Bárbara Juarez Amorim

Statistical voxel-wise analysis of ictal SPECT reveals pattern of abnormal perfusion in patients with temporal lobe epilepsy

OBJECTIVE To investigate the pattern of perfusion abnormalities in ictal and interictal brain perfusion SPECT images (BSI) from patients with temporal lobe epilepsy (TLE). METHOD It was acquired interictal and ictal BSI from 24 patients with refractory TLE. BSIs were analyzed by visual inspection and statistical parametric mapping (SPM2). Statistical analysis compared the patients group to a control group of 50 volunteers. The images from patients with left-TLE were left-right flipped. RESULTS It was not observed significant perfusional differences in interictal scans with SPM. Ictal BSI in SPM analysis revealed hyperperfusion within ipsilateral temporal lobe (epileptogenic focus) and also contralateral parieto-occipital region, ipsilateral posterior cingulate gyrus, occipital lobes and ipsilateral basal ganglia. Ictal BSI also showed areas of hypoperfusion. CONCLUSION In a group analysis of ictal BSI of patients with TLE, voxel-wise analysis detects a network of distant regions of perfusional alteration which may play active role in seizure genesis and propagation.

Laterization of epileptiform discharges in patients with epilepsy and precocious destructive brain insults

Unilateral destructive brain lesions of early development can result in compensatory thickening of the ipsilateral cranial vault. The aim of this study was to determine the frequency of these bone changes among patients with epilepsy and precocious destructive lesions, and whether a relationship exists between these changes and epileptiform discharges lateralization. Fifty-one patients had their ictal / interictal scalp EEG and skull thickness symmetry on MRI analyzed. Patients were divided into three main groups according to the topographic distribution of the lesion on the MRI: hemispheric (H) (n=9); main arterial territory (AT) (n=25); arterial borderzone (Bdz) (n=17). The EEG background activity was abnormal in 26 patients and were more frequent among patients of group H (p= 0.044). Thickening of the skull was more frequent among patients of group H (p= 0.004). Five patients (9.8%) showed discordant lateralization between epileptiform discharges and structural lesion (four of them with an abnormal background, and only two of them with skull changes). In one of these patients, ictal SPECT provided strong evidence for scalp EEG false lateralization. The findings suggest that compensatory skull thickening in patients with precocious destructive brain insults are more frequent among patients with unilateral and large lesions. However, EEG lateralization discordance among these patients seems to be more related to EEG background abnormalities and extent of cerebral damage than to skull changes.

Cumulative doses of radioiodine in the treatment of differentiated thyroid carcinoma: knowing when to stop

OBJECTIVE Evaluate the efficacy of cumulative doses (CDs) of 131I-iodide therapy (RIT) in differentiated thyroid cancer (DTC). SUBJECTS AND METHODS The probability of progressive disease according to CDs was evaluated in patients < 45 years old and > 45 years old and correlated to tumor-node-metastasis (TNM), thyroglobulin values, histological types and variants, age, and zduration of the disease. RESULTS At the end of a follow-up period of 69 ± 56 months, 85 out of 150 DTC patients submitted to fixed doses RIT had no evidence of disease, 47 had stable disease and 18 had progressive disease. Higher CDs were used in the more aggressive variants (p < 0.0001), higher TNM stages (p < 0.0001), and follicular carcinomas (p = 0.0034). Probability of disease progression was higher with CDs > 600 mCi in patients > 45 years old and with CDs > 800 mCi in patients < 45 years. CONCLUSION Although some patients may still respond to high CDs, the impact of further RIT should be carefully evaluated and other treatment strategies may be warranted.

Automated Online Quantification Method for 18F-FDG Positron Emission Tomography/CT Improves Detection of the Epileptogenic Zone in Patients with Pharmacoresistant Epilepsy

Aims To assess the validity of an online method to quantitatively evaluate cerebral hypometabolism in patients with pharmacoresistant focal epilepsy as a complement to the visual analysis of the 18F-FDG positron emission tomography (PET)/CT exam. Methods A total of 39 patients with pharmacoresistant epilepsy and probable focal cortical dysplasia [22 patients with frontal lobe epilepsy (FLE) and 17 with temporal lobe epilepsy (TLE)] underwent a presurgical evaluation including EEG, video-EEG, MRI, and 18F-FDG PET/CT. We conducted the automated quantification of their 18F-FDG PET/CT data and compared the results with those of the visual-PET analysis conducted by experienced nuclear medicine physicians. For each patient group, we calculated Cohen’s Kappa coefficient for the visual and quantitative analyses, as well as each method’s sensitivity, specificity, and positive and negative predictive values. Results For the TLE group, both the visual and quantitative analyses showed high agreement. Thus, although the quantitative analysis could be used as a complement, the visual analysis on its own was consistent and precise. For the FLE group, on the other hand, the visual analysis categorized almost half of the cases as normal, revealing very low agreement. For those patients, the quantitative analysis proved critical to identify the focal hypometabolism characteristic of the epileptogenic zone. Our results suggest that the quantitative analysis of 18F-FDG PET/CT data is critical for patients with extratemporal epilepsies, and especially those with subtle MRI findings. Furthermore, it can easily be used during the routine clinical evaluation of 18F-FDG PET/CT exams. Significance Our results show that quantification of 18F-FDG PET is an informative complementary method that can be added to the routine visual evaluation of patients with subtle lesions, particularly those in the frontal lobes.

Functional electrical stimulation improves brain perfusion in cranial trauma patients.

OBJECTIVE Demonstrate brain perfusion changes due to neuronal activation after functional electrical stimulation (FES). METHOD It was studied 14 patients with hemiplegia who were submitted to a program with FES during fourteen weeks. Brain perfusion SPECT was performed before and after FES therapy. These patients were further separated into 2 groups according to the hemiplegia cause: cranial trauma and major vascular insults. All SPECT images were analyzed using SPM. RESULTS There was a significant statistical difference between the two groups related to patients ages and extent of hypoperfusion in the SPECT. Patients with cranial trauma had a reduction in the hypoperfused area and patients with major vascular insult had an increase in the hypoperfused area after FES therapy. CONCLUSION FES therapy can result in brain perfusion improvement in patients with brain lesions due to cranial trauma but probably not in patients with major vascular insults with large infarct area.

Technetium-99m-L,L-Ethylenedicysteine Is More Effective Than Technetium-99m Diethylenetriamine Penta-acetic Acid for Excluding Obstruction in Patients With Pyelocalicinal Dilation

OBJECTIVE To evaluate the utility of diuretic dynamic renal scintigraphy (DDRS) with technetium-99m-L,L-ethylenedicysteine ((99m)Tc-EC) in patients with indeterminate or possible false-positive results for urinary obstruction by technetium-99m diethylenetriamine penta-acetic acid ((99m)Tc-DTPA) DDRS. METHODS A total of 92 patients (63 male; mean age, 16.6 +/- 21.25 years) were studied, with a total of 103 kidneys presenting indeterminate (20/103) or possible false-positive results for obstruction attributable to reduced renal function or severe kidney dilation (83/103) by (99m)Tc-DTPA DDRS (<60% of radiopharmaceutical excreted in 20 minutes-half-time clearance [T(1/2)] >15 minutes). Patients were reimaged after intravenous injection of (99m)Tc-EC, with dynamic images before and after furosemide administration using the same acquisition parameters applied in the previous (99m)Tc-DTPA study. Time interval between (99m)Tc-DTPA and (99m)Tc-EC renograms was 2-64 days. The percentage of excreted material 20 minutes after furosemide was calculated using both radiopharmaceuticals, and were statistically compared using the paired samples t test. RESULTS The excretion after furosemide injection was 25.3% +/- 18.2% for (99m)Tc-DTPA and 41.2% +/- 26.1% for (99m)Tc-EC, with a statistically significant difference between both radiopharmaceuticals (P <.0001). Using (99m)Tc-EC obstruction was excluded in 36 of 103 kidneys, which excreted >60%. A total of 10 of 83 kidneys (12.0%) with an obstructive pattern by (99m)Tc-DTPA study turned out to be indeterminate by (99m)Tc-EC DDRS. There was an agreement between (99m)Tc-EC and (99m)Tc-DTPA studies in 54 of 83 kidneys with obstructive (65.1%) and in 3 of 20 (15.0%) with indeterminate patterns. CONCLUSIONS (99m)Tc-EC was more effective than (99m)Tc-DTPA for excluding obstruction, presenting less false-positive and indeterminate results. (99m)Tc-EC can substitute (99m)Tc-DTPA to evaluate patients with urinary tract dilation.

Regional CBF changes in Parkinson’s disease: the importance of functional neuroimaging analyses

Parkinson’s disease (PD) affects approximately 1% of the population over the age of 65 years. The basic clinical findings include bradykinesia, cogwheel rigidity, resting tremor and postural instability. However, the diagnosis of PD may be difficult, and it has been estimated that only 53% of patients using antiparkinsonian medication actually present with PD [1]. Thus, researchers are striving to discover the best strategies to help clinicians improve the diagnostic accuracy. Genetic and olfactory tests, magnetic resonance imaging (MRI) and dopamine transporter single-photon emission computed tomography (SPECT) images have been used in the differential diagnosis of PD. In this issue of the European Journal of Nuclear Medicine and Molecular Imaging, Hsu et al. report their interesting and unique findings using Tc-HMPAO brain SPECT perfusion imaging (BSPI) in 27 medicated PD patients, compared with an age-matched control group of 24 subjects [2]. They applied statistical parametric mapping (SPM) to the reconstructed images, which has the advantages of being operator independent and of allowing the findings to be coregistered to an MRI scan. Hsu et al. also used independent component analysis (ICA) tool to separate the “diseaserelated” components of the brain SPECT perfusion images from the “disease-unrelated” components. The authors found significant perfusion differences between the groups. ICA, in theory, increases the sensitivity for detection of perfusion abnormalities related to disease and removes artefacts and other perfusion abnormalities unrelated to PD. This is the first paper published using both SPM and ICA in the analysis of BSPI in PD patients. The authors found significant hypoperfusion in the parieto-occipital cortex, dorsolateral prefrontal cortex, insula and cingulate gyrus. The unique findings were significant hyperperfusion in the putamen, globus pallidus, thalamus, brainstem and anterior lobe of the cerebellum. Hsu et al. also performed a correlation between the BSPI findings and the clinical severity of the motor symptoms, using the motor component of the Unified Parkinson’s Disease Rate Scale (UPDRS). A negative correlation was noted between the UPDRS scores and perfusion in the insula and cingulate gyrus. The authors did not compare each clinical motor feature (akinesia, rigidity, tremor and postural instability) with the perfusion findings, nor did they explore their relationship to the mentation/behaviour/ mood component of the UPDRS scores, which could have provided interesting results. A few questions arise: Can the different perfusion patterns correlate with symptoms, especially cognitive changes, which may even be subclinical? Are there specific patterns of perfusion in PD patients which can aid in the differential diagnosis of PD, especially early in the course of disease or in its very late stages, when dementia has installed and the differential diagnosis between primary nigral degeneration versus dementia due to coincident Alzheimer’s disease (AD), vascular dementia or Lewy body dementia (LBD) becomes difficult to establish? Could functional neuroimaging help target and evaluate specific therapy in PD patients? How well can the newly emerging semi-automatic and automatic quantification tools such as Eur J Nucl Med Mol Imaging (2007) 34:1455–1457 DOI 10.1007/s00259-007-0411-8

Long term effects of manual lymphatic drainage and active exercises on physical morbidities, lymphoscintigraphy parameters and lymphedema formation in patients operated due to breast cancer: A clinical trial.

Purpose evaluate whether manual lymphatic drainage (MLD) or active exercise (AE) is associated with shoulder range of motion (ROM), wound complication and changes in the lymphatic parameters after breast cancer (BC) surgery and whether these parameters have an association with lymphedema formation in the long run. Methods Clinical trial with 106 women undergoing radical BC surgery, in the Women’s Integrated Healthcare Center—University of Campinas. Women were matched for staging, age and body mass index and were allocated to performed AE or MLD, 2 weekly sessions during one month after surgery. The wound was evaluated 2 months after surgery. ROM, upper limb circumference measurement and upper limb lymphoscintigraphy were performed before surgery, and 2 and 30 months after surgery. Results The incidence of seroma, dehiscence and infection did not differ between groups. Both groups showed ROM deficit of flexion and abduction in the second month postoperative and partial recovery after 30 months. Cumulative incidence of lymphedema was 23.8% and did not differ between groups (p = 0.29). Concerning the lymphoscintigraphy parameters, there was a significant convergent trend between baseline degree uptake (p = 0.003) and velocity visualization of axillary lymph nodes (p = 0.001) with lymphedema formation. A reduced marker uptake before or after surgery predicted lymphedema formation in the long run (>2 years). None of the lymphoscintigraphy parameters were shown to be associated with the study group. Age ≤39 years was the factor with the greatest association with lymphedema (p = 0.009). In women with age ≤39 years, BMI >24Kg/m2 was significantly associated with lymphedema (p = 0.017). In women over 39 years old, women treated with MLD were at a significantly higher risk of developing lymphedema (p = 0.011). Conclusion Lymphatic abnormalities precede lymphedema formation in BC patients. In younger women, obesity seems to be the major player in lymphedema development and, in older women, improving muscle strength through AE can prevent lymphedema. In essence, MLD is as safe and effective as AE in rehabilitation after breast cancer surgery.

18 F-Fluoride PET/CT tumor burden quantification predicts survival in breast cancer

Purpose In bone-metastatic breast cancer patients, there are no current imaging biomarkers to identify which patients have worst prognosis. The purpose of our study was to investigate if skeletal tumor burden determined by 18F-Fluoride PET/CT correlates with clinical outcomes and may help define prognosis throughout the course of the disease. Results Bone metastases were present in 49 patients. On multivariable analysis, skeletal tumor burden was significantly and independently associated with overall survival (p < 0.0001) and progression free-survival (p < 0.0001). The simple presence of bone metastases was associated with time to bone event (p = 0.0448). Materials and Methods We quantified the skeletal tumor burden on 18F-Fluoride PET/CT images of 107 female breast cancer patients (40 for primary staging and the remainder for restaging after therapy). Clinical parameters, primary tumor characteristics and skeletal tumor burden were correlated to overall survival, progression free-survival and time to bone event. The median follow-up time was 19.5 months. Conclusions 18F-Fluoride PET/CT skeletal tumor burden is a strong independent prognostic imaging biomarker in breast cancer patients.

SPG11-related parkinsonism: Clinical profile, molecular imaging and l-dopa response: SPG11-Related Parkinsonism

Background: Molecular imaging has proven to be a powerful tool to elucidate degenerated paths in a wide variety of neurological diseases and has not been systematically studied in hereditary spastic paraplegias.