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Biomedical subjects

N Maklad

Publications and source records attributed to N Maklad.

At least 19 recordsLinked to original sources
PubMed1998

Color-flow and power Doppler imaging of the testes.

The development of color-flow imaging has made ultrasound the primary imaging modality for the evaluation of testicular pathology. The ability to distinguish between epididymo-orchitis and torsion is of great clinical significance in those patients with acute onset of pain. Not only does the appropriate treatment depend on the correct diagnosis, but the outcome following that treatment is also dependent on establishment of the diagnosis. Although it is of less importance in the evaluation of testicular neoplasms, color-flow imaging does provide adjunctive information that can aid in establishment of the proper diagnosis in confusing clinical situations. The diagnosis of varicocele depends on color-flow imaging, and the prediction of testicular viability following trauma is essential for proper treatment. More studies concerning the use of power Doppler for imaging of scrotal disorders are necessary to determine what its role will be.

Humans↗
PubMed1998

Color and power Doppler imaging of the kidneys.

Sonography is a widely used modality for the evaluation of both native and transplanted kidneys. It is noninvasive, portable, and requires minimal patient preparation. Renal sonography can estimate kidney size, determine the presence or absence of hydronephrosis, and the presence and characteristics of any intrarenal or extrarenal masses. The addition of color, and, more recently, power Doppler have enhanced the diagnostic capabilities of renal sonography. Color and power Doppler have distinct but complementary uses, and knowledge of the advantages and limitations of each are essential for proper application of these powerful tools. The differences between color and power Doppler is discussed, with emphasis on their relative strengths. Clinical uses of color Doppler include the evaluation of perfusion abnormalities, renal artery stenosis, renal vein thrombosis, pseudoaneurysms, and arteriovenous fistulas. Color and power Doppler are also helpful in the evaluation of the transplanted kidney and can suggest the presence of transplant rejection. The sonographic color and power Doppler features of disease entities which affect the kidneys are discussed. Knowledge of these sonographic features will enable prompt diagnosis, thereby expediting patient care.

Humans↗
PubMed1998

Sonographic detection of echogenic fluid and correlation with culdocentesis in the evaluation of ectopic pregnancy.

OBJECTIVE: Because the presence of echogenic fluid on transvaginal sonography has been shown to correlate well with hemoperitoneum in patients with possible ectopic pregnancy, the aim of this study was to compare echogenic fluid on sonography with the results of culdocentesis in predicting hemoperitoneum. MATERIALS AND METHODS: Free fluid on transvaginal sonography and the results of culdocentesis were correlated with the presence or absence of hemoperitoneum in 46 patients at surgery. Forty ectopic pregnancies and six nonectopic pregnancies were found. Echogenic fluid was the criterion used to establish hemoperitoneum on sonography. For statistical analysis, negative and nondiagnostic culdocentesis results were combined. The sensitivity, specificity, and positive and negative predictive values of each diagnostic technique were compared. RESULTS: In 40 of 46 patients with ectopic pregnancy, the sensitivity and specificity of echogenic fluid for establishing hemoperitoneum were 100% and 100%, respectively, compared with 66% and 80%, respectively, for culdocentesis. More important, the negative predictive value of a nondiagnostic culdocentesis was 25% compared with 100% for echogenic fluid in the ectopic subgroup of patients. In two patients with incomplete abortions, sonography failed to detect small amounts of hemoperitoneum at surgery performed 4 hr and 7 days after sonography. CONCLUSION: Sonography is more sensitive than culdocentesis in the detection of hemoperitoneum. Culdocentesis is invasive, and nondiagnostic results cannot be used to exclude hemoperitoneum. Culdocentesis should play no role in the evaluation of ectopic pregnancy except in the unusual circumstance in which high-resolution sonography cannot be readily performed.

Abortion, Incomplete↗
PubMed1998

Free echogenic pelvic fluid: correlation with hemoperitoneum.

Echogenic fluid is an important extrauterine finding of ectopic pregnancy. The purpose of this study was to determine how accurately echogenic fluid correlates with hemoperitoneum at surgery. Transvaginal sonography was performed in 831 consecutive patients referred to rule out ectopic pregnancy over a 36 month period. Scans were retrospectively evaluated for the presence or absence and echogenicity of free pelvic fluid. Subsequently, 185 patients had a laparotomy or laparoscopy and had documentation of the presence or absence of hemoperitoneum. On transvaginal sonography 125 patients had echogenic fluid, 30 patients had anechoic fluid, and 30 patients had no fluid. Of the 125 patients with echogenic fluid, 122 (98%) patients had hemoperitoneum; none of the patients with anechoic fluid or no detected fluid had hemoperitoneum (0%). Echogenic fluid had a sensitivity of 100%, specificity of 95%, positive predictive value of 98%, and an accuracy of 98% for detecting hemoperitoneum. This study demonstrates that echogenic fluid detected by transvaginal ultrasonography accurately correlates with hemoperitoneum detected at surgery in patients with suspected ectopic pregnancy.

Adolescent↗
PubMed1997

Dynamic high-resolution sonography of the carpal tunnel.

CTS is an increasingly common condition with symptoms resulting from compression of the median nerve. Although most cases are clinically straightforward, those with confusing clinical pictures or equivocal or contradictory diagnostic studies may benefit from imaging. Although MR imaging has been established as a useful imaging technique for the evaluation of CTS, sonography may be a low-cost alternative. Imaging criteria for the diagnosis of CTS apply to both sonography and MR imaging. Sonographic evaluation of a large series of patients is still necessary to determine the definitive role of sonography in CTS.

Adult↗
PubMed1997

Predicting poor neonatal outcome: a comparative study of noninvasive antenatal testing methods.

OBJECTIVE: The assessment of fetal well-being in the third trimester of pregnancy depends on many variables including fetal size, amniotic fluid volume, umbilical cord arterial Doppler waveforms, the nonstress test, and the biophysical profile, yet little has been written that directly compares these variables. In this study, we compared amniotic fluid indexes, umbilical cord arterial Doppler waveforms, nonstress tests, and biophysical profiles for predicting poor neonatal outcomes in fetuses who are small for gestational age (SGA). SUBJECTS AND METHODS: From April 11, 1994, through August 1, 1995, a cohort of 108 SGA fetuses was identified. Follow-up was available in 97 of these cases. Receiver operating characteristic curves were constructed for Doppler systolic:diastolic ratios and for amniotic fluid indexes. Student's t test and logistic regression analysis were used to compare umbilical cord arterial Doppler imaging, amniotic fluid indexes, the nonstress test, and the biophysical profile for predicting poor neonatal outcome. RESULTS: Of the 30 fetuses who had poor outcomes, five were emergency cesarean deliveries, three died, three had intracranial hemorrhages, one had a cerebral infarct, 12 had prolonged admission to the neonatal intensive care unit (NICU) (> 10 days), and six had NICU admissions at term. Of the variables we assessed, the sensitivities for predicting poor outcome were as follows: cord Doppler imaging, 64%; low amniotic fluid volume (oligohydramnios), 32%; biophysical profile, 18%; and nonstress test, 14%. Receiver operating characteristic curves showed that a systolic:diastolic ratio of 4.0 and an amniotic fluid index of 5 cm (independent of gestational age) were the most accurate cutoff values for predicting poor outcome. Logistic regression analysis showed that amniotic fluid indexes and umbilical cord arterial Doppler imaging were independent predictors of poor outcome and that the predictive value of the biophysical profile varied according to the amniotic fluid index. CONCLUSION: Doppler waveform abnormalities were the most accurate predictor of poor neonatal outcome in a cohort of SGA fetuses. Umbilical cord arterial Doppler waveform analysis should be included in the surveillance of SGA fetuses.

Amniotic Fluid↗
PubMed1997

The role of transvaginal sonography and endometrial biopsy in the evaluation of peri- and postmenopausal bleeding.

OBJECTIVE: The number of women seeking medical attention for peri- and postmenopausal bleeding (PMB) has been increasing. Determining the cause of PMB is essential in planning appropriate therapy. In these women, transvaginal sonography (TVS) is a sensitive means for diagnosing the causes of such bleeding, yet endometrial biopsy (EMB) is still preferred as the first diagnostic test. We prospectively compared TVS with aspiration biopsies of the endometrium in the examination of women with PMB. SUBJECTS AND METHODS: Between mid April 1994 and December 1995, 329 consecutive perimenopausal women underwent EMB. Of these EMBs 302 had negative results. We prospectively obtained TVS in 259 of these 302 women within 1 month of EMB (range, 10 days to 2 months) when the results of biopsy were negative. Forty-three patients were lost to follow-up. In 59 women who had endometrial thickening greater than 5 mm, dilatation and curettage, hysteroscopy, or hysterectomy was performed. Ninety-four of the 130 women who were found at TVS to have fibromyomata or diffusely enlarged uteri underwent hysterectomy for pathologic confirmation. The remaining 36 women with fibromyomata or diffusely enlarged uteri had no pathologic confirmation of their TVS findings. Twenty-one of 64 women with endometria thinner than 5 mm underwent dilatation and curettage, and 43 of these women were lost to follow-up. RESULTS: In 259 patients who underwent TVS, 57 patients who had an endometrium thicker than 5 mm and an endoluminal mass on hysterosonography had false-negative results on aspiration biopsies. Of the 18 patients who had malignancies in this series, 12 had false-negative results on biopsies. In the 94 patients with an enlarged uterus and negative EMB results who underwent hysterectomy, we found 87 with fibroids, three with adenomyosis, and four with sarcomas. Of the 64 women with endometria thinner than 5 mm seen on TVS, 21 had negative results from dilatation and curettage. CONCLUSION: EMB alone is not sufficient for screening women for PMB. TVS appears to be more sensitive than is EMB for the detection of abnormalities, particularly those outside the endometrium. For these reasons, TVS should be the initial screening test when examining women with PMB.

Biopsy, Needle↗
PubMed1996

Suspected urolithiasis in pregnant women: imaging algorithm and literature review.

Urolithiasis during pregnancy is a difficult clinical problem in which carefully selected radiologic studies play an essential role. For years excretory urography has been the standard of care in the radiologic evaluation of urolithiasis in pregnancy. Recently, sonography, particularly Doppler sonography, has evolved as an invaluable tool in the armamentarium of radiologists facing this challenging problem. In experienced hands, the diagnosis of urolithiasis in pregnancy can be made confidently using Doppler sonography and, when necessary, excretory urography.

Algorithms↗
PubMed1995

Transvaginal hysterosonography: comparison with biopsy in the evaluation of postmenopausal bleeding.

Transvaginal sonography is a highly sensitive method for detecting endometrial thickening. In the postmenopausal woman such thickening is non-specific and can be due to hyperplasia, polyps, submucosal endoluminal fibroids, or carcinoma. In such cases, transvaginal sonography combined with transvaginal hysterosonography may assist in the workup of these endometrial processes. We compared the combination of transvaginal sonography and transvaginal hysterosonography to aspiration endometrial biopsy in the evaluation of women with postmenopausal bleeding. We prospectively performed transvaginal sonography in 148 women within 1 month (range, 10 days to 2 months) after having had an aspiration endometrial biopsy. Transvaginal hysterosonography was then performed in 81 of these women who had endometrial thickness greater than 5 mm. In these 81 patients, transvaginal hysterosonography confirmed 45 lesions: 23 pedunculated endometrial masses and 22 inhomogeneous sessile lesions. Women with positive transvaginal hysterosonography examinations then underwent hysteroscopy or hysterectomy, whereas women with negative examinations were followed conservatively. Forty-one of the 45 cases with endoluminal masses on transvaginal hysterosonography had false-negative aspiration biopsies. Of the five (11%) lesions that were malignant, three resulted in false-negative biopsies, one biopsy revealed hyperplasia, and only one biopsy was true positive. All 36 women with negative transvaginal hysterosonography examinations also had negative biopsy findings. We conclude that the combination of transvaginal sonography and transvaginal hysterosonography is more sensitive in the detection of endometrial pathologic lesions than is endometrial biopsy, and that transvaginal sonography or transvaginal hysterosonography should be included in the evaluation of women with postmenopausal bleeding.

Adult↗
PubMed1993

Elastography: elasticity imaging using ultrasound with application to muscle and breast in vivo.

Changes in tissue elasticity are generally correlated with its pathological state. In many cases, despite the difference in elasticity, the small size of a lesion or its location deep in the body preclude its detection by palpation. In general, such a lesion may or may not possess echogenic properties that would make it ultrasonically detectable. Elastography is an ultrasonic method for imaging the elasticity of compliant tissues. The method estimates the local longitudinal strain of tissue elements by ultrasonically assessing the one dimensional local displacements. This information can be combined with first order theoretical estimates of the local stress to yield a quantitative measure of the local elastic properties of tissue. The elasticity information is displayed in the form of a gray scale image called an elastogram. An experimental system for elastography in phantoms based on a single element transducer has been described previously [1]. Here we introduce a new elastography system based on a linear array transducer that is suitable for in vivo scanning. We describe tissue mimicking phantom experiments and preliminary in vivo breast and muscle elastograms confirming the feasibility of performing elastography in vivo. An elastogram of a breast containing an 8 mm palpable cancer nodule clearly shows the lesion. Elastograms and their corresponding sonograms show some similarities and differences in the depiction of tissue structures.

Adult↗
PubMed1993

Pitfalls in the transvaginal sonographic diagnosis of ectopic pregnancy.

Transvaginal sonograms (TVS) of 40 adequately documented ectopic pregnancies were reviewed retrospectively. Difficulties that interfered with the accurate demonstration of the adnexal mass of the ectopic pregnancy were identified in 21 of these studies (52.5%). In three cases (7.5%) the ectopic pregnancy was visualized in an erroneous location. In 11 cases (27.5%), the ectopic pregnancy was overshadowed by coexisting pathologic findings, misinterpreted as a bowel segment or poorly demarcated from the adjoining ovary. In seven cases (17.5%), the adnexal mass of an ectopic gestation was completely over-looked on initial TVS. TVS in the women suspected of having an ectopic pregnancy must be performed meticulously and with due consideration to the pitfalls described.

Adolescent↗
PubMed1986

Characteristics of patients with and without gonadotropin surges during follicular recruitment in an in vitro fertilization/embryo transfer program.

Fifteen ovulatory patients undergoing ovarian stimulation with clomiphene citrate-human menopausal gonadotropin-human chorionic gonadotropin (hCG) for in vitro fertilization were studied. All 15 attained peak estradiol (E2) levels of greater than 600 pg/ml. Eight patients had an endogenous luteinizing hormone (LH) surge before the administration of hCG. The characteristics of these "surge" patients were compared with those of the remaining seven "nonsurge" patients. There was no significant difference in the peak morning E2 achieved before hCG or the endogenous LH surge, nor in the peak absolute increase in E2 over a 24-hour period in these two groups. The surge group had significantly higher E2 levels per follicle greater than or equal to 15 mm, measured by ultrasound on the morning of the day of administration of hCG or the LH surge (P less than or equal to 0.005). In addition, nonsurge patients had a greater number of follicles greater than or equal to 15 mm, compared with surge patients (P less than or equal to 0.05). It is hypothesized that greater quantities of nonsteroidal hormones, such as inhibin, produced by a greater number of preovulatory follicles in nonsurge patients, may block the pituitary response to hypothalamic gonadotropin-releasing hormone in the face of high and rising E2 levels.

Chorionic Gonadotropin↗
PubMed1986

Patterns of estradiol response in patients with endogenous gonadotropin surges during follicular recruitment in an in vitro fertilization and embryo transfer program.

This report is an analysis of 16 cycles in 15 patients stimulated with human menopausal gonadotropin and clomiphene citrate for the purpose of follicular recruitment in an in vitro fertilization program, all of which resulted in endogenous luteinizing hormone (LH) surges. A study of the pattern of estradiol (E2) response to stimulation revealed two groups of cycles, designated "leap" pattern (9 cycles) and "plateau" pattern (7 cycles), the rate of rise of E2 increasing or decreasing, respectively, as the time of the LH surge was approached. There were no significant differences between these groups of cycles in the peak E2 level attained or the number of follicles greater than or equal to 12 mm on the day of peak E2. In the plateau, but not in the leap pattern cycles, a significant correlation (r = 0.958) was found between the number of follicles greater than or equal to 12 mm and the peak E2. We tentatively conclude that "plateau" pattern cycles reflect relatively synchronous follicular recruitment; the greater the number of follicles recruited, the higher the E2 level attained, increased amounts of inhibin-like substances being available to restrain the LH surge; "leap" pattern cycles reflect asynchronous follicular recruitment.

Clomiphene↗
PubMed1985

Quantitative assessment of in vivo backscatter enhancement from gelatin microspheres.

Experimental work using a quantitative C-scan technique to measure in situ enhancement of hepatic backscatter resulting from the administration of gelatin microspheres to dogs is reported. We have found that reproducible enhancement of hepatic backscatter on the order of 2 dB followed the peripheral administration of gelatin within minutes, the magnitude of the effect was not sensitive to the rate of infusion, but was likely to be dose dependent, changes in the overlying tissue attenuation had a pronounced effect on the measurement, and the effect was sustained for up to one half hour or longer.

Animals↗
PubMed1983

The use of ultrasound in the expectant management of abruptio placentae.

The use of real-time ultrasound and antepartum nonstress testing in the management of abruptio placentae is discussed. In one patient, fetal distress developed when the retroplacental clot volume reached 480 ml. Two cases in which retroplacental clot was less than 480 ml were managed expectantly with the use of ultrasound and antepartum fetal testing, with excellent results.

Abruptio Placentae↗