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.

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.

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.

The value of 99mTc-HMPAO labelled white blood cell scintigraphy in acute appendicitis patients with an equivocal clinical presentation.

Various imaging studies can be performed in the evaluation of patients with a clinical presentation equivocal for acute appendicitis. One of these studies is technetium-99m hexamethylpropylene amine oxime (HMPAO) labelled white blood cell (WBC) scintigraphy. The aim of this study was to evaluate the accuracy and clinical value of 99mTc-HMPAO WBC scintigraphy in the aforementioned group of patients. Forty-one patients who had acute right lower quadrant abdominal pain with a clinical presentation equivocal for acute appendicitis were included in the study. The anterior abdomen and pelvis were imaged up to 4 h after the injection of 125-300 MBq 99mTc-HMPAO WBCs and the results were immediately reported to the surgeon before a decision was taken on whether to perform laparotomy. Diagnostic accuracy was established by the intra-operative findings and the histopathology in operated patients. In non-operated patients, absence of abdominal symptoms 1 month after scintigraphy and/or identification of another cause of abdominal pain was used to rule out acute appendicitis. There were 16 patients with positive scintigraphy and 81% of these patients were positive within 2 h post injection. There were no false-positive or false-negative results. We operated on 17 (41.4%) patients, and only one patient (5.9%) underwent unnecessary laparotomy. We conclude that 99mTc-HMPAO WBC scintigraphy is a rapid, highly accurate method for the exclusion of acute appendicitis and that its use can lower the unnecessarily high laparotomy rate in patients with an equivocal clinical presentation.

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.

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.

Renal functional reserve in insulin dependent diabetic children.

BACKGROUND: Microalbuminuria has been shown to be predictive for clinical diabetic nephropathy. Renal functional reserve (RFR), as a response to protein loading in a short period of time, is a parameter to assess the ability of kidneys to increase the glomerular filtration rate (GFR). The aim of this study was to predict the early phase of diabetic nephropathy by measuring urinary albumin level and RFR capacity in patients with insulin-dependent diabetes mellitus (IDDM). METHODS: Twenty-two patients with IDDM were studied: 11 with a disease duration of less than 5 years (group 1) and 11 with a disease duration of more than 5 years (group 2). As the control group, 15 healthy children (group 3) were included in the study. At the beginning of the study, glucose was measured and the urinary albumin/creatinine ratio was calculated. Average glycosylated hemoglobin (HbA1c) over 1 year was determined. After protein loading (red meat containing 2 g/kg of protein), the creatinine clearance was calculated at each hour for a duration of 4 h. The RFR was accepted as the peak percentage increase in GFR over the baseline value. RESULTS: Although metabolic control in group 2 was better, the RFR in group 2 was significantly lower than in group 1 (P < 0.05). Urinary microalbumin levels between the groups did not differ (P > 0.05). In two patients in whom microalbuminuria was detected, the RFR was much lower. CONCLUSIONS: Detecting lower RFR levels in patients with normal urinary albumin excretion, as well as in patients with microalbuminuria, may support the idea that the RFR capacity is more sensitive than microalbuminuria in assessing the early phase of diabetic nephropathy.

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.

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.

Beneficial effects of pentoxifylline on cyclosporine-induced nephrotoxicity.

1. Hypertension and renal failure are the two most common and severe complications due to cyclosporine A (CsA) therapy after transplantation. To determine whether an in vivo treatment with pentoxifylline (PTX) can prevent the toxic effects of CsA, three groups of rats were studied. 2. The first group of rats (n = 11) received daily injections of CsA (15 mg/kg, i.m.) and PTX (45 mg/kg, i.p., b.i.d.), the second group of rats (n = 11) was treated with CsA only and the third group of rats (n = 11) served as the control group (vehicle treatment). 3. Whole blood CsA levels were similar in CsA + PTX and CsA alone groups. Although CsA treatment significantly increased mean arterial blood pressure (110.00 +/- 2.48 mmHg; P < 0.01), there was no significant increase in the PTX co-treated group (104.09 +/- 2.96 mmHg) compared with initial values. In both the CsA alone and CsA + PTX groups the heart rate (365.45 +/- 6.65 and 357.27 +/- 7.23 b.p.m., respectively; P < 0.05) were found to be significantly higher than initial values. Serum creatinine levels increased significantly in the CsA alone group (1.40 +/- 0.11 mg/dL; P < 0.01) compared with control values (0.81 +/- 0.04 mg/dL). This increase was prevented by co-treatment with PTX (serum creatinine 1.11 +/- 0.01 mg/dL; P < 0.05). Total [99mTc]-DTPA percentage renal uptake, as an index of glomerular filtration rate (GFR), was markedly and significantly lower in the CsA alone group (10.01 +/- 0.79%; P < 0.01) than in the control group (18.19 +/- 1.32%). Pentoxifylline co-treatment attenuated this decrease compared with GFR in the CsA alone group (13.00 +/- 0.75%; P < 0.01). 4. These results suggest that the co-administration of PTX with CsA may prevent the dose-limiting toxic effects of CsA therapy.

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.

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 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.