1
Q
What is ultrasound?
A
Sound waves with frequencies higher than the human audible range.
2
Q
What is the upper limit of ultrasound?
A
- Considered to be approximately 20kHz
3
Q
Why is ultrasound preferred to infrasound?
A
Infrasound is too low for us to hear.
4
Q
How has ultrasound developed?
A
There is more bedside ultrasound since the development of machines.
5
Q
What is the pulse-echo principle (how does an ultrasound work)?
A
- The ultrasound probe emits a sound wave and then to receive the echoes from the original wave. It happens multiple times a second.
- Whenever the ultrasound wave passes through a tissue boundary, it can be reflected or will pass through and continue propagating.
- Adjacent tissues with varying densities will reflect more of the sound wave, adjacent tissues with similar densities will reflect less.
- This allows us to form images representing the intensity, depth, and position of something within the body e.g. air in lungs creates a poor image.
6
Q
What is the colour scale of ultrasound?
A
It is greyscale. When ultrasound hists something dense, it is sent back as white colour. If it hits fluid, less matter for reflection so darker (black) area.
7
Q
What is the clinical applications of ultrasound? Sonography
A
- Abdominal
- Urinary
- Trauma -POCUS
- Testicular
- Breast
- Head/Neck
- Vascular
- Cardiology
- Musculo-skeletal (MSK)
- Lungs
- Obstetrics
- Gynaecology
8
Q
What are the benefits of ultrasounds?
A
- No radiation
- No documented side effects in humans
- Usually non-invasive
- Widely Accessible
- Results can be often available immediately - bedside
- “Real-Time” Imaging
- Well tolerated
9
Q
What are the negatives of ultrasounds?
A
- No known side effects
- Ultrasound image quality is highly dependent on patient habitus
- Training is more resource-intensive for departments compared to other modalities
- Effectiveness and accuracy are highly operator dependent
10
Q
Why is it important to have a selection of transducers?
A
- Increased choice of technical variables allows for optimisation of your image.
- There is a choice over sector width, scan depth (Resolution), patient habitus, field overview.
11
Q
What is the major advantage of ultrasound over X-ray/CT in obstetric imaging?
A
- All women in the UK are offered ultrasound screening during pregnancy (12/20 weeks)
- If scans are not needed, they are not given.
12
Q
Describe the 12 weeks obstetric ultrasound
A
- The fetus is shown to be approx. 45-84 mm in length (11 +2 weeks - 14 weeks)
- First routine scan offered to most low-risk pregnancies
- Detects “viability”, number of fetus’, gross anatomy, detectable major abnormalities, the morphology of ovaries.
- Gives an accurate gestational age of the fetus
- Plan the rest of the pregnancy dates
13
Q
What is anencephaly?
A
Not correct formation of the skull
14
Q
What is an omphalocele?
A
Herniation e.g. of organs etc
15
Q
What is the body stalk defect?
A
Occurs in 1:14-30,000
- All of the organs herniate and there is the lower prognosis of this
16
Q
What is the survival rate of someone with a cystic hygroma?
A
10% survival rate
17
Q
What is the risk of miscarriage after 12 weeks in someone with a blighted ovum/missed miscarriage?
A
The risk is very low at 12 weeks
18
Q
What is Down’s syndrome?
A
It is a change in one of the genes in the egg before it is fertilised by the sperm (at the time of conception). This is usually a completely random happening, though it is more common in older mothers. Throughout the world, the frequency of DS is about 3 per 2000 births.
19
Q
What is nuchal translucency?
A
It forms part of the lymphatic system and is screened in fetal development to measure the size of the nuchal pad at the nape of the fetal neck. It should be performed between 11 weeks and 13 weeks + 6 days.
20
Q
What are the futures of testing for down’s syndrome?
A
Non-invasive prenatal testing
21
Q
What is the purpose of the 20-week scan?
A
To identify abnormalities that may indicate the baby has a life-limiting condition, may benefit from antenatal treatment and may require early intervention following delivery.
22
Q
What are the other standard aims of the 20-week scan?
A
- Placenta Localisation
- Fetal Biometry
- Fibroid Monitoring
- Liquor Assessment
23
Q
What is placenta localisation?
A
This is when the placenta sits over the cervix which isn’t desirable
24
Q
Which parts are checked in the obstetric ultrasound?
A
- Skull -> measure head and look at brain specifically the cerebellum
- Bones to look at femur length and abdominal circumference
- The stomach has fluid that may show amniotic fluid in a baby
- Looking to see there is no cleft lip
25
What is spina bifida (looked for at the 20-week scan)?
- Incomplete forming of the lumbar-sacral spine leading to paralysis - incontinence etc.
26
What is achondroplasia (looked for at the 20-week scan)?
- Dwarfism
- Short bones
- Frontal bossing and bowing of long bones
- The thickened soft tissue surrounding the long bones
27
What is clinically significant of the low lying placenta (looked for at the 20-week scan)?
- At the 20 week scan, measure the distance from the lowest edge of the placenta to the internal os of the cervix.
- If the placenta is within 2.5 cm of the cervix, then future scans are required.
- Does not raise higher closer to the due date then a C-section may be required.
28
What is talipes (20-week scan)?
- Club foot
- Ponseti Method
- Unilateral/Bilateral
- Mechanical can be caused by an odd position in the womb
- Talipes is linked to chromosomal abnormalities such as Down's etc.
- If one parent had the condition as a baby, their own baby has a 1 in 30 chance of also having talipes
29
What is the growth scans taken to look for?
- Anhydramnios/ Oligohydramnios
| - Polyhydramnios
30
What is the umbilical artery Doppler assessment?
- Can be used to highlight the effects of pre-eclampsia and intrauterine growth restriction (IUGR)
- Is used more frequently now as is being suggested we can improve perinatal mortality and morbidity
31
What is Anhydramnios/Oligohydramnios?
No fluid (anhy-) or less fluid (oligo-)
32
What is polyhydramnios?
Lots of fluid
- Measure on the pubic symphysis
- Too big can be too much fluid in the stomach
- Most common is gestational diabetes
33
When are pregnant women referred to the GP?
- In the case of lower abdominal/pelvic pain
| - Bleeding, confirmed history of recurrent miscarriage and sometimes due to previous obstetric history issues
34
How is an early pregnancy identified in an obstetric ultrasound?
- The fetal pole is detected as an area of thickening along the periphery of a yolk sac.
- Minimum of 1-2 mm in length for detection (5-6 weeks)
- The cardiac activity should be detected routinely from 4-5mm (6 weeks)
- Transabdominal vs. Transvaginal
- It is a challenging area to work as a lot of women attend the EPU clinic for tough reasons meaning strong counselling skills and empathy
35
What is an ectopic pregnancy?
When an egg implants outside of the uterine cavity.
36
What are the symptoms of ectopic pregnancy?
Associated with severe pain and also bleeding
37
What causes an ectopic pregnancy?
Can be caused by tubal damage (from surgery, PIDS, endometriosis)
38
What is the treatment for ectopic pregnancies?
Treatment depends on the individual, medical or surgical
39
What can multiple pregnancies at once usually cause?
It usually causes delays in the fertilized egg reaching the womb before implanting.
- Dichorionic: Lambda sign - non-identical
- Monochorionic: T Sign
40
What is transfusion syndrome?
When one dominant twin has lots of amniotic fluid whereas the other has less. This can occur in twin to twin; conjoined twin and triplets etc.
41
Does 3D/4D have diagnostic value for pregnancy?
It is used in cleft lift scenarios and can look at the normal fetal face.
42
What are the procedures that can be done to look for baby disorders?
- Chronic Villus Sample = sample of the placenta
| - Amniocentesis = sample of the amniotic fluid
43
What are fibroids?
Consist of fibrous muscular tissue, many eventually grow until the blood supply they receive can no longer support further growth, but others can get very large and require surgical interventions (myomectomy/uterine embolisation/hysterectomy)
44
What can cause fibroids?
Pregnancy
45
What are uterine polyps?
Growths from the inner wall of the womb which extend throughout the cavity and into the cervix and womb.
46
Why is it important to rule out ovarian and endometrial cancer from polyps?
- Usually benign but on rare occasion some can turn cancerous. Surgery would need to be considered. Polyps can mimic cancers.
47
What can an abdominal ultrasound be used for?
- Liver
- Kidneys
- Aorta
- Pancreas
- Spleen
- Gallbladder/Biliary Tree
48
What is an abdominal aortic aneurysm (AAA)?
A section of the abdominal aorta is defined as aneurysmal when reaching 3 cm in AP diameter.
49
How are AAAs monitored?
Monitored in specialised clinics and surgery is often considered once the aneurysm meets 5.5cm in AP diameter. Poor prognosis for aneurysms in the aorta and the limbs where blood will flow.
50
What is EVAR?
Endo Vascular Aortic Repair
51
How does Liver Cirrhosis occur and how does it look on the ultrasound?
Liver cirrhosis: (1) formed when large deposits of fat on the liver (fatty liver) then (2) there is liver fibrosis so scar tissue forms and liver cell injury occurs. (3) This leads to cirrhosis which makes the liver hard and unable to work properly. This can be seen on an ultrasound.
52
How can gallstones form? What is the difference between gallstones and polyps on an ultrasound?
- Usually caused by an imbalance in the chemical makeup within the bile in the gallbladder (high cholesterol/bilirubin)
- Gallstones cause shadows and polyps do not.
53
What is the sonographic murphy's sign?
It is a sign of local inflammation around the gallbladder along with right upper quadrant pain, tenderness, and/or a mass.
54
What can be seen on a urinary tract ultrasound?
- Polycystic Kidney Disease
- Renal Calculi
- Enlarged Prostate
- Ecotopic Kidney
55
What can be seen on a testicular ultrasound?
Lumps such as:
- Varicocele
- Simple Cyst: Epididymal Head
- Hydrocele
- Testicular Cancer
56
Why is it difficult to diagnose breast lumps on a mammogram in women under the age of 35?
Breast tissue tends to be denser, this leads to difficulty with diagnosing the nature of breast lumps on mammograms as differentiation between solid and fluid-filled areas is relatively poor, ultrasound can make the differentiation at an improved rate (about 30% increased).
57
Why are ultrasounds taken on breast tissue lumps?
- Enables care biopsies to be taken on breast lumps to allow for the histological investigation to allow for classification of the lump
58
How can the US be used in vascular tests?
- Used to exclude or confirm the presence of deep vein thrombosis in cases of pain and swelling in the lower limbs
- Used as a screening tool for DVT in post-operative patients and those with known pulmonary embolus (to find the source of the clot)
59
What is a colour flow doppler used for?
Using colour flow doppler can be used to demonstrate that the femoral vein is completely occluded by the lack of colour in this region.
60
When are musculoskeletal ultrasounds used?
- Muscle/tendon tears
- Inflammation
- Nerve Entrapments
- Soft tissue lumps
- Cysts
- Hernias
- Paediatric CHD
- Infant Torticollis (neck twisting)
- Early RA
- Joint effusions
- Injection Guidance (contrast therapeutic)
- and many more...
61
What is POCUS?
Point Of Care UltraSound
- It is the focused assessment with sonography of trauma
- Used at bedsite and A+E
- Take specific images and look for free-fluid around liver and kidney
62
What is FAST?
- An ultrasound scan protocol was undertaken at the time of the presentation of a trauma patient.
- Ultrasound can detect as little as 20ml of free fluid, compared to the 200ml required with plain X-ray.
SEM 4:Cellular Pathology
flashcards
Decks in class (13)
# Cards
-
Cellular Growth Regulation53
-
Cell Death and Cell Damage48
-
Mechanisms of Oncogenesis60
-
Oncogenes and Tumour Suppressor Genes52
-
Tumour Angiogenesis, Invasion, and Metastasis37
-
Primary Cell Culture Technqiues47
-
Cell Culture Techniques46
-
Microscopy32
-
MRI and MRS71
-
Ultrasonagraphy62
-
X-ray, CT, PET41
-
Flow Cytometry - Introduction35
-
Flow Cytometry - Applications15
