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.

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.

Accessory abductor digiti minimi muscle, less muscular than thought: an update on prevalence, morphology, and review of the literature.

OBJECTIVE: To update the prevalence and morphology of the accessory abductor digiti minimi muscle using 3T MRI. MATERIALS AND METHODS: A retrospective study of 3T wrist MRI was performed. Presence and morphology of the accessory abductor digiti minimi were evaluated in addition to its relationship to the ulnar nerve. Charts were reviewed for demographics, EMG, neuropathic symptoms, and initial MRI interpretation. RESULTS: Analysis of 396 wrist MRI studies yielded 25% prevalence of the accessory abductor digiti minimi, of which the majority (69%) demonstrated fascial-type morphology proximal to Guyon's canal. A minority (31%) demonstrated a contiguous muscle belly throughout its course. Overall, prevalence of a muscular type was only 8%. All patients were asymptomatic with normal EMG, unremarkable ulnar nerve, and no significant nerve compression. Anterior-posterior muscle dimension was larger in males. Only 1 of 98 accessory abductor digiti minimi muscles was prospectively identified. CONCLUSION: The accessory abductor digiti minimi is not uncommon; however, patients are usually asymptomatic without neuropathic symptoms. The most common anatomic variant is a small muscle belly at the level of the pisiform with fascial morphology proximal to Guyon's canal and origin from the distal antebrachial fascia. A contiguous muscle belly extending from the distal forearm through the wrist occurs much less frequently. Clinicians should be familiar with these anatomic variants to enhance its recognition, understanding that a muscular variant is rarer than previously reported, but historically can serve as a potential source of clinical symptomatology and could be encountered during physical examination or wrist surgery.

The pediatric accessory sacroiliac joint: does it exist?

OBJECTIVE: Determine the prevalence of the accessory sacroiliac joint in the pediatric population and describe variant sacroiliac joint morphology that may predispose patients to the development of an accessory sacroiliac joint. MATERIALS AND METHODS: One hundred and seventy-eight high-resolution pelvic CT scans of patients aged 0 to 15 years were reviewed for the presence of an accessory sacroiliac joint. Patients were stratified based on age and gender. Morphology of the sacroiliac joints was detailed to assess the degree of curvature in the expected characteristic location of the accessory sacroiliac joint. RESULTS: No accessory sacroiliac joint was identified on any of the pediatric pelvic CT scans. The sacroiliac joints demonstrated varying degrees of unilateral or bilateral curvature in the expected region of the accessory sacroiliac joint which increased in both severity and prevalence with age. CONCLUSION: The pediatric accessory sacroiliac joint may not exist and is unlikely to be a congenital variant present at birth. However, curvature of the sacroiliac joint in the expected location of the accessory sacroiliac joint which increases in severity and prevalence with age may predispose patients to the formation of an accessory sacroiliac joint later in life.

Incidental bifid median nerve with a wandering ulnar division separated by the third flexor digitorum superficialis muscle: importance of ultrasound evaluation.

Ultrasound evaluation of the median nerve is commonly performed in patients with suspected carpal tunnel syndrome. Radiologists should be familiar with variant anatomy of the median nerve to assist clinicians in the management of these patients, particularly when surgery is being considered. A 63-year-old female was being evaluated for a ganglion cyst and was incidentally found to have a bifid median nerve with wandering ulnar division which coursed superficial to the third digit flexor digitorum superficialis (FDS) muscle belly. The patient did not have any symptoms of carpal tunnel syndrome so surgery has not been performed; however this case highlights the importance of ultrasound evaluation to avoid potential perioperative complications.

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.

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.

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.

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.

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.

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%.

"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.

Vascular expression, activity and function of indoleamine 2,3-dioxygenase-1 following cerebral ischaemia-reperfusion in mice.

Indoleamine 2,3-dioxygenases-1 (Ido1) and -2 initiate the kynurenine pathway of tryptophan metabolism. In addition to the established immune regulatory effects of Ido1 and the ability of nitric oxide to regulate Ido1 activity, it is now also known that Ido1-mediated metabolism of tryptophan to kynurenine can modulate vascular tone. Ido activity is reportedly elevated in stroke patients and correlates with increased risk of death. Thus, the present goals were to test whether, following cerebral ischaemia, Ido activity and cerebrovascular Ido1 expression are altered and whether expression of Ido1 contributes to stroke outcome. Transient cerebral ischaemia was induced in wild-type and Ido1 gene-deficient (Ido1 (-/-)) mice. Mice were pre-treated with vehicle, the Ido1 inhibitor, 1-methyl-D-tryptophan (1-MT; 50 mg/kg i.p.) or the inducible nitric oxide synthase (Nos2) inhibitor, aminoguanidine (AG, 100 mg/kg i.p.). At 24 h, neurological function, brain infarct size and swelling were assessed. In addition, Ido activity was estimated by plasma kynurenine and tryptophan, and Ido1 expression was examined in cerebral arterioles. Cerebral ischaemia-reperfusion in wild-type mice increased Ido activity and its expression in cerebral arterioles. Ido1 (-/-) and 1-MT-treated wild-type mice had lower Ido activity but similar post-stroke neurological function and similar total brain infarct volume and swelling, relative to control mice. Inhibition of Nos2 with AG also did not affect Ido activity or outcome following stroke. This study provides molecular and pharmacological evidence that the expression and the activity of Ido1 increase following stroke. However, such Ido1 expression does not appear to affect overall outcome following acute ischaemic stroke, and furthermore, a regulatory role of Nos2-derived nitric oxide on Ido activity following cerebral ischaemia-reperfusion appears unlikely.

Tube thoracostomy: a review for the interventional radiologist.

Small-caliber tube thoracostomy is a valuable treatment for various pathologic conditions of the pleural space. Smaller caliber tubes placed under image guidance are becoming increasingly useful in numerous situations, are less painful than larger surgical tubes, and provide more accurate positioning when compared with tubes placed without image guidance. Basic anatomy and physiology of the pleural space, indications, and contraindications of small caliber tube thoracostomy, techniques for image-guided placement, complications and management of tube thoracostomy, and fundamental principles of pleurodesis are discussed in this review.

Kynurenine is an endothelium-derived relaxing factor produced during inflammation.

Control of blood vessel tone is central to vascular homeostasis. Here we show that metabolism of tryptophan to kynurenine by indoleamine 2,3-dioxygenase (Ido) expressed in endothelial cells contributes to arterial vessel relaxation and the control of blood pressure. Infection of mice with malarial parasites (Plasmodium berghei) or induction of endotoxemia in mice led to endothelial expression of Ido, decreased plasma tryptophan concentration, increased kynurenine concentration and hypotension. Pharmacological inhibition of Ido increased blood pressure in systemically inflamed mice but not in mice deficient in Ido or interferon-gamma, which is required for Ido induction. Both tryptophan and kynurenine dilated preconstricted porcine coronary arteries; the dilating effect of tryptophan required the presence of active Ido and an intact endothelium, whereas the effect of kynurenine was endothelium independent. The arterial relaxation induced by kynurenine was mediated by activation of the adenylate and soluble guanylate cyclase pathways. Kynurenine administration decreased blood pressure in a dose-dependent manner in spontaneously hypertensive rats. Our results identify tryptophan metabolism by Ido as a new pathway contributing to the regulation of vascular tone.

Sutureless nerve repair with laser-activated chitosan adhesive: a pilot in vivo study.

OBJECTIVE: The anastomosis of peripheral nerves is a demanding procedure that has potential complications due to foreign body reactions elicited by sutures. In this study, the sutureless in vivo anastomosis of rat tibial nerves was successfully performed, using for the first time a chitosan-based laser-activated adhesive. The nerve thermal damage caused by the laser irradiation was quantitatively assessed. MATERIALS AND METHODS: A novel adhesive composed of chitosan, indocyanine green, acetic acid, and water, was fabricated in thin sheets. Its adhesive strength was tested in vitro by bonding strips (surface area approximately 20 mm2, thickness approximately 20 microm) onto rat sciatic nerves and sheep intestine by laser activation with low fluence ( approximately 50 J/cm2), using a fiber-coupled diode laser (n = 13). The tensile strength of the adhesive/tissue bonds was measured after tissue repair. The chitosan adhesive was then used to perform sutureless anastomosis of tibial nerves in vivo (n = 6). Adhesive strips were also bonded in vivo onto intact rat sciatic nerves (n = 6) in order to quantitatively assess, by counting myelinated axons, the thermal damage induced by the laser. RESULTS: The adhesive bonded well to tissue with a tensile strength of 12.5 +/- 2.6 KPa (mean +/- SD; n = 13). The in vivo anastomosed nerves were in continuity 3 d after surgery. Axon counting showed the number and morphology of myelinated axons were normal proximally ( approximately 96%) compared with intact nerves (100%). Axon demyelination was observed at the operation site ( approximately 49%) and distally ( approximately 27%), and was attributed to laser-induced thermal damage. CONCLUSIONS: Nerve anastomosis, performed by the laser-adhesive procedure, was successful 3 d postoperatively. Proximal myelinated axons were not significantly damaged by the low laser fluence.

Ruminative Responses to Negative and Positive Affect Among Students Diagnosed with Bipolar Disorder and Major Depressive Disorder.

Rumination in response to negative affect has been found to predict the onset, severity, and duration of depressive symptoms. Few researchers, however, have considered rumination within bipolar disorder, nor have studies considered parallel responses that might intensify positive affect. The current study examined self-reported rumination in response to both negative and positive affect among people diagnosed via the SCID with BPD (n = 28), major depressive disorder (MDD; n = 35), or no mood disorder (n = 44). Participants completed the Ruminative Response Scale and the Responses to Positive Affect Questionnaire about their dispositional tendencies. Results indicated that compared to control participants, people with BPD and MDD endorsed heightened rumination in response to negative affect, but only those with BPD endorsed elevated rumination in response to positive affect. Within BPD, ruminative responses to negative affect were explained by depressive symptoms. Goals for understanding responses to negative and positive affect in BPD are suggested.