My third week of placement was spent at the Victoria Hospital. This was the beginning of my special modalities and I spent 2 days in Magnetic Resonance Imaging (MRI) and 2 days in Computed Tomography (CT).

I did some research before going into the MRI suite hoping to have a better understanding of the modality. Prior to attending my placement, my knowledge of the MRI was only basic. Such as the issues surrounding patient safety, patient positioning, how the machine was constructed and how MRI is best used for soft tissue imaging. However, it soon became apparent, that there was a lot more safety issues than I had previously been aware of. The staff put a large emphasis on the importance of knowing all the safety issues involved when working with an MRI machine with regards to both patients and staff. Considerations have to be given to patients wearing makeup, having tattoos and wearing skin patches. Makeup and tattoos are included in the safety protocol due to some having metallic contents within them and skin patches have to be considered due to the possibility of a metal backing which could heat while in the scanner causing burns to the patient. Also pregnant and breast feeding patient are included in the safety check list due to problems that may arise when administering intravenous contrast agents. I was also surprised to learn that patients having an MRI examination can experience an increase in body temperature due to the radio frequency. The repetitive use of RF pulses deposits energy which in turn causes heating in the patient.

Over my two days in the MRI I was shown how to plan and execute routine examinations. Starting with a localiser scan which was done in a coronal plane and called a scout image. They then proceeded with the different scans available such as axial, sagittal and coronal, and also the angles they use for position slices for different examinations. These are not always obvious, for instance, the angulations for a female pelvis vary from a male due to the fact that the patient has a uterus. If the patient has a uterus the angle is such that the slices are parallel to the endometrial cavity. Other idiosyncrasies include the fact that when a T1 scan is performed the fluid shows up as dark, however, when a T2 scan is performed the fluid shows up bright. Scans are also done removing all the fat from the image; these are called a fat saturation scan.
My next two days were in CT. I found this to be much more stimulating and felt very much more in contact with the patients. It is a very busy department and unfortunately suffering from staffing issues. Because of this, staff was unable to spend time explaining procedures to me, and I was only able to observe. CT imaging, which is also referred to as computed axial tomography (CAT), involves the use of rotating x-ray equipment, combined with a digital computer, to obtain images of the body. Using CT imaging, cross sectional images of body organs and tissues are produced. These images can provide detailed views of soft tissue, bone, muscle, and blood vessels, without sacrificing clarity. I observed quite a few examinations which needed intravenous contrast administered and was able to view examinations with a delayed time sequence for an arterial scan and a portal venous scan.
Overall I enjoyed my time in MRI and CT and hope I have gained a better insight to these modalities. There was an interesting case at the beginning of the week when a patient arrived for an MRI after being referred by an ear, nose and throat (ENT) consultant. The patient had a possible lesion and the ENT consultant wanted to see the position and size. It became clear the lesion had possibly erupted through the skull and embedded itself into the anterior part of the brain. The radiologist referred him immediately for a CT and, unfortunately, this proved to be the case and the patient was referred to the Western General. I would have like to have followed this case up, however again due to the shortness of staff, it wasn’t practical for me to pursue this case any further.

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