Considerations about Occlusion of the Intracranial Distal Internal Carotid Artery.

Occlusion of the intracranial distal internal carotid artery (ICA) is one of the most critical conditions among the cases of acute stroke in the anterior circulation. The introduction of selective endovascular treatment first using thrombolytic agents replaced later by the mechanical thrombectomy using various devices has improved the prognosis in a certain number of these patients. Among the factors influencing the prognosis of these patients, one is the collateral circulation which in these cases is mainly characterized by leptomeningeal anastomoses. The collateral can, however, be impaired, by distal embolization and by anomalies of the Circle of Willis: the aim of this study is to describe these aspects.

Characterization of a computed tomography iterative reconstruction algorithm by image quality evaluations with an anthropomorphic phantom.

OBJECTIVE: This study aims to investigate the consequences on dose and image quality of the choices of different combinations of NI and adaptive statistical iterative reconstruction (ASIR) percentage, the image quality parameters of GE CT equipment. METHODS: An anthropomorphic phantom was used to simulate the chest and upper abdomen of a standard weight patient. Images were acquired with tube current modulation and different values of noise index, in the range 10-22 for a slice thickness of 5mm and a tube voltage of 120 kV. For each selected noise index, several image series were reconstructed using different percentages of ASIR (0, 40, 50, 60, 70, 100). Quantitative noise was assessed at different phantom locations. Computed tomography dose index (CTDI) and dose length products (DLP) were recorded. Three radiologists reviewed the images in a blinded and randomized manner and assessed the subjective image quality by comparing the image series with the one acquired with the reference protocol (noise index 14, ASIR 40%). The perceived noise, contrast, edge sharpness and overall quality were graded on a scale from -2 (much worse) to +2 (much better). RESULTS: A repeatable trend of noise reduction versus the percentage of ASIR was observed for different noise levels and phantom locations. The different combinations of noise index and percentage of ASIR to obtain a desired dose reduction were assessed. The subjective image quality evaluation evidenced a possible dose reduction between 24 and 40% as a consequence of an increment of ASIR percentage to 50 or 70%, respectively. CONCLUSION: These results highlighted that the same patient dose reduction can be obtained with several combinations of noise index and percentages of ASIR, providing a model with which to choose these acquisition parameters in future optimization studies, with the aim of reducing patient dose by maintaining image quality in diagnostic levels.

Cerebral venous thrombosis: role of CT, MRI and MRA in the emergency setting.

PURPOSE: It is often difficult to diagnose cerebral venous thrombosis (CVT), an uncommon condition that more frequently affects young subjects, is responsible for 1%-2% of strokes in adults and has a subtle clinic onset. The aim of this study was to evaluate the role of computed tomography (CT), magnetic resonance imaging (MRI) and MR venography in the emergency setting and to discuss the risk factors, clinical presentation, outcome and follow-up of this disease. MATERIALS AND METHODS: We retrospectively studied 40 patients with CVT admitted to the emergency department between 1996 and 2006 and examined with unenhanced CT, MRI and MR venography. Fourteen patients also underwent digital subtraction angiography (DSA). RESULTS: Headache was the most common presenting feature (60%). Unenhanced CT showed typical signs (cord or empty delta sign) in 11 cases and nonspecific signs in the other cases. The diagnosis was achieved with MRI and MR venography in 38/40 cases (95%) and with DSA in 2/40 cases. All patients were treated with heparin. Five patients died, and only one of the remaining patients developed serious disability. CONCLUSIONS: Knowledge of the CT, MRI and MR-venography signs of CVT is crucial and enables an early diagnosis and timely treatment with heparin in the majority of cases. DSA should be reserved for doubtful cases only.

Emergency catheter probe endoscopic sonography (CP-EUS): an effective procedure in the assessment of a bleeding gangliocytic paraganglioma.

Catheter probe endoscopic sonography is a relatively rapid and safe procedure, carried out during standard endoscopy, capable of distinguishing solid from cystic lesions and vascular from avascular masses. Herein we discuss the role of catheter probe endoscopic sonography in the emergency assessment of a patient with recent and severe bleeding from an ulcerated polyp, arising from the papilla. During the endoscopy, catheter probe endoscopic sonography showed the solid and submucosal nature of the lesion, suggesting its localised and benign nature and, most importantly, demonstrating the high risk of rebleeding from vascular structures communicating with the ulcer. Because of this finding three metallic endoclips were positioned. The lesion was not removed endoscopically because of its difficult position and the high risk of haemorrhage. The mass, removed through a duodenotomy, was shown to be a gangliocytic paraganglioma, an uncommon tumour, frequently resulting in surgery because of abdominal pain and gastrointestinal bleeding.

Evidence-based medicine and radiology: how to build a guideline. An attempt in minor head injury.

PURPOSE: To evaluate the use of Evidence-based Medicine (EBM) to build radiological Guidelines, with the aim to have a better compliance by users. It has been decided to work on minor head injury, where we have found, in our institution, a wide and unjustified use of conventional skull x-ray. MATERIAL AND METHODS: A Workgroup, that reunites the main figures that enter in the management of the patient with minor head injury, has been created within our Hospital. The bibliography relative to the problem has been selected, employing criteria that held account of the methodological correctness, and in particular the existing Guidelines have been carefully analysed. It is therefore proceeded drawing up a Guideline that adhered to the principles of the EBM, adapting it to the hospital environment. Subsequently it has been passed to the phase of its implementation, with reunions in small groups of the involved professional figures, the distribution of informative material and the use of poster that reassumed the diagnostic flow-chart. Moreover a survey of the relative data to the number of skull x-ray and brain TC, executed in the patients with head trauma, has been completed. RESULTS: The analysis of the data relative to the variation of the number of demands for skull Rx after introduction of the Guideline has demonstrated a great reduction (-83,8%), with little variation of the number of brain TC (+17,0%); such reduction has naturally implicated an important reduction of costs (-25,2%) and of the x-ray dose to population, measured to the crystalline (34,5%) and to thyroid (-71,0%). CONCLUSIONS: The employ of the EBM in the Guideline creation, beyond representing the more correct methodology, concurs to obtain a greater adhesion from the users involved in management of the patient; in particular this happens if the Guideline is a product of a vast contribution and if it is supported from all additional procedures that can be useful for its implementation.

Disappearance of central pain following iatrogenic stroke.

An exceptional case of long-standing central pain temporarily relieved by a focal stroke in the primary somatosensory area is reported. This case highlights the focal nature of central pain mechanisms and the possible value of selective subparietal leukotomies in the management of central pain.

[Isolated neurofibroma of the stomach. Case report and review of the literature]. / Il neurofibroma isolato dello stomaco. Descrizione di un caso e revisione della letteratura.

An uncommon case of gastric neurofibroma is described: it was an incidental finding during assessment for abdominal pain, possibly due to pancreatitis, in a 58 year old man, with no sign of von Recklinghausen's disease. The generic diagnosis of gastric wall neoplasia was made by CT scanning; the neoplasm was resected with wedge resection of gastric wall. Histological and ultrastructural examination revealed a neurofibroma. Gastrointestinal stromal tumors are rare occurrence and usually are of smooth muscle derivation: a small percentage arises from nerve sheet, but such a distinction is never sharp. Neurogenic gastric tumors are usually benign and only 10% of von Recklinghausen associated neurofibromas can undergo malignant transformation. Wide excision of the tumor appears therefore the treatment of choice.

[Magnetic resonance in the study of residual mediastinal masses after therapy of lymphoma]. / La risonanza magnetica nello studio delle masse mediastiniche residue dopo terapia nei linfomi.

Forty-five patients with mediastinal spread of malignant, Hodgkin's and non-Hodgkin's lymphomas were examined with MR Imaging at 0.5 T. Ninety-two examinations were performed at diagnosis and/or during and after treatment to investigate MR capabilities in distinguishing fibrous tissue from active disease in the masses residuing after therapy--which cannot be done by means of CT. MR results indicated T2-weighted sequences to be the most useful. MR results were compared with the data collected from follow-up, clinics, and biology. MR Imaging had high accuracy (92.1%). The number of false negatives was very low, thanks to the low intensity of fibrous tissue, while a relatively high number of false positives was observed, probably due to the difficulties in discriminating inflammatory from neoplastic tissue.

Role of thoracic computed tomography in the treatment plan of Hodgkin's disease.

Conventional chest X-rays and CT scans, performed at the time of the initial staging in 67 patients affected by Hodgkin's disease, were reviewed and compared. CT scans provided evidence of disease not shown by concomitant conventional chest X-rays in 10 patients (15%). The impact on patient management of the additional CT data was evident in 8 cases (11.9%), either changing the whole treatment plan (4 patients) or enlarging radiation ports (4 patients). Traditional prognostic features did not influence the outcome, and only hilar adenopathy adversely affected event-free survival, without however reaching statistical relevance (p greater than 0.05). Our data suggest that thoracic CT scan is helpful in drawing up the treatment plan, while its role in identifying new prognostic factors is still uncertain.