Ziel: Vergleich zweier nicht invasiver Beurteilungsmethoden: transiente Elastografie (TE) und Acoustic Radiation Force Impulse Imaging (ARFI). Patienten und Methoden: In die Studie wurden 114 Patienten eingeschlossen. 38 gesunde Probanden (ohne Fibrose – F0) und 76 Patienten mit chronischen Lebererkrankungen: 53 hiervon hatten eine Leberbiopsie (LB) (7 mit F1, 24 mit F2 und 22 mit F3 Stadium nach Metavir) und 23 zuvor mit Leberzirrhose diagnostizierte Patienten (F4 nach Metavir). Die Leberelastizität wurde bei allen Patienten mittels TE und ARFI untersucht. ARFI (Quantifizierung transversaler Wellengeschwindigkeiten) wurde an 3 Lokalisationen durchgeführt: ausgehend von der Kapsel bei 0 – 1 cm, bei 1 – 2 cm und bei 2 – 3 cm. In jeder Untersuchungstiefe wurden 5 valide Messungen durchgeführt und daraus der Median kalkuliert (in m/s). Ergebnisse: Es zeigte sich eine direkte starke lineare Korrelation zwischen TE und dem Stadium der Fibrose (Spearman rho = 0,848; p < 0,001). Eine signifikante direkte Korrelation zeigte sich auch zwischen den ARFI Messungen bei 1 – 2 cm und 2 – 3 cm unterhalb der Leberkapsel und dem Stadium der Fibrose (rho = 0,675 bzw. 0,714). Die subkapsulär erhobenen ARFI Werte zeigten nur eine schlechte Korrelation mit dem Fibrosegrad (rho = 0,469). Die beste Methode zur Prädiktion einer signifikanten Fibrose (F ≥ 2) war TE; hier ergab sich eine „area under receiver-operating characteristic curve” (AUROC) von 0,908, was signifikant größer war als die mittels ARFI gemessenen AUROCs. Bezüglich der ARFI Messungen hatten die aus einer Untersuchungstiefe von 1 – 2 cm und von 2 – 3 cm unterhalb der Leberkapsel den besten prädiktiven Wert. Hierbei unterschieden sich die AUROCs nicht signifikant voneinander (0,767 bzw. 0,731). Zur Prädiktion einer Fibrose (F > 0) hatte TE den besten prädiktiven Wert: der optimale Cut-off Wert lag bei 5,65 kPa (AUROC – 0,898). Für ARFI lagen die Cut-off Werte bei 1,4 m/s, AUROC - 0,747 (1 – 2 cm), und 1,26 m/s AUROC – 0,721 (2 – 3 cm). Zur Vorhersage einer Zirrhose (F = 4 nach Metavir) waren die optimierten Cut-off Werte: TE –12,9 kPa (AUROC – 0,994); ARFI – 1,78 m/s für die Messung bei 2 – 3 cm subkapsulär, AUROC – 0,951. Schlussfolgerung: Aktuell ist die Messung der Leberelastizität mittels ARFI der Messung mittels TE zur Beurteilung der Leberfibrose nicht überlegen. Mittels ARFI werden die besten Ergebnisse bei Messung 1 – 2 bzw. 2 – 3 cm subkapsulär erzielt. ARFI ist eine akkurate Untersuchungsmethode zur Diagnose einer Zirrhose. Purpose: To compare two methods of noninvasive assessment: transient elastography (TE) and acoustic radiation force impulse elastography (ARFI). Patients and Methods: Our study included 114 subjects: 38 healthy volunteers, (considered to have no fibrosis – F 0) and 76 patients with chronic liver disease: 53 who had undergone liver biopsy (LB) (7 with F 1, 24 with F 2, 22 with F 3 Metavir) and 23 previously diagnosed with cirrhosis (F4 Metavir). In each patient we performed a liver stiffness measurement by means of TE and ARFI. ARFI (shear wave velocity quantification) was performed at 3 points: at 0 – 1 cm, at 1 – 2 cm and at 2 – 3 cm under the capsule. For each depth, 5 valid measurements were made, and a median value was calculated, measured in m/sec. Results: A direct, strong, linear correlation (Spearman rho = 0.848) was found between TE and the stage of fibrosis (p < 0.001). A significant, direct correlation was found between ARFI measurements made 1 – 2 cm and 2 – 3 cm below the liver capsule and the severity of fibrosis (rho = 0.675 and 0.714 respectively). The subcapsularly measured ARFI values showed a poor correlation with fibrosis (rho = 0.469). The best test for predicting significant fibrosis (F ≥ 2) was TE, with the area under receiver-operating characteristic curve (AUROC) 0.908, significantly larger than the AUROCs for ARFI. If only ARFI is considered, measurements made 1 – 2 and 2 – 3 cm below the capsule have the best predictive value, with AUROCs not significantly different from each other (0.767 and 0.731, respectively). For predicting fibrosis (F > 0), TE had the best predictive value: optimized cut-off 5.65 kPa (AUROC –0.898). For ARFI, the cut-offs were: 1.4 m/sec, AUROC –0.747 (1 – 2 cm), and 1.26 m/sec AUROC –0.721 (2 – 3 cm). For predicting cirrhosis (F = 4 Metavir), the optimized cut-offs were: TE –12.9 kPa (AUROC –0.994); ARFI – 1.78 m/sec for measurements made 2 – 3 cm below the capsule, AUROC – 0.951. Conclusion: At present, liver elasticity evaluation by means of ARFI is not superior to TE for the assessment of liver fibrosis. For ARFI, the most reliable results are obtained if measurements are made 1 – 2 and 2 – 3 cm below the liver capsule. ARFI is an accurate test for the diagnosis of cirrhosis.

Our study compared three elastographic methods--transient elastography (TE), acoustic radiation force impulse (ARFI) imaging and supersonic shear imaging (SSI)--with respect to the feasibility of their use in liver fibrosis evaluation. We also compared the performance of ARFI imaging and SSI, with TE as the reference method. The study included 332 patients, with or without hepatopathies, in which liver stiffness was evaluated using TE, ARFI and SSI. Reliable measurements were defined as a median value of 10 (TE, ARFI imaging) or 5 (SSI) liver stiffness measurements with a success rate ≥60% and an interquartile range interval <30%. A significantly higher percentage of reliable measurements were obtained using ARFI than by using TE and SSI: 92.1% versus 72.2% (p < 0.0001) and 92.1% versus 71.3% (p < 0.0001). Higher body mass index and older age were significantly associated with inability to obtain reliable measurements of liver stiffness using TE and SSI. In 55.4% of patients, reliable liver stiffness measurements were obtained using all three elastographic methods, and ARFI imaging and TE were similarly accurate in diagnosing significant fibrosis and cirrhosis, with TE as the reference method.

ARFI elastography for the evaluation of diffuse thyroid gland pathology: Preliminary results

Chronic liver diseases (CLDs) are a public health problem, even if frequently they are underdiagnosed. Hepatic steatosis (HS), encountered not only in nonalcoholic fatty liver disease (NAFLD) but also in chronic viral hepatitis, alcoholic liver disease, etc., plays an important role in fibrosis progression, regardless of CLD etiology; thus, detection and quantification of HS are imperative. Controlled attenuation parameter (CAP) feature, implemented in the FibroScan® device, measures the attenuation of the US beam as it passes through the liver. It is a noninvasive technique, feasible and well accepted by patients, with lower costs than other diagnostic techniques, with acceptable accuracy for HS quantification. Multiple studies have been published regarding CAP performance to quantify steatosis, but due to the heterogeneity of CLD etiologies, of steatosis prevalence, etc., it had widely variable calculated cut‐off values, which in turn limited the day‐to‐day utility of CAP measurements in clinical practice. This paper reviews published studies trying to suggest cut‐off values usable in clinical practice.