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Biomedical subjects

J Ahmadi

Publications and source records attributed to J Ahmadi.

69 records · Page 4Linked to original sources
PubMedDate not supplied

SPIR MRI in spinal diseases.

We report on our experience with the fat suppression technique of spectral presaturation with inversion recovery MR in imaging certain spinal disorders. This technique may assist in demonstrating or excluding the presence of fat within a lesion (such as lipoma, dermoid, teratoma) or within a normal structure (i.e., vertebral body or epidural space). The method can also be used to suppress normal fat (such as marrow or epidural fat) thus increasing the conspicuity of adjacent high signal intensity lesions seen on T1-weighted images (such as blood and contrast-enhancing tumors or inflammatory lesions).

Abscess↗
PubMedDate not supplied

MRI of intraventricular cysticercosis: surgical implications.

OBJECTIVE: Our goal was to evaluate the role of Gd-enhanced MR in the diagnosis and surgical planning of intraventricular cysticercosis cysts. MATERIALS AND METHODS: Thirty-three patients with intraventricular cysticercosis were evaluated with Gd-enhanced MRI including follow-up studies ranging over time periods from 6 months to 8 years. The patient age ranged from 17 to 65 years. All had lived in Mexico or Central America. RESULTS: Twenty patients had surgical removal of the cysts. The majority of patients (18 of 20) who had surgical removal of the cyst showed improvement with resolution of hydrocephalus. Two of 20 patients required additional shunting to alleviate hydrocephalus. In these two patients, Gd-enhanced MR showed cyst wall enhancement. Ependymitis with adhesion was found at surgery in these two patients. Nine patients had shunt placement; one of nine patients showed cyst enlargement 2.5 years later that required surgical removal. Of the remaining eight patients, four showed irregular, thick, ring-like enhancement mimicking a neoplasm on follow-up imaging studies. Four patients with cysts in the lateral ventricle did not require treatment. Two of the four patients showed irregular, thick, ring-like enhancement on follow-up imaging studies. CONCLUSION: Gadolinium-enhanced MR is more sensitive than contrast-enhanced CT for detecting ependymitis, which is essential in deciding whether surgical removal of the cyst or shunt placement is indicated. A degenerating intraventricular cysticercosis cyst may present as an irregular, thick, ring-like enhancing lesion or a nodular enhancing lesion with varying degrees of surrounding edema, mimicking a neoplasm.

Adolescent↗
PubMedDate not supplied

Cervical intraextradural hematoma secondary to radicular artery injury: a case report.

A young man presented with a 5-year history of high cervical pain after a blunt blow to the neck and clinical evidence of myelopathy. Preoperative radiographic findings, including metrizamide myelography, CT scan, and vertebral angiography, were consistent with a right C2-3 "dumbell" shaped intradural-extradural tumor. At surgery a firm red-grey mass was found beneath an abnormally thin right C2-3 facet joint. This mass was both intradural and extradural and extended laterally through the root canal to merge with an area of dense adhesions surrounding the vertebral artery. Pathological examination showed no tumor and was consistent with chronic, organized hematoma. Aspects of this unique case of intradural-extradural hematoma in the distribution of a radicular vessel, and possible etiologic considerations are discussed.

Adult↗
PubMedDate not supplied

CT anatomy of the craniovertebral junction in infants and children.

Computed tomographic (GE 9800) images of 129 patients (from newborn to 18 years old) with no evidence of cervical spine pathology were reviewed retrospectively from available material to evaluate normal anatomic appearances in childhood. The synchondroses may appear solid at soft-tissue window settings, while, with appropriate bone-window settings, a lucent line will be seen. Residual lucency and then (generally) sclerosis were seen at synchondroses past the age of classic anatomic fusion. A transversely oriented groove on the undersurfaces of the occipital condyles was imaged in children ages 5-12 years. This groove is described radiologically in that age range for the first time in this report. The development of the ossification centers of C1 was illustrated with CT. The two vertically oriented, rod-shaped ossification centers of the lower dens develop a bilobed appearance in axial section when they begin to fuse. An apparent deficiency of the cortex seen posteriorly in this area (in children as old as 7 years) represents the last remnant of the cleft between the dens centers. The cord was always outlined distinctly by CSF at soft-tissue settings at the foramen magnum and C1 levels without intrathecal or IV contrast enhancement. This anatomic feature is particularly useful since it enables the evaluation of the spinal canal in this region in some cases (especially craniovertebral junction anomalies) without the need for intrathecal contrast materials.

Adolescent↗
PubMedDate not supplied

Morgagni-hernias during infancy.

Five cases of Morgagni hernia observed in Teheran Children's Hospital in 1973-1983 are reported. Four of the diagnosed cases were infants less than seven months of age and all presented respiratory symptoms: two of them accompanied by associated malformations. In four cases the hernia was present on the right side and in one on the left. The most common contents of the hernial sac were colon, small-bowel, liver, omentum and stomach. A transthoracic approach was advocated only in cases with solid content in the hernial sac or when differentiation from a solid mass was difficult. For the other cases the transabdominal approach was preferred. The operation chosen of treatment, gave satisfactory results in all the patients.

Abnormalities, Multiple↗
PubMedDate not supplied

Follow-up pathology of cranial computed tomography: pitfalls in clinical-radiological evaluation.

Interpretation of cranial computed tomography in five patients and angiography in one of these patients contributed significantly to primary clinical diagnoses and management; however, the diagnoses were incorrect. The lesions in the radiographic studies were correlated with classical clinical findings. Associated and generally unappreciated clinical or radiographic findings also were present and could have lead to reconsideration of at least some of the primary diagnoses. The unusual or unique presentations resulting in underdiagnosis or overdiagnosis lead to nonbeneficial or improper care. Cerebrovascular and infectious diseases found in most of these cases are recognized as common areas of diagnostic difficulty by previous and present follow-up pathological studies.

Adult↗
PubMedDate not supplied

Early CT detection of intracranial seeding from medulloblastoma.

Since 1975, intracranial subarachnoid metastases of medulloblastoma have been detected in seven of 23 initial contrast-enhanced computed tomographic (CT) scans in children with proven medulloblastoma. Furthermore, four of the seven cases with subarachnoid seeding were diagnosed after the introduction of high-resolution contrast-enhanced CT. Only three cases of seeding had been detected in the previous 17 low-resolution cases studied with CT. Thus, it is quite likely that the incidence of subarachnoid metastases may be substantially more than the overall figure of 30% indicated by this series. This may have an impact on the treatment of these patients, since the frequent appearance of metastases may indicate the need for more vigorous chemotherapeutic regimens. One should be aware of the possibility of early intracranial subarachnoid seeding and that it can be demonstrated by contrast-enhanced CT. This is particularly true when using high-resolution scanners in conjunction with 5 mm sections through the posterior fossa.

Adolescent↗
PubMedDate not supplied

CT patterns in histopathologically complex cavernous hemangiomas.

Computed tomographic (CT) studies were correlated with microscopic findings in 10 histologically verified cavernous hemangiomas in nine patients. In four of the 10 lesions, two or more distinct types of cerebrovascular malformations were identified histopathologically. These included arteriovenous malformations, venous malformations, and telangiectasis. Such coexistence of various types of cerebrovascular malformations has been reported rarely. In each of the four combined lesions, there was evidence of recent or old hemorrhage. The CT findings were nonspecific and were similar to those seen in a variety of intracranial pathologic conditions.

Adult↗
PubMedDate not supplied

CT observations pertinent to septic cavernous sinus thrombosis.

The use of high-resolution computed tomography (CT) is described in four patients with septic cavernous sinus thrombosis. In all patients CT findings included multiple irregular filling defects in the enhancing cavernous sinus. Unilateral or bilateral inflammatory changes in the orbital soft tissues were also present. Enlargement of the superior ophthalmic vein due to extension of thrombophlebitis was noted in three patients.

Aged↗
PubMedDate not supplied

Computed tomography of carotid-cavernous fistula.

Fourteen patients with angiographically-proven carotid-cavernous fistulas were evaluated by computed tomography (CT). Unilateral or bilateral exophthalmos was noted in 12 patients. Slight blurring of the margin of the globe was present in two, presumably due to pulsations of the globe or conjunctival edema. Superior ophthalmic veins were prominent in 12 patients and were often larger on the side of the fistula. Irregularity or absence of contrast enhancement of the superior ophthalmic vein may indicate partial or complete thrombosis. Focal bulging or diffuse distention of the cavernous sinus was noted in nine patients. Enlargement of the extraocular muscles was observed in seven with swelling of the eyelids and edema of the conjunctiva in eight patients. The pattern of venous drainage, type of fistula, and time intervals between trauma, commencement of fistula, and CT scan may affect the CT manifestations of carotid-cavernous fistulas.

Adult↗
PubMedDate not supplied

Ischemic chiasmal syndrome and hypopituitarism associated with progressive cerebrovascular occlusive disease.

Two interesting patients are described with unique clinical and radiographic manifestations of progressive bilateral stenosis-occlusion of the distal internal carotid arteries. Their clinical presentations, ischemic chiasmal syndrome and hypopituitarism, are extremely rare, despite extensive occlusion of the circle of Willis. In one of these patients, the configuration of collateral vessels around the optic chiasm on computed tomography (CT) was so rounded and discrete that it actually had an appearance suggesting a pituitary tumor or an aneurysm. In the second patient, a pseudoaneurysm and a very large intracerebral hematoma with a ring of contrast enhancement were the radiographic manifestations.

Adult↗
PubMedDate not supplied

Intraventricular cysticercal cysts: further neuroradiologic observations and neurosurgical implications.

Intraventricular cysticercosis is potentially lethal. Six of 46 patients died from acute hydrocephalus shortly after hospital admission. The need for early computed tomographic scanning in immigrants from endemic areas complaining of headaches is emphasized by this experience. If time has elapsed since the initial diagnosis, these cysts may migrate within the ventricular system. Reconfirmation of the location of an intraventricular cysticercal cyst is advisable before surgery. Contrast enhancement of an intraventricular cysticercal cyst implies associated granular ependymitis. Surgical removal of such cysts probably should not be attempted as long as the cysts are not causing significant mass effect with neurologic signs and symptoms. Shunting alone is advocated for the treatment of hydrocephalus.

Adolescent↗
PubMedDate not supplied

Spinal epidural hematoma with subarachnoid hemorrhage caused by acupuncture.

Unintentional acupuncture needling of the thoracic spinal canal produced a spinal epidural hematoma and subarachnoid hemorrhage. This case demonstrates that patients are sometimes reluctant to disclose folk medical treatments to Western physicians, and the proper diagnosis may depend upon the prowess of the neuroradiologist.

Acupuncture Therapy↗