Biomedical subjects
R O Bude
Publications and source records attributed to R O Bude.
Urethral disruption with urinary extravasation: a delayed complication of pancreatic transplantation.
PURPOSE: To describe the radiographic features and potential causes of urethral disruption in pancreas transplant recipients. MATERIALS AND METHODS: Eight episodes of urinary extravasation were depicted with retrograde urethrography in five male patients who had undergone pancreatic transplantation. The patients' medical records were reviewed to determine a cause of the extravasations. RESULTS: Four extravasations occurred at the proximal (deep) bulbar urethra, three at the bulbomembranous junction of the urethra, and one at the distal bulbar urethra. Four of eight cases of extravasation were preceded by recent cystoscopy or placement of a Foley catheter; one case was preceded by possible urethral injury due to a fall. CONCLUSION: Urethral disruption occurs as a complication of pancreatic transplantation. It has so far been seen only in male patients and occurs at the bulbar urethra or bulbomembranous junction. If the treating physician is unaware of this condition, diagnosis and institution of appropriate therapy may be delayed. Recent prior urinary tract instrumentation or trauma may be predisposing factors in urinary extravasation.
Endobronchial ultrasound-guided needle aspiration of mediastinal adenopathy.
We conducted a randomized, controlled trial to prospectively confirm that ultrasound-directed transbronchial needle aspiration (USTBNA) results in: (1) improved sensitivity for detecting lymph nodes involved with neoplasm, and (2) a decreased number of aspirates needed to achieve a diagnosis as compared with standard transbronchial needle aspiration (TBNA). The study was conducted in a tertiary medical center on patients undergoing fiberoptic bronchoscopy in the evaluation of enlarged mediastinal lymph nodes. USTBNA or TBNA were followed by rapid, on-site cytopathology examination of the collected specimens. Measurements included the (1) age and sex of the patient, prior diagnosis of cancer, nodal short-axis diameter and node location as determined by computerized tomography (CT), and endobronchial abnormalities at bronchoscopy; (2) number, order, and location of transbronchial aspirates and results of on-site evaluation; (3) results of surgical exploration in patients with negative transbronchial needle aspiration; (4) sensitivity, specificity, and diagnostic accuracy of USTBNA and TBNA; (5) number of aspirates required for successful lymph node aspiration as well as for a diagnosis of cancer for both USTBNA and TBNA; and (6) multiple logistic regression analysis to determine the significance of combinations of clinical predictors and needle aspirate results. Eighty-two bronchoscopic examinations were performed on 80 patients. We found no significant difference between USTBNA and TBNA in sensitivity (82.6% versus 90.5%, respectively), specificity (100% for both), or diagnostic accuracy (86.7% versus 91.7%, respectively). The sensitivity, specificity, and diagnostic accuracy of USTBNA and TBNA were similarly high, regardless of node location (paratracheal or subcarinal). A decrease in the number of aspirates required for lymph node sampling approached statistical significance for all USTBNAs as compared with TBNAs (2.03 +/- 0.19 versus 2.62 +/- 0.25, p = 0.06), but this was not demonstrated for the number required to confirm cancer (1.95 +/- 0.47 versus 2.68 +/- 0.21, p = 0.17). The number of aspirates to successful lymph node aspiration decreased with USTBNA versus TBNA in paratracheal lymph nodes (2.00 +/- 0.20 versus 2.91 +/- 0.34, p = 0.03), but not to a diagnosis of cancer (1.93 +/- 0.25 versus 3.00 +/- 0.58, p = 0.11). No difference was seen in the number of aspirates for subcarinal nodes. The number of TBNA attempts for paratracheal lymph node sampling was inversely correlated with node size (r = 0.48, p = 0.02). No such relation was seen with USTBNA of paratracheal nodes (r = 0.09, p = 0.66), TBNA of subcarinal nodes, or USTBNA of subcarinal nodes. A similar relation was seen between the number of aspirates to a diagnosis of cancer. On multiple logistic regression analysis, a positive transbronchial aspirate was associated only with a larger lymph node and history of prior cancer. We conclude that: (1) in the setting of on-site cytopathology, transbronchial needle aspiration has a high sensitivity, specificity, and diagnostic accuracy in the evaluation of enlarged mediastinal lymph nodes suspected of harboring malignancy; (2) mediastinal anatomy, including vascular structures and lymph nodes, is clearly imaged with endobronchial ultrasonography; (3) a greater short-axis diameter of the mediastinal lymph node and history of a prior malignancy increase the likelihood of a positive transbronchial aspiration; (4) USTBNA exhibits a similarly high diagnostic yield to TBNA in the setting of rapid on-site cytopathology evaluation; (5) USTBNA decreases the number of aspirates required for paratracheal lymph node sampling, which may be particularly useful in sampling smaller paratracheal nodes or at institutions that do not utilize rapid on-site cytopathology evaluation.
Hepatic metastases from granulosa cell tumor of the ovary: CT and sonographic findings.
Explore the source record for details and available documents.
Suspected obstructive pyelocaliectasis: Doppler ultrasonography compared with diuretic renal scintigraphy in proven cases.
OBJECTIVE: To compare Doppler ultrasonography with diuretic renal scintigraphy in the differentiation of obstructive from nonobstructive pyelocaliectasis. PATIENTS AND METHOD: The authors reviewed the findings of Doppler ultrasonography and diuretic renal scintigraphy performed over a 3-year period for 27 pyelocaliectatic kidneys (17 obstructed and 10 unobstructed) in 20 individuals ranging in age from 19 to 88 years. The kidneys were classified as "obstructed" or "unobstructed" on the basis of the resistive index as calculated from Doppler ultrasonographic results and as "obstructed", "unobstructed" or "indeterminate" on the basis of the clearance half-time determined from scintigraphic findings. RESULTS: On the basis of scintigraphy, the obstruction status was indeterminate in 12 of the 27 kidneys. The data were analysed for sensitivity and specificity in two ways, first by classifying the kidneys with indeterminate obstruction status as "obstructed, " and then by excluding them from the analysis altogether. In both situations, the differences in sensitivity and specificity between Doppler ultrasonography and scintigraphy were not statistically significant (chi 2 test, p > 0.05). When the kidneys with indeterminate obstruction status were included in the obstructed category, the sensitivity and specificity of Doppler ultrasonography were 94% and 90% respectively and of scintigraphy 100% and 70% respectively; when the kidneys with indeterminate obstruction status were excluded, the sensitivity and specificity of Doppler ultrasonography were 83% and 89% respectively and of scintigraphy 100% and 78% respectively. CONCLUSIONS: These results suggest that Doppler ultrasonography is comparable to diuretic renal scintigraphy in the work-up of potential obstructive pyelocaliectasis. Because grey-scale ultrasonography is usually performed before scintigraphy, a Doppler examination could be added at this stage, which might reduce the time necessary to establish the diagnosis.
An easily made, low-cost, tissue-like ultrasound phantom material.
Explore the source record for details and available documents.
Nonpulsatile arterial waveforms: observations during graded testicular torsion in rats.
RATIONALE AND OBJECTIVES: We tested whether testicular torsion could completely damp distal arterial pulsatility, resulting in venous-appearing arterial waveforms. METHODS: Progressively increasing testicular torsion was unilaterally produced in five rats. Doppler waveforms of the testicular artery distal to the torsion were obtained as soon as possible after each level of torsion until a complete absence of pulsatility was noted. RESULTS: One animal was not studied further after the first 180 degrees of torsion occluded flow. In three of the remaining four animals, the testicular artery resistive index (RI) at baseline (0.51, 0.58, 0.64) was within the range of the normal human intratesticular RI and decreased with increasing torsion, culminating in nonpulsatile, venous-appearing waveforms at high degrees of torsion. CONCLUSIONS: Testicular torsion can completely damp arterial pulsatility, resulting in nonpulsatile, venous-appearing arterial Doppler waveforms.
Hepatic artery resistance before and after standard meal in subjects with diseased and healthy livers.
PURPOSE: To assess fasting and postprandial resistive index (RI) in subjects with healthy and diseased livers. MATERIALS AND METHODS: Subjects with healthy (n = 10) and diseased (n = 33) livers underwent fasting and postprandial Doppler ultrasonography of the hepatic artery. Findings were compared with parameters for liver disease and Child class A-C and Child score of 5-15. RESULTS: The mean postprandial RI increase in healthy subjects was 42% (all, > or = 20%) and in patients with liver disease was 7% (six, > or = 20%). Patients with class A disease (n = 12) had a significantly greater increase in post-prandial RI (13%) than those with class B or C disease (3%) (P < .05). All patients with class C disease (n = 9) had an increased postprandial RI of less than 10%. The 13 patients with at least 10% increase in postprandial RI had less severe liver disease (Child score, 6.1 +/- 1.3 [standard deviation]) than the 20 patients with less than 10% increase (Child score, 8.4 +/- 1.7) (P < .01). CONCLUSION: A normal marked increase in postprandial RI is generally not seen in patients with severe liver disease.
Detection of renal artery stenosis with Doppler sonography: it is more complicated than originally thought.
Explore the source record for details and available documents.
The location of abdominal wall blood vessels in relationship to abdominal landmarks apparent at laparoscopy.
OBJECTIVE: Our purpose was to evaluate the location of the major blood vessels of the abdominal wall relative to landmarks apparent at laparoscopy. STUDY DESIGN: Abdominal computed tomographic images of 21 reproductive-aged women at an academic center were retrospectively reviewed to determine the location of the inferior epigastric, superficial epigastric, and superficial circumflex iliac arteries and the lateral rectus muscle margins in relation to the symphysis pubis, the umbilicus, and the abdominal midline. These locations were correlated with each other and with body mass index using Pearson's correlation coefficient. RESULTS: Above the symphysis the inferior and superficial epigastric arteries were 5.6 +/- 1.0 cm (mean +/- SD) and 5.5 +/- 2.0 cm from the midline, respectively. Although the location of these two vessels correlated (r = 0.6, p = 0.02), the mean difference in their location was 1.4 +/- 1.1 cm. Near the level of the umbilicus the superficial epigastric and circumflex iliac arteries and the lateral rectus muscle margin were 4.6 +/- 1.4 cm, 10.7 +/- 1.7 cm, and 7.6 +/- 1.5 from the midline, respectively. Only the lateral rectus muscle margin correlated with body mass index (r = 0.65, p = 0.004). CONCLUSION: When laparoscopic landmarks are not visible to guide placement, lateral trocars should be placed approximately 8 cm from the midline and at least 5 cm above the symphysis to minimize the risk of vessel injury.
Effect of furosemide and intravenous normal saline fluid load upon the renal resistive index in nonobstructed kidneys in children.
Recent literature has shown that relative to baseline the renal resistive index remains unchanged in nonobstructed kidneys and increases in obstructed kidneys after administration of furosemide. To our knowledge the effect upon the renal resistive index of furosemide administered in conjunction with intravenous normal saline fluid load has not been reported. We evaluated the renal resistive index in 13 nonobstructed kidneys in 8 children 6 to 18 years old before and after furosemide and intravenous normal saline fluid load. The mean resistive index decreased from baseline (mean decrease was 0.06 +/- 0.06 standard deviation), with the observation of a resistive index decrease significant to p < 0.005). It appears likely that the combination of an intravenous normal saline fluid load and furosemide caused the resistive index decrease, since a decrease was not observed with furosemide alone; however, these results cannot exclude the possibility that the resistive index decrease was due to the intravenous normal saline fluid load alone. Nonetheless, these data are important since they may provide the foundation for the development of a pharmacologically challenged Doppler sonographic examination using furosemide and intravenous normal saline fluid load to evaluate better potentially obstructed kidneys.
Pulsus tardus: its cause and potential limitations in detection of arterial stenosis.
PURPOSE: To determine, with hydrodynamic experiments, the true cause of pulsus tardus, a Doppler waveform alteration that often occurs distal to an arterial stenosis. MATERIALS AND METHODS: A flow phantom was constructed with a pulsatile pump, interchangeable stenoses of varying degree, and interchangeable poststenotic segments of tubing with various degrees of compliance. With the transstenotic pressure drop held constant for each stenosis, Doppler waveforms were obtained before and after stenosis, while the degree of poststenotic vessel compliance was varied. RESULTS: The degree of pulsus tardus increased as the compliance of the poststenotic segment of vessel increased, independent of the transstenotic pressure drop. CONCLUSION: Poststenotic pulsus tardus is caused by the compliance of the poststenotic vessel wall in conjunction with the stenosis, which produces the tardus effect by damping the high-frequency components of the arterial waveform. This information will allow prediction of conditions that may produce false-positive or false-negative results when the tardus phenomenon is used to predict substantial upstream stenosis.
Power Doppler US: a potentially useful alternative to mean frequency-based color Doppler US.
PURPOSE: The authors present a preliminary report to demonstrate a new color Doppler (CD) ultrasonography (US) technique called power Doppler (PD), which displays the total integrated Doppler power in color, and to compare PD with CD imaging, which generally displays an estimate of the mean Doppler frequency shift. MATERIALS AND METHODS: Two standard commercial US scanners that encode the integrated power in the Doppler signal in color were used to demonstrate PD. A standard nonflow-containing US phantom, a normal right kidney, and a torsive and normal contralateral testis were scanned in the power mode. In the phantom and kidney, results with CD and PD were directly compared. RESULTS: PD does not alias, is relatively angle independent, and displays background noise in a way that increases the usable dynamic range of a US scanner. This extended dynamic range should increase machine sensitivity and may demonstrate increased flow in certain circumstances. CONCLUSION: PD is a new CD imaging imaging mode that might be superior to CD in some cases.
Power versus conventional color Doppler sonography: comparison in the depiction of normal intrarenal vasculature.
PURPOSE: To compare power Doppler sonography with color Doppler sonography in the depiction of normal intrarenal vasculature. MATERIALS AND METHODS: Twenty kidneys in 10 healthy, nonobese subjects were studied with color Doppler and power Doppler sonography at 3.5 MHz and a pulse repetition frequency of 800 Hz. The color gain was increased until "noise" first became perceptible. To standardize comparison, an ultrasound phantom was scanned with both techniques at the mean depth of each kidney. RESULTS: Power Doppler sonography demonstrated a diffuse "blush" of either the entire or almost the entire cortex in 18 of 20 kidneys and in approximately half the cortex of the two other kidneys. Color Doppler sonography did not depict a cortical blush in any kidney. In addition, subjective comparison showed that power Doppler sonography demonstrated the intrarenal vasculature better than color Doppler sonography in all kidneys. CONCLUSION: Power Doppler sonography was superior to color Doppler sonography in the demonstration of normal intrarenal vasculature.
The effect of poststenotic vessel wall compliance upon the pulsus tardus phenomenon.
Recent studies have investigated the detection of significant arterial stenoses through identification of the "pulsus tardus" phenomenon in Doppler waveforms obtained distal to the stenosis. The etiology of this phenomenon, however, has not yet been determined. Using an in vitro model based upon an electrical circuit analogy, the authors had as their objective to determine whether the compliance of the vessel wall immediately distal to a stenosis, in conjunction with the stenosis, is the cause of pulsus tardus. For a constant stenosis, it was found that the degree of pulsus tardus, as quantitated by the acceleration index, increased as the compliance of the poststenotic segment increased. It is concluded that pulsus tardus distal to an arterial stenosis is likely due to the compliance of the normally distensible artery, in conjunction with the stenosis. Pathological conditions that alter the compliance of the poststenotic segment may affect the degree of pulsus tardus, perhaps limiting its usefulness for upstream stenosis detection.
Diagnosis of Achilles tendon xanthoma in patients with heterozygous familial hypercholesterolemia: MR vs sonography.
OBJECTIVE: The purpose of this study was twofold: (1) to determine the characteristic MR appearance of the xanthomatous tendons of heterozygous familial hypercholesterolemia and (2) to determine which of two imaging techniques, high-frequency linear-array sonography or MR imaging, is better for detection of xanthomas. SUBJECTS AND METHODS: Sonography and MR imaging were performed to evaluate the Achilles tendons in 10 patients (20 tendons) with heterozygous familial hypercholesterolemia. For sonography, 7.5- (nine patients) and 10.0- (one patient) MHz transducers were used. T1-weighted, proton density-weighted, and T2-weighted MR images were obtained at 0.5 T (four patients) and 1.5 T (six patients), including fat-suppressed (six patients) and water-suppressed (one patient) T1-weighted images at 1.5 T. Tendon abnormalities detected with both techniques were noted, and the results were compared. RESULTS: In all tendons, sonograms showed focal hypoechoic lesions compatible with xanthomas. MR images did not show focal lesions. Instead, all pulse sequences showed a diffuse speckled or reticulated pattern or both on axial images. This speckled or reticulated appearance was more obvious on fat-suppressed T1-weighted images and much less evident on water-suppressed T1-weighted images. Contrast resolution was subjectively better on sonograms than on MR images in all cases. CONCLUSION: The speckled or reticulated appearance is a characteristic, if not pathognomonic, MR feature of xanthomatous tendons and probably is due to edema or inflammation, not intratendinous lipid. However, localized lipid deposits detected on sonograms are more readily quantified than are the lesions seen on MR images. Therefore, we think sonography, rather than MR imaging as performed in our study, is the technique of choice for detecting xanthomas.
Detection of soft-tissue hyperemia: value of power Doppler sonography.
OBJECTIVE: Power Doppler sonography is a new technique that offers extended dynamic range over that provided by conventional color Doppler imaging, thereby facilitating measurement of tissue perfusion. We evaluated the efficacy of power Doppler sonography in depicting soft-tissue hyperemia in musculoskeletal inflammatory conditions. SUBJECTS AND METHODS: Twenty-three patients with predominantly unifocal musculoskeletal symptoms were evaluated with conventional gray-scale imaging and power Doppler sonography. The shoulder was evaluated in 14 patients, the elbow in three, and various other sites in six. For comparison purposes, the contralateral asymptomatic joint or site was examined in 17 cases. Fluid collections were aspirated in seven patients. RESULTS: Soft-tissue hyperemia was seen on power Doppler sonograms at the symptomatic site(s) in 22 of 23 cases studied, with an appearance ranging from frank tissue blush to large, isolated peritendinous/peribursal vessels. Findings associated with hyperemia included rotator cuff tendinitis and/or tear, bursitis, and symptomatic wrist ganglia. Findings on power Doppler sonograms were normal in one patient who had a small, sterile hip joint effusion, and findings on subsequent scintigrams, pelvic radiographs, and CT scans were normal. CONCLUSION: Power Doppler sonography consistently shows hyperperfusion associated with musculoskeletal inflammatory disease. As such, it represents a useful adjunct to gray-scale sonography in these settings, particularly as findings on conventional sonograms in inflammatory conditions can be nonspecific.
Heterozygous familial hypercholesterolemia: detection of xanthomas in the Achilles tendon with US.
Prospective sonographic evaluation of 44 Achilles tendons in 22 patients with heterozygous familial hypercholesterolemia (FH) was performed with linear-array transducers with high frequency and high resolution. Intratendinous hypoechoic regions believed to represent xanthomas, ranging from single hypoechoic nodules to diffusely enlarged tendons that were heterogeneously hypoechoic, were seen in 40 of the 44 tendons (91%) and 21 of the 22 patients (95%). In addition, focal xanthomas were seen in two of three patients whose Achilles tendons were either normal or questionably abnormal at palpation. The direct visualization of xanthomas in most of these patients contrasts with findings from previously published studies, in which sonographically detected involvement was based on secondary tendon enlargement alone. The improved sonographic visualization of tendon xanthomas in FH, rather than the secondary tendon enlargement caused by them, therefore, suggests a new role for ultrasound in the early diagnosis and follow-up of these cases.