Search results for "Image"
showing 10 items of 6818 documents
Endothelin-1 and endothelin receptor status in kidney transplants undergoing acute rejection.
1999
Abstract Endothelin-1 (ET-1) is a potent vasoconstrictor with vasopressor and mitogenic effects. Blood samples were collected from 21 renal transplant patients undergoing acute rejection at the time of diagnostic kidney biopsy: there were 20 men and one woman, mean age 35.6 years. All patients were on triple immunosuppressive therapy with cyclosporine A, azathioprine and methylprednisolone. Twenty living kidney donors pre-uninephrectomy (11 men and nine women, mean age 34 years) served as controls. Control kidney was obtained from fresh autopsy material and normal kidney tissue from nephrectomies for malignancy. Mean plasma ET-1 was significantly increased at 1.56±0.2 pg ml −1 during acute …
Congenital Müllerian anomalies: diagnostic accuracy of three-dimensional ultrasound
1996
Objective To determine whether it is possible to identify and diagnose accurately Mullerian anomalies with three-dimensional (3-D) ultrasound (US). Design Controlled blinded clinical study. Setting Normal human volunteers undergoing infertility evaluation in a university hospital. Patients Forty-two patients who underwent laparoscopy and hysterosalpingography as part of their work up for infertility and were found to have either a normal uterus (30 patients) or a Mullerian abnormality (12 patients) consented to be evaluated with 3-D US by sonographers who were unaware of their infertility history or of their laparoscopy and hysterosalpingography diagnoses. Interventions Transvaginal 3-D US …
Intra‐ and interreader reproducibility of PI‐RADSv2: A multireader study
2018
Background The Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) has been in use since 2015; while interreader reproducibility has been studied, there has been a paucity of studies investigating the intrareader reproducibility of PI-RADSv2. Purpose To evaluate both intra- and interreader reproducibility of PI-RADSv2 in the assessment of intraprostatic lesions using multiparametric magnetic resonance imaging (mpMRI). Study type Retrospective. Population/subjects In all, 102 consecutive biopsy-naive patients who underwent prostate MRI and subsequent MR/transrectal ultrasonography (MR/TRUS)-guided biopsy. Field strength/sequences Prostate mpMRI at 3T using endorectal with phased…
Negative biopsy of focal hepatic lesions: Decision tree model for patient management
2019
OBJECTIVE. The purpose of this study was to investigate patient- and procedure-related variables affecting the false-negative rate of ultrasound (US)-guided liver biopsy and to develop a standardized patient-tailored predictive model for the management of negative biopsy results. MATERIALS AND METHODS. We retrospectively included 389 patients (mean age ± SD, 62 ± 12 years old) who had undergone US-guided liver biopsy of 405 liver lesions between January 1, 2013, and June 30, 2015. We collected multiple patient- and procedure-related variables. By comparing pathology reports of biopsy and the reference standard (further histology or imaging follow-up), we were able to categorize the biopsy r…
Subtemporal Keyhole Approach to the Suprasellar and Petroclival Region: Microanatomic Considerations and Clinical Application
1997
OBJECTIVE: To minimize surgical invasiveness, the keyhole concept is applied to the subtemporal approach. METHODS: Anatomic features were studied in 14 sides of adult cadaver heads, and the technique was used in 162 interventions. Although most of the lesions treated were 3 cm in size or smaller, larger lesions were also treated using this technique. In some cases, if needed, an endoscope-assisted microsurgical technique was used. RESULTS: The cadaveric study provided intimate experience with the microsurgical anatomy of the approach. The 162 consecutive patients who were operated on harbored various types of lesions; the most recent 43 consecutive interventions were investigated in detail.…
3D TOF MR Angiography of Cerebral Arteriovenous Malformations after Radiosurgery
1993
To investigate the potential of three-dimensional time-of-flight MR angiography (MRA) to complement SE imaging, 18 patients with intracerebral arteriovenous malformations were prospectively followed after undergoing radiosurgery. Vessel occlusion after stereotaxic single high dose radiotherapy develops slowly. The MRA detected signs of nidus obliteration earlier and with a higher sensitivity than did SE imaging. Six months after radiosurgery, MRA showed a reduction of the nidus flow signals in nine patients and after 1 year it showed reduction in 15 of the 18 patients. As shown by MRA, the loss of flow signals was related to a reduction of the nidus size in 4 patients after 6 months and in …
Middle patellar tendon to posterior cruciate ligament (PT–PCL) and normalized PT–PCL: New magnetic resonance indices for tibial tubercle position in …
2018
BACKGROUND To demonstrate whether the distance between the middle point of the patellar tendon and posterior cruciate ligament (PT-PCL) calculated on a single axial MR image could be an alternative measure to tibial tubercle-PCL (TT-PCL) distance for TT lateralization without the need of imaging processing. To show that normalization of PT-PCL (nPT-PCL) against the maximum diameter of the tibial plateau may help to identify patients with patellar instability (PI). METHODS MR scans of 30 patients (13 females, age 32 ± 13 years) with known PI and 60 patients (31 females, age 39 ± 19 years) with no history of PI were reviewed. Two operators calculated TT-PCL, and PT-PCL nPT-PCL. Intraclass cor…
Noise estimation from averaged diffusion weighted images: Can unbiased quantitative decay parameters assist cancer evaluation?
2013
Purpose Multiexponential decay parameters are estimated from diffusion-weighted-imaging that generally have inherently low signal-to-noise ratio and non-normal noise distributions, especially at high b-values. Conventional nonlinear regression algorithms assume normally distributed noise, introducing bias into the calculated decay parameters and potentially affecting their ability to classify tumors. This study aims to accurately estimate noise of averaged diffusion-weighted-imaging, to correct the noise induced bias, and to assess the effect upon cancer classification. Methods A new adaptation of the median-absolute-deviation technique in the wavelet-domain, using a closed form approximati…
MAGIC-5: an Italian mammographic database of digitised images for research
2008
The implementation of a database of digitised mammograms is discussed. The digitised images were collected beginning in 1999 by a community of physicists in collaboration with radiologists in several Italian hospitals as a first step in developing and implementing a computer-aided detection (CAD) system. All 3,369 mammograms were collected from 967 patients and classified according to lesion type and morphology, breast tissue and pathology type. A dedicated graphical user interface was developed to visualise and process mammograms to support the medical diagnosis directly on a high-resolution screen. The database has been the starting point for developing other medical imaging applications,…
Rewinding Frankenstein and the body-machine: organ transplantation in the dystopian young adult fiction seriesUnwind
2016
While the separation of body and mind (and the entailing metaphor of the body as a machine) has been a cornerstone of Western medicine for a long time, reactions to organ transplantation among others challenge this clear-cut dichotomy. The limits of the machine-body have been negotiated in science fiction, most canonically in Mary Shelley9s Frankenstein (1818). Since then, Frankenstein9s monster itself has become a motif that permeates both medical and fictional discourses. Neal Shusterman9s contemporary dystology for young adults, Unwind , draws on traditional concepts of the machine-body and the Frankenstein myth. This article follows one of the young protagonists in the series, who is en…