L Pfeifer

Dynamic contrast-enhanced ultrasound (DCE-US) for the characterization of hepatocellular carcinoma and cholangiocellular carcinoma.

PURPOSE In a prospective study, we compared the different perfusion kinetics of HCC and ICC using dynamic contrast-enhanced ultrasound (DCE-US). MATERIALS AND METHODS Patients with proven HCC and ICC were included. Three-minute video clips of CEUS examinations (CPS - low MI mode) after a bolus injection of 1.2 ml SonoVue were recorded and analyzed with quantification software (VueBox). Parameters for the arterial contrast enhancement [rise time (RT), time-to-peak (TTP)] towards portal venous contrast enhancement [mean transit time (local) (mTTl) and fall time (FT)] were quantified. Furthermore, contrast wash-out after peak enhancement (PE) (40 s, 80 s, 100 s and 120 s after PE) was compared between HCC and ICC. RESULTS 43 patients with proven HCC (n = 23 HCC; cirrhosis n = 16) and ICC (n = 20 ICC; Cirrhosis n = 6) were examined. No statistical difference of the arterial DCEUS parameters was found between HCC and ICC. Contrast enhancement of the portal venous and late phases showed significantly lower values in the ICC group indicating early wash-out of the contrast agent: mTTl (p = 0.0209): HCC 118.4 s (SD± 88.4); ICC 64.8 s (SD± 49.7). FT (p = 0.0433): HCC 42.5 s (SD± 27.7); ICC 27.7 s (SD± 16.2). The percental loss of intensity at a definite time point after PE was significantly higher in ICC than in HCC lesions. CONCLUSION DCE-US is able to detect and quantify differences in perfusion kinetics between HCC and ICC. Whereas arterial contrast enhancement patterns may overlap between HCC and ICC, a timed characterization of wash-out kinetics may offer an additional tool to characterize HCC and ICC. The presence of a rapid loss of signal intensity in the early portal venous phase is significantly higher in ICC than in HCC lesions.

Multispectral Optoacoustic Tomography for Assessment of Crohn’s Disease Activity

A preliminary study suggests that intestinal-wall assessment by means of noninvasive multispectral optoacoustic tomography may distinguish remission from active disease in patients with Crohn’s disease.

Multispectral Optoacoustic Tomography in Crohn’s Disease: Noninvasive Imaging of Disease Activity

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Liver Stiffness Assessed by Acoustic Radiation Force Impulse (ARFI) Technology Is Considerably Increased in Patients with Cholestasis

PURPOSE To explore the impact of cholestasis on liver stiffness assessed by acoustic radiation force impulse (ARFI) technology. MATERIALS AND METHODS Over a period of four months, patients with sonographic cholestasis and increased cholestatic blood values (Bilirubin, γGT, AP > 2 times ULN) scheduled for endoscopic therapy were recruited. Exclusion criteria were: known liver disease; signs of cirrhosis at ultrasound (irregular liver veins and/or surface); heart insufficiency (NYHA III-VI). ARFI (Siemens S2000), ultrasound and blood examinations were performed before and in a subgroup after successful biliary drainage. RESULTS In total, 21 patients with cholestasis were included in the study. ARFI measurements were above the cut-off for cirrhosis (1.8  m/s) in all patients with a mean of 2.91  m/s ± 0.89  m/s without a history or signs of cirrhosis. Bilirubin, γGT and AP were elevated on average to 9.7 ± 5.3  mg/dl, 1192 ± 960  U/l and 730 ± 389  U/l. A subgroup of 10 patients was measured after successful drainage. ARFI measurements declined in all patients of that subgroup on average by 0.76  m/s at a mean time interval of 4.5 days (p < 0.001). CONCLUSION Cholestasis significantly increases liver stiffness assessed by ARFI. Therefore, it is important to exclude profound cholestasis when using ARFI for evaluating patients for liver fibrosis.

Acoustic radiation force impulse shear wave elastography (ARFI) of acute and chronic pancreatitis and pancreatic tumor

INTRODUCTION Acoustic Radiation Force Impulse (ARFI) elastography evaluates tissue stiffness non-invasively and has rarely been applied to pancreas examinations so far. In a prospective and retrospective analysis, ARFI shear wave velocities of healthy parenchyma, pancreatic lipomatosis, acute and chronic pancreatitis, adenocarcinoma and neuroendocrine tumor (NET) of the pancreas were evaluated and compared. MATERIAL AND METHODS In 95 patients ARFI elastography of the pancreatic head, and also of the tail for a specific group, was analysed retrospectively. Additionally, prospectively in 100 patients ARFI was performed in the head and tail of the pancreas. RESULTS A total of 195 patients were included in the study. Healthy parenchyma (n=21) and lipomatosis (n=30) showed similar shear wave velocities of about 1.3m/s. Acute pancreatitis (n=35), chronic pancreatitis (n=53) and adenocarcinoma (n=52) showed consecutively increasing ARFI values, respectively. NET (n=4) revealed the highest shear wave velocities amounting to 3.62m/s. ARFI elastography showed relevant differences between acute pancreatitis and chronic pancreatitis or adenocarcinoma. With a cut-off value of 1.74m/s for the diagnosis of a malignant disease the sensitivity was 91.1% whereas the specificity amounted to 60.4%. CONCLUSION ARFI shear wave velocities present differences in various pathologies of the pancreas. Acute and chronic pancreatitis as well as neoplastic lesions show high ARFI values. Very high elasticity values may indicate malignant disease of the pancreas. However, there is a considerable overlap between the entities.

Complete Long-Term Remission of an Inflammatory Pseudotumor under Corticosteroid Therapy

Inflammatory pseudotumors (IPT) form a group of etiologically, histologically, and biologically heterogeneous tumefactive lesions that are histologically characterized by prominent inflammatory infiltrates. IPT has been described in various organs including the lungs, bladder, liver, spleen, heart, and others. It may mimic a malignant tumor clinically and radiologically. We report a case of a 26-year-old woman with an ALK1-negative IPT (7 cm in maximal diameter) mainly located in the 12th right back muscles, surrounding a fractured rib. Histologically, the tumor consisted of an inflammatory infiltrate composed predominantly of diffusely distributed lymphoplasmacytic cells and stromal fibroblasts associated with focal obliterative phlebitis. Conservative steroid treatment resulted in complete remission and the patient remained disease-free for more than 1 year later. To our knowledge this is the first report of IPT involving the skeletal back muscle and complete resolution under corticosteroid treatment.

Acoustic radiation force impulse (ARFI) and high-frequency ultrasound of the liver surface for the diagnosis of compensated liver cirrhosis.

PURPOSE To evaluate the diagnostic value of acoustic radiation force impulse (ARFI) and high-frequency ultrasound of the liver surface, using histology as a gold standard for the diagnosis of compensated liver cirrhosis. MATERIALS AND METHODS 73 patients without ascites undergoing liver biopsy were included in the study. The left and right liver lobes were examined with ARFI and high-frequency ultrasound. Liver surface irregularity was quantified using image analysis software to calculate the difference between the real surface and the approximated physiological surface through a 20 mm standardized line. RESULTS There is a significant difference between cirrhotic and non-cirrhotic patients for both quantified liver surface (QLS) and ARFI (p < 0.001). The mean values for QLS of the left lobe were 0.71 ± 0.24 mm and 1.17 ± 0.80 mm, of the right lobe 0.56 ± 0.26 mm and 0.87 ± 0.26 mm for non-cirrhotic and cirrhotic patients, respectively. The mean values of ARFI measurements of the left lobe were 2.04 ± 0.76 m/s and 2.85 ± 0.81 m/s, of the right lobe 1.65 ± 0.61 m/s and 3.02 ± 0.77 m/s for non-cirrhotic and cirrhotic patients, respectively. Diagnostic accuracy (AUROC) was 0.78/0.80 for QLS and 0.77/0.91 for ARFI of the left/right lobe, respectively. ARFI of the right lobe is significantly better than ARFI of the left (p = 0.023) or QLS of the left (p = 0.025)/right (p = 0.046) lobe of the liver. CONCLUSION Assessment of liver surface irregularity by high-frequency ultrasound (QLS) is a useful diagnostic test for the assessment of compensated liver cirrhosis. ARFI of the right liver lobe is significantly better than high-frequency ultrasound (QLS of the left/right lobe of the liver) and ARFI of the left lobe of the liver.

Diagnostic accuracy of contrast-enhanced ultrasound for the differential diagnosis of hepatocellular carcinoma: ESCULAP versus CEUS-LI-RADS

Objective A comparison is made of two contrast-enhanced ultrasound (CEUS) algorithms for the diagnosis of hepatocellular carcinoma (HCC) in high-risk patients: Erlanger Synopsis of Contrast-enhanced Ultrasound for Liver lesion Assessment in Patients at Risk (ESCULAP) and American College of Radiology Contrast-Enhanced Ultrasound-Liver Imaging Reporting and Data System (ACR-CEUS-LI-RADSv.2016). Patients and methods Focal liver lesions in 100 high-risk patients were assessed using both CEUS algorithms (ESCULAP and CEUS-LI-RADSv.2016) for a direct comparison. Lesions were categorized according to size and contrast enhancement in the arterial, portal venous and late phases. For the definite diagnosis of HCC, categories ESCULAP-4, ESCULAP-Tr and ESCULAP-V and CEUS-LI-RADS-LR-5, LR-Tr and LR-5-V were compared. In addition, CEUS-LI-RADS-category LR-M (definitely/probably malignant, but not specific for HCC) and ESCULAP-category C [intrahepatic cholangiocellular carcinoma (ICC)] were compared. Histology, CE-computed tomography and CE-MRI served as reference standards. Results The reference standard among 100 lesions included 87 HCCs, six ICCs and seven non-HCC-non-ICC-lesions. For the diagnosis of HCC, the diagnostic accuracy of CEUS was significantly higher with ESCULAP versus CEUS-LI-RADS (94.3%/72.4%; p<0.01). Sensitivity, specificity and positive predictive value (PPV) and negative predictive value for ESCULAP/CEUS-LI-RADS were 94.3%/72.4%; 61.5%/69.2%; 94.3%/94%; and 61.5%/27.3%, respectively. The diagnostic accuracy for ICC (LR-M/ESCULAP-C) was identical with both algorithms (50%), with higher PPV for ESCULAP-C versus LR-M (75 vs. 50%). Conclusion CEUS-based algorithms contribute toward standardized assessment and reporting of HCC-suspect lesions in high-risk patients. ESCULAP shows significantly higher diagnostic accuracy, sensitivity and negative predictive value with no loss of specificity compared with CEUS-LI-RADS. Both algorithms have an excellent PPV. Arterial hyperenhancement is the key feature for the diagnosis of HCC with CEUS. Washout should not be a necessary prerequisite for the diagnosis of definite HCC. CEUS-LI-RADS in its current version is inferior to ESCULAP for the noninvasive diagnosis of HCC. There are two ways to improve CEUS-LI-RADS: firstly, combination of the categories LR-4 and LR-5 for the diagnosis of definite HCC, and secondly, use of subtotal infiltration of a liver lobe as an additional feature.

Quantitative perfusion analysis in pancreatic contrast enhanced ultrasound (DCE-US): a promising tool for the differentiation between autoimmune pancreatitis and pancreatic cancer.

In the work-up of focal pancreatic lesions autoimmune pancreatitis (AIP) is a rare differential diagnosis to pancreatic cancer (PC) with similar clinical constellations. The aim of our study was to compare differences between proven AIP and PC using transabdominal dynamic contrast enhanced ultrasound (DCE-US). Therefore we recorded 3-minute-clips of CEUS examinations and analyzed perfusion parameters with VueBox®-quantification software. To obtain DCE-US Parameters, Regions-of-Interest were selected within the lesions and the surrounding pancreas parenchyma, serving as reference tissue. We compared 3 patients with AIP (mean age: 58 years; lesion mean size: 40 mm) to 17 patients with PC (mean age: 68 years; lesion mean size: 35.9 mm). Significant differences between PC and parenchyma could be found in the following parameters: Peak-Enhancement (PE), Wash-in-and-Wash-out-AUC, Wash-in Perfusion-Index. PE of AIP was comparable to normal parenchyma. The relation of PE between parenchyma and lesion (ΔPE) AIP and PC was significantly different [AIP: 0.21 (±0.06); PC: 0.81 (±0.1); p<0.01]. PE of neoplastic lesions was significantly lower as AIP and normal parenchyma (p<0.01). Therefore perfusion analysis in DCE-US can help to differentiate hypovascular PC from AIP presenting nearly isovascular time intensity curves. Diagnostic accuracy of DCE-US in this setting has to be validated in future prospective studies in comparison to CT and MRI.

Two-dimensional shear-wave elastography: a new method comparable to acoustic radiation force impulse imaging?

Objectives Two-dimensional shear-wave elastography (2D-SWE) is an ultrasound-based technique for the noninvasive assessment of tissue stiffness. In contrast to the well-established point-shear-wave elastography (pSWE) method acoustic radiation force impulse imaging, there is little evidence on the performance and usefulness of 2D-SWE in the assessment of liver stiffness. Thus, the aim of our study was to compare 2D-SWE versus pSWE. Materials and methods 2D-SWE and pSWE were performed in 20 cirrhotic patients, 20 healthy individuals and an elasticity phantom. Stiffness values, examination time and number of measurements were compared. For 2D-SWE, the influence of size of the region of interest (ROI) was assessed. Results Elastography values in healthy individuals were slightly higher for 2D-SWE versus pSWE (1.4 m/s, range: 1.21–1.68 vs. 1.23 m/s, range: 1.07–1.39). In cirrhotic patients, there were no significant differences (3.06 m/s, range: 1.83–5.35 vs. 3 m/s, range: 1.67–4.37 m/s). Examination times were significantly longer for 2D-SWE in both patient groups (mean values for healthy/cirrhotic patients: 129.6/157.1 vs. 75/71.6 s). For 2D-SWE, variation of ROI size (5, 10, 20 mm) produced comparable results. After eight measurements, 90% of cirrhotic patients showed less than 5% of deviation from the results after the gold standard of 10 measurements; for healthy individuals, this was observed after six measurements. Conclusion 2D-SWE seems to be comparable to pSWE (acoustic radiation force impulse-imaging) in cirrhotic patients, with slightly higher values in healthy individuals. 2D-SWE measurements require considerably more time. For 2D-SWE, ROI size seems to be of minor importance; multiple measurements should be obtained as single measurements differ. These preliminary results should be confirmed in larger patient collectives with histology as the reference standard.