Subject(s)
Hyperostosis, Diffuse Idiopathic Skeletal/therapy , Long-Term Care , Respiration, Artificial/adverse effects , Respiratory Insufficiency/therapy , Spinal Diseases/therapy , Vocal Cord Paralysis/etiology , Cervical Vertebrae , Comorbidity , Hepatorenal Syndrome/therapy , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Pneumonia/therapy , Tracheotomy , Ventilator Weaning , Vocal Cord Paralysis/therapySubject(s)
Hyperostosis, Diffuse Idiopathic Skeletal/pathology , Hyperostosis, Diffuse Idiopathic Skeletal/rehabilitation , Magnetic Resonance Imaging/methods , Respiration, Artificial/adverse effects , Vocal Cord Paralysis/etiology , Vocal Cord Paralysis/pathology , Diagnosis, Differential , Humans , Hyperostosis, Diffuse Idiopathic Skeletal/complications , Longitudinal Studies , Male , Middle Aged , Vocal Cord Paralysis/prevention & controlABSTRACT
PURPOSE: Functional prostate MR is performed in varying combinations of T2-weighted images with diffusion-weighted imaging (DWI), dynamic contrast-enhanced MRI (DCE-MRI), and spectroscopic imaging (MRSI). Recently, a European consensus meeting proposed the use of a simple 5-point scale for estimating the probability of a lesion being malignant. The aim of the present study was to determine the inter-reader agreement of MR imaging using a scoring system based on the recommendations of the consensus. MATERIALS AND METHODS: The appearance of 108 predefined lesions in three different MR sequences (T2-weighted images, DWI, and DCE-MRI) in 50 functional prostate MR examinations were retrospectively scored by three blinded radiologists using a 5-point scale for each MR sequence. After scoring T2/DWI and T2/DWI/DCE-MRI, every lesion was graded based on its probability for malignancy. The inter-observer reliability was evaluated using Kappa statistics (ĸ). RESULTS: With respect to T2-weighted images, DWI and DCE-MRI ĸ was 0.49, 0.97, and 0.77, respectively. Combined scoring of T2-weighted images and DWI demonstrated correct tumor diagnosis (true positive) in 71-88% (depending on reader) of cases (ĸ=0.78). The accuracy was further improved to 88-96% after scoring all three MR sequences including DCE-MRI (ĸ=0.90). CONCLUSION: The use of a simple 5-point scoring system for T2-weighted images, DWI, and DCE-MRI is feasible in functional prostate MRI and has high inter-observer reliability.
Subject(s)
Diffusion Magnetic Resonance Imaging/methods , Diffusion Magnetic Resonance Imaging/statistics & numerical data , Echo-Planar Imaging/methods , Echo-Planar Imaging/statistics & numerical data , Magnetic Resonance Angiography/methods , Magnetic Resonance Angiography/statistics & numerical data , Magnetic Resonance Imaging/methods , Magnetic Resonance Imaging/statistics & numerical data , Magnetic Resonance Spectroscopy/methods , Magnetic Resonance Spectroscopy/statistics & numerical data , Prostatic Neoplasms/diagnosis , Research Design/statistics & numerical data , Adult , Aged , Biopsy , Contrast Media/administration & dosage , Humans , Male , Middle Aged , Neoplasm Grading , Neoplasm Staging , Observer Variation , Probability , Prostate/pathology , Sensitivity and SpecificityABSTRACT
PURPOSE: To evaluate the effects of a 2D non-linear adaptive post-processing filter (2D-NLAF) on image quality in dose-reduced multi-detector CT (MDCT) of the upper abdomen. MATERIALS AND METHODS: MDCT of the upper abdomen was simulated on a 64-slice scanner using a multi-modal anthropomorphic phantom (CIRS, Norfolk, USA). While keeping the collimation (64 x 0.6 mm) and pitch (p = 1) unchanged, the tube current (100 - 500 mAs) and tube potential (80 - 140 kVp) were varied to perform MDCT as high dose (CTDI > 20), middle dose (CTDI 10 - 20) and low dose (CTDI < 10) level protocols. Four independent blinded radiologists evaluated axial images with a thickness of 7 and 3 mm with respect to the presentation of "mesenteric low contrast lesions", "liver veins", "liver cysts", "renal cysts" and "big vessels". The subjective image quality of original data and post-processed images using a 2D-NLAF (SharpViewCT, Linköping, Sweden) was graded on a 5-point scale (from "1" not visible to "5" excellent) and statistically analyzed. The effective dose (E) was estimated using commercial software (CT-EXPO). RESULTS: For all protocol groups, 2D-NLAF led to a significant improvement in subjective image quality for all examined lesions (p < 0.01), particularly at the protocols of middle dose (E: 5 - 8 mSv) and low dose level (E: 1 - 5 mSv). A maximum effect was seen in middle dose protocols for "low contrast lesions" (score "3.3" with filter versus "2.5" without) and "liver veins" ("4.5" versus "3.9"). CONCLUSION: The phantom study indicates a potential dose reduction of up to 50 % in MDCT of the upper abdomen by use of a 2D-NLAF, which should be further examined in clinical trails.