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Biomedical subjects

W D Foley

Publications and source records attributed to W D Foley.

At least 37 records · Page 2Linked to original sources
PubMed1989

Color Doppler flow imaging of the normal and abnormal orbit.

Twenty-six normal orbits (16 subjects) and seven patients with suspected orbital disease were studied with color Doppler flow imaging CDFI). Arterial structures consistently identified included the ophthalmic artery, central retinal artery, and posterior ciliary branches. The terminal lacrimal branch was seen in the majority of orbits (n = 19). Venous structures consistently seen included the central retinal vein and venae vorticosae; the superior ophthalmic vein was identified in the majority of normal orbits (n = 22). Response of the superior ophthalmic vein to the Valsalva maneuver was assessed in six of the normal subjects (12 orbits). Retrograde flow was typically seen during the maneuver and accentuated antegrade flow after cessation of the maneuver. Pathologic entities correctly diagnosed with CDFI included a dural arteriovenous malformation (AVM) with spontaneous carotid-cavernous fistula, an orbital AVM, and superior ophthalmic vein thrombosis. Vascular lesions were excluded in two patients with orbital masses. Bilaterally enlarged superior ophthalmic veins were identified in a patient with unilateral symptoms suggestive of a varix; CDFI results were confirmed with computed tomography, but orbital venograms were interpreted as normal. These findings suggest that CDFI may be helpful in the evaluation of suspected vascular orbital disease.

Adult↗
PubMed1989

Color Doppler ultrasound imaging of lower-extremity venous disease.

A color Doppler ultrasound imaging device was used to evaluate 475 patients with suspected lower-extremity venous thrombosis. Occlusive and nonocclusive femoral and popliteal thrombi were detected in 200 studies (42%). In phase 1 of the study (240 examinations), peripheral augmentation with the use of periodic calf compression was required to show color flow throughout the femoropopliteal venous segment. In phase 2 (235 examinations), with a software upgrade to enhance detectability of slow flow, spontaneous flow could be appreciated in the normal, partly thrombosed, and recanalized femoral popliteal veins without augmentation. Augmentation was often necessary to view tibioperoneal veins. Of the total study group, conventional venography was performed for correlation in 47 patients. In the other patients, clinicians relied on the color Doppler test for the definitive diagnosis of the presence or absence of femoral popliteal venous thrombosis and treated these patients on the basis of the color Doppler test result. In the femoral veins, color Doppler studies and venography agreed in all 12 positive and 35 negative cases. In the popliteal veins, there was agreement in five isolated popliteal thromboses and in 10 femoral popliteal thromboses; there were two false-negative color Doppler studies of isolated popliteal thromboses. In four patients, Doppler studies detected nonocclusive thrombus not evident on venography. Color Doppler imaging is easy to perform and does not require augmentation to view color flow in the femoropopliteal venous segment. Eccentric thrombus and partially canalized thrombus can be shown. Initial experience suggests color Doppler imaging may be useful in the detection of tibioperoneal venous thrombosis.

Femoral Vein↗
PubMed1989

Stenosis of the internal carotid artery: assessment using color Doppler imaging compared with angiography.

The percentage of diameter stenosis of the internal carotid artery was estimated directly from color Doppler images obtained in both longitudinal and transverse planes and compared with the results of digital subtraction angiography in 49 patients (95 carotid arteries). Peak systolic velocity measurements were obtained by placing the sample volume in the highest-velocity flow stream with the angle-correction cursor parallel to the color-encoded lumen. Arterial stenoses were categorized on a grade 1-5 scale: 1 = 0-15%, 2 = 16-49%, 3 = 50-75%, 4 = 76-99%, and 5 = occlusion. Percent diameter stenosis could not be determined in 12 color Doppler flow imaging studies (13%) due to calcified plaque. Of the remaining 83 arteries evaluated by both techniques, the respective categories by color Doppler flow imaging/angiography were grade 1 (16/26), grade 2 (25/24), grade 3 (30/19), grade 4 (5/8), and grade 5 (7/6). Percent diameter stenosis determined by color Doppler flow imaging was greater than by angiography in 25% and less than by angiography in 4%. Peak systolic velocity measurements did not separate the hemodynamically insignificant (less than 50% diameter stenosis) grade 1 and grade 2 lesions, but were in agreement in 86% of grades 3-5 stenotic categories, as determined by measurements from the color Doppler flow image. A direct measurement of percent diameter stenosis from the color Doppler flow image was possible in 87% of cases. Peak systolic velocity provided correlative diagnostic information when assessing hemodynamically significant lesions.

Angiography↗
PubMed1989

Renal imaging in long-term dialysis patients: a comparison of CT and sonography.

Patients undergoing long-term dialysis are subject to cyst formation, hemorrhage, and neoplasia in their native kidneys. Detection of these complications with incremental dynamic CT and detection with sonography were compared prospectively in 41 patients (79 kidneys) who had been undergoing dialysis intermittently for 3 or more years. Acquired cystic kidney disease (five or more cysts per kidney) was identified in 59% of kidneys by use of CT and in 18% by use of sonography. CT showed a complete renal contour definition in all cases, sonography did so in only 57%. Three solid renal tumors (2- to 4-cm diameter) were identified with both techniques with no false-negative evaluations. Four benign hemorrhagic cysts were identified with combined CT (hyperdense mass) and sonography (benign cysts). CT provided the best anatomic image quality and was more accurate for detection of acquired cystic kidney disease. CT and sonography were equivalent for detection of solid tumors. Our results suggest that dynamic contrast-enhanced CT scanning with the supplemental use of sonography is the best imaging regimen for the evaluation of suspected acquired cystic kidney disease and its potential complications.

Adolescent↗
PubMed1988

Flow reversal in the normal carotid bifurcation: color Doppler flow imaging analysis.

One hundred carotid bifurcations in young asymptomatic volunteers were examined with color Doppler flow imaging in an attempt to determine the frequency, configuration, magnitude, and duration of flow reversal. Areas of flow reversal were identified in all but one bifurcation. Just proximal to the bifurcation, flow reversal was typically located peripherally, opposite the origin of the external carotid artery. Distal to the bifurcation, flow reversal in the internal carotid artery typically assumed a linear configuration in the center of the vessel, extending from the superficial to the deep wall. Variations of these patterns were common. On the average, flow reversal occupied 33% of the lumen of the carotid bulb and extended for a distance of 14 mm. The average duration of flow reversal was 22% of the total cardiac cycle, with reversal typically occurring at peak systole and being replaced by static blood during diastole. These findings indicate that flow reversal in the carotid bifurcation is a normal phenomenon with a variable configuration, magnitude, and duration.

Adult↗
PubMed1988

Renal calculi: sensitivity for detection with US.

The sensitivity of sonography in the detection of renal calculi was tested in a three-phase study in 100 patients. In phase 1, ultrasonographic (US) scanning was performed after review of abdominal radiographs and renal tomograms in 30 patients who had undergone extracorporeal shock wave lithotripsy (ESWL). In this group the sensitivity of US for detecting stones was 98%. In phase 2, scanning was performed in 30 post-ESWL patients without prior review of radiographs or tomograms. The sensitivity of US for stone detection in this group was 95%. In phase 3, sonography was performed in a blinded fashion on a random mix of post-ESWL patients and patients who had undergone urography for reasons unrelated to nephrolithiasis. The sensitivity of US for stone detection in this group of 40 patients was 91%. The overall sensitivity in all three groups was 96%, which was superior to the performance of abdominal radiography and slightly inferior to the combination of abdominal radiography and renal tomography. The ability to detect kidney stones with US depended on stone size but was independent of stone location or patient size. The study findings suggest that US is an effective means for detecting kidney stones in patients with suspected nephrolithiasis.

Humans↗
PubMed1988

Pneumothorax and other lung diseases: effect of altered resolution and edge enhancement on diagnosis with digitized radiographs.

Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).

Humans↗
PubMed1987

High resolution surface coil magnetic resonance imaging of the joints: anatomic correlation.

Magnetic resonance imaging appears to be a particularly promising approach to the evaluation of articular and periarticular abnormalities. Its ability to produce images in multiple planes directly (without reconstruction) provides a unique advantage over CT for the radiologist when he attempts to interpret the complex three dimensional anatomy of most joints. The inherent contrast resolution of MR is excellent, and with the use of surface coils, spatial resolution is sufficient to permit the identification of the small soft tissue structures in and around joints. Artifacts generated by respiratory and cardiac motion are not a problem in MRI of the joints as they are in MR scanning of the body. Based on all these qualities, we believe that MRI will play an important role in the diagnosis of joint abnormalities.

Ankle Joint↗
PubMed1987

Treatment of blunt hepatic injuries: role of CT.

Serial dynamic upper abdominal computed tomography (CT) studies were performed on 20 patients as part of the conservative treatment of blunt hepatic injuries (hematoma, laceration, or fracture). Fourteen of these patients had either major or minor associated hemoperitoneum. In 13 patients, hemoperitoneum was either significantly reduced or absent by 1 week. A severe delayed hemorrhage occurred in one patient 7 1/2 days after admission; a large and unchanged volume of intraperitoneal fluid had been seen on a preceding abdominal CT scan. One other patient who had a satisfactory response underwent surgery for a pancreatic laceration. Serial abdominal CT studies are an integral part of the conservative treatment of blunt hepatic injuries and seem to be useful in monitoring resorption of hemoperitoneum and the pattern of healing of intrahepatic hematomas, lacerations, and fractures.

Hemoperitoneum↗
PubMed1987

False-positive CT diagnosis of gallstones due to thickening of the gallbladder wall.

An erroneous CT diagnosis of cholelithiasis was made at our institution during the past year in seven patients who had thickening of the gallbladder wall. In all cases the mucosa, which had a high attenuation value, was misinterpreted as a calcified stone, and the low-attenuation thickened submucosa was misinterpreted as intraluminal bile surrounding the stone. Depending on the attenuation of the actual intraluminal bile, the pseudostone appeared peripherally calcified (five patients) or uniformly calcified (two patients). Careful analysis of the position and configuration of a suspected stone and of the outer margin of the gallbladder can help avoid an incorrect CT diagnosis of gallstones when high-attenuation thickened mucosa simulates a gallstone and low-attenuation submucosa looks like surrounding bile.

Adult↗
PubMed1987

Contrast optimization for the detection of focal hepatic lesions by MR imaging at 1.5 T.

The relative efficacies of different spin-echo pulse sequences at 1.5 T were evaluated in the detection of focal hepatic disease. Pulse sequences compared were spin-echo with a repetition time (TR) of 200 msec and echo time (TE) of 20 msec, with six excitations; TR = 300 msec, TE = 20 msec, with 16 excitations (T1-weighted sequences); and a double spin-echo with TR = 2500 and TE = 25 and 70, with two excitations (proton-density-weighted and T2-weighted pulse sequences, respectively). Respiratory-motion compensation, which involved a recording of the phase-encoding gradients (Exorcist), was used for the last two sequences. Spin-echo with TR = 2500 msec and TE = 70 msec was superior in lesion detection and contrast-to-noise ratio. The proton-density-weighted and T2-weighted sequences with respiratory compensation produced better artifact suppression than did the short TR, short TE T1-weighted sequence with temporal averaging. In contradistinction to prior results at 0.6 T, T2-weighted pulse sequences appear superior to T1-weighted pulse sequences with multiple excitations for both lesion detection and artifact suppression at 1.5 T.

Cysts↗