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Majda M Thurnher

Publications and source records attributed to Majda M Thurnher.

8 recordsLinked to original sources
PubMed2006

Diffusion-weighted MR imaging (DWI) in spinal cord ischemia.

INTRODUCTION: Spinal cord infarction is a rare clinical diagnosis characterized by a sudden onset of paralysis, bowel and bladder dysfunction, and loss of pain and temperature perception, with preservation of proprioception and vibration sense. Magnetic resonance imaging (MRI) usually demonstrates intramedullary hyperintensity on T2-weighted MR images with cord enlargement. However, in approximately 45% of patients, MR shows no abnormality. Diffusion-weighted MR imaging (DWI) has been widely used for the evaluation of a variety of brain disorders, especially for acute stroke. Preliminary data suggest that DWI has the potential to be useful in the early detection of spinal infarction. METHODS: We performed DWI, using navigated, interleaved, multishot echo planar imaging (IEPI), in a series of six patients with a clinical suspicion of acute spinal cord ischemia. RESULTS: In all patients, high signal was observed on isotropic DWI images with low ADC values (0.23 and 0.86x10(-3) cm(2)/s), indicative of restricted diffusion. CONCLUSION: We analyzed the imaging findings from conventional MR sequences and diffusion-weighted MR sequences in six patients with spinal cord infarction, compared the findings with those in published series, and discuss the value of DWI in spinal cord ischemia based on current experience. Although the number of patients with described DWI findings totals only 23, the results of previously published studies and those of our study suggest that DWI has the potential to be a useful and feasible technique for the detection of spinal infarction.

Adolescent↗
PubMed2006

Analysis of the utility of diffusion-weighted MRI and apparent diffusion coefficient values in distinguishing central nervous system toxoplasmosis from lymphoma.

INTRODUCTION: Toxoplasmosis and lymphoma are common lesions of the central nervous system in patients with AIDS. It is often difficult to distinguish between these lesions both clinically and radiographically. Previous research has demonstrated restricted diffusion within cerebral lymphomas and bacterial abscesses. However, little work has been done to evaluate the diffusion characteristics of toxoplasmosis lesions. This study was designed to explore further the utility of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps and values in making the distinction between toxoplasmosis and lymphoma. METHODS: The magnetic resonance imaging (MRI) studies of 36 patients, including 22 with toxoplasmosis (all of whom had AIDS) and 14 with lymphoma (8 of whom had AIDS), at two institutions were reviewed retrospectively. The characteristics of the lesions on DWI were evaluated, and the ADC ratios of the lesions were calculated and compared. RESULTS: There was significant overlap of the ADC ratios of toxoplasma and lymphoma, most notably in the intermediate (1.0-1.6) range. There was variability in ADC ratios even among different lesions in the same patient. In only a minority of the lymphoma patients were the ADC ratios low enough to suggest the correct diagnosis. CONCLUSION: Our study showed that toxoplasmosis exhibits a wide spectrum of diffusion characteristics with ADC ratios which have significant overlap with those of lymphoma. Therefore, in the majority of patients, ADC ratios are not definitive in making the distinction between toxoplasmosis and lymphoma.

AIDS-Related Opportunistic Infections↗
PubMed2005

Imaging in acute stroke.

Stroke is a syndrome characterized by a sudden neurological deficit caused by intracranial hemorrhage or ischemia. Computed tomography (CT) maintains a primary role in the evaluation of patients with acute stroke. The optimal magnetic resonance imaging (MRI) protocol in acute stroke includes diffusion-weighted imaging (DWI) to show acute ischemic lesion and MR perfusion study to estimate brain perfusion. Careful selection of patients for a thrombolytic therapy is crucial to improve safety and efficacy.

Algorithms↗
PubMed2005

Diffusion-tensor MR imaging of the brain in human immunodeficiency virus-positive patients.

BACKGROUND AND PURPOSE: There is early evidence that diffusion-tensor imaging (DTI) is useful in demonstrating subtle white matter alterations in different diseases of brain. We hypothesize that DTI in several brain regions in human immunodeficiency virus-positive (HIV+) patients is useful in the early detection of HIV-related brain injury. METHODS: MR imaging and DTI were performed in 60 HIV+ patients and in 30 controls. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC; mm/s(2)) maps were generated and coregistered on T2-weighted images. Regions of interest were placed in the splenium and genu of the callosum, the frontal white matter, and the hippocampus. HIV+ patients were divided into those whose CD4 count were <250 cells/mm(3) or >250 cells/mm(3). According to plasma viral loads, patients were divided into those whose viral loads were <50 copies/mL, 50-100,000 copies/mL, or >100,000 copies/mL. RESULTS: Statistically significant decrease of FA was found in the genu of the corpus callosum in HIV+ patients compared with controls. FA was reduced in the frontal white matter and hippocampi in HIV+ patients compared with controls. Differences, however, were not statistically significant. No statistically significant differences were found between the HIV+ groups for FA of the splenium or between these groups and the controls. ADC values were significantly increased in the genu of HIV+ patients when compared with controls and were also increased in other locations, but without statistical significance. CONCLUSION: As used in this study, DTI was not helpful in identifying patients with early HIV infection.

Adolescent↗
PubMed2004

Diffusion-weighted imaging in the assessment of brain abscesses therapy.

BACKGROUND AND PURPOSE: Surgically or conservatively treated brain abscesses may resolve, or pus may re-accumulate, requiring further intervention or treatment change. We hypothesized that diffusion-weighted (DW) imaging is useful in depicting features of abscesses related to therapeutic success or failure. METHODS: Conventional contrast-enhanced T1- and T2-weighted imaging and DW imaging were performed in seven patients (aged 30-69 years) with proved pyogenic brain abscesses. The center of the abscess was qualitatively and quantitatively analyzed at initial and follow-up imaging in all patients. We correlated the signal intensity on trace DW images and the apparent diffusion coefficients (ADCs) with the clinical and laboratory data, particularly with respect to treatment failure and repeat therapy. RESULTS: Surgical drainage was performed in six patients; one patient was treated with only antibiotics. All abscess cavities initially had high signal intensity (restricted diffusion) on DW images, with a mean ADC value of 0.52 x 10 (-3)mm (2)/s. Low signal intensity at DW imaging with high ADC were seen on follow-up images in the patient receiving medication and in four patients in whom the abscesses were drained; this correlated with a good therapeutic response. Two patients underwent drainage; their second follow-up DW images showed areas of high signal intensity and low ADC values suggesting re-accumulation of pus. Increased C-reactive protein level and WBC count correlated well with DW image findings. CONCLUSION: DW imaging was superior to conventional MR imaging in evaluating the success or failure of abscess therapy. Restricted diffusion in a drained abscess corresponded to pus.

Adult↗
PubMed2003

Suspected pulmonary embolism: enhancement of pulmonary arteries at deep-inspiration CT angiography--influence of patent foramen ovale and atrial-septal defect.

PURPOSE: To investigate if abnormal early contrast enhancement of the aorta and decreased attenuation of pulmonary arteries at deep-inspiration spiral computed tomographic (CT) angiography might be caused by a patent foramen ovale (PFO). MATERIALS AND METHODS: Two hundred forty-four spiral CT angiographic images of the pulmonary arteries obtained during deep inspiration in patients suspected of having pulmonary embolism (PE) were reviewed for evidence of abnormal early enhancement of the aorta. In 45 patients, enhancement of the ascending aorta was equal to or more than that of the pulmonary arteries. Nonenhanced or contrast material-enhanced echocardiography was performed in 39 of these cases. All CT images with abnormal enhancement patterns were graded for contrast quality with respect to sufficient enhancement of pulmonary arteries (four grades) at three anatomic levels: right and left main and lobar and segmental branches. In addition, all spiral CT angiographic images were evaluated concerning the diagnosis of PE and the grouping of central (main pulmonary artery to proximal lobar arteries) and peripheral (beyond proximal lobar branches) locations of emboli. Mean attenuation values of ascending aortas and main pulmonary arteries in group 1 (n = 244) were compared with those in groups 2 and 3 (n = 45) by means of the two-tailed Student t test for unpaired data (P <.05). RESULTS: Attenuation values for ascending aortas in group 1 were significantly lower than those in groups 2 and 3 (P <.001). Attenuation values in main pulmonary arteries were significantly higher in group 1 than in groups 2 and 3 (P <.001). Echocardiographic images showed an intracardiac right-to-left shunt in all 39 cases with abnormal contrast dynamics in the CT study (16% of the whole study population). Three patients had an atrial-septal defect, and 36 had a PFO. Images with a shunt had good (9%), intermediate (37%), fair (33%), and poor (23%) contrast of the pulmonary arteries. Sufficient vessel contrast for the diagnosis of PE could not be achieved in 27 of 45 patients with a shunt, but severe central PE could be ruled out. PE could be diagnosed in 31% of the 244 images, 58% were negative, and 11% were indeterminate. CONCLUSION: A PFO may frequently lead to insufficient attenuation of the pulmonary arteries, which potentially limits the diagnosis of PE if the examination is performed during deep inspiration.

Adolescent↗
PubMed2002

Arterial embolization of unresectable hepatocellular carcinoma with use of cyanoacrylate and lipiodol.

PURPOSE: To assess the potential of transarterial permanent embolization with use of a mixture of cyanoacrylate and lipiodol for treatment of unresectable primary hepatocellular carcinoma (HCC). MATERIALS AND METHODS: In a retrospective study, 36 patients with histologically proven HCC were treated with transarterial embolization (TAE) of the hepatic arteries. None of these patients were candidates for surgical resection and some had advanced disease with multinodular disease or bulky tumor, thrombosis of a segmental branch of the portal vein, and/or extrahepatic spread. To induce permanent and more peripheral embolization, cyanoacrylate, an adhesive polymerizing on contact with blood, was used in TAE. From 1990 to 1998, a total of 76 embolization procedures were performed. Cumulative survival rates were calculated. RESULTS: Most of the patients presented with a self-limited postembolization syndrome. Severe procedure-related complications were found after four treatment sessions (5.2%). The 30-day perioperative mortality rate was 2.7%. The mean follow-up period was 20.3 months (range, 1-68 mo), with a median survival of 26 months. The median survival was also estimated for different Okuda stages of disease: stage II (n = 26) versus stage III (n = 5) disease (32 vs 9 months; P <.05); patients with (n = 9) or without (n = 27) extrahepatic metastasis (10 vs 26 months; P <.05); and patients with (n = 10) or without (n = 26) thrombosis of a segmental branch of the portal vein (7 versus 34 months [P <.005]). CONCLUSION: TAE with use of cyanoacrylate and lipiodol for unresectable HCC is a feasible treatment modality. This retrospective report indicates beneficial effects on survival even in patients with advanced disease.

Adult↗