Pinhole versus parallel-hole collimators for parathyroid imaging: an intraindividual comparison.
This study was undertaken to determine the effects of collimators on the accuracy of preoperative sestamibi parathyroid imaging of the neck.


METHODS
Forty-nine patients with primary hyperparathyroidism underwent preoperative (99m)Tc-sestamibi parathyroid imaging. The protocol included early and late pinhole and parallel-hole imaging. One experienced nuclear physician, without knowledge of other test results or final diagnoses, interpreted studies. For both pinhole and parallel-hole images, focally increased sestamibi accumulation outside the normal tracer biodistribution that persisted or increased in intensity from early to late images was interpreted as positive for a parathyroid lesion. Final diagnoses were operatively confirmed in all patients.


RESULTS
Fifty-four parathyroid lesions were resected from the 49 patients. Forty-five patients had single-gland disease. Four patients had multigland disease: 3 had 2 lesions and 1 had 3 lesions. Median lesion weight was 840 mg. Pinhole imaging was significantly more sensitive than parallel-hole imaging (89% vs. 56%; P = 0.0003) for all 54 lesions. Specificity did not significantly differ between pinhole and parallel-hole imaging (93% vs. 96%, P = 0.29). Pinhole imaging was significantly more sensitive than parallel-hole imaging for lesions above (100% vs. 68%, P = 0.003) and below (77% vs. 42%, P = 0.03) the median weight and for single-gland disease (96% vs. 67%, P = 0.001). Pinhole imaging also was more sensitive for multigland disease, although the difference was only marginally significant (55% vs. 0%, P = 0.037).


CONCLUSIONS
Because sensitivity is significantly higher, sestamibi parathyroid imaging of the neck should be performed with a pinhole collimator.
Tomas
Maria B
MB
Division of Nuclear Medicine and Molecular Imaging, North Shore-Long Island Jewish Health System, 270-05 76th Ave., New Hyde Park, NY 11040, USA.
Pugliese
Paul V
PV
Tronco
Gene G
GG
Love
Charito
C
Palestro
Christopher J
CJ
Nichols
Kenneth J
KJ
D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery*; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D010282:Parathyroid Neoplasms / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation* / Q000379:methods
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi