Radiol Clin North Am

Imaging of asthma and allergic bronchopulmonary mycosis.

Lynch DA.
Department of Radiology, University of Colorado Health Sciences Center, USA.
The chest radiograph of the patient with asthma is characterized by bronchial wall thickening and hyperinflation. On CT scanning of patients with asthma one may see airway wall thickening, thickened centrilobular structures, and focal or diffuse hyperlucency. Apparent bronchial dilation may be seen, but the diagnosis of bronchiectasis should be made with caution. Quantification of changes in the airway wall and lung parenchyma may be valuable in understanding the mechanisms of asthma and in evaluating the effects of treatment. Central bronchiectasis occurs in most, but not all, cases of ABPA. Patchy airspace opacity may be the sole radiologic manifestation of ABPA in some cases. Other fungi can rarely cause a similar syndrome. The challenge for the radiologist evaluating the images of a patient with asthma is to find complications, such as ABPA, or alternative diagnoses.

Cystic fibrosis. An overview.

Ruzal-Shapiro C.
Department of Radiology, Columbia University, College of Physicians and Surgeons, New York, New York, USA.
A single gene defect in cystic fibrosis results in a spectrum of clinical presentations. Though expression is variable, the radiographic appearance reflects the underlying pathophysiology. Abnormalities of the small airways result in air-trapping; bronchiectasis and mucus plugging reflect large airway disease. These radiographic findings can be assessed and followed using varying scoring systems.

Hepatic imaging. An overview.

Year 1998
Taylor HM. Ros PR.
Department of Radiology, University of Florida College of Medicine, Gainesville, USA.
Recent advances in ultrasound, CT scan, MR imaging, and scintigraphy permit characterization of a variety of focal and diffuse liver diseases. Accurate clinical information, however, is of vital importance in selecting the optimal imaging modality and interpreting the study accurately. Using a combination of radiologic findings and clinical information, a correct diagnosis may be achieved noninvasively.

MR imaging techniques of the liver.

Year 1998
Siegelman ES. Outwater EK.
Department of Radiology, Hospital of the University of Pennsylvania, University of Pennsylvania Medical Center, Philadelphia, USA.
This article reviews the currently available MR imaging techniques that are useful for the detection and characterization of focal and diffuse liver pathology. The implementation and clinical utility of various T1-weighted, T2-weighted, T2*-weighted, and MR angiographic sequences are described.

Liver-specific MR imaging contrast agents.

Year 1998
Hahn PF. Saini S.
Department of Radiology, Massachusetts General Hospital, USA.
Liver-specific MR imaging contrast agents consist of iron oxide particles or specially designed paramagnetic complexes targeting either the reticulo-endothelial system of the liver or the hepatocytes. These agents enhance the relaxation of water molecules in normal liver tissue and are excluded from abnormal tissue, such as metastases. Relaxation enhancement provides a map of normal liver function, increasing conspicuity of focal abnormalities. Understanding the indications and use of these agents is a central challenge for radiologists practicing liver MR imaging.

Ultrasonography. Update on liver technique.

Year 1998
Abbitt PL.
Department of Radiology, University of Florida College of Medicine, Gainesville, USA.
Sonography is very useful in the evaluation of the patient with severe liver disease before and after the placement of a TIPS, and before and after organ transplantation. Efforts to use ultrasound to evaluate for primary and metastatic lesions to the liver have been reviewed. With its Doppler and color flow capabilities, ultrasound remains an important modality for hepatic imaging, especially in the evaluation of portal vein patency and hepatic artery thrombosis.

Benign lesions of the liver.

Year 1998
Mergo PJ. Ros PR.
Department of Radiology, University of Florida College of Medicine, Gainesville, USA.
Although many hepatic lesions can overlap significantly in their imaging appearance, an imaging approach that is based upon identifying the pathologic and functional components of a lesion can aid in distinction from other entities. In this manner, the diagnostic evaluation can be tailored using the appropriate imaging modality for the lesion at hand. An understanding of the benign liver lesions based on the cellular line of origin and subsequent functional components aids in grasping their expected imaging appearance and may aid in their distinction from malignant tumors. Thus, an imaging approach leading to diagnosis of these tumors should be based on this underlying knowledge of the functional components and cells within the lesion to be studied. For lesions with Kupffer's cell activity, such as FNA, Tc-99m sulfur colloid scan or MR imaging with SPIO may yield the most diagnostic information. For lesions such as hepatic cysts or angiomyolipoma, the diagnosis is usually not a dilemma. For hemangiomas, the most commonly encountered benign hepatic lesion, distinction from other entities may be readily apparent from the initial CT scan or US examination, or it may require additional evaluation with MR imaging. Finally, for other lesions with many cellular components, such as HCA, the imaging findings may not be specific enough by any modality to preclude tissue diagnosis. In any case, it is important to know the diagnostic accuracy and limitations of the imaging modalities available for assessment of any given benign hepatic mass.

Primary hepatic malignant neoplasms.

Year 1998
Fernandez MP. Redvanly RD.
Department of Radiology, Emory University School of Medicine, Atlanta, Georgia, USA.
Although metastatic disease is by far the most common form of neoplastic involvement of the liver, a variety of primary hepatic malignant neoplasms may develop from any of the cell types within the liver. Primary hepatic neoplasms include hepatocellular carcinoma, intrahepatic cholangiocarcinoma, biliary cystadenocarcinoma, and a variety of mesenchymal tumors. This article reviews the clinical presentation and pathology of these tumors and discusses their sonographic, CT scan, and MR imaging appearance.

Hepatic metastases.

Year 1998
Paley MR. Ros PR.
Department of Radiology, University of Florida College of Medicine, Gainesville, Florida, USA.
Developments in ultrasound, CT scan, and MR imaging have increased our ability to detect and characterize focal liver lesions. Advances in the medical and surgical treatment of secondary liver tumors have continued to challenge these advances in radiology. A successful outcome depends on knowledge of the size and location of the tumor burden, and accurate radiologic assessment is crucial to identify those subgroups who may benefit from surgery and to prevent unnecessary radical surgery in those likely to gain only a short-term benefit.

Imaging of diffuse liver disease.

Year 1998
Mergo PJ. Ros PR.
Department of Radiology, University of Florida College of Medicine, Gainesville, USA.
Imaging can play an important role in the diagnosis and planning of treatment for patients with diffuse liver disease. In certain entities, such as iron overload disorders, fatty change, Budd-Chiari syndrome, and schistosomiasis, the imaging findings are characteristic and diagnostic. In others, the findings are less specific, but imaging still has utility in assessment for associated changes of cirrhosis and portal hypertension. In either case, familiarity with these diffuse hepatic diseases and their expected imaging findings enables an organized and thoughtful assessment, with careful attention paid to the key diagnostic features and the important sequlae, such as portal hypertension and the development of HCC.

Focal inflammatory disease of the liver.

Year 1998
Ralls PW.
Department of Radiology, University of Southern California School of Medicine, USA.
Imaging and image-guided intervention have revolutionized management of hepatic inflammatory diseases. Pyogenic abscess is preferentially treated percutaneously. Radiologic techniques are crucial for the diagnosis of amebic liver abscess and infectious conditions of the liver in immunocompromised patients.

Hepatic calcification.

Year 1998
Paley MR. Ros PR.
Department of Radiology, University of Florida College of Medicine, Gainesville, USA.
Although a specific diagnosis of the calcified liver mass may not always be possible, there are some morphologic imaging features that help to indicate the diagnosis (Table 1). The radiologist needs to be aware of the wide spectrum of diseases of the liver that can calcify, and the most common causes. Pathologic correlation with axial imaging has greatly enhanced our understanding and interpretation of the underlying liver lesion, which may help to differentiate benign from malignant etiology.

Pediatric hepatic imaging.

Year 1998
Donnelly LF. Bisset GS 3rd.
Department of Radiology, Duke University Medical Center, Durham, North Carolina, USA.
Common indications for liver imaging in children include trauma, suspected mass, pre-liver transplantation, monitoring after liver transplantation, jaundice, or liver dysfunction. This article highlights areas where the pathology or imaging approach in children differs from that seen in adults. Topics covered include imaging of a suspected hepatic mass, neonatal jaundice, and segmented liver transplantation.

Liver imaging. A surgeons perspective.

Year 1998
Vauthey JN.
Department of Surgery, University of Florida College of Medicine, Gainesville, USA.
This article reviews the segmental anatomy of the liver, which is the basis of modern hepatic surgery. Liver regeneration and the factors affecting liver volumes and the pathophysiology of the atrophy-hypertrophy complex are discussed. Benign and malignant focal liver lesions are reviewed from a surgeon's perspective. Finally, an imaging strategy is proposed and treatment options outlined.