MDCT imaging in Spigelian hernia, clinical, and surgical implications.

OBJECTIVE: Spigelian hernia is an uncommon congenital or acquired defect in the transversus abdominis aponeurosis with non-specific symptoms posing a diagnostic challenge. There is a paucity of radiology literature on imaging findings of Spigelian hernia. The objective of this study is to explore the role of MDCT in evaluating Spigelian hernia along with clinical and surgical implications. MATERIALS AND METHODS: In this IRB approved, HIPAA compliant retrospective observational analysis MDCT imaging findings of 43 Spigelian hernias were evaluated by two fellowship-trained radiologists. Imaging features evaluated were: presence of Spigelian hernia, laterality, relation to "hernia belt" (between 0 and 6 cm cranial to an imaginary axial line between both anterior superior iliac spines), the hernia neck and sac sizes, hernia content, and other coexistent hernias (umbilical, incisional, inguinal). Patient's demographics (age, gender, BMI, conditions with increased intra-abdominal pressure) were also recorded for any correlation. RESULTS: 60% (26/43) of Spigelian hernias were located below the hernia belt while 33% (14/43) within the hernia belt and 7% (3/43) above the hernia belt. The most common subtype of Spigelian hernia encountered was interparietal (84%). The mean hernia neck diameter was 3.4 cm, mean hernia sac volume was 329 cc. Hernia content included: fat (43/43) bowel (23/43), fluid (3/43). 3 patients had no clinical history provided, the remaining 37 patients' clinical presentation was asymptomatic in 73% (27/37), acute abdominal pain in 5% (2/37) and chronic abdominal pain in 22% (8/37). None of the hernia were incarcerated and none of the patients underwent emergent surgery. No significant correlation was noted between Spigelian hernia and causes of increased intra-abdominal pressure. 90% of our patients had other abdominal hernias. 30.9 was the mean BMI (20.8-69.1). CONCLUSION: Most of the Spigelian hernia occurred below the traditionally described hernia belt and the majority are of interparietal subtype that can be best diagnosed with MDCT in contrast to physical examination.

Fluoroscopically Guided Lateral Approach Hip Injection.

A retrospective comparison study of the anterior-oblique and lateral approach to hip injection procedures suggests that the lateral approach may be a valuable interventional skill for those performing hip injections.

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.

Peer support of a faculty "writers' circle" increases confidence and productivity in generating scholarship.

RATIONALE AND OBJECTIVES: Publishing is critical for academic medicine career advancement. Rejection of manuscripts can be demoralizing. Obstacles faced by clinical faculty may include lack of time, confidence, and optimal writing practices. This study describes the development and evaluation of a peer-writing group, informed by theory and research on faculty development and writing. MATERIALS AND METHODS: Five clinical-track radiology faculty members formed a "Writers' Circle" to promote scholarly productivity and reflection on writing practices. Members decided to work with previously rejected manuscripts. After members' initial meeting, interactions were informal, face to face during clinical work, and online. After the first 6 months, an anonymous survey asked members about the status of articles and evaluations of the writing group. RESULTS: Ten previously rejected articles, at least one from each member, were submitted to the Circle. In 6 months, four manuscripts were accepted for publication, five were in active revision, and one was withdrawn. All participants (100%) characterized the program as worth their time, increasing their motivation to write, their opportunities to support scholarly productivity of colleagues, and their confidence in generating scholarship. CONCLUSIONS: Peer-support writing groups can facilitate the pooling of expertise and the exchange of recommended writing practices. Our peer-support group increased scholarly productivity and provided a collegial approach to academic writing.

MR imaging appearances of soft tissue flaps following reconstructive surgery of the lower extremity.

MR imaging appearances of different types of reconstructive muscle flaps following reconstructive surgery of the lower extremity with associated post-surgical changes due to altered anatomy, radiation, and potential complications, can be challenging. A multidisciplinary therapeutic approach to tumors allows for limb salvage therapy in a majority of the patients. Decision-making for specific types of soft tissue reconstruction is based on the body region affected, as well as the size and complexity of the defect. Hematomas and infections are early complications that can jeopardize flap viability. The local recurrence of a tumor within six months after a complete resection with confirmed tumor-free margins and adjuvant radiation therapy is rare. Identification of a new lesion similar to the initial tumor favors a finding of tumor recurrence.

MR imaging of the pelvis: a guide to incidental musculoskeletal findings for abdominal radiologists.

Occasionally patients who undergo magnetic resonance imaging for presumed pelvic disease demonstrate unexpected musculoskeletal imaging findings in the imaged field. Such incidental findings can be challenging to the abdominal radiologist, who may not be familiar with their appearance or know the appropriate diagnostic considerations. Findings can include both normal and abnormal bone marrow, osseous abnormalities such as Paget's disease, avascular necrosis, osteomyelitis, stress and insufficiency fractures, and athletic pubalgia, benign neoplasms such as enchondroma and bone island, malignant processes such as metastasis and chondrosarcoma, soft tissue processes such as abscess, nerve-related tumors, and chordoma, joint- and bursal-related processes such as sacroiliitis, iliopsoas bursitis, greater trochanteric pain syndrome, and labral tears, and iatrogenic processes such as bone graft or bone biopsy. Though not all-encompassing, this essay will help abdominal radiologists to identify and describe this variety of pelvic musculoskeletal conditions, understand key radiologic findings, and synthesize a differential diagnosis when appropriate.

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.

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.

Sonographically guided patellar tendon fenestration: prognostic value of preprocedure sonographic findings.

OBJECTIVES: The purpose of this study was to determine whether any sonographic features of jumper's knee can predict the outcome after sonographically guided percutaneous patellar tendon fenestration. METHODS: Patients were identified between July 2001 and March 2009 who had clinical and sonographic findings of jumper's knee, who had failed conservative treatment, and who had sonographically guided percutaneous fenestration of the patellar tendon. Pain levels were assessed before and 4 weeks after fenestration. Sonograms were retrospectively characterized with regard to echogenicity, size, definition, location, calcification, and hyperemia of the abnormal patellar tendon region. Sonographic findings before fenestration were correlated with clinical outcomes. RESULTS: A total of 45 patellar tendons (32 consecutive patients) were included in the study. The average prefenestration functional pain score was 3.6 (range, 2-5), and the average postprocedure functional pain score after 4 weeks was 1.4 (range, 0-5). The preprocedure sonographic finding that correlated with an improved clinical outcome after tendon fenestration was the presence of a well-defined tendon abnormality. No other sonographic findings were associated with the clinical outcome. After fenestration, 76% (34 of 45) showed clinical improvement; 24% (11 of 45) showed no change; and 0% (0 of 45) had worse symptoms at 4 weeks. CONCLUSIONS: The presence of a well-defined area of tendinosis on sonography was associated with clinical improvement after percutaneous sonographically guided fenestration of the patellar tendon. All tendons either improved (76%) or showed no change (24%) in the functional pain score at 4 weeks after fenestration.

Imaging appearances in gout.

Gout is an ancient disease. Last decade has brought about significant advancement in imaging technology and real scientific growth in the understanding of the pathophysiology of gout, leading to the availability of multiple effective noninvasive diagnostic imaging options for gout and treatment options fighting inflammation and controlling urate levels. Despite this, gout is still being sub-optimally treated, often by nonspecialists. Increased awareness of optimal treatment options and an increasing role of ultrasound and dual energy computed tomography (DECT) in the diagnosis and management of gout are expected to transform the management of gout and limit its morbidity. DECT gives an accurate assessment of the distribution of the deposited monosodium urate (MSU) crystals in gout and quantifies them. The presence of a combination of the ultrasound findings of an effusion, tophus, erosion and the double contour sign in conjunction with clinical presentation may be able to obviate the need for intervention and joint aspiration in a certain case population for the diagnosis of gout. The purpose of this paper is to review imaging appearances of gout and its clinical applications.

Entrapment neuropathies in the upper and lower limbs: anatomy and MRI features.

Peripheral nerve entrapment occurs at specific anatomic locations. Familiarity with the anatomy and the magnetic resonance imaging (MRI) features of nerve entrapment syndromes is important for accurate diagnosis and early treatment of entrapment neuropathies. The purpose of this paper is to illustrate the normal anatomy of peripheral nerves in the upper and lower limbs and to review the MRI features of common disorders affecting the peripheral nerves, both compressive/entrapment and noncompressive, involving the suprascapular nerve, the axillary nerve, the radial nerve, the ulnar nerve, and the median verve in the upper limb and the sciatic nerve, the common peroneal nerve, the tibial nerve, and the interdigital nerves in the lower limb.

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.

Imaging review of skeletal tumors of the pelvis malignant tumors and tumor mimics.

Malignant lesions of the pelvis are not uncommon and need to be differentiated from benign lesions and tumor mimics. Appearances are sometimes nonspecific leading to consideration of a broad differential diagnosis. Clinical history, anatomic location, and imaging characterization can help narrow the differential diagnosis. The focus of this paper is to demonstrate the imaging features and the role of plain films, computed tomography, and magnetic resonance imaging for detecting and characterizing malignant osseous pelvic lesions and their common mimics.

The rotator interval and long head biceps tendon: anatomy, function, pathology, and magnetic resonance imaging.

The rotator interval is an anatomically defined triangular area located between the coracoid process, the superior aspect of the subscapularis, and the anterior aspect of the supraspinatus. It is widely accepted that the rotator interval structures fulfill a role in biomechanics and pathology of the glenohumeral joint and long head biceps tendon. However, there is ongoing debate regarding the biomechanical details and the indications for treatment. A better understanding of rotator interval anatomy and function will lead to improved treatment of rotator interval abnormalities, and guide the indications for imaging and surgical intervention.

Ultrasound of the rotator cable: prevalence and morphology in asymptomatic shoulders.

OBJECTIVE: The objective of our study was to assess the prevalence, morphology, and position of the rotator cable and the relation of this structure to the rotator cuff crescent. MATERIALS AND METHODS: Ultrasound examinations of bilateral shoulders of asymptomatic volunteers and of the asymptomatic shoulder in patients referred for assessment of a symptomatic contralateral shoulder were performed. The images were assessed by two radiologists for the presence of the rotator cable and measurements were performed. RESULTS: The rotator cable was identified in 99% of 108 asymptomatic shoulders (49 men, 59 women) (mean age, 45 years; range, 21-79 years). The mean thickness and the mean width of the rotator cable were 1.86 mm (range, 0.6-3.5 mm) and 11.5 mm (range, 7.6-17.7 mm), respectively. The mean distance between the lateral edge of the rotator cable and the medial aspect of the greater tuberosity was 8.9 mm (range, 3.6-15.4 mm). The mean rotator cuff crescent thickness was 3.7 mm (range, 2.5-5.3 mm). A statistically significant positive correlation was found between the thickness of the rotator cable and the thickness of the rotator cuff (p<0.0001) and between the thickness of the rotator cuff and patient age (p=0.029). CONCLUSION: The rotator cable is a consistent structure seen in 99% of shoulders in this study. The morphology of this structure is variable, but rotator cable thickness correlated positively with the thickness of the rotator crescent.

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.

Ultrasound of the shoulder: asymptomatic findings in men.

OBJECTIVE: The purpose of this study was to examine the range and prevalence of asymp tomatic findings at sonography of the shoulder. MATERIALS AND METHODS: The study sample comprised 51 consecutively enrolled subjects who had no symptoms in either shoulder. Ultrasound of one shoulder per patient was performed by a musculoskeletal sonographer according to a defined protocol that included imaging of the rotator cuff, tendon of the long head of the biceps brachii muscle, subacromial-subdeltoid bursa, acromioclavicular joint, and posterior labrum. The shoulder imaged was determined at random. The 51 scans were retrospectively analyzed by three fellowship-trained musculoskeletal radiologists in consensus, and pathologic findings were recorded. Subtle or questionable findings of mild tendinosis, bursal prominence, and mild osteoarthritis were not recorded. RESULTS: Twenty-five right and 26 left shoulders were imaged. The subject age range was 40-70 years. Ultrasound showed subacromial-subdeltoid bursal thickening in 78% (40/51) of the subjects, acromioclavicular joint osteoarthritis in 65% (33/51), supraspinatus tendinosis in 39% (20/51), subscapularis tendinosis in 25% (13/51), partial-thickness tear of the bursal side of the supraspinatus tendon in 22% (11/51), and posterior glenoid labral abnormality in 14% (7/51). All other findings had a prevalence of 10% or less. CONCLUSION: Asymptomatic shoulder abnormalities were found in 96% of the subjects. The most common were subacromial-subdeltoid bursal thickening, acromioclavicular joint osteoarthritis, and supraspinatus tendinosis. Ultrasound findings should be interpreted closely with clinical findings to determine the cause of symptoms.

Usefulness of the twinkling artifact in identifying implanted mesh after inguinal hernia repair.

OBJECTIVES: Implanted mesh for inguinal hernia repair is often difficult to visualize with gray scale sonography and may present without the knowledge of the sonographer. We sought to evaluate the utility of the twinkling artifact produced by inguinal mesh to assist in mesh identification. METHODS: Two reviewers evaluated focused sonographic examinations of 44 inguinal regions, 24 of which had implanted inguinal mesh. The sonographic examinations consisted of static gray scale and color Doppler images with both linear and curvilinear array transducers. The presence of the twinkling artifact and visibility of the mesh were graded on a 4-point visibility scale. RESULTS: Inguinal mesh was not easily identified on gray scale imaging using either the curvilinear array (P = .5) or linear array (P = .5) transducer. The mesh was definitely seen in 3 of 24 inguinal regions using the linear array transducer and 2 of 24 inguinal regions using the curvilinear array transducer. In 79% of inguinal regions with mesh, the twinkling artifact was produced with the curvilinear array transducer only. The artifact was not elicited when using the linear array transducer. With the use of the curvilinear array transducer and the presence of the twinkling artifact, there was a significant chance of correctly identifying the presence of mesh (P < .005) in the entire study group. CONCLUSIONS: Standard gray scale imaging alone is not reliable when identifying inguinal mesh. The twinkling artifact was present in 79% of inguinal regions with mesh when evaluated with a low-frequency curvilinear array transducer.

The subscapularis: anatomy, injury, and imaging.

The subscapularis is the largest and most powerful of the rotator cuff muscles and fulfills an important role in glenohumeral movement and stability. The spectrum and implications of subscapularis muscle or tendon injury differ from injury to other rotator cuff components because of its unique structure and function. Diagnosing subscapularis injury is clinically difficult and assessment of subscapularis integrity may be limited during arthroscopy or open surgery. Diagnostic imaging plays an important part in diagnosing and evaluating the extent of subscapularis injury. The radiologist should be aware of the anatomy of the subscapularis, the variations in muscle or tendon injury, and the potential implications for treatment and prognosis.

Posterior interosseous nerve of the elbow: normal appearances simulating entrapment.

OBJECTIVE: In our clinical practice, we have noted a caliber change of the posterior interosseous nerve (PIN) at the elbow as seen in the long axis on sonography simulating nerve entrapment. The objective of this study was to characterize the PIN using sonography in asymptomatic individuals. METHODS: Our study retrospectively characterized the PIN in 50 elbows of 47 asymptomatic patients with sonography. Measurements of the PIN in a short-axis cross section using the circumferential trace technique and the anteroposterior (AP) dimension in the long axis were made proximal, at, and distal to the arcade of Frohse. RESULTS: There was reduction of the AP dimension of the PIN distal to the arcade of Frohse when compared with the measurements at the arcade of Frohse and proximal to the arcade (P < .0001); however, there was no significant difference between the cross-sectional area of the PIN at all 3 levels (P = .59). CONCLUSIONS: The PIN normally flattens as it enters into the supinator muscle without a notable change in the cross-sectional area. This appearance should not be misinterpreted as nerve entrapment when imaged in the long axis.