1,721,024 research outputs found
[Doppler color in superficial adenopathies].
No full textSuperficial lymph nodes are frequently involved in different diseases. Their location makes them suitable for effective assessment with high-resolution US and color Doppler has been recently suggested as a tool for increasing sensitivity in lymph node studies. Thus, we investigated the main vascular patterns detectable in abnormal superficial lymph nodes. We evaluated 260 nodes in 180 adult patients; the nodes were located in the cervicofacial ring (78, 30%), internal jugular stations (104, 40%), and supraclavicular (44, 17%), axillary (21, 8%), and inguinal (13, 5%) stations. Color Doppler was performed with 7.5-13 MHz linear transducers, with parameters adjusted for slow-flow detection (5-6 MHz frequency, 700-900 Hz PRF, 50 Hz band filter, high color persistence). Disease assessment required fine-needle biopsy (95 nodes in 95 patients) and clinical follow-up (165 nodes in 85 patients). Fifty-five nodes (21%) presented acute and 130 (50%) chronic inflammation: 75 nodes (29%) were metastatic. The following vascular patterns were detected: a single vascular pole (type I) was seen in chronic inflammation (72% sensitivity, 86% specificity, 57% positive and 92% negative predictive value); an enlarged single vascular pole, with 2-3 enlarged branches (type II) in acute adenitis (80% sensitivity, 81% specificity, 78% positive and 83% negative predictive value); multiple vascular poles with many deformed and displaced branches converging centrally (type III) in metastases (76% sensitivity, 100% specificity, 100% positive and 91% negative predictive value). We conclude that color and power Doppler are useful integrations to B-mode US because they can detect specific signs of malignancy such as peripheral vascular poles and intranodal displacement of vessels.Superficial lymph nodes are frequently involved in different diseases. Their location makes them suitable for effective assessment with high-resolution US and color Doppler has been recently suggested as a tool for increasing sensitivity in lymph node studies. Thus, we investigated the main vascular patterns detectable in abnormal superficial lymph nodes. We evaluated 260 nodes in 180 adult patients; the nodes were located in the cervicofacial ring (78, 30%), internal jugular stations (104, 40%), and supraclavicular (44, 17%), axillary (21, 8%), and inguinal (13, 5%) stations. Color Doppler was performed with 7.5-13 MHz linear transducers, with parameters adjusted for slow-flow detection (5-6 MHz frequency, 700-900 Hz PRF, 50 Hz band filter, high color persistence). Disease assessment required fine-needle biopsy (95 nodes in 95 patients) and clinical follow-up (165 nodes in 85 patients). Fifty-five nodes (21%) presented acute and 130 (50%) chronic inflammation: 75 nodes (29%) were metastatic. The following vascular patterns were detected: a single vascular pole (type I) was seen in chronic inflammation (72% sensitivity, 86% specificity, 57% positive and 92% negative predictive value); an enlarged single vascular pole, with 2-3 enlarged branches (type II) in acute adenitis (80% sensitivity, 81% specificity, 78% positive and 83% negative predictive value); multiple vascular poles with many deformed and displaced branches converging centrally (type III) in metastases (76% sensitivity, 100% specificity, 100% positive and 91% negative predictive value). We conclude that color and power Doppler are useful integrations to B-mode US because they can detect specific signs of malignancy such as peripheral vascular poles and intranodal displacement of vessels
Sonography of cutaneous non-Hodgkin's lymphomas
No full textSonographic examination (10 MHz) of 25 patients with cutaneous non-Hodgkin's lymphomas of B-cell type (10 patients), of T-cell type (nine patients) and non-B non-T-cell type (six patients) demonstrated 'diffuse' (11 patients) and 'focal' patterns (14 patients): the former, which can be described as an homogeneous, hyperechoic thickening of the dermis, occasionally involving the subcutaneous layer, was exclusively observed in T-cell (nine cases) and non-T non-B cell (two cases) types, while the latter, characterized by small, hypoechoic and well-defined nodules, was observed in B-cell (10 cases) and non-T non-B-cell (four cases) types. These observations indicate a possible relationship between histologic and sonographic appearance
Ultrasound findings in intersection syndrome
No full textThe purpose of our study is to demonstrate the role of ultrasound as a first-line technique in the evaluation of intersection syndrome, reporting and illustrating its typical and atypical findings. In a 2-year period, we reviewed nine patients who received an ultrasound examination for non-specific inflammatory signs in the distal forearm: four men (28-53 years old) and five women (34-57 years old), with a mean age of 44.1 years. The ultrasound examination revealed, in all patients, the presence of peritendinous oedema and a small amount of synovial fluid within the tendon sheaths at the crossing intersection point between the first and the second dorsal extensor tendon compartments, with loss of the hyperechoic cleavage plane between the two tendon groups. In two patients, we observed an irregularly thickened tendon sheath, with small hyperechoic nodules within the fluid, related to proliferation of the synovial membrane. In one case, we detected a relevant thickening of the extensor carpi radialis longus and brevis tendon. Only one patient showed moderate muscle oedema within the first extensor compartment muscles, while another one had significant subcutaneous oedema. Ultrasound is effective in the first-level diagnosis of intersection syndrome
[Three-dimensional ultrasonography. Experience with a non-dedicated system].
No full textThe application of three-dimensional (3D) reconstructions to US has been recently proposed, but remains strongly limited by the difficulty to produce parallel and equidistant slices and by the obvious lack of method standardization. This work describes our experience with a workstation on the market in producing 3D images from US exams. Reconstruction involved the following steps: acquisition (US examinations of different organs--i.e. carotid artery, parotid gland, kidney, gallbladder, urinary bladder--were recorded on VHS tape; a small, self-built, motor-driven mechanical arm was used to move the probe along the selected axis of the organ: a 486-class computer with a framegrabbing card was used during the digitizing process to produce a set of slices, white were saved in 320 x 256 x 8 bit format), pre-processing and segmentation (we used interactive contrast enhancement as a pre-processing technique, to emphasize contrast between echoic and anechoic structures or between solid structures with a small difference in echogenicity; as a segmentation technique, we used autotracing with a selected seed point; in a small number of images, where the software could not provide an adequate delimitation, we had to operate manually) and rendering. A commercially available software for radiological use (Analyze-Mayo Foundation, USA) was used for processing, segmentation and rendering. The rendered images can be visualized with multiple zoom factors, rotated and cut on any plane, reconstructed from every user-definable point of view. The good results indicate that 3D acquisition and reconstruction will probably change the way to obtain, display and study US findings
Contributo dell’informatica alla refertazione in radiologia diagnostica - parte II : sistemi realizzati e prospettive
No full textSonography of the cervical vagus nerve: Normal appearance and abnormal findings
No full textOBJECTIVE. The purpose of this study was to assess the appearance of the cervical vagus nerve in healthy individuals and to investigate the potential role of sonography in revealing neck masses that cause vagal dysfunction. SUBJECTS AND METHODS. We examined 150 consecutive patients. In 144 patients the presence of thyroid, salivary gland, or lymph node disease was suspected. In three patients a cervical mass was palpable, and three patients had symptoms of dysfunction of the inferior laryngeal or vagal nerves. The pathologic diagnoses of the masses were obtained at biopsy. RESULTS. In 144 individuals the normal vagus nerve was recognized on each side of the neck as a thin band that occupied the posterior angle formed by the common carotid artery and the internal jugular vein. Three patients had tumors arising from the vagus nerve: one neurofibroma, one neurinoma, and one chemodectoma. These tumors were located in the neurovascular bundle and posterior to the vessels; their origin from the vagus nerve was clearly visible in all patients because of the contiguity of the mass with the nerve bundle. In the other three patients, sonography revealed an extrinsic mass that compressed and displaced the vagus nerve out of its longitudinal axis; two cases were hyperplastic nodules of the thyroid, and in one case the nodule was a branchial cyst. CONCLUSION. Sonography can reveal the vagus nerve in healthy conditions and correctly reveal the vagal origin of some tumors in the parapharyngeal spaces
[Radiological reasoning and its computer-based simulation. Reasons to use computer-based diagnostic systems developed on shells].
No full textResearch on the medical applications of artificial intelligence has increased the knowledge of logical and methodological principles of clinical reasoning. Thus, computer-based diagnostic systems are developed on the basis of progress in this field, because thorough knowledge is necessary to obtain efficient simulation. This work was aimed at analyzing the structure of medical and radiological reasoning and at discussing the modalities to simulate it with computer-based diagnostic systems. The diagnostic process includes two steps: data collection and data interpretation; radiological reasoning involves the following 5 steps: procedural, executive, observative, interpretative and communicative. Each of them needs a different approach to simulation, considering, in its development, the different characteristics of each kind of reasoning. The expert system shells on the market are necessary tools to develop expert systems, but they cannot cover the whole of processes taking place during radiological work. Therefore, a particular, radiology-aimed shell should be developed to help the radiologist
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