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Biomedical subjects

P Cooney

Publications and source records attributed to P Cooney.

4 recordsLinked to original sources

Quality assurance programme applied to mobile C-arm fluoroscopy systems.

The importance of quality assurance (QA) of X-ray equipment in diagnostic imaging departments is well recognised. However, practically no attention has been paid in the literature to the application of QA programmes to mobile C-arm fluoroscopy systems. This equipment is sometimes omitted from these programmes because it is often "off-site" from the main radiological facility and suitable QA protocols are unavailable. The need for QA can be substantiated by the fact that these systems are finding greater clinical use in orthopaedic, vascular and cardiac applications. Hence, there is a growing awareness among users for the need of good image quality and low patient radiation dose. In view of this, the objective of this study was to review the existing literature, design a suitable QA protocol for this equipment and use it to survey 10 C-arms in clinical use. The protocol was designed to address mechanical and electrical safety in addition to radiation safety and image quality. Results indicate substantial performance differences between systems with significant variations in input air kerma rate to the image receptor. The authors believe that such a protocol is necessary with a view to establishing optimal performance levels and assist in the development of suitable "write-off" criteria for such systems.

Equipment Safety↗

Spontaneous regression of non-Hodgkin's lymphoma: a report of nine cases.

Seven previously untreated patients and two previously treated patients with advanced non-Hodgkin's lymphoma (Stages III and IV) and favorable histologic subtypes had spontaneous regression of their lymphomas. Regressions were either complete or partial and were frequently durable. Six of the seven patients who had spontaneous regression of their lymphomas prior to any therapy have yet to require treatment. Seven of the nine spontaneous regressions occurred in a group of 44 patients who were followed with initial therapy deferred. Six patients had regression of their lymphomas prior to any therapy and one patient had previously received a small field of radiation therapy. Temporary spontaneous regression of lymphoma may be common in selected patients with favorable histologies and advanced disease in whom initial therapy is deferred.

Adult↗

Conditions controlling commitment of differentiation in Bacillus megaterium.

The developmental stage at which cells of Bacillus megaterium are committed to continue differentiation, i.e., sporulation, depends on both the previous growth medium and the new medium to which the cells are transferred for the commitment test. The latest "stage of no return," after which cells continue differentiation, no matter how rich in nutrients the medium, is reached as soon as the forespore is completely surrounded by a double membrane.

Bacillus megaterium↗