Using the ILO Classification system, "s", "t", and/or "u" opacities predominate. CT or high-resolution CT (HRCT) are more sensitive than plain radiography at detecting pulmonary fibrosis (as well as any underlying pleural changes). More than 50% of people affected with asbestosis develop plaques in the parietal pleura, the space between the chest wall and lungs. Once apparent, the radiographic findings in asbestosis may slowly progress or remain static, even in the absence of further asbestos exposure. Rapid progression suggests an alternative diagnosis. Asbestosis resembles many other diffuse interstitial lung diseases, including other pneumoconiosis. The differential diagnosis includes idiopathic pulmonary fibrosis (IPF), hypersensitivity pneumonitis, sarcoidosis, and others. The presence of pleural plaques may provide supportive evidence of causation by asbestos. Although lung biopsy is usually not necessary, the presence of asbestos bodies in association with pulmonary fibrosis establishes the diagnosis. Conversely, interstitial pulmonary fibrosis in the absence of asbestos bodies is most likely not asbestosis. Asbestos bodies in the absence of fibrosis indicate exposure, not disease. There is no cure available for asbestosis. Oxygen therapy at home is often necessary to relieve the shortness of breath and correct underlying low blood oxygen levels. Supportive treatment of symptoms includes respiratory physiotherapy to remove secretions from the lungs by postural drainage, chest percussion, and vibration. Nebulized medications may be prescribed in order to loosen secretions or treat underlying chronic obstructive pulmonary disease. Immunization against pneumococcal pneumonia and annual influenza vaccination is administered due to increased sensitivity to the diseases. Those with asbestosis are at increased risk for certain cancers. If the person smokes, quitting the habit reduces further damage. Periodic pulmonary function tests, chest x-rays, and clinical evaluations, including cancer screening/evaluations, are given to detect additional hazards. The death of English textile worker Nellie Kershaw in 1924 from pulmonary asbestosis was the first case to be described in medical literature, and the first published account of disease attributed to occupational asbestos exposure. However, her former employers (Turner Brothers Asbestos) denied that asbestosis even existed because the medical condition was not officially recognised at the time. As a result, they accepted no liability for her injuries and paid no compensation, either to Kershaw during her final illness or to her family after her death.