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Biomedical subjects

L G Shapeero

Publications and source records attributed to L G Shapeero.

18 recordsLinked to original sources
PubMed1992

Adenoid cystic carcinoma of the head and neck: evaluation with MR imaging and clinical-pathologic correlation in 27 patients.

Twenty-seven adenoid cystic carcinomas (ACCs) of the head and neck in 27 patients were evaluated in a retrospective study based on findings at magnetic resonance (MR) imaging and pathologic and clinical examination. Clinical follow-up was obtained over a mean period of 6.3 years (range of follow-up, 3 months to 17 years); all patients underwent one to seven MR examinations. On T2-weighted images, lesions with low signal intensity corresponded to highly cellular tumors (solid subtype) with a poor prognosis; lesions with high signal intensity corresponded to less cellular tumors (cribriform or tubular subtype) with a better prognosis. MR images were not specific in differentiation of ACCs from other types of tumors; this result underscores the need for biopsy to ensure correct diagnosis. Local, intracranial, osseous, and perineural invasion was depicted, but because of its lack of specificity, MR imaging caused overdiagnosis of tumor extension, particularly perineural spread and bone abnormalities.

Adolescent↗
PubMed1992

Osteosarcoma after chemotherapy: evaluation with contrast material-enhanced subtraction MR imaging.

A new magnetic resonance (MR) technique, gadolinium-enhanced subtraction MR imaging, was developed to evaluate the response of patients with osteosarcoma to chemotherapy. Ten patients, who had received chemotherapy for osteosarcoma of the lower extremity, underwent MR imaging 3 days before surgery. After routine MR imaging was performed, subtraction MR was performed in the plane in which the tumor was best visualized. With gadopentetate dimeglumine (0.1 mmol per kilogram) on a standard MR console, subtraction images were created by subtracting precontrast images from gadolinium-enhanced T1-weighted images. The time of maximal tumoral vascular uptake was 1 1/2 minutes after injection, and, therefore, the subtracted image obtained at this time was used for evaluation of viable tumor. Independently, radiologists and histopathologists examined their respective studies for viable tumor to differentiate responders from nonresponders. Four of 10 osteosarcomas were classified as good responders because they appeared as nonenhancing masses, with or without enhancing thin lines, or small nodules (< or = 3 mm wide). At histopathologic examination, all were good responders with less than 3% viable tumor. Six of 10 osteosarcomas were classified as nonresponders because they appeared as enhancing high-signal-intensity masses measuring more than 3 mm in width. Five tumors had between 18% and 43% viable tumor cells.

Adolescent↗
PubMed1992

Imaging in the follow-up of soft tissue tumors.

Local recurrences of aggressive soft tissue tumors are frequent and very difficult to detect clinically after surgery and radiation therapy. Ultrasound is limited because the skin is thick. On contrast-enhanced CT, both scars and recurrences increase their signal. MRI is the best technique, and the only one we presently use in the detection of recurrent tumors. We are reporting 511 follow-up examinations in 182 patients after tumor removal. All patients had histologic confirmation or at least 6 months follow-up. There were 164 malignant tumors and 18 cases of aggressive fibromatosis.

Contrast Media↗
PubMed1989

Mixed müllerian sarcoma of the uterus: MR imaging findings.

MR images of seven patients with histologically documented mixed müllerian sarcoma were analyzed retrospectively to determine whether the scans showed findings that could suggest the diagnosis. Spin-echo T1- and T2-weighted sagittal and transverse images from either a 0.35- or a 1.5-T unit were available for each patient. MR image analysis included evaluation of tumor signal intensity on T1 and T2 images; tumor location, size, and extent; depth of myometrial invasion; and presence of pelvic metastases. In all seven patients, MR images showed a large endometrial mass deeply invading the myometrium or beyond. In addition, MR images showed intraperitoneal (two patients) and ovarian (one patient) metastases. Although the massiveness of the tumors on initial presentation may suggest the diagnosis of mixed müllerian sarcoma, the MR imaging findings are nonspecific and mimic invasive endometrial carcinoma.

Aged↗
PubMed1988

Functional dynamics of the knee joint by ultrafast, cine-CT.

An ultrafast, cine-CT scanner was used to demonstrate the differential mobility of the lateral and medial femoral condyles on their respective tibial plateaus in cadaver knees and to show the kinematic type of motion of the knee joint. Current imaging techniques cannot accomplish this because they do not perform combined quantitative, tomographic, and dynamic studies. Accordingly, this preliminary report presents the data from cine-CT scans of 12 normal intact adult cadaver knees. Scans were obtained at the rate of 14 or 17 per second at 50 or 100 ms exposures through midsagittal planes of the medial and lateral condyles and intercondylar notch. The cine-CT scans were displayed on a CRT and analyzed as closed-loop movies and as isolated images. Each cadaver femoral condyle demonstrated a different combined rolling and gliding motion. Preliminary results on the cadaver knee suggest the lateral femoral condyle moved 2.3 times further on the tibial plateau than its medial counterpart. The percentage of rolling for the lateral condyle was 43%-49%; the percentage of gliding was 51%-57%, with a ratio of rolling to gliding of 1:1.2. The percentage of rolling for the medial condyle was 16%-26%; the percentage of gliding 74%-84% with a ratio of rolling to gliding of 1:3.8. The femoral condyles, tibia, and cruciate ligaments acted as a crossed four-bar linkage in concordance with kinematic theory. The applicability of the cadaver knee results to patient dynamics and diagnosis cannot be determined from this study and awaits further investigations on the in vivo knee. However, ultrafast cine-CT demonstrated the complex knee motion in the cadaver knee joint.

Adult↗
PubMed1987

Endometrial carcinoma staging by MR imaging.

The potential of magnetic resonance (MR) imaging in the detection of endometrial carcinoma and in the assessment of its extent was evaluated prospectively in 51 patients clinically suspected of having the disease. MR imaging findings were compared with the results of surgical-pathologic staging and lymph node sampling following hysterectomy. Histologic findings showed 45 patients to have endometrial carcinoma, three to have no residual tumor after dilatation and curettage, and three to have adenomatous hyperplasia of the endometrium. MR imaging demonstrated an endometrial abnormality in 43 of the 51 patients (84%). Endometrial carcinoma could not be differentiated from adenomatous hyperplasia or blood clots. Therefore, MR imaging was not specific for tumor detection, and histologic diagnosis remains essential. The overall accuracy of MR imaging in staging endometrial carcinoma was 92%; its overall accuracy in demonstrating the depth of myometrial invasion was 82%. Demonstration of lymphadenopathy and adnexal or peritoneal metastases by MR imaging was suboptimal.

Adult↗
PubMed1983

Mycosis fungoides: manifestations on computed tomography.

Mycosis fungoides is a malignant lymphoma of the skin that causes intense erythema, plaques, edema, and induration. The primary computed tomographic findings of mycosis fungoides, i.e., skin thickening, tumorous infiltration, edema of the soft tissues, and lymphadenopathy, are presented in two patients.

Edema↗
PubMed1983

Transrectal sonographic voiding cystourethrography: studies in neuromuscular bladder dysfunction.

To evaluate the efficacy of transrectal real-time gray-scale sonographic voiding cystourethrography in patients with neuromuscular dysfunction of the bladder, 32 men suspected of having neuromuscular dysfunction each underwent sonographic and radiographic voiding cystourethrography and urodynamic studies. The benefits accruing from the sonographic study included: (1) patients received no radiation; (2) it was as diagnostic as, and sometimes more diagnostic than, the radiographic study; (3) drug effects were easily studied; (4) accurate measurements of urethral length could be obtained; and (5) prostate diseases that might affect these patients were visible, such as benign prostatic hyperplasia, prostatic carcinoma; and prostatic calculi. In addition, sonography made one new observation possible: The seminal vesicles were enlarged in 10 patients receiving the alpha-adrenergic blocker, phenoxybenzamine. This enlargement may cause sterility.

Humans↗
PubMedDate not supplied

Synovial sarcomas of the head and neck: CT and MR findings.

The authors present three cases of histologically proved synovial sarcoma. CT is useful in assessing erosive or destructive changes in bone, and in demonstrating calcifications. MR characteristics are nonspecific; calcifications within these tumors can be missed on MR. MR can help to assess tumor extension, vascular invasion, and hemorrhage within the tumor.

Adolescent↗
PubMedDate not supplied

Assessment of carotid artery stenosis by MR angiography: comparison with x-ray angiography and color-coded Doppler ultrasound.

PURPOSE: To compare magnetic resonance angiography (MRA) with duplex Doppler ultrasound (US) and x-ray angiography (XRA) in the evaluation of the carotid bifurcation. METHODS: The carotid arteries of 61 patients were studied using MRA, US, or XRA; 31 of the patients underwent all three examinations. MRA included both 2D and 3D time-of-flight sequences. Internal and external carotid artery origins were graded normal, mild, moderate, severe, or critical stenosis, or complete occlusion by each of the three studies. RESULTS: Spearman rank correlations of both internal and external carotid artery grades were 0.85 (MRA and XRA), 0.69 (MRA and US), and 0.73 (XRA and US). For internal carotid artery origins only, the correlations were 0.94 (MRA and XRA), 0.85 (MRA and US), and 0.82 (XRA and US). Of discrepancies in internal carotid artery interpretation greater than one grade, seven resulted from US error, three from MRA error, and one from XRA error. A 2-cm partially thrombosed aneurysm detected by US and MRA was missed by XRA. Of 16 possible ulcers on XRA, 11 were noted by MRA, none by US. CONCLUSIONS: MRA and XRA are similar in assessment of carotid bifurcation stenosis. MRA, like US, permits direct visualization of plaque. This preliminary study suggests that MRA may be used to clarify equivocal findings of US, or replace XRA in presurgical planning.

Aged↗