4D MRI reliable for diagnosing parathyroid tumors

Four-dimensional (4D) MRI with dynamic contrast-enhanced (DCE) sequencing is a reliable method for localizing parathyroid lesions, reported authors of a single-center study published Jan. 22 in the European Journal of Radiology.

Currently, ultrasound (US) and Technetium-99m-sestamibi (99mTc) are the first-line imaging techniques for localizing parathyroid lesions prior to surgery, wrote first author Mesut Ozturk, with Ondokuz Mayis University in Samsun, Turkey, and colleagues. However, if the technique doesn’t adequately identify the lesions or the condition persists even after surgery, CT and MRI are the second-line options.

Two readers blinded to surgical findings compared 4D MRI scans with DCE and non-contrast enhanced (non-CE) sequences in 41 patients with surgically proven parathyroid lesions. Overall, MRI had higher sensitivity (90.5 percent) compared to US (76.2 percent) and 99mTc-sestamibi (71.4 percent). MRI alone was just as sensitive as combined US and 99mTc-sestamibi.

Broken down by reader, each localized 34 lesions by interpreting the non-CE sequence images. When DCE was incorporated, reader 1 localized 35 lesions and reader 2 identified 36.

“These results suggest that even non-CE MRI at 3 T may be used for parathyroid lesion detection, and a contrast agent may be selectively used for cases with undetermined results,” the authors wrote.

Additionally, when US or 99mTc revealed negative or discrepant results, MRI correctly localized 14 of 17 lesions. Combining MRI with both US and 99mTc led to a higher sensitivity than when the techniques were used alone.

“These findings confirmed that MRI was a complementary imaging modality and are in agreement with previous authors who found that MRI was a second-line imaging modality in cases in which US and sestamibi revealed discrepant or inconclusive results,” they wrote.

 “The results of this study demonstrated that 4DMRI is a feasible modality in the localization of parathyroid lesions,” Ozturk et al. added. “MRI was a useful complementary imaging modality in cases in which first-line imaging techniques revealed negative or discrepant results.