Platelet-rich plasma vs. steroid injections for hamstring injury-is there really a choice?

OBJECTIVE: To assess the effectiveness of pain relief in patients with grade 2 proximal hamstring injury, treated with platelet-rich plasma (PRP) or corticosteroid injection, by using the primary outcome of visual analog scale (VAS) at 1 week and 4 weeks of follow-up. MATERIALS AND METHODS: A single institution retrospective study was performed for image-guided PRP or steroid injections between 12/1/2015 and 10/30/2017 for proximal hamstring injuries. VAS was measured at 1 week and 4 weeks post-injection via telephone interviews and the pain response was recorded into two groups (negative/no change vs. positive). A comparison of pain responses between PRP and steroid was conducted by generalized estimating equation. RESULTS: Among 56 patients, 32 received PRP and 24 received steroid injections with ages from 13 to 75 years old. At 1 week post-injection follow-up, 23 patients (71.9%) from the PRP group and 11 patients (45.8%) from the steroid group showed positive response. After controlling for age, pre-procedure pain level, and gender, the positive response rate in the PRP group was higher than the steroid group (aOR: 4.04, 95% CI: 1.04-15.63, p value = 0.04). At 4 weeks post-injection, 23 patients (71.9%) from the PRP group and 13 patients (54.2%) from the steroid group showed positive response with no statistical significance (aOR: 2.48, 95% CI: 0.63-9.79, p value = 0.19). CONCLUSIONS: The PRP group had shown more favorable response compared to steroid group at 1 week post-injection, which suggests that PRP therapy can be considered as a conservative treatment choice for grade 2 proximal hamstring injuries with better short-term pain relief based on limited pilot data.

The state of emergency radiology fellowships in North America and the development of a standardized curriculum.

BACKGROUND AND OBJECTIVES: The number of emergency radiology (ER) training programs in North America is small compared to the projected growth in demand for ER-trained radiologists. To date, there is no consensus-based training curriculum that sets a standard for all ER fellowship training programs. This study seeks to (1) identify the programmatic measures currently used in North American ER fellowship programs and (2) gather the perspectives of existing ER fellowship program directors (PD) and their recommendations for minimum and ideal curricular standards. METHODS: We distributed an 18-question survey to the PDs of every North American ER fellowship program (N = 15). Surveys were completed during the 2016-2017 academic year. We performed a cross-sectional analysis to gain an understanding of existing training curricula, expected areas of competency by the end-of-training, and PD opinions of what a standard ER training curriculum should contain. RESULTS: The data revealed heterogeneity in programmatic structure across the continent, as well as some areas of agreement. PD suggestions for a standard ER training curriculum showed consistency in many areas, including competency and proficiency expectations and clinical exposures, with some variability. These data were used to inform the creation of the first curricular standard for ER fellowship training. CONCLUSION: This study yielded the creation of a standard fellowship training resource for the field of ER. This deliverable serves as a curricular guideline for existing ER fellowships, as well as a model for new ER fellowship programs.

Core curriculum illustration: posterior column acetabular fracture.

This is the 17th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for study online at: http://www.aseronline.org/curriculum/toc.htm.

A report on the Academic Emergency Medicine 2015 consensus conference "Diagnostic imaging in the emergency department: a research agenda to optimize utilization".

In May 2015, the Academic Emergency Medicine consensus conference "Diagnostic imaging in the emergency department: a research agenda to optimize utilization" was held. The goal of the conference was to develop a high-priority research agenda regarding emergency diagnostic imaging on which to base future research. In addition to representatives from the Society of Academic Emergency Medicine, the multidisciplinary conference included members of several radiology organizations: American Society for Emergency Radiology, Radiological Society of North America, the American College of Radiology, and the American Association of Physicists in Medicine. The specific aims of the conference were to (1) understand the current state of evidence regarding emergency department (ED) diagnostic imaging utilization and identify key opportunities, limitations, and gaps in knowledge; (2) develop a consensus-driven research agenda emphasizing priorities and opportunities for research in ED diagnostic imaging; and (3) explore specific funding mechanisms available to facilitate research in ED diagnostic imaging. Through a multistep consensus process, participants developed targeted research questions for future research in six content areas within emergency diagnostic imaging: clinical decision rules; use of administrative data; patient-centered outcomes research; training, education, and competency; knowledge translation and barriers to imaging optimization; and comparative effectiveness research in alternatives to traditional computed tomography use.

High resolution diffusion tensor imaging of human nerves in forearm.

PURPOSE: To implement high resolution diffusion tensor imaging (DTI) for visualization and quantification of peripheral nerves in human forearm. MATERIALS AND METHODS: This HIPAA-compliant study was approved by our Institutional Review Board and written informed consent was obtained from all the study participants. Images were acquired with T1 -and T2 -weighted turbo spin echo with/without fat saturation, short tau inversion recovery (STIR). In addition, high spatial resolution (1.0 × 1.0 × 3.0 mm(3) ) DTI sequence was optimized for clearly visualizing ulnar, superficial radial and median nerves in the forearm. Maps of the DTI derived indices, fractional anisotropy (FA), mean diffusivity (MD), longitudinal diffusivity (λ// ) and radial diffusivity (λ⊥ ) were generated. RESULTS: For the first time, the three peripheral nerves, ulnar, superficial radial, and median, were visualized unequivocally on high resolution DTI-derived maps. DTI delineated the forearm nerves more clearly than other sequences. Significant differences in the DTI-derived measures, FA, MD, λ// and λ⊥ , were observed among the three nerves. A strong correlation between the nerve size derived from FA map and T2 -weighted images was observed. CONCLUSION: High spatial resolution DTI is superior in identifying and quantifying the median, ulnar, and superficial radial nerves in human forearm. Consistent visualization of small nerves and nerve branches is possible with high spatial resolution DTI. These normative data could potentially help in identifying pathology in diseased nerves. J. Magn. Reson. Imaging 2014;39:1374-1383. © 2013 Wiley Periodicals, Inc.

Relationship Between Bone Bruise Volume and Patient Outcomes After ACL Reconstruction.

Background: Subchondral bone injuries, or bone bruises, are commonly observed on magnetic resonance imaging (MRI) after anterior cruciate ligament (ACL) injury. The current relationship between bone bruise volume and postsurgical outcomes remains poorly understood. Purpose: To examine the influence of bone bruise volume on self-reported and objective functional outcomes at the time of return to play and 2 years following ACL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: Clinical, surgical, and demographic data were obtained for a sample of convenience utilizing a single-surgeon ACL database (n = 1396). For 60 participants, femoral and tibial bone bruise volumes were estimated from preoperative MRI. Data obtained at the time of return to play included International Knee Documentation Committee (IKDC-2000) score, ACL-Return to Sport after Injury (ACL-RSI) score, and performance on an objective functional performance battery. Two-year follow-up data included graft reinjury rate, level of return to sport/activity, and self-reported knee function using the Single Assessment Numeric Evaluation (SANE). The forward stepwise linear regression was used to determine the relationship between bone bruise volume and patient function. Results: The distribution of bone bruise injuries was as follows: lateral femoral condyle (76.7%), lateral tibial plateau (88.3%), medial femoral condyle (21.7%), and medial tibial plateau (26.7%). Mean total bone bruise volume of all compartments was 7065.7 ± 6226.6 mm3. At the 2-year follow up, there were no significant associations between total bone bruise volume and time of return to play (P = .832), IKDC-2000 score (P = .200), ACL-RSI score (P = .370), or SANE score (P = .179). Conclusion: The lateral tibial plateau was the most frequent site to sustain bone bruise injury. Preoperative bone bruise volume was not associated with delayed time to return to sport or self-reported outcomes at time of return to play or at 2 years postoperatively. Registration: NCT03704376 (ClinicalTrials.gov identifier).

Clinical outcomes of rotator cuff repair with subacromial bursa reimplantation: a retrospective cohort study.

Background: The subacromial bursa has been found to be a rich, local, source of mesenchymal stem cells but is removed for visualization during rotator cuff repair. Reimplantation of this tissue may improve rotator cuff healing. The purpose of this study is to evaluate clinical outcomes of rotator cuff repair with and without subacromial bursa reimplantation. Methods: Patients aged 37-77 with a full-thickness or near full-thickness supraspinatus tears underwent arthroscopic transosseous-equivalent double row rotator cuff repair. In patients prior to July 2019, the subacromial bursa was resected for visualization, and discarded. In patients after July 2019, the subacromial bursa was collected using a filtration device connected to an arthroscopic shaver and reapplied to the bursal surface of the tendon at the completion of the rotator cuff repair. Rotator cuff integrity was evaluated via magnetic resonance imaging on bursa patients at 6 months postoperatively. Minimum 18-month clinical outcomes (Single Assessment Numeric Evaluation, American Shoulder and Elbow Surgeons, patient satisfaction) were compared between bursa and nonbursa cohorts. Results: A total of 136 patients were included in the study (control n = 110, bursa n = 26). Preoperative demographics and tear characteristics were not different between groups. Average follow-up was significantly longer in the control group (control: 3.2 ± 0.7 years; bursa: 1.8 ± 0.3 years; P < .001). The control group showed a significantly higher Single Assessment Numeric Evaluation score (control: 87.9 ± 15.8, bursa: 83.6 ± 15.1, P = .037) that did not meet minimum clinically important difference. The American Shoulder and Elbow Surgeons and patient satisfaction scores were similar between the groups. Symptomatic retears were not significantly different between groups (control: 9.1%, bursa 7.7%, P = .86). Seven patients in the control group underwent reoperation (6.4%), compared to 0 patients in the bursa group (0%, P = .2). Six-month postoperative magnetic resonance images obtained on bursa patients demonstrated 85% rotator cuff continuity (n = 17/20) as defined via Sugaya classification. Conclusion: Augmentation of rotator cuff repair with bursal tissue does not appear to have negative effects, and given the accessibility and ease of harvest of this tissue, further research should be performed to evaluate its potential for improved tendon healing or clinical outcomes.

Diffusion tensor imaging of forearm nerves in humans.

PURPOSE: To implement a diffusion tensor imaging (DTI) protocol for visualization of peripheral nerves in human forearm. MATERIALS AND METHODS: This Health Insurance Portability and Accountability Act (HIPAA)-compliant study was approved by our Institutional Review Board and written informed consent was obtained from 10 healthy participants. T(1) - and T(2) -weighted turbo spin echo with fat saturation, short tau inversion recovery (STIR), and DTI sequences with 21 diffusion-encoding directions were implemented to acquire images of the forearm nerves with an 8 channel knee coil on a 3T MRI scanner. Identification of the nerves was based on T(1) -weighted, T(2) -weighted, STIR, and DTI-derived fractional anisotropy (FA) images. Maps of the DTI-derived indices, FA, mean diffusivity (MD), longitudinal diffusivity (λ(//) ), and radial diffusivity (λ(⟂) ) along the length of the nerves were generated. RESULTS: DTI-derived maps delineated the forearm nerves more clearly than images acquired with other sequences. Only ulnar and median nerves were clearly visualized on the DTI-derived FA maps. No significant differences were observed between the left and right forearms in any of the DTI-derived measures. Significant variation in the DTI measures was observed along the length of the nerve. Significant differences in the DTI measures were also observed between the median and ulnar nerves. CONCLUSION: DTI is superior in visualizing the median and ulnar nerves in the human forearm. The normative data could potentially help distinguish normal from diseased nerves.

The Impact of Magnetic Resonance Imaging on the Diagnosis of High-Energy Ipsilateral Femoral Neck and Shaft Fractures.

OBJECTIVE: To evaluate the most common femoral shaft fracture morphology associated with an ipsilateral femoral neck fracture in high-energy blunt trauma using magnetic resonance imaging (MRI). DESIGN: Retrospective review. SETTING: Level 1 trauma center. PATIENTS/PARTICIPANTS: 219 consecutive patients sustaining 228 femoral shaft fractures from high-energy blunt trauma. MAIN OUTCOME MEASUREMENTS: Fracture patterns were analyzed using the OTA/AO classification system. In addition, location of the fracture was measured as the distance from the distal aspect of the lesser trochanter to the center of the femoral shaft fracture. RESULTS: An OTA/AO 31 type fracture was seen in 16.5% (20/121) of patients presenting with OTA/AO 32-A type fractures, 12% (6/50) of patients with OTA/AO 32-B type fractures, and 26.3% (15/57) of patients with OTA/AO 32-C type fractures. The fractures that occurred in the middle or distal third of the femur shaft constituted 95.1% (39/41). CONCLUSIONS: In this cohort, patients with middle and distal third OTA/AO 32-C type fractures had the highest association with an ipsilateral OTA/AO 31 type fracture. OTA/AO 32-A2 and 32-A3 type fractures had the highest association with femoral neck fractures seen only on MRI. The data presented suggest continued usage of the rapid sequence pelvic MRI for all patients with high-energy femoral shaft fractures in whom a femoral neck fracture was not seen on an x-ray or a computed tomography scan. LEVEL OF EVIDENCE: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

ACR Appropriateness Criteria® Chronic Elbow Pain.

Chronic elbow pain can be osseous, soft tissue, cartilaginous, and nerve related in etiology. Imaging plays an important role in differentiating between these causes of chronic elbow pain. This document provides recommendations for imaging of chronic elbow pain in adult patients. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer-reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer-reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Dual-Energy CT to Diagnose Occult Femoral Neck Fracture in MRI-Contraindicated Patient: A Case Report.

CASE: A 79-year-old woman presented after a ground level fall with the inability to bear weight on her right hip. Radiographs and computed tomography (CT) imaging were negative for a femoral neck fracture. Her medical comorbidities precluded magnetic resonance imaging (MRI), so dual-energy CT with focused evaluation for bone edema was performed, identifying a femoral neck fracture that was stabilized surgically. CONCLUSION: Dual-energy CT with processing for edema can successfully identify nondisplaced femoral neck fractures in MRI-contraindicated patients. This imaging modality could be useful for diagnosing femoral neck stress fractures and ipsilateral femoral neck fractures in patients sustaining high-energy femoral shaft fractures.

Implementation of a novel MRI protocol for diagnosing femoral neck fractures in high energy femoral shaft fractures: One year results.

INTRODUCTION: Preliminary results using a novel rapid-sequence MRI to diagnose ipsilateral femoral neck fractures in patients sustaining high-energy femoral shaft fractures have been favorable compared to radiographic and CT imaging alone. To evaluate and optimize this new institutional imaging protocol further, we reviewed our results one year after implementation. METHODS: Rapid-sequence MRI was added to the imaging evaluation of patients with high-energy femoral shaft fractures without femoral neck fractures identified on radiographs or CT imaging. Data was retrospectively reviewed from a consecutive series of patients who met inclusion criteria. RESULTS: From September 2018 through September 2019, 114 patients sustained 121 high-energy femoral shaft fractures. The average patient age was 29.9 years, 73.7% (84/114) of patients were male, and 16.5% (20/121) were open fractures. Of patients indicated for a rapid-sequence MRI, 86% (92/107) underwent MR imaging. 5% (6/121) of patients had an ipsilateral femoral neck fracture identified on radiographs alone. Three additional femoral neck fractures were identified with CT imaging for an initial incidence of 7.4% (9/121). MRI identified 10 additional non-displaced femoral neck fractures, three complete and seven incomplete fractures, for an incidence of 15.7% (19/121). All identified femoral neck fractures were stabilized. DISCUSSION/CONCLUSION: The addition of rapid-sequence MRI of the pelvis in patients with high-energy femoral shaft fractures reliably increases the diagnosis of ipsilateral femoral neck fractures not identified with standard imaging. There were no cases of missed/delayed femoral neck fractures in patients with a negative MRI. This new imaging protocol effectively and safely improves the diagnosis of this injury pattern.

Improving the Diagnosis of Ipsilateral Femoral Neck and Shaft Fractures: A New Imaging Protocol.

BACKGROUND: Despite increased awareness of ipsilateral femoral neck fractures in patients with high-energy femoral shaft fractures and advanced imaging with thin-cut high-resolution computed tomography (CT), failure of diagnosis remains problematic. The purpose of the present study was to determine if the preoperative diagnosis of ipsilateral femoral neck fractures in patients with high-energy femoral shaft fractures can be improved with magnetic resonance imaging (MRI) compared with radiographic and CT imaging. METHODS: In response to delayed diagnoses of femoral neck fractures despite thin-cut high-resolution CT, our institutional imaging protocol for acute, high-energy femoral shaft fractures was altered to include rapid limited-sequence MRI to evaluate for occult femoral neck fractures. All patients received standard radiographic imaging as well as thin-cut high-resolution pelvic CT imaging upon presentation. Rapid limited-sequence MRI of the pelvis was obtained to evaluate for an occult femoral neck fracture. RESULTS: Thirty-seven consecutive patients with 39 acute, high-energy femoral shaft fractures resulting from blunt trauma were included. The average age of the patients was 29.1 years (range, 14 to 82 years). Ten (25.6%) of the 39 femoral shaft fractures were open. Two femoral shaft fractures (5.1%) were associated with ipsilateral femoral neck fractures that were detected on radiographs, and no MRI was performed. None of the remaining 37 femoral shaft fractures were associated with a femoral neck fracture that was identified on CT imaging. Thirty-three (89.2%) of 37 patients underwent pelvic MRI to evaluate the ipsilateral femoral neck. Four (12.1%) of those 33 patients were diagnosed with a femoral neck fracture (2 complete, 2 incomplete) that was not identified on thin-cut high-resolution CT or radiographic imaging. CONCLUSIONS: Rapid limited-sequence MRI of the pelvis for patients with femoral shaft fractures identified femoral neck fractures that were not diagnosed on thin-cut high-resolution CT in 12% of our patients. Our results suggest that the frequency of femoral neck fractures may be underrepresented on CT imaging; rapid limited-sequence MRI was feasible without delaying definitive treatment even in polytraumatized patients. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Quantitative Assessment of In Vivo Human Anterior Cruciate Ligament Autograft Remodeling: A 3-Dimensional UTE-T2* Imaging Study.

BACKGROUND: The timing of return to play after anterior cruciate ligament (ACL) reconstruction is still controversial due to uncertainty of true ACL graft state at the time of RTP. Recent work utilizing ultra-short echo T2* (UTE-T2*) magnetic resonance imaging (MRI) as a scanner-independent method to objectively and non-invasively assess the status of in vivo ACL graft remodeling has produced promising results. PURPOSE/HYPOTHESIS: The purpose of this study was to prospectively and noninvasively investigate longitudinal changes in T2* within ACL autografts at incremental time points up to 12 months after primary ACL reconstruction in human patients. We hypothesized that (1) T2* would increase from baseline and initially exceed that of the intact contralateral ACL, followed by a gradual decline as the graft undergoes remodeling, and (2) remodeling would occur in a region-dependent manner. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twelve patients (age range, 14-45 years) who underwent primary ACL reconstruction with semitendinosus tendon or bone-patellar tendon-bone autograft (with or without meniscal repair) were enrolled. Patients with a history of previous injury or surgery to either knee were excluded. Patients returned for UTE MRI at 1, 3, 6, 9, and 12 months after ACL reconstruction. Imaging at 1 month included the contralateral knee. MRI pulse sequences included high-resolution 3-dimensional gradient echo sequence and a 4-echo T2-UTE sequence (slice thickness, 1 mm; repetition time, 20 ms; echo time, 0.3, 3.3, 6.3, and 9.3 ms). All slices containing the intra-articular ACL were segmented from high-resolution sequences to generate volumetric regions of interest (ROIs). ROIs were divided into proximal/distal and core/peripheral sub-ROIs using standardized methods, followed by voxel-to-voxel registration to generate T2* maps at each time point. This process was repeated by a second reviewer for interobserver reliability. Statistical differences in mean T2* values and mean ratios of T2*inj/T2*intact (ie, injured knee to intact knee) among the ROIs and sub-ROIs were assessed using repeated measures and one-way analyses of variance. P < .05 represented statistical significance. RESULTS: Twelve patients enrolled in this prospective study, 2 withdrew, and ultimately 10 patients were included in the analysis (n = 7, semitendinosus tendon; n = 3, bone-patellar tendon-bone). Interobserver reliability for T2* values was good to excellent (intraclass correlation coefficient, 0.84; 95% CI, 0.59-0.94; P < .001). T2* values increased from 5.5 ± 2.1 ms (mean ± SD) at 1 month to 10.0 ± 2.9 ms at 6 months (P = .001), followed by a decline to 8.1 ± 2.0 ms at 12 months (P = .129, vs 1 month; P = .094, vs 6 months). Similarly, mean T2*inj/T2*intact ratios increased from 62.8% ± 22.9% at 1 month to 111.1% ± 23.9% at 6 months (P = .001), followed by a decline to 92.8% ± 29.8% at 12 months (P = .110, vs 1 month; P = .086, vs 6 months). Sub-ROIs exhibited similar increases in T2* until reaching a peak at 6 months, followed by a gradual decline until the 12-month time point. There were no statistically significant differences among the sub-ROIs (P > .05). CONCLUSION: In this preliminary study, T2* values for ACL autografts exhibited a statistically significant increase of 82% between 1 and 6 months, followed by an approximate 19% decline in T2* values between 6 and 12 months. In the future, UTE-T2* MRI may provide unique insights into the condition of remodeling ACL grafts and may improve our ability to noninvasively assess graft maturity before return to play.

Assessment of a deep-learning system for fracture detection in musculoskeletal radiographs.

Missed fractures are the most common diagnostic error in emergency departments and can lead to treatment delays and long-term disability. Here we show through a multi-site study that a deep-learning system can accurately identify fractures throughout the adult musculoskeletal system. This approach may have the potential to reduce future diagnostic errors in radiograph interpretation.

An uncommon cause of sciatica.

A 67-year-old male patient underwent a left nephrectomy for a renal cell carcinoma. Thirty-eight months later, he presented with right sided lower backache, radiating to the posterior aspect of his thigh, calf and foot, paraesthesiae and numbness in the distribution of the right S1 and S2 dermatomes. The presumptive diagnosis was of nerve root entrapment secondary to a disc prolapse. MRI scan of the lumbosacral spine revealed an enlarged S1 root canal containing a solid solitary lesion suggestive of a neurofibroma of the S1 nerve root. Because of persistent pain, he underwent a right L5/S1 hemilaminectomy. A lesion originating from the right S2 nerve root was found and excised. The patient made an uneventful postoperative recovery with complete resolution of his right leg pain. The histopathological examination revealed a portion of the nerve root and dorsal root ganglion infiltrated by metastatic renal cell carcinoma. Although uncommon, nerve root infiltration by a metastasis should be included in the differential diagnosis of back pain and sciatica, especially if there is a previous history of malignant disease.

Is the Cranial and Posterior Screw of the "Inverted Triangle" Configuration for Femoral Neck Fractures Safe?

OBJECTIVES: To determine the frequency where a posterior and cranial screw in a femoral neck that appeared contained on fluoroscopy violates the cortex. METHODS: Ten specimens including the hemipelvis with the proximal femur were obtained from unidentified embalmed specimens that were to be cremated after an institutional review board waiver was granted. Under fluoroscopy, the posterior and cranial screw of the inverted triangle configuration for the femoral neck was placed using standard technique with a cannulated 6.5-mm screw. Anterior-posterior and lateral images of the final screw placement were blinded to 2 orthopaedic traumatologists and 1 musculoskeletal radiologist who were asked to determine whether the screw radiographically breached the posterior and cranial cortex. Cadavers were stripped of soft tissues and inspected for screw perforation. Screws were grouped as contained, thread extrusion, or core extrusion. RESULTS: Reviewers classified all 10 screws as radiographically contained within the femoral neck. Cadavers were inspected and found to show: 4 of 10 with core extrusion, 3 of 10 with thread extrusion, and 3 of 10 screws contained within the femoral neck. CONCLUSIONS: Seventy percent of screws that were judged to be radiographically contained had cortical breach near the area where the lateral epiphyseal vessels enter the femoral neck. We urge caution against placement of posterior-cranial implants with fluoroscopy alone even if they appear radiographically contained.

Multidetector CT evaluation of active extravasation in blunt abdominal and pelvic trauma patients.

Timely localization of a bleeding source can improve the efficacy of trauma management, and improvements in the technology of computed tomography (CT) have expedited the work-up of the traumatized patient. The classic pattern of active extravasation (ie, administered contrast agent that has escaped from injured arteries, veins, or urinary tract) at dual phase CT is a jet or focal area of hyperattenuation within a hematoma that fades into an enlarged, enhanced hematoma on delayed images. This finding indicates significant bleeding and must be quickly communicated to the clinician, since potentially lifesaving surgical or endovascular repair may be necessary. Active extravasation can be associated with other injuries to arteries, such as a hematoma or a pseudoaneurysm. Both active extravasation and pseudoaneurysm (unlike bone fragments and dense foreign bodies) change in appearance on delayed images, compared with their characteristics on arterial images. Other clues to the location of vessel injury include lack of vascular enhancement (caused by occlusion or spasm), vessel irregularity, size change (such as occurs with pseudoaneurysm), and an intimal flap (which signifies dissection). The sentinel clot sign is an important clue for locating the bleeding source when other more localizing findings of vessel injury are not present. Timely diagnosis, differentiation of vascular injuries from other findings of trauma, signs of depleted intravascular volume, and localization of vascular injury are important to convey to interventional radiologists or surgeons to improve trauma management.

Magnetic resonance imaging of muscle injury in elite American football players: Predictors for return to play and performance.

Muscle injury accounts for about one-third of total sports-related injuries. The lower limb muscles have one of the highest predisposition for injury in high-level professional athletic sports, such as the National Football League. The commonest group of muscles injured among football players include the hamstrings, followed by the quadriceps. Muscle injuries lead to significant time, off the field and affect return to play. Sports physicians and teams have been keen on assessing such injuries and also relying on multiple tools to safely return the player back to the field. MRI plays a key role in evaluation, follow-up, and assessment for return to play (RTP). In this review, we will discuss details of muscle anatomy, incidence of muscle injuries, injury mechanisms, and use of MRI in assessment, grading, follow-up and in predicting the natural course of muscle injuries in the high-end athletic players. While the use of MRI is clear in diagnosis, and for follow up of muscle injuries, there is some limitation in its ability to predict RTP, based on current MRI classification systems. Footballers who have clinical injuries without MRI evidence of significant muscle injury (grade 0 and 1) have a shorter period of RTP. Injuries classified as high grade (3 and 4) on MRI do not correlate well with time to RTP. Further trials are required to improve the capability of MRI in its prediction of RTP.