Consensus report from the 9th International Forum for Liver Magnetic Resonance Imaging: applications of gadoxetic acid-enhanced imaging

Objectives The 9th International Forum for Liver Magnetic Resonance Imaging (MRI) was held in Singapore in September 2019, bringing together radiologists and allied specialists to discuss the latest developments in and formulate consensus statements for liver MRI, including the applications of gadoxetic acid-enhanced imaging. Methods As at previous Liver Forums, the meeting was held over 2 days. Presentations by the faculty on days 1 and 2 and breakout group discussions on day 1 were followed by delegate voting on consensus statements presented on day 2. Presentations and discussions centered on two main meeting themes relating to the use of gadoxetic acid-enhanced MRI in primary liver cancer and metastatic liver disease. Results and conclusions Gadoxetic acid-enhanced MRI offers the ability to monitor response to systemic therapy and to assist in pre-surgical/pre-interventional planning in liver metastases. In hepatocellular carcinoma, gadoxetic acid-enhanced MRI provides precise staging information for accurate treatment decision-making and follow-up post therapy. Gadoxetic acid-enhanced MRI also has potential, currently investigational, indications for the functional assessment of the liver and the biliary system. Additional voting sessions at the Liver Forum debated the role of multidisciplinary care in the management of patients with liver disease, evidence to support the use of abbreviated imaging protocols, and the importance of standardizing nomenclature in international guidelines in order to increase the sharing of scientific data and improve the communication between centers

Functional Adrenal Collision Tumor in a Patient with Cushing's Syndrome.

Adrenal collision tumors are rare and produce unique diagnostic challenges for clinicians. We report the case of a 45-year-old woman with obesity and diabetes mellitus and an incidentally-discovered adrenal mass containing macroscopic fat, thought to be a myelolipoma. A functional workup confirmed adrenocorticotropic hormone- (ACTH-) independent Cushing's syndrome. The patient underwent a successful laparoscopic adrenalectomy with pathology showing an adrenal collision tumor consisting of an adrenocortical adenoma and a myelolipoma. Postoperatively, the clinical symptoms, body mass index, and hemoglobin A1C all improved. Clinicians should consider a functional workup in patients with radiographically diagnosed myelolipomas as some may prove to be hormonally active collision tumors

Functional Adrenal Collision Tumor in a Patient with Cushing’s Syndrome

Adrenal collision tumors are rare and produce unique diagnostic challenges for clinicians. We report the case of a 45-year-old woman with obesity and diabetes mellitus and an incidentally-discovered adrenal mass containing macroscopic fat, thought to be a myelolipoma. A functional workup confirmed adrenocorticotropic hormone- (ACTH-) independent Cushing’s syndrome. The patient underwent a successful laparoscopic adrenalectomy with pathology showing an adrenal collision tumor consisting of an adrenocortical adenoma and a myelolipoma. Postoperatively, the clinical symptoms, body mass index, and hemoglobin A1C all improved. Clinicians should consider a functional workup in patients with radiographically diagnosed myelolipomas as some may prove to be hormonally active collision tumors

MR Angiography of Renal Transplant Vasculature with Ferumoxytol: Comparison of High-Resolution Steady-State and First-Pass Acquisitions

Rationale and objectivesThis work aimed to quantify the differences in signal-to-noise ratio (SNR) and vessel sharpness between steady-state and first-pass magnetic resonance angiography (MRA) with ferumoxytol in renal transplant recipients.Materials and methodsWe performed a retrospective study of adult patients who underwent steady-state and first-pass MRA with ferumoxytol to evaluate renal transplant vasculature. SNR was calculated in the external iliac artery, and vessel sharpness was calculated in the external iliac and renal transplant arteries for both acquisitions. Data were compared using Student's t test.ResultsFifteen patients were included (mean age 56.9 years, 10 males). The mean SNR of the external iliac artery was 42.2 (SD, 11.9) for the first-pass MRA and 41.8 (SD, 9.7) for the steady-state MRA (p = 0.92). The mean vessel sharpness was significantly higher for the steady-state MRA compared to first-pass MRA for both external iliac (1.24 vs. 0.80 mm(-1), p < 0.01) and renal transplant arteries (1.26 vs. 0.79 mm(-1), p < 0.01).ConclusionSteady-state MRA using ferumoxytol improves vessel sharpness while maintaining equivalent SNR compared to conventional first-pass MRA in renal transplant patients

Variability in personal protective equipment in cross-sectional interventional abdominal radiology practices.

PURPOSE: To determine institutional practice requirements for personal protective equipment (PPE) in cross-sectional interventional radiology (CSIR) procedures among a variety of radiology practices in the USA and Canada. METHODS: Members of the Society of Abdominal Radiology (SAR) CSIR Emerging Technology Commission (ETC) were sent an eight-question survey about what PPE they were required to use during common CSIR procedures: paracentesis, thoracentesis, thyroid fine needle aspiration (FNA), superficial lymph node biopsy, deep lymph node biopsy, solid organ biopsy, and ablation. Types of PPE evaluated were sterile gloves, surgical masks, gowns, surgical hats, eye shields, foot covers, and scrubs. RESULTS: 26/38 surveys were completed by respondents at 20/22 (91%) institutions. The most common PPE was sterile gloves, required by 20/20 (100%) institutions for every procedure. The second most common PPE was masks, required by 14/20 (70%) institutions for superficial and deep procedures and 12/12 (100%) institutions for ablation. Scrubs, sterile gowns, eye shields, and surgical hats were required at nearly all institutions for ablation, whereas approximately half of institutions required their use for deep lymph node and solid organ biopsy. Compared with other types of PPE, required mask and eye shield use showed the greatest increase during the SARS-CoV-2 pandemic. CONCLUSION: PPE use during common cross-sectional procedures is widely variable. Given the environmental and financial impact and lack of consensus practice, further studies examining the appropriate level of PPE are needed

CAN THE AMERICAN THYROID ASSOCIATION, K-TIRADS AND ACR-TIRADS ULTRASOUND CLASSIFICATION SYSTEMS BE USED TO PREDICT MALIGNANCY IN BETHESDA CATEGORY IV NODULES?

Objective: Management of thyroid nodules with Bethesda Category III and IV cytology on fine needle aspiration (FNA) is challenging as they cannot be adequately classified as benign or malignant. Ultrasound (US) patterns have demonstrated utility in evaluating the risk of malignancy (ROM) of Bethesda Category III nodules. This study aims to evaluate the value of three well established US grading systems (ATA, Korean-TIRADS, and ACR-TIRADS) in determining ROM in Bethesda Category IV nodules. Methods: 92 patients with 92 surgically resected thyroid nodules who had Bethesda Category IV cytology on FNA were identified. Nodule images were retrospectively graded using the three systems in a blinded manner. Associations between US risk category and malignant pathology for each system were analyzed. Results: Of the 92 nodules, 56 (61%) were benign and 36 (39%) were malignant. 47% of ATA high risk nodules, 53% of K-TIRADS category 5 nodules, and 50% of ACR-TIRADS category 5 nodules were malignant. The ATA high-risk category had 25% sensitivity, 82% specificity, 47% PPV for malignancy. K-TIRADS category 5 had 25% sensitivity, 85% specificity, 53% PPV for malignancy. ACR-TIRADS category 5 had 25% sensitivity, 84% specificity, 50% PPV for malignancy. None of the three grading systems yielded statistically significant correlation between US risk category and the ROM (p =0.30, 0.72, 0.28). Conclusion: The ATA, Korean-TIRADS, and ACR-TIRADS classification systems are not helpful in stratifying ROM in patients with Bethesda Category IV nodules. Clinicians should be cautious of using ultrasound alone when deciding between therapeutic options for patients with Bethesda Category IV thyroid nodules

Contemporary and Emerging MRI Strategies for Assessing Kidney Allograft Complications: Arterial Stenosis and Parenchymal Injury, From the AJR Special Series on Imaging of Fibrosis.

MRI plays an important role in the evaluation of kidney allografts for vascular complications as well as parenchymal insults. Transplant renal artery stenosis, the most common vascular complication of kidney transplant, can be evaluated by MRA using gadolinium and nongadolinium contrast agents as well as by unenhanced MRA techniques. Parenchymal injury occurs through a variety of pathways, including graft rejection, acute tubular injury, BK polyomavirus infection, drug-induced interstitial nephritis, and pyelonephritis. Investigational MRI techniques have sought to differentiate among these causes of dysfunction as well as to assess the degree of interstitial fibrosis or tubular atrophy (IFTA)-the common end pathway for all of these processes-which is currently evaluated by invasively obtained core biopsies. Some of these MRI sequences have shown promise in not only assessing the cause of parenchymal injury but also assessing IFTA noninvasively. This review describes current clinically used MRI techniques and previews promising investigational MRI techniques for assessing complications of kidney grafts

JOURNAL CLUB: Quantification of Fetal Dose Reduction if Abdominal CT Is Limited to the Top of the Iliac Crests in Pregnant Patients With Trauma

OBJECTIVE: The purposes of this study were to correlate fetal z-axis location within the maternal abdomen on CT with gestational age and estimate fetal dose reduction of a study limited to the abdomen only, with its lower aspect at the top of the iliac crests, compared with full abdominopelvic CT in pregnant trauma patients. MATERIALS AND METHODS: We performed a study of pregnant patients who underwent CT of the abdomen and pelvis for trauma at a single institution over a 10-year period. The inferior aspect of maternal liver, spleen, gallbladder, pancreas, adrenals, and kidneys was recorded as above or below the iliac crests. The distance from the iliac crest to the top of the fetus or gestational sac was determined. The CT images of the limited and full scanning studies were independently reviewed by two blinded radiologists to identify traumatic injuries. Fetal dose profiles, including both scatter and primary radiation, were computed analytically along the central axis of the patient to estimate fetal dose reduction. Linear regression analysis was performed between gestational age and distance of the fetus to the iliac crests. RESULTS: Thirty-five patients were included (mean age, 26.2 years). Gestational age ranged from 5 to 38 weeks, with 5, 19, and 11 gestations in the first, second, and third trimesters, respectively. All solid organs were above the iliac crests in all patients. In three of six patients, traumatic findings in the pelvis would have been missed with the limited study. There was high correlation between gestational age and distance of the fetus to the iliac crests (R(2) = 0.84). The mean gestational age at which the top of the fetus was at the iliac crest was 17.3 weeks. Using the limited scanning study, fetuses at 5, 20, and 40 weeks of gestation would receive an estimated 4.3%, 26.2%, and 59.9% of the dose, respectively, compared with the dose for the full scanning study. CONCLUSION: In pregnant patients in our series with a history of trauma, CT of the abdomen only was an effective technique to reduce fetal radiation exposure compared with full abdomen and pelvis CT

JOURNAL CLUB: Quantification of Fetal Dose Reduction if Abdominal CT Is Limited to the Top of the Iliac Crests in Pregnant Patients With Trauma.

ObjectiveThe purposes of this study were to correlate fetal z-axis location within the maternal abdomen on CT with gestational age and estimate fetal dose reduction of a study limited to the abdomen only, with its lower aspect at the top of the iliac crests, compared with full abdominopelvic CT in pregnant trauma patients.Materials and methodsWe performed a study of pregnant patients who underwent CT of the abdomen and pelvis for trauma at a single institution over a 10-year period. The inferior aspect of maternal liver, spleen, gallbladder, pancreas, adrenals, and kidneys was recorded as above or below the iliac crests. The distance from the iliac crest to the top of the fetus or gestational sac was determined. The CT images of the limited and full scanning studies were independently reviewed by two blinded radiologists to identify traumatic injuries. Fetal dose profiles, including both scatter and primary radiation, were computed analytically along the central axis of the patient to estimate fetal dose reduction. Linear regression analysis was performed between gestational age and distance of the fetus to the iliac crests.ResultsThirty-five patients were included (mean age, 26.2 years). Gestational age ranged from 5 to 38 weeks, with 5, 19, and 11 gestations in the first, second, and third trimesters, respectively. All solid organs were above the iliac crests in all patients. In three of six patients, traumatic findings in the pelvis would have been missed with the limited study. There was high correlation between gestational age and distance of the fetus to the iliac crests (R(2) = 0.84). The mean gestational age at which the top of the fetus was at the iliac crest was 17.3 weeks. Using the limited scanning study, fetuses at 5, 20, and 40 weeks of gestation would receive an estimated 4.3%, 26.2%, and 59.9% of the dose, respectively, compared with the dose for the full scanning study.ConclusionIn pregnant patients in our series with a history of trauma, CT of the abdomen only was an effective technique to reduce fetal radiation exposure compared with full abdomen and pelvis CT