CODEWITHSUNDEEP
dicom
diaferiaj
diaferiaj

Reputation: 375

How the number of slices per rotation be derived from required DICOM tags?

Computed Tomography (CT) scanners are often characterized by the number of images they can acquire during a single gantry rotation (ie. 16-slice scanner). 16-slice scanners are considered to be superior to those that take fewer images per rotation.

A similar association of quality in Magnetic Resonance (MR) would be the field strength in Tesla. In my experience with DICOM Standard, the Magnetic Field Strength Attribute (0018,0087) is frequently captured, despite being a Type 3 (optional) attribute.

It appears, however, that there is no similar (easy) way of distilling the CT slice capacity. It would seem that if I could determine the Slice Ordering, in conjunction with the gantry angle/location, then a calculation might be possible.

That said, can the number of slices per rotation be derived from required DICOM tags, per the DICOM Standard?

Upvotes: 0

Views: 358

Answers (1)

Markus Sabin
Markus Sabin

Reputation: 4013

For traditional CT (SOP Class UID= 1.2.840.10008.5.1.4.1.1.2), there is no chance to obtain these values.

For Enhanced CT (SOP Class UID= 1.2.840.10008.5.1.4.1.1.2.1) you may want to take a look at the CT Acquisition Details Macro (PS3.3, Table C.8-119). There you find values for:

  • Rotation Direction (0018,1140)
  • Revolution Time (0018,9305)

Given the revolution time and the Content Time (0008,0033) of the slices you may deduce the number of images acquired in one rotation. However this depends on the precision in which the attribute values are given.

Upvotes: 1

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