Spectral Doppler Sonography Research Articles

Noninvasive assessment of testicular torsion in rabbits using frequency-domain near-infrared spectroscopy: prospects for pediatric urology

We present a quantitative near-IR spectroscopy study of the absolute values of oxygen saturation of hemoglobin before and after surgically induced testicular torsion in adult rabbits. Unilateral testicular torsions (0, 540, or 720 deg) on experimental testes and contralateral sham surgery on control testes are performed in four adult rabbits. A specially designed optical probe for measurements at multiple source-detector distances and a commercial frequency-domain tissue spectrometer are used to measure absolute values of testicular hemoglobin saturation. Our results show: (1) a consistent baseline absolute tissue hemoglobin saturation value of 78+/-5%, (2) a comparable tissue hemoglobin saturation of 77+/-6% after sham surgery, and (3) a significantly lower tissue hemoglobin saturation of 36+/-2% after 540- and 720-deg testicular torsion surgery. Our findings demonstrate the feasibility of performing frequency-domain, multidistance near-IR spectroscopy for absolute testicular oximetry in the assessment of testicular torsion. We conclude that near-IR spectroscopy has potential to serve as a clinical diagnostic and monitoring tool for the assessment of absolute testicular hemoglobin desaturation caused by torsion, with the possibility of serving as a complement to conventional color and spectral Doppler ultrasonography.

Role of Spectral Doppler Sonography in the Evaluation of Partial Testicular Torsion

Role of Spectral Doppler Sonography in the Evaluation of Partial Testicular Torsion

Role of Spectral Doppler Sonography in the Evaluation of Partial Testicular Torsion

The purpose of this series was to evaluate the role of spectral Doppler and color flow Doppler sonography in the evaluation of partial testicular torsion. Eight cases of partial testicular torsion, diagnosed on the basis of abnormal spectral Doppler waveforms or abnormal color flow Doppler findings, were retrospectively pooled from 2 teaching hospitals. The age group ranged from 4 to 85 years. Testicles with partial testicular torsion showed variable spectral Doppler patterns, including increased, similar, or decreased amplitude of the arterial waveform relative to the contralateral testicle. Two cases showed reversal of arterial diastolic flow, and 1 case showed diastolic flow variability within the same testicle. Decreased blood flow was observed on color flow Doppler sonography in 7 of the 8 patients. Variability of the Doppler waveform when compared with the contralateral testicle and reversal of diastolic blood flow are indirect clues that aid in the diagnosis of partial testicular torsion.

Detection of Small Inflammatory and Metastatic Lymph Nodes in Rabbits by Sonography

The aim of this prospective study was to determine whether the resistive index (RI) ratio based on high-resolution spectral Doppler sonography would be useful in the differential diagnosis of small inflammatory and metastatic lymph nodes in rabbit models. The infected and metastatic lymph node models we used were created by subcutaneously inoculating methicillin-susceptible Staphylococcus aureus and VX2 tumor cells respectively into the left hind limbs of 10 New Zealand White rabbits. High-resolution sonography was performed to investigate the popliteal fossa lymph nodes 2 weeks after the inoculation. The sizes, long-/short-axis ratios, and RI ratios (defined as the value of the peripheral RI relative to the central RI) of the nodes were evaluated with sonography and then compared with the histopathologic findings. No statistical differences were found between the volumes (mean +/- SD, 104 +/- 41 versus 87 +/- 24 mm(3); P > .05) and the long-/short-axis ratios (1.97 +/- 0.28 versus 2.03 +/- 0.26; P > .05) of 15 inflammatory and 14 metastatic lymph nodes. On spectral Doppler sonography, the RI ratio was higher in the metastatic lymph nodes than in the inflammatory lymph nodes. With an RI ratio higher than 1.2 as a diagnostic criterion for a metastatic lymph node, the sensitivity, specificity, and positive and negative predictive values of sonography were 71% (10/14), 80% (12/15), 76% (10/13), and 75% (12/16), respectively, with an area under the receiver operating characteristic curve value of 0.824. This experimental study confirms that RI ratio changes based on high-resolution spectral Doppler sonography are associated with histopathologic changes of metastatic and inflammatory lymph nodes during the initial stage in rabbits.

Effects of diffuse fatty infiltration of the liver on portal vein flow hemodynamics

To investigate the effects of various degrees of diffuse fatty infiltration of the liver on portal vein blood flow with Doppler sonography. One hundred forty subjects were examined with color and spectral Doppler sonography. The subjects were divided into 4 groups of 35 subjects each according to the degree (normal, grade 1, grade 2 and grade 3) of hepatic fatty infiltration assessed on gray-scale images. The portal vein pulsatility index (VPI) and time-averaged mean flow velocity (MFV) were calculated for each subject. VPI was calculated as (peak maximum velocity - peak minimum velocity) / peak maximum velocity. VPI and MFV values were, respectively, 0.32 +/- 0.06 and 16.8 +/- 2.6 cm/second in the normal group, 0.27 +/- 0.07 and 14.2 +/- 2.2 cm/second in the group with grade 1 fatty infiltration, 0.22 +/- 0.06 and 12.2 +/- 1.8 cm/second in the group with grade 2 fatty infiltration, and 0.18 +/- 0.04 and 10.8 +/- 1.5 cm/second in the group with grade 3 fatty infiltration. There was a negative inverse correlation between the grade of fatty infiltration and both VPI (f = 55.3, p < 0.001) and MFV (f = 43.9, p < 0.001). The pulsatility index and mean velocity of the portal vein blood flow decrease as the severity of fatty infiltration increases.

A Convenient Sonographic Technique for Diagnosis of Pulsatile Tinnitus Induced by a High Jugular Bulb

The purpose of this report is to describe our experience with sonography in a case of pulsatile tinnitus (PT) due to a high jugular bulb (HJB). A 71-year-old woman came to our hospital with a 1-year history of right PT. A right HJB was shown on cerebral angiography, and enlargement of the right jugular blub compared with the left side was found. First, the ultrasound probe was placed on the anterior right upper neck at the anterior edge of the sternocleidomastoid muscle to identify the ipsilateral internal jugular vein (IJV) and measure the flow velocity. After the measurement, the ultrasound probe gradually compressed the skin until the flow in the IJV decreased. The patient reported that her PT decreased after the flow in the IJV decreased. We decided that the PT in this case was induced by the HJB. This technique is less invasive and convenient for the diagnosis of PT caused by an HJB.

DOPPLER SONOGRAPHIC ANALYSIS OF SYNOVIAL VASCULARIZATION IN A PATIENT WITH RHEUMATOID ARTHRITIS TREATED WITH LEUKOCYT APHERESIS

Synovial vascularization in metacarpophalangeal joints of a patient with rheumatoid arthritis treated with leukocytapheresis (LCAP) was evaluated by Doppler sonography. After the treatment with LCAP, evaluation with American College of Rheumatology core set showed improvement, and the levels of C-reactive protein and serum amyloid A protein decreased. Power Doppler sonography demonstrated a reduction of color flow signals of the joints, and spectral Doppler sonography demonstrated an increase in vascular resistant, indicating a reduction of vessel's permeability. This is the first report evaluating a synovial vascularization and blood flow of the joints by Doppler sonography before and after LCAP therapy. Doppler sonography might be one of the useful methods for evaluating the therapeutic response of LCAP.

Power Doppler and spectral Doppler measurements of knee-joint synovitis in rheumatoid arthritis patients with superficial pattern signals and in those with deep pattern signals

Power Doppler and spectral Doppler ultrasonography were used to scan 127 knee joints of 72 patients with rheumatoid arthritis (RA). Synovial effusion thickness and synovial proliferation (pannus) thickness, as well as the flow signal diameter, were measured on ultrasonogram prints of the power Doppler using digital calipers. In addition, color-flow signal grades on power Doppler and the resistance index (RI) values on spectral Doppler were evaluated. The values of these five variables were compared among 58 joints with superficial pattern flow signals and 69 joints with deep pattern flow signals. Compared with the joints with deep pattern signals, the joints with superficial pattern signals had significantly higher mean values of effusion thickness (P < 0.0001) and flow signal grades (P < 0.0001), and significantly lower mean RI (P < 0.0001). On the other hand, the joints with deep pattern signals had a significantly higher value of signal diameter (P = 0.0125) and had a trend to higher value of pannus thickness (P = 0.079) as well. Significant correlations were observed between effusion thickness and signal grades (P < 0.0001); effusion thickness and RI (P < 0.0001); signal diameter and pannus thickness (P = 0.0102); signal diameter and RI (P < 0.0001); and signal grades and RI (P < 0.0001). The ultrasonographic measurements of synovitis in RA patients provide valuable information on synovial inflammation.

CT Angiography of Stented Carotid Arteries: Comparison with Doppler Ultrasonography

To determine whether computed tomographic angiography (CTA) is a feasible modality for assessing stented carotid arteries and whether in-stent restenosis based on CTA concurs with ultrasonography (US). A retrospective review was conducted of 37 follow-up CTA and US images from 27 patients (23 men; median age 70 years, range 56-77) who received 34 nitinol carotid stents. CTA and US images were compared with respect to assessability and percent stenosis. Both visual estimation (>or=50% or not) and the NASCET method were used to determine percent stenosis in CTA images. For US, a determination of >or=50% stenosis was based on peak systolic velocity (>or=200 cm/s) and an internal carotid artery to common carotid artery ratio >or=2.5. Percent stenosis values by CTA were also compared to values (n=7, 21%) determined by catheter angiography. CTA and US images were "totally assessable" in 27 (73%) and 15 (41%), "totally non-assessable" in 0 (0%) and 3 (8%), and "partially assessable" in 10 (27%) and 19 (51%), respectively. Assessability of CTA images was equal to or better than that of US images in 33 (89%). The percent stenoses by CTA and US were comparable in 20 cases. CTA found >or=50% stenosis using the NASCET method in 4 of 20 stents; none of these showed >or=50% stenosis by visual estimation of CTA or by spectral Doppler US. Compared with catheter angiography, CTA overestimated percent stenosis from 34% to 66% (mean 53%). US confirmed 2 angiographically proven restenoses, but CTA identified only 1. CTA provides better image quality for stented carotid arteries than US, but it might be inferior to US in determining restenosis in assessable cases. Therefore, CTA is likely to be an alternative to US in cases of non-assessability. A large-scale study including more restenosis cases is warranted to reveal which modality is more reliable for diagnosis of restenosis.

CT Angiography of Stented Carotid Arteries:Comparison With Doppler Ultrasonography

To determine whether computed tomographic angiography (CTA) is a feasible modality for assessing stented carotid arteries and whether in-stent restenosis based on CTA concurs with ultrasonography (US).A retrospective review was conducted of 37 follow-up CTA and US images from 27 patients (23 men; median age 70 years, range 56-77) who received 34 nitinol carotid stents. CTA and US images were compared with respect to assessability and percent stenosis. Both visual estimation (>or=50% or not) and the NASCET method were used to determine percent stenosis in CTA images. For US, a determination of >or=50% stenosis was based on peak systolic velocity (>or=200 cm/s) and an internal carotid artery to common carotid artery ratio >or=2.5. Percent stenosis values by CTA were also compared to values (n=7, 21%) determined by catheter angiography.CTA and US images were "totally assessable" in 27 (73%) and 15 (41%), "totally non-assessable" in 0 (0%) and 3 (8%), and "partially assessable" in 10 (27%) and 19 (51%), respectively. Assessability of CTA images was equal to or better than that of US images in 33 (89%). The percent stenoses by CTA and US were comparable in 20 cases. CTA found >or=50% stenosis using the NASCET method in 4 of 20 stents; none of these showed >or=50% stenosis by visual estimation of CTA or by spectral Doppler US. Compared with catheter angiography, CTA overestimated percent stenosis from 34% to 66% (mean 53%). US confirmed 2 angiographically proven restenoses, but CTA identified only 1.CTA provides better image quality for stented carotid arteries than US, but it might be inferior to US in determining restenosis in assessable cases. Therefore, CTA is likely to be an alternative to US in cases of non-assessability. A large-scale study including more restenosis cases is warranted to reveal which modality is more reliable for diagnosis of restenosis.

Power Doppler and spectral Doppler measurements of knee-joint synovitis in rheumatoid arthritis patients with superficial pattern signals and in those with deep pattern signals

Power Doppler and spectral Doppler ultrasonography were used to scan 127 knee joints of 72 patients with rheumatoid arthritis (RA). Synovial effusion thickness and synovial proliferation (pannus) thickness, as well as the flow signal diameter, were measured on ultrasonogram prints of the power Doppler using digital calipers. In addition, color-flow signal grades on power Doppler and the resistance index (RI) values on spectral Doppler were evaluated. The values of these five variables were compared among 58 joints with superficial pattern flow signals and 69 joints with deep pattern flow signals. Compared with the joints with deep pattern signals, the joints with superficial pattern signals had significantly higher mean values of effusion thickness (P < 0.0001) and flow signal grades (P < 0.0001), and significantly lower mean RI (P < 0.0001). On the other hand, the joints with deep pattern signals had a significantly higher value of signal diameter (P = 0.0125) and had a trend to higher value of pannus thickness (P = 0.079) as well. Significant correlations were observed between effusion thickness and signal grades (P < 0.0001); effusion thickness and RI (P < 0.0001); signal diameter and pannus thickness (P = 0.0102); signal diameter and RI (P < 0.0001); and signal grades and RI (P < 0.0001). The ultrasonographic measurements of synovitis in RA patients provide valuable information on synovial inflammation.

B-Flow Imaging of the Hepatic Vasculature: Correlation with Color Doppler Sonography

B-flow imaging is a non-Doppler technology that provides real-time imaging of blood flow during gray-scale sonography. The utility of B-flow imaging is reflected in numerous publications that describe normal and pathologic findings in the carotid arteries and hemodialysis fistulas. However, there is a paucity of articles describing B-flow imaging of the abdominopelvic viscera. The purpose of this article is to illustrate a spectrum of findings encountered during noninvasive flow evaluation of the hepatic vasculature, correlating the Doppler sonography and B-flow imaging findings. Color and spectral Doppler sonography are invaluable for noninvasive evaluation of the hepatic vasculature. However, a number of pitfalls and artifacts have been described that can cause important pathologic findings to be overlooked or can suggest incorrect diagnoses. In our experience, B-flow imaging often correctly displays normal and pathological vascular structures for which Doppler sonographic findings have been misleading or erroneous.

Uterine Arteriovenous Malformations

The purpose of this study was to describe the sonographic features of uterine arteriovenous malformations (AVMs) and to describe the role and clinical outcome after transcatheter arterial embolization of symptomatic uterine AVMs. In our institution, over a 4-year period, symptomatic uterine AVMs were diagnosed in 21 women. Endovaginal sonography with gray scale, color, and spectral Doppler imaging was performed on all patients. Fourteen patients required therapeutic angiography/embolization to control bleeding. These 14 patients had follow-up endovaginal sonography 24 hours after the procedure. The sonographic gray scale findings of uterine AVMs were nonspecific. The most common finding was subtle myometrial heterogeneity (n = 14), whereas other patients had small anechoic spaces in the myometrium (n = 7). Color Doppler sonography showed a tangle of vessels with multidirectional high-velocity flow that produced a "color mosaic" pattern. Spectral Doppler analysis showed arteriovenous shunting with high-velocity, low-resistance flow. Fourteen patients required transcatheter arterial embolization to control bleeding. Thirteen of 14 patients had no sonographic evidence of a residual AVM 24 hours after the procedure. One of 14 patients had a residual AVM requiring additional embolization. One patient had recurrent bleeding at 4 months and required further embolization. The remaining 7 patients were treated conservatively. Endovaginal sonography is the imaging modality of choice in patients with abnormal uterine bleeding. Routine use of color and spectral Doppler sonography allows one to confidently make the correct diagnosis. Transcatheter arterial embolization is an excellent treatment option. Endovaginal sonography should be used to monitor postembolization outcomes.

Prevalence of Upper Extremity Deep Venous Thrombosis Diagnosed by Color Doppler Duplex Sonography in Cancer Patients With Central Venous Catheters

The purpose of this study was to review the literature concerning upper extremity deep venous thrombosis (UEDVT) diagnosed by color Doppler duplex sonography (CDDS) in cancer patients with indwelling central venous catheters (CVCs). From computerized databases (MEDLINE and Ovid), relevant publications regarding CDDS of the upper limb veins in cancer patients with CVCs were reviewed. Patients with malignancy have a higher rate of thrombosis, which is increased by the presence of CVCs. Screening CDDS in asymptomatic patients showed CVC-related UEDVT in 11.7% to 44% of patients. In symptomatic cancer patients, the range was similar to the asymptomatic ones, 6.7% to 48%. The presence of a CVC almost doubled the incidence of UEDVT in symptomatic patients. Color Doppler duplex sonography is an accurate examination for the diagnosis of UEDVT, with sensitivity ranging from 78% to 100% and specificity ranging from 82% to 100%. The main obstacle for the diagnosis of UEDVT is the presence of overlying bones, making it difficult to visualize and impossible to directly assess by compression techniques. Color and spectral Doppler sonography and the use of small transducers aid in the diagnosis. When several parameters are evaluated in combination, CDDS is a reliable method for diagnosing CVC-related thrombosis. Great variability in the prevalence of catheter-related thrombosis in cancer patients has been reported, although it is uniformly higher compared with patients without cancer. Color Doppler duplex sonography is the modality of choice for the diagnosis of CVC-related UEDVT in symptomatic cancer patients and for screening for asymptomatic thrombosis in this specific population.

Vascular complications after liver transplantation: evaluation with Doppler US

To demonstrate the spectral and color Doppler ultrasonography (US) findings that would indicate vascular complications after liver transplantation and to report our single center results of vascular complications detected in liver transplant recipients. Our study was consisted of 326 patients who underwent liver transplantation procedures between November 1997 and May 2004. The records of all patients were reviewed retrospectively for the details of each patient's post-transplant Doppler US examinations, visceral angiographic examinations, and/or surgical procedures. Doppler US findings were correlated with angiographic results or surgery. Sensitivity and specificity of Doppler US parameters for the diagnosis of vascular complications of the hepatic artery, portal vein, and hepatic veins were calculated. Vascular complications occurred in 47 patients (14%). Eight instances of vascular complications were detected intraoperatively by Doppler US at the time of transplantation. For hepatic artery complications, use of a Doppler US criteria resulted in a sensitivity and a specificity of 92% and 97%, respectively. Doppler US parameters also resulted in a sensitivity and a specificity of 100% in detecting portal vein complications, and resulted in a sensitivity of 99% and a specificity of 100% in detecting hepatic vein complications. Although it is clear that Doppler US evaluation is an effective choice for diagnosing vascular complications after liver transplantation, we also observed that Doppler US examination plays an important role in detecting vascular complications intraoperatively and improving the patient's chance for a successful outcome.

Sonography in Budd‐Chiari Syndrome

The objective of this presentation is to provide an overview of sonographic manifestations of Budd-Chiari syndrome (BCS). Patients were scanned with ultrasound systems using mainly a 2- to 5-MHz curvilinear transducer and in some patients a 5- to 12-MHz linear transducer. The patients were asked to fast from the previous night or for at least 6 hours. Color and spectral Doppler sonography was performed in all patients. Commonly seen findings in BCS include inferior vena cava (IVC) webs and thrombi, IVC narrowing, hepatic venous thrombosis, enlarged caudate lobes, ascites, intrahepatic or extrahepatic collaterals, monophasic to absent flow in the hepatic veins, and high flow velocities in areas of stenosis in the IVC or hepatic veins. Inferior vena cava stents used in the treatment of BCS could also be seen. Budd-Chiari syndrome is an uncommon disorder; outcome is poor in many cases; and the condition is often misdiagnosed or underdiagnosed. Sonography is a noninvasive and effective modality for diagnosis of BCS.

CHARACTERIZATION OF CANINE SUPERFICIAL TUMORS USING GRAY‐SCALE B MODE, COLOR FLOW MAPPING, AND SPECTRAL DOPPLER ULTRASONOGRAPHY—A MULTIVARIATE STUDY

Superficial tumors are not routinely evaluated by two- or three-dimensional diagnostic imaging methods as part of the staging of canine cancer patients, although superficial tumors are readily imaged by ultrasound. The objectives of this study were to characterize the ultrasonographic patterns of superficial tumors and to evaluate whether ultrasound can help discriminate between benign and malignant tumors in dogs. Superficial tumors (n=132) in 86 dogs were evaluated by B mode, color flow mapping, and spectral Doppler ultrasonography. Size, echogenicity, tumor border definition, invasiveness, acoustic transmission, presence and distribution of vascular flow to and within the tumor, as well as perfusion indices were measured. The tumors were classified as lipomas, benign tumors, atypical mammary tumors, and malignant tumors. Multivariate statistics using discriminant analysis was used to determine which parameters may be used to predict the status of the tumor. Tumor echogenicity, border shape, acoustic shadowing, total number of vessels to the tumor and the total flow amount are the parameters that in combination resulted in the lowest classification error (24%), meaning that on average three out of four tumors were correctly classified using these parameters. All the lipomas and atypical mammary tumors were classified correctly by ultrasonography. The results of this study show that ultrasonography has an important role in the evaluation of canine superficial tumors, particularly in the evaluation of tissue homogeneity and tumor vascularity.

CHARACTERIZATION OF NORMAL AND ABNORMAL CANINE SUPERFICIAL LYMPH NODES USING GRAY‐SCALE B‐MODE, COLOR FLOW MAPPING, POWER, AND SPECTRAL DOPPLER ULTRASONOGRAPHY: A MULTIVARIATE STUDY

The objective of this study was to characterize the ultrasonographic patterns of normal superficial lymph nodes and to evaluate whether ultrasonography can help discriminate between different lymphadenopathies (reactive, lymphoma, and metastases) in dogs. Three hundred and eighteen superficial lymph nodes in 142 dogs were studied by B-mode, color flow mapping, power, and spectral Doppler ultrasonography. Size, echogenicity, nodal border definition, presence of a nodal hilus, acoustic enhancement and distribution of vascular flow, as well as perfusion indices were measured. Multivariate statistics using discriminant analysis was used to determine which parameters can be used to predict the diagnosis of the lymph node. The size of the lymph node, distribution of vascular flow within the lymph node, and pulsatility index (PI) in combination gave a classification error of 23% for the four groups of lymph nodes. This was improved to 11% if the nodes were divided into two groups: benign and malignant. There was a significant difference in resistive index (RI) and PI between benign and malignant nodes. Cut-off values were determined using receiver operator curves, 0.68 RI and 1.49 PI.

Prenatal ultrasound diagnosis of Down syndrome. After major malformations, soft markers, nuchal translucency and skeletal signs, a new vascular sign?

Prenatal ultrasound diagnosis of Down syndrome. After major malformations, soft markers, nuchal translucency and skeletal signs, a new vascular sign?

Diagnosing Carotid Stenosis by Doppler Sonography

The goal of this review article is to present the state of the art in the clinical applications and technical performance and interpretation of carotid sonographic examinations. Relevant publications regarding color and duplex Doppler sonography (CDDS) of the carotid arteries extracted from a computerized database (MEDLINE) and from references cited in these articles not appearing on the Internet were reviewed. The ability to quickly and efficiently identify stenosis in the carotid artery is an important goal for clinicians and vascular surgeons. Identification of potentially treatable carotid stenosis enables selection of appropriate candidates for endarterectomy or stent implantation. Advances in performance and interpretation of carotid sonographic studies over the last 20 years have been driven by technological improvements in gray scale and CDDS examinations and have made carotid sonography an important means to reach this goal. On the basis of CDDS, intima-media thickness measurements and plaque location and characterization on gray scale imaging, flow disturbance and areas of stenosis on color Doppler sonography, and flow velocities on spectral Doppler sonography are obtained. The degree of the diameter of a stenosis of the internal carotid artery is the main parameter used for therapeutic approaches. Advantages and limitations of the method are included. Carotid sonography is a unique imaging method for the investigation of carotid abnormalities. Noninvasive, accurate, and cost-effective, it provides morphologic and functional information. It is increasingly becoming the first and often the sole imaging study before endarterectomy, whereas costly and invasive procedures are reserved for special cases.