Francesca Di Giuliano

Brain MR diffusion tensor imaging in Kennedy's disease

Introduction Kennedy’s disease (KD) is a progressive degenerative disorder affecting lower motor neurons. We investigated the correlation between disease severity and whole brain white matter microstructure, including upper motor neuron tracts, by using diffusion-tensor imaging (DTI) in eight patients with KD in whom disease severity was evaluated using the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS). Methods From DTI acquisitions we obtained maps of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (L1) and radial diffusivities (L2, L3). We then employed tract-based spatial statistics (TBSS) to investigate within-patient correlations of DTI invariants with ALSFRS and disease duration (DD). Results We found a significant correlation between low ALSFRS and 1) low FA values in association commissural and projection fibers, and 2) high L3 values in commissural tracts and fronto-parietal white matter. Additionally, we found a significant association between longer DD and 1) low FA in the genu and body of corpus callosum, association fibers and midbrain and 2) high L1 in projection and association tracts. Conclusions The associations between clinical variables and white matter microstructural changes in areas thought to be spared by the disease process support the hypothesis of a multisystem involvement in the complex pathogenic mechanisms responsible for the clinical disability of these patients.

Posterior Reversible Encephalopathy Syndrome after Hematopoietic Cell Transplantation in Children with Hemoglobinopathies

Posterior reversible encephalopathy syndrome (PRES) is a serious adverse event associated with calcineurin inhibitors used for graft-versus-host disease (GVHD) prophylaxis. We compared the incidence of PRES in children with thalassemia (n = 222, 1.4 to 17.8 years old) versus sickle cell disease (SCD; n = 59, 2 to 17 years old) who underwent hematopoietic cell transplantation from HLA-matched siblings or alternative donors and analyzed the risk factors for PRES. Overall, 31 children developed calcineurin inhibitor-related PRES (11%), including 30 patients with seizures and 1 patient without seizures. PRES incidence was significantly higher in SCD patients (22%; 95% confidence interval [CI], 10% to 32%) than in thalassemia patients (8%; 95% CI, 5% to 12%;P = .002). In multivariate analysis, factors associated with PRES were hypertension (hazard ratio [HR], 5.87; 95% CI, 2.57 to 13.43; P = .0001), SCD (HR, 2.49; 95% CI, 1.25 to 4.99; P = .009), and acute GVHD (HR 2.27; 95% CI, 1.06 to 4.85; P= .031). In the entire cohort overall survival (OS) was significantly higher in patients without versus with PRES (90% versus 77%; P = .02). In a subgroup analysis that including matched sibling transplants, OS and disease-free survival (DFS) were similar in thalassemia patients without PRES (92% and 88%, respectively) and with PRES (82% and 73%, respectively), whereas SCD patients with PRES had significantly lower OS (67%) and DFS (67%) than patients without PRES (94% and 94%, respectively; P = .008). Thus, SCD patients had a significantly higher incidence of PRES than thalassemia patients, and hypertension and GVHD were the 2 main risk factors for PRES in patients with hemoglobinopathies. Although PRES did not significantly influence survival in patients with thalassemia, patients with SCD had significantly lower survival after PRES.

Accuracy of advanced CT imaging in prediction of functional outcome after endovascular treatment in patients with large-vessel occlusion

Background and purpose Computed tomography perfusion (CTP) and multiphase CT angiography (mCTA) help selection for endovascular treatment (EVT) in anterior ischemic stroke (AIS). Our aim was to investigate the ability of perfusion maps and collateral score to predict functional outcome after EVT. Patients and methods Patients with M1-middle cerebral artery occlusion, evaluated by mCTA and CTP and treated with EVT within six hours of onset, were enrolled. Perfusion parametric maps of cerebral blood flow (CBF), cerebral blood volume (CBV) and time to maximum of tissue residue function (Tmax) were generated; areas of altered perfusion were manually outlined to obtain volumes CBFv, CBVv, T max , v 16 - 25 s and T max , v 9 . 5 - 25 s . Diffusion-weighted imaging (DWI) at 24–36 hours was used to manually outline the ischemic core (volume: DWIv). Collateral vessels were assessed on mCTA considering extent and delay of maximal enhancement (six-point scale). Functional outcome was evaluated by modified Rankin Scale score at three months. Volumes in good and poor outcome groups were compared by Wilcoxon rank-sum test t, and their discriminative ability for outcome was determined by receiver operating characteristic analysis. A logistic regression model, including Tmax, CBF and collaterals, was used to differentiate good and poor outcome. Results Seventy-one patients (mean age 75 ± 11 years, range 45–99 years) were included. T max , v 16 - 25 s , T max , v 9 . 5 - 25 s , CBVv, CBFv and DWIv were statistically different between the two groups. CBF had the best discriminative value for good and poor outcome (area under the curve (AUC) 0.73; 64.5% sensitivity; 74.4% specificity); the logistic regression model might be promising (AUC 0.79, 64.5% sensitivity, 82.1% specificity). Conclusions In patients with AIS, the combined use of CTP and mCTA predicts functional outcome of EVT and might allow better selection.

Radiation-induced parotid changes in oropharyngeal cancer patients: the role of early functional imaging and patient−/treatment-related factors

BackgroundFunctional magnetic resonance imaging may provide several quantitative indices strictly related to distinctive tissue signatures with radiobiological relevance, such as tissue cellular density and vascular perfusion. The role of Intravoxel Incoherent Motion Diffusion Weighted Imaging (IVIM-DWI) and Dynamic Contrast-Enhanced (DCE) MRI in detecting/predicting radiation-induced volumetric changes of parotids both during and shortly after (chemo)radiotherapy of oropharyngeal squamous cell carcinoma (SCC) was explored.MethodsPatients with locally advanced oropharyngeal SCC were accrued within a prospective study offering both IVIM-DWI and DCE-MRI at baseline; IVIM-DWI was repeated at the 10th fraction of treatment. Apparent diffusion coefficient (ADC), tissue diffusion coefficient Dt, perfusion fraction f and perfusion-related diffusion coefficient D* were estimated both at baseline and during RT. Semi-quantitative and quantitative parameters, including the transfer constant Ktrans, were calculated from DCE-MRI. Parotids were contoured on T2-weighted images at baseline, 10th fraction and 8th weeks after treatment end and the percent change of parotid volume between baseline/10th fr (∆Vol10fr) and baseline/8th wk. (∆Volpost) computed.Correlations among volumetric changes and patient-, treatment- and imaging-related features were investigated at univariate analysis (Spearman’s Rho).ResultsEighty parotids (40 patients) were analyzed. Percent changes were 18.2 ± 10.7% and 31.3 ± 15.8% for ∆Vol10fr and ∆Volpost, respectively. Among baseline characteristics, ∆Vol10fr was correlated to body mass index, patient weight as well as the initial parotid volume. A weak correlation was present between parotid shrinkage after the first 2 weeks of treatment and dosimetric variables, while no association was found after radiotherapy. Percent changes of both ADC and Dt at the 10th fraction were also correlated to ∆Vol10fr. Significant relationships were found between ∆Volpost and baseline DCE-MRI parameters.ConclusionsBoth IVIM-DWI and DCE-MRI can help to detect/predict early (during treatment) and shortly after treatment completion the parotid shrinkage. They may contribute to clarify the correlations between volumetric changes of parotid glands and patient−/treatment-related variables by assessing individual microcapillary perfusion and tissue diffusivity.

Pleural thymoma: Radiological and histological findings

Epithelial thymic tumors (thymoma and thymic carcinoma) are rare neoplasms. The incidence of thymomas is estimated to be 0.15 cases per 100.000 persons/year in the USA [1] and it represents less than 1% of primary malignancies in adults. However, it remains the most common primary neoplasm of the anterior mediastinum, accounting for 20% of tumors in this location [2]. Ectopic thymomas have been described in the neck, middle mediastinum, posterior mediastinum, lung and pleura; few reports have described giant intrathoracic tumors, but they account only 4% of all thymomas [3,4]. Usually, about 70% of patients with thymomas remains asymptomatic; the rest of patients may present local symptoms related to tumor encroaching on surrounding structures like cough, chest pain, superior vena cava syndrome, dysphagia, and hoarseness of voice. Only 30% of patients with thymoma has clinic related to myasthenia gravis. An additional 5% of patients have other systemic syndromes including red cell aplasia, dermatomyositis, systemic lupus erythematous, Cushing syndrome and syndrome of inappropriate antidiuretic hormone secretion (SIHAD) [5]. The aim of this report is to describe the main radiological finding on X-ray, computed tomography (CT) and positron emission tomography (PET), in a case of pleural thymoma. We also report how perform radiological thymoma staging. 2. Case discussion

Cerebral blood volume lesion extent predicts functional outcome in patients with vertebral and basilar artery occlusion

Background CT perfusion may improve diagnostic accuracy in posterior circulation stroke. The posterior circulation Acute Stroke Prognosis Early CT score (pc-ASPECTS) on Computed Tomography Angiography source images (CTA-SI) predicts functional outcome in patients with basilar artery occlusion. Aims We assessed the prognostic value of pc-ASPECTS on CT perfusion in patients with vertebral and basilar artery occlusion (VBAO) in comparison with CTA-SI. Methods Whole-brain CT perfusion from consecutive stroke patients with VBAO at four stroke centers was retrospectively analyzed. pc-ASPECTS – a 10-point score assessing hypoattenuation on CTA-SI – was calculated from CT perfusion parameters as focally reduced cerebral blood flow or cerebral blood volume, focally increased time to peak of the deconvolved tissue residue function (Tmax) or mean transit time. Two investigators independently reviewed the images. Reliability was assessed with intraclass correlation coefficient. Good outcome was defined as modified Rankin scale ≤3 at three months. Results We included 60 patients with VBAO. After assessment of four CT perfusion maps simultaneously, area-under-ROC curve (AROC) was 0.83 (95%CI 0.72–0.93) for cerebral blood volume, 0.76 (95%CI 0.64–0.89) for cerebral blood flow, 0.77 (95%CI 0.64–0.89) for Tmax, 0.70 (95%CI 0.56–0.84) for mean transit time versus area-under-ROC curve 0.64 (95%CI 0.50–0.79) for CTA-SI. Cerebral blood volume had greater accuracy compared with CTA-SI for poor outcome (p = 0.04). In logistic regression analysis, cerebral blood volume pc-ASPECTS≤8 was independently associated with poor outcome (OR 9.3 95%CI 2.2–41; p = 0.003, adjusted for age and clinical severity). Inter-rater agreement was substantial for cerebral blood volume pc-ASPECTS (intraclass correlation coefficient 0.82 95%CI 0.71–0.90 versus 0.67 for CTA-SI 95%CI 0.43–0.81). Conclusions Cerebral blood volume pc-ASPECTS may identify VBAO patients at higher risk of disability.

Non-convulsive status epilepticus in a patient with carbon-monoxide poisoning treated with hyperbaric oxygen therapy.

The presentation of carbon monoxide poisoning is non-specific and highly variable. Hyperbaric oxygen therapy is used for the treatment of this condition. Various reports show the occurrence of self-limiting seizures after carbon monoxide poisoning and as a consequence of hyperbaric oxygen therapy. Contrary to the seizures, status epilepticus has been rarely observed in these conditions. The exact pathophysiology underlying seizures and status epilepticus associated with carbon monoxide poisoning and hyperbaric oxygen therapy is not really clear, and some elements appear to be common to both conditions. We describe a case of non-convulsive status epilepticus in a patient with carbon monoxide poisoning treated with hyperbaric oxygen therapy. The mechanism, MRI findings and implications are discussed.

Transient MR-angiography changes associated with morphological alterations in epileptic seizure: A short case series

• MRI is extremely helpful in detecting structural brain abnormalities associated with seizures