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Biomedical subjects

W D Foley

Publications and source records attributed to W D Foley.

At least 19 recordsLinked to original sources
PubMed1996

Ultrasonographic characteristics of testicular adenomatoid tumors.

PURPOSE: We determined the characteristics of testicular adenomatoid tumors which could distinguish these lesions from testicular malignancies. MATERIALS AND METHODS: Clinical presentation and ultrasonographic findings in 3 men with testicular adenomatoid tumors were compared with those in 10 men treated for testicular malignancies. RESULTS: Clinical presentation was similar for all patients. Of the 3 adenomatoid tumors 2 appeared isoechoic on ultrasound and 1 appeared normal. None of the 10 cancers appeared isoechoic or normal on ultrasound. CONCLUSIONS: Small tumors that appear isoechoic on ultrasound should be biopsied through an inguinal incision with frozen section assessment rather than immediate radical orchiectomy.

Case-Control Studies↗
PubMed1995

Detection of pulmonary embolism in patients with unresolved clinical and scintigraphic diagnosis: helical CT versus angiography.

OBJECTIVE: This study was designed to prospectively compare helical CT with pulmonary angiography in the detection of pulmonary embolism in patients with an unresolved clinical and scintigraphic diagnosis. SUBJECTS AND METHODS: Twenty patients with an unresolved suspicion of pulmonary embolism were evaluated with contrast-enhanced helical CT and with selective pulmonary angiography. An average of 11 hr separated the two studies. The CT scans were obtained during one 24-sec or two 12-sec breath-holds. CT scans were interpreted without knowledge of the results of scintigraphy or angiography. Selective pulmonary angiograms were obtained with knowledge of the findings on the ventilation/perfusion scan only. The sensitivity and specificity of CT were compared with those of angiography for central vessels (segmental and larger) only and for all vessels. RESULTS: Eleven of the 20 patients had proved pulmonary embolism (seven in central vessels and four in subsegmental vessels only). When only central vessels were analyzed, CT sensitivity was 86%, specificity was 92%, and the likelihood ratio was 10.7. However, when subsegmental vessels were included, CT results were 63%, 89%, and 5.7, respectively. CONCLUSION: In our subset of patients, helical CT was only 63% sensitive. Subsegmental emboli are difficult to diagnose. Pulmonary angiography remains the study of choice. CT has a limited role in the evaluation of acute pulmonary embolism.

Acute Disease↗
PubMed1995

Variable-mode helical CT: imaging protocols.

Helical CT provides a rapidly acquired, accurately registered, two-dimensional data set during the phase of maximum vascular and parenchymal enhancement. The z-axis can be covered by using either a single acquisition, single breath-hold technique or by using multiple helical groups with intergroup delays for the patient's breathing. The latter approach, called variable-mode helical CT, allows large z-axis coverage of more than one anatomic region during injection of a single bolus of contrast material. We discuss helical scanning protocols, both single-acquisition and variable-mode, that we have developed for detection of disease involving major blood vessels (pulmonary arteries and aorta), perivascular tissue planes (neck, thorax, and pelvis), and abdominal viscera (liver, pancreas, and kidneys).

Humans↗
PubMed1994

Helical CT: clinical performance and imaging strategies.

For nonelectron beam systems, scan speed and image quality have reached a relative plateau of performance. Helical CT makes rapid coverage of the z axis possible, allowing scanning to occur during the optimal phase of vascular and organ enhancement. With the split breath-hold variable-mode approach, extended helical coverage across multiple anatomic regions is possible. The technique adds flexibility in choice of collimation, milliamperage, and breath-hold interval. It is easily tolerated by patients and reproducible, and the intersegment delays produce less heat loading on the x-ray tube.

Humans↗
PubMed1994

Hepatic helical CT: contrast material injection protocol.

PURPOSE: To develop and compare contrast material injection protocols suitable for hepatic helical computed tomography (CT). MATERIALS AND METHODS: Monophasic and biphasic helical CT were performed with contrast material with an iodine load of 50 g at 3 mL/sec for 60 seconds or at 5 mL/sec for 10 seconds and 2 mL/sec for 65 seconds, respectively. In 58 men and 51 women, aged 22-77 years, aortic and hepatic enhancement curves were constructed from a cluster acquisition with a slip-ring scanner operating in a nonhelical mode. RESULTS: The monophasic protocol produced a higher peak aortic enhancement (180 HU +/- 47 [+/- 1 standard deviation]) than the biphasic protocol (150 HU +/- 24). Peak hepatic enhancement (63-64 HU +/- 15) was equivalent. Calculated equilibrium time for the monophasic protocol was 95.1 seconds and for the biphasic protocol was 101.4 seconds. The contrast enhancement index differed only marginally between the two protocols (P < .4). CONCLUSION: Monophasic and biphasic protocols produced equivalent results when tailored for the shorter temporal window of a rapid-sequence helical acquisition.

Adult↗
PubMed1994

Focal masses in cirrhotic liver: CT and MR imaging features.

The development of hepatic cirrhosis triggers attempted repair through regenerative nodules of parenchyma among bands of scar tissue. Some authors believe that this regeneration initiates an evolutionary process that may lead to nodular enlargement and cellular dedifferentiation to malignancy. Both the destructive and reparative processes in cirrhosis produce changes that the radiologist must recognize when imaging the cirrhotic liver. This essay describes the CT and MR features of masses and masslike lesions in the cirrhotic liver, including the identifying characteristics and overlapping appearances of CT and MR.

Carcinoma, Hepatocellular↗
PubMed1993

Periportal halo: a CT sign of liver disease.

Periportal halos are defined as circumferential zones of decreased attenuation identified around the peripheral or subsegmental portal venous branches on contrast-enhanced computed tomography (CT). These halos probably represent fluid or dilated lymphatics in the loose areolar zone around the portal triad structures. While this CT finding is nonspecific, it is abnormal and should prompt close scrutiny of the liver in search of an underlying etiology. Periportal halos which may be due to blood are commonly seen in patients with liver trauma. Periportal edema may cause this sign in patients with congestive heart failure and secondary liver congesion, hepatitis, or enlarged lymph nodes and tumors in the porta hepatis which obstruct lymphatic drainage. This CT sign has also been observed in liver transplants (probably secondary to disruption and engorgement of lymphatic channels) and in recipients of bone marrow transplants who might develop liver edema from microvenous occlusive disease. While the precise pathophysiologic basis of periportal tracking has not been proven, it represents a potentially important CT sign of occult liver disease.

Humans↗
PubMed1993

Image quality in dynamic CT: a clinical discussion.

Modern state-of-the-art computed tomographic (CT) scanners emphasize three capabilities: image quality, dynamic scan capability, and a high-resolution thin-section technique. Image quality is fundamental and dependent on optimum performance and the interrelationship of all system components. Variables that affect the performance of the scanner include x-ray tube output and rate of heat dissipation; quantum detection efficiency; electronic noise in the acquisition system; speed, accuracy, and integration of mechanical motion in the gantry and table; and the algorithm used for image reconstruction. System design must allow for dynamic scan operation, either in the single-scan or cluster mode, with short interscan or intergroup delays or, as more recently developed, with helical acquisition. Dynamic scanning is frequently used for nonneurologic applications, including diagnosis of vascular and perivascular diseases and multifocal organ disease, particularly hepatic disease. Efficient operation depends on rapid reconstruction and display capability. Modern systems have been engineered to provide flexible modes of operation, particularly in dynamic scanning, and rapid on-line review and analysis, all of which serve to improve the quality of images produced with dynamic CT scanning.

Contrast Media↗
PubMed1993

Current imaging strategies for colorectal cancer.

Endoscopy and barium enema examinations are used to identify the primary site of disease in patients with clinical suspicion of colorectal cancer. Once colorectal cancer has been confirmed by imaging studies and biopsy, preoperative evaluation is directed toward accurate disease staging. Most currently available imaging techniques are inaccurate for detecting transmural extension, perienteric spread of tumors and distant lymph node involvement. Although both computed tomography (CT) and magnetic resonance imaging (MRI) have an unacceptably low sensitivity for accurate staging, CT is clearly superior to MRI for detecting extrahepatic metastases. Transrectal ultrasonography, however, is a promising new method for detecting perirectal spread of disease. The diagnostic efficacy of MRI and intravenous dynamic hepatic CT for detecting liver metastases is approximately equal. CT during arterial portography is recommended before resection of solitary liver metastases. Chest radiography is also part of the routine preoperative evaluation. Bone scans are rarely performed in patients without the skeletal pain suggestive of bone metastases. During the years following surgery for colorectal cancer, many patients undergo special imaging studies to identify local tumor recurrence, secondary tumor growth elsewhere within the large bowel and both regional and distant spread of disease. Thus, for the patient with a sharply increasing carcinoembryonic antigen level, CT of the abdomen and liver is the current recommendation. Immunoscintigraphy is a new imaging modality that addresses some of the limitations of current diagnostic procedures for colorectal cancer. This procedure gives whole body information on disease extent, especially in the extrahepatic abdomen and pelvis, and can therefore contribute to patient management decisions.

Colorectal Neoplasms↗
PubMed1992

Color Doppler ultrasonography in the evaluation of the acute scrotum.

Color Doppler ultrasonography was used to assess 20 patients with the acute onset of scrotal pain. Patients were categorized into 3 groups according to the initial clinical impression of the examining physician: ischemia, inflammation or trauma. Color Doppler ultrasonography correctly predicted the need for surgery in 8 of 9 operated patients (89%) and correctly predicted the outcome in all 11 nonoperated patients (100%). The anatomical resolution possible, as well as information regarding blood flow made color Doppler ultrasonography a useful tool in the assessment of acute scrotal processes.

Acute Disease↗
PubMed1992

Color Doppler sonography in the evaluation of erectile dysfunction.

Color Doppler sonography can be useful in the evaluation of erectile dysfunction, which can result from psychogenic, endocrinologic, neurogenic, pharmacologic, and vasogenic causes. It is used to determine the integrity of the vascular mechanism. After an intracavernosal injection of a vasodilatory agent, color Doppler sonography is performed to evaluate cavernosal arteries and dorsal vessels. Color flow imaging allows direct visualization of intrapenile anatomy, vascular variants, and disease. It is also helpful in demonstrating transitions in cavernosal and dorsal blood flow. Color Doppler sonography is combined with spectral interrogation of the cavernosal arteries and dorsal veins to help determine peak systolic and end-diastolic velocities. Cavernosal artery size and systolic velocities help diagnose arterial insufficiency. Recent work on cavernosal artery diastolic flow and dorsal vein flow has indicated that color Doppler sonography, when correlated with cavernosographic findings, may be helpful in diagnosing venous incompetence. Temporal variations in transitions in cavernosal artery and dorsal vein flow during various stages of erection are important in the accurate diagnosis of vasogenic impotence.

Color↗
PubMed1992

Evaluation of traumatic aortic injury: does dynamic contrast-enhanced CT play a role?

To investigate the value of 5-mm contrast material-enhanced computed tomography (CT) in patients with moderate to low probability of aortic laceration after a substantial deceleration injury, scans were obtained through the upper mediastinum in 160 consecutive patients. Thoracic angiography and aortography were performed in patients with evidence of mediastinal hemorrhage at CT. There was no evidence of mediastinal hemorrhage in 132 patients with normal admission chest radiographs. In the 28 patients with abnormal admission chest radiographs, CT helped exclude mediastinal hemorrhage in 22 patients (78%), and 19 patients (68%) were treated without undergoing angiography. Six patients had mediastinal hematoma at CT. Only one had an aortic laceration at angiography. The authors conclude that 5-mm contrast-enhanced CT can help exclude mediastinal hemorrhage and reduce the angiography rate in low-to-moderate-risk patients with a widened or indeterminate mediastinum. There were no unsuspected cases of mediastinal hemorrhage in patients with normal chest radiographs. Angiography is recommended for patients considered to be at high risk for aortic laceration.

Angiography↗
PubMed1992

Ureteric jets: evaluation of normal flow dynamics with color Doppler sonography.

This study was designed to investigate a variety of sonographic features of ureteric jets in order to define patterns of flow and ranges of flow values in an asymptomatic population. The following features of ureteric jets were measured during a period of up to 30 min in a group of 15 asymptomatic volunteers after oral hydration (the mean value was calculated on each side): peak velocity (mean, 57 cm/sec); jet duration (mean, 4.6 sec); and number of peaks and subpeaks (mean, 2.2). Several flow patterns were observed, including discrete jets, ureteric streaming, and rest periods. For each patient the ratios of values obtained on the left and right sides were calculated for peak velocity (1.00-1.74; mean, 1.26); jet duration (1.00-4.69; mean, 1.83); and jet frequency (1.00-1.21; mean, 1.11). The interjet interval (period between jets) ranged from 2 to 150 sec. Bolus volume and jet frequency showed simultaneous moment-to-moment variation. The frequency and velocity rather than the duration ratios may be of greatest value in identifying patients with normal ureterodynamics. Our findings challenge two current concepts of renal pelvic and ureteral response to changes in urine output: (1) ureters have a fixed maximal discharge rate and (2) bolus volumes do not change until this rate is achieved. Asymmetric moment-to-moment fluctuations observed in jet frequency suggest that prolonged examination may be necessary to confirm normal symmetry of jet frequency in some patients with suspected ureteric obstruction.

Adult↗
PubMed1992

Color Doppler sonography in the evaluation of the adult acute scrotum.

Color Doppler sonography (CDS) was used to evaluate 35 adult males with acute scrotal discomfort. Correlative nuclear scintigraphy was performed in 15 patients. Surgical correlation was available in 10 patients with clinical follow-up in the remaining 25. The complete absence of intratesticular color flow was used as our criterion for testicular ischemia. This was found to be 100% sensitive and 100% specific in 8 patients with surgically confirmed testicular ischemia. Spontaneous detorsion was noted in one patient with hyperemia demonstrated by color imaging. Increased color flow was found in 20 patients with the clinical impression of scrotal inflammation. Nuclear scintigraphy and color Doppler imaging had 100% agreement in 15 patients. Color Doppler sonography is a useful and highly accurate diagnostic method in the evaluation of patients with the acute scrotal syndrome. Color flow imaging is comparable to nuclear scintigraphy in the diagnosis of testicular ischemia.

Acute Disease↗
PubMed1991

Hepatic metastases: CT versus MR imaging at 1.5T.

A prospective multi-institutional study was performed to compare the sensitivity of computed tomography (CT) and high-field magnetic resonance (MR) imaging (1.5T) in the detection of hepatic metastases. T1-weighted and 72-weighted spin-echo (SE) MR images were compared with noncontrast, dynamic, and delayed CT. Sixty-nine oncology patients were studied. Noncontrast CT showed an overall sensitivity of 57%, dynamic CT 71%, delayed CT 72%, T1-weighted SE MR 47%, and T2-weighted SE MR 78%. Although there was no statistically significant (p less than 0.05) difference among dynamic CT, delayed CT, and T2-weighted SE MR, these three methods were significantly more sensitive (p less than 0.005) than noncontrast CT or T1-weighted SE MR. T2-weighted SE MR was significantly more sensitive (p less than 0.006) than CT or T1-weighted SE MR in the detection of small (less than 1 cm) lesions. CT was more sensitive in the detection of extrahepatic disease. These data confirm the superiority of T2-weighted SE over T1-weighted SE pulse sequences at 1.5T.

Adult↗
PubMed1991

Color Doppler flow imaging.

The performance requirements and operational parameters of a color Doppler system are outlined. The ability of an operator to recognize normal and abnormal variations in physiologic flow and artifacts caused by noise and aliasing is emphasized. The use of color Doppler flow imaging is described for the vessels of the neck and extremities, upper abdomen and abdominal transplants, obstetrics and gynecology, dialysis fistulas, and testicular and penile flow imaging.

Abdomen↗