Incidental Finding of Benign Trichilemmal Cysts on 99mTc-Octreotide Scan.

A 63-year-old woman with neuroendocrine carcinoma of the colon was referred to our department for staging with Tc-octreotide scan. Two focal, highly intense, superficial lesions were detected in patient's scalp and paralumbar region, medial to the right kidney. Pathology correlation was recommended, revealing them both to be benign trichilemmal cysts. This unexpected finding strengthens the hypothesis of Merkel cell carcinoma and trichilemmal cysts originating from pluripotent stem cells of adnexal epithelium, making a neuroendocrine differentiation for the latter plausible.

Quantitation in Dextrocardia on myocardial perfusion imaging: how to perform quantitative analysis using Cedars-Sinai software.

Dextrocardia, although a rare cardiac abnormality, carries the same risk for cardiac events as other people. SPECT Myocardial perfusion imaging is a potentially helpful diagnostic tool in patients with dextrocardia. Because of swapping of lateral and septal walls on SPECT slices, although visual analysis is possible, quantitation is substantially limited. Here, we introduce a simple practical method to make quantitative analysis feasible and accurate.

POPULATION RADIATION EXPOSURE FROM DIAGNOSTIC NUCLEAR MEDICINE PROCEDURES IN TEHRAN 2011-14; TRENDS IN THE LAST 3 DECADES.

This study represents an update of Tehran population exposure from the diagnostic nuclear medicine procedures and the annual collective effective dose during 2011-14. The diagnostic nuclear medicine procedures data were collected from 58 out of 60 nuclear medicine centers in Tehran and were composed of the type and frequency of diagnostic examinations, radiopharmaceuticals used, administered activities, and age distribution of the patients. The annual number of examinations per 1000 population increased from 13.73 in 2011 to 22.59 in 2014 with an increase of 64.53% during 4 years. Most frequent examinations were cardiac (71.05%), bone (9.80%) and thyroid (7.26%) averaged over the 5 years. The collective effective dose increased from 807.74 person-Sv in 2011 to 1413.81 person-Sv in 2014. The effective dose per capita increased from 44.06 µSv in 2011 to 120.91 µSv in 2014, could be because of 70% increase of examinations, but ~3.42% increase in the population of Tehran.

Pelvic Meckel's Diverticulum Mimicking Bladder on Meckel Scan; The Impact of Quality Control and Technical Issues.

Quality control and technical issues are essential for high-quality imaging. An important technical parameter of image acquisition is selecting zoom factor according to camera field-of-view dimensions and patient's body size. Here, we present a case of atypically located Meckel's diverticulum mimicking bladder on Meckel scan.

An Unexpected and Less Recognized Altered Distribution on Bone Scintigraphy; Possibility of 99mTc-Dextrose Complex as a Cause.

Optimal performance of diagnostic tests and correct interpretation depend on multiple factors, one of which is proper radiopharmaceutical preparation. Unwanted impurities result in altered distribution of radiopharmaceuticals and then poor-quality or uninterpretable studies. Therefore, following the reconstitution steps according to standard and validated protocols by the technologist is mandatory. Here, we present 2 cases with unexpected and less recognized distribution of Tc-methylene diphosphonate on bone scintigraphy.

Prognostic Value of Basal Serum Thyroglobulin Levels, but Not Basal Antithyroglobulin Antibody (TgAb) Levels, in Patients with Differentiated Thyroid Cancer.

OBJECTIVE: The prognostic values of serum thyroglobulin (Tg) and antithyroglobulin antibody (TgAb) levels, measured immediately before I-131remnant ablation in patients with differentiated thyroid cancer (DTC), have been advocated by some researchers; however, it had controversial outcomes. This study was carried out to examine this dilemma and to check the clinical significance of basal serum Tg and TgAb levels and postablation iodine 131whole body scan(WBS) findings in DTC patients. METHODS: In this retrospective study, the records of 500 patients with differentiated thyroid cancer, who had undergone treatment between 2003 and 2010, were assessed. Of those, 149 patients with results of basal serum thyroglobulin concentration and whole body scan using radioactive iodine were included. Age, sex, tumour histology, basal thyroglobulin (Tg), anti-thyroglobulin (TgAb) and TSH concentration, radioactive iodine doses in each hospitalization, numbers of hospitalization, and results of whole body scans were recorded. The relationship among basal Tg, TgAb, TSH, and whole body scan with hospitalization number and total radioactive iodine doses were assessed. RESULTS: A total of 149 patients, including 123 (83%) females and 26 (17%) males, with a mean age of 40±15 years, took part in the study. The mean (SD) basal Tg, TgAb, and TSH were 91.7±169.2 ng/mL (0.1-1000 ng/mL), 250±893 U/mL (0-9000 U/m L), and 64.8±61.5 µU/mL (30-689 U/mLµ), respectively. A total of 52 (34.9%) cases had TgAb levels greater than 100 U/mL. The mean basal Tg in patients who were admitted three or more times was significantly greater than that of patients with one hospitalization (p=0.026). In addition, the mean of Tg in patients who received 7.4 GBq radioactive iodine or less was significantly lower than the others (p=0.003). The mean of TgAb and TSH were not different between these groups. In the results of the whole body scans, patients with metastasis had higher frequency of hospitalization (p=0.010) and received higher radioactive iodine levels (p<0.001). CONCLUSIONS: The findings of this study showed that, in differentiated thyroid cancer, lower basal serum Tg levels and absence of metastasis in radioiodine scan after ablation treatment were correlated with fewer hospitalizations and lower doses of radioactive iodine. Basal TgAb and TSH had no relation. Therefore, it seems that basal Tg could help us in determining which patients need aggressive treatment.

The electromagnetic interference of mobile phones on the function of a γ-camera.

PURPOSE: The aim of the present study is to evaluate whether or not the electromagnetic field generated by mobile phones interferes with the function of a SPECT γ-camera during data acquisition. METHODS: We tested the effects of 7 models of mobile phones on 1 SPECT γ-camera. The mobile phones were tested when making a call, in ringing mode, and in standby mode. The γ-camera function was assessed during data acquisition from a planar source and a point source of Tc with activities of 10 mCi and 3 mCi, respectively. A significant visual decrease in count number was considered to be electromagnetic interference (EMI). RESULTS: The percentage of induced EMI with the γ-camera per mobile phone was in the range of 0% to 100%. The incidence of EMI was mainly observed in the first seconds of ringing and then mitigated in the following frames. CONCLUSIONS: Mobile phones are portable sources of electromagnetic radiation, and there is interference potential with the function of SPECT γ-cameras leading to adverse effects on the quality of the acquired images.

Assessment of radioiodine clearance in patients with differentiated thyroid cancer.

Radioiodine ((131)I iodide) has long been a safe, effective and widely used treatment in the management of differentiated thyroid cancer (DTC). Concerns regarding stochastic radiogenic risks have led to regulatory criteria for the release from medical confinement of patients who receive such radionuclide therapy. Over a 6-y period, the external whole-body dose rates at 1 m from 562 DTC patients were measured with an ionisation chamber calibrated in microsieverts per hour out to 5-d post-administration. Patients were stratified into four administered activity groups: 3.7 GBq (36.8 %), 5.55 GBq (47.3 %), 7.4 GBq (12.8 %) and 9.25 GBq (3 %). Consistent with previously published data, the current study demonstrated that a bi-phasic model accurately described (131)I-iodide kinetics up to at least 5-d post-administration in DTC patients, providing data that would be useful in formulating radiation safety guidelines for staff and other individuals coming into contact with such patients after treatment.

Huge Varicose Inferior Mesenteric Vein: an Unanticipated (99m) Tc-labeled Red Blood Cell Scintigraphy Finding.

Ectopic varices (EcV) are enlarged portosystemic venous collaterals, which usually develop secondary to portal hypertension (PHT). Mesocaval collateral vessels are unusual pathways to decompress the portal system. Here we report the case of a huge varicose inferior mesenteric vein (IMV) that drained into perirectal collateral veins, demonstrated by (99m)Tc-labeled red blood cell (RBC) scintigraphy performed for lower gastrointestinal (GI) bleeding in a 14-year-old girl. This case illustrates the crucial role of (99m)Tc-labeled RBC scintigraphy for the diagnosis of rare ectopic lower GI varices.