Methods
At Montefiore Medical Center (MMC), a standardized MRA scanning protocol
with TE <5 msec based on the SWiTCH protocol was implemented
in May 2016. This study was approved by the Albert Einstein College of
Medicine and MMC Institutional Review Board as a retrospective chart
review that included the following criteria i) patients ≤21 years old at
the time of implementation of the scanning protocol in May 2016 ii)
sickle cell disease (genotypes SS, Sβ0thalassemia, Sβ+thalassemia, SC),
iii) established hematology care at CHAM for at least one year (defined
as having at least one outpatient clinic visit), and iv) MRA performed
at MMC prior to May 1st 2016 AND after May
1st 2016.
Clinical Looking Glass (CLG™), a patented software tool designed by MMC
for practitioners to use medical and administrative data as a means for
continued quality improvement, was used to identify study population.
Inclusion criteria applied to CLG were ICD diagnoses for sickle cell
disease, age ≤21, date range of 2014-2018, and procedure codes for MRI.
Studies performed on MRI machines from any vendors and any MMC sites
were included. Exclusion criteria included incomplete records and
patients with only one MRA. Twenty-nine patients were identified with
any degree of cerebral vasculopathy on the pre-May 2016 images and
included in this study. Patient assembly including ICD codes is
illustrated in Figure 1.
A dedicated neuroradiologist with expertise in interpreting vasculopathy
in sickle cell patients reviewed all images as part of institutional
hematology-neuroradiology rounds that are performed as a routine
component of clinical care. After data collection and prior to analysis,
a separate blinded neuroradiologist reviewed key images for patients in
question. Level of arterial stenosis on MRA, TE, and treatment plans
were documented both pre- and post-May 2016 for each patient. Other
technical factors such as magnet field strength, repetition time (TR)
and slice thickness were also noted.
A McNemar analysis was performed to determine whether there was a
significant change in treatment plan after implementation of the
standardized MRA scanning protocol.