Navigation Links
Less is more in cancer imaging
Date:2/11/2010

When one diagnoses a cancer patient, it's important to gather as much information about that person as possible. But who would have thought an accurate diagnosis would depend on throwing some of that information away?

That's key to the technique employed by researchers at Rice University and the University of Texas M.D. Anderson Cancer Center as they bolster the efficiency of scanners that find and track lung and thoracic tumors.

In a paper published last month in The Journal of Nuclear Medicine, a team led by fifth-year Rice graduate student Guoping Chang described an amplitude gating technique that gives physicians a clearer picture of how tumors are responding to treatment.

Chang's technique works in conjunction with PET/CT scanners, commonly used devices that combine two technologies into a single unit.

CT (computed tomography) scanners capture a three-dimensional image of the inside of the body. PET (positron emission tomography) scanners look for a radioactive signature. Before a PET scan, a patient is injected with slightly radioactive molecules tagged to track and adhere to particular cancer cells. As the molecules gather at those cells and decay, they give off a signal that the PET scanner can read.

Together, the scanners give physicians a good idea of a tumor's location and whether it's malignant or benign. Subsequent scans can show how it's responding to treatment.

But there's a problem. While CT scans take relatively quick snapshots, PET scanners need as long as three minutes to capture an image from a single section of the body. Because patients have to breathe, the images don't always correlate well.

"Patients might have lesions located in organs that move due to respiratory motion," said Chang's technical adviser, Osama Mawlawi, an associate professor in the Department of Imaging Physics at M.D. Anderson and an adjunct lecturer in electrical and computer engineering at Rice. "When patients breathe, these lesions will be blurred."

Since physicians can't ask patients to stop breathing for three minutes, Chang found a way to turn a patient's respiratory motion the amplitude into a waveform that serves as a kind of time code.

In the new method, patients are fitted with a flexible band around the chest that records their breathing cycles during the CT scan -- the three-dimensional X-ray taken as the patient slides through the ring-shaped device.

During the subsequent, much longer PET scan, the program creates a "gate," which allows data for specific points in the breathing cycle to pass through and throws away the rest. The program automatically correlates that data to the CT images.

A patient may take 40 breaths during those three minutes. Combining 40 images from a specific point in the breathing cycle say, mid-breath makes for a much sharper image because the tumor will be in pretty much the same spot.

Even better, Mawlawi said, the radiological signal captured by the "gated" PET scan is more coherent. "One of the important aspects of PET imaging is that it can tell us how malignant a lesion is," he said. "The scan gives us a specific number which is correlated with the measured signal intensity; the more accurate this number is, the better the physician's assessment is of a lesion's malignancy and response to treatment."

When someone undergoing therapy is scanned again, he said, "the change in signal intensity not just the size of the lesion tells us whether the patient is responding or not. This is equally important to the quality of the image."

In tests on 13 volunteer patients at M.D. Anderson, information gathered using the technique on 21 tumors was significantly better with Chang's gated technique than without, the paper shows. Patients were not required to modify their breathing in any way, Chang said; this enabled them to be as comfortable as possible during the scan.

Chang, who earned his bachelor's degree in space physics at Beijing University in his native China, expects to defend his dissertation based on his imaging work in March. He became interested in the project shortly after joining Rice's Department of Electrical and Computer Engineering, where Professor John Clark is his academic adviser.

"Being able to image with good resolution means you might be able to catch a small tumor very early," Clark said. "It's a good piece of work."

"It can save people's lives," Chang said. "That's what I want."


'/>"/>

Contact: David Ruth
druth@rice.edu
713-348-6327
Rice University
Source:Eurekalert  

Related medicine news :

1. Hormone May Prevent Aggressive Breast Cancer
2. Few Women at High Risk for Breast Cancer Take Tamoxifen
3. Short-term radiation therapy successful on breast cancer
4. For Some Breast Cancer Patients, Shorter Radiation Works Well
5. The West Clinic Joins Cancer Clinics of Excellence (CCE)
6. Molecular pathways linked to sex, age affect outcomes in lung cancer
7. Certain genetic profiles associated with recurrence-free survival for non-small cell lung cancer
8. Single gene mutation induces endometrial cancer
9. Genes Play Role in Prognosis With Non-Small Cell Lung Cancers
10. UH Case Medical Center researchers publish promising findings for advanced cervical cancer
11. Soft drinks may increase risk of pancreatic cancer
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Less is more in cancer imaging
(Date:5/2/2016)... and Shelton, CT (PRWEB) , ... May 02, 2016 , ... ... President and Owner of New England Low Vision and Blindness (NELV&B) , announces ... add more flexibility and convenience for people with vision impairments to get assessments, hands-on ...
(Date:5/1/2016)... ... May 01, 2016 , ... ... that gives new mothers a better understanding of what to expect after they ... Adjusting to baby postpartum, · The blues and depression, · Breastfeeding beyond postpartum ...
(Date:4/30/2016)... ... April 30, 2016 , ... Create ... Abstract users can distort and manipulate three-dimensional shapes with ease all within ... ranks, point, lines, polygons, polygon texture animation, opacity texture animation, overall shape texture ...
(Date:4/30/2016)... , ... April 30, 2016 ... ... CBC News on April 4th, 2016 questioned the use of the HyProCure ... EOTTS-HyProCure as “a controversial procedure.” EOTTS-HyProCure is a minimally invasive procedure performed, ...
(Date:4/29/2016)... ... April 29, 2016 , ... In an article published ... her enthusiasm for Botox and lip injections, which she underwent in order to feel ... Valley Music and Arts Festival. The article explains that Ms. Mirmelli’s situation is not ...
Breaking Medicine News(10 mins):
(Date:4/28/2016)... April 28, 2016 New ... 2016" is a report that provides an overview ... R&D pipelines by identifying new targets and MOAs ... Company Profiles discussed in this H1 2016 Osteoarthritis ... Srl, AbbVie Inc., Abiogen Pharma S.p.A., Ablynx NV, ...
(Date:4/27/2016)... BASEL , Schweiz, April 27, 2016 ... des Sachs CEO Forums in Zürich ... Phase-II-Studie ihres führenden Wirkstoffkandidaten STR001 zur Erhaltung ... (CI) eingesetzt wurde, bekannt. Für die umfassende ... Deutschland und Frankreich angeworben. STR001 wird während ...
(Date:4/27/2016)... 2016   , ... Recurring Consumable Sales  Clinical sales grow 16% ... (Euronext: MKEA, OTCQX: MKEAY) inventor of Cellvizio®, the multidisciplinary ... the first quarter ended March 31, 2016 and provided ... its commercial strategy. First Quarter 2016 Revenue ...
Breaking Medicine Technology: