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J D Bowie

Publications and source records attributed to J D Bowie.

At least 19 recordsLinked to original sources
PubMed1992

Diagnosis of placenta previa during the third trimester: role of transperineal sonography.

Placenta previa can be difficult to diagnose with transabdominal sonography during the third trimester of pregnancy, because of difficulties in imaging the cervix late in pregnancy. Although transperineal sonography offers an additional view of the cervix, its value in the diagnosis of placenta previa has not been studied. Accordingly, we performed transperineal sonography on 164 patients who had had transabdominal scans that had shown placenta previa or had been inconclusive during the third trimester of pregnancy. Transabdominal sonograms had been inconclusive for placenta previa in 157 of these patients because the cervix was not visualized. The remaining seven patients had transabdominal scans that showed placenta previa. Transperineal sonography successfully visualized the internal surface of the cervix in all 164 patients, allowing determination of the presence or absence of placenta previa in all cases. Transperineal sonograms showed absence of placenta previa in 154 patients. At delivery, none of these patients had evidence of placenta previa. Transperineal sonography showed placenta previa in 10 patients. In nine of these patients, placenta previa was confirmed at delivery. The 10th patient did not have clinically significant placenta previa at delivery. Our study shows that transperineal sonography is a valuable technique to complement transabdominal sonography for detection of placenta previa during the third trimester of pregnancy. Use of transperineal sonography should be strongly considered when a definitive diagnosis regarding placenta previa is not possible by transabdominal sonography because the cervix is not visualized. In such cases, transperineal sonography will usually show the internal surface of the cervix without overlying placental tissue, allowing confident exclusion of placenta previa. Occasionally, however, transperineal sonography will show a placenta previa that was not seen with transabdominal sonography.

Cervix Uteri↗
PubMed1991

Transperineal US: alternative technique to improve visualization of the presenting fetal part.

Transperineal ultrasound (TPU) was used as an alternative imaging technique to evaluate the anatomy of the presenting part in 27 second- and third-trimester fetuses when transabdominal ultrasound (US) images were suboptimal. Use of TPU improved visualization of the distal fetal spine in 20 of 21 breech cases, providing sufficient information regarding bone anatomy to rule out splaying of the posterior elements. In addition, the intact skin surface overlying the distal spine, not seen at transabdominal US, was well demonstrated at TPU in 18 of these fetuses. TPU was used to improve assessment of intracranial anatomy in six cases with a cephalic presentation in which the fetal head was located low in the maternal pelvis and could not be adequately visualized with the transabdominal technique. In one of these cases, TPU offered improved visualization of anencephaly. Use of TPU should be considered to optimize visualization of the presenting fetal part when results at transabdominal US are suboptimal and the poorly seen part overlies the maternal cervix.

Feasibility Studies↗
PubMed1991

Sonography of the cervix during the third trimester of pregnancy: value of the transperineal approach.

Transabdominal sonography reliably depicts the cervix during the first and second trimesters of pregnancy, but cervical visualization becomes increasingly difficult as the third trimester progresses. To evaluate the possibility of using a perineal approach to bypass the fetus and image the cervix during the third trimester, we used transperineal sonography to image the cervix of 158 third-trimester patients in whom transabdominal visualization was inadequate. The internal os and upper cervix were successfully visualized on transperineal sonograms in all 158 patients, but the region of the external os was obscured by rectal gas in 22 (14%) cases. In some patients in whom the external portion of the cervix was obscured by bowel gas, the problem could be overcome by scanning with the patient in the lateral decubitus position or by rotating the patient. Transperineal sonography is an effective technique for imaging the cervix during the third trimester of pregnancy, allowing cervical visualization in most patients in whom transabdominal sonography of this area is unsuccessful.

Cervix Uteri↗
PubMed1991

Sonographic diagnosis of premature cervical dilatation. Potential pitfall due to lower uterine segment contractions.

Antenatal sonography is an accepted method of evaluating the cervix and lower uterine segment. Dilatation of the endocervical canal can be missed due to compression by an overdistended urinary bladder, intermittent changes in configuration of the cervix, and suboptimal visualization. However, the potential for overdiagnosis of this entity has not been previously emphasized. We present 14 cases demonstrating how contractions in the lower uterine segment can result in an appearance that falsely simulates preterm dilatation of the endocervical canal. The overdiagnosis of this entity can be avoided by distinguishing the following features typical of "pseudodilatation" due to a contraction: (1) apparent cervical length greater than 5 cm; (2) demonstration of normal-appearing cervical tissue distal to the apparently dilated region; and (3) rounding of the myometrium surrounding the apparently dilated area. If any of these features is detected in a patient with sonographic characteristics suggesting dilatation of the cervix, the possibility of pseudodilatation should be considered, and the lower uterine segment should be rescanned later in the examination.

Cervix Uteri↗
PubMed1991

Mild fetal renal pelviectasis. Differentiation from hilar vascularity using color Doppler sonography.

Ultrasound often detects a sonolucent region in the hilum of the fetal kidney. Although this sonolucency is usually assumed to represent mild dilatation of the fetal renal collecting system, in pediatric and adult kidneys blood vessel lumina can simulate pelviectasis. We used color Doppler ultrasound to differentiate the fetal renal collecting system from hilar blood vessels and to evaluate how often blood vessels account for the sonolucent region often demonstrated in the renal hilum during antenatal sonography. Twenty-nine kidneys in fetuses with sonolucent hilar regions greater than 2 mm in anteroposterior (AP) dimension were studied with color Doppler ultrasound. Doppler signal was demonstrated in blood vessels adjacent to, but not within, the sonolucent area in the hilum of all 29 kidneys. Based on the absence of color signal in the sonolucent hilar regions studied, with color signal seen in adjacent blood vessels, these regions were felt to represent mildly dilated collecting systems rather than renal vasculature. We conclude that color Doppler ultrasound can differentiate mild pelviectasis from hilar blood vessels in the fetal kidney. Sonolucent areas measuring 2 mm or greater in AP dimension are unlikely to be attributable to renal vasculature.

Female↗
PubMed1991

In utero sonographic appearance of the atrial septum primum and septum secundum.

We present our observation of the sonographic appearance of the septum primum and septum secundum. The septum primum, as the valve of the foramen ovale, has been previously described as a mobile, echogenic line or dot in the left atrium. We believe that these previous descriptions recognize only a small part of a more complex three-dimensional shape. We studied 14 ideal patients, none of whom were referred for suspected fetal cardiac disease. In 1 case the septum primum was seen as a flaplike structure and in 8 cases as a circular structure. In 5 cases it was seen as both flaplike and circular, depending on the scan plane selected. A three-dimensional description of the shape of the septum primum, based on the work of Crelin, is proposed, which explains these two appearances. A better understanding of this anatomical feature may prevent mistaking the septum primum for an abnormality and provide the basis for future advances in fetal echocardiography.

Echocardiography, Doppler↗
PubMed1991

Ultrasound of the postpartum uterus. Prediction of retained placental tissue.

We reviewed ultrasound images an 53 postpartum patients referred for possible retained products of conception and correlated specific ultrasound patterns with clinical and pathologic follow-up. The most common finding in patients with retained placental tissue was an echogenic mass in the uterine cavity, seen in 9 of 11 patients with pathologically proven retained placental tissue. In the remaining 2 patients with pathologically confirmed retained placenta, a heterogeneous mass was seen in the uterine cavity at some point during the course of serial sonography. Retained placental tissue was unlikely when ultrasound demonstrated a normal uterine stripe (n = 18), endometrial fluid (n = 6), or hyperechoic foci in the uterine cavity without an associated mass (n = 17). The latter finding was often associated with recent uterine instrumentation. The sonographic appearance of retained placental tissue is variable, but detection of an echogenic mass in the uterus strongly supports the diagnosis. A heterogeneous mass is sometimes caused by retained placenta, but can also be secondary to blood clots or infected or necrotic material in the absence of placental tissue. Sonographic evaluation for retained products of conception is best done before uterine instrumentation to avoid confusion with iatrogenically introduced air.

Abortion, Incomplete↗
PubMed1990

Fetal umbilical artery Doppler response to graded maternal aerobic exercise and subsequent maternal mean arterial blood pressure: predictive value for pregnancy-induced hypertension.

Predictive tests for the identification of women at high risk of the development of preeclampsia are critical to allow the most appropriate preventive measures. Preeclampsia is a vasospastic condition of pregnancy characterized by early and enhanced vascular reactivity to endogenous pressor agents. Exercise tolerance testing with cycle ergometry to induce hemodynamic response measured with duplex Doppler A/B ratio of the umbilical artery could unmask latent vascular pressor hypersensitivity. Our prospective cohort study was designed to test the efficacy of the American College of Obstetricians and Gynecologists exercise in pregnancy guidelines for the low-risk athletic, physically active, or sedentary patient. The pattern of fetal response to material exercise testing at 28 weeks' gestation was compared with subsequent maternal mean arterial blood pressure and the development of pregnancy-induced hypertension and preeclampsia. Doppler A/B ratio during the recovery period was assessed as below baseline (18) or elevated above resting baseline values (12). Third-trimester blood pressure pattern was assessed to be elevated in 11 patients, 10 of whom had elevated recovery A/B ratios. The Fisher exact test results were (p = 0.00002) positive predictive value, 83%; negative predictive value, 94%; sensitivity, 91%; and specificity, 89%. Preeclampsia developed in four patients; all had elevated recovery A/B ratios. Fisher exact test results were (p = 0.01806) positive predictive value, 33%; negative predictive value, 100%; sensitivity, 100%; and specificity, 69%.

Blood Pressure↗
PubMed1990

Femur length in the US prediction of trisomy 21 and other chromosomal abnormalities.

After review of 461 consecutive amniocentesis examinations, 428 fetuses with normal karyotype and 13 with chromosomal abnormalities were analyzed. Six of the abnormal fetuses had trisomy 21, and seven had other chromosomal abnormalities. The ratio of measured-to-expected femur length (MFL/EFL) was determined for each fetus. The MFL/EFL values were 1.0 +/- 0.7 (mean +/- standard deviation) for the control group, 0.94 +/- 0.06 for trisomy 21 fetuses, 0.94 +/- 0.10 for non-trisomy 21 fetuses, and 0.94 +/- 0.08 for the entire group of fetuses with chromosomal abnormalities. The mean MFL/EFL value for the abnormal fetuses differed significantly from that for the control group (P less than .003). An MFL/EFL of 0.90 or less resulted in a sensitivity of 46.2% and a specificity of 94.1% for detection of all chromosomal abnormalities. For detecting trisomy 21, the sensitivity and specificity were 50% and 93.5%, respectively. Assuming a pretest probability for trisomy 21 of one in 250, an MFL/EFL of 0.90 or less resulted in a positive predictive value of 3%. It is concluded that an MFL/EFL of less than 0.90 modifies the relative risk for chromosomal abnormalities and may significantly influence the decision for amniocentesis.

Chromosome Aberrations↗
PubMed1990

Value of sonography in the diagnosis of intracranial hemorrhage and periventricular leukomalacia: a postmortem study of 35 cases.

Periventricular leukomalacia and germinal matrix hemorrhages are major causes of neurodevelopmental abnormalities in the premature neonate. Although sonography is widely used to detect these abnormalities and is thought to be sensitive for hemorrhages and the later cystic stages of periventricular leukomalacia, its sensitivity for the more acute phase of periventricular leukomalacia remains to be determined. It has been difficult to study this issue because periventricular leukomalacia often is not lethal, and in postmortem studies there is usually a considerable interval between the time of in vivo imaging, if any, and the death of the patient. A "prospective" autopsy study was performed on brain specimens from infants who died at less than 1 year of age during a 10-month period. Thirty-five formalin-fixed brains were studied and sonographic images of these specimens were compared with histologic findings in whole brain sections to determine the sensitivity and specificity of sonography for the detection of germinal matrix hemorrhage and periventricular leukomalacia. Sonography identified germinal matrix hemorrhages as small as 5 mm, although smaller lesions were not visualized. Postmortem sonography had a sensitivity of 27% and specificity of 88% for all germinal matrix hemorrhages, but a sensitivity of 100% and specificity of 91% for hemorrhages larger than 5 mm. Periventricular leukomalacia, seen as hyperechoic areas in the periventricular white matter, was not detected as readily. For periventricular leukomalacia, the overall sensitivity and specificity were 50% and 87%, respectively. We conclude that sonography is useful for detecting the larger germinal matrix hemorrhages, but has more limited sensitivity in the early diagnosis of periventricular leukomalacia.

Cerebral Hemorrhage↗
PubMed1990

Sonographic characteristics of small cerebral blood vessels. An in vivo and postmortem study.

The ultrasound appearance of small cerebral blood vessels was investigated with in vivo and postmortem sonography. Linear echoes corresponding in distribution to small branches of major cerebral blood vessels, particularly deep medullary veins, were seen during cranial sonography of living neonates, neonatal postmortem brains, and adult postmortem brains following intravascular injection of a barium sulfate-gelatin suspension. Ease of visualization of the echoes was angle dependent, a phenomenon termed anisotropy. When imaged in cross-section, these reflectors appeared as tiny, closely spaced dots, demonstrating their tubular nature. Additionally, the barium-injected adult postmortem specimens were studied by computed tomography and plain-film radiography, enabling correlation between radiography and sonography. This study demonstrates that small branches of the major intracranial blood vessels can be imaged as linear echoes and closely spaced dots by high-resolution sonography. It is important to recognize the vascular origin of these echoes to avoid the pitfall of misinterpreting them as originating from pathologic processes such as periventricular leukomalacia.

Adult↗
PubMed1990

Use of endo-vaginal ultrasound to optimize visualization of the distal fetal spine in breech presentations.

Endovaginal ultrasound was used to evaluate the spine of 13 second-trimester fetuses in which transbdominal images were considered equivocal due to suboptimal visualization of the distal spine and where the fetus was in a breech presentation. Endovaginal sonography demonstrated a small defect in the distal spine and a meningomyelocele in one of the 13 cases. In all of the remaining 12 cases, endovaginal sonography resulted in improved visualization of morphologic detail, providing sufficient information regarding bony anatomy to exclude splaying of the posterior elements. Additionally, in 10 cases the intact skin surface overlying the distal spine, which was not seen by transbdominal sonography, was well demonstrated by endovaginal ultrasound. The authors recommend that endovaginal ultrasound be considered to optimize visualization of the distal fetal spine when transbdominal images are inconclusive and the fetus is in a breech presentation.

Amniocentesis↗
PubMed1990

Fetal gastrointestinal abnormalities.

A wide range of abnormalities of the fetal gastrointestinal tract is currently detectable by antenatal sonography, but the sonographic appearance of normal fetal bowel is variable, with considerable overlap between normal and abnormal patterns. In examining the major gastrointestinal disorders that may be recognized by in utero sonography, this article emphasizes potential pitfalls due to confusion with normal anatomic variants and pathologic processes arising elsewhere in the fetus.

Abdominal Muscles↗
PubMed1989

Normal sonographic appearance of the fetal neck late in the first trimester: the pseudomembrane.

A linear specular reflection simulating a membrane was visualized along the back of the neck on sonograms of ten normal fetuses ranging in age from 10 to 14 menstrual weeks. Follow-up ultrasound studies of eight of the fetuses and postpartum clinical examinations of all subjects were normal, revealing no evidence of neck abnormalities. Although this pseudomembrane is similar in appearance to published examples of early cystic hygroma, it is a normal finding that can be distinguished from early cystic hygroma on the basis of its less bulbous appearance and the absence of underlying septations. This structure corresponds in distribution to the skin along the back of the fetus and likely represents a specular reflection from the skin surface.

Embryonic and Fetal Development↗
PubMed1989

Fetal choroid plexus lesions. Relationship of antenatal sonographic appearance to clinical outcome.

The sonograms and clinical outcomes of 31 fetuses with antenatally detected choroid plexus lesions were retrospectively reviewed. Lesions were classified as simple cysts in 22 cases (71%) and complex lesions in 9 (29%). Simple cysts tended to be smaller in size than the complex lesions and no adverse sequelae were attributed to the sonographic detection of simple cysts. Although complex choroid plexus lesions appeared to be an incidental finding in seven of nine cases (78%), one of the remaining fetuses developed ventriculomegaly with focal cerebral cortical thinning and in utero viral infection was suspected in the other. Amniocentesis was performed in nine patients (five with simple cysts and four with complex lesions) and no chromosomal abnormalities were detected during the study period, although after these data were collected we encountered a fetus in which bilateral large complex choroid plexus lesions were associated with trisomy 18. These findings suggest that antenatally detected choroid plexus lesions are more variable in appearance than previously recognized. We consider fetuses with small simple cysts and otherwise normal sonograms to be at relatively low risk for developing adverse sequelae and recommend repeat sonography in 1 to 2 months to confirm the benign nature of the process. The presence of large and/or complicated lesions is of more concern, although the majority of these lesions (78%) also represented an incidental finding. We suggest consideration of amniocentesis, TORCH titers, and close sonographic follow-up of pregnancies with large or complex choroid plexus lesions.

Amniocentesis↗