Khảo sát giá trị của các số đo đậm độ trên chụp cắt lớp vi tính trong chẩn đoán adenoma tuyến thượng thận

SUMMARY:

Objective: To describe the characteristics of common adrenal lesions on CT and to compare the diagnostic performance of different methods of measurement in diagnosing adenoma.

Materials and Methods: We conducted a retrospective study in 63 patients with adrenal lesions who were performed preoperative CT and had histologic results at the University Medical Center Hospital between January 2016 and January 2020. A radiologist who had more than 10 years of experience of CT measured: lesion size, mean and standard deviation (SD) attenuation value, pixel histogram, calculated p10 based on histogram or following formula P10=mean – (1,282 x SD). The diagnostic performance of mean value, histogram analysis, calculated p10, absoulte and relative washout index were compared.

Results: The study was composed of 32 patients with 32 adenomas and 31 patients with 33 non-adenoma lesions. Adenomas were more common in female (n = 26 [81.3%]) than in male patients. However, non-adenoma were almost equally distributed between male and female patients (n = 15 female patients [48. 4%]). The mean age of patients in the adenoma group was 44.3 ± 12.6 years (range, 12-75 years), which is not significantly different from the mean age of 41.2 ± 15.1 years for patients in the non-adenoma group (range, 13-77 years) (p = 0.26).

Adenoma group had the mean diameter smaller than non-adenoma lesions (p <0,001) and more homogeneous attenuation pattern (p=0.001). The sensitivity, specificity and accuracy of the mean attenuation analysis, histogram, calculated p10, absoulte and relative washout were (37.5%, 100.0% and 66.7%, cutoff 10 HU), (84.4 %, 82.8% and 83.6%, cutoff 10%), (78.1 %, 82.1% and 80%, cutoff 0), (88 %, 72% and 80%, cutoff 60%), and (84.0 %, 65.4% and 74.5%, cutoff 40%), respectively.

Conclusion: The mean attenuation analysis, histogram and calculated p10 play a crucial role in differentiation adrenal adenoma from non-adenoma lesion. The accuracy of histogram analysis and calculated 10th percentile outperformed the mean attenuation as a diag-nostic criterion for adenoma.

Keywords: adrenal gland, adenoma, computed tomography