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M A Kliewer

Publications and source records attributed to M A Kliewer.

At least 19 recordsLinked to original sources
PubMed2001

Outcome in children with fetal mild ventriculomegaly: a case series.

Mild enlargement of the lateral ventricles is associated with schizophrenia and other neurodevelopmental disorders. While it has been hypothesized that ventricle abnormalities associated with neurodevelopmental disorders arise during fetal brain development, there is little direct evidence to support this hypothesis. Using ultrasound, it is possible to image the fetal ventricles in utero. Fetal mild ventriculomegaly (MVM) has been associated with developmental delays in early childhood, though longer-term neurodevelopmental outcome has not been studied. Follow-up of five children (aged 4--9 years) with mild enlargement of the lateral ventricles on prenatal ultrasound and two unaffected co-twins is reported: one child had attention deficit hyperactivity disorder (ADHD), one had autism, and two had evidence of learning disorders. These cases suggest that the mild enlargement of the lateral ventricles associated with these neurodevelopmental disorders arises during fetal brain development and can be detected with prenatal ultrasound. In addition, the presence of mildly enlarged, asymmetric ventricles in two children on prenatal ultrasound and on follow-up MRI at age 6 years indicates that ventricle structure present in utero can persist well into childhood brain development. The study of fetal ventricle development with ultrasound may provide important insights into neurodevelopmental disorders and allow the identification of children at high risk.

Attention Deficit Disorder with Hyperactivity↗
PubMed2001

Infant cerebral ventricle volume: a comparison of 3-D ultrasound and magnetic resonance imaging.

Enlargement of the cerebral lateral ventricles is observed in several neuropsychiatric disorders with origins in early brain development. Lateral ventricle size is also predictive of poor neurodevelopmental outcome in premature infants. Three-dimensional (3-D) ultrasound (US) offers an improved methodology for the study of lateral ventricle volume in neonates and infants. To assess the validity of ventricle volume measures obtained with 3-D US, we compared the volumes obtained by 3-D US with magnetic resonance imaging (MRI) in seven infants. Ventricle volumes were determined using a computer-assisted image analysis program, IRIS. There was excellent correlation between ventricle volumes obtained with 3-D US and those obtained with MRI (intraclass correlation coefficient 0.92, F = 23.28, p = 0.00027), indicating that 3-D US provides valid measures of overall lateral ventricle volume compared to the "gold standard" of MRI. 3-D US can provide an economical and practical means of studying lateral ventricle volume in neonates, a neurostructural marker of abnormal brain development.

Cerebral Ventricles↗
PubMed2001

An electronic device for needle placement during sonographically guided percutaneous intervention.

An electronic device for guiding needle placement during sonographically directed percutaneous intervention was tested in a phantom and then in patients. In the phantom, targeting accuracy was similar for use of the needle guide alone, the needle guide with the device, and freehand techniques with the device, but all were superior to the freehand technique alone (P <.001). In 34 (79%) of 43 patients, the device worked well.

Adult↗
PubMed2001

Nonstenotic internal carotid arteries: effects of age and blood pressure at the time of scanning on Doppler US velocity measurements.

PURPOSE: To assess the effects of age and blood pressure at the time of scanning on internal carotid artery velocities and cross-sectional diameter at Doppler ultrasonography (US). MATERIALS AND METHODS: During 12 months, 1,020 consecutive patients underwent internal carotid artery Doppler US. No or minimal arterial disease was found in 142 patients (67 women, 75 men). Blood pressure was recorded prior to examination. The angle-corrected internal carotid artery peak systolic and end-diastolic velocities were obtained. The effects of systolic blood pressure, diastolic blood pressure, pulse pressure, age, chronic hypertension, and medications for hypertension on velocities were evaluated by using linear regression analysis. RESULTS: Peak systolic velocity was influenced by age (P =.008), systolic blood pressure (P =.009), diastolic blood pressure (P =.003), and pulse pressure (P =.017) but not history of hypertension (P =.53) or antihypertensive medication use (P =.77). Increasing age decreased peak systolic velocity by 0.34 cm/sec/y. End-diastolic velocity was influenced by age (P <.001) but not by systolic, diastolic, or pulse pressure (all P values were >.13). CONCLUSION: Internal carotid artery peak systolic velocities decrease with advancing age and increase with increasing pulse pressure. The effects of blood pressure at the time of scanning are small, but isolated systolic hypertension could cause increases in spurious velocity.

Adult↗
PubMed2001

The anterior iliac separation: alternative index for pelvic morphometry in fetuses with Down syndrome.

OBJECTIVE: The goal of this study was to assess the diagnostic use of an anterior iliac separation measurement as an alternative index for the iliac angle in the assessment of fetal pelvic morphometry. SUBJECTS AND METHODS: In 358 fetuses, the anterior iliac separation, iliac length, and iliac angle were prospectively measured on antenatal sonography. All measurements were obtained at two axial levels (superior and inferior). The gestational age of the fetus was recorded. The anterior iliac separation was normalized by iliac length, and coefficients of variation were calculated for all measurements. The effects of axial level and gestational age were assessed in a linear regression model. The diagnostic use of the anterior iliac separation relative to that of the iliac angle was assessed in a comparison of 24 fetuses with Down syndrome and 247 non-Down syndrome fetuses. RESULTS: The anterior iliac separation was less variable than the iliac angle at both superior and inferior levels. There were statistically significant effects for gestational age and axial level on both the anterior iliac separation and the iliac angle, but there was no significant effect for either factor when the anterior iliac separation was normalized by the iliac length. Comparing Down and non-Down syndrome fetuses, we found that the normalized anterior iliac separation had discriminating power similar to the iliac angle. CONCLUSION: The linear measurement of the anterior iliac separation has diagnostic properties similar to the iliac angle and is subject to less measurement variability. This simpler measurement may be particularly useful when normalized by the iliac length.

Down Syndrome↗
PubMed2001

Breakthrough adverse reactions to low-osmolar contrast media after steroid premedication.

OBJECTIVE: The purpose of this study was to review the nature of adverse reactions, or "breakthrough reactions," experienced by patients who received steroid premedication and low-osmolar contrast media. We compared the demographics of patients having these breakthrough reactions with those of patients who did not develop these reactions. MATERIALS AND METHODS: We retrospectively reviewed our radiology quality improvement database to identify patients with breakthrough reactions that occurred from January 1, 1994, through October 1, 1999, and we reviewed their medical records. We compared these patients with a control cohort of patients who had a history of prior adverse reaction to contrast media but no breakthrough reaction after administration of low-osmolar contrast media and premedication with corticosteroids. RESULTS: Over the 6-year period, 52 patients experienced 61 breakthrough reactions. The breakthrough reaction was mild in 76% of the patients. The breakthrough reaction was similar to the patient's initial adverse reaction in 85% of the patients. A history of seafood allergy or hay fever was statistically more likely to be identified in the breakthrough group than the control group. CONCLUSION: Breakthrough reactions occur in a substantial number of patients despite premedication with steroids and use of low-osmolar contrast agents. Typically the breakthrough reaction is of similar severity to the patient's initial reaction. Severe or life-threatening reactions are seen in 24% of patients.

Adrenal Cortex Hormones↗
PubMed2001

Sonographically guided thrombin injection of iatrogenic femoral pseudoaneurysms: further experience of a single institution.

OBJECTIVE: In September 1998, we began to treat iatrogenic femoral pseudoaneurysms with direct thrombin injection under sonographic guidance. Our purpose was to determine the success and complication rate of this technique. SUBJECTS AND METHODS: We treated 114 consecutive patients who had iatrogenic femoral pseudoaneurysms using direct thrombin injection. A 22-gauge spinal needle was placed into the pseudoaneurysm lumen with sonographic guidance, and bovine or human thrombin (mean dose, 306 U; range, 50--1600 U) was injected under continuous color Doppler sonographic visualization. Distal pulses were monitored. Patient demographics, clinical variables, and pseudoaneurysm characteristics were collected. RESULTS: One hundred three (90%) of 114 patients had pseudoaneurysm thrombosis after the first procedure. Of the remaining 11 patients who required a second procedure 1 day later, thrombosis occurred in seven (64%) of 11. Thus, the overall success rate was 96% (110/114). Of the patients who required one injection, the mean thrombosis time was 12 sec (range, 3--90 sec). Three (3%) of 114 patients required conscious sedation. Of the patients with successful thrombosis, 24-hr follow-up sonograms showed no recurrent pseudoaneurysm. Four patients (4%) had potential complications: a "blue toe" 15 hr after the thrombin injection that resolved spontaneously, a groin abscess, leg ischemia that resolved spontaneously after 4 hr, and crampy buttock pain that resolved spontaneously. CONCLUSION: For the treatment of iatrogenic femoral pseudoaneurysms, thrombin injection under sonographic guidance is a quick and effective method of therapy. Failures and complications are infrequent. At our institution, sonographically guided thrombin injection has replaced compression repair.

Aged↗
PubMed2001

Ultrasonographic evaluation of the cervix: transperineal versus endovaginal imaging.

OBJECTIVE: This study compares transperineal and endovaginal ultrasonography of the gravid cervix to evaluate image quality and assess for a systematic difference in cervical lengths measured by the 2 techniques. METHODS: Transperineal and endovaginal ultrasonography of the cervix was performed on 64 pregnant women. Two physicians reviewed the images and rated the relative diagnostic value of the techniques for assessing the cervix and for evaluating for placenta previa. Cervical length was measured prospectively in both techniques. Data were analyzed to determine if there is a systematic difference in length using the 2 approaches and if length differences are dependent on gestational age. RESULTS: There was a strong reviewer preference for endovaginal ultrasonographic images over transperineal images for both assessing the cervix (P< .001) and evaluating for placenta previa (P< .001). Despite this, transperineal and endovaginal ultrasonographic images were frequently rated as similar in diagnostic quality by both reviewers for depicting the cervix (35.9% of patients) and evaluating for placenta previa (57.8% of patients). The mean length of the cervix was slightly shorter at transperineal ultrasonography (28.4 mm) than at endovaginal ultrasonography (30.1 mm). When cervical lengths were subdivided by gestational age, however, a significant length discrepancy was found only in the 14- to 20-week gestational age range. In this age range, mean cervical length at transperineal ultrasonography (28.6 mm) averaged 5.5 mm less than at endovaginal ultrasonography (34.1 mm). CONCLUSIONS: Both transperineal and endovaginal ultrasonography can provide satisfactory images of the cervix, but endovaginal images are frequently superior to transperineal images. Endovaginal ultrasonography should be considered the optimal method for imaging the cervix in most situations. Transabdominal or transperineal ultrasonography can also be used, but if the cervix is not adequately depicted from these perspectives, endovaginal ultrasonography is indicated. Transperineal measurements of cervical length can be significantly shorter than endovaginal measurements, particularly before 20 weeks; therefore, short cervical lengths documented at transperineal ultrasonography before 20 weeks should be confirmed by endovaginal ultrasonography.

Cervix Uteri↗
PubMed2000

Pelvic CT morphometry in Down syndrome: implications for prenatal US evaluation--preliminary results.

PURPOSE: To characterize pelvic morphometric differences in patients with and those without Down syndrome by using computed tomography (CT) and to determine useful indexes for ultrasonographic (US) evaluation. MATERIALS AND METHODS: Pelvic CT scans in seven patients with Down syndrome and in 27 patients without Down syndrome were reviewed. Iliac angle, iliac length, sacroiliac joint angle, and anterior iliac wing separation were measured at superior, middle, and inferior transverse sacral levels. The effects of chromosomal status and transverse level were evaluated statistically. RESULTS: Significant differences were found for mean iliac angle (P < .007) and length (P < .005) between patients without Down syndrome (angle, 75 degrees; length, 8.4 cm) and those with Down syndrome (angle, 82 degrees; length, 7.5 cm). Depending on the level of measurement, variations in iliac angle between patients without and those with Down syndrome were as much as 13 degrees and 15 degrees, respectively, and variations in length were as much as 1.6 cm and 0.9 cm, respectively. The greatest differences were at the middle sacral level. Sacroiliac joint angle and the anterior iliac wing separation were not different between groups. CONCLUSION: Patients with Down syndrome had a larger mean iliac angle and a shorter mean iliac length. The most pronounced differences were at the middle sacral level, which suggests that this may be the optimal level for measuring these parameters at prenatal US.

Down Syndrome↗
PubMed2000

Variability of Doppler US measurements along the common carotid artery: effects on estimates of internal carotid arterial stenosis in patients with angiographically proved disease.

PURPOSE: To determine the effect of variability of common carotid arterial (CCA) velocities on velocity ratios used to assess internal carotid arterial (ICA) stenosis. MATERIALS AND METHODS: Doppler ultrasonographic (US) velocity measurements were obtained at three levels in the CCA and in the carotid bulb and ICA in all patients referred for carotid US between September 1996 and October 1997. Only ICAs (n = 98, in 57 patients) without ipsilateral CCA disease at angiography were analyzed. The range of CCA peak systolic velocities (PSVs) and end diastolic velocities (EDVs) and velocity ratios were calculated for each CCA measurement. For each ICA/CCA velocity ratio, receiver operating characteristic analysis was performed. RESULTS: CCA PSV and EDV ranges averaged 23.1 cm/sec +/- 15.7 (SD) and 5.1 cm/sec +/- 3.6, respectively. For a given side, the difference averaged 1.0 +/- 1.3 for PSV ratios and 2.7 +/- 6.9 for EDV ratios, depending on where CCA measurements were taken. By using a threshold of 60% stenosis as indication for endarterectomy, variability in CCA velocities could have altered recommendations in 16 (28%) of 57 patients. Receiver operating characteristic analysis showed that ratios made by using the three CCA velocities or their mean were not significantly different. CONCLUSION: Variability in velocity measurements along the course of the CCA in patients with ICA disease can be substantial and can result in inaccuracies in assessment of carotid stenosis.

Aged↗
PubMed2000

Treatment of iatrogenic femoral arterial pseudoaneurysms: comparison of US-guided thrombin injection with compression repair.

PURPOSE: To evaluate and compare the treatment of iatrogenic femoral arterial pseudoaneurysms by using ultrasonographically (US) guided direct thrombin injection with US-guided compression repair. MATERIALS AND METHODS: Twenty-six patients with iatrogenic femoral arterial pseudoaneurysms were treated with direct thrombin injection. With US guidance, a 22-gauge needle was placed into the pseudoaneurysm flow lumen and thrombin (mean volume, 0.35 mL; range, 0.10-0.60 mL) was injected with continuous color Doppler US guidance. Demographics, clinical variables, pseudoaneurysm characteristics, and results in these patients were compared with those in 281 consecutive patients who underwent US-guided compression repair. RESULTS: The success rate of thrombin injection was 96% (25 of 26 patients), which was significantly higher than that of compression, 74% (209 of 281 patients) (P =.013). Twenty of 26 (77%) patients required a single injection, and six (23%) required two injections. Mean thrombosis time for thrombin injection was 6 seconds, compared with 41.5 minutes for compression. For thrombin injection, there were no complications, foot pulses did not change and no patients required conscious sedation. Follow-up US at 24 hours showed no recurrent pseudoaneurysms. CONCLUSION: For the treatment of iatrogenic femoral arterial pseudoaneurysms, thrombin injection with US guidance appears to be superior to compression repair.

Aged↗
PubMed2000

Normal fetal pelvis: important factors for morphometric characterization with US.

PURPOSE: To prospectively evaluate iliac angle and iliac length in a large number of normal fetuses and to identify factors that may influence these measurements. MATERIALS AND METHODS: At antenatal ultrasonography (US) in 356 fetuses, the iliac angle and iliac length were measured at two axial levels (superior and inferior). In mixed linear models, the statistical significance and magnitude of effect on the measurement of iliac angle and iliac length were estimated for gestational age, fetal sex, maternal diabetes status, axial level, and spine position relative to the transducer. RESULTS: Statistically significant effects were found for gestational age, axial level, and spine orientation but not for fetal sex or maternal diabetes status. The iliac angle was found to decrease by 15.7 degrees from the superior to inferior portion of the pelvis, decrease by approximately 0.37 degrees /wk, and decrease by as much as 15.6 degrees when the spine is directed to the side. Iliac length was found to increase by 0.8 mm/wk from 13 weeks to term, decrease by 1.2 mm from the superior to the inferior portion of the pelvis, and increase by as much as 1.29 mm when the spine is not directly subjacent to the transducer. CONCLUSION: The axial level of measurement, gestational age, and spine orientation must be accounted for if these morphometric indexes are used to discriminate fetuses with and those without Down syndrome.

Amniocentesis↗
PubMed2000

Refractory shadowing from pelvic masses on sonography: a useful diagnostic sign for uterine leiomyomas.

OBJECTIVE: Our objective was to determine the diagnostic usefulness of sonography for revealing a recurrent acoustic shadowing pattern when imaging for possible uterine leiomyoma. SUBJECTS AND METHODS: During an 18-month period, all pelvic masses discovered on sonography were prospectively examined for recurrent refractory shadows. Sonograms of 222 masses with a definitive final diagnosis were reviewed by two radiologists unaware of the follow-up results. Each mass was analyzed for the presence of three or more recurrent refractory shadows, each of which did not arise from an echogenic lead point. After all masses were rated independently, a consensus rating was reached for any discrepancy between observers. RESULTS: Of the 222 masses, 152 (68%) were leiomyomas. The remainder resulted from a wide variety of other uterine and adnexal disorders. Agreement between the two observers regarding refractory shadows was excellent. Kappa coefficients were 0.86 at transabdominal and 0.96 at transvaginal approaches. Sensitivity of the refractory shadow pattern for leiomyomas was higher for transvaginal (87%) than for transabdominal (52%) sonography. Specificity of the refractory shadow pattern was 89% for transvaginal and 92% for transabdominal sonography. Using logistic regression analysis, we found a statistically significant association between a refractory shadowing pattern and leiomyoma for both transabdominal and transvaginal sonography (p < 0.001). CONCLUSION: Recurrent refractory shadowing in a pelvic mass on sonography is highly suggestive of leiomyoma and can be a useful diagnostic clue for distinguishing leiomyomas from other pelvic masses.

Adult↗
PubMed2000

Vertebral artery Doppler waveform changes indicating subclavian steal physiology.

OBJECTIVE: The goal of this study was to characterize and classify changes in antegrade vertebral artery waveforms that may represent the early stages of subclavian steal physiology. SUBJECTS AND METHODS: A prospective examination of waveforms from 1914 vertebral arteries produced a total of 40 that had a transient sharp decline in velocities at mid or late systole. In these patients, an ECG tracing was synchronized with the pulsed Doppler waveform, and reactive hyperemia was induced in the ipsilateral arm with a blood pressure cuff. The same protocol was performed in a control group of 52 patients with normal vertebral artery waveforms. Correlation between the waveforms and subclavian disease shown on angiography was made in 10 cases collected from the prospective study and in an additional 10 cases identified from a record search. RESULTS: Four prototypic waveforms were identified on the basis of the degree of flow deceleration in mid systole. Flow velocity at the nadir of the mid systolic notch was greater than that of the end diastole for type 1 waveforms, equal to the end diastole for type 2, at the baseline for type 3, and below the baseline for type 4. The blood pressure cuff maneuver induced a change to more abnormal waveforms in 36 of 40 patients but did not change the waveforms of the control group. The correlation between waveform type and subclavian disease was statistically significant (p = 0.03). CONCLUSION: Identifiable changes in the pulse contour of antegrade vertebral artery waveforms seem to represent the early stages of subclavian steal physiology. These changes can be organized into waveform types that indicate increasingly abnormal hemodynamics.

Aged↗
PubMed2000

Comparison of sonographic and CT guidance techniques: does CT fluoroscopy decrease procedure time?

OBJECTIVE: Procedure times for percutaneous biopsies were compared for various guidance techniques including helical CT, CT fluoroscopy, sonography with an attached needle guide, and freehand sonography with computer guidance. MATERIALS AND METHODS: Three interventional radiologists experienced in CT- and sonographically guided procedures performed biopsies on a phantom model. The phantom simulated hepatic metastases of various sizes and depths with subcostal or intercostal locations. Lesion sizes were 7, 10, and 20 mm, at 3- and 7-cm depths. Using self-aspirating needles, two passes were performed in each lesion. Mean procedure time per biopsy pass was calculated. A two-tailed Student's t test was used to compare guidance techniques. RESULTS: Mean procedure time per biopsy pass for the four guidance techniques was sonography with a needle guide, 36+/-9 sec; sonography with computer guidance, 43+/-10 sec; helical CT, 146+/-42 sec; and CT fluoroscopy, 50+/-18 sec. CT fluoroscopy required 2.6+/-1.0 sec per biopsy. Helical CT required more procedure time than sonography with a needle guide, CT with computer guidance, and CT fluoroscopy (p < 0.0001). Sonography with a needle guide required less procedure time than sonography with computer guidance (p < 0.002) and CT fluoroscopy (p = 0.0003). Procedure times for CT fluoroscopy and sonography with computer guidance were not statistically different (p = 0.06). CT and sonographic guidance were equally effective regardless of lesion size, depth, or location. CONCLUSION: Traditional sonographic biopsy techniques are faster and more cost-effective than traditional CT techniques; however, CT fluoroscopy offers the localization advantages of CT with improved procedure times.

Abdomen↗
PubMed2000

Physician training requirements in sonography: how many cases are needed for competence?

OBJECTIVE: Physician competence in the performance of sonographic studies was assessed after their involvement in predetermined increments of cases to determine whether the case volumes currently required by the American Institute of Ultrasound in Medicine and the American College of Radiology for training in sonography can be lowered substantially. MATERIALS AND METHODS: Sonographic competence tests were administered to 10 first-year diagnostic radiology residents after their involvement in increments of 50 cases, up to a total of 200 cases (four competency tests). Each competency test consisted of the resident's independently scanning and interpreting 10 clinically mandated studies that were scored in comparison with the examination performed by the sonographer and interpreted by an attending radiologist. Trainee studies were graded on the percentage of anatomic landmarks depicted, the number of reporting errors, the number of clinically significant reporting errors, and the percentage of cases receiving a passing score. RESULTS: Although resident performance improved progressively with increasing experience for all parameters assessed, performance of the group was poor even after their involvement in 200 cases. At this testing level, the mean percentage of anatomic landmarks depicted successfully was 56.5%; the mean total reporting errors per case was 1.2; the mean clinically significant errors per case was 0.5; and the mean percentage of cases receiving a passing score was 16%. Impressive performance differences were observed among residents for all parameters assessed, and these differences were not explained by the number of months of radiology training the resident had taken before the sonography rotation. CONCLUSION: Involvement in 200 or fewer cases during the training period is not sufficient for physicians to develop an acceptable level of competence in sonography.

Clinical Competence↗
PubMed2000

Transjugular intrahepatic portosystemic shunts (TIPS): effects of respiratory state and patient position on the measurement of Doppler velocities.

OBJECTIVE: The purpose of this prospective study was to examine the effects of patient position and respiratory state on the measurements of Doppler velocities in transjugular intrahepatic portosystemic shunts. SUBJECTS AND METHODS: Thirty-eight transjugular intrahepatic portosystemic shunts in 34 consecutive patients were studied using Doppler sonography. Peak velocities were measured in the mid shunt with the patient in three positions (supine, sitting upright, and left lateral decubitus) and two respiratory states (deep inspiration and quiet respiration). A mixed linear regression model was used to assess statistically significant differences among the six velocity measurements. RESULTS: Peak velocities in the mid stent averaged 22 cm/sec greater in quiet respiration than in deep inspiration, which was a significant difference (p < 0.00001). Differences in velocities in the three patient positions were not significant (p = 0.53). Using 90-190 cm/sec as the normal range, the peak velocity shifted from normal to abnormal levels by changing respiratory state in 17 (45%) of 38 studies. Using 60 cm/sec as the lower normal limit, the peak velocity fell below the normal range with inspiration in 10 (26%) of 38 studies. In 12 (32%) of 38 studies, a decline in peak velocity exceeding 50 cm/sec could be induced by inspiration. CONCLUSION: Peak systolic velocity in transjugular intrahepatic portosystemic shunts is substantially altered by the respiratory state of the patient at the time of the measurement, but not by the patient position. Respiratory state must be taken into account in the interpretation of peak velocity for shunt stenosis.

Adult↗