CHICAGO – Why not kill two birds with one stone — especially when those fowl are cancer and osteoporosis? That's the theory behind new research which has shown that computed tomography (CT) colonography, also known as virtual colonoscopy, has the potential to screen for both colorectal cancer and osteoporosis in one shot.
Rizwan Aslam, assistant clinical professor of radiology at the University of California San Francisco, reported the findings at the Radiological Society of North America (RSNA; Oak Brook, Illinois) meeting Tuesday.
It was a small retrospective study, just 35 patients, but the results showed agreement between the dual-energy X-ray absorptiometry (DEXA) bone mineral density scores (the standard test for osteoporosis) and the data generated through virtual colonoscopy.
"It's an excellent opportunity to evaluate bone mineral density and the data is there and we should use it," Aslam said during his presentation. "It requires limited training to use the software and there's no additional radiation."
The National Osteoporosis Foundation (Washington) estimates that as many as eight million women in the U.S. have osteoporosis and that by 2020, 14 million people over the age of 50 will have osteoporosis, men included although women comprise the majority. The National Cancer Institute (Bethesda, Maryland) estimates that almost 150,000 men and women were diagnosed colon cancer in 2008 in the U.S. and about 50,000 will die.
"Colon cancer is the third-most-common cancer and the second-leading cause of cancer deaths," Aslam said. "But less than 40% get colon cancer screening. Seventy five million Americans age 50 or older need the screening."
One of the drawbacks is the colon cleansing preparation as well as the need for mild anesthesia which makes for an entire day devoted to the test. With the inclusion of virtual colonoscopy in new screening guidelines, it's hoped that more people have this test performed.
CT colonography begins with an abdominal CT scan, which creates cross-sectional images of all structures in the abdomen including the spine. Computer software then arranges the CT images to create an interior, or "fly-through," view of the colon.
Using the same CT images, another software application can create 3-D images of the spine, allowing bone mineral density to be measured. Low bone mineral density usually is associated with osteoporosis, a disease in which bones become fragile and more likely to break.
In Aslam's study, conducted at the San Francisco Veterans Affairs Hospital (SFVAH), the researchers evaluated the results of 35 patients who underwent CT colonography and bone mineral density testing with DEXA, a standard bone density screening tool. Patients included 30 males and five females ranging in age from 54 to 79.
"We did a retrospective study, mined the data and found patients who also have bone mineral density tests," he said.
The special bone density analysis software was provided by Philips Medical Systems (Andover, Massachusetts). Philips' Bone Mineral Analysis package is a PC-based data analysis system for measuring bone mineral density. It uses a histogram-based method to accurately measure the trabecular bone without the need for an external calibration phantom, according to the company.
"It's off-the-shelf software that any facility can get and use," Aslam said. "These patients are going to be screened for colon cancer already. Potentially, at very little additional cost and no more radiation, they can be screened for bone density. The motivation to do it is up to the patients and doctors."
Judy Yee, MD, a study co-author and chief of CT and GI radiology at the San Francisco VA, pointed out that although the Centers for Medicare & Medicaid Services currently does not provide national coverage of virtual colonoscopy, there was a meeting in November that included an assessment to initiate coverage.
"The results of that assessment will be out in February 2009," she said. "We're still at a stage where we think and hope there will be coverage.
"There has been a significant increase, just over the last several years, with attention now focused on potential for good reimbursement. There already is reimbursement of symptomatic or diagnostic CTC," Yee said.
Portable CT in ER boosts stroke treatment
Many times saving lives isn't about inventing a new device; it's about availability. When a patient arrives in an emergency room (ER) with stroke symptoms, the name of the game is speed. Get that computed tomography (CT) scan fast so the physician can administer life-saving tissue plasminogen activator (tPA), the only true stroke treatment.
But tPA must be administered within a three-hour window.
New research reported at the RSNA meeting has found that the availability of a portable eight-slice CT scanner in an ER can significantly increase the number of stroke victims who receive the life-saving treatment, even if the hospital has a CT scanner somewhere else in the facility.
Results of the study, conducted at North Shore Medical Center (NSMC)-Salem Hospital (Salem, Massachusetts), found that the availability of the CT scanner in the hospital's ER reduced the time between the order and exam from 34 minutes to 15 minutes, a reduction of 54%. Based on simulation modeling, the researchers estimated that this improvement would increase by 86% the number of stroke patients able to be treated with the thrombolytic therapy within the three-hour window.
"The major conundrum of tPA is that many patients are at or beyond the three-hour window," said the study's lead author, David Weinreb, MD, now a resident physician in the department of radiology at Hospital of Saint Raphael (New Haven, Connecticut).
"We are faced with challenge of rapidly managing those patients," he said.
Before a patient receives tPA, a head CT must be performed to ensure that there is no bleeding in the brain. The National Institute of Neurological Disorders and Stroke (Bethesda, Maryland) recommends that patients who arrive in the ER with signs of acute stroke undergo CT imaging within 25 minutes.
For the study, Weinreb and colleagues began using a portable 8-slice head/neck CT scanner called the CereTom, purchased from NeuroLogica (Danvers, Massachusetts) at a cost of $300,000.
During the month prior to the acquisition of the portable scanner and for a four-month period following its installation, researchers measured how much time elapsed between a physician order for a head CT and performance of the scan.
"By decreasing the scan times, we were able to achieve a doubling of tPA eligibility at Salem Hospital," Weinreb said.
The NINDS reports that stroke is the third-leading cause of death in the U.S., and more than 700,000 cases of stroke are diagnosed annually. The most common kind of stroke, ischemic stroke, occurs when a blood clot blocks a blood vessel in the brain.
Patient photos spur radiologists' empathy
Patients rarely know who their radiologist is, until they get the separate bill for services. Likewise, these physicians spend their days viewing body parts, analyzing and diagnosing without ever connecting to the patient.
A young Israeli radiology resident was bothered by this and wondered what would happen if radiologists connected the image of that body part with a face. So he conducted a study of 318 patients who agreed to be photographed prior to their CT exam. The patient photos were added to their files in the hospital's picture archiving and communication system (PACS), a network for storage and retrieval of medical images. The photograph appeared automatically when a patient's file was opened.
"We discovered that when these photos were included, report lengths were longer and the number of incidental findings were greater," said lead author Yehonatan Turner, MD, radiology resident at Shaare Zedek Medical Center (Jerusalem, Israel), who presented his findings as part of the RSNA scientific sessions. "Our study emphasizes approaching the patient as a human being and not as an anonymous case study."
After interpreting the results of the exams, 15 radiologists were given questionnaires to gather data about their experience. All 15 admitted feeling more empathy toward the patients after viewing their photos and agreed that the inclusion of a photograph in a patient's file should be adopted into routine practice.