Cristina Lavini

A Prospective Cohort Study on Sustained Effects of Low-Dose Ecstasy Use on the Brain in New Ecstasy Users

It is debated whether ecstasy use has neurotoxic effects on the human brain and what the effects are of a low dose of ecstasy use. We prospectively studied sustained effects (>2 weeks abstinence) of a low dose of ecstasy on the brain in ecstasy-naive volunteers using a combination of advanced MR techniques and self-report questionnaires on psychopathology as part of the NeXT (Netherlands XTC Toxicity) study. Outcomes of proton magnetic resonance spectroscopy (1H-MRS), diffusion tensor imaging (DTI), perfusion-weighted imaging (PWI), and questionnaires on depression, impulsivity, and sensation seeking were compared in 30 subjects (12M, 21.8±3.1 years) in two sessions before and after first ecstasy use (1.8±1.3 tablets). Interval between baseline and follow-up was on average 8.1±6.5 months and time between last ecstasy use and follow-up was 7.7±4.4 weeks. Using 1H-MRS, no significant changes were observed in metabolite concentrations of N-acetylaspartate (NAA), choline (Cho), myo-inositol (mI), and creatine (Cr), nor in ratios of NAA, Cho, and mI relative to Cr. However, ecstasy use was followed by a sustained 0.9% increase in fractional anisotropy (FA) in frontoparietal white matter, a 3.4% decrease in apparent diffusion (ADC) in the thalamus and a sustained decrease in relative regional cerebral blood volume (rrCBV) in the thalamus (−6.2%), dorsolateral frontal cortex (−4.0%), and superior parietal cortex (−3.0%) (all significant at p<0.05, paired t-tests). After correction for multiple comparisons, only the rrCBV decrease in the dorsolateral frontal cortex remained significant. We also observed increased impulsivity (+3.7% on the Barratt Impulsiveness Scale) and decreased depression (−28.0% on the Beck Depression Inventory) in novel ecstasy users, although effect sizes were limited and clinical relevance questionable. As no indications were found for structural neuronal damage with the currently used techniques, our data do not support the concern that incidental ecstasy use leads to extensive axonal damage. However, sustained decreases in rrCBV and ADC values may indicate that even low ecstasy doses can induce prolonged vasoconstriction in some brain areas, although it is not known whether this effect is permanent. Additional studies are needed to replicate these findings.

Bevacizumab and dose-intense temozolomide in recurrent high-grade glioma

BACKGROUND Angiogenesis inhibition is a rational treatment strategy for high-grade glioma (HGG). Combined antiangiogenic therapy and chemotherapy could be beneficial, taking advantage of different mechanisms of antitumour activity of both therapies. We carried out a phase I-II clinical trial with the combination of bevacizumab and continuous dose-intense temozolomide (TMZ) for patients with a recurrent HGG after first- or second-line treatment. PATIENTS AND METHODS Twenty-three HGG patients were treated with bevacizumab (10 mg/kg i.v. every 3 weeks) and TMZ (daily 50 mg/m(2)), until clinical or radiological progression. Conventional and dynamic magnetic resonance imaging (MRI) were carried out on days -4, 3 and 21 and until clinical or radiological progression. RESULTS Overall response rate (20%), 6-month progression-free survival (PFS6) (17.4%), median progression-free survival (13.9 weeks) and median overall survival (OS) (17.1 weeks) were considerably lower compared with most other studies with bevacizumab-containing regimens. The dynamic MRI parameters contrast transfer coefficient and relative cerebral blood volume decreased rapidly during the early phases of treatment, reflecting changes in vascularisation and vessel permeability but not in tumour activity. In addition, >50% of patients showed oedema reduction and a reduced shift on T1 images. CONCLUSION Treatment with bevacizumab and TMZ is feasible and well tolerated but did not improve PFS6 and median OS.

MRI in Crohn's disease.

Technological developments have extended the role of MRI in the evaluation of the gastrointestinal tract. The potential of MRI to evaluate disease activity in Crohns disease has been investigated extensively, as MRI has intrinsic advantages over other techniques, including noninvasiveness and the absence of ionizing radiation. For perianal fistulizing disease MRI has become a mainstay in evaluation of disease, as localization and extent of disease can be very well appreciated using both T2‐weighted and T1‐weighted sequences, fat suppression, and intravenous contrast medium. Imaging of the small bowel and colon in Crohns disease is more complicated due to bowel peristalsis and respiratory movement. However, using fast breathhold sequences and intravenous spasmolytic medication, images of good diagnostic quality can be acquired. To obtain sufficiently distended bowel, which in our estimation is a prerequisite for evaluation of the bowel, MR enteroclysis can be performed. However, applicability of different oral contrast media has been studied, as a noninvasive method for bowel distension would be preferable. Abdominal MRI is a valuable imaging technique for evaluation of luminal, transmural, and extraintestinal manifestations of Crohns disease as degree of disease activity, presence of luminal pathology (e.g., stenoses), and extraintestinal manifestations of disease (e.g., abscesses, fistulas) can be accurately assessed. J. Magn. Reson. Imaging 2005;22:1–12.

Feasibility of evaluating Crohn's disease activity at 3.0 Tesla

To determine whether abdominal 3.0T MRI can be used for evaluation of Crohns disease (CD) compared with ileocolonoscopy (CS), and to determine patient preference for MRI as opposed to CS.

Rheumatoid Synovial Inflammation: Pixel-by-Pixel Dynamic Contrast-enhanced MR Imaging Time-Intensity Curve Shape Analysis—A Feasibility Study

PURPOSE To analyze the distribution of different shapes of time-intensity curves (TICs) in synovial tissue of patients with rheumatoid arthritis (RA) and to compare relative numbers of TIC shapes between patients with RA and healthy control subjects. MATERIALS AND METHODS This prospective study was approved by the institutional review board; patients and control subjects gave written informed consent. Dynamic contrast material-enhanced magnetic resonance (MR) imaging of the knee joint in five patients with early RA and in five control subjects was performed. Parametric maps showing seven TIC shape types were created. Spatial information of the synovial TIC shape distribution pattern and relative number of TIC shapes were calculated on a three-dimensional region of interest. Relative TIC shape numbers were compared by using a nonparametric Mann-Whitney U test. RESULTS Synovial enhancement in patients with RA consisted of type 2 TIC shapes (slow enhancement) with heterogeneous zones of types 3 (fast enhancement followed by plateau phase), 4 (fast enhancement followed by early washout phase), and 5 (fast enhancement followed by slow enhancement increase) TIC shapes, compared with almost only type 2 TIC shapes in control subjects. The heterogeneous zones were seen in the lateral and medial knee compartments and around the cruciate ligaments. A significantly higher relative number of type 4 TIC shapes was observed in the patient group compared with the control group (16.5% vs 6.9%, P = .008). CONCLUSION The pixel-by-pixel dynamic contrast-enhanced MR imaging TIC shape analysis may help distinguish patients with RA from control subjects on the basis of the relative number of type 4 TIC shapes. This study provides the rationale for future research to evaluate the utility of this approach in clinical practice.

Cerebral impairment in chronic solvent-induced encephalopathy

Worldwide, many workers experience occupational exposure to organic solvents, which may induce chronic solvent‐induced encephalopathy (CSE). Disturbances within the frontostriatothalamic (FST) circuitry might explain the symptomatology of CSE. We tested the hypothesis of FST circuitry abnormalities in CSE, as well as associations with performance of psychomotor speed, attention, and solvent exposure. To detect preclinical, solvent‐related effects, we also studied the FST circuitry in solvent‐exposed, but asymptomatic workers.

Dynamic contrast-enhanced MRI in patients with luminal Crohn's disease

OBJECTIVES To prospectively assess dynamic contrast-enhanced (DCE-)MRI as compared to conventional sequences in patients with luminal Crohns disease. METHODS Patients with Crohns disease undergoing MRI and ileocolonoscopy within 1 month had DCE-MRI (3T) during intravenous contrast injection of gadobutrol, single shot fast spin echo sequence and 3D T1-weighted spoiled gradient echo sequence, a dynamic coronal 3D T1-weighted fast spoiled gradient were performed before and after gadobutrol. Maximum enhancement (ME) and initial slope of increase (ISI) were calculated for four colon segments (ascending colon+coecum, transverse colon, descending colon+sigmoid, rectum) and (neo)terminal ileum. C-reactive protein (CRP), Crohns disease activity index (CDAI), per patient and per segment Crohns disease endoscopic index of severity (CDEIS) and disease duration were determined. Mean values of the (DCE-)MRI parameters in each segment from each patient were compared between four disease activity groups (normal mucosa, non-ulcerative lesions, mild ulcerative and severe ulcerative disease) with Mann-Whitney test with Bonferroni adjustment. Spearman correlation coefficients were calculated for continuous variables. RESULTS Thirty-three patients were included (mean age 37 years; 23 females, median CDEIS 4.4). ME and ISI correlated weakly with segmental CDEIS (r=0.485 and r=0.206) and ME per patient correlated moderately with CDEIS (r=0.551). ME was significantly higher in segments with mild (0.378) or severe (0.388) ulcerative disease compared to normal mucosa (0.304) (p<0.001). No ulcerations were identified at conventional sequences. ME correlated with disease duration in diseased segments (r=0.492), not with CDAI and CRP. CONCLUSIONS DCE-MRI can be used as a method for detecting Crohns disease ulcerative lesions.

Mapping of T1‐values and Gadolinium‐concentrations in MRI as indicator of disease activity in luminal Crohn's disease: A feasibility study

To determine the feasibility of T1‐mapping and calculation of Gadolinium‐values in luminal Crohns Disease (CD).

Midterm clinical and magnetic resonance imaging follow-up of large and giant carotid artery aneurysms after therapeutic carotid artery occlusion.

OBJECTIVEThe purpose of this study was to evaluate aneurysm size and clinical symptoms midterm after therapeutic carotid artery occlusion in 39 patients with large or giant carotid artery aneurysms. METHODSBetween January 1996 and August 2004, 39 patients with large or giant carotid artery aneurysms were treated with therapeutic carotid artery occlusion and had clinical and magnetic resonance imaging follow-up of at least 3 months (mean, 35.9 mo; median, 29 mo; range, 3–107 mo; 117 patient-yr). Initial clinical presentation was mass effect caused by the aneurysm in 32 (82%) of the 39 patients. Three patients presented with subarachnoid hemorrhage and one presented with epistaxis; two aneurysms were an incidental finding and one was additional to another ruptured aneurysm. RESULTSThere were no early or late complications of therapeutic carotid artery occlusion. All aneurysms seemed to have thrombosed completely after carotid artery occlusion as observed on early and late magnetic resonance imaging and magnetic resonance angiographic follow-up studies. At the time of the most recent magnetic resonance imaging follow-up study, 29 (74%) of the 39 aneurysms involuted totally, two aneurysms decreased to 25% of the original diameter, two aneurysms decreased to 50%, and five aneurysms decreased to 75%. Two aneurysms remained unchanged in size after 49 and 58 months, respectively. At the most recent clinical follow-up evaluation, symptoms of mass effect were cured in 19 (60%), improved in 10 (31%), and remained unchanged in three (9%) of the 32 patients. CONCLUSIONTherapeutic carotid artery occlusion was a simple, safe, and effective treatment for large and giant carotid artery aneurysms. Almost all aneurysms involute completely or substantially decrease in size. Alleviation of symptoms of mass effect was achieved in most patients.

Imaging of striatal dopamine transporters in rat brain with single pinhole SPECT and co-aligned MRI is highly reproducible.

A recently developed pinhole high-resolution SPECT system was used to measure striatal to non-specific binding ratios in rats (n = 9), after injection of the dopamine transporter ligand (123)I-FP-CIT, and to assess its test/retest reproducibility. For co-alignment purposes, the rat brain was imaged on a 1.5 Tesla clinical MRI scanner using a specially developed surface coil. The SPECT images showed clear striatal uptake. On the MR images, cerebral and extra-cerebral structures could be easily delineated. The mean striatal to non-specific [(123)I]FP-CIT binding ratios of the test/retest studies were 1.7 +/- 0.2 and 1.6 +/- 0.2, respectively. The test/retest variability was approximately 9%. We conclude that the assessment of striatal [(123)I]FP-CIT binding ratios in rats is highly reproducible.