Operator's Guide
437D140 Rev. I
Basic Operation
4-19
the serial number of the QC Phantom used at the facility
the assigned value of BMD, Fat, and Lean values used to plot the Accuracy graph (Fat and Lean only
entered when Soft Tissue Calibration is enabled)
and the Standard Deviation of each BMD, Fat, and Lean value used to plot the Precision graph.
The assigned values were entered into the system at installation, based on factory characterization of the sys-
tem’s QC Phantom.
QC RESULTS AREA: shows the date of the last Calibration Scan and its resulting BMD and BMC values. If
Soft Tissue Calibration is enabled (an option), the Fat and Lean results are also shown.
Below the last scan date is the numeric result of the last 16 QC’s. There, the mean value and C.V. for the most
recent 16 scans is displayed. If fewer than 16 scans have been performed, all calculated values are used in the
computation.
Next, there are
two graphs
based on the QC Phantom scans.
UPPER GRAPH: displays the precision of the Norland system. The values from the last 180 days (6 months)
of QC Phantom scans are displayed, showing their scatter about the mean. The two dashed horizontal lines
indicate ±2 S.D. about the mean. The points shown between the dotted lines are within ±2 standard deviations.
Statistically, 95% of the values obtained will fall in this range. Note that 5% of the points, or 1 out of 20, are stat-
istically expected to lie outside the dashed lines. Points shown outside the dashed lines are those scans that
exceed the ± 2 S.D.
LOWER GRAPH: displays the accuracy of the system, based on QC Phantom scans. The mean values of the
last 180 days of calculations (6 months) are plotted against the assigned BMD value (or Fat, or Lean values) of
the QC Phantom. The two dashed horizontal lines indicate deviations of ± 1.5% from the BMD assigned value
(or ± 2% from the Fat and Lean values).
QC Results Statistics Messages
The tables that follow describe the possible message readouts for the Precision and Accuracy results. They are
found in the
QC Results
area of the QA Results tab window (see Sample QA Results tab window ).
The criteria for generating the Precision and Accuracy warning messages are modeled after those of Shewart
(see Table 2 in Orwoll, et. al., J. Bone and Mineral Res. 6:1991, p.196.)
PRECISION
MESSAGE
MESSAGE
INDICATION
OPERATOR
ACTION
OK
Precision of the system is within specification.
No Action Required
OUT OF RANGE
Standard deviation estimated from 16 scans is greater than the
expected value.
Repeat QA ("Calibrate the System Using the
QA Calibration Standard" on page 4-8)
WARNING 1
A single value is outside ± 3 standard deviations from the mean.
Repeat QA ("Calibrate the System Using the
QA Calibration Standard" on page 4-8)
WARNING 2
Two consecutive values exceed ± 2 standard deviations from
the mean.
Repeat QA ("Calibrate the System Using the
QA Calibration Standard" on page 4-8)
WARNING 3
Four consecutive values of the same sign (either plus or
minus), exceed one standard deviation from the mean.
Repeat QA ("Calibrate the System Using the
QA Calibration Standard" on page 4-8)
Table 4-8:
QA Results tab Precision Messages and Actions
Содержание Elite 437A150
Страница 1: ...DXA Bone Densitometer Operator s Guide Elite Model 437A150 Operator s Guide 437D140 Rev I...
Страница 22: ...This page intentionally left blank Operator s Guide 437D140 Rev I 1 8...
Страница 41: ...Operator s Guide 437D140 Rev I General Information 2 19 Figure 2 6 Page 2 of the Bone Exam Report...
Страница 45: ...Operator s Guide 437D140 Rev I General Information 2 23 Figure 2 10 Page 2 of the Patient Letter...
Страница 47: ...Operator s Guide 437D140 Rev I General Information 2 25 Figure 2 12 Page 2 of the Referral Letter...
Страница 49: ...Operator s Guide 437D140 Rev I General Information 2 27 Figure 2 14 Page 2 of the Ten Year Fracture Risk Report...
Страница 56: ...This page intentionally left blank Operator s Guide 437D140 Rev I 2 34...
Страница 66: ...11 Click Operator s Guide 437D140 Rev I 3 10 Installation and Setup...
Страница 108: ...This page intentionally left blank Operator s Guide 437D140 Rev I 3 52...
Страница 124: ...Sample Printed QA Results Report Operator s Guide 437D140 Rev I 4 16 Basic Operation...
Страница 137: ...Operator s Guide 437D140 Rev I Basic Operation 4 29...
Страница 165: ...Operator s Guide 437D140 Rev I Scanning Whole Body 5 23 Figure 5 6 Page 2 of the Bone Exam Report...
Страница 166: ...This page intentionally left blank Operator s Guide 437D140 Rev I 5 24...
Страница 176: ...Figure 6 2 Page 2 of the Bone Exam Report Operator s Guide 437D140 Rev I 6 10 Soft Tissue Composition...
Страница 178: ...Figure 6 4 Page 2 of the Body Composition Report Operator s Guide 437D140 Rev I 6 12 Soft Tissue Composition...
Страница 198: ...Operator s Guide 437D140 Rev I 7 20 Scanning AP Spine...
Страница 205: ...Operator s Guide 437D140 Rev I Scanning AP Spine 7 27 Figure 7 5 Page 2 of the Bone Exam Report...
Страница 206: ...This page intentionally left blank Operator s Guide 437D140 Rev I 7 28...
Страница 238: ...Figure 8 6 Page 2 of the Bone Exam Report Operator s Guide 437D140 Rev I 8 32 Scanning Hip...
Страница 289: ...Operator s Guide 437D140 Rev I Scanning Lateral Spine 10 29 Figure 10 6 Page 2 of the Bone Exam Report...
Страница 290: ...This page intentionally left blank Operator s Guide 437D140 Rev I 10 30...
Страница 301: ...Operator s Guide 437D140 Rev I Additional Techniques 11 11 6 The dialog box closes and the file is sent...
Страница 326: ...Operator s Guide 437D140 Rev I 11 36 Additional Techniques...
Страница 378: ...Figure 12 2 Page 1 of the Ten Year Fracture Risk Report Operator s Guide 437D140 Rev I 12 10 Ten Year Fracture Risk...
Страница 412: ...This page intentionally left blank Operator s Guide 437D140 Rev I 14 16...
Страница 428: ...This page intentionally left blank Operator s Guide 437D140 Rev I 16 10...
Страница 446: ...Label Locations continued Operator s Guide 437D140 Rev I 17 18 Technical Reference...
Страница 448: ...Scanner Labels continued Operator s Guide 437D140 Rev I 17 20 Technical Reference...
Страница 449: ...Operator s Guide 437D140 Rev I Technical Reference 17 21 Scanner Labels continued...
Страница 457: ...Operator s Guide 437D140 Rev I Reference Data Sets 18 7 Excerpt from Calcified Tissue International...
Страница 458: ...Excerpt from the Journal of Bone and Mineral Research Operator s Guide 437D140 Rev I 18 8 Reference Data Sets...
Страница 459: ...Operator s Guide 437D140 Rev I Reference Data Sets 18 9...
Страница 466: ...Operator s Guide 437D140 Rev I This page intentionally left blank...
Страница 484: ...Operator s Guide 437D140 Rev I This page intentionally left blank...