PREVENTIVE SCREENING : PROVIDING PEACE OF MIND OR LOOKING FOR TROUBLE ?

Most of us will have direct or indirect experience of ultrasound, computerised (or computed) tomography (CT) or magnetic resonance imaging (MRI) scans. The former being commonly used to check foetal development during pregnancy and the latter two are often used to detect abnormalities or disease such as cancer or degenerative bone disease. However, recent years have seen two significant developments in the use of these forms of scans. First, with the use of scanning technology in preventive screening programmes and second, with such scans being marketed directly to the public as an integral part of health checks offered by commercial health care companies.


Introduction
Most of us will have direct or indirect experience of ultrasound, computerised (or computed) tomography (CT) or magnetic resonance imaging (MRI) scans.The former being commonly used to check foetal development during pregnancy and the latter two are often used to detect abnormalities or disease such as cancer or degenerative bone disease.However, recent years have seen two significant developments in the use of these forms of scans.First, with the use of scanning technology in preventive screening programmes and second, with such scans being marketed directly to the public as an integral part of health checks offered by commercial health care companies.
In this article I focus upon the recent roll-out of the National Abdominal Aortic Aneurysm (AAA) Screening Programme in England, which uses ultrasound scanning to detect AAA disease, 1 and on the use of ultrasound, CT and MRI scans by private companies offering their customers check-ups to test for possible signs of health problems or disease.The latter development has recently been examined by the Nuffield Council on Bioethics in their report, Medical profiling and online medicine: the ethics of 'personalised healthcare' in a consumer age. 2 Finally, I consider some of the practical, ethical and legal implications in relation to the use of scanning in these contexts.
In Part I, I briefly explain what ultrasound, CT and MRI scans involve and their principal risks.In Part II, I examine the National AAA Screening Programme, and the use of scanning technologies in health checks offered by commercial companies, and consider some of the practical and ethical issues and difficulties in relation to these uses of scans.In Part III, I consider possible legal implications in relation to the conduct of scans.

I. Technology Commonly Used in Preventive Screening: Uses and Risks
The National AAA Screening Programme uses ultrasound scanning 3 whilst commercial health care companies offer a variety of checks that make use of ultrasound, CT and MRI technologies. 4It is therefore helpful to begin by considering in simple terms what these methods of scanning do and what the principal risks involved in each form of technology are, before moving on to a more detailed consideration of the practical, ethical and legal implications involved in preventive scanning.5

I.1 Ultrasound Scanning
Ultrasonography, also known as ultrasound scanning, uses high-frequency ultrasound (sound which is of a frequency above 20,000 hertz) to produce pictures of structures within the body, e.g.: organs such as the liver, pancreas and gall bladder; lymph nodes, and the vascular system. 6Since it does not use X-rays, it does not carry the radiation risks associated with CT scanning.Furthermore it is regarded as being safe for use during pregnancy, when it is commonly used to provide images of the developing foetus.Among its many uses are the confirmation of pregnancy, the assessment of gestational age and the detection of foetal abnormality. 7Ultrasonography may produce less satisfactory images in obese patients, because the clarity of the image produced decreases with the depth of tissue which has to be penetrated by the ultrasound. 8In such patients, CT scans are likely to provide more satisfactory images. 9

CT Scanning
CT scanning involves using a computerised X-ray scanner (a CT scanner) to take X-rays of 'slices' of the body and then using a computer to create crosssectional images, which may be displayed in two or three dimensions. 10CT scans have many uses, including the assessment of brain injury and the staging of cancer (assessing the size of a tumour and the extent of any metastases). 11T scanning has advantages over ultrasound scanning in that it provides better defined images in many circumstances, but, since it uses X-rays, it is not suitable to use during pregnancy, and it may expose the patient to quite a high dose of radiation, which may increase their risk of developing radiation-induced cancer.For example, it has been estimated that a CT of the abdomen may expose a patient to a dose of radiation of 8.0 mSv, which is equivalent to 400 chest X-ray examinations or 1217 days of average exposure to natural background radiation. 12There is approximately a one in three lifetime risk of a person in the United Kingdom developing cancer. 13However, data indicates that exposure to radiation via CT scans increases this risk of developing cancer and that the risk further increases with repeat scanning which exposes the patient to higher doses of radiation. 14It has been estimated that exposure to ionising radiation via medical radiological examinations may lead to an additional number of cases of solid tumours amounting to 800 men and 1300 women per year in the United Kingdom, 15 and that one in 270 women aged 40 who undergo CT coronary angiography will develop cancer as a result of their exposure to radiation during the procedure. 16

I.3 MRI Scanning
MRI scanning techniques use a magnetic field to produce images of the body.The powerful magnets within an MRI scanner cause the protons within the nucleus of the hydrogen atoms in the water molecules in the body to align in the same direction.These magnetic nuclei are then subjected to radiofrequency pulses, which causes then to absorb energy and, when the radiofrequency source is switched off, to emit signals in the form of radio waves.Computer analysis is then used "to 'map out' the variation in tissue signals in any plane and to produce images of the tissue." 17It has many uses, particularly to provide images of the brain, spine, limbs and joints and pelvis. 18t is contraindicated for patients who have implants or devices that are either susceptible to magnetic field, or would cause serious harm if they were removed or disabled, e.g.internally implanted defibrillators or heart pacemakers, metal heart valves, or certain types of clip used to repair brain aneurysms. 19

II. Recent Developments in Preventive Screening: Practical and Ethical Implications
As indicated in the introduction, in recent years we have seen two notable developments in the use of scanning technology in preventive screening programmes.First, with the use of ultrasonography in the national AAA screening programme and second, with the direct-to-the-public marketing of scans by commercial health care companies offering private health checks.In this part, I turn to consider the use of scanning technology in this context and to examine possible practical and ethical implications.

II.1 Abdominal aortic aneurysm screening
In 2009 phased implementation of a national abdominal aortic aneurysm (AAA) screening programme was started in England, with the aim of achieving nationwide coverage by 2013. 20Under the scheme, men will be automatically offered an initial NHS ultrasound screening of their abdomen in order to measure the diameter of their aorta in the year that they turn 65. 21 AAA occurs when the wall of the aorta, the main artery supplying blood to the body, becomes weakened and a dilation of the blood vessel occurs in the abdominal region. 22AAAs occur most commonly in the elderly and are six to eight times more common in men. 23Once they form, they tend gradually to become larger, but many with an AAA may experience no symptoms, or merely mild back or abdominal pain.The main health concern is that the AAA may rupture without warning, causing sudden and massive internal bleeding which may lead to the patient dying before he can even be admitted to hospital. 2420 NSC, supra note 1. 21  complications, including haemorrhage, heart attack, limb ischemia, impaired renal function and infection 34 and, even if these do not materialise, the procedure must be regarded as major surgery, from which the patient will take weeks to recover. 35ven the mortality and morbidity rates for repair surgery, as Brownsword and Earnshaw have presciently observed, the AAA screening programme has the "potential to result in the death of an otherwise well individual… If AAA screening is not to be condemned as unnecessarily killing healthy people, it must be scientifically justified and ethically sound." 36Whilst scientific justification may be found in the anticipated significant decrease in deaths from AAA rupture outlined above, there remain significant ethical implications, particularly in relation to informed consent, considered in more depth below.

II.2 Private Health Care Screening
In the last few years a number of commercial private health care providers have begun to market directly to the public a variety of health checks, including scans.These checks may be offered as individual tests or as packages, with the structure and cost of the package varying from company to company, as may be seen from the examples provided in the table below.An examination of the websites of these companies suggests that they are targeting as customers those who might be regarded as the 'worried well', those in middle or late middle age who are currently symptom-less, but are seeking 'peace of mind' about possible major health problems. 69Some of these sites mention that, if detected early, the health problems are easily treatable, 70 and/or suggest periodic repeat scanning. 71he Nuffield Council on Bioethics, in its recent report Medical profiling and online medicine, 72 examines the possible benefits and harms and the ethical implications of the types of scanning which these companies offer directly to the patient. 73These tests and check-ups are not without their potential benefits: they may be seen as providing reassurance, promoting health awareness and patient responsibility for their own health; there may be health benefits if a significant health problem is spotted and can be treated at an early stage, and, if the testing and any subsequent treatment are conducted within the private health care system, there may be a saving of NHS resources. 74wever, as the Nuffield Council identifies, there is potential for CT scans exposing patients to unnecessary and potentially harmful levels of radiation, which may lead to future health problems such as radiation-induced cancer. 75It makes specific recommendations on warning patients about health risks, including radiation risks, in relation to imaging procedures. 76There is also the possibility that scans conducted during these private health checks will disclose many life-threatening diseases can be prevented with quick and simple treatment.Vital Imaging can detect many diseases, including heart, lung and colon conditions before they become serious or untreatable"; iHealth http://www.ihealthltd.com/ourbeliefs.html(13 December 2010): "Most healthcare systems of today are effectively sick care systems where meaningful care often only begins once an individual is symptomatic, often with conditions that could have been prevented.Prevention can help identify risk factors and pick up abnormalities early, leading to enhanced outcomes.For all key killer diseases, preventive diagnostics can help with early identification and risk assessment." 71Prescan offers a 'Repeat Total Body Scan': All you have to do is notify us that you would like to have periodic examinations, and we will do the rest.You will receive an invitation informing you of the time and date of your periodical check-up.Your personal profile will be re-examined each year and will be tailored to suit your needs.As a loyal Prescan customer you will receive a discount.http://www.prescan.co.uk/examinations/regular-examination (13 December 2010). 72Nuffield, supra, n.2. 73Ibid., Ch.  76 Nuffield, supra, note 2, para.10.33,where it is recommended that information should be "prominently available in law language" of "any physical or other harms or risks of the imaging procedure (including relating to the radiological risks of CT scans depending on how much of the body is scanned)."It is recommended that the commercial provision of CT scans "sold as a 'health check' to asymptomatic individuals" be prohibited on the basis that "Any benefits for asymptomatic people do not justify the potential for harms caused as a consequence" (para.10.26).It is also recommended that publicly-funded health service websites should include information about commercial body imaging services, including "the potential risks and benefits, including the possibility of further inventions being recommended and their implications": see para.There is, of course, the possibility that patients will be pleased to have discovered that they have a health abnormality and welcome the chance to be able to obtain treatment before symptoms develop, 81 but the concern is that learning of an incidentalomas will cause stress and upset, perhaps leading to a more serious psychological condition. 82The diagnosis may reveal a condition which cannot be treated, so that the patient is left with the knowledge that they have a serious health condition, but that nothing can be done about it. 83It may also lead to a 'false positive' result, identifying as harmful a benign condition or an abnormality which would never in fact cause health problems, leading the patient to undergo unnecessary further tests and/or treatment. 84ternatively, where conditions or diseases are difficult to identify, scans may lead to 'false negative' results, which leave the patient with the impression that 77 Nuffield, supra note 2, para.10.all is well when, in fact, a significant health problem remains, and the erroneous reassurance which this may provide may lead to future symptoms being ignored. 85Apart from the cost of private body scans or health check-ups and any subsequent private treatment, there may be additional future financial implications for the patient: for example it may affect their insurability, the level of their premiums or, if they fail to disclose such tests or the results, the validity of any insurance claim subsequently made. 86

II.3 Ethical Implications
Both the rolling out of the National AAA Screening Programme and the provision of body scans by commercial companies directly to the public present ethical difficulties.First, there is the issue of whether the preventive screening procedure involved causes harm to the patient.The principle of nonmaleficence, enshrined in the maxim, "Above all, do no harm", 87 is a key concept in medical ethics and imposes on medical practitioners an obligation not merely not to inflict harm on their patients, but also not to expose them to unjustified risks of harm. 88In relation to whole-body CT scans for asymptomatic patients a strong case may be made that, because of the high radiation risks involved in these scans it is ethically permissible to prohibit them because of their potential to cause serious physical harm.The potential harms which such scans may cause by exposing patients to relatively high doses of radiation appear to outweigh any health benefits to such an extent that state action to prohibit such scans may be justified to prevent individual harm and wider public harm such as the imposition of the costs of radiation-induced cancer treatment upon public health care systems. 89Such an approach conflicts with individual autonomy, but as Burger has observed, the potential risks of fullbody CT scans are such that interference with a patient's right to pursue their interests in the way that they see fit may be ethically justified, even in the case of patients who could be fully informed of the health implications: The Nuffield Council on Bioethics has accepted such an approach in concluding that coercive state powers should be used to prohibit this type of imaging. 91n relation to the NHS AAA screening programme and other forms of scanning, a pressing ethical consideration is whether the informed consent of the patient is being obtained in relation to the procedure.In the case of the state-funded NHS AAA screening programme, as Brownsword and Earnshaw have observed, the responsibility "to ensure that invited participants have a sufficient understanding of both the risks and the benefits" 92 falls not merely upon those treating the patient, but upon the State and its agents. 93They suggest that the programme is ethically justified so long as best endeavours are made to ensure that people invited to participate in the programme are making free and informed decisions, 94 including making it "unequivocally clear from the outset that submission to AAA screening is entirely at the option of the man." 95owever, as they recognise, the obtaining of informed consent in this context is "far from a formality." 96me of the main difficulties are highlighted in an American study of patients by Berman et al., 97 which investigated communication between surgeons and patients and the issue of informed consent in relation to AAA repair.This study found that patients who had been informed that they had AAA disease tended to see surgery as their only option, lacking a balanced appreciation of the likely progression of their condition, the risks and causes of rupture and the risks of surgery.The poor understanding of the risks involved was reflected in the comments made by participants in the study.For example, one patient mistakenly believed that her everyday activities might lead to an AAA rupture: "I felt like all of a sudden I was going to bump into something, I'm just going to bleed out like a stuck pig, and it was terrifying", 98 whilst another felt that he had to have surgery because he felt as if he was 'walking on eggshells for fear the thing would burst'. 99As O'Neill has emphasised, merely providing the patient with additional information does not necessarily make them better informed about their options, 100 and care needs to be taken to try to ensure that patients are making free and informed decisions.One way to do this might be to make more use of interactive aids to support decision-making: following a recent pilot study, Berman et al. have suggested that the use of an evidencebased personalised interactive computer-based decision support tool might help patients to become better informed about the relative risks and benefits involved in treatment options. 101 relation to private preventive scanning, concerns also arise regarding the level of information being provided to patients and whether they are being adequately advised as to the benefits and risks of the testing techniques being used, particularly as commercial providers are not required to provide the same level of information as the NHS in relation to screening tests: "...NHS screening programmes are required to provide advisory information to people before they take a test, concerning the risks and benefits, the potential for diagnostic errors and the implications of any subsequent investigations or treatment. 102owever, this information is not required for screening tests offered outside the NHS." 103 The Nuffield Council was unhappy with the information being given to patients by the providers of commercial health checks and concerned about whether sufficient impartial information was being conveyed to enable the patient to make informed choices. 104In an attempt to ensure that ethical requirements in relation to patients making informed decisions about their health care are met, they have recommended that companies providing direct-to-consumer body imaging to asymptomatic customers be regulated.They are also required to provide specific information about the risks and benefits of their services and of possible outcomes before the customer commits to purchase a service, 105 and to recommend that independent information about such services be provided on publicly-funded health service websites. 106Such information could perhaps be made available on the current NHS Choices website, which already provides accessible patient information on a variety of health topics, including private cosmetic surgery both in the UK and abroad. 107

III. Legal Implications
As the Nuffield Council noted, there is currently no overarching regulatory framework which applies to commercial providers of preventive body scanning services in the UK. 108As we shall see below, the provision of CT scans is subject to the regulatory framework governing the use of ionising radiation but, of course, both NHS and private providers of healthcare scanning services are subject to the ordinary law of negligence.Commercial health care companies will additionally have a contractual arrangement with those purchasing scanning services, and these contracts will contain at least an implied term that the scan will be conducted with reasonable care and skill,109 although in practical terms this appears to be "indistinguishable from the duty to take reasonable care in the tort of negligence". 110In this part I also consider some of the circumstances in which civil liability might arise.

III.1 Regulatory Framework
There are clear legal implications in relation to the use of CT scans because they use ionising radiation.Under the Ionising Radiation (Medical Exposure) Regulations 2000 (IR(ME)R), 111 which apply to private companies conducting such scans, 112 providers of such scans are required inter alia to "ensure that doses are kept as low as reasonably practicable consistent with the intended purpose", 113 that exposures to ionising radiation are individually planned 114 , authorised by a medical practitioner 115 , and that medical exposures are justified as "showing sufficient net benefit" 116 giving appropriate weight to: (a) the specific objectives of the exposure and the characteristics of the individual involved; (b) the total potential diagnostic or therapeutic benefits, including the direct health benefits to the individual and the benefits to society, of the exposure; (c) the individual detriment that the exposure may cause; and (d) the efficacy, benefits and risk of available alternative techniques having the same objective but involving no or less exposure to ionising radiation. 117 breach of these Regulations by a commercial provider would amount to a criminal offence. 118The Care Quality Commission, the organisation currently responsible for the enforcement of IR(ME)R, 119 has indicated that it proposes to make the inspection of organisations that provide CT scanning services to asymptomatic patients a priority in 2011/2012. 120It remains to be seen whether the Care Quality Commission acts upon this statement of intent.
The Nuffield Council expressed concern that commercial companies selling imaging services directly to consumers were not subject to any regulatory provisions other than IR(ME)R and recommended that these companies should be subject to regulation by an appropriate regulator, such as the Care Quality Commission. 121Under the Health and Social Care Act 2008 (Regulated Activities) Regulations 2010, 122 from the 1 st October 2010 organisations that provide "diagnostic and screening procedures involving the use of X-Rays and other methods in order to examine the body by the use of radiation, ultrasound or magnetic resonance imaging" 123 will, unless they fall within one of the exemptions provided for in the regulations, 124 have to register with the Care Quality Commission. 125The regulations impose a number of requirements intended to safeguard the health, safety and welfare of service users, including requirements in relation to the safety of equipment,126 the obtaining of consent from patients,127 and accurate record keeping. 128Breach of these requirements is a criminal offence. 129These regulations will help to ensure that appropriate standards of quality and safety are met by the private providers of scanning services, although their effectiveness is likely to depend on how effectively they are policed by the Care Quality Commission.

III.2 Claims in Relation to Diagnosis Following Scans
Litigation may arise when diagnostic errors are made.There have been welldocumented cases in which failures by medical practitioners to detect the signs of a disease on time or at all during the course of screening or scanning programmes have led to actions in negligence.For example, the notorious Gisborne cervical smear scandal 130 in New Zealand, which subsequently led to the litigation in A v. Bottrill, 131 arose out of the widespread misreading of cervical smear tests: a subsequent investigation into the work of the pathologist, Dr. Bottrill, disclosed that he had a false negative reporting rate of 50 percent or higher. 132Litigation also arose out of the negligent failure to identify potentially cancerous cell changes in cervical smears in Penney v. East Kent Health Authority. 133In relation to ultrasound scanning, successful reported claims have arisen in the context of negligent failures to detect prenatal abnormalities, most notably in the cases of Pithers v. Leeds Teaching Hospitals NHS Trust, 134 and Lillywhite v. University College London Hospitals' NHS Trust, 135 both of which are considered in more detail below.
Somewhat ironically, since they are aimed at the early detection of abnormalities and the prevention of severe patient morbidity or mortality, screening programmes for breast and cervical cancer appear to have led to an increase in litigation. 136It has been suggested that this may be due to a failure by the patient to appreciate the limitations of screening, 137 or because patients and their families may have unrealistic and/or erroneous expectations of what scanning can achieve, believing either that scanning prevents, rather than detects, cancer, or that cancers which arise in between scans must have been negligently 'missed' by the scanner. 138ether such a pattern will be repeated in relation to the AAA screening programme remains to be seen, but even before the introduction of the national screening programme in 2009, complaints in relation to vascular surgery were a source of litigation within the NHS.For example, a study by Markides et al. 139 on legal claims made in respect of vascular surgery, identified 395 claims being made to the National Health Service Litigation Authority (NHSLA) 140 between 1995 and 2007.Of these, 160 claims were successful, with claimants receiving compensation (ranging from minimal damages to in excess of £650,000).Of the successful cases, 10 (less than one case per year) involved AAA surgery, but failure or delay in relation to diagnosis and/or treatment, which led to serious complications, was the subject of complaint in seven of the successful cases. 141In relation to screening for AAA, I suggest that fears that the introduction of the national scanning programme will lead to an increase in the number of elderly men being diagnosed with an AAA and thus to an increase in the number of elective surgical AAA repairs that are likely to follow such diagnoses, are not without foundation.
In relation to the standard of care required from those conducting scans, English law requires that a doctor exercises the ordinary skill of their specialty: a doctor "is not guilty of negligence if he has acted in accordance with a practice accepted as proper by a responsible body of medical men skilled in that particular art." 142This is an established and well-known legal principle known as the Bolam test.In the context of routine ultrasound, MRI or CT scanning, the standard is that of a reasonably competent sonologist or radiologist exercising reasonable care at the time when the scan was being conducted.For example, in B v South Tyneside Health Care NHS Trust, 143 the claimant failed to establish a breach of duty because, from the evidence in the case, it was unlikely that the abnormality in question would have been observable at the time of the scan and, even if it had been visible, a sonographer exercising reasonable care could have failed to see an apparent abnormality.
A similar outcome arose in Morris v. University Hospital Birmingham NHS Foundation Trust, 144 where it was held that the defendant's radiologist had not been negligent in failing to detect an abnormally swollen lachrymal gland (which contained a tumour) in a CT brain scan conducted to exclude the possibility that the claimant was suffering from a sub-arachnoid haemorrhage.
In reaching the conclusion that the radiologist had not fallen below the standard of care accepted as reasonable by a body of competent professional and responsible opinion in his specialty, the judge placed emphasis on the fact that the claimant's condition was very rare and that it was "understandable that it might not be picked up," 145 and on the evidence of the defendant's expert that five consultant radiologists shown the scan had also failed to detect the lachrymal tumour. 146wever, the task of a court considering a clinical negligence claim goes beyond merely relying on the Bolam test.First, following the decision of the House of Lords in Bolitho v. City and Hackney Health Authority, 147 if a judge considering expert evidence as to whether the practice of a medical practitioner acted in accordance with responsible professional practice concludes that "...in a rare case, 148 it can be demonstrated that the professional opinion is not capable of withstanding logical analysis, the judge is entitled to hold that the body of opinion is not reasonable or responsible" 149 and to reject it.
Second, it is clear from the Court of Appeal decision of Penney v. East Kent Health Authority 150 concerning the negligent classification of cervical smear tests as negative, that a judge must distinguish between matters of professional judgment, to which the Bolam test applies, and issues of fact, to which it does not and are for the judge to determine. 151In Penney, the question of what could be seen on the slides was regarded as a matter of fact by the Court of Appeal. 152Following Penney, it appears that, in the event of a claim being made in respect of an alleged failure to spot an AAA during a scan, the question of what was apparent from the scan would be a question of fact for the judge who, having determined the answer to that issue, would then have to go on to consider: i. whether a sonographer exercising reasonable care could have failed to see what was on the ultrasound scan; and ii.whether a reasonably competent sonographer, aware of what a sonographer exercising reasonable care would observe on the scan, has treated the appearance of the scan as normal. 153dical Law International 2002-5, p. 205; R. Heywood, 'The Logic of Bolitho', Professional Negligence 2006-22, p. 225; Mulheron, supra note 148.Professor Mulheron, in a detailed examination of the case law which has considered Bolitho, has provided helpful guidance as to "the factors that have indicated...that the requisite logical basis for a defendant doctor's expert medical opinion was absent" (at 610).She suggests inter alia that the case law discloses that Bolitho is likely to be applied and a doctor's conduct is likely to be found to be negligent even if it is supported by a responsible body of medical opinion if he fails to take "a clear precaution", which is "obvious as a matter of common sense, invoking no particular medical knowledge."C.f. French v. , where a similar approach was adopted in relation to what could be seen on slides created from amniotic fluid for the purpose of chromosome analysis. 153Ibid., Lord Woolf MR, 331.This was the approach adopted by Simon J. in B v. South Tyneside Health Care NHS Trust when considering whether the defendant's sonologist had negligently failed to notice a partial sacral agenesis (under-development of the sacral spine) during an ultrasound scan conducted at 19 weeks' gestation: *2004+ EWHC 1169, para.[13].C.f. the Singapore case of Khoo v. Gunapathy d/o Muniandy [2003] 1 LRC 239, in which the Singapore Court of Appeal overturned the trial judge's finding of negligence.The judge had decided that the question of whether a lesion was scar tissue or a tumour was a question of fact, and having concluded that, as a matter of fact the lesion was scar tissue, went on to find that no responsible practitioner would have recommended radiotherapy for a non-existent tumour.The CA found this reasoning to be wrong, stating that: [71] "The salient point in Penney was that the trial judge's finding of fact as to the correct diagnosis was not the touchstone of liability.The crucial question was what the medical practitioner, and not the judge, would have diagnosed under the circumstances.It does not follow then that the doctor would be negligent simply because his conclusion was different from that of the judge.This observation is crucial as it breaks the back of the judge's reasoning in the court below.Having found the nodule to be a scar, the judge went on to discredit all the experts who disagreed with him.We found ourselves unable to agree with this method of reasoning.To follow it would be to surreptitiously import into Bolam by the back door a practice of adjudicating between medical experts on a balance of probabilities.We do not think Bolam should be thus emasculated in content Furthermore, it has been made clear by the Court of Appeal in Lillywhite v. University College London Hospitals' NHS Trust 154 , a case involving antenatal ultrasound scanning, that the context in which the treatment takes place may be relevant to the determination of the standard of care and skill required: a higher standard of care may be required where a patient is referred to a specialist centre. 155Following a routine abnormality scan of Mrs Lillywhite, during which the radiographer had been unable to see the normal anatomy in the front part of the foetal brain, she had been referred to a distinguished consultant at the respondent hospital, who conducted a further scan and concluded after a long examination that the brain of the foetus was normal.
However, in due course, Mrs Lillywhite gave birth to a severely disabled daughter who suffered from holoprosencephaly, a severe malformation of the brain which is caused by the brain failing to separate into two cerebral hemispheres. 156 and Mrs Lillywhite subsequently brought an action in negligence against the respondent Trust, claiming that their consultant had, when conducting the scan, negligently failed to appreciate that it showed foetal brain abnormalities indicative of holoprosencephaly.The trial judge dismissed the claim, concluding that negligence had not been established.However, the majority of the Court of Appeal disagreed and concluded that, given that this was a scan in a tertiary referral centre by a consultant sonologist following a referral because an initial scan had failed to detect normal foetal brain structures, this was a 'scan with a focus', 157 and that the duty of care owed by the respondent's consultant 'demanded a high standard of care and skill'.158 Although this was not a case in which the principle res ipsa loquitur applied, given that the consultant concerned had 'purported to identify structures which were simply not  [2004] EWHC 1392 (QB), Holland J, para.[14], a decision which was endorsed and followed by the majority of the Court of Appeal in Lillywhite: at paras.[30]- [33].In Pithers, a pregnant mother had been referred to the defendant's hospital because the initial sonographer had been unable to see a bladder and suspected an omphalocele (or exomphalos), a defect of the anterior abdominal wall which presents as a sac protruding from the wall which may contain abdominal contents.Subsequent scans at the defendant's hospital identified an exomphalos, but failed to identify the severe cloacal extrophy (which involved an exomphalos with the extrusion of the bladder and bowel and deformity of the male genitalia), from which the claimant's son was found to be suffering when he was born.Holland J found the defendants negligent on the basis that this was a referral to a tertiary centre of a suspected abnormality and the scan was therefore a 'scan with a focus' (para.there',159 he was 'under a heavy burden... to reconcile his incorrect conclusions with the exercise of all reasonable care and skill'.160 Since the House of Lords refused leave to appeal, the approach of the Court of Appeal in Lillywhite appears to be authoritative on this point in this jurisdiction, although the scope and effect of the ruling may be further developed by the courts in subsequent cases.The significance of the decision so far as AAA and other forms of body scanning are concerned, is that a higher standard of care is required from consultant sonologists or radiologists dealing with referrals at tertiary centres than from sonologists or radiologists conducting routine scans.If a claim is brought in respect of a 'scan with a focus' at a tertiary centre, where relevant structures have been misidentified, it is likely that the defendant will need to provide 'a plausible explanation' for the misidentification, if the judge is not to conclude that the sonologist failed to act with reasonable care and skill.

III.3 Failure to Obtain Informed Consent and Civil Claims
I have discussed above some of the difficulties in relation to the obtaining of informed consent both in relation to AAA scanning and in relation to the provision of other scans by commercial health care providers.In particular, there are concerns and problems with regard to providing the patient with adequate information about their options and the risks involved so they may make informed choices about their treatment options.As suggested above, if patients are not properly informed about the risks and benefits of scans, they may fail to appreciate the limitations of screening techniques, leading both them and their families to have unrealistic expectations as to what scanning will achieve.In due course this may lead to complaints or litigation if expectations are not met.For example, in the case of patients who are scanned for AAA disease, they may incorrectly assume that they are 'safe', and if, prior to the next scheduled scan, an aneurysm grows unexpectedly quickly and ruptures with fatal results, their family may leap to the conclusion that the death was caused by a failure of diagnosis.Alternatively, patients faced with a diagnosis of AAA and their families may focus on the benefits of scanning and early treatment, without comprehending the very real risks of surgery.If the patient then dies during surgery, their family may conclude that 'something must have gone wrong' and blame the surgeon. 161 far as the law of negligence is concerned, a doctor is under a duty to advise his patient about his options and the significant risks involved in treatment, 162 and to take "reasonable and appropriate steps to satisfy themselves that the patient has understood the information which has been provided", 163 although he is not under any obligation to make sure that the patient understands this information. 164Given that the risk-benefit assessment in relation to most scanning techniques is not straightforward, care needs to be taken to ensure that patients are properly informed about their condition and its treatment, if Chester v. Afshar-type claims, made on the basis that there was a failure to warn the patient of significant risks and that, had he been properly informed, he would not have undergone that treatment, are to be avoided.I would suggest that it would be prudent to extend care in relation to the provision of information to patients not merely to the aftermath of scanning, but to the scan itself.
Scanning is generally seen (by patients, at least) as a beneficial, or at least a benign process and studies indicate that patients tend to overestimate the benefits of screening tests and to underestimate the risks. 165It appears that some of the commercial providers of preventive scans do not take sufficient steps to emphasis the possible risks of scans: the Nuffield Council noted that the information provided by some of the companies gave "the impression that only useful information can be gained from taking these tests." 166However, as I have already indicated, this may not always be the case.For example a scan may show that a patient has an untreatable but nevertheless potentially fatal condition.In such a case, the patient is placed in the unenviable position of knowing that they have a condition which might suddenly cause their death and that it cannot be treated.In the event that they had not been warned that this was a possible outcome and if, faced with this bleak outcome, they were to develop clinical depression, one might envisage them seeking to bring a claim on the basis that, had they been informed that the scan might reveal a potentially fatal, but untreatable condition they would have decided not to have the scan and would have preferred to remain in blissful ignorance. 167

Conclusion
An examination of the practical, ethical and legal implications in relation to preventive screening leads one to the conclusion that the use of scanning technologies on asymptomatic patients is not necessarily the unalloyed boon that many lay people may assume it to be.Preventive screening may provide benefits to patients by affording them with an opportunity for a significant health problem to be detected and treated at an early stage, providing them with reassurance, and promoting individual health awareness and responsibility for their own health.However, it is not without its risks and potential harms.CT scans pose particular health risks because they expose patients to additional radiation which increases the risk of them developing iatrogenic cancer.Even though ultrasound and MRI scanning techniques do not carry such risks, they cannot be regarded as being 'risk free', since they may disclose 'incidentalomas', which may require extensive further treatment, or may even be untreatable, leaving the patient with the knowledge that, although they have a serious health condition, they can do nothing about it.Scans may also provide 'false positive' results, which lead to unnecessary treatment, or 'false negative' results, which may cause a patient to ignore future symptoms because they mistakenly believe that all is well.
There are particular ethical considerations in relation to CT scanning because of its potential to expose patients to unjustifiable risks of harm, which, it is submitted, justify the more specific regulation of this technology under the IR(ME)R regulations, which aims to ensure that medical exposures to ionising radiation are justified.In the case of whole-body CT scans, whilst it appears that in practice they are not a cause for concern in the United Kingdom, because they are not being performed by NHS or private providers, the health risks involved outweigh any potential benefits to such an extent that state action to prohibit such harm may be justified and it was appropriate for the Nuffield Council on Bioethics to recommend that such a course be taken.
Most of the pressing ethical and legal concerns in relation to preventive screening relate to the provision of information to patients about the risks and benefits of screening and the obtaining of informed consent.These concerns are not without foundation: the Nuffield Council was particularly concerned about the level of information provided by private companies providing preventive screening, suggesting that it did not meet the level of information provided by NHS screening programmes and questioning whether sufficient information was always provided for patients to make informed choices about their health.However, state-provided preventive screening programmes also raise significant concerns about the provision of information to patients: it has been suggested that information provided to patients about the risks and benefits of scanning and its possible outcomes may not always be sufficient or sufficiently accessible, particularly in the case of AAA screening, as the riskbenefit analysis may be particularly complex and difficult for patients to comprehend.
The recommendations made by the Nuffield Council in relation to the provision in an accessible form to patients of proper information about the risks and benefits of screening both by the health care provider, and by the state, via publicly-funded health service websites, will, if followed, address many of these concerns.However, some more general concerns remain, particularly in relation to the regulation of commercial providers who provide direct-toconsumer body imaging to asymptomatic individuals.The recent requirements imposed by the Health and Social Care Act (Regulated Activities) Regulations 2010 on private companies providing ultrasound and MRI scans in relation to registration with the Care Quality Commission and the meeting of appropriate standards of quality and safety, are likely to help to protect patients undergoing preventive scanning tests, and should be welcomed.Ultimately, however, the effectiveness of such regulation is likely to depend on the extent to which the regulator takes steps to ensure that these standards are met.

Table 1 Company 37 Examples of Packages/Tests Offered Advertised Cost 38 iHealth
10.31.what are called 'incidentalomas',77asymptomatic abnormalities which may be detected particularly during the course of MRI scans.Studies of those undergoing MRI scans suggest that the finding of incidentalomas as a result of such scans is fairly common.For example, Hoggard et al.78found a high rate of incidentalomas amongst volunteers participating in brain MRI studies: out of 525 individuals scanned, 46 (8.8 percent) had "definite significant abnormalities", 79 including 4 with tumours and 24 with forms of white matter disease.80 See e.g. the reported experience of the well-known businesswoman, Karren Brady, who discovered following a full-body MRI scan that she had a symptomless brain aneurysm.She describes the fear, panic and shock that she experienced on hearing of this, and her terror that she would 'have a stroke at any minute.'However, following 'coil' surgery to prevent rupture, and in spite of the need to have brain scans for the rest of her life, she described feeling "incredibly glad" to have had the MRI scan and stated that she felt that "my mortality is back in my own hands": L. Atkins, 'I was terrified that I would die at any minute', (2006) The Guardian, April 20, p.24. C.f. Al-Shahi Salman et al., supra note 78, p.3, who cast a rather more critical gaze upon this case: "...the case report clearly illustrates not only the potential adverse consequences of indiscriminate screening in general but also the specific dangers of inappropriate brain MRI." 13. R. Al-Shahi Salman, W.N. Whiteley & C. Warlow, 'Screening using whole-body magnetic resonance imaging scanning: who wants an incidentaloma?' Journal of Medical Screening 2007-14, p. 2. 78 N. Hoggard, G. Darwent, D. Capener et al., 'The high incidence and bioethics of findings on magnetic resonance brain imaging of normal volunteers for neuroscience research', Journal of Medical Ethics 2009-35, p. 194.Morris et al., in a systemic review and meta-analysis of studies of people without neurological symptoms who underwent MRI brain scans, found that incidentalomas (e.g.benign & malignant tumours, structural vascular abnormalities and inflammatory lesions) were common, and that they were more likely in older people and with high resolution MRI sequences: Z. Morris, W.N. Whiteley, W.T. Longstreth, F. Weber, Y.C. Lee, Y. Tsushima, H. Alphs, S.C. Ladd, C. Warlow, J.M. Wardlaw & R. Al-Shahi Salman, 'Incidental findings on brain magnetic resonance imaging: systemic review and meta-analysis', BMJ 2009-339, b3016. 79Idem, p.194. 80Idem, p.197, Table 2. 81 82 Nuffield, supra note 2, para.10.13; C. Shaw, K. Abrams & T.M. Marteau, 'Psychological impact of predicting individuals' risks of illness: a systematic review', Social Science & Medicine 1999-49, p. 1571. 83Nuffield, ibid., Al-Shahi Salman, supra note 78, p.4. 84 Nuffield, ibid.; I.M. Burger & N.E.Kass, 'Screening in the dark: ethical considerations of providing screening tests to individuals when evidence is insufficient to support screening populations', American Journal of Bioethics 2009-9, p.3.
Even if the individual requesting the whole-body CT had a good understanding of the uncertainties of the test and believed he would derive great psychological benefit from screening, these potential psychological benefits are inadequate ...to outweigh the potential medical risks, including radiation exposure, false-positive results leading to invasive, risky and costly follow-up procedures, false negatives and the detection of pseudo-disease... 90 85 Nuffield, ibid.86Nuffield,supra note 2, para.10.15.The Council recommend that both private providers of directto-consumer body imaging and publicly funded health service websites provide information to the public about whether it may be necessary to inform mortgage or insurance companies of tests: paras.10.31, 10.33.
and application.The judge's finding of fact should accordingly have had little direct influence on the question of medical standards."154[2005]EWCACiv1466.155SeeJones, supra note 151, para.4-032.For further discussion of the case see: D. Harris, 'Medical misdiagnosis: a shifting of the burden of proof', Melbourne Journal of International Law 2008-14, p. 8.156The condition is described at[2005]EWCA Civ 1466, para.[3].157Thisterm is taken from the first instance decision in Pithers v. Leeds Teaching Hospitals NHS Trust