0000000000930499
AUTHOR
M. De Maria
Imaging funzionale per diffusione (DWI) e ischemia cerebrale in fase acuta: Potenzialità diagnostiche e confronto con metodiche convenzionali
Stroke is the third leading cause of death and is a major cause of long-term disability. Neuroprotective treatment within a 4-hour «therapeutic window» has proved highly efficacious in reducing morbility and mortality in animal model. It is with this background that the need for emergent diagnosis and therapy of acute stroke in strongly suggested. Computed tomography (CT) shows the parenchymal changes of acute stroke too late to be helpful, and its role has been primarily to evaluate the possibility of intracerebral or subarachnoid hemorrhage. While conventional magnetic resonance (MR) imaging can demonstrate parenchymal abnormalities 4–6 hours after ischemia, newer techniques such as diff…
Vesicoureteral reflux in young patients: Comparison of voiding color Doppler US with echo enhancement versus voiding cystourethrography for diagnosis or exclusion
We assessed the accuracy of voiding color Doppler ultrasonography (US) with echo enhancement for diagnosis or exclusion of vesicoureteral reflux (VUR) versus voiding cystourethrography (VCUG) and evaluated patient tolerance of the echo-enhancing agent. One hundred twenty-two patients (ages range, 1 month to 17 years) with 244 ureterorenal units underwent voiding color Doppler US with echo enhancement, which was followed by VCUG on the same day. After US of the urinary tract, the bladder was filled with saline solution via catheter. Then an echo-enhancing agent was instilled, and color Doppler US was performed. Reflux was diagnosed when microbubbles appeared in the ureter or the pelvicalicea…
MRI findings and evoked potentials in patients with myotonic dystrophy versus facioscapulohumeral dystrophy
Evoked potentials recordings have been applied to many neurological disorders, localizing the lesions in the central nervous system (CNS) pathways. Facioscapulohumeral muscular dystrophy (FSHD) is a slowly progressive degenerative disease involving the muscles of the face and shoulders. On the contrary, myotonic distrophy (MD), the most frequent and severe myotonic disease, is caracterized by myotonia (delay of relaxation after voluntary contraction), muscular atrophy and dystrophic changes in non-muscular tissues. In the present investigation, patients with clinically and electromyographically verified FSHD and MD were examined using somatosensory evoked potentials (SEP) and brainstem aud…
Valutazione comparativa delle sequenze fast Spin-echo e Spin-echo T2-dipendenti nella dimostrazione delle lesioni demielinizzanti encefaliche in corso di sclerosi multipla
We compared T2-weighted fast spin-echo (FSE) magnetic resonance (MR) imaging and conventional spin-echo (CSE) T2-weighted imaging in the detection of brain lesions of multiple sclerosis (MS). 20 patients with clinically definite MS underwent brain imaging with both FSE and CSE T2-weighted imaging. There was no significant difference in total number of lesions detected on FSE vs CSE (1354 vs 1378). Slightly more periventricular and subcortical lesions were detected using CSE than FSE, whereas more posterior cranial fossa lesions were detected by FSE. There was no statistically significant difference in the signal intensity (SI) ratio of MS lesions to that of surrounding normal white matter …
Familial Cavernous Angioma: MRI Study of three Generation in two Italian Families and Literature Review
According to recent magnetic resonance imaging studies, cavernous angioma (CA) seems to involve the central nervous system in 0.5%-1% of the population 1 - in a similar percentage to a large autopsy series 2.The incidence of familial CA is unknown 3: the first paper in the literature concerning familial CA was published in 1936 5: recently however, thank to the widespread use of MR, at least 13 families have been described.We report MR findings in two Italian families with familial CA.In conclusion, familial CA should be included in the differential diagnosis of patients with intracranial haemorrhage, seizures or cerebrovascular disease.
Calibro dei sifoni carotidei e asimmetria del poligono di Willis: Studio Angio-RM
A differenza dell'Angiografia, l'esame Angio-RM consente la simultanea visualizzazione dei vasi del poligono. Si è valutata la correlazione esistente tra calibro dei sifoni e asimmetrie di sviluppo del poligono nella popolazione normale. Sono stati esaminati 3 casi di occlusione totale di una carotide. 120 pazienti privi di patologie vascolari o neoplastiche sono stati sottoposti ad esame Angio-RM 3DTOF con Magnetization Tranfer e TONE. Sono state valutate le immagini di sorgente e 3DMIP, prima e dopo sottrazione dei pixel non vascolari. I pazienti sono stati suddivisi in 5 gruppi: I = aplasia di A1, II = ipoplasia di A1, III = lieve asimmetria di A1, IV ? arteria comunicante posteriore fe…
Static magnetic fields generated by a 0.5T MRI unit affects in vitro expression of activation markers and interleukin release in human peripheral blood mononuclear cells (PBMC)
To investigate the effects of the static magnetic field (SMF) generated by a 0.5 T superconducting MRI unit on in vitro activation marker expression and interleukin release in human peripheral blood mononuclear cell (PBMC) samples from healthy volunteers.PBMC samples were split into two groups: exposed and sham-exposed under isothermal conditions. PBMC were exposed for 2 h at 24 degrees C to the SMF of a 0.5 T superconducting MRI unit. Immediately after exposure, both samples were cultured for 24 h at 37 degrees C with or without mitogenic stimulation by phytohaemagglutinin (PHA). PBMC were examined for expression of CD25, CD69 and CD71 by immunofluorescence analysis and supernatants were a…
The influence of the processing temperature on gamma curing of epoxy resins for the production of advanced composites
Abstract Gamma radiation curing of an epoxy monomer, in the presence of an iodonium salt, as initiator, is studied. Systems have been polymerized at the same irradiation dose and dose rate and at different processing temperatures. The experimental results show that all the irradiated materials exhibit a latent reactivity, undergoing toward an increase of crosslinking density if they are thermally cured after irradiation. The results indicate that the processing temperature affects both the crosslinking density after irradiation and the sensibility to the post-irradiation thermal treatment.
Precision measurement of the K S meson lifetime with the KLOE detector
Using a large sample of pure, slow, short lived K0 mesons collected with KLOE detector at DaFne, we have measured the KS lifetime. From a fit to the proper time distribution we find tau = (89.562 +- 0.029_stat +- 0.043_syst) ps. This is the most precise measurement today in good agreement with the world average derived from previous measurements. We observe no dependence of the lifetime on the direction of the Ks.
Imaging of “Malignant” External Otitis
“Malignant” external otitis or necrotizing external otitis (NEO) is a rare and severe infection of the external auditory meatus, causing destructive changes of the petrous bone, infiltrating inframastoid and intracranial tissues, with potentially lethal consequences. Five male diabetic patients, aged 61 to 85 years-old (mean age was 74 y.o), referred with biopsy-proven NEO, underwent CT and MRI studies for the assessment of the extension of the disease. Clinical data concerning the examined patients are summarized in table 1. Contrast-enhanced MRI does not seem to help in differentiating granulation from neoplastic tissues, as both demonstrate inhomogeneous enhancement. In conclusion, NEO …
MR imaging of pancreatic changes in patients with transfusion-dependent beta-thalassemia major.
The aim of this study was to evaluate MR imaging changes of the pancreas in patients with transfusion-dependent beta-thalassemia major.Twenty patients with transfusion-dependent beta-thalassemia major were examined using MR imaging at 0.5 T, with spin-echo T1-weighted, fast spin-echo T2-weighted, and gradient-echo T2*-weighted sequences. Image analysis was performed to assess pancreas-to-fat signal intensity ratios for all pulse sequences. Pancreatic exocrine and endocrine function and serum ferritin levels were assessed. Twenty healthy volunteers underwent MR imaging with the same three sequences and served as a control group.The pancreas-to-fat signal intensity ratio was significantly dec…
Forty-slice MDCT enteroclysis: evaluation after oral administration of isotonic solution in Crohn's disease.
Objective. The aim of this study was to evaluate the accuracy of multidetector computed tomography (MDCT) enteroclysis after oral hyperhydration with isotonic solution in detecting bowel wall alterations in patients with Crohn’s disease. Materials and methods. Twenty-eight patients with a diagnosis of Crohn’s disease established by ileocolonoscopy and histology were enrolled in the study; 15 patients with negative ileocolonoscopy served as controls. In all cases, MDCT enteroclysis was performed after oral administration of 2,000 ml of isotonic solution and intravenous administration of N-butylscopolamine. Axial, isotropic multiplanar and volume-rendered reconstructions were used to evaluate…
Biologic effects of ultrasound on liver cells of rat embryos.
Experiments on the biologic effects of ultrasound (US) were carried out on rat embryos exposed for 120 s to a US beam showing features similar to those already employed for diagnostic purposes. Electron microscopic investigation of the liver parenchyma of rat embryos confirmed results obtained from adult guinea pigs with the same duration of exposure, i.e. diffuse vacuolization of cytoplasma and varying degrees of mitochondrial damage.
Influence of heart rate in the selection of the optimal reconstruction window in routine clinical multislice coronary angiography
Purpose. The aim of our study was to assess the influence of heart rate on the selection of the optimal reconstruction window with 40-slice multidetector-row computed tomography (40-MDCT) coronary angiography. Materials and methods. We studied 170 patients (114 men, age 60 +/- 11.3 years) with suspected or known coronary artery disease with 40-MDCT coronary angiography. Patients [mean heart rate (HR) 62.9 +/- 9.3 bpm, range 42-94 bpm] were clustered in two groups (group A: HR <= 65 bpm; group B: HR >65 bpm). Multiphase reconstruction data sets were obtained with a retrospective electrocardiogram (ECG)-gated 40-MDCT coronary angiography scan from 0% to 95% every 5% of the R-R interval.…