Faculty Bibliography

Lower extremity superficial venous aneurysms are occasionally encountered by clinicians and are almost always located above the knee. Very few cases of aneurysm of the medial marginal vein in the most distal part, near the origin of the great saphenous vein, have been reported. We present a case of partially thrombosed aneurysm of the medial marginal vein, and briefly review the imaging characteristics and treatment options of this entity. Being aware of the existence of superficial venous aneurysms may help clinicians in their differential diagnosis of foot masses and choice of appropriate treatment.

Scapulothoracic pain is a common ailment, but the underlying cause can be difficult to diagnose in a timely manner, and treatment options are limited. We retrospectively review our experience using ultrasound-guided therapeutic scapulothoracic interval steroid injections to treat scapulothoracic pain and review correlative magnetic resonance imaging findings over a 5-year period. Although a variety of structural causes are known to cause scapulothoracic pain, in our experience, most cases lack correlative imaging findings. Ultrasound-guided scapulothoracic interval injections provide a safe, easily performed diagnostic and therapeutic tool for treating patients with periscapular pain, providing at least short-term symptom relief.

Piriformis syndrome is a common cause of lumbar, gluteal, and thigh pain, frequently associated with sciatic nerve symptoms. Potential etiologies include muscle injury or chronic muscle stretching associated with gait disturbances. There is a common pathological end pathway involving hypertrophy, spasm, contracture, inflammation, and scarring of the piriformis muscle, leading to impingement of the sciatic nerve. Ultrasound-guided piriformis injections are frequently used in the treatment of these pain syndromes, with most of the published literature describing injection of the muscle. We describe a safe, effective ultrasound-guided injection technique for the treatment of piriformis syndrome using targeted sciatic perineural hydrodissection followed by therapeutic corticosteroid injection.

Purpose: To better understand alterations in repaired supraspinatus tendons using a multimodality approach including MRI, assessment of tendon vascularity by power Doppler (PD), and tendon mechanical properties using shear wave elastography (SWE). To investigate whether SWE and PD can provide quantitative assessment of tendon healing following rotator cuff repair.
Material(s) and Method(s): This HIPAA compliant prospective study was approved by the institutional review board with informed consent. Between 9/2013 and 6/2016, twelve patients (7 males, 5 females; mean age 61 years) with unilateral full-thickness supraspinatus tendon tears underwent MRI and ultrasound pre-operatively, 3-months and 6-months post-surgery. The supraspinatus tendon MRI signal intensity, PD and SWE properties were measured. Repaired and asymptomatic shoulders were compared over time within and between modalities.
Result(s): No significant association was seen between mean SWE and MRI signal intensity (non-insertional portion -0.25, p=0.467, insertional portion -0.18, p=0.593), or between PD and MRI signal intensity (non-insertional portion -0.19, p=0.599, insertional portion 0.22, p=0.533) within the supraspinatus tendon. MRI signal intensity and PD within the supraspinatus tendon, both increased and then decreased postoperatively. Shear wave velocities increased throughout the postoperative period in the tendon footprint, while increasing and then decreasing in the distal tendon.
Conclusion(s): MRI and ultrasound parameters did not achieve statistically significant correlation; however, their respective trend behavior suggests that a temporal relationship exists between modali ties. We postul a te that a more detai l ed multiparametric imaging approach and/or comparison with a more selective MR measure, such as T2* values, may be required to evaluate rotator cuff repair

OBJECTIVE:The purpose of this study was to describe clinical experience with ultrasound-guided therapeutic procedures and associated pathologic conditions involving the peripheral nerves of the upper extremity over 5 years at a large academic institution. MATERIALS AND METHODS/METHODS:A retrospective database search of procedure codes was performed for all ultrasound-guided upper extremity peripheral nerve procedures between 2012 and 2017. Retrospective review of the electronic medical record for patient demographics, indications, interval follow-up pain relief, and complications was undertaken. Retrospective review of ultrasound and other correlative imaging findings was performed to assess for neural and perineural abnormalities. RESULTS:In total, 242 procedures performed on a cohort of 183 patients (53% women, 47% men; mean age, 53 years; range, 15-97 years) were reviewed. Nine patients underwent multifocal injections in a single encounter, and 39 underwent repeat injections of previously documented symptom generators. Perineural injections included ulnar (n = 109), median (n = 81), posterior interosseous-deep radial (n = 39), sensory branch of the radial (n = 7), anterior interosseous (n = 2), axillary (n = 2), suprascapular (n = 1), and digital (n = 1) nerves. Structural or dynamic abnormality seen either during the procedure or at preprocedural imaging included loss of normal morphologic features (n = 148), nerve subluxation (n = 8), ganglion cyst (n = 4), and neuroma (n = 7). Forty-four patients reported immediate pain relief after the procedure. Of the 89 patients with documented clinical follow-up, 52 reported a period of symptom relief (mean, 125 days), and six reported complete resolution of symptoms. Subsequent surgical procedures were performed on 32 patients, a combination of those who did (n = 12) and did not (n = 20) experience a period of symptom relief from the perineural injection. There were no complications with regard to the site or distribution of perineural injections. Three episodes of vasovagal reaction were reported. CONCLUSION/CONCLUSIONS:Ultrasound-guided percutaneous interventions for upper extremity neural abnormalities can be safely performed for a variety of indications. Real-time ultra-sound evaluation during the procedure allows assessment for neural and perineural abnormalities and tailoring of the procedure to potentially symptomatic structural abnormalities.

Objective: To describe the role of vascularity in assessing bone tendon healing and describe the application of ultrasound contrast agents in quantitative and visual assessment of the vascular following repair with attention to the rotator cuff. Rotator cuff tears are common, having been described in up to 20.7% of the general population and accounting for approximately 75,000 operations in the United States per year. The reported prevalence of failure of rotator cuff repairs has varied in the literature, ranging from 19-94%. Various factors are thought to account for poor healing of the repair, including intrinsic tendon degeneration, fatty infiltration of the muscle and tendon, muscle atrophy, poor bone quality, and weak tendon-to-bone fixation. Experimental studies have shown that bone-tendon healing begins with the formation of fibrovascular scar tissue between the tendon and bone, followed by gradual bone ingrowth into this fibrous interface extending into the native tendon. Tendon repair therefore involves multiple phases: an inflammatory phase, reparative phase and finally remodeling phase. These phases are linked to a variety of growth factors that appear most active in a temporal sequence. Consequently, an area of active investigation is to determine methods to augment bone-tendon and tendon-tendon healing using endogenous growth factors, such as those derived from platelet rich aggregates to promote bone tendon healing. The role of imaging in this scenario is to provide a non-invasive means to potentially determine various phases of healing and to assess the outcomes of either primary repair or interventions meant to augment healing. In the current talk, we briefly describe the sequence of events associated with tendon degeneration, tearing and subsequent bone-tendon healing, following repair. In particular we review the role of contrast enhanced ultrasound in depicting the temporal changes in vascularity following rotator cuff repair.
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Objectives: To describe our experience applying shear wave elastography to the musculoskeletal system, as well as some potential sources of artifact when applying this new technology. Disease states in the musculoskeletal system often manifest as altered tissue morphology evident on conventional gray-scale ultrasound imaging. These states also display other changes, such as altered tissue vascularity and mechanical properties. An example would be the tendon softening associated with tendinosis. US elastography provides a measure of local soft-tissue stiffness by means of mechanical stimulation. Presently, the two most common forms of US elastography measure tissue stiffness and strain by recording (a) how tissues respond to external compression obtained by applying manual pressure (Quasi-static or compression based on response to acoustic radiation force generated by the ultrasound transducer, the latter referred to as Shear-Wave Elastography (SWE). SWE employs a focused acoustic beam generated by the US transducer to compress the underlying tissue, thereby inducing a local shear wave. The speed of that wave, also known as the shear- wave velocity (SWV), is then measured as it propagates through the tissue and displayed as a parametric image or through selective region-of-interest (ROI) analysis, measured in meters per second. SWV provides a quantitative metric of tissue stiffness because it directly relates to the local shear elastic modulus, such that the stiffer the tissue, the greater the SWV. Consequently, some vendors directly display shear wave data as elastic modulus in kilopascals (KPS). In the current discussion, we briefly review some basic principles of shear wave imaging, review some of the common musculoskeletal applications, to date, and describe our experience using SWE in the musculoskeletal system with attention to skeletal muscle and tendons. We review some potential artifacts that the sonographer should be aware of in applying this new technology to tendon and muscle imaging.
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Objective: To describe our experience performing cryoablative procedures for patients with painful peripheral nerve lesions, excluding patients with chronic regional pain syndrome. The real-time nature of ultrasound makes it ideally suited to provide guidance for a variety of musculoskeletal interventional procedures involving peripheral nerves. Continuous observation of the needle ensures proper placement and allows continuous monitoring when performing localized ablative therapy and therefore, more accurate positioning of a cryoprobe, use of smaller needles, as well as access to small structures. In the current talk, we describe our experience performing cryoablative procedures for a variety of painful peripheral nerve lesions. In our experience, patients undergoing cryoneurolysis have reported varying degrees of long-term pain relief and improvement in function; no serious complications have yet been identified. Ultrasound guided cryoneurolysis can provide a useful, safe alternative to other ablative techniques to achieve long-term analgesia. In as much as there is only limited patient outcome data available to date, we present descriptive information as to our current technique with limited patient follow-up. For purposes of the current discussion, we will not include examples of patients with chronic regional pain syndrome as they form a complex group of patients not easily addressed through simple targeted ablative techniques.
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Objective: At the conclusion of this activity, participants will understand the basic principles of MR-US fusion and potential applications to the musculoskeletal system. Development of a simple phantom for training will be described. Examples of injections performed to date will be shown to illustrate potential applications and challenges in obtaining adequate registration. Ultrasound guided injections have become increasing utilized over the past several years. In many instances, these derive from direct referrals following MR or CT. Correspondence of abnormalities seen on cross-sectional imaging, however, may not always be readily evident on ultrasound, Examples would include deep seated abnormalities which are not amenable to high frequency transducers or low contrast lesions on gray-scaleultrasound that are highly conspicuous on MR. MR-US co-registration provides a method to visualize the relevant soft tissue anatomy with greater confidence, while allowing for differences in the image acquisition plane. MR-US fusion has largely been applied to abdominal applications, with relatively few musculoskeletal applications reported to date. The basic requirements of registration include having a representative high-resolution MR (or CT) data set, a method to track the transducer orientation in space (usually through a "Flock of Birds technique"), and the selection of internal fiduciary points common to both data sets (minimally 3 points at different locations). Based on phantom data, accuracies of approximately 5mm or less can be achieved. A brief survey of the technical aspects of co-registration will be discussed, followed by the typical sequence employed to achieve registration with musculoskeletal applications in mind. A series of clinical examples will be presented from therapeutic injections, aspirations or biopsies in the musculoskeletlal system performed at our institution. Use of a relatively simply constructed gelatin phantom will also be described to serve as a potential learning tool to improve individual throughput in the early phase of performing these procedures. The challenges, limitations and potential benefits of using real-time co-registration techniques will be discussed.
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Dancers exert tremendous stresses on the lower extremities rendering them prone to injuries that can curtail training and performance. The goal of this study was to evaluate clinical improvement in a population of elite dancers following treatment with ultrasound-guided platelet-rich plasma (PRP) injections of various lower extremity sites by assessing when they were able to return to dance. Nineteen dancers (13 female, 6 male; ages 15 to 42) were treated between 2009 and 2016 at sites that included: hamstring tendon (1), proximal iliotibial band (1), patellar tendon (3), posterior tibial tendon (5), peroneus brevis tendon (3), plantar fascia (3), and the first metatarsophalangeal (MTP) joint capsule (3). Injections were performed by a single radiologist using the same PRP kit under ultrasound guidance. All patients adhered to standard post-care instructions, including non-weightbearing and avoidance of NSAIDs for at least 2 weeks post-injection. Clinical charts were reviewed for factors including: adherence to post-injection immobilization and physical therapy, physical exam assessments, and milestones in returning to dance. The time-point for returning to dance was defined by attendance of class or rehearsal without symptoms referring to the treated site. Eighteen subjects achieved return to dance, 13 in 6 months or less, and the majority (10) within 3 months of injection. Five subjects required more than 6 months recovery time. These cases all involved foot and ankle sites; of these, two subjects required repeat injections, and both returned to dance within 11 months of the second injection. In the single case where PRP treatment failed, the injury treated was severe plantar fasciopathy with a high-grade central cord tear. It is concluded that ultrasound-guided PRP injections may play a role in the treatment of various lower extremity injuries in elite dancers, with the majority of subjects in this series returning to dance within 6 months. Recovery time may vary depending on the site treated and severity of the presenting injury.