Objective: Ultrasonography is an established diagnostic modality in the follow-up of thyroid cancer. Color flow Doppler has been proposed by some authors as an additional tool for differentiating benign from malignant cervical lesions in various types of head and neck cancer. Over the last few years, a new generation of high-resolution ultrasound platforms with the ‘power-mode’ feature has become available, that also enables the imaging of small vessel blood flow. The objective of our study was to find ways of optimizing the differentiation of benign and malignant cervical tumors in thyroid cancer follow-up by means of sonography. Methods: Hundred and twelve cervical lesions in 90 patients with thyroid cancer were evaluated by high-end ultrasonography (Sonoline™ Elegra, Siemens) using a small-part transducer (7.5 L 40, Siemens). B-mode sonography was performed at a frequency of 8 MHz. The Solbiati index (SI= ratio of largest to smallest diameter), configuration, echogenicity, intranodular structures, and margins were assessed. Perinodular and intranodular blood flow was evaluated by color flow Doppler (PRF 1250 Hz for conventional color flow Doppler, 868 Hz for power-mode Doppler). Possible malignancy was validated by histology, cytology, scintigraphy, and follow-up. Thirty five lesions were benign (diameter 0.4–3.0 cm) and 77 were malignant (0.4–5.4 cm). The patients were randomized into a test group and a learning group to determine the diagnostic value of various ultrasound criteria by means of statistical analysis. In the learning group, decision rules based on the dichotomized criteria were developed using a logistic regression model. Sensitivity and specificity of these decision rules were then evaluated in the test group. Results: The presence of an echocomplex pattern or irregular hyperechoic small intranodular structures (criterion A) and the presence of an irregular diffuse intranodular blood flow (criterion B) are the best indicators of malignancy, whereas an SI≫2 is highly indicative of benign changes. Color flow Doppler is a useful addition to B-mode scanning for distinguishing benign and malignant neoplasms in the follow-up of thyroid cancer. Power-mode Doppler sonography significantly improves imaging of perinodular and intranodular blood flow when compared with conventional color flow Doppler. Conclusion: We propose the following decision rules based on a combination of the criteria above: (A) and (B) fulfilled: malignant, if SI≤4; (B) but not (A) fulfilled: malignant, if SI≤3; (A) but not (B) fulfilled: malignant, if SI≤2; neither (A) nor (B) fulfilled: malignant, if SI≈1 (sensitivity: 90%; specificity: 82%; accuracy 88%).
Objectives: The aim of this study was to investigate whether ultrasonography can characterise plaque morphology and surfaces independent of the observer. Methods: Computer-assisted image analysis of the grey scales of B-mode scans from 15 patients with stenoses of the internal carotid artery was performed and compared with the histopathological reports. In vitro angioscopy, was used to visualise the plaque surfaces of the thromboendarterectomy specimens. Result: Assessment of the internal plaque structure by ultrasound showed close agreement between the two observers (P<0.01) without correlation with the histopathological results. Ultrasonography was able to characterise the plaque surfaces in 93% of cases. Conclusion: This investigation showed that standardised computer-assisted analysis of the internal plaque structure correlates less closely than histological investigation, but agrees closely with the surface structure of the plaque. The exclusive use of digital image processing and standardisation of the investigative technique are expected to provide even better results.
Objective: Ultrasound (US) measurement of thyroid volume is used in diagnosis and follow-up of patients with thyroid disease. We assessed a new formula and technique for thyroid volume calculation, based on an automatically continuous trace transverse surface area (aTSA) calculation, to ascertain where this technique could reduce inter-observer variation. Methods: Three observers with a different level of US expertise, using a 12–5 MHz linear transducer, examined 25 volunteers. Inter-observer variations were calculated for diameter measurements and for the thyroid lobe volume calculations using the single factor ANOVA method. Results: Using the new technique and formula, no statistically significant differences existed, in contradistinction to using the classical formula for an ellipsoid (P=0.02). Conclusion: When thyroid volume measurements are required, we recommend using a new method of thyroid volume calculation based on the use of an automatically calculated continuous trace aTSA measurement to avoid significant inter-observer variation in calculation of thyroid lobe volumes
As an object rotates with respect to a stationary planar ultrasonic beam, the scattering centres within the object return echoes that are Doppler-shifted in frequency by amounts depending on the velocities of the individual scatterers. The backscattered echo amplitude at any particular frequency is the line integral of the scattered radiation at the cross-range corresponding to that frequency. The amplitude as a function of frequency can be interpreted as a tomographic projection. A tomographic reconstruction algorithm can produce an image of the distribution of scattering centres in the insonified object from these projections. This paper describes the development and characterisation of a microscanner to investigate the approach of using continuous wave ultrasound for three-dimensional cross-sectional imaging. The results of preliminary tissue investigation, conducted using bovine coccygeal intervertebral discs, are described. The radial imaging resolution improves as the Doppler frequency resolution improves but the circumferential resolution degrades proportionally. As the number of projections increases, there is a finite increase in image quality. Two- and three-dimensional images of the intervertebral disc reveal an alternate light and dark banding pattern that is characteristic of the laminar structure of the annulus fibrosus.
The Authors evaluate the diagnostic accuracy of echography in hepatic echinococcosis, particularly in the completely liquid types of cysts without septa or hydatid sand and in the solidified forms where the differential diagnosis with other hepatic pathologies can be difficult. The study was carried out with a 7.5 MHz probe and the results were compared with those from the use of a 3.5 MHz probe and from CT, serology for hydatidosis and echoguided sampling. Seventy one patients, 36 with liquid hepatic lesions and 35 with solid hepatic lesions (31 hydatid and 40 non-parasitic), were evaluated echographically, first with a 3.5 MHz probe and subsequently with a 7.5 MHz probe. All the patients underwent serology for hydatidosis. All the liquid lesions were subjected to percutaneous echoguided aspiration and all the solid lesions to CT; echoguided biopsy was performed in only 24 of the latter lesions. With the 7.5 MHz probe, a wall was revealed in 96.77% of parasitic cysts but in only 5% of non-hydatid ones. Moreover, using the 7.5 MHz probe, it was possible to see a triple-layered aspect of the wall in the hydatid cysts. The results obtained with the 7.5 MHz probe demonstrate a high diagnostic accuracy comparable to that of MR.
Background: The value of color Doppler sonography in thyroid disease continues to be a matter of debate. Over the past few years, several studies have proved unable to yield unequivocal results. Only a few studies concerning color Doppler sonography in patients with hypothyroidism have been published. Methods: 89 patients with hypothyroidism have been evaluated. They were examined clinically; laboratory tests on thyroid function and color Doppler sonography have been performed. The color flow distribution and intensity were estimated and the fastest flow velocity (PSV) detectable with a pw-doppler was registered. The color pattern was graded from 0 to III as has been described by others and the color Doppler findings were then correlated to both the clinical picture and the laboratory results. Results: 56 of the 89 hypothyroid patients showed pattern 0 with a PSV of 22 cm/s. In 33 patients different degrees of increased parenchymal color could be found with a concordant PSV: 16 patients showed pattern I with a PSV of 39 cm/s; 11 showed pattern II with PSV 58 cm/s, and 6 showed pattern III with PSV 63 cm/s. Regarding the corresponding clinical and laboratory variables, there was a very close correlation between color intensity and anti-Tg/anti-TPO antibody levels: pattern 0: anti-Tg 474 IU/ml, anti-TPO-Ab 810 IU/ml; pattern I: 1053/1733; pattern II: 1774/2432; pattern III: 1951/2633. Some correlation could also be found for the TSH values and the calculated volume of the thyroid gland, whereas the duration of hypothyroidism showed an inverse correlation to color intensity. (Pattern 0: TSH 3.1 mE/ml, volume 9.2 ml, duration 43 months; pattern I: 4.2 mE/l, 15.7 ml, 24 mos.; pattern II: 11.5 mE/l, 22.3 ml, 16 mos.; pattern III: 38.2 mE/l, 34.3 ml, 10 mos, respectively). Conclusions: The color Doppler pattern of intense hypervascularization of the thyroid gland formerly attributed only to the hyperthyroid state of active Graves’ Disease can also be seen in hypothyroidism. Our data support the concept that the color flow appearance is not the result of stimulated thyroid hormone production, but a measure of the activity of an autoimmune process.
Background: Patients with colorectal metastases confined to the liver may be cured by resection. Combined bimanual palpation and intraoperative ultrasound (IOUS) augment the detection of colorectal hepatic metastases. The importance of IOUS in the surgical management of hepatic tumors has been demonstrated and should arguably be considered the final diagnostic procedure. Objective: To determine the relevance of routine IOUS prior to hepatic resection compared with improved preoperative Magnetic resonance imaging (MRI). Patients and methods: Eighty patients with metastatic colorectal adenocarcinoma underwent hepatic resection between 1998 and 2001. The IOUS results were compared with preoperative MRI, bimanual palpation, and resection histopathology. The preoperative surgical plan was compared with the surgical procedure performed. Data were retrospectively analyzed. Results: IOUS provided additional useful information not available preoperatively for 37 (47%) patients, including the identification of subcentimetre metastatic lesions, characterization of the lesion, and the anatomy of the hepatic vasculature. The preoperative surgical plan was changed secondary to the IOUS findings alone in 14/80 (18%) patients. IOUS did not provide any additional useful information for 43 (53%) patients. A correlation was demonstrated between the preoperative diagnosis, intraoperative findings, and resection histopathology. Conclusion: Accurate diagnostic studies facilitate critically decisive actions during planned hepatic resection(s). The current findings suggest that IOUS provide the most useful additional information for hepatic lesions, despite recent improvements in preoperative MRI scanning. Furthermore, routine IOUS should be employed during hepatic resection for colorectal metastases.
Objectives: The objectives are to study the correlation between the women's perception of transvaginal sonography (TVS) and the gender of the examiner and the state of the pregnancy. Methods: The population studied was unselected women attending the early assessment unit at Sharoe Green Hospital with various complications of early pregnancy. All the women were in the first trimester. Only women who had TVS and who gave informed consent were included. Results: Four hundred and twenty five (425) women were recruited. A male doctor examined 215 (50.6%), while a female doctor examined the remaining 210 (49.4%). Two hundred and ninety eight (70.1%) of the pregnancies were viable and 127 (29.9%) were non-viable. About 98.1% of the women found TVS acceptable. There was no statistically significant difference in the women's perception of the procedure with regard to the gender of the examiner or the state of the pregnancy. Conclusions: The majority of women (98.1%) perceived TVS favourably. The gender of the examiner and the state of the pregnancy have no influence on the women's perception of the procedure.
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