US of the Peripheral Nerves of the Upper Extremity: A Landmark Approach.

Ultrasonography (US) has become a first-line modality for the evaluation of the peripheral nerves of the upper extremity. The benefits of US over magnetic resonance (MR) imaging include higher soft-tissue resolution, cost effectiveness, portability, real-time and dynamic imaging, and the ability to scan an entire extremity quickly and efficiently. US can be performed on patients who are not eligible for MR imaging. Metallic implant artifacts are usually not problematic. US has been shown to have equal specificity and greater sensitivity than MR imaging in the evaluation of peripheral nerves. Any abnormal findings can be easily compared with the contralateral side. The published literature has shown that US has demonstrated clinical utility in patients with suspected peripheral nerve disease by guiding diagnostic and therapeutic decisions as well as by confirming electrodiagnostic findings. Common indications for upper extremity peripheral nerve US are the evaluation for injury due to penetrating trauma, entrapment by scar tissue, and tumor. US of the upper extremity is most commonly performed to evaluate carpal and cubital tunnel syndrome. It is important for the radiologist or sonographer to have a detailed knowledge of anatomy and specific anatomic landmarks for each nerve to efficiently and accurately perform an examination. The goal of this article is to introduce readers to the basics of US of the peripheral nerves of the upper extremity with a focus on the median, ulnar, and radial nerves. Common sites of disease and the location of important anatomic landmarks will be reviewed.

US of the Peripheral Nerves of the Lower Extremity: A Landmark Approach.

Ultrasonography (US) is commonly used to assess the peripheral nerves of the lower extremity because of its many advantages over magnetic resonance (MR) imaging. The most obvious advantages over MR imaging are superior soft-tissue resolution, low cost, portability, lack of magnetic susceptibility artifact, and the ability to image patients who cannot undergo MR imaging. US has been shown to have equal specificity and greater sensitivity than MR imaging in the evaluation of peripheral nerves. Additional benefits are the capability of real-time and dynamic imaging, and the ability to scan an entire extremity quickly without the need for a patient to lie motionless for long periods of time, as with MR imaging. Any abnormal findings can be easily compared against the contralateral side. Published literature has shown that US has clinical utility in patients suspected of having peripheral nerve disease: US can be used to guide diagnostic and therapeutic decisions, as well as help confirm electrodiagnostic findings. Common indications for lower extremity peripheral nerve US are the evaluation for injury due to penetrating trauma, entrapment by scar tissue, or tumor. To confidently perform US of the peripheral nerves of the lower extremity, it is important to gain a thorough knowledge of anatomic landmarks and the course of each nerve. Readers who may not be familiar with US will be introduced to the basics of scanning the peripheral nerves of the lower extremity. Important anatomic landmarks and common sites of injury and entrapment will be reviewed.

Role of Sonography in Clinically Occult Femoral Hernias.

OBJECTIVES: The purpose of this article is to evaluate the diagnostic accuracy of sonography in clinically occult femoral hernias and to describe our sonographic technique. METHODS: The clinical and imaging data for 93 outpatients referred by general surgeons, all of whom underwent sonographic evaluation and surgery, were reviewed retrospectively. Of these, 55 patients who underwent surgical exploration for groin hernias within 3 months of sonography and met all inclusion criteria were included in the study. The sonographic technique involves using the pubic tubercle as an osseous landmark to identify and appropriately visualize the femoral canal. The Valsalva maneuver is then used to differentiate the movement of normal fat (a potential pitfall) from true herniation in the femoral canal. Surgical findings were used as the reference standard by which sonographic results were judged. Two-by-two contingency tables were used to calculate the sensitivity, specificity, positive predictive value, and negative predictive value. RESULTS: In these 55 patients, surgery revealed 15 femoral hernias. Eight femoral hernias occurred in women, and 7 occurred in men. For diagnosing femoral hernias, sonography demonstrated sensitivity of 80%, specificity of 88%, a positive predictive value of 71%, and a negative predictive value of 92%. True-positive cases of femoral hernias have a sonographic appearance of a hypoechoic sac with speckled internal echoes. When examining during the Valsalva maneuver, a femoral hernia passes deep to the inguinal ligament, expands the femoral canal, displacing the normal canal fat, and effaces the femoral vein. CONCLUSIONS: Sonography can exclude femoral hernias with high confidence in light of its exceptional negative predictive value. With attention to technique and imaging criteria, the diagnostic accuracy of sonography can be enhanced.

Evaluating maternal recovery from labor and delivery: bone and levator ani injuries.

OBJECTIVE: We sought to describe occurrence, recovery, and consequences of musculoskeletal (MSK) injuries in women at risk for childbirth-related pelvic floor injury at first vaginal birth. STUDY DESIGN: Evaluating Maternal Recovery from Labor and Delivery is a longitudinal cohort design study of women recruited early postbirth and followed over time. We report here on 68 women who had birth-related risk factors for levator ani (LA) muscle injury, including long second stage, anal tears, and/or older maternal age, and who were evaluated by MSK magnetic resonance imaging at both 7 weeks and 8 months' postpartum. We categorized magnitude of injury by extent of bone marrow edema, pubic bone fracture, LA muscle edema, and LA muscle tear. We also measured the force of LA muscle contraction, urethral pressure, pelvic organ prolapse, and incontinence. RESULTS: In this higher-risk sample, 66% (39/59) had pubic bone marrow edema, 29% (17/59) had subcortical fracture, 90% (53/59) had LA muscle edema, and 41% (28/68) had low-grade or greater LA tear 7 weeks' postpartum. The magnitude of LA muscle tear did not substantially change by 8 months' postpartum (P = .86), but LA muscle edema and bone injuries showed total or near total resolution (P < .05). The magnitude of unresolved MSK injuries correlated with magnitude of reduced LA muscle force and posterior vaginal wall descent (P < .05) but not with urethral pressure, volume of demonstrable stress incontinence, or self-report of incontinence severity (P > .05). CONCLUSION: Pubic bone edema and subcortical fracture and LA muscle injury are common when studied in women with certain risk factors. The bony abnormalities resolve, but levator tear does not, and is associated with levator weakness and posterior-vaginal wall descent.

Ultrasound of the Groin: Techniques, Pathology, and Pitfalls.

OBJECTIVE: In a patient with symptoms referable to the groin, there can be a number of causes to consider and at times the cause of the symptoms is multifactorial. Although ultrasound can be effective in the evaluation of the groin, the depth and complexity of the anatomy can be problematic. A protocol-driven approach for ultrasound evaluation of the groin will help to ensure an accurate and comprehensive evaluation. This article summarizes the ultrasound technique and protocol for evaluation of the groin to include evaluation of the hip joint, anterior hip musculature, the iliopsoas bursa, the inguinal lymph nodes, the pubic symphyseal region, and the inguinal region for hernias. Common pathologic conditions and pitfalls related to ultrasound evaluation of the groin will be reviewed. CONCLUSION: There are many potential pathologic conditions in a patient with groin symptoms. Because symptoms may be multifactorial and history may be ambiguous or misleading, a protocol-driven evaluation with ultrasound is recommended. The hip joint is evaluated for effusion, synovitis, and labral abnormalities. The muscles and tendons, including the common aponeurosis at the pubic symphysis, are evaluated for tendinosis and tears. Dynamic evaluation should be considered to assess for snapping hip syndrome. Iliopsoas bursal distention and lymph node enlargement are other considerations. Last, inguinal region hernias must be evaluated during the Valsalva maneuver and documented in two orthogonal planes to avoid several important diagnostic pitfalls.

Sonography of traumatic quadriceps tendon tears with surgical correlation.

OBJECTIVES: Using surgical correlation as the reference standard, the purpose of this study was to assess the ability of sonography to detect quadriceps tendon tears that require surgical treatment (high-grade partial tears and complete ruptures). METHODS: Two hundred thirty-nine consecutive sonographic reports of the knee (May 2001 to October 2008) with subsequent surgical correlation were retrospectively reviewed for surgical intervention on the quadriceps tendon. All sonograms were blindly and retrospectively reviewed. Surgical findings were compared with results from the consensus review. Results from the original sonographic reports (nonretrospective interpretation) were also compared with the surgical findings. RESULTS: On the retrospective consensus review, the sensitivity (23 of 23), specificity (16 of 16), and accuracy (39 of 39) were 100% for identifying high-grade partial tears or complete ruptures versus a normal quadriceps tendon. For the original, nonretrospective sonographic reports, 22 of 23 high-grade partial tears or complete ruptures (96%) were correctly diagnosed. CONCLUSIONS: Sonography is an effective tool for identifying quadriceps tendon tears that require surgical treatment (high-grade partial tears and complete ruptures).

Aseptic hip pneumarthrosis following modular total hip arthroplasty: a potential mimic of hip infection.

Pneumarthrosis following total hip arthroplasty accompanied by acute hip symptoms is a potentially ominous finding suggesting infection with gas-forming bacteria, a medical emergency. We describe a case of a 61-year-old male presenting to the Emergency Department 43 months following a titanium/titanium (Ti/Ti) modular neck-stem total hip arthroplasty (MTHA) (Wright Medical Systems, Arlington, Tennessee) with acute presentation of hip symptoms and joint gas on radiographs proven to be aseptic hip pneumarthrosis. We review the imaging features of aseptic hip pneumarthrosis following MTHA which have not been elaborated on previously and suggest a less aggressive workup in select cases. We believe emergency radiologists should be aware of this unusual complication as it may mimic a septic hip which may entail an unnecessarily aggressive workup.

Inguinal lymph nodes: size, number, and other characteristics in asymptomatic patients by CT.

PURPOSE: The purpose of this study was to establish normative data for the CT appearance of inguinal lymph nodes. MATERIALS AND METHODS: After Institutional Review Board approval, search of the radiology information system identified 500 consecutive CT examinations of the pelvis. Patients were included if no lower extremity or perineum pathology, or history of malignancy at the time of CT examination, and a clinical note documenting no tumor at least 2 years after the CT. The final study group was 77 patients. CT examinations were retrospectively reviewed and bilateral inguinal lymph nodes were characterized by size (short axis and largest size in general), number, and presence of fat attenuation. RESULTS: The mean short-axis inguinal lymph node size was 5.4 mm (range 2.1-13.6 mm), measured at 8.8 mm two standard deviations above the mean. The mean number of superficial and deep inguinal lymph nodes was 10.7 (range 3-18) and 1.2 per patient (range 1-2), respectively. Superficial and deep inguinal nodes showed internal fat attenuation in 85 and 78% of nodes, and were oval in shape in 95 and 78%, respectively. CONCLUSION: Inguinal lymph nodes in asymptomatic patients have a mean short axis of 5.4 mm, a short axis of 8.8 mm at two standard deviations above the mean, and are multiple and symmetric in size and number (4-20 per patient). Normal inguinal lymph nodes were commonly oval in shape and contained fat, although such findings may be absent in smaller lymph nodes.

The role of sonography in differentiating full versus partial distal biceps tendon tears: correlation with surgical findings.

OBJECTIVE: The purpose of this study was to determine the accuracy of ultrasound for distinguishing complete rupture of the distal biceps tendon versus partial tear and versus a normal biceps tendon. Surgical findings were used as the reference standard in cases of tear. Clinical follow-up was used to assess the normal tendons. MATERIALS AND METHODS: The study population consisted of 45 consecutive elbow ultrasound cases with surgical confirmation and six cases of a clinically normal distal biceps tendon that underwent elbow ultrasound for suspicion of injury to a structure other than the biceps tendon. Cases underwent consensus review by two fellowship-trained musculoskeletal radiologists. Tendons were classified as normal biceps tendon, partial tear, or complete tear. The presence or absence of posterior acoustic shadowing at the distal biceps tendon was also assessed. The ultrasound findings were then compared with the surgical findings and clinical follow-up. RESULTS: Ultrasound showed 95% sensitivity, 71% specificity, and 91% accuracy for the diagnosis of complete versus partial distal biceps tendon tears. Posterior acoustic shadowing at the distal biceps had sensitivity of 97% and accuracy of 91% for indicating complete tear versus partial tear and sensitivity of 97%, specificity of 100%, and accuracy of 98% for indicating complete tear versus normal tendon. CONCLUSION: Ultrasound can play a role in the diagnosis of elbow injuries when a distal biceps brachii tendon tear is suspected.

Morphology of large rotator cuff tears and of the rotator cable and long-term shoulder disability in conservatively treated elderly patients.

OBJECTIVE: The objective of this study was to describe the morphology of the rotator cuff tendon tears and long-term shoulder disability in conservatively treated elderly patients and determine if an association exists between these factors. METHODS: Assessment of the rotator cuff tendon tear dimensions and depth, rotator interval involvement, rotator cable morphology and location, and rotator cuff muscle status was carried out on magnetic resonance studies of 24 elderly patients treated nonoperatively for rotator cuff tendon tears. Long-term shoulder function was measured using the Western Ontario Rotator Cuff (WORC) index; Disabilities of the Shoulder, Arm, and Hand questionnaire; and the American Shoulder Elbow Self-assessment form, and a correlation between the outcome scores and morphologic magnetic resonance findings was carried out. RESULTS: The majority of large rotator cuff tendon tears are limited to the rotator cuff crescent. Medial rotator interval involvement (isolated or in association with lateral rotator interval involvement) was significantly associated with WORC physical symptoms total (P = 0.01), WORC lifestyle total (P = 0.04), percentage of all WORC domains (P = 0.03), and American Shoulder Elbow Self-assessment total (P = 0.01), with medial rotator interval involvement associated with an inferior outcome. CONCLUSIONS: Medial rotator interval tears are associated with long-term inferior outcome scores in conservatively treated elderly patients with large rotator cuff tendon tears.

Ultrasound of displaced ulnar collateral ligament tears of the thumb: the Stener lesion revisited.

PURPOSE: To retrospectively characterize the ultrasound appearance of displaced ulnar collateral ligament (UCL) tears that are proven at surgery, and then determine the accuracy of the resulting ultrasound criteria in differentiating displaced from non-displaced UCL tears. MATERIALS AND METHODS: After institutional review board approval, 26 patients were identified from the radiology information system over a 10-year period that had ultrasound evaluation of the thumb and surgically proven UCL tear. Retrospective review of the displaced full-thickness tears was carried out to characterize displaced tears and to establish ultrasound criteria for such tears. A repeat retrospective review 4 months later of all UCL tears applied the criteria to determine accuracy of ultrasound in the diagnosis of displaced full-thickness UCL tear. RESULTS: The 26 subjects consisted of 17 displaced full-thickness UCL tears, seven non-displaced full-thickness tears, and two partial-thickness tears at surgery. Retrospective ultrasound review of displaced full-thickness tears identified two criteria present in all cases: non-visualization of the UCL ligament and presence of a heterogeneous mass-like area proximal to the first metacarpophalangeal joint. Applying these criteria at the second retrospective review resulted in 100 % sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. CONCLUSIONS: The ultrasound findings of absent UCL fibers and presence of a heterogeneous mass-like abnormality proximal to the first metacarpophalangeal joint achieved 100 % accuracy in differentiating displaced from non-displaced full-thickness UCL tear of the thumb. Displaced full-thickness UCL tears most commonly were located proximal to the adductor aponeurosis.

Paralabral cysts of the hip: sonographic evaluation with magnetic resonance arthrographic correlation.

This retrospective study demonstrates the sonographic appearance paralabral cysts of the hip with magnetic resonance (MR) arthrography as the reference standard. Consensus review by 2 musculoskeletal radiologists was used to assess the paralabral cysts and determine their characteristics. The 3 paralabral cysts seen on sonography and confirmed with MR arthrography in this study were anechoic or hypoechoic, lobulated, and filled with contrast on MR imaging. A labral tear was also noted in all cases on both sonography and MR arthrography. Sonographic assessment for an anterior hip paralabral cyst and labral tear may be of diagnostic benefit.

Extra-abdominal desmoid tumor with osseous involvement.

Deep fibromatoses, or desmoid tumors, arise from connective tissue. Imaging can frequently suggest the diagnosis of these aggressive, benign neoplasms. Cross-sectional imaging commonly demonstrates an enhancing solid mass that resembles scar tissue, typically without osseous involvement. We report a case of an extra-abdominal desmoid tumor involving the teres minor muscle in a symptomatic 42-year-old woman with unusual features of medullary involvement and negative nuclear beta-catenin staining.

Imaging review of skeletal tumors of the pelvis--part I: benign tumors of the pelvis.

The osseous pelvis is a well-recognized site of origin of numerous primary and secondary musculoskeletal tumors. The radiologic evaluation of a pelvic lesion often begins with the plain film and proceeds to computed tomography (CT), or magnetic resonance imaging (MRI) and possibly biopsy. Each of these modalities, with inherent advantages and disadvantages, has a role in the workup of pelvic osseous masses. Clinical history and imaging characteristics can significantly narrow the broad differential diagnosis for osseous pelvic lesions. The purpose of this review is to familiarize the radiologist with the presentation and appearance of some of the common benign neoplasms of the osseous pelvis and share our experience and approach in diagnosing these lesions.

Groin pain beyond the hip: how anatomy predisposes to injury as visualized by musculoskeletal ultrasound and MRI.

OBJECTIVE: The purpose of this article is to show ultrasound and MRI examples of the normal anatomic structures and their resulting modifications from trauma and disease. CONCLUSION: Although groin pain from hip pathology is well recognized, lower anterior abdominal wall and anterior pelvis structures can be interrelated sources of pain.

Of ghosts, horses, and psychopaths.

Recognition and respect for the cultures of Native Americans constitutes a basic requirement for cancer care and education approaches. This reflection shares the insights gained in fieldwork excavations in a pre-Apache archeological site on the Cibaque reservation. Despite the ghost pollution associated with contact with the dead, the Apache invited me to be a sponsor for a young girl's coming of age ceremony. I owed this gracious invitation to the wild horses, for the Apache had observed the horses' responses to my calls. Since horses are considered spiritually sensitive animals, their acceptance was an indicator of my resistance to ghost pollution. Therefore, I was a strong contender as a sponsor. My days among the tribe made me a better listener and observer, and thus a better physician to the cancer patients I continue to serve as a radiologist.

Patients' perception of care during image-guided breast biopsy in a rural community breast center: communication matters.

This retrospective study surveyed women about their experience with image-guided breast biopsies in a rural cancer center. Our study objectives were to determine: women's perception of their emotional and physical comfort during the biopsy; the clarity and acceptability of the communication about the biopsy, as well as the methods used to provide the results of her biopsy and treatment options; and the overall impressions of the technical and personal care she received. A single mailed survey of 500 biopsy patients. The response rate was 43% (n = 215). Prior to their biopsy, 22% had been concerned that the biopsy would be painful and 43% were concerned that the biopsy might show cancer. Almost all women rated the communication about the biopsy procedure as understandable (99%) and accurately reflecting their experience (99%.). Most (77%) patients characterized the biopsy as producing minimal discomfort, although 5% disagreed. Most patients (98%) characterized their physician and technologists as caring about their emotional and physical comfort. Most patients felt that the typical 1-day wait to receive the results of their biopsy was reasonable (90%) and that the use of the phone to convey the results was acceptable (90%). On comparing patients with a diagnosis of cancer to those without, there was no difference in the level of satisfaction with the use of the phone to communicate biopsy results. This study offers encouragement that communication practices can alleviate the anxiety of women undergoing image-guided breast cancer biopsies.

MRI findings in patients considered high risk for pelvic floor injury studied serially after vaginal childbirth.

OBJECTIVE: The purpose of this article is to characterize pelvic floor injury after vaginal childbirth with serial MRI. SUBJECTS AND METHODS: MR images (3-T) were obtained early (1 month) and late (7 months) after first childbirth in 19 women with risk factors for pelvic floor injury. All women underwent multiplanar intermediate-weighted sequences, and 11 women underwent fluid-sensitive sequences. MR images were evaluated for levator edema and tears and for pubic abnormalities. RESULTS: Three women had unilateral high-grade tears, three had unilateral low-grade tears, and one had bilateral high- and low-grade tears of the levator ani muscles. All tears were focal at the pubis. Levator edema was present in all women on initial imaging and was resolved at follow-up. Six women had bone marrow edema, five with fracture line. None showed a pattern indicating nerve damage separate from muscle tears. CONCLUSION: MRI showed focal levator ani muscle tears at the pubis with bone marrow edema and fracture in patients at risk for pelvic floor injury.

The sternoclavicular joint: can imaging differentiate infection from degenerative change?

OBJECTIVE: The purpose of this study was to determine if there are imaging and clinical findings that can differentiate a septic sternoclavicular joint from a degenerative one. MATERIALS AND METHODS: Search of radiology reports from 2000-2007 revealed 460 subjects with imaging of the sternoclavicular joint, of whom 38 had undergone aspiration or biopsy. The final study group consisted of nine subjects with pathologic proof of sternoclavicular joint infection and ten subjects with pathologic and clinical findings excluding infection consistent with degenerative change. Available ultrasound, computed tomography (CT), and magnetic resonance (MR) images were retrospectively reviewed, and echogenicity, capsular distention, erosions, cysts, hyperemia or enhancement, and intensity of bone marrow signal were recorded. Clinical data were also reviewed. FINDINGS: The findings significantly associated with sternoclavicular joint infection included degree and extent of capsular distention. With infection, average joint distention was 14 mm (range 10-20 mm) and extended over the sternum and clavicle in 60% compared to 5 mm (range 3-8 mm) with degeneration only extending over the clavicle. Other findings significantly associated with infection included bone marrow fluid signal on magnetic resonance imaging (MRI), elevated Westergren red blood cell sedimentation rate, and fever. The two findings significantly associated with degeneration were subchondral cysts on CT and female gender. Other imaging and clinical variables showed no significant differences between infection and degenerative change. CONCLUSION: The clinical and imaging findings significantly associated with sternoclavicular joint infection included joint capsule distention of 10 mm or greater, extension over both the clavicle and sternum, adjacent fluid signal bone marrow replacement, elevated Westergren red blood cell sedimentation rate, and fever.

Automated abnormality classification of chest radiographs using deep convolutional neural networks.

As one of the most ubiquitous diagnostic imaging tests in medical practice, chest radiography requires timely reporting of potential findings and diagnosis of diseases in the images. Automated, fast, and reliable detection of diseases based on chest radiography is a critical step in radiology workflow. In this work, we developed and evaluated various deep convolutional neural networks (CNN) for differentiating between normal and abnormal frontal chest radiographs, in order to help alert radiologists and clinicians of potential abnormal findings as a means of work list triaging and reporting prioritization. A CNN-based model achieved an AUC of 0.9824 ± 0.0043 (with an accuracy of 94.64 ± 0.45%, a sensitivity of 96.50 ± 0.36% and a specificity of 92.86 ± 0.48%) for normal versus abnormal chest radiograph classification. The CNN model obtained an AUC of 0.9804 ± 0.0032 (with an accuracy of 94.71 ± 0.32%, a sensitivity of 92.20 ± 0.34% and a specificity of 96.34 ± 0.31%) for normal versus lung opacity classification. Classification performance on the external dataset showed that the CNN model is likely to be highly generalizable, with an AUC of 0.9444 ± 0.0029. The CNN model pre-trained on cohorts of adult patients and fine-tuned on pediatric patients achieved an AUC of 0.9851 ± 0.0046 for normal versus pneumonia classification. Pretraining with natural images demonstrates benefit for a moderate-sized training image set of about 8500 images. The remarkable performance in diagnostic accuracy observed in this study shows that deep CNNs can accurately and effectively differentiate normal and abnormal chest radiographs, thereby providing potential benefits to radiology workflow and patient care.