Department of Nuclear Medicine, School of Medicine, Selcuk University, Konya, Turkey.
Indian J Med Res. 2017 Apr;145(4):479-487. doi: 10.4103/ijmr.IJMR_305_15.
BACKGROUND & OBJECTIVES: Preoperative localization of parathyroid lesions is essential for improving the results in patients with primary hyperparathyroidism. The purpose of this study was to evaluate retrospectively the value of technetium-99m (Tc-99m) methoxyisobutylisonitrile (MIBI) single photon emission computed tomography (SPECT) and to compare the diagnostic accuracy of iterative reconstruction (IR) and filtered backprojection (FBP) reconstruction algorithms about localization of parathyroid lesions.
Forty four patients with primary hyperparathyroidism, in whom histopathological correlation could be performed, were included in the study. Dual-phase Tc-99m parathyroid scintigraphy was performed 20 and 120 min after injection of 740 MBq Tc-99m MIBI in all patients. Tomographic images were acquired 120 min after the administration of radiopharmaceutical. The SPECT data were evaluated using an IR as well as a FBP algorithm. In 23 of 44 patients, SPECT acquisitions were performed in 64×64 matrix; in the remaining 21 patients, tomographic data were collected in 128×128 matrix. The imaging results were compared with pathological findings and sensitivities of both reconstruction algorithms, and planar views were calculated.
Using planar MIBI scans, abnormal parathyroid glands were correctly localized in 75 per cent of the cases. Sensitivity increased to 77 per cent using SPECT with FBP and to 84 per cent with IR. When the sensitivities were calculated according to the acquisition matrix, these were 95 per cent (20/21) and 85 per cent (18/21) for IR and FBP, respectively in patients in whom 128×128 matrix was used. The sensitivities were lower in patients who were imaged with 64×64 matrix; these were calculated as 74 per cent (17/23) and 70 per cent (16/23) with IR and FBP, respectively.
INTERPRETATION & CONCLUSIONS: Our findings showed that compared to planar scintigraphy, Tc-99m MIBI SPECT was more sensitive diagnostic modality in the detection of abnormal parathyroid tissues. Image quality and sensitivity may be improved further when larger matrices with IR are used instead of FBP algorithm.
甲状旁腺病变的术前定位对于改善原发性甲状旁腺功能亢进症患者的治疗效果至关重要。本研究旨在回顾性评估锝-99m（Tc-99m）甲氧异丁基异腈（MIBI）单光子发射计算机断层扫描（SPECT）的价值，并比较迭代重建（IR）和滤波反投影（FBP）重建算法在甲状旁腺病变定位中的诊断准确性。
本研究纳入了 44 例经组织病理学证实的原发性甲状旁腺功能亢进症患者。所有患者均在注射 740MBq Tc-99m MIBI 后 20 和 120 分钟进行双时相 Tc-99m 甲状旁腺闪烁显像，在放射性药物给药后 120 分钟采集断层扫描图像。SPECT 数据分别采用 IR 和 FBP 算法进行评估。在 44 例患者中，有 23 例采用 64×64 矩阵进行 SPECT 采集，其余 21 例采用 128×128 矩阵进行断层扫描数据采集。将影像学结果与病理发现进行比较，并计算两种重建算法的灵敏度。
使用平面 MIBI 扫描，75%的病例正确定位了异常甲状旁腺。SPECT 联合 FBP 的灵敏度提高至 77%，IR 提高至 84%。当根据采集矩阵计算灵敏度时，在使用 128×128 矩阵的患者中，IR 和 FBP 的灵敏度分别为 95%（20/21）和 85%（18/21）。在使用 64×64 矩阵的患者中，灵敏度较低，IR 和 FBP 的灵敏度分别为 74%（17/23）和 70%（16/23）。
与平面闪烁显像相比，Tc-99m MIBI SPECT 是检测异常甲状旁腺组织更敏感的诊断方法。与 FBP 算法相比，使用较大矩阵结合 IR 可进一步提高图像质量和灵敏度。
