This Review provides an updated approach to the diagnosis of idiopathic pulmonary fibrosis (IPF), based on a systematic search of the medical literature and the expert opinion of members of the ...Fleischner Society. A checklist is provided for the clinical evaluation of patients with suspected usual interstitial pneumonia (UIP). The role of CT is expanded to permit diagnosis of IPF without surgical lung biopsy in select cases when CT shows a probable UIP pattern. Additional investigations, including surgical lung biopsy, should be considered in patients with either clinical or CT findings that are indeterminate for IPF. A multidisciplinary approach is particularly important when deciding to perform additional diagnostic assessments, integrating biopsy results with clinical and CT features, and establishing a working diagnosis of IPF if lung tissue is not available. A working diagnosis of IPF should be reviewed at regular intervals since the diagnosis might change. Criteria are presented to establish confident and working diagnoses of IPF.
Given the potential risk of X-ray radiation to the patient, low-dose CT has attracted a considerable interest in the medical imaging field. Currently, the main stream low-dose CT methods include ...vendor-specific sinogram domain filtration and iterative reconstruction algorithms, but they need to access raw data, whose formats are not transparent to most users. Due to the difficulty of modeling the statistical characteristics in the image domain, the existing methods for directly processing reconstructed images cannot eliminate image noise very well while keeping structural details. Inspired by the idea of deep learning, here we combine the autoencoder, deconvolution network, and shortcut connections into the residual encoder-decoder convolutional neural network (RED-CNN) for low-dose CT imaging. After patch-based training, the proposed RED-CNN achieves a competitive performance relative to the-state-of-art methods in both simulated and clinical cases. Especially, our method has been favorably evaluated in terms of noise suppression, structural preservation, and lesion detection.
To evaluate the effects of contrast medium injection rates and intravenous injection catheter sizes on the time-density curve (TDC) of brain perfusion computed tomography (PCT) images in clinically ...normal Beagles and provide a reference range for the perfusion parameters for clinical application of PCT in veterinary medicine.
5 healthy, sexually intact male Beagles.
All dogs underwent general anesthesia for PCT. Contrast medium (350 mg I/kg) was injected at 3 different injection rates (2, 3, and 4 mL/second) and with 2 sizes of an intravenous catheter (20-gauge and 24-gauge). The rostral cerebral artery and dorsal sagittal sinus were selected as the regions of interest of the TDC. Initiation time of arterial inflow (ta), venous outflow (tv), peak time of arterial enhancement (Tap), and the peak time of venous enhancement (Tvp), were measured, and the difference between Tap and tv (Tap-tv) and between Tap and ta (Tap-ta) was calculated.
Both Tap-tv and Tap-ta were significantly (P < .05) shorter at the rate of 3 mL/second than at 2 mL/second with the 24-gauge catheter. However, there was no significant difference according to catheter sizes. Particularly, a 4 mL/second injection rate using a 24-gauge catheter mostly resulted in contrast medium leakage and catheter rupture.
At a rate of 3 mL/second and with a 24-gauge catheter ensures optimal image acquisition and stable contrast medium injection in brain PCT for small dogs. PCT may be useful for diagnosing cerebrovascular events and hemodynamic changes in small dogs.
Acute gastrointestinal (GI) bleeding is common and necessitates rapid diagnosis and treatment. Bleeding can occur anywhere throughout the GI tract and may be caused by many types of disease. The ...variety of enteric diseases that cause bleeding and the tendency for bleeding to be intermittent may make it difficult to render a diagnosis. The workup of GI bleeding is frequently prolonged and expensive, with examinations commonly needing to be repeated. The use of computed tomography (CT) for evaluation of acute GI bleeding is gaining popularity because it can be used to rapidly diagnose active bleeding and nonbleeding bowel disease. The CT examinations used to evaluate acute GI bleeding include CT angiography and multiphase CT enterography. Understanding the clinical evaluation of acute GI bleeding, including the advantages and limitations of endoscopic evaluation, is necessary for the appropriate selection of patients who may benefit from CT. Multiphase CT enterography is used primarily to evaluate stable patients who have undergone upper and lower endoscopy without identification of a bleeding source. CT angiography is used to examine stable and unstable patients who respond to resuscitation, are believed to be actively bleeding, and are considered unlikely to have an upper GI source of hemorrhage. In the emergent setting, CT may yield critical information regarding the presence, location, and cause of active bleeding-data that can guide the choice of subsequent therapy. Recent developments in the use of and techniques for performing CT angiography have made it a potential first-line tool for evaluating acute GI bleeding.
RSNA, 2018.
PET/CT Today and Tomorrow Townsend, David W; Carney, Jonathan P.J; Yap, Jeffrey T ...
The Journal of nuclear medicine (1978),
01/2004, Letnik:
45, Številka:
1 suppl
Journal Article
Recenzirano
Accurate anatomic localization of functional abnormalities seen with PET is known to be problematic. Even though nonspecific tracers such as 18F-FDG visualize certain normal anatomic structures, the ...spatial resolution is generally inadequate for localization of pathology. Combining PET with a high-resolution anatomic imaging modality such as CT can resolve the localization issue, as long as the images from the two modalities are accurately coregistered. However, software-based registration techniques have difficulty accounting for differences in patient positioning and involuntary movement of internal organs, often necessitating labor-intensive nonlinear mapping that may not converge to a satisfactory result. Acquiring both CT and PET images in the same scanner obviates the need for software registration and routinely provides accurately aligned images of anatomy and function in a single scan.
A CT scanner positioned in tandem with a PET scanner and with a common patient couch and operating console has recently been explored as a solution to anatomic and functional image registration. Axial translation of the couch between the two modalities enables both CT and PET data to be acquired during a single imaging session. In addition, the CT images can be used to generate noiseless attenuation correction factors for the PET emission data. By minimizing patient movement between the CT and PET scans, and after accounting for the axial separation of the two modalities, accurately registered anatomic and functional images can be obtained. Since the introduction of the first PET/CT prototype a little over 5 years ago, several thousand cancer patients have been scanned on combined PET/CT devices. In the past 3 years, a number of commercial designs have become available featuring multidetector spiral CT scanners and high-performance PET devices. Initial experience has demonstrated an increased level of accuracy and confidence in the interpretation of the combined study compared with separate readings, particularly in the ability to distinguish pathology from normal physiologic uptake and to precisely localize abnormal foci.
Combined PET/CT scanners represent an important evolution in technology that is helping to bring molecular imaging to the forefront in cancer diagnosis, staging, and therapy monitoring.
We aimed to compare radiation dose received during contrast-enhanced spectral mammography (CESM) using high- and low-energy projections with radiation dose received during 2D full field digital ...mammography (FFDM) and 3D tomosynthesis on phantoms and patients with varying breast thickness and density.
A single left craniocaudal projection was chosen to determine the doses for 6214 patients who underwent 2D FFDM, 3662 patients who underwent 3D tomosynthesis, and 173 patients who underwent CESM in this retrospective study. Dose measurements were also collected in phantoms with composition mimicking nondense and dense breast tissue.
Average glandular dose (AGD) ± SD was 3.0 ± 1.1 mGy for CESM exposures at a mean breast thickness of 63 mm. At this thickness, the dose was 2.1 mGy from 2D FFDM and 2.5 mGy from 3D tomosynthesis. The nondense phantom had a mean AGD of 1.0 mGy with 2D FFDM, 1.3 mGy with 3D tomosynthesis, and 1.6 mGy with CESM. The dense breast phantom had a mean AGD of 1.3 mGy with 2D FFDM, 1.4 mGy with 3D tomosynthesis, and 2.1 mGy with CESM. At a compressed thickness of 4.5 cm, radiation exposure from CESM was approximately 25% higher in dense breast phantoms than in nondense breast phantoms. The dose in the dense phantom at a compressed thickness of 6 cm was approximately 42% higher than the dose in the nondense phantom at a compressed thickness of 4.5 cm.
CESM was found to increase AGD at a mean breast thickness of 63 mm by approximately 0.9 mGy and 0.5 mGy compared with 2D FFDM and 3D tomosynthesis, respectively. Of note, CESM provides a standard image (similar to 2D FFDM) that is obtained using the low-energy projection. Overall, the AGD from CESM falls below the dose limit of 3 mGy set by Mammography Quality Standards Act regulations.
This paper is the first in a series of two publications relating to the European Crohn's and Colitis Organisation ECCO evidence-based consensus on the diagnosis and management of Crohn's disease and ...concerns the methodology of the consensus process, and the classification, diagnosis and medical management of active and quiescent Crohn's disease. Surgical management as well as special situations including management of perianal Crohn's disease of this ECCO Consensus are covered in a subsequent second paper Gionchetti et al JCC 2016.
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