Lower extremity volumetric arterial blood flow in normal subjects.

The objective of this clinical study was to establish normal values for volumetric blood flow in the leg at rest using Doppler ultrasound, and to determine what biophysical factors influence resting volumetric flow. Arterial blood flow was measured at four sites in the legs of 40 healthy subjects using an ATL Ultramark 9 HDI system. All subjects were nonhypertensive nonsmokers with ankle brachial index values greater than 1 and no history of vascular disease. The subjects, 20 of each gender, in age ranging from 20 to 64 y were examined. Blood flow was calculated from the time-averaged, intensity-weighted mean velocity Doppler waveforms and vessel cross-sectional area at the same site. Thigh and calf circumference measurements were used to estimate muscle masses. The mean flow and standard error measured in four arteries in the leg were: 284+/-21 mL/min in the common femoral (CFA); 152+/-10 mL/min in the superficial femoral (SFA); 72+/-5 mL/min in the popliteal; and 3+/-1 mL/min in the dorsalis pedis. Although women tended to have higher time-averaged mean velocities in the CFA and SFA than men (t-test, p < 0.008), their arterial cross-sectional areas tended to be smaller (t-test, p < 0.004) and no statistically significant difference was found between men and women in volumetric flow at any site. No correlation was found between age, weight, height, muscle mass and volumetric flow at all four sites. These estimates of lower extremity volumetric flow in healthy subjects provide a baseline for future studies of flow rates in patients with vascular disease.

Fibroma and fibrothecoma of the ovary: MR imaging findings.

PURPOSE: To describe the morphologic and signal intensity characteristics on magnetic resonance (MR) images of fibromas and fibrothecomas. MATERIALS AND METHODS: MR images of 11 female patients with histologically proved fibromas or fibrothecomas were reviewed, and morphologic and signal intensity characteristics of the lesions were analyzed. MR imaging findings were correlated with histologic findings. RESULTS: All fibromas and fibrothecomas showed homogeneous low signal intensity on T1-weighted images. On T2-weighted images, the two smallest lesions showed homogeneous low signal intensity, and eight of the other nine lesions showed predominantly low signal intensity. Edema was noted only in larger lesions, and cystic degeneration was noted only in three of the largest lesions. On T2-weighted images, the percentage of low signal intensity in the lesion was not found to be related to lesion size, and the percentage of low signal intensity in fibromas was not significantly different from that in fibrothecomas (P = .55). Many lesions showed heterogeneous signal intensity; the solid component was distributed peripherally, and the cystic component was located centrally or eccentrically. Free intraperitoneal fluid was noted in 10 of 11 lesions and was not significantly correlated with lesion size (r = .52 and P = .10). CONCLUSION: Because of their predominantly low signal intensity on T2-weighted images, fibromas and fibrothecomas display a relatively specific appearance on MR images.

Timing, magnitude, and utility of surgical delay in the TRAM flap: II. Clinical studies.

Transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction was performed in 15 patients 1 week after a preliminary delay procedure. The indications for surgical delay were obesity, smoking, prior radiation therapy, a requirement for large volumes of transmidline tissue, or combinations of these risk factors. The delay procedure consisted of outpatient ligation of the deep and superficial inferior epigastric vessels. Prior to and 1 week following the delay procedure, noninvasive Doppler examinations of the superior epigastric vessels were performed. Following the delay procedure, the diameter of the superior epigastric artery increased from 1.3 +/- 0.2 to 1.8 +/- 0.3 mm (p < 0.001) and the calculated superior epigastric artery flow increased from 7.25 +/- 0.8 to 18.2 +/- 2.7 ml/min (p < 0.001). Breast reconstruction in these high-risk patients was successful without major ischemic complications, but a tendency toward unreliability of zone IV was noted. This clinical observation is consistent with the findings in our animal studies (part I). The preliminary delay procedure was well tolerated with minimal morbidity. We feel that a preliminary delay procedure is a very useful option for breast reconstruction patients at high risk for TRAM flap vascular compromise.

Surgical delay in TRAM flap breast reconstruction: a comparison of 7- and 14-day delay periods.

Thirty-one transverse rectus abdominis musculocutaneous (TRAM) flap breast reconstructions were performed after a delay period either of 1 week (group I, N = 15) or 2 weeks (group II, N = 16). The preliminary delay procedure consisted of bilateral deep inferior epigastric and superficial inferior epigastric artery and vein ligation. In group I the diameter and flow in the superior epigastric artery increased from baseline values of 1.3 +/- 0.3 mm and 7.25 +/- 0.8 ml per minute to 1.8 +/- 0.3 mm and 18.2 +/- 2.7 ml per minute at 1 week. In group II the diameter and flow in the superior epigastric artery increased from baseline values of 1.2 +/- 0.3 mm and 5.85 +/- 1.5 ml per minute to 1.7 +/- 0.4 mm and 23.4 +/- 6.2 ml per minute at 2 weeks. The differences between 1 and 2 weeks were not statistically significant. The complication rate in either group was similar. We conclude that a preliminary delay procedure is highly effective at augmenting TRAM flap vascularity and may be implemented between 1 and 2 weeks prior to TRAM flap breast reconstruction in high-risk patients.

Medical Grand Rounds: refractory hypertension and renal insufficiency in a patient with renal artery stenosis.

Renal artery stenosis has become increasingly common as a cause of refractory hypertension and renal insufficiency. There is a high prevalence of bilateral disease and the lesions tend to progress over time. Newer, less invasive, imaging modalities such as doppler ultrasound, magnetic resonance angiography, and spiral CT scanning are evolving technologies in the diagnosis of renal artery stenosis. Advances in surgical technique, particularly the development of extra-anatomical procedures such as spleno-renal and hepato-renal by pass, have significantly lowered surgical morbidity and mortality and provides revascularization options for patients with complex vascular disease that would previously not have been considered because of their high surgical risk. Improvements in angioplasty technique and the use of stents are broadening the types of lesions that can be successfully approached with these techniques and may be particularly helpful for patients with more severe cardiac or cerebrovascular disease. The benefits of revascularization may be even greater for preservation of renal function than for control of blood pressure in properly selected patients. It is difficult to predict which patients will benefit from surgical revascularization versus medical management of RAS. Knowledge of the progressive nature of RAS, the high prevalence of bilateral disease, and the clinical characteristics that correlate with progression (e.g., decreasing renal size) are helpful in guiding clinical decisions regarding intervention. Additional studies to determine the predictive value of non-invasive tests such as CRS, doppler ultrasound before and after administration of angiotensin converting enzyme inhibitors, and other tests, are needed to assist the clinician in identifying who will benefit most from revascularization both in terms of renal function and blood pressure control.

Doppler color flow imaging surveillance of deep vein thrombosis in high-risk trauma patients.

To determine the prevalence of upper and lower extremity deep vein thrombosis in high-risk trauma patients, 136 consecutive high-risk trauma patients were prospectively evaluated with weekly Doppler color flow imaging. Incomplete compressibility and visualized intraluminal thrombus were considered diagnostic of deep vein thrombosis. Pulmonary embolus was documented by pulmonary arteriography. Deep vein thrombosis occurred at 27 non-contiguous sites in 19 patients (14%). Eight of 27 cases of deep vein thrombosis (30%) involved the upper extremity and 19 (70%) occurred in the lower extremity. Twenty-one of 27 deep vein thromboses (78%) were partially occlusive, whereas six (22%) were occlusive. Pulmonary embolus was documented in three patients (2.2%). Doppler color flow imaging detected occult deep vein thrombosis in 14% of high-risk trauma patients (30% occurring in the upper extremity).

Quantitative Doppler assessment of acute scrotal inflammation.

PURPOSE: To establish quantitative Doppler criteria for acute unilateral epididymitis and/or orchitis. MATERIALS AND METHODS: Triplex ultrasonography (US) was used to prospectively evaluate 31 patients with acute hemiscrotal pain and 15 asymptomatic control subjects. Morphology and perfusion were assessed, and peak systolic velocities (PSVs) were recorded. Ratios of PSV were calculated by using values from the right and left sides. RESULTS: PSVs in control subjects differed significantly from those in patients (P < .0001). A PSV > or = 15 cm/sec produced diagnostic accuracy of 90% for orchitis and 93% for epididymitis: Five of six false-negative findings were in patients younger than age 15 years. Epididymal PSV ratios > or = 1.7 or testicular ratios > or = 1.9 were diagnostic of acute inflammation (P < .0001). In three cases, morphologic and color Doppler findings were normal and only the PSV ratios were diagnostic. CONCLUSION: PSV and PSV ratios provide diagnostic criteria for acute unilateral epididymitis and/or orchitis that are more accurate than morphologic evaluation and color flow imaging either alone or in combination.

Clinical stage I endometrial carcinoma: pitfalls in preoperative assessment with MR imaging. Work in progress.

PURPOSE: To identify potential pitfalls in using magnetic resonance (MR) imaging to determine the depth of myometrial invasion in patients with clinical stage I endometrial carcinoma. MATERIALS AND METHODS: Forty women with clinical stage I endometrial carcinoma underwent preoperative pelvic MR imaging. Uterine length, tumor signal intensity, appearance of the junctional zone, presence of large polypoid tumors, leiomyomata, and congenital uterine anomalies were analyzed. Univariate logistic-regression analysis was performed to identify associations between incorrect MR staging and these variables. RESULTS: MR staging of IA, IB, and IC disease was 55% accurate (22 of 40 cases); MR differentiation of deep myometrial invasion (stage IC) from superficial disease (stages IA and IB) was 78% accurate (31 of 40 cases). Older age (P = .025), presence of polypoid tumors (P = .025), and difficulty in pathologic staging (P < .005) were significantly associated with incorrect MR assessment. CONCLUSION: When present, large polypoid tumors, leiomyomata, congenital anomalies, small uteri, and indistinct zonal anatomy may make it difficult to assess myometrial invasion at MR imaging.

MR evaluation of clinically suspected adnexal masses.

OBJECTIVE: Our goal was to determine the sensitivity, specificity, predictive value, and accuracy of pelvic MRI in the prospective evaluation of women with a clinically suspected pelvic mass. MATERIALS AND METHODS: One-hundred three patients with clinically suspected pelvic masses were prospectively evaluated by pelvic MRI. Masses were analyzed for size, location, morphological characteristics, and signal behavior. Masses were classified as benign, malignant, or indeterminate and in every case an attempt was made to generate a specific diagnosis according to previously reported characteristic MR appearances. Surgical follow-up was obtained within 3 months of MRI examination for all patients, excepting 11 patients with typically appearing leiomyomas. RESULTS: One hundred twenty pelvic masses were confirmed. Magnetic resonance was 100% sensitive and 99% specific in prospectively diagnosing dermoids, 96% sensitive and 100% specific in diagnosing subserosal leiomyomas, and 92% sensitive and 91% specific in diagnosing endometriomas. CONCLUSION: When physical examination or ultrasound examination is inconclusive, pelvic MRI can aid in the evaluation of women with a suspected pelvic mass. By identifying these common benign gynecologic conditions, unnecessary surgery can be avoided.

Zonal anatomy of the cervix: correlation of MR imaging and histologic examination of hysterectomy specimens.

High-resolution magnetic resonance (MR) images of nine hysterectomy specimens were correlated with light microscopy, computer-aided image analysis, and immunohistochemical examination to investigate the histologic counterparts of the zonal anatomy of the cervix. A central stripe of high signal intensity, a surrounding middle layer of low signal intensity, and an outer layer of intermediate signal intensity were found in all specimens. Histologic correlation indicated that the central stripe most likely represents the secretions in the canal, the cervical mucosa, and the plicae palmatae; the other two layers represent fibromuscular stroma. The percentage of nuclear area in the inner zone of the fibromuscular stroma is 2.5 times greater than in the outer zone, which may account for the lower signal intensity of the inner zone. No difference in distribution of collagen, laminin, and fibronectin (common components of the extracellular matrix) was found between the two zones of the cervical fibromuscular stroma.

Pelvic MR imaging findings in gestational trophoblastic disease, incomplete abortion, and ectopic pregnancy: are they specific?

Thirty-nine patients with abnormally elevated levels of serum beta subunit of human chorionic gonadotropin (beta-hCG) were studied to determine whether findings at magnetic resonance (MR) imaging are specific for primary molar disease, persistent gestational trophoblastic disease (GTD), incomplete abortion, and ectopic pregnancy. Among the latter three groups, the only significant differences were a higher prevalence of endometrial distention in the group with incomplete abortion (P < .0035) and the absence of junctional zone disruption in the group with ectopic pregnancy (P < .05). In the group with primary molar disease, total intrauterine volume was significantly increased (P < .001), and endometrial distention and presence of an endometrial mass had a significantly higher prevalence than that in the persistent GTD groups with (P < .04) or without (P < .001) metastases. Myometrial or extrauterine disease was identified in 65% of the patients with persistent disease and a beta-hCG level greater than 500 mIU/mL (500 IU/L). Thus, although MR imaging findings in persistent GTD, incomplete abortion, and ectopic pregnancy are relatively nonspecific, MR imaging can depict invasive disease that may alter therapeutic management in patients with documented GTD.

Ectopic pregnancy: evaluation with endovaginal color flow imaging.

Endovaginal sonography and endovaginal color flow imaging were compared in 155 patients with clinical suspicion of ectopic pregnancy. Sixty-five patients (42%) had surgically confirmed ectopic pregnancies. Thirty-six of the pregnancies were diagnosed with endovaginal sonography alone, the criteria being an extrauterine sac or ectopic fetus (sensitivity, 54%). Sixty-two ectopic pregnancies were diagnosed with endovaginal color flow imaging (sensitivity, 95%) when an ectopic fetus or sac was seen or placental flow was identified in an adnexal mass separate from the ovary and uterus. The diagnosis of ectopic pregnancy was excluded with endovaginal sonography (specificity, 98%) and endovaginal color flow imaging (specificity, 98%) by finding an intrauterine gestation, nonvisualization of an adnexal mass, and absence of placental flow. Three false-positive and three false-negative diagnoses were made with endovaginal color flow imaging (positive predictive value, 97%). The addition of color Doppler flow imaging to endovaginal sonography allows increased sensitivity in the detection of ectopic pregnancy.

Uterine changes after dilation and curettage: MR imaging findings.

To determine what, if any, changes occur in the appearance of the uterus on magnetic resonance (MR) images after dilation and curettage (D&C), nine women without endometrial abnormality underwent imaging before D&C and on day 2 and day 7 after D&C. On day 2, markedly hypointense curvilinear areas in the endometrial canal were noted on MR images in all patients (P = .0002). By day 7, these areas decreased in size in five (62%) and completely resolved in the rest (P = .022). There was no significant change in the width of the endometrial stripe or in the width or signal intensity of the junctional zone or myometrium after D&C. The junctional zone was focally disrupted in one patient who underwent D&C that was complicated by a uterine perforation. Therefore, curvilinear areas of low signal intensity (most likely representing clot) in the endometrial canal were visualized on MR images within 2 days of uncomplicated D&C and decreased in size or resolved over time. Significant widening of the endometrial stripe or disruption of the junctional zone was not observed after uncomplicated D&C.

Junctional zone of the uterus: correlation of MR imaging and histologic examination of hysterectomy specimens.

High-resolution magnetic resonance (MR) images of 12 hysterectomy specimens were correlated with results of light microscopy, image analysis, and immunohistochemical studies to investigate the histologic counterpart of the low-signal-intensity band, or junctional zone (JZ), that surrounds the bright central uterine stripe. All specimens were imaged with a 1.5-T superconducting magnet within 21/2 hours (on average) after hysterectomy. Comparison of histologic findings with measurements obtained at MR imaging indicates that the JZ represents the innermost layer of the myometrium. A threefold increase in percentage of nuclear area was found in the JZ in comparison with the outer myometrium, reflecting an increase in both size and number of nuclei. No difference in distribution of common components of the extracellular space (collagen, laminin, and fibronectin) was found between the two layers.

Pelvic masses in pregnancy: MR imaging.

The value of magnetic resonance (MR) imaging was assessed for 17 pregnant patients with sonograms suggestive of a pelvic mass. The MR imaging signal features improved lesion characterization in 47% (eight of 17) of cases, including two of four mature cystic teratomas of the ovary, three uterine fibroids, one solid ovarian tumor, one endometrioma, and a distended urinary bladder that had been mistaken for an ovarian cystic mass. Both MR imaging and sonography were accurate for the characterization of three ovarian cystadenomas and two simple ovarian cysts. On both MR images and sonograms, two simple ovarian cysts were incorrectly diagnosed as complex cystic masses and one teratoma was incorrectly diagnosed as a simple cyst. The origin of the pelvic mass (13 in the ovary, three in the uterus, and one distended urinary bladder) was accurately determined on 100% (17 of 17) of the MR images versus 71% (12 of 17) of the sonograms. In three cases, the results of MR imaging led to cancellation of surgery, which would have proceeded on the basis of the sonographic results alone. MR imaging is a valuable complement to sonography for preoperative evaluation of pelvic masses in pregnant patients.

Applications of magnetic resonance imaging to gynecology.

The advent of MRI has improved the ability of the diagnostic radiologist to provide useful clinical information to the practicing gynecologist. Although US remains the screening procedure of choice for evaluation of the uterus and adnexa because of its relative safety and low cost, MRI is now considered the next imaging step. In a woman with pelvic pain, MRI can accurately identify adenomyosis, enumerate and localize uterine fibroids, and provide more accurate identification of endometriosis and cystic teratomas of the ovary than US. Although MRI should not be used as a screening procedure for diagnosing endometrial or cervical carcinoma, it can aid in patient management by determining the extent of myometrial or cervical invasion by endometrial carcinoma and can be used to calculate tumor volume in patients with cervical carcinoma. Early studies suggest that MRI may be helpful in distinguishing between long-term radiation fibrosis and tumor recurrence in such patients. MRI findings may be highly indicative of the presence of ovarian malignancy, but the procedure adds little to CT or US findings. Nevertheless, MRI is superior in the localization of pelvic masses and is often indicated in clarifying the origin of a mass as uterine or ovarian.

Doppler US. Part II. Clinical applications.

Duplex and color Doppler ultrasound (US) are noninvasive techniques capable of providing much information about the condition of blood vessels and flow within them throughout the body. Doppler US provides more than noninvasive angiography. Besides assessment of blood vessel patency and direction of flow, analysis of the flow velocity waveform allows quantitation of arterial stenoses and evaluation of both physiologic and pathologic changes in impedance. In certain situations, Doppler US can aid in tissue characterization and estimation of absolute flow volume. Color Doppler flow imaging may both expedite and clarify the duplex Doppler examination. In addition, color Doppler imaging can demonstrate flow orientation and improve the identification of turbulence and soft plaque. Color and duplex Doppler US are complementary, with color Doppler techniques providing spatial orientation and pulse Doppler techniques providing the time-velocity spectrum for quantitation.

High-field MRI and US evaluation of the pelvis in women with leiomyomas.

Magnetic resonance imaging (MRI) and real-time transabdominal ultrasonography (US) were performed on 23 women with uterine leiomyomas. The uterus, ovaries, and cul de sac were evaluated. Accurate determination of uterine volume was possible in all cases by MRI, but was limited on US in uteri larger than 140 cc. Marked enlargement also prevented visualization of contour abnormalities in eight patients on US, but none on MRI. The endometrial stripe and junctional zone could not be adequately visualized in 21/23 US examinations, whereas they were identified in all 23 MRI (8 normal and 15 distorted). Individual leiomyomas were clearly depicted on 4 US and 19 MR scans, the smallest being 1.1 cm and 0.8 cm, respectively. Of the 31 fibroids present on MRI: 13 were intramural, 4 subserosal, and 14 submucosal. MRI successfully identified 44/46 ovaries as compared to 21/46 on US. Cul de sac fluid was noted in seven women by MRI alone. This data suggests that MRI is superior to US in examination of the entire pelvis in women with leiomyomas.