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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5782_Библиотеки_им_академика_М_И_Перельмана.pdf
CHAPTER 12 Transvaginal Scanning Protocol for the Female Pelvis 269
14. Same image as number 13 without calipers.
Labeled: TV SAG RT OV LONG AXIS
Left Ovary • Transvaginal Axial Images
Coronal Plane • Inferior Approach
For the sake of instruction, this assumes that the ovary long axis is
visualized in a sagittal plane.
15. Axial image of the LEFT OVARY measuring ovarian width.
Follicle
Left ovary
Labeled: TV COR LT OV
Follicles
Follicle
270 PART IV Pelvic Scanning Protocols
16. Same image as number 15 without calipers.
Left Ovary • Transvaginal Longitudinal Images
Sagittal Plane • Inferior Approach
For the sake of instruction, this assumes that the ovary long axis is
visualized in a sagittal plane.
17. LONG AXIS image of the left ovary measuring ovarian length and
height.
Labeled: TV COR LT OV
Left ovary
Labeled: TV SAG LT OV LONG AXIS
Follicles
CHAPTER 12 Transvaginal Scanning Protocol for the Female Pelvis 271
18. Same image as number 17 without calipers.
Labeled: TV SAG LT OV LONG AXIS
Review Questions
Answers on page 629.
1. In most cases, transvaginal sonography is used
a) to evaluate ovarian abnormalities.
b) for ultrasound-guided ova retrieval.
c) as a complementary study for transabdominal pelvic studies.
d) in place of transabdominal pelvic sonography.
2. Transvaginal studies must be witnessed by
a) an immediate family member of the patient.
b) another sonographer whose initials should be included on all
images.
c) a female health care professional whose initials should be
included on all images.
d) any health care professional whose initials should be included
on all images.
3. The sound beam approach for transvaginal sonography is
a) inferior.
b) sagittal and coronal.
c) anterior.
d) variable.
4. One disadvantage of transvaginal sonography is
a) transducer placement close to areas of interest.
b) no requirement for the patient to have a full urinary bladder.
c) it can be used during surgery.
d) its narrow field of view.
272 PART IV Pelvic Scanning Protocols
5. When comparing transabdominal sonography to transvaginal
a) transabdominal sonography is considered to be better for evalu-
ating the ovaries.
b) transvaginal sonography is best for demonstrating the size of a
pelvic mass.
c) transabdominal sonography is considered the complementary
study.
d) transvaginal sonography is better at characterizing
abnormalities.
6. Transvaginal sonography is also known as ______ and ______
sonography.
a) endocavital, endovaginal
b) intrapelvic, endovaginal
c) endovaginal, endocanal
d) intra-abdominal, endocavital
7. The limitation of transvaginal sonography is
a) the amount of distance between the transducer and pelvic
structures.
b) higher frequency transducers.
c) limited field of view.
d) not having a full urinary bladder to serve as a “window” for bet-
ter visualization.
8. Resolution of pelvic structures is better with transvaginal imaging
than transabdominal imaging because
a) there is less attenuating tissue between the transvaginal trans-
ducer and pelvic structures.
b) in most cases, the bladder is empty.
c) lower frequency transducers are utilized.
d) transabdominal imaging of the pelvis is outdated.
9. The standard scanning plane(s) utilized in transvaginal imaging are
a) sagittal and transverse.
b) coronal.
c) transverse.
d) sagittal and coronal.
CHAPTER 12 Transvaginal Scanning Protocol for the Female Pelvis 273
10.Transvaginal sonography is a sterile procedure.
a) True
b) False
11. An anteverted uterus cannot be evaluated transvaginally.
a) True
b) False
12. Transvaginal sonography has replaced transabdominal sonography
of pelvic structures.
a) True
b) False
13. Only the fundal portion of the uterus can be evaluated
transvaginally.
a) True
b) False
Decidua capsularis
Amniotic cavity
s
Umbilical vessels
Urinary bladder
Decidua parietalis
Liver
Stomach
Intestines
Myometrium
Uterine cavity
Embryo/fetus
Umbilical cord
Decidua basali
Yolk sac
Chorion
Cervix
First Trimester
Diaphragm
Spleen
Aorta
Placenta
decidua basalis
Amniotic cavity
Chorion
Fetus
Uterine wall
Vagina
Chorionic villi
Amniotic cavity
Cervix
Rectum
Third Trimester
CHAPTER 13
Obstetrical Scanning Protocol
for First, Second, and Third
Trimesters
Betty Bates Tempkin
Key Words
Abdominal circumference (AC)
Amnion
Amniotic cavity
Amniotic fluid
Amniotic membrane
Basal layer
Blastocyst
Biparietal diameter
measurement (BPD)
Chorionic cavity
Chorionic membrane
Chorionic plate
Crown rump length (CRL)
Decidua capsularis
Decidua parietalis
Double bleb sign
Double sac sign
Ectopic pregnancies
Embryo
Embryoblast
Embryonic disk
Fertilization
Foramen ovale
Fronto-occipital diameter (FOD)
Gestational sac
Gravid
Human chorionic gonadotropin
(hCG)
Intradecidual sign
Lacunae
Mean sac diameter (MSD)
Morula
Placenta
Placenta previa
Placental grading
Primary yolk sac
Secondary yolk sac
Trophoblast
Umbilical cord
Umbilical cord insertion
Vitelline duct
Yolk stalk
Zygote
Objectives
At the end of this chapter, you will be able to:
• Define the key words.
• Distinguish the sonographic appearance and development during
the first, second, and third trimesters of pregnancy and the terms
used to describe it.
• Distinguish gestational age during the first, second, and third
trimesters of pregnancy.
• Distinguish the sonographic appearance of fetal anatomy.
• Describe the transducer options for scanning during the first,
second, and third trimesters of pregnancy.
• List the suggested patient position (and options) when scanning
during the first, second, and third trimesters of pregnancy.
• Describe the patient prep for the first, second, and third trimesters of pregnancy.
275
276 PART IV Pelvic Scanning Protocols
• Name the survey steps and explain how to evaluate the first,
second, and third trimesters of pregnancy.
• Explain the order and the specifics of taking representative
images of the first, second, and third trimesters of pregnancy.
• Answer the review questions at the end of the chapter.
Overview
Maternal Anatomy and Physiology
• As discussed in Chapter 11, the female pelvis organs include the
genital tract (uterus, vagina, and uterine tubes), bilateral ovaries,
urinary bladder, a portion of the ureters, and the rectosigmoid
colon. The osseous or bony pelvis forms the outer boundaries of
the female pelvic cavity, whereas the skeletal muscles which line
the pelvic cavity form the inner boundaries. Refer to Chapter 11
for anatomical specifics and sonographic appearance.
• Chapter 11 also discussed how the menstrual cycle prepares the
uterus for implantation by a fertilized ovum. If fertilization does not
occur, hormone levels decrease and the nonimplanted endometrial
lining of the uterus is shed during menses. If fertilization does occur,
it usually takes place within 1 day of ovulation, day 15 of the menstrual cycle, at the ampulla portion of the uterine tube. Fertilization
is complete when the ova and sperm fuse to form a zygote or cell
mass. The cell mass repeatedly divides into the morula, a cluster of
16 or more cells that leave the uterine tube and enter the uterine cavity on the day 18 or 19 of the cycle. The morula is then transformed
into a blastocyst. The outer layer of the blastocyst, the trophoblast
will develop into the chorionic membrane, the fetal component to
the placenta (temporary organ joining mother and fetus; oxygen
and nutrients are transferred from mother to fetus; waste products
are transferred fetus to mother). The inner layer of the blastocyst, the
embryoblast (or embryonic disk) develops into the primary and
secondary yolk sacs
embryo), amnion (innermost layer of developing embryo), embryo
(early stages of fetal growth, from conception to the week 8 of pregnancy), and umbilical cord (flexible cord comprised of 2 arteries
and 1 vein that arises from the umbilicus and connects the fetus
with the placenta). On day 20 or 21 of the cycle, the 1 mm blastocyst
starts to implant the decidualized or gravid (pregnant) uterine endometrium. By the day 28 the blastocyst becomes completely imbedded into uterine myometrial tissue and implantation is complete.
(nutrient-filled sacs adjacent to the deve loping
First Trimester
Using a 28-day menstrual cycle, most radiologists and obstetricians define
the first trimester as the 12 weeks beginning with the first day of the last
CHAPTER 13 Obstetrical Scanning Protocol for First, Second, and Third Trimesters 277
Gestational
Myometrium
Endometrial
Gestational sac
Myometrium
fundus
normal menstrual period. Further, they describe the time span in terms of
gestational age (GA) or menstrual age (MA), which are used interchangeably.
Anatomy and Sonographic Appearance During Early
First Trimester
Gestational Sac
• The blastocyst is too small to be visualized sonographically, but other
intrauterine changes can be detected to confirm a pregnancy during the early first trimester. The following transvaginal image shows
an early pregnancy. It is described by sonologists as the gestational
sac, a term used to represent the small, round or oval, fluid-filled,
anechoic chorionic cavity completely enclosed by bright, echogenic
walls that represent developing chorionic villi (fetal portions of the
placenta that are fingerlike projections of the trophoblast layer that
extend into the endometrium) and the adjacent endometrium.
Endometrium
Uterine
fundus
• The first key sonographic finding in an early intrauterine pregnancy
is referred to as the “intradecidual sign,” which is the location of the
early gestational sac right next to the centrally located endometrial
cavity at the level of the fundus or body of the uterus. Transvaginal
sonography is usually the best choice for visualizing the intradecidual
sign, as illustrated below. Note that there should be no displacement
or change in size of the endometrial cavity at this early stage.
sac
Uterine
cavity
Endometrium
278 PART IV Pelvic Scanning Protocols
Length + Depth + Width = Total/3 = MSD + 3 = GA (in weeks)
• Although transabdominal transducers are not generally the choice
for resolving the intradecidual sign, they can visualize the intrauterine gestational sac as early as 3 to 5 weeks GA when sac diameter is
2 to 4 mm or serum human chorionic gonadotropin (hCG) (hormone secreted by developing placenta to communicate to the rest of
the body that a gestation is present within the uterus) levels exceed
1025 mIU/mL. As the gestational sac enlarges, the walls get thicker
and markedly hyperechoic relative to the imbedded myometrium.
Determining Gestational Age During the First Half of the First
Trimester
Mean Sac Diameter
In the first half of the first trimester, gestational sac size is used to date
a pregnancy. The method most institutions use to calculate the gestational/menstrual age is the mean sac diameter (MSD) method. As seen
in the next image, caliper placement is illustrated between calipers 1 and
2. The three orthogonal dimensions of the chorionic cavity are added
together and divided by 3. Alternatively, the length and anteroposterior
dimensions can be measured on a long axis section of the gestational sac
and width of the sac can be measured on the widest axial section. Notice
how the bright rim of choriodecidual reaction is not included in the measurement. GA (in weeks) is determined by adding 3 to the MSD (in mm).
2
Sonographic Appearance and Development During
the First Half of the First Trimester
Double Sac Sign
• This next transabdominal, sagittal scanning plane image shows
that with further growth the gestational sac takes on the distinctive sonographic appearance known as the “double sac sign.” The
2 bright concentric lines separated by anechoic fluid in the uterine
cavity are the decidua capsularis and decidua parietalis (layers
1
2
1