How well CT scans find parathyroid problems in dogs before surgery

Abstract

In canines with primary hyperparathyroidism, preoperative imaging is recommended to identify abnormal parathyroid glands. However, imaging modalities have been reported to have up to a 19% discrepancy with surgical findings. This study aimed to evaluate the agreement between cervical CT and surgical findings in diagnosing primary hyperparathyroidism. Twenty client-owned dogs with suspected primary hyperparathyroidism were enrolled. Each dog underwent a cervical CT scan under sedation or anesthesia that was interpreted by a board-certified radiologist. Subsequently, all dogs underwent bilateral cervical exploration by a board-certified surgeon or a residency-trained surgery clinician. The laterality, position, and size of suspected parathyroid nodules were recorded from both CT and surgery. Agreement between the two methods was assessed using Cohen's kappa statistic for laterality and position, and Lin's concordance correlation coefficient (CCC) for size. Results showed near-perfect agreement for laterality (κ = 0.81) and position (κ = 0.92), but only fair agreement for gland size (CCC = 0.38). Additionally, in five cases, pathologic parathyroid or thyroid tissue was removed during surgery that was not identified on CT. These findings suggest that while CT provides better agreement than ultrasound for certain aspects of parathyroid pathology, continued bilateral cervical exploration remains essential for accurate diagnosis and treatment.