CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 2, March/April 2014
44
AFRICA
Cardiovascular Topics
Comparison of estimates of left ventricular ejection
fraction obtained from gated blood pool imaging,
different software packages and cameras
Rachelle Steyn, John Boniaszczuk, Theodore Geldenhuys
Abstract
Objective:
To determine how two software packages, supplied
by Siemens and Hermes, for processing gated blood pool
(GBP) studies should be used in our department and whether
the use of different cameras for the acquisition of raw data
influences the results.
Methods:
The study had two components. For the first
component, 200 studies were acquired on a General Electric
(GE) camera and processed three times by three operators
using the Siemens and Hermes software packages. For the
second part, 200 studies were acquired on two different
cameras (GE and Siemens). The matched pairs of raw data
were processed by one operator using the Siemens and
Hermes software packages.
Results:
The Siemens method consistently gave estimates
that were 4.3% higher than the Hermes method (
p
<
0.001).
The differences were not associated with any particular level
of left ventricular ejection fraction (LVEF). There was no
difference in the estimates of LVEF obtained by the three
operators (
p
=
0.1794). The reproducibility of estimates was
good. In 95% of patients, using the Siemens method, the SD
of the three estimates of LVEF by operator 1 was
≤
1.7, opera-
tor 2 was
≤
2.1 and operator 3 was
≤
1.3. The corresponding
values for the Hermes method were
≤
2.5,
≤
2.0 and
≤
2.1.
There was no difference in the results of matched pairs of data
acquired on different cameras (
p
=
0.4933)
Conclusion:
Software packages for processing GBP studies
are not interchangeable. The report should include the name
and version of the software package used. Wherever possible,
the same package should be used for serial studies. If this is
not possible, the report should include the limits of agree-
ment of the different packages. Data acquisition on different
cameras did not influence the results.
Keywords:
gated blood pool studies, cameras, software pack-
ages, results
Submitted 3/7/13, accepted 18/11/13
Cardiovasc J Afr
2014;
25
: 44–49
DOI: 10.5830/CVJA-2013-082
Serial measurement of LVEF using gated blood pool (GBP)
imaging is an established technique for monitoring LVEF in
patients undergoing chemotherapy with cardiotoxic medication
and in patients after heart transplants.
1,2
The nuclear medicine
department at Groote Schuur Hospital performs up to a
thousand GBP studies annually. The majority of these studies
are for patients receiving cardiotoxic chemotherapy and have a
significant impact on patient management.
In our hospital, the radiation oncologists consider not starting
cardiotoxic chemotherapy if the LVEF is below 50% and
terminating chemotherapy if there is a 10% decrease. In patients
who have had heart transplants, the cardiologists start patients on
glucocorticosteroids if a patient’s LVEF decreases by10%. It is
therefore imperative that serial studies on an individual patient
are comparable.
Two software systems are used in our nuclear medicine
department. The Siemens system (Siemens Medical Solutions,
Chicago, USA) was introduced in February 2006 and the
Hermes system (Hermes Medical Solutions, Stockholm Sweden)
in September 2007. After the introduction of the Hermes system,
we found large differences between the LVEFs calculated by
the two systems. This was confirmed by a pilot study and is
consistent with the literature that different software programs for
processing equilibrium gated radionuclide studies cannot be used
interchangeably.
3-7
The department also uses two different cameras, a General
Electric (GE) Starcam 400 AC single-head and a Siemens
Signature Series e.cam dual-head camera to acquire the raw
data. These are then transferred to the Siemens and Hermes
processing systems.
This study was done to determine how the software packages
used for processing GBP studies should be integrated into our
department and if the use of different cameras for acquisition
influences results. The study had two components. The first
examined the values and reproducibility of estimates of LVEF
from two software packages using data acquired on the GE
Department of Nuclear Medicine, Groote Schuur Hospital,
University of Cape Town, South Africa
Rachelle Steyn, MBChB, FCNP, MMed (Nuc Med),
John Boniaszczuk, NAT DIP RAD (NM)
Theodore Geldenhuys, NAT DIP RAD (NM)
