Search results for "diagnostic radiology"
showing 10 items of 58 documents
Automatic classification of tissues on pelvic MRI based on relaxation times and support vector machine
2019
International audience; Tissue segmentation and classification in MRI is a challenging task due to a lack of signal intensity standardization. MRI signal is dependent on the acquisition protocol, the coil profile, the scanner type, etc. While we can compute quantitative physical tissue properties independent of the hardware and the sequence parameters, it is still difficult to leverage these physical properties to segment and classify pelvic tissues. The proposed method integrates quantitative MRI values (T1 and T2 relaxation times and pure synthetic weighted images) and machine learning (Support Vector Machine (SVM)) to segment and classify tissues in the pelvic region, i.e.: fat, muscle, …
Aortic Function's Adaptation in Response to Exercise-Induced Stress Assessing by 1.5T MRI : A Pilot Study in Healthy Volunteers
2015
AIM:Evaluation of the aortic "elastic reserve" might be a relevant marker to assess the risk of aortic event. Our aim was to compare regional aortic elasticity at rest and during supine bicycle exercise at 1.5 T MRI in healthy individuals. METHODS:Fifteen volunteers (8 men), with a mean age of 29 (23-41) years, completed the entire protocol. Images were acquired immediately following maximal exercise. Retrospective cine sequences were acquired to assess compliance, distensibility, maximum rates of systolic distension and diastolic recoil at four different locations: ascending aorta, proximal descending aorta, distal descending aorta and aorta above the coeliac trunk level. Segmental aortic …
Sudden sensorineural hearing loss associated with inner ear lesions detected by magnetic resonance imaging.
2017
Although recent advances in magnetic resonance imaging (MRI) techniques have contributed to the detection of tiny lesions in the internal auditory canal (IAC) that may be responsible for sudden sensorineural hearing loss (SSNHL), there have been relatively few studies on the clinical characteristics of intra-labyrinthine hemorrhage (ILH) and labyrinthitis versus those regarding IAC tumors. Our purpose was to investigate the frequency of those IAC lesions on MRI and their clinical characteristics. Initial MRIs of 200 patients with SSNHL (93 men, 107 women; mean age = 48.61 years, range: 18-84 years), as well as detailed clinical histories, audiological examinations, and thyroid function, lip…
Change in kidney volume after kidney transplantation in patients with autosomal polycystic kidney disease
2018
BackgroundThe indication to bilateral nephrectomy in patients with autosomal dominant polycystic kidney scheduled for kidney transplantation is controversial. Indeed, the progressive enlargement of cysts may increase the risk of complications and the need for nephrectomy. However, very few studies investigated the change in kidney volume after kidney transplantation.Material and methodsIn this prospective cohort study, the change in native kidney volume in polycystic patients was evaluated with magnetic resonance imaging. Forty patients were included in the study. Kidney diameters and total kidney volume were evaluated with magnetic resonance imaging in patients who underwent simultaneous n…
The Right Frontopolar Cortex Is Involved in Visual-Spatial Prospective Memory
2013
The involvement of frontopolar cortex in mediating prospective memory processes has been evidenced by various studies, mainly by means of neuroimaging techniques. Recently, one transcranial magnetic stimulation study documented that transient inhibition of left Brodmann Area (BA) 10 impaired verbal prospective memory. This result raises the issue of whether the BA 10 involvement in prospective memory functioning may be modulated by the physical characteristics of the stimuli used. The present study aimed to investigate the role of the frontopolar cortex in visual-spatial PM by means of the application of inhibitory theta-burst stimulation. Twelve volunteers were evaluated after inhibitory t…
The risk of intravenous thrombolysis-induced intracranial hemorrhage in Taiwanese patients with unruptured intracranial aneurysm.
2017
Background The presence of an intracranial aneurysm is contraindicated to recombinant tissue plasminogen activator (r-tPA) treatment for acute ischemic stroke. However, it is difficult to exclude asymptomatic intracranial aneurysms by using conventional, noncontrast head computed tomography (CT), which is the only neuroimaging suggested before r-tPA. Recent case reports and series have shown that administering r-tPA to patients with a pre-existing aneurysm does not increase the bleeding risk. However, Asians are known to have a relatively higher bleeding risk, and little evidence is available regarding the risk of using r-tPA on Asian patients with intracranial aneurysms. Methods Medical re…
The impact of portal vein tumor thrombosis on survival in patients with hepatocellular carcinoma treated with different therapies: A cohort study.
2020
Background Portal vein tumor thrombosis (PVTT) is a frequent complication of hepatocellular carcinoma (HCC), which leads to classification as advanced stage disease (regardless of the degree of PVTT) according to the Barcelona Clinic Liver Cancer Classification. For such patients, systemic therapy is the standard of care. However, in clinical reality, many patients with PVTT undergo different treatments, such as resection, transarterial chemoembolization (TACE), selective internal radiation therapy (SIRT), or best supportive care (BSC). Here we examined whether patients benefited from such alternative therapies, according to the extent of PVTT. Methods This analysis included therapy-naïve …
Invagination of the Sphenoid Sinus Mucosa after Endoscopic Endonasal Transsphenoidal Approach and Its Significance
2016
Objective To describe the clinical features of invagination of the sphenoid sinus mucosa (ISM) and compare them with other similar cases using a visual analog scale (VAS) to assess the various nasal symptoms and to discuss its clinical significance and means of prevention. Study design Retrospective chart review at a tertiary referral center. Methods Between 2010 and 2015, 8 patients who had undergone EETSA surgery displayed postoperative ISM. The comparison group consisted of 147 patients who underwent the same surgical procedures and were diagnosed with the same diseases. Pre- or postoperative paranasal sinus computed tomography (PNS CT) and VAS were performed and subsequently analyzed. R…
640-Slice CT Measurement of Superior Orbital Fissure as Gateway for Light into the Brain: Statistical Evaluation of Area and Distance.
2016
Objective Our aim was to provide normative data concerning superior orbital fissure area (SOFA), ocular skin and the substantia nigra (D-SS) and orbital fissure and the substantia nigra (D-SOF-S) distances by CT scan in adult Caucasian population. Methods The area of the superior orbital fissure (SOF), the distance between the ocular skin and the substantia nigra and the distance between the superior orbital fissure and the substantia nigra using CT and 3D-CT images. Results Normative data stratified for age and gender were obtained. The data here reported show that some degree of variability in SOFA, D-SS and D-SOF-S measurements can be observed healthy Caucasian subjects. Gender stratifie…
Caliper navigation for craniotomy planning of convexity targets.
2021
Introduction A technique to localize a radiological target on the head convexity fast and with acceptable precision is sufficient for surgeries of superficial intracranial lesions, and of help in the setting of emergency surgery, computer navigation breakdown, limited resources and education. We present a caliper technique based on fundamental geometry, with inexpensive and globally available tools (conventional CT or MRI image viewer, calculator, caliper). Methods The distances of the radiological target from two landmarks (nasion and porus acusticus externus) are assessed with an image viewer and Pythagoras’ theorem. The two distances are then marked around the landmarks onto the head of…