Residual Pyramidal Lobe Increases Stimulated Thyroglobulin and Decreases Endogenous Thyroid Stimulating Hormone Stimulation in Differentiated Thyroid Cancer Patients.

OBJECTIVE: To determine the frequency of pyramidal lobe remnants after total thyroidectomy (TT) and the effect on stimulated thyroglobulin (Tg). METHODS: The study included 1740 differentiated thyroid cancer (DTC) patients who were followed up by our center. The department database was searched to identify DTC patients with residual pyramidal lobe after TT. All postoperative technetium-99m pertechnetate thyroid scintigraphy images were re-evaluated for pyramidal lobe residue. Serum stimulated Tg and thyroid stimulating hormone (TSH) levels measured within the first 6 months after TT were retrieved from the database. RESULTS: Pyramidal lobe residue was detected in 10.4% of the patients who underwent TT. Evidence of the pyramidal lobe was present on preoperative ultrasonography in 1.6% of the patients with residual pyramidal lobe. Stimulated Tg in patients with pyramidal lobe residue was significantly higher than that in patients without residue (P = .01). Endogenous stimulated TSH in patients with residual pyramidal lobe was significantly lower than that in patients without residue (P = .036). In 5.7% of patients with pyramidal lobe residue, a TSH level of >30 mIU/L was not achieved, which was a significantly higher rate than that in patients without pyramidal lobe residue (P = .034) and is the level required for maximum radioiodine uptake. CONCLUSION: Pyramidal lobe residue was found in almost 10% of DTC patients. The pyramidal lobe is often missed on preoperative ultrasonography. Residual pyramidal lobe increased stimulated Tg and decreased endogenous stimulated TSH. Residual pyramidal lobe may complicate the follow-up of DTC patients.

Four Atypical Parathyroid Adenomas Detected by Dual Phase Tc-99m MIBI SPECT

We report a case of a 55-year-old female with tertiary hyperparathyroidism and osteoporosis who had end stage renal disease and a history of hemodialysis for 15 years. Patient's informed is taken. Neck ultrasonography showed multinodular goiter together with a hypoechoic lesion compatible with a parathyroid adenoma. Dual phase technetium (Tc) Tc-99m MIBI single photon emission computed tomography (SPECT) showed pathological uptake in four parathyroid gland locations. Total thyroidectomy and subtotal parathyroidectomy revealed nodular hyperplasia and atypical adenomas in four parathyroid glands. Atypical parathyroid adenoma is a rare clinical entity. Multiple atypical adenomas are even less frequent. A very rare condition, detection of atypical adenomas in four of the parathyroid glands by dual phase Tc-99m MIBI SPECT, is presented in this case.

Giant Abdominal Aortic Aneurysm in Bone Scan

Abdominal aortic aneurysm (AAA) may be incidentally detected in three-phased bone scintigraphy. AAA should be diagnosed prior to the development of symptoms to perform elective repair surgery. We present a rare case who presented with back pain and underwent a 3-phase bone scan with Tc-99m methylene diphosphonate, which revealed a giant AAA on blood-flow and blood-pool phases in addition to bone metastases. F-18-fluorodeoxyglucose positron emission tomography/computed tomography (CT) identified hypermetabolic liver, lung, and bone lesions, and CT component of the study confirmed the diagnosis of AAA with a maximum diameter of 92 mm. The initial two phases of a 3-phase bone scintigraphy are decisive to identify vascular pathologies that may be life-threatening, if left untreated.

Doughnut Shaped Parathyroid Adenoma

A 52-year-old woman presented with a complaint of neck swelling. The patient showed signs of hyperparathyroidism: hypercalcemia, and hypophosphatemia. Tc-99m MIBI dual-phase parathyroid scintigraphy and SPECT revealed increased activity in a regular-bordered, "doughnut"-shaped mass on the left side of the thyroid gland with a central hypoactive area. The cervical ultrasound identified a mixed echoic thyroid nodule with a central large cystic portion, and no parathyroid gland abnormality. Total thyroidectomy and parathyroid exploration was performed. Pathological evaluation of the resected thyroid specimen reported a giant intra-thyroidal hemorrhagic parathyroid adenoma.

Infliximab-induced hot kidneys on bone scintigraphy.

99mTechnetium-methylene diphosphonate bone scintigraphy is widely used in various clinical settings to detect bone abnormalities. Many reasons may cause abnormal tracer uptake in soft tissues on bone scintigraphy. Here, we present a 70-year-old man diagnosed with rheumatoid arthritis receiving chimeric anti-tumor necrosis factor alpha (TNF-α) therapy (infliximab). In order to evaluate the bone involvement of rheumatic disease, the patient underwent a whole-body bone scan that revealed left side dominant diffuse uptake in both kidneys defined as the "hot kidneys." Since the patient had no other identifiable reason, anti-TNF-α therapy might be responsible for the "hot kidneys" on bone scan. Thus, therapy regiment of the patient changed from the chimeric anti-TNF-α to a human monoclonal TNF inhibitor (golimumab). After 6 months of the change of the therapy, the bone scintigraphy was repeated and revealed that the previous "hot kidneys" finding had disappeared.

Earlier Phases of Bone Scintigraphy Can Better Delineate the Extent of Soft Tissue Involvement of Bone Metastasis.

Three-phase bone scintigraphy is sometimes of great value in the detection of uncharacteristic metastases and assists the management of patients in terms of primary focus detection. While evaluating the skeletal system with whole-body bone scintigraphy, other system pathologies may also be detected incidentally. In this case, we present the extraordinary findings on the 3-phase MDP bone scintigraphy and F-FDG PET/CT imaging of the complicated bone metastases in a patient with thyroid carcinoma.

Clinical Significance of Incidental Pituitary TC-99m MIBI Uptake on Parathyroid Spect and Factors Affecting Uptake Intensity.

OBJECTIVE: (1)To define a quantitative cutoff value for incidental pituitary Technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) uptake above which is of clinical importance and (2) to investigate possible factors affecting the intensity of uptake in pituitary adenoma. MATERIALS AND METHODS: A retrospective analysis of 55 patients with a simultaneous parathyroid single-photon emission computed tomography and pituitary magnetic resonance imaging were included. Twenty-four patients with pituitary adenoma were chosen as the study group and 31/55 patients who had no signs of a pituitary adenoma were included in the control group. Mean count values (count/pixel) for pituitary region of interest (ROI)/mean value for normal cortical region ROI (P/C) were calculated in both groups. Median P/C values were compared. A cutoff value for P/C was calculated as a quantitative parameter to indicate pituitary tumors. Possible contributing factors in intensity of pituitary Tc-99m MIBI uptake were investigated. RESULTS: Median P/C ratios were significantly higher in the study group (p < 0.001). A cutoff value of 7.675 was found for P/C to have a sensitivity, spesificity, positive predictive value, and negative predictive value 100%, 96.8%, 96%, and 100%, respectively. There was no correlation between investigated factors and degree of pituitary Tc-99m MIBI uptake. CONCLUSIONS: Incidental pituitary Tc-99m MIBI uptake values above 7.675 for P/C are suspicious for pituitary adenoma and can be further investigated clinically and radiologically. Tc-99m MIBI uptake is not affected from the biochemical nature of the adenoma, the therapies received, size, local invasion, or cystic necrotic component of the tumor.

Inguinal Endometriosis Visualized on I-131 Whole Body Scan.

We present a rare case with inguinal iodine-131 (I-131) uptake on whole body scan. The patient was suffering from a painful right inguinal mass during menstrual period, which was later sonographically and histopathologically confirmed to be an inguinal focus of endometriosis. Endometriosis is a previously reported site of radioiodine uptake and detection of radioiodine uptake in the inguinal region has also been described. Nevertheless, to the best of our knowledge, this is the first case report of I-131 uptake in an inguinal endometriosis focus. History and physical examination of the patient are both very important in identifying the etiology of the ectopic uptake sites on I-131 whole body scan, and inguinal endometriosis should be kept in mind while reporting inguinal radioiodine uptake on I-131 whole body scan.

The relationship between semiquantitative parameters derived from technetium-99m metoxyisobutylisonitrile dual-phase parathyroid single-photon emission computed tomography images and disease severity in primary hyperparathyroidism.

OBJECTIVE: The relationship between multiple semiquantitative indices on technetium-99m metoxyisobutylisonitrile (Tc-99m MIBI) parathyroid single-photon emission computed tomography (SPECT) and clinical, laboratory, and radiological data was investigated in primary hyperparathyroidism. PATIENTS AND METHODS: Ninety-three patients who had a histopathologically confirmed single parathyroid adenoma (PT) were enrolled. Regions of interests were drawn around the PT, neighboring thyroid (T), and background in early and late planar images and isocontour regions of interests around the adenoma in SPECT images (PT SPECT). The relationships between early and late PT, parathyroid adenoma counts/neighboring thyroid counts, parathyroid counts-thyroid counts (PT-T), PT washout, retention index, PT SPECT and serum parathormone (PTH), Ca, P, urinary Ca levels, weight of the adenoma, neck ultrasonography, renal ultrasonography, and bone mineral density findings were investigated. RESULTS: There was a positive correlation between the weight of the adenoma and serum PTH and calcium (Ca) levels (P<0.001), between serum PTH and Ca levels (P<0.001), early PT-T and serum Ca levels (P=0.027), late PT-T and weight of the adenoma (P=0.04), and PT SPECT and serum Ca levels (P=0.046) and a reverse correlation between PT SPECT and serum phosphorus (P) levels (P=0.04). Serum Ca levels were significantly higher and P levels were lower in the group with PT SPECT values above 116. PT SPECT and late parathyroid adenoma counts/neighboring thyroid counts values were significantly higher in the group with serum Ca levels of more than 11 mg/dl. Femoral T and Z scores were significantly lower in patients with lower PT washout. Early PT was significantly lower in patients with coexisting thyroiditis compared with patients with both thyroiditis and thyroid nodules (P=0.034). CONCLUSION: Semiquantitative evaluation of a Tc-99m MIBI parathyroid SPECT study may help predict disease severity in primary hyperparathyroidism.

Cyclosporine and Vancomycin + Amikacin Induced Hot Kidney Appearance in a Young Adult and a Pediatric Patient.

The appearance of a hot kidney on bone scintigraphy is rare and can be seen due to various factors. In our clinic, we observed hot kidney appearance in two patients to whom technetium-99m methylene diphosphonate (Tc-99m MDP) whole body scan has been performed: a young male adult at the age of 18 who was diagnosed with acute lymphocytic leukemia with a presumptive diagnosis of avascular necrosis, and a 9-year-old girl with cystitis for a pre-diagnosis of osteomyelitis. The first patient had a history of cyclosporine usage and the second patient was being treated with amikacin + vancomycin. To the best of our knowledge, we present the first cases where hot-kidney appearance on Tc-99m MDP whole body scan due to the use of cyclosporin and amikacin + vancomycin is demonstrated.

Incidental Tc-99m Methylene Diphosphonate Uptake in an Active Thyroid Nodule.

Tc-99m-methylene diphosphonate (MDP) whole body scintigraphy is the method of choice for detection of metastatic bone diseases. It is primarily used to help diagnose various bone-related conditions such as primary or metastatic cancer of the bone, location of bone inflammation, and fractures that may not be visible on traditional X-ray images, as well as detection of bone damage due to infections and other conditions. In addition, bone scanning is often used for the follow-up or evaluation of response to treatment in some malignancies like prostate and breast cancers. Pathologies of other systems can also be incidentally detected on whole body bone scan. Herein we present an interesting image of an active thyroid nodule that showed Tc-99m MDP uptake in a prostate cancer patient.

18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography for Other Thyroid Cancers: Medullary, Anaplastic, Lymphoma and So Forth.

Positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose (FDG) is used in staging, restaging, and evaluation of therapy response in many cancers as well as differentiated thyroid carcinomas especially in non-iodine avid variants. Its potential in less frequent thyroid tumors like medullary, anaplastic thyroid cancers, thyroid lymphoma and metastatic tumors of the thyroid however, is not well established yet. The aim of this review is to provide an overview on the recent applications and indications of 18F-FDG PET/CT in these tumors and to focus on the controversies in the clinical setting.

Factors affecting the sensitivity of Tc-99m methoxyisobutylisonitrile dual-phase parathyroid single photon emission computed tomography in primary hyperparathyroidism.

OBJECTIVE: The aim of this study was to investigate the effects of thyroid diseases and regularly used medications on the sensitivity of Tc-99m methoxyisobutylisonitrile (MIBI) dual-phase parathyroid single photon emission computed tomography (SPECT) and to define indicatives of the result of the study. PATIENTS AND METHODS: Overall, 218 primary hyperparathyroidism patients (190 women, 28 men, mean age: 57±14 years) with thyroid-parathyroid ultrasonography and Tc-99m MIBI dual-phase parathyroid SPECT were retrospectively enrolled. Patients were divided as follows: a positive SPECT group [119 (54.6%) patients] and a negative SPECT group [99 (45.4%) patients]. The effects of thyroid diseases and use of calcium channel blockers, ß-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, oral antidiabetics, thyroid hormone preparates, nonsteroidal anti-inflammatory drugs, and proton pump inhibitors on the sensitivity of Tc-99m MIBI dual-phase parathyroid SPECT were investigated. RESULTS: The frequency of NSAID usage was higher in the negative scan group (P<0.001). No significant difference was detected in terms of coexisting thyroid disease or usage of other medications. Overall sensitivity, specificity, positive, and negative predictive value of Tc-99m MIBI dual-phase parathyroid SPECT were calculated to be 89.6, 92.5, 94.1, and 86.9%. The sensitivity was low only in nonsteroidal anti-inflammatory drug users (75.6%) compared with nonusers (96.5%). Logistic regression showed that ultrasonography was indicative of a positive scan and the possibility of a negative result was increased by regular usage of nonsteroid anti-inflammatory drugs (odds ratio: 0.262, confidence interval: 0.128-0.538; P<0.001) CONCLUSION: Among various drug groups, NSAIDs may decrease the sensitivity of Tc-99m MIBI SPECT and, provided that these novel data are supported by other studies, patient preparation may be modified to stop NSAIDs before Tc-99m MIBI dual-phase parathyroid SPECT.

Scintigraphic evaluation of renal functional damage in volatile substance abusers.

OBJECTIVE: Volatile organic compounds can be maintained easily and can cause dependency. Volatile substance abuse may cause damage by affecting several systems. The aim of our study was to evaluate renal functional damage in volatile substance abusers by diuretic renogram. METHODS: Twenty nine volatile substance abusers and 30 young healthy voluntary young men were included in our study. Technetium-99m mertiatide diuretic renogram was used to evaluate renal functions and collective system urodynamics to investigate the progress of renal functional damage. Images were evaluated visually and quantitatively. Split renal function of each kidney, time to peak activity (Tmax), and half-time for radiopharmaceutical clearance from pelvicalyceal system (T1/2), ratio of cortical and whole-kidney counts at 20-3 min, and maximum counts (T20/3 and T20/max) were compared in the two groups. RESULTS: In the study group, time to reach peak activity was statistically prolonged compared with the healthy volunteers. In the volatile substance abuser group, the average Tmax values, average T1/2 values, cortical and whole-kidney T20/3, and T20/max values were found to be prolonged compared with the control group in the diuretic renogram. There was no significant difference in the split renal function ratios between the two groups. CONCLUSION: In this study, possible renal functional damage was evaluated in volatile substance abusers by diuretic renogram. In conclusion, diuretic renogram can be useful in the evaluation of renal functional damage before blood renal function tests are affected and it could be used in the follow-up of the disease in volatile substance abusers. The results of this pilot study from our country, of course, should be supported by further clinical studies.

Evaluation of lung epithelial permeability in the volatile substance abuse using Tc-99m DTPA aerosol scintigraphy.

AIM: Chronic inhalant use is associated with significant toxic effects, including neurological, renal, hepatic, and pulmonary damage. However, there is a paucity of reports regarding respiratory complications in inhalant abusers. The aim of this study was to evaluate pulmonary epithelial permeability in the volatile substance abuse (VSA) using Tc-99m DTPA aerosol scintigraphy. METHODS: This study included 18 patients with volatile substance abuse and 18 volunteer controls. All of patients and controls were smokers. Tc-99m DTPA aerosol scintigraphy was performed in all cases. Time-activity curves from each lung were generated and clearance half-time (T(1/2)) of Tc-99m DTPA were calculated. T(1/2) of whole lung was calculated as a mean of the T(1/2) of left and right lung. RESULTS: The T(1/2) values of Tc-99m DTPA clearance in the substance abusers were significantly decreased as compared to the control group with respective mean values of 28.86 ± 8.44, and 62.14 ± 26.12 min (p = 0.001). It was seen Tc-99m DTPA clearance from lung was faster as the duration of substance abuse was increased. CONCLUSIONS: Tc-99m DTPA pulmonary clearance is markedly accelerated in the volatile substance abuse. This suggests that inhalant abuse of substance may produce abnormalities in pulmonary alveolo-capillary membrane function.

Osteoid osteoma simulating osteomyelitis: differentiation with Tc-99m HIG scintigraphy.

We present a case of osteoid osteoma with a history of mild pain, local swelling and point tenderness on the right lower leg. The diagnosis of osteoid osteoma was difficult due to the atypical clinical history and misleading radiological and bone scan findings. When it is difficult to differentiate an osteoid osteoma from osteomyelitis using CT, MRI or bone scan; HIG scintigraphy can be used to exclude an infection.