Trans rectal ultrasound
Contraindications include an acute painful perianal disorder and hemorrhagic diathesis
but recent use should not be considered an absolute contraindication to biopsy.
Currently, the most widely used probe is a 7-MHz transducer within an endorectal probe,
which can produce images in both the sagittal and axial planes. Scanning begins
in the axial plane, and the base of the prostate and seminal vesicles are visualized first.
A small amount of urine in the bladder facilitates the examination. Seminal vesicles are
identified bilaterally, with the ampullae of the vas on either side of the midline.
The seminal vesicles are convoluted cystic structures that are darkly anechoic.
Men who have abstained from ejaculation for a long period may have dilated seminal vesicles
Next, the base of the prostate is visualized.
The central zone comprises the posterior part of the gland and is often hyperechoic.
The mid gland is the widest portion of the gland.
The peripheral zone forms most of the gland volume.
Echoes are described as isoechoic and closely packed.
The transition zone is the central part of the gland and is hypoechoic.
The junction of the peripheral zone and the transition zone is distinct
posteriorly and is characterized by a hyperechoic region,
which results from prostatic calculi or corpora amylacea.
The transition zone is often filled with cystic spaces in
patients with benign prostatic hyperplasia (BPH).
Indications
Diagnostic indications include the following:
Early diagnosis of carcinoma of the prostate (CAP) based on
biopsy results along with abnormal digital rectal examination findings,
elevated prostate-specific antigen (PSA) levels, or both
(Ultrasonographic findings alone cannot be used to establish
or exclude the diagnosis of CAP.)
Evaluation of men with azoospermia to rule out ejaculatory-duct cysts,
seminal vesicular cysts, müllerian cysts, or utricular cysts
Volume determination to plan treatment with brachytherapy, cryotherapy,
or minimally nvasive BPH therapy (eg, radiofrequency, microwave)
Evaluation of prostate volume during hormonal downsizing for brachytherapy
Therapeutic indications include the following:
Brachytherapy for CAP
Cryotherapy for CAP
Deroofing or aspiration of ejaculatory ducts, prostatic cysts, or prostatic abscesses
Transrectal Ultrasonography in the Early Diagnosis of Prostate Cancer
Advances in transrectal ultrasonography (TRUS)
coincided with the development of prostate-specific antigen (PSA) testing,
the most valuable tumor marker test for carcinoma of the prostate (CAP).
PSA levels were found to be abnormal in more than 75% of patients with CAP,
and abnormal PSA levels precede symptoms of CAP by several years.
Therefore, PSA testing was the logical choice for early diagnosis of CAP
coincided with the development of prostate-specific antigen (PSA) testing, the most valuable tumor marker test for carcinoma of the prostate (CAP). PSA levels were found to be abnormal in more than 75% of patients with CAP, and abnormal PSA levels precede symptoms of CAP by several years. Therefore, PSA testing was the logical choice for early diagnosis of CAP
An abnormal PSA level (eg, >4 ng/mL) and/or abnormal digital rectal examination findings
(eg, asymmetry, nodule, firmness) CAP which appear with TRUS image nodule hypoechoic,
hyperechoic, or isoechoic became indications for prostate biopsy.
Prostate volume is assessed during the TRUS examination
The decision to perform biopsy in patients with abnormal
PSA levels can be bolstered by PSA density (PSAD),
which is defined as the PSA level divided by the prostate volume
Transrectal Ultrasonography To Evaluate for Neurogenic Bladder
Patients on intermittent catheterization can develop a ledge
of tissue at the bladder neck from chronic trauma and
bladder irritation. Using TRUS to determine prostate volume
in these patients can help distinguish outlet obstruction
from BPH and/or detrusor-sphincter dyssynergia
Patients on intermittent catheterization can develop a ledge of tissue at the bladder neck from chronic trauma and bladder irritation. Using TRUS to determine prostate volume in these patients can help distinguish outlet obstruction from BPH and/or detrusor-sphincter dyssynergia
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