 16-slice computed tomography for assessment of regional and global left ventricular myocardial function.
ABSTRACT We sought to prospectively compare multisegment and halfscan reconstruction of 16-slice computed tomography (CT) for the assessment of regional and global left ventricular myocardial function with magnetic resonance imaging (MRI) as the reference standard.
Forty-two patients underwent CT with 16 x 0.5-mm detector collimation. Electrocardiogram-gated reconstructions were generated with multisegment reconstruction (using up to 4 segments correlated with the raw data of up to 4 heartbeats) and standard halfscan reconstruction. Steady-state free-precession cine MRI was acquired within 24 hours.
More normal myocardial segments were identified correctly with multisegment (95%, 620/656) compared with halfscan reconstruction (88%, 582/656) of CT (P < 0.001). Also, the accuracy (92% [657/714] vs. 87% [620/714]) and rate of nondiagnostic segments (0% vs. 5% [33/714]) were significantly better when using multisegment reconstruction (P < 0.001). The image quality with multisegment reconstruction was significantly superior to that achieved with halfscan reconstruction (P < 0.001). In the assessment of global left ventricular function, multisegment and halfscan reconstruction of CT showed high correlations for all parameters with MRI, whereas Bland-Altman analysis revealed smaller limits of agreement for assessment of myocardial mass with multisegment reconstruction (P = 0.025), but no significant differences between both reconstruction techniques in the measurement of left ventricular volumes as compared with MRI.
Multisegment reconstruction of 16-detector row CT improves image quality and assessment of regional wall motion compared with standard halfscan reconstruction.
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ABSTRACT: To compare the diagnostic accuracy and image quality of 2 reconstruction algorithms (multisegment and halfscan) for computed tomography (CT) coronary angiography in patients without beta-blocker medication. Thirty-four patients with 42 significant coronary stenoses in 136 main coronary branches were examined using a 16-slice CT scanner (Aquilion, Toshiba, Otawara, Japan). Twenty-seven patients (79%) had heart rates above 65 beats/min. Without exclusion of branches the sensitivity, specificity, accuracy, and rate of nonassessable segments with multisegment versus halfscan reconstruction were 88 versus 74%, 91 versus 71%, 90 versus 72%, and 2 versus 21% (P < 0.01), respectively. Multisegment reconstruction improved the average vessel length free of motion artifacts by 56% compared with halfscan reconstruction (P < 0.01). Image quality in terms of vessel continuity and visibility of side branches (P < 0.005) was significantly better using multisegment reconstruction. Multisegment reconstruction has superior diagnostic accuracy and image quality compared with halfscan reconstruction in patients with normal heart rates.Investigative Radiology 04/2004; 39(4):223-9. · 5.46 Impact Factor
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ABSTRACT: We sought to evaluate the radiation exposure of cardiac CT scans with 16-row multidetector computed tomography (MDCT). Additionally the possibility of dose reduction by using a ECG-controlled tube current modulation technique was evaluated. An Alderson Rando phantom equipped with thermoluminescent dosimeters was used for dose measurements. Effective dose was calculated according to ICRP 60. Exposure was performed on a 16-row MDCT scanner with standard protocols for CT coronary calcium scoring (120 kV, 133 mAs, 12 x 1.5 mm) and CT coronary angiography (120 kV, 400 mAs, 12 x 0.75 mm). Exposure was repeated at a simulated heart rate of 60 bpm with ECG-pulsed tube current modulation. Effective dose was 2.9 mSv (male) and 3.6 mSv (female) for the calcium scoring protocol. CT coronary angiography resulted in an effective dose of 8.1 mSv (male) and 10.9 mSv (female). Using ECG-pulsed tube current modulation radiation exposure can significant reduced: by 46 % (1.6 mSv) in calcium scoring and by 47 % (4.3 mSv) in CT coronary angiography. MDCT of the heart shows a significant radiation exposure, which can significantly be reduced by ECG-pulsed tube current modulation. Radiation exposure of cardiac MDCT is comparable to CT-examinations of chest or abdomen, but seem to be slightly higher compared to conventional coronary angiography.RöFo - Fortschritte auf dem Gebiet der R 09/2003; 175(8):1051-5. · 2.76 Impact Factor
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ABSTRACT: To assess the value of different image reconstruction algorithms for assessment of the left ventricular function using retrospectively ECG-gated multislice spiral computed tomography (MSCT) of the heart. MSCT and cine magnetic resonance (MR) imaging of the heart were performed in 15 patients. For MSCT, standard and multisegmental image reconstruction with improved temporal resolution were used. Standardized multiplanar reformats in the short axis and long axis views were reconstructed from MSCT data. End-systolic (ESV) and end-diastolic volume (EDV), stroke volume (SV), ejection fraction (EF) and myocardial mass (MM) were calculated. Left ventricular wall motion was assessed qualitatively. MSCT was in acceptable agreement with MR imaging for quantification of the ventricular function. According to the Bland-Altman approach the mean differences for the left ventricular volumes (ESV, EDV, SV) ranged from -9.6 ml to 3.1 ml with standard image reconstruction and from -0.6 ml to 1.9 ml utilizing multisegmental image reconstruction with limits of agreement ranging from -26.6 ml to 12.5 ml and -15.6 ml to 15.0 ml, respectively. Applying the multisegmental image reconstruction algorithm, a significantly improved agreement with the MR data was found for EDV, SV and EF. For wall motion analysis, standard image reconstruction showed a significant difference to MR imaging with a correspondence in 83.75% of the 240 assessed segments, while multisegmental image reconstruction agreed with MR imaging in 92.5% of the segments. Multisegmental image reconstruction improves the quantitative assessment of left ventricular function when compared to standard image reconstruction. Multisegmental image reconstruction allows qualitative wall motion analysis.Acta Radiologica 12/2003; 44(6):604-11. · 1.33 Impact Factor