Материал: part05

Long​

Note​

1.​For attributes that were present in ACR-NEMA 1.0 and 2.0 and that have been retired, the specifications of Value​ RepresentationandValueMultiplicityprovidedarerecommendationsforthepurposeofinterpretingtheirvaluesinobjects​ createdinaccordancewithearlierversionsofthisStandard.Theserecommendationsaresuggestedasmostappropriate​ for a particular attribute; however, there is no guarantee that historical objects will not violate some requirements or​ specified VR and/or VM.​

2.​ThelengthofthevalueofUC,URandUTVRsislimitedonlybythesizeofthemaximumunsignedintegerrepresentable​ in a 32 bit VL field minus two, since FFFFFFFFH is reserved and lengths are required to be even.​

3.​In previous editions of the Standard (see PS3.5 2015a), the TAB character was not listed as permitted for the ST, LT​ and UT VRs. It has been added for the convenience of formatting and the encoding of XML text.​

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6.2.1 Person Name (PN) Value Representation​

6.2.1.1 Examples of PN VR and Notes​

Examples:​

•​Rev. John Robert Quincy Adams, B.A. M.Div.​

"Adams^John Robert Quincy^^Rev.^B.A. M.Div."​

[One family name; three given names; no middle name; one prefix; two suffixes.]​

•​Susan Morrison-Jones, Ph.D., Chief Executive Officer​

"Morrison-Jones^Susan^^^Ph.D., Chief Executive Officer"​

[Two family names; one given name; no middle name; no prefix; two suffixes.]​

•​John Doe​

"Doe^John"​

[One family name; one given name; no middle name, prefix, or suffix. Delimiters have been omitted for the three trailing null com-​ ponents.]​

•​(for examples of the encoding of Person Names using multi-byte character sets see Annex H)​

•​"Smith^Fluffy"​

[A cat, rather than a human, whose responsible party family name is Smith, and whose own name is Fluffy]​

•​"ABC Farms^Running on Water"​

[A horse whose responsible organization is named ABC Farms, and whose name is "Running On Water"]​

Note​

1.​A similar multiple component convention is also used by the HL7 v2 XPN data type. However, the XPN data type places​ the suffix component before the prefix, and has a sixth component "degree" that DICOM subsumes in the name suffix.​ There are also differences in the manner in which name representation is identified.​

2.​In typical American and European usage the first occurrence of "given name" would represent the "first name". The​ second and subsequent occurrences of the "given name" would typically be treated as a middle name(s). The "middle​ name" component is retained for the purpose of backward compatibility with existing standards.​

3.​The implementer should remain mindful of earlier usage forms that represented "given names" as "first" and "middle"​ and that translations to and from this previous typical usage may be required.​

4.​For reasons of backward compatibility with older versions of this Standard, person names might be considered a single​ family name complex (single component without "^" delimiters).​

6.2.1.2 Ideographic and Phonetic Characters in Data Elements with VR of PN​

Character strings representing person names are encoded using a convention for PN value representations based on component​ groups with 5 components.​

For the purpose of writing names in ideographic characters and in phonetic characters, up to 3 component groups may be used. The​ delimiter of the component group shall be the equals character "=" (3DH). The three component groups in their order of occurrence​ are: an alphabetic representation, an ideographic representation, and a phonetic representation.​

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Any component group may be absent, including the first component group. In this case, the person name may start with one or more​ "=" delimiters. Delimiters are also required for interior null component groups. Trailing null component groups and their delimiters may​ be omitted.​

The first component group (identified by DICOM as "alphabetic") shall be encoded using the character set specified by the Attribute​ Specific Character Set (0008,0005), value 1. If Attribute Specific Character Set (0008,0005) is not present, the Default Character​ Repertoire ISO-IR 6 shall be used. ISO 2022 escapes for Code Extension shall not be used in this component group. When Specific​ Character Set (0008,0005) value 1 specifies a multi-byte character set without Code Extension (i.e., Unicode in UTF-8, GB18030 or​ GBK), the characters of this component group may be encoded with multiple bytes, but shall be drawn from the code points U+0020​ through U+1FFF of ISO/IEC 10646, or the following ISO/IEC 10646 code points:​

U+3001, U+3002, U+300C, U+300D, U+3099 through U+309C, and U+30A0 through U+30FF​

The second group shall be used for ideographic characters. The character sets used will usually be those from Attribute Specific​ Character Set (0008,0005), value 2 through n, and may use ISO 2022 escapes.​

The third group shall be used for phonetic characters. The character sets used shall be those from Attribute Specific Character Set​ (0008,0005), value 1 through n, and may use ISO 2022 escapes.​

Delimitercharacters"^"and"="aretakenfromthecharactersetspecifiedbyvalue1oftheAttributeSpecificCharacterSet(0008,0005).​ If Attribute Specific Character Set (0008,0005), value 1 is not present, the Default Character Repertoire ISO-IR 6 shall be used.​

AtthebeginningofthevalueofthePersonNamedataelement,thefollowinginitialconditionisassumed:ifAttributeSpecificCharacter​ Set (0008,0005), value 1 is not present, the Default Character Repertoire ISO-IR 6 is invoked, and if the Attribute Specific Character​ Set (0008,0005), value 1 is present, the character set specified by value 1 of the Attribute is invoked.​

At the end of the value of the Person Name data element, and before the component delimiters "^" and "=", the character set shall​ be switched to the Default Character Repertoire ISO-IR 6, if value 1 of the Attribute Specific Character Set (0008,0005) is not present.​ If value 1 of the Attribute Specific Character Set (0008,0005) is present, the character set shall be switched to that specified by value​ 1 of the Attribute.​

Thevaluelengthofeachcomponentgroupis64charactersmaximum,includingthedelimiterforthecomponentgroup.Eachcombining​ character (e.g., diacritics or vowel marks) shall be considered a separate character for this maximum length, regardless of how an​ application may display such combining characters (i.e., combined into the glyph for the base character, or rendered separately).​

6.2.2 Unknown (UN) Value Representation​

The Unknown (UN) VR shall only be used for Private Attribute Data Elements and Standard Data Elements previously encoded as​ someDICOMVRotherthanUNusingtheDICOMDefaultTransferSyntax(ImplicitVRLittleEndian),andwhoseValueRepresentation​ is currently unknown, or whose known Value Representation is none of OB, OD, OF, OL, OW, SQ, UC, UR or UT and whose value​ length exceeds 65534 (216-2) and therefore cannot be encoded as a 16-bit unsigned integer in the Value Length Field defined for the​ known Value Representation (see Section 6.2.1). As long as the VR is unknown the Value Field is insensitive to byte ordering and​ shall not be 'byte-swapped' (see Section 7.3). In the case of undefined length sequences, the value shall remain in implicit VR form.​ SeeSection7.8foradescriptionofPrivateDataAttributeElementsandsection10andAnnexAforadiscussionofTransferSyntaxes.​

The UN VR shall not be used for Private Creator Data Elements (i.e., the VR is equal to LO, see Section 7.8.1).​

The UN VR shall not be used for File Meta Information Data Elements (any Tag (0002,xxxx), see PS3.10).​

Note​

1.​All other (non-default) DICOM Transfer Syntaxes employ explicit VR in their encoding, and therefore any Private and/or​ Standard Data Element Value Field Attribute value encoded and decoded using any Transfer Syntax other than the​ default, and not having been translated to the DICOM Default Transfer Syntax default in the interim, will have a known​ VR.​

2.​IfatsomepointanapplicationknowstheactualVRforanAttributeofVRUN(e.g.,hasitsownapplicabledatadictionary),​ it can assume that the Value Field of the Attribute is encoded in Little Endian byte ordering with implicit VR encoding,​ irrespective of the current Transfer Syntax.​

3.​ThisVRofUNisneededwhenanexplicitVRmustbegiventoaDataElementwhoseValueRepresentationisunknown​ (e.g., store and forward).​

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4.​This VR of UN is also needed for the encoding of Data Elements with explicit VR whose value length exceeds 65534​ (216-2) (FFFEH, the largest even length unsigned 16 bit number) but which are defined to have a 16 bit explicit VR​ length field.​

5.​ThelengthfieldoftheValueRepresentationofUNmaycontainthevalueofUndefinedLength,inwhichcasethecontents​ can be assumed to be encoded with implicit VR. See Section 7.5.1 to determine how to parse Data Elements with an​ Undefined Length.​

6.​An example of a Standard Data Element using a UN VR is a Type 3 or Type U Standard Attribute added to an SOP​ Class definition. An existing application that does not support that new Attribute (and encounters it) could convert the​ VR to UN.​

6.2.3 URI/URL (UR) Value Representation​

TheURI/URL(UR)VRusesasubsetoftheDefaultCharacterRepertoireasdefinedin[RFC3986],andshallnotuseanycodeextension​ or replacement techniques. URI/URL domain name components that in their original form use characters outside the permitted​ charactersetshallusetheInternationalizedDomainNamesforApplicationsencodinginaccordancewithIETFRFC5890andRFC5891.​ Other URI/URL content that uses characters outside the permitted character set shall use the Internationalized Resource Identifiers​ encoding mechanism of IETF RFC 3987, representing the content string in UTF-8 and percent encoding characters as required.​

Note​

For example, the use of a patient name in a URI/URL string may require use of the [RFC3987] technique.​

6.3 Enumerated Values and Defined Terms​

The value of certain Data Elements may be chosen among a set of explicit Values satisfying its VR. These explicit Values are either​ Enumerated Values or Defined Terms and are specified in PS3.3 and PS3.4.​

Enumerated Values are used when the specified explicit Values are the only Values allowed for a Data Element. A Data Element with​ Enumerated Values that does not have a Value equivalent to one of the Values specified in this Standard has an invalid value within​ the scope of a specific Information Object/SOP Class definition.​

Note​

1.​Patient Sex (0010, 0040) is an example of a Data Element having Enumerated Values. It is defined to have a Value​ that is either "M", "F", or "O" (see PS3.3). No other Value shall be given to this Data Element.​

2.​Future modifications of this Standard may add to the set of allowed values for Data Elements with Enumerated Values.​ Such additions by themselves may or may not require a change in SOP Class UIDs, depending on the semantics of​ the Data Element.​

DefinedTermsareusedwhenthespecifiedexplicitValuesmaybeextendedbyimplementerstoincludeadditionalnewValues.These​ new Values shall be specified in the Conformance Statement (see PS3.2) and shall not have the same meaning as currently defined​ Values in this Standard. A Data Element with Defined Terms that does not contain a Value equivalent to one of the Values currently​ specified in this Standard shall not be considered to have an invalid value. An empty (zero length) value is not a valid new Value for​ a Defined Term; empty values shall be considered invalid unless the Standard specifically permits empty values. New Values shall​ not have a meaning of unknown, since that concept, if permitted by the Standard, shall be conveyed explicitly either by allowing the​ Data Element to be zero length or by provision of a standard Defined Term with such a meaning.​

Note​

1.​Reporting Priority (0040,1009) is an example of a Data Element having Defined Terms. It is defined to have a Value​ that may be one of the set of standard Values; HIGH, ROUTINE, MEDIUM, or LOW (see PS3.3). Because this Data​ Element has Defined Terms other reporting priorities may be defined by the implementer.​

2.​The validity of empty values is usually specified by the attribute being defined as Type 2 (see Section 7.4.3). However,​ in the context of a required Type 1 attribute with multiple values, some (but not all) values may be allowed to be empty​ (see Section 7.4.1); in this case the Standard explicitly specifies the validity of empty values in the list of Defined Terms​ for each value. Specific Character Set (0008,0005) is an example of a Data Element for which the Standard specifically​ permits the first value to be empty when multiple values are present. Image Type (0008,0008) is an example of a Data​

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Element that in some IODs defined in PS3.3 is required to be present with multiple values, but if an empty value is not​ explicitly listed in the Defined Terms for Value 3 by an IOD an empty value is invalid.​

The Value Representation may affect the interpretation of Defined Terms and Enumerated Values for numeric values. For binary​ Value Representations, the textual representation of the Value in the Standard does not affect the interpretation. For string Value​ Representations (IS and DS), the meaning of the Value in the Standard shall be used, not the literal string.​

Note​

For example, an Enumerated Value of "1" expressed in the text of the Standard matches an IS or DS value encoded as​ "001", or a DS value encoded as "1.0" or "1." or "1.0000E+00" or any permitted encoding. Leading and trailing spaces are​ defined in Table 6.2-1 not to be significant and hence do not affect the interpretation.​

6.4 Value Multiplicity (VM) and Delimitation​

The Value Multiplicity of a Data Element specifies the number of Values that can be encoded in the Value Field of that Data Element.​ The VM of each Data Element is specified explicitly in PS3.6. If the number of Values that may be encoded in an element is variable,​ it shall be represented by two numbers separated by a dash; e.g., "1-10" means that there may be 1 to 10 Values in the element.​

Note​

Elements having a multiplicity of "S", which represented "single", in older versions of this Standard, will have a multiplicity​ of "1" in this version of this Standard.​

When a Data Element has multiple Values, those Values shall be delimited as follows:​

•​For character strings, the character 5CH (BACKSLASH "\" in the case of the repertoire ISO IR-6) shall be used as a delimiter​ between Values.​

Note​

BACKSLASH ("\") is used as a delimiter between character string Values that are of fixed length as well as variable length.​

•​Multiple binary Values of fixed length shall be a series of concatenated Values without any delimiter.​

Each string Value in a multi-valued character string may be of even or odd length, but the length of the entire Value Field (including​ "\" delimiters) shall be of even length. If padding is required to make the Value Field of even length, a single padding character shall​ be applied to the end of the Value Field (to the last Value), in which case the length of the last Value may exceed the Length of Value​ by 1.​

Note​

A padding character may need to be appended to a fixed length character string value in the above case.​

Only the last UID Value in a multi-valued Data Element with a VR of UI shall be padded with a single trailing NULL (00H) character​ when necessary to ensure that the entire Value Field (including "\" delimiters) is of even length.​

Data Elements with a VR of LT, OB, OD, OF, OL, OW, SQ, ST, UN, UR or UT shall always have a Value Multiplicity of one. See​ Table 6.2-1.​

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