Although all parts of the body can be examined, not all lesions can be accurately diagnosed by CT scan, and there are corresponding indications.
CT scan indications
I. Intracranial lesions: intracranial tumors, cranial trauma, cerebrovascular disease, cerebral degenerative diseases, congenital malformations, intracranial infectious diseases, hydrocephalus, metabolic diseases.
The five senses: orbital inflammation, ophthalmoplegia, orbital tumors, orbital trauma and intraorbital foreign bodies; congenital malformations of the outer ear, middle ear, inner ear, temporal bone trauma, otosclerosis, middle ear inflammation, carotid bulla; sinusitis, sinus cysts and polyps, sinus and nasopharyngeal tumors, laryngeal cancer, salivary gland tumors, and inflammatory diseases.
Neck diseases: neck tumors, thyroid tumors, diffuse thyroid tumors, parathyroid tumors.
Chest: pneumonia, tuberculosis, lung tumors, nodular disease, chest trauma, pulmonary vascular disease, pulmonary cysts, pulmonary isolation disease. Mediastinal tumor, vascular lesions and metastatic lesions, pericardial lesions, pleural effusion, pleural mesothelioma, pleural metastases.
V. Abdomen: benign and malignant tumors of liver, gallbladder, spleen, kidney, adrenal gland, pancreas and other organs, infectious diseases, focal hepatic hyperplasia, cirrhosis, abdominal trauma, biliary and urinary stones, identification of obstructive jaundice, common bile duct cyst, congenital lesions of liver, spleen and kidney, tumors of the gastrointestinal tract and the extent and degree of tumor invasion to the periphery.
Retroperitoneal lesions: retroperitoneal tumor, retroperitoneal fibrosis, abdominal aortic aneurysm, etc.
Pelvis: bladder stones, bladder tumors, prostate hyperplasia and tumors, prostate stones, uterine fibroids, uterine cancer, adnexal cysts and tumors.
VIII. Spine and extremities: trauma to the spine and extremities, fracture, presence of fracture fragments in the spinal canal, deformation and stenosis of the spinal canal, inflammation of the spine, extremities, tuberculosis, tumor, degenerative joint disease, disc herniation, etc.
IX. Special examination: three-dimensional reconstruction of maxillofacial fractures, three-dimensional reconstruction of cerebrovascular and aortic vessels, three-phase scan of liver, etc.
The purpose of enhancement scan
I. To distinguish normal or abnormal vascular structures and to clarify pathological vessels.
II. To show the mass and related blood vessels.
III.To improve the detection rate of lesions.
IV. To improve anatomical details.
V. To show the structure of the urinary tract.
Which patients should not use ionic contrast agents
In general, both ionic and non-ionic contrast agents are used for CT-enhanced scans, but non-ionic contrast agents should be used instead of ionic contrast agents in the following cases
I. Allergy or history of allergy to ionic contrast agents (iodine allergy test should be done first if using ionic contrast agents).
II. Intracranial spinal canal tumors, aneurysms, vascular malformations and infections.
III. Those with a history of epilepsy.
IV. Heart, lung, liver and kidney insufficiency.
V. Starvation due to malignant tumors, hypoproteinemia, and water-electrolyte imbalance.
Infants and children and elderly patients over 60 years old.
VII. Patients with diabetes mellitus, hyperthyroidism, eosinophilic tumor.
VIII. Certain special scans (such as dynamic scans of various parts, liver double/three phase scans, CT angiography, etc.).
In conclusion, CT-enhanced scans should be performed in a safe and comfortable manner. Currently, ionic contrast agents have been increasingly replaced by non-ionic contrast agents, and patients are requested to choose contrast agents according to their own conditions and economic status.
Pre-scan preparation
I. For patients with enhanced scans, fast breakfast for morning examiners and Chinese food for afternoon examiners.
For uncooperative patients, including infants and children, patients who are agitated or have lost consciousness, sedation by clinicians is required before examination.
Patients who do abdominal CT scan should take appropriate amount of water containing contrast agent orally before the examination, and patients who do pelvic CT scan should take large amount of water, or water containing contrast agent, and wait until the bladder feels full and distended before CT scan.
Fourth, patients doing CT scan should remove metal objects from the examination area to reduce artifacts.
CT scan instructions
I. Patients who have a CT scan should take the CT examination application form filled out by the clinician, go to the outpatient injection room for an iodine test, then go to the charge office for payment, and then
Patients should make an appointment in the CT room, and then line up for the CT scan within the time agreed in the appointment form in order of priority.
Patients must write down their home address and contact number on the CT examination application form. Anyone who has had a CT examination in our hospital must indicate the original CT number.
Patients who have undergone chest, spine and limb scans should bring their X-ray films and submit them to the doctor on duty so that the doctor can draw up a scan plan with reference to the X-ray films. Patients who have undergone abdominal and pelvic examinations should bring their ultrasound results, clinical laboratory results and other relevant case information (including CT films from outside hospitals) for the doctor’s reference.
IV. Patients who meet the emergency scope are, in principle, done as they come in and a diagnostic report is issued after one hour.
V. All patients who need enhancement scan need to do iodine allergy test first.
VI. Patients can pick up the results from the registration room with their medical records or invoices.