The Society of Radiologists in Ultrasound convened a panel of specialists from radiology, hepatology, pathology, and basic science and physics to arrive at a consensus regarding the use of elastography in the assessment of liver fibrosis in chronic liver disease. The panel met in Denver, Colo, on October 21-22, 2014, and drafted this consensus statement. The recommendations in this statement are based on analysis of current literature and common practice strategies and are thought to represent a reasonable approach to the noninvasive assessment of diffuse liver fibrosis.

PD is a new CD imaging imaging mode that might be superior to CD in some cases.

The RI is misnamed and should actually be called the "impedance index" because resistance and compliance interact to alter the Doppler arterial waveform. A greater understanding of this relationship may enable future studies that take both resistance and compliance into account to better detect pathologic conditions.

A prospective study of the Doppler color flow features of 55 proved breast cancers was performed. On a three-level scale of low to marked vascularity, visual assessment of the color flow images classified 82% of the cancers as moderately or markedly vascular (minimal: 14%, moderate: 29%, marked: 53%). Four percent of the cancers had no detectable flow. In 29 women, a volume of tissue comparable to the cancer was scanned in the contralateral normal breast. Sixty-nine percent of the normal breasts had moderate or marked vascularity (minimal: 28%, moderate: 41%, marked: 28%), and 3% were avascular. There was poor distinction between normal tissues and cancer which suggests that more sensitive Doppler methods than were employed in this study may be needed in order to detect the small vessel flow reported to be rather specific for malignancy. The high, 82%, detection rate of tumor vessels in this study suggests the potential use of color flow Doppler for directing more specific but lengthy Doppler procedures.

The power Doppler US technique has the potential to more accurately estimate alterations in blood flow and has the advantage of being a continuous parameter that can be depth normalized.

The resistive index (RI),

BACKGROUND Intestinal fibrosis causes many complications of Crohn’s disease (CD). Available biomarkers and imaging modalities lack sufficient accuracy to distinguish intestinal inflammation from fibrosis. Transcutaneous ultrasound elasticity imaging (UEI) is a promising, noninvasive approach for measuring tissue mechanical properties. We hypothesized that UEI could differentiate inflammatory from fibrotic bowel wall changes in both animal models of colitis and humans with CD. METHODS Female Lewis rats underwent weekly trinitrobenzene sulfonic acid enemas yielding models of acute inflammatory colitis (n = 5) and chronic intestinal fibrosis (n = 6). UEI scanning used a novel speckle-tracking algorithm to estimate tissue strain. Resected bowel segments were evaluated for evidence of inflammation and fibrosis. Seven consecutive patients with stenotic CD were studied with UEI and their resected stenotic and normal bowel segments were evaluated by ex vivo elastometry and histopathology. RESULTS Transcutaneous UEI normalized strain was able to differentiate acutely inflamed (−2.07) versus chronic fibrotic (−1.10) colon in rat models of inflammatory bowel disease (IBD; P = .037). Transcutaneous UEI normalized strain also differentiated stenotic (−0.87) versus adjacent normal small bowel (−1.99) in human CD (P = .0008), and this measurement also correlated well with ex vivo elastometry (r = −0.81). CONCLUSIONS UEI can differentiate inflammatory from fibrotic intestine in rat models of IBD and can differentiate between fibrotic and unaffected intestine in a pilot study in humans with CD. UEI represents a novel technology with potential to become a new objective measure of progression of intestinal fibrosis. Prospective clinical studies in CD are needed.

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