Iatrogenic "overshoot" nerve injuries: imaging features.

OBJECTIVE: Describe features of iatrogenic "overshoot" nerve injuries on ultrasound and MRI, which occur when an instrument passes through the bone and injures the nerve after it penetrates the opposite cortex. MATERIALS AND METHODS: After a keyword search of the radiology database at a tertiary care orthopedic hospital from January 2016 to December 2022, those fulfilling the inclusion criteria of (1) instrumentation through the bone during surgery, (2) acute neuropathy immediately after surgery, (3) nerve injury confirmed on electrodiagnostics, and (4) imaging consistent with overshoot nerve injury were included. Imaging studies were retrospectively evaluated to determine primary and secondary signs of an overshoot nerve injury. RESULTS: Six patients (3 females, mean age 26.7 (range 10-49) years) had nerve injury fitting the mechanism of injury: 3 injuries to the radial nerve during fixation of distal humerus fractures, 1 tibial nerve and 1 superficial peroneal nerve injury during fixation of tibial fractures, and 1 posterior interosseous nerve injury during biceps tendon repair. Ultrasounds were performed in all while 4 also had MRI. Secondary signs included (1) cortical defect adjacent to injured nerve (n=2); (2) scar extending from bone to injured nerve (n=2); (3) screw tip pointing to injured nerve (n=1, 4) tract in bone on MRI from previous instrumentation pointing to injured nerve (n=2). CONCLUSION: In addition to primary signs such as laceration or neuroma, secondary signs of "overshoot" nerve injury include cortical defect, scar extending to nerve, screw tip pointing to nerve, and linear tract in the bone on MRI.

Differences in imaging and clinical characteristics are associated with higher rates of decompression-fusion versus decompression-alone in women compared to men for lumbar degenerative spondylolisthesis.

PURPOSE: The goals were to ascertain if differences in imaging/clinical characteristics between women and men were associated with differences in fusion for lumbar degenerative spondylolisthesis. METHODS: Patients had preoperative standing radiographs, CT scans, and intraoperative fluoroscopic images. Symptoms and comorbidity were obtained from patients; procedure (fusion-surgery or decompression-alone) was obtained from intraoperative records. With fusion surgery as the dependent variable, men and women were compared in multivariable logistic regression models with clinical/imaging characteristics as independent variables. The sample was dichotomized, and analyses were repeated with separate models for men and women. RESULTS: For 380 patients (mean age 67, 61% women), women had greater translation, listhesis angle, lordosis, and pelvic incidence, and less diastasis and disc height (all p ≤ 0.03). The rate of fusion was higher for women (78% vs. 65%; OR 1.9, p = 0.008). Clinical/imaging variables were associated with fusion in separate models for men and women. Among women, in the final multivariable model, less comorbidity (OR 0.5, p = 0.05), greater diastasis (OR 1.6, p = 0.03), and less anterior disc height (OR 0.8, p = 0.0007) were associated with fusion. Among men, in the final multivariable model, opioid use (OR 4.1, p = 0.02), greater translation (OR 1.4, p = 0.0003), and greater diastasis (OR 2.4, p = 0.0002) were associated with fusion. CONCLUSIONS: There were differences in imaging characteristics between men and women, and women were more likely to undergo fusion. Differences in fusion within groups indicate that decisions for fusion were based on composite assessments of clinical and imaging characteristics that varied between men and women.

Communication-related experiences of individuals in the early phase of semantic dementia and their families: an interview study.

BACKGROUND: Semantic dementia (SD), a subtype of frontotemporal dementia, manifests as verbal symptoms, including social and behavioural deficits, associated with focal atrophy of the frontotemporal lobes. This study aimed to clarify the experiences of individuals with early-onset SD receiving speech and language rehabilitation (hereafter referred to as 'rehabilitation'), with the intent of making it routine, as well as the experiences of their families. METHODS: Individual interviews were conducted with nine families with members who had adopted rehabilitation. Verbatim transcripts were used as data, and analyzed inductively according to the content analysis process. RESULTS: The family members realised the changes in the personality and behaviour of the individual with SD early, to the extent that they thought the individual with SD was different from before and were distressed by the loss of verbal communication. Nevertheless, the family members found a way to communicate by maintaining residual functions through rehabilitation and utilising their unique relationship with the individual with SD. CONCLUSIONS: It is important to carefully explain the characteristics of the disease and the long-term significance of rehabilitation to individuals with SD and their families in the early stages of the disease.

Imaging of the Peripheral Nerves of the Lower Extremity.

Continued advancements in magnetic resonance (MR) neurography and ultrasound have made both indispensable tools for the workup of peripheral neuropathy. Ultrasound provides high spatial resolution of superficial nerves, and techniques such as "sonopalpation" and dynamic maneuvers can improve accuracy. Superior soft tissue contrast, ability to evaluate both superficial and deep nerves with similar high resolution, and reliable characterization of denervation are strengths of MR neurography. Nevertheless, familiarity with normal anatomy, anatomic variants, and common sites of nerve entrapment is essential for radiologists to use both MR neurography and ultrasound effectively.

Sonographic Assessment of Hand Injuries: Diagnostic Accuracy and Review of Pathology.

Background: The high soft-tissue contrast of magnetic resonance imaging (MRI) makes it useful for evaluation of hand injuries, but its limitations include cost, imaging artifacts, and patient claustrophobia. Ultrasound is readily available, fast, noninvasive, and radiation free, but its utility for the evaluation of hand soft-tissue injury and pathology is less well known. Purpose: We sought to examine the accuracy of ultrasound for the evaluation of hand injury at a single institution. Methods: We queried a radiology information system for ultrasound cases between 2014 and 2020 at a tertiary care institution using the keyword "hand" and injury terms. We performed a retrospective chart review of cases found according to the type of injury detected on ultrasound. To evaluate the diagnostic accuracy of ultrasound in hand injury and pathology, we recorded postimaging clinical diagnoses and surgical findings. Results: We found 154 patients who underwent ultrasound for hand injuries and had confirmed surgical diagnosis and/or robust clinical follow-up. Tendon injury was the most commonly diagnosed condition on ultrasound (70/154); others detected were retained foreign body (31), mass (21), ligamentous injury (9), pulley injury (8), nerve injury (11), and traumatic arthropathy (4). Ultrasound correctly characterized hand injury in 150/154 cases (97.4%) based on surgical and/or clinical follow-up. Ultrasound failed to diagnose 3 cases of partial tendon tear and 1 case of digital nerve injury. Conclusion: In this retrospective, single-institution review, ultrasound was found to be highly accurate in the detection of soft tissue hand injury and pathology, demonstrating a high concordance rate with surgical and clinical findings. Further study is warranted.

Recovery-oriented daily care practice for community-based mental health service consumers in Japan: A grounded theory approach.

Recovery, which is a non-linear, unique process allowing mental health service consumers to live autonomously, has become a prominent concept. However, adapting recovery-oriented practice to daily care is challenging. We explored recovery-oriented practice among mental health professionals in Japan via semi-structured interviews including nurses, occupational therapists, and psychiatric social workers (17 professionals in total). Data were analysed using grounded theory. Six categories emerged. The core category was 'Continuing to adjust care to meet consumers' needs for their unique lives'. The professionals stated that they practised in accordance with the service consumers' sincere hopes based on an equitable relationship because they believed that this approach would enhance consumers' personal agency, proactive behaviour, and self-choice. Despite negative consequences, the professionals did not view the consumers' choices as 'failures' and instead helped them to find meaning in their experiences. Although the therapeutic relationship tended to be paternalistic, participants described how concrete practices helped build an equitable relationship. In recovery-oriented practice, the provision of support centred on consumer values is important, without imposing own's own values. Care practices should also be aligned with consumers' hopes, needs and goals.

Dynamic ultrasound assessment of hip instability and anterior and posterior hip impingement.

OBJECTIVE: In this technical report, we describe our protocol for the dynamic sonographic evaluation of the hip and assess reliability of the ultrasound assessment of hip microinstability. MATERIALS AND METHODS: Our clinical experience with a standardized dynamic ultrasound of the hip performed in a series of 27 patients with imaging performed by an experienced musculoskeletal radiologist during physical examination by an orthopedic surgeon specializing in hip preservation is illustrated with clinical photographs and ultrasound images from volunteers and selected patients. Interrater reliability for the diagnosis of microinstability was calculated. RESULTS: Dynamic ultrasound technique and findings of hip instability, femoroacetabular impingement, and ischiofemoral impingement with corresponding clinical photos showing the necessary physical examination maneuvers are described. Interrater agreement for the diagnosis of microinstability was substantial (κ 0.606 [0.221-0.991]). CONCLUSION: At our institution, dynamic ultrasound of the hip during physical examination complements information gathered from static imaging by providing real-time correlation of symptoms with what is occurring anatomically.

Imaging of total hip arthroplasty: Part I - Implant design, imaging techniques, and imaging of component wear and fracture.

Despite being one of the most reliable procedures in orthopedic surgery, complications can occur after total hip arthroplasty, and radiology plays an essential role in their evaluation. This article will review the various types of hip arthroplasty and their normal appearances on imaging, followed by mechanisms and imaging appearances of component wear and fracture.

Instability Missed by Flexion-Extension Radiographs Subsequently Identified by Alternate Imaging in L4-L5 Lumbar Degenerative Spondylolisthesis.

STUDY DESIGN: Cross-sectional preoperative and intraoperative imaging study of L4-L5 lumbar degenerative spondylolisthesis (LDS). OBJECTIVE: To determine if alternate imaging modalities would identify LDS instability that did not meet the criteria for instability based on comparison of flexion and extension radiographs. SUMMARY OF BACKGROUND DATA: Pain may limit full flexion and extension maneuvers and thereby lead to underreporting of true dynamic translation and angulation in LDS. Alternate imaging pairs may identify instability missed by flexion-extension. MATERIALS AND METHODS: Consecutive patients scheduled for surgery for single-level L4-L5 LDS had preoperative standing radiographs in the lateral, flexion, and extension positions, supine computed tomography (CT) scans, and intraoperative fluoroscopic images in the supine and prone positions after anesthesia but before incision. Instability was defined as translation ≥3.5 mm or angulation ≥11° between the following pairs of images: (1) flexion-extension; (2) CT-lateral; (3) lateral-intraoperative supine; (4) lateral-intraoperative prone; and (5) intraoperative supine-prone. RESULTS: Of 240 patients (mean age 68 y, 54% women) 15 (6%) met the criteria for instability by flexion-extension, and 225 were classified as stable. Of these 225, another 84 patients (35% of total enrollment) were reclassified as unstable by comparison of CT-lateral images (21 patients) and by lateral-intraoperative images (63 patients). Nine of the 15 patients diagnosed with instability by flexion-extension had fusion (60%), and 68 of the 84 patients reclassified as unstable by other imaging pairs had fusion (81%) ( P =0.07). The 84 reclassified patients were more likely to undergo fusion compared with the 141 patients who persistently remained classified as stable (odds ratio=2.6, 95% CI: 1.4-4.9, P =0.004). CONCLUSIONS: Our study provides evidence that flexion and extension radiographs underreport the dynamic extent of LDS and therefore should not be solely relied upon to ascertain instability. These findings have implications for how instability should be established and the extent of surgery that is indicated.

Imaging of total hip arthroplasty: part II - imaging of component dislocation, loosening, infection, and soft tissue injury.

Despite the remarkable success of total hip arthroplasty as treatment of arthritis of the hip, complications can still occur, and imaging plays a crucial role for both diagnosis and guiding management. Component dislocation in total hip arthroplasty is usually diagnosed on radiographs, but cross-sectional imaging is necessary to quantitatively assess component orientation which may have predisposed to the dislocation. The definitive sign of component loosening on radiography is progressive motion of the component, but CT will provide more osseous detail and recent studies have shown the role of MRI in assessing component loosening as well. Infection is a devastating complication for which early diagnosis is crucial. Radiographs are not sensitive for infection, but there are certain MRI features that can suggest infection, and ultrasound and fluoroscopy are useful for guiding arthrocenteses to diagnose infection. Tendon and neurovascular injuries can be a source of long-term disability after total hip arthroplasty, and radiological studies, particularly advanced cross-sectional imaging such as MRI and ultrasound, often play an important role in their diagnoses.

Experiences of families of people living with frontotemporal dementia: a qualitative systematic review.

Frontotemporal dementia (FTD) is characterised by atrophy of the frontal and/or temporal lobes. People with FTD show language and emotional disturbances from onset, and communication problems usually affect people with FTD and their families even before diagnosis. These unique characteristics of FTD are not well understood and create substantial problems for people living with FTD and their families. This review explores the experiences of families of people living with FTD. Studies were selected and screened according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched four bibliographic databases for articles up to February 2021 to identify qualitative data on the experiences of families. The Critical Appraisal Skills Programme checklist for qualitative studies was used to assess all included studies. Of 235 identified articles, we included six studies in the qualitative synthesis. Meta-ethnography was conducted to interpret families' experiences of people living with FTD. The emergent concepts were synthesised into five themes: Something is wrong with my loved one; No one fully understands; Existential pain of caring for a loved one with FTD; Increased burden owing to specific FTD symptoms; and Forced to adapt to new and unique ways of living with a loved one with FTD. This review highlighted families' confusion and suffering (which began in the early stages of the disease, and sometimes before diagnosis) and the difficulty of communicating with people with FTD. These findings have implications for future practice, as they demonstrate the positive effect on family life of appropriate support that is provided early, rather than after the disease has progressed.

Diagnostic Performance of MRI for Component Loosening in Total Knee Arthroplasty Compared with Radiography.

Background Because loosening of total knee arthroplasty (TKA) occurs due to poor osseous integration at component-bone interfaces, interface assessment may be helpful in diagnosing loosening at MRI. Purpose To determine interreader reproducibility for characterizing component interfaces and diagnosing loosening and to evaluate the diagnostic performance of MRI for diagnosing loosening after TKA compared with radiography. Materials and Methods Consecutive knees with TKA that underwent revision between July 2018 and June 2019 and were imaged at MRI and radiography were included in this retrospective study. Interface type (normal, fibrous membrane, fluid, or osteolysis), percent integration (<33%, 33%-66%, or >66%), and presence of bone marrow edema pattern were assessed. Loosening was diagnosed at MRI if no or almost no normal interface was present. Sensitivity and specificity were compared with radiographs by using surgical findings as reference. Gwet agreement coefficient evaluated interreader reproducibility between two readers and multivariable logistic regression assessed risk factors for loosening. Results Among 116 knees in 114 patients (mean age, 63 years ± 10 [SD]; 59 women), 61 of 116 knees (52.6%) had at least one loose component. Interreader reproducibility of MRI was substantial to excellent (Gwet agreement coefficient, 0.67-0.96). Loosening was associated with fluid interface (odds ratio [OR], 20.1; 95% CI: 5.7, 70.9) or osteolysis (OR, 3.1; 95% CI: 1.8, 5.3), absence of any normal interface (OR, 11.8; 95% CI: 6.3, 22.2), poor (<33%) osseous integration (OR, 20.4; 95% CI: 9.7, 42.6), and bone marrow edema pattern (OR, 4.7; 95% CI: 2.8, 7.8). Sensitivity and specificity of MRI for loosening were 84% (27 of 32; 95% CI: 72, 97) and 85% (71 of 84; 95% CI: 77, 92) for the patellar, 31% (eight of 26; 95% CI: 13, 49) and 100% (90 of 90; 95% CI: 100, 100) for the femoral, and 81% (22 of 27; 95% CI: 66, 96) and 98% (87 of 89; 95% CI: 95, 100) for the tibial component, respectively. MRI had higher sensitivity (84% vs 31%; P < .001) but lower specificity (85% vs 96%; P = .003) for patellar component loosening than did radiography, respectively, whereas no evidence of a difference was found for femoral (sensitivity and specificity, MRI vs radiography: 31% vs 46% [P = .20] and 100% vs 99% [P > .99], respectively) or tibial (sensitivity and specificity, MRI vs radiography: 81% vs 70% [P = .16] and 98% vs 97% [P = .32], respectively) component loosening. Conclusion MRI demonstrated substantial to excellent interreader reproducibility and higher sensitivity than did radiography for diagnosing patellar component loosening after total knee arthroplasty. © RSNA, 2022 Online supplemental material is available for this article.

Evaluation of deep learning reconstructed high-resolution 3D lumbar spine MRI.

OBJECTIVES: To compare interobserver agreement and image quality of 3D T2-weighted fast spin echo (T2w-FSE) L-spine MRI images processed with a deep learning reconstruction (DLRecon) against standard-of-care (SOC) reconstruction, as well as against 2D T2w-FSE images. The hypothesis was that DLRecon 3D T2w-FSE would afford improved image quality and similar interobserver agreement compared to both SOC 3D and 2D T2w-FSE. METHODS: Under IRB approval, patients who underwent routine 3-T lumbar spine (L-spine) MRI from August 17 to September 17, 2020, with both isotropic 3D and 2D T2w-FSE sequences, were retrospectively included. A DLRecon algorithm, with denoising and sharpening properties was applied to SOC 3D k-space to generate 3D DLRecon images. Four musculoskeletal radiologists blinded to reconstruction status evaluated randomized images for motion artifact, image quality, central/foraminal stenosis, disc degeneration, annular fissure, disc herniation, and presence of facet joint cysts. Inter-rater agreement for each graded variable was evaluated using Conger's kappa (κ). RESULTS: Thirty-five patients (mean age 58 ± 19, 26 female) were evaluated. 3D DLRecon demonstrated statistically significant higher median image quality score (2.0/2) when compared to SOC 3D (1.0/2, p < 0.001), 2D axial (1.0/2, p < 0.001), and 2D sagittal sequences (1.0/2, p value < 0.001). κ ranges (and 95% CI) for foraminal stenosis were 0.55-0.76 (0.32-0.86) for 3D DLRecon, 0.56-0.73 (0.35-0.84) for SOC 3D, and 0.58-0.71 (0.33-0.84) for 2D. Mean κ (and 95% CI) for central stenosis at L4-5 were 0.98 (0.96-0.99), 0.97 (0.95-0.99), and 0.98 (0.96-0.99) for 3D DLRecon, 3D SOC and 2D, respectively. CONCLUSIONS: DLRecon 3D T2w-FSE L-spine MRI demonstrated higher image quality and similar interobserver agreement for graded variables of interest when compared to 3D SOC and 2D imaging. KEY POINTS: • 3D DLRecon T2w-FSE isotropic lumbar spine MRI provides improved image quality when compared to 2D MRI, with similar interobserver agreement for clinical evaluation of pathology. • 3D DLRecon images demonstrated better image quality score (2.0/2) when compared to standard-of-care (SOC) 3D (1.0/2), p value < 0.001; 2D axial (1.0/2), p value < 0.001; and 2D sagittal sequences (1.0/2), p value < 0.001. • Interobserver agreement for major variables of interest was similar among all sequences and reconstruction types. For foraminal stenosis, κ ranged from 0.55 to 0.76 (95% CI 0.32-0.86) for 3D DLRecon, 0.56-0.73 (95% CI 0.35-0.84) for standard-of-care (SOC) 3D, and 0.58-0.71 (95% CI 0.33-0.84) for 2D.

Diagnostic ultrasound of tendon injuries in the setting of distal radius fractures.

OBJECTIVE: Describe tendon injuries and their structural causes seen on ultrasound in wrists with distal radius fractures and estimate the accuracy of ultrasound and its impact on clinical management. MATERIALS AND METHODS: Ultrasounds of 226 wrists (221 patients) with distal radius fractures were retrospectively reviewed. Ultrasound findings of tendon injuries and their structural causes were correlated with surgery and clinical outcome. Accuracy and inter- and intra-observer reproducibilities were calculated. RESULTS: Twenty-five wrists were treated non-operatively while 201 underwent surgery. Ultrasound demonstrated hardware contact with flexor pollicis longus (FPL) in 76 wrists, extensor pollicis longus (EPL) in 21, and other tendons in 94. Ultrasound identified tendon ruptures in 23 wrists (13 EPL/8 FPL/2 extensor indicis proprius (EIP)), most of which were surgically confirmed. Among 12 wrists with confirmed EPL ruptures, distal radius fracture had been treated with volar plating in 6 and non-operatively in 6, and ultrasound showed osseous irregularity at the rupture site in 8. All FPL ruptures occurred in wrists with volar plating. Ultrasound findings were concordant with subsequent clinical management in most. In 2, ultrasound findings led to the decision to remove hardware despite lack of symptoms. Ultrasound had sensitivity/specificity/accuracy of 88/99/98% for identifying a specific tendon as ruptured and 88/87/88% for tendon abnormalities in general. Inter- and intra-observer reproducibilities were excellent (kappa = 0.85 ~ 1.0). CONCLUSION: Certain wrist tendons, particularly EPL and FPL, are vulnerable after distal radius fractures. Ultrasound is accurate and useful for detecting tendon injury and sources of tendon irritation and can guide clinical management.

Strategies Employed by Forensic Community Mental Health Nurses to Resolve Difficulties in Supporting Offenders With Mental Disorders Under the Medical Treatment and Supervision Act in Japan.

OBJECTIVE: This study aimed to identify the strategies used by forensic community mental health nurses to resolve difficulties in supporting offenders with mental disorders under the Medical Treatment and Supervision Act in Japan. METHOD: Interviews were conducted with 13 nurses, and the data were analyzed using content analysis. RESULTS: The study identified the strategies for difficulties in (a) assessing and managing risk potential of forensic service patients, (b) addressing offending behavior, (c) managing the transition of patients, (d) supporting patients to understand the impact of justice processes and applying knowledge of legislation to nursing, and (e) promoting the role of forensic community mental health nurses within the multidisciplinary team. CONCLUSIONS: The findings can benefit and support forensic community mental health nurses' practices. The Japanese forensic community mental health nurses experiencing difficulties and providing home visits to patients can utilize the identified strategies.

MRI Visualization of Polyethylene Post Fractures in Posterior Stabilized Total Knee Arthroplasty.

Polyethylene post fracture is a recognized complication of posterior stabilized total knee arthroplasty. Two radiologists retrospectively reviewed MRI examinations of 19 reported post fractures in 18 patients; all fractures were subsequently confirmed surgically with no false-positive cases. All post fractures were visualized as a combination of post deformity and signal-void fragment in a joint recess. A metal artifact reduction 3D multispectral imaging sequence improved fracture visualization versus conventional sequences in 47% of cases.

Helpful resources recognized by adult children of parents with a mental illness in Japan.

AIM: This study aimed to identify the resources recognized as helpful by children of parents with a mental illness (COPMI) to cope with the difficulties they experienced in their lives. METHODS: A qualitative descriptive design was employed. Semi-structured interviews were conducted with 10 adults who experienced parental mental illness in their childhood. Participants were asked to discuss resources that were beneficial to them. Text segments from the verbatim transcriptions were identified with summarizing codes, and the codes were compared and contrasted to generate subcategories and categories. The case characteristics and subcategories were reorganized to retest the validity of the categories. RESULTS: Parental mental illness onset occurred before birth or in early childhood for four participants and during elementary or junior high school for six participants. Six categories emerged: protection from the harmful influences of parents' symptoms; care received from adults at home and school; occasional experience of mutual affection and support within the family; emotional validation and sustained support by others; understanding how to cope using information on mental illnesses; and time for oneself and experiences away from the parent. CONCLUSIONS: Helpful resources recognized by COPMI involved not only emotional connections, but also resources related to their daily lives and time for themselves. Understanding the gaps in COPMI's resources can facilitate effective support. Emotional validation by others and time for themselves and away from the parent are important for promoting their development. Society needs to better understand mental illness.

Improved nerve conspicuity with water-weighting and denoising in two-point Dixon magnetic resonance neurography.

BACKGROUND: T2-weighted, two-point Dixon fast-spin-echo (FSE) is an effective technique for magnetic resonance neurography (MRN) that can provide quantitative assessment of muscle denervation. Low signal-to-noise ratio and inadequate fat suppression, however, can impede accurate interpretation. PURPOSE: To quantify effects of principal component analysis (PCA) denoising on tissue signal intensities and fat fraction (FF) and to determine qualitative image quality improvements from both denoising and water-weighting (WW) algorithms to improve nerve conspicuity and fat suppression. STUDY TYPE: Prospective. SUBJECTS: Twenty-one subjects undergoing MR neurography evaluation (11/10 male/female, mean age = 46.3±13.7 years) with 60 image volumes. Twelve subjects (23 image volumes) were determined to have muscle denervation based on diffusely elevated T2 signal intensity. FIELD STRENGTH/SEQUENCE: 3 T, 2D, two-point Dixon FSE. ASSESSMENT: Qualitative assessment included overall image quality, nerve conspicuity, fat suppression, pulsation and ringing artifacts by 3 radiologists separately on a three-point scale (1 = poor, 2 = average, 3 = excellent). Quantitative measurements for FF and signal intensity relative to normal muscle were made for nerve, abnormal muscle and subcutaneous fat. STATISTICAL TESTS: Linear and ordinal regression models were used for quantitative and qualitative comparisons, respectively; 95% confidence intervals (CIs) and p-values for pairwise comparisons were adjusted using the Holm-Bonferroni method. Inter-rater agreement was assessed using Gwet's agreement coefficient (AC2). RESULTS: Simulations showed PCA-denoising reduced FF error from 2.0% to 1.0%, and from 7.6% to 3.1% at noise levels of 10% and 30%, respectively. In human subjects, PCA-denoising did not change signal levels and FF quantitatively. WW decreased fat signal significantly (-83.6%, p < 0.001). Nerve conspicuity was improved by WW (odds ratio, OR = 5.8, p < 0.001). Fat suppression was improved by both PCA (OR = 3.6, p < 0.001) and WW (OR = 2.2, p < 0.001). Overall image quality was improved by PCA + WW (OR = 1.7, p = 0.04). CONCLUSIONS: WW and PCA-denoising improved nerve conspicuity and fat suppression in MR neurography. Denoising can potentially provide improved accuracy of FF maps for assessing fat-infiltrated muscle.

Ultrasound features of traumatic digital nerve injuries of the hand with surgical confirmation.

OBJECTIVE: Characterize the appearance of digital nerve injuries in different ultrasound planes and correlate the presence and size of neuromas with time from injury. MATERIALS AND METHODS: Surgically confirmed nerve injuries were retrospectively evaluated. Appearances of the nerve injury in the available imaging planes were reviewed by two readers. Associations between presence and size of neuroma with time from injury were analyzed. RESULTS: Injuries of 29 digital nerves (3 incomplete lacerations, 17 complete lacerations, 6 with 7 stump neuromas, 3 neuromas-in-continuity) noted on ultrasound were surgically confirmed. Among the 20 lacerations, long-axis images were obtained in 15, of which 10 depicted the injury and 4 did not. Among the 10 depicting the injury in long axis, 2 showed a discrete gap, and 7 showed the nerve obscured by laceration tissue without a gap. In short axis, the nerve injury was visible in all 20, and nerve laceration was seen as a discrete gap in 2, and obscuration by laceration tissue in 14. Neuromas were hypoechoic and well-defined. There was a positive association between time and presence of neuroma (OR = 1.3, p = 0.002). Correlations between time and cross-sectional area (rs = 0.45) and volume (rs = 0.57) of neuromas were moderately positive. CONCLUSION: Ultrasound long axis may be less useful, and those short axis may be more reliable for assessing digital nerve injuries than previously reported. Neuromas are hypoechoic and well-defined, and their size can vary based on time from injury.