In recent years, the technology available to help physicians detect and diagnose cancer has changed dramatically. More than half of the clinical imaging tools used by Siteman Cancer Center clinicians today to take images of tumors and cancer cells had not been fully developed or did not exist 35 years ago. These advances help radiologists (it seems odd to say doctors, but I can see why you want to make it more general detect cancers earlier and more precisely. X-ray, which produces images of specific parts of the body, is the oldest and still most frequently used imaging. When the detail of X-ray is not enough, state-of-the-art imaging systems get them the information they need.
At Siteman, clinical expertise in diagnostic imaging comes from the acclaimed faculty of Mallinckrodt Institute of Radiology (MIR) at Washington University School of Medicine, an international leader in the imaging of cancer and other diseases and disorders. MIR offers the latest imaging tools for cancer. No other local radiology group is better trained to read your imaging exam. Mallinckrodt radiologists are nationally and internationally recognized for their expertise. They are leaders in the field, editors for professional journals and are subspecialty trained. This means they have additional training and expertise in imaging specific organs and body systems. Because that is all they do, they know how to interpret the subtleties of a scan or other imaging tests and see what others may miss. Subspecialization also means that their interpretation is more detailed and specific, and apt to be more helpful in determining the course of treatment. Their expertise helps you avoid unnecessary imaging exams that can increase your exposure to radiation.
Three-dimensional technology has been applied to many imaging types to enhance existing images and increase the amount of detail available for diagnosis.
Similarly, nuclear medicine can enhance the information obtained from different imaging techniques, such as CT, X-ray, and MRI (see below). Nuclear medicine exams assess the function of organs by using small amounts of radioactive material (radiopharmaceuticals) and a special camera to create images. The radiopharmaceutical is either taken by mouth or injected into the vein and is designed to go to a specific place in the body where there could be disease or an abnormality and is drawn to specific organs, bones or tissues. These areas of the body then emit gamma rays that are detected by the camera. Because nuclear medicine procedures are able to pinpoint molecular activity within the body, they offer the potential to identify disease in its earliest stages, as well as a patient’s immediate response to treatment.
History of Excellence
- The Joanne Knight Breast Health Center at Barnes-Jewish Hospital is one of the original Breast Imaging Centers of Excellence as designated by the American College of Radiology and its radiologists interpret more than 50,000 exams annually. The most up-to-date digital images and imaging techniques are read by breast imaging specialists to get the information doctors need to accurately diagnose and treat a specific cancer.The Breast Health Center offers mammography (screening and diagnostic), tomosynthesis (3D mammography), breast ultrasound and breast magnetic resonance imaging (MRI), as well as image-guided biopsies and needle localizations. The most specialized exams and procedures are available at the Joanne Knight Breast Health Center at the Siteman Cancer Center. Mammography is offered at satellite locations and in a mobile mammography van. Images are all digital for a more accurate diagnosis.
- Washington University radiologist at Siteman are pioneers in the development of a machine combining two often-used types of scanning – PET/CT. It provides high-quality images of body structures — as well as cancer activity in the cells — at the same time in a single scan. Because the scan reveals so much detail, it can pinpoint the smallest cancer that has metastasized, or spread, to other parts of your body. Treatment can then target the cancer in a way that will cause the least amount of damage possible to the rest of the body.
- Similarly, Mallinckrodt had one of the first PET/MR scanners in the world. MRI (magnetic resonance imaging) offers excellent contrast among soft tissues while PET (positron emission tomography) offers excellent images of molecular activity within the body. Therefore, the combination of PET and MRI provides many advantages to the patient for modern medical diagnosis.
- In the last year, Mallinckrodt Institute of Radiology has performed:
- 793,757 diagnostic examinations
- 14,255 nuclear medicine examinations
- 52,805 interventional radiology procedures
Tomosynthesis (3D mammography)
The Breast Health Center is now an all-tomosynthesis site. Tomosynthesis, or 3-D mammography, captures images of the breast from multiple angles. The breast is positioned the same way it is in a conventional mammogram, but only a little pressure is applied — just enough to keep the breast in a stable position during the procedure. The X-ray tube moves in an arc around the breast while 11 images are taken during a 7-second examination. Then the information is sent to a computer, where it is assembled to produce clear, highly focused 3-dimensional images throughout the breast. The call-back rate for additional scans has been reduced by up to 40 percent because radiologists receive all the views they need the first time.
Positron emission tomography (PET)
Developed by MIR researchers in 1972, PET captures tumor cells in action. It is widely used to evaluate patients with various cancers, including esophageal cancer, lung cancer and colorectal cancer. It accurately gauges the severity and spread of cancer by revealing the metabolic activity of tissues using small amounts of a radioactive compound. In some cases, PET imaging gives radiologists a way to detect cancer in early, more treatable stages – sometimes months before a tumor becomes evident through other forms of diagnostic testing. It can also be used to track tumor response to treatment so if a particular treatment is not effective, it can be changed sooner to something more effective.
PET/CT provides high-quality images of body structures — as well as cancer activity in the cells — at the same time in a single scan. Because the scan reveals so much detail, it can pinpoint the smallest cancer that has metastasized, or spread, to other parts of your body. Treatment can then target the cancer in a way that will cause the least amount of damage possible to the rest of the body.
Mallinckrodt Institute had the one of the first CT scanners in North America, and continues to refine and expand applications for this technology. CT is an X-ray procedure that uses a computer to produce a detailed image of a cross-section of the body in thin slices. CT images help verify the presence of kidney and pancreatic cancer, among others. These scanners are also being used at MIR to detect colorectal polyps, which are precancerous growths of the colon. Two-dimensional colonography images are obtained that are then transferred to a specialized computer workstation, where a 3D rendering of the torso is created. Similar 3DCT techniques are used to evaluate the blood vessels and the urinary tract.
A single photon emission computed tomography (SPECT) scan is a type of nuclear imaging test that shows how blood flows to tissues and organs. A SPECT scan integrates two technologies to view your body: computed tomography (CT) combined with a radioactive material or tracer. Before the SPECT scan, a patient is injected with the tracer. A computer collects the information emitted by gamma rays and translates them into two-dimensional and three dimensional images for interpretation by a Nuclear Medicine radiologist.
This technique is used at MIR to determine whether tumor cells in women with breast cancer have an abundance of the protein p-glycoprotein. Women whose tumor cells are covered with this protein may be poor candidates for chemotherapy, and knowing this allows doctors to switch to other forms of treatment.
Magnetic resonance imaging (MRI) is a noninvasive medical test that helps physicians diagnose and treat medical conditions. It uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed pictures of organs, soft tissues, bone and virtually all other internal body structures — all without any radiation exposure. MRI provides very detailed information that is not always visible using other methods. The images can then be examined on a computer monitor by a radiologist. Because of the sharp detail it provides, MRI is a mainstay for viewing the complex anatomy of the brain and detecting tumors there and in other internal organs. Detailed MR images allow physicians to evaluate various parts of the body and determine the presence of certain diseases.
Certain subsets of MRI are moving cancer treatment along in other ways:
- Functional MRI (brain mapping): Mapping the brain is critical for neurosurgeons who not only want to get a detailed fix on areas targeted for surgery but also need to minimize the risks of surgical damage to healthy brain regions that perform essential tasks. Never is this more critical than in the brain and spinal cord.
For many years, neurosurgeons have accomplished the job using a time-intensive approach called functional magnetic resonance imaging (fMRI). Patients perform several simple tasks—saying their name or moving an arm, for example—while their brain is repeatedly scanned. Researchers have now discovered that resting state fMRI is also useful for precisely mapping all of an individual patient’s critical brain networks: speech, motor control and others in one session while the patient lies in the scanner and rests.
- Intraoperative MRI: In the operating room, with the data from the genetic tumor map and the functional MRI, the surgery can commence. However, as a tumor is removed and cerebrospinal fluid drained, the map becomes inaccurate for tumor margins. That’s where real-time intraoperative MRI (iMRI) comes in to give the surgeons the updated information to complete the surgery accurately. A mobile MRI machine located between two surgical suites can be moved into either operating room as needed to remap the remaining tumor.
- MRI-Guided laser interstitial therapy: Washington University neurosurgeons are among the first in the nation to use an MRI-guided, high-intensity laser probe designed especially for the treatment of inoperable brain tumors to “cook” cancer cells deep within the brain while leaving surrounding brain tissue undamaged. Patients who are candidates for this procedure have a small burr hole the diameter of a pencil drilled through their skull. Neurosurgeons then use real-time MR imaging to guide the probe through the brain and into the tumor. Once inside the tumor, the laser discharges highly focused heat energy to coagulate and kill cancer cells. The technology is FDA-approved for several types of brain tumors and metastatic cancers that have spread from other regions of the body, some radiation-resistant tumors, and radiation necrosis due to prior radiation therapy.
Simultaneous PET/MRI is used when the information from both modalities is needed for diagnosis or tumor staging. Tumors that are well-evaluated by MRI, like cervical, ovarian or endometrial for women and colorectal cancers in men and women, are good candidates. Liver tumors or other cancers that have metastasized to the liver lend themselves well to the new technology because MRI-can outline the shape and appearance of the tumors and PET can detect distant lesions that might otherwise be missed. Washington University School of Medicine and Mallinckrodt Institute of Radiology opened the first clinical service in Missouri offering simultaneous PET/MRI in 2014.
Ultrasound is safe and painless, and produces pictures of the inside of the body using sound waves. Ultrasound imaging, also called sonography, involves the use of a small probe and ultrasound gel placed directly on the skin or in a body orifice, such as the colon or the vagina. High-frequency sound waves are transmitted from the probe through the gel into the body. The probe collects the sounds that bounce back and a computer then uses those sound waves to create an image.
Ultrasound examinations do not use ionizing radiation (as used in X-rays), so there is no radiation exposure to the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of the body’s internal organs, as well as blood flowing through blood vessels. Conventional ultrasound displays the images on computer monitors for interpretation by a radiologist. Mallinckrodt has the most advanced ultrasound technology available, including three-dimensional (3-D) ultrasound that formats the sound wave data into 3-D images.
- Endoscopic Ultrasound: A variation of ultrasound, endoscopic ultrasound involves the use of a probe on the end of a fiber-optic endoscope to look at intestinal abnormalities. It allows physicians to differentiate between tumors, cysts and stones in the bile duct, pancreas and other abdominal organs. Endoscopic ultrasound also can visualize rectal tumors and determine whether they have spread.
- Doppler ultrasound is a special type of ultrasound that evaluates blood speed as it flows through a blood vessel. This type of ultrasound is used to view the veins and arteries of the abdominal organs as well as other vessels throughout the body.
Mallinckrodt’s Optical Radiology Laboratory developed wearable technology that helps surgeons more clearly visualize cancer cells. These high-tech glasses make cancer cells glow blue when viewed through the eyewear. Cancer cells are notoriously difficult to see, even under high-powered magnification. The glasses are designed to make it easier for surgeons to distinguish cancer cells from healthy cells, helping to ensure that no stray tumor cells are left behind during surgery.
So far, the goggles have been tested in breast cancer, pancreatic cancer and melanoma surgery. They are not yet available as a standard of care.