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Biomedical subjects

S M McCarthy

Publications and source records attributed to S M McCarthy.

At least 37 records · Page 2Linked to original sources
PubMed1991

Junctional zone of the uterus: correlation of MR imaging and histologic examination of hysterectomy specimens.

High-resolution magnetic resonance (MR) images of 12 hysterectomy specimens were correlated with results of light microscopy, image analysis, and immunohistochemical studies to investigate the histologic counterpart of the low-signal-intensity band, or junctional zone (JZ), that surrounds the bright central uterine stripe. All specimens were imaged with a 1.5-T superconducting magnet within 21/2 hours (on average) after hysterectomy. Comparison of histologic findings with measurements obtained at MR imaging indicates that the JZ represents the innermost layer of the myometrium. A threefold increase in percentage of nuclear area was found in the JZ in comparison with the outer myometrium, reflecting an increase in both size and number of nuclei. No difference in distribution of common components of the extracellular space (collagen, laminin, and fibronectin) was found between the two layers.

Adult↗
PubMed1991

Uterine changes after dilation and curettage: MR imaging findings.

To determine what, if any, changes occur in the appearance of the uterus on magnetic resonance (MR) images after dilation and curettage (D&C), nine women without endometrial abnormality underwent imaging before D&C and on day 2 and day 7 after D&C. On day 2, markedly hypointense curvilinear areas in the endometrial canal were noted on MR images in all patients (P = .0002). By day 7, these areas decreased in size in five (62%) and completely resolved in the rest (P = .022). There was no significant change in the width of the endometrial stripe or in the width or signal intensity of the junctional zone or myometrium after D&C. The junctional zone was focally disrupted in one patient who underwent D&C that was complicated by a uterine perforation. Therefore, curvilinear areas of low signal intensity (most likely representing clot) in the endometrial canal were visualized on MR images within 2 days of uncomplicated D&C and decreased in size or resolved over time. Significant widening of the endometrial stripe or disruption of the junctional zone was not observed after uncomplicated D&C.

Adult↗
PubMed1991

Chemical shift artifact: dependence on shape and orientation of the lipid-water interface.

On magnetic resonance images, chemical shift artifact (CSA) can be seen at a planar lipid-water interface oriented within the plane of the phase-encoding and section-select directions (ie, perpendicular to the frequency-encoding direction). Phantoms and a clinical case were used to demonstrate that when a lipid-water interface is curvilinear (eg, spherical) or planar but not oriented along the section-select direction, CSA may be absent or diminished. This effect can be seen at interfaces of normal structures (kidneys, bladder) as well as at interfaces with pathologic lesions such as lipid-containing dermoids. Not only is this effect dependent on section thickness, field of view, matrix size, and receiver bandwidth, but it is also strongly dependent on the orientation of the interface with respect to the section-select direction. Knowledge of the factors that can alter CSA is important since it is used to distinguish lipid-containing from nonlipid-containing structures of similar signal intensities.

Adult↗
PubMed1990

Pelvic masses in pregnancy: MR imaging.

The value of magnetic resonance (MR) imaging was assessed for 17 pregnant patients with sonograms suggestive of a pelvic mass. The MR imaging signal features improved lesion characterization in 47% (eight of 17) of cases, including two of four mature cystic teratomas of the ovary, three uterine fibroids, one solid ovarian tumor, one endometrioma, and a distended urinary bladder that had been mistaken for an ovarian cystic mass. Both MR imaging and sonography were accurate for the characterization of three ovarian cystadenomas and two simple ovarian cysts. On both MR images and sonograms, two simple ovarian cysts were incorrectly diagnosed as complex cystic masses and one teratoma was incorrectly diagnosed as a simple cyst. The origin of the pelvic mass (13 in the ovary, three in the uterus, and one distended urinary bladder) was accurately determined on 100% (17 of 17) of the MR images versus 71% (12 of 17) of the sonograms. In three cases, the results of MR imaging led to cancellation of surgery, which would have proceeded on the basis of the sonographic results alone. MR imaging is a valuable complement to sonography for preoperative evaluation of pelvic masses in pregnant patients.

Adolescent↗
PubMed1990

Applications of magnetic resonance imaging to gynecology.

The advent of MRI has improved the ability of the diagnostic radiologist to provide useful clinical information to the practicing gynecologist. Although US remains the screening procedure of choice for evaluation of the uterus and adnexa because of its relative safety and low cost, MRI is now considered the next imaging step. In a woman with pelvic pain, MRI can accurately identify adenomyosis, enumerate and localize uterine fibroids, and provide more accurate identification of endometriosis and cystic teratomas of the ovary than US. Although MRI should not be used as a screening procedure for diagnosing endometrial or cervical carcinoma, it can aid in patient management by determining the extent of myometrial or cervical invasion by endometrial carcinoma and can be used to calculate tumor volume in patients with cervical carcinoma. Early studies suggest that MRI may be helpful in distinguishing between long-term radiation fibrosis and tumor recurrence in such patients. MRI findings may be highly indicative of the presence of ovarian malignancy, but the procedure adds little to CT or US findings. Nevertheless, MRI is superior in the localization of pelvic masses and is often indicated in clarifying the origin of a mass as uterine or ovarian.

Endometriosis↗
PubMed1988

Brachial plexus: correlation of MR imaging with CT and pathologic findings.

Thirty-two patients with symptoms referable to the brachial plexus were evaluated with magnetic resonance (MR) imaging. Sixteen patients had undergone concurrent computed tomography (CT). MR imaging demonstrated normal findings in 16, 12 neoplasms, three cases of trauma, and one case of possible neural edema. Of the 16 patients with normal findings on MR images, eight had CT scans that were also normal. In one patient, MR images showed that the "mass" seen on CT was actually a tortuous blood vessel. In six of the 12 cases of neoplasm in which CT scans were available, MR imaging revealed more extensive disease. In the other six cases of tumor, MR imaging provided sufficient clinical information to obviate the need for CT or any other imaging modality. MR imaging provided definitive diagnoses in the three cases of trauma without further imaging. In one patient with paresthesia, MR imaging showed high signal intensity of the nerves on T2-weighted images, which was compatible with neural edema. A concurrent CT scan was normal.

Brachial Plexus↗
PubMed1988

Detection of renal masses: sensitivities and specificities of excretory urography/linear tomography, US, and CT.

A prospective blinded study of 201 patients was performed to determine the relative sensitivities and specificities of excretory urography/linear tomography (EU/LT) and ultrasound (US) for the diagnosis of renal parenchymal masses. Computed tomography (CT) was used as a standard. EU/LT permitted detection of 10% of CT-confirmed masses (cystic or solid) less than 1 cm, 21% of lesions greater than or equal to 1 cm but less than 2 cm, 52% of lesions greater than or equal to 2 cm but less than 3 cm, and 85% of lesions 3 cm or more in diameter. US permitted detection of 26% of CT-confirmed lesions less than 1 cm, 60% of lesions greater than or equal to 1 cm but less than 2 cm, 82% of lesions greater than or equal to 2 cm but less than 3 cm, and 85% of lesions 3 cm or more in size. The results confirm the relative insensitivity of EU/LT for masses less than 3 cm in diameter and of US for masses less than 2 cm. Further, they suggest that CT may have a role not only in evaluation of cases in which the urographic or sonographic results are questionable or positive, but also in confirmation of apparently negative urographic findings when clinical suspicion of a lesion is high.

Carcinoma, Renal Cell↗
PubMed1986

Utility of ceruletide in promoting intestinal opacification for abdominal and pelvic computed tomography.

An analysis of the utility of parenteral ceruletide, a cholecystokinin-like synthetic decapeptide, in promoting bowel opacification for computed tomography (CT) scanning was performed. Abdominal and pelvic CT scans of 85 patients who had received intramuscular ceruletide following oral contrast administration and of 85 control patients were reviewed and the degree of bowel opacification evaluated. No significant advantage was conferred by ceruletide in opacifying the stomach or major part of the small intestine. However, a statistically significant difference was found between the 2 groups in the presence or absence of contrast in the terminal ileum and right colon. Contrast was detected in the terminal ileum in 52 experimental compared with 35 control patients (p less than 0.009) and in the right colon in 56 experimental and 39 control subjects (p less than 0.01). Intramuscular administration of ceruletide will be helpful when terminal ileal opacification is essential or in patients in whom colonic opacification is desired but rectal contrast contraindicated.

Ceruletide↗
PubMed1985

Obstetrical magnetic resonance imaging: maternal anatomy.

Eleven patients whose pregnancies were at 34-36 weeks of gestational development underwent magnetic resonance (MR) imaging. Images of the maternal pelvis were assessed for anatomical changes of pregnancy in comparison with MR images of five non-pregnant volunteers. The relationship of the fetal presenting part to the internal os of the cervix was seen in all patients. Effacement of the cervix was identified when present. The maternal spine demonstrated disk abnormalities in nine patients. Changes in venous flow patterns were readily identified in all patients. The inferior vena cava was flattened or obliterated, a high signal was present in the iliac vessels (TE 56), and large collateral vessels were present.

Adult↗
PubMed1985

Obstetrical magnetic resonance imaging: fetal anatomy.

Nine patients who were 34-36 weeks pregnant underwent magnetic resonance (MR) imaging. Sagittal images using spin echo technique (TR 2.0 sec, TE 28 msec) were optimal for delineating fetal anatomy. The fetal cardiovascular, pulmonary, and central nervous systems were depicted in all cases. The heart and major vessels were readily seen due to the natural contrast of flowing blood. The intensity of the fluid-filled lungs greatly increased with a longer TR or TE, delimiting thorax from liver. The brain was relatively featureless due to the lack of gray-white matter differentiation. The umbilical cord within the amniotic fluid and its insertion into the placenta and fetus was identified in all cases. MR is a new modality for fetal imaging that offers tissue-characterization information that complements the superior anatomic detail of ultrasound scanning.

Amniotic Fluid↗
PubMed1985

Intrauterine growth retardation: evaluation by magnetic resonance. Work in progress.

Eleven high risk fetuses between 32 and 37 menstrual weeks gestational age were examined by magnetic resonance (MR) imaging. Serial obstetrical sonograms, birth weights, and serial postnatal examinations were obtained in all subjects. Sagittal MR spin echo images obtained using TR = 0.5 sec and TE = 28 msec were useful for assessing subcutaneous fat. Prospective estimates of fetal fat stores correlated with neonatal outcome better than sonographic measurements of fetal growth parameters or actual birth weight. MR appears to be a safe and useful technique that offers information complementary to obstetrical sonography when IUGR is suspected.

Adipose Tissue↗
PubMed1985

Detection of abdominal aortic graft infection: comparison of CT and in-labeled white blood cell scans.

Aortic graft infections are a rare but potentially lethal complication of aortic graft surgery. If the infection is limited to the groin, local therapy and preservation of the graft may be possible in some cases, whereas infections extending into the retroperitoneum require removal of the graft and revascularization of the lower limbs. The diagnosis and assessment of the extent of a graft infection is difficult on clinical grounds. A prospective study compared CT and indium-labeled white blood cell (In-WBC) scans in the diagnosis of aortic graft infection. Five patients with aortic graft infection and three patients without aortic graft infection were studied by both methods. CT correctly detected the retroperitoneal extension of the infection in three patients with groin infection; In-WBC scans diagnosed the extension only in one patient. Both CT and In-WBC were positive in two patients with aortic graft infection but no groin infection. Both studies were negative in the three patients without evidence of aortic graft infection. The study suggests that CT is more sensitive than In-WBC in evaluating the extent of aortic graft infection and should be the imaging method of choice.

Aorta, Abdominal↗
PubMed1985

Detection of recurrent rectosigmoid carcinoma: prospective evaluation of CT and clinical factors.

Twenty-nine patients who underwent curative resection for rectosigmoid carcinoma were followed for 1-4 years by history and physical examination, computed tomography, liver function tests, and carcinoembryonic antigen levels. Recurrences occurred in 13 patients: seven asymptomatic and six symptomatic. CT scans, obtained in 10 of these 13 patients, were positive in nine. Liver function tests were not elevated in any and carcinoembryonic antigen was abnormal in six of 11 patients. CT is the most sensitive test for the detection of recurrent disease.

Aged↗
PubMed1985

Pelvimetry by magnetic resonance imaging.

Sagittal and transverse multisection magnetic resonance imaging (MRI) in 10 patients was used to obtain dimensions of the maternal pelvis, determine fetal position, and examine maternal and fetal soft tissues. Dimensions were measured with less than 1% instrument error, and bony landmarks were readily identified. MR pelvimetry is an accurate technique for obtaining traditional pelvimetric measurements without exposure to ionizing radiation. These techniques can be further used to investigate soft-tissue dystocia and obstructed labor.

Dystocia↗
PubMed1985

Magnetic resonance imaging of fetal anomalies in utero: early experience.

Five cases of fetal dysmorphology were examined with high-resolution sonography and magnetic resonance imaging (MRI). Postpartum confirmation was available in all cases. The high contrast resolution of MRI resulted in clear depiction of the abnormalities, particularly dilated fluid-filled structures, whereas the real-time capability and spatial resolution of sonography permitted better appreciation of anatomic detail. While sonography will remain the primary imaging method for pregnancy, MRI appears to be a promising complementary technique in difficult cases.

Female↗
PubMed1984

Computed tomography of malignant carcinoid disease.

Twenty-two patients with malignant carcinoid syndrome were evaluated with CT, the largest series to date. A mass representing the primary tumor or local adenopathy was identified in four patients, appearing as a homogeneous mass involving mesentery and bowel. In two other patients the primary was not identifiable by barium series, angiography, CT, or laparotomy. In the remaining 16 patients who were scanned after resection of the primary four had mesenteric thickening and five had adenopathy. Malignant ascites was present in seven of 21 patients. All hepatic metastases were hypodense on the precontrast study. The effect of contrast administration on lesion detectability was variable, obscuring at least one or more metastases in eight of 21 scans. We recommend noncontrast scans of the liver in patients in whom the number and size of metastases are critical to therapy.

Contrast Media↗
PubMed1983

Radiology of postnatal skeletal development. VIII. Distal tibia and fibula.

Initially the distal tibial physis is a relatively transverse structure. As the epiphysis matures, undulations develop within the physis and lappet formation occurs peripherally. Within the first two years a significant physeal undulation develops anteriorly above the medial malleolus. This undulation must not be misinterpreted as premature epiphyseodesis following distal tibial fracture. Secondary ossification in the distal tibia begins centrally and initially expands to fill the area over the tibial plafond. At the lateral side of the tibial epiphysis the ossification center may be wedge-shaped. The medial margin adjacent to the medial malleolus is often irregular and may show small peripheral foci of ossification. By seven to eight years, the secondary center extends into the medial malleolus, with complete distal extension often not occurring until adolescence (although usually complete by ten to eleven years). The malleolar tip may exhibit an accessory ossification center. However, this center also may be a traumatic avulsion in the symptomatic patient. Physiologic epiphyseodesis begins over the medial malleolus and subsequently extends laterally. This pattern of closure appears to predispose to fracture of the lateral portion of the distal tibial epiphysis (fracture of Tillaux), as well as to triplane fractures. The articular surface curves onto the lateral side of the distal tibia to form an articulation with the lateral malleolus (distal tibiofibular joint). A similar extension occurs along the medial side of the fibula. These surfaces extend proximally as a recess to the level of the distal tibial physis, at which point the syndesmosis begins. The initially transverse distal fibular physis becomes a convoluted structure, with extensive peripheral lappet formation. Within these regions of physeal overlap there may be small areas of accessory ossification (both medially and laterally) that should not be misinterpreted as fractures. This overlapping also minimizes specific physeal separation and displacement (especially when compared to the incidence of distal tibial physeal injuries). Stress views may be necessary to show such an undisplaced fracture. The fibular physis normally is level with the tibial articular surface or distal extent of the tibial ossification center, especially after the second year of life (however, it may be more proximal in infants). As in the medial malleolus, there may be accessory ossification at the tip of the fibula. While this usually is a normal variant of secondary ossification, occasionally it also may result from trauma. Extensive porosity of the distal fibular metaphysis predisposes to buckling or torus injuries that may have severe, multiangular deformation.

Adolescent↗