Jacob William Sechrist MD, Presenter: Nothing to Disclose

Seyed Mohammadi, Abstract Co-Author: Nothing to Disclose

Rajarsi Mandal MD, Abstract Co-Author: Nothing to Disclose

Umamaheswar Duvvuri MD, Abstract Co-Author: Nothing to Disclose

Robert L. Ferris MD, PhD, Abstract Co-Author: Nothing to Disclose

Ashok Muthukrishnan MD, Abstract Co-Author: Nothing to Disclose

The use of multiphase 4DCT in the preoperative detection of parathyroid adenomas has been on the rise recently. On the other hand, with the recent advent of high quality SPECT-CT gamma cameras with better CT capabilities, the localization accuracy of sestamibi SPECT-CT has vastly improved. At our institution, we have introduced a novel hybrid technique by incorporating two of the four phases (the arterial and non-contrast) of the 4DCT with concomitant sestamibi SPECT. We evaluated the value of this dual-phase 2D SPECT-CT technique in comparison with the conventional SPECT-CT in preoperative localization of parathyroid adenomas.

A total of 58 patients who underwent sestamibi SPECT-CT imaging on the Siemens SymbiaT6™ slice SPECT-CT scanner in the past two years at our institution were retrospectively analyzed. 32 of these had the conventional early/delayed SPECT-CT protocol with CT for localization and attenuation correction purposes only. 26 had dual phase (arterial and noncontrast) CT during the concomitant early/delayed SPECT respectively. The images were interpreted on a diagnostic confidence scale of 0 to 3 (0 negative, 1=possible, 2=probable and 3=definite evidence of parathyroid lesion). The size and number of the lesions were also analyzed and correlated with final pathology results for concordance.

The conventional SPECT-CT identified a total of 35 lesions in 32 patients. 34 of these were true parathyroid lesions and only 1 was false positive. 23 of 35 lesions were categorized as definite(score 3) and all of them were > 1 cm on imaging. On the dual phase 2D SPECT-CT, a total of 27 lesions in 26 patients were identified. 4 patients had false-negative results. It correctly identified 3 multiglandular and 19 single lesions. 20 lesions were identified with the highest diagnostic confidence (score 3).17 of these were >1cm. Overall, there was no statistically significant difference in the concordance rate between the two techniques (p=0.65).  

Dual phase contrast Sestamibi SPECT-CT did not increase the sensitivity of lesional detection in hyerparathyoid patients for preoperative disease localization, when compared with the conventional noncontrast SPECT-CT.

Dual-phase Sestamibi 2DSPECT-CT technique does not warrant routine adoption in parathyroid imaging. However, it could benefit those with extensive thyroid nodules, prior negative imaging and/or failed exploration.

Sechrist, J, Mohammadi, S, Mandal, R, Duvvuri, U, Ferris, R, Muthukrishnan, A, Value of Novel Contrast-enhanced Dual-phase (Arterial and Noncontrast) Sestamibi 2D SPECT-CT Technique in Preoperative Localization of Parathyroid Disease.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14006561.html