Radiation Dose Drastically Reduced During Whole Chest MDCT

Emergency physicians who evaluate patients with non-specific chest pain using whole chest multi-detector CT (MDCT) combined with retrospective electrocardiogram (ECG) gating can reduce the patient radiation dose by 71% using MDCT combined with prospective ECG triggering instead, according to a study performed at the University of Washington School of Medicine, Seattle, WA. Prospective ECG triggering enables the CT scanner to monitor the ECG signal of several heart beats in real time and turns the radiation beam on only during alternate beats; retrospective ECG gating also monitors the ECG signal of heartbeats but turns the radiation beam on throughout several consecutive beats, thus delivering more radiation.

Seventy-two emergency department patients with non-specific chest pain were referred for MDCT of the whole chest. A total of 41 patients were scanned using retrospective gating and 31 were scanned using prospective triggering. “The average radiation dose delivered with retrospective gating was approximately 32 mSv; the average radiation dose delivered with prospective triggering was 9 mSv,” said William P. Shuman, MD, lead author of the study. In addition, image quality was slightly better with prospective triggering.

“As our study suggests, patients benefit from MDCT scans using ECG triggering because it delivers a much lower radiation dose—opening the utility of CT to more patients. This lower dose is particularly useful when non-specific indications suggest scanning of the whole chest, such as in the “triple rule-out.” Emergency rooms face severe congestion and cost constraints in today’s world, plus a need for accurate, swift diagnosis. Lower dose, high image quality ECG triggered CT will help significantly on all of those fronts,” said Dr. Shuman.



Less Invasive CT-Scan Based Colorectal Cancer Screening Method Shows Good Accuracy

Newswise — Computed tomographic (CT) colonography may offer patients at increased risk of colorectal cancer an alternative to colonoscopy that is less-invasive, is better-tolerated and has good diagnostic accuracy, according to a study in the June 17 issue of JAMA.

Colorectal cancer (CRC) accounts for approximately 210,000 deaths each year in Europe. CT colonography is a procedure in which a detailed picture of the colon is created by an x-ray machine linked to a computer. It has been shown to be sufficiently accurate in detecting colorectal neoplasia (abnormal growth of cells) and is now considered a valid alternative for CRC screening in the general population. Individuals at increased risk of CRC include those with a first-degree family history of advanced colorectal neoplasia and those with positive results from fecal occult blood tests (FOBTs). “However, adherence to follow-up colonoscopy in these individuals is suboptimal. Being less invasive and thus more tolerable, CT colonography may increase acceptability and adherence to screening, but little information is available on its performance,” the authors write.

Daniele Regge, M.D., of the Institute for Cancer Research and Treatment, Candiolo, Turin, Italy, and colleagues assessed the accuracy of CT colonography in detecting advanced colorectal neoplasia in asymptomatic individuals at increased risk of CRC using colonoscopy as the reference standard. The multicenter study included individuals at increased risk of CRC due to either family history of advanced neoplasia in first-degree relatives, personal history of colorectal adenomas (benign tumors), or positive results from FOBTs. Each participant underwent CT colonography followed by colonoscopy on the same day.

source: Newswise


Knee replacements: Pinpointing the cause of infection

PET accurately detects hard-to-diagnose infections following knee replacement, say researchers at SNM's 56th Annual Meeting

TORONTO—A new study reveals that PET scans accurately detect infections in prosthetic knee joints more than 90 percent of the time, according to researchers at the SNM's 56th Annual Meeting. The findings could represent a significant breakthrough in the treatment of patients who undergo joint replacements. Joint replacements are prone to a number of complications following implantation.

"Infections following joint replacement surgery are very serious, very common and very difficult to distinguish from other problems such as loosening of the prosthetic," said Abass Alavi, professor of Radiology at the University of Pennsylvania, Philadelphia, and the principal investigator of the study. "Our study shows that no other diagnostic tool comes close to PET in accurately diagnosing infection with minimal discomfort for patients. What's more, the broader implication is that PET could eventually be used to successfully detect infections and inflammation for other conditions."

It is estimated that more than one million joint replacements are performed in the United States each year. Infections following implant procedures are difficult to fight because the immune system is unable to destroy bacteria that live on the implanted material. Even after treatment with strong antibiotics, the infections can persist. As a result, it is often necessary to remove prosthetic joints if they become infected.

source: Eurekalert


New Study Demonstrates NanoScan's Novel Contrast Agent May Identify Heart Attack In Waiting

NanoScan Imaging, LLC announced the publication of new data demonstrating the use of its investigational, radio-opaque contrast agent (N1177) to visualize vulnerable plaques that can cause heart attack or stroke using advanced, non-invasive and high-resolution computed tomography (CT) techniques. Results of the study were published in the current issue of the peer-reviewed Journal of Nuclear Medicine (J Nucl Med. 2009 Jun;50(6):959-965).

N1177, an emulsified suspension that is composed of crystalline iodinated particles dispersed with surfactant, is being developed to visualize blood vessels and organs of the body, with particular interest in the arteries, veins and the heart chambers using a technique known as CT angiography (CTA). N1177 also accumulates in macrophage cells allowing for their detection with CT.

source: Medical News Today


Baylor Dallas Opens Nation's First Neurosurgical OR Suite Featuring BrainSUITE IMRI, GE Healthcare MR Surgical Technology

Baylor University Medical Center at Dallas is the first hospital in the country to collaborate with GE Healthcare and BrainLAB to open technically advanced neurosurgery operating room (OR) suites that will allow neurosurgeons to use real-time, intra-operative images of the brain during surgery. The $16.5 million operating suites will be the first to combine the BrainSUITE(R) iMRI and GE Healthcare MR Surgical Suite.

The four operating room suites opened this week and are equipped to use a high-definition magnetic resonance scanner and BrainSUITE iMRI navigation system that will help physicians more accurately view a tumor's location and remove diseased tissue.

source: Medical News Today


Oxygen Plus MRI Might Help Determine Cancer Therapy Success

ScienceDaily (June 3, 2009) — A simple magnetic resonance imaging (MRI) test involving breathing oxygen might help oncologists determine the best treatment for some cancer patients, report researchers at UT Southwestern Medical Center.

Prior research has shown that the amount of oxygen present in a tumor can be a predictor of how well a patient will respond to treatment. Tumors with little oxygen tend to grow stronger and resist both radiotherapy and chemotherapy. Until now, however, the only way to gauge the oxygen level in a tumor, and thus determine which treatment might be more effective, was to insert a huge needle directly into the cancerous tumor.

The new technique, known as BOLD (blood oxygen level dependent) MRI, can detect oxygen levels in tumors without the need for an invasive procedure. The patient need only be able to breathe in oxygen when undergoing an MRI.

source Science Daily (press release)


Toshiba Introduces New Multi-Detector CT Systems

TUSTIN, California — May 20, 2009 — Toshiba America Medical Systems, Inc. today introduces two advanced multi-detector CT systems, the Aquilion® Premium edition and the Aquilion CX edition. The Aquilion Premium rounds out the company's CT portfolio to include a product with 160-detector rows and coverage up to 8 cm in a single rotation. This system is also field-upgradeable to an Aquilion ONE. The Aquilion CX is Toshiba's next generation 64-detector row CT system featuring faster reconstruction standards with up to 28 images per second, Toshiba's proven Quantum Advantage detector technology and a patient couch that can accommodate up to 660 lbs. The Aquilion Premium and Aquilion CX are both available now.

"Toshiba is committed to listening to its customers and providing the right technology mix for the community," said Doug Ryan, senior director, CT Business Unit, Toshiba. "We developed the Aquilion Premium and Aquilion CX to meet our customers' ever-changing medical imaging needs. The Aquilion Premium provides an upgrade path to the Aquilion ONE, the world's first dynamic volume CT, while the Aquilion CX is an advanced 64-detector row CT system that incorporates superior features of the existing Aquilion 64."

source: Toshiba Medical Ststems