Reduction in camera-specific variability in [(123)I]FP-CIT SPECT outcome measures by image reconstruction optimized for multisite settings: impact on age-dependence of the specific binding ratio in the ENC-DAT database of healthy controls.

PURPOSE: Quantitative estimates of dopamine transporter availability, determined with [(123)I]FP-CIT SPECT, depend on the SPECT equipment, including both hardware and (reconstruction) software, which limits their use in multicentre research and clinical routine. This study tested a dedicated reconstruction algorithm for its ability to reduce camera-specific intersubject variability in [(123)I]FP-CIT SPECT. The secondary aim was to evaluate binding in whole brain (excluding striatum) as a reference for quantitative analysis. METHODS: Of 73 healthy subjects from the European Normal Control Database of [(123)I]FP-CIT recruited at six centres, 70 aged between 20 and 82 years were included. SPECT images were reconstructed using the QSPECT software package which provides fully automated detection of the outer contour of the head, camera-specific correction for scatter and septal penetration by transmission-dependent convolution subtraction, iterative OSEM reconstruction including attenuation correction, and camera-specific "to kBq/ml" calibration. LINK and HERMES reconstruction were used for head-to-head comparison. The specific striatal [(123)I]FP-CIT binding ratio (SBR) was computed using the Southampton method with binding in the whole brain, occipital cortex or cerebellum as the reference. The correlation between SBR and age was used as the primary quality measure. RESULTS: The fraction of SBR variability explained by age was highest (1) with QSPECT, independently of the reference region, and (2) with whole brain as the reference, independently of the reconstruction algorithm. CONCLUSION: QSPECT reconstruction appears to be useful for reduction of camera-specific intersubject variability of [(123)I]FP-CIT SPECT in multisite and single-site multicamera settings. Whole brain excluding striatal binding as the reference provides more stable quantitative estimates than occipital or cerebellar binding.

Implementation of the European multicentre database of healthy controls for [(123)I]FP-CIT SPECT increases diagnostic accuracy in patients with clinically uncertain parkinsonian syndromes.

PURPOSE: Even though [(123)I]FP-CIT SPECT provides high accuracy in detecting nigrostriatal cell loss in neurodegenerative parkinsonian syndromes (PS), some patients with an inconclusive diagnosis remain. We investigated whether the diagnostic accuracy in patients with clinically uncertain PS with previously inconclusive findings can be improved by the use of iterative reconstruction algorithms and an improved semiquantitative evaluation which additionally implemented a correction algorithm for patient age and gamma camera dependency (EARL-BRASS; Hermes Medical Solutions, Sweden). METHODS: We identified 101 patients with inconclusive findings who underwent an [(123)I]FP-CIT SPECT between 2003 and 2010 as part of the diagnostic process of suspected PS at the University of Munich, and re-evaluated these scans using iterative reconstruction algorithms and the new corrected EARL-BRASS. Clinical follow-up was obtained in 62 out of the 101 patients and constituted the gold standard for the re-evaluation to assess the possible improvement in diagnostic accuracy. RESULTS: Clinical follow-up confirmed the diagnosis of PS in 11 of the 62 patients. In patients in whom both visual and semiquantitative analysis showed concordant findings (48 patients), a high negative predictive value (93 %), positive predictive value (100 %) and accuracy (94 %) were found, and thus a correct diagnosis was obtained in 45 of the 48 patients. Among the 14 patients with discordant findings, the additional semiquantitative analysis correctly identified all five of nine patients patients without PS by nonpathological semiquantitative findings in visually pathological or inconclusive scans. In contrast, four of the remaining five patients with decreased semiquantitative values but visually normal scans did not show a PS during follow-up. CONCLUSION: The age-corrected and camera-corrected mode of evaluation using EARL-BRASS provided a notable improvement in the diagnostic accuracy of [(123)I]FP-CIT SPECT in PS patients with previously inconclusive findings. The gain in accuracy might be achieved by better discrimination between physiological low striatal [(123)I]FP-CIT binding due to age-related loss of the dopamine transporter or pathological loss of binding.

Liver schwannoma incidentally discovered in a patient with breast cancer.

BACKGROUND: Benign schwannomas, also referred to as neurilemomas, neurinomas, and perineural fibroblastomas, are encapsulated nerve sheath tumors. Primary schwannomas of the liver are extremely rare. We present a case of liver schwannoma, incidentally found in a patient with breast cancer. CASE: A 66-year-old female consulted her physician for a mass she palpated on her left breast. The abdominal ultrasonography (USG) revealed a 44 x 28 mm mass in the medial segment of the left lobe of her liver suspicious of a metastasis. An USG-guided biopsy was performed and the histo-pathological examination revealed a "peripheral nerve sheath tumor". Positron emission tomography (PET-CT) revealed a pathologic FDG uptake in the lesion that was previously defined in the liver. The tumor resected from the liver was 5 x 4 x 3 cm, yellowish, soft, and capsulated tumor. Microscopic examination revealed that the mass consisted of bundles of spindle cells with hypercellular and hypocellular areas. In immunohistochemistry, there was a strong positive staining for S-100. The tumor was diagnosed as benign liver schwannoma. CONCLUSION: Schwannomas are benign, encapsulated neoplasms. Symptoms and signs vary depending on the anatomical site and the size of the neoplasm; however, most schwannomas present as an asymptomatic or painless mass. Recurrence is unusual, despite of an incomplete removal, and malignant transformation is exceedingly rare (Fig. 4, Ref. 8). Full Text (Free, PDF) www.bmj.sk.

Brain single photon emission computed tomographic evaluation of patients with childhood absence epilepsy.

This study was performed to determine the utility of 99mTc-hexamethylpropylenamine oxime (HMPAO) brain single photon emission computed tomography (SPECT) in evaluating patients with childhood absence epilepsy. Twenty-three patients (13 female, 10 male), aged 7 to 15 years (mean age 10.3 +/- 2.2), were studied. All patients underwent a detailed neurologic examination, interictal and ictal electroencephalography (EEG), computed tomography, and/or magnetic resonance imaging, and SPECT. The baseline study was performed during the interictal period and the activation study was performed on a separate day while the patients were having seizures provoked by hyperventilation. Their EEGs were monitored at the same time. Transaxial, sagittal, and coronal slices were obtained for both studies. The mean counts per pixel were calculated on 11 regions of interest on three representative transaxial slices. Count density was calculated for each region. Region-to-occipital cortex ratios were obtained. For each region, normalized ratios were used to obtain a side-to-side percent asymmetry index between baseline and activation studies. Visual interpretation of the baseline study showed that 10 of the 23 patients had a detectable abnormality in regional cerebral blood flow during the interictal period. These abnormalities consisted of relative hypoperfusion in the frontal lobes that could involve neighboring parietal and temporal regions. The activation study revealed that 13 of 23 patients had relative hyperperfusion in these brain regions that were relatively hypoperfused in the baseline study. These hyperperfused regions occupied larger areas than baseline hypoperfused regions. All patients had global increased perfusion in the ictal study. The side-to-side asymmetry indexes for these visually interpreted regional cerebral blood flow abnormalities ranged from 2 to 6%. The relatively consistent pattern of frontal regional cerebral blood flow alterations suggests that altered frontal lobe functions can be implicated in patients with childhood absence epilepsy.

Effects of diuretics on iodine uptake in non-toxic goitre: comparison with low-iodine diet.

Low-iodine diet has been employed to achieve iodine depletion prior to radioiodine (RI) therapy. However, treatment with diuretics may be more effective than low-iodine diet in causing iodine depletion and subsequent increase in RI uptake by the thyroid. Fifty-five patients with non-toxic goitre were given 0.20 MBq RI p.o. on the first day of the study and thyroid uptake was measured. In 15 patients, a low-iodine diet was started and continued for 14 days. The remaining 40 patients received furosemide 40 mg/day orally for 5 days with an unrestricted diet. On the 15th day of the study, all patients were given 0.20 MBq RI p.o. and thyroid RI uptake was measured again. Additionally, 24-h urinary iodine excretion and RI clearance were measured on the 1st and 6th days in 21 patients from the furosemide group and on the 1st and 15th days in eight patients from the diet group. Furosemide administration led to a 58.40% increase in iodine uptake over the baseline value, which was significantly higher than the increase caused by low-iodine diet (17.22%) ( P<0.0001). Urinary excretion of RI decreased in both groups similarly (furosemide, 29.45%; low-iodine diet, 21.06%; P=0.33). Iodine clearance also decreased in each group similarly (10.61% vs 7.53%, P=0.53). Treatment with furosemide prior to administration of RI increases the uptake of RI by the thyroid more effectively than does low-iodine diet.