Ultrasound
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
Ultrasound is a simple, fast and non-invasive exam that is radiation-free. It uses an ultrasound beam to create an image. It is the preferred exam for front-line investigation of many pathologies, among them those of the liver, gall bladder and bile duct, pancreas, spleen, both kidneys, large blood vessels, pelvic area and certain targeted digestive pathologies such as appendicitis, diverticulitis and illeitis. Doppler allows for a more specific study of the cardiovascular circulation,...
SPIRAL CT SCAN
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
Spiral CT scan is a non-invasive, easy access exam that uses x-rays moving rotationally and multiple detectors for fast data acquisition. Subsequently, fine and multiplanar reconstructions are obtained through computer processing. CT scan has many indications. It allows investigation of the brain, lumbar spine, facial bones, sinus, neck/ORL, thorax, abdomen, pelvis, osteoarticular issues, circulatory system (angio-CT of the carotids, detection of cerebral or aortic aneurysm and pulmonary...
Magnetic resonance imaging (MRI)
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
Magnetic resonance imaging (MRI) is an exam that does not use ionizing radiation, and therefore, no x-rays.
MRI uses radiofrequency waves in a powerful magnetic field to generate images. This exam sometimes requires the injection of an iodine-free contrast medium (Gadolinium), which helps analyze the enhanced lesions and organs. It is a very safe exam.
As opposed to the CT scan, which helps evaluate several organs simultaneously, MRI is a last resort exam that focuses mainly on one...
DIGESTIVE INVESTIGATION
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
CT scan is useful in investigating inflammatory diseases, such as appendicitis (Figure 1), diverticulitis (Figure 2), ileitis or colitis. It is also recommended for investigating intestinal sub-occlusions; to determine their cause (adhesions, obstructive neoplasia, neighboring diseases), specify their location and evaluate signs of intestinal distress. CT scans are also useful in evaluating mesenteric ischemia.
MRI plays a limited role in digestive investigation, being mainly...
ÉVALUATION DE L'INTESTIN GRÊLE (ENTÉRO-TDM / ENTÉRO-IRM)
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
Ces examens d’exploration de l’intestin grêle, qui sont nettement plus performants que le "transit du grêle", utilisent la technique de la tomodensitométrie (Entéro-TDM) ou de l’imagerie par résonance magnétique (Entéro-IRM) pour l’évaluation. Afin de détecter les anomalies intestinales, ces examens nécessitent une distension du grêle qui s’effectue par l’ingestion de 1...
HEPATIC AND BILE DUCT LESIONS
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
Ultrasound is generally used to detect a hepatic lesion. If the lesion is consistent with a cyst, the investigation need not go any further. If it is consistent with hemangioma, ultrasound follow-up will be sufficient. If the type of lesion cannot be determined by ultrasound, such as atypical hemangioma on a steatosic liver, a solid lesion, or if the ultrasound is technically limited with incomplete viewing of the parenchyma, in particular if the patient is suffering from a primary neoplasia,...
RENAL LESION
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
A renal lesion is first evaluated using ultrasound. If it is consistent with a simple cyst, the investigation need not go any further. In the case of a complex cyst, a CT scan is the preferred exam method to evaluate its overall enhancement and the presence or not of enhanced septations or intracystic nodules, in order to classify their neoplastic risk, based on the Bosniak classification system. Magnetic resonance imaging is indicated with patients who are allergic to iodine or who suffer...
ÉVALUATION DES ADÉNOMES SURÉNALIENS
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
L’IRM avec contraste endoveineux peut aider à la caractérisation des adénomes
surrénaliens à faible contenu lipidique.
La plupart des adénomes surrénaliens ont un contenu graisseux intracellulaire. En résonance magnétique, la séquence en phase et hors phase permet la suppression du signal graisseux. Cette séquence, à elle seule et sans contraste endoveineux, permet de diagnostiquer avec confiance,...
PANCREAS ASSESSMENT
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
During the assessment of pancreatitis and its complications, or in efforts to detect a pancreatic tumour dictated by an endocrine assessment or an obstruction of the bile ducts or clinical doubts, a CT scan is the preferred exam, allowing to assess the parenchyma, adjacent vascular structures and adenopathies. MRI/MRCP has proven useful in detecting small lesions (such as a small neuroendocrine lesion) or in characterizing certain tumoral cystic lesions further. Viewing of the pancreatic duct...
RETROPERITONIUM ASSESSMENT
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
A CT scan offers complete viewing of the retroperitonium, as opposed to an ultrasound exam where digestive stacking creates a barrier for ultrasound. Thus, a CT scan is the preferred investigation method for detecting adenopathies, evaluating adrenal glands and finding pathologies of the abdominal aorta, aneurysms and stenoses, and evaluating the origin of large abdominal blood vessels (coeliac artery, mesenteric arteries, renal arteries). MRI is the method of choice for diagnosing...
PELVIC ASSESSMENT
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
Ultrasound is the imaging method of choice for investigating pelvic organs (the uterus, ovaries and the prostate). It allows for an evaluation of the endometrium and the myometrium in detecting fibroma, and of ovarian lesions, which it is able to characterize (simple cystic or complex solid). The assessment of the prostatic parenchyma is performed using endorectal ultrasound. CT scans are used in evaluating a locoregional disease in neoplasia cases.
MRI is indicated when ultrasound results...
INVESTIGATION OF UROLITIASIS (KIDNEY STONES)
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
Investigation of urolitiases is mainly conducted using ultrasound or CT scan (urology scan).
Despite the fact that 90% of urinary litiases are radiopaque, their detection using a single plate on the abdomen is relatively insensitive (in the order of 45%), given the multiple stacking present. Sensitivity to ultrasound can vary from 60 to 80%, depending on whether or not obstructive phenomena are also present, as well as on the size of the urolitiasis and its location. In fact, its...
DYNAMIC FLOOR PELVIC MRI
# Imaging of the abdomen - Ultrasound, CT scan or magnetic resonance imaging
Pelvic floor dysfunction is common among the population. It impacts considerably on quality of life and causes a range of symptoms including incontinence, pelvic pain and constipation. Diagnosing this condition can be challenging, uncomfortable and time consuming. Dynamic Pelvic Magnetic Resonance Imaging (MRI) can greatly aid in the diagnosis of conditions affecting the pelvic floor and help plan their treatment. It can evaluate all three compartments, their organs, ligaments and muscles:...
THE SPIRAL CT SCAN
# Imaging of the vertebral spine - CT scan or magnetic resonance imaging?
Spiral CT scan is a non-invasive, easy access exam that uses x-rays moving rotationally and multiple detectors for fast data acquisition. Subsequently, fine and multiplanar reconstructions are obtained through computer processing. CT scan has many indications. It allows investigation of the brain, lumbar spine, facial bones, sinus, neck/ORL, thorax, abdomen, pelvis, osteoarticular issues, circulatory system (angio-CT of the carotids, detection of cerebral or aortic aneurysm and pulmonary...
MAGNETIC RESONANCE IMAGING (MRI)
# Imaging of the vertebral spine - CT scan or magnetic resonance imaging?
Magnetic resonance imaging (MRI) is a non-invasive exam, without ionizing radiation (without x-rays), that uses radiofrequency waves in a magnetic field to generate images. Thanks to its spatial resolution, it allows the precise evaluation of soft tissues within the spinal canal (vertebral canal), which is a major asset. Moreover, MRI is capable of multiplanar acquisitions. It is a very safe exam that sometimes requires the injection of a contrast medium, known as Gadolinium.
Its main...
ASSESSMENT OF THE CERVICAL OR DORSAL SPINE
# Imaging of the vertebral spine - CT scan or magnetic resonance imaging?
The assessment of the cervical or dorsal spine is far superior using magnetic resonance imaging, as it allows for better differentiation of soft ductal tissues; disks, roots, thecal sac and spinal cord, and can also assess the bone marrow. In the presence of a hernia, bone marrow disease can be predictive of a clinically significant or painful diskal disturbance, as opposed to hernias visible with magnetic resonance imaging, but clinically silent. In the case of degenerative disease, MRI...
LUMBAR SPINE INVESTIGATION
# catgory 1
Investigation of the lumbar spine is begun using simple x-rays that can show spondylolisis/listhesis, osteoporotic fractures, degenerative disease or more rarely, ankylosing spondylitis. It consists in an overall analysis, but given its ease of access, it is useful since it can reveal significant clinical anomalies. The decision to pursue investigation using a CT scan or magnetic resonance imaging depends on many factors, among them accessibility, costs, age of the patient and the...
POST-OPERATIVE LUMBAR SPINE INVESTIGATION
# catgory 1
Magnetic resonance imaging is the preferred exam for evaluating painful postoperative syndromes of the spine, allowing to differentiate between a recurrent hernia and postsurgical fibrosis, and evaluating arachnoiditis phenomena. The literature suggests a minimum waiting period of 8 weeks before MRI monitoring, for better clinico-radiological correlation after resorption of acute postoperative inflammatory phenomena. It also helps evaluate infectious complications, such as spondylitis.
MEDULLARY INVESTIGATION
# Imaging of the vertebral spine - CT scan or magnetic resonance imaging?
Investigation of a medullar pathology, whether cervical, dorsal or of the conus medullaris, is performed using magnetic resonance. It is the only imaging method capable of performing this assessment and offers excellent sensitivity. MRI is used to analyze the signal and enhancement of the lesion, evaluate its extent, as well as its possibly contributive adjacent structures; for example, in the case of spinal stenosis with secondary myelomalacia focus or medullary compression caused by...
INVESTIGATION DES NODULES THYROÏDIENS
# Neck imaging
Nodules Thyroïdiens trouvés fortuitement (NTF) sur des examens non dédiés (CT, IRM, TEP, écho):
Taux de malignité des NTF (variable selon les études):
% de malignité des NTF en autopsie : 36%
% de malignité des NTF biopsiés: 12%
% de malignité de population en générale: 1,6%
% de malignité des NTF au CT/IRM: 0-11%
% de malignité des NTF au TEP: 33-35%
Conduite...
BREAST MRI
# Magnetic resonance imaging of the breast
Breast MR imaging has specific indications . It is complimentary to mammography for high risk patients like those positive for BRCA-1 and BRCA-2 gene mutations and their untested relatives as well as patients suffering from Li-Fraumeni, Cowden, Bannayan-Riley-Ruvalcaba syndromes and their first degree relatives. Patients who received chest radiation therapy treatments between the ages of 10 and 30 years and those with a general 20%increased risk for breast cancer are also eligible. That risk...
MAGNETIC RESONANCE IMAGING OF THE PROSTATE
# Magnetic resonance imaging of the prostate
Prostate cancer is the second most common cancer in Canadian men and the third cause of death among them. One of eight men will suffer from it and one out of 28 will die from it.
One of the most crucial issues is detecting the significant versus less significant prostate cancers. APS levels and prostatic biopsies suffer from major flaws. APS levels may increase in non neoplastic disease. Biopsies might not survey the most agressive part of the neoplasia or might detect non significant...
Arthrography of the Shoulder
# Musculoskeletal imaging
Arthrography of the Shoulder: A Simple Fluoroscopically Guided Approach for Targeting the Rotator Cuff Interval
1. AJR February 2004 vol. 182 no. 2 329-332
American Journal of Roentgenology
Article publié dans "American Journal of Radiology"