The evaluation of sacroiliitis using 99mTc-nanocolloid and 99mTc-MDP scintigraphy.

The role of imaging studies in the evaluation of patients with sacroiliitis is controversial. We aimed to evaluate the role of nanocolloid and bone scintigraphy in patients with sacroiliitis and to investigate the clinical relevance of imaging findings. Thirty-two patients with clinically sacroiliac disease (nine females, 23 males, aged 22-47 years) underwent scintigraphic and radiographic examinations and all imaging studies were performed within 2 weeks. Twenty-five subjects were also included as a control group (10 females, 15 males, aged 20-51 years) for quantitative analysis of the bone scan. The quantitative analysis was done by using regions of interest drawn over the right and left sacroiliac (SI) joint and sacrum (S) and SI/S ratios were calculated. Abnormal uptake was defined as an uptake higher than the mean +/- 2 SD of the control SI/S values. Bone scintigraphy was performed using a three-phase technique and single photon emission computed tomography (SPECT). Nanocolloid scintigraphy (NS) was performed 1 h later, after administration of 370 MBq 99mTc-nanocolloid, and evaluated visually. Each of the scintigraphic examinations was performed on separate days within the same week. Sensitivity values were 25%, 47%, 69% and 97%, and specificity values were 80%, 90%, 95% and 90% in quantitative bone scanning (QBS), 99mTc-NS, planar and SPECT bone imaging, respectively, when the clinical findings were considered as the 'gold standard'. Our results showed that bone SPECT scanning was more sensitive than planar imaging, but planar imaging was the most specific method. SPECT was also the most associated technique with clinical findings. 99mTc-NS was neither specific nor sensitive enough in the detection of sacroiliitis although it could be helpful for the confirmation of inflammation.

Parasternal lymphoscintigraphy using 99Tcm-dextran.

99Tcm-dextran was evaluated as a lymphoscintigraphic agent in 10 normal volunteers and 24 patients with breast cancer. 99Tcm-dextran (0.5-1 mCi) in a volume of 0.1-0.2 ml was injected into the posterior rectus sheath in the subcostal site on one side. Scintigrams were obtained at 2-2.5 h after injection and the injection was repeated on the other side. The final image was taken at 4.5-5 h after the first injection. The normal distribution of lymph nodes and anatomical variations in scintigraphic images were first determined in normal subjects. In the patient group, eight scintigrams were evaluated as pathological and the rest as normal. In the 25 women whose lymphoscintigrams were normal the mean number of parasternal nodes visualized was six (range: 3-11). Bilateral symmetrical or asymmetrical chain was observed in 20 subjects (80%) and unilateral chain in five subjects (20%). There was cross-drainage in five subjects (20%). Supraclavicular lymph nodes were visualized in 11 subjects (44%). Varying abnormal images were obtained in eight patients. Our results are in good agreement with those reported in the literature, using radiocolloids. It is concluded that 99Tcm-dextran is a promising agent and may well replace radiocolloids because of the simplicity of the labelling procedure, stability of the label, easy availability and low cost.

Regional cerebral blood flow in schizophrenia before and after neuroleptic medication.

In order to investigate cerebral perfusion changes induced by neuroleptic drugs, we performed 99Tc(m) hexamethyl propyleneamine oxime (HMPAO) single-photon emission computed tomography (SPET). Fifteen patients (nine drug naive, six non-naive) diagnosed by using the DSM-III-R criteria, and 10 right-handed age and sex matched normal volunteers were included in this study. The SPET study was performed with 740 MBq 99Tc(m)-HMPAO by using a 128 x 128 matrix, 30 s/frame for a total 64 view over 360 degrees before and after 1 month of neuroleptic treatment. A semiquantitative method was used for the analysis. Patients were clinically assessed using the Brief Psychiatric Rating Scale (BPRS). There was no significant regional cerebral blood flow (rCBF) difference between the patient group and control group in whole-brain regions except in the left temporal lobe. Although clinical scores of the patients improved after neuroleptic treatment no statistically significant difference was found in the rCBF between pre- and post-treatment. Moreover, there was no statistically significant correlation between the rCBF and BPRS in any region. These results suggest that there was a discrepancy between the clinical situation and rCBF in schizophrenia and the lateralized temporal lobe blood flow, which may have important implications for the evaluation of patients with schizophrenia.

The value of 99mTc-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 with 99mTc-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.

Tc-99m-HMDP bone uptake quantification and plasma osteocalcin levels in hemodialysis patients--a preliminary study.

In this preliminary study plasma osteocalcin levels and Tc-99m-HMDP (Technetium 99m hydroxymetylene diphosphonate) bone uptake (BU) were measured in 10 chronic end-stage renal failure patients who were on maintenance hemodialysis. The aim of this study was to determine the correlation between bone uptake and osteocalcin-a sensitive and specific marker of osteoblastic activity. There was a statistically significant increase in both 20 and 180 minute uptake in the patient group (36 +/- 2.7 and 39 +/- 3.6) when compared to the normal volunteers (32 +/- 3.1 and 19 +/- 2.7). Plasma osteocalcin levels were also significantly high (24.5 +/- 5.6 ng/ml) when compared with normal values (6.5 +/- 2.3 ng/ml). The correlations between osteocalcin and 20 and 180 min BU were high (r = 0.62 and 0.72 respectively). In conclusion, our preliminary study suggests that, in hemodialysis patients, Tc-99m-HMDP bone uptake quantification is a sensitive and non-invasive method for showing increased osteoblastic activity.

The value of Tc-99m tetrofosmin thyroid scintigraphy in patients with nodular goiter.

The aim of this study is to investigate the value of Tc-99m tetrofosmin (Tc-99m-TF) in conjunction with conventional Tc-99m-pertechnetate (Tc-99m-P) scintigraphy in the differentiation of malignant nodules from benign thyroid nodules. Forty-two patients [(32 females, 10 males; mean age 41 +/- 13 years; twenty-two multinodular goiter (MNG) patients with 58 nodules and 20 solitary thyroid nodules (STN)] were included in the study. Thyroid scintigraphy with Tc-99m-P and Tc-99m-TF, thyroid ultrasonography and fine needle aspiration cytology (FNAC) were performed. After i.v. injection of 370-550 MBq Tc-99m-TF, images were obtained at 15 minutes and evaluated semiquantitatively by using a five point (0-4) scoring system. Four patients with a hypoactive STN, and 1 patient with a hypoactive MNG was found to have thyroid malignancy by histopathological examination; 2 of these patients had false negative benign FNAC results. The tetrofosmin uptake score (TUS) was 2-3-3-3 and 3 in these 5 malignant nodules. Five hyperactive (hot or warm) STN with benign FNAC had a TUS of 2-3-3-3-3. All hypoactive (cold) MNG nodules with benign FNAC (n = 21) had TUS < or = 2. Our preliminary results suggest that follicular adenomas and thyroid cancers have higher tetrofosmin uptake than benign colloidal goiter nodules. Mitochondrial sequestration of tetrofosmin in benign or malignant follicular cells that proliferate more rapidly than normal follicular cells and/or hypervascularity may be responsible for this. The use of Tc-99m-TF in conjunction with Tc-99m-P thyroid scintigraphy will be helpful in the evaluation of patients with nodular goiter (NG). In patients with a STN, a hypoactive nodule with a high TUS has a higher probability of malignancy; whereas a hyperactive nodule with a high TUS is a follicular adenoma. In patients with MNG, a hypoactive nodule with a high TUS may be suggestive of malignancy despite a benign FNAC result. We think that further studies with Tc-99m-TF are required to confirm these results.

Scintigraphic diagnosis of intrathoracic extramedullary hematopoiesis in a patient with beta-thalassemia.

We report the scintigraphic diagnosis of intrathoracic extramedullary hematopoiesis (EMH) in a patient with beta-thalassemia. A patient had a mass in the right thoracic paravertebral region on radiography and CT. Bone marrow imaging of the thorax by means of both Tc-99m nanocolloid and phytate demonstrated uptake of the tracer in the mediastinal mass, establishing the diagnosis of EMH.

Esophageal clearance scintigraphy, in diabetic patients--a preliminary study.

The aim of this preliminary study was to evaluate the predictive value of esophageal clearance scintigraphy (ECS) in the diagnosis of esophageal autonomic neuropathy in diabetic patients without any esophageal symptoms. A single swallow ECS was performed in 12 diabetic patients and 15 normal volunteers, and esophageal transit time (ETT) and esophageal (Es) T 1/2 values were calculated. ETT and Es T 1/2 were found to be significantly prolonged in the diabetic group (p less than 0.01 and p less than 0.05, respectively). In this preliminary study, our results strongly suggest that ECS may be an important noninvasive diagnostic tool in the evaluation of diabetic patients with asymptomatic esophageal autonomic neuropathy.

Quantitative sacroiliac joint scintigraphy in normal subjects and patients with sacroiliitis.

The aim of this study is to determine the sacroiliac index (SII) of healthy subjects and to compare these values with patients having sacroiliitis (SI). Quantitative sacroiliac scintigraphy (QSS) was performed with Tc-99m hydroxy methylene diphosphonate (HMDP) and whole sacroiliac joint-to-sacrum ratio was calculated as a SII by the region of interest (ROI) method. Forty-seven nonarthritic healthy subjects and 13 patients with SI were studied. Effects of aging, gender and laterality on SII were evaluated in 47 healthy subjects. The sacroiliac index was higher in men than women (p < 0.05). SII did not change significantly in aged men, but it decreased significantly in aged women (p < 0.05). Eleven of 13 patients with SI had a higher SII than healthy subjects (> mean + 2SD). In the other two cases by using small ROIs, SIIs were found to be higher than the normal range. Our results suggest that QSS is a sensitive method for the diagnosis of early stage SI and every institution should establish its own normal SII.

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 by E. coli and S. aureus. Serial scintigrams were performed at 1, 4, 24 hr after injection. Tc-99m HIG showed greater accumulation at all times with both infections agents than Ga-67 citrate (p < 0.05). While Tc-99m HIG showed greater accumulation in S. aureus than E. coli (p < 0.05), there was no statistically significant difference between E. coli and S. 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.

Transfer of native insulin through the peritoneal membrane during CAPD in non-diabetic and diabetic patients.

Because of its relatively small molecular size of 5800 daltons, insulin is a transperitoneally diffusable substance. Insulin is also known to be a mitogenic coadjuvant for mice fibroblasts, and safety of its long-term intraperitoneal use has been questioned because of the potential risk for peritoneal fibrosis. For similar reasons native insulin content of the peritoneal effluent should also not be neglected. To our knowledge, no sufficient data are available about native insulin transfer to dialysate during continuous ambulatory peritoneal dialysis (CAPD). In this study we measured plasma and dialysate immune-reactive insulin levels during a 4 hour peritoneal exchange in 9 nondiabetic and 4 type II diabetic end-stage renal disease patients on CAPD. In both plasma and dialysate, insulin levels were higher in diabetic patients. At hour 4 of dwell time, plasma insulin was 37.5 +/- 7.9 microU/mL in non-diabetics and 64.2 +/- 34.1 microU/mL in type II diabetics. In both groups, dialysate insulin was 1.5 to 2 x higher than their simultaneous peripheral vein insulin levels and was measured as 88.1 +/- 26.8 microU/mL in nondiabetic group and 101.7 +/- 52.6 microU/mL in the diabetic group at hour 4 (p < 0.005 vs 4 hour plasma level). In conclusion, in both diabetic and nondiabetic CAPD patients, native insulin was present in the dialysate in amounts exceeding simultaneous plasma levels. Equilibration with high portal vein insulin content through hepatic capsule may explain higher insulin concentrations measured in the dialysate.(ABSTRACT TRUNCATED AT 250 WORDS)

The volume effect of the stomach on intestinal activity on same-day exercise--rest Tc-99m tetrofosmin myocardial imaging.

PURPOSE: The aim of this study was to investigate quantitatively the volume effect of the stomach on the prevention of intestinal artifacts in the rest phase on same-day exercise--rest Tc-99m tetrofosmin myocardial perfusion scintigraphy. MATERIALS AND METHODS: The study was performed in 81 consecutive patients (43 men, 38 women; mean age, 57 +/- 9 years) who were referred for routine Tc-99m tetrofosmin exercise--rest SPECT myocardial perfusion imaging with normal scintigrams or completely normal inferior wall perfusion on visual assessment of SPECT images. Group A (control group, n = 41) and group B (n = 40) were given 200 ml milk to enhance the hepatobiliary clearance of tetrofosmin 30 minutes before the exercise SPECT acquisition study and just after the injection for the rest SPECT acquisition study. For the rest SPECT acquisition study, patients in group B were given, in addition to milk, a standard solid and fluid meal to enhance the volume of the stomach after the injection of Tc-99m tetrofosmin. In all patients, both exercise and rest SPECT acquisitions were started 45 minutes after the injection of Tc-99m tetrofosmin. Myocardial and abdominal activity were assessed on three separate views in the rest phase of the study, and the mean myocardium-to-abdomen count ratios were calculated. In addition, the presence of interfering intestinal activity was assessed visually on SPECT images. Infracardiac activity was described as absent when it was equal to lung background. RESULTS: The myocardial-to-abdominal ratios were 1.38 +/- 0.05 and 1.95 +/- 0.04 in groups A and B, respectively (P < 0.0001). Interfering intestinal activity with varying degrees of intensity was seen in 20 patients in group A (49%) and in 5 patients in group B (13%; P < 0.001). CONCLUSIONS: These results suggest that filling of the stomach with some fluid and solid food before rest acquisition on the same-day stress--rest protocol, because of its volume effect, may provide a high target-to-nontarget ratio for myocardial imaging and thus may reduce the frequency of intestinal artifacts.

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.

Contractility evaluation by 2 dimensional echocardiography and gated SPECT myocardial perfusion scintigraphy in hypertensive patients with clinical presentation of atypical chest pain.

BACKGROUND: Hypertension (HT) is a growing health problem in the population and associated with increased cardiovascular event risk and mortality. In hypertensive patients, progressive left ventricular (LV) contractility deterioration is detectable by gated single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy9. We planned this study to explore the agreement in ejection fraction (EF) determination between 2 dimensional echocardiography and gated SPECT analysis in selected group of patients with hypertension. PATIENTS AND METHODS: We studied 26 consecutive patients (mean age 56.5 ± 8.8 years; 6 men) with hypertension. Quantitative contractility analysis by both echocardiography and SPECT at rest was performed to investigate the agreement between two diagnostic tests. RESULTS: EF at rest was greater than 55 % in all patients. All patients had a clinical presentation of atypical chest pain. Therefore, in addition to quantitative contractility analysis at rest by echocardiography and myocardial SPECT perfusion scintigraphy, we examined ischemia by stress induction and determined that 10 patients had ischemic finding (38.4 %). The mean value of EF calculated by echocardiography was 67.5 ± 5.7 %, while EF by gated SPECT was 72.8 ± 8.5 %. We documented an acceptable agreement in EF determination between these 2 diagnostic tests by meaningful correlation (r = 0.556, p = 0.003). There was no regional contractility deterioration despite existence of ischemia in 10 patients of the study group. CONCLUSIONS: We observed that both echocardiography and gated SPECT can be used for quantification of EF in the hypertensive patients with an acceptable agreement.