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Biomedical subjects

P T Weatherall

Publications and source records attributed to P T Weatherall.

11 recordsLinked to original sources
PubMed1995

Radiographic diagnosis of breast implant rupture: current status and comparison of techniques.

Rupture of a breast implant is a recognized complication of augmentation mammaplasty and reconstructive breast surgery. Due to concerns over the extravasation of silicone gel within adjacent tissue and distant body sites, considerable attention has been given to the radiographic detection of mammary implant rupture. A metaanalysis comparing the accuracy of various currently available imaging modalities was conducted and an algorithm suggested to guide clinicians in the detection of breast implant rupture. Advantages and limitations of mammography, xeromammography, ultrasonography, MRI, and CT are outlined as well as some of the most specific radiographic signs of each with illustrative examples from patients evaluated at our institution. Results of our retrospective analysis corroborated by a review of the most recent literature reveal that mammography supplemented with ultrasonography constitutes the most cost-effective initial study, followed by MRI if these are equivocal. MRI is the most sensitive and specific study to evaluate breast implant rupture.

Breast↗
PubMed1995

Benign and malignant masses. MR imaging differentiation.

Not only is MR imaging maximally sensitive to the presence of musculoskeletal soft-tissue lesions, but also it provides exquisite definition of their features. Categorization of the many distinct attributes of the lesions is the key to differentiation of benign from malignant processes. Combining the observations concerning the architectural details with the location and pattern of growth, and finally with the specific MR signal characteristics and contrast enhancement patterns, will produce the most limited differential diagnosis possible. Although there are few, if any, pathognomonic findings for malignant or benign lesions in diagnostic imaging, a high degree of confidence or statistical likelihood can be achieved in many instances using MR imaging.

Bone Diseases↗
PubMed1995

Musculotendinous injury.

Over the past decade, MR imaging has become one of the most valuable imaging tools for evaluation of musculoskeletal pathology. This is due to its high sensitivity to the vast majority of acute and chronic musculoskeletal injuries and the starting anatomic clarity provided. The latter feature allows definition of characteristic injury patterns, which is the key to most diagnoses and also usually allows accurate grading of the severity of injuries. Careful attention to imaging technique and the specific architectural patterns of musculotendinous disruption by the imaging specialist will result in accurate diagnoses for the patient and referring physician.

Bone and Bones↗
PubMed1994

Chondroblastoma: classic and confusing appearance at MR imaging.

PURPOSE: To define the characteristics of chondroblastoma at magnetic resonance (MR) imaging and the combination of findings that are diagnostic for chondroblastoma. MATERIALS AND METHODS: From January 1987 through December 1992, 22 patients with histologically confirmed chondroblastoma and prior MR imaging examinations were seen. Patients included 16 men and six women, aged 10-58 years (median, 17 years). Retrospective analysis of findings at MR imaging, plain radiography, computed tomography, and bone scanning was performed. RESULTS: Low to intermediate heterogeneous signal intensity, lobular internal architecture, and fine lobular margins were well defined with high-resolution T2-weighted (repetition time > or = 1,500 msec, echo time > or = 70 msec) MR imaging. Adjacent bone-marrow and soft-tissue edema and periosteal reactions were more dramatically demonstrated on MR images than on radiographs. Bone marrow edema was prominent in all but five cases. Obvious periosteal reaction and adjacent soft-tissue edema were visible in 17 cases. CONCLUSION: Knowledge of the MR imaging findings of chondroblastoma will allow accurate diagnosis and help avoid confusion with infection and aggressive neoplasms.

Adolescent↗
PubMed1993

An evaluation of the effect of gonadotropin-releasing hormone analogs and medroxyprogesterone acetate on uterine leiomyomata volume by magnetic resonance imaging: a prospective, randomized, double blind, placebo-controlled, crossover trial.

The purpose of this study was to prospectively compare the effectiveness of administering medroxyprogesterone acetate (MPA; 20 mg/day) in either the first (protocol A) or last (protocol B) 12-week period along with a 6-month course of the GnRH analog (GnRH-a; leuprolide acetate; 1 mg/day, sc) on uterine and leiomyomata volumes and hormone (estradiol, LH, and FSH) and serum lipid (total cholesterol, triglycerides, and high and low density lipoprotein) levels. Sixteen women were randomized into protocol A or B, received either MPA or placebo along with GnRH-a, respectively, and were then crossed over at 12 weeks to placebo or MPA, respectively, for the final 12-week interval of GnRH-a therapy. Total, myoma, and nonmyoma uterine volumes were determined by magnetic resonance imaging, and serum studies were performed at the beginning of the study and at 12 and 24 weeks. In both protocols, LH and estradiol levels declined by 80-90% (P < 0.03) and 55-72% (P < 0.02) of the baseline, respectively, at 12 weeks and remained at this level at 24 weeks. There were no significant changes in the other laboratory tests between protocols or longitudinally over time. Total uterine volume decreased to 73% of the baseline at 12 weeks in protocol B (P < 0.04), but did not change in protocol A. After crossover at 12 weeks, the total uterine volume of women in protocol A decreased to 74% of the baseline (P < 0.02) at 24 weeks. Between-protocol comparisons demonstrated a greater decline in total uterine volume in protocol B than A at 12 weeks, but after cross-over, MPA addition was associated with a significant increase in total uterine volume (protocol B) compared to a decrease in protocol A at 24 weeks (P < 0.005). In contrast, although myoma volume declined in both protocols, no significant changes in myoma volume were detected within or between groups over the treatment period. Nonmyoma volume changes in protocols A and B roughly paralleled total uterine volume changes, with MPA coadministration showing a correlation with a reversal in the GnRH-a-associated decrease in nonmyomatous tissue volume.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1991

Osteomyelitis: characteristics and pitfalls of diagnosis with MR imaging.

Prospective and retrospective magnetic resonance (MR) imaging (0.35-T) interpretations were compared with final diagnoses in 110 patients suspected to have osteomyelitis. Diagnostic criteria of dark marrow on T1-weighted images and bright marrow on short-tau inversion-recovery images yielded a prospective sensitivity of 98% and a prospective specificity of 75%. Sixty percent of uncomplicated septic joint effusions demonstrated abnormal marrow signal intensity that was mistaken for osteomyelitis. Retrospective review revealed that overall specificity could be improved to 82% without loss of sensitivity if increased marrow signal intensity on T2-weighted images were included as an additional criterion. Specificity may be further increased by use of knowledge of morphologic patterns that distinguish various forms of osteomyelitis. Ten patients (9%) had potential pitfall diagnoses (eg, fracture, infarction, healed infection) that mimic osteomyelitis. MR imaging can be sensitive and specific for osteomyelitis if characteristic appearances and pitfall diagnoses are incorporated into the diagnostic criteria.

Acute Disease↗
PubMed1991

Locomotor system assessment by muscle magnetic resonance imaging.

Clinical evaluation of the locomotor system has long been hampered by difficulty in assessing the morphologic and functional integrity of skeletal muscles. Diagnostic imaging represents a major advance in the diagnosis and management of patients with locomotor dysfunction through the possibility of probing beyond overlying soft tissues to identify muscle lesions, determine their extent, characterize their composition, direct invasive procedures, and monitor therapies. Magnetic resonance imaging (MRI) appears to be the most promising of available imaging methods, because of its great sensitivity to changes in muscle water distribution and fat content. Also, it can distinguish between individual deep and superficial muscles. Serial evaluations of many muscles are practical because of the safety of MRI. While the cost effectiveness in the workup of locomotor dysfunction remains to be determined, the scientific and practical clinical information now available merits further investigation by clinicians and radiologists alike. The purpose of this review is to describe the potential role of skeletal muscle MRI in evaluating the locomotor system.

Humans↗
PubMed1989

Sports-related muscle injuries: evaluation with MR imaging.

Sports-related muscle pain is frequent in both trained and untrained persons; however, its severity and significance may be difficult to assess clinically. The authors used magnetic resonance (MR) imaging to evaluate acute strains and delayed-onset muscle soreness in sedentary subjects and postmarathon myalgia in trained runners. MR imaging documented the distribution of affected muscles and the absence of focal hematoma, fascial herniation, subsequent fibrosis, and fatty infiltration. Pain associated with strain and that occurring several days after exercise were both associated with prolongation of muscle T1 and T2. In a prospective evaluation of delayed-onset muscle soreness, abnormalities depicted at MR imaging persisted longer than symptoms by up to 3 weeks, indicating that MR imaging is sensitive to tissue alteration that is not apparent clinically. Highly trained marathon runners tended to have relatively mild abnormalities involving the myotendinous junctions.

Athletic Injuries↗
PubMedDate not supplied

MR of cord transection.

Spinal cord transection following breech or difficult cephalic deliveries has been well described. It is important to be aware that spinal cord transection in children may occur following severe trauma such as motor vehicle accidents often without evidence of underlying skeletal injury. We report three pediatric cases, one of which showed no evidence of underlying skeletal injury and two where the level of cord transection was below and remote from the site of a cervical fracture. When a neurologic deficit does not correlate with a known bony or ligamentous level of injury or is present despite normal routine plain radiographs, further imaging is warranted to exclude a remote cord transection as demonstrated in our patients.

Accidents, Traffic↗
PubMedDate not supplied

Neuroangiography with iohexol.

Iohexol is a new, nonionic water-soluble contrast agent undergoing early clinical trials in the United States. Using a double-blind, parallel format, iohexol was compared with meglumine iothalamate (60 patients) for selective cerebral angiography, and with sodium meglumine diatrizoate (40 patients) for arch aortography. Iohexol produced significantly less pain than meglumine iothalamate or sodium meglumine diatrizoate. There were no significant differences in terms of heart rate, blood pressure, or electrocardiogram (ECG) changes. Both produced a transient tachycardia and hypotension after arch aortography, but significantly less so with iohexol. No significant complications occurred. Film quality was comparable between contrast agents except for diminished motion artifacts with iohexol. Iohexol appears to be a superior neuroangiographic contrast agent to current ionic drugs.

Adult↗