Mutlu Demirer

Dr. Mutlu Demirer


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 March 2020 in IEEE Journal of Biomedical and Health Informatics
Verified
Journal Article
Open access
EDEngin Dikici
Engin Dikici
JRJohn L. Ryu
John L. Ryu
MDMutlu Demirer
Mutlu Demirer
MBMatthew Bigelow
Matthew Bigelow
RWRichard D. White
Richard D. White
LPLuciano M prevedello
Luciano M prevedello
Brain Metastases (BM) complicate 20-40% of cancer cases. BM lesions can present as punctate (1 mm) foci, requiring high-precision Magnetic Resonance Imaging (MRI) in order to prevent inadequate or delayed BM treatment. However, BM lesion detection remains challenging partly due to their structural similarities to normal structures (e.g., vasculature). We propose a BM-detection framework using a single-sequence gadolinium-enhanced T1-weighted 3D MRI dataset. The framework focuses on the detection of smaller (< 15 mm) BM lesions and consists of: (1) candidate-selection stage, using Laplacian of Gaussian approach for highlighting parts of an MRI volume holding higher BM occurrence probabilities, and (2) detection stage that iteratively processes cropped region-of-interest volumes centered by candidates using a custom-built 3D convolutional neural network (“CropNet”). Data is augmented extensively during training via a pipeline consisting of random gamma correction and elastic deformation stages; the framework thereby maintains its invariance for a plausible range of BM shape and intensity representations. This approach is tested using five-fold cross-validation on 217 datasets from 158 patients, with training and testing groups randomized per patient to eliminate learning bias. The BM database included lesions with a mean diameter of ~5.4 mm and a mean volume of ~160 mm3. For 90% BM-detection sensitivity, the framework produced on average 9.12 false-positive BM detections per patient (standard deviation of 3.49); for 85% sensitivity, the average number of false-positives declined to 5.85. Comparative analysis showed that the framework produces comparable BM-detection accuracy with the state-of-art approaches validated for significantly larger lesions.

1 November 2019 in Radiology: Artificial Intelligence
Verified
Journal Article
Closed access
MDMutlu Demirer
Mutlu Demirer
SCSema Candemir
Sema Candemir
MBMatthew T. Bigelow
Matthew T. Bigelow
SYSarah M. Yu
Sarah M. Yu
VGVikash Gupta
Vikash Gupta
BEBarbaros S. Erdal
Barbaros S. Erdal
A graphical user interface promoted involvement of local-expert subspecialty radiologists in ongoing image data curation, including case-by-case annotation, potentially concurrent with artificial i... Purpose To delineate image data curation needs and describe a locally designed graphical user interface (GUI) to aid radiologists in image annotation for artificial intelligence (AI) applications i...

15 October 2020 in PLOS ONE
Verified
Journal Article
Open access
PDF file
BEBarbaros S. Erdal
Barbaros S. Erdal
MDMutlu Demirer
Mutlu Demirer
KLKevin J. Little
Kevin J. Little
CAChiemezie C. Amadi
Chiemezie C. Amadi
GIGehan F. M. Ibrahim
Gehan F. M. Ibrahim
RWRichard D. White
Richard D. White
Consistency and duplicability in Computed Tomography (CT) output is essential to quantitative imaging for lung cancer detection and monitoring. This study of CT-detected lung nodules investigated the reproducibility of volume-, density-, and texture-based features (outcome variables) over routine ranges of radiation dose, reconstruction kernel, and slice thickness. CT raw data of 23 nodules were reconstructed using 320 acquisition/reconstruction conditions (combinations of 4 doses, 10 kernels, and 8 thicknesses). Scans at 12.5%, 25%, and 50% of protocol dose were simulated; reduced-dose and full-dose data were reconstructed using conventional filtered back-projection and iterative-reconstruction kernels at a range of thicknesses (0.6–5.0 mm). Full-dose/B50f kernel reconstructions underwent expert segmentation for reference Region-Of-Interest (ROI) and nodule volume per thickness; each ROI was applied to 40 corresponding images (combinations of 4 doses and 10 kernels). Typical texture analysis metrics (including 5 histogram features, 13 Gray Level Co-occurrence Matrix, 5 Run Length Matrix, 2 Neighboring Gray-Level Dependence Matrix, and 3 Neighborhood Gray-Tone Difference Matrix) were computed per ROI. Reconstruction conditions resulting in no significant change in volume, density, or texture metrics were identified as “compatible pairs” for a given outcome variable. Our results indicate that as thickness increases, volumetric reproducibility decreases, while reproducibility of histogram- and texture-based features across different acquisition and reconstruction parameters improves. To achieve concomitant reproducibility of volumetric and radiomic results across studies, balanced standardization of the imaging acquisition parameters is required.

1 September 2022 in Journal of Medical Imaging
Verified
Journal Article
Open access
PDF file
RWRichard D. White
Richard D. White
MDMutlu Demirer
Mutlu Demirer
VGVikash Gupta
Vikash Gupta
RSRonnie Sebro
Ronnie Sebro
FKFrederick M. Kusumoto
Frederick M. Kusumoto
BEBarbaros Selnur Erdal
Barbaros Selnur Erdal
PurposeChest X-ray (CXR) use in pre-MRI safety screening, such as for lead-less implanted electronic device (LLIED) recognition, is common. To assist CXR interpretation, we “pre-deployed” an artificial intelligence (AI) model to assess (1) accuracies in LLIED-type (and consequently safety-level) identification, (2) safety implications of LLIED nondetections or misidentifications, (3) infrastructural or workflow requirements, and (4) demands related to model adaptation to real-world conditions.ApproachA two-tier cascading methodology for LLIED detection/localization and identification on a frontal CXR was applied to evaluate the performance of the original nine-class AI model. With the unexpected early appearance of LLIED types during simulated real-world trialing, retraining of a newer 12-class version preceded retrialing. A zero footprint (ZF) graphical user interface (GUI)/viewer with DICOM-based output was developed for inference-result display and adjudication, supporting end-user engagement and model continuous learning and/or modernization.ResultsDuring model testing or trialing using both the nine-class and 12-class models, robust detection/localization was consistently 100%, with mAP 0.99 from fivefold cross-validation. Safety-level categorization was high during both testing (AUC ≥ 0.98 and ≥0.99, respectively) and trialing (accuracy 98% and 97%, respectively). LLIED-type identifications by the two models during testing (1) were 98.9% and 99.5% overall correct and (2) consistently showed AUC ≥ 0.92 (1.00 for 8/9 and 9/12 LLIED-types, respectively). Pre-deployment trialing of both models demonstrated overall type-identification accuracies of 94.5% and 95%, respectively. Of the small number of misidentifications, none involved MRI-stringently conditional or MRI-unsafe types of LLIEDs. Optimized ZF GUI/viewer operations led to greater user-friendliness for radiologist engagement.ConclusionsOur LLIED-related AI methodology supports (1) 100% detection sensitivity, (2) high identification (including MRI-safety) accuracy, and (3) future model deployment with facilitated inference-result display and adjudication for ongoing model adaptation to future real-world experiences.

25 April 2025 in Journal of Stroke and Cerebrovascular Diseases
Verified
Journal Article
Open access
SVSai Krishna Vallamchetla
Sai Krishna Vallamchetla
MDMutlu Demirer
Mutlu Demirer
EMErik Middlebrooks
Erik Middlebrooks
MLMichelle P. Lin
Michelle P. Lin
White matter disease (WMD) is common among aging populations and is associated with adverse neurological outcomes. While age is a known risk factor for WMD burden, the precise relationship between age and the rate of WMD volume progression remains unclear. The purpose of this study is to investigate the age-dependent acceleration of WMD volume progression across different age groups and its potential clinical implications. This retrospective study included 2356 patients aged 40 years or older who underwent longitudinal MRI brain scans between 2011 and 2019 at Mayo Clinic. Baseline demographic and clinical characteristics, including vascular risk factors, were collected. The primary outcome was the annual rate of WMD volume progression, which was analyzed across the five age groups (40-49, 50-59, 60-69, 70-79, and 80-99 years). Analysis of Covariance (ANCOVA) assessed the effect of different age groups on WMD progression, while linear ridge regression was used to identify predictors of WMD progression. The mean age of the cohort was 67.6 ± 11.5 years, with 52.7% female and 95.1% White. The baseline WMD volume averaged 13.05 ± 14.49 cm³, increasing to 18.30 ± 17.10 cm³ after a median follow-up of 4.8 years, corresponding to an annual progression rate of 1.19 ± 3.01 cm³/year. The annualized rate of WMD volume progression increased significantly with age, from 0.39 cc/year in the 40-49 age group to 1.63 cc/year in the 80-99 age group (p< 0.001). Additionally, the linear ridge regression model identified age, female sex, ever-smoker, diabetes, and baseline WMD volume as significant predictors of faster WMD progression (p<0.05). Our study revealed a significant age-dependent acceleration in WMD volume progression. Age, female sex, ever smoker, diabetes, and baseline WMD volume emerged as significant predictors of the rate of WMD volume progression.

21 November 2023 in JMIR Preprints
Verified
Preprint
Open access
BEBarbaros Selnur Erdal
Barbaros Selnur Erdal
VGVikash Gupta
Vikash Gupta
MDMutlu Demirer
Mutlu Demirer
KFKimberly H Fair
Kimberly H Fair
RWRichard D White
Richard D White
BGBrad Genereaux
Brad Genereaux
UNSTRUCTURED This paper reviews the challenges hindering the widespread adoption of artificial intelligence (AI) solutions in the healthcare industry, focusing on computer vision applications for medical imaging, and how interoperability and enterprise-grade scalability can be used to address these challenges. The complex nature of healthcare workflows, intricacies in managing large and secure medical imaging data, and the absence of standardized frameworks for AI development pose significant barriers and require a new paradigm to address them. The role of interoperability is examined in this paper as a crucial factor in connecting disparate applications within healthcare workflows. Standards such as DICOM™, Health Level 7 HL7®, and Integrating the Healthcare Enterprise (IHE) are highlighted as foundational for common imaging workflows. A specific focus is placed on the role of DICOM gateways, with Smart Routing Rules and Workflow Management leading transformational efforts in this area. To drive enterprise scalability, new tools are needed. Project MONAI, established in 2019, is introduced as an initiative aiming to redefine the development of medical AI applications. The MONAI Deploy App SDK, a component of Project MONAI, is identified as a key tool in simplifying the packaging and deployment process, enabling repeatable, scalable, and standardized deployment patterns for AI applications. The abstract underscores the potential impact of successful AI adoption in healthcare, offering physicians both life-saving and time-saving insights and driving efficiencies in radiology department workflows. The collaborative efforts between academia and industry, are emphasized as essential for advancing the adoption of healthcare AI solutions.