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Zoran Rumboldt

Publications and source records attributed to Zoran Rumboldt.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of first-pass and second-bolus dynamic susceptibility perfusion MRI in brain tumors.

INTRODUCTION: Our goal was to evaluate whether the T1 shortening effect caused by contrast leakage into brain tumors, a well-known confounding effect in the quantification of relative cerebral blood volume (rCBV) measurements, may be corrected by the administration of a predose of gadolinium-DTPA. METHODS: As part of their presurgical imaging protocol, 25 patients with primary brain tumors underwent two consecutive dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion MR studies. Intratumoral rCBV measurements and normalized rCBV values obtained during the first-pass and second-bolus studies were compared (Wilcoxon signed-ranks test). The frequency of relatively increased rCBV ratios on the second-bolus study was compared between enhancing and non-enhancing neoplasms (Fisher's exact test). Postprocessing perfusion studies were evaluated for image quality on a scale of 0-3 (Wilcoxon signed-ranks test). Four studies were excluded due to unacceptable image quality. RESULTS: Mean normalized rCBVs were 9.04 (SD 4.64) for the first-pass and 7.99 (SD 3.84) for the second-bolus study. There was no statistically significant difference between the two perfusion studies in either intratumoral rCBV (P=0.237) or rCBV ratio (P=0.181). Five enhancing and four non-enhancing tumors showed a relative increase in rCBV ratio on the second-bolus study, without a significant difference between the groups. Image quality was not significantly different between perfusion studies. CONCLUSION: Our results did not demonstrate a significant difference between first-pass and second-bolus rCBV measurements in DSC perfusion MR imaging. The administration of a predose of gadolinium-DTPA does not appear to be an efficient way of compensating for the underestimation of intratumoral rCBV values due to the T1 shortening effect.

Adolescent↗
PubMed2006

Imaging in head and neck cancer.

The goals of imaging in head and neck cancer are to establish tumor extent and size, to assess nodal disease, to evaluate for perineural tumor spread, and to distinguish recurrent tumor from post-treatment changes. MRI is the preferred modality for assessment of nasopharyngeal, sinonasal, and parotid tumors, because of better contrast resolution, high frequency of perineural spread, and less prominent motion artifacts. MRI is the best modality to delineate the extent of intraorbital and intracranial extension of malignant tumors. Tumors of the oropharynx, larynx, and hypopharynx are frequently primarily imaged with CT, which is less affected by breathing and swallowing artifacts. MRI is also the initial study of choice for tumors confined to the oral tongue, and possibly also for other oral cavity locations because MRI is superior in detection of tumor spread into the bone marrow. There is no clear advantage of CT or MRI for evaluation of nodal disease. Positron emission tomography (PET) is very sensitive for metastatic lymph nodes that are at least 8 mm in size and is the technique of choice in dubious cases. Imaging-guided biopsies are performed whenever needed. For imaging of treated head and neck cancer, PET scans have been found to generally offer higher sensitivity than MRI or CT. Combined PET/CT may be the modality of choice because it almost completely eliminates the false-positive and false-negative PET findings. Patients with head and neck cancer who are referred to tertiary care centers commonly arrive with cross-sectional images obtained at other institutions. Reinterpretation of these studies by dedicated radiologists frequently leads to changes in findings, which alter treatment and affect prognosis.

Biopsy↗
PubMed2005

Disseminated primary diffuse leptomeningeal gliomatosis: a case report with liquid based and conventional smear cytology.

BACKGROUND: Primary diffuse leptomeningeal gliomatosis is a rare neoplasm confined to the meninges without evidence of primary tumor in the brain or spinal cord parenchyma. Cerebrospinal fluid diversion via ventriculoperitoneal shunt may be used as a therapeutic modality. Herein, we describe the first report of cytologic findings of a case of this neoplasm with shunt-related peritoneal metastasis. CASE PRESENTATION: A 19-year-old male presented with a 6-month history of severe headaches. He had bilateral papilledema on physical exam. Cerebrospinal fluid examination was negative. Four months later a ventriculoperitoneal shunt was placed. Shortly thereafter, he was diagnosed with primary diffuse leptomeningeal gliomatosis based on the biopsy of an intradural extramedullary lesion adjacent to the lumbar spinal cord at a referral cancer center. The histology featured an infiltrating growth pattern of pleomorphic astrocytes with diffuse positivity for glial fibrillary acidic protein. A couple of months later he presented at our institution with ascites and an anterior peritoneal mass. Repeat cerebrospinal fluid cytology and fine needle aspiration of the mass confirmed disseminated gliomatosis. Cytologic characteristics included clusters of anaplastic cells of variable size, high nuclear to cytoplasm ratio and scant to moderate cytoplasm. Occasional single bizarre multinucleated cells were seen with eccentric "partial wreath-like" nuclei, clumped chromatin and prominent nucleoli. Patient expired 13 months after initial presentation. CONCLUSION: Disseminated primary diffuse leptomeningeal gliomatosis should be considered in the differential diagnosis of chronic aseptic meningitis and in the presence of a peritoneal tumor in patients with ventriculoperitoneal shunts. Immunocytochemistry may be of diagnostic value.

Journal Article↗
PubMed2005

Arterial compression of the retro-olivary sulcus of the medulla in essential hypertension: a multivariate analysis.

OBJECTIVE: Pulsatile arterial compression (AC) of the ventrolateral medulla (VLM) has been postulated to cause neurogenically mediated essential hypertension (EHTN). We aimed to establish whether the association between AC of specifically the retro-olivary sulcus (ROS) of the VLM and EHTN was significant, while controlling for other risks associated with EHTN. DESIGN: Case-control study. METHODS: Posterior fossa magnetic resonance imaging scans of 131 subjects, including 58 subjects with EHTN and 73 normotensives, were reviewed to determine the presence of AC in the ROS. The history of other risk factors for EHTN was obtained by reviewing medical records. RESULTS: Multivariate logistic regression analysis of these data shows a significant association between AC in the ROS (right and/or left) and EHTN [odds ratio (OR) = 3.03, 95% confidence interval (CI) = 1.30, 7.06]. This analysis was done controlling for other known EHTN risk factors such as age, race, sex, diabetes, and obesity. A secondary analysis also controlling for these variables shows that AC of both the right and left ROS are independently associated with EHTN (right AC: OR = 5.04, 95% CI = 1.33, 19.17; left AC: OR = 3.39, 95% CI = 1.20, 9.60). CONCLUSIONS: In this retrospective study of subjects with EHTN and normotensive controls that had undergone magnetic resonance imaging of the posterior fossa, AC of the ROS on either side of the medulla is a significant independent risk factor in EHTN. Further studies are required to determine whether this is true for the general population of patients with neurogenically mediated EHTN.

Adult↗
PubMed2005

Pituitary adenomas.

Pituitary adenomas are by far the most common sellar tumor and magnetic resonance imaging is the modality of choice for their detection and characterization. However, most of these neoplasms are asymptomatic and frequently incidentally visualized. One also has to be aware of common other incidental findings and normal age-related changes in the appearance of the gland. By convention, 10 mm is used as the size threshold to separate macroadenomas from microadenomas. For microadenomas, imaging is primarily used for lesion detection and localization, whereas with macroadenomas, the goal is to establish whether the mass represents a pituitary tumor or some other lesion and to precisely delineate its extent.

Adenoma↗
PubMed2005

Perfusion CT for head and neck tumors: pilot study.

BACKGROUND AND PURPOSE: Differentiation of malignant from benign head and neck lesions is often very difficult on imaging studies, especially in patients with treated cancer. We evaluated the feasibility and reproducibility of perfusion CT (CTP) after enhanced head and neck CT and attempted to differentiate benign from malignant processes. METHODS: CTP was attempted in 17 patients after head and neck contrast-enhanced CT. Data were postprocessed by using deconvolution-based perfusion analysis. Ipsilateral and contralateral internal, external, and common carotid arteries were used as arterial input vessels. Postprocessing-generated maps showed mean transit time (MTT), blood volume, blood flow, and capillary permeability surface product. Two readers independently placed regions of interest through the primary site, salivary glands, thyroid gland, paraspinous muscles, muscles of mastication, sternocleidomastoid muscle, base of tongue, and subcutaneous fat. One reader repeated the measurements on separate dates. Data were statistically analyzed, and histologic specimens were obtained. RESULTS: CTP was not possible in four patients, and one was lost to follow-up. Of the remaining 12, five had cancer, and seven had benign processes. We found no significant interreader or intrareader differences and no significant difference between various input vessels. Differentiation between malignant and nonmalignant lesions was most reliable by using MTTs. Measurements were comparable to those in the literature. CONCLUSION: CTP after enhanced head and neck CT is feasible, except perhaps at the laryngeal level. It appears to be reader independent and reproducible regardless of the input vessel. CTP shows promise in distinguishing benign and malignant processes, primarily by means of MTTs.

Adolescent↗
PubMed2005

Transient traumatic spinal venous hypertensive myelopathy.

We present a case of a reversible spinal venous hypertensive myelopathy that occurred following a traumatic mediastinal hematoma. The mediastinal hematoma caused compression of the brachiocephalic vein, resulting in elevation of the venous pressures that ultimately resulted in dilation of the epidural venous plexus and spinal cord edema. The secondary neurologic deficits were the culmination of venous outflow obstruction at the level of the spinal cord that resolved on the resolution of the mediastinal hematoma.

Adolescent↗
PubMed2005

Diffusion-weighted imaging, apparent diffusion coefficients, and fluid-attenuated inversion recovery MR imaging in endophthalmitis.

We describe the appearance of endogenous bacterial endophthalmitis in a patient who underwent MR imaging of the orbits before and during the course of treatment. Intraocular hyperintensity on fluid-attenuated inversion recovery and diffusion-weighted images were found very useful for diagnosing endophthalmitis. After a few days of treatment, a marked relative increase in intraocular mean apparent diffusion coefficient values was observed, which appears to indicate good treatment response.

Anti-Bacterial Agents↗
PubMed2005

Brain MR imaging abnormalities in kidney transplant recipients.

BACKGROUND AND PURPOSE: On the basis of limited available data, brain MR imaging abnormalities in kidney transplant recipients (KTRs) have been predominantly attributed to calcineurin inhibitors (CIs), characteristically presenting as posterior reversible encephalopathy syndrome (PRES). The goal of this study was to evaluate whether CIs play an important role in the incidence, nature, and location of MR imaging brain lesions in adult KTRs by comparing them with dialysis-dependent patients. METHODS: We retrospectively analyzed 98 brain MR imaging examinations in 77 consecutive KTRs presenting with neurologic symptoms from 1990 to 2003. The data were separated into 3 groups according to duration after transplantation of MR imaging: group 1, 0-3 months; group 2, 3-12 months; and group 3, >12 months. Twenty-six MR imaging examinations from 24 additional dialysis-dependent adults were used as controls and comprised group 0. RESULTS: Acute changes (infarcts, infections, PRES) comprised 24% and 19% of lesions in KTRs and group 0 patients, respectively, with infarcts being the most common in all groups. Chronic lesions were responsible for 76% of changes in KTR and 81% in group 0 and were predominantly vascular in etiology. No statistically significant differences in incidence of PRES or other acute changes were found between dialysis-dependent patients and either individual KTR groups or all KTR patients combined. The deep gray matter lesions were more common in KTR, whereas frontal white matter was more frequently affected in patients on dialysis. CONCLUSION: Our study does not support suggestion that MR imaging brain abnormalities in KTR are predominantly due to direct CI toxicity.

Adolescent↗
PubMed2005

Nonenhancing spinal subdural metastatic tumor.

We describe a case of a spinal subdural metastatic tumor that became rapidly symptomatic after a minor trauma, as a result of severe cord compression and cord hemorrhage. On MR imaging, the lesion was oval, hyperintense with a dark rim on T2-weighted fast spin-echo images, isointense to the cord on T1-weighted images, and had dark and bright areas on gradient-echo T2*-weighted images, consistent with a hyperacute-to-acute hematoma. The hemorrhagic tumor showed no evidence of contrast enhancement.

Cervical Vertebrae↗
PubMed2003

Herpes encephalitis.

Explore the source record for details and available documents.

Encephalitis, Herpes Simplex↗
PubMed2003

Magnetization transfer, HASTE, and FLAIR imaging.

Continuous technologic developments and research have increased the clinical applications of MT, HASTE, and FLAIR imaging in neuroradiology. HASTE has become the MR imaging sequence of choice for fetal neuroimaging. Other promising uses, such as for diffusion-weighted imaging, have not been fully exploited. FLAIR has been firmly established as one of the cornerstones of brain imaging; however, post-contrast FLAIR images have not offered a clear advantage over standard T1-weighted images as suggested by early studies. FLAIR imaging with echoplanar acquisition is not considered advantageous, because the decreased imaging times are obtained at the expense of lower sensitivity. For a number of applications, diffusion-weighted imaging has surpassed FLAIR. Nevertheless, FLAIR images may be more sensitive for the detection of acute brain infarction. Recently described methods for the elimination of CSF flow artifacts may lead to improved quality and reliability of FLAIR images for subarachnoid space disease. MT preparation is now routinely incorporated in time-of-flight MR angiography and gradient-echo T2*-weighted spine imaging sequences and provides increased sensitivity for postcontrast MR imaging. These applications may not be advantageous in all clinical settings. MTR analysis offers valuable information for an increasing number of pathologic processes but has not yet gained wide clinical acceptance owing to sophisticated postprocessing and significant intercenter variations. Different modifications of these techniques are being evaluated, and further developments are expected.

Brain↗