X-Ray acquisition start date and time

(111526, DCM, "Date Time Started") of the Irradiation Event in TID 10003 and TID 10042.

Acquisition Datetime (0008,002A)

The date and time that the application of X-Rays started for this irradiation event. This corresponds to the start of the first irradiation in the Irradiation Event, which defines the starting point for the calculation of (113742, DCM, "Irradiation Duration").

The date and time that the acquisition of data that resulted in the image instance started.

It can be equal to the Frame Acquisition DateTime (0018,9074) of frame #1, or equal to Content Date (0008,0023) and Content Time (0008,0033).

It is not necessarily equal between image header and RDSR: typically, the image acquisition starts before the first X-Ray pulse (e.g., triggered by manual activation of an X-Ray switch before the actual X-Ray). On the other hand, when an image acquisition has applied pre-pulses before the first actual frame stored in the multi-frame image, the image acquisition starts after the pre-pulses which are not stored as image frames but they are counted in the RDSR as actual radiation.

Number of X-Ray pulses during the acquisition

(113768, DCM, "Number of Pulses") of the Irradiation Event in TID 10003 and TID 10042.

Number of Frames (0028,0008)

Number of pulses applied by X-Ray systems during an irradiation event (acquisition run or pulsed fluoro).

The number of resulting 2D images (pixel data).

In the image Instance, Number of Frames (0028,0008) typically does not correspond to the actual number of X-Ray pulses. For instance, if frame averaging or recursive filtering, the number of irradiation pulses may be higher than the number of resulting 2D images. Therefore, it is not necessarily equal between image header and RDSR.

X-Ray Duration since first to last X-Ray pulse

(113742, DCM, "Irradiation Duration") of the Irradiation Event in TID 10003B.

Not encoded as is in Enhanced RDSR, but it can be calculated from (111526, DCM, "Date Time Started") and (111527, DCM, "Date Time Ended") in TID 10042.

Acquisition Duration (0018,9073)

Clock time from the start of loading time of the first pulse until the loading time trailing edge of the final pulse in the same irradiation event.

Duration of the single continuous gathering of data over a period of time that resulted in this instance, in seconds. Also defined as the time in seconds needed for the complete acquisition.

In the image Instance, Acquisition Duration (0018,9073) is not accurately defined, as the trigger to start counting the time is defined by the manufacturer, and could be dictated by the protocol or by a manual activation of an X-Ray switch (pedal press) before the actual X-Ray. Therefore, it is not necessarily equal between image header and RDSR.

Pulse Width

(113793, DCM, "Pulse Width") of the Irradiation Event in TID 10003B and in TID 10045.

Average Pulse Width (0018,1154).

Time of X-Ray emission (i.e., tube current flowing) of a single pulse in msec.

In TID10003B it can be encoded either as a single value, or as multiple values. If a single value is provided, it contains the average pulse width. If multiple values are provided, it contains the value of the pulse width for each pulse.

Pulse width if the time of X-Ray emission (i.e., tube current flowing) of a single pulse in msec.

The value of the Average Pulse Width (0018,1154) in the image header is the same as the value of (113793, DCM, "Pulse Width") in Traditional RDSR when encoded as a single value. Otherwise, if RDSR encodes the Pulse Width for each pulse, it will typically be different between image header and RDSR.

Note that in Enhanced XA IOD, the Attribute Frame Acquisition Duration (0018,9220) is the time that was used to acquire data for one frame, and is not accurately defined. It could be longer than the duration of one pulse in case of frame averaging or recursive filtering.

Exposure Time

(113824, DCM, "Exposure Time") of the Irradiation Event in TID 10003B and TID 10042.

Exposure Time (0018,9328)

The total time the patient has received X-Ray exposure (i.e., when the tube current is flowing) during the irradiation event.

If the pulse width is provided with a single value, it could be equivalent to the multiplication of (113793, DCM, "Pulse Width") * (113768, DCM, "Number of Pulses").

If the pulse width is provided with one value per pulse, it could be equivalent to the sum of all values of pulse width.

Duration of X-Ray exposure in milliseconds, which is the time of X-Ray emission (i.e., tube current flowing) for the multi-frame image.

It is equal between image header and RDSR.

Total Fluoro Time

(113730, DCM, "Total Fluoro Time") in TID 10004 and TID 10041.

There is no equivalent Attribute in the image.

Total accumulated clock time of Fluoroscopy in the scope of the RDSR, defined as the SUM of (113742, DCM, "Irradiation Duration") of all Irradiation Events of type "Fluoroscopy".

If all the fluoroscopy irradiations were stored in DICOM Instances, (113730, DCM, "Total Fluoro Time") would be the SUM of Acquisition Duration (0018,9073) of all the images for which the Radiation Setting (0018,1155) equals "SC", i.e., low dose (fluoroscopy).

Total Acquisition Time

(113855, DCM, "Total Acquisition Time") in TID 10004 and TID 10041.

There is no equivalent Attribute in the image.

Total accumulated acquisition clock time in the scope of the RDSR, defined as the SUM of (113742, DCM, "Irradiation Duration") of all Irradiation Events of type "Acquisition".

If all the acquisition irradiations were stored in DICOM Instances, (113855, DCM, "Total Acquisition Time") would be the SUM of Acquisition Duration (0018,9073) of all the images for which the Radiation Setting (0018,1155) equals "GR", i.e., high dose (acquisition, digital spot or cine).