Imaging of coronary artery anomalies: the role of multidetector computed tomography

Anomalous Coronary Arteries: A State-of-the-Art Approach

Congenital coronary anomalies are not an infrequent occurrence and their clinical presentation typically occurs during early years, though may be manifested only in adulthood. In the setting of anomalous aortic origin of a coronary artery, this is particularly concerning as it inflicts sudden loss of healthy young lives. Risk stratification remains a challenge and so does the best management decision-making in these patients, particularly if asymptomatic. Standardized approach to evaluation and management, with careful data collection and collaboration among centers, will likely impact future outcomes in this patient population, thus allowing for exercise participation and healthier lives.

Anomalous Coronary Arteries: A State-of-the-Art Approach

Congenital coronary anomalies are not an infrequent occurrence and their clinical presentation typically occurs during early years, though may be manifested only in adulthood. In the setting of anomalous aortic origin of a coronary artery, this is particularly concerning as it inflicts sudden loss of healthy young lives. Risk stratification remains a challenge and so does the best management decision-making in these patients, particularly if asymptomatic. Standardized approach to evaluation and management, with careful data collection and collaboration among centers, will likely impact future outcomes in this patient population, thus allowing for exercise participation and healthier lives.

Intermodality agreement between TTE and low kVp ECG-gated MDCTA in diagnosis of complex CHD in pediatrics

Background

Transthoracic echocardiography (TTE) is considered the primary diagnostic modality in congenital heart disease (CHD). However, it has limited role in evaluation of extra-cardiac major vessels abnormalities. Cardiac catheterization angiography is considered the gold standard investigation, yet, it is invasive. The aim of this study is to evaluate the agreement between TTE and low kVp ECG-gated cardiac multi-detector CT angiography (MDCTA) in detecting cardiac and extra-cardiac findings of complex congenital heart disease in a sample size of 36 patients (19 males and 17 females) with an age ranged between 30 days and 12 years (mean age 25.5 months). All cases were diagnosed to have complex CHD clinically and by TTE then referred to undergo cardiac low kVp ECG-gated MDCTA to confirm diagnosis and for better assessment of extra-cardiac major vessels abnormalities. Data derived from both modalities were then compared to calculate the inter-technique variability by using Cohen’s kappa statistics.

Results

TTE diagnosed 96% of intra-cardiac anomalies and only 54% of extra-cardiac major vessels anomalies detected by MDCTA, with variable degrees of intermodality agreement in detection different anomalies ranging between perfect agreement in diagnosing most of intra-cardiac lesions and very poor agreement in diagnosing extra-cardiac SVC anomalies.

Conclusion

Low kVp ECG-gated cardiac MDCTA is a rapid, non-invasive and reliable diagnostic modality in complex congenital heart diseases. It confirms TTE findings in intra-cardiac anomalies and significantly surpasses TTE reliability in diagnosis of extra-cardiac major vessels anomalies. So, it is indispensable as part of adequate preoperative assessment algorithm in cases of complex CHD and can't be replaced by TTE even with the later providing accurate assessment of intra-cardiac anomalies.

An entire coronary system arising from right coronary cusp: a rare anomaly

The prevalence of coronary artery anomalies is approximately 0.6% in individuals undergoing angiography. Most of the anomalies are benign, but some can lead to myocardial infarction, cardiomyopathy, and sudden cardiac death. It is very rare to have an entire coronary circulation that arises from the right coronary cusp. We present a case of a 57-year-old male who presented with complaints of chest pain and dyspnea on exertion. An invasive angiogram revealed all the three coronary arteries originating from the right coronary cusp. It is crucial to define coronary anatomy as anomalies dictate which cardiac intervention should be attempted in cases of ischemia.

Anatomical variants and coronary anomalies detected by dual-source coronary computed tomography angiography in North-eastern Thailand

Purpose

Congenital coronary anomalies are uncommon, with an incidence ranging from 0.17% in autopsy cases to 1.2% in angiographically evaluated cases. The recent development of dual-source coronary computed tomography angiography (coronary CTA) allows accurate and noninvasive depiction of coronary artery anomalies.

Material and methods

A retrospective study included a total of 924 patients who underwent coronary CTA because of known or suspected coronary artery disease. In each study, coronary artery anomalies (CAs) were investigated.

Results

A total of 924 patients (mean age 51.2 ± 12.8 years), who underwent dual-source coronary CTA, were studied. The overall prevalence of CAs in our study was 3.7%, with the following distribution: four single coronary artery, 14 anomalous origin from opposite sinus of Valsalva, three absent left main, four high take-off coronary artery, three anomalous left coronary artery from pulmonary artery, and eight coronary artery fistulas.

Conclusions

The present study supports the use of coronary CTA as a reliable noninvasive tool for defining anomalous coronary arteries in an appropriate clinical setting and provides detailed three-dimensional anatomic information that may be difficult to obtain with invasive coronary angiography.

Unusual Association of Three Types of Congenital Coronary Artery Diseases

Congenital coronary artery disease (CAD) is commonly asymptomatic and often benign. Investigation of potential myocardial ischemia is also necessary. We report an original observation of abnormal origin and course of the right coronary artery (RCA), abnormal left main artery, and agenesis of the left anterior descending (LAD) artery. This is the first report of an association of 3 types of congenital coronary artery anomaly according to the modified Angelini's classification. This high-risk condition was successfully treated surgically.

Successful percutaneous coronary intervention in the setting of an aberrant left coronary artery arising from the right coronary cusp in a patient with acute coronary syndrome: a case report

BACKGROUND

An aberrant origin of the left coronary artery (LCA) from the right coronary cusp (RCC) is an extremely rare congenital anomaly. We here report on successful percutaneous coronary intervention (PCI) in a patient presenting with acute coronary syndrome and an aberrant origin of the LCA from the RCC.

CASE PRESENTATION

A 50-year-old man presented at our emergency department with recurrent resting chest pain. Following unsuccessful attempts at visualizing the left coronary artery using Judkins left and Amplatz catheters, an aortogram using a pigtail catheter suggested anomalous left coronary artery origin and showed a significant occlusive lesion at proximal left anterior descending artery. A Judkins right 4 guiding catheter was placed around the left coronary ostium and exchanged for a Judkins left 3.5 guiding catheter after introducing a .014" coronary long wire into the left circumflex artery. With excellent angiographic visualization and guide support, a drug-eluting stent was then successfully implanted. Cardiac computed tomography (CT) demonstrated left coronary artery origin from right coronary cusp.

CONCLUSION

This report presents a case of LCA originating from the RCC accompanied with acute coronary syndrome that was treated with successful PCI.

Symptomatic bilateral coronary artery fistula to pulmonary artery in elderly patient

We report the imaging findings of an uncommon coronary vascular termination anomaly, with fistula to the pulmonary artery.

This 70 year old female patient presented unstable angina, showing a coronary artery fistula depicted in coronary angiogram from the left coronary to the pulmonary artery, with no significant atherosclerotic pathology.

Due to development of ventricular tachycardia in stress echocardiogram examination, she was proposed for coronary fistula closure.

Coronary CT was performed for procedure planning and allowed the identification of a second unsuspected fistula from the right coronary to the right pulmonary artery.

Congenital coronary anomalies are a possible cause of symptomatic coronary pathology in patients of any age. In older patients, coronary artery fistulas are rare, especially when symptomatic. Adequately performed CT examinations, using its post processing capabilities, with 3D and MIP reconstructions are invaluable in delineating coronary anatomy, essential for further treatment planning.

Pulmonary hypertension and right ventricular dysfunction in patients with left to right shunt coronary artery fistula: evaluation with cardiac CT

In this study, we aimed to evaluate whether patients with left to right shunt coronary artery fistula (LRSCAF) are predisposed to developing pulmonary hypertension and right ventricular dysfunction compared with healthy individuals. The value of cardiac CT findings in determining the necessity of intervention for these patients was investigated. We retrospectively studied 19 patients with LRSCAF and 19 healthy patients. Several parameters were observed on cardiac CT by two radiologists, including pulmonary trunk diameter (PA diameter), right ventricular diameter (RVD), left ventricular diameter (LVD), RVD/LVD ratio, septal bowing and CT score of right ventricular dysfunction (CSRVD). Data from both groups were compared. The inter- and intra-observer variabilities and correlations were examined. The disease group was further divided into intervention (n = 9) and non-intervention (n = 10) groups, and their data were compared. All cardiac CT findings showed significant intra- and inter-observer correlation without significant variability. Mann-Whitney U tests and χ(2) analysis showed that PA diameter, RVD/LVD ratio acquired from two observers, and CSRVD were higher in the disease group than in the control group (all P values < 0.05 for χ(2) and almost all P values < 0.05 for Mann-Whitney U). The RVD/LVD ratio and CSRVD were higher in the intervention group than in the non-intervention group (all P values < 0.05). Receiver operating curve analysis identified RVD/LVD = 1.036 and CSRVD = 3.5 as the best cut-off values to determine the necessity of further intervention. Patients with LRSCAF are more predisposed to pulmonary hypertension and right ventricular dysfunction compared with the normal population. RVD/LVD > 1.0 and CSRVD ≥ 4.0 may determine the necessity of intervention for patients with LRSCAF.

A case of anomalous coronary artery origin: The role of computerised tomography

OBJECTIVE

To illustrate the utility of CT coronary angiography in the assessment of patients with anomalous coronary arteries.

METHODS

A 65-year-old woman who presented with a clinical history of unstable angina was investigated with both computerised tomography and invasive coronary angiography.

RESULTS

Coronary angiography demonstrated aberrant coronary arteries all arising from separate ostia from the right coronary cusp. Computerised tomography coronary angiography was required to confirm the course of the aberrant coronary arteries in relation to other cardiovascular structures.

CONCLUSIONS

This case illustrates the important role of computerised tomography coronary angiography and that early use might avoid the need for invasive coronary angiography.

Identification of Coronary Artery Orifice to Prevent Coronary Complications in Bioprosthetic and Transcatheter Aortic Valve Replacement

BACKGROUND

The aim of this study was to identify anatomical variations in coronary artery orifices among high-risk patients with a small aortic root undergoing bioprosthetic aortic valve replacement (BAVR) and transcatheter aortic valve replacement (TAVR) in order to prevent coronary orifice obstruction perioperatively.

METHODS AND RESULTS

Coronary orifice and root structure were identified in 400 patients using aortic multidetector-row computed tomography (MDCT). We measured the aortic root diameter; intercommissural distances; and distance from coronary orifice to valve annulus, commissure, and sinotubular junction. We examined positional relationships between the coronary orifice and stent post, or sewing cuff of the bioprosthetic valve and leaflet of the transcatheter aortic valve. Most left coronary artery orifices were distributed near the center of the non-left and left-right commissures; right ones were relatively distributed on the non-right commissural side. Thirty-four patients (8.5%) with BAVR (coronary orifice near the commissure: 31, 7.8%; low takeoff: 5, 1.3%; and both: 2) and 39 (9.8%) with TAVR were at risk for coronary orifice obstruction. During BAVR, one-stitch rotation of the stent and one-stitch rotation with intra-annular implantation were used in near-commissure and low takeoff cases, respectively. During TAVR, percutaneous coronary intervention may be required in the height of the coronary orifice was ≤10 mm from the base of the ventricle aortic junction.

CONCLUSIONS

Potential coronary complications during BAVR and TAVR in high-risk patients for coronary obstruction were identified using preoperative aortic MDCT. Choice of appropriate surgical technique or valve is essential.

Korean guidelines for the appropriate use of cardiac CT

The development of cardiac CT has provided a non-invasive alternative to echocardiography, exercise electrocardiogram, and invasive angiography and cardiac CT continues to develop at an exponential speed even now. The appropriate use of cardiac CT may lead to improvements in the medical performances of physicians and can reduce medical costs which eventually contribute to better public health. However, until now, there has been no guideline regarding the appropriate use of cardiac CT in Korea. We intend to provide guidelines for the appropriate use of cardiac CT in heart diseases based on scientific data. The purpose of this guideline is to assist clinicians and other health professionals in the use of cardiac CT for diagnosis and treatment of heart diseases, especially in patients at high risk or suspected of heart disease.

Congenital anomalies of coronary arteries in complex congenital heart disease: diagnosis and analysis with dual-source CT

BACKGROUND

Congenital heart diseases (CHDs) are sometimes associated with coronary artery anomalies (CAAs). Accurate preoperative evaluation of coronary artery anatomy is essential for successful surgical repair of complex CHD.

OBJECTIVE

The aim of this study was to evaluate the incidence of congenital CAAs in patients with complex CHD at dual-source CT.

METHODS

Four hundred seventeen consecutive patients with complex CHD underwent contrast-enhanced cardiac CT angiography. The results were retrospectively analyzed, including the types and incidences of CAAs in various forms of complex CHD. Each patient was analyzed independently by 2 experienced cardiovascular radiologists. Image quality of coronary arteries was assessed on a 5-point scale with 2 or less being nondiagnostic.

RESULTS

Thirty-five of 417 studies were nondiagnostic (8.39%). Sixty-three cases of CAA (15.11%) were detected by anomalous ostia and coronary arteries. CAA was involved in 6 of 108 patients with tetralogy of Fallot (5.56%), 18 of 84 patients with double outlet right ventricle (21.43%), 11 of 97 patients with pulmonary artery atresia (11.34%), 7 of 36 patients with transposition of the great arteries (22.22%), 15 of 41 patients with single ventricle (36.59%), 4 of 12 patients with truncus arteriosus/aortopulmonary window (33.33%), and 2 of 39 patients with interruption of the aortic arch/coarctation of the aorta (5.13%). Twenty of these were accompanied with an anomalous coronary course (31.74%).

CONCLUSION

Patients with complex CHD have a higher prevalence of CAAs, which should be considered before surgery. Dual-source CT is an effective technique to visualize and evaluate complex CHD.

Diagnostic and therapeutic approach of congenital solitary coronary artery fistulas in adults: Dutch case series and review of literature

BACKGROUND

Coronary artery fistulas (CAFs) are infrequent anomalies, coincidentally detected during coronary angiography (CAG).

AIM

To elucidate the currently used diagnostic imaging modalities and applied therapeutic approaches.

MATERIALS AND METHODS

Five Dutch patients were found to have CAFs. A total of 170 reviewed subjects were subdivided into two comparable groups of 85 each, treated with either percutaneous 'therapeutic' embolisation (PTE group) or surgical ligation (SL group).

RESULTS

In our series, the fistulas were visualised with several diagnostic imaging tests using echocardiography, multidetector computed tomography, and CAG. Four fistulas were unilateral and one was bilateral; five originated from the left and one originated from the right coronary artery. Among the reviewed subjects, high success rates were found in both treatment groups (SL: 97% and PTE: 93%). Associated congenital or acquired cardiovascular disorders were frequently present in the SL group (23%). Bilateral fistulas were present in 11% of the SL group versus 1% of the PTE group. The fistula was ligated surgically in one and abolished percutaneously in another. Medical treatment including metoprolol was conducted in two, and watchful waiting follow-up was performed in one.

CONCLUSIONS

Several diagnostic imaging techniques are available for assessment of the anatomical and functional characteristics of CAFs.

An unusual pattern of three major components of the cardiovascular system: multimodality imaging and review of the literature

INTRODUCTION

Coronary artery anomalies are found in 0.4% to 1.4% of patients who undergo coronary angiography. Anomalous origin of left coronary artery from the right sinus of Valsava is the rarest, with a reported prevalence of 0.02 -0.03% according to angiographic studies.

CASE PRESENTATION

We present the rare case of a 42-year-old-man suffering from stable angina with unusual development of 3 major components of the cardiovascular system Coronary angiography revealed an anomalous origin of the left coronary artery from the ostium of the right coronary artery. Magnetic resonance angiography depicted an anomalous origin of the left common carotid artery from the innominate artery and an aneurysm of descending thoracic aorta. Coronary computed tomography angiography revealed the course of left coronary artery between aortic root and conus arteriosus at the level of the right ventricular outflow tract. In this report we attempt to highlight the rarity of this vascular anatomy.

CONCLUSION

Anomalous origins of the coronary arteries are rare, but may cause myocardial ischemia and sudden death. Thus, their reliable identification is a matter of paramount importance possibly evaluating the effects of therapeutic intervention. Newer imaging modalities improve the illumination of vascular system anatomy, shedding light to diagnostic dilemmas that come up in daily medical practice.

Congenital absence of left circumflex artery detected by computed tomography coronary angiography: a case report

The congenital absence of the left circumflex artery (LCx) is a very rare congenital anomaly of coronary arteries, but it is benign. Currently, the best modality for the diagnosis of coronary anomalies is computed tomography coronary angiography (CTCA). We report a case of congenitally absent LCx with an atypical chest pain.

The prevalence of coronary artery variations on coronary computed tomography angiography

BACKGROUND

Coronary computed tomography angiography (CCTA) can delineate the coronary artery anatomy precisely. Basic knowledge of the normal coronary artery anatomy and familiarity with its common variations are essential in order to assess CCTA accurately.

PURPOSE

To determine the prevalence of coronary artery variations detected by 64-slice mutidetector CT.

MATERIAL AND METHODS

CCTA images of 2096 patients were evaluated retrospectively. Relatively unusual coronary artery morphological features that were seen in greater than 1% of the study population were classified as variations.

RESULTS

Coronary artery circulation was right dominant in 86.6%, left dominant in 9.6%, and balanced in 3.8% of patients. The conus artery arose from the right coronary artery in 83%, or directly from the aorta with a separate ostium in 17% of cases which was much more common in men than women. The sinoatrial node artery originated from the right coronary artery (65.6%) or the circumflex artery (33.7%). The atrioventricular node artery originated from the right coronary artery in 86.4% or the circumflex artery in 13.6% of cases. The left main coronary artery was shorter than 0.5 cm in 4.7% of cases and trifurcated into the intermediate artery in 31.3% of cases. A myocardial bridge was observed in 21.6%, coronary ectasia-aneurysm in 2%, dual left anterior descending artery (LAD) type 1 in 1.38%, and a variant of type 1 in 0.1% of cases. The presence of coronary atherosclerosis was higher in patients with coronary ectasia-aneurysm than the patients who did not have coronary ectasia-aneurysm (90.5% vs. 72.2%, P = 0.000).

CONCLUSION

CCTA is a non-invasive imaging modality for the depiction of variations of the coronary arteries. The incidence of coronary artery variations is high and various, and readers should be familiar and looking for these conditions during interpretation of CCTA examinations.

Combined anatomical and functional imaging using coronary CT angiography and myocardial perfusion SPECT in symptomatic adults with abnormal origin of a coronary artery

There has been a lack of standardized workup guidelines for patients with congenital abnormal origin of a coronary artery from the opposite sinus (ACAOS). We aimed to evaluate the use of cardiac hybrid imaging using multi-detector row CT (MDCT) for coronary CT angiography (Coronary CTA) and stress-rest myocardial perfusion SPECT (MPS) for comprehensive diagnosis of symptomatic adult patients with ACAOS. Seventeen symptomatic patients (12 men; 54 ± 13 years) presenting with ACAOS underwent coronary CTA and MPS. Imaging data were analyzed by conventional means, and with additional use of 3D image fusion to allocate stress induced perfusion defects (PD) to their supplying coronary arteries. An anomalous RCA arose from the left anterior sinus in eight patients, an abnormal origin from the right sinus was detected in nine patients (5 left coronary arteries, LCA and 4 LCx). Five of the 17 patients (29%) demonstrated a reversible PD in MPS. There was no correlation between the anatomical variants of ACAOS and the presence of myocardial ischemia. Image fusion enabled the allocation of reversible PD to the anomalous vessel in three patients (two cases in the RCA and the other in the LCA territory); PD in two patients were allocated to the territory of artery giving rise to the anomalies, rather than the anomalies themselves. In a small cohort of adult symptomatic patients with ACAOS anomaly there was no relation found between the specific anatomical variant and the appearance of stress induced myocardial ischemia using cardiac hybrid imaging.

Current characteristics of congenital coronary artery fistulas in adults: A decade of global experience

AIM

To describe the characteristics of coronary artery fistulas (CAFs) in adults, including donor vessels and whether termination was cameral or vascular.

METHODS

A PubMed search was performed for articles between 2000 and 2010 to describe the current characteristics of congenital CAFs in adults. A group of 304 adults was collected. Clinical data, presentations, diagnostic modalities, angiographic fistula findings and treatment strategies were gathered and analyzed. With regard to CAF origin, the subjects were tabulated into unilateral, bilateral or multilateral fistulas and compared. The group was stratified into two major subsets according to the mode of termination; coronary-cameral fistulas (CCFs) and coronary-vascular fistulas (CVFs). A comparison was made between the two subsets. Fistula-related major complications [aneurysm formation, infective endocarditis (IE), myocardial infarction (MI), rupture, pericardial effusion (PE) and tamponade] were described. Coronary artery-ventricular multiple micro-fistulas and acquired CAFs were excluded as well as anomalous origin of the coronary arteries from the pulmonary artery (PA).

RESULTS

A total of 304 adult subjects (47% male) with congenital CAFs were included. The mean age was 51.4 years (range, 18-86 years), with 20% older than 65 years of age. Dyspnea (31%), chest pain (23%) and angina pectoris (21%) were the prevalent clinical presentations. Continuous cardiac murmur was heard in 82% of the subjects. Of the applied diagnostic modalities, chest X-ray showed an abnormal shadow in 4% of the subjects. The cornerstone in establishing the diagnosis was echocardiography (68%), and conventional contrast coronary angiography (97%). However, multi-slice detector computed tomography was performed in 16%. The unilateral fistula originated from the left in 69% and from the right coronary artery in 31% of the subjects. Most patients (80%) had unilateral fistulas, 18% presented with bilateral fistulas and 2% with multilateral fistulas. Termination into the PA was reported in unilateral (44%), bilateral (73%) and multilateral (75%) fistulas. Fistulas with multiple origins (bilateral and multilateral) terminated more frequently into the PA (29%) than into other sites (10.6%) (P = 0.000). Aneurysmal formation was found in 14% of all subjects. Spontaneous rupture, PE and tamponade were reported in 2% of all subjects. In CCFs, the mean age was 46.2 years whereas in CVFs mean age was 55.6 years (P = 0.003). IE (4%) was exclusively associated with CCFs, while MI (2%) was only found in subjects with CVFs. Surgical ligation was frequently chosen for unilateral (57%), bilateral (51%) and multilateral fistulas (66%), but percutaneous therapeutic embolization (PTE) was increasingly reported (23%, 17% and 17%, respectively).

CONCLUSION

Congenital CAFs are currently detected in elderly patients. Bilateral fistulas are more frequently reported and PTE is more frequently applied as a therapeutic strategy in adults.

Technical principles of computed tomography in patients with congenital heart disease

Cardiac magnetic resonance imaging and echocardiography are often the primary imaging techniques for many patients with congenital heart disease (CHD). However, with modern generations of CT systems and recent advances in temporal and spatial resolution, cardiac CT has been gaining an increasing reputation in the field of cardiac imaging and in the evaluation of patients with congenital heart disease. The CT imaging protocol depends on the suspected cardiac defect, the type of previous surgical repair, and the patient’s age and level of cooperation. Various strategies are available for reducing radiation exposure, which is of utmost importance particularly in paediatric patients. A sequential segmental analysis is a commonly used approach to analysing congenital heart defects. Familiarity of the performing radiologist with dedicated CT protocols, the complex anatomy, morphology and terminology of CHD, as well as with the surgical procedures used to correct congenital abnormalities is a prerequisite for correct diagnosis.

Radiation dose and cancer risk from pediatric CT examinations on 64-slice CT: a phantom study

OBJECTIVE

To measure the radiation dose from CT scans in an anthropomorphic phantom using a 64-slice MDCT, and to estimate the associated cancer risk.

MATERIALS AND METHODS

Organ doses were measured with a 5-year-old phantom and thermoluminescent dosimeters. Four protocols; head CT, thorax CT, abdomen CT and pelvis CT were studied. Cancer risks, in the form of lifetime attributable risk (LAR) of cancer incidence, were estimated by linear extrapolation using the organ radiation doses and the LAR data.

RESULTS

The effective doses for head, thorax, abdomen and pelvis CT, were 0.7mSv, 3.5mSv, 3.0mSv, 1.3mSv respectively. The organs with the highest dose were; for head CT, salivary gland (22.33mGy); for thorax CT, breast (7.89mGy); for abdomen CT, colon (6.62mGy); for pelvis CT, bladder (4.28mGy). The corresponding LARs for boys and girls were 0.015-0.053% and 0.034-0.155% respectively. The organs with highest LARs were; for head CT, thyroid gland (0.003% for boys, 0.015% for girls); for thorax CT, lung for boys (0.014%) and breast for girls (0.069%); for abdomen CT, colon for boys (0.017%) and lung for girls (0.016%); for pelvis CT, bladder for both boys and girls (0.008%).

CONCLUSION

The effective doses from these common pediatric CT examinations ranged from 0.7mSv to 3.5mSv and the associated lifetime cancer risks were found to be up to 0.16%, with some organs of higher radiosensitivity including breast, thyroid gland, colon and lungs.