Unreimbursed Costs of Multidisciplinary Conferences to a Radiology Department: A Prospective Analysis at an Academic Medical Center

PURPOSE

Multidisciplinary conferences (MDCs) are important for clinical care but are unreimbursed and can be time-consuming for radiologists to prepare for and present. The purpose of this single-center, prospective, survey-based study is to measure the per-conference time and total time radiologists devote to MDCs at a single academic medical center. Secondary objectives are to determine the source of radiologist preparation time, and calculate the per conference and overall radiology departmental costs of MDC participation.

METHODS

A prospective survey was performed to capture all radiology preparation and presentation time for MDCs in a 3-month period, which was then annualized. Total cost was calculated on the basis of Association of Administrators in Academic Radiology survey data for nonchair academic radiologist compensation plus a 30% fringe-benefit rate.

RESULTS

The survey response rate was 86.9%. A total of 3,358 hours were devoted annually to MDCs, which represents time equivalent to 1.9 full-time equivalents or $1,155,152 in unreimbursed radiology departmental costs. Per-MDC total preparation and presentation time was 2.7 hours, at an annual cost of $46,440 for each weekly MDC. Radiologists used a combination of personal time (49.7%), academic time (42%), and/or clinical time (35.4%) to prepare for MDCs. Radiologists devoted a mean of 47.9 hours (1.2 weeks) of time per annum to MDCs.

CONCLUSIONS

Radiologist time devoted to MDCs at the survey institution was substantial, and preparation time was drawn disproportionately from personal and academic time, which may have negative implications for burnout, recruitment and retention, and academic productivity unless it is effectively mitigated.

Surgical decompression of an accessory bicipital aponeurosis associated with median neuropathy in the antecubital fossa: A case report

Background:

Accessory muscles in the arm are well-known anatomical variants which have been hypothesized as sources of neurovascular compression syndromes. We report a rare presentation of neuropathy secondary to an accessory biceps aponeurosis causing compression of the median nerve in the antecubital fossa.

Case Description:

A 65-year-old man presented with a 5-year history of numbness and pain associated with arm flexion. Electromyography was normal and exam revealed mild weakness in the median nerve distribution; however, magnetic resonance imaging demonstrated an accessory biceps tendon overlaying the median nerve in the antecubital fossa. The patient underwent surgical decompression of the median nerve with detachment of the accessory tendon resulting in clinical improvement.

Conclusion:

Anomalous biceps musculature should be considered in the workup and treatment of proximal median neuropathy.

Intravenous contrast does not improve detection of nerve lesions or active muscle denervation changes in MR neurography of the common peroneal nerve

OBJECTIVE

To evaluate the effect of intravenous (IV) contrast on sensitivity, specificity, and accuracy of magnetic resonance (MR) neurography of the knee with attention to the common peroneal nerve (CPN) in identifying nerve lesions and active muscle denervation changes.

MATERIALS AND METHODS

A retrospective search for contrast-enhanced MR neurography cases evaluating the CPN at the knee was performed. Patients with electrodiagnostic testing (EDX) within 3 months of imaging were included and those with relevant prior surgery were excluded. Two radiologists independently reviewed non-contrast sequences and then 4 weeks later evaluated non-contrast and contrast sequences. McNemar's tests were performed to detect a difference between non-contrast only and combined non-contrast and contrast sequences in identifying nerve lesions and active muscle denervation changes using EDX as the reference standard.

RESULTS

Forty-four exams in 42 patients (2 bilateral) were included. Twenty-eight cases had common peroneal neuropathy and 29, 21, and 9 cases had active denervation changes in the anterior, lateral, and posterior compartment/proximal muscles respectively on EDX. Sensitivity, specificity, and accuracy of non-contrast versus combined non-contrast and contrast sequences for common peroneal neuropathy were 50.0%, 56.2%, and 52.3% versus 50.0%, 56.2%, and 52.3% for reader 1 and 57.1%, 50.0%, and 54.5% versus 64.3%, 56.2%, and 61.4% for reader 2. Sensitivity, specificity, and accuracy of non-contrast and combined non-contrast and contrast sequences in identifying active denervation changes for anterior, lateral, and posterior compartment muscles were not significantly different. McNemar's tests were all negative.

CONCLUSION

IV contrast does not improve the ability of MR neurography to detect CPN lesions or active muscle denervation changes.

Core curriculum online lecture series in musculoskeletal imaging: initial results

OBJECTIVE

To augment the educational resources available to training programs and trainees in musculoskeletal (MSK) radiology by creating a comprehensive series of Web-based open-access core curriculum lectures.

MATERIALS AND METHODS

Speakers with recognized content and lecturing expertise in MSK radiology were invited to create digitally recorded lecture presentations across a series of 42 core curriculum topics in MSK imaging. Resultant presentation recordings, organized under curriculum subject headings, were archived as open-access video file recordings for online viewing on a dedicated Web page (http://radiologycorelectures.org/msk/). Information regarding the online core curriculum lecture series was distributed to members of the International Skeletal Society, Society of Skeletal Radiology, Society of Chairs of Academic Radiology Departments, and the Association of Program Directors in Radiology. Web page and online lecture utilization data were collected using Google Analytics (Alphabet, Mountain View, CA, USA).

RESULTS

Forty-two lectures, by 38 speakers, were recorded, edited and hosted online. Lectures spanned ACGME curriculum categories of musculoskeletal trauma, arthritis, metabolic diseases, marrow, infection, tumors, imaging of internal derangement of joints, congenital disorders, and orthopedic imaging. Online access to the core curriculum lectures was opened on March 4, 2018. As of January 20, 2019, the core curriculum lectures have had 77,573 page views from 34,977 sessions.

CONCLUSIONS

To date, the MSK core curriculum lecture series lectures have been widely accessed and viewed. It is envisioned that the initial success of the project will serve to promote ongoing content renewal and expansion to the lecture materials over time.

Imaging of Kingella kingae musculoskeletal infections in children: a series of 5 cases

PURPOSE

Kingella kingae musculoskeletal infections continue to be under-diagnosed and there remains a paucity of literature on its imaging features. The purpose of this manuscript is to review the imaging, clinical, and laboratory findings of microbiology-proven K. kingae infections.

MATERIALS AND METHODS

A retrospective review of musculoskeletal infections between January 1, 2013 and Dec 31, 2016 yielded 134 patients from whom 5 patients had confirmed K. kingae infections (3 boys and 2 girls, mean age of 16 months, range 9-38 months). Picture archiving and communication system and electronic medical records were reviewed.

RESULTS

At presentation, none of the patients had a fever and not all patients had abnormal inflammatory markers. Three patients had septic arthritis (2 knee and 1 sternomanubrial joints), one had epiphyseal osteomyelitis, and one had lumbar spondylodiscitis. The case of epiphyseal osteomyelitis of the distal humerus also had elbow joint involvement. A combination of radiography (n = 4), ultrasound (n = 2), and magnetic resonance (MR) imaging (n = 5) were performed. Prominent synovial thickening was observed for both knee and elbow joints and extensive regional myositis for all except for the patient with sternomanubrial joint infection. The diagnosis of K. kingae infection resulted in a change in the antibiotic regimen in 80% of the patients.

CONCLUSION

Disproportionate synovial thickening, prominent peri-articular myositis, and/or characteristic sites of involvement demonstrating imaging features of infection or inflammation in a young child with mild infectious symptoms and elevated inflammatory markers should invoke the possibility of an underlying K. kingae infection.

Molecular image-directed biopsies: improving clinical biopsy selection in patients with multiple tumors

Site selection for image-guided biopsies in patients with multiple lesions is typically based on clinical feasibility and physician preference. This study outlines the development of a selection algorithm that, in addition to clinical requirements, incorporates quantitative imaging data for automatic identification of candidate lesions for biopsy. The algorithm is designed to rank potential targets by maximizing a lesion-specific score, incorporating various criteria separated into two categories: (1) physician-feasibility category including physician-preferred lesion location and absolute volume scores, and (2) imaging-based category including various modality and application-specific metrics. This platform was benchmarked in two clinical scenarios, a pre-treatment setting and response-based setting using imaging from metastatic prostate cancer patients with high disease burden (multiple lesions) undergoing conventional treatment and receiving whole-body [¹⁸F]NaF PET/CT scans pre- and mid-treatment. Targeting of metastatic lesions was robust to different weighting ratios and candidacy for biopsy was physician confirmed. Lesion ranked as top targets for biopsy remained so for all patients in pre-treatment and post-treatment biopsy selection after sensitivity testing was completed for physician-biased or imaging-biased scenarios. After identifying candidates, biopsy feasibility was evaluated by a physician and confirmed for 90% (32/36) of high-ranking lesions, of which all top choices were confirmed. The remaining cases represented lesions with high anatomical difficulty for targeting, such as proximity to sciatic nerve. This newly developed selection method was successfully used to quantitatively identify candidate lesions for biopsies in patients with multiple lesions. In a prospective study, we were able to successfully plan, develop, and implement this technique for the selection of a pre-treatment biopsy location.

ACR Appropriateness Criteria acute trauma to the ankle

Acute ankle injuries are frequently diagnosed and treated in emergency departments and outpatient clinics. Recent evidence-based clinical treatment guidelines and systematic review of economic analyses support the use of 3-view (anteroposterior, lateral, and mortise) radiographic evaluation of patients meeting the criteria of the Ottawa ankle rules. Cross-sectional imaging has a limited secondary role primarily as a tool for preoperative planning and as a problem-solving technique in patients with persistent symptoms and suspected of having occult fractures. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR Appropriateness Criteria Follow-Up of Malignant or Aggressive Musculoskeletal Tumors

Appropriate imaging modalities for the follow-up of malignant or aggressive musculoskeletal tumors include radiography, MRI, CT, (18)F-2-fluoro-2-deoxy-D-glucose PET/CT, (99m)Tc bone scan, and ultrasound. Clinical scenarios reviewed include evaluation for metastatic disease to the lung in low- and high-risk patients, for osseous metastatic disease in asymptomatic and symptomatic patients, for local recurrence of osseous tumors with and without significant hardware present, and for local recurrence of soft tissue tumors. The timing for follow-up of pulmonary metastasis surveillance is also reviewed. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Imaging update on the glenoid labrum: variants versus tears

This article reviews the normal labral variants of the shoulder and describes imaging features, including secondary signs, to help discriminate tears from normal variants. The labral variants can be divided into two main groups. One group is composed of nonstandard appearances in the labral shape, signal intensity, or the site of affixation to the glenoid rim. The other group consists of classic labral variants, where the labrum is partially or completely unattached to the subjacent bone, or a segment of the labrum is absent.

Hamstring strength and morphology progression after return to sport from injury

PURPOSE

Hamstring strain reinjury rates can reach 30% within the initial 2 wk after return to sport (RTS). Incomplete recovery of strength may be a contributing factor. However, relative strength of the injured and unaffected limbs at RTS is currently unknown.The purpose was to characterize hamstring strength and morphology at the time of RTS and 6 months later.

METHODS

Twenty-five athletes who experienced an acute hamstring strain injury participated after completion of a controlled rehabilitation program. Bilateral isokinetic strength testing and magnetic resonance imaging (MRI) were performed at RTS and 6 months later. Strength (knee flexion peak torque, work, and angle of peak torque) and MRI (muscle and tendon volumes) measures were compared between limbs and over time using repeated-measures ANOVA.

RESULTS

The injured limb showed a peak torque deficit of 9.6% compared to the uninjured limb at RTS (60°·s, P < 0.001) but not 6 months after. The knee flexion angle of peak torque decreased over time for both limbs (60°·s, P < 0.001). MRI revealed that 20.4% of the muscle cross-sectional area showed signs of edema at RTS with full resolution by the 6-month follow-up. Tendon volume of the injured limb tended to increase over time (P = 0.108), whereas muscle volume decreased between 4% and 5% in both limbs (P < 0.001).

CONCLUSIONS

Residual edema and deficits in isokinetic knee flexion strength were present at RTS but resolved during the subsequent 6 months. This occurred despite MRI evidence of scar tissue formation (increased tendon volume) and muscle atrophy, suggesting that neuromuscular factors may contribute to the return of strength.

Non-femoroacetabular impingement

Femoroacetabular impingement is one of the causes of hip pain leading to acetabular labral tears and cartilage damage that may lead to the development of early osteoarthritis. More recently other causes of impingement have been recognized that may be the culprit for the painful hip. These causes include ischiofemoral, anterior inferior iliac spine/subspine and iliopsoas impingement. Ischiofemoral impingement syndrome is related to narrowing between the ischial tuberosity and lesser trochanter with abnormalities of the quadratus femoris muscle producing hip pain. Anterior inferior iliac spine/subspine impingement syndrome is defined as hip pain produced by abnormal contact between the anterior inferior iliac spine and proximal femur. Iliopsoas impingement may produce hip pain that is related to a thickened or taut iliopsoas tendon at the level of the acetabular rim/anterior hip capsule. Radiographs, magnetic resonance imaging, ultrasound, or computed tomography may help to better elucidate the problem while excluding intra-articular pathology or femoroacetabular impingement. Keeping these causes of impingement in mind when evaluating the painful hip will aid in diagnosis.

Sublabral clefts and recesses in the anterior, inferior, and posterior glenoid labrum at MR arthrography

PURPOSE

To determine the prevalence of a normal variant cleft/recess at the labral-chondral junction in the anterior, inferior, and posterior portions of the shoulder joint.

MATERIALS AND METHODS

One hundred and three consecutive patients (106 shoulders) who had a direct MR arthrogram followed by arthroscopic surgery were enrolled in this IRB-approved study. Scans were carried out on a 1.5-T scanner with an eight-channel shoulder coil. The glenoid rim was divided into eight segments and the labrum in all but the superior and anterosuperior segments was evaluated by two radiologists for the presence of contrast between the labrum and articular cartilage. We measured the depth of any cleft/recess and correlated the MR findings with surgical results. Generalized estimating equation models were used to correlate patient age and gender with the presence and depth of a cleft/recess, and Cohen's kappa values were calculated for interobserver variability.

RESULTS

For segments that were normal at surgery, a cleft/recess was present within a segment on MR arthrogram images in as few as 7 % of patients (within the posteroinferior segment by observer 1), and in up to 61 % of patients (within the posterosuperior segment by observer 1). 55-83 % of these were only 1 mm deep. A 2- to 3-mm recess was seen within 0-37 % of the labral segments, most commonly in the anterior, anteroinferior, and posterosuperior segments. Age and gender did not correlate with the presence of a cleft/recess, although there was an association between males and a 2- to 3-mm deep recess (p = 0.03). The interobserver variability for each segment ranged between 0.15 and 0.49, indicating slight to moderate agreement.

CONCLUSION

One-mm labral-chondral clefts are not uncommon throughout the labrum. A 2- to 3-mm deep smooth, medially curved recess in the anterior, anteroinferior or posterosuperior labrum can rarely be seen, typically as a continuation of a superior recess or anterosuperior labral variant.

Imaging algorithms for evaluating suspected rotator cuff disease: Society of Radiologists in Ultrasound consensus conference statement

The Society of Radiologists in Ultrasound convened a panel of specialists from a variety of medical disciplines to reach a consensus about the recommended imaging evaluation of painful shoulders with clinically suspected rotator cuff disease. The panel met in Chicago, Ill, on October 18 and 19, 2011, and created this consensus statement regarding the roles of radiography, ultrasonography (US), computed tomography (CT), CT arthrography, magnetic resonance (MR) imaging, and MR arthrography. The consensus panel consisted of two co-moderators, a facilitator, a statistician and health care economist, and 10 physicians who have specialty expertise in shoulder pain evaluation and/or treatment. Of the 13 physicians on the panel, nine were radiologists who were chosen to represent a broad range of skill sets in diagnostic imaging, different practice types (private and academic), and different geographical regions of the United States. Five of the radiologists routinely performed musculoskeletal US as part of their practice and four did not. There was also one representative from each of the following clinical specialties: rheumatology, physical medicine and rehabilitation, orthopedic surgery, and nonoperative sports medicine. The goal of this conference was to construct several algorithms with which to guide the imaging evaluation of suspected rotator cuff disease in patients with a native rotator cuff, patients with a repaired rotator cuff, and patients who have undergone shoulder replacement. The panel hopes that these recommendations will lead to greater uniformity in rotator cuff imaging and more cost-effective care for patients suspected of having rotator cuff abnormality.

ACR appropriateness criteria(®) acute trauma to the knee

There are more than 1 million visits to the ER annually in the United States for acute knee trauma. Many of these are twisting injuries in young patients who can walk and bear weight, and emergent radiography is not required. Several clinical decision rules have been devised that can considerably reduce the number of radiographic studies ordered without missing a clinically significant fracture. Although fractures are seen on only 5% of emergency department knee radiographs, 86% of knee fractures result from blunt trauma. In patients with falls or twisting injuries who have focal tenderness, effusion, or inability to bear weight, radiography should be the first imaging study performed. If radiography shows no fracture, MRI is best for evaluating for a suspected meniscal or ligament tear or patellar dislocation. Patients with knee dislocation should undergo radiography and MRI, as well as fluoroscopic angiography, CT angiography, or MR angiography. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Magnetic resonance imaging of rotator cuff disease and external impingement

Magnetic resonance (MR) imaging plays a major role in helping to identify rotator cuff disease and in demonstrating the pathology associated with external impingement. Many surgeons rely on MR imaging to assist in decision making and presurgical planning for patients with rotator cuff pain. This article reviews the etiology of external impingement and rotator cuff tears, and describes the MR imaging appearance of the normal and the pathologic rotator cuffs. It focuses on the supraspinatus tendon because this is the tendon involved in 95% of rotator cuff tears.

MR imaging of early hip joint degeneration

MR imaging is one of the most commonly used imaging techniques to evaluate patients with hip pain. Intra-articular abnormalities of the hip joint are better assessed with recent advances in MR imaging technology, such as high-field strength scanners, improved coils, and more signal-to-noise ratio-efficient sequences. This article discusses the causes of early hip joint degeneration and the current use of morphologic and physiologic MR imaging techniques for evaluating the articular cartilage of the hip joint. The article also discusses the role of MR arthrography in clinical cartilage imaging.

The current state of imaging the articular cartilage of the upper extremity

MR imaging has increasingly been used to image joints since its inception. Historically, there has been more emphasis on the evaluation of internal derangement rather than cartilaginous disease. This article reviews cartilaginous diseases of the upper extremity emphasizing those that can be assessed using current clinical MR imaging protocols and addresses the limitations of current imaging techniques in evaluating the articular cartilage of smaller joints. It also provides a brief overview of novel techniques that may be instituted in the future to improve the diagnostic performance of MR imaging in the evaluation of the articular cartilage of the upper extremity.

Imaging of triathlon injuries

Injuries in triathletes are common and are mostly overuse injuries. Rotator cuff tendinitis is the most common complaint from swimming, but the incidence of tendinopathy and rotator cuff tears on magnetic resonance imaging is comparable in triathletes without and with shoulder pain. Cycling injuries are mainly to the knee, including patellar tendinosis, iliotibial band syndrome, and patellofemoral stress syndrome, and to the Achilles tendon and the cervical and lumbar spine. Running is associated with most injuries in triathletes, during both training and racing, causing the athlete to discontinue the triathlon. In addition to knee injuries from running, triathletes may also develop foot and ankle, lower leg, and hip injuries similar to single-sport distance runners. Some injuries in triathletes may be mainly symptomatic during one of the three sports but are exacerbated by one or both of the other disciplines.

Cartilage morphology at 3.0T: assessment of three-dimensional magnetic resonance imaging techniques

PURPOSE

To compare six new three-dimensional (3D) magnetic resonance (MR) methods for evaluating knee cartilage at 3.0T.

MATERIALS AND METHODS

We compared: fast-spin-echo cube (FSE-Cube), vastly undersampled isotropic projection reconstruction balanced steady-state free precession (VIPR-bSSFP), iterative decomposition of water and fat with echo asymmetry and least-squares estimation combined with spoiled gradient echo (IDEAL-SPGR) and gradient echo (IDEAL-GRASS), multiecho in steady-state acquisition (MENSA), and coherent oscillatory state acquisition for manipulation of image contrast (COSMIC). Five-minute sequences were performed twice on 10 healthy volunteers and once on five osteoarthritis (OA) patients. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured from the volunteers. Images of the five volunteers and the five OA patients were ranked on tissue contrast, articular surface clarity, reformat quality, and lesion conspicuity. FSE-Cube and VIPR-bSSFP were compared to IDEAL-SPGR for cartilage volume measurements.

RESULTS

FSE-Cube had top rankings for lesion conspicuity, overall SNR, and CNR (P < 0.02). VIPR-bSSFP had top rankings in tissue contrast and articular surface clarity. VIPR and FSE-Cube tied for best in reformatting ability. FSE-Cube and VIPR-bSSFP compared favorably to IDEAL-SPGR in accuracy and precision of cartilage volume measurements.

CONCLUSION

FSE-Cube and VIPR-bSSFP produce high image quality with accurate volume measurement of knee cartilage.

MR observations of long-term musculotendon remodeling following a hamstring strain injury

OBJECTIVE

The objective of this study was to use magnetic resonance (MR) imaging to investigate long-term changes in muscle and tendon morphology following a hamstring strain injury.

MATERIALS AND METHODS

MR images were obtained from 14 athletes who sustained a clinically diagnosed grade I-II hamstring strain injury between 5 and 23 months prior as well as five healthy controls. Qualitative bilateral comparisons were used to assess the presence of fatty infiltration and changes in morphology that may have arisen as a result of the previous injury. Hamstring muscle and tendon-scar volumes were quantified in both limbs for the biceps femoris long head (BFLH), biceps femoris short head (BFSH), the proximal semimembranosus tendon, and the proximal conjoint biceps femoris and semitendinosus tendon. Differences in muscle and tendon volume between limbs were statistically compared between the previously injured and healthy control subjects.

RESULTS

Increased low-intensity signal was present along the musculotendon junction adjacent to the site of presumed prior injury for 11 of the 14 subjects, suggestive of persistent scar tissue. The 13 subjects with biceps femoris injuries displayed a significant decrease in BFLH volume (p < 0.01), often accompanied by an increase in BFSH volume. Two of these subjects also presented with fatty infiltration within the previously injured BFLH.

CONCLUSION

The results of this study provide evidence of long-term musculotendon remodeling following a hamstring strain injury. Additionally, many athletes are likely returning to sport with residual atrophy of the BFLH and/or hypertrophy of the BFSH. It is possible that long-term changes in musculotendon structure following injury alters contraction mechanics during functional movement, such as running and may contribute to reinjury risk.

Sacroiliac joint imaging

The sacroiliac (SI) joint has several unique anatomical features that make it one of the more challenging joints to image. The joint is difficult to profile well on radiographic views, and therefore the radiographic findings of sacroiliitis are often equivocal. Computed tomography images can usually show the findings of sacroiliitis and osteoarthritis earlier than radiographs. Magnetic resonance imaging performed with proper sequences is excellent for diagnosing even very early sacroiliitis and for following treatment response. The SI joint is often involved in patients with osteoarthritis or one of the inflammatory spondyloarthritides, most notably ankylosing spondylitis. Ankylosing spondylitis often presents with sacroiliitis, which appears as erosions, sclerosis, and joint space narrowing, eventually leading to ankylosis. Several disorders can cause sacroiliitis-like changes of the joint, including hyperparathyroidism and repetitive shear-stress injuries in athletes. The joint can become painful during pregnancy as it widens and develops increased motion, and some postpartum women develop iliac sclerosis adjacent to the joint termed osteitis condensans ilii. Another cause of SI joint pain is a disorder called sacroiliac joint dysfunction, which typically has few abnormal imaging findings. Patients with SI joint dysfunction, as well as sacroiliitis, often get relief from image-guided SI joint therapeutic injections.

Shoulder MR arthrography of the posterior labrocapsular complex in overhead throwers with pathologic internal impingement and internal rotation deficit

PURPOSE

To determine if overhead-throwing athletes with internal impingement pain and internal rotation deficit have thickening of the posterior inferior labrocapsular complex on MR arthrogram images.

MATERIALS AND METHODS

This study was approved and a waiver of consent granted by our institutional review board. Twenty-six overhead-throwing athletes with internal impingement pain and internal rotation deficit, and 26 controls who had undergone MR arthrograms, were retrospectively examined. The MR studies were combined and read in a blind fashion. On an axial image through the posteroinferior glenoid rim, the readers measured the labral length, capsule-labrum length, and the posterior recess angle. A t-test was used to determine statistical significance.

RESULTS

The mean labral length was 4.9 mm [standard deviation (SD) 1.4 mm] for the controls, and 6.4 mm (SD 1.6 mm) for the athletes (P = 0.001). The mean capsule-labrum length was 5.4 mm (SD 2.1 mm) for the controls, and 8.8 mm (SD 2.9 mm) for the athletes (P < 0.001). The mean posterior recess angle measured 65 degrees (SD 27 degrees) for the controls and 94 degrees (SD 38 degrees) for the athletes (P = 0.002).

CONCLUSIONS

Overhead-throwing athletes with internal impingement pain and internal rotation deficit tend to have a thicker labrum and a shallower capsular recess in the posterior inferior shoulder joint than do non-overhead-throwing athletes. In many, the posteroinferior capsule is also thickened. These MR findings should alert the radiologist to closely inspect the posterior cuff and posterosuperior labrum for the tears associated with internal impingement.

Use of the "two-slice-touch" rule for the MRI diagnosis of meniscal tears

OBJECTIVE

We reviewed our experience with knee MRI to determine if using the "two-slice-touch" rule increased our positive predictive value for diagnosing meniscal tears. This rule classifies a meniscus as torn if there are two or more MR images with abnormal findings and as possibly torn if there is only one MR image with an abnormal finding. We also compared our sensitivity and specificity using fast spin-echo imaging with previously reported studies.

MATERIALS AND METHODS

We reviewed the medical records of 174 patients who had knee MR examinations and correlative knee arthroscopy to determine our accuracy when we diagnosed menisci as torn, possibly torn, or intact using knee arthroscopy as the gold standard.

RESULTS

Our positive predictive value increased from 91% to 94% (p = 0.37) for medial meniscal tears and from 83% to 96% (p = 0.02) for lateral meniscal tears when using the two-slice-touch rule compared with the standard criterion of diagnosing a meniscus as torn if one or more images are abnormal. When using the standard criterion, we had 95% sensitivity and 85% specificity for diagnosing medial meniscal tears and 77% sensitivity and 89% specificity for diagnosing lateral meniscal tears.

CONCLUSION

When using the two-slice-touch rule, we had an increased positive predictive value for diagnosing menisci as torn, which was statistically significant for the lateral meniscus. Our accuracy using the standard criterion with fast spin-echo imaging was comparable to that reported in previous studies with spin-echo imaging.

Sports-related injuries of the elbow: an approach to MRI interpretation

MRI is a valuable tool for evaluating the athlete with elbow pain, particularly in those with nonlocalizable pain. MRI also is helpful in sorting out the cause of pain in athletes who may have acute trauma superimposed on tendinopathy or other chronic injuries from repetitive microtrauma. Even in athletes in whom the cause of pain confidently can be diagnosed clinically, MRI can document the injury severity, which can be helpful for estimating recovery time or in preoperative planning. By contributing to an accurate early diagnosis, MRI also can help minimize the time that athletes are away from their sports. The authors describe their approach to the MRI interpretation of elbow injuries in athletes, including osteochondral lesions, epicondylitis, and tears of the medial collateral ligament.

The painful hip: new concepts

Hip pain is a common condition, and the work-up often includes imaging. This article reviews the normal MR anatomy of the hip and the imaging findings of internal derangements, snapping hip, and femoral acetabular impingement. We will describe the role of MR arthrography in evaluating the patient with suspected labral and articular cartilage abnormalities, as well as the pitfalls in interpretation. We will review the causes of a snapping hip, and the role of sonography in evaluating and guiding treatment of the snapping iliopsoas tendon. We will also review the radiographic and MRI signs of femoroacetabular impingement (FAI), a cause of early degenerative joint disease and hip pain.

Width of high signal and extension posterior to biceps tendon as signs of superior labrum anterior to posterior tears on MRI and MR arthrography

OBJECTIVE

The purpose of our study was to determine the accuracy of two signs for superior labrum anterior to posterior (SLAP) tears: increased width of high signal between the superior labrum and glenoid, and high signal posterior to the biceps tendon.

MATERIALS AND METHODS

Forty-one patients with SLAP tears and 40 patients without a tear at surgery who had undergone MRI or MR arthrography were retrospectively evaluated. The MR studies were combined and interpreted in a blinded manner. The reviewers measured the width of high signal that extended to the articular surface on oblique coronal images and determined whether the high signal extended posterior to the biceps. A Student's t test was used to determine statistical significance between the means of the signal width.

RESULTS

High-signal width was greater in patients with a SLAP tear than in the control group on both MRI and MR arthrography (both p = 0.003). The sensitivity and specificity of at least 2.0 mm on MRI are 39% (11/28) and 89% (24/27) and at least 2.5 mm on MR arthrography are 46% (6/13) and 85% (11/13). The sensitivity and specificity of high signal posterior to the biceps are 54% (15/28) and 74% (20/27) on MRI and 69% (9/13) and 54% (7/13) on MR arthrography.

CONCLUSION

Increased width of high signal has a moderate specificity but a poor positive predictive value for distinguishing a SLAP tear from a normal recess. In addition, labral signal posterior to the biceps tendon is not rare in patients with no SLAP tear.

MR imaging of sports injuries to the rotator cuff

Impingement pain and rotator cuff injury are common in athletes, particularly in overhead throwers. The cuff can be injured in these patients in the typical location in the anterior supraspinatus tendon and near the junction of the supraspinatus and infraspinatus tendons. The cuff tears in athletes are usually small, articular surface partial-thickness tears. The posterior cuff tears in overhead throwers are seen best at MR arthrography with the arm in abduction and external rotation. Other abnormalities, such as instability lesions or labral fraying, can be associated with rotator cuff tears in athletes.

MR imaging of the tendons of the foot and ankle

Hindfoot pain from tendon pathology is common and seen in a wide range of patients from young athletes to older sedentary individuals. Magnetic resonance (MR) is an excellent technique for imaging tendons and for identifying injuries that can be treated with surgery. MR also demonstrates the presence of bone marrow edema, which is a cause of pain and often a marker for adjacent tendon injury. Finally, MR can reveal other etiologies that cause similar hindfoot pain, such as osteochondral injuries and impingement. In this article, we review the normal MR appearance of the ankle tendons and tendon sheath fluid. MR protocols for imaging the various ankle tendon groups are presented. We discuss the MR appearance of tendon pathology, including tendonosis/ tendinopathy, tenosynovitis and peritendonosis, partial and complete tears, subluxation and dislocation, and entrapment. The Achilles, medial, lateral, and anterior tendon groups are discussed separately so as to focus on the MR appearance specific to each region of the ankle.

Sublabral foramen and buford complex: inferior extent of the unattached or absent labrum in 50 patients

PURPOSE

To determine the inferiormost extent of the anterosuperior labral variants on conventional transverse MR images.

MATERIALS AND METHODS

We reviewed transverse MR images in 50 consecutive patients with a sublabral foramen or Buford complex at arthroscopy. Images were randomly mixed with those of 58 patients with either a normal labrum (n = 20) or an anterior labral tear (n = 38) at arthroscopy. MR imaging was fat suppressed fast spin echo intermediate or T2 weighted (repetition time msec/effective echo time msec, 1,800-3,000/30-102). Two radiologists evaluated by means of consensus the anterior labrum while blinded to patient history and arthroscopic results. Transverse images obtained through the glenoid fossa were totalled to determine the midpoint. Sensitivity, specificity, and accuracy of MR for depicting a sublabral foramen or Buford complex were calculated along with 95% CIs, by using surgical findings as the reference standard.

RESULTS

The sensitivity of MR for diagnosing a sublabral foramen or Buford complex was 0.94 (47 of 50 patients, 95% CI: 0.87, 1.00), specificity was 0.80 (16 of 20 patients, 95% CI: 0.62, 0.97), and accuracy was 0.90 (63 of 70 patients, 95% CI: 0.82, 0.97). The anterior labrum was abnormal on the first transverse section inferior to the midpoint in nine (18%) patients. The labrum was also abnormal on the second section below the midpoint in three (6%) patients. Because of the anterior tilt of the scapula, the midpoint was near the anterior glenoid notch at about the position between 2- and 3-o'clock.

CONCLUSION

The labrum may be unattached or absent on the first two transverse images obtained below the midpoint.

MR imaging of the postoperative meniscus of the knee

Surgery for tears of the menisci of the knee has evolved greatly over the last century and is now an extremely common procedure. Meniscal repair and conservative therapy are the preferred methods of treatment, but most symptomatic torn menisci do not meet the requirements for these options and necessitate partial meniscectomy. After surgery, patients often have recurrent pain and need additional diagnosis. Conventional magnetic resonance imaging (MRI) in the postoperative patient is very helpful at diagnosing extrameniscal pathology. It has lower sensitivity for detecting retears after partial meniscectomy, however, as it relies primarily on demonstration of fluid entering the meniscal retear on T2-weighted images. Similarly, conventional MRI is less accurate after meniscal repair, in which the repair site usually maintains altered signal for years. MR arthrography has higher sensitivity for detecting retears in menisci and is the procedure of choice in many situations.

CT and MR Arthrography of the Glenoid Labroligamentous Complex

Because they distend the shoulder joint and bathe the labrum with contrast, CT arthrography (CTa) and MR arthrography (MRA) are both excellent tests for evaluating the labrum. In this article, we discuss the advantages and disadvantages of each examination. We also describe techniques for performing CTa and MRA, including how to maximize image quality. The normal anatomy of the labrum and glenohumeral ligaments is described and demonstrated on both CTa and MRA images. To improve communication with orthopedic surgeons, the discussion of the pathology and normal variants of the labroligamentous complex is organized by functional anatomic regions. CTa and MRA images are then used to demonstrate a variety of pathologic and normal variant appearances of the labroligamentous complex.

Angled oblique sagittal MR imaging of rotator cuff tears: comparison with standard oblique sagittal images

OBJECTIVE

To compare the accuracy for diagnosing rotator cuff tears of oblique coronal images supplemented with standard oblique sagittal images versus thinner-section angled oblique sagittal images.

DESIGN AND PATIENTS

The study included 75 consecutive patients who had a shoulder MR scan followed by arthroscopy. MR images included oblique coronal, oblique sagittal (4 mm thick, 1 mm interslice gap), and angled oblique sagittal (3 mm/0.2 mm) images perpendicular to the lateral cuff. A musculoskeletal staff radiologist and fellow separately evaluated the cuff for tears on the oblique coronal images supplemented with either the oblique sagittal or the angled sagittal images.

RESULTS

For distinguishing a cuff tear from no tear, the staff radiologist had an accuracy of 0.76 (95% confidence interval: 0.67, 0.85) with the standard sagittal set, and 0.88 (0.80, 0.95) with the angled set (P=0.04). There was a nonsignificant improvement in accuracy for the fellow, calculated as 0.73 (0.63, 0.83) on the standard sagittal set and 0.76 (0.67, 0.85) on the angled set. Both readers also improved their diagnostic accuracy for partial-thickness tears with the angled set, although the improvement was statistically significant only for the staff radiologist.

CONCLUSION

There is a slight improvement in accuracy for diagnosing rotator cuff tears, particularly partial-thickness tears, for the more experienced radiologist using thinner-section angled oblique sagittal images. These images may be useful as a supplemental sequence in patients where it is important to identify partial-thickness tears accurately.

Superior labrum anterior-posterior (SLAP) tears: evaluation of three MR signs on T2-weighted images

PURPOSE

To compare the sensitivity and specificity of three magnetic resonance (MR) imaging signs for the diagnosis of superior labrum anterior-posterior (SLAP) tears.

MATERIALS AND METHODS

The study involved 23 consecutive patients with a type 2, 3, or 4 SLAP tear at arthroscopy and 31 age-matched control patients with an arthroscopically normal or type 1 SLAP lesion. The superior labrum was evaluated on MR images for high signal intensity extending to the articular surface in the posterior third of the labrum, an irregular or laterally curved area of high signal intensity, or two high-signal-intensity lines.

RESULTS

The sensitivity, specificity, and accuracy of posterior high signal intensity for a type 2, 3, or 4 SLAP tear were 48%, 94%, and 74%, respectively, for observer 1 and 61%, 81%, and 72%, respectively, for observer 2. For laterally curved area of high signal intensity, these values were 65%, 84%, and 76%, respectively, and 56%, 84%, and 72%, respectively. For two high-signal-intensity lines, these values were 17%, 94%, and 61%, respectively, and 13%, 94%, and 59%, respectively. For the presence of either posterior or laterally curved high signal intensity, the sensitivity was 65% for both observers, whereas the specificity was 84% for observer 1 and 74% for observer 2. The kappa values for interobserver agreement were 0.60 for posterior high signal intensity and 0.58 for laterally curved high signal intensity.

CONCLUSION

Laterally curved and posterior high signal intensities are specific signs for distinguishing a SLAP tear from a normal-variant superior sublabral recess.

"Dem bones": osteochondral injuries of the knee

MR imaging plays a valuable role in the diagnosis and staging of osteochondral injuries of the femorotibial joint. Bone contusions may be the source of a patient's pain, and MR imaging characteristics of certain types may help to predict which contusions might progress to more serious osteochondral lesions. MR imaging also is vital in the diagnosis of occult osteochondral fractures and in accurately classifying displaced intra-articular fractures. Although osteochondral dissecans usually is diagnosed radiographically, MR imaging is the best noninvasive test for determining if an osteochondral fragment is unstable. Unstable lesions are a treatable cause of knee pain.

Fat-suppressed fast spin-echo mid-TE (TE[effective]=34) MR images: comparison with fast spin-echo T2-weighted images for the diagnosis of tears and anatomic variants of the glenoid labrum

OBJECTIVE

To compare the sensitivity, specificity, and accuracy of fat-suppressed fast spin-echo (FSE) mid-TE (TE[effective]=34) images with fat-suppressed FSE T2-weighted images for the diagnosis of labral abnormalities.

DESIGN AND PATIENTS

The study included 27 consecutive patients who had axial fat-suppressed FSE T2-weighted and fat-suppressed FSE mid-TE MR images, and had labral abnormalities diagnosed at arthroscopy. The acquisition time was about 5 min for each sequence, but the mid-TE sequence allowed a higher spatial resolution than the T2-weighted images (256x256 versus 256x192). Twenty-eight age-matched patients with arthroscopically normal labra were included as a control group. The labrum was graded on the MR images as normal or abnormal separately by two musculoskeletal radiologists who were masked to the history and arthroscopic results. The surgical findings were used as the gold standard for calculating the sensitivity, specificity, and accuracy for interpreting the correct location of a labral abnormality. The sensitivity, specificity, and accuracy for the two sequences were compared with a McNemar test, and significance defined as P<0.05.

RESULTS

For observer 1, the sensitivity for labral abnormalities was 0.59 on the T2-weighted images, and 0.78 on the mid-TE images (P=0.12). The specificity was 0.54 for the T2-weighted, and 0.64 for the mid-TE images (P=0.51). The accuracy was 0.56 for the T2-weighted, and 0.71 for the mid- TE images (P=0.08). For observer 2, the sensitivity/specificity/accuracy was 0.67/0.93/0.80 for the T2-weighted, and 0.70/0.86/0.78 for the mid-TE images (all P>0.5).

CONCLUSION

In this small study there is no statistically significant difference for demonstrating labral abnormalities between FSE T2-weighted images, and higher-resolution fat-suppressed FSE mid-TE (TE[effective]=34) images obtained with a similar acquisition time. Although there was a general trend toward higher sensitivity and accuracy with the mid-TE sequence, particularly for one of the two observers, a larger study is needed to determine whether this is the preferred single axial pulse sequence for conventional MR imaging of the labrum.

Anterior versus posterior, and rim-rent rotator cuff tears: prevalence and MR sensitivity

PURPOSE

To determine the relative distribution of the locations of rotator cuff tears, and the sensitivity of anterior versus posterior tears on MR images.

PATIENTS AND METHODS

We identified 110 consecutive patients who had a shoulder MR and either a partial-thickness or a small full-thickness rotator cuff tear diagnosed at arthroscopy. From the arthroscopy videotapes, we classified the tears as centered in the anterior or posterior half of the cuff, and as either in the critical zone or adjacent to the bony insertion. The original MR interpretation was compared with the arthroscopic findings. MR sensitivity and patient age were compared between patients with tears in the anterior and posterior halves of the cuff. In addition, in patients with partial tears less than 2 cm in diameter, an age comparison between those with tears in the critical zone and those with articular surface tears adjacent to the bony insertion (rim-rent tear) was performed.

RESULTS

The tear was centered in the anterior half of the rotator cuff in 79% of the patients younger than 36 years old, and in 89% of the patients 36 years old and over. The average age of the patients with tears in the anterior half (44 years) was not significantly different from the average age of those with posterior tears (40 years) (P = 0.23). The sensitivity of MR for anterior tears was 0.69, and for posterior tears it was 0.56 (P = 0.17). The average age of the 9 patients with rim-rent tears was 31 years, while that of the 28 patients with similarly-sized partial tears not involving the insertion was 40 years old (P = 0.048). Five of the nine rim-rent tears (0.56) were interpreted correctly on the original MR report; two of the other tears were misinterpreted as intratendinous fluid but were diagnosable in retrospect.

CONCLUSION

Even in patients less than 36 years old, most partial and small full-thickness rotator cuff tears are centered in the anterior half of the supraspinatus. Although our figure for MR sensitivity for these tears is lower than in recent articles, we found no significant difference between the sensitivity of MR for diagnosing posterior tears versus tears in the anterior half of the supraspinatus tendon. Rim-rent tears can be mistaken for intratendinous signal, and should be carefully looked for in younger patients with shoulder pain.

Anteroinferior tears of the glenoid labrum: fat-suppressed fast spin-echo T2 versus gradient-recalled echo MR images

OBJECTIVE

To compare fat-suppressed fast spin-echo (FSE) T2-weighted images with gradient-recalled echo (GRE) T2*-weighted images in the evaluation of anteroinferior labral tears.

DESIGN

MR images were retrospectively reviewed by two radiologists masked to the history and arthroscopic findings. They separately interpreted the anteroinferior labrum as torn or intact, first on one pulse sequence and then, 4 weeks later, on the other sequence. The MR interpretations were correlated with the arthroscopic findings.

PATIENTS

Nine patients with anteroinferior labral tears, and nine similarly-aged patients with normal, labra were studied.

RESULTS AND CONCLUSIONS

Observer 1 had a sensitivity of 0.56 on the GRE images and 0.67 on the FSE images (P > 0.5), with a specificity of 1.0 for both sequences. Observer 2 had a sensitivity of 0.78 and a specificity of 0.89 for both sequences. In this small study there is no significant difference between GRE and fat-suppressed FSE images in their ability to diagnose anteroinferior labral tears. When evaluating the labrum with conventional MRI, axial fat-suppressed FSE T2-weighted images can be used in place of GRE images without a loss of accuracy.

CNS lymphoma in an AIDS patient involving the posterior fornix case report

We report an unusual presentation of CNS lymphoma involving the posterior fornix in a patient with AIDS. The patient's initial symptoms included progressive cognitive impairment, consistent with AIDS dementia, as well as impotence and urinary retention suggestive of myelopathy. An MR scan with gadolinium-DTPA enhancement demonstrated enhancing lesions in the cerebellum and in the posterior fornix. At autopsy, the later lesions proved to be lymphoma. This case demonstrates the unusual clinical features that may occur with lesions in the limbic system and importance of gadolinium-enhanced MRI in the evaluation of symptoms of cognitive impairment in patients with advanced HIV infection.