Liem T. Bui-Mansfield

Humeral Avulsion of the Glenohumeral Ligaments The HAGL Lesion

Background Anterior instability of the shoulder is a frequently encountered clinical problem that is seen after avulsion of the capsulolabral complex from the glenoid rim (Bankart lesion). Recently, it has been determined that avulsion of the glenohumeral ligaments is an infrequent but important cause of recurrent instability after shoulder injury. Although the various forms of this injury have been described in the literature, no standardized nomenclature exists. This is of concern given the need for different surgical approaches to repair the various forms of this injury and therefore the inherent need to accurately convey the location of the avulsion and presence of concomitant injuries. Hypothesis Based on the available literature for humeral avulsion of the glenohumeral ligament lesions, a nomenclature can be created to enhance the understanding and improve communication about these uncommon but important pathologic changes that occur with shoulder instability. Study Design Systematic review. Methods The findings pertaining to 6 patients with humeral avulsion of the glenohumeral ligament lesions encountered at our institution were combined with a literature search of the MEDLINE database conducted using the PubMed search engine of the National Library of Medicine and National Center for Biotechnology Information. Results The West Point nomenclature was developed to clearly describe the various forms of humeral avulsion of the glenohumeral ligament lesions encountered as well as their associated injuries. Conclusions The West Point nomenclature provides a practical and easy to understand means by which to classify humeral avulsion of the glenohumeral ligament lesions. This allows for more effective communication, which should result in improved clinical care.

MRI of Quadratus Femoris Muscle Tear: Another Cause of Hip Pain

OBJECTIVE The objective of this study is to report the MR appearance of quadratus femoris muscle tear, another cause of hip pain. We will review the pertinent anatomy of the quadratus femoris muscle, summarize the current literature on quadratus femoris muscle tear, and report our experience in the diagnosis of quadratus femoris muscle tear on MRI. CONCLUSION MRI is an important tool in assisting clinicians to make a correct diagnosis for the patient who presents with hip pain. Although quadratus femoris muscle tear is an uncommon injury, radiologists should be aware of this entity to assist with making a diagnosis that is usually unsuspected clinically.

Musculoskeletal Lesions With Fluid-fluid Level: A Pictorial Essay

Abstract: A fluid-fluid level was identified in 11.2% of focal lesions of bone.1 Fluid-fluid levels are observed on cross-sectional imaging with either computed tomography (CT) or magnetic resonance (MR) imaging. They become apparent when a fluid collection containing substances of different density is allowed to settle, and when the plane of imaging is perpendicular to the fluid level. For instance, within a collection of blood, the cellular components will settle dependently, with the lower density plasma forming a layer superiorly. The difference in the density of these layers can be observed on CT imaging. With MR imaging, these layers will have different signal characteristics, allowing for visualization of the fluid-fluid level. The presence of fluid-fluid levels within a musculoskeletal lesion is an important finding, which can significantly aid in the differential diagnosis. This finding can be observed in a wide variety of lesions: osseous and soft tissue masses, neoplastic or nonneoplastic lesions, malignant or benign neoplasms, and primary or metastatic malignancies.2 When a fluid-fluid level is detected, in conjunction with clinical history, the differential diagnosis for a lesion can often be limited to a few choices. For this reason, it is important to be aware of the multiple lesions that can produce fluid-fluid levels, as well as their differentiating characteristics and typical presentations. We will review both osseous and soft tissue lesions, focusing on their imaging characteristics and other important findings.

Radiologic demonstration of temporal development of bizarre parosteal osteochondromatous proliferation

We report a case of bizarre parosteal osteochondromatous proliferation (BPOP) in which radiologic examinations showed temporal development of BPOP following a traumatic event. This evidence supports the theory that BPOP is caused by trauma.

Radiologic-pathologic conference of Brooke Army Medical Center: endometriosis of the canal of Nuck.

3Department of Pathology, Brooke Army Medical Center, Fort Sam Houston, TX 78234. 41-year-old woman undergoing clinical and imaging evaluation for adrenocorticotropic hormone (ACTH)-independent Cushing’s syndrome was found to have a lipid-poor left adrenal adenoma on abdominal CT. Further evaluation with PET/CT supported a diagnosis of lipid-poor adrenal adenoma but also revealed a spiculated 3-cm soft-tissue mass in the right inguinal region that exhibited intense (standardized uptake value, 4.0) 18F-FDG activity (Fig. 1A). MRI showed the lesion to have intermediate T1 (Fig. 1B) and markedly low T2 (Fig. 1C) signal characteristics, extending through the right inguinal canal into the right lateral mons pubis (Fig. 1C). Sonography-guided core biopsy was performed, and histologic findings were consistent with endometriosis (Fig. 1D). Low T2 signal intensity characteristic of a soft-tissue lesion is of considerable aid in narrowing the radiologist’s differential diagnosis. The mnemonic CHAFT (calcification, hemosiderin, amyloid/air, fibrous lesions, and tophaceous gout) can be used to easily formulate a differential diagnosis in such lesions. Correlation with conventional radiographs and CT plays an important role in distinguishing among these entities through more precise identification of calcifications, air, and tophi. In addition, clinical presentation and anatomic location can effectively exclude tophaceous gout from differential consideration. Inguinal hernia, fibrous neoplasm, and extrapelvic endometriosis remain in the differential diagnosis. Although PET/CT is a valuable technique in evaluating for neoplasms, this case illustrates the importance of correlating increased 18F-FDG activity with cross-sectional imaging examinations. Infection, inflammation, physiologic muscular activity, brown fat, and metabolically active lesions (i.e., endometriosis) all can show markedly increased 18F-FDG uptake. Endometriosis is a common gynecologic disease affecting 1–2% of all women. Classically, it is characterized by implantation of endometrial tissue outside the uterine cavity, resulting in bleeding, cyclical pain, and scarring. Typically, endometriosis occurs within the ovaries and peritoneum [1]. However, rarer cases have been reported in the vagina, rectum, lung (potentially leading to catamenial pneumothorax), subcutaneous tissues, and inguinal canal [2, 3]. The prevailing theory to explain the mechanism of endometriosis is retrograde menstruation (implantation theory), which proposes that viable endometrial tissue is refluxed through the fallopian tube during menstruation and deposited on the peritoneal surface or pelvic organs [1]. The gubernaculum testis, which is embryologically a cord of fibrous and muscular tissue, A

MRI of giant cell tumor of the tendon sheath in the cervical spine

The authors present a case of giant cell tumor of the tendon sheath (GCTTS) in the cervical spine, not previously described in the radiologic literature. Diagnostic imaging includes plain film radiographs, bone scintigraphy, CT, and MRI. Only one case of tenosynovial giant cell tumor of the cervical spine has been reported. The radiological features of this tumor are described along with a brief review of GCTTS.

Magnetic resonance appearance of bone marrow edema associated with hydroxyapatite deposition disease without cortical erosion

The authors report the magnetic resonance (MR) appearance of bone marrow edema associated with hydroxyapatite deposition disease without cortical erosion. Hydroxyapatite deposition disease may have bone marrow edema on MR imaging without radiographic evidence of cortical erosion, mimicking the appearance of fracture, neoplasm, or infection. Awareness of this association can prevent unnecessary additional imaging evaluation or biopsy.

Magnetic resonance diagnosis of tarsal tunnel syndrome due to flexor digitorum accessorius longus and peroneocalcaneus internus muscles.

Anomalous muscles of the ankle are common. Although they are often asymptomatic, they can sometimes cause tarsal tunnel syndrome. We report a case of tarsal tunnel syndrome due to flexor digitorum accessorius longus and peroneocalcaneus internus muscles diagnosed on magnetic resonance imaging. Recognition of the most common accessory muscles of the ankle on magnetic resonance imaging and tarsal tunnel syndrome are also reviewed.

Bare area of the glenoid: magnetic resonance appearance with arthroscopic correlation.

Objective: To review the radiologic findings of a rarely reported focal area of acquired cartilage thinning located at the center of the glenoid fossa. Methods: We retrospectively reviewed the medical records of 3 patients, each possessing a bare area of the glenoid detected on magnetic resonance (MR) imaging. A literature search was performed to obtain the most current information regarding this uncommon entity. Results: Magnetic resonance imaging of the glenoid demonstrated a smoothly marginated subcentimeter area of thinning of the central articular cartilage containing hyperintense joint fluid or contrast in the case with MR arthrography. Arthroscopic correlation was obtained in a single case. Conclusions: The bare area of the glenoid is an acquired cartilage defect located at the center of the glenoid articular surface. Characteristic findings can be seen on MR imaging. Care should be taken not to mistake this acquired condition for posttraumatic defects of the glenoid articular cartilage.

Osteochondritis dissecans of the tarsal navicular bone: imaging findings in four patients.

We report the imaging characteristics of osteochondritis dissecans of the tarsal navicular bone in four cases and review the current literature. Its radiological findings are similar to osteochondritis dissecans found in other sites: focal lucency that disrupts the sharp cortical line, the presence of sclerosis, and cortical depression.