Sensitivity of (18)F-FDG PET in evaluation of solitary pulmonary nodules.

INTRODUCTION: The solitary pulmonary nodule (SPN) may be an early sign of lung cancer. Due to the difficulties of radiological imaging techniques in differentiation of benign/malignant nodules, functional imaging techniques like PET-CT are required in patients diagnosed with SPN. The aim of this study was the evaluation of the role of PET-CT in differentiation of malignant/benign SPN by some characteristic findings in PET-CT. Moreover, among the nodules with histopathologically diagnosed as benign, malignant or metastatic, the SUVmax and Hounsfield Units (HU) of PET-CT imaging were also aimed to be compared to assess the role of PET-CT in discrimination of malignant/benign SPN. MATERIAL AND METHOD: Among the patients evaluated with PET-CT with the pre-diagnosis of pulmonary nodule or non-pulmonary malignancies, between July 2010 and January 2012, in Konya University Meram Medical School Nuclear Medicine Department, 241 patients (167 male, 74 female) diagnosed with pulmonary nodule were enrolled in the study. In visual evaluation of PET-CT of all patients, there was only one nodule in lung parenchyma. The diameter in cm, location as central or peripheral, regularity of borders, presence of calcification and HU and Maximum standardized uptake values (SUVmax) values with quantitative analysis of all nodules was recorded. The histopathological evaluation of nodules was available in 91 of those 241 patients and they were also recorded. RESULTS: In comparison of mean SUVmax values in regards to the characteristic findings of nodules in PET-CT, the mean SUVmax value of patients was statistically significantly higher in patients with the nodule diameter ≥1 cm, centrally located nodules, or nodules with irregular borders. CONCLUSION: In malignant/benign differentiation of solitary pulmonary nodules with the diameter of higher than 1 cm, PET-CT plays an essential role; however, for the nodules smaller than 1 cm in diameter, in small, single metastatic nodules and some benign nodules with high SUVmax values, PET-CT may be unsatisfactory. However, it is clear that, in especially undetermined nodules, PET-CT is an important complementary tool in diagnosis.

Evaluation of osteoblastic activity around dental implants using bone scintigraphy.

OBJECTIVES: The aim of this study was to evaluate the osteoblastic activity around delay-loaded intraosseous dental implants using nuclear medicine imaging techniques. MATERIAL AND METHODS: Seven totally edentulous patients (two females and five males, between 48 and 57 years of age) were included in the study. Two implants were inserted into mandibular canine regions and removable prostheses were produced after 3 months. Whole-body bone scintigraphies with 20 mCi technetium 99m labelled methylene diphosphonate were taken from the patients before implant insertion, 3 months after implant placement just before the prostheses were made and 1 year after implant placement. Standardized count/pixel (SC/P) rates were calculated for each patient. Preimplantation SC/P values were compared with the 3- and 12-month values. Three-month values were compared with the 12-month values as well. RESULTS: SC/P rates in the third month were significantly higher (P<0.05) than preoperative values and the SC/P rates of the 12th month were significantly lower (P<0.05) than 3-month values. The SC/P rates of the 12th month were relatively higher than first scintigraphies but the difference was insignificant (P>0.05). CONCLUSIONS: Within the limitations of this study, in which delayed loading was applied, we showed that osteoblastic activity persisted more in delay loaded implants than immediate and early loading. After 1 year, there was no cellular activity around two implants and this implied that two implants were sufficient for a total prosthesis.

A new reversible ischemic neurologic deficit model in dogs.

BACKGROUND: The aim of this study was to produce an internal carotid artery (ICA) occlusion model in dogs that can be used for studying the effects of surgical revascularization procedures. MATERIAL/METHODS: After left frontoparietal craniectomy, the ICA and arterial circle of the brain were coagulated and transected, letting the middle cerebral artery be perfused by the contralateral ICA by way of the rostral cerebral artery in five mongrel dogs. Magnetic resonance imaging (MRI) and brain single-photon emission computed tomography (SPECT) were performed during the first 24 to 48 hours and 7 to 10 days after the operation. Paired t and Wilcoxon matched pair tests were used for statistics (p<0.05). RESULTS: All the dogs had postoperative hemiparesis that returned to normal after 7 to 10 days. Early MRI showed cerebral ischemia in the left parietal cortical area extending to the subcortical white matter, sparing the basal ganglion and the internal capsule. Early brain SPECT demonstrated hypoperfusion corresponding to the same area. This area became significantly restricted to a small cortical area in late MRI and SPECT images (p<0.05). CONCLUSIONS: It is concluded that, as symptoms resolved spontaneously, this model can be used as a "reversible ischemic neurological deficit" model for diagnostic imaging and pharmacological studies.

Diagnostic role of 99mTc hexamethyl-propyleneamine oxime brain single photon emission computed tomography in Sydenham's chorea.

BACKGROUND: The objective of this study was to determine whether technetium-99m hexamethyl-propyleneamine oxime (HMPAO) brain single photon emission computed tomography (SPECT) imaging is capable of detecting perfusional abnormalities in Sydenham's chorea (SC) patients and contributing to diagnosis of SC. METHODS: In this study, 17 SC patients were evaluated. HMPAO SPECT was performed on all patients at the acute phase and six of them at the recovery phase. Magnetic resonance imaging (MRI) of the brain was performed to 13 patients. SPECT images of basal ganglia and thalamus were evaluated both visually and by measuring the radioactivity uptakes. Ten subjects constituted the control group. RESULTS: HMPAO SPECT was visually evaluated as indicating hyperperfusion in the basal ganglia and thalamus in 16 patients, and evaluated as normal in one patient at the acute phase. The radioactivity uptakes of basal ganglia and thalamus of the patients at the acute phase were found statistically higher than those of the patients at the recovery phase, and also higher than those of the control group (P < 0.05). A significant difference between the radioactivity uptake of the patients at the recovery phase and those of the control group was not found (P > 0.05). Only one patient did not show any abnormality in both acute and recovery phases. MRI study did not show any abnormality in the basal ganglia and thalamus. CONCLUSION: It is suggested that brain SPECT can contribute to the diagnosis of SC as an objective tool. Resolving of the hyperperfusion at the recovery phase provides further support for the diagnosis of SC.

Inter-observer and intra-observer reproducibility of diferential Tc-99m DMSA uptake

One hundred and twenty-eight patients referred for DMSA scintigraphy were analyzed retrospectively. Two nuclear medicine specialists drew regions of interest around each kidney twice in different times. The first and the second observer's intraobserver and interobserver correlation coefficients were 0,998, 0,999, and 0,999, respectively. There was an excellent correlation (p<0,005). The mean absolute difference between the first and the second measurements of the first observer was 0,69 ñ 0,94 and the one of the second observer was 0,5 ñ 0,68. We conclude that measurement of relative renal function with Tc-99m scintigraphy is a reliable, simple and reproducible method