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Biomedical subjects

L G Shapeero

Publications and source records attributed to L G Shapeero.

At least 19 recordsLinked to original sources
PubMed2000

Imaging evaluation of the response of high-grade osteosarcoma and Ewing sarcoma to chemotherapy with emphasis on dynamic contrast-enhanced magnetic resonance imaging.

Response of high-grade osteosarcoma and Ewing sarcoma to preoperative chemotherapy can significantly affect the surgical approach to patients with these tumors and their disease-free survival. This article presents the findings and limitations of different imaging modalities (radiography, angiography, sonography, scintigraphy, and magnetic resonance [MR] imaging and spectroscopy) for evaluating this chemotherapeutic response. Particular emphasis is given to the currently most effective modality--dynamic contrast-enhanced MR imaging.

Antineoplastic Agents↗
PubMed1998

Dynamic contrast-enhanced MRI with subtraction of aggressive soft tissue tumors after resection.

OBJECTIVE: To report the application of dynamic contrast-enhanced subtraction MRI for detecting recurrences in aggressive or malignant soft tissue tumors. DESIGN: The imaging studies consisted of static (T1- and T2-weighted spin-echo) acquisitions, followed by dynamic conventional spin-echo short TR/TE images (at 45 s, 1 min 30 s and 5 min) after a bolus of intravenous contrast medium. Contrast images were subtracted from the precontrast scan on the console. PATIENTS: Ninety-eight patients were studied who had had aggressive or malignant soft tissue tumors treated by surgery, and were followed up to assess recurrences. RESULTS: Subtraction MRI characterized recurrences better than routine sequences in 10 patients (1 lesion was seen only with this technique, 6 were better delineated, and 3 inflammatory pseudotumors were identified), and less well in 4 cases. CONCLUSION: As the number of levels studied on dynamic images is limited, and all but one recurrence were detected on T2-weighted images, it remains logical to start the examination with T2-weighted spin-echo images, and to use the dynamic study only if contrast injection is required.

Adult↗
PubMed1997

Primary tumors of the musculoskeletal system.

The excellent soft-tissue contrast and multiplanar imaging capabilities of MR imaging have led to its emergence as the most significant advance in the imaging of musculoskeletal tumors. MR imaging is the modality of choice for local staging, evaluating response to preoperative chemotherapy, and long-term follow-up in bone tumors. MR imaging is the most effective modality for both primary staging of soft-tissue malignancy and detecting recurrences. This article reviews the role of conventional spin echo techniques versus newer techniques, and then discusses the indications in the diagnosis, staging, evaluation of preoperative chemotherapy, and detection of recurrences in bone and soft-tissue tumors.

Bone Neoplasms↗
PubMed1995

Can clinical data help to screen patients with lymphoma for MR imaging of bone marrow?

BACKGROUND: Previous studies have suggested combining magnetic resonance (MR) imaging and biopsy in patients with lymphoma but association between MR results and clinical symptoms have never been investigated. The purpose of this retrospective study was to better delineate patients profiles requiring bone marrow (BM) imaging in lymphoma. MATERIAL AND METHODS: 50 MR studies and blind biopsies (BB) were reviewed in 40 patients with lymphoma. MR results were compared to clinical, laboratory-based and BM follow-up data to determine potential associations between MR results and these parameters. RESULTS: 46% of MR studies were abnormal with a normal BB; 2% were normal with an abnormal BB. Abnormal MR results were significantly associated with subsequent bone marrow involvement (p < 0.01). Abnormal MR studies were significantly associated with constitutional symptoms, bone pains (p < 0.05) and an elevated alkaline phosphatase level (p < 0.01). MR imaging excluded malignancy in three patients and caused therapy to be modified in three. CONCLUSION: Abnormal clinical and laboratory-based data should be used to screen patients with normal BB for MR imaging, especially in patients with Hodgkin's disease and high grade non-Hodgkin's lymphoma.

Adolescent↗
PubMed1994

MR imaging in the follow-up of malignant and aggressive soft-tissue tumors: results of 511 examinations.

PURPOSE: To present magnetic resonance (MR) imaging findings from 511 follow-up examinations of aggressive soft-tissue tumors. MATERIALS AND METHODS: One hundred eighty-two patients with aggressive soft-tissue tumours underwent postoperative T1- and T2-weighted imaging; 41 also underwent 51 gadolinium-enhanced T1-weighted examinations, and five underwent dynamic gadolinium-enhanced subtraction imaging. RESULTS: Twenty-four of 25 patients (101 of 102 examinations) without high signal intensity (HSI) at T2-weighted imaging had no recurrence. Among 79 patients (321 examinations) who demonstrated HSI without a mass, only two tumors recurred within 1 year. An HSI mass was found in 88 studies of 78 patients and represented recurrence (n = 60), hygroma (n = 24), or a radiation-induced pseudomass (n = 4). Hygromas did not enhance, while recurrences enhanced at 1-3 minutes and postirradiation change enhanced at 4-7 minutes. CONCLUSION: T2-weighted imaging can be used to identify possible recurrence of aggressive soft-tissue tumors, while gadolinium-enhanced imaging can be used to differentiate recurrences from hygromas and inflammatory change.

Adolescent↗
PubMed1994

Periosteal Ewing sarcoma.

PURPOSE: To evaluate the imaging and histopathologic findings and clinical course of patients with periosteal Ewing sarcoma (PES). MATERIALS AND METHODS: Conventional radiographs, computed tomographic (CT) scans, and magnetic resonance (MR) images in 10 adolescents and one adult were evaluated for the extent and character of PES. RESULTS: Ten of 11 masses were in the proximal extremities and one in the fibula; nine were diaphyseal and two, metadiaphyseal. Radiographs and CT scans showed a subperiosteal mass that did not invade the medullary cavity, was contiguous with and elevated the periosteum, and produced a Codman triangle and periosteal reaction. No PES exhibited osseous or cartilaginous matrix calcifications. MR imaging and histopathologic examination helped confirm the sparing of cancellous bone and the subperiosteal location. CONCLUSION: PES differs from the more common medullary and soft-tissue Ewing sarcomas in location, marked male predominance, and lack of presenting metastases. Except for the absence of matrix calcifications, PES resembles other periosteal sarcomas in imaging characteristics and a less aggressive clinical course.

Adolescent↗
PubMed1993

Aggressive fibrous dysplasia of the maxillary sinus.

Fibrous dysplasia is usually a slowly progressive, benign disease that develops over several years and presents with deformity or mild symptomatology. Five of 34 patients (ages 4-21 years), who were subsequently diagnosed histologically as having fibrous dysplasia of the maxillary sinus, rapidly developed soft tissue masses of the malar region over a period of less than 4 months with accompanying pain (2 patients) and nasal obstruction and exophthalmos (2 patients). Each was clinically suspected of having a sarcoma; two had been thought to have an "osteofibrosarcoma" on initial biopsy at outside hospitals. After resection, all lesions developed regrowth. At histopathologic examination, both initial and recurrent masses proved to be typical fibrous dysplasia with spicules of woven bone in cellular, sometimes vascular, fibrous tissue. No malignant degeneration was found. On conventional radiography, aggressive fibrous dysplasia produced opacification and expansion of the maxillary sinus and apparent disruption of its wall with an associated soft tissue mass. Computed tomography (CT) demonstrated voluminous heterogeneous masses with "ground glass appearance", calcifications, areas of enhancement, low attenuation, cystic areas, and a thinned, sometimes interrupted, maxillary wall. Despite the aggressive clinical course for both initial and recurrent lesions, the CT findings of a "ground glass" mass with calcifications surrounded by a maxillary sinus wall, even if incomplete, can suggest the diagnosis of aggressive fibrous dysplasia.

Adolescent↗
PubMed1993

Bone metastases as the presenting manifestation of rhabdomyosarcoma in childhood.

Rarely, rhabdomyosarcoma can present with bone pain and bone lesions on radiographs without evidence of a primary tumor. Of 428 children with biopsy-proven rhabdomyosarcoma, four presented with radiographic evidence of bone metastases, but no primary tumor was found on subsequent evaluation. On radiographs, these metastases, located most commonly in the metaphyses of the extremities and in the spine, displayed a destructive or diffusely permeative pattern without sclerotic margins and mimicked the more common neuroblastoma. One patient also had diaphyseal cortical lytic metastases of the tibia. Radiographs defined metastases of the extremities better than the correlative bone scans. In the spine, on T2-weighted magnetic resonance (MR) images, metastases displayed high signal intensity which contrasted with the low-signal-intensity marrow in these pediatric patients. On histopathologic examination, metastatic rhabdomyosarcoma was composed of small cells of variable size, shape, and growth pattern similar to other round cell tumors. A positive desmin immunohistochemical test helped to establish the diagnosis. The radiologist, pathologist, and clinician should be aware of this unusual presentation of rhabdomyosarcoma so that suitable immunohistochemical tests are performed and appropriate chemotherapy given.

Adolescent↗
PubMed1993

Epidermoid cysts of testes and role of sonography.

Four patients with histologically proved epidermoid cysts of the testicle were managed with radical orchiectomy. High-resolution testicular sonography demonstrated similar findings in all cases, but these findings were not specific and did not preclude other malignant or teratomatous lesions. The lack of both unique clinical features and specific sonographic findings would suggest that extreme caution must be used if wedge resection or enucleation is contemplated for a patient with presumed epidermoid cyst.

Adolescent↗
PubMed1993

Extraskeletal mesenchymal chondrosarcoma.

Among seven patients with extraskeletal mesenchymal chondrosarcoma (EMC), three children (aged 3-6 years) developed EMC in a central location and four adults (aged 38-54 years) developed EMC in both central and peripheral sites. Conventional radiography and tomography and computed tomography (CT) depicted EMC as a soft-tissue mass with ring, arc, stippled, and highly opaque calcifications in four patients. Contrast-enhanced CT showed lobulation and peripheral tumoral enhancement, sometimes with central low-attenuation areas. On magnetic resonance (MR) images, EMC was a lobulated mass with high signal intensity on T2-weighted images and enhancement with low-signal-intensity focal areas on contrast-enhanced T1-weighted images. All adults developed recurrences and/or metastases and died. Of the three children, two were living and free of disease at the end of the study and the third child died of chemotherapeutic-induced leukemia. Although imaging features of EMC are nonspecific, its chondroid-type calcifications and foci of low signal intensity within enhancing lobules may reflect its dual histopathologic morphologic characteristics of differentiated cartilage islands interspersed within vascular undifferentiated mesenchyme.

Adult↗
PubMed1993

Assessment of breast cancer recurrence with contrast-enhanced subtraction MR imaging: preliminary results in 26 patients.

Local relapse was suspected in 26 women treated conservatively for breast cancer. All women underwent routine magnetic resonance (MR) imaging and a dynamic MR subtraction study after injection of gadolinium-tetraazacyclododecanetetra-acetic acid. Twelve women had no local relapse. Surgical biopsy enabled confirmation of recurrence in 14 patients. Routine MR imaging did not allow differentiation of recurrence from glandular or scar tissue. Except for one case of fat necrosis, patients without local relapse showed no contrast enhancement 1 minute 34 seconds after injection. At dynamic MR imaging, all recurrences showed contrast enhancement 1 minute 34 seconds after injection. Nodular enhancement (n = 11) was found in invasive carcinoma, whereas linear enhancement was seen in intraductal carcinoma (n = 3). Subtraction of precontrast from postcontrast images always allowed better visualization of contrast enhancement. Contrast-enhanced subtraction dynamic MR imaging may prove to be accurate in diagnosis of local relapses of breast cancer.

Adult↗
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↗