8 research outputs found
Segmentation of Juxtapleural Pulmonary Nodules Using a Robust Surface Estimate
An algorithm was developed to segment solid pulmonary nodules attached to the chest wall in computed
tomography scans. The pleural surface was estimated and used to segment the nodule from the
chest wall. To estimate the surface, a robust approach was used to identify points that lie on the pleural
surface but not on the nodule. A 3D surface was estimated from the identified surface points. The
segmentation performance of the algorithm was evaluated on a database of 150 solid juxtapleural pulmonary
nodules. Segmented images were rated on a scale of 1 to 4 based on visual inspection, with 3 and
4 considered acceptable. This algorithm offers a large improvement in the success rate of juxtapleural
nodule segmentation, successfully segmenting 98.0% of nodules compared to 81.3% for a previously published
plane-fitting algorithm, which will provide for the development of more robust automated nodule
measurement methods
Evaluation of emphysema on thoracic low-dose CTs through attention-based multiple instance deep learning
Abstract In addition to lung cancer, other thoracic abnormalities, such as emphysema, can be visualized within low-dose CT scans that were initially obtained in cancer screening programs, and thus, opportunistic evaluation of these diseases may be highly valuable. However, manual assessment for each scan is tedious and often subjective, thus we have developed an automatic, rapid computer-aided diagnosis system for emphysema using attention-based multiple instance deep learning and 865 LDCTs. In the task of determining if a CT scan presented with emphysema or not, our novel Transfer AMIL approach yielded an area under the ROC curve of 0.94 ± 0.04, which was a statistically significant improvement compared to other methods evaluated in our study following the Delong Test with correction for multiple comparisons. Further, from our novel attention weight curves, we found that the upper lung demonstrated a stronger influence in all scan classes, indicating that the model prioritized upper lobe information. Overall, our novel Transfer AMIL method yielded high performance and provided interpretable information by identifying slices that were most influential to the classification decision, thus demonstrating strong potential for clinical implementation
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The importance of low-dose CT screening to identify emphysema in asymptomatic participants with and without a prior diagnosis of COPD
Chronic Obstructive Pulmonary Disease (COPD) includes chronic bronchitis, small airways disease, and emphysema. Diagnosis of COPD requires spirometric evidence and may be normal even when small airways disease or emphysema is present. Emphysema increases the risk of exacerbations, and is associated with all-cause mortality and increased risk of lung cancer. We evaluated the prevalence of emphysema in participants with and without a prior history of COPD.
We reviewed a prospective cohort of 52,726 subjects who underwent baseline low dose CT screening for lung cancer from 2003 to 2016 in the International Early Lung Cancer Action Program.
Of 52,726 participants, 23.8%(12,542) had CT evidence of emphysema. Of these 12,542 participants with emphysema, 76.5%(9595/12,542) had no prior COPD diagnosis even though 23.6% (2258/9595) had moderate or severe emphysema. Among 12,542 participants, significant predictors of no prior COPD diagnosis were: male (OR = 1.47, p < 0.0001), younger age (ORage10 = 0.72, p < 0.0001), lower pack-years of smoking (OR10pack-years = 0.90, p < 0.0001), completed college or higher (OR = 1.54, p < 0.0001), no family history of lung cancer (OR = 1.12, p = 0.04), no self-reported cardiac disease (OR = 0.76, p = 0.0003) or hypertension (OR = 0.74, p < 0.0001). The severity of emphysema was significantly lower among the 9595 participants with no prior COPD diagnosis, the OR for moderate emphysema was ORmoderate = 0.58(p = 0.0007) and for severe emphysema, it was ORsevere = 0.23(p < 0.0001).
Emphysema was identified in 23.8% participants undergoing LDCT and was unsuspected in 76.5%. LDCT provides an opportunity to identify emphysema, and recommend smoking cessation.
•Emphysema was identified in 23.8% participants and was unsuspected in 76.5%.•23.6% of participants with unsuspected COPD had moderate or severe emphysema on LDCT.•COPD is underdiagnosed in patients undergoing LDCT.•LDCT provides an opportunity to identify emphysema, reduce morbidity and mortality