Negative association of pretreatment cigarette use with smoking-induced striatal dopamine release in smokers receiving bupropion treatment.

BACKGROUND AND OBJECTIVES: In an effort to help identify factors that maintain heavy smoking, this study tested the association of pretreatment cigarette use (cigarettes per day) with striatal dopamine release during smoking-cessation treatment. METHODS: Thirteen regular smokers (≥10 cigarettes per day) were evaluated on parameters of smoking behavior, and they entered a smoking cessation treatment protocol, including bupropion administration and individual counseling for 2 months. On week 7 of treatment, 10 of the participants underwent brain scans using [(11) C]raclopride with positron emission tomography to assess smoking-induced dopamine release in the caudate nucleus and putamen, inferred from changes in dopamine D2 -type receptor availability. RESULTS: Receptor availability, measured as binding potential referred to non-displaceable uptake (BPND ) in both striatal regions re-demonstrated a significant decrease after smoking a cigarette; and pre-treatment cigarette use significantly negatively correlated with smoking-induced dopamine release in the caudate. CONCLUSIONS AND SIGNIFICANCE: The negative association of cigarette use with dopamine release suggests tolerance or down-regulation of the dopamine system by chronic smoking, or a pre-existing condition that promotes more frequent smoking. This association should be regarded as preliminary evidence that warrants verification. (Am J Addict 2016;25:486-492).

Gated blood pool SPECT: The estimation of right ventricular volume and function is algorithm dependent in a clinical setting.

BACKGROUND: Gated blood pool SPECT (GBPS) requires further validation for the assessment of the right ventricle (RV). This study evaluated three algorithms: BP-SPECT, QBS, and TOMPOOL (results are referred using this order). We compared (1) their "quantitative-accuracy": estimation of RV ejection fraction (EF), end-diastolic volume (EDV), and cardiac output (CO); (2) their "qualitative-accuracy": threshold values allowing diagnosing an impairment of the RV function; (3) their reproducibility: inter-observer relative variability (IOV). METHODS AND RESULTS: Forty-eight consecutive patients underwent GBPS. Recommended reference standards were used: cardiac magnetic resonance imaging (CMR) (EDV, EF, n = 48), catheter measurements from thermodilution (TD) (CO, n = 25). (1) "Quantitative-accuracy": r = 0.42, 0.30, 0.42 for RVEF (CMR); r = 0.69, 0.77, 0.53 for RVEDV (CMR); 0.32, 0.36, 0.52 for RCO (TD). (2) "Qualitative-accuracy": optimal thresholds were 54.7%, 38.5%, 45.2% (AUC: 0.83, 0.80, 0.79) for RVEF; 229, 180, 94 mL (AUC: 0.83, 0.81, 0.81) for RVEDV; 4.1, 4.4, 2.6 L·minute(-1) (AUC: 0.73, 0.77, 0.80) for RCO. (3) Reproducibility: IOV was 5% ± 6%, 8% ± 12%, 17% ± 18% for RVEF; 6% ± 8%, 4% ± 4%, 21% ± 18% for RVEDV; 8% ± 8%, 11% ± 15%, 24% ± 20% for RCO. CONCLUSION: Diagnostic accuracies are similar. A CMR-based calibration is required for a quantitative-analysis (cautious interpretation) or an accurate qualitative analysis (thresholds must be adjusted). Automatic procedures (BP-SPECT, QBS) offer the best compromise accuracy/reproducibility.

Nonsurgical giant cell tumour of the tendon sheath or of the diffuse type: are MRI or 18F-FDG PET/CT able to provide an accurate prediction of long-term outcome?

PURPOSE: To investigate whether MRI (RECIST 1.1, WHO criteria and the volumetric approach) or (18)F-FDG PET/CT (PERCIST 1.0) are able to predict long-term outcome in nonsurgical patients with giant cell tumour of the tendon sheath or of the diffuse type (GCT-TS/DT). METHODS: Fifteen "nonsurgical" patients with a histological diagnosis of GCT-TS/DT were divided into two groups: symptomatic patients receiving targeted therapy and asymptomatic untreated patients. All 15 patients were evaluated by MRI of whom 10 were treated, and a subgroup of 7 patients were evaluated by PET/CT of whom 4 were treated. Early evolution was assessed according to MRI and PET/CT scans at baseline and during follow-up. Cohen's kappa coefficient was used to evaluate the degree of agreement between PERCIST 1.0, RECIST 1.1, WHO criteria, volumetric approaches and the reference standard (long-term outcome, delay 505 ± 457 days). The response rate in symptomatic patients with GCT-TS/DT receiving targeted therapy was also assessed in a larger population that included additional patients obtained from a review of the literature. RESULTS: The kappa coefficients for agreement between RECIST/WHO/volumetric criteria and outcome (15 patients) were respectively: 0.35 (p = 0.06), 0.26 (p = 0.17) and 0.26 (p = 0.17). In the PET/CT subgroup (7 patients), PERCIST was in perfect agreement with the late symptomatic evolution (kappa = 1, p < 0.05). In the treated symptomatic group including the additional patients from the literature the response rates to targeted therapies according to late symptomatic assessment, and PERCIST and RECIST criteria were: 65 % (22/34), 77 % (10/13) and 26 % (10/39). CONCLUSION: (18)F-FDG PET/CT with PERCIST is a promising approach to the prediction of the long-term outcome in GCT-TS/DT and may avoid unnecessary treatments, toxicity and costs. On MRI, WHO and volumetric approaches are not more effective than RECIST using the current thresholds.

Is TOMPOOL (gated blood-pool SPECT processing software) accurate to diagnose right and left ventricular dysfunction in a clinical setting?

BACKGROUND: The assessment of right ventricular function is crucial for management of heart disease. TOMPOOL is a software that processes data acquired with Tomographic Equilibrium Radionuclide Ventriculography. In this report, TOMPOOL's diagnostic accuracy and inter-observer reproducibility were assessed in a cohort of patients with various etiologies of ventricular dysfunction. METHODS AND RESULTS: End-diastolic volume (EDV), ejection fraction (EF), and cardiac output (CO) were calculated for the right ventricle (RV) and the left ventricle (LV) using TOMPOOL in 99 consecutive patients. Thirty-five patients underwent cardiac magnetic resonance imaging (CMR) considered as the reference-standard to measure EDV and EF; the Spearman's rho correlation coefficients were r = 0.73/0.80 and 0.67/0.73 for right/left EF and EDV, respectively. Twenty-one patients had thermodilution measurements of right CO (reference-standard), the correlation was r = 0.57. The best cut-off points (sensitivity/specificity) in order to diagnose a ventricular dysfunction or enlargement were 46% for RVEF (67%/89%), 62% for LVEF (100%/90%), 94 mL for RVEDV (77%/73%), and 84 mL for LVEDV (100%/91%). The areas under the ROC curve were, respectively, 0.79, 0.91, 0.83, and 0.99. Inter-observer reproducibility was r = 0.81/0.94, 0.77/0.90, and 0.78/0.75 for Right/Left EF, EDV, and CO, respectively. CONCLUSION: TOMPOOL is accurate: measurements of EDV, EF, and CO are reproducible and correlate with CMR and thermodilution. However, thresholds must be adjusted.

Gating, enhanced gating, and beyond: information utilization strategies for motion management, applied to preclinical PET.

BACKGROUND: Respiratory gating and gate optimization strategies present solutions for overcoming image degradation caused by respiratory motion in PET and traditionally utilize hardware systems and/or employ complex processing algorithms. In this work, we aimed to advance recently emerging data-driven gating methods and introduce a new strategy for optimizing the four-dimensional data based on information contained in that data. These algorithms are combined to form an automated motion correction workflow. METHODS: Software-based gating methods were applied to a nonspecific population of 84 small-animal rat PET scans to create respiratory gated images. The gated PET images were then optimized using an algorithm we introduce as 'gating+' to reduce noise and optimize signal; the technique was also tested using simulations. Gating+ is based on a principle of only using gated information if and where it adds a net benefit, as evaluated in temporal frequency space. Motion-corrected images were assessed quantitatively and qualitatively. RESULTS: Of the small-animal PET scans, 71% exhibited quantifiable motion after software gating. The mean liver displacement was 3.25 mm for gated and 3.04 mm for gating+ images. The (relative) mean percent standard deviations measured in background ROIs were 1.53, 1.05, and 1.00 for the gated, gating+, and ungated values, respectively. Simulations confirmed that gating+ image voxels had a higher probability of being accurate relative to the corresponding ungated values under varying noise and motion scenarios. Additionally, we found motion mapping and phase decoupling models that readily extend from gating+ processing. CONCLUSIONS: Raw PET data contain information about motion that is not currently utilized. In our work, we showed that through automated processing of standard (ungated) PET acquisitions, (motion-) information-rich images can be constructed with minimal risk of noise introduction. Such methods have the potential for implementation with current PET technology in a robust and reproducible way.

Brain activation and heart rate during script-driven traumatic imagery in PTSD: preliminary findings.

Patients with posttraumatic stress disorder (PTSD) experience psychological and physiological distress. However, imaging research has mostly focused on the psychological aspects of the disorder. Considered an expression of distress, heart rate (HR) in PTSD is often elevated. In the current study, we sought to identify brain regions associated with increased HR in PTSD. Nine patients with PTSD and six healthy trauma survivors were scanned while resting, clenching teeth, and listening to neutral and traumatic scripts. Brain function was evaluated using H2O15 positron emission tomography (PET). HR was monitored by electrocardiogram. Data were analyzed using statistical parametric mapping (SPM). Subjects with PTSD exhibited a significant increase in HR upon exposure to traumatic scripts, while trauma survivors did not. Correlations between regional cerebral blood flow and HR were found only in patients with PTSD, in orbitofrontal, precentral and occipital regions. Neither group showed correlation between rCBF and HR in the amygdala or hippocampus. These preliminary results indicate that "top down" central nervous system regulation of autonomic stress response in PTSD may involve associative, sensory and motor areas in addition to regions commonly implicated in fear conditioning.

11C-acetate PET/CT in bladder urothelial carcinoma: intraindividual comparison with 11C-choline.

OBJECTIVE: We present a first study of the use of 11C-acetate (ACET) positron emission tomography (PET)/computed tomography (CT) in bladder urothelial carcinoma (UC) and an intraindividual comparison with 11C-choline (CHOL) PET/CT. METHODS: Fourteen patients with biopsy-proven UC (11 T2, 3 T1 refractory to treatment) were prospectively evaluated before radical cystectomy and excision of pelvic lymph nodes (LNs), with ACET and CHOL PET/CT scans performed within 1 week. Image acquisition started 5 minutes after intravenous injection of 12 to 14 mCi for both tracers. Standardized uptake values (SUVs) and tumor-to-background ratios (TBR) were calculated for all tumor and nodal findings and correlated with histopathology and follow-up. RESULTS: ACET and CHOL were taken up in all UCs, involved LNs, and prostate pathology. SUVs were on average slightly, nonsignificantly higher for CHOL uptake (SUV) in UCs and significantly higher for ACET in LNs. TBR was nonsignificantly higher with CHOL for UC and significantly higher for LNs. CONCLUSIONS: In this preliminary series, 11C-ACET and 11C-CHOL PET/CT showed equivalent results in the preoperative evaluation of UC. Both tracers have the potential to contribute to selecting patients who would benefit from combined treatment--neoadjuvant chemotherapy and surgery--by identifying pathologic LNs or from surgery only, thanks to their high negative predictive value for LN involvement.

Ga-68 DOTA-NOC uptake in the pancreas: pathological and physiological patterns.

OBJECTIVE: Gallium-68 (Ga-68) DOTA-1-NaI3-octreotide (DOTA-NOC) positron emission tomography (PET)/computed tomography (CT) is increasingly used for neuroendocrine tumors (NETs), often found primarily in the pancreas. However, physiologic uptake of DOTA-NOC has been described in the uncinate process of the pancreas. We studied DOTA-NOC uptake in this organ. MATERIALS AND METHODS: Ninety-six patients underwent 103 DOTA-NOC scans, with pathology-proven pancreatic NET (n = 40) and nonpancreatic NET or biochemical suspicion of NET (n = 63). RESULTS: DOTA-NOC uptake was detected in 35 documented pancreatic tumor sites (SUV: 5.5-165; mean: 25.7 ± 28.8; median: 17.8). Among 63 cases without previous known pathology, uptake was suspicious for tumor in 24 sites (SUV: 4.7-35; mean 16.3 ± 8.0; median: 14.1), and in 38 sites, it was judged as physiological, generally lower relative to adjacent structures (SUV: 2.2-12.6; mean: 6.6 ± 2.2; median: 6.2). In 24 scans with suspected tumor and in 37 of 38 scans with physiological uptake, diagnostic computed tomography or magnetic resonance imaging or endoscopic ultrasonography failed to detect tumor. CONCLUSIONS: Pancreatic DOTA-NOC uptake must be interpreted with caution, and further studies are required.

Hyperintensities on T2-weighted images in the basal ganglia of patients with major depression: cerebral perfusion and clinical implications.

White matter hyperintensities on T2-weighted images (WMH T2-WI) are prevalent in depressed, particularly elderly, patients. In an earlier study we used structural magnetic resonance imaging (MRI) to study 37 depressed and 27 healthy control subjects to show that prevalence of WMH T2-WI is higher in depressed patients and that severity of depression and cognitive impairment is associated with presence of WMH T2-WI in basal ganglia. The occurrence of WMH T2-WI in depression may also be associated with cerebrovascular deficiency, although this association has not been adequately studied. We therefore performed single photon emission computed tomography (SPECT) with Technetium-99m hexamethylpropyleneamineoxime (Tc-99m HMPAO) as tracer in this same sample to seek an association between presence/location of WMH T2-WI and cerebral perfusion deficits. In addition, we examined the relationship between presence/location of WMH T2-WI and treatment response. We found that severely depressed, cognitively compromised patients with WMH T2-WI in the basal ganglia display more profuse cerebral perfusion deficits than less depressed patients with WMH T2-WI in other regions or with no WMH T2-WI but are not less responsive to antidepressant treatment. WMH T2-WI in depression are associated with cerebral perfusion deficits, although not necessarily located in the same regions as the MRI findings. Clinical symptoms are largely reversible even in depressed patients with WMH T2-WI in basal ganglia.

68Ga-DOTA-NOC PET/CT imaging of neuroendocrine tumors: comparison with ¹¹¹In-DTPA-octreotide (OctreoScan®).

PURPOSE: Recent data have indicated that 68Ga-DOTA-NOC positron emission tomography/X-ray computed tomography (PET/CT) may yield improved images in a shorter acquisition protocol than ¹¹¹In-DTPA-octreotide (OctreoScan®, OCT). Therefore, we performed a prospective comparison of 68Ga-DOTA-NOC and OCT for the detection of neuroendocrine tumors (NETs). METHODS: Nineteen patients (eight carcinoid, nine pancreatic NETs, and two NE carcinoma of unknown origin) with previous positive OCT scans underwent 68Ga-DOTA-NOC PET/CT and OCT single-photon emission computed tomography imaging for staging or follow-up. Findings were compared by region and verified with conventional imaging. RESULTS: All images of both modalities demonstrated focal uptake, often at multiple sites. 68Ga-DOTA-NOC images were clearer than OCT images, facilitating interpretation. Similar foci were identified with both modalities in 41 regions, with additional foci on 68Ga-DOTA-NOC in 21 and on OCT in 15 regions. CT, magnetic resonance imaging, or ultrasound confirmed the concordant findings in 31 of 41 regions and findings seen with 68Ga-DOTA-NOC only in 15 of 21 regions. Findings seen with OCT only were less clear and were only confirmed in 4 of 15 regions. 68Ga-DOTA-NOC had impact on staging in four patients and on management in three patients. CONCLUSIONS: Although 68Ga-DOTA-NOC and OCT images were similar, in this study, 68Ga-DOTA-NOC demonstrated more true positive tumor foci and was better tolerated by patients. This direct comparison supports replacement of OCT with 68Ga-DOTA-NOC-PET/CT in the evaluation of NETs.

18F-fluorodeoxyglucose-PET/CT imaging of lungs in patients with cystic fibrosis.

BACKGROUND: Airway inflammation plays a critical role in the progression of cystic fibrosis (CF) lung disease, and in the destruction of airways and lung parenchyma. Current methods to assess CF lung disease (BAL, spirometry, and high-resolution CT scanning), do not always accurately reflect actual disease states. Fluorodeoxyglucose (FDG)-PET scanning has been used previously to image infection and inflammation. In this study, we assessed the use of (18)F-FDG PET/CT scanning to evaluate and monitor lung inflammation and/or infection in patients with CF. METHODS: PET/CT scans were performed in 20 patients with CF (age range, 14 to 54 years); 7 of 20 patients underwent repeat PET/CT scans during and after acute exacerbations. The results were compared with clinical information and with images from eight control subjects with no known lung disease. RESULTS: Foci of enhanced activity were observed on FDG-PET scans of patients with CF but not those of control subjects. Higher focal activity (standardized uptake value, > 3.0) was seen during disease exacerbation and infection. Coregistered CT scan images assisted in the localization of PET foci and showed corresponding CT scan findings, with many additional findings on CT scans that were not seen on PET scans. Foci seen on high-intensity PET scans during exacerbations disappeared after antibiotic therapy and the resolution of exacerbation, while corresponding CT scan findings remained unchanged. CONCLUSIONS: PET/CT imaging demonstrated the presence of foci of enhanced uptake that may reflect active focal infectious or inflammatory processes in the lungs. These foci can be cleared with antibiotic therapy. Further studies are needed to validate these results and to determine whether FDG-PET/CT scanning can predict the nature/severity of disease in patients with CF.

Cerebral perfusion after a 2-year remission in major depression.

Although patients suffering from major depression respond to antidepressant treatment within several weeks, full reinstatement of premorbid capabilities requires much longer. Nevertheless, most research in major depression seeking the pathophysiological correlates of remission has focused upon the acute post-treatment period. Brain imaging research offers no exception. We have recently shown that cerebral perfusion in depressed patients responding to 6-wk antidepressant medication increases in parieto/cerebellar regions and becomes similar to that of healthy control subjects. We now present technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (99mTc-HMPAO SPECT) data collected from 11 of these patients 2 years in remission. Images were analysed using Statistical Parametric Mapping. After 2 years, perfusion normalization found immediately after treatment was maintained, with further increases in frontal and decreases in parieto/cerebellar regions. These findings suggest that perfusion increases in parieto/cerebellar regions may be involved in acute response to treatment whereas increases in frontal regions may be related to its consolidation.

Added value of SPECT/CT for correlation of MIBG scintigraphy and diagnostic CT in neuroblastoma and pheochromocytoma.

OBJECTIVE: In pheochromocytoma and neuroblastoma, pathologic findings on metaiodobenzylguanidine (MIBG) scintigraphy (planar and SPECT) and on diagnostic CT are sometimes difficult to correlate. Furthermore, CT reading may be impaired by anatomic distortion after surgery or irradiation and if contrast agent is not injected. The present study evaluates the impact of SPECT/CT fusion images on correlation and image analysis of both techniques. MATERIALS AND METHODS: Eleven patients, three adults (age range, 27-64 years) with pheochromocytoma and eight children (age range, 16-72 months) with neuroblastoma, underwent 15 (123)I-MIBG scintigraphy (whole body and SPECT/CT) and diagnostic CT during follow-up after treatment, with a time interval of 2 to 30 days (mean, 12 days) between MIBG scintigraphy and diagnostic CT. The diagnostic CT scans were read twice: blindly and with knowledge of the SPECT/CT findings. The scintigraphic and anatomic data were subsequently compared and were verified by clinical outcome. RESULTS: Of 15 imaging studies, there were nine cases of discordance between SPECT/CT and diagnostic CT, whereas concordant findings of planar MIBG and diagnostic CT were observed in six studies. Overall, SPECT/CT provided additional information in eight of the 15 cases (53%) and in eight of nine discordant studies (89%). In one case of pheochromocytoma in which anatomy was distorted by previous surgery and contrast agent was not injected, SPECT/CT findings guided the diagnostic CT that had initially misinterpreted the right adrenal gland as the inferior vena cava. In three of 11 studies performed for neuroblastoma, SPECT/CT facilitated the diagnostic CT reading: in one study, a small paravertebral thickening was overlooked at blind CT reading and in another case, SPECT/CT localized and characterized a soft-tissue mass medial to the iliac bone, which was missed on diagnostic CT in an area of difficult differential anatomy (bowel loops and eventual involved lymph nodes). In the third case, SPECT/CT directed the diagnostic CT to the MIBG abnormality after multiple surgical procedures. In these four cases, MIBG SPECT/CT allowed for localization of the pathologic site that was difficult to visualize on diagnostic CT. In four additional neuroblastoma studies in which a residual mass was present on diagnostic CT, planar MIBG scintigraphy was negative. SPECT/CT, focused on the area of the diagnostic CT abnormality, showed no focal MIBG uptake, thus increasing the diagnostic certainty of remission. CONCLUSION: In cases of equivocal diagnostic CT, SPECT/CT bridges the gap between MIBG scintigraphy and diagnostic CT, with guidance of the diagnostic CT and characterization of its findings. In this small series, MIBG SPECT/CT increased the diagnostic certainty in 89% of discordant studies.

Brain imaging study of the acute effects of Delta9-tetrahydrocannabinol (THC) on attention and motor coordination in regular users of marijuana.

PROCEDURE: Twelve regular users of marijuana underwent two positron emission tomography (PET) scans using [18F] Fluorodeoxyglucose (FDG), one while subject to the effects of 17 mg THC, the other without THC. In both sessions, a virtual reality maze task was performed during the FDG uptake period. RESULTS: When subject to the effects of 17 mg THC, regular marijuana smokers hit the walls more often on the virtual maze task than without THC. Compared to results without THC, 17 mg THC increased brain metabolism during task performance in areas that are associated with motor coordination and attention in the middle and medial frontal cortices and anterior cingulate, and reduced metabolism in areas that are related to visual integration of motion in the occipital lobes. CONCLUSION: These findings suggest that in regular marijuana users, the immediate effects of marijuana may impact on cognitive-motor skills and brain mechanisms that modulate coordinated movement and driving.

99mTc-HMPAO SPECT study of cerebral perfusion after treatment with medication and electroconvulsive therapy in major depression.

UNLABELLED: Compromised regional cerebral blood flow (rCBF) in major depressive disorder may be partly reversed by successful antidepressant treatment. However, it is not known if the reversal of rCBF compromise is dependent on the mode of antidepressant treatment. The current study aimed to address this question. METHODS: Thirty-three patients (19 women and 14 men; mean age +/- SD, 53 +/- 16 y) with moderate major depressive disorder were studied before 6 wk of treatment with tricyclic antidepressants, selective serotonin reuptake inhibitors, or a course of electroconvulsive therapy, and 31 of these patients were also studied afterward. A comparison group of 25 healthy volunteers (13 women and 12 men; mean age, 49 +/- 15 y) were studied once. rCBF was assessed using 99mTc-hexamethylpropyleneamine oxime SPECT. Images were analyzed using globally normalized statistical parametric mapping localized to the Montreal Neurologic Institute brain atlas. RESULTS: Baseline rCBF was lower in depressed patients than in controls in the frontal cortex and subcortical nuclei bilaterally. A response to medication was associated with normalization of rCBF deficits, whereas a response to electroconvulsive therapy was associated with an additional rCBF decrease in the parietotemporal and cerebellar regions bilaterally. CONCLUSION: Hypoperfusion in major depressive disorder largely normalizes after a response to pharmacotherapy. Perfusion changes after a response to electroconvulsive therapy may follow a different course.

Cerebral glucose utilization and platelet mitochondrial complex I activity in schizophrenia: A FDG-PET study.

Altered cerebral energy metabolism and mitochondrial dysfunction in periphery and in brain are implicated in the pathophysiology of schizophrenia. This study investigated whether cerebral glucose metabolism (rCGM) abnormalities are linked to altered mitochondrial complex I activity in the periphery, in schizophrenia. Sixteen schizophrenic patients, 8 with total positive PANSS score >or=20 (high positive schizophrenics; HPS), and 8 with total positive score

Brain SPECT study of common ground between hypothyroidism and depression.

Hypothyroidism and major depressive disorder (MDD) share neuropsychiatric features. Cerebral perfusion deficits are found in both disorders. We compared regional cerebral blood flow (rCBF) in hypothyroidism and MDD to determine if clinical similarities are mediated by common neurocircuitry. Ten hypothyroid and 10 depressed patients underwent 99mTc-HMPAO-SPECT and clinical evaluation before and after response to respective treatments. Ten healthy controls underwent a similar, single, evaluation. Before treatment, rCBF in hypothyroid and depressed patients was lower than in controls, in posterior and anterior aspects of the brain respectively. rCBF in hypothyroidism was lower than in MDD in right posterior cingulate and parieto/occipital regions, and higher in frontal, prefrontal and sub-genual regions. Reduced rCBF in pre- and post-central gyri was found in both groups. Following treatment, rCBF in depressed patients increased and normalized, but remained unchanged in hypothyroidism. Affective symptoms in hypothyroidism may be mediated by neurocircuitry different from that of major depression.

Contribution of 11C-choline positron emission tomography/computerized tomography to preoperative staging of advanced transitional cell carcinoma.

PURPOSE: Current imaging modalities for preoperative staging of advanced transitional cell carcinoma of the bladder or upper urinary tract are not sensitive for detection of metastases. This study examines the contribution of 11C-choline positron emission tomography/computerized tomography to preoperative staging of transitional cell carcinoma. MATERIALS AND METHODS: We prospectively evaluated 18 patients with 19 advanced transitional cell carcinomas (17 bladder tumors and 2 upper tract transitional cell carcinomas). All patients had computerized tomography of the chest, abdomen and pelvis negative for metastases. 11C-choline positron emission tomography/computerized tomography was performed on a Discovery ST(R) positron emission tomography/computerized tomography system. Finally 16 patients underwent radical surgery and positron emission tomography/computerized tomography images were compared to histopathological findings. Two patients were not operated on due to the findings on 11C-choline positron emission tomography/computerized tomography. RESULTS: 11C-choline uptake was found in all primary transitional cell carcinomas, with a maximum standardized uptake value of 7.3 +/- 3.2 (mean +/- SD). The series included 3 patients with refractory bladder carcinoma in situ, which was visualized in all 3, with a standardized uptake value of 6.9 +/- 5.6. In 6 patients uptake of 11C-choline in lymph nodes as small as 5 mm was visualized (standardized uptake value 3.8 +/- 1.4). Of these patients 4 underwent surgery and histopathology confirmed malignancy in 3 of 4. No additional patients with positive lymph nodes were found on histopathology. Metastases were visualized in bones with normal architecture on computerized tomography in 4 patients (standardized uptake value 5.2 +/- 1.1) and were confirmed by followup computerized tomography. CONCLUSIONS: In this small series 11C-choline positron emission tomography/computerized tomography was highly sensitive for primary and metastatic transitional cell carcinoma. Carcinoma in situ, lymph node metastases and early bony metastases were visualized. 11C-choline positron emission tomography/computerized tomography is a promising tool for preoperative staging of advanced transitional cell carcinoma.