Hydatid disease of the CNS: imaging features

OBJECTIVE: The objective of this study was to assess the usefulness of dynamic single-shot MR cholangiopancreatography in the evaluation of the morphology and contractility of the normal Vaterian sphincter complex and to assess whether i.v. injection of glucagon can improve visualization. SUBJECTS AND METHODS: Sixty patients without signs of Vaterian sphincter complex dysfunction were studied. A fast single-shot MR imaging sequence was used to obtain 20 consecutive images of the Vaterian sphincter complex during successive episodes of breathholding. In patients of group A (n = 30), 10 images were obtained before and 10 after i.v. administration of a sphincter-relaxing agent (glucagon). In the patients of group B (n = 30), no glucagon was administered. The degree of visualization of the Vaterian sphincter complex was assessed. RESULTS: Overall, the morphology and contractility of the Vaterian sphincter complex was adequately assessed in 57 patients (95%). However, the number of repetitions required to obtain this result varied greatly (mean, seven; range, two to 18). Glucagon had no apparent effect on the visibility of the most distal portion of the common bile duct. CONCLUSION: Nonvisualization of the most distal portion of the common bile duct on MR cholangiopancreatography studies is a normal variant that can simulate disease. Obtaining serial breath-hold images using a single-shot technique is helpful to avoid diagnostic errors.     

Hydatid disease: biology, pathology, imaging and classification

Rupture and the sequellae of rupture are more important than the mass effect of hydatid cysts, except in the brain where the mass effect by itself has severe consequences. The biology of hydatid disease, including the complex interaction between primary and secondary hosts, is reviewed. The hydatid cyst always starts as a fluid-filled, cyst-like structure (Type I) which may proceed to a Type II lesion if daughter cysts and/or matrix develop. In some instances the Type II lesion becomes hypermature and due to starvation dies to become a mummified, inert calcified Type III lesion. Type I and II lesions may undergo three types of rupture: contained, communicating and direct. Contained rupture is clinically silent, but communicating rupture may cause biliary obstruction and evacuation or infection of the cyst. Direct rupture has the greatest clinical consequences which include anaphylaxis, dissemination of hydatid disease (secondary hydatosis) within the host, and bacterial infection of the pericyst cavity. The clinical implications of the hydatid disease at different stages are discussed. A plea is made for the development of an international medical hydatid registry employing uniform nomenclature and consistent reporting in order to allow more rational comparisons of different types of management.     

Hydatid disease of liver and its complications (author''s transl)

This is a report on 121 cases of hydatid disease of liver. The alteration of the false cyst, explaining the most common complications of the disease, is discussed. Complications were present in 61 (50.41%) of our 121 patients: calcification in 13.22%, infection in 10.74%, perforation in bile ducts in 9.91%, thorax in 5.78% and abdominal cavity in 10.74% of our cases. Diagnostic importances of clinical findings, immunoelectrophoretic studies and radioisotopic liverscanning is emphasized. In 28 cases the complete excision of cysts were carried out, in 110 cases only removal of the hydatid membrane was performed. Other therapeutic methods are discussed. Of 108 treated patients 7 died postoperatively: they were all over 70 years old.     

Drug-induced interstitial lung disease

Cationic liposomes provide a means to introduce genes into cells both ex vivo and in vivo. In the past few years their use has been described in several tissues, e.g. lungs, liver, endothelium, brain. In this study we evaluated a commercially available poly-cationic liposome formulation in delivering a reporter gene into cultured myogenic cell lines from mouse and rat, and primary fetal human myoblasts. We also examined the effect of serum on liposome-mediated transfection and designed a new procedure to enhance transfection efficiency, based on the pre-condensation of plasmid DNA with polylysine. Polylysine pre-condensation was particularly effective when transfecting the cells in the presence of serum, a finding that could be significant for in vivo transfections.     

HIV-related interstitial lung disease

The progressive breakdown of the cell-mediated immunity, which characterizes the natural history of HIV infection, invariably leads to the development of miscellaneous opportunistic infections or neoplasms involving a number of tissues, including the respiratory tract. In particular, given the extent and the severity of most infectious complications, it is not surprising that respiratory failure is a common finding in patients who have AIDS-related interstitial lung disease. Extensive knowledge of the sequence of events that starts with HIV infection of CD4+ cells and leads to the development of respiratory complications has been recently achieved. The present understanding of the pathogenesis of AIDS-related interstitial lung disease comes from the evaluation of cell populations retrieved from bronchoalveolar lavage fluid. In particular, the information gained from bronchoalveolar lavage studies led to the realization that HIV strains are present in the respiratory tract of HIV-seropositive subjects at all stages of infection. Furthermore, the characterization of bronchoalveolar lavage fluid cells proved to be central in evaluating the striking local immunologic reactions that can be detected in the lungs of these patients. Bronchoalveolar lavage studies have also demonstrated that local protective mechanisms may cause the shift toward accelerated progression to AIDS and the development of respiratory failure. This reviews briefly examines clinical aspects and cellular patterns of HIV infection in the respiratory tract. We will also consider data showing that HIV infection evokes an inflammatory response, initiated and sustained by cytotoxic T lymphocytes and macrophages and mediated by a number of cytokines that amplify host defenses as well as facilitate the spread of the retrovirus throughout the lower respiratory tract.     

Thoracoscopic lung biopsy or open lung biopsy for interstitial lung disease

Both traditional open lung biopsy through a limited thoracotomy and VATS lung biopsy are effective methods for obtaining parenchymal samples in patients who have respiratory insufficiency and radiographic pulmonary infiltrates. For patients with slowly progressive disease processes, who require an elective biopsy, VATS biopsy is the procedure of choice because of the ability to visualize and sample multiple areas of the lung, and because of the decreased postoperative pain. On the other hand, when patients are critically ill and already on high-level ventilatory support, the VATS method offers no advantages over the standard minimal thoracotomy.     

Hydatid liver cyst perforation into the digestive tract

Complications of liver hydatid disease include those related to the compression of adjacent viscus, to the infection of the cyst's contents or to the perforation of the cyst. Perforations into hollow abdominal organs are rare, and can occur secondary to the infection of the cyst or to a primary pathology of the perforated organ. We report on 2 cases of perforation of a liver cyst into the duodenum, 1 due to the presence of a duodenal ulcer, and 1 secondary to a hydatid abscess. The surgical treatment of the lesions and their complications was, in both cases, successful.     

Clinical overview of occupational lung disease

The workplace has been a source of lung injury for centuries, yet awareness of the types of injuries has varied over time. Because of distinctive differences among the occupational lung disorders, a continual update of the clinical findings, dose response data, physiologic characteristics, and radiographic findings is needed. The radiologist plays a key role for the evaluation of miners, foundry or factory workers exposed to mineral dusts, and of workers exposed to the "biologic" dusts, infectious agents, cancer causing agents, and chemicals causing interstitial lung diseases. This overview includes a discussion of classification systems, criteria for diagnosis of occupational lung diseases, the pulmonary clinician's evaluation, and important aspects of specific disorders and concludes with a discussion of pulmonary disability determination.     

Farmer''s lung disease in Somerset

A survey of laboratory records was made to assess the value of the precipitin test and isolation methods in the diagnosis of farmer's lung disease and also to determine its prevalence in the farming population of Somerset. A link was established between the clinical diagnosis as written on the form that accompanied the specimen and the actual number of positive laboratory diagnoses made. Fifty (43%) of the clinically diagnosed patients were serologically positive for farmer's lung during a four-year period. If the clinically diagnosed but serologically negative cases of farmer's lung disease are added to this number, a prevalence of about 23 per 1000 of the farming population of Somerset is obtained.     

Ventilation in the patient with unilateral lung disease

Severe ULD presents a challenge in ventilator management because of the marked asymmetry in the mechanics of the two lungs. The asymmetry may result from significant decreases or increases in the compliance of the involved lung. Traditional ventilator support may fail to produce adequate gas exchange in these situations and has the potential to cause further deterioration. Fortunately, conventional techniques can be safely and effectively applied in the majority of cases without having to resort to less familiar and potentially hazardous forms of support. In those circumstances when conventional ventilation is unsuccessful in restoring adequate gas exchange, lateral positioning and ILV have proved effective at improving and maintaining gas exchange. Controlled trials to guide clinical decision making are lacking. In patients who have processes associated with decreased compliance in the involved lung, lateral positioning may be a simple method of improving gas exchange but is associated with many practical limitations. ILV in these patients is frequently successful when differential PEEP is applied with the higher pressure to the involved lung. In patients in whom the pathology results in distribution of ventilation favoring the involved lung, particularly BPF, ILV can be used to supply adequate support while minimizing flow through the fistula and allowing it to close. The application of these techniques should be undertaken with an understanding of the pathophysiology of the underlying process; the reported experience with these techniques, including indications and successfully applied methods; and the potential problems encountered with their use. Fortunately, these modalities are infrequently required, but they provide a critical means of support when conventional techniques fail.