Radiological predictors of recurrent primary spontaneous pneumothorax following non-surgical management.

BACKGROUND: Studies to date have not identified any reliable predictors for recurrence of primary spontaneous pneumothorax (PSP) on plain chest radiograph (CXR). The aim of this study was to assess whether abnormalities on CXR at first presentation of PSP can be used to predict recurrence of PSP. METHOD: The study included all patients admitted to The Canberra Hospital between 1998 and 2004. CXRs taken at initial presentation were reviewed retrospectively by an independent radiologist. Radiological abnormalities on CXR included: pleural thickening: blebs/bullae; pleural irregularities and pleural adhesions. RESULTS: One hundred patients were followed up for a mean duration of 57 months. The total rate of recurrence was 54%. Multivariate analysis found that the presence of an abnormality (irrespective of the type) increased the likelihood of recurrence and the risk of recurrence increased with each additional abnormality. Patients having one, two and three or more abnormalities were 3.0 (95% CI=2.09, 3.91, p=0.018), 5.3 (95% CI=4.47, 6.13, p<0.001) and 12.6 (95% CI=11.57, 13.63, p<0.001) times more likely to develop recurrence respectively. CONCLUSION: In view of these results we now offer surgical treatment at first presentation PSP in patients in whom we identify two or more radiological abnormalities on CXR.

Surface imaging microscopy using an ultramiller for large volume 3D reconstruction of wax- and resin-embedded tissues.

Three-dimensional reconstruction of large tissue volumes using histological thin sections poses difficulties because of registration of sections, section distortion, and the possibility of incomplete data set collection due to section loss. We have constructed an integrated surface imaging system that successfully addresses these problems. Embedded tissue is mounted on a high precision XYZ stage and the upper surface is iteratively: (i) stained to provide an effective optical section, (ii) imaged using a digital camera, and (iii) removed with an ultramiller. This approach provides for the reconstruction of high-quality 3D images by inherently preserving image registration, eliminates section distortion, thus removing the need for complex realignment and correction, and also ensures full capture of all image planes. The system has the capacity to acquire images of tissue structure with voxel sizes from 0.5 to 50 mum over dimensions ranging from micrometers to tens of millimeters. The ultramiller enables large samples to be imaged by reliably removing tissue over their full extent. The ability to visualize key features of 3D tissue structure across such a range of scale and resolution will facilitate the development of a greater understanding of the relationship between structure and function. This understanding is essential for better analyses of the structural changes associated with different disease states, and the development of structure-based computer models of biological function.