Biomedical subjects

F E Zanella

Publications and source records attributed to F E Zanella.

At least 19 recordsLinked to original sources

PubMed2006

Proton magnetic resonance spectroscopy in childhood brainstem lesions.

BACKGROUND: Diagnosis of brainstem lesions in children based on magnetic resonance imaging alone is a challenging problem. Magnetic resonance spectroscopy (MRS) is a noninvasive technique for spatial characterization of biochemical markers in tissues and gives information regarding cell membrane proliferation, neuronal damage, and energy metabolism. METHODS: We measured the concentrations of biochemical markers in five children with brainstem lesions and evaluated their potential diagnostic significance. Images and spectra were acquired on a 1.5-T imager. The concentrations of N-acetylaspartate, tetramethylamines (e.g., choline), creatine, phosphocreatine, lactate, and lipids were measured within lesions located at the brainstem using Point-resolved spectroscopy sequences. RESULTS: Diagnosis based on localized proton spectroscopy included brainstem glioma, brainstem encephalitis, demyelination, dysmyelination secondary to neurofibromatosis type 1 (NF 1), and possible infection or radiation necrosis. In all but one patient, diagnosis was confirmed by biopsy or by clinical follow-up. CONCLUSIONS: This small sample of patients suggests that MRS is important in the differential diagnosis between proliferative and nonproliferative lesions in patients without neurofibromatosis. Unfortunately, in cases of NF 1, MRS can have a rather misdiagnosis role.

Adolescent↗

PubMed2006

[Endovascular treatment for intracranial stenoses. A common statement by neurologists and neuroradiologists].

Intracranial stenoses cause 5-10% of all strokes and are increasingly detected by means of modern imaging methods. The stroke danger of high-grade symptomatic stenoses is relatively high, with an annual risk of approximately 10% under medical treatment. Coumadin increases the risk of hemorrhage, and after risk/benefit considerations, antiplatelets should be preferred for antithrombotic therapy. Despite optimized medical treatment, a small group of patients with recurrent symptoms or symptomatic stenoses without adequate collateral supply probably carry higher spontaneous stroke risk and may be considered for intracranial stenting, which itself is associated with procedural risks of up to 10%. Currently published case series show relatively high complication rates as a major drawback of endovascular treatment, mainly strokes after occlusion of perforating branches extending from the stenotic vessel segment or hemorrhagic complications. According to data from smaller feasibility studies, stroke rates in follow-up after successful stenting seem to be low. The average rate of high-grade restenosis with possible indication for reintervention is 10%. Improvements in endovascular treatment aim at reducing vessel wall trauma during balloon angioplasty by underdilatation or the use of self-expanding stents. Until complication rates are dependably reduced to values of 5-6%, indication for endovascular treatment should be restricted to patients without therapeutic alternatives. According to limited data with large variation between different studies, a prospective multicentric registry is proposed for systematic evaluation and further development of the method.

Algorithms↗

PubMed2006

Conformability of balloon-expandable stents to the carotid siphon: an in vitro study.

BACKGROUND AND PURPOSE: Endovascular placement of coronary balloon-expandable stents in patients with recurrent cerebral ischemia has emerged as a treatment option for intracranial arterial occlusive disease. We have developed an in vitro model matching the tortuous curve of the carotid siphon that allows the assessment of apposition of stents to a curved vessel wall. METHODS: Six types of balloon-expandable coronary stents were implanted in a silicone model of the carotid siphon. Digital radiographs and 3D rotational angiograms were obtained. Stent morphology was evaluated and the degree of apposition between stent and wall of the model was measured on a digital workstation. RESULTS: All 6 stents showed lack of apposition between stent and the wall at the convexity of the anterior segment of the carotid siphon and the wall at the concavity at both extremities of the stent. In and around the curve, the modules of the stents did not expand completely to their nominal diameter and were distorted to an oval shape. CONCLUSION: The tested coronary balloon-expandable stents did not completely conform to the vessel wall of the model of the carotid siphon and further development is needed to approach the goal of an "ideal intracranial stent."

Angiography, Digital Subtraction↗

PubMed2005

Accelerated myelination associated with venous congestion.

Magnetic resonance imaging is currently the gold standard in the assessment of brain myelination. The normal pattern of brain myelination conforms to a fixed chronological sequence. Focal accelerated myelination is a usual pathological state and previously has only been associated with Sturge-Weber syndrome. The purpose of our study is to describe alternate causes for accelerated myelination. We retrospectively reviewed serial MR scans, MR angiography, conventional angiography and the clinical progress of three children with accelerated myelination. Two patients with accelerated myelination had an underlying cerebral sinovenous thrombosis. The third patient had Sturge-Weber syndrome. Our study strongly suggests that cerebral venous thrombosis with the consequent restriction of venous outflow could be a key factor in the induction of accelerated myelination. We recommend that in patients with accelerated myelination, the search for an underlying etiology should include careful evaluation of the intracranial vascular pathology, especially cerebral venous thrombosis.

Brain↗

PubMed2005

Assessment of changes in cerebral circulation time due to vasospasm in a specific arterial territory: effect of angioplasty.

This study demonstrates that in experienced hands, intracranial angioplasty is a feasible and safe option in a selected group of patients with severe (>50% stenosis) symptomatic vasospasm following subarachnoid hemorrhage. Cerebral circulation time is a surrogate parameter closely linked to cerebral perfusion. The study presented shows that not only stenosis but also changes in circulation time are obtained by angioplasty. Twenty angioplasties of one or two vessel segments were performed over 2 years in 18 consecutive patients with posthemorrhagic vasospasm fulfilling criteria for invasive treatment. In all patients, degree of stenosis and circulation time could be reduced by angioplasty. Clinical results were ranked according to Glasgow Outcome Scale. Imaging after 15/20 angioplasties showed no additional infarction. In 4/20 cases, CT showed demarcation of infarction after angioplasty. In 1/20 cases of posterior circulation angioplasty, CT is not sensitive enough to exclude smaller infarctions. Imaging and clinical outcome reveal a definite benefit.

Adolescent↗

PubMed2005

[Mechanical recanalization in acute stroke treatment].

The development of endovascular techniques for the treatment of acute stroke began with the introduction of local intra-arterial fibrinolysis. In parallel to designing new systemic therapy approaches, catheter systems for loosening, disintegrating, or removing cerebral thrombi have undergone assessment in recent years to serve as alternatives or supplements to fibrinolytic treatment. Mechanical alteration of intracranial thrombi with balloon catheters, manipulations with the guide wire, or ultrasound waves transmitted into the vascular system as well as techniques for thrombus aspiration, snare extraction, or more complex hydrodynamic or laser-guided thrombectomy systems have been tested in feasibility studies, which evidenced basic functionality and relative safety. Broad clinical applications outside of the clinical trial setting cannot yet be recommended since the new catheter systems are still in early phase clinical testing.

Acute Disease↗

PubMed2005

[Stenting in acute stroke].

Hemodynamic impairment caused by pseudo-occlusion or occlusion of the internal carotid artery (ICA) is a rare etiology of stroke. Acute revascularization of the vessel can restore the flow to the brain. This retrospective study shows that ICA stenting with proximal and distal protection devices in patients with acute stroke and pseudo-occlusion or occlusion of the ICA is technically feasible and can prevent further hemodynamic strokes. In contrast, selected patients have a high risk of reperfusion syndrome with intracranial hemorrhage and peri-interventional monitoring of blood pressure in an ICU is recommended.

Acute Disease↗

PubMed2005

[Local chemotherapy for squamous cell cancer of the oral cavity and oropharynx].

BACKGROUND: Modern treatment concepts for patients suffering from oral and oropharyngeal cancer include more and more adjuvant therapeutic options. Local chemotherapy offers the possibility to apply an extremely high drug concentration at the tumor site while minimizing possible side effects by systemic neutralization at the same time. PATIENTS AND METHODS: A total of 289 patients with histologically proven carcinoma of the oral cavity and the oropharynx underwent neoadjuvant intra-arterial chemotherapy with high-dosage cisplatin within a multimodal therapeutic setting. Concerning the TNM classification, more than 70% of the patients were classified as stages III and IV. The mean age at the time of intervention was 60 years, and 71% of the patients were male. RESULTS: After the first cycle 19.3% of the patients presented with complete remission (grade I); 35.4% and 41.5% showed partial remissions (grade II) or stable disease (grade III), respectively. The mean observation time after treatment was 28 months (median: 24.2 months). Of the 137 patients who completed the full multimodal therapeutic scheme, 11% developed local recurrence, and 12.4% developed lymph node or distant metastasis. At the time of evaluation, 72.5% of these patients were still alive. CONCLUSION: Intra-arterial chemotherapy is a safe and highly effective procedure that should be considered as an important option in multimodal therapeutic concepts for oral and oropharyngeal cancer.

Adult↗

PubMed2005

Hydrocephalus due to superior sagittal sinus thrombosis.

The great variability of clinical appearance is one of the main features of superior sagittal sinus thrombosis. However, hydrocephalus associated with cerebral sinus thrombosis is rare. We report on a patient presented with thunderclap headache, accompanied by nausea, vomiting, and drowsiness. Lumbar puncture ruled out subarachnoid hemorrhage, whereas CT revealed marked hydrocephalus. In addition, magnetic resonance venography then confirmed the diagnosis of cerebral sinus thrombosis. It is a rare occurrence but clinically important, since it entails disastrous sequels if unrecognized, and hydrocephalus is treated in the usual fashion with ventricular drainage.

Humans↗

PubMed2005

Importance of diffusion-weighted imaging in the diagnosis of cystic brain tumors and intracerebral abscesses.

OBJECTIVE: It is often difficult to decide whether a cystic brain lesion is a tumor or an abscess by means of conventional MRI techniques. The immediate diagnosis of a brain abscess is important for the patient's outcome. Our goal was to study the ability of diffusion-weighted imaging and calculation of the apparent diffusion coefficient (ADC) to differentiate between these two pathologies. PATIENTS AND METHODS: Ten patients (five men, five women) with cystic brain lesions were examined with MRI. The ADC maps were calculated for each subject and the ADC value of each lesion was measured. Histology revealed glioblastoma multiforme in six patients and abscess in four patients. RESULTS: All brain abscesses showed markedly hyperintense signal changes on diffusion-weighted imaging, whereas the appearance of glioblastoma varied from slightly hyperintense to hypointense signal conversion. The mean ADC value calculated in the six patients with cystic brain tumor was: 2.05 x 10 (-3) mm(2)/s (1.38-2.88 x 10 (-3) mm(2)/s). The mean ADC value of the four patients with brain abscess was: 0.57 x 10 (-3) mm(2)/s (0.38-0.77 x 10 (-3) mm(2)/s). CONCLUSION: Diffusion-weighted imaging and calculation of ADC maps constitute a helpful tool to differentiate between cystic brain tumors and brain abscesses.

Adult↗

PubMed2005

Isolated CNS relapse in neuroblastoma.

We report three patients with primary extracerebral neuroblastoma and central nervous system (CNS) relapse. As the survival of children with metastatic neuroblastoma improves with recent advances in treatment, CNS involvement becomes more frequently detected. MR imaging of the brain and spine are strongly indicated in the follow-up of patients with increased risk of developing CNS disease.

Central Nervous System Neoplasms↗

PubMed2004

Granulocytic sarcoma in children.

We report three children with leukaemia (two acute myeloid and one acute lymphoblastic) and granulocytic sarcoma in the skull, orbit and sinuses. Lesions in these sites in children, with or without bone changes, are suggestive of systemic diseases such as lymphoproliferative conditions. Although involvement by granulocytic sarcoma, with or without acute myeloid leukaemia, is described, an association with acute lymphoblastic leukaemia is rare. Recognition of this rare entity is important, because early aggressive chemotherapy can bring about regression of the tumour and improve survival.

Child, Preschool↗

PubMed2004

[Distal protection devices in carotid stent].

Endovascular treatment of carotid stenoses is increasingly used. Frequently temporary occlusion balloons or filters are placed distal to the stenosis to gain additional protection against cerebral emboli. There is still a scientific debate about the usefulness of such distal protection devices. The following contribution reviews existing techniques and their clinical results and should allow for a critical discussion and selection of current techniques and materials.

Angioplasty, Balloon↗

PubMed2004

[Stents in the treatment of intracranial atherosclerotic stenoses].

The treatment of intracranial atherosclerotic stenoses, which account for 10-15% of all ischemic strokes, is technically feasible for few years by the use of new flexible stent devices. Especially patients who fail best medical treatment have a poor prognosis and stenting becomes a reasonable treatment option. Herein we discuss treatment concepts and the principles of stent placement against the background of epidemiology and pathophysiologic basics.

Angiography, Digital Subtraction↗

PubMed2004

Central nervous system imaging in childhood leukaemia.

The aim of this study was to document the imaging abnormalities seen in the central nervous system (CNS) in cases of childhood leukaemia or as complications of its treatment. Magnetic Resonance (MR) images and Computed Tomographic (CT) scans were reviewed retrospectively in 22 children and adolescents with neurological manifestations/complications of leukaemia or its treatment. Among the 22 patients, nine had two or more different CNS abnormalities. The imaging abnormalities seen in 15 patients before or during treatment included sinus thrombosis, cortical vein thrombosis, cerebral haemorrhage, meningeal leukaemia, infections, skull leukaemic infiltration and treatment-related neurotoxicity. After therapy, seven patients had CNS abnormalities, including secondary brain tumours, skull tumour, mineralising microangiopathy, leucoencephalopathy, transient white matter abnormalities, spinal intradural haematoma, chronic subdural haematoma, radiation necrosis, meningeal leukaemia and leukaemic infiltration at the vertebral body. CNS complications are related to the inherent risk of leukaemia itself, to the treatment method and to the duration of survival.

Adolescent↗

PubMed2004

Comparison of intracranial 3D-ToF-MRA with and without parallel acquisition techniques at 1.5T and 3.0T: preliminary results.

PURPOSE: To evaluate the performance of four 3D-ToF magnetic resonance angiography (MRA) sequences with and without integrated parallel acquisition techniques (iPAT) at 1.5T and 3.0T in imaging intracranial vessels. MATERIAL AND METHODS: Seven volunteers and 5 patients (4 aneurysms, 1 AVM) underwent 3D-ToF-MRA at 1.5T (Magnetom Sonata) and 3.0T (Magnetom Trio) with and without parallel acquisition techniques (iPAT) using similarly designed 8-channel phased-array head coils. Imaging time of the pulse sequences was set to 7.15 and 7.35 min, respectively. Images were analyzed quantitatively by calculating signal-to-noise (SNR) and contrast-to-noise (CNR) ratios of proximal M2 segments and qualitatively by using a 5-point scale. RESULTS: SNR and CNR were significantly higher for both 3D-ToF sequences at 3.0T compared with both pulse sequences at 1.5T. The highest SNR and CNR were obtained at 3.0T without iPAT. However, because of a higher spatial resolution (matrix 512 x 640) visualization of small vessel details was best at 3.0T with iPAT. CONCLUSION: Intracranial 3D-ToF-MRA at 3.0T offers superior image quality compared with 1.5T, particular in the delineation of smaller vessels. In contrast to 1.5T, implementation of iPAT at 3.0T is of additional benefit since the high SNR available at 3.0T allows for higher spatial resolution without prolongation of measurement time.

Artifacts↗

PubMed2003

Posterior encephalopathy with vasospasm: MRI and angiography.

Posterior encephalopathy is characterised by headache, impairment of consciousness, seizures and progressive visual loss. MRI shows bilateral, predominantly posterior, cortical and subcortical lesions with a distribution. Our aim was to analyse the MRI lesion pattern and angiographic findings because the pathophysiology of posterior encephalopathy is incompletely understood. We report three patients with clinical and imaging findings consistent with posterior encephalopathy who underwent serial MRI including diffusion-weighted imaging (DWI) and construction of apparent diffusion coefficient (ADC) maps, and four-vessel digital subtraction angiography (DSA). DWI revealed symmetrical subcortical and cortical parieto-occipital high signal. High and also low ADCs indicated probable vasogenic and cytotoxic oedema. On follow-up there was focal cortical laminar necrosis, while the white-matter lesions resolved almost completely, except in the arterial border zones. DSA revealed diffuse arterial narrowing, slightly more marked in the posterior circulation. These findings suggest that posterior encephalopathy may in some cases be due to diffuse, severe vasospasm affecting especially in the parieto-occipital grey matter, with its higher vulnerability to ischemia. Cerebral vasospasm due to digitoxin intoxication, resulting in posterior encephalopathy, has not yet been described previously.

Adult↗

PubMed2003

Vasogenic edema in Bickerstaff's brainstem encephalitis: a serial MRI study.

The authors report serial MRI of a patient with Bickerstaff's brainstem encephalitis (BBE), disclosing caudal migration of an initial upper midbrain lesion. High apparent diffusion coefficient values imply a vasogenic rather than cytotoxic edema as the cause of the hyperintense signal changes on T2-weighted images.

Brain Edema↗