Sung Moon Kim

CT-guided biopsy of bone: a radiologist's perspective.

OBJECTIVE We present an overview of approaches for bone biopsy used to minimize potential tumor seeding of adjacent soft-tissue structures and compartments. We discuss a variety of approaches related to specific anatomic parts and review pertinent anatomy. CONCLUSION We provide important guidelines and key examples that will help readers perform percutaneous needle bone biopsy safely.

Subcutaneous epidermal inclusion cysts: Ultrasound (US) and MR imaging findings

ObjectiveTo describe the characteristic US and MR findings of subcutaneous epidermal inclusion cysts.Materials and methodsSeventy-nine patients with subcutaneous epidermal inclusion cysts underwent US (n = 70), MR (n = 7), or both (n = 2). On US, the margin, shape, echogenicity, through-transmission, wall, internal debris and vascularity were evaluated. On MR, the shape, wall, signal intensity, internal debris, and enhancement pattern were evaluated.ResultsOn US, characteristic findings were well circumscribed (n = 69, 96%), ovoid-shaped (n = 56, 78%), heterogeneously and mildly echogenic (n = 66, 92%), increased through-transmission (n = 66, 92%) and low echoic rim (n = 48, 67%). Internal debris was seen in 31 cases (43%) and often contained linear echogenic reflections (n = 12, 17%), dark clefts (n = 13, 18%), or a mixture (n = 5, 7%). Most masses showed no Doppler flow (n = 70, 97%). On MR, all cases demonstrated a well-demarcated oval-shaped mass with a surrounding rim. On T1-weighted image (WI), the mass showed slightly high T1 signal in 4/9 (44%) and iso-signal in 5/9 (56%). On T2WI, the mass showed high signal in 6/9 (67%), intermediate in 2/9 (22%), and a target appearance in 1/9 (11%). Internal linear dark T2 signal debris was observed in 4/9 (44%). All lesions showed peripheral rim enhancement without central enhancement.ConclusionsOn US, subcutaneous epidermal inclusion cysts are usually well-circumscribed, oval-shaped, mildly echogenic masses with occasional linear anechoic and/or echogenic reflections, increased through-transmission, hypoechoic rim and no Doppler flow. On MR, an intermediate to high T2 signal mass with occasional low signal debris and no central enhancement can strengthen the diagnosis.

Sonography of fat necrosis involving the extremity and torso with magnetic resonance imaging and histologic correlation.

Objective. The purpose of this study was to describe the sonographic appearance of pathologically proven isolated fat necrosis involving the extremities or torso with magnetic resonance imaging (MRI) correlation. Methods. A query of the Department of Pathology database at our institution for the diagnosis of fat necrosis resulted in 1539 cases. Review of the cases and medical records excluded cases without sonographic imaging, those involving the breast, and those within or adjacent to a primary process, including masses or prior surgery, which resulted in a total of 5 cases of primary fat necrosis, 2 of which were evaluated with MRI. Sonograms were reviewed by 2 musculoskeletal radiologists and characterized with regard to location, echogenicity, shadowing, posterior through‐transmission, a hypoechoic rim or halo, definition of borders, homogeneity, a mass effect, and vascularity. The patient medical records, histologic results, and MRI findings were also reviewed. Results. Of the 5 cases of isolated fat necrosis, 2 involved the torso and 3 the lower extremities. On sonography, all were located in the subcutaneous fat; 2 were isoechoic; 3 were hyperechoic; 2 had a hypoechoic halo; none showed shadowing or posterior through‐transmission; 2 were well defined; 3 were masslike; 4 were heterogeneous; and 2 showed increased flow on color or power Doppler imaging. Magnetic resonance imaging showed an intermediate signal and either diffuse or ring enhancement. Conclusions. Isolated fat necrosis of the extremities and torso had 2 sonographic appearances, which included a well‐defined isoechoic mass with a hypoechoic halo and a poorly defined hyperechoic region in the subcutaneous fat.

Ultrasound and MRI of the peroneal tendons and associated pathology

Lateral ankle pain is common with overuse and sports-related injuries and may cause considerable morbidity. The differential diagnosis of lateral ankle pain is extensive. Disorders of the peroneal tendons should be an important consideration during interpretation of a routine ankle magnetic resonance imaging (MRI) or ultrasound (US). This article presents a review of the common causes of peroneal tendon pathology with particular reference to anatomy, US, and MRI features. The importance of dynamic evaluation with ultrasound is also emphasized.

Ultrasound-Guided Fenestration of Tendons About the Hip and Pelvis Clinical Outcomes

Percutaneous ultrasound‐guided needle fenestration has been used to treat tendinopathy of the elbow, knee, and ankle with promising results. The purpose of this study was to evaluate the clinical outcome of ultrasound‐guided fenestration of tendons about the hip and pelvis.

Sonography of partial-thickness tears of the distal triceps brachii tendon.

The purpose of this study was to retrospectively characterize the sonographic appearance of partial‐thickness distal triceps brachii tendon tears.

Distal Pectoralis Major Tears Sonographic Characterization and Potential Diagnostic Pitfalls

Distinction between musculotendinous tears of the pectoralis major and distal tendon avulsions is important, as the latter typically requires surgical repair. The objective of this study was to characterize the sonographic appearances of surgically proven distal tendon avulsion tears of the pectoralis major.

Sonography of Benign Palpable Masses of the Elbow

The purpose of this pictorial essay is to show the sonographic appearances of benign masses found in and around the elbow, including fat‐containing tumors, fibrous tumors, vascular lesions, selected skin lesions, and other miscellaneous lesions. Sonographic features, including the use of dynamic and color Doppler imaging, can be helpful in characterizing these masses and in narrowing the differential diagnosis.

Ultrasound-Guided Percutaneous Tenotomy

Of the many treatment options for tendinopathy, percutaneous tenotomy has been used throughout the body with success. With this procedure, a needle is repeatedly passed into the abnormal tendon with the goal of converting a chronic degenerative process to an acute inflammatory condition that will progress to tendon healing. Ultrasound guidance for this procedure is essential to ensure that the abnormal region of the tendon is accurately targeted. The treatment has few contraindications, and negligible complications have been described. This article reviews the rationale behind tenotomy for the treatment of tendinopathy and the ultrasound-guided technique. The current literature comparing the results of tenotomy to other percutaneous tendon treatments is also reviewed, although many of the other tendon injection treatments incorporate tenotomy as part of the procedure.

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.