Modern CT and PET/CT imaging of the liver
ABSTRACT Computed tomography (CT) is now widely available and represents an important and rapid method for the diagnostics of acute liver disease, characterization of focal liver lesions, planning of interventional therapy measures and postintervention control. In recent years CT has not become less important despite the increasing value of magnetic resonance imaging (MRI). By the use of different contrast medium phases good characterization of space-occupying lesions can be achieved. For the diagnostics of hepatocellular carcinoma (HCC) a triphasic examination protocol should always be implemented. The introduction of dual energy CT increased the sensitivity of imaging of hypervascularized and hypovascularized liver lesions and by the use of virtual native imaging it has become possible to avoid additional native imaging which reduces the x-ray exposition of patients. Positron emission tomography (PET) has an advantage for imaging in oncology because nearly the complete body of the patient can be screened and this is the main indication for PET/CT (whole-body staging). For purely hepatic problems 18F-fluorodeoxyglucose (FDG)-PET/CT using diagnostic CT data has a higher precision than CT alone but is inferior to MRI.
- SourceAvailable from: Joachim Hohmann
[Show abstract] [Hide abstract]
- "Furthermore, US is hampered by its observer dependence, i.e. poor interobserver agreement. Therefore, the diagnosis of focal liver lesions has mainly been the domain of contrast enhanced computed tomography (CT) and contrast enhanced magnetic resonance imaging (MRI), where the use of intravenous contrast material and the assessment of dynamic enhancement patterns play a crucial role  . "
ABSTRACT: To compare on-site and blinded off-site reading of baseline ultrasound (US) and contrast enhanced ultrasound (CEUS) for classification and characterisation of focal liver lesions. 99 patients (57 women and 42 men, age range 18-89 years, mean age: 59 years) with 53 malignant and 46 benign liver lesions were studied with unenhanced US followed by contrast enhanced US after injection of 2.4 ml SonoVue® (Bracco, Milano, Italy). Image interpretation was performed on-site with clinical information available by consensus of two readers and off-site by two independent blinded readers at two different centers. Comparison of pre and post contrast scans and of the different readers was performed. Reference examinations were histology, intraoperative US, MRI or CT. Sensitivity for malignancy improved from 81/89/66% (on-site/off-site reader 1/2) before to 100/96/96% post contrast administration (p<0.05, except for reader 1). Specificity improved from 48/48/54% on baseline US to 89/80/76% on CEUS (p<0.05). Accuracy for specific lesion diagnosis was 62/59/50% pre and 90/77/72% post contrast (p<0.05). Classification and characterisation post contrast were mildly inferior for off-site reading. Agreement between on-site and off-site readers of unenhanced scans was fair (κ=0.29-0.39) while it was good for CEUS (κ=0.63-0.79). CEUS improves classification and characterisation of focal liver lesions and interobserver agreement compared to conventional US. Classification and characterisation post contrast were mildly but statistically significantly better for on-site than for off-site reading.European journal of radiology 11/2011; 81(3):e317-24. DOI:10.1016/j.ejrad.2011.10.015 · 2.37 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: A survey was conducted to give an overview about the practice of radioembolization in malignant liver tumors by European centers. A questionnaire of 23 questions about the interventional center, preinterventional patient evaluation, the radioembolization procedure and aftercare were sent to 45 European centers. The response rate was 62.2% (28/45). The centers performed 1000 (median = 26) radioembolizations in 2009 and 1292 (median = 40) in 2010. Most centers perform preinterventional evaluation and radioembolization on an inpatient basis. An arterioportal shunt not amendable to preinterventional embolization is considered a contraindication. During preinterventional angiography, the gastroduodenal artery is embolized by 71%, the right gastric artery by 59%, and the cystic artery by 41%. In case of bilobar disease, yttrium-90 microspheres are infused into the common hepatic artery (14%) or separately into left and right hepatic artery (86%). 33% prefer a time interval between right and left liver lobe radioembolization to prevent radiation induced liver disease. 43% of the respondents do not prescribe prophylactic medication after radioembolization. In case of iatrogenic manipulation to the biliary duct system most centers perform radioembolization with prophylactic antibiotics. Despite standardization of the procedure, there are some differences in how radioembolization of liver tumors is performed in Europe.European journal of radiology 04/2012; 81(7):e804-11. DOI:10.1016/j.ejrad.2012.04.004 · 2.37 Impact Factor