PS-2020a / part17

Table BBBB.2-2. Example data for the Dimension Organization Module​

Table BBBB.2-3. Example data for the Pixel Measures Macro​

Table BBBB.2-4. Example data for the Frame Content Macro​

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Page 812​ DICOM PS3.17 2020a - Explanatory Information​

Table BBBB.2-5. Example data for the Identity Pixel Value Transformation Macro​

Table BBBB.2-6. Example data for the Frame VOI LUT With LUT Macro​

Table BBBB.2-7. Example data for the Real World Value Mapping Macro​

The Palette Color Lookup Table used is the Spring Color Palette (see Figure BBBB.1-3 Resulting Color LUT Spring).​

This can be described as follows through the Palette Color Lookup Table:​

Red has a constant value of 255​

Green has a linear segment that starts at 0 and ends at 255​

Blue has a linear segment that starts at 255 and ends at 0​

Using the Segmented Color Lookup Table all three can be described by a discrete segment with length 1 to specify the starting value​ (0,1,value) followed by a linear segment of length 255 with the end-value (1,255,end-value).​

Table BBBB.2-8. Example data for the Palette Color Lookup Table Module​

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Figure BBBB.1-3. Resulting Color LUT Spring​

The values specifying the range to be mapped to the Color LUT are given by the Minimum Stored Value Mapped and the Maximum​ Stored Value mapped.​

Table BBBB.2-9. Example data for the Stored Value Color Range Macro​

Table BBBB.2-10. Example data for the Parametric Map Frame Type Macro​

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CCCC Populating The Simplified Echo​

Procedure Report Template (Informative)​

This Annex provides guidance to understand and populate the TID 5300 “Simplified Echo Procedure Report” and its sub-templates.​ For implementers familiar with the TID 5200 “Echocardiography Procedure Report”, which is largely replaced by TID 5300, some re-​ lationships and differences are also explained.​

CCCC.1 Structure Overview​

Measurements in this template (except for the Wall Motion Analysis) are collected into one of three containers, each with a specific​ sub-template and constraints appropriate to the purpose of the container.​

•​Pre-coordinated Measurements​

•​Are fully standardized measurements (many taken from the ASE practice guidelines).​

•​Each has a single pre-coordinated standard code that fully captures the semantics of the measurement.​

•​The only modifiers permitted are to indicate coordinates where the measurement was taken, provide a brief display label, and​ indicate which of a set of repeated measurements is the preferred value. Other modifiers are not permitted.​

•​Post-coordinated Measurements​

•​Are measurements for which DICOM has not established pre-coordinated codes, but that are performed with enough regularity​ to merit configuration and capturing the full semantics of the measurement. For example these measurements may include those​ configured on the Ultrasound System by the vendor or user site. Some of these may be variants of the Pre-coordinated Measure-​ ments.​

•​A set of mandatory and conditional modifiers with controlled vocabularies capture the essential semantics in a uniform way.​

•​A single pre-coordinated code is also provided so that when the same type of measurement is encountered in the future, it is not​ necessarytoparseandevaluatethefullconstellationofmodifervalues.Sincethismeasurementhasnotbeenfullystandardized,​ the pre-coordinated code may use a private coding scheme (e.g., from the vendor or user site).​

•​Adhoc Measurements​

•​Are non-standardized measurements that do not merit the effort to track or configure all the details necessary to populate the​ set of modifiers required for a post-coordinated measurement.​

•​The measurement code describes the elementary property measured.​

•​Modifiers provide a brief display label and indicate coordinates where the measurement was taken. Other modifiers are not per-​ mitted.​

CCCC.2 Use Cases​

CCCC.2.1 Use Case 1: Store and Extract Specific Measurement​

TheuserwishestoperformmeasurementsontheUltrasoundSystem,storethemtothePACSandlaterhaveaspecificmeasurement​ (sayABC)automaticallydisplayedintheoverlayorautomaticallyinsertedintoareportpageonthereviewsystem.Thisdoesnotrequire​ the receiver to understand any of the semantics of the measurement.​

CCCC.2.1.1 Configuration​

TheUltrasoundSystemisconfiguredtoencodeaparticularmeasurementusingaspecificpre-coordinatedcode(andcodemeaning).​

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In the case of measurements from the Core Set, it is a well-known pre-coordinated code (i.e., the code is in CID 12300 “Core Echo​ Measurements”), the full semantics are well-known and the measurement will be recorded in TID 5301 “Pre-coordinated Echo​ Measurement” . Likely most, if not all, of the Core Set measurements come pre-configured on the Ultrasound System.​

In the case of vendor-specific or site-specific measurements, it is a pre-coordinated code managed by the site or the vendor which​ is entered and persisted on the Ultrasound System. Since the code is not well-known, the measurement will be recorded in TID 5302​ “Post-coordinated Echo Measurement” along with the modifiers describing its semantics.​

The receiver (i.e., the PACS display package or the reporting package) is configured to associate the specific pre-coordinated code​ with a location on the overlay or a slot in the report.​

The form of the user interface for these capabilities is up to the implementer.​

CCCC.2.1.2 Operation​

The user takes measurements on the Ultrasound System, including measurement ABC. All these measurements are recorded in the​ SimplifiedAdultEchoSRobject.IfmultipleinstancesofmeasurementABCareincluded,oneofthemmaybeflaggedbytheUltrasound​ System by setting the Selection Status for that instance to the reason it was selected as the preferred value.​

The Ultrasound System stores the SR object to the PACS.​

ThePACSorthereportingpackageretrievestheSRobjectandscansthecontentslookingformeasurementswiththepre-coordinated​ code for measurement ABC. If multiple instances are found, the receiver takes the one for which the Selection Status has been set.​

The receiver renders the measurement value to the display or report, annotating it with the recorded Units, Code Meaning, and/or​ Short Label as appropriate.​

Note that in this use case the receiver handles the measurement in a mechanical way. As long as the measurement can be unam-​ biguously identified, the semantics do not need to be understood by the receiver.​

CCCC.2.2 Use Case 2: Store and Process Measurements​

The user wishes to perform measurements on the Ultrasound System, store them to the PACS and later perform processing of some​ or all of the measurements on a CVIS (Cardiovascular Information System) or other system. Processing may include incorporating​ measurements into a database, performing trend analysis, plotting graphs, driving decision support, etc. One measurement taken at​ end systole may be compared to the "same" measurement that is taken at end diastole, etc. Measurements at the same Finding Site​ might be collected together.​

CCCC.2.2.1 Configuration​

As in Use Case 1, the Ultrasound System is configured to encode each measurement using a specific pre-coordinated code (and​ code meaning).​

Again, measurements from the Core Set use a well-known pre-coordinated code and are recorded in TID 5301 “Pre-coordinated​ Echo Measurement” while vendor-specific or site-specific measurements use locally managed codes and are recorded in TID 5302​ “Post-coordinated Echo Measurement” along with the modifiers describing their semantics.​

CCCC.2.2.2 Operation​

The user again takes measurements on the Ultrasound System which are recorded in the Simplified Adult Echo SR object and if​ multiple instances of a measurement are included, one of them may be flagged by the Ultrasound System by setting the Selection​ Status for that instance to the reason it was selected as the preferred value.​

The Ultrasound System stores the SR object to the PACS.​

ThereceivingdatabaseorprocessingsystemretrievestheSRobjectandparsesthecontents.ThecontentsofTID5301“Pre-coordin-​ ated Echo Measurement” have known semantics and are processed accordingly.​

On first encounter, measurements in TID 5302 “Post-coordinated Echo Measurement” will likely have unfamiliar pre-coordinated​ codes (since the pre-coordinated code in Row 1 of TID 5302 is not taken from CID 12300 “Core Echo Measurements”, but rather was​ likely produced by the vendor of the Ultrasound System). Depending on the sophistication of the receiver, parsing the modifiers may​

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provide sufficient information for the receiver to automatically handle the new measurement. If not, the measurement can be put in​ an exception queue for a human operator to review the values of the modifiers and decide how the measurement should be handled.​ In between those two possibilities, the receiver may be able to compare the modifier values of known measurements and provide the​ operator with a partially categorized measurement.​

In any case, once the semantics of the measurement are understood by the receiver, the corresponding pre-coordinated code can​ be logged so that future encounters with that measurement can be handled in an automated fashion.​

The receiver may also make use of the Selection Status values or may database all the provided measurement values or allow the​ human to select from the provided set.​

Note that in this use case the receiver handles the measurements based on the semantics associated with the measurement.​

CCCC.3 Differences of Note Between TID_5200 and TID 5300​

CCCC.3.1 Report Sections​

In TID 5200 “Echocardiography Procedure Report”, containers and headings were used to facilitate the layout of printed/displayed​ reports by collecting measurements into groups based on concepts like anatomical region. Further, TID 5200 permitted Ultrasound​ Systems to add new sections freely, TID 5300 “Simplified Echo Procedure Report” does not. Section usage was a source of problem-​ aticvariabilityforreceiversofTID5200.TID5300constrainsthis.Whensuchgroupingsareuseful,forexamplewhenprintingreports,​ it makes more sense to configure it in one place (in the receiving database/reporting system) rather than configuring such groupings​ independently(andpossiblyinconsistently)oneachultrasounddeviceinadepartment.Receiversmaychoosetogroupmeasurements​ based on Finding Site or some other logic as they see fit. This avoids the problem of trying to keep many Ultrasound Systems in sync.​ SRobjectsareconsideredacquisitiondata/evidence.IfthefindingsaretranscodedintoCDAreports,sectionswilllikelybeintroduced​ in the CDA as appropriate.​

CCCC.3.2 Finding Observation Type​

The Finding Site is the location at which the measurement was taken. While some measurements will be an observation of the​ structure of the finding site itself, other measurements will be an observation of something like flow, in which case the Finding Site is​ simplythelocation,nottheactualthingbeingobserved/measured.Toclarifythisdistinction,FindingObservationTypewasintroduced​ in TID 5302 “Post-coordinated Echo Measurement” . For example, when the measurement is a peak velocity and the Finding Site is​ a valve, to distinguish between a measurement of the velocity of the blood through the valve, and a measurement of the velocity of​ thevalvetissue,theFindingObservationTypewouldbesetto"HemodynamicMeasurement"or"BehaviorofFindingSite"respectively.​

CCCC.4 Usage Guidance​

CCCC.4.1 Finding Site​

Modifiers are not permitted on the Finding Site in TID 5302 “Post-coordinated Echo Measurement” since such modifiers resulted in​ different ways of encoding the same concept. TID 5302 requires the use of a single anatomical code that fully pre-coordinates the​ location details of the measurement. CID 12305 “Basic Echo Anatomic Sites” has proven to be sufficient to encode the ASE Core​ Set of measurements. Implementers are strongly recommended to using codes from that list. If there is a truly significant location​ detail that needs to be captured, e.g., to identify a specific segment of the atrial wall, or a specific leaf of a valve as the location of the​ measurement, then the implementer may introduce a new code (CID 12305 is extensible) or better yet, new codes can be added to​ CID 12305 through a DICOM Change Proposal.​

CCCC.4.2 Measured Property​

ThecodesinCID12304“EchoMeasuredProperties”havealsoproventobesufficienttoencodetheASECoreSetofmeasurements.​ It is expected that the majority of vendor-specific or site-specific measurements can also be encoded using these properties, but it is​ understandable that some additional codes may be needed. When introducing new codes, implementers should be careful not to in-​ troduce elements of the other modifiers, such as Finding Site or Cardiac Cycle Point, into the Measured Property. For example, do​ not introduce a property for Diastolic Atrial Length to be used for the left and right atria, rather for such a measurement, use Prop-​ erty=Length, Cardiac Cycle Point=End Diastole and Finding Site=Left Atrium or Right Atrium respectively.​

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CCCC.4.3 Image View​

Implementers may use codes for image views beyond those listed in DCID 12226 “Echocardiography Image View” as needed, but​ note that Image View is only recorded if it is significant to the interpretation of the measurement. Inclusion of the Image View will likely​ isolate the measurement from other measurements of the same feature taken in different views.​

CCCC.4.4 Cardiac Cycle Point​

Note that (111973004, SCT, "Systole") is used here to refer to the entire duration of ventricular systole, while (416430001, SCT, "End​ Systole") is used to refer to the point in time where the aortic valve closes (or in the case of the right ventricle, the pulmonary valve).​ Therefore, a Vmax measurement for systole would mean the maximum velocity over the period of systole, and a Vmax measurement​ for end systole would mean the maximum velocity at the time point of end systole.​

CCCC.4.5 Measurement Method​

This distinguishes between two measurements that convey the same concept, but are obtained or derived in a different way. As with​ the Image View, this is only recorded if it is significant to the interpretation of the measurement.​

CCCC.4.6 Selection Status​

This is used to flag the preferred value when multiple instances of the same measurement are recorded in the SR object. Using this​ to communicate the value preferred by the operator or the Ultrasound System is very useful for receivers that lack the logic to make​ a selection themselves. In cases where there is no need or value in sending multiple instances of the same measurement, the issue​ can be avoided by only sending a single instance of any given measurement in the SR object.​

CCCC.4.7 Additional Modifiers​

The concept modifiers in the template are sufficient to accurately encode all the best practice echo measurements recommended by​ the ASE. Although TID 5302 “Post-coordinated Echo Measurement” is extensible and adding new modifiers is not prohibited, the​ meaning and significance of such new modifiers will generally not be understood by receiving systems, delaying or preventing import​ of such measurements. Further, adding modifiers that replicate the meaning of an existing modifier is prohibited.​

CCCC.5 Example​

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