Multiple biliary hamartomas (von Meyenburg complex). A case report.
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Bile Duct Neoplasms↗
Biomedical subjects
N Montanari
Publications and source records attributed to N Montanari.
Dynamic contrast enhanced magnetic resonance imaging subtraction in evaluating osteosarcoma response to chemotherapy.
PURPOSE: To evaluate the results of a new technique of dynamic contrast enhanced Magnetic Resonance (MR) imaging subtraction in the assessment of osteosarcoma response to chemotherapy. METHODS: 24 patients with high grade osteosarcoma, treated with preoperative neo-adjuvant chemotherapy, underwent MR at high field strength (1.5 T). Both unenhanced conventional SE T1- and T2-weighted sequences in the coronal and axial plane and dynamic Gd-DTPA-enhanced SE T1-weighted sequences in the coronal plane were performed. Image postprocessing included subtraction of unenhanced image from enhanced images (arbitrary called "angiographic subtraction") and subtraction of each enhanced image from the last-enhanced image (arbitrary called "pathologic area" subtraction). The early enhancing areas detected in the angiographic subtraction and the pathologic areas detected in the pathologic area subtraction were correlated with histopathological findings on histological macrosections obtained from the resected specimen. The sensitivity, specificity, accuracy, positive and negative predictive value of both the subtraction techniques were calculated. RESULTS: The early enhancing areas of angiographic subtraction were related not only to viable tumor but also to the host reactions such as flogosis and granulation tissue. The pathologic areas detected at the pathologic area subtraction correlated in most cases with viable tumor, while in 3 cases they did not correspond to viable tumor tissue and in 1 case a small area of residual viable tumor was missed. In assessing response to chemotherapy, pathologic areas subtraction had an accuracy of 95% (specificity: 100%, sensitivity: 93%, PPV: 100%, NPV: 88%), whereas angiographic subtraction had an accuracy of 79% (specificity: 37%, sensitivity: 100%, PPV: 76%, NPV: 100%). CONCLUSIONS: Pathologic area subtraction may be a useful technique for assessing the response of osteosarcoma to chemotherapy and for detecting residual viable tumor tissue.
Adolescent↗
Malignant tumors of the osteogenic matrix.
This article focuses on major clinical and imaging features that are of practical interest in the diagnosis and management of osteosarcoma, a malignant tumor arising from the osteogenic matrix. The current histologic classification of this tumor is also reported. Different types of osteosarcoma are described, each of them with a definite clinical and radiographic pattern. Conventional radiography is the keystone to diagnosis because it allows analysis of the patterns relevant to the different lesions (location, site, bone destruction, periostal reaction, soft tissue masses). The most common type of osteosarcoma is defined classic or conventional high grade (75%) and it typically involves the medullary cavity. Radiographically, it may be predominantly osteosclerotic or osteolytic, but more frequently it has a mixed (osteoslerotic/osteolytic) pattern. The teleangiectatic osteosarcoma is an aggressive form (5%) characterized by marked vascularization with large blood-filled cystic cavities; its typical radiographic pattern is purely osteolytic. Juxtacortical osteosarcoma (8-10%) indicates a group of osteosarcomas apparently arising on bone surface. The most common type is parosteal osteosarcoma which affects older subjects and has a better prognosis than the classic type. Radiography shows a heavily ossified mass with a broad base attached to the underlying cortex. CT and MRI are useful in the differential diagnosis of osteosarcoma and myositis ossificans or osteocondroma. Rare types of osteosarcoma include the periosteal and high-grade surface variants, as well as secondary and multifocal osteosarcoma (osteosarcomatosis). CT and MRI are the imaging procedures of choice in locoregional staging (intraosseous and extraosseous spread, skip metastases, growth plate and articular involvement). CT of the chest is a useful tool for detecting lung metastases. Also MRI has a role in monitoring the response to chemotherapy and in detecting recurrence. It permits a more accurate study of the tumor volume than other imaging techniques and clinical examination. MRI becomes even more useful when paramagnetic contrast agents are administered because dynamic MRI with contrast enhancement help differentiate postchemotherapy changes from viable tumor--the latter enhancing rapidly and the former slowly. Thus, dynamic MRI allows a precise mapping of any residual tumor activity.
Bone Neoplasms↗
[Giant renal angiomyolipoma. Presentation of a case].
A case of large sized angiomyolipoma with atypical clinical presentation is reported. The retroperitoneal mass, showed by ultrasonography, was mainly made by fat tissue, as showed by CT and MRI, and it was associated with focal, probably metastatic, liver lesions. The diagnostic hypothesis of retroperitoneal liposarcoma with liver metastases was made. In the same time a colon neoplasm was found and US-guided biopsies of both the liver lesions and the retroperitoneal mass were carried out. The former were found to be metastases from colon cancer while the latter was a renal angiomyolipoma. The reported case underlines that renal angiomyolipoma if large sized and with atypical clinical presentation may be difficult to differentiate from retroperitoneal, even malignant masses. The hystological evaluation by means of needle biopsy or surgical resection becomes therefore mandatory.
Adenocarcinoma↗
[Magnetic resonance of the brachial plexus: anatomy and study technique].
Brachial plexopathies are a common diagnostic problem: conventional imaging techniques can be useful in the detection of associated conditions (Pancoast tumors, first rib or clavicle fractures, etc.) but they cannot visualize brachial plexus structures directly. Also Computed Tomography (CT) is limited in the study of the retroclavicular region because of the artifacts due to the presence of the humeral heads in the slice. CT myelography exhibits very high accuracy in posttraumatic brachial plexopathies but fails to reveal the postganglionic plexus. In contrast, Magnetic Resonance Imaging (MRI) allows the direct detection of the brachial plexus, from spine to axilla, thanks to its multiplanarity and high contrast resolution. However, MR images are so rich in anatomical details (particularly on the oblique planes) that sometimes they become very difficult to interpret. To better define the anatomical relationships of the brachial plexus and to assess the best planes to study its different portions, 9 healthy volunteers were examined with MRI and MR images were compared with anatomical drawings and frozen cadaver sections. MRI depicts the brachial plexus from its origin to the axilla, but none of the investigated planes is sufficient, alone, to study the whole plexus adequately. The paraganglionic portion is clearly depicted on oblique sagittal images, while coronal and sagittal images are more useful for primary trunks and spinal nerves; the distal portion is perfectly visualized on sagittal images. Thus, we conclude that different examination protocols are necessary for every specific plexus portion, which means that brachial plexus MRI must be performed to try to solve a specific question by the orthopedic surgeon or the clinician.
Brachial Plexus↗
[Interactive atlas with magnetic resonance on CD-ROM for Macintosh].
Computer assisted education in radiology has been increasingly used during the past ten years and now complements traditional learning resources. Magnetic Resonance Imaging (MRI) of musculoskeletal anatomy, and particularly of joints, lends itself naturally to learning modules on computer. This paper describes the design, development and use of an interactive computer assisted teaching module of MR joint anatomy on CD-ROM for Macintosh: to date, we have used this atlas for ankle and elbow anatomy. The atlas is divided into three main sections: MR anatomy, traditional anatomy and a quiz. On each MR image, any anatomical detail can be identified clicking on it with the mouse. Buttons allow to visualize cross-reference points and to go directly on the desired image. If the student wants to look at anatomical drawings of the last identified structure, a button retrieves all the cards in the traditional anatomy section containing that structure. Finally, the student can make his own self-assessment, verifying his learning immediately with the exam mode: the software makes a random selection of 10 MR images where an anatomical structure must be indicated: if the answer is wrong, the software gives the right one and shows the misinterpreted structure. Then, the student is given a total score for his performance. The computer assisted teaching modules present some advantages: the images can be viewed in a given sequence (like traditional learning resources) or in any self-paced, customized way; this possibility, together with the friendly interface of Macintosh computers could make learning more active and pleasant.
Anatomy↗
[The epiphyseal involvement of metaphyseal bone sarcomas in patients with fertile growth plates. A magnetic resonance assessment].
The growth plate is thought to be capable of limiting tumor spread. To assess the presence and extent of epiphyseal involvement in bone tumors, the plain radiographs and the MR images of 41 patients with metaphyseal sarcoma and radiographically apparent growth plate were studied. The results were compared with surgical, microscopic and histologic findings. Histology demonstrated that in 3 patients the tumor did not reach the growth plate, in 25 the epiphysis was involved while in 13 cases the tumor reached the physis but did not spread to the epiphysis. In the latter group of patients, histology demonstrated a microinfiltration of the physis in 5 cases. Radiography and MR sensitivities were 77.2% and 100%, respectively, while specificity was 94% for both methods. Histology showed that the epiphysis was involved in 25/41 cases (61%) and the growth plate in 30/41 (73%). Our results show that the growth plate does not usually act as a barrier against tumor spread and that MRI is the diagnostic tool of choice in the assessment of epiphyseal spread in metaphyseal tumors even though it cannot detect growth plate microinfiltrations.
Adolescent↗
[Role of Gadolinium-DTPA in the assessment of renal tumors with magnetic resonance].
To investigate the role of Gd-DTPA in the MR study of renal cancers, 30 patients affected with primary (28) or recurrent (2) renal cancers were submitted to high-field MRI (1.5 T). T1- and T2-weighted and Gd-DTPA-enhanced T1-weighted sequences were always acquired. Based on qualitative and quantitative criteria (calculation of the signal-to-noise ratio in the tumor mass and of the signal-difference-to-noise ratio between tumor and renal parenchyma), Gd-DTPA influence was studied on the following variables: signal intensity and tumor demonstration, detectability of morphostructural features of tumor tissue and staging accuracy. As for the latter variable, MR results were compared with the results of anatomical and surgical staging (28 cases). Relative to unenhanced T1- and T2-weighted sequences, on Gd-DTPA-enhanced sequences 80% of the lesions were markedly hypointense relative to renal parenchyma and they were better demonstrated in 93% of cases. The S/N and the SD/N ratios were higher on Gd-DTPA-enhanced than on unenhanced images. After Gd-DTPA administration, the intratumoral necrotic areas, the walls and the septations of the cystic masses and the boundaries between tumors and renal parenchyma were better demonstrated. Staging accuracy was the same (90%) on both Gd-DTPA-enhanced T1-weighted and unenhanced images. Therefore, Gd-DTPA, although failing to increase staging accuracy, improves tumor depiction and demonstrates the morphostructural features of the mass. Since Gd-DTPA caused no side-effects, Gd-DTPA-enhanced T1-weighted sequences can replace T2-weighted sequences, whose acquisition time is definitely longer.
Adult↗
[The intrahepatic portosystemic aneurysmal shunt studied by echo-Doppler and magnetic resonance].
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Aneurysm↗
[Alpha-fetoprotein secreting adrenal metastasis after hepatectomy for non-secreting hepatocarcinoma. Description of a case].
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Adrenal Gland Neoplasms↗
[MR in the characterization of benign ovarian masses].
To investigate the role of MRI in characterizing benign ovarian masses, the MR images of 64 patients affected with benign ovarian masses were retrospectively reviewed. The benign nature of the masses was proven at surgery (42 cases), fine-needle biopsy (10 cases), laparoscopy (6 cases) and follow-up (6 cases). MRI correctly characterized 56 of 64 masses (87.5%). In particular, all the cases of simple serous cyst (9), of hemorrhagic cyst (10), of fibroma (4), of dermoid cyst (18) and of tubo-ovarian abscess (7). MRI misdiagnosed 4 endometrial cysts--2 of them as hemorrhagic cysts and 2 as dermoid cysts-, 1 serous cystoadenoma as cystoadenocarcinoma and 1 suppurative mucinous cystoadenoma as tubo-ovarian abscess. Moreover, 1 angiofibroma and 1 hematosalpynx were misdiagnosed as endometrial cysts. In conclusion, MRI can be considered a second-choice diagnostic tool which can replace CT in the evaluation of the patients in whom US alone fails to yield an unquestionable diagnosis.
Adolescent↗
MRI of hepatocellular carcinoma before and after transcatheter chemoembolization.
OBJECTIVE: Magnetic resonance imaging of hepatocellular carcinomas (HCCs) was performed before and after transcatheter arterial chemoembolization (TACE). The changes of tumor signal intensity were compared to residual tumor or tumor recurrence in the follow-up period. MATERIALS AND METHODS: Fifteen cirrhotic patients with HCC were studied. All patients were examined with MRI both before and 3 months after TACE. Requirement for the study was that all lesions were detectable by MR before TACE. RESULTS: Magnetic resonance imaging detected 31 tumors. The changes of tumor signal intensity were compared to residual tumor or tumor recurrence in the follow-up period. On T1-weighted (T1W) images before TACE, 16 tumors were hyperintense, 11 were isointense, and 4 were hypointense; on T2W images, 26 tumors were hyperintense, 5 were isointense, and none were hypointense. On T1W images 3 months after TACE, 8 tumors were hyperintense, 18 were isointense, and 9 were hypointense; on T2W images, 11 were hyperintense, 11 were isointense, and 9 were hypointense. All the tumors that became hypointense on T2W images after TACE did not recur on follow-up. All lesions that were still hyperintense on T2W images after TACE showed residual tumor during the follow-up. Among 11 tumors that were isointense on T2W images after TACE, 7 were hyperintense on T2W images before TACE; 6 of these did not recur. Four tumors were isointense on T2W images before and after TACE; 2 of these showed residual tumor in the follow-up. On T2W images after TACE, 15 of 16 HCCs that decreased in signal intensity did not recur on follow-up. On T1W images no correlation was seen between the changes of the signal intensity of the lesion and tumor recurrence in the follow-up; however, 9 of 17 HCCs that did not recur after TACE showed decreased signal intensity. All the tumors (10 of 10) with decreased signal intensity on both T1W and T2W images after TACE did not show tumor recurrence on follow-up. CONCLUSION: The results suggest that MRI is useful in the assessment of the therapeutic effect of TACE in HCC.
Aged↗