Contraindications to MRI procedure

The principal contraindications of the MRI procedure are mostly related to the presence of metallic implants in a patient. The risks of MRI scans increase with the used field strength. In general, implants are becoming increasingly MR safe and an individual evaluation is carried out for each case.

Absolute Contraindications for the MRI scan:

# Intracranial aneurysm clips (Unless the referring physician is certain that it is made of nonferromagnetic material such as titanium).

# Intra-orbital metal fragments

# Any electrically, magnetically or mechanically activated implants (including cardiac pacemakers, biostimulators, neurostimulators, cochlear implants, and hearing aids).

Relative Contraindications for the MRI scan:

-cochlear implants
-other pacemakers, e.g. for the carotid sinus
-insulin pumps and nerve stimulators
-lead wires or similar wires (MRI Safety risk)
-prosthetic heart valves (in high fields, if dehiscence is suspected)
-haemostatic clips (body)
-non-ferromagnetic stapedial implants

Normal Anatomy of Gall bladder

This ultrasound images show the normal anatomy of the gall bladder taken from different angles of the transducer during sonography. The parts seen here are the fundus, body, neck and the cystic duct.
Note the close relation of the cystic duct to the portal vein. The cystic duct is well seen and appears tortuous in these images.

Obstructive hydrocephalus at Level of foramen of Monro

In CT scan you can find Enlargement of the lateral ventricles with normalsized third and fourth ventricles.

Causes: Colloid cyst; suprasellar tumors (especially craniopharyngioma); intraventricular tumors; arachnoid cysts of the suprasellar cistern; intraventricular hemorrhage (trauma, arteriovenous malformation, hemophilia). Unilateral tumors, such as those arising in the hypothalamus, basal ganglia, or cerebral parenchyma, may obstruct only one side and cause dilatation of the opposite ventricle and mass compression of the ipsilateral ventricle.

Level of the foramen of Monro. (A) Bilateral enlargement of the frontal horns with a normal-sized third ventricle in a patient with a hyperdense colloid cyst (c). (B) Unilateral enlargement of the left frontal horn caused by a tiny hypodense unilateral tumor (arrow).

Happy Holidays from Stanford Hospital & Clinics 2010

Stanford Hospital & Clinics asked its employees what they are thankful for this holiday season, here are their answers.

Stanford Hospital & Clinics wishes everyone a very happy hoiday season and a happy New Year!

Skull (Anterior, Lateral & Mandible) Bony Landmarks

About Technique of Head CT

In order to perform a head CT, the patient is placed on the CT table in a supine position and the tube rotates around the patient in the gantry. In order to prevent unnecessary irradiation of the orbits and especially the lenses, Head CTs are performed at an angle parallel to the base of the skull. Slice thickness may vary, but in general, it is between 5 and 10 mm for a routine Head CT. Intravenous contrast is not routinely used, but may be useful for evaluation of tumors, cerebral infections, and in some cases for the evaluation of stroke patients.

Differences between sutures and fractures in skull x-ray

Linear fracture results from low-energy blunt trauma over a wide surface area of the skull. It runs through the entire thickness of the bone and, by itself, is of little significance except when it runs through a vascular channel, venous sinus groove, or a suture.
In these situations, it may cause epidural hematoma, venous sinus thrombosis and occlusion, and sutural diastasis, respectively. Differences between sutures and fractures are summarized in this Table

Click here for enlargment