Basso Danny, Passmore Gregory, Holman Michael, Rogers Ward, Walters Leslie, Zecchin Thomas, Butler Jayme
Cardiac Imaging of Augusta, Augusta, Georgia 30912, USA.
J Nucl Med Technol. 2009 Dec;37(4):233-9. doi: 10.2967/jnmt.109.063644. Epub 2009 Nov 13.
SPECT myocardial perfusion imaging (MPI) now accounts for well over 90% of all MPI studies performed in the United States. A means of reducing the acquisition time while maintaining diagnostic-quality images would be beneficial for both patients and nuclear cardiology clinics. Wide-beam reconstruction (WBR) is a processing algorithm that attempts to address the challenge of obtaining diagnostic-quality images with shorter counting times. This study was designed to incorporate semiqualitative assessments (physician rankings of image parameters) into quantitative assessments (morphologic measurements), as other researchers have done, in an effort to compare filtered backprojection (FBP)-the gold standard-with WBR.
Forty-seven MPI studies (from 34 men and 13 women) were masked to 3 physicians who qualitatively rated the images for image quality, myocardial normality, lesion reversibility, and treatment recommendation on a scale of 1-5, with 1 representing "good" and 5 representing "poor." Quantitative values for summed stress scores, summed rest scores, summed difference scores (SDS), end-diastolic volume, end-systolic volume, and the ejection fraction were calculated and reported.
The semiqualitative analyses of image interpretation indicated that WBR yielded significant improvements over FBP in image quality and showed very good to moderate agreement with FBP among physicians for myocardial normality, lesion reversibility, and treatment recommendation. The quantitative analyses of the morphometric values representing myocardial perfusion, through SDS comparisons, were equivalent for the 2 reconstruction methods. Regression analysis indicated that WBR seemed to underestimate the gated stress-derived FBP ejection fraction by 9%-10%.
Overall, the WBR method was equivalent or superior to the FBP reconstruction method for MPI with a rest-gated stress same-day protocol in terms of image quality, interpretation, and SDS. Additionally, the advantage of patient comfort derived from shorter imaging times should help reduce motion artifacts and repeat acquisitions as well as enhance patient care and throughput.
单光子发射计算机断层扫描心肌灌注成像（SPECT MPI）目前在美国所有MPI研究中所占比例超过90%。在保持诊断质量图像的同时减少采集时间的方法对患者和核心脏病诊所都有益处。宽束重建（WBR）是一种处理算法，试图应对在更短计数时间内获得诊断质量图像的挑战。本研究旨在像其他研究人员那样，将半定性评估（医生对图像参数的排名）纳入定量评估（形态学测量），以比较滤波反投影（FBP）——金标准——与WBR。
47项MPI研究（来自34名男性和13名女性）对3名医生保密，这3名医生对图像的图像质量、心肌正常性、病变可逆性和治疗建议进行定性评分，评分范围为1 - 5分，1代表“好”，5代表“差”。计算并报告了负荷总分、静息总分、差值总分（SDS）、舒张末期容积、收缩末期容积和射血分数的定量值。
图像解读的半定性分析表明，WBR在图像质量方面比FBP有显著改善，并且在心肌正常性、病变可逆性和治疗建议方面，医生之间WBR与FBP的一致性非常好到中等。通过SDS比较，代表心肌灌注的形态测量值的定量分析在两种重建方法中是等效的。回归分析表明，WBR似乎使门控负荷衍生的FBP射血分数低估了9% - 10%。
总体而言，对于采用静息门控负荷同日方案的MPI，WBR方法在图像质量、解读和SDS方面等同于或优于FBP重建方法。此外，较短成像时间带来的患者舒适度优势应有助于减少运动伪影和重复采集，以及提高患者护理质量和通量。
