Lincoln L. Berland

Managing incidental thyroid nodules detected on imaging: white paper of the ACR Incidental Thyroid Findings Committee.

The incidental thyroid nodule (ITN) is one of the most common incidental findings on imaging studies that include the neck. An ITN is defined as a nodule not previously detected or suspected clinically, but identified by an imaging study. The workup of ITNs has led to increased costs from additional procedures, and in some cases, to increased risk to the patient because physicians are naturally concerned about the risk of malignancy and a delayed cancer diagnosis. However, the majority of ITNs are benign, and small, incidental thyroid malignancies typically have indolent behavior. The ACR formed the Incidental Thyroid Findings Committee to derive a practical approach to managing ITNs on CT, MRI, nuclear medicine, and ultrasound studies. This white paper describes consensus recommendations representing this committees review of the literature and their practice experience.

Managing Incidental Findings on Abdominal and Pelvic CT and MRI, Part 1: White Paper of the ACR Incidental Findings Committee II on Adnexal Findings

This white paper describes adnexal (ovarian and paraovarian) incidental findings found on CT and MRI in nonpregnant postmenarchal patients in whom no adnexal disorder is clinically known or suspected. This represents the first of 4 such papers from the ACR Incidental Findings Committee II, which used a consensus method based on repeated reviews and revisions and a collective review and interpretation of relevant literature. Recommendations for the management of incidental adnexal findings are organized into 4 main categories: benign-appearing cysts, probably benign cysts, adnexal masses with characteristic features, and all other adnexal masses, with pathways on the basis of patient menstrual status or age (when last menstrual period is unknown). A table and flowchart are provided for reference.

Fat distribution, physical activity, and cardiovascular risk factors.

The purpose of this study was to report the relationship between fat distribution, physical activity (PA), and cardiovascular disease (CVD) risk factors. Percent fat, computed tomography intra-abdominal adipose tissue (IAF), anthropometrics, Baecke activity questionnaire, and CVD risk (blood pressure, cholesterol, HDL, HDL2, HDL3, IDL, LDL, VLDL, and triglycerides) were evaluated in 137 men 30-71 yr old. IAF was consistently more highly related to CVD risk than other fat distribution variables including percent fat and waist:hip ratio (r = 0.3-0.45). IAF was significantly related to CVD risk after adjusting for other fat distribution variables. With the exception of the sum of biceps, triceps, thigh, and calf skinfolds (peripheral skinfolds), which was negatively related to CVD risk, no other fat distribution variable had consistent significant partial correlations with CVD risk. PA was related to IAF after adjusting for peripheral skinfolds, but PA was not related to peripheral skinfolds after adjusting for IAF, indicating more active men have relatively low IAF. IAF was related to CVD risk after adjusting for PA, but PA was not related to CVD risk after adjusting for IAF. These results indicate that IAF is directly related to CVD risk while the lower CVD risk found with more active men is more directly related to the low IAF found in more active men.

Single-source dual-energy spectral multidetector CT of pancreatic adenocarcinoma: Optimization of energy level viewing significantly increases lesion contrast

AIM To evaluate lesion contrast in pancreatic adenocarcinoma patients using spectral multidetector computed tomography (MDCT) analysis. MATERIALS AND METHODS The present institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant retrospective study evaluated 64 consecutive adults with pancreatic adenocarcinoma examined using a standardized, multiphasic protocol on a single-source, dual-energy MDCT system. Pancreatic phase images (35 s) were acquired in dual-energy mode; unenhanced and portal venous phases used standard MDCT. Lesion contrast was evaluated on an independent workstation using dual-energy analysis software, comparing tumour to non-tumoural pancreas attenuation (HU) differences and tumour diameter at three energy levels: 70 keV; individual subject-optimized viewing energy level (based on the maximum contrast-to-noise ratio, CNR); and 45 keV. The image noise was measured for the same three energies. Differences in lesion contrast, diameter, and noise between the different energy levels were analysed using analysis of variance (ANOVA). Quantitative differences in contrast gain between 70 keV and CNR-optimized viewing energies, and between CNR-optimized and 45 keV were compared using the paired t-test. RESULTS Thirty-four women and 30 men (mean age 68 years) had a mean tumour diameter of 3.6 cm. The median optimized energy level was 50 keV (range 40-77). The mean ± SD lesion contrast values (non-tumoural pancreas - tumour attenuation) were: 57 ± 29, 115 ± 70, and 146 ± 74 HU (p = 0.0005); the lengths of the tumours were: 3.6, 3.3, and 3.1 cm, respectively (p = 0.026); and the contrast to noise ratios were: 24 ± 7, 39 ± 12, and 59 ± 17 (p = 0.0005) for 70 keV, the optimized energy level, and 45 keV, respectively. For individuals, the mean ± SD contrast gain from 70 keV to the optimized energy level was 59 ± 45 HU; and the mean ± SD contrast gain from the optimized energy level to 45 keV was 31 ± 25 HU (p = 0.007). CONCLUSION Significantly increased pancreatic lesion contrast was noted at lower viewing energies using spectral MDCT. Individual patient CNR-optimized energy level images have the potential to improve lesion conspicuity.

Comparison of contrast media injection rates and volumes for hepatic dynamic incremented computed tomography.

Contrast injection techniques now in use for hepatic dynamic incremented computed tomography (DICT) were designed for scanners using slower scan acquisition rates than the currently available 6 to 12 scans/minute. Of 53 patients examined, (1) 19 received a conventional 2-minute injection of 150 or 120 mL of 60% contrast material selected by patient weight; (2) 19 received the same doses within 1 minute; and (3) 15 received 20% lower doses within 1 minute. The faster injection groups 2 and 3 reached peak enhancement sooner (57 and 60 seconds vs. 97 seconds) with similar or higher peak hepatic enhancement (73 and 64 HU vs. 58 HU) and equivalent hepatic enhancement (52 and 48 HU vs. 54 HU) after 150 seconds. Because detecting neoplastic liver lesions often depends on enhancement, 1-minute injections of high doses of contrast material with rapid scan rates may be superior to 2-minute injections. When cost or dose-related toxicity are important, 1-minute injections of 20% lower contrast doses may be considered.

ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee

Thyroid nodules are a frequent finding on neck sonography. Most nodules are benign; therefore, many nodules are biopsied to identify the small number that are malignant or require surgery for a definitive diagnosis. Since 2009, many professional societies and investigators have proposed ultrasound-based risk stratification systems to identify nodules that warrant biopsy or sonographic follow-up. Because some of these systems were founded on the BI-RADS® classification that is widely used in breast imaging, their authors chose to apply the acronym TI-RADS, for Thyroid Imaging, Reporting and Data System. In 2012, the ACR convened committees to (1) provide recommendations for reporting incidental thyroid nodules, (2) develop a set of standard terms (lexicon) for ultrasound reporting, and (3) propose a TI-RADS on the basis of the lexicon. The committees published the results of the first two efforts in 2015. In this article, the authors present the ACR TI-RADS Committees recommendations, which provide guidance regarding management of thyroid nodules on the basis of their ultrasound appearance. The authors also describe the committees future directions.

Managing Incidental Findings on Abdominal and Pelvic CT and MRI, Part 4: White Paper of the ACR Incidental Findings Committee II on Gallbladder and Biliary Findings

This white paper describes gallbladder and biliary incidental findings found on CT and MRI. Recommendations for management are included. This represents the fourth of 4 such papers from the ACR Incidental Findings Committee II, which used a consensus method based on repeated reviews and revisions and a collective review and interpretation of relevant literature. Topics include the management of a variety of gallbladder abnormalities and biliary dilation. A table is provided for reference.

Thyroid Ultrasound Reporting Lexicon: White Paper of the ACR Thyroid Imaging, Reporting and Data System (TIRADS) Committee.

Ultrasound is the most commonly used imaging technique for the evaluation of thyroid nodules. Sonographic findings are often not specific, and definitive diagnosis is usually made through fine-needle aspiration biopsy or even surgery. In reviewing the literature, terms used to describe nodules are often poorly defined and inconsistently applied. Several authors have recently described a standardized risk stratification system called the Thyroid Imaging, Reporting and Data System (TIRADS), modeled on the BI-RADS system for breast imaging. However, most of these TIRADS classifications have come from individual institutions, and none has been widely adopted in the United States. Under the auspices of the ACR, a committee was organized to develop TIRADS. The eventual goal is to provide practitioners with evidence-based recommendations for the management of thyroid nodules on the basis of a set of well-defined sonographic features or terms that can be applied to every lesion. Terms were chosen on the basis of demonstration of consistency with regard to performance in the diagnosis of thyroid cancer or, conversely, classifying a nodule as benign and avoiding follow-up. The initial portion of this project was aimed at standardizing the diagnostic approach to thyroid nodules with regard to terminology through the development of a lexicon. This white paper describes the consensus process and the resultant lexicon.

Incidental Extracolonic Findings on CT Colonography: The Impending Deluge and Its Implications

The probable future widespread adoption of computed tomographic colonography (CTC) will lead to the detection of numerous incidental extracolonic findings (ECFs). Defining, characterizing, and making diagnostic and management recommendations for such ECFs are likely to be inconsistent and, averaged over the patient population, may be more costly than CTC itself. Several reports that suggested a modest cost for evaluating ECFs did not include all of the downstream costs of diagnosis and treatment, while studies that more closely tracked costs arrived at figures up to 5 times as high. The ECF aspect of CTC is analogous to total-body screening, which has been widely criticized, and the cost-effectiveness of evaluating and managing ECFs is unproven and controversial, which also has implications for managing incidental findings from other applications for abdominal and pelvic computed tomography. The author reviews studies that have assessed the frequency, costs, and effects of ECFs. Establishing national or local criteria for detecting ECFs and providing recommendations for referring clinicians may be an important step toward achieving the most effective patient care for ECFs, which are the inevitable consequence of performing CTC.

CT and MR imaging in the evaluation of retroperitoneal fibrosis.

We have performed CT and MR on five patients with biopsy proven retroperitoneal fibrosis (RPF). Magnetic resonance (MR) accurately displayed a retroperitoneal mass of low signal intensity on T1-weighted scans and of heterogeneous medium signal intensity on T2-weighted scans. The coronal MR views demonstrated a retroperitoneal mass: the shape, signal intensity, and effects on the ureters and major vessels appear characteristic of RPF.