prostate – normal
prostate anatomy
prostate anatomy
longitudinal view
prostate anatomy
axial view
normal prostate ultrasound images transrectal (trus)
prostate volume
axial image
transabdominal ultrasound images prostate
angle the probe caudally and in the midline to get a sagittal view of the prostate.
turn the probe 90 degrees and angle caudally to get the transverse view.
prostate is situated postero-inferior to the bladder the bladder.
transverse ultrasound view prostate
scan protocol
role of ultrasound
visualisation of the prostate using the trus ( transrectal ultrasound) technique has improved the diagnostic ability of the sonologist. it plays an important role in most prostatic diseases. it is necessary for all prostate biopsies.
if the psa is elevated or increasing rapidly or there is an abnormal prostate examination then a transrectal ultrasound and prostate biopsy may be indicated to obtain tissue to make the diagnosis of prostate cancer.
transabdominal ultrasound can assess the volume of the prostate but is not reliable to diagnose carcinoma.
limitations
some patients are not able to cope with the probe inside their rectum for the duration of the scan ( especially for a biopsy) during a trus.
if patients are unable to fill their bladder with at least 60mls of fluid then an accurate volume cannot be measured using a transabdominal approach.
patient preparation
trus the rectum should be emptied prior to the scan .a small amount of fluid in the bladder is needed to identify it while scanning. the patient lies in a lateral decubitus position. ensure that a generous amount of gel is put into the sphincter before inserting the probe.
transabdominal technique needs the patient supine.
equipment setup
an endorectal, high frequency probe is used. it must have colour and doppler capabilities.3d scanning and contrast agents such as microbubbles will improve the assessment of vascularity.
if scanning transabdominally a 3.5mhz to 6mhz curved linear array probe, depending on the size of the patient should be used.
common pathology
- cysts
- benign prostatic hyperplasia (bph)
- prostate carcinoma
- prostatitis
- enlarged seminal vesicles
- stones in the seminal vesicles,prostate or ejaculatory ducts
scanning technique
trus technique
it is ideal to have a small amount of urine in the bladder.
ask the patient to try and relax and “bear down” to open the sphincter as the transducer is inserted slowly.ensure the transducer has a latex free dedicated probe cover with plenty of gel. the highest frequency sector probe 7-12mhz should be used.
the scanning begins in the axial plane. the seminal vesicles are examined initially. as the probe is angled caudally the base of the prostate is seen.
once the prostate is examined in its entirety in this plane the probe is turned 90degrees in a sagittal plane. the probe is angled from one side across to the other.
a volume is taken by measuring height x length in the sagittal plane and x width in the axial plane and multiply by 0.52.
look for changes in the contours and echogenicity in each zone.
transabdominal technique
the patient lies supine. the patient should have a half full bladder . this can be achieved with drinking 500 mls of water 1 hr before the scan if possible is recommended.
the probe is angled approximately 30 degrees caudal using the bladder as a window. slight compression to ensure the inferior portion of the prostate is not obscured by the shadow artifact from the base of the bladder.
basic hardcopy imaging
image the prostate in sagittal and axial views.
volume should be measured with the machine settings using the length, width and height.
images using power doppler and contrast enhanced doppler in suspected tumours.