Radiology, Ethics and education

Question 1

A 19-year-old female is admitted with left upper abdominal pain and is diagnosed with pancreatitis.

Answer 1

Ranson’s

Ranson’s criteria are used to predict prognosis in acute pancreatitis. They are based on variables measured on admission and again at 48 hours after admission. Bad prognosis on admission include

Age > 55 years
Blood glucose >11 mmol/L
WCC > 16
Serum lactate dehydrogenase (LDH) > 70
Serum aspartate aminotransferase (AST) > 60.
At 48 hours a bad prognosis is predicted by

Serum calcium 10
Haematocrit decreased by > 10%
Base excess > 4
PaO2

Question 2

A 24-year-old male motorcyclist is admitted following an RTA with fractures to the pelvis and lower limbs.

Answer 2

RTS, ISS

The injury severity score (ISS) and the revised trauma score (RTS) are tools used to compare severity of injuries and outcome of interventions in trauma patients.

The ISS uses the AIS90 dictionary to score every injury; the abbreviated scale score in each of six areas are taken

Head
Abdomen and pelvis
Bony pelvis and limbs
Face
Chest 
Body surface.
The squares of the three highest scores are then added together to give the ISS.

The revised trauma score combines coded measurements of

Respiratory rate
Systolic blood pressure and
Glasgow coma scale
to provide a general assessment of physiological derangement. The RTS is calculated from parameters recorded when the patient first arrives in the emergency unit.

Question 3

A 72-year-old patient is admitted to the intensive care unit following abdominal aortic aneurysmal repair.

Answer 3

APACHE II

The APACHE II scoring system is used widely on intensive care units to evaluate chronic ill health. The 12 variables measured include

Temperature
Mean arterial blood pressure
Heart rate
Respiratory rate
PaO2
pH
Serum sodium
Potassium
Creatinine
Haematocrit
White cell count (WCC)
Glasgow coma scale.
It can be used for a variety of disease processes.

Question 4

A 45-year-old male is admitted with marked jaundice, ascites and encephalopathy.

Answer 4

Child’s

The Child-Pugh classification of liver function is used to quantify the degree of liver failure and is used in the selection of patients for liver transplantation. Variables measured include

Ascites
Encephalopathy
Serum albumin
Serum bilirubin and
Prolongation of prothrombin time.

Question 5

A surgical team presented their data demonstrating an increased rate of post-surgical wound infection following gastrointestinal surgery compared with published standards from the Royal College of Surgeons.

Answer 5

Implement change
This group have collected and analysed their data and found a problem. Changes need to be implemented then re-audited.

Identify standards
The standards against which the audit should be compared need to be identified.

The audit cycle comprises an initial needs assessment where the requirements of the department/section/individual are determined and the actual audit itself determined.

Then what is to be audited is decided upon; it is important to identify the standards against which the audit will be compared. These can be national standards or clinical guidelines determined by the national bodies or comparisons can even be made within the department.

Question 6

A vascular team intend to compare their future results for aortic aneurysm repair with national standards.

Answer 6

Data collection
They have specified the standards and can now collect their data.

Once the standards are set data collection is undertaken with selection of retrospective data followed by data analysis. Prospective clinical audit allows for accurate real time accrual of data that reflects current rather than historical practice whereas retrospective audit can act as a historical benchmark.

The results can then be presented, compared to the standards and from this recommendations for improvements/implementation of change are made.

Finally, to assess how effectively these recommendations have been implemented, a re-audit is suggested for some stage in the future.

Question 7

A team wish to audit their departmental results on the use of anticoagulation in patients with atrial fibrillation.

Answer 7

Identify standards
The standards against which the audit should be compared need to be identified.

The audit cycle comprises an initial needs assessment where the requirements of the department/section/individual are determined and the actual audit itself determined.

Then what is to be audited is decided upon; it is important to identify the standards against which the audit will be compared. These can be national standards or clinical guidelines determined by the national bodies or comparisons can even be made within the department.

Once the standards are set data collection is undertaken with selection of retrospective data followed by data analysis. Prospective clinical audit allows for accurate real time accrual of data that reflects current rather than historical practice whereas retrospective audit can act as a historical benchmark.

The results can then be presented, compared to the standards and from this recommendations for improvements/implementation of change are made.

Finally, to assess how effectively these recommendations have been implemented, a re-audit is suggested for some stage in the future.

Question 8

In relation to assessment of a patient’s capacity to make decisions, which one of the following statements is correct?
(Please select 1 option)
A patient who has given power of attorney to a carer no longer has capacity to make decisions about medical care
A person who is unable to believe or understand what you are telling them about a particular treatment may have capacity to refuse the treatment
Assessment of capacity of an elderly person to refuse life-sustaining treatment must be made by a psychogeriatrician
For a person to have capacity, they must be able to retain the information that you give them about the decision they are being asked to make
Once a patient has been found to be mentally incapacitated, capacity can safely be assumed to be impaired in the future

Answer 8

For a person to have capacity, they must be able to retain the information that you give them about the decision they are being asked to make

Capacity to make decisions may fluctuate: a person who has capacity to make one decision may not necessarily have capacity to make another, and a person who lacks capacity to make a decision now may regain the capacity to make that decision as the situation changes.

For a patient to be said to have capacity to make a particular decision, the patient should understand the information they are given about the decision at hand and be able to retain the information long enough to weigh it in the balance and come to a decision for themselves. The assessment of capacity to make a decision does not necessarily have to be made by a psychiatrist or psychogeriatrician although, where there are any doubts about the capacity of a person who is making an important decision, it may be helpful to seek a specialist view.

Many patients make decisions that appear to doctors to be irrational, but this in itself is not an indication of lack of capacity.

Under the Mental Capacity Act 2005, an individual will be able to appoint a person to act as their attorney (Lasting Power of Attorney, LPA) if and when the individual becomes mentally incapacitated in the future. LPAs will be able to make some decisions about health and welfare on behalf of the patient, but only when the patient has lost the capacity to make those decisions for him or herself.

Question 9

Lipoma

Answer 9

The diagnosis is a lipoma.

There is a 3 cm mass related to the anterior surface of the parotid. This mass is barely visible because it has a similar appearance to the overlying fat in the superficial tissue.

There is a fine line related to its anterior surface.

The feature of note is that there are no solid elements and it is of homogeneous low attenuation. It is, therefore, probably benign.

Question 10

Carotid body tumour

Answer 10

The diagnosis is a carotid body tumour.

There is an intensely enhancing mass between the divisions of the internal and external carotid arteries.

These appearances are classical of a carotid body tumour.

Question 11

Klippel Trenaunay syndrome

Answer 11

The diagnosis is Klippel Trenaunay syndrome.

There are elongated, enlarged bones with soft tissue swelling and phleboliths within the soft tissue. This condition is common in the lower limbs.

Question 12

Haemophilia.

Answer 12

The diagnosis is haemophilia.

There is overgrowth of the epiphyseal plates due to associated synovial hyperaemia with gross degenerative changes secondary to the multiple bleeding episodes.

Question 13

Lipoma

Answer 13

The diagnosis is a lipoma.

There is a 3 cm mass related to the anterior surface of the parotid. This mass is barely visible because it has similar appearances to the overlying fat in the superficial tissue. There is a fine line related to its anterior surface.

The feature of note is that there are no solid elements and it is of homogeneous low attenuation. It is therefore benign.

Question 14

Ischaemic colitis

Answer 14

The diagnosis is ischaemic colitis.

There is an abnormal thickening of the distal transverse colon with a paucity of bowel gas in the descending colon. This segment of colon is involved as it is a watershed area at the anastomosis between the superior and inferior mesenteric arteries around the region of the splenic flexure. Here the marginal artery may be small or absent.

A CT scan may confirm the clinical diagnosis

Question 15

Gall bladder carcinoma

Answer 15

The diagnosis is Gall bladder carcinoma.

There is gross dilatation of the intra-hepatic biliary tree with narrowing of the common hepatic duct and only proximal filling of the cystic duct due to a large mass replacing the gall bladder.

Question 16

A 40-year-old complains of pain in the neck following a whiplash injury in road traffic accident. He is aware of marked soreness in the neck and has limited movements.
What is the most significant diagnosis on this film?

Answer 16

Fracture of the facet joint

There is a fracture of the posterior facets of C5 with posterior displacement of the spinous process.

On reviewing the lateral cervical spine, the anterior and posterior line of the vertebral bodies should be in alignment as should be the posterior lamina line connecting the fused portion of the spinous processes.

A line drawn through the posterior laminae is normal and contiguous until it reaches C5 where there is posterior displacement of the posterior lamina line. This is subtle but very important as this requires further investigation and possible surgical fixation.

Question 17

A 78-year-old male dies and is found by his children the following morning (after having seen him alive the night before). His GP attends to certify him dead.
The patient had a known history of ischaemic heart disease and was treated in the local hospital where angiography performed nine months previously for angina had revealed some insignificant coronary artery disease of two vessels for which medical therapy was deemed most appropriate. He had also been diagnosed eight years previously with diabetes mellitus for which he took metformin and gliclazide.
He had seen the practice nurse two weeks ago for review of his diabetes. One month ago he had seen the diabetologists for his annual review and had seen the cardiologists approximately six months ago. He had last seen a partner in the practice six weeks ago for advice concerning driving licence registration.
The family are keen to have a death certificate issued and proceed to cremation. They do not want any post mortem examination.
Which of the following is true with regard to issuing of a death certificate in this scenario?
(Please select 1 option)
The certifying doctor may issue a death certificate
The death needs to be referred to the coroner
The diabetologist can certify the death
The partner in the practice may issue a death certificate
The practice nurse can certify the death

Answer 17

The death needs to be referred to the coroner

A death certificate may be completed if the practitioner has seen the deceased within 14 days of the death (28 days in NI). In this case the patient had been seen six weeks previously by the partner.

Consequently, and in view of the sudden death, the coroner should be informed, although he may decide that in the circumstances reported the doctor may be able to issue a death certificate stating ischaemic heart disease if he deems it appropriate, and on the balance of advice given to him.

Question 18

You intend to undertake a study of patients who have undergone excision of minor lumps and bumps over the last five years.
Specifically you wish to compare postoperative infection rates and also whether there are any differences between the clinical diagnosis and the histological diagnosis between the differing grades of practitioner performing the procedure.
Which of the following statements are correct concerning this study?
(Please select 1 option)
Approval for the study must be obtained from the local ethics committee
If a study has already published with exactly the same concept then this constitutes plagiarism
If such a study has already been published then the investigators must obtain consent from the original authors to replicate their work
The study is flawed in its design and should not be performed
This is an audit and does not require ethical committee approval

Answer 18

Approval for the study must be obtained from the local ethics committee

This is not an audit.

There is no information provided to indicate that there are either any local or national guidelines relating to such a study. Furthermore, there is no information provided to indicate that there is a specific clinical problem to which an audit should be addressed.

Consequently, this is a research study and is a retrospective study. As such, it requires local ethical committee approval.

The study itself seems very reasonable and even if it were published elsewhere it would still be reasonable to perform in the investigator’s practice as the outcomes may be completely different.

Using the same methods as another study is perfectly justifiable, if only to prove the veracity of the original publication.

No consent is required from the original authors if a similar study has already been published.

Question 19

A 22-year-old female is admitted following severe injuries sustained in a road traffic accident.
She is communicative but in shock with low blood pressure and tachycardia. You realise that without a transfusion she will die but she informs you that she has recently become a Jehovah’s Witness and that she adamantly refuses transfusion despite knowledge that she could die.
Her distraught parents tell you that she has only recently joined the Jehovah’s Witnesses and implore you to transfuse her, as they insist that she does not know her own mind.
Together with other intervention which she permits, what is the most appropriate action regarding possible transfusion?
(Please select 1 option)
Declare her incompetent and transfuse
Do not transfuse even if it means that she will die
Get immediate psychiatric intervention to section her and then transfuse
Transfuse immediately, irrespective of the patient’s wishes
Wait until she becomes unconscious and then get consent from her parents to transfuse

Answer 19

Do not transfuse even if it means that she will die

The patient appears competent and has elected to refuse the transfusion.

Despite the parents’ protestation, you must respect the patient’s wishes if, as seems likely here, she is making a reasoned judgement.

If the patient refuses the transfusion then even if she slips into unconsciousness you are not permitted to treat with transfusion, even if it is in her best interests.

Question 20

A report is filed by the registrar to the clinical governance team concerning a patient who developed a DVT after having undergone hip replacement but did not receive any thromboprophylaxis.

Answer 20

Adverse incident reporting

Clinical Governance is the most recent of a series of initiatives mounted by the DoH in its quest to promote more uniform standards of high quality, evidence-based clinical care.

Clinical Governance is a cornerstone of the quality agenda presented in the DoH’s 1998 publication A First Class Service 1 where it is defined as: ‘a framework through which NHS organisations are accountable for continuously improving the quality of their services and safeguarding high standards of care by creating an environment in which excellence in clinical care will flourish.’

The principal components of ‘Clinical Effectiveness’, which was the DoH quality initiative immediately preceding Clinical Governance, were:

Clinical guidelines to inform healthcare professionals about evidence-based practice for discrete clinical topics
Education and training to bring such information to the attention of clinicians and health service managers
Clinical audit to monitor practice and to promote change where indicated.
These three components may be viewed as the principal tools envisaged within the Clinical Effectiveness initiative for implementing high quality, evidence-based care. Now, with Clinical Governance, additional components have been added. Principal among these are:

Continuing professional development (CPD)
Clinical risk management
Formal appraisal of complaints from patients and their families
Revalidation of specialists
Accreditation of services against explicit standards.
Management, IT skills, teaching and ethics courses would be recognised as training rather than CPD.

With regard to the thromboprophylaxis after high risk orthopaedic procedures, the report could be recognised as a ‘white card’ event or adverse event reporting.

The construction of the patient information website would seem to be best suited to R and D activity.

Question 21

A report is submitted concerning the planned construction of a clinic website providing patient and clinic information.

Answer 21

Research and development

Question 22

A circular provides information concerning a one day course on management in the NHS for registrars.

Answer 22

Training

Question 23

A registrar submits a report detailing the results of a comparative study of weight loss in subjects in the weight management clinic with and without clinical psychology support.

Answer 23

Research and development

Question 24

A report indicates that 50% of type 2 diabetics are failing to meet the BHS recommended targets amongst a practice’s diabetic population.

Answer 24

Clinical audit

Clinical governance is the most recent of a series of initiatives mounted by the DoH in its quest to promote more uniform standards of high quality, evidence-based clinical care. The principal components of ‘Clinical Effectiveness’, which was the DoH quality initiative immediately preceding Clinical Governance, were:

Clinical guidelines to inform healthcare professionals about evidence-based practice for discrete clinical topics.
Education and training to bring such information to the attention of clinicians and health service managers.
Clinical audit to monitor practice and to promote change where indicated.
These three components may be viewed as the principal tools envisaged within the Clinical Effectiveness initiative for implementing high quality, evidence-based care. Now, with Clinical Governance, additional components have been added. Principal among these are:

Continuing professional development (CPD)
Clinical risk management
Formal appraisal of complaints from patients and their families
Revalidation of specialists
Accreditation of services against explicit standards.
Therefore, in the examples given,

The completion of a register is part of CPD for the health professionals
A business plan for the appointment of personnel is recognised as a staffing issue
The comparison of clinic outcomes with national standards is part of audit
Patients’ complaints may concern quality of care, waiting times, staff or cleanliness.
Complaints may be verbal or written.

Question 25

A register that details the attendance of health professionals at the weekly postgraduate seminars in hospitals.

Answer 25

Continuous professional development

Question 26

A patient writes in concerning the hour that she waited beyond her actual appointment time.

Answer 26

Complaints procedures

Question 27

A business plan is constructed for the appointment of a research nurse to the asthma clinic.

Answer 27

Staffing and staff management

Question 28

A vascular team assessing the mortality of patients in ITU/HDU following surgery for abdominal aortic aneurysm have retrospectively collected data over the last five years on 133 patients.

Answer 28

Data analysis

The audit cycle comprises an initial needs assessment where the requirements of the department/section/individual are determined and the actual audit itself determined.

Then when what is to be audited is decided upon, it is important to identify the standards against which the audit will be compared. These can be national standards or clinical guidelines determined by the national bodies or even comparisons can be made within the department.

Once the standards are set, data collection is undertaken with selection of retrospective or prospective data followed by data analysis. The results can then be presented, compared with the standards and from this recommendations for improvements/implementation of change are/is made.

Finally, to assess how effectively these recommendations have been implemented, a re-audit is suggested for some stage in the future.

The vascular team having collected data on AAA procedures needs to analyse and then present their data. Finally, having presented their data, the a re-audit of post-operative pain control is now required to see if the recommendations have been implemented.

Question 29

At a recent directorate meeting an ENT consultant has been nominated to undertake the next clinical audit.

Answer 29

Needs assessment

In the case of the ENT team nominated to take on an audit, they have to decide what needs to be audited.

Question 30

A team presented their audit of post-operative analgesia for GI surgery approximately one year ago from which a number of recommendations were made and changes implemented.

Answer 30

Re-audit

Question 31

A 30-year-old male is unconscious on admission following a road traffic accident.
He was the driver of the car and there is the suspicion that he was responsible for the accident in which a passenger of another car died.
In attendance with the patient is his wife who was uninjured in the accident.
The police are keen to obtain a blood sample for alcohol measurement but the patient is incapable of giving consent for this procedure.
What is the most appropriate action in these circumstances?
(Please select 1 option)
Draw a blood sample for later analysis when the patient is competent to consent
Draw a blood sample which can be analysed immediately
Inform the police that you may only take blood samples on medical grounds
Obtain consent from his wife, as next of kin, to draw the blood sample
Refuse to obtain a blood sample until the patient is competent to provide consent

Answer 31

Draw a blood sample for later analysis when the patient is competent to consent

The BMA have published clear guidance on the subject of taking blood specimens from incapacitated drivers (2010).

Following the Police Reform Act, it is no longer necessary to obtain consent from unconscious or incapacitated drivers. However, the sample is not tested until the person regains competence and gives valid consent to it being tested.

A competent person who refuses to allow his or her sample to be tested might be liable to prosecution.

The new law recognises the duty to justice.

Question 32

Which of the following is not true of the physics of ultrasound?
(Please select 1 option)
A thicker piezoelectric crystal has a longer wavelength
A thicker piezoelectric crystal has a lower resonance frequency
Acoustic velocity determines beam reflection
As the angle of incidence increases less sound is reflected
The acoustic refraction of a material is the product of its density and the velocity of sound within it

Answer 32

Acoustic velocity determines beam reflection

The physics of ultrasound appear quite commonly in the examination.

Acoustic Impedance is a product of the density of a material and the speed of sound in that material.

Acoustic impedance mismatch determines beam reflection. A very high impedance mismatch (e.g. muscle/bone or fluid/air) results in very high reflection and very little transmission.

Refraction is the bending of a wave beam when it crosses at an oblique angle the interface of two materials, through which the waves propagate at different velocities.

Question 33

Which of the following is not true of the physics of ultrasound?
(Please select 1 option)
Impedance determines the proportion of sound energy reflected and transmitted at an interface
The size of a pulse generated in an A-scan is a measure of the intensity of the reflected ultrasonic echo
The sound travels poorly through air
The velocity is dependent on the temperature of the material through which it travels
Ultrasound waves pass more slowly through denser materials

Answer 33

Ultrasound waves pass more slowly through denser materials This is the correct answerThis is the correct answer
The velocity of the ultrasound is dependent on the compressibility of the medium through which it travels and the density.

The greater the compressibility the slower the velocity.

Compressibility is affected by temperature and hence this too will affect velocity of ultrasound.

Question 34

Regarding the consent process, which of the following is correct?
(Please select 1 option)
Advanced directives are not legally binding
Any conflict of interest of the surgeon does not need to be declared to the patient in the consent process
Responsibility for consent is with the person taking the consent
The person taking consent must ensure that no undue pressure is being applied to the patient
The process of consent may not be delegated by the operating surgeon

Answer 34

The person taking consent must ensure that no undue pressure is being applied to the patient

In the United Kingdom, the consultant in charge is responsible for obtaining consent.

Obtaining consent may be delegated to a trained and qualified trainee or consultant with sufficient knowledge and understanding of the procedure.

Conflict of interest in an investigation or treatment must be declared to the patient.

The doctor must ensure that no undue pressure is being applied by other bodies, for example, family, employer.

An advanced directive prepared while the patient is still competent is legally binding.

Question 35

Which of the following would give the appearance of cardiomegaly on plain chest x ray?
(Please select 1 option)
Chronic obstructive airway disease (COAD)
Mitral stenosis
Pericardial effusion
Pneumonia
Pulmonary hypertension

Answer 35

Pericardial effusion

Causes of cardiomegaly on x ray include

Myocardial dilatation as in congestive failure
Valvular defects such as aortic regurgitation
Mitral regurgitation (not mitral stenosis as this causes increased pulmonary pressures)
Pericardial effusions
Hypertensive/dilated heart disease.
COAD causes pulmonary hypertension, which in turn produces right ventricular hypertrophy, not cardiomegaly, on x ray.

Question 36

Which of the following is not a recognised consequence of pelvic irradiation?
(Please select 1 option)
	 Carcinoma of the colon
	 Obstructive uropathy
	 Pelvic fractures
	 Pelvic melanomas
	 Small bowel fibrosis

Answer 36

Pelvic melanomas

Pelvic irradiation has been used for both rectal and gynaecological malignancies, particularly so in the 1970s.

However, the late complications include

Increased risk of fractures (recently described)
Metachronous malignancy - colonic
Small bowel fibrosis
Obstructive uropathy
Leg oedema
Fistulae.
Melanomas are not described.

Question 37

Which of the following does not require reporting to the coroner?
(Please select 1 option)
A 42-year-old female is admitted 48 hours after consuming a paracetamol overdose and dies six days later with liver failure
A 62-year-old male with paraplegia is admitted from a residential home. He is malnourished and has bed sores. He dies 20 days after admission with sepsis
A 72-year-old male is admitted to hospital with abdominal pain and fever and dies one week later. The cause of death is unknown
An 82-year-old female is admitted following a fall at home with a fractured neck and femur. She dies three days later with pneumonia
An 82-year-old female is admitted with severe abdominal pain and is found to have a perforated bowel obstruction. She dies two days after the operative procedure with pneumonia and sepsis

Answer 37

An 82-year-old female is admitted with severe abdominal pain and is found to have a perforated bowel obstruction. She dies two days after the operative procedure with pneumonia and sepsis

Increasingly emphasis is placed on the appropriate reporting of deaths, particularly from the enquiries into Shipman, and the Coroner’s Reform Bill.

In fact, it is the duty of the Registrar of Births, Deaths and Marriages to report a death to the coroner, but doctors need to be aware of the circumstances in which a death should be reported.

These include:

The cause of death is unknown
The deceased was not seen by the certifying doctor either after death or within 14 days before death
The death was violent or unnatural
The death may be due to an accident (as in the case of the 82-year-old, with death following accident which may be contributory)
The death may be due to self neglect or neglect by others
The death may be the result of industrial illness or due to the person’s employment
The death may be due to an abortion
The death occurred during an operation or before recovery from anaesthesia
The death may be suicide
The death occurred during or shortly after being taken into police custody.
Not all post-operative deaths need to be reported to the coroner. In the case of the woman with a perforated obstruction the cause of death is clear. However, if there had been a delay in admission (neglect) or delay in surgical referral (potential negligence/neglect) then it would be appropriate to report the death. It may be wise to discuss some post-operative deaths cases with the Coroner’s Officer for reassurance.

Question 38

Which of the following is true concerning intravenous contrast agents used in radiology?
(Please select 1 option)
It is safe to take metformin before a contrast CT scan
Modern, non-ionic contrast agents carry no risk of renal impairment
Patients taking gliclazide should hold off this medication prior to the use of a contrast agent
Patients with asthma should receive prophylactic corticosteroids prior to the use of a contrast agent
The overall incidence of adverse reactions to intravenous contrast agents is 25%

Answer 38

Patients with asthma should receive prophylactic corticosteroids prior to the use of a contrast agent

Intravenous contrast agents increase the diagnostic yield of plain radiography and can be used to delineate the kidneys, ureters and bladder and also blood vessels in angiography.

Modern non-ionic contrast agents have a reduced incidence of side effects.

Side effects have an overall incidence of 5% and include:

Nausea
Vomiting
Hives
Rash
Flushing
Renal impairment
Cardiopulmonary and
Anaphylactic reactions.
The last two can occur with little or no warning and can be fatal.

The use of intravenous contrast agents carries a mortality risk of 1 per 100000 injections.

Patients with asthma are given prophylactic corticosteroids prior to the use of these agents.

The use of contrast agents in patients taking metformin carries a risk of lactic acidosis and should be stopped prior to the use of these agents and should not be restarted until the renal function has returned to normal.

Question 39

Which of the following is true regarding ultrasound scans?
(Please select 1 option)
Are safe in all patients
Fluid appears white
Give better diagnostic images in obese patients
Give good visualisation of the retroperitoneum
Is operator independent

Answer 39

Are safe in all patients

Ultrasound waves from the probe are transmitted through the tissues and are either reflected back, deflected or absorbed at the interfaces between tissue planes. The reflected sound waves make up the image you see.

Ultrasound scans are useful to image soft tissues.

High density tissues (for example, bone) reflect a large amount of the waves and appear white, low density tissue (for example, cyst fluid) appear black.

Bowel gas can prevent adequate examination of the abdomen and the retroperitoneum is often poorly visualised.

In obese patients a large proportion of the sound waves are absorbed and thus scans can be difficult and of low quality in these patients.

Ultrasound is also highly operator dependant. It is, however safe to use in any patient, gives dynamic, real time images, and is relatively cheap and mobile.

Question 40

For demonstrating which of the following is a plain x ray an ineffective technique?
(Please select 1 option)
	 Bone
	 Calcification
	 Fat
	 Lungs
	 Soft tissue

Answer 40

Soft tissue This is the correct answerThis is the correct answer
A chest x ray is an excellent examination.

There is a high contrast between the lucent lungs which contain very little beyond the pulmonary vessels and the thin walled alveoli. Therefore they appear black as they do not impede the beam.

Bones are heavily calcified and so impede the beam as do calcified objects.

Some fat can also be demonstrated on plain films and is responsible for the separation of muscle plains in the soft tissue and the fat density sometimes seen with an ovarian dermoid.

Plain films are very poor at providing details of the soft tissue.