Detection of cerebral hypoperfusion with a dynamic hyperoxia test using brain oxygenation pressure monitoring.

INTRODUCTION: Brain multimodal monitoring including intracranial pressure (ICP) and brain tissue oxygen pressure (PbtO2) is more accurate than ICP alone in detecting cerebral hypoperfusion after traumatic brain injury (TBI). No data are available for the predictive role of a dynamic hyperoxia test in brain-injured patients from diverse etiology. AIM: To examine the accuracy of ICP, PbtO2 and the oxygen ratio (OxR) in detecting regional cerebral hypoperfusion, assessed using perfusion cerebral computed tomography (CTP) in patients with acute brain injury. METHODS: Single-center study including patients with TBI, subarachnoid hemorrhage (SAH) and intracranial hemorrhage (ICH) undergoing cerebral blood flow (CBF) measurements using CTP, concomitantly to ICP and PbtO2 monitoring. Before CTP, FiO2 was increased directly from baseline to 100% for a period of 20 min under stable conditions to test the PbtO2 catheter, as a standard of care. Cerebral monitoring data were recorded and samples were taken, allowing the measurement of arterial oxygen pressure (PaO2) and PbtO2 at FiO2 100% as well as calculation of OxR (= ΔPbtO2/ΔPaO2). Regional CBF (rCBF) was measured using CTP in the tissue area around intracranial monitoring by an independent radiologist, who was blind to the PbtO2 values. The accuracy of different monitoring tools to predict cerebral hypoperfusion (i.e., CBF < 35 mL/100 g × min) was assessed using area under the receiver-operating characteristic curves (AUCs). RESULTS: Eighty-seven CTPs were performed in 53 patients (median age 52 [41-63] years-TBI, n = 17; SAH, n = 29; ICH, n = 7). Cerebral hypoperfusion was observed in 56 (64%) CTPs: ICP, PbtO2 and OxR were significantly different between CTP with and without hypoperfusion. Also, rCBF was correlated with ICP (r = - 0.27; p = 0.01), PbtO2 (r = 0.36; p < 0.01) and OxR (r = 0.57; p < 0.01). Compared with ICP alone (AUC = 0.65 [95% CI, 0.53-0.76]), monitoring ICP + PbO2 (AUC = 0.78 [0.68-0.87]) or ICP + PbtO2 + OxR (AUC = 0.80 (0.70-0.91) was significantly more accurate in predicting cerebral hypoperfusion. The accuracy was not significantly different among different etiologies of brain injury. CONCLUSIONS: The combination of ICP and PbtO2 monitoring provides a better detection of cerebral hypoperfusion than ICP alone in patients with acute brain injury. The use of dynamic hyperoxia test could not significantly increase the diagnostic accuracy.

The clinical spectrum of Fontan-associated liver disease: results from a prospective multimodality screening cohort.

AIMS: Liver fibrosis and cirrhosis are a consequence of a Fontan physiology, and determine prognosis. It is unclear whether non-invasive assessment of liver pathology is helpful to provide clinically relevant information. The aims of this study were to assess the spectrum of Fontan-associated liver disease (FALD) and usefulness of non-invasive methods to assess biopsy confirmed liver fibrosis. METHODS AND RESULTS: Hepatic screening of consecutive patients consisted of a blood panel, ultrasonography, elastography, contrast-enhanced magnetic resonance imaging (MRI)/computed tomography (CT) scan, and liver biopsy (scored with Fontan specific fibrosis scores and collagen proportionate area; CPA). Fibrosis parameters, varices, ascites, and splenomegaly were measured on imaging. Thirty-eight of 49 referred patients (27 ± 6.6 years, 73.7% male) underwent the complete screening protocol. Liver fibrosis on biopsy was present in all patients, and classified as severe (Stages 3-4) in 68%. Median CPA was 22.5% (16.9-29.5) and correlated with individual fibrosis scores. ELF® and liver stiffness were elevated, but MELD-XI scores were low in all patients. Fibrosis severity neither correlated to ELF® and liver stiffness, nor to (semi-) quantitative fibrosis parameters on MRI/CT. Varices were present in 50% and hyperenhancing nodules in 25% of patients, both independent of fibrosis stage, but varices were associated with higher CPA values. CONCLUSION: The FALD spectrum includes both hepatic congestion and severe fibrosis, with signs of portal hypertension and hyperenhancing nodules as significant manifestations. Routine imaging, transient elastography, and serum biomarkers are unable to accurately assess severity of liver fibrosis in this cohort. Future research should focus on validating new diagnostic tools with biopsy as the reference standard.

Low specificity of washout to diagnose hepatocellular carcinoma in nodules showing arterial hyperenhancement in patients with Budd-Chiari syndrome.

BACKGROUND & AIMS: It remains unclear whether the classic imaging criteria for the non-invasive diagnosis of hepatocellular carcinoma (HCC) can be applied to chronic vascular liver diseases, such as Budd-Chiari syndrome (BCS). Herein, we aimed to evaluate the diagnostic value of washout for the discrimination between benign and malignant lesions in patients with BCS. METHODS: This retrospective study included all patients admitted to our institution with a diagnosis of BCS and focal lesions on MRI from 2000 to 2016. MRI images were reviewed by 2 radiologists blinded to the nature of the lesions. Patient and lesion characteristics were recorded, with a focus on washout on portal venous and/or delayed phases. Lesions were compared using Chi-square, Fisher's, Student's t or Mann-Whitney U tests. RESULTS: A total of 49 patients (mean age 35 ±â€¯12 years; 34 women [69%] and 15 men [31%]) with 241 benign lesions and 12 HCC lesions were analyzed. Patients with HCC were significantly older (mean age 44 ±â€¯16 vs. 33 ±â€¯9 years, p = 0.005), with higher alpha-fetoprotein (AFP) levels (median 16 vs. 3 ng/ml, p = 0.007). Washout was depicted in 9/12 (75%) HCC, and 69/241 (29%) benign lesions (p <0.001). A total of 52/143 (36%) lesions ≥1 cm with arterial hyperenhancement showed washout (9 HCC and 43 benign lesions). In this subgroup, the specificity of washout for the diagnosis of HCC was 67%. Adding T1-w hypointensity raised the specificity to 100%. A serum AFP >15 ng/ml was associated with 95% specificity. CONCLUSION: Washout was observed in close to one-third of benign lesions, leading to an unacceptably low specificity for the diagnosis of HCC. The non-invasive diagnostic criteria proposed for cirrhotic patients cannot be extrapolated to patients with BCS. LAY SUMMARY: Washout on MRI is depicted in a significant proportion of benign nodules in patients with Budd-Chiari syndrome (BCS), limiting its value for the differentiation between benign and malignant lesions. Criteria proposed for the non-invasive diagnosis of hepatocellular carcinoma in patients with cirrhosis cannot be extrapolated to patients with BCS. Additional imaging findings and patient characteristics, including alpha-fetoprotein serum level, can help determine the probability of a nodule being HCC in patients with BCS.

Value of dual-energy CT angiography in patients with treated intracranial aneurysms.

PURPOSE: To evaluate the ability of dual-energy CT angiography (DECTA) in metal artifact reduction in patients with treated intracranial aneurysms by comparing DECTA-based virtual monoenergetic extrapolations (VMEs) and mixed images (MI). METHODS: Thirty-five patients underwent prospectively a dual-source DECTA (Somatom Force, Siemens Medical Solutions, Forchheim, Germany) after aneurysm repair. A total number of 40 aneurysms (23 treated by coil embolization and 17 treated by surgical clipping) were analyzed. Mixed images (equivalent to a conventional single-energy CT angiography) were compared to VMEs at 75, 95, and 115 keV. Artifact severity was assessed quantitatively by measuring the mean attenuation value and standard deviation within regions of interest placed in the most hypodense coil or clip artifact area. Artifact severity score and contrast vessel score were also assessed qualitatively by two independent blinded readers. RESULTS: In those aneurysms treated by surgical clipping, quantitative and qualitative analyses showed significant reduction of artifacts on VMEs compared to MI with the best compromise being obtained at 95 keV in order to keep an optimal vessel contrast in the adjacent vessel. In those aneurysms treated by coil embolization, there was no significant reduction of artifacts both on quantitative and qualitative analyses. CONCLUSION: Dual-source DECTA was helpful in order to reduce clip artifacts on VMEs with the optimal adjacent vessel visualization obtained at 95 keV, whereas this technique was not helpful in aneurysms treated by coiling.

A Longitudinal Study on Fetal Weight Estimation at Third Trimester of Pregnancy: Comparison of Magnetic Resonance Imaging and 2-D Ultrasound Predictions.

OBJECTIVE: To prospectively compare magnetic resonance (MR) estimation of fetal weight (MR-EFW) performed at third trimester with ultrasound (US) estimation of fetal weight (US-EFW) and actual birth weight, and to evaluate factors influencing fetal growth rate near term. METHODS: US-EFW and MR-EFW were calculated at a median of 33.0 and 37.7 weeks of gestation in 37 fetuses and plotted on curve centiles to predict birth weights at 39.3 weeks of gestation. The median absolute relative errors for predicted US-EFW and MR-EFW were calculated. Regression analysis was used to investigate the effect of different variables on fetal growth rate at 35.2 weeks of gestation. RESULTS: The relative error of actual birth weight as predicted by US at 33.0 weeks was significantly higher compared with MR (7.33 vs. 4.11%; p = 0.001). This was also the case for fetal weight predicted by US at 37.7 weeks as compared with MR (6.63 vs. 2.60%; p < 0.01). Fetal growth rate was significantly and independently positively associated with the mother's weight and with gestational age at estimation (p < 0.05 for both variables). CONCLUSION: Fetal weight estimates predicted using MR at third trimester are better than those given by prenatal US. Fetal growth rate depends on fetal and maternal characteristics.

Cystic fibrosis: unenhanced CT description of the appendix in asymptomatic adults.

OBJECTIVE: The purpose of this study was to describe the unenhanced CT appearance of the appendix in adults with cystic fibrosis. SUBJECTS AND METHODS: Among adults with cystic fibrosis undergoing follow-up at our hospital, 71 patients (35 women, 36 men; mean age, 33 years; range, 18-59 years) without a history of appendectomy or current abdominal pain were prospectively included in this study and underwent unenhanced abdominopelvic MDCT. Two readers coded visualization of the appendix, measured the diameter of the appendix, and described the attenuation of its contents in relation to the intestinal wall. They also coded the presence of colonic wall redundancy, pancreatic fatty replacement, and cirrhosis. Lung transplant status and CFTR gene mutations were recorded. Analysis of variance, linear regression analysis, Student t test, and Pearson test were used. RESULTS: The appendix was detected in all patients. The mean diameter was recorded as 10.6 ± 3.5 mm. The mean diameter was larger when the appendix contained hyperattenuating material (p = 0.001). There was no association between diameter and the other coded CT findings (p = 0.076-0.466), transplant status (p = 0.788), or CFTR mutation (p = 0.078). In 75% of the patients, the appendix contained hyperattenuating material with a higher proportion in homozygous ΔF508 mutation (p = 0.029) without any significant effect of the other CT features (p = 0.056-0.392), or transplant status (p = 1.000). CONCLUSION: The appendix is larger in adults with cystic fibrosis than in those without it and appears hyperattenuating at unenhanced CT in 75% of patients, more commonly in those with ΔF508 homozygous mutation.

MR imaging features and long-term evolution of benign focal liver lesions in Budd-Chiari syndrome and Fontan-associated liver disease.

PURPOSE: To compare the magnetic resonance imaging (MRI) features of benign liver lesions developed on Budd-Chiari syndrome (BCS) with those on Fontan-associated liver disease (FALD) and to describe their long-term progression. MATERIALS AND METHODS: Patients with BCS or FALD who underwent MRI between 2010 and 2020 were retrospectively included. MRI features of nodules (≥ 5 mm) at baseline and at final follow-up were reviewed. The final diagnosis of benign lesion was based on a combination of clinical and biological data and findings at follow-up MRI examination. RESULTS: Two-hundred and thirty benign liver lesions in 39 patients with BCS (10 men, 29 women; mean age, 36 ±â€¯11 [SD] years; age range: 15-66 years) and 84 benign lesions in 14 patients with FALD (2 men, 12 women; mean age, 31 ±â€¯10 [SD] years; age range: 20-48 years) were evaluated. On baseline MRI, BCS nodules were more frequently hyperintense on T1-weighted (183/230, 80%) and hypointense on T2-weighted (142/230; 62%) images, while FALD nodules were usually isointense on both T1- (70/84; 83%) and T2-weighted (64/84; 76%) images (all P< 0.01). Most lesions showed arterial phase hyperenhancement (222/230 [97%] vs. 80/84 [95%] in BCS and FALD, respectively; P = 0.28) but wash-out was more common in BCS (64/230 [28%] vs. 9/84 [11%]; P < 0.01). At follow-up, changes were more frequent in BCS nodules with more frequent disappearance (P < 0.01), changes in size, signal intensity on T2-weighted, portal, and delayed phase, and in the depiction of washout and capsule (all P ≤ 0.03). CONCLUSION: MRI features of benign lesions are different at diagnosis and during the course of the disease between BCS and FALD. Changes in size and MRI features are more frequent in benign lesions developed in BCS.

Hepatobiliary MR contrast agents are useful to diagnose hepatocellular carcinoma in patients with Budd-Chiari syndrome.

BACKGROUND & AIMS: Hepatobiliary phase (HBP) images can discriminate between benign and malignant liver lesions, but it is unclear if this approach can be used in patients with Budd-Chiari syndrome (BCS). Thus, we aimed to assess the diagnostic utility of HBP images in patients with BCS. METHODS: This retrospective study included all patients admitted to our institution with a diagnosis of BCS and focal liver lesions on hepatobiliary contrast agent-enhanced MR imaging (HBCA-MRI) from 2000 to 2019. MR images were reviewed by 2 radiologists blinded to the diagnosis of the lesions. Patient and lesion characteristics were recorded, focusing on HBP imaging features. RESULTS: Twenty-six patients (mean 35 ± 11 years old [13-65]; 21 women [81%] 35 ± 12 years old [13-65]; 5 men [19%] 36 ± 10 years old [19-44]) with 99 benign liver lesions and 12 hepatocellular carcinomas (HCCs) were analyzed. Patients with HCC were significantly older than those with benign lesions (mean 50 ± 10 vs. 33 ± 9 years old, p = 0.003), with higher alpha-fetoprotein (AFP) levels (3/4 [75%] vs. 1/22 [5%] with AFP >15 ng/ml, p <0.001). Homogeneous hypointense signals were identified on HBP in 14 lesions, including 12/12 (100%) HCCs, and 2/99 (2%) benign lesions (p <0.001). Most benign liver lesions showed either peripheral (n = 52/99 [53%]) or homogeneous hyperintensity (n = 23/99 [23%]) on HBP. Lesions with signal hypointensity on HBP in patients with AFP serum levels >15 ng/ml were all HCCs. CONCLUSION: Most benign lesions showed homogeneous or peripheral hyperintensity on HBP images while all HCCs were homogeneously hypointense. HBP images are helpful to differentiate between benign lesions and HCCs and outperform other sequences. They should be systematically acquired for the characterization of focal lesions in patients with BCS. LAY SUMMARY: Hepatobiliary phase imaging is an approach that has recently been shown to discriminate between benign and malignant lesions in the liver. However, it was not known whether this imaging approach could be used effectively in patients with Budd-Chiari syndrome. Herein, we have shown that hepatobiliary phase imaging appears to be useful for differentiating between benign and malignant liver lesions in patients with Budd-Chiari syndrome.

Diagnosis of Budd-Chiari syndrome.

Budd-Chiari syndrome (BCS) is defined by clinical and laboratory signs associated with partial or complete impairment of hepatic venous drainage in the absence of right heart failure or constrictive pericarditis. Primary BCS is the most frequent type and is a complication of hypercoagulable states, in particular myeloproliferative neoplasms. Secondary BCS involves tumor invasion or extrinsic compression. Most patients present with chronic BCS including a non-cirrhotic, dysmorphic, chronic liver disease with various degrees of fibrosis deposition. Acute BCS is rare, and patients present with hepatomegaly, ascites, and hepatic insufficiency. The diagnosis is based on imaging. Imaging features include (1) direct signs, in particular occlusion or compression of the hepatic veins and/or the inferior vena cava and venous collaterals and (2) indirect signs, in particular morphological changes in the liver with hypertrophy of the caudate lobe and delayed nodule formation. Ultrasound and magnetic resonance imaging are the gold standard for diagnosis. The aim of this review is to provide an overview of the role of imaging in the diagnosis of BCS.

Benign and malignant hepatocellular lesions in patients with vascular liver diseases.

A variety of vascular liver disorders can induce hepatocellular tumors. They may be related to portal venous deprivation, venous outflow obstruction, or arterial diseases. Their common feature is an imbalance between hepatic arterial and portal venous blood flow leading to an increased hepatic arterial inflow. Consequently, hepatocellular tumors may arise, most commonly focal nodular hyperplasia-like lesions but hepatocellular adenomas and hepatocellular carcinoma may be seen as well. This article will review the most common vascular liver diseases associated with hepatocellular nodules (Budd-Chiari syndrome, congenital portosystemic shunt, hereditary hemorrhagic telangiectasia, and portal cavernoma). For each condition, imaging findings will be described as well as the differential diagnosis and the diagnostic clues.