Faculty Bibliography

OBJECTIVE:To perform a clinical and payer-based analysis of the value of dual-energy computed tomography (DECT) for workup of incidental abdominal findings. METHODS:This was a single-center, retrospectively designed, Health Insurance Portability and Accountability Act-compliant study approved by our institutional review board. Sixty-nine examinations in 69 patients (45 men, 24 women; mean age, 57.7 years) who underwent single-phase postcontrast abdominal DECT studies between January 1, 2011, and December 31, 2017, were included. Two radiologists, blinded to study objective and design, reviewed all cases and identified incidental abdominal findings needing further imaging. All incidental findings were reviewed by 2 other investigators, who determined whether an imaging-based diagnosis could be made using DECT virtual noncontrast images and iodine maps. Additional studies and associated payer-reimbursement amounts avoided by use of DECT were estimated. All imaging costs were estimated based on the US Centers for Medicare & Medicaid Services reimbursement amounts. RESULTS:Thirty-four incidental findings (renal mass, n = 20; adrenal nodule, n = 8; pancreatic cystic lesions, n = 3; others, n = 3) were identified in 19 (27.5%) of 69 patients. Dual-energy computed tomography characterized 27 incidental findings in 15 patients and accounted for cost savings of 15 additional imaging examinations (abdominal magnetic resonance imaging, n = 11; abdominal computed tomography, n = 4). Based on Centers for Medicare & Medicaid Services reimbursement amounts, we estimated that, by abolishing the need for additional imaging use, DECT saved US $84.95 per patient. CONCLUSIONS:Dual-energy computed tomography can provide an imaging-based diagnosis of incidental abdominal findings, otherwise incompletely characterized on routine abdominal computed tomography, in approximately 21% of patients. In select patients, the monetary savings from abolishing additional imaging may reduce payer costs associated with use of DECT.

Congenital cardiac anomalies are a common finding during prenatal anatomical survey ultrasound examination. Cardiac anomalies are a major cause of prenatal and neonatal mortality and morbidity. If the anomaly is not lethal, most would require surgical correction. Therefore, early recognition of these abnormalities is essential for parental counseling and delivery planning, as well as analysis of neonatal treatment options. Although prenatal ultrasound plays an important role in identification of such anomalies, diagnosis and interpretation of imaging findings require familiarity and knowledge of the common imaging features. In this article, we provide a comprehensive review of ultrasound appearance of common fetal cardiac anomalies.

OBJECTIVES/OBJECTIVE:The purpose of this study was to compare Superb Microvascular Imaging (SMI; Toshiba America Medical Systems, Tustin, CA) with conventional color flow Doppler (CFD) and power Doppler (PD) imaging in the liver to distinguish between malignant and benign liver neoplasms. METHODS:After Institutional Review Board approval (number 449984-ED), patients undergoing routine pre-radiofrequency ablation planning ultrasound examinations for suspected hepatocellular carcinomas (HCCs) of less than 2 cm in diameter between January 1, 2015, and July 1, 2016, were prospectively identified. Four readers reviewed the ultrasound images independently for the presence or absence of flow centrally and along the periphery of the lesion. RESULTS:Higher peripheral vessel grades were found on SMI than CFD (P < .001) and PD (P < .001) imaging: in particular, more grade 2 (39% versus 16% and 11%, respectively) and grade 3 (8% versus 0% and 0%). Overall, more central and peripheral vessels were found on SMI than CFD and PD imaging for both HCC lesions (P < .001) and benign lesions (P < .001). Vascular grades were significantly higher in HCC lesions than benign lesions in nearly all cases, although the corresponding area under the curve values were relatively low, at 0.54 to 0.59 for the central vessel grades and 0.63 to 0.64 for the peripheral vessel grades. CONCLUSIONS:More central and peripheral vessels were found around liver lesions on SMI than on CFD and PD imaging. Although there was significantly more vascularity on the periphery of malignant liver lesions than benign lesions, the overall diagnostic performance based on this criterion alone was relatively low, with an area under the curve of 0.64.

Cardiac amyloidosis is an under-appreciated cause of heart failure. Establishing a diagnosis is important because traditional heart failure treatment regimens can worsen left ventricular failure in this disease. Endomyocardial biopsy is the gold standard for diagnosis; however, scintigraphy with radiolabeled phosphate derivatives and cardiac magnetic resonance imaging have been shown to have high sensitivity and specificity in diagnosing cardiac amyloidosis. Furthermore, cardiac scintigraphy can reliably differentiate amyloid subtypes. We present a case of transthyretin-related cardiac amyloidosis with a negative endomyocardial biopsy but positive 99m-technetium pyrophosphate single photon emission computed tomography scan and cardiac magnetic resonance imaging. We discuss the utility of 99m-technetium pyrophosphate imaging in cardiac amyloidosis and the role of single photon emission computed tomography. Finally, we review the several forms of cardiac amyloidosis and how they pertain to cardiac scintigraphy.

It is important to understand normal and abnormal radiotracer biodistribution patterns in patients who undergo cardiac Tc-2-methoxyisobutyl-isonitrile (Tc-sestamibi) scans to provide important clinical guidance. Our case describes a 75-year-old man with a history of multiple myeloma in remission, who presented to the emergency department for unrelated chest pain and shortness of breath. The patient underwent a nuclear cardiac stress test with Tc-sestamibi scintigraphy as part of his cardiac workup. The images demonstrated diffuse radiotracer uptake in the skeletal structures raising concern for progression of multiple myeloma, of which, subsequent biopsy confirmed the presence of recurrent disease.

We present a case of metastatic neuroblastoma to the mandible in an 11-month-old patient presenting with worsening right-sided proptosis and scalp swelling after a fall 2 weeks prior. Initial evaluation with computed tomography of the head demonstrated soft tissue masses centered at the right sphenoid and right mandible. These masses proved to be metastatic lesions from an intra-abdominal neuroblastoma. Review of the literature revealed 20 cases of neuroblastoma metastasis to the mandible over the past 70 years. To our knowledge, our patient is the youngest reported case with asymptomatic mandibular metastasis related to neuroblastoma and the first to be characterized with magnetic resonance imaging.

We present a case of a 50-year-old female with a 2-day history of back and abdominal pain who was discovered to have innumerable chronically retained acupuncture needles, which had migrated throughout her abdomen and pelvis. Although many of these needles were in precarious positions, including the epidural space, renal parenchyma, small bowel, and vasculature, there was no evidence for acute injury. We also briefly discuss evidence for the magnetic resonance imaging compatibility of acupuncture needles. Although a rare complication, given the high frequency of acupuncture therapy in the United States, physicians must be aware of the potential for retained and migrated needles.

We present a case of an intensely hypermetabolic intracavitary cardiac mass, standardized uptake values max 44.4, that was pathologically proved to be organizing and organized thrombus, negative for tumor. Our patient had previous right atrial mass resection 2 years prior that was pathologically described as either thrombus or infarcted atrial myxoma. She had since been on lifelong controlled anticoagulation; and on routine follow-up imaging, she had recurrent slow growth of a new right atrial mass. During a later hospital admission for chest pain, the mass was evaluated on both transthoracic and transesophageal echo cardiogram, which could not differentiate thrombus vs neoplasm. Cardiac magnetic resonance imaging was equivocal for mass enhancement. The patient underwent fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) evaluation, which revealed intensely hypermetabolic activity within the mass concerning for malignancy, potentially an aggressive tumor. Subsequently, the mass was surgically excised for pathological diagnosis.