Primary hyperparathyroidism (pHPT) causes hypercalcemia. The treatment for pHPT is surgical dissection of the hyperfunctioning parathyroid gland. Lower rates of hypocalcemia and recurrent laryngeal nerve injury imply that minimally invasive parathyroidectomy (MIP) is safer than bilateral neck resection. Current trends in MIP use can be inferred only by reference to preoperative localization studies. Noninvasive imaging studies (typically preoperative localization studies) show good detection rates of hyperfunctioning glands; however, there have also been cases of nonlocalization or discordant results. Selective venous sampling (SVS) is an invasive localization method for detecting elevated intact parathyroid hormone in the thyroid and/or internal jugular and brachiocephalic veins. SVS was developed mainly for postoperative patients with persistent or recurrent pHPT; however, SVS could also be useful before initial operations due to its high sensitivity to pHPT. Currently, SVS is generally indicated for recurrent HPT, and for cases with negative imaging study results for HPT or discordant results. Multi-detector row helical CT is useful for imaging the anatomy of the jugular and thyroid veins. Knowledge of the thyroid vein anatomy enables the creation of sampling points in the internal jugular and brachiocephalic veins for catheterization of the thyroid veins and venous anastomoses.

BackgroundSelective venous sampling (SVS) is an invasive localization study for persistent or recurrent hyperparathyroidism.PurposeTo assess the role of SVS in addition to non-invasive imaging for primary hyperparathyroidism (pHPT).Material and MethodsThis study was approved by the institutional review board and included 14 patients who underwent SVS and subsequent parathyroidectomy between January 2014 and April 2017 following a clinical diagnosis of pHPT. All patients underwent pre-SVS non-invasive imaging, including ultrasound, computed tomography (CT), and 99mTc-MIBI scintigraphy, and sensitivity was assessed using the operative and pathological findings.ResultsIn all but one case, a single parathyroid adenoma was responsible for the pHPT; the remaining case exhibited a chemical response following surgical removal of parathyroid tissue. The sensitivity (%) for ultrasound, CT, 99mTc-MIBI scintigraphy, and SVS was 76.9, 84.6, 69.2, and 76.9, respectively. SVS yielded positive results in four patients with discordant results and one patient with non-detectable results on imaging. In seven patients, a significant increase in the intact parathyroid hormone level was recognized only in the thyroid veins. The procedure time was in the range of 52–183 min (median = 89.5 min).ConclusionThe addition of SVS to a non-invasive imaging study would be helpful to locate the responsible lesion of pHPT with discordant or non-detectable results on imaging for initial surgical treatment as well.

ObjectivesThe aim of the study was to compare the diagnostic performance of early-phase 123I-metaiodobenzylguanidine (MIBG) scintigraphy with that of delayed-phase imaging in Lewy body disease (LBD).MethodsA retrospective cohort study of 123I-MIBG scintigraphy was carried out in 192 patients who were suspected of having LBD. Clinical diagnosis was obtained using the UK Parkinson’s Disease Brain Bank Criteria in some cases or the third report of the Dementia with Lewy bodies Consortium in others. The participants consisted of 81 patients with LBD and 111 nondiseased patients. An injection of 111 MBq of 123I-MIBG was used. Planar images were obtained in an early phase and again in a delayed phase and the heart to mediastinum count ratio was calculated for both phases. Diagnostic performance was compared using a receiver-operator characteristic analysis. The cutoff value was chosen to maximize the Youden index. The sensitivity and specificity of each phase were calculated from the optimal cutoff value.ResultsThe heart to mediastinum ratio of the LBD group (median 1.8 and 1.45 for early and delayed phases, respectively) was significantly lower than that of the nondiseased group (median 2.93 and 3.18 for early and delayed phases, respectively). The area under the receiver-operating characteristic curve was not significantly different between the early and delayed phases (0.871 vs. 0.893; P=0.0914). Sensitivity and specificity were 80.2 and 91% for early-phase imaging (cutoff value at 2.28) and 81.5 and 95.5% (cutoff value at 1.91) for delayed-phase imaging, respectively.ConclusionThe diagnostic performance of 123I-MIBG scintigraphy was not significantly different between early-phase and delayed-phase imaging.