Материал: part03

C.34.2.1 Predecessor Protocol Sequence​

A Protocol may be a derivation of another Protocol (the "predecessor"). For example, a Protocol may be originally published as a​ non-model-specific Protocol for a certain purpose. Subsequently, a new Protocol may be derived from the original by making it spe-​ cific to a certain model of scanner. Derivation may involve adjusting constraints or specifying additional constraints. If a Protocol no​ longer satisfies any of the indications of the Predecessor Protocol from which it was derived, the Predecessor shall not be referenced​ in this Sequence.​

Note​

IncludingpredecessorinformationmakesitpossibletofilterasetofProtocols,forexampletolistallProtocolsthatarederived​ versions of a certain known Protocol (e.g., ACRIN 6678), or list only the one that has been specialized for a specific model​ of equipment.​

Sites that receive a generic Protocol might create a specialized variant to fit their local practice and avoid the tech having to make​ selections/changes each time it is used.​

Onlytheimmediatepredecessorshallbereferenced,butmorethanonepredecessormaybereferencedifmultipledistinctpredecessors​ were merged.​

C.34.2.2 Protocol Planning Information​

This information describes activities that are related to the effective performance of the Protocol but are not typically performed in the​ scanning room. This could include things like:​

•​Instruct patient to fast for 4 hours before imaging​

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•​Obtain creatinine within 7 days before imaging​

•​Schedule scan 12-24hrs before surgery​

•​Premedicate patient with diphenhydramine 1 hr before imaging​

•​Schedule an additional liver Acquisition Protocol Element 10-15 minutes after contrast injection if the patient has a history of​ cholangiocarcinoma; note this example would affect both the length of the scheduled time slot and the actual performance with a​ delayed acquisition​

•​If available run the followup scan on the same device as the original scan.​

C.34.2.3 Protocol Management​

The Protocol Context Module contains Attributes for grouping and managing Protocol objects.​

The Responsible Group Code Sequence (0008,0220) can be used by the department or clinical specialty to collect the Protocols for​ which they are responsible for review and management.​

The Potential Scheduled Protocol Code Sequence (0018,9906) and Potential Reasons for Procedure Code Sequence (0018,9909)​ can gather Protocols associated with a given procedure code or indication respectively.​

The contents of the Referenced Defined Protocol Sequence (0018,990C) in a collection of Performed Procedure Protocol objects​ can be used to determine the frequency of usage of the corresponding Defined Procedure Protocol objects.​

C.34.3 Patient Protocol Context Module​

The patient specific context in which the described Protocol is performed. This Module is applicable to performed procedures.​

Table C.34.3-1. Patient Protocol Context Module Attributes​

One or more Items shall be included in this​ Sequence.​

>Include Table 10-11 “SOP Instance Reference Macro Attributes”​

C.34.4 Clinical Trial Context Module​

Table C.34.4-1 contains Attributes that identify a clinical trial context independent of any specific Clinical Trial Subjects.​

Table C.34.4-1. Clinical Trial Context Module Attributes​

See Section C.7.1.3.1.4.​

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C.34.5 Patient Specification Module​

Table C.34.5-1 contains patient characteristics for which a Protocol may be considered applicable.​

Table C.34.5-1. Patient Specification Module Attributes​

>Include Table 10.25-1 “Attribute Value Constraint Macro​Only Attributes defined in the Patient Module (See Table C.7-1) or the​ Attributes”​ Patient Study Module (See Table C.7-4a) may be specified as Selector​ Attributes.​

See Section C.34.9.3.​

The same Attribute shall not be constrained in more than one Item in this​

Sequence.​

Note​

Since these constraints are being placed on the Attributes that​ will appear in the Patient Module or Patient Study Module of the​ resulting instances, the Patient Specification Sequence will not​ appear in the Selector Sequence Pointer (0072,0052).​

Attributes that might commonly be specified in this Sequence include:​

•​Patient's Age (0010,1010), to indicate Protocols for age ranges like adults, pediatrics, infants​

•​Patient's Sex (0010,0040), to indicate Protocols for males, females, both​

•​Patient's Weight (0010,1030), to indicate Protocols for different weight ranges​

C.34.6 Equipment Specification Module​

Table C.34.6-1 contains equipment characteristics for which a Protocol may be considered appropriate.​

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Page 1564​ DICOM PS3.3 2020a - Information Object Definitions​

Table C.34.6-1. Equipment Specification Module Attributes​

The Protocol details in other Modules may implicitly further constrain the appropriate equipment. For example, the specified hardware​ may not have the ability to perform acquisitions that satisfy the acquisition parameter constraints, to perform reconstructions that​ satisfy the reconstruction parameter constraints, or to produce images with the desired characteristics.​

C.34.6.1 Model Specification Sequence​

EachItemintheSequence,containsmultipleAttributestobesatisfiedatonce.ItisonlynecessarytomatchoneItemintheSequence.​ The decision about whether an Item is a suitable match is up to the executing device. The intention is to provide values that would​ allow a scanner device to identify whether a Protocol is appropriate for it.​

Note​

ThevaluesmaynotnecessarilymatchexactlywhatthescannerwouldputintocorrespondingAttributesininstancesitcreates.​

C.34.7 Instructions Module​

Table C.34.7-1 contains instructions relating to preparation and performance of the Protocol.​

Table C.34.7-1. Instructions Module Attributes​

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C.34.7.1 Instruction Sequence​

This Sequence describes instructions to be performed by the scanner staff in conjunction with the Protocol. The instructions are​ generally limited to activites that happen inside the scan suite and might include​

•​preparation of the scanner (e.g., running a particular calibration, mounting a head holder or patient grab handles on the table) ,​

•​preparation of the patient (e.g., asking if they have fasted, placing padding or shielding, giving the patient water as oral contrast,​ turning the patient prone for the second acquisition in a virtual colonoscopy Protocol) ,​

•​instructions to the patient during the imaging procedure (e.g., asking the patient to hold their breath, asking the patient to hyper-​ ventilate prior to breathold)​

•​instructions to the technologist during the imaging procedure (e.g., obtain the spiral acquisition during a single breathhold, take​ additional images if some condition is true).​

The instruction may also include timing or triggering details, for example:​

•​Start the Portal Venous phase Acquisition Protocol Element when an ROI placed over the liver detects a contrast bolus at 50 HU​ above baseline​

•​Start the Delay phase Acquisition Protocol Element three minutes after start of contrast injection​

•​Start the AP Localizer Acquisition Protocol Element eight minutes after start of contrast injection and repeat the AP Localizer Ac-​ quisition Protocol Element at one minute intervals until adequate ureter opacification is observed, then proceed to the abdomen​ Acquisition Protocol Element​

Instructions related to the initial positioning of the patient are included in the Patient Positioning Module. This Module may describe​ subsequent changes in position between steps of the protocol.​

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