Sage Journals: Discover world-class research

Abstract

Objective:

Fatty liver disease (FLD) affects hepatic hemodynamics, which can be assessed using Doppler indices. Understanding variations in these indices can enhance noninvasive diagnostic and monitoring tools for FLD. The aim of this review was to assess and analyze variations in hepatic artery resistive index (HARI), portal vein pulsatility index (PVPI), and portal vein velocity (PVV) in patients with FLD.

Materials and Methods:

This study reviewed variations in hepatic Doppler indices in patients with fatty liver disease (FLD) by analyzing peer-reviewed studies published between 2000 and 2024. A total of 52 articles were identified across several scientific databases, using Boolean operators and relevant search phrases. The meta-analysis utilized a random-effects model to account for heterogeneity, which was further assessed using chi-square tests (p < .05) and I² statistics (low: ≤ 25%, moderate: 50%, high: ≥75%).

Results:

The procured data revealed that FLD patients exhibited significantly lower HARI (15% reduction), VPI (10% reduction), and PVV (25% reduction) than healthy controls (p < .05), indicating reduced portal vein flow and increased hepatic artery flow. The liver compensated for fatty infiltrations in hepatic portal vessels by vasodilation of the hepatic arteries, increasing hepatic artery flow, and decreasing HARI. The severity of FLD in the study participant samples was found to influence Doppler indices, emphasizing their potential as noninvasive biomarkers for diagnosing and monitoring FLD.

Conclusion:

This literature review was focused on FLD, which has been consistently associated with reduced portal vein indices and compensatory increases in hepatic artery flow. Variations in HARI, PVPI, and PVV reflected both the hemodynamic consequences of fatty infiltration and the liver’s compensatory adaptations. It may be clinically valuable to further explore these parameters, as noninvasive biomarkers for the diagnosis, staging, and monitoring of FLD.

Keywords

Fatty liver disease hepatic Doppler indices Liver sonography systematic review

The liver plays a critical role in overall health, performing essential functions such as detoxification, metabolism, and protein synthesis.^1,2 However, abnormalities in liver function can lead to serious conditions, including fatty liver disease (FLD) or steatotic liver disease, which has emerged as a global health concern.³ FLD is characterized by excess fat accumulation in liver cells and is broadly categorized into metabolic dysfunction-associated steatotic liver disease (MASLD), also known as nonalcoholic fatty liver disease (NAFLD), and alcoholic fatty liver disease (AFLD). NAFLD, the more prevalent form, ranges from simple steatosis to metabolic dysfunction-associated steatohepatitis (MASH), also called nonalcoholic steatohepatitis (NASH), which can progress to cirrhosis and liver cancer.⁴ AFLD, caused by chronic alcohol consumption, shares similar pathophysiological changes with NAFLD, including inflammation, oxidative stress, and vascular changes.^5,6

Doppler has become an invaluable noninvasive tool for evaluating blood flow dynamics.^7,8 Hepatic Doppler indices (hepatic artery resistive index [HARI], portal vein pulsatility index [PVPI], and portal vein velocity [PVV]) can be assessed quantitatively to determine intrahepatic vascular flow and integrity. These indices are essential for diagnosing and monitoring liver diseases, including FLD, portal hypertension, and cirrhosis,⁹ as elevated values of HARI suggest cirrhosis or fibrosis,⁹ the PVPI assists with identifying vascular abnormalities,⁹ and abnormal PVV values raise suspicion of portal hypertension and/or advanced liver disease.^7,10

Recent evidence indicates that changes in Doppler indices may occur in patients with fatty liver disease due to structural, physiologic and hemodynamic changes in the liver, as the disease progresses.^11,12 In FLD, HARI may decrease due to compensatory vasodilation from fat-induced inflammation (i.e., if FLD progresses to fibrosis or cirrhosis, the HARI will increase), PVPI reduces because of increased portal venous pressure, reduced vascular compliance within the liver, due to parenchymal stiffening, and diminished right atrial compliance, and PVV reduces, due to progressive increased intrahepatic resistance. However, findings are heterogeneous across published studies, and there appears to be no standardized reference for interpreting these variations observed during different stages of FLD. In addition, a variety of conflicting outcomes are due to differences in Doppler protocols, disease classification, and patient demographics.

The purpose of this systematic review was to synthesize current evidence concerning variations in hepatic Doppler indices in patients with FLD, compare findings between disease severity and healthy controls, and to review whether Doppler can serve as a diagnostic staging tool for MASLD/MASH.

Materials and Methods

Research Design

This study used a systematic review, and a meta-analysis based on the PRISMA 2020 guidelines, to synthesize evidence regarding the diagnostic utility of hepatic Doppler indices for FLD patients. The goal of this review was to quantify differences in Doppler parameters between individuals with FLD and a healthy control group, using HARI, PVV, and PVPI, as examples of such parameters.

To provide context to the Doppler findings, normative standards of the studies that were included were analyzed. The values of PVV and PVPI are substantially decreased in NAFLD patients when compared with healthy individuals.^12–15 It is also reported that NAFLD patients have HARI that is reduced,^13,14 and the reduction of PVV, PVPI, and HARI tends to confirm the diagnosis of FLD.^4,16 Other reports indicate specific cutoff values in the identification of advanced liver disease: PVV < 13 cm/s and HARI > 1.1.¹⁵ Also, it has been proposed that a PVPI < 0.26 will indicate the presence of steatosis.¹⁷ These values form a noninvasive way to grade the NAFLD severity and confirm the diagnosis.¹⁸

Eligibility Criteria

Studies were included if they met the following criteria:

Published in English between January 2000 and January 2024.

Peer-reviewed, human clinical studies (observational or experimental).

Involved patients diagnosed with NAFLD/NASH or FLD, confirmed via clinical or imaging criteria.

Reported quantitative values for at least one of the following Doppler indices: HARI, PVV, or VPI.

Included a comparative group of healthy individuals.

Exclusion Criteria

Studies involving other chronic liver diseases (e.g., hepatitis B/C and autoimmune liver disease).

Case reports, reviews, editorials, or studies without original data.

Studies that did not use Doppler as the primary diagnostic tool.

Search Strategy

A comprehensive literature search was conducted across PubMed, Google Scholar, ResearchGate, and Semantic Scholar. The search was carried out between November 2024 and January 2025. A representative search string used in PubMed was

(“fatty liver disease” OR “FLD” OR “NAFLD” OR “non-alcoholic steatohepatitis”) AND (“hepatic Doppler indices” OR “resistive index” OR “pulsatility index” OR “portal vein velocity” OR “Doppler ultrasound”)

Search terms were combined using Boolean operators (AND, OR). Searches were restricted to titles and abstracts for PubMed, while Google Scholar, ResearchGate, and Semantic Scholar retrieved content using full-text matching, as per their platform default behaviors. The bibliographies of the included studies were also screened manually for additional eligible records. In addition, the bibliographies of included articles were searched manually to identify any other relevant studies.

Study Selection

A total of 52 articles were initially identified for review. Of these, 24 were screened based on title relevance, resulting in the exclusion of 12 articles due to irrelevance. An additional four articles were excluded after abstract and content review for not aligning with the study’s aims. Furthermore, two articles were removed for failing to meet eligibility criteria, such as the absence of quantifiable Doppler parameters or methodological limitations. One additional article was retrieved through manual reference searching. Following this rigorous screening process, seven full-text articles were deemed suitable and included in the final meta-analysis. The screening was conducted in an independent manner by several reviewers, and disagreements were resolved by group consensus. A PRISMA flow diagram illustrating the selection process of the study (See Figure 1).

Figure 1.

A flowchart that outlines the process of the database search and studies procured.

Data Extraction

A standardized data extraction form was used to retrieve the following information from each included article: Author(s), year of publication, country, study design and sample size, diagnostic criteria for FLD, Doppler indices evaluated: HARI, PVV, and PVPI, mean and standard deviation of indices in FLD patients and the healthy controls groups. Data were extracted independently by two independent review groups and cross-checked for consistency.

Data Synthesis and Statistical Analysis

A random-effects meta-analysis was done to consider expected heterogeneity between studies. For each Doppler index (HARI, PVV, PVPI), the pooled mean difference between FLD patients and healthy controls, and their corresponding 95% confidence intervals (CIs) were calculated for each. The I² statistics was used to assess heterogeneity, and was considered low: ≤ 25%, moderate: 50%, high: ≥75%¹⁹ and by the chi-square test (significance at p < .05). Each Doppler parameter (HARI, PVV, PVPI) was analyzed for differential effects by subgroup analysis. IBM SPSS Statistics, version 24 (IBM Corp., Armonk, NY, USA) was used to conduct all statistical analyses. The chi-square (χ²) test, the I-squared (I²) statistic, and the Tau-squared (Tau²) estimation were used in the evaluation of heterogeneity across studies. When χ² is significant (p < .10), it implies that the differences that have been observed between studies are not likely to be by chance. I² values above 75% are interpreted as indicating substantial heterogeneity.¹⁹ Tau² estimates the variance between studies in a random-effects model; higher Tau² values reflect more dispersion in effect sizes, although there is no cutoff associated with such a value. Interpretation is based on the context of the analysis, the number of included studies, and the magnitude of variance.

Results

A total of 52 studies were retrieved from PubMed, Google Scholar, Semantic Scholar and ResearchGate. There were 44 studies excluded because they did not meet the inclusion criteria after screening titles and abstracts. Eight full-text articles were reviewed, of which two were excluded due to lack of Doppler index data or irrelevant diagnostic focus. By the manual search of the references of included articles, an extra article was retrieved. Therefore, seven articles were included in both the qualitative synthesis and in the meta-analysis because they met the eligibility criteria. These seven articles included studies that were conducted in Egypt, Saudi Arabia, India, Iran, and Turkey, and all used Doppler for the assessment of hepatic vascular parameters in patients with FLD. HARI, PVV, and PVPI were typically compared between FLD patients and healthy controls in most studies. The summary of the included studies is presented in Table 1.

Table 1.

A Summary of the Data That was Procured From the Retained Articles.

Reference ID	Paper title	Methodology	Findings
Mousa et al²⁰	Value of hepatic artery resistive index (HARI) in evaluation of liver fibrosis related to nonalcoholic fatty liver diseases (NAFLD)	This study was conducted on 100 NAFLD patients who had undergone Doppler. The HARI was measured to determine the degree of steatosis. The HARI scores were correlated with the other factors using a Spearman’s correlation.	The mean ± SD of HARI among the study subjects was 0.69±0.1. The study revealed a statistically significant positive correlation of HARI with age, fasting blood sugar, LDL, HDL, and albumin. At a cutoff value of 0.76, HARI had 80% sensitivity and 76% specificity for predicting advanced fibrosis. Conclusively, HARI is a good noninvasive way to determine how likely it is that liver fibrosis will progress in patients with NAFLD, especially if they already have severe fibrosis or cirrhosis.
Sabry et al¹³	Portal venous and hepatic artery hemodynamic variation in NAFLD	The 80 participants in this case-control research were split into four groups: volunteers who were healthy and patients in grades 1, 2, and 3 with NAFLD. Doppler was performed on all the participants, and MFV, PVPI, HARI, peak maximum velocity, and peak minimum velocity were measured. SPSS 25 was used to analyze the data that was gathered.	Compared with healthy patients, NAFLD patients had substantially decreased V_max, V_min, MFV, PVPI, and HARI Doppler indices. The NAFLD grade was substantially inversely proportional to V_max, MFV, VPI, and HARI.The mean±S.D of HARI among the case group was 0.74±0.04 as compared with a mean of 0.82±0.02 for the controls. The MFV for the case group was 12.56±2.56 as compared with 22.95±0.67 for the control group. The case group’s PVPI was 0.37±0.12, while the controls were 0.65±0.02. The study concluded that fatty liver disease may be diagnosed and graded noninvasively by measuring the decrease in portal flow and the rise in hepatic artery flow, which correspond with the severity of the illness.
Bedewi et al²¹	Doppler hemodynamics in NAFLD	This was case-control research carried out in 34 participants with a sonographically diagnosed NAFLD and 15 subjects. Additionally, the hepatic artery flow, PSV, and the hepatic artery RI were determined by Doppler, along with the portal vein width and flow direction. Mean values ± SD are used to display the results.	Findings from this study revealed that there was no statistically significant difference between HARI and NAFLD (0.7327±0.0695) and the control group (0.70±0.1361). There was a lack of statistical significance between the control group’s mean PV velocity (20.1± 5.683) and that of NAFLD patients (20.37 ± 5.142) (p= 0.7623). NAFLD patients had a significantly higher HA PSV (40.878 ± 12.833) than the control group (12.700 ± 3.129) (p<0.0001).
Balasubramanian et al¹⁴	Assessment of Portal Venous and Hepatic Artery Haemodynamic Variation in NAFLD Patients	The portal vein and hepatic artery Doppler investigation was performed on 90 patients who had been diagnosed with NAFLD based on abdominal sonography (30 in grade 1, grade 2, and grade 3 NAFLD) and 30 healthy subjects. The Doppler parameters that were evaluated were the peak V_max, PVPI, peak V_min, HARI, and the MFV.	NAFLD patients had mean portal vein Vmax, Vmin, MFV, and PVPI of 12.23 ± 1.74 cm/sec, 9.31 ± 1.45 cm/sec, 10.76 ± 1.48 cm/sec, and 0.24 ± 0.04, respectively. The control group, conversely, had equivalent values of 14.05 ± 2.43 cm/sec, 10.01 ± 2.27 cm/sec, 12.23 ± 2.47 cm/sec, and 0.3 ± 0.08. NAFLD patients had a mean HARI of 0.65 ± 0.06, which was considerably lower than the controls’ 0.75 ± 0.06 (p= .001). MFV demonstrated a mild negative connection (r = −0.182) with NAFLD severity, but HARI showed the highest negative correlation (r = −0.517), followed by PVPI (r = −0.44) and Vmax (r = −0.293). Reduced portal vein flow and increased hepatic artery flow are shown by the considerable decreases in Vmax, MFV, PVPI, and HARI in NAFLD patients compared with controls. HARI and PVPI were the two indices that most strongly correlated with the severity of NAFLD
Tarzamni et al⁹	Hepatic Artery and Portal Vein Doppler in NAFLD Before and After Treatment to Prevent Unnecessary Health Care Costs	A decrease in liver enzyme levels was used to measure the response to therapy in this study, which evaluated 48 consecutive NAFLD patients referred to clinics in Iran between 2009 and 2011. Three liver Doppler parameters—the portal vein waveform [PVW], HARI, and hepatic artery PI, were examined in all subjects who displayed a decline in liver function test results using Wilcoxon and paired student’s t-tests.	Before and after therapy, the mean HARI rose from 0.60 ± 0.07 to 0.83 ± 0.27. In conclusion, a rise in HARI as determined by Doppler may indicate that an NAFLD patient is getting better while receiving treatment.
Ulusan et al²²	Evaluation of Portal Venous Velocity with Doppler in Patients with NAFLD	In this prospective research, Doppler was used to measure the portal venous velocity in 29 normal subjects and 35 NAFLD patients. The portal venous velocity differences between NAFLD patients and normal participants were compared using the Student’s t-test. A difference was considered statistically significant if its p-value was less than 0.05.	Patients with NAFLD and the control group had significantly different portal vein velocities (p<.0001). Patients with NAFLD had a mean portal vein velocity of 27.60 cm/s (range: 18.10-46.60 cm/s), whereas the controls had a mean of 32.15 cm/s (range: 13.60-55.00 cm/s). In summary, this study indicates that compared with healthy persons, patients with NAFLD had decreased portal venous velocities.
Solhjoo et al¹¹	Comparison of Portal Vein Doppler Indices and Hepatic Vein Doppler Waveform in Patients with NAFLD with Healthy Control	In this case-control research, there were 31 NAFLD patients and 31 controls participants. The right hepatic venous waveform patterns, portal vein width, grade of fatty liver, PVPI, and MFV were assessed following an 8-hour fast, followed by grayscale and duplex Doppler.	In the control group, the PVPI and MFV values were 0.42 ± 0.92 and 17.27 ± 5.34 cm/second, respectively, compared with 0.25 ± 0.50 and 12.82 ± 4.32 cm/second in NAFLD patients (p<.01). The prevalence of abnormal hepatic vein Doppler waveform patterns (biphasic or monophasic) was significantly higher in NAFLD patients (55.2%) compared with the control group (3.2%) (p<.001). In summary, NAFLD patients exhibit a higher frequency of abnormal hepatic vein Doppler waveform patterns, and the observed reductions in VPI and MFV indicate decreased vascular compliance in the liver.

Meta-analysis of Doppler Indices

The mean HARI, PVV, and PVPI are shown in Table 2, indicating significant alterations in hepatic hemodynamics among FLD patients.

Table 2.

Reported Hepatic Doppler Indices in FLD Patients.

	Experimental (HARI)			Control (HARI)				Mean Difference
Study/Subgroup	Mean	SD	Total	Mean	SD	Total	Weight	IV, Random, 95% CI
Tarzamni et al⁹	0.6	0.07	22	0.83	0.27	22	10.2%	−0.23 [−0.35, −0.11]
Balasubramanian et al¹⁴	0.65	0.06	90	0.75	0.06	30	34.2%	−0.10 [−0.12, −0.08]
Bedewi and Kamal²¹	0.73	0.0695	34	0.7	0.1361	15	18.5%	0.03 [−0.04, 0.10]
Sabry et al¹³	0.74	0.04	60	0.82	0.02	20	37.1%	−0.08 [−0.09, −0.07]
Total (95%CI)			206			87	100.0%	−0.08 [−0.13, −0.04]

Heterogeneity: Tau²=0.00, χ² = 17.38, df = 3 (p = .0006), I² = 83%, Test for overall effect: Z = 3.69 (p = .0002).

Four out of the seven studies compared the mean HARI between FLD patients and healthy adults (see Table 3), which was significantly higher in healthy adults (range: 0.75–0.83) than in the FLD patients (range: 0.6–0.74). In the pooled analysis, the HARI was significantly lower in FLD patients than in the control groups, with a mean difference of −0.08 (95% CI: −0.13 to −0.04, p = .0006). However, there were large variations (I² = 83%, χ² = 17.38, df = 3), possibly owing to patient differences, disease staging, and imaging protocols. An exception to this overall trend was observed by Bedewi and Kamal, who found slightly higher HARI in controls (0.70 ± 0.14) compared with FLD patients (0.73 ± 0.07). Pooled means and ranges are summarized in Table 3 (An associated forest plot is provided as Supplemental Figure 2, use the QR code).

Table 3.

Hepatic Artery Resistive Index (HARI) Between Patients With FLD and Healthy Individuals.

Study	HARI (mean±S.D)	Mean PVV (cm/second)	Venous Pulsatility Index (VPI)
Solhjoo et al¹¹	N/A	12.82±4.32	0.25±0.50
Ulusan et al²²	N/A	27.60	N/A
Tarzamni et al⁹	0.60±0.07	16.8±0.04	N/A
Balasubramanian et al¹⁴	0.65±0.06	10.01±2.27	0.24±0.04
Bedewi and Kamal²¹	0.73±0.07	N/A	N/A
Sabry et al¹³	0.74±0.04	12.56±2.56	0.37±0.12
Mousa et al²⁰	0.69±0.10	N/A	N/A

Five studies reported that the mean PVV was significantly higher in healthy participants (12.23–32.15 cm/sec) than in FLD patients (10.01–27.60 cm/sec) (See Table 4). The pooled analysis demonstrated that PVV was significantly lower in FLD patients, with a mean difference of −2.92 cm/s (95% CI: −4.61 to −1.23, p < .00001). Heterogeneity was high (I² = 97%, χ² = 133.06, df = 4), possibly due to variability and differences in the methods with which these indices were measured. These results are summarized in Table 4 (An associated forest plot is provided as Supplemental Figure 3; use the QR code).

Table 4.

Portal Vein Velocity (PVV) Between Patients With FLD and Healthy Individuals.

	Experimental (PVV)			Control (PVV)				Mean Difference
Study/Subgroup	Mean	SD	Total	Mean	SD	Total	Weight	IV, Random, 95% CI
Solhjoo et al¹¹	12.82	4.32	31	17.27	5.34	31	20.7%	−0.90 [−1.43, −0.38]
Ulusan et al²²	27.6	0.6	35	32.15	0.5	29	18.0%	−8.07 [−9.59, −6.54]
Tarzamni et al⁹	16.8	0.04	22	17.02	0.36	22	20.5%	−0.84 [−1.46, −0.22]
Balasubramanian et al¹⁴	10.01	2.27	90	12.23	2.47	30	20.8%	−0.95 [−1.38, −0.52]
Sabry et al¹³	12.56	2.56	60	22.95	0.67	20	20.0%	−4.57 [−5.46, −3.69]
Total (95%CI)			238			132	100.0%	−2.92 [−4.61, −1.23]

Heterogeneity: Tau²=3.53, χ² = 133.06, df = 4 (p<0.00001), I² = 97%, Test for overall effect: Z = 3.39 (p = .0007).

The three studies assessing VPI found significantly lower values in the FLD patients (See Table 5). The pooled mean difference was −1.32 (95% CI: −2.54 to −0.09, p < .00001). Although the direction of effect was consistent across studies, heterogeneity remained substantial (I² = 94%, χ² = 32.93, df = 2). According to Sabry et al and Balasubramanian et al, the clear differences between the FLD and control groups (VPI: 0.24–0.37 vs 0.3–0.65) indicated that liver steatosis was associated with venous flow impedance (see Table 5 and the associated pooled estimates and forest plot, provided as Supplemental Figure 4, use the QR code).

Table 5.

Portal Vein Pulsatility Index (PVPI) Between Patients With FLD and Healthy Individuals.

	Experimental (VPI)			Control (VPI)				Mean Difference
Study/Subgroup	Mean	SD	Total	Mean	SD	Total	Weight	IV, Random, 95% CI
Solhjoo et al¹¹	0.25	0.5	31	0.42	0.92	31	33.6%	−0.023 [−0.73, 0.27]
Balasubramanian et al¹⁴	0.24	0.04	90	0.3	0.08	30	34.1%	−1.13 [−1.57, −0.69]
Sabry et al¹³	0.37	0.12	60	0.65	0.02	20	32.3%	−2.65 [−3.30, −1.99]
Total (95%CI)			181			81	100.0%	−1.32 [−2.54, −0.09]

Heterogeneity: Tau²=1.10, χ² = 32.93, df = 2 (p<0.00001), I² = 94%, Test for overall effect: Z = 2.10 (p = .04).

Heterogeneity and Outlier Analysis

High heterogeneity was observed across all indices (see Tables 3 –5). While the direction of effect remained largely consistent (i.e., Doppler indices lower in FLD), variation in sample size, operator technique, disease severity, and Doppler angle likely contributed to the heterogeneity. Bedewi and Kamal²¹ was the most prominent outlier, with findings inconsistent with the rest of the dataset.

Discussion

This systematic review and meta-analysis examined variations in hepatic Doppler indices, HARI, PVV, and PVPI in patients with FLD and compared them to healthy individuals. The findings revealed significant alterations in hepatic hemodynamics among FLD patients, with potential implications for diagnosis and monitoring. The reviewed studies reported a wide range of HARI values (0.60–0.74), which may be influenced by geographical and climatic conditions. For example, studies conducted in arid regions (e.g., Egypt, Saudi Arabia) reported higher HARI values,^13,21 while other studies conducted in more stable and humid regions reported lower HARI values.^9,14,20 Further research is needed to explore the relationship between environmental factors and hepatic Doppler indices. PVV and PVPI also varied significantly across studies, with PVV ranging from 10.01 to 27.60 cm/sec and PVPI ranging from 0.24 to 0.37. These variations were often correlated with FLD severity, consistent with previous findings that fatty infiltrations reduce portal vein flow.²³ However, some studies found no significant correlation, highlighting the need for standardized measurement techniques. The studies by Tarzamni et al,⁹ Sabry et al¹³ and Balasubramanian et al¹⁴ showed a consistently lower HARI in FLD patients than in healthy controls, with a confidence interval (CI) that does not overlap the line of no effect (i.e., zero) in the forest plot, indicating a statistically significant difference in the compared groups. None of the included studies that compared PVV overlapped the line of no effect (i.e., zero, indicating a significant difference in all the measured PVV across the studies. Three out of the seven included literature compared the PVPI of the two groups but only two studies (e.g., Sabry et al¹³ and Balasubramanian et al¹⁴) had a significant reduction in the PVPI of FLD patients when compared with the healthy control (did not cross the line of no effects on the forest plot). Although Solhjoo et al¹¹ showed a slight decrease in the PVPI of the two groups, it was statistically significant. The pooled mean difference for HARI was −0.08 (95% CI: −0.13 to −0.04; p = .0002), indicating significantly lower HARI in FLD patients. Similarly, PVV and PVPI were significantly reduced in FLD patients, with pooled standardized mean differences of −2.92 (95% CI: −4.61 to −1.23; p = .0007) and −1.32 (95% CI: −2.54 to −0.09; p = .04), respectively. These negative values indicate that these indices in FLD patients are significantly lower than in normal individuals, ultimately suggesting altered hepatic hemodynamics in FLD, characterized by reduced portal vein flow and compensatory hepatic artery vasodilation. However, the heterogeneity across the included studies was high (I²>83%), which suggests a significant variation across them, possibly due to differences in Doppler measurement protocols, subjectivity of the operator, patient characteristics (e.g., age and metabolic syndrome), disease staging (NAFLD vs NASH), and environmental factors.

The significant differences in HARI, PVV, and PVPI between FLD patients and healthy individuals highlight the potential of Doppler indices as noninvasive biomarkers for FLD diagnosis and monitoring. Two studies (e.g., Sabry et al¹³ and Balasubramanian et al¹⁴) further demonstrated that these indices correlate with FLD severity, supporting their use in tracking disease progression and treatment response. Doppler, being affordable, readily available, and radiation-free, is a valuable first-line tool for FLD management, particularly in resource-limited settings.

Limitations

This review has several limitations that may hamper generalization. Many of the studies conducted were in Asia and Africa, and this fact limits the level of generalizability to other populations. Some lacked control groups, which may have weakened comparative analysis. Also, the search was limited to four databases (PubMed, Google Scholar, ResearchGate, and Semantic Scholar), which may have excluded relevant studies found in Embase, Scopus, or CINAHL. As much as these databases were selected based on their access and coverage of peer-reviewed and gray literature, it is important to underscore this drawback and suggest considering more databases in future systematic reviews. Statistically, the small number and sample sizes of included studies may limit the reliability of heterogeneity measures like I² and Tau². According to Thorlund et al,²⁴ these estimates can be very different in small meta-analyses, and they are to be interpreted cautiously.

Conclusion

This systematic review and meta-analysis highlight significant variations in hepatic Doppler indices, HARI, PVV, and PVPI, among patients with FLD. Compared with healthy controls, FLD patients exhibited a 0.08 reduction in HARI, a 2.92 cm/sec reduction in PVV, and a 1.32 reduction in PVPI, indicating altered hepatic hemodynamics. These changes are attributed to compensatory mechanisms, such as vasodilation of the hepatic arteries, which increase hepatic artery flow and reduce resistance in response to decreased portal vein flow. The severity of FLD in the study cohorts influenced the range of Doppler indices observed, with more advanced disease associated with greater reductions in PVV and VPI. These findings emphasize the benefit of using Doppler as a nonionizing and low-cost noninvasive tool to diagnose and monitor the FLD, especially in areas having limited access to other diagnostic imaging tools. The application of hepatic Doppler indices for future research to predict disease progression and treatment response, and to standardize measurement techniques to reduce variability between studies should be considered. In summary, this review finds that Doppler plays an important expanding role in the management of FLD as a less invasive approach to diagnostic intervention.

Supplemental Material

sj-png-1-jdm-10.1177_87564793251380858 – Supplemental material for Variations in Hepatic Doppler Indices in Patients Presenting With Fatty Liver Disease: A Meta-Analysis

Supplemental material, sj-png-1-jdm-10.1177_87564793251380858 for Variations in Hepatic Doppler Indices in Patients Presenting With Fatty Liver Disease: A Meta-Analysis by Sobechukwu Warric Iwene Onwuzu, Uchenna Ugbala, Chukwunonso Ugbome, Ebubechi Udeh, Christiana Udeh, Stanley Udeh, Chelfrey Ucheoma and Kasiemobi Udegbunam in Journal of Diagnostic Medical Sonography

Supplemental Material

sj-png-2-jdm-10.1177_87564793251380858 – Supplemental material for Variations in Hepatic Doppler Indices in Patients Presenting With Fatty Liver Disease: A Meta-Analysis

Supplemental material, sj-png-2-jdm-10.1177_87564793251380858 for Variations in Hepatic Doppler Indices in Patients Presenting With Fatty Liver Disease: A Meta-Analysis by Sobechukwu Warric Iwene Onwuzu, Uchenna Ugbala, Chukwunonso Ugbome, Ebubechi Udeh, Christiana Udeh, Stanley Udeh, Chelfrey Ucheoma and Kasiemobi Udegbunam in Journal of Diagnostic Medical Sonography

Supplemental Material

sj-png-3-jdm-10.1177_87564793251380858 – Supplemental material for Variations in Hepatic Doppler Indices in Patients Presenting With Fatty Liver Disease: A Meta-Analysis

Supplemental material, sj-png-3-jdm-10.1177_87564793251380858 for Variations in Hepatic Doppler Indices in Patients Presenting With Fatty Liver Disease: A Meta-Analysis by Sobechukwu Warric Iwene Onwuzu, Uchenna Ugbala, Chukwunonso Ugbome, Ebubechi Udeh, Christiana Udeh, Stanley Udeh, Chelfrey Ucheoma and Kasiemobi Udegbunam in Journal of Diagnostic Medical Sonography

Footnotes

ORCID iDs

Sobechukwu Warric Iwene Onwuzu

Uchenna Ugbala

Supplemental Material

Supplemental material for this article is available online. Scan the QR code with your smart device to view the online supplemental materials available at .

References

Kalra

Yetiskul

Wehrle

Tuma

: Physiology, Liver. Treasure Island, FL, StatPearls Publishing; 2025. https://pubmed.ncbi.nlm.nih.gov/30571059/. Accessed September 17, 2025.

Trefts

Gannon

Wasserman

: The liver. Curr Biol 2017;27(21):R1147–R1151. doi:10.1016/j.cub.2017.09.019.

De Siervi

Cannito

Turato

: Chronic liver disease: latest research in pathogenesis, detection and treatment. Int J Mol Sci 2023;24(13):10633. doi:10.3390/ijms241310633.

Dilek

Kaya

: Can portal vein pulsatility index be used as predictive parameter with hepatic artery resistive index for liver fibrosis in non-alcoholic hepato-steatosis? Acta Med Alanya 2020;4(2):156–160. doi:10.30565/medalanya.689601.

Pouwels

Sakran

Graham

, et al: Non-alcoholic fatty liver disease (NAFLD): a review of pathophysiology, clinical management and effects of weight loss. BMC Endocr Disord 2022;22(1):63. doi:10.1186/s12902-022-00980-1.

Maurice

Manousou

: Non-alcoholic fatty liver disease. Clin Med 2018;18(3):245–250. doi:10.7861/clinmedicine.18-3-245.

El-Nakeep

Ziska

: Doppler Liver Assessment, Protocols, and Interpretation of Results [Internet]. Treasure Island, FL, StatPearls Publishing; 2023. https://pubmed.ncbi.nlm.nih.gov/33620802. Accessed October 21, 2024.

Zhang

Yin

Duan

Yang

Yuan

Cao

: Assessment of intrahepatic blood flow by Doppler ultrasonography: relationship between the hepatic vein, portal vein, hepatic artery and portal pressure measured intraoperatively in patients with portal hypertension. BMC Gastroenterol 2011;11(1):84. doi:10.1186/1471-230x-11-84.

Tarzamni

Khoshbaten

Sadrarhami

, et al: Hepatic artery and portal vein Doppler indexes in non-alcoholic fatty liver disease before and after treatment to prevent unnecessary health care costs. Int J Prev Med 2014;5(4):472–477.

10.

Stine

Wang

Shah

, et al: Decreased portal vein velocity is predictive of the development of portal vein thrombosis: a matched case-control study. Liver Int 2018;38(1):94–101. doi:10.1111/liv.13500.

11.

Solhjoo

Mansour-Ghanaei

Moulaei-Langorudi

Joukar

: Comparison of portal vein doppler indices and hepatic vein doppler waveform in patients with nonalcoholic fatty liver disease with healthy control. Hepat Mon 2011;11(9):740–744. doi:10.5812/kowsar.1735143x.729.

12.

Erdogmus

Tamer

Buyukkaya

, et al: Portal vein hemodynamics in patients with non-alcoholic fatty liver disease. Tohoku J Exp Med 2008;215(1):89–93. doi:10.1620/TJEM.215.89.

13.

Sabry

Youssef

Shaker

Salama

Assem

Anwar

: Portal venous and hepatic artery hemodynamic variation in non-alcoholic fatty liver disease. Egypt Liver J 2021;11(1):58. doi:10.1186/s43066-021-00130-7.

14.

Balasubramanian

Boopathy

Govindasamy

Venkatesh

: Assessment of portal venous and hepatic artery haemodynamic variation in non-alcoholic fatty liver disease (NAFLD) patients. J Clin Diagn Res 2016;10(8):TC07–TC10. doi:10.7860/jcdr/2016/20697.8267.

15.

Iwao

Toyonaga

Oho

, et al: Value of Doppler ultrasound parameters of portal vein and hepatic artery in the diagnosis of cirrhosis and portal hypertension. Am J Gastroenterol 1997;92(6):1012–1017.

16.

Mohammadi

Ghasemi-rad

Zahedi

Toldi

Alinia

: Effect of severity of steatosis as assessed ultrasonographically on hepatic vascular indices in non-alcoholic fatty liver disease. Med Ultrason 2011;13(3):200–206.

17.

Gonçalves Dos Reis Monteiro

Ferreira De Almeida

Borges

Machado De Alcântara

Borges De Araújo

De Fátima Pinheiro

Lemos Debs Diniz

: Liver hemodynamic patterns in nonalcoholic steatosis: Doppler ultrasonography and histological evaluation. Minerva Gastroenterol Dietol 2016;62(1):19–29.

18.

Tana

Rossi

Silingardi

Schiavone

: Hepatic artery resistive index (HARI) and non-alcoholic fatty liver di sease (NAFLD) fibrosis score in NAFLD patients: cut-off suggestive of non-alcoholic steatohepatitis (NASH) evolution. J Ultrasound 2016;19(3):183–189. doi:10.1007/s40477-016-0203-8.

19.

Higgins

JPT

Thompson

Deeks

Altman

: Measuring inconsistency in meta-analyses. BMJ 2003;327(7414):557–560. doi:10.1136/bmj.327.7414.557.

20.

Mousa

EL-Eraky

Arafa

, et al: Value of hepatic artery resistive index in evaluation of liver fibrosis related to non-alcoholic fatty liver diseases. Med J Viral Hepat 2023;72(2):1–8. doi:10.21608/mjvh.2023.296888.

21.

Bedewi

Kamal

: Doppler sonographic hemodynamics in non-alcoholic fatty liver disease. J Int Pharm Res 2019;46:283–286.

22.

Ulusan

Yakar

Koc

: Evaluation of portal venous velocity with Doppler ultrasound in patients with non-alcoholic fatty liver disease. Korean J Radiol 2011;12(4):450–455. doi:10.3348/kjr.2011.12.4.450.

23.

Balci

Karazincir

Sumbas

Oter

Egilmez

Inandi

: Effects of diffuse fatty infiltration of the liver on portal vein flow hemodynamics. J Clin Ultrasound 2008;36(3):134–140. doi:10.1002/jcu.20440.

24.

Thorlund

Imberger

Johnston

, et al: Evolution of heterogeneity (I2) estimates and their 95% confidence intervals in large meta-analyses. PLoS ONE 2012;7(7):e39471. doi:10.1371/journal.pone.0039471.

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

0.00 MB

0.12 MB

0.13 MB

0.11 MB