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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

MRI is synonymous with proton imaging. It provides detailed images of gross anatomy and pathology owing to the excellent soft-tissue contrast, signal void of flowing blood, versatile geometry, and freedom from streak artifacts, as well as other advantages summarized in Table 8-2. In the CNS, MRI has emerged as the most sensitive imaging modality in virtually all pathologies--some reservations remaining concerning acute hemorrhage, focal calcifications, and bone detail. Hence, it should be considered the premier noninvasive examination in the evaluation of the cancer patient with any suspicion of CNS pathology. Economics and availability must, of course, be considered when evaluating MR's role relative to CT. MR clearly provides the best means of excluding pathology, particularly in the posterior fossa, and must be considered after a negative CT examination with persistent clinical suspicions. MRI must also be considered in routine surveillance, if the earliest possible detection of metastasis, demyelination, and other pathologies is to be achieved. MRI should be considered in the evaluation of vertebral metastases, spinal cord compression, and back pain because of its ability to depict CSF, spinal cord, disk, and vertebral body as distinct structures and its sensitivity to marrow disease. In the extremities and pelvis, clearer depiction of soft tissues, vessels, and marrow is a proven advantage. Hence, MRI is indicated in the evaluation of prostate/bladder/rectal carcinoma, uterine/cervical carcinoma, soft tissues/bony sarcomas, and bone metastasis/infarction. In the abdomen, MRI's display of the retroperitoneum and sensitivity to liver lesions indicates its use in the evaluation and staging of renal/adrenal carcinoma, retroperitoneal sarcomas, primary liver tumors, and metastases. Moreover, MRI is also indicated in the evaluation of liver or adrenal masses of uncertain histology owing to a limited specificity of the MR signal for adenoma, carcinoma, and hemangioma. In the chest, MRI's advantages are currently limited owing to the excellent quality of CT images of mediastinum and lung parenchyma and the deleterious effects of respiratory motion. MRI's primary indications in the chest are for the distinction of mediastinal and hilar masses from vessels and aneurysms; evaluation of lumenal patency and superior vena cava syndrome; detection and display of pericardial effusion and the relationship of tumor to the pericardium; and evaluation of internal cardiac anatomy, thrombi, and tumor. Because of rapid technological advances, statements concerning MRI's limitations must be guarded.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Nuclear magnetic resonance imaging in oncology. 333 79

From March 1985 to February 1987, 41 patients (pts) presenting with a neuroblastoma underwent 52 MRI to detect bone marrow metastases. Mean age was 4 years (R: 6 m, 13 y). Acquisitions were done with a 1.5 t unit. Images were obtained in coronal (legs and pelvis) and sagittal (dorso-lumbar spine) sections. Nine out of 52 examinations were excluded because of artifacts or technical failure. In 13 cases, MRI was performed for initial staging, in 30 during follow-up. Out of 24 anatomically proven medullary involvement (18 pts), MRI showed focal abnormal signals in 23 (17 pts): foci of hypersignal in T2 weighted images, compared to the normal value of bone marrow and fat tissue, were more often detected in lower limbs than dorso-lumbar vertebral body or iliac bone. In our series, the sensitivity of MRI to detect BM metastases is 84% and the specificity is 88%. In comparison to the medullograms and bone marrow biopsy, MRI explores distinct sites, especially lower limbs which are often involved.
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PMID:[Magnetic resonance imaging for bone marrow metastases of neuroblastoma]. 335 59

Twenty-five patients affected by adrenal glands pathology underwent CT and MRI: 6 non-functioning adenomas, 2 Cushing's adenomas, 2 Conn's adenomas, 6 metastases, 3 cysts, 2 carcinomas (Cushing's syndrome), 1 lymphoma and 3 pheochromocytomas. Diagnosis was subsequently confirmed either at surgery, or autopsy, or with needle biopsy. In all cases normal adrenal glands and pathological lesions were showed by MRI. T1 signal intensity and mass diameter were compared with T2 signal intensity, represented by the intensity ratio between the adrenal mass vs normal hepatic parenchyma. MRI signal intensity, usually high in case of malignancy and low in adenomas, shows a mean value which is much wider than that referred to mass diameter evaluation (carcinoma is larger than adenoma); for this reason those findings have proved to be insufficiently accurate for adrenal tissue characterization, even for the evaluation of cysts and pheochromocytomas. In the same cases CT showed higher accuracy.
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PMID:[MR tomography in adrenal pathology. Preliminary report on 25 histologically controlled cases]. 337 95

Forty-one patients (pts) presenting with a neuroblastoma underwent 52 MRI to detect bone marrow metastases. Mean age was 4 years. Acquisitions were done with a 1.5 tesla unit. T1 and T2 weighted images were obtained in coronal (legs and pelvis) and sagittal (dorso-lumbar spine) sections. In 13 cases MRI was performed for initial staging, in 30 during the follow-up. 43/52 examinations were evaluable. Out of 24 anatomically proven medullary involvement (19 pts), MRI showed focal abnormal signals in 23 (18 pts): foci hypersignal in T2 weighted images and hyposignal in T1 weighted images compared to the normal bone marrow (BM) and fat tissue. The lesions were more often detected in lower limbs than dorso-lumbar vertebral body or iliac bone. Nineteen examinations were performed in 15 pts with cytologically and histologically normal BM. MRI raised suspicion of BM metastases in 5 pts (7 MRI). Out of those 5 pts, 1 (2 MRI) had BM relapse 9 months later; 1 (2 MRI) had intra cranial relapse 6 months later; 1 (1 MRI) is disease free 1 1/2 year later; the follow-up is too short for 2 remaining pts (2 MRI). MRI's specificity was 88.9% and sensitivity 84.4%.
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PMID:Bone marrow metastases in children's neuroblastoma studied by magnetic resonance imaging. 340 18

The histologic type of adrenal tumors can be accurately predicted by MRI on the basis of their signal intensity on a T2-weighted image. However, a small but significant number of nonfunctioning adenomas, carcinomas, and metastases cannot be differentiated because they have similar signal intensities on a spin-echo 2500/80 scan. Eight (21%) of 38 of these tumors fell into this group. Differentiation between incidental adenomas and metastases can be conclusively achieved only when the primary neoplasm can also be imaged and displays high signal intensity on T2-weighted images.
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PMID:MRI of indeterminate adrenal masses. 348 52

In a prospective study, the role of MRI in the staging of prostatic cancer has been assessed in 32 patients. The results of MRI has been compared with those conventional staging modalities for prostatic cancer including pelvic CT, cystoscopy, bimanual examination and biopsy of the prostate. The final clinical and/or pathologic staging was obtained. The results of CT were compared with those of MRI in a blind fashion. In 22 of Stage A and B neither MRI nor CT were able to define the extension of the disease. In no cases were results of CT superior to the MRI. However, in 10 cases, the seminal vesicles were involved and these cases were interpreted as stage C. In exploration 2 out of 10 cases had metastases shown by MRI. It is concluded that MRI is more sensitive in revealing the detail of the seminal vesicles thereby detecting the bulk of the tumor and the extension of cancer into the soft tissue of the lymphadenopathy of this organ. The role of MRI in the detection of and the utilization of paramagnetic media remains to be studied.
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PMID:Magnetic resonance imaging (MRI) in staging of the prostatic cancer. 365 53

36 Patients with glioblastomas (17 cases) and cerebral metastases (19 cases) were investigated by MRI. The typical signal behavior at different acquisition parameters (T1-, T1/T2-, Rho- and Rho/T2-weighted) was analysed using an interlaced triple sequence. In most cases the NMR-tissue parameter T1, T2 and proton-density (Rho) were determined to evaluate the potentials for tissue characterisation. The results of unenhanced vs. enhanced scans (MRI plus Gd-DTPA, CT) were analysed.
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PMID:[MR tomography in glioblastomas and cerebral metastases]. 368 27

A variety of diagnostic techniques has enhanced our ability to detect and accurately stage urothelial carcinoma. Urine cytology is a sensitive method for detecting occult high-stage tumors in both the upper and lower tracts. Rigid ureteroscopy has extended direct visualization from the bladder (with cystoscopy) to the renal pelvis. The evaluation of metastatic disease has been improved by CT and MRI. However, caution must be applied in interpreting bladder masses demonstrated by these studies after transurethral resections. The mainstay of local therapy continues to be transurethral resection. This established technique has been aided by intravesical chemotherapy and immunotherapy. Intravesical instillation of chemotherapeutic drugs or BCG may help preserve some bladders that would otherwise be sacrificed. The appropriate role of laser therapy as a primary form of treatment remains to be defined. Photodynamic therapy appears to be a powerful new treatment modality for carcinoma in situ. However, photodynamic therapy should still be considered a clinical experiment at this time. Patients with more advanced local disease will require either cystectomy or definitive radiation therapy. The survival results with primary surgical therapy appear to be slightly better than radiation therapy, particularly when younger individuals are being treated. Persons with metastatic disease are best treated with chemotherapy. Combination cisplatin-based regimens appear to be particularly promising and offer a high incidence of objective remissions with good duration of response. Although the five-year survival of patients with bladder carcinoma has steadily improved, there is still room for additional progress. The basis for any such improvement rests in accurate diagnosis and treatment and careful surveillance for recurrent disease.
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PMID:Diagnosis and treatment of bladder carcinoma. 374 97

Reviewing the literature and summarizing our own experience, the role of various imaging modalities concerning diagnosis of metastases to lymph nodes and organs in the pelvic cavity is discussed. Especially ultrasound, CT and lymphography are compared, the importance of fine-needle-aspiration is emphasized. Possible advantages of MRI are mentioned.
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PMID:[Radiologic diagnosis of metastases in the lesser pelvis]. 388 97

Carcinomas of the prostate and breast are the most common sources of osteosclerotic metastases. The osteoblastic response is related to stromal bone formation and reactive bone formation. Purely osteosclerotic or mixed osteolytic-osteosclerotic lesions are encountered. Frequent differential diagnoses are enostoses and Paget's disease. The classical MRI pattern is a signal of low intensity on T1 and T2- weighted sequences, but some osteoblastic metastases have an inhomogenous signal. Evaluation of the response to treatment is difficult and requires confrontation with clinical and biological data.
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PMID:[Imaging of osteosclerotic metastases]. 747 96


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