Screening for Breast Cancer
Cancer screening is testing done on people who may be at risk of getting cancer, but who have no symptoms and generally feel fine. Screening can find breast cancers when they are small, less likely to have spread and more likely to be treated successfully. Women ages 50 to 74 have a lower risk of dying from breast cancer when they are screened regularly with mammograms.
Mammography (also called mastography) is the process of using low-energy x-rays (usually around 30 kVp) to examine the human breast for diagnosis and screening. The goal of mammography is the early detection of breast cancer typically through detection of characteristic masses or microcalcifications.
Like all X-rays, mammograms use doses of ionizing radiation to create images. These images are then analyzed for any abnormal findings. It is normal to use lower-energy X-rays, typically Mo (K-shell x-ray energies of 17.5 and 19.6 keV) and Rh (20.2 and 22.7 keV) than those used for radiography of bones. Ultrasound, ductography, positron emission mammography (PEM), and magnetic resonance imaging (MRI) are adjuncts to mammography. Ultrasound is typically used for further evaluation of masses found on mammography or palpable masses not seen on mammograms. Ductograms are still used in some institutions for evaluation of bloody nipple discharge when the mammogram is non-diagnostic. MRI can be useful for further evaluation of questionable findings as well as for screening pre-surgical evaluation in patients with known breast cancer to detect any additional lesions that might change the surgical approach, for instance from breast-conserving lumpectomy to mastectomy. Other procedures being investigated include tomosynthesis. https://en.wikipedia.org/wiki/Mammography
Obstetric ultrasonography is the use of medical ultrasonography in pregnancy, in which sound waves are used to create real-time visual images of the developing embryo or fetus in its mother’s uterus (womb). The procedure is a standard part of prenatal care in many countries, as it can provide a variety of information about the health of the mother, the timing and progress of the pregnancy, and the health and development of the embryo or fetus.
Pregnant women should have routine obstetric ultrasounds between 18 weeks and 22 weeks gestational age to confirm pregnancy timing, to measure the fetus so that growth abnormalities can be recognized quickly later in pregnancy, and to assess for congenital malformations and multiple pregnancies (i.e. twins). Performing an ultrasound at the early stage of pregnancy can more accurately confirm the timing of the pregnancy and can also assess for multiple fetuses and major congenital abnormalities at an earlier stage.
In the first trimester, a standard ultrasound examination typically includes; Gestational sac size, location, and number, identification of the embryo and/or yolk sac, Measurement of fetal length (known as the crown-rump length), Fetal number, including number of amnionic sacs and chorionic sacs for multiple gestations, Embryonic/fetal cardiac activity, Assessment of embryonic/fetal anatomy appropriate for the first trimester, Evaluation of the maternal uterus, tubes, ovaries, and surrounding structures, Evaluation of the fetal nuchal fold, with consideration of fetal nuchal translucency assessment
Second and Third Trimester
In the second trimester, a standard ultrasound exam typically includes; Fetal number, including number of amnionic sacs and chorionic sacs for multiple gestations, Fetal cardiac activity, Fetal position relative to the uterus and cervix, Location and appearance of the placenta, including site of umbilical cord insertion when possible, Amnionic fluid volume, Gestational age assessment, Fetal weight estimation, Fetal anatomical survey, Evaluation of the maternal uterus, tubes, ovaries, and surrounding structures when appropriate
Dating and growth monitoring
Gestational age is usually determined by the date of the woman’s last menstrual period, and assuming ovulation occurred on day fourteen of the menstrual cycle. Sometimes a woman may be uncertain of the date of her last menstrual period, or there may be reason to suspect ovulation occurred significantly earlier or later than the fourteenth day of her cycle. Ultrasound scans offer an alternative method of estimating gestational age. The most accurate measurement for dating is the crown-rump length of the fetus, which can be done between 7 and 13 weeks of gestation. After 13 weeks of gestation, the fetal age may be estimated using the biparietal diameter (the transverse diameter of the head, across the two parietal bones), the head circumference, the length of the femur, the crown-heel length (head to heel), and other fetal parameters. Dating is more accurate when done earlier in the pregnancy; if a later scan gives a different estimate of gestational age, the estimated age is not normally changed but rather it is assumed the fetus is not growing at the expected rate.
Not useful for dating, the abdominal circumference of the fetus may also be measured. This gives an estimate of the weight and size of the fetus and is important when doing serial ultrasounds to monitor fetal growth. https://en.wikipedia.org/wiki/Obstetric_ultrasonography
The procedure is very much like an internal exam that is performed at your doctor’s office. This involves the insertion of a transducer into the vagina after emptying your bladder. The tip of the transducer is smaller than the standard speculum used when performing a Pap test. A protective cover is placed over the transducer, lubricated with a small amount of sterile gel and then inserted into your vagina which allows for better visualization of your pelvic organs. Then the required images are captured at various planes. When the exam is over the sonographer will wipe off the gel and disinfect the transducer.
Gynecologic ultrasonography or Gynecologic sonography refers to the application of medical sonography to the female pelvic organs, specifically the uterus, the ovaries, the Fallopian tubes, as well as the bladder,the adnexa, the Pouch of Douglas, and any findings in the pelvis of relevance outside of pregnancy
Transvaginal imaging utilizes a higher frequency imaging, which gives better resolution of the ovaries, uterus and endometrium (the fallopian tubes are generally not seen unless distended), but is limited to depth of image penetration. whereas larger lesions reaching into the abdomen are better seen transabdominally. Having a full bladder for the transabdominal portion of the exam is helpful because sound travels through fluid with less attenuation to better visualize the uterus and ovaries which lies posteriorly to the bladder. The procedure is regarded as not painful, noninvasive, and relatively safe as no radiation is used. Scans are performed by health care professionals call sonographers, or gynecologists trained in ultrasound.
Gynecologic sonography is used extensively :
- to assess pelvic organs,
- to diagnose and manage gynecologic problems including endometriosis,leiomyoma, adenomyosis, ovarian cysts and lesions,
- to identify adnexal masses, including ectopic pregnancy,
- to diagnose gynecologic cancer in infertility treatments
- to track the response of ovarian follicles to fertility medication (i.e. Pergonal).
Through transvaginal sonography ovarian cysts can be aspirated. This technique is used to obtain human eggs (oocytes) through sonographic directed transvaginal puncture of ovarian follicles in IVF.
Sonohysterography is a specialiced procedure by which fluid, usually sterile saline, is installed into the uterine cavity, and gynecologic sonography performed at the same time. The procedure delineates intrauterine pathology such as polyps, Asherman’s syndrome, or submucous leiomyoma.