460 likes | 601 Views
SPIE Medical Imaging Conference Lung Imaging Database Consortium (LIDC). LIDC Data Elements and Data Collection Process February 13, 2005. The Database. The Database will contain: A collection of CT scan images. Low Dose Lung Cancer Screen CTs. 1. 2. 3. 4. 5. The Database.
E N D
SPIE Medical Imaging ConferenceLung Imaging Database Consortium (LIDC) LIDC Data Elements and Data Collection Process February 13, 2005
The Database • The Database will contain: • A collection of CT scan images
The Database • CT scan image data • Low Dose, Full Chest Lung Cancer Screening CTs • Conventional Dose, Full Chest CTs (Retrospective Cases, e.g. Lung Ca Patients) • Conventional Dose, Limited Chest CTs (e.g. Scan of a single nodule; biopsy) • All image data in DICOM format • Indexing to identify cases of each type
The Database • The database will contain: • A collection of CT scan images • Technical factors about the CT scan
The Database • Technical factors about the CT scan • All Image data will be anonymized • Much of DICOM header info will be preserved and stored along with image data • Database fields (can be queried) will have Non-patient information from DICOM header
The Database • Technical factors about the CT scan • Technical factors such as: • kVp • Tube current • Rotation time • Exposure • Reconstructed slice thickness and slice location (will still have to calc. spacing) • Reconstruction algorithm • Reconstructed field of view, pixel size • Content in private fields WILL BE removed
The Database • The database will contain: • A collection of CT scan images • Technical factors about the CT scan • Nodule Markings and Descriptions
The Database • Nodule Markings and Descriptions • For Nodules > 3 mm diameter • Radiologist drawn boundaries • Description of characteristics (from defined list) • For Nodules < 3 mm • Radiologist marks only centroid • No description characteristics
Nodule MarkingInitial Approach • Multiple Reads with Multiple Readers • First Read – 4 readers, each reads independently (Blinded) • Compile 4 blinded reads and distribute to readers • Second Read – Same 4 readers, this time unblinded to the results of the other readers from the first reading. • No forced consensus on either location of nodules nor on their boundaries.
Blinded Reads – Each Reader Reads Independently (Blinded to Results of Other Readers)
Blinded Read for Reader 2 – Marks Two Nodules (Note: One nodule is same as Reader 1) Reader 2
Blinded Read for Reader 3 – Marks Two Nodules (Note: Again, One nodule is same as for Reader 1) Reader 3
Blinded Read for Reader 4 – Did Not Mark Any Nodules Reader 4
2nd Round - UnBlinded Reads Readings in Which Readers Are Shown Results of Other Readers Each Reader Marks Nodules After Being Shown Results From Their Own and Other Readers’ Blinded Reads (Each Reader Decides to Include or Ignore).
Unblinded Read for Reader 1 – Now Marks Two Nodules (Originally only marked one) Reader 1
Unblinded Read for Reader 2 – Still Marks Two Nodules (No Change) Reader 2
Unblinded Read for Reader 3 – Now Marks Three Nodules (Originally only marked two) Reader 3
Unblinded Read for Reader 4 – Now Marks Three Nodules (Originally did not mark any) Reader 4
Results of Unblinded Reads from All Four Readers 4/4 Markings 2/4 Markings 2/4 Markings We will capture one aspect of reader variability in this way
The Database • The database will contain: • A collection of CT scan images • Technical factors about the CT scan • Nodule Markings and Descriptions • Pathology results or diagnosis information whenever available
Pathology Information In those cases in which pathology is available, we will extract from reports: • Whether histology or cytology was performed • If histology, try to establish the cell type according to WHO classifications • If cytology, establish whether it was benign or malignant
Pathology Information • If no pathology, other diagnostic information may be substituted when available (such as 2 years Dx F/U with no change in radiographic appearance). • If neither is available, then case will be used for detection purposes only.
Summary • LIDC Data Elements • Image Data • Technical Factors • Radiologists’ Contours of Nodules • Data Collection Process • Diagnosis Information where available