ORIGINAL RESEARCH HEAD&NECK

BACKGROUNDAND PURPOSE: A 4DCT protocol for detection of parathyroid lesions involves obtaining unenhanced, arterial, early, and delayed venous phase images. The aim of the study was to determine the ideal combination of phases that wouldminimize radiation dose without sacrificing diagnostic accuracy. MATERIALS ANDMETHODS: With institutional reviewboard approval, the records of 29 patientswith primary hyperparathyroidismwhohad undergone surgical exploration were reviewed. Four neuroradiologists whowere blinded to the surgical outcome reviewed the imaging studies in 5 combinations (unenhanced and arterial phase; unenhanced, arterial, and early venous; all 4 phases; arterial alone; arterial and early venous phases)withan intervalof at least 7daysbetweeneach review.Theaccuracyof interpretation in lateralizinganabnormality to thesideof theneck (right, left, ectopic) and localizing it to a quadrant in the neck (right or left upper, right or left lower) was evaluated. RESULTS: The lateralization and localization accuracy (90.5 % and 91.5%, respectively) of the arterial phase alone was comparable with the other combinations of phases. There was no statistically significant difference among the different combinations of phases in their ability to lateralize or localize adenomas to a quadrant (P .976 and.996, respectively). CONCLUSIONS: Assessment of a small group of patients shows that adequate diagnostic accuracy for parathyroid adenoma localization may be achievable by obtaining arterial phase images alone. If this outcome can be validated prospectively in a larger group of patients, then the radiation dose can potentially be reduced to one-fourth of what would otherwise be administered