Faculty Bibliography

Imaging plays a role in the management of patients with acute kidney injury or chronic kidney disease. However, clinical circumstances strongly impact the appropriateness of imaging use. In patients with newly detected renal dysfunction, ultrasonography can assess for reversible causes, assess renal size and echogenicity, and thus, establish the chronicity of disease. Urinary obstruction can be detected, but imaging is most useful in high-risk groups or in patients in whom there is a strong clinical suspicion for obstruction. Computed tomography, computed tomography or magnetic resonance arteriography, and percutaneous ultrasound-guided renal biopsy are valuable in other clinical situations. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Although localized renal cell carcinoma can be effectively treated by surgery or ablative therapies, local or distant metastatic recurrence after treatment is not uncommon. Because recurrent disease can be effectively treated, patient surveillance after treatment of renal cell carcinoma is very important. Surveillance protocols are generally based on the primary tumor's size, stage, and nuclear grade at the time of resection, as well as patterns of tumor recurrence, including where and when metastases occur. Various imaging modalities may be used in the evaluation of these patients. Literature on the indications and usefulness of these radiologic studies is reviewed. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

BACKGROUND: Base of tongue (BOT) is a difficult subsite to examine clinically and radiographically. Yet, anatomic delineation of the primary tumor site, its extension to adjacent sites or across midline, and endophytic vs. exophytic extent are important characteristics for staging and treatment planning. We hypothesized that ultrasound could be used to visualize and describe BOT tumors. METHODS: Transcervical ultrasound was performed using a standardized protocol in cases and controls. Cases had suspected or confirmed BOT malignancy. Controls were healthy individuals without known malignancy. RESULTS: 100% of BOT tumors were visualized. On ultrasound BOT tumors were hypoechoic (90.9%) with irregular margins (95.5%). Ultrasound could be used to characterize adjacent site involvement, midline extent, and endophytic extent, and visualize the lingual artery. No tumors were suspected for controls. CONCLUSIONS: Ultrasonography can be used to transcervically visualize BOT tumors and provides clinically relevant characteristics that may not otherwise be appreciable.

On computed tomography (CT), gallbladder pathology may be detected incidentally or as the etiology of symptoms that prompted imaging. Accurate pathologic diagnosis can be challenging, however, due to overlapping appearances of malignant and benign gallbladder disease. This pictorial essay takes a pattern-based approach to CT of the gallbladder, to help the radiologist formulate the proper differential diagnosis.

OBJECTIVE: The purpose of this study was to determine the prevalence and types of renal and extrarenal abnormalities that preclude renal donation or lead to alteration of the surgical approach on the basis of abdominal CT angiography (CTA) in a large group of potential renal donors. MATERIALS AND METHODS: In this retrospective study, 654 potential renal donors undergoing dual-phase CTA were identified from January 2005 to January 2009. The CT reports were systemically reviewed by two radiologists to determine the presence of renal and extrarenal abnormalities. The operative notes of the renal donors were reviewed by one radiologist to determine whether the presence of renal pathology had affected the surgical approach. In the candidates who did not proceed to kidney donation, the reasons that precluded kidney donation were abstracted from the transplant database. RESULTS: Four hundred seventeen potential donors (269 men and 385 women; mean age, 44.0 years; age range, 17-79 years) proceeded to renal donation and 237 did not. The most common renal abnormalities were cysts (34%) and renal stones (4.4%). Renal artery disease was identified in 3.4% of potential donors, including renal artery stenosis, possible fibromuscular dysplasia, and renal artery aneurysm. Suspicious renal masses were incidentally found in 0.5% of potential donors. The most common extrarenal pathology was an incidental adrenal nodule (2.6%). Other significant extrarenal pathology identified included gallbladder mass (0.2%), Crohn disease (0.2%), ovarian mass (0.2%), and possible sarcoidosis (0.2%). Although renal and extrarenal abnormalities were present in 41% of potential renal donors, abnormalities seen on CT only contributed to exclusion of 27 potential donors (4.1%). The most common reason for exclusion was the presence of renal stones or scarring (1.8%). Significant CT findings also contributed to the selection of the right kidney in 29 donors, most commonly due to presence of ipsilateral vascular disease or complex left vascular anatomy. CONCLUSION: Renal parenchymal and vascular abnormalities are common in asymptomatic potential kidney donors. Although most of these represent incidental CT findings, abnormalities can exclude potential renal donors and alter the surgical approach in a small minority of cases.