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Cancer causes inflammation as it progresses through healthy tissue. The differentiation of tumoral growth from the surrounding inflammatory change is paramount in planning surgeries seeking to preserve function. This retrospective study aims at illustrating how a careful use of imaging (computed tomography (CT)/magnetic resonance imaging (MRI)) can help to draw the line between infiltration and inflammation. Out of 72 cases of parosteal osteosarcoma in our institution we selected 22 which had pretreatment imaging, and out of those, 14 that had both MRI and CT. Using Fisher's exact test, we evaluated the performance of each technique on accurately diagnosing medullary tumor infiltration, using histological analysis as a gold standard. All cases (14/14) demonstrated medullary abnormality on MRI, but only 6/14 (42.9%) demonstrated abnormality on CT. The 8/14 cases with MRI abnormality but no CT abnormality (57.1%) showed inflammation with no tumoral cells present on histological analysis. In the cases where the two examinations showed medullary abnormality (6/14) histology demonstrated tumoral infiltration. MRI demonstrated high sensitivity and negative predictive value, but low specificity and low positive predictive value and accuracy (P=1). CT demonstrated high sensitivity, specificity, high positive and negative predictive values and accuracy (P = 0.000333). MRI is highly sensitive for the detection of medullary abnormality but lacks specificity for tumor invasion. Correlation with CT is recommended in all cases of positive MR to add specificity for tumors. The adequate use of the two imaging methods allows to differentiate between inflammatory change and tumoral infiltration in POS, relevant for surgical planning.

A 51-year-old man presented with elastofibroma (EF) of the gluteal region with a concomitant contralateral lesion. The patient presented with a slow growing mass of the proximal third of the right buttock and had swelling, discomfort in sitting, and right-hip pain during walking for 2 months. On MRI, a soft-tissue mass was noted between the gluteus maximus and the gluteus medius muscle. The mass showed similar signal intensity to the surrounding tissue on T1- and T2-weighted images and with linear hyperintense areas in its internal structure. At surgery, a soft, non-encapsulated, irregular, and rubber-like mass was found attached to the gluteus medius muscles. It was pathologically confirmed to be an EF. This unusual manifestation of an EF is discussed.

At present, there is no standardised approach for the radiological evaluation of soft tissue sarcomas following radiotherapy (RT). This manuscript, produced by a European Organisation for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group (EORTC-STBSG) and Imaging Group endorsed task force, aims to propose standardisation of magnetic resonance imaging techniques and interpretation after neoadjuvant RT for routine use and within clinical trials., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Lipofibromatosis is a rare, benign, but infiltrative, soft tissue tumor seen in children. We present three cases of lipofibromatosis, each with different magnetic resonance imaging features and correlate this with the histological findings. The patients comprised two males and one female who presented in infancy; at birth, 5 months, and 7 months of age. Clinically, the masses were painless and slow-growing. The masses ranged in size from 2 to 6 cm and involved the distal extremities in two cases (one foot, one wrist) and the trunk. Magnetic resonance imaging showed lipomatous lesions with varying amounts of adipose and solid components in each case. There were no capsules at the periphery of the lesions. One case showed a fat-predominant lesion, another an equal mixture of fat and solid tissue, and the third was predominantly solid. This was reflected in the histology, which showed corresponding features. Radiological and histopathological differential diagnoses are reviewed.

Introduction: Parosteal osteosarcomas and well-differentiated liposarcomas (WDLPS) of soft tissue share several features: they are slowly progressive, locally aggressive tumors, tend to recur locally, and rarely or never metastasizes if not dedifferentiated. Their treatment is wide surgical resection. Microscopically, both are well differentiated tumors, very like their normal tissue counterpart. They share simple karyotypes with supernumerary ring chromosomes or giant marker chromosomes containing amplified 12q sequences including MDM2 and CDK4 genes, with subsequent overexpression of MDM2 and CDK4 proteins. We present the case of a parosteal osteoliposarcoma made of closely intermingled components of a low-grade osteosarcoma and a WDLPS., Case: In a 34 year-old woman with a slowly growing mass of the arm, imaging revealed a large well-defined heterogeneous parosteal mass of the upper humerus, with two main components: bone at the base and fat at the periphery. Microscopically, these two components were consistent respectively with low grade osteosarcoma and WDLPS. Cells of the two components were labeled with anti-CDK4 antibody. No labeling with anti-MDM2 antibody and no signal detected with MDM2 FISH analysis were likely due overdecalcification. No frozen tumor tissue was available for FISH analysis nor array-CGH., Discussion: Differential diagnoses of this new entity would be a well-differentiated liposarcoma with a low-grade osteosarcomatous component that originates from the soft tissues, ruled out on imaging, and an ossifying parosteal lipoma, ruled out on immunohistochemistry., Conclusion: This is the first description of a low-grade parosteal sarcoma with two components that morphologically and immunophenotypically demonstrate characteristics of a parosteal osteosarcoma and of a well-differentiated liposarcoma., (Copyright © 2011. Published by Elsevier Ireland Ltd.)

Background: Patellar tumors are rare; only a few series have been described in the literature and radiographic diagnosis can be challenging. We reviewed all patellar tumors at one institution and reviewed the literature., Materials and Methods: In an evaluation of the database at one institution from 1916 to 2009, 23,000 bone tumors were found. Of these, 41 involved the patella. All had imaging studies and microscopic diagnostic confirmation. All medical records, imaging studies, and pathology were reviewed., Results: There were 15 females and 26 males, ranging from 8 to 68 years old (average 30). There were 30 benign tumors; eight giant cell tumors, eight chondroblastomas, seven osteoid osteomas, two aneurysmal bone cysts, two ganglions, one each of chondroma, exostosis, and hemangioma. There were 11 malignant tumors: five hemangioendotheliomas, three metastases, one lymphoma, one plasmacytoma, and one angiosarcoma., Conclusion: Patellar tumors are rare and usually benign. As the patella is an apophysis, the most frequent lesions are giant cell tumor in the adult and chondroblastoma in children. Osteoid osteomas were frequent in our series and easily diagnosed. Metastases are the most frequent malignant diagnoses in the literature; in our series malignant vascular tumors were more common. These lesions are often easily analyzed on radiographs. CT and MR define better the cortex, soft tissue extension, and fluid levels. This study presents the imaging patterns of the more common patellar tumors in order to help the radiologist when confronted with a lesion in this location., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Introduction: There is no clear radiologic or pathologic agreement on the differences between enchondroma and conventional chondrosarcoma, which has huge therapeutic consequences. Microscopically, an enchondroma is composed of "islands of intramedullary hyaline cartilage surrounded by marrow fat", and a chondrosarcoma a "diffuse cartilaginous replacement (invasion) of the marrow which leads to complete 'trapping' of host lamellar bone trabeculae." The marrow around islands of cartilage should be detectable on magnetic resonance imaging (MR). Enchondroma may be the precursor of chondrosarcoma; benign cartilaginous islands are often seen microscopically at the periphery of chondrosarcoma. We attempted to detect these islands at the periphery of chondrosarcomas on MR and correlate them microscopically., Materials and Methods: We examined our database for all patients with a chondrosarcoma of the long and flat bones between 1990 and 2007. Only those with a preoperative MR who underwent an en bloc resection were included, yielding 32 patients. We looked for low-signal islands surrounded by high (fat) signal on T1-weighted images, and high-signal islands surrounded by low signal on T2-weighted fat saturated images at the periphery of the main tumour mass. Microscopic correlation was performed in all cases., Results: On microscopy, there were 23 conventional chondrosarcomas, nine dedifferentiated. Peripheral islands surrounded by fat were detected on MR in 19 cases, corresponding to benign cartilage in 18 cases and to the benign scar of a needle biopsy tract in one. There were no peripheral islands detected radiographically or microscopically in 13 cases., Conclusion: Cartilaginous islands microscopically detected at the periphery of some chondrosarcomas are easily and reliably diagnosed on MR., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To identify radiological features of malignant vascular tumors of bone, which can be used to avoid erroneously diagnosing metastases based on radiological multifocality, and histological epitheloid phenotype., Materials and Methods: From the databases of the Bologna & Netherlands Committee on Bone Tumors, 63 patients with a histological diagnosis of malignant vascular tumor of bone were retrieved. Epidemiological and imaging characteristics were recorded on a case record form., Results: In 63 patients, 185 lesions were detected by radiographs (61 patients) and/or CT (30 patients) and/or MRI (19 patients). Multifocality was observed in 25 patients (40%), in these patients most lesions were located in the femur. Typically lesions were well-defined, osteolytic, had a geographically pattern of destruction and were also located in the femur. Most lesions showed cortical destruction (118 lesions). No periosteal reaction was seen in most cases (121 lesions). In 13 of 39 patients (33%) tumor extension was more advanced and/or (additional) lesions (29 lesions; 17%) were visible on MRI and CT. In 20 cases (51%) cortex destruction was better shown on CT or MRI. In six patients (15%) periosteal reaction was only seen on MRI or CT and not on radiographs. In 16 (41%) cases soft tissue extension was only seen on MRI or CT, and not on radiographs. Extensive reactive changes on T2-weighted images were seen in 11 patients (58%)., Conclusion: When single, or regional multifocal osteolytic, well-marginated lesions with cortical destruction are seen, in the femur, and with marked reactive soft tissue changes on MRI, a diagnosis of malignant vascular tumor should trigger the use of additional immunohistochemistry to confirm the vascular nature of the tumor. CLINICAL RELEVANCE STATEMENT: Because of epithelioid phenotype at histology, radiological signs are key in entertaining a diagnosis of malignant vascular tumor of bone which should trigger the use of appropriate immunohistochemical stainings., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Purpose: To retrospectively review magnetic resonance (MR) imaging features in a series of six infantile fibrosarcomas to find out if MR can suggest this unusual diagnosis and to highlight the value of MR during and following treatment., Materials and Methods: The records of six cases of histologically proven infantile fibrosarcoma were retrieved from the files of our cancer center. All imaging data available were consensually reviewed by two radiologists., Results: There were five females and one male (age range at diagnosis, 0-12 months; mean, 6 months). The most common finding was a well-circumscribed single mass in five patients (83%). All tumors had arisen on limbs; at their proximal or distal extremity or at the root of the limb. The masses were 9 cm large in mean diameter. The initial tumor signal was isointense to muscle on T1-weighted and hyperintense on T2-weighted sequences. All masses were well circumscribed and half of them contained internal fibrous septa. The internal signal was homogeneous in three patients and heterogeneous in the three others. An intense enhancement was seen in all three contrast-enhanced exams available; heterogeneous in two cases and homogeneous in one. Osseous erosion was observed in only one patient who was the only one with distant metastasis. After treatment (chemotherapy and very limited surgery), tumors had totally disappeared, leaving muscle fat infiltration in two patients and subcutaneous fat hypertrophy in one patient., Conclusion: Although imaging findings are not specific of infantile fibrosarcoma, this diagnosis could be suggested when MR imaging depicts a large well-circumscribed mass arising in a limb at birth or during the neonatal period. This mass is sometimes heterogeneous and septate and exhibits an isointense T1- and hyperintense T2-weighted signals and strong enhancement. MR is also the technique of choice for follow-up during treatment which consists nowadays almost exclusively in chemotherapy.

Introduction: The differential diagnosis between benign and low-grade well-differentiated malignant lipomatous tumors might be very difficult for both the radiologist and the pathologist, although it has practical consequences. Among the criteria, muscular fibers detected inside the lesion are considered radiologically and histologically as a reliable sign of a benign intramuscular lipoma. New genetic criteria are now available. We report two cases of fat tumors containing muscular fibers both radiologically and histologically, but which are definitely malignant, considering genetic criteria., Material and Methods: Two cases of soft tissue fat tumors, containing muscular fibers on imaging examinations as well as histologically, had an aggressive behaviour, suggesting malignancy. Genetic criteria were therefore used to confirm the clinical impression., Results: MDM2 and CDK4 confirmed the malignancy in the two cases., Conclusion: Intra lesional muscular fibers detected on imaging or histological examinations should not be considered as a completely reliable sign of a benign intramuscular lipoma. In case of atypical clinical behaviour, genetic criteria should be used to prove the aggressiveness of the tumor.

Magnetic resonance imaging (MRI) is the only imaging technique allowing the direct visualization of the bone marrow and is the most sensitive to detect bone metastases. Sensitivity is high, but a good understanding and an informed choice of acquisition sequences can easily improve specificity. Fat and water distribution (spin echo), indirect visualization of bone trabeculae (in-phase gradient echo), evaluation of bone edema and cell density (diffusion), and the study of vascularization (contrast medium) should be cleverly combined to enable good detection and lesion characterization.

Purpose: Aggressive fibromatosis is an invasive non-metastasizing soft-tissue tumor. Until recently, the standard treatment combined surgery and radiation therapy, but new studies reported that conservative strategies with or without medical treatment could be the best management. The aim of this study was to analyze and correlate the size and MR imaging signal features of aggressive fibromatosis with its behavior in order to choose the best treatment., Materials and Methods: Between March 1985 and December 2005, 27 patients with at least 2 consecutive MRI examinations and no surgery or radiation therapy in between were recorded. There were 9 men and 18 women, and median age was 31 years. They underwent 107 MRI examinations of 47 lesions, 29 of which were medically treated, while the remaining 18 did not receive any drug administration. The size and signal changes of each lesion were studied over time on T2- and/or T1-weighted sequences after injection of contrast medium. RECIST criteria were used for size: only a 30% decrease or a 20% increase in the size of the main dimension was considered significant. We classified the appearance of the signal into six categories in order of increasing intensity and then we established the related variations over time., Results: The size of 79% of the lesions in the treated group and 82% in the untreated group remained stable. The initial signal of stable lesions or those exhibiting an increase in size was most frequently high. There was a high rate of signal stability over time, whatever the initial signal and size changes. Changes in size were not correlated with the initial MR signal. A decrease in size associated with a decreased signal was observed in three cases exclusively in the treated group., Conclusion: Fibromatoses are a group of soft-tissue tumors with variable characteristics on MRI, but it is not possible to predict their behavior based on the MRI signal.

Purpose: To describe the imaging findings of germ cell tumours (GCT) containing non-germ cell malignant components (also designated teratoma with malignant transformation or TMT)., Patients and Methods: The records of 14 male patients with GCT and a non-germ cell histological component TMT were retrospectively reviewed. All patients had computed tomography (CT) and/or magnetic resonance (MR) studies before and after initial surgery and chemotherapy, as well as during follow-up. Imaging findings were correlated with the response to treatment and with overall survival. Pathological evaluation, immunohistochemistry, serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) were also taken into consideration. Sarcoma was identified in 10 out of 14 patients, with rhabdomyosarcoma ranking first (n=4), followed by osteosarcoma (n=2), fusiform cell sarcoma (n=1), undifferentiated sarcoma (n=1), neurosarcoma (n=1) and myxoid sarcoma (n=1). Other histological types of malignant transformation included adenocarcinoma (n=3) and bronchoalveolar carcinoma (n=1). Overall, 9 patients relapsed at a median time of 84 months (range 60-168)., Results: Non-GCT malignant transformation was identified in the retroperitoneum (5), testis (3), mediastinum (3), peritoneum (2) and lungs (1). The CT and MR imaging findings before treatment and after relapse were evaluated with emphasis on imaging features that could possibly imply the presence of malignant transformation (heterogeneously enhancing soft-tissue masses, ossified masses with calcified lymph nodes, diffuse epiploic thickening associated with ascites and peritoneal nodules, pulmonary alveolar infiltration with septal thickening). All but 1 patient with TMT presented with nodal and distant metastases. The prognosis was poor: within a median follow-up of 59 months (range 3-180), 4 out of 14 patients were alive., Conclusion: TMT is rare and associated with poorer survival compared to GCT. Imaging can be useful as CT and MR findings may suggest this entity and lead to an early biopsy and appropriate treatment.

The role of imaging in treatment evaluation and detection of recurrences of musculoskeletal primary tumours is discussed.

Magnetic resonance imaging (MRI) is the best technique for bone marrow imaging. The MRI signal of bone marrow depends on the quantity of fat it contains and on its cellularity. Evaluation of marrow of patients treated for cancer is complicated by age and osseous site related changes in the distribution of normal haematopoietic (red) and fatty (yellow) marrow and by the changes induced by treatments: decrease in pathological cellularity, increase in fat proportion, conversion of red marrow to fatty marrow or, conversely, reconversion of fatty marrow in normal haematopoietic red marrow. The treatments used in oncology modify pathological marrow but also normal marrow and may sometimes lead to complications. These modifications may be focal or diffuse, homogeneous or patchy and symmetrical or asymmetric. The knowledge of bone marrow physiological status and post-therapeutic patterns is important for the interpretation of marrow disorders and effects of therapy and to avoid false-positive diagnosis of marrow metastases and tumour progression. The aim of this paper is to recall the MRI patterns of normal bone marrow and normal variations and to show the effects of treatments on bone tissue and normal bone marrow and treatment-related modifications on pathological marrow., ((c) International Cancer Imaging Society.)

The purpose of our study was to explore and evaluate an innovative imaging approach, which consists on imaging the breast parenchyma by means of photoluminescence detectors (LED) and analysis of dynamic data. Breast magnetic resonance imaging (MRI) was chosen as the reference imaging method, as this is considered to be nowadays the gold standard for breast vascularisation evaluation. Preliminary results reveal a good correlation between breast MRI findings and light images.

Purpose: To prospectively evaluate the use of MRI with dynamic sequences during isolated limb perfusion (ILP) for soft tissue sarcomas, an aggressive local treatment using very high-dose chemotherapy and tumor necrosis factor aimed at avoiding limb amputation., Design and Patients: Twenty-six patients were referred for ILP over one and a half years; eight were excluded as the lesions were either too proximal or suspicious inflammatory changes without tumor were found on the initial MRI, or the vascular status was poor. The indications for ILP were: vessel nerve involvement (13), multiple lesions (8), tumor size (4) or the presence of pulmonary metastases (2). MRI was performed 1 and 2 months after ILP, immediately prior to surgery and histological analysis. The MR examinations included T1-weighted SE and fast SE T2-weighted fat-saturated sequences, as well as dynamic sequences (T1-weighted SE repeated six times every 40 s), displaying the maximum intensity slope in each pixel., Results: The tumor had disappeared in three patients. One patient still had histologically proven isolated widespread tumor cells without a mass. The tumor size had increased in two patients. In six patients, the size of the tumor had not changed but it had become completely necrotic, with a thin wall. In three patients, after an initially good result MRI demonstrated that the tumor wall had become thickened from 1 to 2 months after ILP. Dynamic MRI was mainly useful during the initial examination, demonstrating two patients with inflammatory changes without tumor. Three amputations and a second ILP were proposed based on poor results. Conservative limb-sparing surgery was successful in the other cases., Conclusion: MRI proved valuable in demonstrating the variable responses to ILP.

Purpose: To describe and correlate with radiation therapy the occurrence of cerebral radiation necrosis in patients irradiated for nasopharyngeal or ethmoidal tumor. Materials and Methods. From 1986 to 1998, 1 201 patients, 981 with nasopharyngeal tumors, and 220 with ethmoidal tumors were treated by radiotherapy. Twenty eight developed cerebral necrosis. MRI were performed in all patients and CT in 18 patients. Diagnosis was considered at imaging, and confirmed by follow-up., Results: The incidence of cerebral radionecrosis was 2.33%. The time interval between treatment and necrosis ranged from 2 months to 9 years. CT showed edema and/or focal enhancement in all cases except for 4 patients with normal CT examinations. MRI showed edema and/or abnormal focal punctate or gyriform enhancement in all patients. Lesions were localized in the temporal lobe (n=18), frontal lobe (n=9), pons (n=3) and optic nerve (n=2). The doses related to the areas of necrosis ranged from 13 to 135Gy. In 2 cases necrosis was situated at the boundaries of the radiation field. Imaging follow-up showed complete (n=3) or incomplete remission (n=1), lesion progression (n=11), cerebral atrophy (n=5) and stability (n=7)., Conclusion: MRI is useful to diagnose cerebral necrosis. New technologies may reduce the incidence of this complication.

Because dynamic (fast) contrast-enhanced magnetic resonance imaging with its temporal resolution allows evaluation of contrast kinetics of soft tissue sarcomas, its efficacy for defining viable tumor in these neoplasms was studied for three applications: biopsy localization, chemotherapeutic response, and differentiation between recurrence and inflammation after treatment. After conventional T1-weighted and T2-weighted magnetic resonance sequences to localize the lesion, patients had dynamic contrast-enhanced magnetic resonance imaging with fast and ultrafast sequences and postprocessing techniques (subtraction, time-intensity curves, and parametric color-encoding). In 10 of 40 patients, dynamic imaging more precisely defined the most malignant foci of tumor for biopsy than conventional magnetic resonance imaging. After chemotherapy, dynamic imaging distinguished 11 good responders from 21 poor responders. In followup of 196 patients, dynamic imaging detected 42 early enhancing recurrences and excluded recurrent tumor in six late enhancing pseudotumors. Dynamic imaging can differentiate viable tumor from nonviable tumor and inflammation by showing two temporally different phases of contrast enhancement: an early phase correlative with viable tumor at histologic examination, and a late phase when all tissues enhance simultaneously and may be indistinguishable. By showing tumor viability, dynamic contrast-enhanced magnetic resonance imaging can help define biopsy sites, chemotherapeutic response, and presence or absence of recurrences and therefore affect the initial evaluation, treatment, and followup of patients with soft tissue sarcomas.

Background and Purpose: Synovial sarcomas are soft-tissue tumors that rarely occur in the head and neck. The purpose of this study was to evaluate their CT and MR imaging appearance and to show that they may have a surprisingly benign imaging appearance., Methods: Eight patients with histologically proved synovial sarcoma underwent CT; additionally, MR imaging examinations were performed in five of the eight cases. Attenuation and signal intensity on CT scans and MR images, respectively, were studied by two radiologists. They analyzed the location, size, margins, homogeneity, presence of adenopathies and infiltrative signs, and enhancement after injection of contrast medium., Results: Four tumors were located in the hypopharynx, two arose from the infratemporal fossa, one arose from the maxillary sinus, and one arose from the faucial tonsil. Tumor sizes ranged from 27 to 70 mm. On CT scans and MR images, six lesions were homogeneous and well defined, with smooth margins. The remaining tumors were heterogeneous. In two cases, adjacent tissues were invaded. Calcifications were observed in one case and adenopathy in two cases. In three cases, the lesions were isointense on T1-weighted MR images and hypointense on T2-weighted MR images, and in the other two cases in which MR imaging was performed, the lesions were both isointense and hypointense on both T1- and T2-weighted images. Only the two local recurrent lesions were multilocular., Conclusion: Synovial sarcomas are aggressive sarcomas that may appear "benign" in some cases. In a young man, a synovial sarcoma may be suspected when a well-demarcated, homogeneous lesion is found in the head and neck.

Objective: To report the imaging findings of 24 periosteal chondrosarcomas diagnosed, staged, treated and followed in a single institution, to analyze and define their pattern, and discuss their practical consequences., Design and Patients: Plain films, 16 CT examinations and four MRI examinations were reviewed, and compared with the histological evaluation., Results: There were 20 men and four women, aged from 17 to 65 years. Twelve lesions involved the distal femoral metaphyses (8 posteriorly), five the proximal humerus, two the proximal metaphyses of the femur and two of the tibia, two the humeral shafts and one the iliac wing. Size varied from 4 to 11 cm. The cortex was always involved (thick, 15; thin, 13). Typical cartilaginous calcifications and cartilaginous lobules were very frequent. Radial thick periosteal bone formations (n = 6) indicated calcifications between the lobules of cartilage. Medullary involvement was rare (n = 2). All patients are alive and free of disease., Conclusions: Recognizing periosteal chondrosarcoma is of paramount importance because the prognosis is excellent after adequate local surgery alone. The patterns of other surface tumors of bone are usually different.

Objective: To evaluate MR imaging and pathology findings in order to define the characteristic features of clear cell sarcoma of the soft tissues (malignant melanoma of the soft parts)., Design and Patients: MR examinations of 21 patients with histologically proven clear cell sarcoma of the musculoskeletal system were retrospectively reviewed and assessed for shape, homogeneity, delineation, signal intensities on T1- and T2-weighted images, contrast enhancement, relationship with adjacent fascia or tendon, secondary bone involvement, and intratumoral necrosis. In 19 cases the pathology findings were available for review and for a comparative MR-pathology study., Results: On T1-weighted images, lesions were isointense (n=3), hypointense (n=7) or slightly hyperintense to muscle (n=11). Immunohistochemical examination was performed in 17 patients. All 17 specimens showed positivity for HMB-45 antibody. In nine of 11 lesions with slightly increased signal intensity on T1-weighted images, a correlative MR imaging-pathology study was possible. All nine were positive to HMB-45 antibody., Conclusions: Clear cell sarcoma of the musculoskeletal system often has a benign-looking appearance on MR images. In up to 52% of patients, this lesion with melanocytic differentiation has slightly increased signal intensity on T1-weighted images compared with muscle. As the presence of this relative higher signal intensity on T1-weighted images is rather specific for tumors displaying melanocytic differentiation, radiologists should familiarize themselves with this rare entity and include it in their differential diagnosis when confronted with a well-defined, homogeneous, strongly enhancing mass with slightly higher signal intensity compared with muscle on native T1-weighted images.

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.

Four factors can be used in MR of bone marrow: fat-water distribution, artifacts induced by bone trabeculae, diffusion, and uptake of contrast media. Fat-water is imaged using T1-weighted spin-echo, short tau inversion recovery (STIR), and fast STIR, in- and out-of-phase gradient echo, and fat pre-saturation sequences; bone trabeculae by gradient echo with long TE; diffusion by single-shot spin-echo. The injection of contrast media is a more easy and efficient way to improve the specificity. The value and limitations of those sequences are discussed in marrow replacements (metastases, lymphoma, leukemia) and in myeloid hyperplasia or depletion.

Purpose: To evaluate magnetic resonance (MR) imaging results after administration of gadolinium texaphyrin, a tumor-selective radiation sensitizer that is detectable at MR imaging, and to determine an appropriate intravenous dose of gadolinium texaphyrin for repeated injections during radiation therapy, the dose-limiting toxicity of reiterated doses of gadolinium texaphyrin, the maximal tolerated dose, the biolocalization of gadolinium texaphyrin (as assessed at MR examinations), and the response to treatment., Materials and Methods: Ten daily intravenous injections of gadolinium texaphyrin, each followed by whole-brain radiation therapy (total of 10 fractions, 30 Gy), were administered to patients with brain metastases in a multicenter study. At the study institution, 11 patients underwent MR imaging before and after the first injection, after the 10th injection, and 8 weeks after entry into the study., Results: MR imaging revealed selective drug uptake in metastases, without enhancement of normal brain tissue. In 10 patients, tumor uptake was higher after the 10th injection than after the first injection, which indicated accumulation of gadolinium texaphyrin in metastases. One lesion was visible only after the 10th injection and not at the pretherapeutic MR examination with injection of conventional gadolinium-based contrast material. Response to treatment was defined as a reduction in the size of the metastases between the preinjection MR study and the last MR study; seven patients achieved partial remission with tumor regression exceeding 50% of the initial size, and four achieved a minor response with less than 50% tumor regression., Conclusion: These preliminary results indicate that gadolinium texaphyrin is tumor selective and that brain metastases can be depicted at MR imaging long after the administration of gadolinium texaphyrin.

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.

Purpose: To evaluate the clinical and biologic safety of ultrasmall superparamagnetic iron oxide particles (AMI-227) as a contrast agent for magnetic resonance (MR) lymphography and to assess their efficacy for the differentiation of metastatic and benign nodes in patients with urologic and pelvic cancer., Materials and Methods: Thirty adults suspected of having lymph node metastases underwent MR imaging before and 22-26 hours after intravenous infusion of AMI-227 (1.7 mg Fe/kg). Sixty histopathologically proved lymph nodes were analyzed on MR images, and 29 of these nodes were also analyzed quantitatively., Results: AMI-227 was well tolerated with no major side effects. It allowed the detection of 10 additional nodes relative to those detected at MR imaging without AMI-227. None of the 27 metastatic nodes showed a decrease in signal intensity (SI) on AMI-227-enhanced images; nine of 27 metastatic nodes showed an increase in SI on T1-weighted images, probably resulting from altered capillary permeability in the tumor. A visually perceptible reduction in SI, indicating active AMI-227 uptake, was observed on postcontrast T2- and T2*-weighted images in 16 of 21 benign nodes. The SI ratio of benign nodes was lower than that of metastatic nodes on T2- and T2*-weighted images. The sensitivity of AMI-227-enhanced MR lymphography was 100%, and the specificity was 80%., Conclusion: AMI-227 is safe and may facilitate the differentiation of metastatic and benign nodes in patients with urologic and pelvic cancers.

Cardiac leiomyosarcoma is a rare tumour which can grow either intramurally or extramurally. Its prognosis is dismal. Surgery lengthens survival, but recurrences usually occur in the short term. Gated MRI is useful for the assessment of cardiac masses since it provides fine spatial and contrast resolution. We present the case of a left atrial leiomyosarcoma whose recurrence was diagnosed by gated MRI. Our patient underwent a second resection but died soon after.

Some knowledge of MR theory is required to be able to achieve high contrast between bone metastases and normal marrow. Three factors are used in MR to diagnose bone metastases; fat-water distribution, artifacts induced by bone trabeculae, and uptake of contrast medium. Using MR-histological correlations based on specimens of the lumbar spine, and studies of patients, we explain the advantages and limitations of sequences studying fat and water (spin-echo T1, STIR, in- and out-of-phase gradient echo, fat presaturation), bone trabeculae (gradient echo with long TE), and the injection of contrast medium.

Purpose: To compare dynamic contrast material-enhanced subtraction and T2-weighted spin-echo (SE) magnetic resonance (MR) imaging in the differentiation of fibrosis from tumor recurrence during the follow-up of treated gynecologic pelvic malignancy., Materials and Methods: Thirty-four patients (aged 24-82 years) with 18 benign and 35 malignant lesions confirmed by means of surgery (n = 18), biopsy (n = 25), or 18-month follow-up examination (n = 10) underwent dynamic contrast-enhanced subtraction and T2-weighted SE MR imaging. Contrast material enhancement of an abnormal pelvic structure within the first 90 seconds on dynamic contrast-enhanced subtraction images or high signal intensity on T2-weighted SE images was considered indicative of malignancy., Results: The sensitivity, specificity, accuracy, and positive and negative predictive values were 91%, 67%, 83%, 86%, and 86%, respectively, for dynamic contrast-enhanced subtraction imaging and 91%, 22%, 68%, 70%, and 57%, respectively, for T2-weighted SE imaging. More lesions were correctly classified with dynamic contrast-enhanced subtraction imaging than with T2-weighted SE imaging (P < .01)., Conclusion: Dynamic contrast-enhanced subtraction imaging is more accurate than T2-weighted SE imaging for differentiating fibrosis from tumor recurrence during the follow-up of treated gynecologic pelvic malignancy. However, use of both sequences is recommended.

Growth factors associated with chemotherapy may induce red marrow reconversion. This may simulate a tumor increase on MRI. We report such a case.

Aim: To determine the accuracy of dynamic contrast-enhanced subfraction MRI to diagnose nonpalpable breast lesions in a prospective multicenter study., Material and Methods: From June to November 1994, 72 patients had a surgical biopsy for a nonpalpable breast lesion and a preoperative dynamic MR after an informed consent was obtained. MR examinations were performed on 0.5, 1 and 1.5T MR unit. Each center underwent dynamic sequences either in spin or gradient echo in T1 weighted images obtained in less than two minutes before and after injection of Gadolinium-DOTA. The presence/absence of contrast enhancement within two minutes after injection of Gadolinium were considered as positive/negative findings respectively., Results: These 72 women had mammographic (n = 80) or ultrasonographic lesions (n = 2). Mammograms showed mass (n = 23), asymmetrical density (n = 2), architectural distorsion (n = 8), clustered microcalcifications (n = 47) or was normal (n = 2). Dynamic Breast MR imaging showed early contrast enhancement in 44 malignant lesions (sensitivity: 89.8%) and 13 benign lesions (specificity: 60.6%). Five intraductal carcinoma of comedo (n = 1) or non-comedo (n = 4) type did not demonstrate any early contrast enhancement., Conclusion: This prospective mulcentric study confirms the high sensitivity of dynamic breast MRI whatever the type of MR unit or sequences.

Teratomas of the nasopharynx occur usually in neonates. We present a case of teratoma which was discovered in an adult, and which relapsed after 34 years. The conventional radiograms, CT, MR, and histologic appearances are described.

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.

Intracavitary brachytherapy is an effective treatment for gynecologic cancers. Twelve magnetic resonance (MR) imaging studies were performed during intracavitary brachytherapy (10 initial studies and two during repeat brachytherapy) in 10 patients with clear cell adenocarcinoma (n = 9) or epithelioma (n = 1). Fifty percent of the vaginal lesions did not demonstrate high signal intensity on T2-weighted images. Individually tailored molded applicators allowed easy detection of abnormal vaginal parietal thickening on T1-weighted images: Results in seven cases were concordant with results of clinical examination, and there were no false-negative results. MR imaging was useful in controlling the relationships between the tumor and the applicator and facilitated treatment planning, since the radiation dose to the tumor volume and adjacent critical organs could be calculated accurately. Limitations of MR imaging were underestimation of superficial vaginal tumors and the inability to differentiate between tumor and inflammation after recent surgery or repeat intracavitary brachytherapy. MR imaging during intracavitary brachytherapy appears to be a useful adjunct to clinical examination.

Purpose: To compare dynamic contrast-enhanced subtraction (DCES) and T2-weighted spin-echo (SE) magnetic resonance (MR) imaging in the differentiation of fibrosis from recurrence during the follow-up of treated colorectal neoplasms., Materials and Methods: Forty-one patients with 39 malignant and 16 benign lesions confirmed by means of surgery (n = 23), biopsy (n = 24), or 12-month follow-up examination (n = 8) underwent DCES MR imaging and T2-weighted SE MR imaging. Enhancement of an abnormal pelvic structure within the first 90 seconds on DCES images or high signal intensity on T2-weighted SE images was considered indicative of malignancy., Results: Sensitivity, specificity, and positive and negative predictive values were, respectively, 97%, 81%, 93%, and 100% for DCES MR imaging and 77%, 56%, 81%, and 56% for T2-weighted MR imaging. The number of correctly classified lesions was significantly higher with DCES imaging compared with T2-weighted imaging (P < or = .006)., Conclusion: DCES imaging is more accurate than T2-weighted SE imaging for differentiating fibrosis from recurrence during the follow-up of treated colorectal neoplasms.

Because contemporary treatment of oral cavity cancer involves procedures that spare the tongue and mandible, an adequate assessment of the oral cavity is essential for appropriate surgical and radiation therapy planning. Computed tomography (CT) and magnetic resonance (MR) imaging, which allow differentiation between soft tissues, are valuable tools for assessing this complex region. Their main advantage resides in their capacity to show at best the normal anatomy and the exact extent of a low-lying tumor. For display of soft tissues and tumor, MR imaging, being a multiplanar and multicontrast technique, is superior to CT. Nonenhanced T1-weighted MR imaging is better for defining the exact extent of medullary bone invasion, which appears as a low-signal-intensity area within hyperintense medullary fat. CT is optimal in detection of cortical bone invasion, which appears as an interruption or erosion of the peripheral hyperattenuating rim. Thus, in cancer of the tongue, MR imaging should be performed first. If tumor extension to the mandible is suspected (due to clinical or MR imaging findings), CT should be added. In cancer of the floor of the mouth, both MR imaging and CT should be performed in the initial work-up, especially in those cases in which there is a clinical doubt about mandibular extension of disease. The main drawback of both modalities is their lack of specificity; other methods are needed to discriminate between tumors and inflammatory or infectious diseases, particularly in the mandible. However, once the diagnosis has been confirmed histologically, treatment can be chosen based on complementary information obtained from CT and MR imaging.

Objective: Our goal was to evaluate dynamic contrast-enhanced subtraction MRI in the diagnosis of isolated clustered calcifications of the breast., Materials and Methods: One hundred seventy-two patients underwent surgical biopsy for isolated clustered breast calcifications. Their mammograms showed round (n = 88) or linear/irregular (n = 84) microcalcifications. All patients had a preoperative Gd-DOTA-enhanced subtraction dynamic study. Any early contrast enhancement in the breast parenchyma concomitant with early enhancement of normal vessels was considered positive., Results: Fifty-eight in situ carcinomas, 22 invasive carcinomas, and 92 benign lesions were found at histological analysis. Dynamic MR sequences showed early contrast enhancement in 76 of 80 malignant lesions (sensitivity 95%) and in 45 of 92 benign lesions (specificity 51%). Two invasive and two intraductal carcinomas did not show early contrast enhancement. Three independent observers agreed in rating early contrast enhancement in 143 of 172 lesions., Conclusion: Poor specificity limits the diagnostic accuracy of dynamic contrast-enhanced subtraction MRI in distinguishing benign from malignant microcalcifications on mammography.

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.

The aim of this study is to determine the diagnostic value of magnetic resonance imaging in the diagnosis of local recurrence of breast cancer. From 1991 to 1994, 61 women were studied prospectively using magnetic resonance imaging. All examinations were made on a 1.5 Testa machine with T1 weighted images and after gadolium-dota injection and dynamic images (T1 weighted sequences every 47 seconds during injection of a gadolinium-dota bolus). All the pre-injection, images in the dynamic series were subtracted from the images after injection. A surgical biopsy was obtained in 39 patients yielding a diagnosis of local recurrence (n = 28) or a benign lesion (n = 11). Among the 28 local recurrences, pathology examination reported invasive cancer in 22 and intra-ductal carcinoma in 6. In 22 patients with normal magnetic resonance imaging, follow-up examinations were performed every 6 months. There were no local recurrences within a delay of 6 to 36 months. Twenty-six of the 28 patients with a local recurrence, cystosteatonecrosis and surgery scar tissue less than 6 months old showed contrast uptake 1 min and 34 s after gadolinium injection during the dynamic sequence. This product uptake yielded nodular images within the invasive carcinomas and linear images in the intraductal cancers. In all cases, it is easier to visualize this contrast uptake in subtraction images. In conclusion, magnetic resonance imaging is a simple reliable method for the diagnosis of local recurrence of breast cancer.

Purpose: To evaluate factor analysis of medical image sequences (FAMIS), a means whereby physiologic contrast enhancement kinetics, called factors, and their spatial distribution, termed factor images, are estimated after acquisition of dynamic MR images. The method is intended to recognize and characterize the different tissue kinetics automatically., Methods: This method was evaluated in a series of 22 patients with head and neck tumors. Eleven patients presented with a previously untreated lesion. Six were examined for tumor recurrence, previously treated by multiple therapies. Five patients had preoperative chemotherapy and underwent MR before and after chemotherapy. In all cases, MR images were correlated with surgical and pathologic data. MR examinations were performed on a 1.5-T unit with static sequences and dynamic sequences acquired after bolus injection of gadolinium and processed by FAMIS., Results: FAMIS was able to identify three factors representing contrast-enhancement kinetics and their associated factor images. The neoplastic component was associated with the earlier factor image, F1. Fibrosis and chemotherapy and/or radiation-induced changes were associated with the two later factors, F2 and F3. The limits of this method were highly vascularized tissues whose earlier factor was similar to that of neoplastic tissues (mucosae and salivary glands), patient motion, responsible for artifacts in FAMIS, and lesions of less than 5 mm., Conclusion: FAMIS of dynamic MR studies was useful for differentiating neoplastic tissue from tissue having undergone changes by chemotherapy and/or radiotherapy, but it did not improve the ability of MR to characterize neoplastic tissues in previously untreated patients.

Purpose: To determine the accuracy of contrast material-enhanced subtraction dynamic magnetic resonance (MR) imaging in the diagnosis of nonpalpable breast tumors., Materials and Methods: One hundred forty-three patients underwent surgical biopsy of a nonpalpable breast lesion. Their mammograms showed microcalcifications (n = 80), opacity (n = 52), architectural distortion (n = 10), or asymmetric density (n = 1). All patients underwent a preoperative gadolinium tetraazacyclododecanetetraacetic acid-enhanced subtraction dynamic study. Any early contrast enhancement in the breast parenchyma was considered pathologic., Results: At histologic analysis, 27 intraductal carcinomas, 37 invasive carcinomas, and 79 benign lesions were found. Dynamic MR studies showed early contrast enhancement in 61 of 64 breast cancers (sensitivity, 95%) and in 37 of 79 benign lesions (specificity, 53%). Two invasive lobular carcinomas and one tubular carcinoma showed no early contrast enhancement., Conclusion: Subtraction dynamic MR imaging may be helpful to rule out malignancy in nonpalpable breast tumors.

Purpose: To determine the value of contrast material-enhanced subtraction magnetic resonance (MR) imaging in assessment of response to chemotherapy in locally advanced breast cancer., Materials and Methods: Eighteen women treated with chemotherapy because of locally advanced breast cancer underwent preoperative MR examination including both routine and dynamic MR sequences after injection of gadolinium tetraazacyclododecanetetraacetic acid. Any early contrast enhancement, concomitant with early vascular enhancement during the dynamic MR study, was considered pathologic., Results: Dynamic MR studies showed early contrast enhancement in all women with residual tumor except one with nodular residual tumor. Histopathologic analysis and dynamic MR images of contrast-enhanced lesions correlated well, but in one patient, intraductal extension was not seen on MR images, and in another, additional isolated tumor cells were seen in the histologic specimen. Subtraction images always facilitated visualization of vascular and pathologic contrast enhancement., Conclusion: Dynamic MR contrast-enhanced subtraction studies are useful in assessment of residual tumor after chemotherapy.

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.