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S R Ganti

Publications and source records attributed to S R Ganti.

At least 19 recordsLinked to original sources
PubMed1986

CT of pineal region tumors.

The computed tomographic (CT) features of pineal region tumors were analyzed in 60 histologically proven tumors. This is the largest reported series of histologically verified pineal region tumors studied with CT. The tumors were classified as germ-cell tumors, glial tumors, pineal parenchymal tumors, and meningiomas. Preenhancement germinomas revealed characteristically high-density areas with calcification; uniform enhancement was seen after injection of contrast material. When present, pineal calcification was engulfed by the tumor. Teratomas, present only in male patients, revealed areas of mixed densities (e.g., calcification and fatty areas) and did not show significant contrast enhancement. Spontaneous intraventricular rupture was noted in one case. Unlike other tumors, the original pineal calcification could be recognized in two-thirds of glioma cases and was displaced anteriorly and superiorly in most. Gliomas were hypodense to isodense on precontrast scans and enhanced in a nodular and a ring fashion. Benign pineal parenchymal tumors showed iso- to hyperdense areas with nodular enhancement after injection of contrast material. Pineoblastomas were well defined hyperdense masses without calcification on precontrast scans. After injection of contrast material, they showed well defined enhancement with occasional small, central lucencies. Meningiomas were hyperdense in most cases, uniformly enhanced in a homogeneous fashion, and showed a tentorial attachment.

Brain Neoplasms↗
PubMed1986

Primary and adjunctive intra-arterial digital subtraction arteriography of the lower extremities.

Standard contrast arteriography (SCA) and intra-arterial digital subtraction arteriography (DSA) were performed during a 26-month period in 459 cases. The DSA group consisted of 22 aortoiliac studies, 66 crural-pedal arch studies, and 227 combinations. In addition, postoperative DSA was performed in 42 patients to evaluate graft patency, morphology, and inflow and runoff circulations. There were no significant differences in the quality of the preoperative aortoiliac studies performed by either SCA or DSA although, in select cases, one or the other of these techniques resulted in a superior study. Distal crural-pedal arch visualization was enhanced with DSA compared with SCA (85% vs. 65%) but when both were compared with their corresponding intraoperative completion arteriograms, the interpretive error rates resulted in comparable accuracies, false positive and negative rates, and predictive values. The likelihood of achieving graft patency in patients who have unsatisfactory preoperative visualization of the distal circulation by DSA is reasonable (11 of 27 patients) but inferior to the number obtained when there is adequate DSA visualization (40 of 53 patients). We conclude that DSA is a valuable adjunct to preoperative SCA but should not be used as the sole criterion for the assessment of operability for limb salvage. Intraoperative prereconstruction arteriography or direct surgical exploration of the crural arteries in patients with inadequate preoperative visualization will result in graft patency in a significant percentage of cases. Intra-arterial DSA for postoperative evaluation of lower limb bypass adds another dimension to analysis of graft structure and status of the host circulatory beds and also provides a method for accurate interpretation of postoperative data.

Angiography↗
PubMed1985

CT and angiography of primary extradural juxtasellar tumors.

The computed tomographic and angiographic features of 15 histologically proven primary extradural juxtasellar tumors were retrospectively reviewed. Five chordomas were characterized by prominent bone erosion and a significant posterior fossa component. Four trigeminal nerve neuromas each demonstrated bone erosion centered about Meckel's cave and moderate to marked contrast enhancement. Two cavernous sinus meningiomas revealed moderate contrast enhancement, expansion of the cavernous sinus, and moderate angiographic stain. Two cavernous hemangiomas of the cavernous sinus were intensely enhancing and demonstrated angiographic stain. Opacification of the sphenoid sinus with prominent bone destruction and lack of contrast enhancement was characteristic of a sphenoid sinus mucocele. The dural reflection could be directly visualized or indirectly inferred in each case.

Adolescent↗
PubMed1984

Computed tomography of the carotid space and related cervical spaces. Part I: Anatomy.

The carotid space, parapharyngeal space, and paraspinal space are described. The carotid space is shown on computed tomography (CT) to be posterior to the parapharyngeal space and separated from it by the styloid apparatus. The paraspinal space is posterior to the carotid space and separated from it by the longus and anterior scalene muscles.

Humans↗
PubMed1984

Occlusive vascular disease associated with cerebral arteriovenous malformations.

Selective carotid angiography and computed tomography were used in a study of the association of occlusive vascular disease with cerebral arteriovenous malformations in 13 patients. The arterial occlusions ranged from focal stenosis in the major artery supplying the malformation to complete occlusion of the supraclinoid internal carotid artery with subsequent development of "moyamoya" collaterals. The majority of the arterial occlusions were proximal to the vascular malformation. Some, however, extended distal to the major branch supplying the arteriovenous malformation (AVM). Selective angiography with subtraction techniques defines the distinct angioarchitecture of these AVMs and the associated stenoses and collateral telangiectases.

Adult↗
PubMed1984

Transient neurological deficits secondary to saccular vertebrobasilar aneurysms. Report of two cases.

Aneurysms have rarely been implicated as a possible cause of transient neurological deficits, and most reports of this phenomenon describe aneurysms in the anterior circulation. There is only one previous report of a saccular posterior circulation aneurysm associated with transient ischemic attacks. The authors document two cases of giant saccular vertebrobasilar artery aneurysms associated with transient neurological deficits.

Adolescent↗
PubMed1984

The carotid region: normal and pathologic anatomy on CT.

The carotid region of the neck is defined in terms of three longitudinally oriented spaces: parapharyngeal, carotid, and paraspinal. Displacements of these spaces by neurogenic tumors of the neck are analyzed. The CT appearance and histology of these tumors are correlated.

Carotid Arteries↗
PubMed1983

Computed tomography of the nasopharynx and related spaces. Part II: Pathology.

Malignant tumors of the nasopharynx were analyzed by region of origin and route of spread. Nasopharyngeal carcinomas produced early submucosal infiltration of the deglutitional muscle layer with enlargement of the levator palati muscle and lateral displacement of the parapharyngeal space. Serous otitis media was frequently associated, and the trigeminal nerve was occasionally involved. Intracranial extension via the foramen lacerum was frequent. Metastases to the infratemporal fossa produced early involvement of the masticatory muscle layer with medial displacement of the parapharyngeal space. Adenoid cystic carcinomas showed late but disproportionate involvement of the sphenoid sinus. Chordomas extended into the retropharyngeal soft tissues via the petro-occipital fissure. Maxillary sinus carcinomas, which were very large at the time of presentation and impinged on the nasopharynx, showed extensive destruction of the pterygoid plates.

Carcinoma, Adenoid Cystic↗
PubMed1983

Computed tomography of the nasopharynx and related spaces. Part I: Anatomy.

The normal computed tomographic anatomy of the nasopharynx and pterygopalatine and infratemporal fossae is analyzed. Particular attention is given to the distinction between deglutitional and masticatory muscles. The relations of the palatal muscles to the eustachian tube are described in detail. Those soft-tissue features that, when they deviate from normal, can provide early detection of nasopharyngeal lesions are emphasized.

Humans↗
PubMed1983

Computed tomography of the brain stem with intrathecal metrizamide. Part I: the normal brain stem.

In summary, the anatomic details of the brain stem are exquisitely demonstrated with metrizamide CT. The obex is the zone of transition from the closed medulla, which has a conical pear-shaped appearance to the quadriconcave open medulla. The pyramids and inferior olivary nuclei characterize the anterior surface of the open medulla, whereas the median sulcus and the cranial nerve nuclei constitute the floor of the fourth ventricle at the same level. The mushroomlike appearance of the pontomedullary junction is easily reproducible with the restiform bodies forming the posteriorly diverging biped. The seventh and eighth nerves are usually seen at this level or on the adjacent higher section of the low pons. The brachia pontis are well delineated in almost their entire length at the level of the low pons as they bound the fourth ventricle laterally. The trigeminal nerves are seen at the level of the midpons, which is a few millimeters lower than the isthmus. The latter constitutes the junction of the pons with the mesencephalon. The colliculi divide the midbrain into two levels of axial cross section: the inferior collicular level, which may or may not show the trochlear nerve, and the superior collicular level, which features anteriorly the suprasellar cistern and its contents. Air is an inadequate contrast agent for CT for the demonstration of the surface features of the brain stem because of partial filling of the cisterns and meniscus formation that precludes a detailed outline. Metrizamide, however, with careful technique, fills the fourth ventricle and subarachnoid space both infra- and supratentorially. High-resolution scanning using primary reconstruction, and thin tomographic sections of no more than 5 mm are a necessity for metrizamide CT. Consecutive scans should not be spaced more than 5 mm apart if all the features of the brain stem are to be evaluated. The demonstration of the various grooves and protuberances on the surface of the brain stem provides a unique opportunity for evaluating focal atrophy and focal swelling henceforth impossible to visualize consistently.

Brain Stem↗
PubMed1983

Computed tomography of the brain stem with intrathecal metrizamide. Part II: lesions in and around the brain stem.

The practical usefulness of computed tomography with intrathecal metrizamide in imaging the brain stem is illustrated in six examples where the lesions were misdiagnosed on intravenously enhanced computed tomography, angiography, or air study. Focal and diffuse atrophic changes of the brain stem were demonstrated in symptomatic patients where none of the other radiographic or clinical investigations were conclusive. Metrizamide computed tomography is probably the most sensitive method for imaging lesions in and around the brain stem and cerebellopontine angle.

Adolescent↗
PubMed1982

Computed tomography of cerebellar hemangioblastomas.

Ten patients with proven cerebellar hemangioblastomas were studied by computed tomography (CT). Angiography was obtained in seven cases. Eight patients had a cyst and a nodule, one presented with a nodule only, and one with a cyst only. Some morphological features on CT were found particularly helpful in establishing the histological diagnosis of this tumor. All cysts in this series had either a nonenhancing wall or a thin, discontinuous enhancement rim. The remarkable thinness of the cyst is a helpful feature in differentiating between hemangioblastomas and ring enhancement due to metastases. All hemangioblastoma nodules are near the pia, particularly the tentorial surface or the occipital surface of the cerebellum. The nodules in this series were isodense with brain before and enhanced significantly after contrast medium injection, matching or exceeding the density of the straight sinus. In three cases, a large vessel leading to the nodule could be identified on CT. In only one of 10 cases was there a central lucency in the enhancing nodule. The CT density of the hemangioblastoma cyst correlated with the size of the nodule, i.e., the larger the nodule, the denser the cyst on precontrast studies. Compared to cerebellar astrocytomas, hemangioblastomas are not calcified and tend to have relatively small nodule associated with a large cyst. For a given size cyst, the nodule in an astrocytoma is usually larger.

Adult↗
PubMed1982

Computed tomography of tumors involving the atria of the lateral ventricles.

Computed tomograms, angiograms, and operative findings in 18 intra-atrial and 6 para-atrial lateral ventricle tumors were reviewed. Intra-atrial tumors were characteristically homogeneous, with an intraluminal mass effect. The benign types engulfed the choroid glomus; on angiography, the choroidal arteries were enlarged, with a definite tumor blush. Intra-atrial tumors without choroid involvement were usually gliomas. Para-atrial tumors had a low-density center on CT scans (in adults) with an extraluminal mass effect, displaced the glomus, and were avascular on angiography. They were low-grade gliomas in adults and ependymoblastomas in children. Forty non-atrial paraventricular and intraventricular masses were also reviewed. In general, an intraventricular, homogeneous mass which engulfs the choroid glomus on CT and has a significant choroidal artery supply on angiography is of choroidal origin and likely to be benign.

Cerebral Angiography↗
PubMed1981

Computed tomography of cerebral syphilis.

The computed tomographic findings in two patients with clinical and laboratory evidence of neurosyphilis are reported. Two patterns were described, one with pronounced lucency of the white matter and the other with multiple infarctions of unusual distribution.

Aged↗
PubMed1981

Computed tomography in the diagnosis of colloid cysts of the third ventricle.

The computed tomographic findings in 14 cases of colloid cysts of the third ventricle are discussed. These tumors usually present as homogeneous, rounded lesions at the level of the foramina of Monro, with widening of the septum pellucidum. They are commonly hyperdense and show some enhancement upon injection of contrast material. The differential diagnosis of these tumors includes aneurysms of the tip of the basilar artery and the various gliomas of the third ventricle.

Adult↗