How machine learning is embedded to support clinician decision making: an analysis of FDA-approved medical devices.

Objective: To examine how and to what extent medical devices using machine learning (ML) support clinician decision making.

Methods: We searched for medical devices that were (1) approved by the US Food and Drug Administration (FDA) up till February 2020; (2) intended for use by clinicians; (3) in clinical tasks or decisions and (4) used ML. Descriptive information about the clinical task, device task, device input and output, and ML method were extracted.

MRI of THA Correlates With Implant Wear and Tissue Reactions: A Cross-sectional Study.

Background: MRI is predictive of adverse local tissue reactions (ALTRs) after THA but how MRI directly relates to implant surface wear, fretting, and trunnion corrosion at different articulations between implant components remains unclear. MRI generates high-contrast images to display soft tissues around arthroplasty and may provide a surgeon the means to distinguish and differentiate host-related synovial patterns as a response to either polyethylene wear or metal wear and corrosion products.

Questions/purposes: The purposes of this study were (1) to correlate findings from MRI in patients who have undergone THA with direct assessment of implant wear, corrosion, and fretting from retrieved components; and (2) to distinguish the unique synovial responses on MRI in patients who have undergone THA based on bearing materials.

Diagnostic Accuracy of Zero-Echo Time MRI for the Evaluation of Cervical Neural Foraminal Stenosis.

Study Design: A cohort study.

Objective: The aim of this study was to evaluate the clinical utility of Zero-Echo-Time (ZTE) magnetic resonance imaging (MRI) for the assessment of cervical neural foraminal stenosis (CNFS) through the comparison of inter-modality [computed tomography (CT) and ZTE-MRI] CNFS grade severity agreements.

Summary Of Background Data: Conventional MRI limited in its ability to provide direct visualization of cortical bone.

Off-resonance based assessment of metallic wear debris near total hip arthroplasty.

Purpose: The presence of metallic debris near total hip arthroplasty can have a significant impact on longitudinal patient management. Methods for magnetic resonance imaging-based quantification of metallic debris near painful total hip replacements are described and applied to cohorts of symptomatic and control subject cases.

Methods: A combination of metal artifact reduction, off-resonance mapping, off-resonance background removal, and spatial clustering methods are utilized to quantify off-resonance signatures in cases of suspected metallosis.

Assessment of Osteonecrosis in the Presence of Instrumentation for Femoral Neck Fracture Using Contrast-Enhanced MAVRIC Sequence.

Background: Evaluating postoperative femoral neck facture (FNF) with metal fixation hardware is commonly performed using radiographs. MRI has greater sensitivity and specificity to evaluate osteonecrosis (ON) but is often challenging due to the image distortion caused by metallic hardware.

Questions/purposes: The aim of this study is to compare fast spin-echo (FSE) and multi-acquisition variable-resonance image combination (MAVRIC) sequences in assessing ON following metallic fixation of FNF and determining feasibility of semi-quantitative perfusion using MAVRIC.

Quantitative Ultrashort Echo Time Magnetic Resonance Imaging Evaluation of Postoperative Menisci: a Pilot Study.

Background: Magnetic resonance imaging (MRI) visualization of meniscal signal is particularly challenging as the highly organized ultrastructure of meniscal fibrocartilage yields very short T2 values (∼6 ms) and a paucity of signal intensity during conventional image acquisition.

Question/purpose: The purpose of this study was to evaluate the feasibility of imaging postoperative menisci using an experimental, quantitative ultrashort echo time (UTE) MRI pulse sequence. This sequence acquires short echo images (echo time (TE) ∼0.

Word-finding impairment in veterans of the 1991 Persian Gulf War.

Approximately one quarter of 1991 Persian Gulf War Veterans experience cognitive and physiological sequelae that continue to be unexplained by known medical or psychological conditions. Difficulty coming up with words and names, familiar before the war, is a hallmark of the illness. Three Gulf War Syndrome subtypes have been identified and linked to specific war-time chemical exposures.

The effect of freeze-thawing on magnetic resonance imaging T2* of freshly harvested bovine patellar tendon.

Background: Analysis of fresh specimens in research studies is ideal; however, it is often necessary to freeze samples for evaluation at a later time. Limited evaluation of the effect of freeze-thawing of tendon tissue samples on inherent magnetic resonance imaging (MRI) parameters, such as ultrashort echo time (UTE) T2* values, have been performed to date.

Methods: This study performed UTE MRI on 14 bovine patellar tendons at harvest and after four consecutive freeze-thaw cycles.

Imaging of physeal injury: overuse.

Context: As the intensity of youth participation in athletic activities continues to rise, the number of overuse injuries has also increased. A subset of overuse injuries involves the physis, which is extremely susceptible to injury. This paper aims to review the utility of the various imaging modalities in the diagnosis and management of physeal injuries in the skeletally immature population.

Flexible longitudinal magnetization contrast in spectrally overlapped 3D-MSI metal artifact reduction sequences: Technical considerations and clinical impact.

Purpose: It has previously been demonstrated that increased overlap of spectral bins in three-dimensional multispectral imaging techniques (3D-MSI) can aid in reducing residual artifacts near metal implants. However, increasing spectral overlap also necessitates consideration of saturation effects for species with long T1 values. Here, an interleaved spectral bin acquisition strategy is presented for overlapping 3D-MSI that allows for flexible choice of repetition times while simultaneously addressing these cross talk concerns.

Ultrashort echo imaging of cyclically loaded rabbit patellar tendon.

Tendinopathy affects individuals who perform repetitive joint motion. Magnetic resonance imaging (MRI) is frequently used to qualitatively assess tendon health, but quantitative evaluation of inherent MRI properties of loaded tendon has been limited. This study evaluated the effect of cyclic loading on T₂* values of fresh and frozen rabbit patellar tendons using ultra short echo (UTE) MRI.

Clinical implementation of MRI of joint arthroplasty.

Objective: The purpose of this article is to explain the basic physics of imaging patients with metal implants, explain conflicting information regarding MRI scanning of "MR Conditional" devices, and relate our experience of scanning total joint arthroplasty (TJA) at our institution.

Conclusion: MRI near TJA is effective with appropriate imaging protocols and standardized safety precautions. Strict adherence to MR Conditional labeling may preclude broad use of MRI for TJA assessment.

Three-dimensional magnetic resonance imaging of physeal injury: reliability and clinical utility.

Background: Injuries to the physis are common in children with a subset resulting in an osseous bar and potential growth disturbance. Magnetic resonance imaging allows for detailed assessment of the physis with the ability to generate 3-dimensional physeal models from volumetric data. The purpose of this study was to assess the interrater reliability of physeal bar area measurements generated using a validated semiautomated segmentation technique and to highlight the clinical utility of quantitative 3-dimensional (3D) physeal mapping in pediatric orthopaedic practice.

Quantifying image distortion of orthopedic materials in magnetic resonance imaging.

Purpose: To determine the magnitude of image distortion between two-dimensional (2D) fast-spin-echo (FSE) images and 3D-MAVRIC by using a phantom with samples of common materials used in total joint arthroplasty.

Materials And Methods: A phantom was constructed to hold samples of 316 stainless steel, cobalt chrome, titanium, and ultra-high molecular weight polyethylene (UHMWPE), and to permit tracking of points between 2D-FSE and 3D-MAVRIC sequences. Imaging was performed with a 1.

MRI after arthroplasty: comparison of MAVRIC and conventional fast spin-echo techniques.

Objective: The goal of this study was to evaluate the quality of images obtained with a prototype imaging technique, multiacquisition variable-resonance image combination (MAVRIC), compared with fast spin-echo (FSE) images in the evaluation of patients who have undergone hip, shoulder, or knee arthroplasty.

Materials And Methods: MRI with metal-artifact reduction FSE and MAVRIC sequences was performed in the care of 122 patients who had undergone 74 hip, 27 shoulder, and 21 knee arthroplasties. The FSE and MAVRIC images were subjectively graded for visualization of the synovium, prosthesis-bone interface, and hip abductors or supraspinatus tendon.

Diagnosis of adult hereditary pulmonary disease and the role of genetic testing.

Genetic testing is becoming a common component of medical practice and is used to determine definitive diagnoses for several adult pulmonary diseases. It is important for pulmonologists to know when to use genetic tests for diagnosis and medical management. This article describes diagnosis of rare hereditary pulmonary disease in adults and the role of genetic testing.

Effects of papillary muscle position on in-vitro dynamic strain on the porcine mitral valve.

Background And Aim Of The Study: Improved knowledge of mitral valve (MV) mechanics is essential to understand normal MV function and design and evaluate new surgical repair procedures. Initially, the dynamic deformation of the central region of the porcine MV anterior leaflet was quantified under simulated physiological conditions to explore the effects of varying papillary muscle (PM) position.

Methods: Fresh porcine MVs were mounted in an in-vitro physiological flow loop.

An analysis of turbulent shear stresses in leakage flow through a bileaflet mechanical prostheses.

In this work, estimates of turbulence were made from pulsatile flow laser Doppler velocimetry measurements using traditional phase averaging and averaging after the removal of cyclic variation. These estimates were compared with estimates obtained from steady leakage flow LDV measurements and an analytical method. The results of these studies indicate that leakage jets which are free and planar in shape may be more unstable than other leakage jets, and that cyclic variation does not cause a gross overestimation of the Reynolds stresses at large distances from the leakage jet orifice.