Philips Research Technology Backgrounder
Philips SmartExam one-touch MRI software automates MRI scans |
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Magnetic Resonance Imaging (MRI) is a commonly used medical imaging
modality. The first clinical MRI brain scan was performed in 1980,
and since then many improvements have been made in terms of
resolution and speed. Using a broad range of contrast enhancement
options, MRI can acquire detailed 3-D images with sub-millimeter
image resolution. It offers unique capabilities to image
musculoskeletal abnormalities as well as neurological and other soft
tissue lesions of traumatic, inflammative, degenerative or
neoplastic (abnormal proliferation of cells – e.g. tumor) origin.
Scientists at Philips Research have developed software that makes MRI scanners easy to operate, while also shortening the scanning time and increasing the reproducibility of the images obtained. This will reduce the time a patient has to spend in the scanner, as well as leading to better images and improve hospital efficiency. As part of an MRI scan, radiology technicians first perform a low-resolution survey scan that allows them to locate the organ of interest in the patient’s body and plan a detailed scan. It’s a time-consuming process that needs to be done by a highly skilled operator if the detailed scan is to produce the right image for accurate diagnosis of the patient’s condition. The SmartExam system developed by scientists at Philips Research automates the scan planning process, allowing less skilled operators to achieve the same high quality images as highly experienced radiologists. The Philips system learns from an expert radiologist or technician and then automatically applies the acquired knowledge to subsequent scan planning. Improved scan planning leads to better images that are easier to compare with healthy anatomy or a patient history, thereby leading to more reliable diagnoses and improved patient outcomes. SmartExam also speeds up the scan planning process, allowing radiology departments to shorten the examination time per patient and reduce operating costs. SmartExam allows diagnosing clinicians to train the system to produce exactly the type of image they want. Alternatively, a radiology department can have their SmartExam system trained by specialists from all over the world, thereby raising the quality of their MRI scans towards a gold standard. Whichever approach is adopted, SmartExam achieves the desired objective of generating reproducible high-quality MRI scans irrespective of the operator. Scans will always cover the right volume of tissue and show it from the correct angle. The SmartExam system can even annotate images with additional information, such as anatomical landmarks, for post-processing purposes. The expert knowledge and decision making techniques built into SmartExam are designed to be highly rugged to variations between patients, even those that have severe anatomical abnormalities or who have suffered severe trauma. SmartExam is currently available for scans of the brain and knee. However, scientists at Philips Research are currently extending it to include scans of the spine and the heart. Between them, these scans make up the vast majority of the MRI scans currently performed by hospitals. Philips Research is currently looking at the possibility of applying the technology to other types of imaging and of incorporating patient-specific data from other imaging modalities into SmartExam’s decision making processes – for example, using data from molecular imaging to zoom in onto tumors. It is also examining the possibility of optimizing SmartExam’s scan planning for subsequent input to computer aided diagnostic systems. Navigation via landmarks SmartExam uses image recognition techniques to automatically identify landmarks in the human anatomy, such as the contours of the skull or the division between the two halves of the brain, so that it can correctly orient MRI scans. The geometrical positioning of these landmarks is derived from a sample set of scans – for example, scans of male, female, young and old people’s brains – to produce a mean model of the appropriate body part anatomy. These mean models are then integrated into the system. To train SmartExam, an experienced radiologist or technician performs a survey scan to plan a patient’s MRI scan in the conventional way. The expert knowledge represented by her/his selected plan geometry (the selected boundaries and orientation of the scan) is then stored in the SmartExam system’s plan database. During subsequent automated scan planning, the SmartExam system automatically identifies the appropriate landmarks in the patient and compares them to its mean model in order to accurately determine the patient’s position and orientation in the scanner – for example, the angle of their head or the flexion of their knee. It then refers to its stored plan database in order to select and orient the required scan. If necessary, the selected plan can be further refined by the radiologist and added back into the plan database.
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