False-Negative 99mTc Medi-MIBI Parathyroid Scintigraphies: A Report on the Possible Role of Diagnostic Two-Phase Single-Acquisition CT
|Afzelius P1*, Iyer V1, Lelkaitis G2 and Henriksen SD3|
|1Department of Nuclear Medicine, Aalborg University Hospital, Denmark|
|2Department of Pathology, Aalborg University Hospital, Denmark|
|3Department of Otolaryngology, Head and Neck Surgery, Aalborg University Hospital, Denmark|
|Corresponding Author :||Pia Afzelius
Department of Nuclear Medicine
Aalborg University Hospital
Hobrovej 18-22, 9000 Aalborg, Denmark
E-mail: [email protected]
|Received March 03, 2013; Accepted March 25, 2013; Published March 28, 2013|
|Citation: Afzelius P, Iyer V, Lelkaitis G, Henriksen SD (2013) False-Negative 99mTc Medi-MIBI Parathyroid Scintigraphies: A Report on the Possible Role of Diagnostic Two-Phase Single-Acquisition CT. OMICS J Radiology. 2:112. doi: 10.4172/2167-7964.1000112|
|Copyright: © 2013 Afzelius P, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.|
Introduction: Dual-phase 99mTc-Medi-MIBI parathyroid scintigraphy is often used for preoperative localization of
primary parathyroid adenomas. The overall accuracy has been reasonably high; however, some false-negative cases
occasionally occur. Two such cases are presented, and the advantages of adding two-phased single-acquisition
diagnostic CT to guide the surgeon are demonstrated.
Case presentations: A 54-year old male was admitted due to persistent elevated parathyroid hormone and
calcium concentrations in the blood despite medical treatment consistent with primary hyperparathyroidism. A dualphase
parathyroid scintigraphy performed 6 months earlier in another hospital was unable to confirm the diagnosis.
There was no change over time in levels of parathyroid hormone and calcium in the blood. In the second case, a 46-
year old woman was examined due to the same symptoms and findings; 18 months earlier she also had no retention
of tracer on late images. In this case, the patient also had had a CT performed, which showed morphological signs
of a parathyroid adenoma. We therefore planned dual-phase parathyroid scintigraphy with single-photon emission
computed tomography/computed tomography (SPECT/CT) in the early phase. The low-dose CT was unable to confirm
the impression of slight amounts of tracer uptake and retention at the lower right thyroid pole in both cases. Diagnostic
in both cases, but still with a low dose, the CT revealed a parathyroid adenoma situated in a common parathyroid
location at the lower pole of the right thyroid lobe, where activity retention was seen in late images. The surgeon was
able to perform minimally invasive neck surgery based on accurate anatomical localization of the adenoma.
Conclusion: This case report highlights the potential of two-phase single-acquisition CT as a useful tool in exact
localization of parathyroid adenoma for guiding the surgeon in minimally invasive surgery.