Uterine Wall Thickness Research Articles

CT-guided high–dose-rate dose prescription for cervical carcinoma: the importance of uterine wall thickness •

Purpose: To evaluate the use of CT imaging to guide dose prescription for high-dose-rate brachytherapy in cervical cancer, by defining the uterine wall thickness and the proximity of the rectosigmoid, bladder, and small bowel. Methods and Materials: From 1994–2000, 40 patients with cervical cancer underwent treatment with external beam radiation therapy plus high–dose-rate brachytherapy. A pelvic CT scan was performed following applicator placement, and was analyzed to determine anterior and posterior uterine wall thickness, and the distance to the bladder and rectosigmoid. The dose prescription was initially at Point A, but in some patients, was altered based on the thickness of the uterine wall. Results: Measurements in the region of the lower and upper uterine wall were analyzed separately. Nearly half (46%) of the patients had an average anterior or posterior wall thickness of <20 mm. A correlation was observed between thinner anterior lower uterine walls and increased late bladder and ureteral toxicity, and between thinner anterior upper uterine walls and increased late small-bowel toxicity. Conclusions: A significant number of patients have uterine walls <2 cm in thickness. The use of CT imaging can identify patients in whom the conventional dose specification point may need to be altered to maintain the therapeutic ratio.

Changes in Myometrial Thickness during Hysteroscopic Resection of Deeply Invasive Submucous Myomas

Study ObjectiveTo evaluate the efficacy of hysteroscopy in resecting submucous myomas with deep intramural invasion. DesignProspective, observational study (Canadian Task Force classification II–2). SettingDepartment of gynecology at a general hospital. PatientsSixteen women with a solitary submucous myoma, in which myometrial thickness between the outer edge of the myoma and inner edge of the serosa was between 5 and 10 mm. InterventionOne-step hysteroscopic myomectomy. Measurements and Main ResultsMedian myoma diameter and weight were 3.3 cm and 30 g, respectively. Myometrial thickness between the myoma and serosa increased gradually and significantly from 6.7 mm before, to 8.9 mm during, to 16.1 mm immediately after hysteroscopic myomectomy (p <0.001). The thickness of the opposite uterine wall increased from 10.1 mm before, to 11.4 mm during, to 18.8 mm after operation (p <0.001). ConclusionOne-step hysteroscopic myomectomy may be performed to remove deeply infiltrating submucous myomas when myometrial thickness at the implantation site is as thin as 5 mm.

Myometrial contractile strain at uteroplacental separation during parturition

Objective: A simplified geometric model of the uterine wall during the second and third stages of labor was created to estimate the magnitude of myometrial strain associated with the initiation of placental separation. Study Design: The uterine wall was modeled as an isovolumetric, incompressible spherical shell whose overall radius decreased and mural thickness increased on uterine muscle contraction after delivery of the fetus. Either a 3.5-MHz or a 5-MHz ultrasonography probe was used to measure the change in uterine mural thickness of 14 healthy patients from just before delivery to the time of initial separation of the placenta. The measured change in uterine wall thickness was then used to calculate its average radial and circumferential strain with a simple mathematic model. Results: Placental separation occurred at radial and circumferential strains (mean ± SD) of 450% ± 182% and –75% ± 11%, respectively. These strains are consistent with the known maximal contractile strains achievable by smooth muscle. Conclusion: Placental separation is likely associated with maximal myometrial contractile strain. Before birth the presence of the fetal and amniotic fluid volumes usually renders such contractile strains unachievable, thereby helping to guard against premature placental separation. (Am J Obstet Gynecol 2000;183:156-9.)

Myometrial contractile strain at uteroplacental separation during parturition*1

<h2>Abstract</h2> <b>Objective:</b> A simplified geometric model of the uterine wall during the second and third stages of labor was created to estimate the magnitude of myometrial strain associated with the initiation of placental separation. <b>Study Design:</b> The uterine wall was modeled as an isovolumetric, incompressible spherical shell whose overall radius decreased and mural thickness increased on uterine muscle contraction after delivery of the fetus. Either a 3.5-MHz or a 5-MHz ultrasonography probe was used to measure the change in uterine mural thickness of 14 healthy patients from just before delivery to the time of initial separation of the placenta. The measured change in uterine wall thickness was then used to calculate its average radial and circumferential strain with a simple mathematic model. <b>Results:</b> Placental separation occurred at radial and circumferential strains (mean ± SD) of 450% ± 182% and –75% ± 11%, respectively. These strains are consistent with the known maximal contractile strains achievable by smooth muscle. <b>Conclusion:</b> Placental separation is likely associated with maximal myometrial contractile strain. Before birth the presence of the fetal and amniotic fluid volumes usually renders such contractile strains unachievable, thereby helping to guard against premature placental separation. (Am J Obstet Gynecol 2000;183:156-9.)

Radiographic and ultrasonographic evaluation of the normal feline postpartum uterus.

The radiographic and ultrasonographic appearance of the normal involution process of the feline postpartum uterus has not been previously described. Six queens were examined to determine the normal radiographic and ultrasonographic appearance of the involuting postpartum uterus. Radiographic and ultrasonographic examinations were performed daily from days one through ten, then on days 12, 14, 18, 24, and 28 postpartum. Radiographically the mean total uterine thickness was 16.5 mm at day one postpartum. By day 14 the mean total uterine thickness was 10.5 mm and by day 24 postpartum the uterus was not radiographically visible. Ultrasonographically at day one postpartum the mean total uterine thickness was 16.6 mm and the mean uterine wall thickness was 2.7 mm. At day 14 postpartum the mean total uterine thickness was 6.2 mm and the mean wall thickness was 2.1 mm. At day 28 postpartum the uterus could still be identified ultrasonographically however individual wall layers were not discernable.

Myometrial thickness in pregnancy: longitudinal sonographic study.

The purpose of this study was to evaluate in vivo the changes in myometrial thickness throughout pregnancy. Myometrial thickness was measured in 25 singleton uncomplicated pregnancies. Ultrasonographic sagittal and transverse sections were used to measure uterine wall thickness from the low anterior wall (lower segment) and the anterior, posterior, right, and left walls of the upper segment and from the fundus. In each case four measurements were made in the second and third trimesters. Myometrial thickness of the upper uterine segment remains fairly constant in the first and second trimesters of pregnancy, whereas a significant linear trend was found between a decreasing thickness of the lower uterine segment and advancing gestational age. Myometrial thickness is significantly increased behind the placental insertion site as compared to other portions of the uterine wall. These data may serve as baseline reference values for further studies in the antepartum fetal surveillance of high-risk pregnancies.

T-shaped IUD move vertically with endometrial growth and involution during the menstrual cycle

Ultrasound has been used to detect and evaluate intrauterine device (IUD) position for some years. Different definitions of the IUD in the uterine cavity have been discussed trying to relate them to bleeding and pain complaints. Most of these definitions do not take into account the uterine wall or endometrial thickness. This is a secondary analysis of a previous cross-sectional study, in which 481 IUD users had their T-shaped IUD evaluated by transvaginal sonography. The correlation between the endometrium thickness and the IUD-myometral distance was studied, defined by the linear measurement between the upper end of the IUD and the myometrium/endometrium interface. These two measurements were highly correlated over the entire sample range ( r = 0.29) and an even stronger correlation existed ( r = 0.66) when only cases below the 90 percentile of the IUD-endometrial distance distribution were considered. These results suggest that the IUD position in the uterine cavity is influenced by the growth and thinning of the endometrium, and that this information should be considered when evaluating the IUD position by sonography.

Dosimetric considerations in the treatment of inoperable endometrial carcinoma by a high dose rate afterloading packing technique

A series of 23 patients with early adenocarcinoma of the endometrium who underwent a total of 37 modified Heyman packings treated on a high dose rate Microselectron has been reviewed. Using computed tomography (CT), the uterine wall thickness was measured retrospectively and doses calculated at a number of points on the uterine serosa and related normal tissues. The mean and maximum fundal serosal doses were found to be highest posteriorly and the sigmoid colon was adjacent to the posterior surface of the uterus in all instances. By superimposing the isodose distribution on CT sections of the uterus, it is now possible to prescribe to a serosal dose, or, in patients too heavy for the CT scanner, a dose can be prescribed to a point S, which is a reasonable approximation to the serosal position. Since the initial study, a further ten patients have been treated by the same method and, where relevant, data from all 33 patients have been used.

Sonographic evaluation of the wall thickness of the lower uterine segment in patients with previous cesarean section

In pregnant women with a history of cesarean section, wall thickness of the lower uterine segment may help determine the risk and safety of vaginal delivery. Determination of wall thickness may help identify the potential risk of uterine rupture in pregnant women who do not wish to have another cesarean section or who are not eligible for surgery due to other systemic disorders. In this study, 50 pregnant women with previous cesarean sections were evaluated with ultrasound preoperatively, and measurements of the lower uterine segment wall thickness were compared with intraoperative assessment of uterine thinning. These findings correlated highly with each other (sensitivity: 100%; specificity: 82% positive predictive value: 87%; negative predictive value: 100%), suggesting the reliability and safety of ultrasound in evaluating uterine wall thickness. © 1996 John Wiley & Sons, Inc.

Ultrasonographic appearance of the uterus, placenta, fetus, and fetal membranes throughout accurately timed pregnancy in Beagles

Summary Serial ultrasonographic examinations were performed on 8 Beagle bitches from 20 to 60 days pregnant to determine time of first detection, appearance, and sizes of selected features of pregnancy. Gestation was timed from the day of the preovulatory luteinizing hormone surge. Findings related to gestational age were consistent among bitches. Gestational ages at earliest detection of the following features were: chorionic cavity at day 20; placental layers in the uterine wall at day 22 to 24; zonary placenta at day 27 to 30; embryo and heartbeat at day 23 to 25; yolk sac membrane at day 25 to 28; allantoic membrane at day 27 to 31; choroid plexus of the brain at day 31 to 35; fetal movement at day 34 to 36; skeleton at day 33 to 39; bladder and stomach at day 35 to 39; kidney at day 39 to 47; and liver hypoechoic, compared with lung, at day 38 to 42. Extra-fetal structures were measurable from day 20 or 22 through day 48. Chorionic cavity diameter increased from 0.2 ± 0.0 cm to 3.3 ± 0.2 cm, outer uterine diameter increased from 0.8 ± 0.03 cm to 4.8 ± 0.2 cm, length of chorionic cavity or zonary placenta increased from 0.3 ± 0.03 cm to 4.9 ± 0.05 cm, uterine wall thickness increased from 0.3 ± 0.03 cm to 0.8 ± 0.01 cm, and placental thickness increased from 0.1 ± 0.0 cm to 0.5 ± 0.05 cm. Chorionic cavity diameter, outer uterine diameter, and placental length each increased at a linear rate through day 37, after which time, each had a marked plateau in growth. Of the extra-fetal structures, chorionic cavity diameter was the most accurate for estimation of gestational age. All of the fetal structures studied increased at an increasing (second order) rate. Crown-rump length increased from 0.3 ± 0.05 cm on day 24 to 9.2 ± 0.2 cm on day 48. Body diameter increased from 0.2 ± 0.03 cm on day 24 to 4.6 ± 0.15 cm on day 60. Head diameter increased from 0.8 ± 0.05 cm on day 34 to 2.7 ± 0.04 cm on day 60. Of the fetal structures, head diameter was the most accurate for estimation of gestational age.

Use of angio computed tomography to evaluate extent of endometrial carcinoma

Patients with endometrial carcinoma underwent angio computed tomography (CT) prior to surgery to evaluate the extent of the carcinoma. The subjects of the study were 87 patients operated on at the Cancer Institute Hospital during the period 1983 to 1986. After preoperative bilateral internal iliac angiography, angio CT was performed using the already inserted catheters. Although the intact uterine wall was enhanced by the angio CT, the cancerous lesion was not, which permitted easy recognition of the cancerous lesion as a low-density area. To evaluate the degree of myometrial invasion, the minimal thickness of intact uterine wall was measured in the CT image, and was compared later with findings from the operative materials. The comparison showed that for all the patients, the minimal thickness of the intact uterine wall as shown in the CT image was comparable to the actual minimal thickness of the operative materials. Because depth of myometrial invasion is known as an important prognostic factor, measurement of the minimal thickness of the intact uterine wall as shown in the CT image is useful as an objective prognostic factor. Angio CT facilitates recognition of myometrial invasion preoperatively.

Effects of various doses of estradiol on chlamydial genital infection in ovariectomized guinea pigs.

The effect of various doses of estradiol on genital tract infection by the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC) was investigated in ovariectomized guinea pigs. Prolongation of infection, as determined by chlamydial inclusion counts of cells in Giemsa-stained smears of vaginal scrapings, was observed in animals receiving daily doses of 1.0, 10.0, 100.0, or 1000 micrograms of estradiol. In contrast to controls, ascending infection resulting in endometritis was found in animals receiving doses of greater than or equal to 1.0 microgram of estradiol per day. Response to estradiol treatment was reflected in an increase in cervical-uterine wet weight and uterine wall thickness. No differences were observed in time of appearance of antibody titers to GPIC in serum, but a delay in appearance of IgA antibody to GPIC in genital secretions was found in estradiol-treated animals receiving doses of greater than or equal to 1.0 microgram per day.

The prognostic importance of the stage in patients operated for carcinoma of the endometrium (author's transl)

The operative specimens of 216 patients who underwent operation for adenocarcinoma of the endometrium stage I and stage II were thoroughly examined. It was found that measuring the maximal depth of infiltration of the carcinoma in relation to the thickness of the uterine wall and other morphological criteria of the tumours such as tumour grading, and carcinomatous lymphangiosis have greater prognostic value than clinical staging and the length of the uterine cavity to the sound. In contradistinction to other observations we found that patients with a short length of the uterus had more often recurrences and distant metastases than patients with a long uterine length to the sound.

UTERO-OVARIAN INTERRELATIONSHIPS IN PREPUBERAL AND GONADOTROPHS TREATED GILTS

Reproductive tracts from 66 prepuberal, 45 cycling and 59 gonadotrophin-treated prepuberal gilts were examined and measured to determine the effect of puberty and gonadotrophin treatment on utero-ovarian interrelationships. Occurrence of the first ovulation resulted in significant (P &lt; 0.05) increases in uterine weight and length but not in uterine wall thickness. This change was observed after both the first spontaneous ovulation and ovulation induced by injecting 1000 IU or 2000 IU of pregnant mare’s serum (PMS) followed 48 hours later by an injection of 500 IU of human chorionic gonadotrophin. Increasing the dose of PMS from 1000 IU to 2000 IU had no effect on uterine growth. Within untreated puberal females, ovarian weight was positively (P &lt; 0.01) correlated with uterine horn weight, length and wall thickness, whereas within prepuberal females only uterine wall thickness was correlated (P &lt; 0.01) with ovarian weight. Seven (41%) of the 17 gilts induced to ovulate at 55 kg and slaughtered at 90 kg were cycling when slaughtered, while none of the control females were cycling. Effects of the gonadotrophin treatment on tract development in prepuberal gilts were not apparent after the first spontaneous ovulation.