The primary use of this guide is to provide a standardized approach for the data file to be used for the transfer of digital ultrasonic data from one user to another where the two users are working with dissimilar ultrasonic systems. This guide describes the contents, both required and optional, for an intermediate data file that can be created from the native format of the ultrasonic system on which the data was collected and that can be converted into the native format of the receiving ultrasonic or data analysis system. The development of translator software to accomplish these data format conversions is being addressed under a separate effort; this will include specific items needed for the data transfer, for example, language used, memory requirements and intermediate specification, including detailed data formats and structures. Ths guide will also be useful in the archival storage and retrieval of ultrasonic data as either a data format specifier or as a guide to the data elements that should be included in the archival file.
Although the recommended field listing includes more than 120 items, only about one third of those are regarded as essential and marked with Footnote C in Table 1. Fields so marked must be addressed in the data base. The other recommended fields provide additional information that a user will find helpful in understanding the ultrasonic examination result. These header field items will, in most cases, make up only a very small part of an ultrasonic examination file. The actual stream of ultrasonic data that make up the image will take up the largest part of the data base. Since an ultrasonic image file will normally be large, the concept of data compression will be considered in many cases. Compressed data should be noted, along with a description of the compression method, as indicated in Field No. 122.
This guide describes the structure of a data file for all of the ultrasonic information collected in a single scan. Some systems record multiple inspection results during a single scan. For example, through transmission attenuation data as well as pulse echo thickness data may be recorded at the same time. These data may be stored in separate image planes; see Field No. 102. In other systems, complete digitized waveforms may be recorded at each inspection point. It is recognized that the complete examination record may contain several files, for example, for the same examination method in different object areas, with or without image processing, for different examination methods (through-transmission, pulse-echo, radiologic, infrared, etc.) collected during the same or during different scan sessions, and for variations within a single method (frequency change, etc.). Information about the existence of other images/examination records for the examined object should be noted in the appropriate fields. A single image plane may be one created by overlaying or processing results for multiple examination approaches, for example data fusion. For such images, the notes sections must clearly state how the image for this file was created.
TABLE 1 Field Listing
| Field NumberA | Field Name and Description | Data Type/UnitsB | |
|---|---|---|---|
| Header Information: | |||
| 1C | Intermediate file name | Alphanumeric string | |