The American Institute of Ultrasound in Medicine and the Society of Radiologists in Ultrasound--future directions in diagnostic US.
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Contrast Media↗
Biomedical subjects
L Needleman
Publications and source records attributed to L Needleman.
Increased soft-tissue blood flow in patients with reflex sympathetic dystrophy of the lower extremity revealed by power Doppler sonography.
OBJECTIVE: We evaluated the ability of power Doppler sonography to show increased soft-tissue blood flow in patients with reflex sympathetic dystrophy of the lower extremity. SUBJECTS AND METHODS: Power Doppler sonography was performed in 30 patients with reflex sympathetic dystrophy of the lower extremity and in 26 asymptomatic control subjects. The bilateral power Doppler sonograms that were obtained of the soft tissues of the dorsum of the foot of each subject were grouped in pairs, and three sonologists who were unaware of clinical information independently reviewed the images. Images were evaluated for the amount of power Doppler signal shown on the following scale: 1 = no flow or minimal flow; 2 = mild flow; 3 = moderate flow; and 4 = marked flow. RESULTS: More power Doppler flow was seen in the patients with reflex sympathetic dystrophy than in the control subjects (p < .005). In addition, side-to-side asymmetry of flow was seen in patients, but this trend was not statistically significant (p < .20). Receiver operating characteristic (ROC) analysis showed that combined flow and asymmetry were more related to reflex sympathetic dystrophy than either parameter alone (area under the ROC curve: for flow, 0.748; for asymmetry, 0.566; for both, 0.799). We found that when the sum of power Doppler flow in both feet was greater than or equal to five, and asymmetry of flow was greater than or equal to one, the sensitivity of power Doppler sonography for reflex sympathetic dystrophy was 73% and the specificity was 92%. CONCLUSION: Patients with reflex sympathetic dystrophy of the lower extremity have increased power Doppler flow compared with asymptomatic control subjects. Patients may also exhibit more side-to-side asymmetry of flow than control subjects.
Adolescent↗
Hemodynamic factors affecting uterine artery Doppler waveform pulsatility in sheep.
Quantitative analysis of vascular resistance from the Doppler time-velocity waveform relies on measuring arterial pulsatility. However, input pressure waveform pulsatility, impedance, and resistance have all been found to effect artery flow waveform pulsatility in circulatory mathematic models and in umbilical sheep preparations in vivo. The present study used an in vivo sheep preparation to determine that embolization of the uteroplacental circulation and maternal angiotensin II administration caused changes in the uterine Doppler time-velocity waveform pulsatility that were dependent on input pressure waveform pulsatility, fundamental impedance, and resistance changes. Uteroplacental vascular embolization increased vascular resistance and the uterine artery Doppler waveform resistive index; the mean component of flow (mean pressure/resistance) decreased. Decreased uterine artery Doppler resistive index occurred despite angiotensin II-induced vasoconstriction and increased vascular resistance because the pulse component of flow (pulse pressure/impedance) decreased.
Angiotensin II↗
Use of needle-vibrating device and color Doppler imaging for sonographically guided invasive procedures.
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Adult↗
Effects of training and experience in interpretation of emergency body CT scans.
PURPOSE: To determine the effects of level of training and other factors on the rate of discrepant interpretation of emergency body computed tomographic (CT) scans by trainees and staff radiologists. MATERIALS AND METHODS: Five hundred ninety-eight consecutive emergency CT studies were prospectively interpreted by radiology residents or board-certified body imaging fellows over a 12-month period. Each interpretation was reviewed within 12 hours by an attending body CT radiologist. Major discrepancies between staff radiologists' and trainees' interpretations were defined and those with the potential to affect immediate patient therapy; minor discrepancies were defined ad those without such potential. The effects on discrepancy rates were examined for abnormal versus normal CT findings and trauma versus nontrauma cases. RESULTS: Major and minor discrepancy rates were 1.2% and 6.5%, respectively, between interpretations made by the trainee and the staff radiologist. Overall, fellows demonstrated statistically significantly lower discrepancy rates than did senior of junior residents (5.9%, 13.7%, and 13.3%, respectively). The discrepancy rate was higher when CT findings were abnormal than when they were normal (13.5% vs 2.6%). There were no differences between discrepancy rates for trauma and nontrauma cases. CONCLUSION: Experience appeared to decrease discrepancy rates. Trainees were more likely to miss findings than to read normal scans as abnormal.
Certification↗
Pseudoaneurysm of the breast.
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Aneurysm, False↗
Laparoscopic liver sonography: preliminary experience in liver metastases compared with CT portography.
This study evaluated the ability of laparoscopic ultrasonography to detect, localize, and characterize focal liver masses. Laparoscopic ultrasonography and CT portography of the liver were performed in 13 patients with known or suspected malignancy. Laparoscopic ultrasonography directly influenced surgical management in four (31%) cases; three by detection of small focal masses and one by exclusion of masses suspected on CT portography. Laparoscopic ultrasonography provided guidance for biopsy or added important anatomic information in three cases. Laparoscopic ultrasonography was complementary to CT portography but added no additional information in three cases, and it failed to provide any information in two cases. Laparoscopic ultrasonography was falsely negative in one case. In this preliminary series, laparoscopic ultrasonography assisted surgeons in critical decision-making by either providing important new information, clarifying questionable areas, or complementing CT portography.
Adult↗
Transient arteriovenous fistulae after transrectal prostate biopsy: diagnosis with color Doppler ultrasonography.
To assess the prevalence and significance of arteriovenous fistulae after prostate biopsy, we performed color Doppler ultrasonography immediately after 136 consecutive transrectal prostate needle biopsies. Pathologic results were correlated with color Doppler ultrasonographic findings. Arteriovenous fistulae developed after 17 biopsies (13%), all closed spontaneously within 18 minutes, and none were associated with unusual bleeding. Carcinoma was noted in 25 biopsy specimens (18%), 10 (40%) of which were followed by arteriovenous fistula. The correlation between malignancy and postbiopsy arteriovenous fistula was statistically significant (P < 0.0004), consistent with hypervascularity known to be present in many prostate cancers.
Arteriovenous Fistula↗
Portal vein pulsatility in normal and cirrhotic adults without cardiac disease.
The literature indicates that Doppler demonstration of pulsatile flow in the portal vein suggests heart disease, and that retrograde transsinusoidal transmission of atrial pulsations is the mechanism. We noninvasively investigated portal vein pulsatility (PVP) in normal subjects and in patients with cardiac and liver disease, and performed invasive studies in cirrhotic humans and normal pigs. We found that accentuated PVP occurred in some normal subjects and in some patients with cirrhosis, and that mechanisms other than transsinusoidal transmission of atrial pulsations contributed to PVP. Determinants of PVP may include pulsatile portal inflow, transmission of pulsations from the vena cava (IVC) and location of the Doppler sample volume relative to the IVC.
Adolescent↗
The cause of pulsus tardus in arterial stenosis.
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Adult↗
Renal artery stenosis: should we study the main renal artery or segmental vessels?
PURPOSE: To compare the sonographic diagnosis of renal artery stenosis (RAS) with Doppler interrogation of the main renal artery versus Doppler ultrasonography of segmental vessels. MATERIALS AND METHODS: The main renal artery-to-aortic peak systolic velocity ratio (RAR) and early systolic acceleration in segmental arteries were obtained in 186 patients. Conventional arteriographic correlation was available for 42 kidneys in 21 patients. Paired receiver operating characteristic (ROC) analyses were performed to evaluate RAR and minimum, average, and maximum early systolic acceleration in these 42 kidneys. RESULTS: Minimum early systolic acceleration was a better test than RAR (P = .05). Minimum early systolic acceleration plus RAR resulted in improved sensitivity for detection of RAS, but this improvement was not significant (P = .16). CONCLUSION: Minimum early systolic acceleration is the ultrasonographic method of choice to screen for RAS. RAR may provide marginal improvement in sensitivity but is probably not warranted in most clinical situations.
Adult↗
Normal renal artery spectral Doppler waveform: a closer look.
PURPOSE: To characterize the spectral Doppler tracing of the normal renal artery. MATERIALS AND METHODS: Doppler tracings were obtained from a phantom of a vessel with variable compliance and from the kidneys of 15 healthy volunteers. RESULTS: In the phantom, vascular compliance had the following effects on systolic flow velocity patterns: low compliance, little change in the sharp appearance of the systolic component of the transmitted pulse; mildly increased compliance, down-stream dampening of early systolic acceleration (ESA) with the appearance of a sharp early systolic transmitted peak and of a more rounded late systolic compliance peak; high compliance, delayed and diminished transmitted peak that eventually disappeared within the enlarging down-stream compliance peak. Healthy subjects with compliant vessels had greater ESA and more frequently visualized early systolic peaks in the renal hilum than in the renal sinus. CONCLUSION: Absence of a discrete early systolic peak is a normal finding in young patients, especially in the more distal interlobar arteries. Loss of the early systolic peak may be explained on the basis of vascular compliance.
Acceleration↗
Normal interval fetal growth rates based on obstetrical ultrasonographic measurements.
Analyzing fetal interval growth may improve detection of growth abnormalities. This study establishes normal limits for growth rates of fetal biparietal diameter, abdominal diameter, abdominal circumference, and femur length. Fetal measurements were obtained during 1450 obstetrical sonographic examinations in 510 patients with normal-weight term deliveries. Using a random-effects model for longitudinal data, cubic curves of size versus mean gestational age were fitted using a restricted maximum likelihood technique. Quadratic growth rate curves were then calculated as derivatives of the fitted curves. The growth rate equations are as follows: Biparietal diameter growth rate = 2.59 + 0.127 (MGA) - 0.000447 (MGA)2; abdominal diameter growth rate = 3.61 + 0.0325 (MGA) - 0.0017 (MGA)2; abdominal circumference growth rate = 11.3 + 0.102 (MGA) - 0.00534 (MGA)2; and femur length growth rate = 5.49 - 0.17 (MGA) + 0.00181 (MGA)2. Rates are expressed in mm/wk and mean gestational age in wk. Because standard deviations depend on the time interval between examinations, separate growth rate tables are provided for intervals of 4, 6, 8, and > or = 10 weeks.
Crown-Rump Length↗
Right common carotid artery reconstruction after extracorporeal membrane oxygenation: vascular imaging, cerebral circulation, electroencephalographic, and neurodevelopmental correlates to recovery.
OBJECTIVE: Right common carotid artery (RCCA) ligation after extracorporeal membrane oxygenation by venoarterial bypass may contribute to lateralized cerebral injury. Reconstruction of this artery after extracorporeal membrane oxygenation has proved feasible but has not been evaluated for neurologic outcome in any substantial series of infants. METHODS: We evaluated RCCA reconstruction in 47 infants treated with ECMO and compared their cerebrovascular and neuroanatomic imaging findings, electroencephalograms, and developmental outcomes with those of 93 infants who had no reconstruction. SUMMARY RESULTS: Color Doppler blood flow imaging revealed that carotid artery patency was usually obtained after RCCA reconstruction. Right internal carotid and bilateral anterior and middle cerebral arterial blood flow velocities were generally higher, and were more symmetrically distributed in infants with reconstructed RCCA. Electroencephalography did not disclose an increased risk of deterioration or marked abnormalities in infants after reconstruction, nor were neuroimaging findings consistent with an increased number of either focal or generalized abnormalities. Neurodevelopmental follow-up revealed no differences in the incidence of delays between those with a reconstructed RCCA and those with a ligated RCCA during the first year of life. CONCLUSIONS: Reconstruction of the RCCA after extracorporeal membrane oxygenation may facilitate normal distribution of cerebral blood flow through the circle of Willis, and may augment both left and right middle cerebral artery blood flow immediately after decannulation. The long-term consequences of either ligation or reconstruction of the RCCA will require careful scrutiny, however, before either course is recommended routinely.
Blood Flow Velocity↗
Noncardiac applications of Albunex.
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Albumins↗
Arterial abnormalities following orthotopic liver transplantation: arteriographic findings and correlation with Doppler sonographic findings.
OBJECTIVE: We studied the findings on conventional arteriography in patients who had suspected graft ischemia after orthotopic liver transplantation to determine the value of a single Doppler signal in predicting these lesions. MATERIALS AND METHODS: We retrospectively reviewed selective visceral arteriograms with abnormal findings from 20 adults who had suspected graft ischemia after orthotopic liver transplantation and a single Doppler signal from the hepatic artery at the porta hepatis on sonograms obtained before arteriography. Arteriographic abnormalities were categorized according to morphology and location as follows: stenosis of recipient's hepatic artery, occlusion or stenosis of the transplanted extrahepatic artery, and occlusion or stenosis of the transplanted intrahepatic artery. RESULTS: Twenty-three arteriographic abnormalities were detected: four recipient celiac axis stenoses, seven extrahepatic occlusions, nine extrahepatic stenoses, and two occlusions and one stenosis of the transplanted intrahepatic artery. Six of the extrahepatic occlusions, two of the extrahepatic stenoses, and none of the recipient artery stenoses or the intrahepatic occlusions or stenoses were correctly diagnosed on the basis of Doppler findings. One patient with both an extrahepatic stenosis and an extrahepatic occlusion was thought to have an intrahepatic occlusion, and two patients with mild (< 50%) extrahepatic stenoses and one with an intrahepatic occlusion were thought to have an extrahepatic occlusion. CONCLUSION: A wide spectrum of abnormalities in the recipient's celiac axis or the transplanted arteries that may be associated with graft ischemia after orthotopic liver transplantation are often not detected or findings are misinterpreted on routine Doppler examination. In patients with suspected graft ischemia, visceral arteriography should be performed promptly to confirm the diagnosis and to allow early intervention.
Adult↗
CT done 4-6 hr after CT arterial portography: value in detecting hepatic tumors and differentiating from other hepatic perfusion defects.
OBJECTIVE: Nontumorous perfusion defects occur during CT arterial portography (CTAP) as normal variants or in cirrhosis, focal fatty infiltration, and portal vein obstruction. The purpose of this study was to determine whether delayed CT 4-6 hr after CTAP improves sensitivity to hepatic tumors and differentiates them from other hepatic perfusion defects. SUBJECTS AND METHODS: CTAP was done at 1-cm increments on 26 patients for evaluation of hepatic tumors. Delayed CT scans were obtained 4-6 hr later in all patients. Two observers retrospectively reviewed the CT scans obtained during CTAP and recorded size, shape, and location of suspected hepatic tumors. Confidence levels were assigned for each tumor. The delayed CT scan was then interpreted in conjunction with the CT scans obtained during CTAP, and confidence levels were reassigned. Surgical correlation was obtained for all patients. In the 26 patients, 86 masses were found at surgery. The sensitivity and number of false-positives for both CTAP alone and CTAP combined with delayed CT were compared with a two-tailed Student t-test. Receiver-operating-characteristic analysis also was performed. RESULTS: CTAP detected 73 (85%) of the 86 hepatic masses. Delayed CT had no effect on the sensitivity of CTAP. However, adding delayed CT decreased the total number of false-positives by 11, a statistically significant difference (p < .05). Receiver-operating-characteristic analysis revealed a significantly greater (p < .05) area under the curve (Az index) of 0.927 +/- 0.025 for CTAP combined with delayed CT compared with 0.886 +/- 0.032 for CTAP alone. Delayed CT was most useful for larger (> 1 cm) wedge-shaped perfusion defects and least useful for smaller (< 1 cm) round defects. CONCLUSION: Delayed CT has no effect in detecting tumors but may be useful for differentiating tumors from other hepatic perfusion defects seen on CTAP. The greatest benefit of delayed CT is in evaluating regions obscured by large wedge-shaped perfusion defects on CT scans obtained during CTAP.
Colorectal Neoplasms↗
Sonographic evaluation of fetal growth: growth rate variability as a function of the interval between examinations.
OBJECTIVE: Fetal growth rates determined on the basis of findings at two separate sonographic examinations can be used to detect growth abnormalities. This article determines the relationship between the length of the interval between examinations and the associated variability in measured fetal growth rates. MATERIALS AND METHODS: We analyzed 1479 fetal measurements of the biparietal diameter, average abdominal diameter, and femur length from 539 normal pregnancies. Mean growth rates were computed as functions of gestational age. The standard deviation of the growth rate was computed as a function of the interval between examinations. RESULTS: The standard deviation of fetal growth rates is relatively constant when the interval between examinations is 8-10 weeks or more, but increases substantially when the interval is fewer than 6 weeks. CONCLUSION: From a purely statistical point of view, the optimal interval for assessment of fetal growth rates is 8-10 weeks or more. Shorter intervals, however, usually are mandated by the clinical situation. Correction factors can be used to determine the standard deviations and associated confidence intervals for fetal growth measured over a period of fewer than 10 weeks.
Embryonic and Fetal Development↗