REVIEW OF THE LITERATURE
Nuclear cardiology in the literature: A selection
of recent, original research papers
Saurabh Malhotra, MD, MPH, FASNC
a
a
Division of Cardiovascular Medicine, Department of Medicine (Cardiology) and Nuclear
Medicine, Clinical and Translational Research Center, Jacobs School of Medicine and
Biomedical Sciences, University at Buffalo, Buffalo, NY
Received May 24, 2018; accepted May 24, 2018
doi:10.1007/s12350-018-1318-4
Quantification and Determination of Normal
123
I-
Meta Iodobenzylguanidine Heart-to-Mediastinum
Ratio (HMR) from Cardiac SPECT/CT and Corre-
lation with Planar HMR.
Raza Alvi, Edward J. Miller, Taraneh Hashemi Zonouz,
Veronica Sandoval, Noor Tariq, Rachel Lampert, Albert
J. Sinusas and Yi-Hwa Liu
New Haven, CT
J Nucl Med 2018; 59:652–658
Context: The heart-to-mediastinal ratio (HMR) on
planar
123
I-Meta Iodobenzylguanidine (
123
I-mIBG) is
used to assess myocardial sympathetic function, and
provides prognostic value among patients with heart
failure and reduced ejection fraction. The SPECT cor-
relate for the lower limit of normal (LLN) HMR by
planar
123
I-mIBG has not been studied.
Methods and Results: The authors of this study
evaluated novel semiautomated quantitative method-
ologies for assessing SPECT HMR. Planar and SPECT
123
I-mIBG imaging was performed in 21 healthy vol-
unteers (48% males; mean age = 48 ± 12 years), on two
different cameras, after a single injection of
123
I-mIBG
(209 ± 44 MBq; AdreView [GE Healthcare]). Planar
imaging was performed at 30 minutes (early) and 180
minutes (delayed) using a dual-head SPECT system with
LEHR collimators. Hybrid SPECT/CT imaging was
performed for 15 minutes, on a high-resolution cadmium
zinc telluride (CZT) system (Discovery NM/CT 579c;
GE Healthcare) at 30, 90, 120, and 180 minutes after
isotope injection. Planar HMR was calculated as per
standard guidelines, and by two institutional-specific
(Yale University) quantification methods—elliptic
region-of-interest (Elip-ROI) and region-growing (RG-
ROI) techniques. SPECT HMR was quantified using a
novel technique incorporating various cardiac and
mediastinal segmentation schemes in which upper and
lower limits of the heart were determined from CT and
the left ventricular ROI. Mean counts on SPECT were
calculated using Elip-ROI and RG-ROI techniques.
Mean counts in mediastinal ROI were computed from a
fixed volume (5 9 5 9 5 voxel in size) in 3 different
regions: upper mediastinum (UM), lower mediastinum
(LM), and contralateral lung (CL). HMRs were pro-
cessed by 2 observers, and reproducibility was assessed
by intraclass correlation coefficient (ICC) and Bland–
Altman analysis. The authors reported a LLN from
planar HMR as being similar to that reported previously
(range: 1.56-1.64), and that among the planar tech-
niques, the RG-ROI method showed the highest intra-
and interobserver levels of agreement compared with
Elip-ROI and manual traditional methods. SPECT HMR
calculated on the basis of UM, LM, and CL background
regions showed excellent intra- and interobserver
agreement (ICC range 0.96-0.97). SPECT HMR with
UM resulted in the highest correlation (R = 0.91) with
planar RG-ROI HMR compared with that with LM (R =
0.74) and CL (R = 0.73) methods. The LLN of SPECT
HMR with UM and that of planar HMR was calculated
to 5.5 and 1.6, respectively, and a linear correlation was
observed between the normal values of SPECT-derived
and planar-derived HMR. Results of this confirm the
previously reported planar HMR threshold and provide
the LLN for SPECT HMR on high-resolution hybrid
SPECT/CT imaging with CZT systems.
Significance: Cardiac-dedicated SPECT cameras
with solid-state detectors allow for high-resolution
SPECT imaging of a small, ‘cardia-centric,’ region of
Reprint requests: Saurabh Malhotra, MD, MPH, FASNC, Division of
Cardiovascular Medicine, Department of Medicine (Cardiology) and
Nuclear Medicine, Clinical and Translational Research Center,
Jacobs School of Medicine and Biomedical Sciences, University at
Buffalo, 875 Ellicott Street, Suite 7030, Buffalo, NY 14203;
drsmalhotra@hotmail.com, smalhot@buffalo.edu
1071-3581/$34.00
Copyright Ó 2018 American Society of Nuclear Cardiology.
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