Imaging, endoscopy and procedures
What each technique shows — and just as importantly, what it cannot show. Preparation, duration, radiation, and what staff need to hear from you before you start.
A technique that costs more does not see more of everything. An MRI shows ligaments an X-ray cannot, and misses fine bone detail an X-ray shows plainly. A normal ECG lasts six seconds and says nothing about the other 86,394 seconds of your day.
Each entry here has a section called "what it cannot show". That is the section worth reading before you agree to anything.
Imaging
X-ray
Fractures and alignment. Lung fields. Air and fluid in cavities. Radio-opaque foreign bodies…
CT scan
Acute bleeding, complex bone injury, detailed lung tissue, the abdomen, and blood vessels wh…
MRI scan
Brain and spinal cord, discs, ligaments, joint cartilage, muscle, liver, pelvis.…
Ultrasound
Liver, gallbladder, kidneys, uterus, ovaries, thyroid, pregnancy, free fluid, blood vessels …
PET-CT
Areas of high metabolic activity across the whole body. Commonly used for staging and assess…
Mammogram
Small calcifications and masses in breast tissue, including ones too small to feel.…
Bone density scan
Bone mineral density, used to track change over years.…
Bone scan
Areas of abnormal bone activity across the whole skeleton in a single study.…
CT coronary angiography
Plaque and narrowing in the coronary arteries, and the amount of calcium.…
Endoscopy
Upper endoscopy (gastroscopy)
Inflammation, ulcers, narrowing, bleeding, mucosal lesions. Biopsies can be taken during the…
Colonoscopy
Polyps, inflammation, ulcers, bleeding, abnormal growths. Polyps are usually removed during …
Laryngoscopy
Whether the vocal cords move normally, and any lesions, nodules, polyps, inflammation or gro…
Cystoscopy
Inflammation, stones, tumours and bleeding points in the bladder and urethra. Biopsies can b…
Procedures
Biopsy
The cellular nature of a lesion. This is the step that gives certainty instead of inference …
Coronary angiography
The site and severity of narrowing in each coronary branch. Ballooning and stenting can be d…
Aspiration / tap
The nature of the fluid: infection, blood, inflammatory fluid, abnormal cells. The analysis …
Function tests
Electrocardiogram
Heart rhythm, arrhythmias happening at the moment of recording, and signs suggesting reduced…
Holter monitor
Intermittent rhythm problems that a clinic recording would miss.…
Lung function test
Whether airways are narrowed, whether the lungs expand poorly, and whether there is improvem…
Echocardiogram
How strongly the heart muscle contracts, valve narrowing or leaking, fluid around the heart,…
Exercise stress test
How the heart responds when it has to work harder, and whether symptoms appear on exertion.…
Hearing test (audiometry)
The degree and frequency pattern of hearing loss, and whether it is conductive or sensorineu…
Electroencephalogram
Abnormal electrical patterns suggesting a tendency to seizures, and some other disorders.…
EMG and nerve conduction study
Which nerve is affected, at which segment, and whether muscle has lost its nerve supply.…