Susceptibility-Weighted Angiography for the Follow-Up of Brain Arteriovenous Malformations Treated with Stereotactic Radiosurgery.

The criterion standard for assessing brain AVM obliteration postradiosurgery is DSA. To explore the value of susceptibility-weighted angiography, we followed 26 patients with brain AVMs treated by radiosurgery using susceptibility-weighted angiography and DSA. Studies were evaluated by 2 independent readers for residual nidi. Susceptibility-weighted angiography demonstrated good intermodality (κ = 0.71) and interobserver (κ = 0.64) agreement, and good sensitivity (85.7%) and specificity (85.7%). Susceptibility-weighted angiography is a useful radiation- and contrast material-free technique to follow-up brain AVM obliteration postradiosurgery.

Subtentorial cerebral nocardiosis in immunocompetent patients: CT and MR imaging findings.

PURPOSE: To describe the clinical presentation and computed tomography (CT) and magnetic resonance imaging (MRI) appearances of subtentorial nocardia cerebral abscesses developing in immunocompetent patients. PATIENTS AND METHODS: The clinical findings and the results of CT and MRI examinations of three immunocompetent patients with nocardiosis located initially only in the subtentorial region were studied. Three patients underwent CT examination and two patients had MRI. RESULTS: Clinically, two patients had cerebellar syndrome and the third had meningism with fever. The diagnosis of nocardiosis was bacteriologically confirmed by demonstrating the organism in lumbar puncture fluid in one patient and by an aspiration biopsy of the abscess in the other two. Two of the patients improved under targeted antibiotic therapy whereas the third patient died. The main imaging features of the lesions were a multiloculated appearance with peripheral enhancement after intravenous administration of iodinated contrast material on CT and a multicystic appearance on MRI, with a peripheral hypointense rim on T2-weighted images, a relatively minor mass effect and a multiloculated appearance on gadolinium-chelate enhanced T1-weighted images. CONCLUSION: The clinical presentation of cerebral nocardiosis is relatively non-specific. A microcystic lesion surrounded by hypointensity on T2-weighted MR images with a multiloculated pattern after gadolinium chelate administration on T1-weighted MR images in association with a relatively minor mass effect should suggest this diagnosis even if the lesion is single and in the absence of immunosuppression.

Dynamic susceptibility contrast-enhanced MRI evaluation of cerebral intraventricular tumors: preliminary results.

INTRODUCTION: The aims of the present study were to determine the perfusion characteristics of several types of intraventricular tumors and to evaluate the usefulness of dynamic contrast-enhanced MRI in making the differential diagnosis. METHODS: A total of 28 patients with intraventricular tumors (five meningiomas, five papillomas, three ependymomas, four subependymomas, seven central neurocytomas, two subependymal giant cell astrocytomas and two metastases) underwent conventional and dynamic susceptibility contrast-enhanced MRI. Cerebral blood volume (CBV) maps were obtained and the relative CBV (rCBV) calculated for each tumor. Mean rCBV(max) values were compared across the different types of tumors (ANOVA, P=0.05). RESULTS: Intraventricular tumors presented with three different patterns of vascularization: highly vascularized tumors (mean rCBV(max)>3), including papillomas, meningiomas and renal carcinoma metastases; poorly vascularized tumors (mean rCBV(max)<2), including ependymomas and subependymomas; and intermediately vascularized tumors (mean rCBV(max)>2 but<3), including central neurocytomas and lung metastases. There was a significant difference between the highly vascularized (papillomas, meningiomas) and poorly vascularized (subependymomas) tumors. In cases of suspected meningioma, papilloma or neurocytoma, low rCBV values (<3) point to a diagnosis of neurocytoma rather than either of the other tumor types. CONCLUSION: Susceptibility contrast-enhanced MRI can provide additional information on the vascularization of intraventricular cerebral tumors and may help in making the differential diagnosis.

[Impact of PACS implementation in a university center on radiology practice profile]. / Changements des pratiques radiologiques induites par l'implantation d'un réseau images en milieu hospitalo-universitaire.

PURPOSE: To determine the impact of a joint PACS implementation at a university medical center and cancer center on the radiology practice profile. Materials and methods. In 5 radiology sections, patients, selected based on identifiable acute or chronic diseases, underwent US, CT or MRI. Data were collected on datasheets from each provider with regards to clinical history, availability of prior examinations, description of patient management during the different phases of the examination, duration of examinations, and satisfaction. Data obtained prior to PACS implementation and 6-12 months and 30-36 months after implementation were compared. RESULTS: A total of 1098 datasheets were collected. Hard copy readings rapidly decreased. Comparison with prior examinations improved (+20.6% to 25.6%) as well as frequency of post-processing (+29%). The time required for image management was much more reduced for technologists (-75%) than for physicians (-23%). PACS implementation only temporarily improved the availability of radiology reports and the distribution of work between senior and junior radiologists. User satisfaction, initially high, progressively decreased due to saturation of the archival capabilities. CONCLUSION: PACS implementation in a large university center improves the efficiency of image acquisition but does not solve some of the inefficiencies of hospital organization.

[MRI imaging of the neural pituitary]. / Imagerie par résonance magnétique nucléaire de la neurohypohyse.

The main illness of the neural pituitary is diabetes insipidus (DI). MRI is essential if DI occurs during childhood, in order to highlight malignant germinoma prognosis of which remains excellent if the diagnosis is made as early as possible. In adults, primary intracranial tumours causing DI include craniopharyngioma, or pineal tumours. Infiltrative histiocytosis is another frequent aetiology. One third of previously considered idiopathic DI is in fact auto-immune. Early MRI findings advocate for such a diagnosis. Finally, meticulous analysis of the neural pituitary imaging may avoid several pitfalls and help the analysis of adenopituitary abnormalities.

Giant cystic widening of Virchow-Robin spaces: an anatomofunctional study.

We describe 2 patients with unusual white matter cystic dilations, which could correspond to widening of the perivascular spaces. They underwent morphologic MR imaging with tractography, functional MR imaging (fMRI), and neuropsychological evaluation. fMRI examination showed no functional reorganization of cortical areas. Tractography showed an apparent decrease of white matter tract vectors into the regions of concern. Findings of the neuropsychological examination were normal. It seems that even an extensive cystic dilation of white matter does not deteriorate brain function.

[Carotid Stenting in France after the EVA 3S and SPACE publications]. / Stenting carotidien en France après les publications d'EVA 3S et de SPACE?

Angioplasty of stenoses of the carotid bifurcation is a revascularization procedure that is used successfully in many patients. With more than 10 years of experience now, the feasibility of carotid stenting has been demonstrated. Its distribution is highly variable depending on the country, with a mean penetration rate in Europe of 15% of the number of carotid revascularizations. However, the complication rate is highly variable from one series to another and depends on the type of patient treated and the operator's learning curve. The results of the first two randomized studies comparing endarterectomy and carotid stenting, EVA 3S in France and SPACE in Germany, have just been published. The conclusions of these studies only relate to symptomatic patients, who make up a small proportion of revascularized patients. At 30 days, the French study concluded that surgery was better, and the German study showed no advantage to stenting. The analysis of these results compared to other publications should make it possible to best define the current indications for carotid stenting.

Outcome of children treated with preradiation chemotherapy for a high-grade glioma: results of a French Society of Pediatric Oncology (SFOP) Pilot Study.

BACKGROUND: To evaluate the efficacy of BCNU, cisplatin, and vincristine (BCV regimen) in a prospective nonrandomized study among newly diagnosed children with high-grade glioma. PROCEDURE: Following surgery, patients received a combination of BCNU + cisplatin + VP16 (BCV), over 3 consecutive days. Patients with residual tumor continued this regimen unless no further improvement was observed on MRI, for a maximum of six courses. Patients who underwent complete surgical resection received six courses of adjuvant BCV. RESULTS: Seventy-three patients were enrolled. Out of 66 eligible patients with central pathology review, the diagnosis of high-grade glioma was confirmed in 53 cases. The response rate was 20%. With a median follow-up of 128 months, 5- and 10-year event free survival rates are 16 +/- 9 and 13.3 +/- 9.4%. In univariate analysis, two prognostic factors were statistically significant: extent of resection and tumor location, while macroscopic total resection was the only significant prognostic factor in the multivariate analysis. The response to BCV did not translate into improved event free survival. Interstitial pneumonitis occurred in seven patients, leading to six deaths. CONCLUSION: This BCV regimen could not be recommended in the treatment of high-grade gliomas in children, according to its lack of efficacy and its unacceptable pulmonary toxicity.

[Imaging follow-up of post-traumatic myelomalacia]. / Evolution d'une myelomalacie post-traumatique vers une syringomyelie: suivi iconographique.

The authors report a case of secondary worsening of neurological symptoms in a patient 2 months after cord injury at T5 causing paraplegia. The MRI showed myeolomalacia, which appears as cord oedema, located in the grey matter, extending increasingly from the initial lesion (eighth thoracic vertebra) to the bulb. This cord lesion known as grey matter cytotoxic oedema, evolved into a syringomyelic cavity.

Treatment of high risk medulloblastomas in children above the age of 3 years: a SFOP study.

AIM: Improvement of EFS of children older than 3 years with high risk medulloblastoma. METHODS: Between 1993 and 1999, 115 patients (3-18 years, mean 8 years) with high risk medulloblastoma were included. After surgery treatment consisted of chemotherapy ('8in1' and etoposide/carboplatin) before and after craniospinal radiotherapy. RESULTS: Patients were staged using Chang-criteria (PF residue only, M1 and M2/M3) by local investigator as well as by central review panel (82.4% concordance). Chemotherapy was well tolerated without major delays in radiotherapy. With a mean follow up of 81 months (9-119), 5-year EFS was 49.8% and OS 60.1%. In detail according to subgroups EFS was 68.8% for PF residue only, 58.8% for M1 disease and 43.1% for M2/M3. CONCLUSION: M1 patients are legitimate high risk patients. Survival rates are still very low for high risk medulloblastoma patients and future trials should therefore focus on more intensive (chemotherapy/radiotherapy) treatment.

Endovascular treatment of intracranial aneurysms with matrix detachable coils: immediate posttreatment results from a prospective multicenter registry.

BACKGROUND AND PURPOSE: Endovascular treatment of intracranial aneurysms by using detachable coils has become an accepted alternative to surgery. To reduce the rate of aneurysm recanalization after treatment, biologically active polyglycolic/polylactic acid-covered platinum coils have been proposed. A prospective and multicenter registry was conducted in France to evaluate the safety and short-term and long-term efficacy of Matrix detachable coils. This first analysis is focused on the safety and short-term efficacy. METHODS: Two hundred sixty-one patients having ruptured or unruptured aneurysms treated via endovascular approach were included in this registry. Patients with giant aneurysms or in poor clinical condition (Glasgow Coma Scale < 10) were excluded. Because of various protocol violations, clinical analysis was conducted in 236 patients having 244 aneurysms. Technical and clinical complications were systematically recorded. Angiographic analysis was performed by a core laboratory by using the Raymond Grading Scale on 224 patients having 232 aneurysms. RESULTS: Complete occlusion was achieved in 102 aneurysms (44.0%); neck remnant, in 58 aneurysms (25.0%); and aneurysm remnant, in 72 aneurysms (31.0%). Technical and clinical complications related to the procedure were encountered in 43 patients (18.2%). Postoperative modification of the clinical status was observed in 12 patients (5.1%). Two patients died (0.8%), 6 had a permanent deficit (2.5%), and 4 had a transient deficit (1.7%). Treatment-related mortality was 0.8% and permanent morbidity was 2.5%. CONCLUSION: Endovascular treatment of intracranial aneurysms by using Matrix detachable coils is feasible and demonstrated initial angiographic results and overall morbidity and mortality rates that are within the ranges found in the literature in the use of bare platinum coils.

[Cerebral gliomas: imaging diagnosis and follow-up]. / Imagerie cérébrale des gliomes: diagnostic et suivi conventionnels.

The management of gliomas evolves towards more aggressive strategies with a combination of surgery, radiotherapy and chemotherapy. Follow-up imaging based on morphological MRI, with simple and reproducible protocols, may be associated with functional MRI and spectroscopy. Baseline postsurgical MRI must be performed within the first three days. Follow-up examinations should be done 2 months after radiotherapy and during chemotherapy, usually after each cycle of two or three treatments. Continued follow-up after therapy is recommended to assess response and detect recurrences or therapeutic complications.

Symptomatic Radionecrosis after AVM Stereotactic Radiosurgery. Study of 16 Consecutive Patients.

SUMMARY: The purpose of our study was to analyze the outcome of symptomatic radionecrosis following stereotactic radiosurgery for brain arteriovenous malformations. Of 225 patients treated by linear accelerator radiosurgery for brain AVM, 16 (7,1%) presented post-radiosurgery symptomatic radionecrosis on a mean follow-up period of 50 months (range 1-123 months). Once diagnosed with radionecrosis, 14 of 16 patients were subjected to high dose corticotherapy consisting of escalating doses of dexamethasone for several weeks. The mean interval of occurrence of new symptoms was 11.6 months post-radiosurgery (range 6-20 months). The mean time of follow-up was 2.9 years post radiotherapy ranging from seven months to eight years. Of the 16 patients with symptomatic radionecrosis, 11 (68,75%) showed complete resolution of symptoms while five (31,25%) showed improvement but still presented a neurological deficit at the closing date of the study. At the closing date, 11 patients (68.75%) had angiographically completely obliterated arteriovenous malformations while another two patients had an obliteration of 95% to 98% and one patient had a 98% obliteration with development of a new contralateral AVM. In our series, symptomatic radionecrosis occurred in 7.1% of patients treated with stereotactic radiosurgery for brain AVM. These patients where subjected to a prompt, high dose corticosteroid treatment and most presented symptom resolution or improvement with a fair obliteration rate, offering protection from bleeding. Permanent neurologic deficits attributable to radionecrosis occurred in 2.2% of our patient population treated with stereotactic radiosurgery for brain AVM.

Contribution of dynamic contrast MR imaging to the differentiation between dural metastasis and meningioma.

PURPOSE: To determine the perfusion-sensitive characteristics of cerebral dural metastases and compare them with the data on meningiomas. METHODS: Twenty-two patients presenting with dural tumor underwent conventional and dynamic susceptibility-contrast MR imaging: breast carcinoma metastases, two patients; colorectal carcinoma metastasis, one patient; lung carcinoma metastasis, one patient; Merkel carcinoma metastasis, one patient; lymphoma, one patient; meningiomas, 16 patients. The imaging characteristics were analyzed using conventional MR imaging. The cerebral blood volume (CBV) maps were obtained for each patient and the relative CBV (rCBV) in different areas was calculated using the ratio between the CBV in the pathological area (CBVp) and in the contralateral white matter (CBVn). RESULTS: The differentiation between a meningioma and a dural metastasis can be difficult using conventional MR imaging. The rCBVs of lung carcinoma metastasis (1 case: 1.26), lymphoma (1 case: 1.29), breast carcinoma metastasis (2 cases: 1.50,1.56) and rectal carcinoma metastasis (1 case: 3.34) were significantly lower than that of meningiomas (16 cases: mean rCBV = 8.97+/-4.34, range 4-18). Merkel carcinoma metastasis (1 case: 7.56) showed an elevated rCBV, not different from that of meningiomas. CONCLUSION: Dural metastases are sometimes indistinguishable from meningiomas using conventional MR imaging. rCBV mapping can provide additional information by demonstrating a low rCBV which may suggest the diagnosis of metastasis.

[Primary spinal melanoma: a case report]. / Mélanome primitif intrarachidien. A propos d'un cas.

Intra spinal primary melanoma is a rare entity. We report a new case, atypical in relation to its primary radicular location, and to its early metastatic intradural and extra-medullary location, six months later. MRI is the more valuable examination, showing a spontaneously hyper-intense lesion on T1-weighted MR images, intense enhancement after gadolinium administration, and decreased signal on T2-weighted MR images, thus suggesting a diagnosis of melanocytic or hemorrhagic lesion. Signal abnormalities are not specific and definitive diagnosis is established after histological analysis.

[Thrombus of the left lateral sinus spreading to the internal jugular vein]. / Thrombose du sinus latéral gauche étendue à la veine jugulaire interne.

Cerebral venous thrombosis is an uncommon event which presents a wide spectrum of sometimes extraneurological signs different from the classical clinical presentation. We report the cases of two middle-aged women who developed thrombosis of the left lateral sinus spread-ing to the internal jugular vein from the sigmoid sinus. The time course of the symptoms suggested that intracranial thrombosis occurred first. No infectious or neoplastic local disease could be found but both women were taking oral contraceptives. Medical treatment led to good reperfusion of the intracranial sinuses but occlusion of the jugular vein persisted despite prolonged oral anticoagulants. Long-term outcome was favorable with residual benign epilepsy in one patient, and occurrence of an arteriovenous fistula in the other.

[Imaging of non-traumatic intracerebral hematoma]. / Magerie des hématomes intracérébraux non traumatiques.

Intracerebral hematoma is mainly due to the spontaneous rupture of small vessels damaged by chronic hypertension or amyloid angiopathy. In some cases, intracerebral hemorrhage may be associated with a vascular malformation, a tumor, venous thrombosis or hemorrhagic transformation of a cerebral infarct. The objective of brain imaging is to identify the hematoma according to its different stages and to find a potential underlying cause because of the risk of recurrence and the possibilities of treatment. In emergency, a diagnosis of hematoma may be obtained by CT scan or MRI but the etiologic work-up requires early MRI. According to the patient's age, the medical history and the location of the hematoma, it may be necessary to perform conventional angiography in order to exclude an intracranial vascular malformation. The aim of this review is to detail the different aspects of intracerebral hemorrhages and to discuss the main causes that can be found at brain imaging.