Diagnostic value of additional 18F-FDG PET/CT imaging using a vaginal catheter in patients with paravaginal malignant lesions.

BACKGROUND: In routine noncontrast-enhanced PET/computed tomography (CT) studies, the female pelvis is one of the most challenging anatomical regions to interpret. In surgically treated patients, it may be more difficult to determine the accurate location of paravaginal hypermetabolic lesions. In this study, the aim was to investigate the contribution of additional PET/CT imaging using a vaginal catheter in patients with pelvic malignant disease. METHODS: Forty-seven patients with pelvic malignancies were enrolled in this study. Following routine whole-body fluorine-18 fluorodeoxyglucose (F-FDG) PET/CT scanning, an additional pelvic scan was obtained after placement of a plastic catheter in the vaginal lumen (v-catheter). All suspected foci in vaginal and paravaginal areas were evaluated for both studies. The contribution of additional v-catheter imaging was determined visually by five experienced interpreters. RESULTS: Pathological F-FDG uptake in various vaginal and/or paravaginal locations was detected in 24 of 47 patients after conventional PET/CT imaging. In 10 of these 24 patients, anatomic relations within the uptake area could not be confidently described and v-catheter imaging provided a significant contribution in all 10 cases. In seven of these 10 sites examined, pathological F-FDG uptake was safely ruled out and three sites were confirmed to be malignant. In total, the final interpretation in 13 of 24 patients (54%) was modified by additional v-catheter imaging. The contribution rate of catheter imaging was 89% in treated patients and 33% in untreated patients with vaginal and/or paravaginal lesions on initial scans. CONCLUSIONS: Additional v-catheter imaging of pelvis may be of diagnostic value in the accurate anatomical definition of hypermetabolic lesions in the vaginal/paravaginal area on noncontrasted PET/CT studies.

The role of coughing as a gastroesophageal-reflux provoking maneuver: the scintigraphical evaluation.

BACKGROUND: Attempts have been made to improve the positivity of the radionuclide detection of gastroesophageal reflux (GER). The aim of this study was to examine the possible contribution of coughing as a provoking maneuver in GER scintigraphy. METHODS: One hundred and twenty-five patients (mean age: 9.2+/-3.2 years) who had a clinical probability of having GER and were fully able to cooperate for coughing on command were included in the study. The patients were asked to cough gently four to six times per minute in the 2nd, 4th, and 6th 10-min periods within a 60-min total study time. The presence and number of GER episodes were noted for each period in all patients. RESULTS: Sixty-one of 125 patients (48.8%) showed no scintigraphic finding of GER and were interpreted as normal. In the remaining 64 patients (51.2%), GER was observed and these patients were interpreted as abnormal (GER+). Among patients with abnormal results, 25 (39%) presented GER episodes only during the coughing intervals of the study. In 33 (51.6%) patients, the reflux was seen both at coughing and noncoughing periods. In only six patients (9.4%) with GER in noncoughing periods, coughing did not provoke any reflux episodes. No overall correlation between cough-provoked frequency of reflux, number of GER episodes, and symptom severity was found in 64 GER+ patients (P>0.5); but in the subgroup of patients presenting GER episodes only during the coughing intervals, 60% (15 of 25), presented GER episodes only in one of the three cough-provoked intervals and also had the lowest symptom severity scores. CONCLUSION: The results of our study showed that 39% (25 of 64) of the observed GER findings were achieved exclusively by means of cough provocation.

Left ventricular aneurysm in the scope of gated perfusion SPECT: accuracy of detection and ejection fraction calculation.

PURPOSE: The objective of this trial was to investigate the capacity of gated perfusion SPECT (GPS) to detect left ventricular aneurysm (ANV) by comparing QGS and 4D-MSPECT (4DM) algorithms with radionuclide ventriculography (RVG). Secondarily, the comparison of GPS ejection fraction (EF) measurements with those of contrast left ventriculography (LVG) and RVG was aimed. METHODS: Twenty-five patients with ANV confirmed by LVG were studied. The patients underwent RVG and rest Tc-99m-tetrofosmin GPS 1 week after LVG. A 9-segment model was used both in RVG and GPS evaluation. Aneurysm was defined by scoring the wall motion (WM) and phase analysis in RVG; perfusion, wall thickening and WM in GPS. RESULTS: The detection rate of ANV was 96%, 84% and 52% for RVG, QGS and 4DM, respectively. The LVG mean EF (43.52% +/- 16.93%) was significantly higher (P < 0.01) than those of RVG (29.40% +/- 10.90), QGS (30.04% +/- 13.25%) and 4DM (34.92% +/- 13.01%). Moderate to high EF correlation values were obtained between LVG and GPS (r = 0.71-0.79) and GPS-RVG (r = 0.69). There was no significant EF difference between the radionuclide methods except between 4DM-EF and RVG-EF (5.52%, P < 0.05). Wide Bland-Altman limits were observed between the radionuclide methods in EF comparisons (range: 30.5-38.5%). CONCLUSION: GPS seems to have a role in the non-invasive investigation of ANV. QGS-GPS proved to be more reliable (84%) than 4DM-GPS (52%) in the ANV detection. The localization and the extent of the aneurysm itself as well as perfusion and function of adjacent segments may affect aneurysm diagnosis by means of GPS. RVG, QGS-GPS and 4DM-GPS seem not to be interchangeable for routine EF calculation in ANV patients.

Effect of types of resection and manipulation on trocar site contamination after laparoscopic colectomy: An experimental study in rats with intraluminal radiotracer application.

BACKGROUND: The etiology and incidence of port-site metastases after laparoscopic surgery for colorectal cancer remain unknown. The purpose of this experimental study was to detect and quantify the amount of contamination at the port-site by means of a method utilizing radiolabelled colloid particles following extra- or intracorporeal laporoscopic resection of cecum. METHODS: Prior to experimental surgery, we obtained a high concentration of luminal colonic radiotracer activity by per anum application of sulphur colloid molecules labelled with Tc-99m pertechnetate. In three main groups of rats, we either resected a portion of cecum extracorporeally or intracorporeally, or did no resection. Each main group was further divided into two subgroups, in which the manipulations were either autraumatic or traumatic. We excised trocar sites as 2 cm doughnuts after completion of the surgical procedure. We used gamma camera imaging to quantify the amount of radioactive contamination at trocar sites. The background corrected trocar site activity for each rat was calculated. Activities exceeding the maximum background activity were accepted as trocar site contamination. RESULTS: We detected an overall incidence of contamination in 44% of rats. This rate were 71% and 17% in traumatic and atraumatic subgroups. The resection itself increased the rate and intensity of contamination, as well (p = 0.04). The most intensive contamination was detected in the intracorporeal resection with traumatic manipulation subgroup (p = 0.0007). CONCLUSIONS: Both the presence of resection and manipulative trauma seemed to be increasing the rate and intensity of the radioactive activity at the trocar site. When traumatic manipulatiun was exercised, the contamination was so intense that the type of resection did not differ. We concluded that our scintigraphic method would be useful in the intraoperative detection of port site contamination by the tumor cells, and that surgeons would take some preventive measures to prevent future port-site metastases.

Periodontal & systemic bone changes in rats with experimental lathyrism.

BACKGROUND & OBJECTIVE: It is not clear how lathyrism affects the systemic bone metabolism. We therefore undertook a study to observe periodontal and systemic bone changes by performing radiological, metabolic, and bone densitometric evaluations in rats with experimental lathyrism. METHODS: A total of 30 rats were used. Experimental lathyrism was induced by once daily subcutaneous administration of beta-aminopropionitrile (beta-APN), at a dose of 5 mg beta-APN/0.4 ml per 100 g of body weight for 40 days. After 40 days, vertebral bone mineral density was analyzed by means of dual energy X-ray absorbtiometry in both groups. Blood was drawn by cardiac puncture and the animals were decapitated. Serum calcium levels were measured. Right mandibles were removed and radiographs were obtained. Alveolar bone level was determined in the radiographs. RESULTS: In all lathyritic rats, alveolar bone level was pathologically decreased with visible resorption. Vertebral bone mineral density values of lathyritic rats did not differ significantly from those of the control group. Compared to controls, there was a statistically significant decrease in serum calcium levels in the lathyritic group (P<0.001). INTERPRETATION & CONCLUSION: Significant alveolar bone resorption without alterations in vertebral bone mineral density indicated that lathyrogen administration for 40 days presumably has not caused systemic demineralization. This model could be used for studying the role of local and systemic agents on periodontal alveolar bone resorption.

Frontal functions in young patients with essential tremor: a case comparison study.

Essential tremor (ET) is classified as a pure motor system disease. It has been previously reported that impairments in cognitive functions can be associated with ET. The authors assessed cognitive functions in a relatively young patient group with ET and comparison subjects. Correlations between tremor severity and regional cerebral blood flow (rCBF) and neuropsychological test performances of ET patients and comparison subjects were investigated. Sixteen patients with ET and 16 comparison subjects were assessed by a comprehensive neuropsychological test battery designed to assess global attention, language, memory, visuospatial functions, and executive functions. In 11 of 16 patients and in nine of 16 comparison subjects, rCBF was measured by technetium-99m-hexamethyl propylene amine oxime single photon emission computed tomography (technetium-99m-HMPAO SPECT). The tremor severity was quantified using the Clinical Rating Scale for Tremor (CRST). Findings revealed that ET patients differed significantly from comparison subjects on tests assessing visuospatial functions and verbal memory, whereas differences in other tests did not reach statistical significance. There was no significant difference between the rCBF of ET patients and comparison subjects. There were statistically significant inverse correlations between tremor severity and executive functions. Tremor severity was inversely correlated with bilateral frontal blood flow by technetium-99m-HMPAO SPECT. Conclusions suggest that the subclinical cognitive deficits characterized by visuospatial and verbal memory impairments and executive dysfunction may be a clinical feature of ET, and the cerebello-thalamo-frontal network may play a role in the pathophysiology of this disorder.

The evaluation of microleakage and bond strength of a silicone-based resilient liner following denture base surface pretreatment.

STATEMENT OF PROBLEM: The failure of adhesion between a silicone-based resilient liner and a denture base is a significant clinical problem. PURPOSE: The purpose of this study was to examine the effects of denture base resin surface pretreatments with different chemical etchants preceding the silicone-based resilient liner application on microleakage and bond strength. The initial effects of chemical etchants on the denture base resin in terms of microstructural changes and flexural strength were also examined. MATERIAL AND METHODS: Forty-two polymethyl methacrylate (PMMA) denture base resin (Meliodent) specimens consisting of 2 plates measuring 30 x 30 x 2 mm were prepared and divided into 7 groups (n = 6). Specimen groups were treated by immersion in acetone for 30 (A30) or 45 (A45) seconds, methyl methacrylate monomer for 180 (M180) seconds, and methylene chloride for 5 (MC5), 15 (MC15) or 30 (MC30) seconds. Group C had no surface treatment and served as the control. Subsequently, an adhesive (Mollosil) and a silicone-based resilient denture liner (Mollosil) were applied to the treated surfaces, and all specimens were immersed in the radiotracer solution (thalium-201 chloride) for 24 hours. Tracer activity (x-ray counts), as a parameter of microleakage, was measured using a gamma camera. For bond-strength measurement, 84 rectangular PMMA specimens (10 x 10 x 40 mm) were surface-smoothed for bonding and treated with the different chemical etchants using the same previously described group configurations. The adhesive and the silicone-based denture liner were applied to the treated surfaces. Tensile bond-strength (MPa) was measured in a universal testing machine. Flexural strength measurement was performed with 49 PMMA specimens (65 x 10 x 3.3 mm according to ISO standard 1567) in 7 groups (n = 7), with 1 flat surface of each treated with 1 of the chemical etchants preceding adhesive application. The flexural strength (MPa) was measured using a 3-point bending test in a universal testing machine. The data were analyzed by 1-way analysis of variance and the Tukey HSD test (alpha = .05). RESULTS: Significant differences were found between the groups in terms of microleakage (P < .0001). The lowest microleakage was observed in group M180 (30,000 x-ray counts) and the highest in the control group (44,000 x-ray counts). The mean bond strength to PMMA resin ranged from 1.44 to 2.22 MPa. All treated specimens showed significantly higher bond strength than controls (P < .01). The flexural strength values all significantly differed (P < .05). All experimental specimens that had chemical surface treatments showed lower flexural strength than controls (P < .05). CONCLUSION: Treating the denture base resin surface with chemical etchants increased the bond strength of silicone-based resilient denture liner to denture base and decreased the microleakage between the 2 materials. Considering the results of both tests together, the use of methyl methacrylate monomer for 180 seconds was found to be the most effective chemical treatment.

Myocardial perfusion defects with near-to-absent count reduction: a comparison of gated SPECT to radionuclide ventriculography in the determination of left ventricular function.

OBJECTIVE: The main aim of the study was, to estimate the impact of perfusion defects including significantly depleted areas of varying size on gated perfusion SPECT (GPS) determined ejection fraction (EF) measurements in comparison to radionuclide ventriculography (RVG). A secondary objective was the evaluation of the GPS-RVG agreement of EF in patients with normal and deteriorated left ventricular function, separately. METHODS: Fifty-nine patients having perfusion defects including at least one segment with no visible tracer uptake in rest myocardial GPS related to myocardial infarction (older than 15 days) were studied. Myocardial perfusion was visually analyzed using a 17 segment-model, on a five-point (0-4) grading system in which Grade-4 (0-9% maximal uptake) represents cold defects. The patients with >or=4 adjacent, with 2-3 adjacent and with 1 single cold segments were named as Group1(GR1), Group2(GR2) and Group3(GR3), respectively. Secondly, the patients were re-grouped according to RVG-EF values. (Group A: patients with EF<50%; Group B: patients with EF>or=50%). In each group, the GPS-EFs were compared with RVG performed within one week and also the variations of GPS-RVG EF differences among the groups were statistically analyzed. RESULTS: In overall (r=0.86) and in each subgroup, EFs obtained by GPS were well correlated with RVG. However, in overall (difference mean EF% [dEF%]=4.6+/-6.7, p<0.001) as well as in subgroup evaluation, GPS significantly (p<0.005) underestimated EF. There was no statistically significant difference in GPS-RVG EF variations between GR1, GR2 and GR3 (p>0.05). The RVG-mean differences and RVG-correlation coefficients calculated for GR1,GR2 and GR3 were dEF%=3.1+/-4.6, r=0.85; dEF%=3.7+/-6.03, r=0.80 and dEF%=6.2+/-8.03, r=0.79, respectively. Mean dEF% was statistically higher in group-B than group-A (mean difference of dEF%=4,2, p<0.05). In group-A, GPS-EF values were better agreed with RVG (dEF%=3.34, r=0.75) than in group-B (dEF%=7.52, r=0.53). CONCLUSION: The stability of the calculation algorithm of QGS in EF calculation of patients with large depleted infarct areas could be confirmed. The agreement of GPS determined EF is higher in patients having myocardial integrity loss and left ventricular dysfunction.

Bladder exstrophy: effects on bone age, bone mineral density, growth, and metabolism.

Bladder exstrophy patients with or without augmentation have not been investigated according to metabolic bone problems, bone ages and growth, and development in details yet. We studied alterations in growth, bone ages, biochemistry of bone, bone mineral densities (BMD) of the forearm, neck of femur and lumbar vertebrae, blood gases, glomerular filtration rates (GFR), and electrolytes of 15 bladder exstrophy patients with augmentation and in those who had no augmentation. In six patients, a sigmoid colon was used for bladder augmentation and one patient underwent a ureterosigmoidostomy. Growth charts of all children were analyzed for determination of the percentiles. The parameters were compared with normal children and a comparison between augmented and nonaugmented patients were made. Growth retardation and decreased bone age were detected in all of the children. Ten patients with bladder exstrophy were below the 10th percentile for height. The mean age/bone age ratio of the patients was 1.59. The mean lumbar and femoral Z scores of the patients were -1.00 and -0.49, respectively. Mean BMD for distal radius was 0.239 g/cm2. Seven patients had a marked BMD decrease, their femoral and/or lumbar Z scores were below -1. Four cases had a pH lower than 7.35. In five patients, a HCO3 level less than 19 mmol/l was detected, four of them had an augmentation. Chloride measurements were slightly increased in six patients and alkaline phosphatase levels in five cases. Reduced GFR values were detected in two patients. There were no significant difference in laboratory values, in percentile height, and weights, in BMDs of femur, vertebra, forearm nor were any differences noted in age/bone age ratios in patients with augmentation when compared with those who had no augmentation. We found varying alteration in bone mineral density and HCO3 levels in patients with bladder exstrophy. Patients with bladder exstrophy, with or without augmentation, may develop serious growth retardation. As much as 45% of them, regardless of presence of augmentation, have an osteopenia or osteoporosis. We found a considerable difference in percentiles of heights as well as bone ages in bladder exstrophy patients when compared with normal population. We recommend close follow up of children with bladder exstrophy for linear growth, development of osteopenia, and bone ages.

Cold infarction areas of varying size in the presence of left ventricular dysfunction: the impact on left ventricular ejection fraction determination by gated SPECT compared to radionuclide ventriculography.

The agreement in left ventricular (LV) ejection fraction (EF) determination between the gated perfusion SPECT (GPS) and radionuclide ventriculography (RVG) methods has been reported to show a systematic reduction with increasing EF values. In some reports, this EF difference exceeds 5%, indicating a critical underestimation rate by GPS in terms of clinical reliability. Although the accuracy of endocardial edge detection by means of GPS proves to be reliable, even in patients with large perfusion defects, the accuracy of EF calculation seems to depend on the level of individual EF values. Our objective was to investigate the RVG-GPS agreement in EF determination specifically in patients with myocardial infarction (MI) having perfusion defects including extremely depleted areas and LV dysfunction. Our patients had a EF<50%, a population in which the best agreement values between the above two methods should be found according to the literature. The idea was to test the accuracy of QGS algorithm in the presence of cold perfusion defects and a low probability of EF level influence. Thirty-six patients (26 males; 61.8+/-9.1 y and 10 female; 64.1+/-10.7 y) with MI older than two weeks, having perfusion defects, including all regions of varying size with no visible tracer uptake in rest GPS and RVG-EF<50% were included in the study. Rest-GPS was performed by injecting iv 925 MBq 99mTc-sestamibi (8-time bins) using a dual-headed gamma camera and rest-RVG was performed within the following three days by injecting iv 740 MBq 99mTc-pertechnetate-pyrophosphate (24 time bins). Myocardial perfusion was visually analyzed on a 17 segment-model and summed rest perfusion scores (SRS) were determined. The cold defect number (CDN) was calculated by selecting the myocardial segments with 0%-9% of maximal tracer uptake (grade 4) to identify the extent of the depleted tissue in each patient. The patients with (3)4 adjacent myocardial segments with grade 4 perfusion were considered as having large cold defects (Group 1: GR1). Patients with two or three CDN constituted the Group 2 (GR2; medium cold defects) and those with only one CDN constituted Group 3 (GR3; small cold defects). Hereafter, the relative weight of cold perfusion defects (CD%) and infarcted segments (IS%) were calculated for all patients and subgroups. Of 36 patients studied, 14 patients (39%, GR1) had large cold defects. Eleven patients (30.5%, GR2) had moderate and 11 (30.5%, GR3) had small cold defects. The overall mean value of CDN was 3.03+/-1.96 (1-9). Mean EF values in RVG and GPS among Groups 1, 2 and 3 were 28.78%+/-6.32%, 38.46%+/-6.43%, 38.73%+/-8.55% and 27.0%+/-6.93%, 37.82%+/-8.80%, 33.27%+/-11.65%, respectively. The percentage of patients showing an EF difference pound 5% between RVG and GPS in Groups 1, 2 and 3 were 93%, 73% and 27%, respectively. The CD% and IS% were 19+/-12, 30+/-7, 14+/-3, 6 and 52+/-20, 61+/-18, 50+/-17, 42+/-23 in overall, GR1, GR2 and GR3, respectively. It is concluded that: the negligible underestimation of EF in GR1 by GPS compared to RVG confirms the stability of the geometric modeling algorithm of QGS in this particular patient sub-group. Although the agreement results in patients with smaller defects were probably influenced through the realization of RVG and GPS studies performed on different days, it seems to be rational to set the threshold of RVG-GPS agreement dependency on EF levels in patients with myocardial infarction lower than 50%.

Effect of denture base surface pretreatment on microleakage of a silicone-based resilient liner.

STATEMENT OF PROBLEM: Microleakage between resilient liner and denture base resins is a significant clinical problem, often responsible for debonding of the resilient liner from the denture base resin. PURPOSE: This study investigated the effect of 2 surface treatments, airborne-particle abrasion (APA) and wetting with methyl methacrylate monomer (MMA), on microleakage between a silicone-based resilient liner and denture base resin using a gamma camera imaging technique. MATERIAL AND METHODS: Thirty-three specimens, each having 2 plates measuring 40 x 40 x 2 mm, were prepared by packing and processing an acrylic denture base resin (QC-20) into square plates following manufacturer's instructions. Specimens were divided into 3 groups (n=11) as APA-, MMA-, and control-treatment groups. For the APA group, the inner surfaces of both plates were airborne-particle abraded with 250-microm Al 2 O 3 particles and, for the MMA group, surfaces were treated with monomer (QC-20). Control specimens were not surface treated. Following application of an adhesive (Ufi Gel P-specific), a silicone lining material (Ufi Gel P) was prepared and applied to the inner surfaces of all 33 specimens. Eleven size-matched polymethyl methacrylate (PMMA) specimen blocks (40 x 40 x 6 mm) were prepared to calculate the level of residual radioactivity for the denture base itself, the entire outer surface count (OSC). All specimens and PMMA blocks were immersed in a radioactive solution (thallium-201 chloride) for 24 hours. Specimen activities (gamma-ray cts/sec, representing thallium-201 concentration) were then measured using a high-resolution gamma camera. The amount of OSC-subtracted total specimen counts was a direct indicator of the quantity of inward diffusing tracer. The subtracted values were analyzed using a 1-way analysis of variance (ANOVA) and Bonferroni multiple comparison tests (alpha=.05). RESULTS: OSC levels averaged 754 +/- 110 gamma-ray cts/sec. OSC-subtracted APA, control, and MMA values were 5,546 +/- 1,534, 3,392 +/- 738, and 1,405 +/- 392 gamma-ray cts/sec, respectively. All 3 groups were significantly different ( P <.05) from each other. Surface wetting with MMA showed the lowest microleakage values among all specimen groups. CONCLUSION: In terms of microleakage, surface treatment with MMA monomer preceding the adhesive application demonstrated lower values than adhesive application alone. APA pretreatment resulted in 4 times the microleakage found in MMA-treated specimens, and 1.5 times the microleakage of the untreated control. None of the surface pretreatments completely prevented microleakage. Microleakage between the silicone-based resilient liner and denture base resin can be quantitatively determined using the gamma camera imaging technique.

Reduced bone mineral density in childhood chronic idiopathic thrombocytopenic purpura treated with high-dose methylprednisolone.

PURPOSE: To evaluate whether repeated courses of high-dose methylprednisolone (HDMP) affect the lumbar spine bone mineral density (BMD) in children with chronic idiopathic thrombocytopenic purpura (ITP). MATERIALS AND METHODS: This study included 24 patients with chronic ITP and 149 healthy controls. The patients were allocated into three groups according to the number of HDMP courses (30 mg/kg per day as a single dose for 7 days); group 1 (10 patients), group 2 (9 patients), and group 3 (5 patients) had received less than 5, 6-10, and more than 10 courses, respectively. Lumbar spine BMD and body composition were measured using dual energy X-ray absorptiometry of lumbar spine (L2-L4), and volumetric bone mineral density (vBMD) values were calculated and compared with the controls. The z score of the vBMD was also calculated and compared in the patients of each other groups. Serum markers of the bone turnover were measured to exclude other factors that could effect BMD. RESULTS: The vBMD values of the patients, corrected BMDs for age, were significantly lower than the values of controls (P = 0.018). It was significantly lower in group 3 than groups 1 and 2 (P = 0.005 and P = 0.006, respectively), but there was no statistically significant difference between groups 1 and 2 (P = 0.87). The vBMD z scores were significantly lower in group 3 than in groups 1 and 2 (P = 0.003 and P = 0.004, respectively), and also in group 2 than in group 1 (P = 0.034). There were a weak negative correlation between the cumulative dose of HDMP and vBMD (r = -0.39, P = 0.054), and strong negative correlation between the cumulative dose of HDMP and vBMD z score (r = -0.63, P = 0.001). CONCLUSION: Children with chronic ITP are at risk for decreased BMD because of the repeated courses of HDMP; especially more than 2100 mg of cumulative dose. We therefore recommend that BMD should be monitored in patients with chronic ITP who received repeated courses of HDMP.

Intracoronary versus intravenous injection of 99mTc-tetrofosmin: comparison of myocardial perfusion patterns and wall motion.

OBJECTIVES: The accuracy of viability and defect size detection by Tc-tetrofosmin has been discussed by several authors. The lower myocardial extraction fraction of the latter compared with Tc-sestamibi or Tl has often been emphasized. We hypothesized that the intracoronary (i.c.) injection of tracer activity, i.e. higher than that theoretically achievable in the case of intravenous (i.v.) administration, could demonstrate the clinical relevance of this finding intra-individually. In this study, myocardial perfusion images obtained after tracer injection down the infarct-related artery were compared with i.v. injection images in the same patients. The trial also provided us with the opportunity to compare the wall motion values calculated using conventional Tc-tetrofosmin gated single-photon emission computed tomography (SPECT) studies with those obtained using optimal target/background ratios after i.c. injection. METHODS: Fourteen patients with acute myocardial infarction, no history of previous cardiac events, single vessel disease and no visible collaterals in the coronary arteriogram were included in the study. Electrocardiogram gated SPECT was carried out separately after i.c. and i.v. injections of the tracer within 5-7 days following thrombolytic therapy. Myocardial perfusion patterns were compared by contingency table analysis after semi-quantitative visual scoring. Segmental wall motion was compared using quantified polar map data in a subset of patients (eight of 14) with normal to moderately hypoperfused myocardium supplied by the left coronary artery. RESULTS: Visual perfusion scores of both studies showed good concordance (kappa, 0.70), with complete agreement in 94 of 119 segments. Nearly all of the discordant segments (24 of 25) were mildly better scored in i.c. studies than in i.v. studies. The mean wall motion values calculated on polar maps of 78 segments for i.c. and i.v. studies were 8.4 +/- 1.2 mm and 8.2 +/- 1.3 mm (mean Delta wall motion=0.23 mm), respectively. High segmental wall motion correlation was observed (R=0.90; P<0.0001). CONCLUSION: It can be concluded that infarct-related myocardial perfusion scores obtained after i.c. and i.v. injections of Tc-tetrofosmin compare favourably, with a total agreement rate of 79%. However, the additional information obtained in 21% of the total number of myocardial segments by i.c. injection may indicate a mild underestimation of myocardial viability by i.v. injection. Conventional gated SPECT using i.v. Tc-tetrofosmin was demonstrated to be a reliable technique in the detection of true wall motion.

Scintigraphic patterns in patients with subclinical hyperthyroidism.

The occurrence of suppressed thyroid stimulating hormone (TSH) levels in the presence of normal free thyroxine (fT4) and free triiodothyronine (fT3) is not rare. Although this entity may be defined as "subclinical hyperthyroidism", many patients presented with the above laboratory findings, suffer from non-specific signs and symptoms that could be related to hyperthyroidism. The aim of this study was to evaluate this entity using the standard method of radionuclide thyroid imaging by (99m)Tc-pertechnetate ((99m)TcO(4)(-)). Fifty-two patients (18 males; mean age: 45+/-9 years and 34 females; mean age: 43+/-11 years) with suppressed serum TSH levels and normal fT3 and fT4 levels, who were referred to our nuclear medicine department for thyroid scintigraphy were prospectively included in the study. Any thyroidal or non-thyroidal medication, thyroid surgery or non-thyroidal diseases constituted the main exclusion criteria. Thyroid scintigraphy was performed 15 min after the i.v. injection of 111 MBq (99m)TcO(4)(-) using a pinhole collimator. Scintigraphic findings were visually evaluated. All patients had normal serum levels of fT4 (mean value 1.53+/-0.14 ng/dl, normal range: 0.89-1.8 ng/dl) and fT3 (mean value 3.9+/-0.17 ng/dl, normal range: 2.3-4.2 ng/dl). Mean value of serum TSH levels was 0.09+/-0.12 microIU/ml (normal range: 0.35-5.5 microIU/ml). The above hormones were tested by the chemiluminescent method. Patients showed seven different scintigraphic patterns in their thyroid scintigrams as follows: hyperactive+hypoactive multinodular goiters, 27%; hyperactive multinodular goiters, 23%; hypoactive multinodular goiters, 15%; solitary hypoactive nodular glands, 14%; normal glands, 9%; solitary hyperactive nodular glands, 8%; and diffuse hyperactive glands, 4%. All but two patients (50/52 = 96%) showed mild to moderate hyperplasia of the thyroid gland. It is concluded that most patients with subclinical hyperthyroidism, (96%) show mild to moderate hyperplasia of the thyroid, and many (65%) show multinodularity with at least one hyperactive nodule.

Comparison of gated planar Tc-99m tetrofosmin scintigraphy with radionuclide ventriculography and echocardiography in the evaluation of left ventricular wall motion.

Assessment of ventricular function is an important diagnostic and prognostic tool in coronary heart disease (CHD). The objective of this study was to compare radionuclide ventriculography (RVG), echocardiography (ECHO) and gated planar tetrofosmin myocardial scintigraphy (GPTF) in patients with CHD. Radionuclide ventriculography in left anterior oblique (LAO) and left lateral (LLT) projections was performed in 44 patients. Two days later, rest tetrofosmin perfusion tomoscintigraphy (SPECT) and rest GPTF in RVG identical parameters and projections were acquired. Within the two following days, the patients underwent two-dimensional ECHO. GPTF studies were processed and interpreted in original (NI-GPTF) and image inverted, RVG like form (I-GPTF). All visual interpretations were evaluated with a semi-quantitative scoring system. Quantitative analysis was performed on parametric images by means of segmental regions of interest. Linear regression and contingency analysis were carried out in overall analysis and on a segmental basis separately by accepting the RVG as the standard for the whole investigation. In overall cine-mode evaluation, NI-GPTF (r = 0.77, p < 0.001, complete agreement (CA) = 84%) was superior to I-GPTF (r = 0.73, p < 0.001, CA = 82%) and ECHO (r = 0.39, p < 0.001, CA = 78%), compared to RVG. On a segmental basis, NI-GPTF showed the best RVG-correlations except for inferoapical, mid-inferior, mid-anterior and anterobasal segments. In visual analysis of functional images, the best RVG-agreement was observed in I-GPTF (r = 0.72, p < 0.001, CA = 77%). On a segmental basis, I-GPTF showed the best RVG-correlations except for posterolateral, mid-inferior, mid-anterior and anterobasal segments. In overall quantitative evaluation, amplitude values in both I-GPTF (r = 0.76, p < 0.001) and NI-GPTF (r = 0.75, p < 0.001) studies were well correlated with RVG amplitude. I-GPTF gave the best RVG-correlation of phase (r = 0.59, p < 0.001). The mean phase and standard deviation RVG-correlations of I-GPTF were r = 0.92, p < 0.001 and r = 0.53, p < 0.001 respectively. In segmental quantification, amplitude values of all segments in I-GPTF were better RVG-correlated than in NI-GPTF. In conclusion, GPTF could be a time saving alternative to ECHO in the evaluation of wall motion by the nuclear medicine physician. Because of differing segmental RVG correlations, NI-GPTF and I-GPTF should be both interpreted to improve the diagnostic value of the method. Cine-mode and parametric image interpretations in GPTF studies should be done simultaneously since the former is more closely correlated to RVG.