It is the science that uses medical imaging to diagnose and sometimes also treat diseases within the body.
A variety of imaging techniques such as radiography, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) are used to diagnose and/or treat diseases. Interventional radiology is the performance of (minimally invasive) medical procedures with the guidance of imaging technologies.
The acquisition of medical images is usually carried out by the radiographer, often known as a Radiologic Technologist. The Diagnostic Radiologist, a specially trained doctor, then interprets or "reads" the images and produces a report of their findings and impression or diagnosis. Medical images are stored digitally in the picture archiving and communication system (PACS) where they can be viewed by the radiologist.
The department of Radiology and Imaging in Ruby General Hospital has a competent, experienced and devoted team of doctors and female radiologists and is equipped with the Siemens make Magnatom Esenza MRI and 128 slice CT Scan and an advanced mammography machine for best results.
Radiographs (originally called roentgenographs, named after the discoverer of X-rays, Wilhelm Conrad Röntgen) are produced by transmitting X-rays through a patient. The X-rays are projected through the body onto a detector; an image is formed based on which rays pass through (and are detected) versus those that are absorbed or scattered in the patient (and thus are not detected).
In film-screen radiography, an X-ray tube generates a beam of X-rays, which is aimed at the patient. The X-rays that pass through the patient are filtered through a device called a grid or X-ray filter, to reduce scatter, and strike an undeveloped film, which is held tightly to a screen of light-emitting phosphors in a light-tight cassette. The film is then developed chemically and an image appears on the film.Film-screen radiography is being replaced by phosphor plate radiography but more recently by digital radiography (DR) and the EOS imaging.
Plain radiography was the only imaging modality available during the first 50 years of radiology. Due to its availability, speed, and lower costs compared to other modalities, radiography is often the first-line test of choice in radiologic diagnosis. Also despite the large amount of data in CT scans, MR scans and other digital-based imaging, there are many disease entities in which the classic diagnosis is obtained by plain radiographs. Examples include various types of arthritis and pneumonia, bone tumors (especially benign bone tumors), fractures, congenital skeletal anomalies, etc.
CT imaging uses X-rays in conjunction with computing algorithms to image the body. In CT, an X-ray tube opposite an X-ray detector (or detectors) in a ring-shaped apparatus rotate around a patient, producing a computer-generated cross-sectional image (tomogram). CT is acquired in the axial plane, with coronal and sagittal images produced by computer reconstruction. Radiocontrast agents are often used with CT for enhanced delineation of anatomy. Although radiographs provide higher spatial resolution, CT can detect more subtle variations in attenuation of X-rays (higher contrast resolution). CT exposes the patient to significantly more ionizing radiation than a radiograph.
On spiral multidetector CT uses 128 or more detectors during continuous motion of the patient through the radiation beam to obtain fine detail images in a short exam time. With rapid administration of intravenous contrast during the CT scan, these fine detail images can be reconstructed into three-dimensional (3D) images of carotid, cerebral, coronary or other arteries.
The introduction of computed tomography in the early 1970s revolutionized diagnostic radiology by providing Clinicians with images of real three-dimensional anatomic structures. CT scanning has become the test of choice in diagnosing some urgent and emergent conditions, such as cerebral hemorrhage, pulmonary embolism (clots in the arteries of the lungs), aortic dissection (tearing of the aortic wall), appendicitis, diverticulitis, and obstructing kidney stones. Continuing improvements in CT technology, including faster scanning times and improved resolution, have dramatically increased the accuracy and usefulness of CT scanning, which may partially account for increased use in medical diagnosis.The introduction of computed tomography in the early 1970s revolutionized diagnostic radiology by providing Clinicians with images of real three-dimensional anatomic structures. CT scanning has become the test of choice in diagnosing some urgent and emergent conditions, such as cerebral hemorrhage, pulmonary embolism (clots in the arteries of the lungs), aortic dissection (tearing of the aortic wall), appendicitis, diverticulitis, and obstructing kidney stones. Continuing improvements in CT technology, including faster scanning times and improved resolution, have dramatically increased the accuracy and usefulness of CT scanning, which may partially account for increased use in medical diagnosis.
Medical ultrasonography uses ultrasound (high-frequency sound waves) to visualize soft tissue structures in the body in real time. No ionizing radiation is involved, but the quality of the images obtained using ultrasound is highly dependent on the skill of the person (ultrasonographer) performing the exam and the patient's body size. Examinations of larger, overweight patients may have a decrease in image quality as their subcutaneous fat absorbs more of the sound waves. This results in fewer sound waves penetrating to organs and reflecting back to the transducer, resulting in loss of information and a poorer quality image. Ultrasound is also limited by its inability to image through air pockets (lungs, bowel loops) or bone. Its use in medical imaging has developed mostly within the last 30 years.
Because ultrasound imaging techniques do not employ ionizing radiation to generate images (unlike radiography, and CT scans), they are generally considered safer and are therefore more common in obstetrical imaging. The progression of pregnancies can be thoroughly evaluated with less concern about damage from the techniques employed, allowing early detection and diagnosis of many fetal anomalies. Growth can be assessed over time, important in patients with chronic disease or pregnancy-induced disease, and in multiple pregnancies (twins, triplets, etc.). Color-flow Doppler ultrasound measures the severity of peripheral vascular disease and is used by cardiologists for dynamic evaluation of the heart, heart valves and major vessels. Stenosis, for example, of the carotid arteries may be a warning sign for an impending stroke. A clot, embedded deep in one of the inner veins of the legs, can be found via ultrasound before it dislodges and travels to the lungs, resulting in a potentially fatal pulmonary embolism. Ultrasound is useful as a guide to performing biopsies to minimise damage to surrounding tissues and in drainages such as thoracentesis. Small, portable ultrasound devices now replace peritoneal lavage in trauma wards by non-invasively assessing for the presence of internal bleeding and any internal organ damage.
MRI uses strong magnetic fields to align hydrogen protons within body tissues, then uses a radio signal to disturb the axis of rotation of these nuclei and observes the radio frequency signal generated as the nuclei return to their baseline states. The radio signals are collected by small antennae, called coils, placed near the area of interest. An advantage of MRI is its ability to produce images in axial, coronal, sagittal and multiple oblique planes with equal ease. MRI scans give the best soft tissue contrast of all the imaging modalities. With advances in scanning speed and spatial resolution, and improvements in computer 3D algorithms and hardware, MRI has become an important tool in musculoskeletal radiology and neuroradiology.
One disadvantage is the patient has to hold still for long periods of time in a noisy, cramped space while the imaging is performed. Claustrophobia (fear of closed spaces) severe enough to terminate the MRI exam is reported in up to 5% of patients. Recent improvements in magnet design including stronger magnetic fields (3 teslas), shortening exam times, wider, shorter magnet bores and more open magnet designs, have brought some relief for claustrophobic patients. However, for magnets with equivalent field strengths, there is often a trade-off between image quality and open design. MRI has great benefit in imaging the brain, spine, and musculoskeletal system. The use of MRI is currently contraindicated for patients with pacemakers, cochlear implants, some indwelling medication pumps, certain types of cerebral aneurysm clips, metal fragments in the eyes and some metallic hardware due to the powerful magnetic fields and strong fluctuating radio signals to which the body is exposed.
A Doppler ultrasound is a noninvasive test that can be used to estimate the blood flow through your blood vessels by bouncing high-frequency sound waves (ultrasound) off circulating red blood cells. A regular ultrasound uses sound waves to produce images, but can't show blood flow.
Magnetic resonance cholangiopancreatography (MRCP) is an alternative to diagnostic endoscopic retrograde cholangiopancreatography (ERCP) for investigating biliary obstruction. The use of MRCP, a non-invasive procedure, may prevent the use of unnecessary invasive procedures. MRCP is a type of magnetic resonance imaging (MRI). See separate leaflet called MRI Scan for more details. MRCP produces detailed images of your liver, gallbladder, bile ducts, pancreas and pancreatic duct.
A mammogram is a specialized medical imaging using a low dose X-ray to screen and detect early breast cancer. It aids in the early detection and diagnosis of breast diseases in women. Doctors use a mammogram to look for early signs of breast cancer. It can also be used to screen for breast cancer in women who have no signs or symptoms of the disease or have a lump or any other sign of breast cancer. Mammograms can detect cancer early, when it is most treatable, long before it can be felt. This improves the chances of survival and can help avoid more extensive treatment. Mammograms are also recommended for younger women who have symptoms of breast cancer or who have a high risk of the disease. Mammograms can also be used for a breast tissue or fluid biopsy.
During a mammogram, the breasts are compressed between two firm surfaces to spread out the breast tissue. While under compression the breasts are imaged in multiple planes. Compression of the breasts helps to show subtle abnormalities and decreases the dose of radiation to the breasts. Then an X-ray captures black-and-white images of the breasts that are displayed on a computer screen and examined by a doctor who looks for signs of cancer.
Mammography can be used either for screening or for diagnostic purposes in evaluating a breast lump:
Screening mammography - Screening mammography is used to detect signs of breast cancer in women who have no signs or symptoms or new breast abnormalities. The goal is to detect cancer before clinical signs are noticeable.
Diagnostic mammography - Diagnostic mammography is used to investigate suspicious breast changes, such as a new breast lump, breast pain, an unusual skin appearance, nipple thickening or nipple discharge. It is also used to evaluate abnormal findings or if a change is seen on a screening mammogram. A diagnostic mammogram includes additional mammogram images. Sometimes diagnostic mammograms are used to screen women who were treated for breast cancer in the past.
There is no ideal age to start screening for breast cancer nor when women should begin regular mammograms or how often the tests should be performed. Following, are some general guidelines for when to begin screening mammography :
Women with an average risk of breast cancer - Women may begin mammograms at the age of 40 and have them every one to two years. The American Cancer Society advises women with an average risk of cancer to begin screening mammograms yearly at the age of 45 until the age of 54, and then continue every two years.
Women with a high risk of breast cancer - Women with a high risk of breast cancer may benefit by beginning screening mammograms before the age of 40 after consultation with the doctor about evaluation of an individual’s risk of breast cancer. The risk factors, such as a family history of breast cancer or a history of precancerous breast lesions, may suggest recommendation of Magnetic Resonance Imaging (MRI) in combination with mammograms.
Mammography is the standard approach for early detection of breast cancer. Women, usually, fail to understand breast cancer in its early stages. If there is presence of small tumours in the breast, it can be detected in its initial stages.
Mammography is recommended for women above the age of 40 years and should be done at least once a year. In Ruby General Hospital, we also provide a consultation with a female doctor free of cost.
Though, there are other means for detection of breast cancer, and women above 40 years usually fail to understand whether they have breast cancer, it is recommended to get a mammogram done once a year, since, this detects breast cancer in its initial stages.
Not only mammography, there is an exposure to radiation in all the radiological tests, but, with the help of mammography breast cancer can be detected in its initial stages, facilitating in early treatment and quick recovery. The treatment cost is minimal and there is complete recovery too.
Annual screening mammograms are recommended for women who are 40 years or older, or for younger women with specific risk factors for breast cancer. One need not have to have any signs or symptoms of a breast abnormality in order to receive a screening; they are used for the early detection of breast cancer and other breast health issues. Annual mammograms are the best tool for early detection of breast cancer.