Week 4: Analysis of MRI Images

I spent much of this week performing analysis of the MRI data we collected last week from loaded and unloaded porcine patellar tendon. This included using preexisting software as well as code developed by the MRI Lab. Often, the first step in medical image processing is segmentation. In this case, we were interested in only looking at T2* relaxation times in the tendon. Using a software called ITK-SNAP I was able to outline the tendon in every slice where it appeared in the MR image stack. Next a MATLAB code that calculates the decrease in T2* signal intensity over time was used to determine T2* relaxation times over the segmented region. For each pixel, the code fits a curve to the signal intensity vs. time. This can be a time consuming process, so part of my job this week was try different curve fitting algorithms for determining these values.

On Friday I had the opportunity to see a hip revision surgery. The patient volunteered to be part of a study collecting MR images, tissue biopsy, and implant mechanics data and correlating with implant performance and reasons for implant failure. We first had to consent the patient which involved explaining the study and asking them to filling out a questionnaire. During the surgery a sample was collected in an area that appeared to have adverse local tissue reaction in the MRI. Blood samples were also collected to detect any cobalt or chromium from the implant in the patient's blood. It was very informative to see the additional steps taken in research involving human subjects.

Comments

Post a Comment

Popular posts from this blog

Week7

With the end of our summer immersion approaching, I feel sad to say goodbye to all the persons I've met in the hospital during this summer. The past 7 weeks has been very fulfilling and exciting to me, and I will never forget my experience here. As a student will electrical engineering background, I never thought that I can be able to go to a real operation room in the hospital and observe doctors operating on surgeries. But in the past 7 weeks, I was able to go to OR every week, and there's always surgery techniques that are impressing to me. Beside clinical experience, I also had a research project, automatic segmentation of zebra fish neuron images. As I have presented in my previous bloggers, for my project, I have tried several different algorithms. The first is simple thresholding. It is usually used as a preprocessing step in image analysis. The second method is watershed algorithm. It works pretty well, but, it's very sensitive to noise, resulting in over segmenta...
Read more

Week 5: Prostates & Autopsies

Image
This was a fun and interesting week! The prostate biopsy chip slides from last week were evaluated, and more testing was done. On Wednesday and Thursday, two people from the company were here to do some trials with the new chips. This time, real prostate biopsies were taken, and sections were used to evaluate the quality of the tissue. Each chip holds up to 6 biopsies inside the little grooves. The color of the dividers (blue, yellow, and black) orient each sample to distinguish where in the prostate each biopsy came from. It also allows six biopsy cores to be placed on one slide which saves space and resources [1]: Instead of all 12 of the slides on the left (although that is a little excessive), you just need two with the BxChip. It also seems to keep the cores flat and aligned. This is what a magnified core might look like [2]: The tissue fits right inside the little grooves (although it can be slightly difficult to get them in there), and then the whole chip can be ...
Read more

Week 5: Spine Surgeries and Excel Files

Image
On the context of my clinical research project, I continue extracting the different demographic and skeletal specific factors for the patients of our study. I was also able to attend an additional spinal fusion surgery under the supervision of Dr. Kim at HSS. During this week, I was particularly interested in the surgical equipment that he uses for the procedure. Dr. Kim uses the Zimmer Biomet Vitality Spinal Fixation System for his spine surgeries. The components of the system are made from medical grade titanium alloy and medical grade cobalt chromium alloy. In summary, these were the main steps of the process for installing the screws into the patient spine which, personally, was the most interesting part of the procedure.  Initially, the pedicle area of the vertebrae is localized, and an insertion is made in the cortical shell. Then, a probe, included with the system, creates a pathway for the polyaxial pedicle screw to be inserted into the pedicle and the vertebral body. ...
Read more