Clinical features and MR imaging in children with repaired myelomeningocele.

The aim of the study is to define the role of associated malformations in the clinical evolution of children affected by myelomeningocele. MRI investigation of the spinal cord was carried out on 25 patients between the age of 7.3 and 18.10 with MMC repaired and followed up for at least 7 years. The relation between associated malformations demonstrated by MRI and clinical trend was analysed. The results are the following: 1) presence of asymptomatic tethered cord in all cases; 2) high frequency (92%) of Chiari malformation; 3) presence of syringomyelia in 20% of patients, symptomatic in 1; 4) presence of ventricular enlargement in 72% of cases without increased intracranial pressure syndrome. For a better therapeutic approach prospective MRI studies are needed in order to follow up associated malformations.

Amelanotic leptomeningeal melanoblastosis. Case report.

Leptomeningeal melanoblastosis is a rare phakomatosis; the amelanotic variant has not till now been described. In this paper we report the case of a young man suffering from amelanotic leptomeningeal melanoblastosis manifested as medullary syndrome and secondary intracranial hypertension. The diagnosis of leptomeningeal melanoblastosis was hypothesized on the basis of CSF and neuroradiological findings and it was finally confirmed by the histopathology.

[Magnetic resonance in brain tumors: a classification based on signal behavior in multiple echo sequences]. / La Risonanza Magnetica nei tumori cerebrali: classificazione in base al comportamento di segnale nelle sequenze in multieco.

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.

Intra-arterial digital subtraction angiography of vascular lesions of the spinal cord. Personal experience.

IDSA studies were performed in 6 patients with AVM and hemangioblastomas of the spinal cord. IDSA appears to be the most suitable angiographic approach for the study and embolization of this kind of lesions of the spinal cord even when special conditions require repeating some injections on conventional angiography.

[Magnetic resonance in the study of cerebral gliomas]. / La risonanza magnetica nello studio dei gliomi cerebrali.

Forty surgically proved gliomas have been studied by MR: 21 were low-grade gliomas and 19 were anaplastic astrocytomas and glioblastomas. The examination involved the use of T1-weighted (IR and/or SE, TR 500 ms, TE 50 ms) and T2-weighted scans (SE, TR 1000 ms, TE 50 with multiple echos). All patients underwent CT and surgical removal or stereotactic biopsy whose findings were retrospectively compared with those of MR. MR findings were similar in low-grade and anaplastic astrocytomas, but quite different from imaging of glioblastomas. Tumoral cyst and areas of necrosis were recognized on MR studies and confirmed by surgical findings. Differentiation between tumor and oedema was difficult. The MR images did not allow a more specific diagnosis of nature or of malignancy than available with CT up to now, but offer major advantages, such as a superior depiction of tumor extent and anatomic relationships.

Magnetic resonance imaging in intracranial gliomas. Comparison with computed tomography and serial stereotactic biopsy.

Findings at magnetic resonance imaging (MRI) and computed tomography (CT) where reviewed in 53 surgically confirmed cases with glioma. Astrocytomas showed a constant MR signal pattern in 87 per cent and glioblastomas in 80 per cent. This pattern was found useful when it was correlated with CT. MRI was also found to be of value in planning stereotactic biopsy and in confirming the trajectory.

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.

Unusual computerized tomography appearance of a carotid-cavernous fistula. Case report.

A case of carotid-cavernous fistula characterized by an unusual computerized tomography (CT) pattern is reported. The CT study showed a hyperdense lesion in the right frontoparietal region, and angiography demonstrated an uncommonly large venous network in the same area. After embolization by a detachable balloon technique, these findings gradually resolved. The CT pattern was probably due to the unusually large venous drainage and to the related ischemia of the brain parenchyma.

Intracranial neurinomas of the nerves of the jugular foramen. Report of 12 personal cases.

12 patients, 10 women and 2 men, were operated on for removal of a jugular foramen neurinoma. Removal was total in 11 cases and operative mortality was 16.6%. As there are no clinical or instrumental signs that permit sure distinction between these tumours and those of the cerebellopontine angle, only a thorough radiological study of the jugular foramen allows correct diagnosis. Often, however, the diagnosis is made during the operation.