Doppler parameters of hepatic and renal hemodynamics in patients with liver cirrhosis

Interleaved x-ray imaging: A method for simultaneous acquisition of quantitative and diagnostic digital subtraction angiography

BACKGROUND

Flow altering angiographic procedures suffer from ill-defined, qualitative endpoints. Quantitative digital subtraction angiography (qDSA) is an emerging technology that aims to address this issue by providing intra-procedural blood velocity measurements from time-resolved, 2D angiograms. To date, qDSA has used 30 frame/s DSA imaging, which is associated with high radiation dose rate compared to clinical diagnostic DSA (up to 4 frame/s).

PURPOSE

The purpose of this study is to demonstrate an interleaved x-ray imaging method which decreases the radiation dose rate associated with high frame rate qDSA while simultaneously providing low frame rate diagnostic DSA images, enabling the acquisition of both datasets in a single image sequence with a single injection of contrast agent.

METHODS

Interleaved x-ray imaging combines low radiation dose image frames acquired at a high rate with high radiation dose image frames acquired at a low rate. The feasibility of this approach was evaluated on an x-ray system equipped with research prototype software for x-ray tube control. qDSA blood velocity quantification was evaluated in a flow phantom study for two lower dose interleaving protocols (LD1:3.7 ± 0.02 mGy / s $3.7 \pm 0.02\ {\mathrm{mGy}}/{\mathrm{s}}$ and LD2:1.7 ± 0.04 mGy / s $1.7 \pm 0.04{\mathrm{\ mGy}}/{\mathrm{s}}$ ) and one conventional (full dose) protocol (11.4 ± 0.04 mGy / s ) $11.4 \pm 0.04{\mathrm{\ mGy}}/{\mathrm{s}})$ . Dose was measured at the interventional reference point. Fluid velocities ranging from 24 to 45 cm/s were investigated. Gold standard velocities were measured using an ultrasound flow probe. Linear regression and Bland-Altman analysis were used to compare ultrasound and qDSA.

RESULTS

The LD1 and LD2 interleaved protocols resulted in dose rate reductions of -67.7% and -85.5%, compared to the full dose qDSA scan. For the full dose protocol, the Bland-Altman limits of agreement (LOA) between qDSA and ultrasound velocities were [0.7, 6.7] cm/s with a mean difference of 3.7 cm/s. The LD1 interleaved protocol results were similar (LOA: [0.3, 6.9] cm/s, bias: 3.6 cm/s). The LD2 interleaved protocol resulted in slightly larger LOA: [-2.5, 5.5] cm/s with a decrease in the bias: 1.5 cm/s. Linear regression analysis showed a strong correlation between ultrasound and qDSA derived velocities using the LD1 protocol, with aR 2 ${R}^2$ of0.96 $0.96$ , a slope of1.05 $1.05$ and an offset of1.9 $1.9$  cm/s. Similar values were also found for the LD2 protocol, with aR 2 ${R}^2$ of0.93 $0.93$ , a slope of0.98 $0.98$ and an offset of2.0 $2.0$  cm/s.

CONCLUSIONS

The interleaved method enables simultaneous acquisition of low-dose high-rate images for intra-procedural blood velocity quantification (qDSA) and high-dose low-rate images for vessel morphology evaluation (diagnostic DSA).

Renal arterial resistance index among subjects with liver cirrhosis in a Nigerian population

PURPOSE

To describe the relationship between renal artery resistance index (RARI) and liver function based on Child-Pugh system among patients with liver cirrhosis (LC) in Southwest Nigeria.

METHODS

About 50 patients with LC and 50 controls were consecutively recruited into this prospective comparative case control study. Each LC patient was classed based on Child-Turcotte-Pugh (CTP) system after relevant tests. Subjects underwent abdominal ultrasonography with triplex Doppler examination of the right kidney to obtain RARI.

RESULTS

About 50 cirrhotic and 50 controls completed the study. Age range of cirrhotic subjects was 19-69 years (mean ± SD = 47.5 ± 13.3) while that of controls was 18-69 years (46.9 ± 15.0). RARI was higher (P = <.001) in patients with LC (0.68) than in controls (0.57). RARI was also significantly higher (P = <.001) in cirrhotic subjects in CTP class C (0.72) than in those in classes B (0.66) and A (0.58). Additionally, RARI showed significant correlation with CTP total score (r = .662; P = <.001), serum bilirubin (r = .297; P = .036), serum albumin (r = -.494; P = <.001), serum sodium (r = -.369; P = .008), Model for End Stage Liver Disease (MELD) score (r = .316; P = .026) and MELD-Na score (r = .470; P = .001). RARI showed no significant relationship with serum creatinine (r = .110; P = .445) and blood urea nitrogen (r = .112; P = .437).

CONCLUSION

Liver cirrhosis is associated with renovascular changes which manifest as increased resistance in the renal arteries. RARI is a useful noninvasive tool for the assessment of these changes and should be done routinely in the evaluation of patients with LC.

Hemodynamic Changes of Hepatic & Renal Vessels in Systemic Bacterial Infection with Fever in HCV Related Cirrhosis

OBJECTIVES

To study the hemodynamic changes of hepatic & renal vessels in systemic bacterial infection with fever in HCV related cirrhosis with possible complications.

METHODS

Three groups of patients with systemic bacterial infection with fever were included in the study; group І included 15 patients with decompensated cirrhosis, group ІІ included 15 patients with compensated cirrhosis and group ІІІ included 10 patients without liver affection. Laboratory parameters and Doppler US of hepatic and renal vessels were evaluated during and after subsidence of fever in all patients.

RESULTS

Forty patients were enrolled in this prospective study. There were 22 male and 18 female patients. We found that the direction of blood flow in the portal and splenic veins was hepatopetal and the veins were non pulsatile in all cases with no change during and after subsidence of infection. There was no significant difference in portal or splenic vein diameters during and after subsidence of infection in the three studied groups. However, the mean values of portal and splenic veins peak velocities were significantly lower during infection in cirrhotic groups. The mean value of hepatic artery resistive index during fever was significantly higher than after fever in cirrhotic groups. Renal resistive and pulsatility indices were significantly higher during fever in cirrhotic groups.

CONCLUSION

Systemic bacterial infection with fever can affect hepatic haemodynamics leading to aggravation of portal hypertension and increasing the risk of complications as variceal bleeding and hepatic encephalopathy and can also affect renal haemodynamics with increased risk of renal impairment.

Doppler ultrasound in liver cirrhosis: correlation of hepatic artery and portal vein measurements with model for end-stage liver disease score in Egypt

Background

Liver cirrhosis is a multi-etiological entity that alters the hepatic functions and vascularity by varying grades. Hereby, a cross-sectional study enrolling 100 cirrhotic patients (51 males and 49 females), who were diagnosed clinically and assessed by model for end-stage liver disease (MELD) score, then correlated to the hepatic Doppler parameters and ultrasound (US) findings of hepatic decompensation like ascites and splenomegaly.

Results

By Doppler and US, splenomegaly was evident in 49% of patients, while ascites was present in 44% of them. Increased hepatic artery velocity (HAV) was found in70% of cases, while 59% showed reduced portal vein velocity (PVV).

There was a statistically significant correlation between HAV and MELD score (ρ = 0.000), but no significant correlation with either hepatic artery resistivity index (HARI) (ρ = 0.675) or PVV (ρ =0.266).

Moreover, HAV had been correlated to splenomegaly (ρ = 0.000), whereas HARI (ρ = 0.137) and PVV (ρ = 0.241) did not significantly correlate.

Also, ascites had correlated significantly to MELD score and HAV (ρ = 0.000), but neither HARI (ρ = 0.607) nor PVV (ρ = 0.143) was significantly correlated.

Our results showed that HAV > 145 cm/s could confidently predict a high MELD score with 62.50% and 97.62 % sensitivity and specificity.

Conclusion

Doppler parameters of hepatic vessels (specifically HAV) in addition to the US findings of hepatic decompensation proved to be a non-invasive and cost-effective imaging tool for severity assessment in cirrhotic patients (scored by MELD); they could be used as additional prognostic parameters for improving the available treatment options and outcomes.

Multi-organ assessment of compensated cirrhosis patients using quantitative magnetic resonance imaging

BACKGROUND & AIMS

Advancing liver disease results in deleterious changes in a number of critical organs. The ability to measure structure, blood flow and tissue perfusion within multiple organs in a single scan has implications for determining the balance of benefit vs. harm for therapies. Our aim was to establish the feasibility of magnetic resonance imaging (MRI) to assess changes in Compensated Cirrhosis (CC), and relate this to disease severity and future liver-related outcomes (LROs).

METHODS

A total of 60 patients with CC, 40 healthy volunteers and 7 patients with decompensated cirrhosis were recruited. In a single scan session, MRI measures comprised phase-contrast MRI vessel blood flow, arterial spin labelling tissue perfusion, T₁ longitudinal relaxation time, heart rate, cardiac index, and volume assessment of the liver, spleen and kidneys. We explored the association between MRI parameters and disease severity, analysing differences in baseline MRI parameters in the 11 (18%) patients with CC who experienced future LROs.

RESULTS

In the liver, compositional changes were reflected by increased T₁ in progressive disease (p <0.001) and an increase in liver volume in CC (p = 0.006), with associated progressive reduction in liver (p <0.001) and splenic (p <0.001) perfusion. A significant reduction in renal cortex T₁ and increase in cardiac index and superior mesenteric arterial blood flow was seen with increasing disease severity. Baseline liver T₁ (p = 0.01), liver perfusion (p <0.01), and renal cortex T₁ (p <0.01) were significantly different in patients with CC who subsequently developed negative LROs.

CONCLUSIONS

MRI enables the contemporaneous assessment of organs in liver cirrhosis in a single scan without the requirement for a contrast agent. MRI parameters of liver T_1, renal T_1, hepatic and splenic perfusion, and superior mesenteric arterial blood flow were related to the risk of LROs.

LAY SUMMARY

This study assesses the changes to structure, blood flow and perfusion that occur in the key organs (liver, spleen and kidney) associated with severe liver disease (Compensated Cirrhosis), using magnetic resonance imaging. The magnetic resonance imaging measures which changed with disease severity and were related to negative liver-related clinical outcomes are described.

Impact of Propranolol on Preventing Renal Dysfunction in Patients with Cirrhosis

BACKGROUND One of the earliest diagnostic signs of hepatorenal syndrome in patients suffering from liver cirrhosis is an increase in the renal vascular resistive index (RI). In this study, the impact of propranolol on decreasing this index and to postpone the probability of hepatorenal syndrome has been investigated. METHODS In the current research, 30 patients with liver cirrhosis with different age and sexes have been enrolled. Demographic data and complete medical history have been collected using a specific questionnaire. At first, renal artery Doppler ultrasonography was performed to determine the RI. The patients were then treated with propranolol, and under supervision, the dose of the drug was increased gradually every 3 to 5 days to reach the target of 25% decrease in resting heart rate. One month after reaching the target dose of the medicine, Doppler ultrasonography was repeated for the patients and the second RI was compared with the pretreatment ones. RESULTS According to our results after treatment with propranolol, a significant decrease of RI was observed (p < 0.01). However, there was no significant difference in the glomerular filtration rate (GFR) before and after treatment with propranolol (p = 0.290). In our study, we found that administering propranolol was associated with significant changes in RI and GFR between the patients with compensated and decompensated cirrhosis (mean change: -0.005 ± 0.017 vs. -0.058 ± 0.045; p < 0.01 for RI and -4.226 ± 17.440 vs. 13.486 ± 12.047; p < 0.01 for GFR in patients with compensated and decompensated cirrhosis, respectively). CONCLUSION Propranolol reduces renal vascular RI in patients with cirrhosis. The response rates in the patients with decompensating cirrhosis were significantly higher than the patients with compensating cirrhosis.

Doppler Ultrasound in Liver Cirrhosis: Correlation of Hepatic Artery and Portal Vein Measurements With Model for End-Stage Liver Disease Score

OBJECTIVES

To determine whether hepatic arterial and portal venous Doppler ultrasound measurements of the liver in cirrhotic patients correlate with patients' Model for End-Stage Liver Disease (MELD) scores, splenomegaly, or ascites.

MATERIALS AND METHODS

Sonographic images and reports were reviewed of 264 patients with hepatic cirrhosis who underwent abdominal ultrasound with Doppler in this internal review board-approved retrospective study. MELD scores were recorded at the time of ultrasound. On gray-scale ultrasound, spleen length was measured and the presence of ascites was noted. Hepatic arterial velocity (HAv) with angle correction, hepatic arterial resistive index, and portal vein velocity with angle correction were measured on Doppler ultrasound. Correlation of hepatic arterial and portal venous Doppler values with MELD score, presence of splenomegaly, and presence of ascites was tested using linear or binary logistic regression analysis. Diagnostic performance of Doppler parameters for high-risk MELD was assessed.

RESULTS

The HAv statistically significantly correlated with the MELD score (P = .0001), spleen size (P =.027), and presence of ascites (P =.0001), whereas the hepatic arterial resistive index and portal vein velocity did not correlate with these factors. For MELD scores greater than 19, an HAv greater than 120 cm/s showed accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 74, 42, 90, 67, and 76%, respectively. With an HAv greater than 160 cm/s, the odds ratio for MELD scores greater than 19 was 42.1.

CONCLUSIONS

We found a statistically significant correlation with elevated HAv and increasing MELD scores, splenomegaly, and presence of ascites in patients with cirrhotic liver disease; this may be a useful imaging biomarker in the evaluation of patients with cirrhosis.

Splenic artery trunk embolization reduces the surgical risk of liver transplantation

BACKGROUND

Portal hypertension is one of the most important clinical conditions that cause intraoperative intensive hemorrhage in cirrhotic patients undergoing liver transplantation. Pre-transplant portal decompression may reduce the intraoperative bleeding during liver transplantation.

METHODS

Splenic artery trunk embolization (SATE) was performed one month prior to liver transplantation. Platelet count, prealbumin, international normalized ratio, and blood flow in the portal vein and hepatic artery were monitored before and one month after SATE. The measurements above were collected on admission and before surgery in the non-SATE patients, who served as controls. We also recorded the intraoperative blood loss, operating time, required transfusion, post-transplant ascites, and complications within three months after operation in all patients.

RESULTS

SATE significantly reduced portal venous blood flow, increased hepatic arterial blood flow, normalized platelet count, and improved prealbumin and international normalized ratio in the patients before liver transplantation. Compared to the non-SATE patients, the pre-transplant SATE significantly decreased the operating time, intraoperative bleeding, post-transplant ascites and severe surgical complications.

CONCLUSION

Pre-transplant SATE decreases portal pressure, improves liver function reserve, and reduces the surgical risk of liver transplantation effectively in patients with severe portal hypertension.