Introduction:
Diagnosis is an essential part of the medical field. It helps to understand the disease entity and determine the treatment protocol. Medical imaging is one of the most advanced methods for visualizing tissues in detail. Among all the imaging methods, ultrasound is the most commonly used. Because of its non-invasive nature and economic cost, it is very popular among medical professionals. Certain physical and mechanical rules must be followed for a good ultrasound image.
Most importantly, the accurate orientation of the transducer tip and its closeness to the anatomical structure is necessary for proper imaging. In certain gynecological cases, the transvaginal approach is preferred for imaging pelvic organs. Detailed knowledge of this approach is necessary for proper imaging.
What Is the Ultrasound in Gynecology?
Gynecological ultrasound or gynecological sonography is a non-invasive technique. In this procedure, ultrasound sound waves are projected toward the organs through a transducer. These soundwaves bounce off the organs like an echo and are captured by the transducer, which then processes these data from an image of the object. The most commonly used method for ultrasound in gynecology is the trans-abdominal approach. This method is very useful for imaging the abdominal structure. Pelvic structures are viewed through the anterior abdominal wall in this method. As a result, several errors may happen. These are:
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As the distance between the transducer and the pelvic region increases, a lower frequency must be used to minimize image distortion.
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The beam degrading effect of the anterior abdominal wall, specifically in obese patients, distorts the images.
The transvaginal approach for ultrasound was first introduced in 1985. This method reduces the distance between the probe and the pelvic structures, allowing the use of higher frequency for better image quality.
Who Are Eligible for This Process?
Any woman above the age of sixteen is eligible for this procedure. Also, this technique can be used for transgender men, transgender women, and people who identify as asexual, intersex or non-binary person.
What Are the Indications?
Indications for the use of transvaginal ultrasound are:
Evaluation of Pregnancy:
Various stages and types of pregnancy can be evaluated in this method.
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Fetal Evaluation: Baby’s various physical structures, like the heart, head, and spine, are evaluated in this method. Any physical anomalies can be detected at this stage.
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Nature of Pregnancy: The nature of pregnancy, whether intrauterine (normal pregnancy) or ectopic pregnancy (fertilized egg is implanted outside the main cavity of the uterus).
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Abortive Process: The success of abortion is evaluated in this technique.
Infertility:
Baseline screening of the pelvic structures, their anatomy, the thickness of the lining, and the presence of any anomalies are identified in the technique. Follicular assessment and its monitoring (stages of maturation of the follicles) can be done through this process. A saline infusion sonogram is employed in trans vaginal technique to access the uterine cavity three-dimensionally.
- Abnormal Uterine Bleeding
This is the first liner of an imaging method for the detection of uterine bleeding both in premenopausal and postmenopausal women. Structural causes of the bleeding, like polyps (small limp of cells), adenomyosis (increase in the thickness of the uterus), leiomyomas (a group of benign smooth muscle tumors), and hyperplasia can be identified by this technique.
- Presence of Infection
Transvaginal sonography is used to detect pelvic inflammatory disease (infection of the upper reproductive system, including the uterus, fallopian tubes, and ovaries).
- Examination of Non - Gynecologic Entities
Non-gynecological structures like the urinary bladder, urethra, and distal-most portion of the uterus are examined by this process. Pathological conditions like urethral diverticula (formation of unwanted pockets in the urethra), periurethral masses, and funneling of the urethra can be diagnosed by this method.
What Is the Procedure?
The procedure for this technique can be divided into three parts:
Equipment:
The machinery used for this procedure includes:
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Ultrasound machine with a transvaginal ultrasound probe (Transducer, the frequency of the transducer is 5 to 7.5 MHz with an effective range of 7 to 10 centimeters).
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Ultrasound gel.
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Probe cover.
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Table for proper positioning of the patient.
The technician will perform transvaginal ultrasonography, and after completion, the sonography images are uploaded into the PACS ( Picture archiving and communication system) for analysis.
Patient Preparation:
Before starting the procedure, patients should be explained about the process, and written consent must be taken. For juvenile patients, parents' consent should be taken. A female attendant must be present in the examination, and patients’ dignity must be maintained. A full bladder is recommended for this procedure as it can displace the adjacent bowel loops. Patients are asked to undress from the waist and cover themselves with a gown. For examination purposes, patients are placed in the lithotomy position (supine position of the body when the patient is face-up, arms to the sides, but the legs are separated and raised).
Scanning Procedure:
The probe is covered with a latex condom to prevent contamination, and coupling gel should be placed inside the tip of the condom. The transvaginal transducer should be inserted into the lower vaginal canal under direct vision, with the transducer marker at the 12 o’clock position. To minimize discomfort, the transducer is pointed slightly downward towards the rectum while gently advancing into the vaginal canal. The probe is placed in the distal vagina or against the external cervical wall. The scanning procedure includes:
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For the sagittal scanning probe is moved in side to side direction.
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The transducer is moved in 90-degree angulation for the transverse and semi-coronal orientation.
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The transducer penetration should be changed for different structures to bring them within the field of view/focal zone.
What Are the Contraindications?
The contraindications regarding transvaginal ultrasound include:
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Pediatric patients.
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Recent vaginal surgery.
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Premature rupture of the placenta during pregnancy.
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Bleeding is associated with conditions like placenta previa (the placenta covers all the parts of the baby’s exit).
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Imperforated hymen.
What Are the Shortcomings?
The complications associated with this procedure are very minimal. Mild pain, discomfort, or rupture in the vaginal wall can be observed. One of the limitations of this procedure is the viewing field is limited. That is why it is often followed by transabdominal ultrasonography.
Conclusion:
The traditional transabdominal approach is not sufficient for imaging the pelvic structures. Transvaginal ultrasound provides better visualization of the female genital organs. It also helps in the observation of the fetus and urinary tract. Moreover, because of its non-invasive nature and better resolution. It is gaining popularity. Proper patient motivation and communication before the procedure are essential for a successful outcome.
