Breast Cancer Diagnosis: Benefits And Shortcomings Of Imaging Techniques

Mammography

Discuss about the Intended for Journal of Medical Radiation Sciences.

Both men and women globally have breast cancer and this is an emerging leading killer. Currently, it is the commonest cause of mortality in women and 16% of cancer deaths in adult women are due to it (Campbell, 2008). It is prevalent type in women globally, accounting for twenty five percent of all cases. An estimate of 16.8 million cases and 522, 000 deaths were seen in the year 2012.Mostly, it is rampant in developing countries and women are majorly affected. This type of cancer affects breast. Women with this cancer show lump in portions affected, skin dimpling, fluid oozing from nipples and breast shape change. Among the risk factors associated with this cancer are indulging in alcohol, obesity, being female, ionizing radiations, family history and having children late among others (American Cancer Society, 2013). One’s recovery is function of early notice. Diagnostic breast imaging involves capturing the interior images of a woman’s breast. The abnormalities and the symptoms their causes in a patient is determined by this kind of imaging. Imaging methods include mammography, magnetic resonance and ultrasound. Diagnosis and classification of cancer of the subject is also made possible by these medical imaging techniques. Classification is hinged upon grade, histopathology or cancer stage. This article looks at the benefits and shortfalls of imaging techniques for breast cancer diagnosis, and their merits and demerits. Three areas are discussed herein (Freeman, 2010).

Mammogram refers to pictography of breast from x-rays. It ascertains for breast cancer in women with unknown conventional signs. This is a screening mammogram. Two x-rays images that show the nature of every breast are captured here. These x-ray images enable a medical practitioner to detect tumours that cannot be ordinarily felt. They do detect tiny deposits of calcium (micro calcifications) which normally indicates presence of breast cancer (Puliti, Duffrey& Miccinesi, 2012). We also have a mammographic diagnostic. This is used to determine the existence of the actual breast cancer once conventional signs listed are observed. This type of mammogram also evaluates changes observed during screening mammogram (Gheonea et al., 2011).

Screening mammogram helps in early detection of breast cancer which may facilitate early commencement of treatment before the disease advances. One may also be exposed to a host of risks. Therefore demerits must be analysed parallel to benefits. Screening mammogram may offer results that may be both false and positive. This occurs when radiologists makes decision that a mammogram is abnormal when in actual sense there is no cancer. This scenario is overcome by ensuring that all abnormal mammograms are reanalysed with more accurate as diagnostic mammograms, ultrasound, and/or biopsy to confirm the presence of the disease in question. False-positive result can be significant e.g. psychological distress and anxiousness. Additional tests for confirming cancers are mostly costly and consume time (Berman, 2007). Additionally, location of cancers and a condition called ducal carcinoma in situ is possible through screening mammograms. However, ducal carcinoma in situ are not life threatening since they are merely accumulation of abnormal cells in the lining of the breast ducts. Exaggerated diagnosis may also result. Consequently, “overtreatment” may also occur. Fatal effects may emerge from overtreatment. Furthermore, mammograms expose one to tiny magnitude of radiations which is not risky. However, repetitions of x-rays may in the long run cause cancer. Taken together, the benefits are more than harm due to radiation (James, 2004).

Shortcomings of Conventional Mammography

Similar to conventional mammography, the technique of pictures of breast by x-rays. An obvious difference is that conventional mammography stores images on a film whereas, in digital mammography, a computer file stores the breast images. The digital image is modifiable, magnified, or can be manipulated to reveal more details. Advantages associated with it are many and include sharing of the electronic image by the health care providers in different locations, the minor differences between normal and abnormal tissues may be easily noticed, it reduces the follow-up procedures and no need for many images thereby reducing the exposure of a patient to radiation (Pisano, Chandramouli, & Hemminger, 2005). Any health facilities offering digital mammography services must obtain license from the Food and Drug Administration. No contrasts between the processes of conducting conventional or digital mammography (Nishikawa, Mawdsley, A. Fenster, & Yaffe, 1987).

This may also be termed as chemosynthesis. It is a special type of digital mammography where x-ray machines thin sliced images at various angles. Software also offers reconstruction of images. This extreme x-ray magnitude is utilised by this technique. Usually, it is performed concurrently with standard two-dimensional digital mammography hence the radiation magnitude is a bit higher than that of conventional mammography. The accuracy of this or two-dimensional methods is unclear. Therefore, it is not known whether it may be superior or inferior to the standard mammography in managing false-positive results and early cancer diagnosis (Karellas, & Vedantham, 2008).

This is an imaging technique used for screening of tumours and other breast abnormalities. Frequencies of high sound waves are used in production of detailed interior breast. It uses no radiation and is therefore safe for pregnant women and breast feeding mothers. If one has a suspicious lump in the breast, it can detect if the lump is a mere fluid-filled cyst or a tangible tumour. Ultrasound can be used to visualize a lump that is not clearly visible on a mammogram. It enables medic to precisely locate and lump. In an ultrasound procedure, gel is spread on ones breast, and tiny instrument (transducer) is passed above breast. Sound waves are emitted and reflected by a transducer to form images on a screen. It usually confirms presence or absence of cancer. However, ultrasound can examine a swelling but cannot confirm whether it’s cancerous nature. Additional tests on fluid from the breast are required. Overall, this technique is suitable for a group of women who must avoid radiation, such as women aged below 25, pregnant women, breast feeding women and women with silicone breast implants. This technique does not pose any known risk to a woman due to its non-radiation nature (Itoh, 2007).

Digital Mammography

Breast ultrasound has a number of advantages which makes it to be a common imaging technique in breast cancer diagnosis. It is non-invasive and effectively detects presence of a lump. It is to a large extent painless unless ones breasts are over sensitive (Kaplan, 2001). Ultrasound technology is usually less costly and is available. Real time images of soft tissues are always very visible. It is harmless since no radiation is used (Gordon & Goldenberg, 1995).

Although ultrasound has many advantages it has a few limitations which must be taken into account whenever the decision to undertake a breast ultrasound is to be made. It replaces mammograms in women above forty years. It has to be followed by magnetic resonance imaging or biopsy, and ultrasounds cannot detect calcifications in breasts which in some cases are a sign of breast cancer, in many cases, ultrasound is never covered by insurance policies. It is also worth noting that choosing the right radiologist is crucial in this technique (Weigert& Steenbergen, 2102). 

This is usually a non-invasive technique used for treating or diagnosing various medical ailments. In magnetic resonance imaging, magnetic field which is quite powerful, pulses of the radio frequency and a computer generates detailed picture of a given part of the body or tissues. Magnetic resonance imaging does not use ionizing radiation (Baek, Yu, Chen, Nalcioglu, & Su, 2008). Magnetic resonance imaging of the breast shows more valuable information on the breast that other imaging techniques may not reveal. This does not replace other methods but supplements them. It is important for screening women who are highly predisposed to breast cancer e.g. due to family history, MRI is usually an indicator of the extent to which cancer has reduced after new cancer diagnosis, it helps in deciding whether abnormalities observed in breast by the other techniques require biopsy or can be left alone, it is also suitable for evaluating lumpectomy, and magnetic resonance, imaging may be used to monitor how well one is responding to chemotherapy, the amount of tumour remaining before a surgery is conducted (Harms, 1998).

No ionizing radiation is used here. In this case, hydrogen atoms that emanates from the body naturally redirected and aligned by the radio waves while one is in the scanner without any alterations in chemical components of the tissues. When hydrogen atoms resume their normal alignment, energy that varying in accordance with the type of body tissues from which they emerge is emitted (Saslow, Boetes, & Burke, 2007). Energy and images are captured by magnetic resonance scanner. Production of field of magnet is via passage of an electric current through wire inside a magnetic resonance imaging unit. Coils located in the machine or near the part of the body being scanned, send and receive radio waves, resulting in signals detection on the coils. Signals, series of images are computer generated. Thin body slices are shown. Radiologist studies the images from different angles (Baek et al., 2008).

Three-Dimensional Mammography

Magnetic resonance imaging machine is a huge cylindrical tube surrounded by a circular magnet. Patients lie on the mobile surface. It slides towards a magnets center. A magnetic resonance imagingunit, known as short-bore systems, are designed in such a way that the patient is not surrounded completely by the magnet. A new magnetic resonance imaging unit is therefore designed to accommodate larger patients with claustrophobia and has a larger diameter bore. There is another type called an open magnetic resonance imaging. This is also meant for examining big-sized patients or those suffering from claustrophobia. Newer open magnetic resonance imaging units have the advantage of producing high quality images. Usually computer for image processing is located in a different room from the scanner (Saslow et al., 2007).

Benefits of magnetic resonance are myriad. They include its non-invasive nature which does not expose a patient to ionizing radiation, it is critical in detecting and staging breast cancer, it also helps in evaluating women at risk of breast cancer, it normally provides direction for biopsy and the contrast material used in magnetic resonance through imaging technique which rarely produce allergic reactions unlike the contrast material used in x-rays. The risks that a patient may be exposed to include excessive exposure to sedation, implanted medical devices containing metals may be affected or lead to problems during the procedure, MRI may also carry a slight risk of an allergic reaction if contrast material is injected and it is sometimes advisable for a breast feeding mother to avoid breastfeeding for 24-48 hours (Morris, 2002). 

The magnetic resonance imaging has a number of limitations which must be taken into account before deciding on it. Quality images are only obtained if one is still and adhere to breath-holding instructions. It does not require anxiety or confusion; a huge person may fail to fit an opening of many magnetic resonance imaging machines. Availability of a metallic object or the movement of a patient may affect quality of image. An irregular heartbeat that may also interfere with image quality. It is also not advisable for pregnant women during first trimester. It is only used during this stage of pregnancy if it is very necessary. Magnetic resonance imaging may not differentiate between a cancer tissue and fluid. It is more costly and consumes more time (Kristoffersen, Aspelin, Perbeck, & Bone, , 2002).

This is likely to be the newest techniques for breast examination. Cancer affected tissue is hard and that is what this method anchors on. Several elasticity imaging approaches are available in the market under review. In recent years, it has been examined the elasticity of breast tissues. Findings have shown that a malignant tissue is more elastic than that of a normal tissue. The mechanical properties of tissues can be used for tissue diagnosis (Itoh, Ueno, & Tohno, 2006). Sonoelastography compares stiffness of lesions and those of the nearby tissues. Various colours or shades of grey are super imposed on two-dimensional images. Areas that are stiff are usually coded as dark-grey or blue tints. The softer, elastic tissues appear reddish, greenish or show grey shades (Tardivon et al., 2007).

Breast Ultrasound

This technique allows a medic to quantitatively measure the entire chorine in the tumours. It has been demonstrated that chorine is lower in normal breast tissue than in a malignant tumour (Avril et al., 2001). As an adjunct to magnetic resonance imaging, magnetic resonance imaging shows superior sensitivity and specificity. Magnetic resonance imaging is suitable for early determination of neoadjuvant chemotherapy. A number of studies have shown that magnetic resonance spectroscopic imaging is very specific (Hu et al., 2008).

Perfusion and diffusion imaging techniques differentiates masses that are benign from themalignantones. It is known that the apparent coefficient diffusion which is a measure of cellularity is smaller in invasive malignancies. Additionally, tumours that are malignant have been shown to have more in them than the normal and benign tumours. This provides a way of characterizing tissues in a non-invasive fashion (Gheonea et al., 2011).

Here, injection of a substance that is radioactive is usually is done on one’s arm vein. It then travels to various portions of the body where cancerous areas are extremely. A positron-emission tomography scanner forms images that it detects from the gadgetemitting small amounts of radiation. A combination of the positron-emission tomography scanner and computer tomography shows functional and anatomical aspects of the suspicious cells (Avri et al., 2000).

Conclusion

Medical imaging is an interesting field that has given rise to important methods for detection of cancer of the breast at different stages. The methods detailed above are pivotal for diagnosing and classification of breast cancer based on factors such as histopathology, grade and stage. Each of these techniques has its pros and cons and is useful for diagnosis breast cancer at various stages. It is necessary for a medical practitioner to properly weigh benefits and harms that each procedure may have. From the discussion above it is emerging that the limitations of each technique does not outweigh the benefits of controlling a spreading breast cancer. This is because most of the limitations are things that can be managed during or after performing an imaging technique. Medical imaging is therefore a field that holds promise for humanity especially with the upsurge of breast cancer in the recent past.

I would like to extend my gratitude to my faculty tutors for their encouragement and inspiration to undertake this review. In a special way, I thank the course instructor who introduced me to medical imaging and made me develop an interest in this field. I would love to acknowledge my dear parents and family members for supporting my studies and this review. Furthermore, I thank my friends and classmates for their understanding and providing me with ample time to work on this article. I thank my funder for providing funds to access internet and obtain relevant information for this review.

Advantages and Disadvantages of Ultrasound

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