Quantitative liver magnetic resonance imaging: correlation between conventional magnetic resonance imaging, laboratory values, and prognostic indices in Budd-Chiari syndrome

PURPOSE

In Budd-Chiari syndrome (BCS), unevenly distributed parenchymal changes and perfusion abnormalities occur due to hepatic venous outflow obstruction. This study aimed to evaluate the changes in the liver parenchyma in BCS using the quantitative magnetic resonance (MR) techniques of MR elastography, T1 and T2 mapping, and diffusion imaging and correlate the quantitative MR parameters through biochemical results and prognostic indices.

METHODS

Fourteen patients with BCS (seven men and seven women) were examined retrospectively. Liver stiffness (kPa), T1 relaxation times (ms) were achieved using the modified Look-Locker inversion recovery (MOLLI) 3(2)3(2)5 sequence and B1-corrected variable flip angle methods, T2 relaxation times (ms), and apparent diffusion coefficient (ADC) values (mm2/s) were measured using regions of interest placed in the same region in all quantitative methods. Measurements were repeated at the precontrast and postcontrast hepatobiliary phases. The reduction rate (RR; %) and adjusted postcontrast T1 (%) were calculated. The values obtained from different liver parenchyma areas (whole liver, caudate lobe, pathological T2 hyperintense tissue, and relatively preserved normal-appearing tissue) were compared using the Wilcoxon signed-rank test. Spearman's correlation coefficient was used to investigate the correlation between quantitative MR parameters and biochemical parameters/ prognostic scores (Child-Pugh score, Clichy score, and Rotterdam index).

RESULTS

The parenchymal stiffness and precontrast T1 values of the caudate lobe were significantly lower than those of the remainder of the parenchyma, whereas the adjusted postcontrast T1 percentages (MOLLI) were significantly higher (P ≤ 0.027). The parenchymal stiffness value, T1 and T2 values, percentages of RR (MOLLI), and adjusted postcontrast T1 values for the pathological tissue and relatively normal tissue were significantly different (P < 0.028). No significant difference was found in terms of ADC values between any of the distinct regions of the liver. A strong correlation was detected between the Child-Pugh score, Clichy score, and precontrast T1 values obtained through the MOLLI sequence (r = 0.867, P = 0.012, r = 0.821, P = 0.023, respectively). No correlation was found between the whole liver stiffness values and the laboratory parameters, fibrosis markers, prognostic indices, or MR parameters. A significant correlation was identified between creatinine levels and several T1 parameters and the T2 relaxation time (r ≥ 0.661, P ≤ 0.052).

CONCLUSION

Tissue stiffness and T1 relaxation values are high in the areas identified as fibrosis compared with those in the relatively preserved parenchyma. The T1 relaxation time can offer quantitative information for assessing segmental functional changes and prognosis in BCS.ion for assessing segmental functional changes and prognosis in BCS.

Evaluation of abdominal computed tomography findings in patients with COVID-19: a multicenter study

PURPOSE

To evaluate the frequency of abdominal computed tomography (CT) findings in patients with coronavirus disease-2019 (COVID-19) and interrogate the relationship between abdominal CT findings and patient demographic features, clinical findings, and laboratory test results as well as the CT atherosclerosis score in the abdominal aorta.

METHODS

This study was designed as a multicenter retrospective study. The abdominal CT findings of 1.181 patients with positive abdominal symptoms from 26 tertiary medical centers with a positive polymerase chain-reaction test for severe acute respiratory syndrome coronavirus 2 were reviewed. The frequency of ischemic and non-ischemic CT findings as well as the association between CT findings, clinical features, and abdominal aortic calcific atherosclerosis score (AA-CAS) were recorded.

RESULTS

Ischemic and non-ischemic abdominal CT findings were detected in 240 (20.3%) and 328 (27.7%) patients, respectively. In 147 patients (12.4%), intra-abdominal malignancy was present. The most frequent ischemic abdominal CT findings were bowel wall thickening (n = 120; 10.2%) and perivascular infiltration (n = 40; 3.4%). As for non-ischemic findings, colitis (n = 91; 7.7%) and small bowel inflammation (n = 73; 6.2%) constituted the most frequent disease processes. The duration of hospital stay was found to be higher in patients with abdominal CT findings than in patients without any positive findings (13.8 ± 13 vs. 10.4 ± 12.8 days, P < 0.001). The frequency of abdominal CT findings was significantly higher in patients who did not survive the infection than in patients who were discharged after recovery (41.7% vs. 27.4%, P < 0.001). Increased AA-CAS was found to be associated with a higher risk of ischemic conditions in abdominal CT examinations.

CONCLUSION

Abdominal symptoms in patients with COVID-19 are usually associated with positive CT findings. The presence of ischemic findings on CT correlates with poor COVID-19 outcomes. A high AA-CAS is associated with abdominal ischemic findings in patients with COVID-19.

Compression of the Distal Common Bile Duct by Enlarged Inferior Pancreaticoduodenal Artery Branches in a Patient with Celiac Trunk Stenosis: A Case Report

Various benign and malignant pathologies/conditions can cause compression of the extrahepatic biliary system. Anatomical and/or topographic variations of the hepatic artery have long been recognized as a possible cause of the EBS compression. However, anatomical and/or topographic variations, other than the hepatic artery's, should also be considered during the evaluation of the EBS compression. We, herein, report a unique case of the distal common bile duct compression by tortuous and enlarged inferior pancreaticoduodenal artery branches due to severe stenosis of the celiac trunk orifice.

Ectopic opening of common bile duct into the duodenal bulb: magnetic resonance cholangiopancreatography findings

PURPOSE We aimed to evaluate the spectrum of magnetic resonance cholangiopancreatography (MRCP) findings in patients with ectopic opening of the common bile duct (CBD) into the duodenal bulb and to determine the effectiveness of the MRCP technique in diagnosis. METHODS Morphologic and morphometric MRCP/MRI features in 16 patients and 36 controls were retrospectively analyzed by 2 radiologists. The frequency of MRCP findings was determined. The significance of the difference between the MRCP observations in patients and controls was evaluated statistically and the diagnostic effectiveness of MRCP was investigated. RESULTS Hook-shaped ending of CBD and bulbar deformity were the most frequent morphologic findings seen on MRCP in the ectopic bulbar opening. Mean pylorus-papilla distance and mean CBD length were significantly shorter and the median diameter of CBD was significantly larger than the control group (patients: 28.6 ± 15.3 mm, 33.7 ± 12.8 mm, 8.6 (2-16) mm; controls: 66.7 ± 11.7 mm, 50.3 ± 14.4 mm, 3.2 (1.5-10) mm, P < .001, respectively). Receiver operating curve analysis showed sensitivity and specificity of MRCP in the diagnosis to be 87.5% and 100%, respectively, if any 3 of the 4 signs (hook-shaped ending of CBD, bulbar deformity, large, and short CBD) were present in a patient whose pylorus-papilla distance was <50 mm. CONCLUSION At MRCP, the presence of short and large CBD with a hook-shaped ending in the deformed duodenal bulb may support the diagnosis of ectopic biliary drainage.

Biphasic split-bolus injection protocol for routine contrast-enhanced chest CT: comparison with conventional early-phase single bolus technique

OBJECTIVES

To present a routine contrast-enhanced chest CT protocol with a split-bolus injection technique achieving combined early- and delayed phase images with a single aquisition, and to compare this technique with a conventional early-phase single-bolus chest CT protocol we formerly used at our institution, in terms of attenuation of great thoracic vessels, pleura, included hepatic and portal venous enhancement, contrast-related artifacts, and image quality.

METHODS

A total of 202 patients, who underwent routine contrast-enhanced chest CT examination aquired with either conventional early-phase single-bolus technique (group A,n = 102) or biphasic split-bolus protocol (group B,n = 100), were retrospectively included. Attenuation measurements were made by two radiologists independently on mediastinal window settings using a circular ROI at the following sites: main pulmonary artery (PA) at its bifurcation level, thoracal aorta (TA) at the level of MPA bifurcation,portal vein (PV) at porta hepatis, left and right hepatic lobe, and if present, thickened pleura (>2 mm) at the level with the most intense enhancement. Respective normalized enhancement values were also calculated. Contrast-related artifacts were graded and qualitative evaluation of mediastinal lymph nodes was performed by both reviewers independently. Background noise was measured and contrast-to-noise ratios (CNRs) of the liver and TA were calculated.

RESULTS

While enhancement of thoracic vessels and normalised MPA enhancement did not differ significantly between both groups (p > 0.05), enhancement and normalised enhancement of pleura, liver parenchyma and PV was significantly greater in group B (p < 0.001). Perivenous artifacts limiting evaluation were less frequent in group B than in A and mediastinal lymph nodes were judged to be evaluated worse in group A than in group B with an excellent agreement between both observers. No significant difference was detected in CNRTA (p = 0.633), whereas CNR liver was higher in group B (p < 0.001).

CONCLUSION

Our split-bolus chest CT injection protocol enables simultaneous enhancement for both vascular structures and soft tissues, and thus, might raise diagnostic confidence without the need of multiple acquisitions.

ADVANCES IN KNOWLEDGE

We think that this CT protocol might also be a promising alternative in lung cancer staging, where combined contrast-enhanced CT of the chest and abdomen is indicated. We therefore suggest to further evaluate its diagnostic utility in this setting, in particular in comparison with a late delayed chest-upper abdominal CT imaging protocol.

MRI quantification techniques in fatty liver: the diagnostic performance of hepatic T1, T2, and stiffness measurements in relation to the proton density fat fraction

PURPOSE

Nonalcoholic fatty liver disease (NAFLD) can progress to liver cirrhosis and is predicted to become the most frequent indication for liver transplantation in the near future. Noninvasive assessment of NAFLD is important for diagnosis and patient management. This study aims to prospectively determine the liver stiffness and T1 and T2 values in patients with NAFLD and to compare the diagnostic performance of magnetic resonance elastography (MRE) and mapping techniques in relation to the proton density fat fraction (PDFF).

METHODS

Eighty-three patients with NAFLD and 26 participants with normal livers were imaged with a 1.5 T scanner. PDFF measurements obtained from the multiecho Dixon technique were used to quantify the liver fat. MRE, native T1 mapping (modified Look-Locker inversion recovery [MOLLI] schemes 5(3)3, 3(3)3(3)5, and 3(2)3(2)5 and the B1-corrected variable flip angle [VFA] method), and T2 mapping values were correlated with PDFF. The diagnostic performance of MRE and the mapping techniques were analyzed and compared.

RESULTS

T1 values measured with the MOLLI schemes and the B1-corrected VFA (P < 0.001), and the stiffness values from MRE (P = 0.047) were significantly higher in the NAFLD group. No significant difference was found between the groups in terms of T2 values (P = 0.127). In differentiation of the NAFLD and control groups, the B1-corrected VFA technique had slightly higher accuracy and area under the curve (AUC) than the MOLLI schemes. In the NAFLD group, there was a good correlation between the PDFF, MOLLI 3(3)3(3)5 and 3(2)3(2)5, and VFA T1 measurements (r=0.732; r=0.735; r=0.716, P < 0.001, respectively).

CONCLUSION

Liver T1 mapping techniques have the potential to distinguish steatotic from nonsteatotic livers, and T1 values seem to have a strong correlation with the liver fat content.

Is it possible to discriminate pulmonary carcinoids from hamartomas based on CT features?

PURPOSE

The purpose of this study was to determine whether the computed tomography (CT) features might be used in distinguishing pulmonary carcinoids from hamartomas.

MATERIALS AND METHODS

Ninety solid pulmonary nodules (43 carcinoids and 47 hamartomas) in 90 patients were evaluated. The following CT scan features were evaluated: size, location (peripheral/central), contour (lobulated/nodular), number of lobulation, attenuation, calcification, endobronchial status, bronchial extension and involvement, parenchymal abnormalities distal to the lesion e.g. hyperlucency, atelectasis, and nodularity. The final pathologic diagnosis of the lesions and bronchial extension were confirmed by review of histopathological specimens.

RESULTS

Out of 43 carcinoids, 37 (86%) were typical. Twenty-three carcinoids and four hamartomas were central (p < 0.001). Ten carcinoids and one hamartoma were endobronchial. The majority of tumors had lobulated contours (65% of carcinoids, 44% of hamartomas) and carcinoids tended to have more lobulations (p = 0.052). Distal nodularity (p = 0.001), distal hyperlucency (p < 0.001), and atelectasis (p = 0.005) were significantly more common in carcinoids. Carcinoids had significantly more bronchial extension and involvement (p < 0.001; respectively). In addition, a new sign that we call "bronchial triangle sign" differentiated carcinoids with a sensitivity and specificity of 84.9% (95% CI: 69,1%-93.4%) and 91% (95% CI: 79.7%-96.6%).

CONCLUSION

To the best of our knowledge this is the first study on discrimination of carcinoids and hamartomas. A new CT sign called "bronchial triangle sign" might be used to differentiate carcinoids from hamartomas. Distal parenchymal abnormalities are more common in carcinoids than in hamartomas.

Neuro-Ophthalmologic MRI Findings in the Detection of Rhinorrhoea Aetiology

The purpose of this study is to evaluate the importance of neuro-ophthalmological magnetic resonance imaging (MRI) findings in the identification of the aetiology of rhinorrhoea, and the differentiation of spontaneous rhinorrhoea from non-spontaneous rhinorrhoea. MR images of 25 patients with spontaneous and 21 patients with non-spontaneous rhinorrhoea were evaluated for the presence of neuro-ophthalmological findings of intracranial hypertension (IHT). These include optic nerve vertical tortuosity, optic nerve sheath enlargement, flattening of the posterior sclera and optic nerve protrusion, as well as other MRI findings of ICH, such as partial empty sella, dilatation of Meckel's cave and the presence of arachnoid pits. IHT findings were more common in the spontaneous group. Six criteria (optic nerve distention, optic nerve vertical tortuosity, posterior flattening of the sclera, partial empty sella, Meckel's cave dilatation and presence of arachnoid pits) differentiate between patient and control groups. Patients with spontaneous cerebrospinal fluid (CSF) leaks should be evaluated for signs of IHT on MRI, as they are present in the majority of spontaneous CSF leaks and are representative of increased intracranial pressure.

Magnetic resonance elastography: basic principles, technique, and clinical applications in the liver

Magnetic resonance elastography (MRE) is a constantly advancing technique for assessment of stiffness of tissues with newer technology and sequences. It is being increasingly used for the assessment of liver fibrosis. In this article, we discuss the advantages of MRE over biopsy and noninvasive methods such as US elastography in the assessment of liver fibrosis. Image acquisition and interpretation of liver MRE is also discussed.