Investigation with a digital tomograph performing a multislice spiral scan allowing the study of body sections with three-dimensional elaborations with 3D reconstructions.
The different body parts examined are:
- skull: brain, skull base, ear.
- head and neck: pharynx, larynx, salivary glands, orbit, sinonasal cavities, lymph nodes.
- thorax: lungs, pleura and organs of the mediastinum.
- chest with high-resolution technique (HRCT) for the study of the pulmonary interstitium.
- abdomen: liver, biliary tract, pancreas, adrenal, kidney, aorta and large abdominal vessels, retroperitoneum.
- male and female pelvis.
- musculoskeletal system: spine, pelvis, various joints.
Study of teeth, mouth and jaw with dedicated software in particular for implantology.
Some of the exams listed above, depending on the diagnosis, requires the administration of intravenous contrast medium.
It is the study of the vessels, especially arteries, with the CT method.
The vascular systems studied are:
- intracranial arterial circle
- epiaortic vessels / supra-aortic trunks (TSA)
- abdominal arteries
- arteries of the upper and lower limbs
- pulmonary arteries
The study always requires the use of the intravenous contrast medium.
The images can be processed by the radiologist with 3D electronic reconstructions such as volume rendering (VR), maximum intensity projection (MIP), multi planar reformation (MPR)
Virtual colonoscopy is a radiological examination that allows the study of the entire surface of the large intestine in a non-invasive way, simulating traditional colonoscopy (optic).
It's a computerized tomography (CT) examination, performed at low dose after introducing air or carbon dioxide into the intestine via a small rectal probe using an automatic insufflator.
The images obtained from the two CT scans, performed in two different decubitus and lasting a few seconds, are processed on a computer with specialized software, producing two-dimensional and three-dimensional images including a 3D reconstruction of the intestinal mucosa in endoscopic vision.
The entire duration of the examination lasts just few minutes (about 10 minutes from the patient's placement on the CT bed until the end of the exam), does not require sedation and, in order to screen for polyps or tumors, is performed low dosage and without contrast agent.
INDICATIONS FOR VIRTUAL COLONOSCOPY
What are the indications for performing a virtual colonoscopy?
Based on the evidence from scientific literature and the guidelines of the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), virtual colonoscopy examinations demand the following main indications.
Previous execution of an incomplete or failed optical colonoscopy (causes eg: intestinal tortuosity, intolerance / pain, severe diverticulosis, obstructions due to masses, colonic spasms, ...).
Elderly or frail patients (comorbidity, very advanced age, difficulty in performing optimal intestinal preparation essential for optical colonoscopy, anticoagulant therapies).
Study of diverticular disease and follow-up of diverticulitis (potentially risky with optical colonoscopy).
Symptomatic patients (gastrointestinal symptoms of alarm for colorectal cancer risk: bleeding, weight loss, pain, hypochromic anemia) who refuse optical colonoscopy.
Other indications: exact location of the tumor site established in colonoscopy before laparoscopic surgery, colon study in patients with ostomy, study of endometriotic localizations known on the intestinal wall.
Prevention, as an individual choice instead of optical colonoscopy.
II-level screening of colorectal cancer in subjects with positive occult blood, or refusing optical colonoscopy, incompleteness and/or failure of the latter.
Surveillance of colorectal cancer patients by associating the administration of intravenous contrast medium for evaluation in a single follow-up examination (chest-abdomen CT) of both colonic and extra-colonic specimens (possible metastases).
Acute abdominal diseases such as diverticulitis or acute inflammatory bowel disease (virtual colonoscopy can be performed two weeks after resolution of the disease).
Recent endoscopic resection and recent biopsy (virtual colonoscopy can be performed after two weeks).
Long history of chronic inflammatory intestinal diseases (ulcerative rectocolitis and Crohn's disease).
Hereditary diseases such as Lynch's syndrome or hereditary non-polyposis colon-rectal cancer (HNPCC), familial adenomatous polyposis (APC-associated polyposis).
Complications are very rare, the most fearful is perforation (extremely rare compared to the traditional colonoscopy and that generally does not provide the need for surgery as opposed to those caused by the endoscope). Other possible and even more rare complications reported in literature, are vagal crises and angina.