Potential Utility of Contrast‐Enhanced Ultrasound in the Preoperative Evaluation of Primary Hyperparathyroidism

Objectives We aimed to compare the effectiveness of contrast‐enhanced ultrasound (CEUS), technetium Tc 99m methoxyisobutylisonitrile ( 99m Tc‐MIBI) single‐photon emission computed tomographic (SPECT) scintigraphy, and high‐resolution ultrasound (US) in the detection of a pathologic parathyroid gland in patients with primary hyperparathyroidism (pHPT). Methods Twenty‐nine consecutive patients with pHPT were prospectively enrolled and underwent preoperative imaging with 99m Tc‐MIBI SPECT scintigraphy, high‐resolution US, and CEUS and subsequent parathyroidectomy. Contrast‐enhanced US examinations were performed by an experienced examiner who was blinded to the results of scintigraphy and high‐resolution US. The diagnostic performance of all of the imaging tests was analyzed in comparison with the pathologic anatomic findings. All investigations were performed at La Paz University Hospital. Results In the 29 patients (22 female and 7 male), a total of 31 parathyroid adenomas were detected: single lesions in 27 patients and a double lesion in 2 patients. Contrast‐enhanced US revealed sensitivity of 66.7% (95% confidence interval [CI], 46%–82.7%) for detection of single adenomas in comparison with 77.8 % (95% CI, 57.3%–90.6) for 99m Tc‐MIBI SPECT scintigraphy and 51.8% (95% CI, 32.3%–70.8%) for high‐resolution US ( P = .100). With CEUS, double adenomas could be detected in both cases (sensitivity, 100%); however, scintigraphy and high‐resolution US did not detect any cases of double adenomas. In addition, CEUS allowed the differentiation of lymphatic nodes from parathyroid glands in 2 patients. No side effects were observed for CEUS. Conclusions In our study, CEUS facilitated the detection and diagnosis of double adenomas compared with high‐resolution US and 99m Tc‐MIBI SPECT scintigraphy. Additionally, CEUS was useful in the differentiation between parathyroid adenomas and lymph nodes.