Role of non-coding RNAs in age-related vascular cognitive impairment: An overview on diagnostic/prognostic value in Vascular Dementia and Vascular Parkinsonism.

Age is the pivotal risk factor for different common medical conditions such as cardiovascular diseases, cancer and dementia. Among age-related disorders, cardiovascular and cerebrovascular diseases, represent the leading causes of premature mortality strictly related to vascular ageing, a pathological condition characterized by endothelial dysfunction, atherosclerosis, hypertension, heart disease and stroke. These features negatively impact on the brain, owing to altered cerebral blood flow, neurovascular coupling and impaired endothelial permeability leading to cerebrovascular diseases (CVDs) as Vascular Dementia (VD) and Parkinsonism (VP). It is an increasing opinion that neurodegenerative disorders and cerebrovascular diseases are associated from a pathogenetic point of view, and in this review, we discuss how cerebrovascular dysfunctions, due to epigenetic alterations, are linked with neuronal degeneration/dysfunction that lead to cognitive impairment. The relation between neurodegenerative and cerebrovascular diseases are reviewed with a focus on role of ncRNAs in age-related vascular diseases impairing the endothelium in the blood-brain barrier with consequent dysfunction of cerebral blood flow. In this review we dissert about different regulatory mechanisms of gene expression implemented by ncRNAs in the pathogenesis of age-related neurovascular impairment, aiming to highlight the potential use of ncRNAs as biomarkers for diagnostic/prognostic purposes as well as novel therapeutic targets.

MR Imaging of Bilateral Paramedian Thalamic and Mesencephalic Infarcts. A Case Report.

We describe MR imaging of bilateral infarction of the paramedian portion of the mesencephalus and thalamus due to an occlusion of the Percheron artery. This entity is due to one of the anatomic variants of the perforating arteries supplying the thalamus and mesenchephalus. Clinically this kind of infarction presents with neurologic impairment as a disorder of consciousness, memory dysfunctions, various types of vertical gaze palsy and psychic changes, which need to be differentiated from delirium and coma. At MRI evaluation infarction of the paramedian portion of thalami and midbrain, with a "butterfly wings" pattern, was demonstrated as high signal intensity areas on FLAIR and FSE-T2W images and with diffusion restriction on DWI images.

Imaging processing for CT angiography of the cervicocranial arteries: evaluation of reformatting technique.

PURPOSE: The aim of this study was to compare computed tomography angiography (CTA) sliding-thin-slab (STS) multiplanar reformatting (MPR), STS maximum intensity projection (MIP) and three-dimensional (3D) volume rendering (VR) reformatting techniques in the evaluation of cervicocranial arteries. MATERIALS AND METHODS: Twenty patients examined with multislice CT were included in this study. CTA images were reformatted as STS-MIP, STS-MPR and 3DVR in orthogonal planes and in the oblique-coronal plane. Images were evaluated in consensus by two radiologists, with a third radiologist to resolve discordances in grading image quality parameters. The Spearman correlation analysis was performed to compare results and to obtain the correlation between scores resulting from the evaluation of parameters considered with the different techniques used (STSMIP, STS-MPR and 3DVR). RESULTS: STS-MIP images were significantly superior to STSMPR images for all parameters considered (p<0.05). Obliquecoronal 3DVR images were significantly superior to obliquecoronal STS-MIP images in the evaluation of vertebrobasilar vessels (p<0.05); in all other cases, 3DVR images were equivalent to STS-MIP images. CONCLUSION: STS-MIP images should be the primary reformatting technique for CTA of the cervicocranial arteries in addition to viewing the source images; 3DVR images can play an important role after a previsional diagnosis is made on the STS-MIP images.

Perfusion CT in acute stroke: predictive value of perfusion parameters in assessing tissue viability versus infarction.

PURPOSE: The aim of this study was to assess the value of computed tomography (CT) perfusion parameters in differentiating tissue viability in acute stoke patients. MATERIALS AND METHODS: Thirteen patients (mean age 63.3 years) with nonhaemorrhagic stroke underwent multidetector perfusion CT within 3 h of symptom onset. Images were continuously acquired at the basal ganglia over 40 s during injection of 90 ml of iodinated contrast medium injected at a rate of 9 ml/s with a 9-s delay. Z-axis coverage was 20 mm. All patients underwent diffusion-weighted magnetic resonance imaging (DWI) within 12 h of perfusion CT to define the extent of the infarct. Perfusion CT data were analysed in regions of interests (ROIs) on regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF) and mean transit time (MTT) maps placed in various parts of the perfusion-deficient territory and in the contralateral hemisphere. Statistical analysis was performed using the analysis of variance (ANOVA) test to assess differences in CT perfusion parameters. Receiver operator characteristics (ROC) analysis was performed to assess possible threshold values that predict tissue infarction vs. viability. RESULTS: Normal CT findings with abnormal CT perfusion parameters were seen in the region of infarction and in the viable tissue (penumbra) within a 1.5-cm distance from the infarct margin as outlined on DWI images. Infarcted areas demonstrated significant prolongation of MTT values compared with noninfarcted areas (p<0.0001). Average MTT was 9.8 s in areas of infarction, 5.1 s in the viable tissue adjacent to the infarct (penumbra), and 3.4 s in the contralateral control area. An MTT threshold level of 6.05 s has a 100% positive predictive value (sensitivity 84.6%, specificity 100%, accuracy 92.3%) for the presence of infarcted tissue. Average rCBF was 24.6 ml/100 g per min in infarcted tissue, 64.8 in penumbra and 70.8 in normal tissue. Average rCBV was 3.5 ml/100g in infarcted tissue, 3.9 in penumbra and 2.9 in normal tissue. CONCLUSIONS: Prolongation of MTT was the most frequent CT perfusion finding observed in acute stroke patients. Average MTT values of 5.1 s may distinguish viable tissue, whereas MTT values >6.05 s identify infarcted tissue.

Gastrointestinal stromal tumour: 40-row multislice computed tomography findings.

PURPOSE: The purpose of this study was to describe the findings and evaluate the role of multidetector (40-slice) computed tomography (MDCT) in the preoperative assessment of gastrointestinal stromal tumours (GISTs). MATERIALS AND METHODS: Thirteen patients with histologically proven GIST (size: 4-30 cm; mean: 9 cm) underwent 40-slice MDCT after the ingestion of 1,000 ml of water. Images were obtained before and 70 s after intravenous injection of 120 ml of iodinated contrast agent. Two experienced radiologists reviewed the CT findings to evaluate lesion site, size, margins, attenuation, growth pattern, enhancement pattern, ascites, lymphadenopathy, direct invasion to adjacent organs and distant metastasis. Multiplanar maximum intensity projection and three-dimensional (3D) reconstructions were also obtained. RESULTS: Seven out of 13 GISTs were located in the jejunumileum, 3/13 in the stomach, 2/13 in the rectum and in one case, the origin remained unknown. Eleven out of 13 were exophytic, and ten had well-defined borders. Two out of 13 showed calcifications. Thirteen out of 13 exhibited inhomogeneous enhancement due to areas of necrosis and cystic degeneration. Direct invasion to adjacent organs (n=3), ascites (n=3), and liver (n=1) and peritoneal (n=1) metastases were also detected. Bowel obstruction, vascular invasion and lymphadenopathy were never seen. CONCLUSIONS: MDCT allowed reliable preoperative assessment of GIST, providing useful clues for lesion characterisation.

Pitfalls and limitations of Magnetic Resonance Imaging in bucket-handle tears of knee menisci.

PURPOSE: The aim of the present study was to assess the accuracy of magnetic resonance imaging (MRI) in the diagnosis of bucket-handle tears of the knee menisci, determining the sensitivity and specificity of the imaging for each of the signs typical of these tears. MATERIALS AND METHODS: MR examinations of 495 patients suffering from knee traumas were assessed retrospectively. Forty-eight patients had arthroscopically-proven bucket-handle tears of the meniscus. MR examinations were performed using a 0.5-T superconducting magnet, with T1-weighted spin-echo (SE) and gradient-echo (GE) T2*-weighted sequences. Imaging findings used for the diagnosis were: a) double posterior cruciate ligament sign; b) flipped meniscus sign; c) presence of a displaced fragment of the meniscus in the intercondylar notch, visible in coronal and axial images; d) truncated triangular shape of the peripheral non-displaced portion of the meniscus, visible in coronal images. RESULTS: A total of 43 out of 48 bucket-handle tears of the meniscus were correctly diagnosed at MR, thus overall MR accuracy was 98%. In 12 (28%) cases three signs were present simultaneously the double posterior cruciate ligament (sensitivity 28%, specificity 99%, accuracy 93%) + the displaced fragment in the intercondylar notch (sensitivity 69.8%, specificity 98.7%, accuracy 96.2%) + the truncated triangular shape of the peripheral portion of the meniscus (sensitivity 74.4%, specificity 98%, accuracy 96%). In 18 (42%) cases two signs were present together the displaced fragment of the meniscus + the truncated triangular shape of the peripheral portion of the meniscus. In 13 (30%) cases only one sign was presenting two cases the truncated triangular shape of the peripheral portion of the meniscus and in 11 cases the flipped meniscus sign (sensitivity 25.6%, specificity 93.4%, accuracy 87.5%). No statistically significant differences were found comparing the results for tears of the medial meniscus with those for the lateral meniscus. CONCLUSIONS: MR imaging is highly accurate in diagnosing bucket-handle tears of the menisci due to its ability to identify a displaced fragment of the meniscus in the intercondylar notch or flipped over the anterior horn of the meniscus of origin. We speculate that bucket-handle tears not found by MR imaging are cases where the meniscus was displaced after MR examination.

[Thrombolytic therapy in myocardial infarction. Computerized tomography of encephalic complications]. / Terapia trombolitica nell'infarto del miocardio. Aspetti con Tomografia Computerizzata della complicanze encefaliche.

PURPOSE: To evaluate the CT findings of intracerebral hemorrhage in patients undergoing thrombolytic therapy for acute myocardial infarction and to correlate the type of intracerebral hemorrhage with clinical outcome. MATERIAL AND METHODS: We retrospectively reviewed the clinical records and CT scans of intracerebral hemorrhage on a total of 302 patients who underwent thrombolytic therapy for acute myocardial infarction at our institution from January 1996 to September 1999. In each patient we evaluated: the number, sites and size of hemorrhage, and the presence and severity of mass effect. The site of the hemorrhage was classified as intraparenchymal, intraventricular, subdural and subarachnoid. RESULTS: Six patients (2%, mean age 74, range 66-80) developed intracerebral hemorrhage. There was a total of 22 hemorrhages: 1 subdural hemorrhage, 6 subarachnoid, 11 intraparenchymal and 4 intraventricular. Excluding intraventricular hemorrhage, 14/18 hemorr-hages were located supratentorially. In five patients there was a fluid-blood level. Three patients had severe mass effect with midline shift. Symptoms presented within 24 hours from the administration of thrombolytic therapy in all patients. All the patients who died had a large hematoma with a severe mass effect and a severe midline shift at CT scan. In the remaining patients, the hematoma was of medium size and no mass effect was seen. CONCLUSIONS: The most common site of hemorrhage was supratentorial and intraparenchymal. Large volume intracerebral hemorrhage, multiple hemorrhages and mass effect with midline shift were associated with increased mortality. The most commonly observed finding was a fluid-blood level hematoma.

Retroaortic left renal vein joining the left common iliac vein.

Retroaortic left renal vein joining the left common iliac vein is a rare congenital anomaly in the development of the inferior vena cava. To our knowledge, only one case has been reported in the literature; however, its imaging features have never been described. A 27-year-old male presented with a 1-year history of recurrent right flank pain, dysuria, hematuria, and fever (39 degrees C). Computed tomography and MR venography showed a retroaortic left renal vein joining the left common iliac vein. We present the CT and MR venography findings and discuss their feasibility in showing this congenital anomaly.

Transfusional hemochromatosis: quantitative relation of MR imaging pituitary signal intensity reduction to hypogonadotropic hypogonadism.

PURPOSE: To assess the relationship between magnetic resonance (MR) imaging pituitary signal intensity reduction in patients with transfusional hemochromatosis and the clinical manifestation of hypogonadotropic hypogonadism. MATERIALS AND METHODS: Pituitary MR imaging at 0.5 T was performed in 38 consecutive patients affected by secondary hemochromatosis and in 20 healthy volunteers. Serum ferritin levels were estimated in the affected population. Twenty (53%) of the 38 patients had hypogonadotropic hypogonadism diagnosed. Pituitary-to-fat signal intensity ratios were calculated from coronal gradient-echo (GRE) T2*-weighted MR images. The relationship between the quantitative reduction of the pituitary-to-fat signal intensity ratio and the clinical manifestation of pituitary dysfunction was assessed in the affected population. Signal intensity reduction in the anterior lobe of the pituitary gland was also correlated with the serum ferritin level. RESULTS: The degree of reduction of the pituitary-to-fat signal intensity ratio correlated with the presence of hypogonadotropic hypogonadism, with a sensitivity of 90%, a specificity of 89%, and an overall accuracy of 89%. In addition, the reduction of pituitary signal intensity was greater in patients with higher ferritin levels (r = -0.55, r(2) = -0.30, P <.001). CONCLUSION: The degree of signal intensity reduction, measured as the pituitary-to-fat signal intensity ratio for GRE T2*-weighted images, in patients with secondary hemochromatosis correlates with the severity of pituitary dysfunction.

Brain damage in hanging: a new CT finding.

We report a 23-year-old man who attempted suicide by hanging. There have been few reports of involvement of the brain parenchyma shown on CT, all showing ischaemic lesions. This is the first report of multifocal intracerebral haematomas due to hanging seen on CT.

Magnetic resonance imaging of the pituitary gland in patients with secondary hypogonadism due to transfusional hemochromatosis.

To identify pituitary iron overload in patients with transfusional hemochromatosis causing secondary hypogonadism, we prospectively evaluated signal intensity abnormalities of the anterior lobe of the pituitary gland of 18 patients affected by transfusion-dependent thalassemia major and secondary hypogonadism. Magnetic resonance (MR) imaging is useful to assess pituitary iron overload in patients with transfusional hemochromatosis and secondary hypogonadism by detection of a significant decreased signal intensity of the anterior lobe of the pituitary gland on GRE T2*-weighted images. The decreased signal intensity of the anterior lobe of the pituitary gland on GRE T2*-weighted images was correlated to increasing serum ferritin level (r = -0.84, r2 = -0.70, P < 0.001). Indeed, the lower the signal intensity of the pituitary gland, the greater the serum ferritin level. However an exact quantification of pituitary iron overload by correlation with serum ferritin level is not allowed. No correlation was found between MR imaging results and hormonal status; however, the detection of pituitary iron overload on GRE T2*-weighted images is consistent with the hypothesis of hypogonadotrophic pituitary insufficiency due to iron-induced cellular damage.

Reversible MRI abnormalities in an unusual paediatric presentation of Wernicke's encephalopathy.

BACKGROUND: We report an unusual paediatric presentation of acute Wernicke's encephalopathy in a 12-year-old boy affected by chronic gastrointestinal disease. MRI demonstrated, in addition to the typical diencephalic and mesencephalic signal abnormalities on T2-weighted images, enhancement of the mammillary bodies and the floor of the hypothalamus. MATERIALS AND METHODS: Following parenteral administration of thiamine for 4 days, the patient recovered from his neurological deficits and on follow-up enhanced MRI 1 month later, no signal abnormalities were found nor was there diencephalic or mesencephalic atrophy, as is usual in the chronic phase of the disease. RESULTS: MRI provides crucial information in the diagnosis of Wernicke's encephalopathy, either in the acute or chronic phases of the disease. CONCLUSION: Our report provides an additional clue for recognition of the acute phase of the disease; enhancement of the floor of the hypothalamus has not previously been described despite its recorded involvement at autopsy.

[Cerebral vascular autoregulatory dysfunction. Neuroradiologic aspects]. / Encefalopatia da disreattività vasoregolatoria cerebrale. Aspetti neuroradiologici.

PURPOSE: We report the neuroimaging findings in a group of systemic disorders with a common pathophysiological pattern of derangements in cerebral vascular autoregulatory mechanism producting potentially reversible brain lesions. MATERIAL AND METHODS: We reviewed the brain CT and MR examinations of 14 patients with clinical diagnosis of vasculopathy not related to atherosclerosis or cardiogenic embolism. The patients were admitted at the onset of neurologic deficit and were affected with one of the following systemic disorders: thrombotic thrombocytopenic purpura (TTP, 6 cases), uremic encephalopathy (4 cases), eclampsia (2 cases), 1 chronic renal failure from systemic lupus erythematosus and 1 cyclosporin neurotoxicity. All patients underwent neuroimaging follow-up within 7-20 days of the onset of neurologic deficit and the start of anti-edema therapy. RESULTS: CT and MR findings were characterized by cortical-subcortical or deep brain lesions related to edema. Ten patients presented bilateral lesions, which were symmetric in 4 cases. Edema resolution was demonstrated on follow-up examinations after therapy in 4 patients (2 with eclampsia, 1 with TTP and 1 with uremic encephalopathy). The lesions showed no signs of regression in 10 patients. CONCLUSIONS: Brain lesions with a common pathogenesis from derangements in vascular autoregulatory mechanism--i.e., not due to atherosclerosis or cardiogenic embolism--should be properly and promptly recognized because they can be reversible and readily treatable.

MR imaging of pancreatic changes in patients with transfusion-dependent beta-thalassemia major.

OBJECTIVE: The aim of this study was to evaluate MR imaging changes of the pancreas in patients with transfusion-dependent beta-thalassemia major. SUBJECTS AND METHODS: Twenty patients with transfusion-dependent beta-thalassemia major were examined using MR imaging at 0.5 T, with spin-echo T1-weighted, fast spin-echo T2-weighted, and gradient-echo T2*-weighted sequences. Image analysis was performed to assess pancreas-to-fat signal intensity ratios for all pulse sequences. Pancreatic exocrine and endocrine function and serum ferritin levels were assessed. Twenty healthy volunteers underwent MR imaging with the same three sequences and served as a control group. RESULTS: The pancreas-to-fat signal intensity ratio was significantly decreased in 17 (85%) of the 20 patients on spin-echo T1-weighted images (p < .05), fast spin-echo T2-weighted images (p < .01), and gradient-echo T2*-weighted images (p < .01) when compared with the 20 volunteers in the control group. The pancreas-to-fat signal intensity ratio was significantly increased in three (15%) of the 20 patients on spin-echo T1-weighted images (p < .01) and fast spin-echo T2-weighted images (p < .05). In addition, in the 20 patients, we found a significant correlation between increased pancreas-to-fat signal intensity ratios and decreased serum trypsin levels (r = -.77, p < .01 for spin-echo T1-weighted sequences; r = -.75, p < .05 for fast spin-echo T2-weighted sequences; and r = -.74, p < .05 for gradient-echo T2*-weighted sequences). Likewise, for the 20 patients, we found a significant correlation between decreased pancreas-to-fat signal intensity ratios and increased serum ferritin levels for gradient-echo T2*-weighted images (r = -.65, p < .01). No correlation was found for the other clinical parameters evaluated. CONCLUSION: MR imaging revealed signal intensity changes in the pancreas of patients with transfusion-dependent beta-thalassemia major. Patients with a major impairment of the exocrine pancreatic function had higher signal intensity of the pancreas because of fatty replacement of the parenchyma.