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Diagnostic Possibilities (diagnostic + possibility)
Selected AbstractsAnalysis of b -value calculations in diffusion weighted and diffusion tensor imagingCONCEPTS IN MAGNETIC RESONANCE, Issue 1 2005Daniel Güllmar Abstract Diffusion weighted imaging has opened new diagnostic possibilities by using microscopic diffusion of water molecules as a means of image contrast. The directional dependence of diffusion has led to the development of diffusion tensor imaging, which allows us to characterize microscopic tissue geometry. The link between the measured NMR signal and the self-diffusion tensor is established by the so-called b matrices that depend on the gradient's direction, strength, and timing. However, in the calculation of b -matrix elements, the influence of imaging gradients on each element of the b matrix is often neglected. This may cause errors, which in turn leads to an incorrect extraction of diffusion coefficients. In cases where the imaging gradients are high (high spatial resolution), these errors may be substantial. Using a generic pulsed gradient spin-echo (PGSE) imaging sequence, the effects of neglecting the imaging gradients on the b -matrix calculation are demonstrated. By measuring an isotropic phantom with this sequence it can be analytically as well as experimentally shown that large deviations in single b -matrix elements are generated. These deviations are obtained by applying the diffusion weighting in the readout direction of the imaging dimension in combination with relatively large imaging gradients. The systematic errors can be avoided by a full b -matrix calculation considering all the gradients of the sequence or by generating cross-term free signals using the geometric average of two diffusion weighted images with opposite polarity. The importance of calculating the exact b matrices by the proposed methods is based on the fact that more precise diffusion parameters are obtained for extracting correct property maps, such as fractional anisotropy, volume ratio, or conductivity tensor maps. © 2005 Wiley Periodicals, Inc. Concepts Magn Reson Part A 25A: 53,66, 2005 [source] Spindle-cell lesions of the liver: Diagnosis by fine-needle aspiration biopsyDIAGNOSTIC CYTOPATHOLOGY, Issue 2 2001Cynthia D. Guy M.D. Abstract Rarely, spindle-cell lesions in liver fine-needle aspiration biopsies (FNABs) are encountered. A retrospective review of our experience with lesions that are mesenchymal in origin or appearance was undertaken to elucidate the frequency and spectrum of these lesions. Image-guided liver FNABs performed over a 3-year period (n = 585) at our institution (1996,1998) were retrospectively evaluated. Cytologic smears, cell block preparations, and clinical follow-up of lesions with spindle-cell morphology were reviewed. Twenty-nine of 585 cases were of spindle-cell morphology (5%). Hemangiomas (n = 12, 41%) and metastatic sarcomas (n = 6, 21%) comprised the largest categories, followed by granulomatous inflammation (n = 3, 10%). Other cases included primary angiosarcoma and fibrolamellar hepatocellular carcinoma. The most frequent spindle-cell liver lesion encountered is hemangioma, followed by metastatic leiomyosarcoma and granulomatous hepatitis. Awareness of diagnostic possibilities, special attention to specimen adequacy, and use of ancillary procedures can maximize diagnostic yield. Diagn. Cytopathol. 2001;25:94,100. © 2001 Wiley-Liss, Inc. [source] Pseudotumoral encapsulated fat necrosis with diffuse pseudomembranous degenerationJOURNAL OF CUTANEOUS PATHOLOGY, Issue 8 2004F. Felipo An extraordinary case of encapsulated fat necrosis characterized by its large size, diffuse formation of pseudomembranes, and tendency to recur after excision is reported. A 67-year-old Caucasian woman suffering from morbid obesity was admitted for diagnosis and surgical treatment of a soft tissue mass showing a longest diameter of 14 cm and lying adjacently to the scar from previous appendicectomy. Histopathologic features were consistent with a nodular-cystic encapsulated fat necrosis with diffuse pseudomembranous transformation. Eight months after surgery, a new larger mass (longest diameter of 18 cm) sharing identical histopathologic features appeared in the same location. Encapsulated fat necrosis is a well-defined entity even though several names have been proposed for this condition, including mobile encapsulated lipoma, encapsulated necrosis, or nodular-cystic fat necrosis. Its pathogenesis seems to be related to ischemic changes secondary to previous trauma. It may occasionally show degenerative changes, including dystrophic calcifications and presence of pseudomembranes. To our knowledge, these are the first reported cases of encapsulated fat necrosis presenting as lesions of such size and showing diffuse formation of pseudomembranes; these particular features made diagnosis difficult and led to consideration of a wide range of potential diagnostic possibilities. This case expands the clinico-pathologic spectrum of membranocystic fat necrosis, including the potential ability of this subcutaneous fatty tissue abnormality to recur after surgical excision. [source] Rheumatoid Leptomeningitis: Magnetic Resonance Imaging and Pathologic Findings,A Case ReportJOURNAL OF NEUROIMAGING, Issue 2 2010Alessandro Cianfoni MD ABSTRACT BACKGROUND AND PURPOSE Rheumatoid arthritis (RA) is a chronic inflammatory multisystem disease with articular and extra-articular manifestations. Intracranial manifestations of RA are rare. Purpose of this article is to report on a rarely described leptomeningeal involvement in RA, and on its neuroimaging features, including diffusion-weighted imaging (DWI). METHODS The authors describe the case of a 74-year-old woman with a 5-year history of RA presenting with progressive left-side weakness and hypoesthesia. The patient underwent laboratory investigation and brain contrast-enhanced MRI, also with DWI, before undergoing brain biopsy. RESULTS Neuroimaging revealed abnormal high T2-signal in right frontal and parietal lobes, restricted diffusion in the subarachnoid space, and diffuse thick linear leptomeningeal contrast-enhancement. These findings were interpreted as rheumatoid leptomeningitis, and brain biopsy confirmed this diagnosis. CONCLUSIONS In summary, rheumatoid meningitis is a rare neurological complication of RA, but it should be considered in the proper clinical setting when patient presentation and laboratory results fail to support the other differential diagnostic possibilities proposed by the MR imaging findings. [source] Lichenoid and granulomatous stomatitis: an entity or a non-specific inflammatory process?JOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 5 2006C. Max Robinson Background:, The presence of lichenoid or granulomatous inflammation in an oral mucosal biopsy usually suggests a distinct range of diagnostic possibilities. However, the presence of both patterns of inflammation in the same biopsy is uncommon. Methods:, A clinico-pathological study of six patients. Results:, All the patients in this study presented with similar mucosal lesions of the upper lip. Microscopically the lesions were characterized by the presence of lichenoid inflammation with concomitant granulomatous inflammation. The lesions were persistent and refractory to treatment with steroid medications, but remained localized and did not appear to herald the onset of systemic inflammatory or neoplastic disease. Conclusion:, We propose the designation ,lichenoid and granulomatous stomatitis' for the cases described in this study. The clinico-pathological features of a subset of these cases suggest an unusual drug eruption. [source] Quantitative Electromyographic Examination in Myogenic Disorders of 6 HorsesJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 2 2003I.D. Wijnberg Electromyographic needle examination (EMG), including the semiautomatic quantitative analysis of motor unit action potential (MUAP), is an important diagnostic tool for myopathy in humans. The diagnostic possibilities of this technique have not been fully explored in horses; however, recent studies have shown that MUAP analysis can be performed in conscious horses. To determine the diagnostic possibilities of EMG in horses, we compared the EMG results of the subclavian muscle, the triceps, and the lateral vastus muscle in 6 equine patients thought to have myogenic disorders with those in 7 normal control horses. The EMG results were compared with the results of the histopathologic examination of the lateral vastus muscle in patients and controls. Histopathologic examination showed muscle disease in 3 patients. In the patient group, several types of abnormal spontaneous activities were observed (mainly fibrillation potentials and positive sharp waves), and the MUAPs of the patient group had a markedly shorter duration and lower amplitude than those of the control group. In the subclavian muscle, triceps, and lateral vastus muscle of affected horses, the MUAP duration was 5.0 ± 0.4 (mean ± SD), 3.9 ± 0.3, and 4.7 ± 1.1 milliseconds, respectively. The MUAP amplitude was 217 ± 55, 150 ± 74, and 180 ± 54 MV; the number of phases was 2.4 ± 0.2, 2.5 ± 0.3, and 2.3 ± 0.1; and the number of turns was 2.6 ± 0.2, 2.4 ± 0.2, and 2.8 ± 0.5, respectively. In conclusion, it appears that the EMG may be a more sensitive method than other techniques for examining muscle biopsies for diagnosis of early-stage myopathy in horses. [source] The distribution of oral mucosal pH values in healthy saliva secretorsORAL DISEASES, Issue 4 2006DJ Aframian Objectives:, To establish the normal range of oral mucosal pH and to correlate these measurements to salivary flow rate in healthy individuals according to age and gender. Subjects and methods:, Measurements of pH levels using a flat pH meter and salivary secretion rates were established in eight mucosal sites from a total of 50 healthy individuals. Results:, The mean pH (±s.d.) of all sites was 6.78 ± 0.04 with significant differences between mean pH values in the palate (7.34 ± 0.38), the floor of the mouth (6.5 ± 0.3), the buccal mucosa (6.28 ± 0.36) and the tongue (6.8 ± 0.26). A significant correlation was found between age and pH at palatal and tongue sites but no gender effects were noted. Conclusions:, This method is easy and relatively quick to manipulate, and may offer many diagnostic possibilities for oral related diseases and disorders such as oral malodour, mouth breathing, dysgeusia, acidic diet consumption and gastrointestinal disorders affecting the mouth. [source] Fine-needle aspiration cytology of Castleman disease: Case report with review of the literatureDIAGNOSTIC CYTOPATHOLOGY, Issue 12 2008Majorie Deschênes M.D. Abstract Organs involved by Castleman disease (CD) may be investigated by fine-needle aspiration cytology. No specific cytomorphological criteria are currently described for a definitive diagnosis. The cytological features of three fine-needle aspirations from three different lymph nodes of a patient with histologically confirmed CD of the hyaline-vascular type are herein reported, with a review of the literature. The fine-needle aspirations showed branching capillaries associated with fragments of germinal center. Review of the literature yielded 12 other case reports with over half describing similar findings. Because branching hyalinized small blood vessels penetrating follicular germinal center are characteristic of CD of the hyaline-vascular type on histology, this finding in fine-needle aspirates should raise that diagnostic possibility. Diagn. Cytopathol. 2008. © 2008 Wiley-Liss, Inc. [source] Torticollis as a sign of cervico-thoracic epidural haematoma in an infant with severe haemophilia AHAEMOPHILIA, Issue 6 2006G. D. E. CUVELIER Summary., We describe the case of a spinal epidural haematoma in an infant with severe haemophilia A. Initial signs and symptoms were non-specific resulting in delay of the diagnosis and more definitive therapy. The patient eventually developed torticollis, acute flaccid paralysis of the upper extremities, and respiratory distress, prompting radiological examination of the spinal cord. The patient was treated with recombinant FactorVIII and laminectomy. Neurological recovery was complete 3 months following the event. We hypothesize that infants with haemophilia may be at higher risk for this rare complication because of their increasing mobility, frequent falls while cruising furniture, and lack of prophylactic factor replacement. Non-specific signs such as irritability without a focus should alert the clinician to this diagnostic possibility. Torticollis should prompt rapid radiological evaluation of the cervical spine with magnetic resonance imaging to avoid delay in diagnosis. [source] | ||||||||||