GE LightSpeed 16 Product Data Sheet

g

Product Data Sheet – rev 4.2
July 4th 2003
Page 1

Introduction

The LightSpeed16 CT Scanner with

TM

Xtream

GE’s CT Continuum and its award­winning LightSpeed CT platform. The
LightSpeed
acquires 16 sub-millimeter slices in one
rotation, at a scan speed of 0.5 seconds.
As with the very first LightSpeed product
introduction, the LightSpeed
Designed for Six Sigma (DFSS
methodology in all aspects of
manufacturing and engineering.

LightSpeed
system or as a cost-effective upgrade to
an existing LightSpeed system.

Primary Benefits

• Routine use of sub-millimeter slices

• Small lesion and small vessels

• The 6.3 MHU Performix X-Ray Tube

technology is the next step in

16

CT Scanner routinely

16

utilizes

TM

)

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is available both as a new

without image noise or coverage
compromise.

assessments – pancreas, liver or circle
of willis, renal arteries, coronary arteries
and peripheral vascular arteries.

demonstrates the highest reliability and
delivers the power you need for image
quality. The Performix Tube now comes
standard with a one-year, non pro-rated
warranty.

LightSpeed16

With Xtream

CT Scanner System

TM

• microVoxel

reformatted 2D resolution through the
optimum choice of sub-millimeter slice
thickness and reconstructed voxel size.

• Unmatched Volume Image Quality
specification in all planes (sagittal, coronal
and axial): 15.4 lp/cm @ 0% MTF @ 0.5
sec. Rotation

• HiLight

deliver consistent image quality with its
21,888 individual elements: 16 rows of

0.625mm thickness and 8 rows of 1.25mm
thickness

• Xtream

workflow design, breaks through existing
limits on speed, image quality and flexibility
to provide an optimized workflow solution
from acquisition to final report.

• Lowest dose acquisition using SmartmA,
an automatic modulation technique and DLP
display that tells the operator the dose
before the scan starts.

• HyperPlane

tackles the inherent issues with fast, high
pitch helical scanning by reducing helical
artifacts and dose, and optimizing the slice
profile.

• CrossBeam

solves the technical challenge of cone beam
artifacts.

• Large breadth of Advanced Software
Applications: Advanced Lung Analysis, CT

Colonography, Advanced Vessel Analysis,
Brain and Body Perfusion, Cardiac Analysis,

imaging improves 3D and

TM

Matrix II Detector is designed to

TM

technology, a revolutionary new

TM

reconstruction algorithm

TM

reconstruction algorithm

GE Medical Systems-America
Milwaukee, USA - Fax: [phone]
GE Medical Systems-Asia:
Tokyo, Japan - Fax: [phone]
Hong Kong - Fax: [phone]
GE Medical Systems-Europe

Cardiac Function, SmartScore Pro and
Advantage Sim.

• Compact system design of the
LightSpeed
28m² (302 square feet).

• Productivity features designed for the CT
Technologist: In-Room Start, Remote
Gantry Tilt, Breathing Lights with countdown
timer, Gantry Controls mounted on all four
corners of the gantry and an Integrated IV
Pole at the foot of the table.

• 1700 mm scannable range for full body
scans.

• 254 GB Disk (system, image, scan disks)
stores up to 250,000 512
scan data files.

• Cardiac acquisition with Segment, Burst
and Burst Plus enable you to scan patients

with heart rates from 40 to 110 BPM, and
provide for temporal resolution up to 65
ms.

• Color Coding for Kids, winner of a
National Heroes Award from the Emergency
Medical Services for Children, provides
pediatric scan protocols based on the
Broselow-Luten
Color Coding system is incorporated into the
protocol selection on the operator’s console
and is designed to facilitate pediatric
emergency care and reduce medical errors.

• VariViewer

review mode that can change the slice
thickness reconstruction instantaneously,
resulting in the ability to “scan thin and view
thick.”

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allows for installation in only

2

images and 2881

TM

Pediatric System. This

TM

: provides an interactive axial

Clinical Performance

Chest / Abdomen / Pelvis

TM

Coverage 600 mm
Rotation 0.5 sec.
Mode 16 x 0.625 mm
Pitch 1.75:1
mA 420
mAs 210
Speed 35 mm/s
Scan Time 17.1 seconds

* Option

g

Product Data Sheet – rev 4.2
July 4th 2003
Page 2

Peripheral Run-Off

Coverage 1,400 mm
Rotation 0.5 sec.
Mode 16 x 1.25 mm
Pitch 1.75:1
mA 380
mAs 190
Speed 70 mm/s
Scan Time 20 seconds

High Resolution Chest

Coverage 200 mm
Rotation 0.5 sec.
Mode 16 x 0.625 mm
Pitch 1.75:1
mA 440
mAs 220
Speed 35 mm/s
Scan Time 5.7 seconds

The net result is that in many cases, helical
scans on the Lightspeed
faster than 4-slice CT systems. With the
Lightspeed
second scan speed and 0.5625:1, 0.9375:1,

1.375:1, and 1.75:1 helical pitches. This
added performance, at the same image
quality, may allow you to: reduce contrast
media, perform better thin-slice CT
angiography exams, use thinner slices for
most exams, and perform longer helical exams
without tube cooling delays.

The LightSpeed
performance through a balanced design
that focuses on image quality, coverage,
and exam speed.

16

Main Features

• Full 360° rotation speed of 0.5 sec. provides
for improved temporal resolution and image
quality in areas such as cardiac imaging;

• Faster scan times enable shorter breath
holds and more comfortable exams for
patients;

• Faster scan times reduce the occurrence of
re-scans by lowering the possibility of
patient motion during the exam;

• Routine scanning with a slice thickness of

0.625mm - optimizes lesion detection and
facilitates the use of thinner images for
volume presentations.

• Reduced partial volume artifacts:

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are up to 12 times

, users can routinely use a 0.5

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delivers this level of

LightSpeed16

With Xtream

CT Scanner System

• Prospective or retrospective image
reconstruction of 0.625 mm, 1.25 mm,

2.5 mm, 3.75 mm, 5 mm, 7.5 mm or 10
mm images from inherently thinner
acquisition data sets;

• For both helical and axial acquisitions.

• Image decomposition to:

• Retrospective reconstruction of thin

images from data sets where thicker
images were initially reconstructed;

• Facilitates more detailed image analysis
without need for re-scans;

• Improves 3D visualization;

• For both helical and axial acquisitions

• Up to 2,881 multi-slice 1-sec scan rotations

stored on disk. Facilitates retrospective
image decomposition during off hours.

• Eight fundamental scan modes to simplify
the inherently complex nature of multi-slice
helical scanning.

• Standard set of clinically- proven
protocols derived from leading luminary

sites around the world. Up to 8,460
protocols can be edited, modified and stored
on the system.

• Remote Gantry Tilt from the Operator’s
Console to increase exam speed, including
built-in safety features to prevent accidental
contact of the gantry with the patient.

• Built-in patient breathing lights and digital
counter provides a goal-oriented approach
to coach the patients in holding their breath
during an exam.

• SmartStart gantry-mounted start scan
button and countdown display, facilitates
single-technologist operation by allowing
start of scan at the gantry, with a visual
reminder of time until X-ray initiation.

• SmartHelical GE proprietary, non-linear
interpolation algorithms, balance slice
profile, helical pitch, image noise and
required technique.

• SmartTrack advanced hardware and
software for X-ray beam tracking minimizes
patient dose.

• SmartTools software automates every
exam task in order to increase throughput.

• SmartBeam

optimizes X-ray beam filtration
independently for body and head
applications.

• HiRes Chest software provides a single­slice, high-resolution scan mode that
minimizes dose for this critical application.

TM

hardware and software

GE Medical Systems-America
Milwaukee, USA - Fax: [phone]
GE Medical Systems-Asia:
Tokyo, Japan - Fax: [phone]
Hong Kong - Fax: [phone]
GE Medical Systems-Europe

16

• SmartPrep, standard on LightSpeed
provides software for real-time monitoring of
contrast enhancement.

• * Direct3D, makes 3D routine and instant
by building the 3D model during axial image
reconstruction, reducing the need for user
interaction.

• * SmartScorePro, provides EKG-gated
hardware and software on the Advantage
Workstation for coronary artery calcium
scoring.

• * CardiacSnapShot, provides software
and hardware to perform EKG-gated
reconstructions of the heart in SnapShot
Segment mode.

- SnapShot Segment is a single sector
protocol using information from one heart
cycle to generate an image with temporal
resolution of 250ms.

- SnapShot Burst is a multi-sector protocol
using up to two sectors from two different
heart cycles to produce an image with
temporal resolution of 125ms.

- SnapShot Burst Plus is a multi-sector
protocol using up to four sectors of data
from four different heart cycles to produce
images with temporal resolution to 65ms.

, DLP (Dose Length Product), and

• CTDI

w

Dose Efficiency display during scan

prescription provides patient dose
informatbon to the operator.

,

Interactive CT Technology

The LightSpeed
exceptional computer and image processing
power that significantly enhances clinical
productivity, building upon the strength of the
LightSpeed family - true interactive CT
technology.

Interactive CT embodies a variety of design
choices all striving to enhance operator and
department productivity. A truly interactive CT
system will:

• Provide a user interface beyond “intuitive”
to become purely “natural” - from the
screens to the console hardware itself;

• Allow two users to review cases side-by-
side, with minimal interference;

• Supply a truly multi-tasking environment
where even advanced image processing
can take place quickly and simultaneously
with other processes underway;

• Operate with a very high degree of
automation, yet allow patient-specific

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CT Scanner supplies

* Option

g

Product Data Sheet – rev 4.2
July 4th 2003
Page 3

changes to be easily made, with virtually no
restrictions;

• Be as self-teaching as possible, and have
on-line access to tutorials as needed.

One key element of this design is to combine
some of the best features from several
product families into one state-of-the art CT
system. For example, the LightSpeed
Scanner combines:

• SmartTools productivity software to
automate every step of the examination,
critical for ensuring the highest productivity
and throughput possible with the
LightSpeed

• Large screen interface for controlling scan
acquisition easily, with virtually everything at
a single glance;

• Excellent simultaneity and multi-tasking
performance;

• Completely protocol-driven scan control
with a dramatic reduction in number of
screens;

• Highly flexible editing tools that allow easy
tailoring of the exam to the patient;

• Large, 1024 color display;

• Leading edge, real-time image processing

(MPR, MPVR, Volume Viewer*).

In summary, primary benefits of Interactive
CT on the LightSpeed

• A natural scan control user interface

• Dramatic reduction in the number of

• Easier and more flexible protocols

• Much more flexible and intuitive graphic

• View/Edit Wizard™ intuitively adjusts

• DynaPlan Plus™ full screen display

• Large color screen

• Extensive use of picture icons and color

• Large on-screen controls and attractive

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CT Scanner;

16

Scanner:

screens; only 2 screens to set up first
scan and 1 screen for real-time
monitoring while scanning;

prescription process with a 1024
Localizer;

dependent parameters automatically in
response to operator-initiated changes
and highlights them for quick review; also
alerts the operator to incompatible
dependencies requiring operator
intervention;

illustrates scan status pictorially, with
real-time feedback.

cues enhance ease of use;

color palette provide comfortable viewing
over extended periods.

16

CT

LightSpeed16

With Xtream

CT Scanner System

• Enhanced multi-tasking allows operators to
review more than one exam simultaneously,
independently - even with AutoView and
AutoFilm on/

• BrightBox™ dedicated controls for
image next, prior, manual paging and
trackball W/L helps make two person
image review practical;

• Up to four 512x512 images from four
different exams can be viewed on a large
1024 color display.

• SmartmA™ User Interface - automatically
optimizes mA to maintain constant image
noise when collimation/detector
configuration, scan mode, scan rotation
speed, table speed, or image thickness
changes. It takes the guesswork out of
setting scan technique when changing
parameters (note: user must select initial
Noise Index as well as maximum mA
setting). Noise index enable 100% Image
Quality reproducibity from one patient to
another and from one user to another.

• Protocol Pro™ protocol manager - provides
operator control of automated features (like
AutoFilm, AutoStore, and AutoTransfer) on
per patient basis.

• Patient demographics and exam protocols
can be preprogrammed in advance of
patient arrival through the Schedule Patient
feature.

• A preprogrammed selection of AutoView
and Image Review Layouts allow simple
customization of the image presentation to
match the anatomical area of interest ­without the complexity of free-form
“windows”.

• ImageWorks™ provides instant access to
advanced image processing features such
as MIP, MPR, MPVR, Volume Viewer*,
Advanced Vessel Analysis*, CT Perfusion
2* and DentaScan*.

• No waiting for network transfer or image
retrieval from archive media.

• Background filming allows use of the full
screen for AutoView and image
review/processing without interruption when
auto or batch filming. Special “one touch”
controls provide on-screen viewing of
camera progress during AutoFilm without
disrupting other image processes in
progress.

• ProView™ visualization algorithms
available to enhance anatomical structures
without additional image reconstruction
time.

GE Medical Systems-America
Milwaukee, USA - Fax: [phone]
GE Medical Systems-Asia:
Tokyo, Japan - Fax: [phone]
Hong Kong - Fax: [phone]
GE Medical Systems-Europe

• Operator console convenient to locate in
suite.

• Computer, image processor and image
reconstruction hardware completely
integrated in base of console - no
separate computer cabinet to site;

• Split table top allows unrestricted patient
viewing while still supporting 2 large color
monitors;

• Front and back work surfaces can be set
during installation within a range of
vertical heights that help accommodate a
variety of siting requirements - especially
surrounding the height of the console
relative to the window into the scanning
suite.

• Work surface accommodates a large variety
of working conditions and individual
operator preferences.

• Wide work surface has room for papers,
patient charts, logbooks or other
peripheral devices;

• Wide area also helps make two person
operation more comfortable and
practical;

• All console components (monitors,
keyboard, mouse and BrightBox) are
free-standing and can be easily moved
on the front work surface;

• All surfaces made of high-impact resin
that hides marks and are easy to clean.

• Direct network connection means a multi-
suite Ethernet card is not required for a
gateway out of the suite - saving costs and
simplifying installation.

• Learning Solutions provides an on-line
Operator manual detailing system operation
via a multi-media CD-ROM player integrated
into the front of the operator console.
Learning Solutions can also be accessed on
a stand alone PC providing flexibility and
productivity for on demand learning of
system operation

Advanced Tube & Generator
Technology

• The Performix X-ray tube, with 6.3 MHU of
storage and 53.2 kW operation, provides
increased helical performance with greater
patient throughput and virtually no tube
cooling. Advanced technology in the
Performix tube includes a metal-ceramic
frame for long life, a high-speed bearing for
sub-second scanning, a high-efficiency
motor to accelerate the large anode and

* Option

g

Product Data Sheet – rev 4.2
July 4th 2003
Page 4

efficient cooling for high throughput and
superior helical performance.

• Wide range of technique factors (10 to 440
mA, in 5 mA increments) gives the operator
and physician flexibility to tailor technique to
specific needs, optimizing patient dose, and
providing the power needed to perform a
broad spectrum of axial and helical
examinations.

System Specifications

Scan Modes:

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The LightSpeed
virtually any clinical application due to its wide
variety of scan modes. With the LightSpeed
body CT studies are easier to perform and
more productive than ever before.

Helical:

• Continuous 360° scanning with table
incrementation and no interscan delay.

• Scans can be acquired in a wide variety of
speeds.

Axial:

• Up to 16 contiguous axial slices acquired
simultaneously with each 360° rotation, with
the time between scans set by the user­selected interscan delay (ISD) or intergroup
delay (IGD).

• Scans may be easily clustered in groups to
allow multiple scans in a single breath hold.

• Minimum scan-to-scan cycle time of only 1.5
sec with table moves of ≤ 10 mm (any scan
time).

Scout™:

• Single radiographic plane for scan

• Extended range matches helical scannable

localization and graphical prescription of
prospective reconstruction;

range.

Helical Scans

Slip ring technology has advanced axial
scanning by enabling scans with zero
interscan delay and simultaneous table
movement.

CT system can perform

16

GE Medical Systems-America
Milwaukee, USA - Fax: [phone]
GE Medical Systems-Asia:
Tokyo, Japan - Fax: [phone]

LightSpeed16

With Xtream

Hong Kong - Fax: [phone]
GE Medical Systems-Europe

CT Scanner System

Helical Multi-slice Modes: Prospective Multiple-

Simplified scan prescriptions and easy-to-use
default protocols make the LightSpeed
and efficient in patient set up.

Multi-slice acquisitions and short intergroup
delays significantly reduce potential mis­registration between scans by increasing the
number of scans possible in a patient breath
hold. Contrast agents may be better utilized
as well due to significantly faster scan
acquisition.

Helical protocols are almost identical to
“classical” axial scan protocols. At the
beginning of a study, the operator selects the

,

type of exam with the anatomical programmer,
and indicates the desired scan range - either
manually, or from a Scout.

After completing the prescribed exam, the
system remains ready to continue with
additional helical scans or a set of axial scans.

The operator may reconstruct helical scans
prospectively with up to 90% overlap, and
retrospectively, at any arbitrary table location
in 0.1 mm increments.

Helical Multi-slice Modes

The complex nature of helical multi-slice
scanning has been simplified by grouping
all critical acquisition parameters within 8
basic scan modes, all optimized for image
quality and speed. For eight-slice
acquisition: 0.625: 1; 0.875: 1; 1.35: 1 and

1.675: 1. For sixteenslice acquisition:

0.5625: 1; 0.9375: 1; 1.375: 1 and 1.75: 1.
These clinically derived multi-slice scan
modes offer a wide range of selections
that carefully balance acquisition speed,
image thickness, artifact level and
retrospective image reconstruction
flexibility.

This simplified user interface guides the
user in the choice of scan parameters.
The user selects a pitch mode, a desired
image slice thickness and table travel per
rotation. The user interface also displays
the resulting choice of retrospective image
thicknesses available for each choice of
acquisition parameters.

The 16 slice helical acquisition modes
provide table speeds from 5.625
mm/rotation up to 35 mm per rotation,
enabling scan speeds that are up to 12
times faster than 4-slice helical scanners.

16

fast

Thickness Reconstruction:

For all helical scan modes, the operator can
choose to reconstruct images prospectively in
any of the defined nominal slice thicknesses.

In addition to the initial reconstructed slice
thickness, the operator has the option to
prospectively specify additional images to be
reconstructed from a single raw data set.
These images can be reconstructed at any of
the defined nominal slice thicknesses
available for a given table speed and scan
mode.

This effectively facilitates later, more detailed
image analysis without additional patient
scans and subsequent dose and image
registration concerns.

8-SLICE HELICAL MODES

Table Speed (mm/rotation)

Slice

Thick

-ness

(mm)

1.25 6.25 8.75 13.5 16.75

3.75 6.25

Pitch

0.625:1

2.5 6.25

12.5

12.5

5 6.25

12.5

7.5 6.25

12.5

10 6.25

12.5

0.875:1

8.75

17.5

8.75

17.5

8.75

17.5

8.75

17.5

8.75

17.5

1.35:1

13.5

27.0

13.5

27.0

13.5

27.0

13.5

27.0

13.5

27.0

1.675:1

16.75

33.5

16.75

33.5

16.75

33.5

16.75

33.5

16.75

33.5

* Option

g

Product Data Sheet – rev 4.2
July 4th 2003
Page 5

16-SLICE HELICAL MODES

Table Speed (mm/rotation)

Slice

Thick-

ness

(mm)

0.625 5.625 9.375 13.75 17.5

1.25 5.625

3.75 5.625

Helical Scan Parameters

Scan Speeds: Full 360° rotational scans in

0.5, 0.6, 0.7, 0.8, 0.9, 1.0 seconds.

Scan Technique

— kVp: 80, 100, 120, 140

— mA: 10 to 440 in 5 mA increments

— Power: 0.8 to 53.2 kW

— Focal Spot Selection:

Small spot for up to 24 kW

Large spot for greater than 24 kW

Single Acquisition
maximum.

Helical Tilt
with the gantry tilted to a maximum of 30
degree, in half degree increments.

Multiple Acquisition Maximum
Multiple scans may be acquired in one
series to produce up to 3,000 contiguous
helical images. Up to 2,881 seconds
helical coverage is possible in multiple
series.

Minimum Inter-Group Delay
seconds between adjacent helical scans

Pitch

0.5625

:1

11.25

2.5 5.625

11.25

11.25

5 5.625

11.25

7.5 11.25 18.75 27.5 35

10 11.25 18.75 27.5 35

: helical acquisition is possible

0.9375

9.375

18.75

9.375

18.75

9.375

18.75

9.375

18.75

:

: 120 second scan

1.375

:1

13.75

27.5

13.75

27.5

13.75

27.5

13.75

27.5

Scan Time:

(IGD): 5

:1

1. 75:1

17.5

35

17.5

35

17.5

35

17.5

35

LightSpeed16

With Xtream

CT Scanner System

Scan Fields of View

— 25 cm for adult head

— 25, 50 cm for body

— 25 cm for pediatric head

Helical Scan Enhancements

Full simultaneity allows complete image
display, processing and analysis, as well
as image archival and filming, concurrent
with scanning and reconstruction -- even
when acquiring helical images in a multi­slice mode.

Confirm Rx to X-Rays on: < 15 sec. for
any state of tube and gantry; < 10 sec.
with the gantry rotating

Anatomical Programmer: a ten-region
anatomical selector allows quick and easy
access to 90 user-programmable
protocols per region. Separate selector
for adult and pediatric exams. There are
four selection tabs to select: GE, User,
Service and Most Recent Patient.
Copy/Paste is supported for easy
modification and copying of protocols.

Ten user-defined regions. Each region
has one default protocol displayed with the
anatomical selector for very fast access to
most commonly used protocols

Protocols include preset scan time, kVp,
mA, scan mode, slice thickness and
spacing, table speed, scan FOV, display
FOV and center, recon algorithm and
special image acquisition and processing
options

Any scan parameters may be edited for
each scan or all scans - either before or
during an exam. The number of scans
may also be easily changed.

AutoScan™: Fully automates longitudinal
table movement and start of each scan.

AutoVoice™: 3 preset (English) and 17
user-defined messages automatically
deliver patient breathing instructions;
especially useful for multiple helical
scanning.

Trauma Patient: Allows patient scans and
image display/analysis without entering
patient data before scanning.

:

GE Medical Systems-America
Milwaukee, USA - Fax: [phone]
GE Medical Systems-Asia:
Tokyo, Japan - Fax: [phone]
Hong Kong - Fax: [phone]
GE Medical Systems-Europe

Biopsy: Simplified prescription for single
or multiple scans around an arbitrary table
position aids biopsy studies.

Advanced Artifact Reduction (AAR)
Filter significantly reduces streaking
artifacts when highly absorbent objects
are in the field of view – ie: large
shoulders, screws.

Helical Image Reconstruction

Reconstruction Algorithms: Soft Tissue,
Standard, Detail, Bone, Bone Plus, Lung
and Edge

Reconstruction Matrix

Display Matrix

Display FOV
center, prospective/retrospective target
selection.

CT Number Scale

Helical Reconstruction Times:

 Reconstruction time as fast 6

 Typical 0.167 sec. image-to-image

 Maximum image-to-image cycle

 Iterative bone processing

Minimum DFOV:

Minimum Pixel Size:

Queued Recon
processed continuously and
simultaneously with other processes on
the system including scanning.
Prospective recon will be prioritized over
retrospective recon.

Priority Recon Queuing
selection marks most recent rotation for

: Freely variable center/off-

images per second

recon in normal 16 slice recon mode.

time is ± 10% for prospective and
retrospective image-to-image display.
This applies for 512 matrix; any
display FOV; in AutoView (all
layouts); with concurrent filming and
image archival for all scan modes.

increases time by 250 milliseconds.
Iterative bone processing, which is
always enabled for adult head
scanning, reduces image artifacts in
head scans stemming from X-ray
beam hardening effects.

: 512

: 1024.

: -1024 to 3071 HU

9.6 cm

0.19 mm

: Requests will be

: One touch

* Option

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Product Data Sheet – rev 4.2
July 4th 2003
Page 6

next available recon. Available during or
after scanning.

Images annotated to indicate continuous
scan acquisition with table incrementation:

HE (helical) + Pitch

Table speed

Prospective Multiple Reconstruction
(PMR): Up to 3 sets of reconstructions can
be pre-programmed as part of the scan
protocol prior to acquisition. The operator
can select different start/end location, slice
thickness, interval, reconstruction
algorithms and display fields of view for
each reconstruction. This frees the
operator from sitting at the console and
directly contributes to increased
productivity.

Prospective Recon: Operator may initiate
full recons at any table location in
increments of 1/10 the image thickness;
image thickness remains constant.

Retrospective Recon: Operator may
initiate full recons at any table location in

0.1 mm increments; image thickness

remains constant.

Retrospective Image Decomposition:
The operator has the option to
retrospectively decompose the original
raw data set and reconstruct additional
images at any of the defined nominal
image thickness available for a given table
speed and scan mode.

LightSpeed16

With Xtream

CT Scanner System

Helical Scan Protocols

All protocols assume 120 kVp scans under
typical clinical conditions.

Single Helical Scans:

Scan
Time

10 sec. 440
20 390-440
30 330-380
40 290-350
50 260-320
60 230-310
70 210-300
80 180-280
90 170-270
100 160-260
110 150-250
120 140-230

Multiple Helical Scans

(contiguous helical coverage with 5­second IGD):

Scan
Time IGD

10 sec. 5 sec. 3 340-420

20 sec. 5 sec. 2 300-360

30 sec. 5 sec. 2 230-310

40 sec. 5 sec. 2 190-290

50 sec. 5 sec. 2 170-270

60 sec. 5 sec. 2 140-240

Contiguous Helical Coverage

Multiple helical scans can be performed in
succession with only 5-second delays
between helical scans, providing up to
2,881 contiguous rotations (with up to
1,500 images in one series).

(The following chart assumes 120-second
helical with 5-sec IGD)

Maximum
mA

No.

Scans

4 300-400
5 270-390
6 240-360

3 240-330
4 180-310

3 180-280
4 140-240

3 140-230
4 110-190

3 120-200
4 90-160

3 100-170

Max

mA

GE Medical Systems-America
Milwaukee, USA - Fax: [phone]
GE Medical Systems-Asia:
Tokyo, Japan - Fax: [phone]
Hong Kong - Fax: [phone]
GE Medical Systems-Europe

Total Scan Total Elapsed Max
Time (sec.) Time (sec.) mA

150 155 100-200
200 205 80-150
450 465 50-70

Helical Scan Image Quality

Volumetric Helical Scan Image Quality

16

With LightSpeed
isotropic CT scanner, it is now possible to
specify coronal and sagittal image quality:

1. Visual Measurement:

Reformatted resolution is demonstrated on
the Nuclear Associates AAPM High
Contrast Resolution Insert #76-413.

0.5mm

0.4mm

An Effective 0.5 mm voxel size is clearly
seen in coronal and sagittal views.

2. Statistic Measurement:

Volumetric MTF is computed from the X,Y
and Z axis of a 0.2mm bead using sagittal
and coronal images of the 8” Catphan,
MTF module with bead source #CTP445.

Detail Algorithm

MTF (z-axis) is 12.4 lp/cm @ 10%, 15
lp/cm @ 0% which is a 0.333 mm limiting
resolution

In Plane Helical Scan Image Quality

For details of scan technique please refer
to the technical reference manual.

High-Contrast Spatial Resolution

On GE Performance phantom:

Standard Algorithm

being a sub-millimeter

* Option