Intracavitary Magnetic Resonance Elastography for Prostate Cancer Imaging
Bibliographic record
Abstract
Prostate cancer is currently the most prevalent cancer and third leading cause of cancer related deaths amongst Canadian men. Highly sensitive, but non-specific, diagnostic techniques have made it challenging for clinicians to balance treatment efficacy with associated side-effects. Prostate imaging techniques are being investigated to assist in diagnosis, staging, monitoring, and localizing prostate cancer within the gland itself. Measuring changes in tissue biomechanics could provide important functional and morphological information about prostate cancer. Magnetic resonance elastography (MRE) is a potential candidate for imaging tissue mechanical properties, in vivo. MRE gives quantitative stiffness measurements by transmitting micrometer amplitude shear waves into tissues. Previous reports of performing MRE in prostate cancer patients have used an external source to generate shear waves inside the prostate, which has imposes limitations on the spatial resolution of the stiffness maps (elastograms). An alternative approach is to use an internal or intra-cavitary actuator to generate shear waves in closer proximity to the prostate in order to produce higher resolution elastograms. Since clinically significant prostate cancers can have diameters on the order of 1 cm, high resolution elastograms are essential in order to evaluate MRE as a potential tool for assisting in disease prognosis. This thesis demonstrates the technical feasibility of intra-cavitary (transurethral, endorectal) MRE for the purposes of evaluating localized regions of stiffness within the prostate gland. First, a combination of gel and canine experiments were performed to help outline the imaging characteristics of intra-cavitary MRE. Secondly, the feasibility of performing endorectal MRE by connecting a piezoceramic actuator to an endorectal radiofrequency receive coil while simultaneously preserving the signal to noise ratio of the acquired images wave demonstrated. Thirdly, the feasibility and tolerability of endorectal MRE in conjunction with current clinical endorectal RF coil designs was successfully demonstrated in human volunteers. This represented the first evaluation of endorectal MRE in humans. Lastly, a compliant mechanical amplifier was designed in order to develop a reliable high amplitude piezoceramic actuator for performing intracavitary MRE. Taken together, this work demonstrates the feasibility of intracavitary MRE and provides a method for locally probing the biomechanical properties of the prostate gland.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.019 | 0.007 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".