Rizwan Ahmad
Ohio State University, OH·Biomedical Engineering
Magnetic resonance imaging gives the most complete picture of the heart available without surgery or radiation, but it is slow. Because a scanner collects data gradually, standard cardiac MRI asks patients to hold their breath and stitches images together across many identical heartbeats.
- Fields
Biomedical Engineering
Engineering
Medicine & Clinical Research
- Topics
cardiovascular magnetic resonance
MRI reconstruction
real-time MRI
- Grants
- 3 known grants, through Mar 2031
What they work on
- Develop and validate GeMM, an unsupervised reconstruction framework using a generative prior with multi-dynamic modeling, to produce 3D real-time cardiac cine and late gadolinium enhancement images from a free-running, ungated scan, starting with 3D digital cardiac phantoms.
- Validate 3D real-time cardiac MRI with GeMM in healthy subjects and in clinical patients without arrhythmia, establishing image quality against conventional acquisitions.
- Test 3D real-time CMR in patients with frequent premature ventricular contractions to quantify fibrosis plus beat-specific left ventricular mechanics, regional strain and dyssynchrony, measures that often change before ejection fraction falls.
- Build a stress cardiac MRI protocol with ferumoxytol-enhanced whole-heart 4D flow imaging that needs no breath-holds, regular rhythm or navigator gating and works during exercise, to quantify leakage in mitral valve regurgitation.
- Validate the stress CMR protocol's accuracy and reproducibility in 55 healthy subjects and 55 patients with mitral regurgitation, testing whether it assesses the condition more reliably than transthoracic echocardiography alone.
- Train and select application-specific convolutional neural network denoisers for cardiac cine, 2D brain and 3D brain MRI, to serve as the learned image model inside the PnP-DL plug-and-play reconstruction framework.
- Compare plug-and-play algorithm variants for reconstruction accuracy and speed and implement the best in Gadgetron for inline processing on the scanner.
- Benchmark PnP-DL against compressed sensing and other deep-learning reconstructions on retrospectively undersampled data, then evaluate it on prospectively undersampled scans from adult and pediatric patients.
More about the research
That assumption breaks down exactly where good images matter most: in patients whose hearts beat irregularly, and in scans that need to cover a whole three-dimensional volume. These projects attack the problem from the computation side, developing reconstruction algorithms that recover high-quality images from far less data than classical methods require, and then validating those algorithms in digital simulations, healthy volunteers and patients. A second thread applies the same acceleration gains to measuring blood flow through a leaking heart valve during exercise.
Why it matters
Faster, more reliable cardiac and brain MRI could change who can be scanned and what clinicians learn. Patients with irregular heartbeats, in whom current three-dimensional methods routinely fail to yield diagnostic images, could get usable assessments of scar and beat-by-beat heart mechanics. For mitral valve regurgitation, quantitative stress MRI could sharpen decisions about the timing of surgery. Shorter scans may also reduce the need for sedation in children and make slow protocols such as whole-heart 4D flow practical in routine care.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Jiwon Kim
Weill Medical College of Cornell University, NY·Medicine & Clinical Research
Test whether right ventricle tissue injury, measured with high-resolution 3D LGE MRI (a scan that highlights scar) and extracellular volume mapping, predicts heart remodeling and worsening of the tricuspid leak in at least 265 patients with functional tricuspid regurgitation.
Kara Goss
University of Texas Southwestern Medical Center, TX·Medicine & Clinical Research
Identify features that impair cardiac growth from childhood into early adulthood after preterm birth, building sex-specific growth curves from repeated MRI measures of left ventricular volume and mass with mixed-effect quantile regression.
Ethan Tumarkin
University of Utah, UT·Biomedical Engineering
Design and build a trans-nasal transesophageal echocardiography prototype that passes an ultrasound probe through the nasal orifice to image the heart from the esophagus without sedation.
The school
Ohio State University: 71 labs on PI Pages, $1.6B a year on research, 882 research doctorates a year.
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