Focal liver lesions are commonly encountered and often demonstrate nonspecific findings at initial imaging. Although most incidentally discovered liver lesions are benign, their noninvasive diagnosis is necessary, especially if they are large or atypical. Imaging characterization of focal liver lesions and exclusion of malignancy are of prime importance, particularly in high-risk populations. Contrast agent-enhanced ultrasonography of liver lesions is both accurate and reproducible for evaluation of benign and malignant liver tumors. Use of an imaging algorithm and a controlled sonographic technique, including dedicated arterial phase cine imaging and imaging every 30 seconds in the portal venous phase and the delayed (or late) phase, is essential for accurate characterization. This algorithmic analysis of focal liver lesions focuses first on the determination of malignancy by imaging the portal venous phase and the late phase; washout in these phases correlates with a malignant tumor, and sustained enhancement in these phases is suggestive that a lesion is benign. In addition, the timing and the intensity of washout differentiate hepatocellular malignancies from nonhepatocellular malignancies. Nonhepatocellular tumors demonstrate early and strong washout, whereas hepatocellular malignancies show delayed and weak washout. Subsequent analysis of dynamic real-time enhancement patterns in the arterial phase demonstrates specific enhancement patterns of common benign and malignant focal liver lesions. Hemangiomas show classic peripheral nodular enhancement, and spoke-wheel centrifugal enhancement is suggestive of focal nodular hyperplasia. Hepatic adenomas may show centripetal filling. However, arterial phase enhancement in malignancy has less specificity. Online supplemental material is available for this article. RSNA, 2017 •.

Contrast-enhanced ultrasound (CEUS) of the gastrointestinal tract provides vascular information helpful for characterizing masses and other pathologies in and around the bowel, similar to contrast applications in other solid organs. However, the use of microbubble contrast agents for the bowel provides additional unique contributions as it gives both subjective and objective information about mural and mesenteric blood flow, invaluable for the determination of disease activity in those many patients affected by inflammatory bowel disease (IBD). IBD is a lifelong chronic disease and has its peak age of onset in adolescence or young adult life. Today, we have moved away from treating patient’s symptoms and strive instead to alter the course of disease by obtaining mucosal healing. Expensive and aggressive biologic therapies and lack of agreement of patient’s symptoms with their disease activity and complications necessitate frequent imaging surveillance, which must be safe, readily available, inexpensive, and effective. Ultrasound with the benefit of contrast enhancement meets these requirements and is shown in meta-analysis to be equivalent to CT and MRI scans for these indications.Electronic supplementary materialThe online version of this article (10.1007/s00261-017-1399-6) contains supplementary material, which is available to authorized users.

Bowel ultrasound (US) is accurate for assessing bowel inflammation and complications in Crohn disease. Additionally, contrast‐enhanced US provides a quantitative, objective measurement of inflammatory activity in inflammatory bowel disease, and shear wave elastography predicts the stiffness of bowel, an increase of which suggests less response to medical therapy, often necessitating surgery. Overall, bowel US is an excellent, safe, and repeatable choice for routine surveillance and for urgent imaging. We describe an approach to evaluating inflammatory bowel disease and review its features on standard grayscale US with Doppler imaging and show how contrast‐enhanced US and shear wave elastography can distinguish between inflammatory and fibrostenotic bowel.

Objectives Following positive surveillance ultrasound (US), magnetic resonance imaging (MRI) is recommended for further characterization. We propose contrast‐enhanced ultrasound (CEUS) shows equivalent efficacy. Methods This prospective institutional review board approved study recruited 195 consecutive at‐risk patients with a positive surveillance US. All had CEUS and MRI. Biopsy (n = 44) and follow‐up are gold standard. MRI and CEUS results are classified according to liver imaging reporting and data system (LI‐RADS) and patient outcome. Results As an US‐based modality, CEUS is superior in confirming findings from surveillance US, correlation in 189/195 (97%) on CEUS compared to 153/195 (79%) on MRI. Within these negative MRI examinations, there are 2 hepatocellular carcinoma (HCC) and 1 cholangiocarcinoma (iCCA) diagnosed on CEUS and proven by biopsy. From 195 patients, there are 71 malignant diagnoses from all sources, including 58 LR‐5 (45 on MRI and 54 on CEUS) and 13 others, including HCC outside of LR‐5 category, and LR‐M with biopsy proven iCCA (3 on MRI and 6 on CEUS). CEUS and MRI show concordant results in the majority of patients (146/195, 75%), including 57/146 malignant and 89/146 benign diagnoses. There are 41/57 concordant LR‐5 and 6/57 concordant LR‐M. When CEUS and MRI are discordant, CEUS upgraded 20 (10 biopsy‐proven) from MRI LR‐3/4 to CEUS LR‐5 or LR‐M by showing washout (WO) that MRI failed to show. Additionally, CEUS characterized time and intensity of WO and diagnosed 13/20 LR‐5 by showing late and weak WO and 7 LR‐M by showing fast and marked WO. CEUS is 81% sensitive and 92% specific in diagnosing malignancy. MRI is 64% sensitive and 93% specific. Conclusions CEUS performance is at least equivalent if not superior to MRI for initial evaluation of lesions from surveillance US.

onalcoholic fatty liver disease (NAFLD) is common in patients with diabetes, obesity, dyslipidemia and metabolic syndrome, and has become the leading cause of liver disease in North America. 1,2 Patients with NAFLD at risk for advanced fibrosis require specialist care for urgent assessment and management of liver cirrhosis complications. 3,4 Intense lifestyle modification and treatment of underlying risk factors are the main approach for treating patients with NAFLD with advanced fibrosis. 3,5 Early clinical intervention and patient education lead to better outcomes, including possible reversal of histopathologic liver changes, especially in patients who achieve a 7%-10% weight loss. 6,7 Therefore, recent guidelines have emphasized the high yield of targeting patients with NAFLD who have advanced fibrosis for intense lifestyle modification. 3,5 Although awareness of NAFLD among primary care physicians is increasing, identifying patients with NAFLD

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Objectives-To demonstrate the usefulness of contrast-enhanced ultrasound (CEUS) for the evaluation of focal liver masses via a direct comparison to standard ultrasound and computed tomography/magnetic resonance imaging (CT/MRI).Methods-A cohort of 214 patients with previously undiagnosed focal liver masses were included from 5 different centers. Each patient was imaged using CEUS and CT and/or MRI. Anonymized and randomized images were interpreted by 4 separate blind readers from 3 of the participating centers (2 readers for CEUS and 2 readers for CT/MRI). Readers were blinded to patient demographics and past medical history. Readers were asked to decide if the lesion was benign or malignant, provide a final diagnosis for the lesion, and provide a confidence interval. Results were compared to truth standard from pathology or expert consensus.Results-In determination of malignancy, CEUS had a sensitivity of 95%, specificity of 82%, PPV of 82%, NPV of 95%, statistically better than standard ultrasound (sensitivity 82%, specificity 56%, PPV 60%, NPV 78%) with P < .01 and not statistically different from CT (sensitivity 90%, specificity 73% PPV 81%, NPV 86%) or MRI (sensitivity 85%, specificity 79%, PPV 68%, NPV 91%) with P ≥ .01. In assigning a final diagnosis, CEUS had an accuracy of 78% statistically better than standard ultrasound (46%) with P < .01 and not statistically different from CT (68%) or MRI (71%) with P > .01.Conclusions-In the evaluation of focal liver lesions, both for determination of malignancy and in accuracy of final diagnosis, CEUS performs better than standard ultrasound and at least equivalent to both CT and MRI.

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