Threats Deforestation and fragmentation
Both legal and illegal logging are a major threat to the Sumatran orangutan. The species’ main habitat, primary lowland forest, has been devastated in the last 30 years due to large scale forest conversion to agricultural land and oil palm plantations (Singleton et al, 2008). One study between 1990 and 2000 recorded a 13% loss of orangutan habitat forest (Gaveau et al, 2007). Another study by van Schaik et al (2001) found that during the late 1990’s habitat supporting 100 orangutans was lost each year in the Leuser Ecosystem in Sumatra. This habitat loss was largely due to legal logging concessions from the Indonesian government for oil palm conversion (van Schaik et al, 2001). The orangutans habitat of lowland forest has been targeted due to the fact that it is easily and cheaply accessible for logging (Campbell-Smith et al, 2011). The forest is being destroyed in order to provide hardwood to developed nations, providing income to boost Indonesia’s economy, as well as to clear land for agricultural conversion and expanding human populations (DWCT, 2006). Within the last decade the scale of logging in Sumatra has continued to expand. This was partly due to the surge in demand for timber since the 2004 tsunami (Singleton et al, 2008), as well as a peace agreement in the Aceh province. A moratorium on logging during the conflict meant a lower rate of forest loss, however a peace accord in 2005 led to a lift of the moratorium and re-issuing of logging permits in Aceh (Singleton et al, 2008). In addition, the history of political unrest in the province has greatly impacted past conservation efforts (Marshall et al, 2009). This recorded habitat loss is the main contributor to the species’ declining population.
orangutans are particularly vulnerable due to the fact that they are an arboreal species. They spend the majority of their lives in the canopy to avoid the threat of tigers, meaning the species is restricted to areas untouched by deforestation. However, the spread of human settlements and development of new road systems has caused severe fragmentation of their remaining habitat. In addition, a proposal for the Ladia Galaska road network in Aceh has been put forward, and if allowed will quickly fragment the last remnants of habitat (Singleton et al, 2008). The remaining forest within the orangutans range cannot support its prior ecosystems, and further deforestation and fragmentation could lead to multiple extinctions. Indonesia has converted over 3 million hectares of land to oil palm plantations, with plans to convert a further 4 million (Brown and Jacobson, 2005). However areas of oil palm monoculture only supports 20% of its previous diversity (Marchal and Hill, 2009). Even small scale selective logging can reduce local orangutan densities by as much as 60% (Rao and van Schaik, 1997), which shows how sensitive the species are to the destruction of habitat. The threats to orangutans from deforestation are made greater by the fact that the Indonesian government supports development (orangutan National Action Plan, 2007), and are therefore willing to issue large numbers of logging permits. Furthermore, the decentralisation of forest management in 2001 has aided the rise in forest destruction, as it means that regional land use plans are made without any though for conservation (The Ministry of Forestry, 2009). The increase in human population also increases pressure, as greater resource degradation occurs to meet an ever increasing demand for timber and agricultural land. A paper by Robertson and van Schaik (2001) suggests that ultimate causal factor of deforestation is corruption, as well as feeble compliance with legislation and poor law enforcement. Corruption is the most difficult threat to overcome, but law enforcement and compliance need to be improved in order to have a chance of protecting the remaining orangutan population.
As well as being severely threatened by habitat destruction, orangutans are also in high demand for the pet trade across Indonesia. The central demand is for infant orangutans, considered as good pets as they do not reach full size until the age of 7, and are known for their trait of human imitation. Currently around 200-500 infants are taken from the wild for the pet trade each year in Kalimantan (Nijman, 2005). No data is available for the Sumatran orangutan, but demand for pets is high in both Borneo and Sumatra, and the number of infants being removed from the wild is unsustainable. Wild orangutans are also threatened by their conflict with humans, and they are at times killed as pests. They are forced to encroach upon agricultural land as a result of habitat destruction, but are considered pests by farmers and often killed when found raiding crops at forest edges. In a study interviewing farmers in northern Sumatra, 28% of those interviewed feared orangutans. They also on average believed orangutans to be the third most frequent, and the fourth most destructive pest (Campbell-Smith et al, 2010). This shows that a high proportion of orangutans are being forced to raid crops due to destruction of habitat and food sources, but also that the human-orangutan conflict may not easily be reconciled as it is largely driven by fear. Finally, the current small nature of the remaining orangutan population means it is highly vulnerable to stochastic events such as natural disasters, random genetic fluctuations and disease outbreak (Caughley, 1994). The species’ relatively slow reproductive rate (25 years per generation) and the ongoing vulnerability to habitat reduction means it is at constant risk of extinction.
Past and current recovery strategies Rehabilitation centres
During the 1970s the Indonesian government began to establish reserves for orangutans, which are now seen across Sumatra. The reserves act as rehabilitation centres where orphans are taught how to live in the wild and then returned, but also as sanctuaries for individuals unable to be reintroduced. Individuals found in logging areas, as well as orphans and orangutans confiscated by the forestry department, are moved to these sanctuaries (DWCT, 2006). It is estimates that around 63-97% of intakes by orangutan centres are under 7 years old (Russon, 2009). The orangutans are treated medically until their health is regained, as they are often in bad condition. For example many have gunshot and machete wounds, scars from tight chains, and internal damage, as well as behavioural and psychological damage as a result of prolonged isolation, abuse, and abnormal associations with humans (Russon, 2009). In addition many orangutans arrive carrying human diseases such as Tuberculosis, as well as significantly high parasite loads (Russon, 2009) after living in close proximity with humans. Once treated, the orangutans are taught ecological and social skills, and gradually weaned from human contact in order for them to be able to live independently in the wild once released (Beck et al, 2007). When the rehabilitation centres were initially established, uncertainty over orangutan numbers meant that rehabilitation programmes concentrated on releasing individuals into areas with existing wild populations to supplement those that were too small (Russon, 2009). Between 1973 and 2000, 218 orangutans were released at Bohorok in Gunung Leuser National Park, Sumatra, to supplement the rapidly declining population. The Sumatran orangutan Conservation Programme (SOCP) is one of the orangutan rehabilitation centres in Sumatra, but it also concentrates on other aspects of orangutan conservation. The SOCP rehabilitation centre and quarantine site is in the Medan region, and individuals are released in Bukit Tigapuluh National Park. Over ten years, 190 orangutans have been through quarantine, with 125 individuals released into Bukit Tigapuluh, and 3 wild births by reintroduced females (DWCT, 2006). In addition the programme is helping to improve law enforcement through providing facilities for confiscated or unwanted orangutans. The availability of sanctuaries means that illegally kept individuals are more readily reported (DWCT, 2006). A mobile education unit from SOCP is used as an educational tool to teach conservation and the importance of orangutan tolerance, particularly in human-orangutan conflict areas. This provides a vital part of the orangutan conservation effort, as building understanding within local communities will help to reduce threats. Additionally, the programmes links with the Durrell Wildlife Conservation Trust means they also have access to the latest research in orangutan medicine, husbandry and captive care (DWCT, 2006).
There are many protected areas across Sumatra, however illegal logging still occurs within the majority of them. The Leuser Ecosystem Conservation area, established in 1998, is considered a conservation ‘stronghold’ for orangutan populations (Singleton et al, 2008). It is a 2.6 million hectare area consisting of two National parks and containing around 5,800 (over 85%) of the remaining Sumatran orangutan population (Mittermeier et al 2009). It is the only conservation area within Sumatra with viable populations of the Sumatran orangutan, Sumatran tiger, Sumatran Rhinoceros and the Sumatran elephant. This shows that the Leuser Ecosystem Conservation area is highly important in the conservation and protection of the Sumatran orangutan. However, the national park is predominantly a mountainous region, which is highly unsuitable for the lowland orangutan species. This means that most of the orangutan population is found outside of park boundaries, leaving them even more vulnerable to habitat destruction. It is estimated that only around 30% of the orangutan population in Sumatra are found within park boundaries (Mittermeier et al, 2009), causing more problems and difficulties for their conservation.
The Sumatran orangutan was listed on Appendix I of the Convention on International Trade in Endangered Species of wild fauna and flora (CITES) in 1975 (DWCT, 2006). This means that no trade is allowed in live orangutans or orangutan products. The ban was put in place due to the expanding pet trade in Indonesia, and by 1980 over 30,000 orangutans had been killed as result of this trade across Sumatra and Borneo (DWCT, 2006). In addition the species has been protected under Indonesian domestic law (Singleton et al, 2008). Act no.5, which was made law in 1990, legally protects the orangutan from hunting throughout its range. The Act also aims to protect “environmental support structures” and preserve biodiversity in Indonesia. However, a ban on hunting is extremely difficult to enforce, and current law enforcement of legislation appears to be very weak.
Many foreign non-governmental organisations (NGO’s) have invested an interest in the future survival of the Sumatran orangutan. For example, the Durrell Wildlife Conservation Trust based in Jersey joined the effort to conserve Sumatran orangutans in 1968. Durrell has contributed greatly to the survival of the species, breeding 7 babies in Jersey for the international Sumatran orangutan breeding programme (DWCT, 2006). The trust also helps by sharing information with orangutan rehabilitation centres, as well as sending experts to the field in Sumatra to help in the rehabilitation process. Some governmental support for the protection of the Sumatran orangutan has also been shown. Through the United Nations Programme on Reducing Emissions from Deforestation and Forest Degradation in Developing Countries (REDD), the Norwegian government pledged US$1 billion to Indonesia to reduce deforestation rates (Butler et al, 2009).
Success of species recovery to date
The Sumatran orangutan has been listed as Critically Endangered by the IUCN since 2000 when it was first categorised (Singleton et al, 2008). The species data was re-examined in both 2007 and 2008, and in both cases it was found to still be Critically Endangered (Singleton et al, 2008). The population in Sumatra has been decreasing since the 1900s, with the most recent decline from 7,300 individuals in 2004 (Singleton et al, 2004), to around 6,500 in 2008 (Wich et al, 2008). It appears that, despite efforts to restore orangutan populations over the last 40 years, the species recovery has been unsuccessful to date. The predominant reason behind the continued decline of orangutan populations is the sustained level of deforestation, allowed by legal logging permits, illegal logging, poor law enforcement and ultimately corruption. Legislation is ineffective and reserves are not sufficiently policed, allowing commercial forestry to continue to occur even within protected areas. The rate of illegal logging to legal logging is 4:1 (DWCT, 2006), meaning that without drastic improvements in law enforcement orangutans will remain at constant threat of extinction. Furthermore, despite the illegalisation of trade in orangutans, the pet trade for the species is still booming throughout Indonesia. Although the forestry department are responsible for confiscating many illegally owned orangutans for reintroduction, a huge proportion of individuals remain in human possession. The current level of protection for orangutans is not enough to combat the threats to the species.
The most successful recovery attempt has been through the rehabilitation centres, but even they have a limited capacity. The rehabilitation process is only able to reintroduce a relatively small number of individuals, with one centre returning 125 orangutans to the wild over a ten years period. Over the same 10 year period only 3 wild births from ex-captive mothers occurred, and a high infant mortality was found at many release sites (Russon, 2009). Several observations of released orangutans at Bohorok release site showed individuals returning ill, underweight or wounded by wild counterparts (Dellatore, 2009). It is clear that there are still some problems with the rehabilitation and reintroduction process, and room to expand projects to a larger scale. However, it is also evident that these projects are the most successful aspect of the species recovery to date. The centres carry out highly important medical and genetic screening of individuals. orangutans are susceptible to human diseases, and the risk of spreading disease is great, so medical screenings help prevent disease from entering wild populations. Genetic screening is also highly valuable, as it helps monitor genetic diversity and maintain a healthy population. Rehabilitation centres also play an important role in orangutan welfare, allowing the confiscation of poorly kept individuals and providing safe places to go (Russon, 2009). In this aspect, they are an important part of the limited law enforcement available. Finally, the centres provide vital infrastructure and logistical support in the translocation of wild orangutans away from deforested areas (Beck et al, 2007).
Recommendations for future management practices It is estimated that if the current rate of orangutan decline is sustained, we could see a further 50% loss of the population within ten years (Mittermeier et al, 2009). In order to ensure the Sumatran orangutans future, drastic action needs to be taken. Conservation of the species relies on immediate improvement of forest and wildlife laws, an increase in consideration for biodiversity in land use planning, and greater law enforcement effectiveness.
The implementation of patrols to prevent illegal activity is vital as the first step to stopping illegal logging (Mittermeier et al 2009). In order to do this regular funding is required to put operations in place, and a forum for monitoring the enforcement of current legislation needs to be established. It is also important to implement anti-hunting patrols, as even very low hunting levels have strong deleterious effects (1% annual hunting rate sustainable) (Marshall et al, 2009). Patrols will also stem some of the supply to the pet trade, and attempt to reduce levels of illegal logging. In addition it is advised to temporarily halt legal logging and forest conversion, as well as road development plans (Mittermeier et al, 2009) in order to establish a more viable orangutan population. However, it is unlikely that the Indonesian government would halt development plans as it is essential for the country’s economic growth. A final step in the improvement of law enforcement would be the establishment of more patrols to confiscate illegally owned and poorly kept individuals to be taken to rehabilitation centres. This means that it is also vital to ensure the future expansion of rehabilitation centres across Sumatra. It is important to build capacity within current centres, as well as establishing new release sites across the island to restore populations in areas outside the Aceh province. Funding and volunteers would be required to expand the reintroduction projects across Sumatra.
The future of orangutans also relies on the provision of protected areas and reserves with strict controls to prevent illegal activity from still occurring. Again, this would involve the supply of regular reserve patrols and stringent regulation. National park perimeters should also be increased to enhance the conservation areas. It is important to include large areas of forest below 1000 metres above sea level within the protected areas (Singleton et al, 2008), as this is the orangutans primary habitat. Habitat restoration is also needed within the protected areas in order to make it suitable for orangutan reintroduction. In addition, the re-establishment of habitat corridors is greatly needed (Robertson and van Schaik, 2001) to improve genetic flow between fragmented populations. Improving habitat connectivity will increase genetic diversity and therefore make the species more adaptable to its constantly changing environment. The conversion of any remaining orangutan habitat to other uses should be strictly prohibited immediately, as only a very small fraction remains. In order to do this, alternative livelihoods will need to be provided to many local communities which may have relied on the land. This should be done by employing locals in orangutan conservation projects, helping with rehabilitation, habitat restoration and law enforcement. Not only will this provide an income for communities, it will provide an economic incentive to protect orangutans, and may potentially start to change local opinion of the species. Building tolerance of the species and changing attitudes towards them is an important part of their conservation. It is important to address the human-orangutan conflict, especially as in the future more orangutans are likely to be living in close proximity to humans. In Batang Serangan in Northern Sumatra, a small group of orangutans were found to live in peaceful co-existence with farmers. The landscape is made up of degraded natural forest, smallholder farms and oil palm monoculture plantations (Campbell-Smith et al, 2011). Although not an ideal habitat for orangutans, the mixed landscape was still suitable for the small group to live. Once tolerance of the species has grown, it would be possible to begin establishing small populations in these mixed agro-forest systems which occur across Sumatra. The ultimate aim is to create a landscape of primary lowland forest within protected areas, joined by corridors through major agricultural land. With the addition of further release sites, a connected habitat and better law enforcement, it is possible to establish viable populations across the island of Sumatra.
Conclusion In order to reduce the current threats to the Sumatran orangutan immediate action needs to be taken. The species’ critically endangered status and its vulnerability to habitat destruction mean it is at great risk of extinction if further protection measures are not put in place. By following some of the recommendations laid out above, and increasing the level of support for orangutan projects, the species may yet have a future.
Overview of Mammography and its Importance
Mammography is the radiographic imaging of the breasts. It is a special diagnostic and screening tool of the human breasts. A mammography is done with specific x-ray equipment which is able to find tumors too small to be felt. Mammography examination’s ultimate goal is the early detection of breast cancer, typically through detection of characteristics masses and / or micro calcifications. A mammogram is the best radiographic method available for early breasts cancer detection. It is ideal and indispensable for women above the age of 40 years old, for whom the risk of breast cancer is increased. Like x-rays, mammogram uses doses of ionizing radiation to create images but at lower dose amplitude-x-rays (most often around 0.7mSv). Radiologists then analyze the produced images for any abnormalities. A longer wavelength x-rays (typically Mo-K) is normally used for mammogram compared to those used in radiography of bones. Like many other medical tests, mammograms are not 100% accurate. Therefore, a regular mammogram scheduling is needed to detect any early breasts changes before any obvious signs or symptoms show up. It is also scientifically proven that mammogram can reduce breast cancer mortality rate by more than a third. Despite its function in early detection of breast cancer, mammography has a false-negative (missed cancer) rate of at least ten percent. This is due to the dense tissue obscuring the cancer and the large overlap of cancer appearance in mammograms with normal tissues appearance.
Mammography first started in 1960s. However, modern mammography has only existed since 1969 when the first x-ray unit dedicated to breasts imaging was made available to the public. Such examination as a screening device became standard practice by the year of 1976. Mammography then continues to improve as lower dose of radiation able to detect smaller potential problem earlier. Throughout the years, mammography has made advances to further improve its diagnostic ability. Digital mammography and computer aided detection are two examples of recent advances in the field of mammography. Digital mammography, also known as full field digital mammography (FFDM), is a mammography system in which solid-state detectors that convert x-rays to electrical signals replace the conventional x-ray film. These detectors are similar to those found in digital cameras where electrical signals produced are used to create images of breasts which are then projected on a computer screen or printed on a special film similar to conventional mammograms. A digital mammogram is essentially the same as a conventional film screen mammogram. Computer aided detection (CAD) systems help to detect abnormalities by using computer software. A digitized mammographic image that can be obtained either from a digitally acquired mammogram or a conventional film mammogram is used by the computer aided systems. The computer software then searches for abnormal areas of mass, density or calcification that may indicate the presence of cancer. It highlights the abnormal areas on the images, alerting the radiologists to the need of further analysis.
A special mammography machine is used for the screening of breasts. The machine comprises of an x-ray tube connected to a breasts support which houses the film cassette or imaging device on a C shaped arm, with moveable compression paddle between the two. There are few standard functional requirements for the mammography machine in order to produce a good quality image. The high voltage generator of mammography machine shall supply a near direct current high voltage with ripple less than 5 percent. Most modern mammography machines have a automatic selection for kilo voltage (kVp) output in order to optimize contrast. The generator produces a constant potential and the high voltage applied to the tube must be from 22 to 35kVp in increments of 1kVp. The focal spot size of mammography machine should be as small as possible to ensure adequate resolution. A focal spot size of 0.3mm is recommendable for general mammography and 0.1mm (small focus) for magnification views. The tube current of mammography machine should be set as high as possible in order to minimize exposure time and thus reducing the likelihood of motion artifact. A moving grid with grid factor of less than 2.5 at 30 kVp is essential to ensure optimum image quality. An automatic exposure control (AEC) is important in mammography machine. This is due to the wide variation in breasts sizes and compositions. There is little scope for mAs selection errors as there is a need for high radiographic contrast and consequently the system has low latitude. As for image recording material, most of the mammography facilities are still utilizing traditional cassettes, intensifying screens and single emulsion film with processing being taking place. Mammography usually uses cassette containing a single intensifying screen and the film which is usually green sensitive has a single emulsion layer. Both these equipment are essential to give optimum resolution. A mammography film requires high spatial resolution. It should has enough speed to ensure that the dose is acceptable without being so fast that it causes visible quantum mottle and high contrast with enough latitude to show both dense glandular tissue and the skin edge. Quality control, assurance programs and strict processing parameters are vital to ensure the standard in film quality is not compromised. Any reduction in film quality may lead to misinterpretation of image and incorrect diagnosis. In the modern days, digital mammography is slowing making its way to the imaging field. This modern modality has some advantages over the conventional film mammography. The examination time and time between examining patients decreases as chemical processing and changeover of cassette is no longer necessary. Markers can be applied on image digitally. Images produced can also be manipulated. One of the major advantages of image manipulation is the ability for image magnification with significantly less unsharpness compared to those associated with macro or magnification images that are sometimes required to demonstrate suspicious areas already seen on mammograms. Unlike the conventional magnification views, digital magnification does not involve an additional exposure to radiation.
Patients are required to do some preparations prior to a mammography examination. Fasting or observation in particular dietetic rules days before mammogram examination is not necessary. However, for women sensitive to caffeine, they shall refrain from taking caffeine containing products such as cola, chocolate and coffee two weeks before undergoing the test. This is because caffeine could make the breasts more tender which may affect the quality of radiograph. Menstrual cycle phase usually does not affect the outcome of the examination. However, it is also highly recommendable to schedule for mammogram one week following patients’ menstrual cycle. This is so as the breasts are less tender compared to that during pre-ovulatory and postovulatory period (half cycle) as well as during premenstrual period. It is also advisable for patients to wear two piece clothing on examination day to ease the undressing process for mammogram. Cosmetics, oils, creams, lotion and talc or deodorant must not be applied hours prior to test at the underarms and breasts areas. Failure in doing so may result in those appearing in mammogram as calcium spots. Patients are also encouraged to bring along all previous mammograms for comparison purposes by the radiologist. Most often, mammograms are done on older patients compared to younger patients. this is due to the breast tissue changes during life. The breast tissue density in younger women often makes mammogram rather difficult to interpret. However, as women age increases, some changes in the structure of breasts occurs as glandular and fibrous tissues reduce in size and this results in breasts tissues become more fatty. On the examination day, a simple interview with the patients is conducted before the examination takes place. They will be asked on any prior surgeries history, family or personal history of breasts cancer as well as hormone use. It is also the responsibility of the radiographer or technologist to enquire the patients’ last menstrual period as to determine whether the patient is pregnant. Pregnant patients are not recommendable for such examination. Upon completion of the short interview, patients are then ushered to change into hospital gown and remove all potential artifact before proceeding for the examination.
When the examination takes place, the breast is compressed using compression paddle on the mammography unit. A parallel plate compression evens out the breast tissue. Compression of breast reduces the thickness of tissue that x-rays penetrate, decreases the amount of scattered radiation, and reduces the required radiation dose and holding the breast (remove movement unsharpness) still and thus improving the image quality. Both craniocaudal, CC view (head to foot) and mediolateral oblique, MLO (angled side view) of the breast are taken in screening mammography. Extra views such as geometrically magnified and spot-compressed views of particular area of concern may be taken in diagnostic mammography. While performing the craniocaudal (CC) view, the mammography unit is positioned with the breast support table (image receptor holder) horizontal and the height adjusted to slightly above the level of patient’s inframammary angle. The patient is then instructed to face the machine, standing with approximately 5-6cm back, feet facing the machine but body rotated 15-20° away from the side under examination. This is so that the breast under examination is brought closer to the image receptor holder and aligned with the center of it. The patient’s arms hang loosely by her side and head is turned away from the side to be examined. The breast is then lifted gently up and away from the chest wall of patient. While supporting the breast, the height of the machine is adjusted so that the image receptor holder makes contact with the breast at the inframammary fold and the breast is approximately 90° to the chest wall. The breast is then carefully placed in contact with the cassette. Hand is then slowly removed from the breast, whilst ensuring that no skin folds are created underneath the breast. Patient’s arm of the side under examination is then flexed at the elbow and the hand is placed on the patient’s lower abdomen or relaxed at the side of the trunk. This relaxes the pectoral muscle. Patient’s shoulder is gently pressed down to bring the outer quadrant of the breast into contact with the image receptor. Slight pressure is maintained at the patient’s back to ensure she does not inadvertently pull back from the unit and cause some tissue to be lost from the resultant image. Radiographer’s thumb is then placed n the medial aspect and middle finger on the superior aspect of the breast, gently pulling forward towards the nipple while the compression is applied slowly. Radiographer’s other hand is placed on the patient’s shoulder of the side being examined to ensure that it stays relaxed. The light beam diaphragm can be used during the application of compression. This is to ensure the nipple is in profile, all breast is included in the main beam, both medial and lateral margins are included, no skin folds and an adequate breast compression. A CC marker with left or right identifier is positioned on the axillary edge of the cassette, within the primary beam. Patient is strongly advised not to move and the projection is done quickly after that. The same CC procedure is performed on both left and right breast. The CC view with the same procedure is performed on patient’s both breasts.
Besides the CC view, a mediolateral oblique (MLO) view of patient’s both breasts is also taken for screening mammogram. The positioning of patients for left breast MLO view is to have patient facing the mammography unit with feet pointing towards it. From the position used for CC projection, the unit is rotated through 45° with the x-ray tube on patient’s right and the beam angled caudally. The height is adjusted to bring the lower border of cassette 2.5cm below the inferior portion of the left breast. It may be necessary to further adjust the height during patient positioning. The lateral edge of the left of the thorax is in line with the image receptor holder so that the left breast also lies next to it. The radiographer then stands behind and slightly to the right of patient. Patient is then asked to raise her left arm and chin. The raising of chin may prevent the superimposition of the mandible over the breast. Patient’s left breast is then held with right hand and patient is kept in position by holding on to the right shoulder. Patient who is advised to lean forward into machine with feet still facing forward is asked to lean slightly laterally. The left axilla of patient should lie over the corner of image receptor that is nearest to chest wall. Radiographer then proceeds to life the posterior skin edge of the left axilla to prevent skin folds from occurring. Patient’s left arm is then pulled across and behind the image receptor holder. Patient’s elbow is also flexed so that the forearm can be placed on the unit for support and elbow is positioned so that it hangs down comfortably behind the holder. The humeral head is gently pushed forward and the corner of image receptor lies in the axilla, anterior to posterior fold. While the patient maintains the position, radiographer double check to ensure there is no skin fold in the axilla or under the lateral aspect of the breast and to check for and remove any creases at the inframammary angle. The breast is then lifted up and away from the chest wall while holding the patient’s left shoulder. The breast is then placed on the image receptor and compression is applied. Projection on the left breast is then taken. The same MLO view projection is then repeated vice versa on the right breast of patient.
Upon completion of the examination, patient is advised to change back to her clothes. Patient is then escorted out and at the same time patient is informed on her next appointment for the review of results with the radiologist. Any discussion on the results with patient prior to the review of radiologist is prohibited.
Mammography has been long known to be an effective modality for breast screening. Such examination improves physician’s ability to detect small tumors and early treatment can be performed to reduce mortality rate. Mammogram is also the only proven method to reliably detect tumors as well as all types of breast cancer, including invasive ductal and invasive lobular cancer. Radiation used in mammography examination is of low dosage and usually has no side effects towards patient. Moreover, radiation does not remain in patient’s body after the examination. Despite its benefits in the purpose of screening and diagnostic, mammography poses certain risks towards its patients. There is a slight chance of cancer from excessive exposure to radiation. The effective radiation dose for this procedure varies depending on the thickness of tissue. However, radiographers are trained to use the lowest radiation dose possible for radiation protection purposes while producing the best images for evaluation. False positive mammogram is also one of the risks in performing mammogram. Five percent to 15 percent of screening mammograms need more testing such as additional view for mammograms or ultrasound to further determine suspected abnormality. Most of the further tests turn out to be normal. However if there is an abnormal finding, biopsy may be performed on the patient to determine whether the tumor is benign or malignant. Women above the age of 40 are normally advised for a mammogram annually as they pose a higher risk of being diagnose with breast cancer. However, an ultrasound is more preferably performed on patients below the age of 40 as their breasts tissue is denser. Last but not least, women of all age should go for routine breast check up regularly for early detection on any breast abnormalities.
Above diagram shows a conventional cassette film mammogram machine.
Above diagram shows a Craniocaudal (CC) mammography view in progress.
Above diagram shows a Mediolateral Oblique (MLO) view in progress.
Above diagram shows a normal (left) mammography image compared to cancerous (right) mammography image.