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Biomedical subjects

S W Fitzgerald

Publications and source records attributed to S W Fitzgerald.

35 records · Page 2Linked to original sources
PubMed1994

Magnetic resonance imaging of the meniscus. Advanced concepts.

Magnetic resonance imaging plays a valuable role in the evaluation of the full range of meniscal pathology including the primary diagnosis of meniscal tear, the detection of recurrent tear after resection or repair, and the demonstration of associated injuries and complications. The accuracy of MR imaging in meniscal diagnosis is dependent on the appropriate choice of MR imaging pulse sequences, imaging parameters, and diagnostic criteria. The importance of small details such as protocol parameters and image photography should not be underestimated. The role of new techniques including fast imaging sequences, three-dimensional imaging, and MR arthrography in improving meniscal diagnostic performance is under investigation and appears promising.

Cartilage Diseases↗
PubMed1993

Renal manifestations of AIDS.

The kidneys in patients with acquired immunodeficiency syndrome (AIDS) are subject to a variety of insults. Renal manifestations can be seen with imaging studies of AIDS patients. Computed tomographic (CT) and ultrasound (US) scans of 64 patients with AIDS and renal dysfunction were retrospectively reviewed and compared with clinical, laboratory, and, when available, biopsy results. Imaging abnormalities included increased cortical echogenicity, nephromegaly, pyelonephritis, lobar nephronia, focal masses caused by abscess and lymphoma, parenchymal calcification, hydronephrosis, and infarct. Generally, patients with AIDS as a result of intravenous drug abuse and those with multiple risk factors were more likely to have abnormalities demonstrated at imaging as well as poorer prognosis than were patients in the homosexual transmission group in this series. Although US should be the screening study used in patients with AIDS and suspected renal dysfunction, CT and magnetic resonance imaging may be necessary to identify focal infectious, ischemic, and neoplastic processes.

Acquired Immunodeficiency Syndrome↗
PubMed1993

CT of the azygoesophageal recess in infants and children.

The contour of the azygoesophageal recess (AER) as seen with computed tomography (CT) is an important indicator of mediastinal disorders. Radiologists must recognize, however, that the AER contour varies with patient age. The configuration of the AER is dextroconvex in children younger than 6 years, nonconcave (ie, equally divided between convex and straight) in children aged 6-12 years, and concave (or adult-like) in adolescents and young adults (aged 12-20 years). The cause of this variation is not certain; however, chest wall configuration does not seem to be an important factor. Although a convex AER is normal and common in pediatric patients, this normal appearance must be distinguished from that of mediastinal abnormalities (eg, foregut malformation cysts, vascular anomalies, lymphadenopathy), which can also produce obvious or subtle convexity of the AER. An appreciation for the age-related variation in AER configuration helps in the interpretation of CT scans. Criteria such as attenuation, morphologic characteristics, cephalocaudal extent, and multicompartmental involvement may be helpful in the differential diagnosis, but, generally, mediastinal abnormalities that alter the AER are nonspecific in appearance.

Adolescent↗
PubMed1993

MR evaluation of the anterior cruciate ligament: value of supplementing sagittal images with coronal and axial images.

OBJECTIVE: Most studies evaluating the anterior cruciate ligament have focused on sagittal MR images for the diagnosis of injury. Limitations of sagittal images have been reported, however, including nonvisualization and incomplete visualization of the ligament. This study was undertaken to assess the value of adding coronal and axial MR images to sagittal images in the evaluation of the anterior cruciate ligament. MATERIALS AND METHODS: We reviewed oblique sagittal T1-weighted, coronal T2-weighted, and axial T2-weighted images to determine the status of the anterior cruciate ligament in 325 patients. All patients had arthroscopy. Sagittal images were initially interpreted alone and then in combination with coronal and axial images. RESULTS: Sagittal T1-weighted images alone had a 94% sensitivity and an 84% specificity for determining the status of the anterior cruciate ligament. A multiplanar evaluation of the anterior cruciate ligament resulted in a change in MR interpretation in 21 patients (6%), which led to an improved sensitivity of 98% and a specificity of 93%. Diagnostic confidence was improved in an additional 14 patients (4%). CONCLUSION: Our results show that the efficacy of MR imaging for the detection of anterior cruciate ligament tears is greater when axial and coronal images are used in combination with sagittal images than when sagittal images are used alone.

Adult↗
PubMed1993

Transient lateral patellar dislocation: diagnosis with MR imaging.

OBJECTIVE: Transient lateral patellar dislocation is frequently difficult to diagnose accurately on the basis of clinical findings. Accordingly, we studied the MR findings in 26 cases to determine if MR imaging is useful in establishing the diagnosis. MATERIALS AND METHODS: A retrospective review of 1450 MR examinations of acutely injured knees was performed to determine the MR findings resulting from transient lateral patellar dislocation. A distinctive constellation of MR findings reflecting the known mechanism of injury indicative of transient lateral patellar dislocation was found in 26 patients. Patellar dislocation was not clinically suspected before imaging in 19 (73%) of these 26 patients; most patients had been referred for suspected injury of the cruciate ligaments or menisci. Axial, sagittal, and coronal MR images were obtained in all patients, and all had clinical follow-up. Correlation of MR findings with surgical findings was possible in six. RESULTS: Specific components of the constellation of MR findings included disruption or sprain of the medial retinaculum in 25 (96%) of 26 patients, lateral patellar tilt or subluxation in 24 patients (92%), lateral femoral condyle contusion in 21 patients (81%), osteochondral injury in 15 patients (58%), and joint effusion in all 26 patients (100%). Concomitant injury to major ligaments or menisci was present in eight (31%). CONCLUSION: Our findings suggest that patients with transient lateral patellar subluxation have a distinctive constellation of MR findings that can be used to distinguish this entity from other common knee injuries.

Adolescent↗
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

Anterior cruciate ligament injury: MR imaging diagnosis and patterns of injury.

The anterior cruciate ligament (ACL) is an important stabilizer of knee motion. Injury of the ACL can lead to substantial disability; an accurate diagnosis of ACL injury is vital in both short-term and long-term patient care. Magnetic resonance (MR) imaging has emerged as the study of choice to evaluate the status of the ACL and other associated structures in the knee. Sagittal MR images have been commonly used in the evaluation of the ACL. However, the authors believe that coronal and axial imaging planes can add useful information about ACL injury and, thus, lead to improved accuracy and confidence regarding diagnosis. Multiplanar imaging can readily demonstrate meniscal, ligamentous, and bone marrow injuries that commonly occur with the most frequent mechanisms of ACL injury. These mechanisms, in order of frequency, include internal rotation and valgus stress, hyperextension, and varus stress with external rotation. An understanding of these mechanisms is helpful in the MR diagnosis of ACL injury.

Anterior Cruciate Ligament Injuries↗
PubMed1992

Long bicipital tendon of the shoulder: normal anatomy and pathologic findings on MR imaging.

The tendon of the long head of the biceps muscle (long bicipital tendon) has a complex course from its muscle belly to its insertion onto the supraglenoid tubercle/glenoid labrum. It is stabilized by numerous tendinous and ligamentous structures and is, in turn, partly responsible for maintenance of normal glenohumeral function. In this report we describe the anatomy of this tendon, correlating high-resolution MR images with cryomicrotome sections. We illustrate typical MR findings in pathologic conditions affecting the long bicipital tendon sheath, the substance of the tendon, and finally the tendon position.

Chondromatosis, Synovial↗
PubMed1992

Azygoesophageal recess: normal CT appearance in children.

The azygoesophageal recess is the interface of the subcarinal portion of the mediastinum and the right lower lobe. The configuration of the recess on CT can be used as a sensitive indicator of abnormality in the mediastinum. In normal adults the recess is concave. A convex contour is a normal variant, particularly in young adults. The normal appearance of the azygoesophageal recess in children has not been studied. Accordingly, we reviewed chest CT examinations performed in 253 children ranging from 1 month to 20 years old. Forty patients were excluded from further analysis either because the recess could not be evaluated properly or because underlying disease caused the mediastinum to have an abnormal configuration. An age-related spectrum of normal configurations was observed in the remaining 213 patients. A convex or straight contour was found in 96% of children less than 3 years old. Scans of children 3-12 years old revealed a spectrum of configurations. The typical adult concave configuration was seen in 78% of adolescents more than 12 years old. Overall, in only 90 (42%) of 213 children in this study was a concave recess observed on CT. Our experience shows a convex azygoesophageal recess on CT should be considered the normal configuration in infants and young children. Recognition of this age-related variation is useful in the CT evaluation of the mediastinum in children.

Adolescent↗
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

MR imaging of the lateral collateral ligament of the ankle.

The ankle is stabilized by three sets of ligaments: the medial collateral (deltoid) ligament, the syndesmotic ligamentous complex, and the lateral collateral ligament. Of these three, the lateral collateral ligament is the one most often injured in ankle sprains. Assessment of the extent of injury has classically relied on clinical evaluation; plain film radiographs (including stress views); and, in some acute situations, ankle arthrography and/or peroneal tenography. In this report we illustrate the use of MR in the evaluation of the lateral collateral ligament. The normal anatomy, pitfalls in image interpretation, and findings in cases of ligamentous injury are demonstrated.

Ankle Joint↗
PubMed1991

Color Doppler sonography in the evaluation of erectile dysfunction: patterns of temporal response to papaverine.

Most studies of duplex Doppler sonography for the assessment of erectile dysfunction involve determination of peak systolic velocities 5 min after intracavernosal injection of papaverine. The purpose of this study was to determine the effect of the timing of Doppler measurements of flow after papaverine injection for establishing the presence of arterial and venous abnormalities. Color Doppler sonography was performed in 75 patients for evaluation of vasculogenic impotence. After intracavernosal injection of 60 mg of papaverine, measurements of peak systolic and end-diastolic velocities were obtained in each cavernosal artery at 5-min intervals for a total of 30 min. A peak systolic velocity of less than 25 cm/sec was used as the threshold for arterial insufficiency. An end-diastolic velocity of greater than 5 cm/sec was used to predict venous incompetence. Scanning was performed for direct assessment of dorsal venous flow. Thirty patients were subsequently evaluated by cavernosometry and cavernosography. In most patients (76%), maximum response to papaverine was achieved within the first 5 min. In eight patients, significant increases in systolic velocity were seen only after 5 min. In 10 patients, significant changes in end-diastolic velocity between 5 and 30 min resulted in diagnostic reclassification. Data acquisition for 30 min significantly improved the sensitivity (95%) and specificity (83%) for the prediction of venous incompetence in patients with correlative cavernosography. Transient, early dorsal vein flow was noted in normal subjects. Persistent dorsal vein flow had an 80% sensitivity and 100% specificity for venous incompetence. Our results suggest that, when using color Doppler sonography, gathering data for 30 min may improve the prediction of vasculogenic impotence.

Adult↗
PubMed1987

Pediatric thoracic aorta: normal measurements determined with CT.

Normal thoracic aortic dimensions in adults have been established by means of computed tomography (CT), but such measurements are not available in children. To establish normal standards, contrast material-enhanced chest CT scans of 117 children and adolescents, ranging in age from 2 weeks to 19 years, were reviewed retrospectively. Patients with congenital heart disease, vascular anomalies, renal disease, hypertension, and connective-tissue disorders were excluded, resulting in 97 studies. Diameters of the thoracic aortas were measured at three levels. Interobserver and intraobserver variances were determined. A direct linear relationship to patient age was observed, and regression analysis was performed. These standards help in differentiating the normal from the abnormal aorta on chest CT scans of children.

Adolescent↗
PubMed1982

Evidence for the presence of subpopulations of Arenicola marina coelomocytes identified by their selective response towards Gram+ve and Gram-ve bacteria.

In Arenicola marina (L.), in vitro attachment and phagocytosis of bacteria appears to be serum-independent and thus, non-specific. Mixtures of Gram+ve and Gram-ve bacterial species (Gram+ve/-ve, of two Gram+ve (Gram+ve/+ve) and of two Gram-ve bacterial species (Gram-ve/-ve)were overlaid on coelomocyte monolayers, in order to introduce competition for cell surface 'receptors'. An enhanced total phagocytosis was only recorded in the Gram+ve/-ve mixtures in comparison with their controls. The results are interpreted in terms of coelomocyte subpopulations and indicate that A. marina coelomocytes may possess specific carbohydrate/glycoprotein determinants capable of recognizing basic carbohydrate differences between the cell walls of Gram+ve and Gram-ve bacteria.

Alcaligenes↗
PubMedDate not supplied

Evaluation of loose bodies in the elbow with MR imaging.

The evaluation of loose bodies in the elbow is usually done by means of clinical examination, radiography, and postarthrographic computed tomography (CT). The authors review their experience with magnetic resonance (MR) imaging in place of post-arthrographic CT for the evaluation of loose bodies in the elbow. The prospective interpretation of MR studies of the elbow in 20 patients was compared with arthroscopic findings. All elbows were imaged in multiple planes with thin sections, surface coils, and combinations of T1, T2, and proton-density weighting. The sensitivity for showing loose bodies with MR imaging was 100%, and the specificity was 67%. Because this was a nonblinded study, the results are biased and caution must be used when extrapolating these results to the general population. In this limited experience, MR imaging has reliably shown loose bodies in the elbow, and in the authors' institutions has replaced postarthrographic CT for that purpose.

Adolescent↗