Contrast-enhanced Mammography: How Does It Work?

Contrast-enhanced mammography (CEM) is an imaging technique that uses iodinated contrast medium to improve visualization of breast lesions and assessment of tumor neovascularity. Through modifications in x-ray energy, high- and low-energy images of the breast are combined to highlight areas of contrast medium pooling. The use of contrast material introduces different workflows, artifacts, and risks related to the contrast medium dose. In addition, the need to acquire multiple images in each view introduces different workflows, artifacts, and risks associated with the radiation dose. Although CEM and conventional mammography share many underlying principles, it is important to understand how these two mammographic examinations differ and the mechanisms that facilitate image contrast at CEM. ©RSNA, 2021.

Contact dermatitis from Eriodictyon parryi: a novel cause of contact dermatitis in California.

Allergic contact dermatitis caused by Eriodictyon parryi, better known as poodle-dog bush, is a growing cause of contact dermatitis in California. Blooming after a large fire, E parryi is a threat to reforestation workers as well as countless outdoor enthusiasts across the state. This paper focuses on the epidemiology, identification, immunochemistry, pathophysiology, prevention, and treatment of contact dermatitis from this little-researched plant.

Sonography of the Post-Operative Rotator Cuff: Normal Postoperative Findings, Postsurgical Complications and Common Artifacts.

This review sets forth an approach to performing and interpreting shoulder ultrasound in patients with prior rotator cuff repair and presents a comprehensive review of normal expected findings, postsurgical complications and common artifacts encountered in clinical practice.

Ultrasound-Guided Phrenic Nerve Block for Lung Nodule Biopsy: Single-Center Initial Experience.

RATIONALE AND OBJECTIVES: Biopsy of lung nodules in the lower lung fields can be difficult because of breathing motion. Ipsilateral phrenic nerve block (PNB) before biopsy should make the biopsy safer, easier, and more precisely targeted. We describe the use of ultrasound-guided PNB before lung nodule biopsy, including relevant anatomy and variations, complications, and technique, along with our first 40 cases. MATERIALS AND METHODS: We retrospectively reviewed patients who underwent PNB before computed tomography (CT)- or ultrasound-guided lung nodule biopsy from April 2015 through March 2020. Patient demographics, CT fluoroscopy time, radiation dose, complications, diagnostic yield, and effectiveness of PNB were recorded. Effectiveness of PNB was based on direct observation of diaphragmatic motion. Control group data for biopsies during the same time frame were collected and matched with nodules ≤1 cm from the PNB group. RESULTS: Among 40 patients identified, no complications occurred related to the PNB. Mean (SD) nodule size was 12.4 (6.2) mm. True-positive results were obtained in 39 patients (98%), with 1 false-negative after an ineffective PNB. PNB was effective in 70%. When CT fluoroscopy was used for the biopsy, radiation dose was significantly lower after an effective PNB than an ineffective PNB (p < .001). Effective PNB was significantly more common with injection of ≥4 mL of local anesthetic (p = .01). Comparison with 19 matched controls showed significantly fewer instances of pneumothorax (p = .02) and greater diagnostic success (p = .03) for the PNB group. CONCLUSION: Ultrasound-guided PNB is safe and effective and can improve outcomes when used before lung nodule biopsy.

Inflammatory and infectious aortic diseases.

Aortitis is aortic inflammation, which can be due to inflammatory or infectious diseases. Left undiagnosed, aortitis can lead to aneurysm formation and rupture, in addition to ischemic compromise of major organs. Infectious aortic diseases include mycotic aneurysm and graft infection; the most common inflammatory diseases are Takayasu's and giant cell arteritis. We review the epidemiology, etiology, presentation and diagnosis, and treatment of these entities.

Detection of transplant renal artery stenosis: determining normal velocities at the renal artery anastomosis.

PURPOSE: Renal artery anastomosis peak systolic velocity (RAA PSV) exceeding 250 cm/s and a ratio of the renal artery to the adjacent external iliac artery (RAA:EIA) exceeding 1.8 historically suggest significant transplant renal artery stenosis (TRAS). However, the range of RAA PSV in transplants without TRAS has not been established. METHODS: A retrospective review of renal transplants at a single institution over 5 years was performed identifying patients without graft dysfunction, failure, or refractory hypertension. RAA PSV obtained during interval postoperative sonograms was recorded. RESULTS: Of 1141 patients, 844 met the inclusion criteria. Mean RAA PSV for 377 patients evaluated within 2 days of transplant measured 195 cm/s; RAA PSV exceeded 250 cm/s in 97 patients (26%). Mean RAA PSV for 820 patients evaluated 1-month post-transplant measured 206 cm/s; RAA PSV exceeded 250 cm/s in 224 patients (27%). Mean RAA PSV for 785 patients evaluated 4-month post-transplant measured 203 cm/s; RAA PSV exceeded 250 cm/s in 201 patients (26%). Mean RAA PSV for 766 patients evaluated 1-year post-transplant measured 189 cm/s; RAA PSV exceeded 250 cm/s in 141 patients (18%). At each of the given time points, 24%-34% of normal patients had RAA-to-EIA ratios greater than 1.8. CONCLUSION: Approximately, 26% of patients without TRAS have RAA PSV > 250 cm/s in the first 9 months, and 18% do at 1 year. Similar findings also occurred with regards to the RAA-to-EIA ratio threshold of 1.8. In isolation, a PSV over 250 cm/s or 1.8 ratio threshold for suspicion of TRAS will lead to a large number of false-positive assessments.

Sonographic evaluation of deep endometriosis: protocol for a US radiology practice.

Endometriosis is a common condition with significant morbidity, including pain and subfertility, which is often subject to a delay in diagnosis. Ultrasound has been successfully utilized, mostly outside North America, to preoperatively stage deep endometriosis, but in these international settings, imaging is typically performed solely by expert radiologists and gynecologists. We outline a method for detailed sonographic survey of the lower abdomen and pelvis to ensure optimum detection and communication of disease extent that is geared to radiologists practicing ultrasound in the United States, with the use of diagnostic medical sonographers.