AIM:To evaluate the spatial distribution of cerebral abnormalities in cirrhotic subjects with and without hepatic encephalopathy (HE) found with magnetization transfer imaging (MTI). METHODS:Nineteen cirrhotic patients graded from neurologically normal to HE grade 2 and 18 healthy control subjects underwent magnetic resonance imaging.They gave institutional-review-board-approved written consent.Magnetization transfer ratio (MTR) maps were generated from MTI.We tested for significant differences compared to the control group using statistical non-parametric mapping (SnPM) for a voxelbased evaluation. RESULTS:The MTR of grey and white matter was lower in subjects with more severe HE.Changes were found in patients with cirrhosis without neurological deficits in the basal ganglia and bilateral white matter.The loss in magnetization transfer increased in severity and spatial extent in patients with overt HE.Patients with HE grade 2 showed an MTR decrease in white and grey matter: the maximum loss of magnetization transfer effect was located in the basal ganglia [SnPM (pseudo-)t = 17.98,P = 0.0001]. CONCLUSION:The distribution of MTR changes in HE points to an early involvement of basal ganglia and white matter in HE.
Background Aim of this study was to assess the glycosaminoglycan content in hip joint cartilage in mature hips with a history of Legg-Calvé-Perthes (LCPD) disease using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC). Methods Thirty one hips in 27 adults (mean age: 30.5±10.9 y) with LCPD in childhood were included. Mean follow-up after diagnosis was 24.5±11.4 years. Clinical symptoms and standard radiographic parameters were evaluated. dGEMRIC indices were calculated as T1Gd mean values in four coronal MRI slices medially, centrally, and laterally. For comparison, the morphologically normal appearing contra-lateral hips (21 hips) were assessed. Results The following T1Gd values for the LCPD group were noted: medial (507±100 ms), central (543±104 ms), and lateral (553±105 ms). The total T1Gd mean value was 534±104 ms. The difference between LCPD and normal hips was statistically significant only for the medial compartment (P=0.018). Conclusions Hip joint cartilage after LCPD shows a significant glycosaminoglycan loss in the medial compartment while this decrease is less apparent centrally and laterally. dGEMRIC allows direct assessment of cartilage matrix biochemistry and may depict the complex damage pattern of hip joint cartilage after LCPD spatially and qualitatively better than other radiographic methods. Level of Evidence Prognostic study, Level II-1 (retrospective study).
Introduction: The purpose of the present study was to evaluate the feasibility of delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) in the detection of cartilage changes versus morphologic imaging in the long-term course of Legg–Calvé–Perthes disease (LCPD). Methods: A total of 31 hips in 26 patients (mean age, 30.0 years; range, 18–54 years) who were diagnosed with LCPD in childhood were included. Twenty-one radiographically normal contralateral hips served as controls. dGEMRIC indices of femoral and acetabular cartilage in the weight-bearing zone. Cartilage morphology was classified on radial PD-weighted images according to the modified Outerbridge classification. Results: Mean dGEMRIC values of cartilage were significantly lower in hips after LCPD than in the radiographically normal contralateral hips (513 ± 100 ms vs. 579 ± 103 ms; P = 0.026). In 24 out of 31 LCPD hips and in 4 out of 21 radiographically normal contralateral hips, morphological cartilage changes were noted. Analysis of variance analysis revealed a significant influence of Outerbridge grading on decreased T1-values (P = 0.031). Conclusion: Our results suggest that dGEMRIC at 1.5 T is suitable to assess cartilage quality changes in the long-term follow-up after LCPD. The evaluation of biochemical cartilage quality with dGEMRIC may provide additional information about early cartilage changes occurring without visible alterations of cartilage morphology.
The purpose of this study was to evaluate the relevance for the prediction of clinical benefit of first-line treatment with erlotinib using different quantitative parameters for PET with both 18F-FDG and 3′-deoxy-3′-18F-fluorothymidine (18F-FLT) in patients with advanced non–small cell lung cancer. Methods: Data were used from a prospective trial involving patients with untreated stage IV non–small cell lung cancer. 18F-FDG PET and 18F-FLT PET were performed before and 1 (early) and 6 (late) weeks after erlotinib treatment. Several quantitative standardized uptake values (SUVs) using different definitions of volumes of interest with varying isocontours (maximum SUV [SUVmax], 2-dimensional peak SUV [SUV2Dpeak], 3-dimensional [3D] peak SUV [SUV3Dpeak], 3D isocontour at 50% of the maximum pixel value [SUV50], 3D isocontour at 50% adapted for background [SUVA50], 3D isocontour at 41% of the maximum pixel value adapted for background [SUVA41], 3D isocontour at 70% of the maximum pixel value [SUV70], 3D isocontour at 70% adapted for background [SUVA70], and relative SUV threshold level [SUVRTL]) and metabolically active volume measurements were obtained in the hottest single tumor lesion and in the sum of up to 5 lesions per scan in 30 patients. Metabolic response was defined as a minimum reduction of 30% in each of the different SUVs and as a minimum reduction of 45% in metabolically active volume. Progression-free survival (PFS) was compared between patients with and without metabolic response measured with each of the different parameters, using Kaplan–Meier statistics and a log-rank test. Results: Patients with a metabolic response on early 18F-FDG PET and 18F-FLT PET in the hottest single tumor lesion as well as in the sum of up to 5 lesions per scan had a significantly longer PFS, regardless of the method used to calculate SUV. However, the highest significance was obtained for SUVmax, SUV50, SUVA50, and SUVA41. Patients with a metabolic response measured by SUVmax and SUV3Dpeak on late 18F-FDG PET in the hottest single tumor lesion had a significantly longer PFS. Furthermore, Kaplan–Meier analyses showed a strong association between PFS and response seen by metabolically active volume, measured either in early 18F-FLT or in late 18F-FDG. Conclusion: Early 18F-FDG PET and 18F-FLT PET can predict PFS regardless of the method used for SUV calculation. However, SUVmax, SUV50, SUVA50, and SUVA41 measured with 18F-FDG might be the best robust SUV to use for early response prediction. Metabolically active volume measurement in early 18F-FLT PET and late 18F-FDG PET may have an additional predictive value in monitoring response in patients with advanced non–small cell lung cancer treated with erlotinib.
The aim was to assess the value of tumor lesion glycolysis (TLG) and tumor lesion proliferation (TLP) determined by FDG and 3'-deoxy-3'-F-fluorothymidine (FLT) PET for response prediction and prognostic differentiation in patients with advanced non-small cell lung cancer (NSCLC) treated with erlotinib.FDG-PET and FLT-PET were performed in 30 patients with untreated Stage IV NSCLC before start of therapy, 1 (early) and 6 (late) weeks after erlotinib treatment. Functional tumor volume parameters including TLG in FDG-PET and TLP in FLT-PET were measured in the sum of up to 5 lesions per scan. Metabolic response was assessed using different cutoff values for percentage changes of TLG and TLP. Absolute baseline and residual levels of TLG and TLP were used for dichotomizing the patients into 2 groups. Kaplan-Meier analysis and the log-rank test were performed to analyze the association with progression-free survival (PFS).Patients with a metabolic response measured by early changes of TLP and late changes of TLG and TLP showed a significantly better PFS than metabolically nonresponding patients. A lower cutoff value of 20% or 30% for definition of metabolic response showed better differentiation between metabolically responding and nonresponding patients in cases where the 45% cutoff value revealed no significant results. Furthermore, patients with lower absolute early and late residual TLG and TLP levels had a significantly prolonged PFS. In contrast, absolute baseline TLG and TLP levels showed no significant association with PFS.In patients with advanced NSCLC, percentage changes of TLG and TLP and absolute residual TLG and TLP levels under erlotinib treatment emerged as strong predictive factors for PFS. Our findings indicate that a cutoff value of 20% or 30% for definition of metabolic response measured by percentage changes of TLG and TLP provides suitable results for response prediction, which should be further validated.
Background T2 and T2* mapping are novel tools to assess cartilage quality. Purpose To evaluate hip cartilage quality in the long-term follow-up of patients with slipped capital femoral epiphysis (SCFE) with T2 and T2* mapping. Material and Methods Thirty-three patients (19 men, 14 women, mean age 24 ± 6.0 years, range 18–51 years) with a history of SCFE in 41 hips and 10 healthy controls (seven men, mean age 22 ± 4 years) were included. Follow-up period was 12 ± 6 (range 4–39 years) years. Coronal T2 and T2* mapping were performed on a 1.5 T scanner. T2 and T2* values of the hip articular cartilage were determined in the medial, central, and lateral portion of the hip within the weight bearing zone. Clinical symptoms including pain were assessed with the Harris hip score. Statistical analysis was performed using Mann-Whitney U test and Spearman rank sum test. Results In hips after SCFE T2 (central portion: 25.71 ms ± 4.84 ms vs. 29.71 ms ± 7.04 ms, p <0.05) and T2* (central portion: 20.76 ms ± 3.17 ms vs. 23.06 ms ± 2.68 ms, P < 0.01) of cartilage were significantly lower, compared to controls. The differences were most apparent in the lateral portion of the hip articular cartilage. Abnormal cartilage T2 and T2* were not associated with hip pain or impaired hip function. SCFE was unilateral in 23 cases (70%). In the patients' unaffected hips without SCFE, areas of significantly reduced T2 (central portion: 26.07 ms ± 4.27 ms, P < 0.05) and T2* (lateral portion: 23.23 ms ± 2.45 vs. 25.11 ms ± 3.01 ms, P < 0.05) were noted. Conclusion T2 and T2* mapping of the hip in patients after SCFE are significantly different from healthy controls and may offer additional information about cartilage quality.
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