Publications by authors named "Torigian D"

Article Synopsis
  • Prostate cancer is a prevalent and serious health issue for men, and this study aims to evaluate how effective radiomics is in predicting the cancer grade.
  • The research systematically reviewed 43 studies involving nearly 10,000 patients, using advanced imaging techniques and established quality assessment tools to analyze data.
  • Results indicate that radiomics models show high accuracy in predicting prostate cancer grades, suggesting they could enhance traditional diagnostic methods and improve clinical decision-making.
View Article and Find Full Text PDF

Background: Increased epicardial adipose tissue (EAT) has adverse effects in cardiovascular diseases, independent of body mass index (BMI). Estrogen levels may impact EAT accumulation. Little is known about the predictors and potential impact of EAT in PAH.

View Article and Find Full Text PDF
Article Synopsis
  • The study focuses on using dynamic magnetic resonance imaging (dMRI) to analyze diaphragm motion in patients with thoracic insufficiency syndrome (TIS), providing insights into the severity of respiratory disorders without exposing patients to radiation.
  • The paper outlines a three-step approach to segment the left and right hemi-diaphragm from dMRI images, overcoming challenges like low resolution and motion blur by employing advanced deep learning techniques for accurate recognition and delineation.
  • Results showed a mean-Hausdorff distance of approximately 3 mm for diaphragm delineation and a positional error of about 3 mm in identifying the mid-sagittal plane, validated using 100 test images of TIS patients.
View Article and Find Full Text PDF

Purpose: Vision Transformers recently achieved a competitive performance compared with CNNs due to their excellent capability of learning global representation. However, there are two major challenges when applying them to 3D image segmentation: i) Because of the large size of 3D medical images, comprehensive global information is hard to capture due to the enormous computational costs. ii) Insufficient local inductive bias in Transformers affects the ability to segment detailed features such as ambiguous and subtly defined boundaries.

View Article and Find Full Text PDF
Article Synopsis
  • The study aimed to evaluate a new MRI technique to assess lung aeration in children, especially focusing on those with thoracic insufficiency syndrome (TIS).
  • Researchers used standardized signal intensity (sSI) measurements from MRI scans of both healthy children and TIS patients to determine lung function pre- and post-surgery.
  • Results indicated that the MRI method can detect lung aeration changes, showing a general decrease in lung sSI after surgery, although the changes were not statistically significant.
View Article and Find Full Text PDF

Organ segmentation is a crucial task in various medical imaging applications. Many deep learning models have been developed to do this, but they are slow and require a lot of computational resources. To solve this problem, attention mechanisms are used which can locate important objects of interest within medical images, allowing the model to segment them accurately even when there is noise or artifact.

View Article and Find Full Text PDF

Medical image auto-segmentation techniques are basic and critical for numerous image-based analysis applications that play an important role in developing advanced and personalized medicine. Compared with manual segmentations, auto-segmentations are expected to contribute to a more efficient clinical routine and workflow by requiring fewer human interventions or revisions to auto-segmentations. However, current auto-segmentation methods are usually developed with the help of some popular segmentation metrics that do not directly consider human correction behavior.

View Article and Find Full Text PDF

Early diagnosis of Type 2 Diabetes Mellitus (T2DM) is crucial to enable timely therapeutic interventions and lifestyle modifications. As the time available for clinical office visits shortens and medical imaging data become more widely available, patient image data could be used to opportunistically identify patients for additional T2DM diagnostic workup by physicians. We investigated whether image-derived phenotypic data could be leveraged in tabular learning classifier models to predict T2DM risk in an automated fashion to flag high-risk patients the need for additional blood laboratory measurements.

View Article and Find Full Text PDF

Organ segmentation is a fundamental requirement in medical image analysis. Many methods have been proposed over the past 6 decades for segmentation. A unique feature of medical images is the anatomical information hidden within the image itself.

View Article and Find Full Text PDF
Article Synopsis
  • Auto-segmentation is crucial for improving the efficiency and accuracy of medical image analysis, particularly in precision radiology and oncology, as it reduces the need for manual corrections.
  • The study evaluates various segmentation metrics, including the Dice Coefficient and Hausdorff Distance, to better assess auto-segmentation outcomes based on clinical needs and the effort required for manual corrections.
  • The research includes experiments with different metrics and introduces a new metric, the Mendability Index, along with exploring deep learning predictions for mending effort, using datasets from multiple institutions.
View Article and Find Full Text PDF

Background: The International Prostate Symptom Score (IPSS) is a patient-reported measurement to assess the lower urinary tract symptoms of bladder outlet obstruction. Bladder outlet obstruction induces molecular and morphological alterations in the urothelium, suburothelium, detrusor smooth muscle cells, detrusor extracellular matrix, and nerves. We sought to analyze MRI-based radiomics features of the urinary bladder wall and their association with IPSS.

View Article and Find Full Text PDF

Background: The diaphragm is a critical structure in respiratory function, yet in-vivo quantitative description of its motion available in the literature is limited.

Research Question: How to quantitatively describe regional hemi-diaphragmatic motion and curvature via free-breathing dynamic magnetic resonance imaging (dMRI)?

Study Design And Methods: In this prospective cohort study we gathered dMRI images of 177 normal children and segmented hemi-diaphragm domes in end-inspiration and end-expiration phases of the constructed 4D image. We selected 25 points uniformly located on each 3D hemi-diaphragm surface.

View Article and Find Full Text PDF

Purpose: Analysis of the abnormal motion of thoraco-abdominal organs in respiratory disorders such as the Thoracic Insufficiency Syndrome (TIS) and scoliosis such as adolescent idiopathic scoliosis (AIS) or early onset scoliosis (EOS) can lead to better surgical plans. We can use healthy subjects to find out the normal architecture and motion of a rib cage and associated organs and attempt to modify the patient's deformed anatomy to match to it. Dynamic magnetic resonance imaging (dMRI) is a practical and preferred imaging modality for capturing dynamic images of healthy pediatric subjects.

View Article and Find Full Text PDF
Article Synopsis
  • Thoracic insufficiency syndrome (TIS) restricts respiratory function due to spinal and thoracic deformities, making corrective orthopedic surgery a potential solution to improve lung space and diaphragm movement.
  • A study involving 149 TIS pediatric patients and 190 healthy controls used free-breathing dynamic MRI to analyze diaphragm motion and changes before and after surgery.
  • Results showed significant increases in diaphragm mobility, particularly in the posterior regions, with the surgery having a more pronounced effect on diaphragm function than spinal curve reductions.
View Article and Find Full Text PDF

Purpose: Lung tissue and lung excursion segmentation in thoracic dynamic magnetic resonance imaging (dMRI) is a critical step for quantitative analysis of thoracic structure and function in patients with respiratory disorders such as Thoracic Insufficiency Syndrome (TIS). However, the complex variability of intensity and shape of anatomical structures and the low contrast between the lung and surrounding tissue in MR images seriously hamper the accuracy and robustness of automatic segmentation methods. In this paper, we develop an interactive deep-learning based segmentation system to solve this problem.

View Article and Find Full Text PDF
Article Synopsis
  • A new database called VGC has been created to measure respiratory parameters in healthy children, aimed at filling the gap in existing normative data.
  • The study analyzed 3D respiratory measurements across different age and gender groups, finding significant differences in lung function, particularly among adolescents.
  • Results suggest that the VGC database can help assess respiratory abnormalities in patients with conditions like TIS, aiding in treatment planning and evaluation of surgical outcomes.
View Article and Find Full Text PDF

Purpose: There is a concern in pediatric surgery practice that rib-based fixation may limit chest wall motion in early onset scoliosis (EOS). The purpose of this study is to address the above concern by assessing the contribution of chest wall excursion to respiration before and after surgery.

Methods: Quantitative dynamic magnetic resonance imaging (QdMRI) is performed on EOS patients (before and after surgery) and normal children in this retrospective study.

View Article and Find Full Text PDF

Interlobular septa thickening (ILST) is a common and easily recognized feature on computed tomography (CT) images in many lung disorders. ILST thickening can be smooth (most common), nodular, or irregular. Smooth ILST can be seen in pulmonary edema, pulmonary alveolar proteinosis, and lymphangitic spread of tumors.

View Article and Find Full Text PDF

The objective of this study is to define CT imaging derived phenotypes for patients with hepatic steatosis, a common metabolic liver condition, and determine its association with patient data from a medical biobank. There is a need to further characterize hepatic steatosis in lean patients, as its epidemiology may differ from that in overweight patients. A deep learning method determined the spleen-hepatic attenuation difference (SHAD) in Hounsfield Units (HU) on abdominal CT scans as a quantitative measure of hepatic steatosis.

View Article and Find Full Text PDF

Purpose: Body composition analysis (BCA) of the body torso plays a vital role in the study of physical health and pathology and provides biomarkers that facilitate the diagnosis and treatment of many diseases, such as type 2 diabetes mellitus, cardiovascular disease, obstructive sleep apnea, and osteoarthritis. In this work, we propose a body composition tissue segmentation method that can automatically delineate those key tissues, including subcutaneous adipose tissue, skeleton, skeletal muscle tissue, and visceral adipose tissue, on positron emission tomography/computed tomography scans of the body torso.

Methods: To provide appropriate and precise semantic and spatial information that is strongly related to body composition tissues for the deep neural network, first we introduce a new concept of the body area and integrate it into our proposed segmentation network called Geographical Attention Network (GA-Net).

View Article and Find Full Text PDF

Background: The exact role of the levator ani (LA) muscle in male continence remains unclear, and so this study aims to shed light on the topic by characterizing MRI-derived radiomic features of LA muscle and their association with postoperative incontinence in men undergoing prostatectomy.

Method: In this retrospective study, 140 patients who underwent robot-assisted radical prostatectomy (RARP) for prostate cancer using preoperative MRI were identified. A biomarker discovery approach based on the optimal biomarker (OBM) method was used to extract features from MRI images, including morphological, intensity-based, and texture-based features of the LA muscle, along with clinical variables.

View Article and Find Full Text PDF

We have previously shown that vaccination with tumor-pulsed dendritic cells amplifies neoantigen recognition in ovarian cancer. Here, in a phase 1 clinical study ( NCT01312376 /UPCC26810) including 19 patients, we show that such responses are further reinvigorated by subsequent adoptive transfer of vaccine-primed, ex vivo-expanded autologous peripheral blood T cells. The treatment is safe, and epitope spreading with novel neopeptide reactivities was observed after cell infusion in patients who experienced clinical benefit, suggesting reinvigoration of tumor-sculpting immunity.

View Article and Find Full Text PDF

Purpose: Unstructured data are an untapped source for surgical prediction. Modern image analysis and machine learning (ML) can harness unstructured data in medical imaging. Incisional hernia (IH) is a pervasive surgical disease, well-suited for prediction using image analysis.

View Article and Find Full Text PDF

Altered systemic and cellular lipid metabolism plays a pivotal role in the pathogenesis of prostate cancer (PCa). In this study, we aimed to characterize T1-magnetic resonance imaging (MRI)-derived radiomic parameters of periprostatic adipose tissue PPAT) associated with clinically significant PCa (Gleason score ≥7 [3 + 4]) in a cohort of men who underwent robot-assisted prostatectomy. Preoperative MRI scans of 98 patients were identified.

View Article and Find Full Text PDF