Correction of iodine-123-labeled meta-iodobenzylguanidine uptake with multi-window methods for standardization of the heart-to-mediastinum ratio

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• 作者：Kenichi Nakajima ; Kosuke Matsubara ; Takehiro Ishikawa ; Nobutoku Motomura ; Ryo Maeda ; Nasima Akhter ; Koichi Okuda ; Junichi Taki ; Seigo Kinuya
• 关键词：¹²³I meta-iodobenzylguanidine ; collimator ; iodine-dual-energy window method ; triple-energy window method ; quantification
• 刊名：Journal of Nuclear Cardiology
• 出版年：2007
• 出版时间：November-December 2007
• 年：2007
• 卷：14
• 期：6
• 页码：843-851
• 全文大小：865 K

文摘

Background

To overcome differences in the choice of collimator for an iodine-123 (¹²³I)-labeled meta-iodobenzylguanidine (MIBG) heart-to-mediastinum (H/M) ratio, we examined multi-window correction methods with ¹²³I dual-window (IDW) and triple-energy window (TEW) acquisition.

Methods and Results

Standard phantoms, which consisted of the heart, mediastinum, lung, and liver, were generated. Three correction methods were compared: TEW and two IDW methods (IDW₀ and IDW₁). Low-energy high-resolution (LEHR), medium-energy (ME), and ¹²³I-specific low-medium-energy high-resolution (LMEHR) collimators were used. Clinical studies were performed in 10 patients. In the phantom study, the H/M ratio was significantly underestimated without correction, with both the LEHR and ME collimators (70 % and 88 % of the true value). When H/M with the LEHR collimator was divided by uncorrected H/M with the ME collimator, the ratio (mean ± SD) was 80 % ± 5 % , 98 % ± 5 % , 104 % ± 7 % , and 98 % ± 5 % for the no-correction, TEW, IDW₀, and IDW₁ methods, respectively. Clinical studies with the LEHR collimator after TEW and IDW correction (uncorrected average H/M ratio, 1.86 ± 0.23; TEW, 2.47 ± 0.46, P = .0015; IDW, 2.46 ± 0.46, P = .0017) provided comparable values to the uncorrected ME collimator (2.56 ± 0.46, P = NS vs TEW and IDW).

Conclusions

The H/M ratio with the ME collimator, after application of the TEW or IDW methods, was close to the theoretical value in the phantom study. However, the corrected H/M ratios with the LEHR collimator provided comparable H/M ratios to the uncorrected ME data in phantom and clinical studies.