Magnetic Resonance Imaging Assessment of Ulnar Wrist Pain: A Practical Guide for Surgeons.

Ulnar-sided wrist pain is a challenging clinical scenario due to multiple overlapping pathologies and involved anatomic structures. Advanced imaging such as magnetic resonance imaging can be used as an effective diagnostic adjunct if interpreted correctly. In this article, clinically relevant structures and radiographic correlates of the ulnar wrist are discussed and a corresponding systematic approach to reviewing magnetic resonance imaging is presented.

Prevalence of accessory sacroiliac joint anatomy and associated clinical features.

OBJECTIVE: The accessory sacroiliac joint (ASIJ) is the most common sacroiliac joint anatomical variant; however, its literature-reported prevalence is inconsistent. Previous CT-based studies of the ASIJ have used thick axial slices, which may not adequately detail ASIJ anatomy. The aims of this study are to (1) evaluate ASIJ prevalence and radiographic features in a large age- and sex-balanced cohort using thin-section CT and (2) determine associations between ASIJ anatomy, patient features, and treatment strategies. MATERIALS AND METHODS: Thin-section CTs (0.75 to 2.00 mm) of the pelvis from 800 patients were reviewed by two musculoskeletal radiologists. Degree of degenerative change and ankylosis at ASIJs were detailed. The EMR was used to capture demographics, lower back or sacroiliac joint symptoms, and treatments. RESULTS: The ASIJ was present in 25.8% of patients and bilateral in 53.3% of those with any ASIJ. ASIJs were more common at the S2 than S1 neural foramen level (75.7% and 27.2%). There was a statistically significant difference between age and presence of any ASIJ anatomy (mean (SD) 69.0 (19.8) with ASIJ versus 55.9 (22.1) years without ASIJ). Degenerative changes and ankylosis were found in 93.5% and 20.3% of ASIJs, respectively. There was a higher odds ratio of having received a sacroiliac joint corticosteroid injection in those with ASIJ anatomy. CONCLUSION: Radiologists should be familiar with the ASIJ and consider its age-related association, propensity to show ASIJ degenerative change, and ability to serve as a potential pain generator. Steroid injections may be considered for diagnostic and therapeutic purposes.

Multicentric reticulohistiocytosis: the Mayo Clinic experience (1980-2017).

OBJECTIVES: Multicentric reticulohistiocytosis (MRH), a rare histiocytic disease that can mimic other rheumatic conditions, may be associated with cancer and other autoimmune disorders. To better understand the disorder and its other associations, we aimed to evaluate clinical correlates and outcomes of all patients with MRH seen at Mayo Clinic, Rochester between 1980 and 2017. METHODS: A retrospective medical record review was conducted to identify all patients with MRH between 1 January 1980 and 30 April 2017. RESULTS: We identified 24 patients with biopsy-proven MRH (58% female, 75% Caucasian, median age at diagnosis 52 years, median follow-up of 2.3 years). All patients had cutaneous and articular involvement; 23 (96%) patients had papulonodular skin lesions (87% periungual and dorsal hand) and seven (30%) mucosal nodules; and 22 (92%) patients had arthralgias, 21 (88%) joint effusions and 13 (54%) synovitis. Most frequently used therapies included corticosteroids, cyclophosphamide, methotrexate and bisphosphonates. Biologics were used in four patients. Nine patients had symptomatic resolution at 1 year and 12 partial improvement. Radiological findings included erosive changes in three (60%) patients and arthritis mutilans in two patients (40%). Twenty-nine per cent of patients had a concomitant autoimmune disease and 25% malignancy including melanoma, endometrial, peritoneal and lung carcinoma. The 5-year survival rate was 85% (95% CI: 74, 100%). CONCLUSION: To our knowledge, this is the largest single-centre series of patients with MRH highlighting the rarity of the condition and an unmet need for treatment options that can allow sustained disease remission. It also highlights the need for a high vigilance for malignancy and autoimmune diseases.

Ultrasonography of Plantar Fibromatosis: Updated Case Series, Review of the Literature, and a Novel Descriptive Appearance Termed the "Comb Sign".

The purpose of this series is to review the appearance of plantar fibromatosis with high-resolution ultrasonography (US) and highlight a new imaging sign termed the "comb sign." A retrospective study was performed for patients with a clinical diagnosis of plantar fibromatosis. Charts of 43 patients (age range, 26-77 years; mean age, 54 years) were reviewed to gather patient demographics and symptoms. Several US characteristics were evaluated with emphasis on any new imaging features. A total of 57 plantar fibromas in 43 patients were examined. Plantar fibromatosis was seen as a lobular marginated oval nodule along the superficial plantar fascia involving the central or medial cord, often at the middle third (84%) of the plantar fascia, showing posterior acoustic enhancement (65%), mixed echogenicity (82%), and intralesional vascularity (53%). Slightly more than half (51%) of the lesions showed a previously unrecognized appearance, designated the comb sign. This sign was more commonly seen in the setting of larger fibromas (P < .05). Plantar fibromatosis is usually a clinical diagnosis that can be aided by a typical US appearance. Although the imaging characteristics are largely similar to prior literature, this series suggests that most show mixed echogenicity and posterior acoustic enhancement, and approximately half show internal vascularity. A new US sign, termed the comb sign, shows alternating bands of hypoechogenicity and isoechogenicity, particularly in larger plantar fibromas, and can help in further characterization.

MRI of pathology-proven peripheral nerve amyloidosis.

OBJECTIVE: To highlight the MRI characteristics of pathologically proven amyloidosis involving the peripheral nervous system (PNS) and determine the utility of MRI in directing targeted biopsy for aiding diagnosis. MATERIALS AND METHODS: A retrospective study was performed for patients with pathologically proven PNS amyloidosis who also underwent MRI of the biopsied or excised nerve. MRI signal characteristics, nerve morphology, associated muscular denervation changes, and the presence of multifocal involvement were detailed. Pathology reports were reviewed to determine subtypes of amyloid. Charts were reviewed to gather patient demographics, neurological symptoms and radiologist interpretation. RESULTS: Four men and three women with a mean age of 62 ± 11 years (range 46-76) were identified. All patients had abnormal findings on EMG with mixed sensorimotor neuropathy. All lesions demonstrated diffuse multifocal neural involvement with T1 hypointensity, T2 hyperintensity, and variable enhancement on MRI. One lesion exhibited superimposed T2 hypointensity. Six of seven patients demonstrated associated muscular denervation changes. CONCLUSION: Peripheral nerve amyloidosis is rare, and the diagnosis is difficult because of insidious symptom onset, mixed sensorimotor neurologic deficits, and the potential for a wide variety of nerves affected. On MRI, peripheral nerve involvement is most commonly characterized by T1 hypointensity, T2 hyperintensity, variable enhancement, maintenance of the fascicular architecture with fusiform enlargement, multifocal involvement and muscular denervation changes. While this appearance mimics other inflammatory neuropathies, MRI can readily detect neural changes and direct-targeted biopsy, thus facilitating early diagnosis and appropriate management.

Voriconazole-induced periostitis: beyond post-transplant patients.

Voriconazole-induced periostitis (VIP) is a rare but increasingly encountered entity since Food and Drug Administration (FDA) approval of the second generation antifungal medication in 2002. Literature reports most commonly include transplant recipients on immunosuppressive therapy simultaneously requiring antifungal therapy. Nontransplant patients receiving long-term voriconazole have an equal risk of developing the disease, but may experience a delay in diagnosis due to a lack of familiarity with the process outside of the post-transplant and/or immunosuppressed population. We present a case of VIP in a nontransplant, immunocompetent patient on suppressive antifungal therapy for prior abdominal aortic stent graft fungal infection. Radiologist review of current medications and recognition of periostitis on multiple imaging modalities may hasten the diagnosis and lead to earlier treatment and resolution of symptoms.

CT characteristics of Morel-Lavallée lesions: an under-recognized but significant finding in acute trauma imaging.

OBJECTIVE: To highlight the significance and imaging characteristics of Morel-Lavallée (ML) lesions, which have been well characterized on MRI, but are potentially under-recognized on CT. MATERIALS AND METHODS: Twenty-eight Morel-Lavallée lesions were identified in 18 patients and were all clinically or surgically confirmed. Lesions were grouped into acute (<3 days), subacute (3-30 days), and chronic (>30 days) at the time of CT imaging. Charts were reviewed to gather patient characteristics, injury patterns, radiologist interpretation, treatment, and outcomes. RESULTS: Sixteen male and 2 female patients with a mean age of 50 years (range 19-80) at the date of their initial evaluation were identified. All patients had significant trauma that accounted for 28 ML lesions, all of which were in a characteristic subcutaneous location overlying the muscular fascial plane. Lesions on CT went through an evolution from hyperdense, poorly or moderately marginated without a pseudocapsule to being hypodense, with internal fat globules or septations and well marginated with a complete enhancing pseudocapsule. Only 1 (4 %) of the ML lesions was suggested and 7 (25 %) lesions were not commented on at all by the interpreting radiologist. CONCLUSION: Morel-Lavallée lesions are post-traumatic closed, internal, soft-tissue, degloving lesions that are potentially underrecognized on CT. Most acute ML lesions are nonspecific, resembling simple hematomas or contusions. ML lesions evolve as they age with subacute and chronic lesions demonstrating the known features described on MR imaging that should allow for an accurate imaging diagnosis.

Renal artery fibromuscular dysplasia in 2,640 renal donor subjects: a CT angiography analysis.

PURPOSE: To present the incidence, demographics, and clinical presentation of patients diagnosed with renal fibromuscular dysplasia (FMD) who underwent computed tomography (CT) angiography for evaluation of living renal donor protocol. METHODS AND MATERIALS: A retrospective review was performed from January 1, 2000, to December 31, 2011 on patients who underwent CT angiography for evaluation of living renal donor protocol. Of 2,640 patients identified, only patients with a diagnosis of FMD by the radiology report underwent independent reader evaluation of CT angiography for the presence of FMD and associated characteristics. The demographics, medical history, and presentation were reviewed using the electronic medical chart. RESULTS: The independent readers who evaluated CT angiography identified a diagnosis of FMD in 68 patients (2.6%; 59 female) with an average age of 52 years ± 10. Unilateral FMD was observed in 46 patients (68%), and bilateral FMD was observed in 22 patients (32%). Three patients had aneurysms of the renal artery. Comorbidities included hypertension (n = 21, 31%), dyslipidemia, (n = 13, 19%), history of migraines (n = 3, 4%), and history of smoking (n = 14, 21%). No patients had diabetes mellitus, coronary artery disease, or family history of FMD. Of 21 patients (31%) with a history of hypertension, 13 patients (62%) were treated with antihypertensive medications. CONCLUSIONS: The incidence of FMD in patients who underwent CT angiography for evaluation of living renal donor protocol is 2.6%.

Impact of flow pattern, body mass index, and age on intraprocedural fluoroscopic time and radiation dose during sacroiliac joint injections.

PURPOSE: Understanding all factors that may impact radiation dose and procedural time is crucial to safe and efficient image-guided interventions, such as fluoroscopically guided sacroiliac (SI) joint injections. The purpose of this study was to evaluate the effect of flow pattern (intra- vs. periarticular), patient age, and body mass index (BMI) on radiation dose and fluoroscopy time. METHODS: A total of 134 SI joint injections were reviewed. Injectate flow pattern, age, and BMI were analyzed in respect to fluoroscopy time (minutes), radiation dose (kerma area product (KAP); µGy m2), and estimated skin dose (mGy). RESULTS: BMI did not affect fluoroscopy time, but increased BMI resulted in significantly higher skin and fluoroscopy doses (p < 0.001). There was no association between fluoroscopy time and flow pattern. Higher skin dose was associated with intraarticular flow (p = 0.0086), and higher KAP was associated with periarticular flow (p = 0.0128). However, the odds ratios were close to 1. There was no significant difference between fluoroscopy time or dose based on patient age. CONCLUSION: Increased BMI had the largest impact on procedural radiation dose and skin dose. Flow pattern also showed a statistically significant association with radiation dose and skin dose, but the clinical difference was small. Proceduralists should be aware that BMI has the greatest impact on fluoroscopy dose and skin dose during SI joint injections compared to other factors.

Sonography of active rheumatoid arthritis during pregnancy: a case report and literature review.

Disease activity in rheumatoid arthritis usually subsides in pregnancy, however a subset of patients have worsened symptoms with joint pain and swelling. Monitoring and mitigating disease activity in pregnancy is important for preventing deforming structural changes which can affect the ability of the patient to care for themselves and the newborn. Ultrasound is a safe and low-cost imaging modality for detecting active changes from an inflammatory arthritis, which can help guide management. We describe a case of an acute disease flare during pregnancy, readily detected with ultrasound, and present a review of sonographic evaluation of rheumatoid arthritis in pregnancy.

"The flipping bullet" with associated intramedullary dystrophic calcification: an unusual cause for migratory myelopathy and radiculopathy.

We report the case of a 24 year old male who had a retained bullet within his thoracic spine from a gunshot wound resulting in paraplegia. After 7 months he began experiencing painful dysesthesias at his sensory level. Repeat imaging demonstrated migration of the bullet as well as the development of intramedullary dystrophic calcification associated with the bullet. This case demonstrates not only the ability for retained bullets to migrate within the spinal canal but also demonstrates they can lead to remote symptoms due to the development of dystrophic calcification.