PubMed Health⌕ Search

Biomedical subjects

Koenraad J Mortele

Publications and source records attributed to Koenraad J Mortele.

8 recordsLinked to original sources

MR imaging features of solid pseudopapillary tumor of the pancreas in adult and pediatric patients.

OBJECTIVE: This study was conducted to describe the MR imaging features of solid pseudopapillary tumor of the pancreas. CONCLUSION: Solid pseudopapillary tumor of the pancreas, a tumor typically seen in young women, is a large, well-defined, encapsulated lesion with heterogeneous high or low signal intensity on T1-weighted, heterogeneous high signal intensity on T2-weighted, and early peripheral heterogeneous enhancement with progressive fill-in on gadolinium-enhanced dynamic MR imaging. These features help differentiate this rare tumor from other pancreatic neoplasms.

Adolescent↗

MR imaging in chronic hepatitis and cirrhosis.

The role of magnetic resonance imaging (MRI) in the evaluation of diffuse parenchymal abnormalities of the liver has been expanded by recent technical advances of MR systems as well as the evolution of intravenous contrast media. Currently, MR is undoubtedly the most useful imaging modality for detecting the presence of chronic liver disease. Tailored sequences allow acurate depiction of specific disorders, including steatohepatitis and iron-overload states. Morphologic changes and signal intensity effects not only facilitate the diagnosis of chronic liver disease with MRI but they also help to distinguish between different etiologies, and they assist in staging the histologic severity of certain chronic conditions. Moreover, the faster MRI scanning techniques presently available permit the dynamic assessment of contrast enhancement, which permits improved characterization of focal hepatic lesions, including regenerative nodules, dysplastic nodules, and hepatocellular carcinoma (HCC). Although overlap in MRI findings still may exist among different types of chronic liver disease and among focal liver lesions, familiarity with certain specific imaging features may be diagnostic in the proper clinical setting. Finally, comprehensive MRI examination, including MR angiography and MR cholangiography, is the most sensitive and cost-effective technique for detecting extrahepatic disease, diagnosing vascular disorders, and evaluating the patient before or after liver transplantation. This article focuses on the current role of MR imaging in patients with chronic liver disease. The subjects covered include the detection and characterization of chronic hepatitis and cirrhosis, specific findings seen in steatohepatitis and certain metabolic diseases, the evaluation of extrahepatic vascular complications of cirrhosis, and patient assessment before and after liver transplantation. The characterization of hepatic masses is also included briefly. This subject is covered in greater depth elsewhere in this issue.

Chronic Disease↗

Hepatic imaging. An overview.

For optimal detection and characterization of focal or diffuse liver disease, it is essential to obtain the most appropriate imaging test in the correct clinical setting. Access to clinical information and medical history is, therefore, essential. Moreover, familiarity with currently available modalities for imaging the liver [figure: see text] allows the optimal use of the technical advances in ultrasound imaging, CT scanning, MR imaging, and nuclear scintigraphy technology and contributes to improved diagnostic accuracy.

Humans↗

Current techniques of computed tomography. Helical CT, multidetector CT, and 3D reconstruction.

The many recent advances in CT technology have secured its position as the modality of choice in routine liver imaging and have improved its performance in several problem-solving applications. In addition, improvements in postprocessing software (e.g., in speed, efficiency, and automated algorithms) have increased their use in clinical practice. Multiplanar reformations, 3D renderings, and high-quality CT angiographic displays have become extremely valuable both in image interpretation and in communicating information to surgeons and referring physicians.

Angiography↗

Benign liver neoplasms.

A variety of benign focal liver lesions are easily characterized with currently available imaging techniques and contrast agents. The most common benign liver lesions, such as hemangioma, bile duct cyst, and FNH, reveal characteristic cross-sectional imaging features that allow an accurate diagnosis. For atypical variants and more uncommon lesions, including HCA, angiomyelioma, infantile hemagioendothelioma, and mesenchymal hamartoma, integration of clinical data can often help in the interpretation of imaging studies. Finally, for the remaining lesions, such as hepatic adenomatosis, the imaging findings may not be specific enough to negate the need for a tissue biopsy.

Adenoma↗

Diffuse liver disease.

During the last decade, the role of the radiologist in evaluating patients with diffuse liver disease has increasingly expanded. In many cases, the management choices for the hepatologist in the imaging work-up of a patient with suspicion of a diffuse liver disease have significantly widened. In some instances, imaging may point directly to the diagnosis; in many instances, imaging helps narrow the differential diagnosis or is crucial in the follow-up of patients. Although some rare entities still have nonspecific radiologic features, the imaging pattern, in combination with appropriate clinical information, may provide the most likely diagnosis.

Humans↗

Detection of liver metastases: comparison of gadobenate dimeglumine-enhanced and ferumoxides-enhanced MR imaging examinations.

PURPOSE: To compare gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance (MR) imaging with ferumoxides-enhanced MR imaging for detection of liver metastases. MATERIALS AND METHODS: Twenty consecutive patients known to have malignancy and suspected of having focal liver lesions at ultrasonography (US) underwent 1.0-T MR imaging with gradient-recalled-echo T1-weighted breath-hold sequences before, immediately after, and 60 minutes after Gd-BOPTA injection. Subsequently, MR imaging was performed with turbo spin-echo short inversion time inversion-recovery T2-weighted sequences before and 60 minutes after ferumoxides administration. All patients subsequently underwent intraoperative US within 15 days, and histopathologic analysis of their resected lesion-containing specimens was performed. Separate qualitative analyses were performed to assess lesion detection with each contrast agent. Quantitative analyses were performed by measuring signal-to-noise and contrast-to-noise ratios (CNRs) on pre- and postcontrast Gd-BOPTA and ferumoxides MR images. Statistical analyses were performed with Wilcoxon signed rank and Monte Carlo tests. RESULTS: Sensitivity of ferumoxides-enhanced MR imaging was superior to that of Gd-BOPTA-enhanced MR imaging for liver metastasis detection (P <.05). Ferumoxides MR images depicted 36 (97%) of 37 metastases detected at intraoperative US, whereas Gd-BOPTA MR images depicted 30 (81%) metastases during delayed phase and 20 (54%) during dynamic phase. All six metastases identified only at ferumoxides-enhanced MR imaging were 5-10 mm in diameter. There was a significant increase in CNR between the lesion and liver before and after ferumoxides administration (from 3.8 to 6.8, P <.001) but not before or after Gd-BOPTA injection (from -4.8 to -5.5, P >.05). CONCLUSION: Ferumoxides-enhanced MR imaging seems to be superior to Gd-BOPTA-enhanced MR imaging for liver metastasis detection.

Colorectal Neoplasms↗