ABSTRACT
The aim of this study is to determine the factors affecting the CT attenuation of bone marrow, and its correlation with 18F-FDG uptake. The mean standardized uptake value (SUV) of vertebral bone marrow (Vertebral-SUV) and femoral bone marrow (Femoral-SUV) as well as CT number of bone marrow (BM-CT number) were measured in 243 patients who had undergone 18F-FDG PET/CT. The correlations among BM-CT number, Femoral-SUV, and Vertebral-SUV were investigated. The relationships of Femoral-SUV, Vertebral-SUV, and BM-CT number with blood parameters, age, blood sugar, and body weight were analyzed by correlation and multi-regression analyses. The Mann-Whitney U test and chi-square test and Binomial logistic analysis were used to examine the relationships between high BM-CT number (≥ 0 HU) and the above parameters. Significant correlations were observed between: BM-CT number and Femoral-SUV (r = 0.73, P < 0.01); Vertebral-SUV and Femoral-SUV (r = 0.78, P < 0.01); and BM-CT number and Vertebral-SUV (r = 0.52, P < 0.01). BM-CT number was correlated with patients' age in both univariable (r = -0.27) and multivariable analyses (ß = -0.20). Positive BM-CT number correlated with WBC in both univariable (P = 0.04) and multivariable (P < 0.01) analyses. Bone marrow glucose metabolism had a tendency to decrease with age, was increased in patients with elevated CRP. In conclusion, CT attenuation of bone marrow correlated well with bone marrow metabolism and also tended to decrease with age. High bone marrow attenuation (≥ 0 HU) could predict elevated serum WBC.
ABSTRACT
OBJECTIVE: The aim of this study was to elucidate the causes of false-negative cases of technetium-99 m methoxyisobutylisonitrile scintigraphy (MIBI) for hyperparathyroidism. METHODS: Consecutive MIBI examinations performed in 154 patients between April 2011 and March 2017 were retrospectively reviewed. Sensitivities of MIBI, CT and US were calculated. The effects of serum calcium, phosphorus, PTH, weight of parathyroid lesions, use of NSAIDs and Ca-channel blocker (CCB), presence of cyst in parathyroid lesions, and a number of lesions observed by MIBI were investigated. RESULTS: Seventy-nine patients (21 men and 58 women), ranging from 18 to 88 years of age (mean ± SD: 57.6 ± 15.3 years), who underwent parathyroidectomy, were included. MIBI and preoperative US were performed in the 79 patients and single-phase parenchymal contrast-enhanced CT (CE-CT) was performed in 55 patients. A total of 120 parathyroid proliferative nodules were detected by MIBI and US, and 92 lesions were detected by CE-CT. In the lesion base, MIBI detected 82 out of the 120 lesions (sensitivity = 68.3%), US detected 103 out of the 120 lesions (sensitivity = 85.8%), CE-CT detected 63 out of the 92 lesions (sensitivity = 68.5%), and MIBI plus CE-CT detected 72 of the 92 lesions (sensitivity = 78.3%). A significant difference in the sensitivity was found between US and MIBI (P < 0.01), and between US and CT (P < 0.01). In the patient base, MIBI detected 67 out of the 79 patients (sensitivity = 84.8%), US detected 74 out of the 79 patients (sensitivity = 93.7%), CE-CT detected 45 out of the 55 patients (sensitivity = 81.8%), and MIBI plus CE-CT detected 52 out of the 55 patients (sensitivity = 94.5%). No significant difference was observed in any of the comparisons. A significant difference was observed in lesion weight (P < 0.01), single or multiple lesions (P = 0.02), and presence of cyst (P < 0.01) between the MIBI false-negative (n = 38) and the true-positive groups (n = 82). CONCLUSION: The presence of cyst in parathyroid proliferative lesions as well as small size and multiple number of parathyroid lesions contribute to false negative in parathyroid MIBI scan.
