Comprehensive Overview of Transvaginal Scan (TVS)
ASIF KHAN
Introduction
Transvaginal Scan (TVS) is a diagnostic imaging technique commonly used in gynecology to visualize and assess the female reproductive organs, including the uterus, ovaries, and surrounding structures, using ultrasound technology.
TVS plays a crucial role in the evaluation of various gynecological conditions such as infertility, abnormal bleeding, pelvic pain, and ovarian abnormalities. It provides detailed images of pelvic structures, aiding in diagnosis, treatment planning, and monitoring of gynecological disorders.
Anatomy of TVS
TVS allows for detailed visualization of the female reproductive anatomy, including:
Uterus: Fundus, body, cervix
Ovaries: Follicles, corpus luteum, ovarian stroma
Cervix: Length, morphology These structures are examined to assess their size, shape, position, and any abnormalities that may be present.
Physiology of TVS
How TVS works: During TVS, high-frequency sound waves are emitted from a transducer inserted into the vagina. These waves bounce off pelvic structures and create real-time images on a monitor, allowing for the visualization of the internal organs.
Patient positioning and preparation: Patients are positioned in lithotomy position, lying on their back with legs elevated and knees bent. The transducer is gently inserted into the vagina after applying a water-based gel for lubrication. Patients may be advised to empty their bladder prior to the procedure to optimize imaging.
Organs of TVS
Uterus: TVS evaluates the size, shape, and position of the uterus, assessing for abnormalities such as fibroids, adenomyosis, and congenital anomalies.
Ovaries: TVS provides detailed images of the ovaries, including the size, number, and characteristics of follicles, as well as the presence of cysts or tumors.
Cervix: TVS assesses the length, morphology, and integrity of the cervix, aiding in the evaluation of cervical incompetence and other cervical pathologies.
Probe Use in TVS
Types of probes:
TVS probes come in various sizes and frequencies, including 5-9 MHz for general gynecological imaging and higher frequencies (up to 12 MHz) for detailed assessment of small structures such as the ovaries.
Technique for probe insertion:
The transvaginal transducer is gently inserted into the vagina, ensuring patient comfort and minimizing discomfort. Proper technique involves angling the transducer to obtain optimal imaging of pelvic structures.
Patient comfort measures:
To enhance patient comfort, providers should communicate effectively with patients, explain the procedure, and provide privacy and draping during the examination. The use of a warm gel for lubrication can also improve patient comfort during transducer insertion.
Follicular Tracking in TVS
Importance in fertility assessment:
Follicular tracking using TVS is essential in fertility assessment and monitoring. It involves serial ultrasound scans to monitor follicular development throughout the menstrual cycle, helping to predict ovulation timing and optimize fertility treatment protocols.
Timing and frequency of scans:
Scans are typically performed starting from the early follicular phase (around day 5-7 of the menstrual cycle) and continued every few days until ovulation is detected. The frequency of scans may vary depending on the individual’s menstrual cycle and response to treatment.
Criteria for follicle size and maturity:
Follicles are considered mature when they reach a certain size, usually around 18-20 mm in diameter. Maturity is assessed based on follicle size, growth rate, and the presence of a thickened, echogenic rim (corona radiata) surrounding the follicle.
Normal Reporting of TVS
Standard parameters for reporting:
Uterine size and shape: The uterus is assessed for size, shape, and symmetry, with measurements taken of the uterine length, width, and thickness of the endometrium.
Ovarian appearance and follicle count: Ovarian size, volume, and morphology are evaluated, with the number and size of follicles noted. A normal ovarian follicle count varies depending on the age and menstrual cycle phase of the individual.
Endometrial thickness: The endometrial thickness is measured in the sagittal plane, with variations in thickness observed throughout the menstrual cycle. A normal endometrial thickness in the proliferative phase is typically less than 10 mm, while in the luteal phase, it may range from 8-15 mm. Illustrative examples of normal TVS images: Include sample TVS images demonstrating normal uterine, ovarian, and endometrial findings, highlighting the key parameters mentioned above.
Scanning Methods of TVS
Sagittal, transverse, and coronal views:
TVS can be performed in various scanning planes, including sagittal (longitudinal), transverse (axial), and coronal (cross-sectional) views, allowing for comprehensive evaluation of pelvic structures from different angles.
3D/4D TVS:
Advanced imaging techniques such as three-dimensional (3D) and four-dimensional (4D) TVS provide enhanced visualization of pelvic organs, enabling better assessment of anatomical relationships and spatial orientation. These techniques offer valuable diagnostic information, particularly in complex cases or for surgical planning.
Doppler imaging:
Doppler ultrasound can be used in conjunction with TVS to assess blood flow in pelvic organs, including the uterus, ovaries, and pelvic vasculature. Doppler imaging aids in the evaluation of ovarian and uterine perfusion, helping to diagnose conditions such as ovarian torsion, endometriosis, and pelvic congestion syndrome.
Common Diseases in TVS
Polycystic Ovarian Syndrome (PCOS):
PCOS is a common endocrine disorder characterized by multiple small follicles in the ovaries, irregular menstrual cycles, and hormonal imbalances. TVS findings in PCOS may include enlarged ovaries with multiple small follicles arranged peripherally (string of pearls appearance).
Common Diseases in TVS
Ovarian cysts:
Ovarian cysts are fluid-filled sacs that develop within or on the surface of the ovaries. Types of ovarian cysts include functional cysts (e.g., follicular cysts, corpus luteum cysts), dermoid cysts, and endometriotic cysts (endometriomas). TVS helps differentiate between various types of ovarian cysts based on their characteristic features and assists in determining the need for further evaluation or intervention.
Common Diseases in TVS
Fibroids:
Uterine fibroids (leiomyomas) are benign smooth muscle tumors that develop within the uterine wall. TVS enables the detection and characterization of fibroids, including their location, size, and impact on surrounding structures. Fibroids may cause symptoms such as pelvic pain, abnormal bleeding, and pressure symptoms, necessitating treatment or surveillance.
Common Diseases in TVS
Endometrial abnormalities:
Endometrial hyperplasia, polyps, and other endometrial abnormalities can be detected and evaluated using TVS. TVS allows for the measurement of endometrial thickness and visualization of endometrial pathology, aiding in the diagnosis and management of conditions such as endometrial hyperplasia, endometrial polyps, and endometrial cancer.
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