We present an asymptomatic patient with history of prolonged hemodialysis through right internal jugular vein catheter which was compatible with SVC obstruction during 99mTc-DTPA renal transplant scintigraphy. During the angiographic phase in anterior view of the abdomen an unusual pattern of vascular filling was observed. Angioscintigraphic imaging of the chest wall was suggestive of superior vena cava obstruction. The cause of SVC obstruction in our patient is long-term indwelling catheter in the central venous system, which is a known complication of this procedure. There are also evidences of hypercoagulability state in dialyzed uremic cases, which made the patient more susceptible for development of SVC thrombosis. Acquired compensatory dilatation of the azygos vein is rather a rare finding.
To our knowledge, this is the first report describes an asymptomatic patient with SVC obstruction suspected on renal scintigraphy.

Extrapulmonary primary small cell carcinomas (EPSSC) arising from urogenital tract is uncommon. It can rarely arise from the prostate and even more rarely from seminal vesicles. We present the case of a 79 year-old male who was admitted with acute renal failure on the background of treated prostate adenocarcinoma with radical radiotherapy 13 years prior. The prostate specific antigen (PSA) level was not elevated. CT scan of abdomen and pelvis showed markedly enlarged seminal vesicles causing bilateral ureteric obstruction and mildly enlarged prostate. Further evaluation with 18F-FDG PET/CT demonstrated extensive 18F-FDG uptake in the pelvis with diffuse involvement of both seminal vesicles and the prostate without suspicious uptake in the lungs or elsewhere in the body. Core biopsies of the prostate and both seminal vesicles showed diffuse involvement by small cell carcinoma. Therapy could not be instituted due to a rapid terminal deterioration in the patient’s clinical condition.

INTRODUCTION: Detection of primary tumor site in patients with Carcinoma of Unknown Primary (CUP) syndrome has always been a diagnostic dilemma, necessitating extensive workup. Early detection of primary tumor site coupled with specific therapy improves prognosis. The low detection rate of the primary tumor site can be attributed to the biological behavior or very small tumor size of primary tumor to be picked up by the conventional imaging. Study objective is to evaluate the diagnostic accuracy of 18F-FDG PET-CT in carcinoma of unknown primary.
METHODS: Retrospective, cross-sectional analysis of 100 PET-CT scans in patients with CUP syndrome -enrolled between October 2009 and December 2013. Eighteen patients were excluded from analysis whose final histopathology was not available for correlation. The hypermetabolic sites were assessed in correlation with histopathology. Diagnostic accuracy, sensitivity, specificity, positive predictive value and negative predictive values of PET-CT were assessed.
RESULTS: Of 82 patients, primary tumor was correctly identified by 18F-FDG PET-CT in 57.3% patients (True Positive). In 15% patients PET-CT scans results were negative for primary site localization (False Negative). While 21% were True Negative. 7.3% false positive results were found. PET-CT scan upstaged disease in 27% cases. Overall diagnostic accuracy was found to be 78%, sensitivity 80%, specificity 74%, positive predictive value 88.7% and negative predictive value 59%.

DISCUSSION AND CONCLUSION: Our data supports the utility of 18F-FDG PET-CT scan in localization and staging of carcinoma of unknown primary syndrome.

INTRODUCTION: Application of distinct PET scan reconstruction algorithms can lead to statistically significant differences in measuring lesion functional properties. We look at the influence of two-dimensional filtered backprojection (2D FBP), two-dimensional ordered subset expectation maximization (2D OSEM), three-dimensional ordered subset expectation maximization without 3D maximum a posteriori (3D OSEM) and with (3D OSEM MAP) on lesion hypoxia tracer uptake using a pre-clinical PET scanner.
METHODS: Reconstructed images of a rodent tumour model bearing P22 carcinosarcoma injected with hypoxia tracer Copper-64-Diacetyl-bis(N4-methylthiosemicarbazone) ( i.e. Cu-64 ATSM) were analysed at 10minute intervals till 60minute post injection. Lesion maximum standardized uptake values (SUVmax) and SUVmax/background SUVmean (T/B) were recorded and investigated after application of multiple algorithm and reconstruction parameters to assess their influence on Cu-64 ATSM measurements and associated trends over time.
RESULTS: SUVmax exhibited convergence for OSEM reconstructions while ANOVA results showed a significant difference in SUVmax or T/B between 2D FBP, 2D OSEM, 3D OSEM and 3D OSEM MAP reconstructions across all time frames. SUVmax and T/B were greatest in magnitude for 2D OSEM followed by 3D OSEM MAP, 3D OSEM and then 2D FBP at all time frames respectively. Similarly SUVmax and T/B standard deviations (SD) were lowest for 2D OSEM in comparison with other algorithms.
DISCUSSION AND CONCLUSION: Significantly higher magnitude lesion SUVmax and T/B combined with lower SD were observed using 2D OSEM reconstruction in comparison with 2D FBP, 3D OSEM and 3D OSEM MAP algorithms at all time frames. Results are consistent with other published studies however more specimens are required for full validation.

INTRODUCTION: This phase-I imaging study examined the imaging characteristic of 3’-deoxy-3’-(18F)fluorothymidine (18F-FLT) positron emission tomography (PET) in patients with pancreatic cancer and comparisons were made with (18F)fluorodeoxyglucose (18F-FDG). The ultimate aim is to develop a molecular imaging tool that could better define the biologic characteristics of pancreas cancer, and to identify the patients who could potentially benefit from surgical resection who were deemed inoperable by conventional means of staging.
METHODS: Six patients with newly diagnosed pancreatic cancer underwent a combined FLT and FDG PET/CT imaging protocol. The FLT PET/CT scan was performed within 1 week of FDG PET/CT imaging. Tumor uptake of a tracer was determined and compared using various techniques: statistical thresholding (Z-score =2.5), and fixed standardized uptake value (SUV) thresholds of 1.4 and 2.5, and applying a threshold of 40% of maximum SUV (SUVmax) and mean SUV (SUVmean). The correlation of functional tumor volumes (FTV) between 18F-FDG and 18F-FLT was assessed using linear regression analysis.
RESULTS: It was found that there is a correlation in functional tumor volumes due to metabolic and proliferation activity when using a threshold of SUV 2.5 for FDG and 1.4 for FLT (r = 0.9606, p < 0.05), but a better correlation was obtained when using SUV of 2.5 for both tracers (r = 0.973, p<0.05). The Z score thresholding (Z =2.5) method showed lower correlation between the FTVs (r=0.698, p-value = ns) of FDG and FLT PET.
DISCUSSION AND CONCLUSION: Different tumor segmentation techniques yielded varying degree of correlation in functional tumor values between FLT and FDG-PET images.

Nükleer tıp görüntüleme nörolojik hastalığı olan çocukların klinik yönetimine sağladığı önemli bilgiler ile katkı yapmaktadır. Medikal tedaviye dirençli epilepsi hastalarında cerrahi tedavi öncesinde epileptojenik odağın belirlenmesi pediyatrik nörolojide nükleer tıp görüntülemenin en sık endikasyonudur. Temporal lob epilepsisinde nükleer tıp görüntüleme özellikle manyetik rezonans görüntüleme bulguları normal olduğunda veya bulgular elektroensefalografi bulguları ile uyumsuz olduğunda yararlıdır. Beyin tümörü tanılı pediyatrik hastalarda nükleer tıp görüntüleme tanıda, biyopsi yerinin belirlenmesinde, tedavinin planlanmasında, rezidü/rekürren tümör ile tedaviye bağlı değişikliklerin ayırıcı tanısında ve tedaviye yanıtın değerlendirilmesinde kullanılır. Nükleer tıp görüntülemenin yararlı olduğu gösterilen diğer nörolojik hastalıklar arasında kafa travması, enflamatuvar-enfeksiyöz hastalıklar ve hipoksik-iskemik ensefalopati yer alır.

Nuclear medicine imaging can provide important complementary information in the management of pediatric patients with neurological diseases. Presurgical localization of the epileptogenic focus in medically refractory epilepsy patients is the most common indication for nuclear medicine imaging in pediatric neurology. Regarding patients with temporal lobe epilepsy nuclear medicine imaging is particularly useful when the magnetic resonance imaging findings are normal or its findings are discordant with electroencephalogram findings. In pediatric patients with brain tumors nuclear medicine imaging can be clinically helpful in diagnosis, directing biopsy, planning therapy, differentiating tumor recurrence from post-treatment sequelae, and assessment of response to therapy. Among other neurological diseases in which nuclear medicine has proved to be useful are patients with head trauma, inflammatory-infectious diseases and hypoxic-ischemic encephalopathy.

Introduction: The estimation of tissue perfusion as a haemodynamic consequence of peripheral artery disease (PAD) in diabetic patients is of great importance in management of these patients.
Method: We present a noninvasive, functional method of 99mTc-MIBI (methoxy - isobutil – isonitrile) tissue - muscle perfusion scintigraphy (TMPS) of lower limbs, which assesses tissue perfusion in basal conditions ("rest" study) and workload conditions ("stress" study). Emphasis is given on perfusion reserve (PR), as an important indicator of preservation of microcirculation and its local autoregulatory mechanisms in terms of PAD.
Case report: We present a case of a 71-year-old male diabetic patient, with skin ulcers of the right foot and an ankle-brachial index (ABI) >1.2 (0.9-1.1).
Results: TMPS of lower limbs in dynamic phase showed lower and late arterial vascularization of the right calf (RC) with lower % of radioactivity in the 1st minute: RC-66%, left calf (LC)-84%. PR had border-line value of LC-57% and lower of RC-42%.
Conclusion: Functional assessment of the haemodynamic consequences of PAD is important to evaluate advanced, as well as the initial, especially asymtpomatic form of PAD. The method used, TMPS of lower limbs, can differentiate these subtle changes on the level of the microcirculation and tissue perfusion.

INTRODUCTION: The aim of current study was to compare 180° and 360° data collection modes to measure end diastolic volume (EDV), end systolic volume (ESV) and ejection fraction (EF) of cardiac system in gated myocardial perfusion tomography.
METHODS: Number of 39 patients underwent gated myocardial perfusion tomography. SPECT data of patients’ heart were acquired by 180°, 45° left posterior oblique to 45° right anterior oblique, and 360°to obtain EDV, ESV,EF and cardiac volume changes (V1, V2, V3, V4, V5, V6, V7 and V8) throughout each cardiac cycle.
RESULTS: Results of current study indicated that there were no significant difference between 180° and 360° angular sampling to measure EDV, ESV and EF in myocardial perfusion imaging. Pattern of cardiac volume changes during a cardiac cycle measured in by 360° and 180° scans were also the same. We also observed that there is no difference in EDV, ESV and EF of groups that performed exercise to induce stress with the group who experienced stress by dipyridamole.
DISCUSSION AND CONCLUSION: As there is no difference between 180°and 360° cardiac scan to measure EDV, ESV and EF, it is recommended to use half-orbit scan to study these parameters of cardiac system because it offers more comfort to patients and shorter scanning time.