Evaluation of Coronary Artery Calcification using Gated Stationary Chest Tomosynthesis (PI: Yueh Lee)

Purpose: The proposed research, if successfully implemented, will result in a new method for evaluating coronary artery calcium scores (CACS) in individuals with coronary artery disease. Using the Cardiac Gated Stationary Chest Tomosynthesis (CG-SDCT) system the imaging dose for a a full tomosynthesis scan is expected to be only 10% of that from a low-dose CT. The targeted imaging time of 25-30 seconds is 1/2 of that from a current commercial DCT system at the same imaging dose. As with current commercial DCT systems, our s-DCT system will expose patients to less radiation and deliver comparable data for CACS. CG-SDCT will likely result in accurate CAC scoring and allow for a more complete patient risk assessment as compared to Framingham risk scoring alone.

Participants: Twenty (20) patients who have undergone clinical outpatient non-contrast CT of the chest will be asked to have a CG-SDCT within 4 weeks (+/- 1 week) of their clinical CT, with no intervening procedure or therapy (i.e. biopsy, line placement, etc). Alternatively, patients scheduled to undergo a clinical CT for transcatheter aortic valve replacement (TAVR) may also be included with a modified field of view.

Procedures (methods): This is a one arm study of 20 patients who have undergone a clinical, outpatient non-contrast CT of the chest or will undergo a modified clinical CT for transcatheter aortic valve replacement (TAVR) at UNC Hospitals that consent to undergo an experimental CG-SDCT. The sensitivity of the non-contrast CT and the experimental s-DCT for CACS wil be estimated separately, using the CT as the gold-standard. The precision of the CG s-DCT will then be compared to conventional CT.

Evaluation of the Lung nodule Sensitivity of Stationary Chest Tomosynthesis versus Chest Radiographs in Patients with Known Lung Nodules (PI: Yueh Lee)

Purpose:  The proposed research, if successfully implemented, will result in a low-dose, low-cost, and highly effective method for screening of lung cancer, leading to reduction of the lung cancer mortality rate. Using the s-DCT system the imaging dose for a full tomosynthesis scan is expected to be only 10% of that from a low-dose CT. The targeted imaging time of 2s is 1/5 to 1/3 of that from a current commercial DCT system at the same imaging dose.  Beyond lung cancer screening, the low-dose and sensitive 3D lung imaging modality will likely to find applications in areas such as monitoring of pediatric cystic fibrosis patients where reduction of imaging dose is critical.

Participants:  One hundred (100) patients undergoing a clinical non-contrast CT for their lung nodules will be asked to have this procedure (scan) within 4 weeks of their clinical CT and chest radiograph, with no intervening procedures or therapies.

Procedures (methods):  This is a nonrandomized, single-center, non-interventional, observational study. The purpose and endpoint of this study is to compare the sensitivity of the s-DCT system to the conventional chest radiographs with non-contrast chest CT as the reference standard. One hundred (100) patients undergoing a clinical non-contrast CT for their lung nodules will be asked to have this procedure (scan) within 4 weeks of their clinical CT and chest radiograph, with no intervening procedures or therapies.

LCCC 1822-Clinical Evaluation of Primary Sampling Scatter Correction for Chest Tomosynthesis (PI: Ertan Pamuklar)

Purpose: This is a study that will evaluate the utility of a scatter reduction technique in reducing dose and increasing the sensitivity of stationary digital chest tomosynthesis (s-DCT) in the detection of lung. Digital tomosynthesis is an imaging modality that produces 3D sectional information using x-ray projections acquired over a limited scanning angle.  Scatter is known to be the primary source of image degradation in x-ray based imaging.

Participants: Fifty (50) patients who have undergone a clinical non-contrast CT with lung nodules will be asked to have an s-DCT (scan) within 4 weeks (+/- 2 week) of their clinical CT with no intervening procedures or therapies (i.e. biopsy of lung nodules).

Procedures (methods): We have developed an approach that measures scatter through a low dose (3% of the conventional scan) scatter measurement technique. We plan to characterize the reader confidence in lung nodule detection in our scatter corrected chest tomosynthesis imaging approach as compared to our conventional chest tomosynthesis.