Dual-phase 11C-choline PET/computed tomography in the early evaluation of prostate cancer recurrence.

PURPOSE: The aim of this study was to assess dual-phase 11C-choline PET/computed tomography (CT) for differentiating benign from malignant lesions in patients with biochemical recurrence of prostate cancer. MATERIALS AND METHODS: We prospectively studied 56 patients with prostate cancer treated by surgery (n=22) or radiotherapy (n=34) who had hypermetabolic foci on 11C-choline PET/CT determined for biochemical recurrence (prostate-specific antigen 1.23-9.9 ng/ml). We used the dual-phase technique, calculating the standardized uptake value (SUV) for early (SUVearly) and late (SUVdelay) acquisitions and the difference between the two (SUVvariation) to determine whether tracer uptake remained stable or increased (accumulative pattern) or decreased (washout pattern). We used t-tests to compare mean and receiver operating characteristic curve analysis (SUVearly/SUVdelay/SUVvariation vs. benign/malignant). RESULTS: We identified 106 hypermetabolic foci (34 local, 10 inguinal, 34 infradiaphragmatic, 14 supradiaphragmatic, and 14 in bone). We identified 34 local foci (eight after prostatectomy and 26 after radiotherapy). The eight postsurgical foci had an accumulative pattern and recurrence was confirmed (three histology, five follow-up). Of the 26 postradiotherapy foci, three had a washout pattern and follow-up ruled out recurrence; 23 had an accumulative pattern and recurrence was confirmed (14 histology, nine follow-up). The 10 inguinal foci had a washout pattern and were reactive (three histology, seven follow-up). The 34 infradiaphragmatic foci had an accumulative pattern and were malignant (34 follow-up). Of the 14 supradiaphragmatic foci, the three with a washout pattern were benign (three histology) and the 11 with an accumulative pattern were malignant (11 histology). Of the 14 foci in bone, two had a washout pattern and corresponded with signs of spondyloarthropathy. On the receiver operating characteristic curve analysis, SUVvariation best discriminated benign from malignant lesions [area under the curve (AUC)=0.993], followed by SUVdelay (AUC=0.933) and finally SUVearly (AUC=0.665). CONCLUSION: Dual-phase PET/CT with 11C-choline is technically feasible despite this tracer's short physical half-life and is useful for discriminating benign from malignant lesions. SUVvariation accurately discriminated between benign and malignant lesions.

Acute myocardial infarction: estimation of at-risk and salvaged myocardium at myocardial perfusion SPECT 1 month after infarction.

PURPOSE: To estimate at-risk and salvaged myocardium by using gated single photon emission computed tomography (SPECT) myocardial perfusion imaging after acute myocardial infarction (AMI). MATERIALS AND METHODS: The study was approved by the hospital's Ethical Committee on Clinical Trials (trial register number, PR(HG)36/2000), and all patients gave informed consent. Forty patients (mean age, 61.78 years; eight women) with a first AMI underwent two gated SPECT examinations--one before percutaneous coronary intervention (PCI) and one 4-5 weeks after PCI. Myocardium at risk was estimated by assessing the perfusion defect at the first gated SPECT examination, and salvaged myocardium was estimated by assessing the risk area minus necrosis at the second examination. Myocardium at risk was estimated by determining the discordance between the areas of left ventricular (LV) wall motion and perfusion at the second examination. Concordance between tests was analyzed by means of linear regression analysis, the Pearson correlation, the intraclass correlation coefficient, and Bland-Altman analysis. RESULTS: An improvement in perfusion, wall motion, wall thickening, and LV ejection fraction (P < .001) was observed at 1 month. At 1 month, the area with abnormal wall motion was greater than the area of altered perfusion (35.47 vs 23.1 cm(2); P = .007). The extent of myocardium at risk estimated from this discordance correlated well with myocardium at risk measured at the first gated SPECT examination and with salvaged myocardium between both studies (Pearson correlation: 0.78 and 0.6, respectively). Concordance for correct classification of patients with salvaged myocardium of 50% or greater was 83% (κ = 0.65). CONCLUSION: Myocardial perfusion gated SPECT performed 1 month after early PCI in a first AMI provides potentially useful information on at-risk and salvaged myocardium. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13122324/-/DC1.

Reversible hemichorea associated with extracranial carotid artery stenosis.

Hemichorea associated with carotid artery occlusive disease is extremely rare. It has been recently suggested that carotid artery stenosis should be considered in the differential diagnosis of chorea, even in the absence of a preceding stroke or transient ischemic attack. Although the pathophysiology of this condition is still under discussion, some reports suggest that impaired cerebral blood flow in the basal ganglia is a key contributing factor. We herein report a case of hemichorea related to severe stenosis of the left internal carotid artery with no basal ganglia lesions on brain MRI. After carotid revascularization, hemichorea gradually subsided and reversible left thalamic and putaminal hypoperfusion were demonstrated by functional neuroimaging. This case report supports the hypothesis about the central role of hemodynamic ischemia in the pathophysiology of hemichorea associated with carotid artery stenosis, and highlights the importance of vascular imaging studies for the early identification of carotid disease in patients with chorea, even in the absence of other clinical signs.

Brain perfusion correlates of visuoperceptual deficits in mild cognitive impairment and mild Alzheimer's disease.

Visuoperceptual processing is impaired early in the clinical course of Alzheimer's disease (AD). The 15-Objects Test (15-OT) detects such subtle performance deficits in mild cognitive impairment (MCI) and mild AD. Reduced brain perfusion in the temporal, parietal, and prefrontal regions have been found in early AD and MCI patients. The objectives of this study were to confirm the role of the 15-OT in the diagnosis of MCI and AD and to investigate the brain perfusion correlates of visuoperceptual dysfunction (15-OT) in subjects with MCI, AD, and normal aging. Forty-two AD, 42 MCI, and 42 healthy elderly control subjects underwent a brain Single Photon Emission Tomography (SPECT) and separately completed the 15-OT. An analysis of variance compared 15-OT scores between groups. SPM5 was used to analyse the SPECT data. 15-OT performance was impaired in the MCI and AD patients. In terms of the SPECT scans, AD patients showed reduced perfusion in temporal-parietal regions, while the MCI subjects had decreased perfusion in the middle and posterior cingulate. When MCI and AD groups were compared, a significant brain perfusion reduction was found in temporo-parietal regions. In the whole sample, 15-OT performance was significantly correlated with the clinical dementia rating scores, and with the perfusion in the bilateral posterior cingulate and the right temporal pole, with no significant correlation in each separate group. Our findings suggest that the 15-OT performance provides a useful gradation of impairment from normal aging to AD, and it seems to be related to perfusion in the bilateral posterior cingulate and the right temporal pole.

Cortical and subcortical patterns of I-123 iodobenzamide SPECT in striatal D(2) receptor parkinsonisms.

INTRODUCTION: The D(2) receptor is the most widely expressed dopaminergic receptor in the central nervous system, and it is present at the pre- and postsynaptic dopaminergic regions. It is mainly located in the neostriatum as well as in the globus pallidus, substantia nigra, cerebral cortex, thalamus, etc. The objective of this study was to analyze qualitatively and quantitatively the distribution pattern of the postsynaptic dopamine receptors through SPECT with iodobenzamide (IBZM) in patients with parkinsonism and to determine the benefit of this imaging technique in the differential diagnosis of the parkinsonian syndromes. MATERIALS: A total of 26 patients with clinical and imaging (Iodine-123 fluoropropyl-carbomethoxy-3 beta-(4-iodophenyltropane) [FP-CIT]) diagnostics of parkinsonism, to all of which a study of postsynaptic D(2) receptors with IBZM was made, were retrospectively reviewed. Of total, 12 patients were male (42.85%). The average age was 73 years old (range, 64-83 years). The patients were imaged using SPECT 2 hours after administration of I-123 Iolopride (IBZM) and their images were evaluated qualitatively and quantitatively. To measure the relative density of the D(2) receptors, the studies were registered to a common space in which the structures to be analyzed were delimited over a RM template. Caudate/frontal (C/FI) and putamen/frontal (P/FI) activity indexes were obtained. RESULTS: Of total, 10 patients presented normal IBZM uptake (C/FI of 1.23 + or - 0.13; P/FI of 1.53 + or - 0.11). The 16 studies listed as abnormal were divided into 2 degrees: (I) appearance of thalamic activity with preserved striatal uptake and (II) thalamus and frontal increased uptake with decrease of striatal activity. In the patients with abnormal patterns, the region that showed a greater reduction of uptake was the putamen (P/FI of 1.1 + or - 0.07 for degree 1, P < 0.05 and P/FI of 1.25 + or - 0.19 for degree 2, P < 0.001). For the differential diagnosis of Parkinson disease in relation to the atypical parkinsonisms, the sensitivity was 68.4% (confidence interval, 51.9-87.6) and the specificity was 57.1% (confidence interval, 20.2-88.2). The patients with Parkinson disease with longer evolution times showed a decrease of D(2) activity (3/7). CONCLUSION: The appearance of thalamic activity may be an early indicator of a decrease of D(2) striatal receptors in atypical parkinsonisms and in patients with long-term Parkinson disease.

Reserva contráctil negativa con bajas dosis de dobutamina en los pacientes con miocardiopatía isquémica estudiados mediante gated-SPECT de perfusión miocárdica / Negative contractile reserve with low-dose dobutamine in patients with ischemic cardiomyopathy investigated by gated myocardial perfusion SPECT

Introducción y objetivos. Analizar la respuesta contráctil negativa (RCN) del ventrículo izquierdo (VI) en la gated-SPECT con bajas dosis de dobutamina (BDD) en pacientes con miocardiopatía isquémica (MI). Métodos. Se estudió prospectivamente a 68 pacientes (media de edad, 60 ± 11 años; 7 mujeres) con MI mediante gated-SPECT en reposo y durante la infusión de BDD. Se relacionó la RCN (aumento de la puntuación del engrosamiento ≥ 1 unidad) con los criterios gammagráficos de viabilidad y los resultados de la coronariografía. Resultados. El 42,6% (29/68) de los pacientes presentó uno o más segmentos con RCN. En el 14,7% (n = 10) de los pacientes se observó una disminución de la fracción de eyección ≥ 4% con las BDD. Estos pacientes se caracterizaron por tener un mayor número de segmentos con RCN (2,8 ± 2,5 frente a 0,87 ± 0,4; p = 0,042), con un valor de corte en el análisis de curva ROC ≥ 2 segmentos con RCN (sensibilidad, 70%; especificidad, 74%; +LR, 2,71; -LR, 0,40). El 94% (74/79) de los segmentos con RCN correspondía a miocardio vivo (normal o viable gammagráficamente). De los 17 segmentos con acinesia o hipocinesia severa y RCN, 12 (71%) tenían criterios gammagráficos de viabilidad y en su mayoría (10/12) correspondían a territorios con arteria coronaria abierta. Conclusiones. La RCN no es un fenómeno infrecuente en los pacientes con MI y se relaciona con una disminución de la función sistólica general del VI. Mayoritariamente se observa en segmentos con criterios gammagráficos de viabilidad y dependientes de una arteria coronaria abierta (AU)

Introduction and objectives. To investigate negative contractile responses in the left ventricle during low-dose dobutamine (LDD) gated single-photon emission computed tomography (SPECT) in patients with ischemic cardiomyopathy. Methods. Sixty-eight consecutive patients (mean age, 60±11 years; 7 male) with ischemic cardiomyopathy (i.e., left ventricular ejection fraction [LVEF] ≤40%) were evaluated using gated-SPECT at rest and during LDD infusion. Associations between a negative contractile reserve (i.e., a ≥1-grade improvement in wall thickening score with LDD infusion) and scintigraphic viability criteria and coronary angiography findings were analyzed. Results. Some 42.6% (29/68) of patients had a negative contractile reserve in one or more segments. In 14.7% (n=10), the LVEF decreased by ≥4% with LDD. These patients had more segments with a negative contractile reserve (2.8±2.5 vs. 0.87±0.40; P=.042), and the cut-off value on receiver operating characteristic curve analysis was ≥2 segments with a negative contractile reserve (sensitivity 70%, specificity 74%, positive likelihood ratio 2.71, negative likelihood ratio 0.40). Some 94% (74/79) of segments with a negative contractile reserve were in viable myocardium (i.e. normal or viable on scintigraphy). Twelve of 17 segments with akinesia or severe hypokinesia and a negative contractile reserve satisfied scintigraphic viability criteria, with the majority (10/12) lying in territories supplied by a patent coronary artery. Conclusions. A negative contractile reserve was not uncommon in patients with ischemic cardiomyopathy and was associated with a general decrease in left ventricular systolic function. It was observed mainly in myocardial segments that appeared viable on scintigraphy and were supplied by a patent coronary artery (AU)

Negative contractile reserve with low-dose dobutamine in patients with ischemic cardiomyopathy investigated by gated myocardial perfusion SPECT.

INTRODUCTION AND OBJECTIVES: To investigate negative contractile responses in the left ventricle during low-dose dobutamine (LDD) gated single-photon emission computed tomography (SPECT) in patients with ischemic cardiomyopathy. METHODS: Sixty-eight consecutive patients (mean age, 60 + or - 11 years; 7 male) with ischemic cardiomyopathy (i.e., left ventricular ejection fraction [LVEF] < or = 40%) were evaluated using gated-SPECT at rest and during LDD infusion. Associations between a negative contractile reserve (i.e., a > or = 1-grade improvement in wall thickening score with LDD infusion) and scintigraphic viability criteria and coronary angiography findings were analyzed. RESULTS: Some 42.6% (29/68) of patients had a negative contractile reserve in one or more segments. In 14.7% (n=10), the LVEF decreased by > or = 4% with LDD. These patients had more segments with a negative contractile reserve (2.8 + or - 2.5 vs. 0.87 + or - 0.40; P=.042), and the cut-off value on receiver operating characteristic curve analysis was > or =2 segments with a negative contractile reserve (sensitivity 70%, specificity 74%, positive likelihood ratio 2.71, negative likelihood ratio 0.40). Some 94% (74/79) of segments with a negative contractile reserve were in viable myocardium (i.e. normal or viable on scintigraphy). Twelve of 17 segments with akinesia or severe hypokinesia and a negative contractile reserve satisfied scintigraphic viability criteria, with the majority (10/12) lying in territories supplied by a patent coronary artery. CONCLUSIONS: A negative contractile reserve was not uncommon in patients with ischemic cardiomyopathy and was associated with a general decrease in left ventricular systolic function. It was observed mainly in myocardial segments that appeared viable on scintigraphy and were supplied by a patent coronary artery.

Brain dysfunction in multiple chemical sensitivity.

Multiple Chemical Sensitivity (MCS) is a chronic acquired disorder of unknown pathogenesis. The aim of this study was to ascertain whether MCS patients present brain single photon emission computed tomography (SPECT) and psychometric scale changes after a chemical challenge. This procedure was performed with chemical products at non-toxic concentrations in 8 patients diagnosed with MCS and in their healthy controls. In comparison to controls, cases presented basal brain SPECT hypoperfusion in small cortical areas of the right parietal and both temporal and fronto-orbital lobes. After chemical challenge, cases showed hypoperfusion in the olfactory, right and left hippocampus, right parahippocampus, right amygdala, right thalamus, right and left Rolandic and right temporal cortex regions(p

Amyloid-targeted therapeutics in Alzheimer's disease: use of human albumin in plasma exchange as a novel approach for Abeta mobilization.

A clinical investigation program was carried out to replace endogenous albumin of patients with mild to moderate Alzheimer's disease (AD) with 5% Human Albumin Grifols(R) through a plasma exchange (PE) schedule, in order to alter the dynamic equilibrium between albumin-bound Abeta in plasma and Abeta in cerebrospinal fluid. In a pilot proof-of-concept study, 7 patients underwent 6 PE in 3 weeks and 1 year of follow-up. Plasma Abeta determinations demonstrated a variation pattern in levels in relation with the PEs. Cognitive status scores (MMSE and ADAS-Cog) were more stable than expected. In a phase II clinical trial, 29 patients were randomized into PEtreated and control groups with 1 year follow-up. Interim results point toward the occurrence of Abeta40 mobilization in the PE-treated patients, who scored better in cognitive tests (differences at 9 months: 2.5 in MMSE and 5.5 in ADAS-cog). These results suggest that a PE program with 5% Human Albumin Grifols may have a promising role in the treatment of mild to moderate AD.

Thallium-201SPECT assessment in the detection of recurrences of treated gliomas and ependymomas.

INTRODUCTION: The aim of this study was to establish the value of thalium-(201) single-photon emission computed tomography ((201)Tl-SPECT) in the detection of recurrences in the follow-up of patients with treated primary neuroepithelial tumours. MATERIAL AND METHODS: Sixty-three (201)Tl-SPECT were performed in 36 patients with glioma (12 males, mean age of 46 +/- 13 years). All patients underwent surgery and adjuvant radiotherapy (and some of them received chemotherapy). All patients were submitted to morphological neuroimaging techniques as well (and (201) Tl-SPECT). Mean follow-up was 18.3 +/- 14.6 months. Gold standard was based on clinical follow-up, therapeutical decisions (at least 4 months after (201)Tl-SPECT) and imaging features. RESULTS: Sensitivity and specificity of (201)Tl-SPECT to detect glioma recurrences were 90% and 100% respectively and 93% accuracy. Sensitivity and specificity for high grade tumours, were 100% respectively. Due to 4 false negatives, sensitivity and specificity for low grade gliomas were 78% and 100%. In the positive (201)Tl-SPECT group of patients overall survival was 13.64% at the end of the study. The negative (201)Tl-SPECT group had 84.62% overall survival at the end of the study (p = 0.0003). CONCLUSIONS. (201)Tl-SPECT is a valuable and noninvasive diagnostic procedure to detect recurrence or progression disease for treated gliomas and ependymomas. (201)Tl-SPECT has a good correlation with short term prognosis with excellent diagnostic accuracy.