2006 CRCPD

2005-06 NEXT survey of Computed Tomography

David Spelic, PhysicistCenter for Devices and Radiological HealthFood and Drug Administration

2006 CRCPD

2005-06 NEXT CT Survey

• 38 states attended spring 2005 training• Two full days: didactic and two site visits

• Phantoms shipped in two waves: October 05 and January 06- training video

• Currently: Approximately 20% completion

• Survey: On-site data collection, Facility Questionnaire, and Physics survey report

2006 CRCPD

2006 CRCPD

slice

EXAMPLE Adult Head (brain) 35 1 A Y HEAD 120 200Foramen magnum to

apex 1 1 12/8 5/10 5/10 35% 0% 65%

Adult Head (brain) 80 1 A N Head 140 200Base of skull thru entire head 2 unkn 32 5 2i 50% 25% 25%

Adult temporal bones, or sinus, or orbits 40 2 H N Head 140 300

Top of teeth thru sinus 0.6 unkn 174 0.625 5.62 80% 10% 10%

Adult chest 50 2 H N Large 120 200Top of apices thru adenals 0.8 unkn 77 5 27.5 50% 25% 25%

Adult abdomen 50 2 H N Large 120 200Top of liver thru L5, S1 0.6 unkn 113 5 27.5 50% 25% 25%

Adult abdomen + pelvis 50 2 H N Large 120 255Top of Liver thru entire pelvis 0.6 unkn 190 5 27.5 50% 25% 25%

Adult chest + abdomen + pelvis 40 2 H N Large 120 200

Top of apices thru chest and top of liver thru pelvis 0.8 unkn 205 5 27.5 50% 25% 25%

Adult cervical spine, or thoracic spine, or lumbar 20 2 H N Large 140 295

Top of base of Sa 4 thru 1 1 unkn 175 1.25 1375% 80% 20%

Adult colon

Adult coronary angiography

5 1 A N Ped 120 145Base of skull thru brain 1 unkn 25 5 2i 50% 50%

5 1 A N Head 120 170Base of skull thru brain 1 unkn 25 3.75 4i 50% 50%

3 2 H N Small 120 160Top of liver thru pelvis 0.5 unkn 80 3.75 27.5 50% 50%

3 2 H N Large 120 126Top of liver thru pelvis 0.5 unkn 80 5 27.5 50% 50%

% of exams exclusively

with contrast

Pediatric routine infant head child

Pediatric infant thoracic survey child

Pediatric abdm + infant pelvis survey child

Brief description of anatomical range

scanned

Scanning field-of-

view (SFOV)

Acquisition slice

thickness (mm)

Table FEED per

rotation (mm)

% of exams with a no-

contrast phase AND a contrast

phase

% of exams with NO contrast

Time per rotation (seconds)

No. of slices per

phase

No. of slices

acquired per rotation

No. of scout views before exam

Weekly no. of

exams mAExam category

Helical or Axial scan? (H/A)

AEC mode used? (mA

varies during scan) (Y/N) kVp

Each ROW should add to 100%

Facility Questionnaire: CT practice and Exam Protocols

2006 CRCPD

2006 CRCPD

Facility DataNo. of CT units at facility: 78%- one unit

Hospitals: 1.8 units Non-Hosp: 1.1 units

Type of facilities surveyed: 65% hospitals

% ACR-accredited or in-progress: 10.1%

% Doing screening CT exams: 20.5%

Whole body: 3.4% Colon: 7.0% Lung: 8.8% Cardiac: 8.8%

Surveyed CT Unit Features % Multi-slice units: 75%

Most frequent multi-slice format: 4 slice

Preliminary Results: 65 surveys

2006 CRCPD

Age of Surveyed CT Unit

<=1 2-3 4-5 6-7 8-9 10 +0

10

20

30

40

Per

cent

of

Sur

vey

Age (years)

2006 CRCPD

Facility Weekly Workload: Adult CT exams

< 50 50-99 100-199 200-299 300 +0

5

10

15

20

25

30

35

Per

cent

of

Sur

vey

Exams per Week

Mean: 128 exams/wk

2006 CRCPD

<5 5-9 10-19 20-39 40 +0

10

20

30

40

50

60P

erc

en

t o

f S

urv

ey

Exams per Week

Facility Weekly Workload: Pediatric CT exams

Mean: 7.2 exams/wk

2006 CRCPD

Adult Head and Body CT

• Adult Head Exam– % done helical scanning: 15.6%– % using AEC technology: 6.7%

• Adult Abdomen-Pelvis Exam– % done helical scanning: 100%– % using AEC technology: 54.4%

2006 CRCPD

Exam Weekly Workloads onSurveyed CT Unit

Exam Adult Child Infant

Head 32.9 1.42 0.72

Sinus 10.6

Chest 19.0 0.11 0.13

Abdomen 15.3

Abdm + Pelvis 32.4 1.03 0.44

Chest + Abdm + Pelvis 9.1

Spine 7.9

Colon 1.4

Coronary Angiography 0.16

2006 CRCPD

0 50 100 15040

50

60

70

80

90

100

110

120

130

Tube

Cur

rent

(mA)

Position (mm)

Variation of CT x-rayTube current

Example: FemaleRando Phantom

2006 CRCPD

AEC response to NEXT phantom

chest abdm pelvis140

160

180

200

220

240

260

280

300

320

340C

urre

nt (

mA

)

Body Section

Mean CT tube current1,2 for chest, abdomen, and pelvis

1Statistics based on sample size of 39 surveys2Error bars are std error estimates.

2006 CRCPD

Number of CT examsperformed in US

Annual number of exams (millions) Adult Pediatric

Total no. of all CT exams performed in hospitals

50 3

Total no. of all CT exams performed in non-hospital sites 8 0.3

Total no. of all CT exams performed in U.S.

58 ± 9 3.3 ± 1

Compare: 2000 NEXT CT survey46 ± 4

(adult + pediatric)Estimate is based on published data from IMV (published in Imaging Economics, June 2005) and the American Hospital Association on the number of facilities having at least one CT unit, combined with NEXT 2005-06 survey data on facility exam workloads.

2006 CRCPD

And finally…• Preliminary results show:

– 26% increase in number of CT exams performed annually in US since previous survey (2000)

– Routine Head and Abdomen-Pelvis- most frequently performed CT exams

– Document dose savings from AEC technologies

• MANY THANKS-– State programs– ACR– Shady Grove Adventist Hospital– U.S. Naval Medical Center- Bethesda