Intravascular gas as an incidental finding at US after blunt abdominal trauma.

PURPOSE: To describe the occurrence and importance of intravascular gas at ultrasonography (US) during the initial examination of patients after blunt abdominal trauma. MATERIALS AND METHODS: Reports of all abdominal US examinations performed at one institution for blunt trauma from October 1995 through June 1996 were reviewed. The charts of patients with intravascular gas were examined to determine the mechanism of injury, associated findings, and clinical outcome. RESULTS: A total of 730 patients underwent abdominal US examinations during the 9 months of study; five had intravascular gas demonstrated. Two patients had portal venous gas, one had hepatic venous gas, and two had inferior vena caval gas. Four of the five patients were involved in motor vehicle accidents, and one had been assaulted. In patients in whom follow-up studies were obtained, there was no evidence of intravascular gas at US or computed tomography. No cause was found at imaging or clinical examination. CONCLUSION: Intravascular gas may occur as a transient incidental finding after blunt abdominal trauma.

A prospective evaluation of abdominal ultrasound in blunt trauma: is it useful?

OBJECTIVE: The purpose of this study is to evaluate the utility and feasibility of abdominal ultrasound (US) in blunt trauma patients. DESIGN: This prospective study examined the operational issues and the diagnostic accuracy of US in selected blunt trauma patients triaged to a Level 1 trauma center. MATERIALS AND METHODS: All patients were evaluated by an attending trauma surgeon and our usual criteria for objective evaluation of the abdomen were applied. US was performed by US technicians and interpreted by the trauma surgeon. We prospectively evaluated the availability (time to arrival), the ease with which the US could be integrated into the resuscitation (minutes to start after arrival), and the time required to perform the study. The US results were compared to diagnostic peritoneal lavage and computed tomography findings, clinical course, operative findings, and to repeat US examinations to determine sensitivity, specificity, and usefulness. MEASUREMENTS AND MAIN RESULTS: A total of 800 US studies were performed over 15 months. In four cases (0.5%), the US was incomplete for technical reasons. The results in the remaining 796 studies were as follows: [table: see text] The average time to arrival of the US was 17.3 minutes (range 0-120) and the average minutes to start after arrival was 7.0 (range 1-49). The average time required to perform the study was 10.6 minutes (range 2-26). CONCLUSIONS: This study demonstrates that US can be obtained rapidly, integrated into the resuscitation, and completed quickly. US provides a highly accurate, noninvasive method to evaluate the abdomen in the blunt trauma patient, and has supplanted the previously used methods at this institution.

Digital tapping of the superficial temporal artery: significance in carotid duplex sonography.

To determine whether tapping on the superficial temporal artery correctly identifies the ECA during carotid sonography, prospective evaluation of the reflection of the temporal tap on the spectral waveform was recorded and graded as 3+, 2+, 1+, or 0 in each ECA, ICA, and CCA, with 3+ being the most brisk response in each carotid system (ipsilateral CCA, ICA, and ECA). The pattern of response was evaluated in patients with and without hemodynamically significant (> than 50% diameter) stenoses in CCA, ICA, and ECA. The most frequent pattern of response to tapping on the superficial temporal artery was 3+ in the ECA, 2+ in the CCA, and 1+ or 0 in the ICA. This pattern was found in 41% (82/200) of systems overall. Whether or not stenoses were present in any branch of the extracranial carotid system, the strongest response (3+) was found in the ECA (58/200 [87%] with stenosis; 119/200 [89%] without stenosis, and lesser responses in the other arteries: 2+ in the CCA 31/200 [46%] with stenosis; 63/200 [47%] without stenosis, and 1+ or 0 in the ICA 58/200 [87%] with stenosis and 103/200 [77%] without stenosis). This pattern was unaltered by the degree of stenosis in the ECA or in the ICA. In 92.5% of the systems interrogated, the response was greater in the ECA than in the ICA. Tapping on the superficial temporal artery may be used as a reliable method of identifying the ipsilateral ECA even in instances of significant atherosclerotic disease in the ECA, CCA, or ICA.

Duplex sonography of the carotid arteries in patients with isolated aortic stenosis: imaging findings and relation to severity of stenosis.

OBJECTIVE: The purposes of this study were to identify carotid artery duplex waveform abnormalities in patients with isolated aortic stenosis and to determine whether waveform abnormalities correlate with the severity of valvular disease. MATERIALS AND METHODS: Twenty-four patients with various degrees of aortic stenosis diagnosed by echocardiography and/or cardiac catheterization had preoperative carotid artery duplex sonograms that were retrospectively reviewed for acceleration time, peak velocity, waveform contour, upstroke delay, and presence of a dicrotic notch and a second systolic peak. Data were collected for the right and left internal, external, and common carotid arteries separately. These findings were correlated with aortic valve area and compared with data for a control group of 11 age-matched patients with normal echocardiographic findings. Two additional patients with isolated aortic stenosis diagnosed by echocardiography and/or cardiac catheterization were prospectively evaluated in a similar fashion, with acceleration time being calculated directly from the sonography unit. RESULTS: Unlike the patients with mild or moderate stenosis, the patients with critical or severe stenosis had a mean acceleration time that was significantly longer than that in the control subjects (p = .008-.0001). Peak velocities were decreased in all cases of aortic stenosis regardless of severity only in the common carotid arteries. All 13 patients with critical aortic stenosis had delayed upstrokes and rounded waveforms in the common, internal, and external carotid arteries. Twenty percent (one of five) of the patients with severe stenosis and 17% (one of six) of the patients with moderate or mild stenosis also had these characteristics. The two prospectively evaluated patients, who had critical and severe aortic stenoses, had similar findings. None of the control subjects showed these abnormalities. The presence or absence of a second systolic peak or a dicrotic notch was not different between patients with aortic stenosis and control subjects. CONCLUSION: Increased acceleration time, decreased peak velocity, delayed upstroke, and rounded waveform are characteristic abnormalities found in duplex sonographic studies of the carotid arteries in patients with aortic stenosis. The degree of each of these abnormalities correlates with the valve area. Patients with critical or severe aortic stenosis had findings significantly different from those in the control group. Patients with mild or moderate disease showed few or no sonographic abnormalities.

Change in endometrial thickness in postmenopausal women undergoing hormone replacement therapy.

PURPOSE: To evaluate the effect over time of hormone replacement on endometrial thickness in asymptomatic postmenopausal women. MATERIALS AND METHODS: Endometrial thickness was measured on 644 sonograms of 120 postmenopausal volunteers receiving no hormones or one of three hormone regimens. Each subject underwent ultrasound (US) two to nine times. In addition, eight women using sequential hormones underwent US seven to 20 times over 2 months. The greatest endometrial thickness and change in endometrial thickness over time were evaluated. RESULTS: Endometrial thickness was statistically significantly greater in women using sequential hormones (8 mm) compared with that in control subjects (5 mm). Change in endometrial thickness (> 3-mm difference) was seen in 23 of 40 women using sequential hormones compared with six of 61 controls. Women using sequential hormones demonstrated maximum endometrial thickness on days 13-23 of the cycle. CONCLUSION: Women using sequential hormones show greater endometrial thickness than that in controls and show the most variation in measurements. They should undergo US either early or late in the hormone cycle to evaluate the endometrium at its thinnest.

Simple adnexal cysts: the natural history in postmenopausal women.

Transabdominal and transvaginal ultrasound (US) examinations were performed in 184 asymptomatic postmenopausal volunteers to determine prospectively (a) the frequency and natural history of simple adnexal cysts in healthy postmenopausal women and (b) the relationship between cyst activity and both hormone replacement and length of time since menopause. Eighty-three simple adnexal cysts were found in 52 women. Thirty-two of 184 women (17%) had 37 cysts identified at initial examination; 46 new cysts appeared in 31 women (11 of whom previously had cysts). Forty-nine women with 72 cysts were reevaluated with subsequent US scanning over a period of 3-23 months. Thirty-eight of the 72 cysts (53%) disappeared completely, 20 (28%) remained constant in size, eight (11%) enlarged by 3 mm or more, two (3%) decreased in size by 3 mm or more, and four (6%) both increased and decreased in size on repeated examinations. No statistical relationship was found between presence of cysts or cyst activity with respect to the type of hormone replacement or length of time since menopause.

Percutaneous intraluminal US in the gallbladder and bile ducts.

The authors describe their initial experience with a dedicated intraluminal ultrasound (US) device that was coupled to a catheter and introduced percutaneously into the gallbladder and/or bile ducts. Access was created with interventional radiologic techniques in 22 patients and at laparoscopy in four patients. Thirty-one examinations in 26 patients revealed information on normal anatomy, pathologic processes, and responses to therapy. The pathologic processes seen included bile duct and gallbladder debris, stones, ductal strictures, and tumors. Additional information provided with this technique over other diagnostic studies included differentiation of intraluminal filling defects, examination of areas inaccessible to conventional imaging, and observations about the walls of the ducts and gallbladder. Percutaneous US examination of metallic stents within the bile ducts and of filling defects in the ducts at laparoscopic cholecystectomy was of particular interest and altered subsequent therapy. The procedure is simple, straightforward, and devoid of complications. While refinements and improvements are needed, this diagnostic technique holds promise.

Internal carotid artery dissections: duplex ultrasound imaging.

Duplex ultrasound findings in seven patients (eight vessels) demonstrating extracranial internal carotid artery (ICA) dissections are presented. The two-dimensional (2D) sonographic findings of ICA dissection consisted of three categories: (1) normal, (2) luminal flap with or without thrombus formation, and (3) hypoechoic thrombus with or without lumen narrowing. The Doppler ultrasound waveforms were variable. In the common carotid artery (CCA) these included (1) normal, (2) resistive, damped, or biphasic CCA waveforms, and (3) positive temporal artery tap in the mid-CCA. In the ICA, the appearances included (1) normal, (2) damped, resistive, or biphasic waveforms, (3) absent flow, and (4) high velocity flow. Although these appearances are nonspecific, the finding of some of these duplex ultrasound waveforms in the appropriate clinical setting suggests a diagnosis of extracranial internal carotid artery dissection.

Carotid duplex sonography: bisferious pulse contour in patients with aortic valvular disease.

Characteristic systolic and diastolic pulse contours occur in the carotid Doppler waveforms of patients with aortic valvular disease that have not previously been described in publications concerning carotid duplex sonography. The purpose of this study was to evaluate the presence and characterize the nature of these carotid duplex waveform abnormalities in patients with known aortic valve disease and to correlate these changes with the severity of valve dysfunction. The study group consisted of 26 patients with aortic regurgitation or combined aortic regurgitation and aortic stenosis. Duplex studies were retrospectively reviewed by two radiologists for the presence of two systolic peaks, and for the presence of diastolic reversal of flow direction. This pattern of two systolic peaks, characteristic of aortic regurgitation, is called bisferious from the Latin "twice beating." Aortic regurgitation was graded by echocardiography as mild, moderate, or severe by the cardiologists reviewing the examination. A group of 20 age-matched patients without aortic valvular disease were similarly assessed. The bisferious pattern was demonstrated in 13 (50%) of 26 patients. Five (19%) of 26 patients had significant reversal of diastolic flow. Four patients were studied both before and after aortic valve replacement. Three had bisferious wave contours preoperatively; two of these also had diastolic reversal of flow. The fourth patient had retrograde flow in diastole without systolic contour abnormality. Postoperatively, all carotid waveforms were normal. None of the duplex waveforms in the control group demonstrated characteristic systolic or diastolic abnormalities. The bisferious waveform and retrograde diastolic flow are Doppler patterns associated with aortic valvular disease. These patterns are reversible after aortic valve replacement. While echocardiography remains the study of choice in the evaluation of suspected valvular dysfunction, up to one third of patients with aortic regurgitation may not have a detectable murmur. Therefore, identifying these patterns on carotid duplex examinations may provide clinically useful information and serve as a clue to previously unsuspected cardiovascular disease.

Endometrial thickness after menopause: effect of hormone replacement.

Ultrasound (US) images of the pelvis were evaluated in 112 asymptomatic postmenopausal women to investigate the normal range of endometrial thickness (double-layer measurement) and the effect of hormone replacement on these measurements. Twenty-one patients (19%) had endometrial thickness greater than 0.8 cm. One patient, with an endometrial thickness of 2.5 cm, had endometrial carcinoma. Consideration of the known actions of estrogen and progestogen on the endometrium led the authors to believe that the clinical significance of an endometrium measuring more than 0.8 cm depends on the patient's hormonal status. Among asymptomatic postmenopausal women with an endometrial thickness between 0.8 and 1.5 cm, those receiving unopposed estrogen or continuous estrogen and progestogen need to undergo dilatation and curettage (D&C) or biopsy and those receiving no hormones or receiving sequential estrogen and progestogen should be encouraged to undergo D&C or biopsy. If a patient in one of the latter two groups is unwilling to undergo an invasive procedure, then US examination at 3-month intervals is acceptable. Any patient with endometrial thickness of at least 1.5 cm should undergo histologic diagnosis, regardless of symptoms or hormone status.

Prevalence of simple adnexal cysts in postmenopausal women.

This prospective study was performed with ultrasound (US) to determine the prevalence of unilocular, nonseptated adnexal cysts ("simple cysts") in healthy postmenopausal women and the relationship between cyst occurrence and both hormone replacement and length of time since onset of menopause. Transabdominal and transvaginal US were performed on 149 volunteers aged 50 years or older. Patients were classified according to hormone regimens (no hormones, unopposed estrogen, continuous daily estrogen and progesterone, and sequential estrogen and progesterone) and time since onset of menopause (less than 5 years, 5-10 years, and greater than 10 years). Simple adnexal cysts were found in 22 women with the aid of transvaginal and/or transabdominal US, yielding a relative frequency of 14.8% +/- 5.7% and a prevalence of 14,800 patients with cysts per 100,000 patients. No statistical relationship was found between cyst frequency and type of hormone replacement or length of time since onset of menopause.

Duplex carotid sonography. Peak systolic velocity in quantifying internal carotid artery stenosis.

Duplex ultrasonography combining high-resolution imaging and Doppler spectrum analysis was performed in 92 consecutive patients (total, 180 vessels) and compared with the findings of conventional arteriography. All duplex studies were categorized into four groups based upon the maximum internal carotid artery (ICA) velocity: group 1: less than 125 cm/sec; group 2: 125 to 224 cm/sec; group 3: greater than 225 cm/sec; and group 4: no flow. Sensitivities and specificities were highest when peak ICA velocity was used as one of several criteria in quantifying the degree of ICA stenosis. These additional criteria were: (1) the presence of extensive sonographically visible plaque within the ICA; (2) an abnormal spectral waveform with elevated diastolic velocity (greater than 100 cm/sec); (3) resistive pattern ("externalization") of the common carotid artery (CCA) waveform; and (4) the ratio of the right CCA peak velocity to the left of less than 0.7 or greater than 1.3. The overall accuracy for the combined groups using all criteria was 94%.

The reliability and predictive value of an amniotic fluid scoring system in severe second-trimester oligohydramnios.

Sixty-two cases of oligohydramnios diagnosed by ultrasound between 13-28 weeks' gestation were reviewed. Three experienced ultrasonographers used a subjective scale to rate the oligohydramnios as mild, moderate, severe, or anhydramniotic. Interobserver reliability was excellent (intraclass correlation coefficient 0.81). The overall perinatal mortality rate was 43%, and the incidence of pulmonary hypoplasia was 33%. One-third had lethal congenital anomalies. The frequency of adverse outcome correlated strongly with the most severe degrees of oligohydramnios; 88% of the fetuses with severe oligohydramnios or anhydramnios had lethal outcomes, compared with 11% in the mild/moderate group. The presence of an anuric urinary tract anomaly was associated with the most severe grades of oligohydramnios and was uniformly fatal. Pulmonary hypoplasia was diagnosed in 60% of the severe group versus 6% in the moderate group. We conclude that subjective grading of oligohydramnios by experienced observers is both reliable and predictive of outcome. The finding of severe oligohydramnios in the second trimester is highly predictive of poor fetal outcome and should stimulate a thorough search for etiology and consideration of intervention. Moderate grades of reduced amniotic fluid may be managed with relative optimism.

Serial magnetic resonance and carotid duplex examinations in the management of carotid dissection.

We followed 2 patients with extracranial internal carotid dissection and associated occlusion or preocclusive stenosis with serial magnetic resonance and carotid duplex examinations. These studies demonstrated progressive anatomic resolution in both cases.

Sonographic evaluation of the fetal stomach: significance of nonvisualization.

The stomach was successfully visualized in 1051 (98%) of 1071 consecutive sonograms obtained in 995 fetuses after 14 weeks gestational age. All patients were studied prospectively. Stomach nonvisualization was associated with an abnormal outcome in 55% of the fetuses studied after 14 weeks and in 100% of the fetuses studied after 19 weeks. Fetal abnormalities included gastrointestinal and CNS malformations. Oligohydramnios was often present. The absence of a stomach on fetal sonograms obtained after 14 weeks gestational age strongly suggests fetal abnormality. Repeat sonograms should be obtained in all such cases.