Involvement of renal vessels and the inferior vena cava (IVC) plays a decisive role during operative planning for removal of abdominal masses in pediatric patients. Advantages and limitations of MR ...angiography and color Doppler sonography for determining these factors were evaluated.
MR angiography and color Doppler sonography were performed preoperatively in 42 neonates, infants, and children with abdominal masses and were compared with spin-echo MR imaging and with surgical findings. Variables evaluated were anatomic variants, vessel displacement, patency of vessels, collateral circulation, and intravascular tumor extension. Quality of vessel visualization was assessed in vessels not affected by tumor.
In 88% of unaffected renal vessels, the entire vessel course could be visualized on MR angiography compared with 58% on color Doppler sonography and 43% on spin-echo MR imaging. In four of nine cases, color Doppler sonography revealed an accessory renal artery, whereas MR angiography revealed these variants in seven of nine cases. MR angiography showed 79% and color Doppler sonography 66% of displaced vessels. Unlike MR angiography, color Doppler sonography did not reveal five stenotic renal veins because they could not be completely imaged. In two cases, however, MR angiography falsely indicated an occlusion of the IVC, whereas color Doppler sonography showed residual flow.
Anatomic variants, vessel displacement, collateral circulation, and neoplastic vessel infiltration were revealed more accurately by MR angiography than by color Doppler sonography. In cases in which patency of the IVC is unclear on MR angiography, color Doppler sonography should also be performed.
Background: It is a challenge to reliably measure the lobar volumes from magnetic resonance imaging (MRI) data.
Objective: Description of a landmark-based method for volumetric segmentation of the ...brain into the four cerebral lobes from MR images.
Method: The segmentation method relies on a combination of anatomical landmarks and geometrical definitions. The first step, described previously, is a segmentation of the four lobes on the surface of the brain. The internal borders between the lobes are defined on the axial slices of the brain. The intra- and inter- rater reliability was determined from the MRI scans of a group of 10 healthy control subjects measured by 2 independent raters.
Results: The intra-rater relative error (and intra-class correlation coefficient) of the lobar volume measures ranged from 0.81% to 3.85% (from 0.97 to 0.99). The inter-rater relative error (and intra-class correlation coefficient) ranged from 0.55% to 3.09% (from 0.94 to 0.99).
Conclusion: This technique has been shown to have high intra- and inter-rater reliability. The current method provides a method to obtain volumetric estimates of the 4 cerebral lobes.
The case of a 66-year-old, asymptomatic patient with a papillary adenoma of type-II pneumocytes is reported. Following the coincidental radiologic finding of a solitary pulmonary nodule, the ...diagnosis could be established in a bronchoscopically obtained endobronchial biopsy. A resection of the involved segments S8-10 on the left side was performed. Papillary adenoma of type-II pneumocytes is a rare tumor, whose origin is suspected in progenitor cells of the bronchioloalveolar epithelium with the potential to differentiate towards type-II pneumocytes and clara cells. The tumor is regarded as benign, however, a malignant potential is not excluded by some authors.
To validate xenon-133 dynamic single photon emission tomography (SPECT) clinically, 74 patients were examined. Strictly unilateral cerebrovascular disease was confirmed in 47 patients by clinical ...history and by transmission computerized tomography (TCT) and contrast angiography. Twenty-seven were excluded, considered normal. SPECT flow maps were evaluated visually (against TCT) or by automated region of interest (ROI) techniques (12 areas per slice) to measure area flow (AF) (ml/100 g-min) and interhemispherical area flow ratios (AR). These were compared with normal values. Minimum AF in affected hemisphere decreased, and AR-to-normal difference increased, with the severity of the disease. Visually, low-flow areas were detected twice as frequently in SPECT as areas of low density of TCT. In reversible episodes, sensitivity of AF alone ws significantly below the sensitivity of combined evaluation of flow and ratio.
Immunoscintigraphy of malignant tumours has become an encouraging tool in nuclear medicine. Early diagnosis of small lesions is mandatory for successful cancer therapy. The scintigraphic ...detectability of small lesions (less than 1 cm in diameter) by immunoscintigraphy is shown in 39 patients suffering from ocular tumours (37 malignant choroidal melanoma, two benign choroidal naevi) using 99Tcm-labelled F(ab')2 fragments of the anti-melanoma monoclonal antibody 225.28S; this antibody recognizes the high molecular weight melanoma-associated antigen. No adverse effects were observed. In terms of true-positive results, single photon emission computed tomography (SPECT) proved to be superior to planar scans (73% versus 41% true-positive results).
This study investigated the effect on brain morphology of an interleukin-1beta genetic polymorphism (C-->T transition at position -511) in patients with schizophrenia.
In vivo magnetic resonance ...imaging and genotype analysis were used in the examination of 44 male schizophrenic patients and 48 healthy male comparison subjects.
No association between the interleukin-1beta polymorphism and schizophrenia was detected. Within the patient group, bifrontal-temporal gray matter volume deficits and generalized white matter tissue deficits in allele 2 carriers (genotype T/T or C/T) were found. In contrast, the interleukin-1beta polymorphism had no influence on brain morphology within the healthy subjects.
The data suggest that allele 2 within the promoter region of the interleukin-1beta gene at position -511 contributes to structural brain alterations in patients with schizophrenia.
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