Akin Yildiz

Gamma probe-guided resection and scanning with TC-99m MIBI of a local recurrence of follicular thyroid carcinoma.

A 30-year-old woman underwent two operations for multinodular goiter and follicular thyroid carcinoma. The residual thyroid tissue was ablated by I-131 therapy. After 7 years of follow-up, Tc-99m MIBI and I-131 scintigraphy were performed, because her serum thyroglobulin level was much higher compared with the control analysis performed in the sixth year. Tc-99m MIBI showed pathologic accumulation, which could be consistent with a local recurrence, whereas the results of I-131 scintigraphy were negative. The locally recurring follicular thyroid carcinoma was resected using a gamma probe and Tc-99m MIBI. The thyroglobulin level decreased to a normal level after surgery. This case shows that the intraoperative use of a gamma probe with Tc-99m MIBI allows localization of recurrent thyroid tissue in the scarred area in patients with increased radionuclide accumulation, and scanning of the affected area using the gamma probe may be helpful in determining whether resection is complete.

Technetium-99m hexamethyl propylene amine oxime-labeled leukocyte scintigraphy at three different times in active ulcerative colitis: comparison with colonoscopy and clinico-biochemical parameters in the assessment of disease extension and severity

ObjectiveIn this study, our objective was to define the usefulness of technetium-99m hexamethyl propylene amine oxime (Tc-99m HMPAO)-labeled leukocyte scintigraphy at three different time points in the assessment of disease extension and severity in patients with active ulcerative colitis (UC).MethodsTwenty-one consecutive patients (10 women, 11 men; mean age 42.4 ± 12 years) with active UC were prospectively studied. All patients were diagnosed by colonoscopy and histopathology prior to inclusion. Scintigraphy was performed at 1 h, 2 h, and 4 h after Tc-99m HMPAO-labeled leukocyte injection. Clinic-biochemical activity score, total colonoscopic activity score, and total scintigraphic activity score at 1 h, 2 h, and 4 h were calculated for each patient.ResultsSensitivity, specificity, and accuracy values of Tc-99m HMPAO-labeled leukocyte scintigraphy were calculated as follows, respectively: 1 h imaging 86%, 73%, and 83%; 2 h imaging 89%, 74%, and 86%; 4 h imaging 90%, 58%, and 83% in the detection of active inflammatory segments. Even though no statistically significant difference was found between 1 h, 2 h, and 4 h imaging with respect to the sensitivity, specificity of labeled leukocyte scintigraphy, the largest area under the curve value was found for 2 h imaging.ConclusionsTc-99m HMPAO-labeled leukocyte scintigraphy has been found to be correlated well with colonoscopy in the assessment of both the extension and severity of UC. We recommend 2 h scintigraphic imaging because it provides the largest area under the curve value and decreases the number of false-positive results.

Tc-99m HMPAO brain SPECT findings in mild and moderate Alzheimer's disease: Correlation with event related potentials

We investigated whether brain SPECT findings show any differences between patients with mild and moderate Alzheimers disease (AD) and to compare results with event related potentials (ERPs). Twenty-two patients with mild to moderate AD diagnosed according to NINCDS-ADRDA criteria and 10 age-matched control subjects were included in this prospective study. All subjects underwent ERP recordings and Tc-99m HMPAO brain SPECT study. Cortical perfusion index (CPI) was calculated as the ratio of cortical activity to the cerebellum activity. CPI was found to be statistically lower in bilaterally posterolateral temporal cortex and precuneus in the moderate AD compared to the control group. There was no statistically significant difference between the mild AD and control groups for CPI in any cortical areas. The mean P300 latency was statistically prolonged in the mild and moderate AD compared to the control group. In addition, in moderate AD P300 latency was longer than in mild AD. While the mean P300 amplitude was statistically reduced in moderate AD compared to the control and mild AD, there was no statistically significant difference between the mild AD and control groups. There was a strong negative correlation between P300 latency and CPI in the right and left precuneus in the moderate AD group. The present study suggested that Tc-99m HMPAO SPECT study is the more appropriate technique for patients with moderate AD rather than mild AD. Our results indicated that alterations in ERPs, especially prolongation of P300 latency could be a finding that occurred earlier than the deterioration in cerebral blood flow. We thought that precuneus is closely related to cognitive function and may have an important role in the pathophysiology of AD.

The Role of Technetium-99m Methoxyisobutyl isonitrile Scintigraphy in Suspected Recurrent Breast Cancer

The aim of this study was to determine the role of technetium-99m methoxyisobutyl isonitrile (99mTc-MIBI) scintigraphy in the evaluation of recurrence and metastases in breast cancer patients with mastectomy and/or radiotherapy. A prospective study was designed to assess the accuracy of 99mTc-MIBI scintigraphy in 36 patients (mean age 49 years) with suspected recurrent breast cancer. The scintigraphic studies were correlated with radiological findings and/or with histopathology. At 10-15 min after 740MBq 99mTc-MIBI injection, standard planar images were obtained in prone lateral and anterior supine views and then single-photon emission computed tomography (SPECT) imaging was performed. A whole body imaging was also performed to demonstrate distant metastatic lesions. Totally 52 lesions were evaluated which 19 of them in 9 patients were malignant, while 33 lesions in 27 patients were benign. The sensitivity was 33%, 88% and the specificity was 96%, 93% for planar and SPECT imaging, respectively in loco-regional lesions. Overall, the sensitivity and the specificity of MIBI imaging including whole body were 89%, 81%, in other conventional radiological imaging methods were 95%, 65%, respectively. 99mTc-MIBI scintigraphy using SPECT imaging may provide useful complementary information in patients with suspected recurrence breast cancer.

Analysis of TPO gene in Turkish children with iodide organification defect: identification of a novel mutation

The objective was to determine molecular genetic analysis of the TPO gene in Turkish children with iodide organification defect (IOD). Patients with a diagnosis of primary hypothyroidism were evaluated. Subjects having a definite diagnosis of autoimmune thyroiditis, thyroid gland dysplasia and, or iodine deficiency were excluded. A total of 10 patients from nine unrelated Turkish families, with an unknown etiology of hypothyroidism, and with a presumptive diagnosis of IOD were included in the study. A perchlorate discharge test (PDT) was performed to all subjects, and sequence analysis of TPO gene was applied in patients with a positive PDT. Five out of 10 patients have a total IOD, while the five remaining patients have a partial IOD according to PDT results. In two sisters, one has a partial and the other one has a total IOD a novel homozygous nonsense p.Q315X mutation was found in exon 8. Additionally, a previously known homozygous missense p.R314W mutation was detected in the same exon in another patient with a total IOD. No TPO gene mutation was detected in any of the seven remaining patients. Two different TPO gene mutations were found to be responsible for IOD in two unrelated Turkish families from the same ethnic background. More subjects should be screened for detecting the prevalence and spectrum profile of TPO mutations in our population that might be helpful for understanding the pathophysiology of congenital hypothyroidism.

Unilateral spermatic cord torsion without ipsilateral spermatogenetic material: effects on testicular blood flow and fertility potential

This experiment was planned to answer the question of how the elimination of ipsilateral spermatogenetic material, which is necessary for contralateral testicular damage caused by an autoimmune response, affects contralateral testicular blood flow and fertility potential in unilateral spermatic cord torsion (USCT). Thirty-four male and 68 female adult albino rats were divided into three groups. Group 1 rats underwent a control operation, group 2 rats underwent subepididymal orchiectomy to eliminate spermatogenetic material, and group 3 rats underwent USCT after subepididymal orchiectomy. Testicular blood flows of the rats were measured by 133Xe clearance technique. Additionally, to determine fertility potential, each male rat was housed with two female rats. Numbers of impregnated and delivered rats were recorded. Both mean testicular blood flow and fecundity of group 3 were significantly lower than those of groups 1 and 2. When compared with groups 1 and 2, fertility and mean number of the impregnated rats of group 3 were lower but the differences were not significant. These findings suggest that absence of spermatogenetic material in USCT reduces contralateral blood flow and fertility potential. Therefore, contralateral testicular damage originating from blood flow alterations rather than autoimmune mechanism should be considered to explain fertility problems encountered following USCT.

Comparison of Tc-99m HIG and Ga-67 citrate in the evaluation of bacterial abscess in a rat model

Tc-99m labeled polyclonal human immunoglobulin (HIG) has been shown to be able to localize an inflammatory site. There are several possible explanations for HIG accumulation at focal infection sites such as increased vascular permeability, binding of the Fc part of Ig to Fc receptors of leucocytes and binding directly to bacteria. In this study, we compared Tc-99m HIG and Ga-67 citrate scintigraphy in localizing acute bacterial abscesses induced byE. coli andS. aureus. Serial scintigrams were performed at 1, 4, 24 hr after injection. Tc-99m HIG showed greater accumulation at all times with both infectious agents than Ga-67 citrate (p < 0.05). While Tc-99m HIG showed greater accumulation inS. aureus thanE. coli (p < 0.05), there was no statistically significant difference betweenE. coli andS. aureus (p > 0.05) by Ga-67 citrate. Our study suggests that Tc-99m HIG is a superior agent to Ga-67 and bacterial affinity can be a factor responsible for HIG accumulation at focal sites of inflammation.

Final diagnosis in children with subclinical hypothyroidism and mutation analysis of the thyroid peroxidase gene (TPO).

AIM To determine the final diagnosis of patients with subclinical hypothyroidism (SCH), and to perform mutation screening of the thyroid peroxidase gene (TPO). METHODS Infants with SCH without an identified etiology were included in the study. Patients with thyroid dysgenesis were excluded. Children > or = 2 years of age, and still on L-thyroxine (LT4) treatment underwent a diagnostic algorithm. After LT4 was discontinued for 4 weeks, thyroid function tests (TFT) were obtained. A perchlorate discharge test (PDT) was performed in patients with normal thyroid ultrasound but abnormal TFT. Sequence analysis of TPO was studied in all children who underwent a PDT. RESULTS Forty-eight patients (23 males and 25 females) completed the trial. Among these children, 19 (39.5%) had transient SCH, and 29 (60.5%) had permanent SCH. Among patients with permanent SCH, 19 had thyroid hypoplasia, six had partial iodide organification defect with positive PDT, and four had other dyshormonogenesis with negative PDT. Mean LT4 dose before the medication ceased was 1.2 +/- 0.5 microg/kg/day in transient cases, and 1.7 +/- 0.4 in those with permanent SCH (p < 0.05). No TPO mutation was detected. However, in five patients, seven different previously known TPO polymorphisms were detected: c.102C > G, L4L; > A, A576A; c.2088C > T, D666D; c.2263A > C, T725P; c.2630 T >C, V847A. CONCLUSIONS LT4 treatment should be stopped after the age of 2 years in infants with SCH without a definite pathology of the thyroid gland to exclude cases with transient hypothyroidism. Additionally, we should consider particularly thyroid gland hypoplasia, and also partial defects in iodide organification in infants with SCH.

The diagnosis of peritoneo-pleural communication with Tc-99m MAA scintigraphy in the absence of ascites.

A 54-year-old man with a history of cirrhosis had a right-sided large pleural effusion despite the absence of abdominal ascites. After injection of Tc-99m MAA into the peritoneal space under ultrasound guidance, rapid accumulation of radioactivity in the right pleural effusion was noted, suggesting a peritoneo-pleural communication. Demonstration of the origin of the pleural effusion in the absence of abdominal ascites using Tc-99m MAA scintigraphy may play an important role in the treatment of patients with this problem.

The value of99mTc-DTPA renal scintigraphy in the evaluation of post-traumatic abdominal fluid collection

A patient with a post-traumatic retroperitoneal urinoma is presented. On admission, there was a clinical suspicion of retroperitoneal hematoma and ultrasonography (US) was performed which showed a hypoechoic fluid collection suggesting retroperitoneal hematoma. In order to determine the nature of the fluid, radionuclide angiography and renal scan were performed successively with99mTc-DTPA. Demonstration of urinary leakage into the mass in the delayed renal scintigraphic images suggested a urinoma. At laparotomy, total transection of the left ureter in the uretero-pelvic region was found and the diagnosis of urinoma was confirmed.