ACR Appropriateness Criteria® Chronic Hand and Wrist Pain: 2023 Update.

Chronic hand and wrist pain is a common presenting complaint. The intricate anatomy results in a variety of pain generators-multiple bones, articular cartilage, intrinsic ligaments, triangular fibrocartilage complex, joint capsules and synovium, tendons and tendon sheaths, muscles, and nerves-in a compact space. The need for imaging and the choice of the appropriate imaging modality are best determined by the patient's presentation, physical examination, and the clinician's working differential diagnosis. Radiography is usually appropriate as the initial imaging study in the evaluation of chronic hand or wrist pain. The American College of Radiology 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 where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Imaging After Total Hip Arthroplasty.

This article reviews evidence for performing various imaging studies in patients with total hip prostheses. Routine follow-up is generally performed with radiography. Radiographs are also usually the initial imaging modality for patients with symptoms related to the prosthesis. Following acute injury with pain, noncontrast CT may add information to radiographic examination regarding the presence and location of a fracture, component stability, and bone stock. Image-guided joint aspiration, noncontrast MRI, and white blood cell scan and sulfur colloid scan of the hip, are usually appropriate studies for patients suspected of having periprosthetic infection. For evaluation of component loosening, wear, and/or osteolysis, noncontrast CT or MRI are usually appropriate studies. Noncontrast MRI is usually appropriate for identifying adverse reaction to metal debris related to metal-on-metal articulations. For assessing patients after hip arthroplasty, who have trochanteric pain and nondiagnostic radiographs, ultrasound, or MRI are usually appropriate studies. The American College of Radiology 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 where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Imaging After Total Knee Arthroplasty: 2023 Update.

Total knee arthroplasty is the most commonly performed joint replacement procedure in the United States. This manuscript will discuss the recommended imaging modalities for six clinical variants; 1. follow-up of symptomatic or asymptomatic patients with a total knee arthroplasty. Initial imaging, 2. Suspected infection after total knee arthroplasty. Additional imaging following radiographs, 3. Pain after total knee arthroplasty. Infection excluded. Suspect aseptic loosening or osteolysis or instability. Additional imaging following radiographs, 4. Pain after total knee arthroplasty. Suspect periprosthetic or hardware fracture. Additional imaging following radiographs, 5. Pain after total knee arthroplasty. Measuring component rotation. Additional imaging following radiographs, and 6. Pain after total knee arthroplasty. Suspect periprosthetic soft-tissue abnormality unrelated to infection, including quadriceps or patellar tendinopathy. Additional imaging following radiographs. The American College of Radiology 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 where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Chronic Extremity Joint Pain-Suspected Inflammatory Arthritis, Crystalline Arthritis, or Erosive Osteoarthritis: 2022 Update.

Evaluation for suspected inflammatory arthritis as a cause for chronic extremity joint pain often relies on imaging. It is essential that imaging results are interpreted in the context of clinical and serologic results to add specificity because there is significant overlap of imaging findings among the various types of arthritis. This document provides recommendations for imaging evaluation of specific types of inflammatory arthritis, including rheumatoid arthritis, seronegative spondyloarthropathy, gout, calcium pyrophosphate dihydrate disease (or pseudogout), and erosive osteoarthritis. 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.

ACR Appropriateness Criteria® Chronic Hip Pain: 2022 Update.

Chronic hip pain is a frequent chief complaint for adult patients who present for evaluation in a variety of clinical practice settings. Following a targeted history and physical examination, imaging plays a vital role in elucidating the etiologies of a patient's symptoms, as a wide spectrum of pathological entities may cause chronic hip pain. Radiography is usually the appropriate initial imaging test following a clinical examination. Depending on the clinical picture, advanced cross-sectional imaging may be subsequently performed for further evaluation. This documents provides best practice for the imaging workup of chronic hip pain in patients presenting with a variety of clinical scenarios. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Chronic Shoulder Pain: 2022 Update.

Chronic shoulder pain is an extremely common presenting complaint. Potential pain generators include the rotator cuff tendons, biceps tendon, labrum, glenohumeral articular cartilage, acromioclavicular joint, bones, suprascapular and axillary nerves, and the joint capsule/synovium. Radiographs are typically the initial imaging study obtained in patients with chronic shoulder pain. Further imaging may often be required, with modality chosen based on patient symptoms and physical examination findings, which may lead the clinician to suspect a specific pain generator. The American College of Radiology 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 where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Osteoporosis and Bone Mineral Density: 2022 Update.

Osteoporosis constitutes a significant public health risk. An estimated 10.2 million adults in the United States >50 years of age have osteoporosis, a systemic condition that weakens the bones increasing the susceptibility for fractures. Approximately one-half of women and nearly one-third of men >50 years of age will sustain an osteoporotic fracture. These fractures are associated with a decrease in quality of life, diminished physical function, and reduced independence. Dual-energy X-ray absorptiometry (DXA) is the primary imaging modality used to screen for osteoporosis in women >65 years of age and men >70 years of age. DXA may be used in patients <65 years of age to evaluate bone mass density if there are additional risk factors. In certain situations, vertebral fracture assessment and trabecular bone score may further predict fracture risk, particularly in patients who are not yet osteoporotic but are in the range of osteopenia. Quantitative CT is useful in patients with advanced degenerative changes in the spine. Given the proven efficacy of pharmacologic therapy, the role of imaging to appropriately identify and monitor high-risk individuals is critical in substantially reducing osteoporosis-associated morbidity and mortality, and reducing the considerable cost to the health care system. 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 where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Imaging After Shoulder Arthroplasty: 2021 Update.

Shoulder arthroplasty is a common orthopedic procedure with a complication rate reported to be as high as 39.8% and revision rates as high as 11%. Symptoms related to postoperative difficulties include activity-related pain, decreased range of motion, and apprehension. Some patients report immediate and persistent dissatisfaction, although others report a symptom-free postoperative period followed by increasing pain and decreasing shoulder function and mobility. Imaging plays an important role in diagnosing postoperative complications of shoulder arthroplasties. The imaging algorithm should always begin with radiographs. The selection of the next imaging modality depends on several factors, including findings on the initial imaging study, clinical suspicion of an osseous versus soft-tissue injury, and clinical suspicion of infection.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Advanced Magnetic Resonance Imaging in Osteoarthritis.

Osteoarthritis (OA) is one of the most common causes of disability throughout the world. Current therapeutic strategies are aimed at preventing the development and delaying the progression of OA, as well as repairing or replacing worn articular surfaces, because the regeneration of lost hyaline articular cartilage is not currently a clinically feasible option. Imaging is useful in formulating treatment strategies in patients at risk for OA, allowing assessment of risk factors, the degree of preexisting tissue damage, and posttreatment monitoring. Magnetic resonance imaging (MRI), in particular, provides in-depth evaluation of these patients, with optimal clinical sequencing allowing sensitive assessment of chondral signal and morphology, and the addition of advanced MRI techniques facilitating comprehensive evaluation of joint health, with increased sensitivity for changes in articular cartilage and surrounding joint tissues.

A CT-based approach with 3D modeling to determine optimal radiographic views of the scaphotrapezial and scaphotrapezoid joints.

PURPOSE: To use a CT-based approach with 3D modeling to determine novel radiographic views of the scaphotrapezial (STl) and scaphotrapezoid (STd) joints. MATERIALS AND METHODS: Consecutive wrist CT scans excluding those with pathology of the distal radius, scaphoid, trapezium, or trapezoid of subjects between ages 18 and 60 years were retrospectively reviewed. Three-dimensional reconstructions of CT scans were created and best-fit planes of the STl and STd joints were generated. Angles of these planes relative to a distal radial coordinate system were calculated to determine tilt of the wrist and the X-ray beam for novel radiographic views of these joints. RESULTS: Fifty eligible wrist CT scans were identified. The mean age was 38 years (range, 18 to 59). For the novel STl PA view, the wrist is supinated 17° from the standard PA view and the X-ray beam is canted 6° caudad. In the STl lateral view, the wrist is pronated 17° from the standard lateral view, and the X-ray beam is canted 20° caudad. In the STd PA tilt view, the wrist is supinated 28° from the standard PA view, and the X-ray beam is canted 13° caudad. In the STd joint lateral tilt view, the wrist is pronated 28° from the standard lateral view, and the X-ray beam is canted 29° caudad. CONCLUSION: We describe novel radiographic views of the STl and STd joints based on 3D modeling of wrist CT scans. Further studies are required to assess the efficacy of these views in detecting joint pathology.

Does my patient have a pulmonary embolism? The Wells vs. PISA 2 rule in orthopedic patients.

The diagnosis of venous thromboembolism is difficult in the postoperative setting because signs such as hypoxemia, leg pain, and swelling are so common. CTPA can also detect subsegmental PE (SSPE), of which the clinical significance has been widely debated. Clinical decision rules (CDR), such as the Wells and PISA 2, have been developed to identify symptomatic patients at low risk for PE who could forgo imaging. We performed this study in order to (1) compare the performance of the Wells and PISA 2 CDR in orthopedic patients; (2) compare CDR scores in patients with subsegmental PE (SSPE) versus larger clots; and (3) identify variables that improve performance of the Wells in orthopedic patients. This retrospective cohort study included all orthopedic surgery patients that underwent computerized tomographic pulmonary angiography at a single institution from 1/1/13 to 12/31/14 and had data to calculate both Wells and PISA 2 scores. CDR sensitivity, specificity and c-statistics were calculated. Multivariable logistic regression was used to identify variables that improved CDR performance. 402 patients were included in the study. The Wells rule (cutoff > 4) had sensitivity 74% and specificity 45%. PISA 2 (cutoff 0.6) had sensitivity 90% and specificity 11%. The Wells performed better than PISA 2: c-statistic 0.60 vs. 0.50; p = 0.007. The mean Wells score was 5.20 ± 1.68 for patients with SSPE and 5.41 ± 1.86 for patients with larger clots. Adding the variables prior smoking and varicose veins improved the performance of the Wells rule (c-statistic 0.66 vs. 0.60, p = 0.008). The Wells rule (cutoff > 4) performs better than PISA 2 in orthopedic patients. Neither can distinguish patients with SSPE from those with larger clots. Although adding past smoking and varicose veins to the Wells improves its performance, this requires validation in other populations.

Distal rupture of the adductor longus in a skier.

Acute adductor longus ruptures occur infrequently and have been rarely described in the literature. Schlegel et al. reviewed a series of adductor longus tendon ruptures and found that all ruptured proximally. A 42-year-old man with right hip pain 3 weeks following a skiing injury underwent magnetic resonance imaging (MRI), which demonstrated a distal adductor longus avulsion. The diagnosis of acute adductor longus injury can be difficult on physical examination alone, but MRI can accurately depict the site of injury. Surgery may be indicated for a proximal avulsion, but a distal injury may heal with nonoperative treatment, as in our case.

Ultrasound-guided perineural injection for nerve blockade: Does a single-sided injection produce circumferential nerve coverage?

PURPOSE: Our current clinical technique for sonographic-guided perineural injection consists of two-sided perineural needle placement to obtain circumferential distribution of the injectate. This study aimed to determine if a single-side needle position will produce circumferential nerve coverage. METHODS: Fresh-frozen cadaveric specimens were used for this study. In six upper extremities, a needle was positioned along the deep surface of median, radial, and ulnar nerves in the carpal tunnel, radial tunnel, and cubital tunnel, respectively, and 2 ml of contrast was injected for each nerve. In three pelvic specimens, a needle was positioned deep to the sciatic nerves bilaterally, and 5 ml of contrast was injected. An additional four median nerve injections were performed using superficial surface needle position. The specimens then underwent CT scanning to assess the distribution of the perineural contrast medium. RESULTS: One hundred percent of the radial, ulnar, and sciatic nerves demonstrated circumferential distribution on CT. Only 50% of the median nerve injections with the needle placed deep to the nerve produced circumferential coverage, whereas 100% of median nerves injected with the needle between the nerve and retinaculum demonstrated circumferential coverage. The average length of spread of perineural injectate was 11.6 cm in the upper extremity and 10.3 cm for the sciatic nerves. CONCLUSIONS: Using clinical volumes of fluid, needle positioning at the deep surface of upper extremity and sciatic nerves was sufficient to produce circumferential coating of the nerve, except in the carpal tunnel, where placement of the needle between the nerve and flexor retinaculum is recommended. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:465-469, 2016.

MRI Evaluation of Femoroacetabular Impingement After Hip Preservation Surgery.

OBJECTIVE: This article reviews the surgical treatment options for femoroacetabular impingement (FAI), including labral repair and osteochondroplasty, and the expected postoperative appearance on MRI. Complications, including residual osseous deformities, chondral injury, adhesions, femoral neck stress fractures, osteonecrosis, instability, malpositioned suture anchors, and infection, will also be discussed. CONCLUSION: Knowledge of the surgical treatment of FAI can assist in improving our understanding of the expected postoperative MRI appearance and in evaluating surgical complications.

MRI for the preoperative evaluation of femoroacetabular impingement.

Femoroacetabular impingement (FAI) refers to a condition characterized by impingement of the femoral head-neck junction against the acetabular rim, often due to underlying osseous and/or soft tissue morphological abnormalities. It is a common cause of hip pain and limited range of motion in young and middle-aged adults. Hip preservation surgery aims to correct the morphological variants seen in FAI, thereby relieving pain and improving function, and potentially preventing early osteoarthritis. The purpose of this article is to review the mechanisms of chondral and labral injury in FAI to facilitate an understanding of patterns of chondrolabral injury seen on MRI. Preoperative MRI evaluation of FAI should include assessment of osseous morphologic abnormalities, labral tears, cartilage status, and other associated compensatory injuries of the pelvis. As advanced chondral wear is the major relative contraindication for hip preservation surgery, MRI is useful in the selection of patients likely to benefit from surgery. Teaching points • The most common anatomical osseous abnormalities predisposing to FAI include cam and pincer lesions. • Morphological abnormalities, labral lesions, and cartilage status should be assessed. • In cam impingement, chondral wear most commonly occurs anterosuperiorly.• Pre-existing advanced osteoarthritis is the strongest predictor of poor outcomes after FAI surgery. • Injury to muscles and tendons or other pelvic structures can coexist with FAI.

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. EVIDENCE ACQUISITION: A search for the keywords pediatric, physis, growth plate, x-ray, computed tomography, magnetic resonance imaging, and overuse injury was performed using the PubMed database. No limits were set for the years of publication. Articles were reviewed for relevance with an emphasis on the imaging of growth plate injuries. STUDY DESIGN: Retrospective literature review. LEVEL OF EVIDENCE: Level 4. RESULTS: Three major imaging modalities (radiographs, computed tomography, and magnetic resonance imaging) complement each other in the evaluation of pediatric patients with overuse injuries. However, magnetic resonance imaging is the only modality that offers direct visualization of the physis, and it also offers the best soft tissue contrast for evaluating the other periarticular structures for concomitant injury. CONCLUSION: Imaging has an important role in the diagnosis of physeal injuries, and the information it provides has a tremendous impact on the subsequent management of these patients.

Assessment of the lateral patellar facet in varus arthritis of the knee.

BACKGROUND: Lateral patellar arthritis has been associated with poor outcomes in unicompartmental knee arthroplasty. The current study correlates intraoperative findings with MRI imaging, skyline radiographs and the presence of anterior knee pain. METHODS: In 92 consecutive knees with varus arthritis, the patellofemoral compartment was assessed during surgery, on skyline radiographs and on MRI. Anterior knee pain was recorded on a visual-analog-scale. Intraoperative assessment was based on the Outerbridge grading scale. Skyline radiographs were evaluated according to the Ahlbäck grading scale; MRIs were assessed according to a modified Outerbridge grading scale. RESULTS: There was an excellent correlation (rs=0.833; p<0.001) in the cartilage assessment of the lateral patellar facet between MRI and surgery. A good correlation (rs=0.664; p<0.001) was seen between Ahlbäck Grades and macroscopic Outerbridge Grades of the lateral patella. Ahlbäck Grades and MRI modified Outerbridge Grades showed a good correlation (rs=0.643; p<0.001) for the lateral patella. Twelve percent of knees (seven out of 60) with Ahlbäck Grade 0 or 1 and mild to moderate anterior knee pain had a macroscopic Outerbridge Grade of 3 on the lateral patella. None of these 60 knees had a full-thickness cartilage defect on MRI. CONCLUSION: Normal skyline radiographs in patients with mild to moderate anterior knee pain can rule out full-thickness cartilage defects of the lateral patellar facet as observed during surgery and on MRI. The MRI allows for the most accurate assessment of the patellofemoral joint and is warranted in all patients with radiographic abnormalities or severe anterior knee pain. LEVEL OF EVIDENCE: Diagnostic study, Level II.

Does intraarticular inflammation predict biomechanical cartilage properties?

BACKGROUND: Intact cartilage in the lateral compartment is an important requirement for medial unicompartmental knee arthroplasty (UKA). Progression of cartilage degeneration in the lateral compartment is a common failure mode of medial UKA. Little is known about factors that influence the mechanical properties of lateral compartment cartilage. QUESTIONS/PURPOSES: The purposes of this study were to answer the following questions: (1) Does the synovial fluid white blood cell count predict the biomechanical properties of macroscopically intact cartilage of the distal lateral femur? (2) Is there a correlation between MRI grading of synovitis and the biomechanical properties of macroscopically intact cartilage? (3) Is there a correlation between the histopathologic assessment of the synovium and the biomechanical properties of macroscopically intact cartilage? METHODS: The study included 84 patients (100 knees) undergoing primary TKA for varus osteoarthritis between May 2010 and January 2012. All patients underwent preoperative MRI to assess the degree of synovitis. During surgery, the cartilage of the distal lateral femur was assessed macroscopically using the Outerbridge grading scale. In knees with an Outerbridge grade of 0 or 1, osteochondral plugs were harvested from the distal lateral femur for biomechanical and histologic assessment. The synovial fluid was collected to determine the white blood cell count. Synovial tissue was taken for histologic evaluation of the degree of synovitis. RESULTS: The mean aggregate modulus and the mean dynamic modulus were significantly greater in knees with 150 or less white blood cells/mL synovial fluid compared with knees with greater than 150 white blood cells/mL synovial fluid. There was no correlation among MRI synovitis grades, histopathologic synovitis grades, and biomechanical cartilage properties. CONCLUSIONS: The study suggests that lateral compartment cartilage in patients with elevated synovial fluid white blood cell counts has a reduced ability to withstand compressive loads. LEVEL OF EVIDENCE: Level III, diagnostic study. See the Instructions for Authors for a complete description of levels of evidence.

Magnetic resonance imaging in the diagnosis and management of hip pain after total hip arthroplasty.

Evaluation of pain following total hip arthroplasty (THA) can be challenging in the absence of radiographic pathology. This study aimed to examine the diagnostic utility of magnetic resonance imaging (MRI) in the evaluation of enigmatic hip pain following THA. We reviewed a series of patients who were evaluated with MRI after presenting with enigmatic hip pain following THA. MRI was able to demonstrate pathology in the periprosthetic tissues in all hips with minimal artifact. Patients underwent a range of conservative and operative interventions depending on the underlying pathology. If used discriminately in situations where pathology cannot be detected by conventional methods, MRI is a highly effective modality that can aid in the diagnosis of a wide range of disorders thereby allowing the clinician to determine the most appropriate intervention.

Imaging of the rotator cuff following repair: human and animal models.

Imaging of the rotator cuff following repair may be challenging due to the type of fixation, surgical manipulation of the tissue and the presence of residual defects that may exist in the presence of good functional outcome. Both ultrasound and magnetic resonance (MR) imaging present unique advantages in evaluation of the postoperative tissue. MR imaging has superior soft tissue contrast and provides a more global shoulder assessment, including the degree of arthrosis, while ultrasound enables a more dynamic testing of the repaired tissue. Power Doppler ultrasound and new contrast agents provide insight into the degree of vascular recruitment following repair.