Yahara Y, Nomura Y, Okamoto S, Saitou K, Okamoto R, Makino K, Aoki S, Takeda K
Department of Radiology, Mie University School of Medicine.
Kaku Igaku. 2000 May;37(3):217-25.
Quantification of 123I-metaiodobenzylguanidine (MIBG) myocardial uptake is widely accepted as a useful tool for estimating the severity of congestive heart failure. However, most reliable method has not been determined yet because of the difficulty of background (BG) subtraction. In this study, the most appropriate BG subtraction method was evaluated as compared with plasma atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), norepinephrine (NEP) and left ventricular ejection fraction (LVEF).
Twenty-one patients with chronic heart failure were examined. After bolus injection of 123I-MIBG (111 MBq), dynamic anterior chest images were collected every second for 2 minutes. Planar anterior chest images were obtained 15 minutes (early image) and 4 hours later (delayed image) respectively. The parameters for quantification of 123I-MIBG myocardial uptake used in this study were heart to mediastinum ratio (H/M), myocardial washout rate and uptake ratio. Background was calculated using the region of interest (ROI) placed over a part of upper mediastinum, whole upper mediastinum, right lung and pericardial space respectively. The values of these parameters were calculated with and without BG subtraction and compared with plasma ANP, BNP and others.
H/M did not correlate with ANP or BNP. Myocardial washout rate without BG subtraction showed significant correlation with ANP (p < 0.01) and BNP (p < 0.05). After BG subtraction employing ROI placed over the part of upper mediastinum and whole upper mediastinum, myocardial washout rate showed better correlation with BNP (p < 0.01). Myocardial uptake ratio did not showed any correlation with ANP or BNP without BG subtraction. However, myocardial uptake ratio showed significant correlation with BNP (p < 0.05) after subtraction of upper mediastinal BG. BG subtraction using ROI over right lung or pericardial area revealed poor results in both myocardial washout rate- and uptake ratio.
BG subtraction using ROI over the upper mediastinum is likely to be suitable for quantitative analysis of 123I-MIBG myocardial scintigram.
123I-间碘苄胍（MIBG）心肌摄取量的定量分析作为评估充血性心力衰竭严重程度的一种有用工具已被广泛接受。然而，由于背景（BG）扣除困难，尚未确定最可靠的方法。在本研究中，将最适宜的BG扣除方法与血浆心房利钠肽（ANP）、脑利钠肽（BNP）、去甲肾上腺素（NEP）和左心室射血分数（LVEF）进行比较来评估。
对21例慢性心力衰竭患者进行检查。静脉推注123I-MIBG（111 MBq）后，每秒采集一次动态前胸图像，共采集2分钟。分别于15分钟（早期图像）和4小时后（延迟图像）获取平面前胸图像。本研究中用于定量分析123I-MIBG心肌摄取的参数为心纵隔比（H/M）、心肌洗脱率和摄取率。背景分别使用置于上纵隔部分、整个上纵隔、右肺和心包腔的感兴趣区（ROI）进行计算。计算有和没有BG扣除时这些参数的值，并与血浆ANP、BNP等进行比较。
H/M与ANP或BNP无相关性。未进行BG扣除时的心肌洗脱率与ANP（p < 0.01）和BNP（p < 0.05）显著相关。采用置于上纵隔部分和整个上纵隔的ROI进行BG扣除后，心肌洗脱率与BNP的相关性更好（p < 0.01）。未进行BG扣除时，心肌摄取率与ANP或BNP均无相关性。然而，扣除上纵隔BG后，心肌摄取率与BNP显著相关（p < 0.05）。使用右肺或心包区域的ROI进行BG扣除，在心肌洗脱率和摄取率方面均显示效果不佳。
使用上纵隔的ROI进行BG扣除可能适用于123I-MIBG心肌闪烁显像的定量分析。
