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H Forsberg

Publications and source records attributed to H Forsberg.

40 records · Page 3Linked to original sources
PubMedDate not supplied

Clinically acceptable tolerance of roentgen generator exposure parameters.

The clinical demands for accuracy of roentgen generator scales were investigated in order to define suitable levels of tolerance to be required during calibration procedures and preventive maintenance on modern equipment. Radiographs of various film densities were made of four body parts. As test observers 59 radiologists and 53 radiologic technicians were asked to judge which radiographs they considered acceptable or not acceptable. Ninety-five per cent of the radiographs were accepted with the under- or overexposure of one mAs step. The spread of the estimations of suitable exposure data made by 38 radiologic technicians was also investigated. From these data the clinically acceptable tolerance of roentgen generator exposure parameters could be derived. It is suggested that the tolerance of tube voltage (kV) should be less than +/- 5 per cent, current-time product (mAs) -20 to +25 per cent and automatic exposure control systems (AEC) -20 to +25 per cent.

Cadaver↗
PubMedDate not supplied

Sensitometric control of roentgen film processors.

Monitoring of film processors performance is essential since image quality, patient dose and costs are influenced by the performance. A system for sensitometric constancy control of film processors and their associated components is described. Experience with the system for 3 years is given when implemented on 17 film processors. Modern high quality film processors have a stability that makes a test frequency of once a week sufficient to maintain adequate image quality. The test system is so sensitive that corrective actions almost invariably have been taken before any technical problem degraded the image quality to a visible degree.

Radiography↗