Use of Radiology Procedure Codes in Health Care: The Need for Standardization and Structure

Abstract

Radiology procedure codes are a fundamental part of most radiology workflows, such as ordering, scheduling, billing, and image interpretation. Nonstandardized unstructured procedure codes have typically been used in radiology departments. Such codes may be sufficient for specific purposes, but they offer limited support for interoperability. As radiology workflows and the various forms of clinical data exchange have become more sophisticated, the need for more advanced interoperability with use of standardized structured codes has increased. For example, structured codes facilitate the automated identification of relevant prior imaging studies and the collection of data for radiation dose tracking. The authors review the role of imaging procedure codes in radiology departments and across the health care enterprise. Standards for radiology procedure coding are described, and the mechanisms of structured coding systems are reviewed. In particular, the structure of the RadLex™ Playbook coding system and examples of the use of this system are described. Harmonization of the RadLex Playbook system with the Logical Observation Identifiers Names and Codes standard, which is currently in progress, also is described. The benefits and challenges of adopting standardized codes-especially the difficulties in mapping local codes to standardized codes-are reviewed. Tools and strategies for mitigating these challenges, including the use of billing codes as an intermediate step in mapping, also are reviewed. In addition, the authors describe how to use the RadLex Playbook Web service application programming interface for partial automation of code mapping. ^© RSNA, 2017.

Figure 1a.

RadLex Playbook example codes. Each RadLex Playbook code, or RPID, is defined by using a unique set of attribute values; the RID is shown in italics. See Table 2 for a list of RadLex Playbook attributes. (a) In certain instances, more than one value for a given attribute may be specified, such as for RPID145 (“CT Abd/Pelv w”). In this case, two body regions are specified by using the attributes BODY_REGION and BODY_REGION_2, as shown. (b) In other instances, a more specific anatomic area of interest may be specified, such as in the code RPID5959 (“MR Prostate w”). Here, the attribute BODY_REGION is assigned the value PELVIS, and the attribute ANATOMIC_FOCUS is used to indicate the more specific organ PROSTATE.

Figure 1b.

RadLex Playbook example codes. Each RadLex Playbook code, or RPID, is defined by using a unique set of attribute values; the RID is shown in italics. See Table 2 for a list of RadLex Playbook attributes. (a) In certain instances, more than one value for a given attribute may be specified, such as for RPID145 (“CT Abd/Pelv w”). In this case, two body regions are specified by using the attributes BODY_REGION and BODY_REGION_2, as shown. (b) In other instances, a more specific anatomic area of interest may be specified, such as in the code RPID5959 (“MR Prostate w”). Here, the attribute BODY_REGION is assigned the value PELVIS, and the attribute ANATOMIC_FOCUS is used to indicate the more specific organ PROSTATE.

Figure 2a.

Structured procedure codes consisting of components, or attributes, that facilitate semantic interoperability. Consider the RadLex Playbook codes shown, with corresponding examination names and selected attributes. For each attribute value, the RID is shown in italics. (a) All of these examinations represent chest imaging studies by virtue of their shared body region value, CHEST (RID1243, dark gray). (b) Among these examinations, the CT examinations of the chest consist of procedures with the codes RPID16, RPID18, RPID147, and RPID6001 by virtue of the additional shared modality value, CT (RID10321). (c) Among these examinations, the contrast material–enhanced CT examinations of the chest consist of procedures with the codes RPID18 and RPID147 by virtue of the additional shared pharmaceutical value, WITH IV CONTRAST (RID28769). The key observation is that with use of structured codes, groups of codes may be computed by virtue of their attributes rather than derived by using error-prone rules or text parsing.

Figure 2b.

Structured procedure codes consisting of components, or attributes, that facilitate semantic interoperability. Consider the RadLex Playbook codes shown, with corresponding examination names and selected attributes. For each attribute value, the RID is shown in italics. (a) All of these examinations represent chest imaging studies by virtue of their shared body region value, CHEST (RID1243, dark gray). (b) Among these examinations, the CT examinations of the chest consist of procedures with the codes RPID16, RPID18, RPID147, and RPID6001 by virtue of the additional shared modality value, CT (RID10321). (c) Among these examinations, the contrast material–enhanced CT examinations of the chest consist of procedures with the codes RPID18 and RPID147 by virtue of the additional shared pharmaceutical value, WITH IV CONTRAST (RID28769). The key observation is that with use of structured codes, groups of codes may be computed by virtue of their attributes rather than derived by using error-prone rules or text parsing.

Figure 2c.

Structured procedure codes consisting of components, or attributes, that facilitate semantic interoperability. Consider the RadLex Playbook codes shown, with corresponding examination names and selected attributes. For each attribute value, the RID is shown in italics. (a) All of these examinations represent chest imaging studies by virtue of their shared body region value, CHEST (RID1243, dark gray). (b) Among these examinations, the CT examinations of the chest consist of procedures with the codes RPID16, RPID18, RPID147, and RPID6001 by virtue of the additional shared modality value, CT (RID10321). (c) Among these examinations, the contrast material–enhanced CT examinations of the chest consist of procedures with the codes RPID18 and RPID147 by virtue of the additional shared pharmaceutical value, WITH IV CONTRAST (RID28769). The key observation is that with use of structured codes, groups of codes may be computed by virtue of their attributes rather than derived by using error-prone rules or text parsing.

Figure 3a.

Examples of harmonized codes in the LOINC/RSNA Radiology Playbook. The LOINC/RSNA Radiology Playbook model, which is currently in draft form (Table 3), is an update of the RadLex Playbook attribute model to improve semantics. In the harmonized model, RPIDs are matched with LOINC codes, and attributes continue to be assigned values from the RadLex lexicon. (a) In some instances, such as the case of code RPID5959, corresponding to LOINC code 36244–2 (“MR Prostate w”), the harmonized code is quite similar to the original RadLex Playbook code (see Fig 1b). Note that the harmonized model includes subattributes (7), which are the basis for the multiple values for the attributes ANATOMIC_LOCATION and PHARMACEUTICAL. (b) In other instances, the harmonized code differs from the original RadLex Playbook code in that it enables a hierarchical structure of attribute values, as in the code RPID2512, corresponding to LOINC code 83021–6 (“XR C-Spine 2-3V+Flex/Ext”). This structure makes clear that a portion of the examination consists of two to three views and another portion consists of additional views with flexion and extension maneuvers.

Figure 3b.

Examples of harmonized codes in the LOINC/RSNA Radiology Playbook. The LOINC/RSNA Radiology Playbook model, which is currently in draft form (Table 3), is an update of the RadLex Playbook attribute model to improve semantics. In the harmonized model, RPIDs are matched with LOINC codes, and attributes continue to be assigned values from the RadLex lexicon. (a) In some instances, such as the case of code RPID5959, corresponding to LOINC code 36244–2 (“MR Prostate w”), the harmonized code is quite similar to the original RadLex Playbook code (see Fig 1b). Note that the harmonized model includes subattributes (7), which are the basis for the multiple values for the attributes ANATOMIC_LOCATION and PHARMACEUTICAL. (b) In other instances, the harmonized code differs from the original RadLex Playbook code in that it enables a hierarchical structure of attribute values, as in the code RPID2512, corresponding to LOINC code 83021–6 (“XR C-Spine 2-3V+Flex/Ext”). This structure makes clear that a portion of the examination consists of two to three views and another portion consists of additional views with flexion and extension maneuvers.

Figure 4a.

Use of the RadLex Playbook Web service application programming interface to map local procedure codes to standardized codes. CPT codes from a local chargemaster can serve as useful intermediary codes in the mapping of local codes to standardized codes. (a) In this example, a single entry from a chargemaster (top) shows the association of local code 1010 (“CT BRAIN WITHOUT CONTRAST”) with CPT code 70450 (yellow). Using this CPT code with the RadLex Playbook Web service call (7) (dotted box) yields the (excerpted) XML (xml) result shown (shadowed box). This XML result contains any matching RPIDs and associated metadata (selected elements shown in green), which can then be used to populate new fields in the chargemaster to map the local code to the standardized code (bottom). In this case, a single matching RPID is found (RPID22). In general, a given CPT code may map to multiple RPIDs, and multiple local codes may be associated with a single CPT code, so this approach does not facilitate fully automated mapping. Even so, using CPT codes as intermediary codes in this way can narrow the list of possible matches. Note also that the associated attribute values such as modality and body region may be stored and used to facilitate various workflows. (b) In this example, the chargemaster entry (top) for local code 1082 (“MRI SHOULDER WITHOUT CONTRAST”) is shown with its associated CPT code, 73221 (yellow). In this case, the RadLex Playbook Web service call (dotted box) yields four matching RPIDs (shadowed box); the XML is further excerpted as compared with that in a. Manual inspection leads to the correct match, RPID525 (bottom), from these four RPIDs.

Figure 4b.

Use of the RadLex Playbook Web service application programming interface to map local procedure codes to standardized codes. CPT codes from a local chargemaster can serve as useful intermediary codes in the mapping of local codes to standardized codes. (a) In this example, a single entry from a chargemaster (top) shows the association of local code 1010 (“CT BRAIN WITHOUT CONTRAST”) with CPT code 70450 (yellow). Using this CPT code with the RadLex Playbook Web service call (7) (dotted box) yields the (excerpted) XML (xml) result shown (shadowed box). This XML result contains any matching RPIDs and associated metadata (selected elements shown in green), which can then be used to populate new fields in the chargemaster to map the local code to the standardized code (bottom). In this case, a single matching RPID is found (RPID22). In general, a given CPT code may map to multiple RPIDs, and multiple local codes may be associated with a single CPT code, so this approach does not facilitate fully automated mapping. Even so, using CPT codes as intermediary codes in this way can narrow the list of possible matches. Note also that the associated attribute values such as modality and body region may be stored and used to facilitate various workflows. (b) In this example, the chargemaster entry (top) for local code 1082 (“MRI SHOULDER WITHOUT CONTRAST”) is shown with its associated CPT code, 73221 (yellow). In this case, the RadLex Playbook Web service call (dotted box) yields four matching RPIDs (shadowed box); the XML is further excerpted as compared with that in a. Manual inspection leads to the correct match, RPID525 (bottom), from these four RPIDs.