The following tests and procedures may be required to make an accurate diagnosis of a condition or disorder.
Pathology tests
Blood test
Blood tests form an important part of the diagnostic procedure for a range of medical conditions affecting children and young adults. In some instances, the blood sample will need to be taken on an empty stomach (fasting) - the clinic will advise you in advance if this is the case.
Young children can find blood tests distressing, even though the process is normally relatively quick and painless. It does help for a parent or caregiver to be with the child when the blood sample is being taken. Numbing cream (EMLA) can be used prior to help reduce the pain of the procedure.
The best approach is to explain calmly what will happen and why the blood sample is needed, and to distract them during the short time that the blood is being taken. Where a child is very anxious, there are other strategies that can be employed. It should be collected at a centre that has experience with infants and children.
Urine test
Urine tests are also an important part of the diagnostic process for many conditions affecting children and young adults. If a urine sample cannot be given during your visit, you will be provided with a paediatric urine collection kit including a urine bag.
For babies and very young children only approximately 2ml of urine is required, but it is important that this is not contaminated by for example a soiled nappy. You will receive full instructions on how to use the urine collection kit.
Urea breath test
This test - also referred to by the abbreviation UBT - is used specifically to test for the presence of Helicobacter pylori infection, which may be causing gastritis or a gastric or peptic ulcer. It measures the ability of the bacterium to convert urea into CO2 and ammonia and is the preferred non-invasive testing option for the condition.
The test takes around 20 minutes and involves swallowing a small capsule containing 14C urea, which has a very low level of radioactivity (as a comparison this radioactivity is less than half of the normal daily background radiation exposure).
Around 7 minutes after the capsule has been swallowed, the child will need to blow into a special balloon. Some medications, including antibiotics, can interfere with the test. It is also important not to eat or drink anything during a 4-6 hour period immediately before the test.
Imaging tests
X-ray
X-rays (also called 'radiographs') are sometimes required to help in the diagnosis of various conditions, by showing an image of for example bone structure or the lungs. The process of taking an x-ray generally takes only a few seconds and in some cases the child will be asked to hold their breath and stay still while the x-ray is taken.
After the x-rays have been taken, the radiographer will need 5-10 minutes to check the images and in some cases an x-ray may need to be taken again. Children can generally return home (or to school) immediately after the test as there are no side effects.
Ultrasound
Ultrasound is a safe non-invasive test which creates an image of internal organs and blood vessels within the abdomen. Unlike other tests (e.g. x-rays) it does not use radiation and is used to assess and help diagnose conditions affecting the abdomen and organs in the abdomen, the pelvis or (in boys) the scrotum, or (in girls) the uterus and ovaries.
The test involves sending high frequency sound waves and monitoring the 'echo' which creates an image on a screen. In most cases the patient is lying down and the transducer - the equipment that emits the sounds waves, is placed on the abdomen (or other relevant part of the body) using some water-based gel to ensure accurate readings.
The test generally takes around 30 minutes or less and in some cases your child may need to drink water before the test or not urinate, or sometimes not eat anything during the two hours before the test. We will let you know if any of these requirements apply when we book the test.
MRI
An MRI - Magnetic Resonance Imaging - scan may be required to examine the structure / function of a part of the body to check for indications of any disease, or for pre-operative planning or to aid planning for any follow-up treatment after surgery.
MRI scanning machines use very strong magnetic fields to provide an accurate image of internal organs and tissue in the body. For this reason, there is a questionnaire that should be filled out before the scan and anything metallic that is likely to be affected by the magnetic field must be removed before the scan.
In some cases, a 'contrast injection' may be needed, where a clear fluid in injected via a vein to show blood vessels and blood flow more clearly. Although the machine does make some loud noises during a scan, it is completely painless. Your child will normally need to lie on their back on a narrow flat surface which moves into the 'tunnel' in the machine. They will need to stay perfectly still during the scan.
To avoid any claustrophobia, there are mirrors positioned inside the tunnel to allow the child to see the room, and they can talk with the radiologist via a microphone. If the process is too distressing for your child, they may need to be sedated before the scan.
MRI scans normally take around 30 minutes from start to finish. If no sedation or contrast injection was needed, you and your child can leave immediately after the scan.
In some cases, it may be necessary to avoid food and drink for a short period before the scan - we will advise you if this is necessary.
Diagnostic tests
Hearing tests
There are a number of different hearing tests used to diagnose hearing issues. These include:
- Newborn screening tests (SWISH).
- Audiology tests for children (as part of public screening programs).
- Audiologist hearing assessments - these test hearing and middle ear function for children older than 3.
- Central Auditory Processing Disorder (CAPD) assessment - this test diagnoses specific listening issues affecting speech development where there is no detectable hearing loss.
There are two diagnostic test services available through the Centre for Paediatrics including:
- Skin prick testing.
- Psychological assessment.
Skin prick testing
Also referred to as a 'puncture test' or 'scratch test', the skin prick test is the primary test (although not the only type of test) used to determine whether a particular substance or range of substances are causing an allergic reaction in someone. It is commonly used to diagnose allergies in conditions such as…
- Allergic rhinitis (otherwise known as hay fever).
- Asthma.
- Atopic Dermatitis (eczema).
- Food related allergies.
Skin prick testing works well in detecting reactions caused by airborne allergens, such as pet dander, dust mites, mould and pollen and also works well in detecting food allergies, although these can be more complex and require other tests, such as blood tests.
The test itself is quick (20-40 minutes) and involves using needles to scratch the surface of the skin to introduce very small quantities of each allergen being tested to the skin. This involves at most mild discomfort for a few seconds, and within 15 minutes or so, if there is any reaction to one or more of the allergens being tested, a small itchy red bump (a 'wheal') will appear on the skin. To check that the test is valid, a 'control' substance is used - histamine.
Skin prick tests can be affected by medication, so it is important that the doctor knows about any medication being taken such as antihistamines. In some cases, skin prick tests are not advised, particularly where there has been a previous severe allergic reaction or where very extensive eczema or psoriasis is present and no large enough section of clear skin is present for the test.
Psychological assessment
Psychological assessments are conducted for Autism and Attention Deficit Hyperactivity Disorder.
Autism
Autism and Autism Spectrum Disorders (ASD) affect around 1% of all children to varying degrees from mild to severe. Autism Spectrum Disorders include conditions previously referred to as Autistic Disorder, Asperger's and/or Pervasive Developmental Disorder (not otherwise specified). A positive diagnosis can help parents, family and caregivers to understand the impact of the condition and develop a management and learning support plan, as well as access special government funding for their child.
An early diagnosis helps achieve better outcomes for someone with ASD. The assessment itself may involve a range of medical specialists, for example speech pathologists, occupational therapists and psychologists in addition to the paediatric specialist.
The assessment itself involves an observation schedule component (Autism Diagnostic Observation Schedule - 'ADOS') and a parental interview component (Autism Diagnostic Review - ADI). The assessment process is generally offered for children from 2 years of age.
Attention Deficit Hyperactivity Disorder (ADHD)
Just under 7% of children are diagnosed with ADHD. As with diagnosis of ASD, assessment is generally made by a small group of medical specialists, generally including a Paediatrician, a Psychologist, a Psychiatrist and sometimes an Occupational therapist and/or Speech pathologist.
The process involves a detailed analysis of the child's health record, development and behaviour and interviews with parents, caregivers and teachers. Some other tests, such as memory tests and attention tests may also be recommended.