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 (Tc-99m-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 Tc-99m-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 Tc-99m-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 Tc-99m-MIBI SPECT scintigraphy. Additionally, CEUS was useful in the differentiation between parathyroid adenomas and lymph nodes.