Effect of copolymer-1 on serial gadolinium-enhanced MRI in relapsing remitting multiple sclerosis.

We examined the effect of Copolymer-1 (Cop1) on magnetic resonance (MR) imaging changes in 10 patients with relapsing-remitting multiple sclerosis (RRMS). Monthly gadolinium (Gd)-enhanced MR imaging was performed for 9 to 27 months in the pretreatment period followed by 10 to 14 additional months during Cop1 treatment. MR images were evaluated by two radiologists (F.S. and R.C.P.) masked to the scan date. We found a 57% decrease in the frequency of new Gd-enhancing lesions and in the mean area/month of new Gd-enhancing lesions in the Cop1 treatment period compared with the pretreatment period (0.92 versus 2.20 lesions per month and 22 mm2 versus 43 mm2 area/month; p = 0.1, Wilcoxon signed rank test). Percentage change in lesion load area on T2-weighted images showed a decrease in the accumulation of lesion area during treatment, which was significant for the patient group with a longer pretreatment period (p = 0.05, Friedman test). These results demonstrate a reduction in the number of new Gd-enhancing lesions and in the lesion load during Cop1 treatment compared with the preceding period without therapy and are suggestive of an effect of Cop1 on MR abnormalities observed in multiple sclerosis.

Deposition of docosahexaenoic acid (DHA) is limited in forebrain of young obese fa/fa Zucker rats fed a diet high in α-linolenic acid but devoid of DHA.

Docosahexaenoic acid (DHA) is required for neurotransmitter synthesis and learning. Conversion of α-linolenic acid (ALA) to DHA is considered adequate to support brain function in youth, but it is unknown if brain DHA can be maintained in insulin resistant states. This study investigated brain fatty acid and desaturase activities in young insulin resistant Zucker rats on diets with and without DHA. Male fa/fa and lean rats were fed diets enriched with flaxseed (FXO, ALA: 35.5% fatty acids), menhaden (MO, DHA: 9.2%) or safflower oil (SO, linoleic acid: 54.1%) for 9 weeks, n=8 per diet per genotype. Compared to lean, the 15 week old fa/fa rats were obese (56% heavier) and insulin-resistant (>18-fold in homeostasis model assessment of insulin resistance). The forebrain of fa/fa rats had higher palmitoleic (16:1n-7) and dihomo-γ-linolenic (20:3n-6) acids, and higher Δ9, Δ6 but lower Δ5 (all P≤.006) desaturase indices than lean. The Δ9 and Δ6 desaturase indices positively, while the Δ5 negatively (all P≤.01) correlated with insulin resistance. The Δ9 desaturase index positively correlated with adiposity index. The percentage of forebrain DHA of fa/fa rats was lower (P=.011) than lean rats when fed FXO diet while there was no difference (P>.05) between fa/fa and lean rats fed MO or SO diet. Thus, the alterations in the fatty acid and desaturase indices in the brain were consistent inhibited forebrain synthesis of DHA in the fa/fa rats. ALA may not have potential to effectively serve as a precursor for synthesizing DHA for youth forebrain during insulin resistance since Δ5 desaturase activity is limited.

(n-3) fatty acids reduce the release of prostaglandin E2 from bone but do not affect bone mass in obese (fa/fa) and lean Zucker rats.

Childhood obesity is prevalent and linked to the development of Type 2 diabetes mellitus (DM) and poor bone health. Some PUFA enhance bone mass and thus may improve bone health in obese children. The study objective was to determine the effects of dietary (n-6) compared with (n-3) essential PUFA and long-chain PUFA (LCPUFA) on bone in an obese and insulin-resistant state. Male fa/fa (n = 48) and lean Zucker rats (n = 48) were fed diets containing safflower oil [SO, high (n-6) PUFA], flaxseed oil [FXO, high (n-3) PUFA], or menhaden oil [MO, high (n-3) LCPUFA] for 9 wk. Measurements included the following: femur bone area (BA), mineral content (BMC), density (BMD), morphometry and ex vivo release of prostaglandin E(2) (PGE(2)); plasma osteocalcin and C-terminal telopeptides of type I collagen. Differences among groups were detected using 2-way ANOVA. Genotype effects in the fa/fa rats included lower femoral weight, length, BA, and BMC, as well as femoral head and proximal epiphysis widths compared with the lean rats, but BMD was not affected. Femur BA, BMC, and BMD did not differ among the dietary groups, but diaphysis width was elevated in the MO group and PGE(2) release was reduced by the FXO and MO diets. No genotype x diet interactions were observed. These data indicate that the fa/fa Zucker rat is at risk for low bone mass and that dietary (n-3) FA effectively reduce PGE(2) release. Whether reduced PGE(2) will support optimal peak bone mass during childhood and conserve bone mass with aging warrants investigation.

Advanced diagnostic tools: virtual colonoscopy.

Regarding new prospects in detecting polyps and cancers of the colon and the rectum, it is impossible to neglect the rising role of CT colonography, also called virtual colonoscopy (VC). The aim of this brief paper is to show the state of the art of VC as a relatively new radiological diagnostic tool, discussing techniques, applications, problems, results in the literature and prospects.

Magnetic resonance evaluation of autonomous thyroid nodules treated by percutaneous ethanol injection.

Magnetic resonance (MR) imaging was used to evaluate the effect of ultrasound-guided percutaneous ethanol injection (PEI) of autonomous thyroid nodules (ATNs). Nine patients affected with ATN (3.7-32.2 mL volume) underwent PEI (4-19 mL ethanol, subdivided in 3-6 weekly procedures). MR imaging (1.5 T) was performed before each alcoholization and 1 month after the last PEI procedure with the following parameters: T1- (550/12) and T2-weighted (2200/160) spin-echo images; 4-mm slices, 10% gap; coronal planes. A further seven patients with normal thyroid function, who had undergone PEI 6-18 months before, underwent an MR examination with the same parameters. The signal-to-noise ratio (S/N) of ATN and extranodular gland, as well as ATN volume, were evaluated on the T2-weighted images. On T1-weighted images, ATNs appeared mostly hypointense before treatment, with hyperintense areas during treatment, and were lightly hyperintense 6-18 months after treatment. S/N on T2-weighted images: extranodular gland 3.5-9.2; ATNs, before treatment 13.2-19.7, before the last procedure 7.7-11.6, 1 month after the last procedure 5.6-10.9; previously treated ATNs, 4.3-8.2. No significant volume reduction was observed with MR 1 month after the last procedure. The MR examination time was about 15 minutes. In conclusion, the effect of PEI on ATNs can be evaluated with an MR examination that is not very time consuming.

[Magnetic resonance mammography in suspected tumor recurrences]. / La mammografia con Risonanza Magnetica nelle sospette recidive tumorali.

Twenty patients with clinically suspected breast cancer recurrence underwent MRI before and after paramagnetic contrast agent administration (MR mammography, MRM), after negative (4/20), questionable (11/20) or positive (5/20) X-ray mammography (XM). Spin-echo T1-weighted images before and after the i.v. administration of Gd-DTPA (0.15 mmol/kg) were acquired at 1, 3, 5, 7 and 10 minutes. Tissue behavior was studied directly on the images (qualitative analysis) and with dynamic curves of the signal-to-noise ratio and of enhancement rate (quantitative analysis). The histologic examination was performed in all cases--18 of them by surgical excision and in two by needle biopsy only. Seven of seven recurrences exhibited early (at 1 and 3 minutes) and focal qualitative enhancement, exceeding 100% at the quantitative analysis. Twelve of thirteen non-recurrences exhibited no significant qualitative enhancement, less than 40% at the quantitative analysis, while the extant lesion exhibited multifocal delayed (at 5-10 minutes) qualitative enhancement, about 60% at the quantitative analysis, and slight bilateral diffuse enhancement (proliferative dysplasia). MRM had 100% sensitivity, 92.3% specificity, 87.5% positive predictive value and 100% negative predictive value. XM had 100%, 30.8%, 43.7% and 100%, respectively (if we consider as positive all the questionable XM cases). To conclude, MRM is confirmed as a useful imaging technique in suspected breast cancer recurrences, especially after questionable XM exams.

[The role of T2*-weighted gradient-echo magnetic resonance sequences in the study of suspected dorsal-lumbosacral vertebral metastases]. / Ruolo delle sequenze di Risonanza Magnetica gradient-echo T2*-pesate nello studio delle sospette metastasi vertebrali dorso-lombosacrali.

INTRODUCTION: Magnetic resonance (MR) imaging showed high reliability in detecting spine metastases with spin-echo (SE) sequences, T1-weighted sequences being generally more sensitive than T/-weighted ones. We investigated the value of T2*-weighted gradient-echo (GE) sequences in studying spine metastases. MATERIALS AND METHODS: Twenty patients with established diagnosis of primary carcinoma and clinically suspected thoracic and/or lumbosacral spine metastases underwent .5-T MR imaging and 99mTc-HDP bone scan. The disagreement of GET2*- versus SET2-weighted images as well as versus bone scan and the disagreement of total MR results versus bone scan results were evaluated by McNemar test. The agreement of GET2*- versus SET1-weighted images was evaluated by Cohen's kappa. RESULTS: Of a total of 111 MR signal abnormalities consistent with metastasis, 109 (98.2%) were T2*-hyperintense, whereas only 50 (45.1%) were T2-hyperintense (p < .0001) and 51 (45.9%) were detected with bone scan (p < .0001). Of a total of 121 MR and/or bone scan findings consistent with metastasis, 111 (91.7%) were MR positive, with high disagreement with 61 (50.4%) positive at bone scan (p < .00001). T2*-hyperintensity associated with T1-hypointensity (with or without T2-hyperintensity) was the most frequent pattern (104/111), 93.7%). CONCLUSIONS: T2*-weighted GE sequences seem to be more effective than T2-weighted SE sequences and as effective as T1-weighted SE sequences. MR imaging confirms its ability in detecting abnormalities consistent with spine metastases.

Magnetic resonance imaging of the breast in characterizing positive or uncertain mammographic findings.

A total of 38 suspected primary (26) or recurrent (12) breast tumors underwent enhanced magnetic resonance imaging (MRI) of the breast after positive (19) or uncertain (19) mammography. Spin echo T1-weighted images before and after intravenous administration of 0.15 mmol/kg Gd-DTPA, the latter ones at 1, 3, and 5 min, were obtained to characterize the mammographic findings. When contrast enhancement was absent, the same images were also obtained at 10 min. Evident and early focal enhancement was considered as an MRI sign of malignancy. All the lesions were submitted to histological examination (seven by core-biopsy only). Mammography results were 23 true positives and 15 false positives. MRI results were 22 true positives, 13 true negatives, 2 false positives, and 1 false negative. Twelve uncertain-mammography cases became true negatives at MRI; 1 uncertain-mammography case was the only MRI false negative; 1 positive-mammography cases became true negative at MRI. Resting on this limited series of patients, MRI is confirmed as a useful imaging technique after uncertain mammography.

Dynamic helical CT of breast tumors.

PURPOSE: The purpose of our study was to test dynamic helical CT (hCT) in the evaluation of breast tumors. METHOD: Thirty-six patients with 39 suspected lesions underwent breast hCT before and 1, 3, and 8 min after intravenous contrast medium administration. A marked enhancement (> or = 100%) at 1 or 3 min without increase at 8 minutes was considered as the primary indicator for malignancy. Twenty carcinomas, one metastatic non-Hodgkin lymphoma, six fibroadenomas, and six other benign findings were histologically assessed. Six cases had negative fine needle aspiration cytology and at least a 2 year negative follow-up. RESULTS: hCT showed a 100% sensitivity and 83.3% specificity. Considering carcinomas and fibroadenomas, significant differences were found for the percent enhancement at 1 min (p = 0.002) as well as for the density increase or decrease at 3 versus 1 min (p = 0.0035), at 8 versus 1 min (p = 0.0027), and at 8 versus 3 min (p = 0.0180). CONCLUSION: hCT proved to have a high diagnostic efficacy in evaluating breast tumors. Even though it involves some exposure to radiation, it should be considered in patients in whom MR is contraindicated.