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V M Rao

Publications and source records attributed to V M Rao.

At least 19 recordsLinked to original sources
PubMed1992

Unusual MRI findings in metastatic carcinoma to the choroid and optic nerve: a case report.

A 51 year old man with biopsy proven pulmonary sarcoidosis and skin test positive for tuberculosis presented with features of an amelanotic flat choroidal mass suggestive of choroiditis. The mass enlarged despite corticosteroids and anti-tuberculous medications. A thorough systemic evaluation for possible primary tumor metastatic to the choroid was negative. Further clinical evaluation and magnetic resonance imaging suggested a diffuse primary choroidal malignant melanoma with optic nerve invasion. The eye was enucleated and the mass proved histopathologically to be a mucin secreting adenocarcinoma of unknown origin despite a repeat systemic work-up. The patient died three months after the onset of symptoms and three weeks after enucleation with diffuse metastases from an unknown primary cancer. Magnetic resonance imaging (MRI) is usually helpful in the differentiation of uveal melanoma from uveal metastasis. In this case, however, it suggested the diagnosis of a diffuse choroidal melanoma. The reason for the atypical MRI findings will be discussed.

Adenocarcinoma↗
PubMed1992

Role of magnetic resonance imaging in the evaluation of the hydroxyapatite orbital implant.

The role of magnetic resonance imaging (MRI) in the assessment of fibrovascular ingrowth in the integrated hydroxyapatite orbital implant is evaluated. Fifteen patients who underwent enucleation and placement of a hydroxyapatite orbital implant were evaluated for degree of implant vascularity with gadolinium-DPTA-enhanced MRI with surface coil before drilling the implant. On T1-weighted images, the hydroxyapatite sphere appeared with intermediate signal. After gadolinium-DPTA administration, all patients showed an enhancement in the implant consistent with the presence of fibrovascular ingrowth. The enhancement was most notable in the peripheral portions of the sphere and was seen as early as 5 months after implantation. Comparison of gadolinium-DPTA-enhanced MRI with contrast-enhanced computed tomography, ultrasonography, and color Doppler imaging suggests that these latter techniques are not as helpful in the detection of the fibrovascular tissue in the orbital implant. Bone scan, a technique used by many surgeons, demonstrates fibrovascular ingrowth, but it is limited by its one-dimensional low-resolution image. Because of its three-dimensional capability and its highest resolution, contrast-enhanced MRI with surface coil appears to be the best imaging method for evaluating the hydroxyapatite orbital implant and its fibrovascular ingrowth.

Adolescent↗
PubMed1992

Polycythemia vera and myelofibrosis: correlation of MR imaging, clinical, and laboratory findings.

Magnetic resonance (MR) imaging was performed in 14 patients with biopsy-proved polycythemia vera (n = 4) or myelofibrosis (n = 10) to determine whether MR imaging findings can be correlated with the clinicopathologic diagnosis and established clinical parameters of severity (serum lactate dehydrogenase [LDH] and cholesterol levels) and chronicity (spleen size). Evaluation of marrow in the proximal femurs showed that patients could be categorized into three distinct groups based on anatomic patterns of normal fatty and abnormal low-signal-intensity (non-fatty) marrow in the femoral capital epiphysis (FCE) and greater trochanter (GT). Patients with nonfatty marrow in both the FCE and GT (n = 8) had significantly higher serum LDH (P less than .02) and lower serum cholesterol (P less than .02) levels than patients with fatty marrow in at least the GT (n = 6). Splenic volume, as measured from MR images, was significantly greater in the myelofibrosis group than in the polycythemia vera group (P less than .001). MR imaging provided a better understanding of these hematologic disorders and novel parameters for classification that are different from conventional histologic and laboratory data.

Adult↗
PubMed1992

The CT and MRI features of an unusual case of isolated orbital neurofibroma.

A 35-year-old woman developed painful proptosis of the left eye over a period of 3 weeks. Orbital computed tomography and magnetic resonance imaging revealed a well-circumscribed superior orbital tumor with variable density. The mass was removed entirely by way of a superior orbitotomy. Histopathologically, it was found to be a neurofibroma. The patient had no clinical findings of neurofibromatosis. The presence of extensive myxomatous degeneration and the dense collection of collagen bundles in the tumor are correlated with the unusual computed tomography and magnetic resonance imaging features.

Adult↗
PubMed1991

Nondiscogenic causes of temporomandibular joint pain.

Magnetic resonance imaging of the temporomandibular joint is a topic of recent interest and has gained widespread use for the assessment of internal derangement and other temporomandibular joint-related symptoms. In this article the authors present six proven cases of pathologic abnormalities of the temporomandibular joint region that may clinically mimic internal derangement. These cases demonstrate the importance of the monitoring of studies by a radiologist and also the utility of computed tomography as an adjunctive modality. Magnetic resonance imaging and computed tomography are often complimentary in diagnosing etiologies that may mimic internal derangement. Because abnormalities other than internal derangement are often encountered during the use of magnetic resonance imaging, it is essential for the radiologist to assume an active role in monitoring such cases.

Adolescent↗
PubMed1991

Magnetic resonance imaging in choroidal osteoma.

High resolution magnetic resonance imaging (MRI) with surface coil and contrast material was used to demonstrate the presence of bone in choroidal osteoma. Contrary to initial impressions, choroidal osteoma does not show typical negative image of the bone in MRI scans. The ossifying tumor of the choroid appears as a bright (hyperintense) signal on T1-weighted images and as an area of relative low intensity on T2-weighted images. On contrast T1-weighted scans, the tumor showed gadolinium-DPTA (Gd-DPTA) enhancement. These MRI findings are discussed in relation with histopathologic features of choroidal osteoma and the presence of fat marrow in the intertrabecular spaces of the bone at the level of the choroid.

Adult↗
PubMed1991

Parenchymal versus reticuloendothelial iron overload in the liver: distinction with MR imaging.

Parenchymal iron deposition occurs in hemochromatosis, while iron is deposited in reticuloendothelial (RE) cells after blood transfusions or rhabdomyolysis. Magnetic resonance images of patients with decreased liver signal intensity on T2-weighted images at 1.5 T were blindly compared in an effort to distinguish these conditions. In each of five patients with hemochromatosis, the pancreas had low signal intensity, but splenic signal intensity was decreased in only one. In contrast, only three of the 16 patients with RE iron overload had low pancreatic signal intensity, while all of these patients either had low splenic signal intensity (n = 14) or previously underwent splenectomy (n = 2). Distinction among these causes of iron deposition is clinically important because parenchymal iron overload from hemochromatosis may produce significant tissue damage, while the RE iron of transfusions and rhabdomyolysis is of little clinical consequence.

Adolescent↗
PubMed1991

Noninvasive diagnostic imaging in hemoglobinopathies.

We have provided a global review of the current applications of newer modalities, particularly MR imaging, as applicable to the major manifestations of sickle cell disease, the most common hemoglobinopathy. There is a need for well-designed prospective longitudinal studies utilizing MR imaging to gain further insight into the pathophysiology of this intriguing disease. Additionally, MR imaging, because of lack of ionizing radiation, is ideally suited for long-term sequential studies and may thus provide an objective means for monitoring response to therapy.

Adolescent↗
PubMed1991

Imaging of the parapharyngeal space: anatomy and pathology.

A multitude of histologic neoplasms occur within the boundaries of the parapharyngeal space. Contrast enhanced computed tomography and recently MRI have greatly enhanced the preoperative diagnosis of parapharyngeal space tumors. MRI is currently the modality of choice in evaluating masses originating in the parapharyngeal space or masses from adjacent spaces which grow into the parapharyngeal space. Gadolinium DTPA enhanced MRI of head and neck tumors is helpful for demonstrating neoplastic involvement of paranasal sinus, perineural tumor extension, or intracranial extension of neoplasms. Parapharyngeal space tumors are equally demonstrated by unenhanced MRI. The majority of tumors involving the parapharyngeal space are from the deep portion of the parotid gland or from minor salivary glands, and the majority of these tumors are benign mixed tumors. Based on the CT appearance and enhancement characteristics, it is difficult to accurately distinguish a minor salivary gland tumor from a neurogenic tumor. MR tissue signal characteristics alone cannot be reliably utilized in making this distinction. Internal carotid artery displacement remains the most reliable distinguishing feature. Minor salivary gland tumors will displace the internal carotid artery posterior and lateral, whereas neurogenic tumors will displace the internal carotid artery anterior and medial.

Branchioma↗
PubMed1990

Altered condylar morphology associated with disc displacement in TMJ dysfunction: observations by MRI.

Magnetic resonance images of 276 TM joints in 138 symptomatic patients were analyzed in a retrospective study to determine the condylar shape and size and to correlate it with internal derangement. Internal derangement by MRI was noted in 66% of the TM joints. Our study demonstrates that the regressive condylar changes in TM joints with internal derangement were more common (61%) than proliferative bony changes (39%). On the converse, none of the TM joints with regressive condyles revealed normal disc. The altered bony morphology also correlated with the severity of internal derangement, i.e. bony changes in TM joints with anterior closed lock were noted in 64% compared to 45% with reducible disc. The cause and effect relationship of the regressive condylar remodeling and disc abnormality is not clear and needs further study.

Adolescent↗
PubMed1990

Temporomandibular joint dysfunction: correlation of MR imaging, arthrography, and arthroscopy.

This prospective study correlated the results of magnetic resonance (MR) imaging, arthrography, and arthroscopy in 27 patients with clinically suspected temporomandibular joint (TMJ) dysfunction. Open surgical confirmation was available in 12 TMJs. The variables assessed with each modality were disk position and morphology, disk perforation, joint adhesions, and degenerative joint disease. MR imaging was superior to dual joint arthrography with arthrotomography in delineation of the disk position. MR imaging accurately demonstrated the disk position in 11 joints (92%); arthrography was accurate in nine of the 12 joints (75%) with surgically confirmed dysfunction. Disk perforations and joint adhesions were not demonstrated with MR imaging. Arthroscopy was superior to arthrography and MR imaging in the detection of disk perforations, joint adhesions, and early degenerative changes along the articular eminence and glenoid fossa. The authors believe MR imaging should constitute the first line of imaging because it provides accurate information about disk position in a noninvasive manner. In most cases, information obtained with MR imaging is adequate in deciding whether to institute conservative or surgical management; in difficult cases, triple correlation may be needed.

Adult↗
PubMed1990

Magnetic resonance imaging of bone marrow: diagnostic value in diffuse hematologic disorders.

Magnetic resonance imaging (MRI) has value in characterizing normal and abnormal bone marrow because of its ability to distinguish fat from other tissues. Due to this advantage, hematologic disorders resulting in alterations of the normal cellular and fatty marrow distribution can be appreciated. In this article, the role of MRI in diffuse hematologic disorders is emphasized. At birth, almost all marrow is cellular, but by age 25, cellular marrow is restricted to the axial skeleton and proximal femoral and humeral metaphysis. The remainder is fatty, consisting of 80% fat, 15% water, and 5% protein. With increased need for hematopoiesis, reconversion from fatty to cellular marrow occurs in many diffuse disease states. Diffuse diseases that affect bone marrow production are divided into four categories representing conditions that affect the pluripotent hematopoietic stem cell. These include stem cell failure resulting in aplastic anemia, uncontrolled stem cell proliferation as exemplified by polycythemia vera, stem cell dysplasia such as sickle cell anemia, and malignant transformations or replacement. The MRI appearance of these disorders is discussed in this article. The use of spin-echo (SE) sequences is the most common approach to bone marrow imaging. With T1-weighted SE images, fatty marrow will appear bright and cellular marrow, with lower fat content, will exhibit a lower density signal. With T2-weighted SE pulse sequences, contrast between fatty marrow and cellular marrow decreases. Contrast between fatty and cellular marrow is enhanced with chemical shift imaging, including Dixon out-of-phase imaging, as emphasized in this article. MRI presents a more global view of the bone marrow than biopsy material and should provide a better understanding of diffuse hematologic disease progression and resolution.

Bone Marrow↗
PubMed1989

Computed tomography of salivary glands in Sjögren's syndrome.

Three cases of Sjögren's syndrome, one with uncomplicated disease, and the other two complicated by pseudolymphoma and malignant lymphoma, respectively, are presented. Computed tomography can provide information useful in the diagnosis, detection of complications, and, therefore, management of Sjögren's syndrome.

Aged↗
PubMed1989

The prevalence of avascular necrosis in sickle cell anemia: correlation with alpha-thalassemia.

The purpose of the present study was to investigate the effect of alpha-thalassemia on the prevalence of avascular necrosis in 52 adult patients with sickle cell anemia. alpha-Globin genotypes were determined by restriction endonuclease mapping of genomic DNA extracted from peripheral blood leukocytes. Radiographs of humeral and femoral heads were interpreted by two radiologists who were not aware of the clinical picture and the genotype of the patients in the study. We present data showing that there is a significant positive correlation between alpha-gene deletion and the prevalence and extent of avascular necrosis in our patient population.

Adult↗