Clinical Evaluation of Primary Sampling Scatter Correction for Chest Tomosynthesis

Not Applicable

Completed

Brief Summary: 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 lesions.

Detailed Description: 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.

The investigators have developed an approach that measures scatter through a low dose (3% of the conventional scan) scatter measurement technique. Preliminary studies have shown that scatter reduction in DCT can significantly improve quality. The approach will characterize the reader confidence in lung nodule detection in a scatter corrected chest tomosynthesis imaging approach as compared to the conventional chest tomosynthesis.

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). Investigators will then perform a reader study to evaluate the radiologist reader confidence in images generated from the scatter reduction technique versus more conventional chest tomosynthesis imaging.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Patients who may not fit on a 35 x 35 detector (BMI > 35)
Planned procedures or therapies during study (in between SOC scans and study scan on s-DCT) (biopsy or removal of lung lesion)
Any woman who is pregnant, has reason to believe she is pregnant, or is lactating

Arm && Interventions

Group	Intervention	Description
Scatter corrected s-DCT	Scatter corrected s-DCT	The study scan, s-DCT and correction scan, will be performed within two weeks of the patient's clinical evaluations by chest CT and x-ray. The study scan may be done within 2 weeks prior or two weeks following standard of care imaging. There cannot be any intervening therapies or procedures (i.e. biopsy or excision of lesions) done in between the standard of care (SOC) imaging and the s-DCT. All patients will have a breath held s-DCT scan in an anterior-posterior direction.

Primary Outcome Measures

Name	Time	Method
Reader Confidence in s-DCT Images Compared to Conventional CT (Units on a Scale)	Baseline	Readers will rate their confidence in images from the experimental modality (sDCT with scatter correction) as compared to the conventional scan (chest CT with x-ray) on a 7 point Likert scale (-3 to 3) based on ability to identify lesion(s) present comparing each modality. A value of -3 is significantly less confident in the s-DCT representation 0 is the same confidence in modalities, and 3 is significantly more confident in the s-DCT representation compared to the conventional. Each individual will have a single value per reader. Two readers compared each scan. The overall reader preference between modalities was calculated by determining the mean value.

Secondary Outcome Measures

Name	Time	Method
Sensitivity of s-DCT Images (Percentage of Positive Scans)	Baseline	Sensitivity will be defined as the ability of s-DCT images to detect lesions positively identified on gold standard CT images.