RR.2.4 Traditional Charts

The Traditional charts used in clinical practice are not standardized; they have an irregular progression of letter sizes and a variable number of characters per line. Measurement accuracy may further suffer from hidden errors that cannot be captured by any recording device, such as an inconsistent, non-standardized protocol, inaccurate viewing distance, inaccurate projector adjustment and contrast loss from room illumination. Therefore, the difference between two routine clinical measurements should not be considered significant, unless it exceeds 5 rows in the table (1 line on an ETDRS chart).

Table RR-1 contains many blank lines to make the vertical scale consistent with that used in Table RR-2. Notations within the same gray band are interchangeable for routine clinical use, since their differences are small compared to the clinical variability, which is typically in the order of 5 rows (1 ETDRS line).

TABLE RR-1Reference table for use with TRADITIONAL CHARTS

DICOM Notations for Clinical Use with Traditional Charts Scales for statistics and graphical displays

Decimal Visual Acuity Traditional scales Linear Scales
Decimal US 6 m LogMAR VAS
2.00 E+00 2.0 20/10 6/3 -0.30 115
1.74 E+00 -0.24 112
1.66 E+00 -0.22 111
1.38 E+00 -0.14 107
1.30 E+00 1.3 20/15 6/4.5 -0.12 106
1.10 E+00 1.1 20/18 6/5.5 -0.04 102
1.05 E+00 -0.02 101
8.70 E-01 0.06 97
8.30 E-01 0.08 96
7.00 E-01 0.7 20/28 6/8.7 0.16 92
6.60 E-01 0.66 20/30 6/9 0.18 91
5.50 E-01 0.26 87
5.25 E-01 0.28 86
4.37 E-01 0.36 82
4.17 E-01 0.38 81
3.50 E-01 0.46 77
3.33 E-01 0.33 20/60 6/18 0.48 76
2.75 E-01 0.56 72
2.63 E-01 0.58 71
2.20 E-01 0.66 67
2.10 E-01 0.68 66
1.74 E-01 0.76 62
1.66 E-01 0.17 20/120 6/36 0.78 61
1.38 E-01 0.86 57
1.30 E-01 0.13 20/150 6/45 0.88 56
1.10 E-01 0.96 52
1.05 E-01 0.98 51
8.70 E-02 1.06 47
8.30 E-02 0.083 20/240 6/72 1.08 46
7.00 E-02 1.16 42
6.60 E-02 0.065 20/300 6/90 1.18 41
5.50 E-02 1.26 37
5.25 E-02 1.28 36
4.40 E-02 1.36 32
4.20 E-02 1.38 31
3.50 E-02 1.46 27
3.33 E-02 1.48 26
2.75 E-02 1.56 22
2.63 E-02 1.58 21
2.20 E-02 1.66 17
2.10 E-02 1.68 16
1.74 E-02 1.76 12
1.66 E-02 1.78 11
1.38 E-02 1.86 7
1.30 E-02 1.88 6
1.10 E-02 1.96 2
1.05 E-02

Decimal Visual Acuity Use with suffixes Calculated values Linear Scales

Figure SS.3-1: Colon radiograph as Described in Example 1

The content tree structure would resemble:

Node Code Meaning of Concept Name Code Meaning or Example Value TID
1 Colon CAD Report 4120
1.1 Language of Content Item and Descendants English 1204
1.2 Image Set Properties 4122
1.2.1 Frame of Reference UID 1.2.840.114191.123 4122
1.2.2 Study Instance UID 1.2.840.114191.456 4122
1.2.3 Study Date 20060924 4122
1.2.4 Study Time 090807 4122
1.2.5 Modality CT 4122
1.2.6 Horizontal Pixel Spacing 0.80 mm 4122
1.2.7 Vertical Pixel Spacing 0.80 mm 4122
1.2.8 Slice Thickness 2.5 mm 4122
1.2.9 Spacing between slices 1.5 mm 4122
1.2.10 Recumbent Patient Position with respect to gravity Prone 4122
1.3 CAD Processing and Findings Summary All algorithms succeeded; without findings 4121
1.4 Summary of Detections Succeeded 4120
1.4.1 Successful Detections 4015
1.4.1.1 Detection Performed Nodule 4017
1.4.1.1.1 Algorithm Name “Colon Polyp Detector” 4019
1.4.1.1.2 Algorithm Version “V1.3 4019
1.4.1.1.3 Series Instance UID 1.2.840.114191.789 4017
1.5 Summary of Analyses Not Attempted 4120