Anterior tibial artery pseudoaneurysm after ankle arthroscopy and Brostrom procedure treated with thrombin injection.

Ankle arthroscopy and the Brostrom procedure are common interventions for ankle instability, but they do carry a risk of vascular injury resulting in a pseudoaneurysm. We present a rare case of anterior tibial artery pseudoaneurysm after ankle arthroscopy and Brostrom procedure treated with direct thrombin injection. A 40-year-old male patient presented with progressive left anterior ankle pain and swelling 5 months after a left ankle arthroscopy and Brostrom procedure. MRI and ultrasound imaging was consistent with anterior tibial artery pseudoaneurysm. He was referred to interventional radiology for treatment. His pseudoaneurysm was successfully treated with an ultrasound guided direct thrombin injection. Several potential treatments are available for treatment of pseudoaneurysms. This includes surgical intervention, endovascular treatment, external compression, and direct thrombin injection. All of these treatment options have been explored in literature. Of these possible treatments, direct thrombin injection has the best combination of efficacy, complication rate, and recurrence rate, which makes it the preferred treatment for a pseudoaneurysm.

A rare case of sino-nasal aneurysmal bone cyst.

Aneurysmal bone cysts (ABC) are rare in the paranasal sinuses. They are benign expansile multicystic masses containing blood-filled spaces which typically occur in the long bones of pediatric patients. The lesion often produces symptoms due to the compression of adjacent structures or pathological fracture and depends on localization. In this case report, we discuss a 28-year-old female who presented with left-sided headache, left eye proptosis, and diplopia. Radiologic evaluation revealed a left paranasal sinus expansile multicystic mass with internal blood fluid levels displacing and thinning the left medial orbital wall which suggested the diagnosis of ABC. Radiologists should be familiar with and comfortable diagnosing ABC in the head and neck, and be able to differentiate this entity from others, such as telangiectatic osteosarcoma. Biopsy can be challenging since blood products may be the only material identified and may produce tissue that is difficult to interpret or misdiagnosed.

Transthoracic Echocardiography: Beginner's Guide with Emphasis on Blind Spots as Identified with CT and MRI.

Transthoracic echocardiography (TTE) is the primary initial imaging modality in cardiac imaging. Advantages include portability, safety, availability, and ability to assess the morphology and physiology of the heart in a noninvasive manner. Because of this, many patients who undergo advanced imaging with CT or MRI will have undergone prior TTE, particularly when cardiac CT angiography or cardiac MRI is performed. In the modern era, the increasing interconnectivity of picture archiving and communication systems (PACS) has made these images more available for comparison. Therefore, radiologists who interpret chest imaging studies should have a basic understanding of TTE, including its strengths and limitations, to make accurate comparisons and assist in rendering a diagnosis or avoiding a misdiagnosis. The authors present the standard TTE views along with multiplanar reformatted CT images for correlation. This is followed by examples of limitations of TTE, focusing on potential blind spots, which have been placed in seven categories on the basis of the structures involved: (a) pericardium (thickening, calcification, effusions, cysts, masses), (b) aorta (dissection, intramural hematoma, penetrating atherosclerotic ulcer), (c) left ventricular apex (infarcts, aneurysms, thrombus, apical hypertrophic cardiomyopathy), (d) cardiac valves (complications of native and prosthetic valves), (e) left atrial appendage (thrombus), (f) coronary arteries (origins, calcifications, fistulas, aneurysms), and (g) extracardiac structures (primary and metastatic masses). Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article . ©RSNA, 2021.

Central skull base osteomyelitis manifesting with a preclival mass and internal carotid artery mycotic aneurysm.

Central skull base osteomyelitis is a rare entity that can demonstrate confounding radiologic, clinical, and laboratory data leading to a delay in diagnosis. The morbidity and mortality for skull base osteomyelitis are both high, thus a rapid diagnosis is required for appropriate treatment. In this case report, we discuss a 68-year-old male who presented with acute left facial nerve paralysis in the setting of chronic headache and left mucoid middle ear effusion. Radiologic evaluation revealed abnormal hypointense marrow of the central skull base on T1 weighted magnetic resonance imaging, preclival mass-like tissue, and short segment luminal narrowing of the left cervical ICA with mycotic aneurysm formation. Extensive workup via a multidisciplinary approach, including neurology, otolaryngology, neurosurgery and radiology led to a diagnosis of central skull base osteomyelitis. A familiarity of this disease process is important for the radiologist in order to facilitate appropriate patient referral and treatment. This case emphasizes the importance of considering this diagnosis in the setting of headache, cranial neuropathy, and abnormal skull base imaging with adjacent preclival soft tissue mass.

Nested stromal epithelial tumor of the liver: A multidisciplinary approach to the treatment of an extremely rare malignancy.

Nested stromal epithelial tumor (NSET) of the liver is an extremely rare and unusual liver neoplasm with limited evidence of best practice for management. We report a 28-year-old male with NSET managed with primary partial hepatectomy with subsequent disease recurrence with follow-up metastectomy and successful radiofrequency ablation (RFA). Management of NSET of the liver requires a multidisciplinary approach. RFA proves beneficial in a patient with disease recurrence following tumor resection. In order to validate the regular use of RFA, more long term studies would be required.

Radiation-induced osteosarcoma following treatment of Ewing's sarcoma.

Radiation-induced sarcomas are a known, rare, complication from prior therapeutic radiation therapy. Radiation-induced sarcomas have been reported to have poor associated prognoses with increased morbidity and mortality when compared to primary sarcomas. In this case report, we discuss a 27-year-old female who presented at the age of 17 during pregnancy with an inability to bear weight and was subsequently diagnosed with Ewing's sarcoma of her femur. Adequate response to treatment was obtained with the initial treatment and the patient represented with acute, severe pain of her femur at the site of prior Ewing's. Extensive workup demonstrated radiation-induced osteosarcoma at the site of her prior Ewing's sarcoma in the radiation field. Multidisciplinary teams including orthopedics, pathology, medical oncology, and radiology are vital for appropriate and efficacious diagnosis of radiation-induced sarcomas. Despite the rarity of radiation-induced sarcoma, the ability to recognize and diagnose recurrent sarcoma is important for radiologists, particularly considering the associated poor prognosis. Early diagnosis and aggressive multidisciplinary treatment is crucial to improving patient morbidity and mortality. In this case, the diagnosis of radiation-induced osteosarcoma allowed expedited workup and initial aggressive, lifesaving treatment for our patient.