Diagnosis of liver cirrhosis by transit-time analysis at contrast-enhanced ultrasonography. Radiol Med. 2008;113:860-874. [PMID: 18587531 DOI: 10.1007/s11547-008-0292-3]

Application of the Hepatic Transit Time (HTT) in Evaluation of Portal Vein Pressure in Gastroesophageal Varices Patients

OBJECTIVES

To analyze the clinical significance of using hepatic transit time (HTT) to evaluate portal vein pressure in gastroesophageal varices patients.

METHODS

For the observation group, we enrolled 50 gastroesophageal varices patients who had received esophagogastric variceal embolization in our hospital between January 2015 and February 2018. Patients without liver disease populated the control group and were recruited during the same time period. All patients underwent contrast-enhanced sonography. In the observation group, free portal pressure (FPP) was detected during esophagogastric variceal embolization with ultrasound guidance. Differences in hepatic artery-hepatic vein transit time (HA-HVTT), portal vein-hepatic vein transit time (PV-HVTT), and parenchyma-hepatic vein transit time (PA-HVTT) were compared between groups. Correlations between HA-HVTT, PV-HVTT, PA-HVTT, and FPP in the observation group were analyzed using the Pearson coefficient and linear regression analysis.

RESULTS

HA-HVTT (t = 5.078; P < .001), PV-HVTT (t = 12.163; P < .001), and PA-HVTT (t = 2.649; P = .009) within the observation group were significantly lower than those of the control group. The areas under the curve of HTT were 0.771 (HA-HVTT), 0.951 (PV-HVTT), and 0.652 (PA-HVTT), and the sensitivity and specificity of PV-HVTT at 7.99 seconds were 86.0% and 88.0%, respectively. The HA-HVTT (r = -0.799; P < .001), PV-HVTT (r = -0.554; P < .001), and PA-HVTT (r = -0.735; P < .001) negatively correlated to FPP in the observation group. Linear regression analysis showed y = -0.410x + 7.254 (HA-HVTT and FPP), y = -0.335x + 4.983 (PV-HVTT and FPP), and y = -0.566x + 4.997 (PA-HVTT and FPP) in the observation group.

CONCLUSION

Compared with the control patients, the HTT of patients with portal hypertension-esophagogastric varices was significantly shorter, and showed an inverse relationship with FPP.

Progress in non-invasive detection of liver fibrosis

Liver fibrosis is an important pathological precondition for hepatocellular carcinoma. The degree of hepatic fibrosis is positively correlated with liver cancer. Liver fibrosis is a series of pathological and physiological process related to liver cell necrosis and degeneration after chronic liver injury, which finally leads to extracellular matrix and collagen deposition. The early detection and precise staging of fibrosis and cirrhosis are very important for early diagnosis and timely initiation of appropriate therapeutic regimens. The risk of severe liver fibrosis finally progressing to liver carcinoma is >50%. It is known that biopsy is the gold standard for the diagnosis and staging of liver fibrosis. However, this method has some limitations, such as the potential for pain, sampling variability, and low patient acceptance. Furthermore, the necessity of obtaining a tissue diagnosis of liver fibrosis still remains controversial. An increasing number of reliable non-invasive approaches are now available that are widely applied in clinical practice, mostly in cases of viral hepatitis, resulting in a significantly decreased need for liver biopsy. In fact, the non-invasive detection and evaluation of liver cirrhosis now has good accuracy due to current serum markers, ultrasound imaging, and magnetic resonance imaging quantification techniques. A prominent advantage of the non-invasive detection and assessment of liver fibrosis is that liver fibrosis can be monitored repeatedly and easily in the same patient. Serum biomarkers have the advantages of high applicability (>95%) and good reproducibility. However, their results can be influenced by different patient conditions because none of these markers are liver-specific. The most promising techniques appear to be transient elastography and magnetic resonance elastography because they provide reliable results for the detection of fibrosis in the advanced stages, and future developments promise to increase the reliability and accuracy of the staging of hepatic fibrosis. This article aims to describe the recent progress in the development of non-invasive assessment methods for the staging of liver fibrosis, with a special emphasize on computer-aided quantitative and deep learning methods.

Assessment of liver fibrosis by ultrasound elastography and contrast-enhanced ultrasound: a randomized prospective animal study

This study aimed to assess liver fibrosis by contrast-enhanced ultrasound (CEUS) and point shear-wave elastography (pSWE) in rabbits and compare the performance of the two techniques. Eighty rabbits were divided into experimental (n=60) and control group (n=20). In the experimental group, liver fibrosis (F1-F4) was induced by subcutaneous injection of carbon tetrachloride. CEUS and pSWE of the liver was performed for the two groups at a 4-week interval for 40 weeks. The portal vein rise time (PV-RT), time to peak (PV-TTP), mean transit time (PV-MTT) and the maximum signal intensity (PV-Imax) were analyzed with time-intensity curves (TICs). Liver stiffness value (LSV) was obtained through pSWE. Histologic examination of liver specimens of the rabbits was performed to evaluate the fibrosis stage. PV-RT, PV-TTP, PV-Imax and LSV were significantly different among five liver fibrosis stages (F0-F4) (P<0.01). PV-Imax and LSV displayed better diagnostic performance than PV-RT, PV-TTP, PV-MTT. For diagnosing≥F1 stage fibrosis, the area under the receiver operating characteristic curve (AUROC) of PV-Imax was 0.870, which was similar to that of LSV 0.874 (P=0.94). For diagnosing ≥F2, ≥F3 and ≥F4 stage fibrosis, the AUROC of PV-Imax and LSV was 0.845 vs. 0.956 (P=0.04), 0.789 vs. 0.954 (P=0.01) and 0.707 vs. 0.933 (P=0.03). Both CEUS and pSWE had the potential to be complementary imaging tools in the evaluation of liver fibrosis. The performance of pSWE may be better than CEUS.

Diagnostic Accuracy of Hepatic Vein Arrival Time Performed with Contrast-Enhanced Ultrasonography for Cirrhosis: A Systematic Review and Meta-Analysis

Background/Aims

We identified reports in the literature regarding the diagnostic accuracy of hepatic vein arrival time (HVAT) measured by contrast-enhanced ultrasonography (CEUS) to assess hepatic fibrosis in cirrhosis.

Methods

The Ovid MEDLINE, Embase, and Cochrane databases were searched for all studies published up to 23 July 2015 that evaluated liver status using CEUS and liver biopsy (LB). The QUADAS-II (quality assessment of diagnostic accuracy studies-II) was applied to assess the internal validity of the diagnostic studies. Selected studies were subjected to a meta-analysis with MetaDisc 1.4 and RevMan 5.3.

Results

A total of 12 studies including 844 patients with chronic liver disease met our inclusion criteria. The overall summary sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of the HVAT measured by CEUS for the detection of cirrhosis compared to LB were 0.83 (95% confidence interval [CI], 0.77 to 0.89), 0.75 (95% CI, 0.69 to 0.79), 3.45 (95% CI, 1.60 to 7.43), and 0.28 (95% CI, 0.10 to 0.74), respectively. The summary diagnostic odds ratio (random effects model) was 15.23 (95% CI, 3.07 to 75.47), the summary receiver operator characteristics area under the curve was 0.74 (standard error [SE]=0.14), and the index Q was 0.69 (SE=0.11).

Conclusions

Based on a systematic review, the measurement of HVAT by CEUS exhibited an increased accuracy and correlation for the detection of cirrhosis.

Hepatic Vein Arrival Time for Diagnosis of Liver Cirrhosis: A 10-Year Single-Center Experience With Contrast-Enhanced Sonography

OBJECTIVES

To evaluate the performance of contrast-enhanced sonography with a second-generation contrast agent in assessing the severity of chronic diffuse liver disease and differentiating cirrhotic from noncirrhotic liver disease.

METHODS

Contrast-enhanced sonography was performed after intravenous bolus injection of a second-generation contrast agent in 14 healthy control participants and 160 consecutive patients with cirrhotic and noncirrhotic liver disease (n = 78 and 82, respectively) enrolled between March 2004 and April 2014. The intensity of enhancement in a main hepatic vein was used to determine hepatic vein arrival time, time to peak intensity, and peak contrast enhancement.

RESULTS

The hepatic vein arrival time was lower in cirrhotic patients compared with both noncirrhotic patients and controls (mean ± SD, 15.0 ± 2.8, 21.5 ± 3.4, and 25.6 ± 4.7 seconds, respectively; P < .05). The hepatic vein arrival time in noncirrhotic patients was also significantly lower than that in controls (P < .05). The time to peak intensity was significantly lower in cirrhotic patients compared with noncirrhotic patients and controls (40.7 ± 13.7, 49.4 ± 12.8, and 51.2 ± 13.7 seconds; P < .05). A receiver operating characteristic curve analysis revealed that the hepatic vein arrival time more accurately excluded a diagnosis of liver cirrhosis than the time to peak intensity (area under the receiver operating characteristic curve, 0.953 versus 0.694). Specifically, a hepatic vein arrival time cutoff value of 17 seconds excluded liver cirrhosis with 91.1% sensitivity and 93.6% specificity.

CONCLUSIONS

Contrast-enhanced sonography is a valid alternative method for noninvasive staging of liver diseases. The hepatic vein arrival time could be used to exclude liver cirrhosis in a clinical setting.

Non-invasive diagnosis of liver fibrosis and cirrhosis

The evaluation and follow up of liver fibrosis and cirrhosis have been traditionally performed by liver biopsy. However, during the last 20 years, it has become evident that this “gold-standard” is imperfect; even according to its proponents, it is only “the best” among available methods. Attempts at uncovering non-invasive diagnostic tools have yielded multiple scores, formulae, and imaging modalities. All are better tolerated, safer, more acceptable to the patient, and can be repeated essentially as often as required. Most are much less expensive than liver biopsy. Consequently, their use is growing, and in some countries the number of biopsies performed, at least for routine evaluation of hepatitis B and C, has declined sharply. However, the accuracy and diagnostic value of most, if not all, of these methods remains controversial. In this review for the practicing physician, we analyze established and novel biomarkers and physical techniques. We may be witnessing in recent years the beginning of the end of the first phase for the development of non-invasive markers. Early evidence suggests that they might be at least as good as liver biopsy. Novel experimental markers and imaging techniques could produce a dramatic change in diagnosis in the near future.

Non-invasive diagnosis of advanced fibrosis and cirrhosis

Liver cirrhosis is a common and growing public health problem globally. The diagnosis of cirrhosis portends an increased risk of morbidity and mortality. Liver biopsy is considered the gold standard for diagnosis of cirrhosis and staging of fibrosis. However, despite its universal use, liver biopsy is an invasive and inaccurate gold standard with numerous drawbacks. In order to overcome the limitations of liver biopsy, a number of non-invasive techniques have been investigated for the assessment of cirrhosis. This review will focus on currently available non-invasive markers of cirrhosis. The evidence behind the use of these markers will be highlighted, along with an assessment of diagnostic accuracy and performance characteristics of each test. Non-invasive markers of cirrhosis can be radiologic or serum-based. Radiologic techniques based on ultrasound, magnetic resonance imaging and elastography have been used to assess liver fibrosis. Serum-based biomarkers of cirrhosis have also been developed. These are broadly classified into indirect and direct markers. Indirect biomarkers reflect liver function, which may decline with the onset of cirrhosis. Direct biomarkers, reflect extracellular matrix turnover, and include molecules involved in hepatic fibrogenesis. On the whole, radiologic and serum markers of fibrosis correlate well with biopsy scores, especially when excluding cirrhosis or excluding fibrosis. This feature is certainly clinically useful, and avoids liver biopsy in many cases.

Noninvasive assessment of portal hypertension in cirrhosis: Liver stiffness and beyond

Liver stiffness measurement (LSM) is a good, but still limited tool to noninvasively assess complications and prognosis in patients with advanced liver disease. This review aims to consider the role of LSM for the diagnosis of portal hypertension-related complications and for assessment of prognosis in cirrhotic patients, and to highlight the drawbacks as well as some alternatives for improving the performance. Hence, this field is far from being closed, and deserves more attention. There is still a place for more carefully designed studies to find new, innovative and reliable approaches.

Latest developments in the imaging of fibrotic liver disease

According to the World Health Organization, liver cirrhosis accounted for 1.8% of all deaths in Europe, causing about 170,000 deaths per year. Approximately 29 million persons in the EU suffer from chronic liver disease and this trend is on the rise. Liver disease is the EU's fifth most common cause of death accounting for at least one in six deaths. Early detection and monitoring of fibrosis has the potential to direct management of these chronic liver diseases and avert morbidity and mortality. Although the available techniques are in their infancy and the very early stages of fibrosis are difficult to detect, there have been significant advances in imaging over the last decade that has resulted in the use of these new imaging techniques being introduced into the patient pathway. This review explores the accuracies of these imaging techniques, their role in the management of patients, and the potential for the future.

Contrast-enhanced ultrasound evaluation of hepatic microvascular changes in liver diseases

AIM: To assess if software assisted-contrast-enhanced ultrasonography (CEUS) provides reproducible perfusion parameters of hepatic parenchyma in patients affected by chronic liver disease.

METHODS: Forty patients with chronic viral liver disease, with (n = 20) or without (n = 20) cirrhosis, and 10 healthy subjects underwent CEUS and video recordings of each examination were then analysed with Esaote’s Qontrast software. CEUS dedicated software Qontrast was used to determine peak (the maximum signal intensity), time to peak (TTP), region of blood value (RBV) proportional to the area under the time-intensity curve, mean transit time (MTT) measured in seconds and region of blood flow (RBF).

RESULTS: Qontrast-assisted CEUS parameters displayed high inter-observer reproducibility (κ coefficients of 0.87 for MTT and 0.90 TTP). When the region of interest included a main hepatic vein, Qontrast-calculated TTP was significantly shorter in cirrhotic patients (vs non-cirrhotics and healthy subjects) (71.0 ± 11.3 s vs 82.4 ± 15.6 s, 86.3 ± 20.3 s, P < 0.05). MTTs in the patients with liver cirrhosis were significantly shorter than those of controls (111.9 ± 22.0 s vs 139.4 ± 39.8 s, P < 0.05), but there was no significant difference between the cirrhotic and non-cirrhotic groups (111.9 ± 22.0 s vs 110.3 ± 14.6 s). Peak enhancement in the patients with liver cirrhosis was also higher than that observed in controls (23.9 ± 5.9 vs 18.9 ± 7.1, P = 0.05). There were no significant intergroup differences in the RBVs and RBFs.

CONCLUSION: Qontrast-assisted CEUS revealed reproducible differences in liver perfusion parameters during the development of hepatic fibrogenesis.

Accuracy and reliability of microbubble ultrasound measurements for the non-invasive assessment of hepatic fibrosis in chronic hepatitis C

AIM

  Contrast-enhanced ultrasound can be used to assess liver disease severity non-invasively by observing intra- and extrahepatic hemodynamic changes. Transit times are calculated to include intra- and extrahepatic components (hepatic vein transit time, HVTT) or the intrahepatic component (hepatic transit time, HTT), but these have not been compared directly. We aimed to compare diagnostic accuracy of HVTT and HTT in gauging the severity of chronic hepatitis C (CHC) and to assess inter- and intra-observer reliability.

METHODS

  Recorded ultrasound scans performed on 75 patients with biopsy-staged CHC, using the microbubble contrast agent Sonovue were analyzed.

RESULTS

  Diagnostic accuracy of HTT and HVTT for diagnosis of cirrhosis was 0.78 and 0.71 (P = 0.24). Diagnostic accuracy of HTT and HVTT for diagnosis of fibrosis stage >2 was 0.76 and 0.72 (P = 0.23). Negative predictive value for cirrhosis using this cut-off was high for both techniques (HVTT, 88%; HTT, 92%), suggesting utility for exclusion of cirrhosis. Inter-observer reliability for HTT and HVTT were 0.92 and 0.94, respectively. Intra-observer reliability for HTT and HVTT were 0.98 and 0.99.

CONCLUSION

  In this cohort, reliability exceeded 90% while diagnostic accuracy was in keeping with previous studies of microbubble transit time analysis. Despite higher numerical diagnostic accuracy for HTT, no significant difference was demonstrated between the techniques, suggesting that both methods can be used reliably.

Intrahepatic transit time predicts liver fibrosis in patients with chronic hepatitis B: quantitative assessment with contrast-enhanced ultrasonography

We investigated the use of contrast-enhanced ultrasonography (CEUS) with quantitative measurements to assess the stages of liver fibrosis in patients with chronic hepatitis B. One-hundred twenty-two patients with chronic hepatitis B were divided into three groups according to the Scheuer scoring system pathologically and according to clinical evidence: mild fibrosis (S0 and S1, n = 36); moderate fibrosis (S2 and S3, n = 24); and cirrhosis (S4 and clinically typical cirrhosis, n = 62). CEUS of hepatic vessels and parenchyma was performed using the Cadence contrast pulse sequencing technique, with an intravenous bolus injection of a contrast agent (SonoVue). Real-time CEUS imaging of the liver was recorded and analyzed offline. Contrast arrival time, baseline, and peak intensity in the hepatic artery, portal vein, right hepatic vein, and liver parenchyma were used to calculate intrahepatic transit times, hepatic artery to hepatic vein transit time (HA-HVTT) and portal vein to hepatic vein transit time (PV-HVTT), as well as increased signal intensity (ISI). The correlations between these quantitative parameters and the stages of fibrosis were analyzed using Spearman rank correlation coefficients. HA-HVTT and PV-HVTT were shortened gradually with the progression of liver fibrosis. PV-HVTT was statistically significant differences existed between the two paired groups (mild vs. moderate vs. cirrhosis groups, p < 0.001), whereas HA-HVTT was changed significantly between mild and moderate or cirrhosis groups (p < 0.001). HA-HVTT and PV-HVTT changes were significantly correlated with liver fibrosis severity (r = -0.5930, p < 0.001; r = -0.8215, p < 0.001). Area under receiver operating characteristic curves for HA-HVTT and PV-HVTT were 0.891 +/- 0.034 and 0.955 +/- 0.020 at fibrosis scores >or=S2, and 0.785 +/- 0.040 and 0.946 +/- 0.018 at fibrosis score >or=S4, respectively. ISI values in the portal vein and liver parenchyma decreased with the severity of fibrosis. This study demonstrated that hepatic CEUS with quantitative measurements of intrahepatic transit time reflected the severity of liver fibrosis. The real-time CEUS imaging with use of software-based quantitative analysis could provide reliable information of hepatic hemodynamic changes to noninvasively assess the severity of liver fibrosis in patients with chronic hepatitis B.

Advances in ultrasonic diagnosis of hepatic fibrosis and early cirrhosis

With the development of medical ultrasonic technology, sonography has become an important means for diagnosis and evaluation of hepatic fibrosis and early cirrhosis. Two-dimensional sonography is the basic means of ultrasonic diagnosis and can be used to display the appearance and echo of the liver. Color Doppler sonography and Doppler frequency spectrum permit assessment of the portal venous system and detection of portal blood flow. They can be used not only for estimation of hepatic parenchymal changes but also for evaluation of portal hypertension and its complications. Contrast-enhanced ultrasound permits use of a blood-pool tracer and can assess the blood flow perfusion of hepatic parenchyma. Elasticity imaging indirectly reflects tissue pathological changes by measuring tissue elastic modulus. Fibroscan has shown great promise for staging and diagnosing hepatic fibrosis and monitoring the development of hepatic cirrhosis and portal hypertension, thus offering a new method for noninvasive diagnosis of hepatic diseases. The clinical application of these techniques has greatly improved the diagnosis of hepatic diseases. In this article, we will review the recent advances in ultrasonic diagnosis of hepatic fibrosis and early cirrhosis.

Systematic review: non-invasive methods of fibrosis analysis in chronic hepatitis C

BACKGROUND

Accurate determination of the presence and degree of liver fibrosis is essential for prognosis and for planning treatment of patients with chronic hepatitis C virus (HCV). Non-invasive methods of assessing fibrosis have been developed to reduce the need for biopsy.

AIM

To perform a review of these non-invasive measures and their ability to replace biopsy for assessing hepatic fibrosis in patients with chronic HCV.

METHODS

A systematic review of PUBMED and EMBASE was performed through 2008 using the following search terms: HCV, liver, elastography, hepatitis, Fibroscan, SPECT, noninvasive liver fibrosis, ultrasonography, Doppler, MRI, Fibrotest, Fibrosure, Actitest, APRI, Forns and breath tests, alone or in combination.

RESULTS

We identified 151 studies: 87 using biochemical, 57 imaging and seven breath tests either alone or in combination.

CONCLUSIONS

Great strides are being made in the development of accurate non-invasive methods for determination of fibrosis. Although no single non-invasive test or model developed to date can match that information obtained from actual histology (i.e. inflammation, fibrosis, steatosis), combinations of two modalities of non-invasive methods can reliably differentiate between minimal and significant fibrosis, and thereby avoid liver biopsy in a significant percentage of patients.

Non-invasive evaluation of liver cirrhosis using ultrasound

Ultrasound (US) is essential in both assessment of the potentially cirrhotic liver and surveillance of selected patients with chronic hepatitis as liver biopsy can be misleading or inaccurate in up to 25% of cases. Various techniques are already in routine use, such as grey-scale imaging, Doppler US, and contrast-enhanced US (CEUS), while newer techniques such as elastography and hepatic vein transit time (HVTT) have the potential to exclude patients without significant fibrosis or cirrhosis; however, they are operator dependent and require specific software. Grey-scale imaging may demonstrate changes, such as volume redistribution, capsule nodularity, parenchymal nodularity, and echotexture changes. The Doppler findings in the hepatic and portal veins, hepatic artery, and varices allow assessment of liver cirrhosis. However, the operator needs to be aware of limitations of these techniques. Low mechanical index CEUS plays an important role in the assessment of complications of cirrhosis, such as hepatocellular carcinoma and portal vein thrombus. Optimized US technique is crucial for accurate diagnosis of the cirrhotic liver and its complications.