Littrell, Laurel A.

AbstractThe well‐referenced structural shielding design NCRP Report No. 147 uses workload information based on self‐reported film‐screen data from the AAPM Task Group 9 survey. The aim of this study was to assess the clinical workload distributions of modern digital radiography (DR) systems in general hospital and pediatric‐only practices. A retrospective analysis of DR imaging data on four radiographic systems in a hospital practice and two radiographic systems in a pediatric practice, through a custom clinical DICOM header analytics program. A total of 203, 294 exposures from the general hospital practice and 25,415 from the pediatric practice from 2019 and 2021 were included. Values for kVp, mAs, and detector type (wall bucky, table bucky, or free detector) were extracted. For each exam, mAs was accumulated in a kVp histogram with bins 5 kVp wide and further parsed by detector type. Total workload was calculated by summing all exposures, then normalized by the number of patients. The median (25th and 75th percentile) workload in the hospital practice was 0.43 (0.22, 1.13) mA‐min per patient, while the average was 1.36 ± 3.08. Pediatric data yielded a median (25th and 75th percentile) of 0.10 (0.05, 0.23) and an average of 0.29 ± 0.69 mA‐min per patient. Mean number of patients per week was 230 adult and 57 pediatric. Hospital workload data is approximately 44% less than the NCRP Report No. 147 value.

AbstractBackgroundDigital radiography (DR) still presents many challenges and could have complex imaging acquisition and processing patterns in a clinical practice hindering quality standardization.PurposeThis technical note aims to report the 4‐year experience with utilizing a custom DICOM metadata analytics program in clinical DR at a large institution.MethodsThirty‐eight DR systems of three vendors at multiple locations were configured to automatically send clinical DICOM images to a DICOM receiver. A suite of custom MATLAB programs was established to extract and store public and private header data weekly. Specific use cases are provided for systematic image acquisition investigation, image processing harmonization, exposure index (EI) longitudinal monitoring and EI target optimization.ResultsFor systematic acquisition investigation, an example of adult lumbar spine exam analysis was provided with statistics on manual acquisition versus the use of automatic exposure control (AEC, including AEC dose level, active cell, and backup timer), grid usage, and collimation for various projections. For processing harmonization, up to 12.6% of protocols were revealed to have processing parameter differences in an example of a mobile radiography fleet. In addition, inconsistent use of a post‐acquisition image size function was also demonstrated, which resulted in anatomy size display variations. Bimonthly monitoring of median EI values showed expected trends, including changes after an AEC dose level adjustment for adult posterior‐anterior chest imaging on a scanner system. An example of adult axillary shoulder EI target refinement was shared using the median value, eμ, based on the lognormal EI data distribution after parsing down to acquisitions with appropriate techniques.ConclusionsThis analytics program enables systematic analysis of image acquisition and processing details. The information provides invaluable insights into real practice patterns, which can support data‐driven quality standardization and optimization.

Background We hypothesize that different positions of the wrist in the coronal plane makes the carpus susceptible to ulnar impaction. Methods We prospectively enrolled 10 adult volunteers and obtained fluoroscopic images of each wrist in 12 different positions using a standardized protocol. Distances from the ulna to the lunate (UL) and ulna to the triquetrum (UT) were digitally measured as was the portion of the lunate surface area that was uncovered (LUR) with wrist deviation. Results A wrist position of Pronation, Neutral Deviation, and Grip (P-ND-G) significantly shortened the ulnocarpal distance when compared to a position of Neutral Rotation, Neutral Deviation, and No Grip (NR-ND-NG). Radial deviation during pronation and gripping (Pronated, Radial Deviation, Gripping [P-RD-G]) resulted in the lowest mean UL distance (1.2 mm). UT distance was minimized by a position of ulnar deviation during a pronated grip (Pronated, Ulnar Deviation, Gripping [P-UD-G]) (3.1 mm). The lunate becomes more uncovered with radial deviation. Conclusion Radial deviation minimizes the UL distance while ulnar deviation minimizes the UT distance during a wrist position of pronation and gripping. Further, there is more proximal lunate surface area uncoverage during all positions of radial deviation compared to ulnar deviation.

AbstractThe role of quantitative magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) techniques continues to grow and evolve in the evaluation of musculoskeletal tumors. In this review we discuss the MRI quantitative techniques of volumetric measurement, chemical shift imaging, diffusion-weighted imaging, elastography, spectroscopy, and dynamic contrast enhancement. We also review quantitative PET techniques in the evaluation of musculoskeletal tumors, as well as virtual surgical planning and three-dimensional printing.

AbstractBone marrow edema (BME) can be a late finding in osteoarthritis or a sign of subchondral insufficiency. The purpose of this study was to describe the magnetic resonance imaging (MRI) finding we refer to as “osteomeniscal impact edema” (OMIE), or reactive BME adjacent to a displaced meniscus flap tear. In addition, this edema pattern is compared with a control group of medial meniscus posterior root tears (MMPRT) with subchondral insufficiency edema. MRI records from 2000 to 2017 were retrospectively reviewed for studies that showed the presence of a medial meniscus displaced flap tear and an adjacent area of BME. The selected MRIs were matched to an equal number of MMPRT MRI studies. All MRI studies were assessed for cartilage surface grade using the modified Outerbridge classification system and for the extent of accompanying structural abnormalities using the whole-organ magnetic resonance imaging score. Descriptive statistics and hypothesis testing were utilized to compare the MRI findings between groups. Twenty-two flap tear (OMIE group) patients with a mean age of 57 (SD: 15) and 22 root tear (MMPRT) group patients with a mean age of 61 (SD: 10) were included. MRIs in the OMIE group showed a distinctive pattern of focal, peripheral edema adjacent to the meniscus flap tear, compared with more diffuse, central edema in the MMPRT group. Quantitatively, MRIs of the MMPRT group showed significantly worse mean femoral Outerbridge scores (3.72 vs. 2.68, p < 0.0001), more severe central (1.63 vs. 0.5, p = 0.0007) and posterior (0.31 vs. 0.0, p = 0.04) subchondral edema grades, and a higher incidence of tibial subchondral fractures (3 vs. 0, p = 0.036). Meniscus flap tears may present with a distinct MRI pattern of focal, adjacent, peripheral edema, which we refer to as OMIE. Patients with meniscus flap tears showed significantly less arthritic change, lower subchondral edema grades, and a lower incidence of insufficiency fractures and subchondral collapse compared with the diffuse overload edema pattern found with root tears. The Level of Evidence for this study is III.

AbstractMedial meniscus posterior root tears (MMPRTs) are a significant source of pain and dysfunction. The purpose of this study was to evaluate changes in the medial compartment of the knee over time following the diagnosis of a MMPRT on MRI. A retrospective review of the institutional database was performed for patients with an initial MRI diagnosis of a MMPRT. Patients were included if they had a subsequent follow-up MRI on the same knee. Patients with surgical intervention, including debridement or repair, were excluded. MRIs were evaluated by two board-certified musculoskeletal radiologists. MMPRTs were defined using the LaPrade classification, and the medial compartment articular cartilage was graded using the modified Outerbridge classification. MRIs were reviewed for meniscus extrusion, subchondral bone edema, and insufficiency fractures. Patients were divided into two groups for the analysis to account for differences in MRI time intervals. Group 1 had a follow-up MRI within 12 months of initial imaging (subacute group) and Group 2 had a follow-up MRI greater than 12 months after initial imaging (chronic group). Forty-one knees and 82 MRIs were analyzed, including 20 knees/40 MRIs (13 females, 7 males) in the subacute group and 21 knees/42 MRIs (14 females, 7 males) in the chronic group. Subacute patients had a mean age of 59.5 ± 8.8 years and a mean interval of 4.8 ± 2.6 months between MRIs compared with 53.6 ± 11.0 years and 38.2 ± 20.8 months, respectively, for the chronic group. Meniscal extrusion, femoral modified Outerbridge grade, and tibial modified Outerbridge grade worsened between initial and final MRI in both groups (p < 0.05). In both groups, there were no significant differences between initial and final MRIs with regard to the LaPrade classification, insufficiency fracture, or subchondral cysts of the tibia. Progressive meniscus extrusion and medial compartment articular cartilage degeneration were seen in patients with MMPRTs within a year from diagnosis.