Biomedical subjects

M G Bruzzone

Publications and source records attributed to M G Bruzzone.

24 records · Page 2Linked to original sources

PubMed1990

Technical basis for magnetic resonance images.

The spin-echo procedure is the basic technique in a magnetic resonance (MR) study (the magnetization vector is flipped by 90 degrees onto the ortogonal plane to the main magnetic field). Very soon after the MR procedure was developed, it was pointed out how important it is to achieve the needed contrast with shorter repetition times (TRs) to reduce the imaging time. Recently, fast imaging techniques have been introduced (partial flip angles, short TRs, and the lack of 180 degrees radiofrequency pulses to refocus the spins are their main characteristics; the spins are refocused by the application of a gradient reversal technique). These techniques are particularly needed in pediatric neuroradiology, where the examination time must be as short as possible. At present, partial flip-angle techniques are almost completely replacing the conventional spin-echo procedure, but the variations in flip angle could result in a change in contrast. For these reasons, conventional spin-echo techniques may still be useful in a routine MR study.

Brain Diseases↗

PubMed1989

[Magnetic resonance in brain tumors: a classification based on signal behavior in multiple echo sequences].

MR is generally known to be more sensitive but less specific than CT in the detection of brain lesions. In our opinion multiple echo sequences can markedly improve MR specificity in the diagnosis of tumors. We reviewed a series of 343 intracranial tumors studied with MR using multiple echo sequences and histologically verified. On the basis of the different signal patterns we divided brain tumors into 5 classes. Class 1: the signal intensity of the tumor increases progressively in T2 WI (100% of craniopharyngiomas, 21/21; 100% of epidermoid tumors, 12/12; 81% of astrocytomas (grades I to III), 64/79; 65% of neurinomas, 30/46). Class 2: the signal intensity of the lesion decreases progressively in T2 WI: A) the tumor has higher signal intensity than the parenchyma in all echoes (100% of medulloblastomas, 14/14; 53% of pituitary adenomas, 15/28); B) the tumor has the same signal intensity as the parenchyma in late echo acquisitions (100% of ependymal tumors, 12/12; 60% of meningiomas, 25/41). Class 3: the tumor has the same signal intensity as the parenchyma in all echoes (34% of meningiomas, 14/41). Class 4: glioblastoma model: one or more cysts of high signal intensity in T2 WI and slightly hyperintense nodules and/or rings and hyperintense peritumoral edema (73% of glioblastomas, 35/48; 72% of metastases, 18/25). Class 5: oligodendroglioma model: mixed hyper/hypointense pattern; cyst, calcifications and edema are very difficult to recognize within the lesion (95% of oligodendrogliomas, 18/19). The signal pattern was sometimes characteristic but never pathognomonic. Nevertheless, this classification proved to be an useful criterion to restrict the number of possible diagnoses. The study of T1 and T2 values seems to be less useful.

Brain↗

PubMed1988

Subarachnoid hemorrhage of unexplained cause.

During a 7-year period, we observed 58 patients with signs and symptoms of subarachnoid hemorrhage (SAH) in whom clinical and neuroradiological investigations failed to reveal a reasonable cause of the bleeding. Repeat panangiography was negative in the 2 patients with spasm. Rebleeding episodes soon after admission were rare, and the overall rebleeding rate was 3.4% (equivalent to an annual recurrence of 0.6%). In 1 case, a second extensive angiographic evaluation showed a small cerebral arteriovenous malformation, which was successfully treated surgically. On follow-up, 89% of the patients experienced a good outcome, with return to normal activities. This study confirms a good prognosis for patients with SAH of unknown cause. The necessity of performing a second angiographic study and the role of small infundibular dilations of the cerebral arteries are discussed.

Activities of Daily Living↗

PubMed1985

Intracranial tumors arising from the floor of the middle fossa.

Tumors involving or arising from the floor of the middle fossa in cases seen at the Neurological Institute C. Besta were reviewed, and the radiological findings of plain films, angiographic and CT studies are described. Meningiomas, metastases, trigeminal neurinomas, epidermoids, chordomas and chondromas were included in the study.

Brain Neoplasms↗

PubMed1984

Alexia in recent and late Broca's aphasia.

The hypothesis was tested that alexia associated with Broca's aphasia may often be a residual receptive disorder of a broader picture of global aphasia. It was found that alexia does tend to be associated, as expected, to the long-standing Broca's aphasias more often than to the recent ones. However, the CT scan failed to disclose larger and more posterior lesions in Broca's alexic than in Broca's non-alexic patients.

Adult↗

PubMedDate not supplied

Spinal cord involvement and systemic lupus erythematosus: clinical and magnetic resonance findings in 5 patients.

We report the clinical, magnetic resonance imaging (MRI) and laboratory findings in 5 patients with clinical spinal cord involvement with an acute or subacute course; in two of the patients the myelitic episode preceded, in one it was concomitant to, and in two it followed the diagnosis of systemic lupus erythematosus (SLE). The marked clinical and MRI heterogeneity detected in our patients suggests that various factors may be implied in the pathogenesis of spinal cord involvement in SLE. The possibility of a future evolution to SLE should be kept in mind in women presenting spinal cord involvement with no other explanation, and should be assessed by means of extensive and repeated clinical and laboratory evaluations.

Adolescent↗