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Biomedical subjects

F Calliada

Publications and source records attributed to F Calliada.

At least 19 recordsLinked to original sources
PubMed2001

Hepatocellular carcinoma treated with radiofrequency ablation: comparison of pulse inversion contrast-enhanced harmonic sonography, contrast-enhanced power Doppler sonography, and helical CT.

OBJECTIVE: The purpose of this study was to compare the efficacy of contrast-enhanced pulse inversion harmonic imaging with contrast-enhanced power Doppler sonography and helical CT to determine incomplete local treatment after radiofrequency ablation in patients with hepatocellular carcinoma. MATERIALS AND METHODS: Thirty-five consecutive patients (24 men and 11 women; mean age, 64 years) with 43 hepatocellular carcinomas (3.6 +/- 1.1 cm) were treated using internally cooled radiofrequency ablation therapy. Therapeutic response was evaluated at 4 months with dual-phase contrast-enhanced helical CT, conventional power Doppler Sonography, and pulse inversion harmonic imaging using a sonographic contrast agent (SH-508). CT and sonographic studies were reviewed separately in random order by four radiologists at different consensus conferences. Sensitivity and specificity of the sonographic methods were determined using CT as a gold standard and results were compared using the McNemar test. RESULTS: CT examinations identified residual tumor in 12 lesions (27.9%). Although conventional contrast-enhanced power Doppler sonography identified residual viable tumor foci in four incompletely treated lesions (9.3%), contrast-enhanced pulse inversion harmonic imaging identified residual tumoral enhancement in 10 lesions (23.3%). Thus, the sensitivity of pulse inversion harmonic imaging (83.3%) was significantly greater (p < 0.05) for detecting residual nonablated tumor compared with conventional contrast-enhanced power Doppler sonography. CONCLUSION: Our study suggests that contrast-enhanced pulse inversion harmonic imaging may enable the detection of residual nonablated tumor in more cases than contrast-enhanced power Doppler sonography and may ultimately prove to be a useful adjunct for percutaneous ablation therapies. Nevertheless, contrast-enhanced axial imaging (CT or MR imaging) is currently the most sensitive test for managing thermal ablation for patients with hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed2000

Power Doppler ultrasound of gallbladder wall vascularization in inflammation: clinical implications.

We investigated the role of Power Doppler US in the diagnosis and follow-up of cholecystitis. We reviewed the examinations of 21 surgical patients aged 27-48 years with US findings of cholecystitis. We performed B-mode and then Power Doppler US. Wall thickness and US structure, the presence/absence of stones, and US Murphy's sign were assessed at B-mode US, whereas only the presence/absence of wall vascularization was studied with Power Doppler. B-mode and Power Doppler changes post treatment were also investigated. Ultrasound showed wall thickening in all patients. In addition, positive Murphy's sign and/or gallbladder stones were seen in 6 patients each at B-mode US and wall vascularization in 7 patients with Power Doppler. Acute cholecystitis was diagnosed in these patients. The other 14 patients presenting wall thickening but no vascularization and negative US Murphy's sign were diagnosed as having chronic cholecystitis; 10 of them had gallbladder stones. Two of seven acute cholecystitis patients were operated on in the acute stage for the onset of complications and histologic findings confirmed the US diagnosis. As for the remaining patients, histology diagnosed chronic cholecystitis in 17, whereas wall thickening was not inflammatory in 2 cases. All the cases with early wall vascularization were eventually diagnosed as cholecystitis. Power Doppler US permits confirmation of the diagnosis of acute cholecystitis and distinguishing of chronic disease, which helps in planning of surgery.

Adult↗
PubMed1999

Selection of patients for carotid endarterectomy: the role of ultrasound.

Stroke is the third leading cause of death in the western world and the major cause of disability among the middle aged and elderly populations. Carotid artery stenosis is the single most important risk factor for stroke. The North American Symptomatic Carotid Endarterectomy Trial and the European Carotid Surgery Trial have demonstrated that the risk of stroke is reduced by surgery in patients with high grade stenosis. Carotid plaque morphology also plays an important role; plaques which are ulcerated and echolucent are associated with a higher risk of stroke. Arteriography has long been regarded as the gold standard diagnostic tool for evaluation of carotid artery disease, but it is an invasive and costly technique which carries the risk of potentially serious complications. Doppler ultrasound can provide functional and anatomical information on vessel stenosis and plaque morphology at sub-millimetric resolutions and is an inexpensive and noninvasive tool. Color and spectral Doppler ultrasound are now recognized as the best screening tests for carotid artery stenosis. The evidence for its use as the sole diagnostic imaging modality prior to carotid endarterectomy is examined. The recent availability of ultrasound contrast agents helps to distinguish between pseudo- and true occlusions, improves ultrasound images and should help to reduce operator variability.

Blood Flow Velocity↗
PubMed1999

[Evaluation of results of leg tendon reconstruction. Ultrasonography features].

INTRODUCTION: The role of ultrasound (US) in the postoperative assessment of tendon reconstruction is not clearly defined and there is no systematic arrangement of US patterns. MATERIAL AND METHODS: We examined 34 patients submitted to surgery or conservative treatment for total/partial tear or musculotendinous detachment of patellar or Achilles tendon in the last 5 years. All patients underwent physical and US examinations. RESULTS: The surgical tendon exhibited the same US patterns in 23/28 patients: it was markedly enlarged (three-/fourfold the normal diameter) and more rounded, with inhomogeneous and hypoechoic appearance not only at the tear/surgical site but also above and below it, for some cm. Small hyperechoic images, mainly dots, were seen in 19 cases, which were referrable to small calcifications and stitches. More and larger calcifications were found in 8 patients, where they were associated with anechoic degeneration areas. Color Doppler US showed moderate or strong hypervascularization around the tear in the first months postinjury. US patterns did not correlate with physical findings, but color Doppler patterns did. In 6 cases of musculotendinous detachment submitted to conservative treatment, US showed enlargement and hypoechogenicity in the injury site only, with no involvement of the remaining tendon. US was also used to time and guide drainage of perilesional hematomas, which were often quite large. CONCLUSIONS: US is the method of choice in the postoperative follow-up of tendon tears and musculotendinous detachments because it shows abnormal signs which are missed at clinics and provides additional information needed for treatment planning.

Adult↗
PubMed1998

Ultrasound contrast agents: basic principles.

INTRODUCTION: Ultrasonography lacked substances to be administered to patients to improve or increase the diagnostic yield, which is peculiar considering that contrast agents have long been used with all the other imaging techniques. Fortunately some contrast agents, most of them consisting in gas microbubbles, have been recently introduced for ultrasound imaging too: this review will focus on their history, behavior, current applications and future developments. Echocontrast agent research is in progress and many new agents are expected to be marketed this and next year, to be added to Levovist by Schering AG (Berlin, Germany), to enhance the ultrasound signal safely and effectively. No definitive conclusions can be drawn yet on the actual merits of each contrast agent, but all of them seem to be both effective and safe, meaning that their future success will depend on the relative cost-effectiveness and peculiarities. THE BASIC PRINCIPLES OF ECHOCONTRAST AGENTS: The microbubbles act as echo-enhancers by basically the same mechanism as that determining echo-scattering in all the other cases of diagnostic ultrasound, namely that the backscattering echo intensity is proportional to the change in acoustic impedance between the blood and the gas making the bubbles. The different acoustic impedance at this interface is very high and in fact all of the incident sound is reflected, even though not all of it will of course go back to the transducer. But the acoustic wave reflection, though nearly complete, would not be sufficient to determine a strong US enhancement because the microbubbles are very small and are sparse in the circulation. Moreover, reflectivity is proportional to the fourth power of a particle diameter but also directly proportional to the concentration of the particles themselves. SECOND HARMONIC IMAGING: As we said above, the microbubbles reached by an ultrasound signal resonate with a specific frequency depending on microbubble diameter. However, the main resonance frequency is not the only resonance frequency of the bubble itself and multiple frequencies of the fundamental one are emitted, just like in a musical instrument. These harmonic frequencies have decreasing intensity, but the second frequency, known as the second harmonic, is still strong enough to be used for diagnostic purposes. The theoretical advantage of the harmonic over the fundamental frequency is that only contrast agent microbubbles resonate with harmonic frequencies, while adjacent tissues do not resonate, or else their harmonic resonation is very little. Thus, using a unit especially set to produce ultrasounds at a given frequency (3.5 MHz) and receive an ultrasound signal twice as powerful (7 MHz) it will be possible to show the contrast agent only, without any artifact from the surrounding anatomical structures, with a markedly improved signal-to-noise ratio. A similar effect to digital subtraction in angiography can thus be obtained, even though through a totally different process. Moreover, second harmonic imaging permits to show extremely small vessels (down to 40 microm) with very slow flow, which would be missed with a conventional method. B-mode imaging can also depict the microbubbles in the myocardium suppressing nearly all the artifacts from cardiac muscle motion. Recently a peculiar behavior of microbubbles has been observed which may permit contrast agent detection even in capillaries. This method is variously known as sonoscintigraphy, loss of correlation, stimulated acoustic emission and transient scattering. The contrast agent microbubbles reached by an ultrasound beam powerful enough explode producing a strong and very short backscatter echo which is read by the unit as a Doppler signal and results in a color pixel where the individual microbubble exploded. CONCLUSIONS: The microbubble contrast agents developed and introduced as safe and effective echo-enhancers in present-day clinical practice will open up new oppurtunities

Albumins↗
PubMed1998

Contrast enhancing agents in ultrasonography: clinical applications.

INTRODUCTION: As ultrasound remains a poorly sensitive method, echocontrast agents make a real difference. At least 29 echocontrast agents are currently on trial worldwide; their chemical composition, mechanisms of action and possible clinical applications are different. The state of the art of echocontrast agents is discussed: their established applications, those expected in the near future and finally their hypothetical, ideal applications. POTENTIAL CLINICAL APPLICATIONS: An extravascular and a vascular domain can be considered. The former includes the gastrointestinal tract and body cavities--both the normal (bladder, uterus, tubes and so on) and the abnormal (abscesses, fistulas, pericardium, peritoneum and so on) ones. Echocontrast agents can: (1) create or improve an acoustic window; (2) distend some organs and fill them with a liquid, with homogenous attenuation of the ultrasound beam; (3) displace the air-containing intestinal loops; (4) depict the walls, the shape and the contours of a normal or abnormal cavity; (5) detect abnormal communications, fistulas and drainages; and (6) evaluate the amount of fluid in the pleural, pericardial or peritoneal cavities. As for vascular applications, this domain sees the highest number of echocontrast agents on trial or on the market. The best know of them are: Levovist (Schering AG, Berlin, Germany), BR1 (Bracco, Milan, Italy) and EchoGen (Abbott, USA). All these act by enhancing arteries, veins and capillaries. The clinical applications validated in clinical trials mainly regard studies in intracranial and neck vessels and the vascularity of upper and especially lower limbs of renal vessels. Tumor macrovascularity (and in the future, hopefully microvascularity) can also be studied in parenchymatous and/or glandular organs, as well as in intra- and extra-abdominal parenchymatous organs in the periskeletal soft tissues. Clinical validation has also been obtained in the follow-up of tumors submitted to ablation therapy (chemoembolization, ethanol injection, thermal ablation) and in echocardiography, both for morphological studies in the cardiac cavities and for the cardiac wall perfusion. CONCLUSIONS: In a subgroup of 513 out of 1275 patients examined Europe-wide, the contrast agent Levovist increased the diagnostic confidence from 27.4 +/- 22.5 to 77.2 +/- 22.5%. Such data encourage further trials to validate current preliminary results.

Contrast Media↗
PubMed1998

New prospects for ultrasound contrast agents.

Considering the several suggestions regarding the future developments of echocontrast agents, there is a striking difference between the few compounds actually available on the market and used in clinical practice and those undergoing experimental clinical trials. It is therefore difficult to predict what will be the actual impact of these agents in the next future. Future developments will probably go beyond color enhancement which was the end-point till a very short time ago. They can be schematically summarized as follows: (1) development of new substances which enhance both color and gray scales; (2) use of new-generation substances, such as BR1 (Bracco, Milan, Italy) and EchoGen (Sonus, Bothell, WA), which use a gas other than air, such as perfluorate compounds which are more stable and guarantee longer and stronger effects; (3) use of more complex compounds acting at different levels. For example, SHU 536A (Sonovist) produces resonance phenomena with the second and third harmonics, and also stimulated acoustic emission which permits the morphological study of liver parenchyma. Other promising compounds are liposomes and aerosomes. Among the new possibilities in recording and observing phenomena, we can distinguish two main application fields: one is based on the physics of ultrasound and related to the presence of microbubbles in an acoustic field. These phenomena are generally obtained increasing the emission acoustic pressure, which eventually results in microbubble destruction and they are called nonlinear because there is no direct relationship between emission and return frequencies. These phenomena, which are detectable only with dedicated equipment, include: the resonance phenomenon with harmonic emission; intermittent harmonic emission and stimulated acoustic emission. The other application field is not strictly related to ultrasound physics and includes all the systems which can detect the presence of microbubles qualitatively or quantitatively. Other possible applications are related to the possibility of acquiring not only morphological but also functional data, especially in cardiology and neurology. Finally, targeted agents are potentially capable of demonstrating receptor sites or specific molecules, which may open very interesting therapeutic routes.

Acoustics↗
PubMed1998

The latest in ultrasound: three-dimensional imaging. Part II.

INTRODUCTION: The three-dimensional (3D) reconstruction of ultrasound images has become a widespread option in ultrasound equipment. Specific softwares have become available and 3D reconstruction feasible since the early 1990s, particularly since 1994. POSSIBLE CLINICAL APPLICATIONS: Several clinical applications are feasible in all parenchymatous organs (mainly the liver and prostate), hollow viscera (e.g. the bladder and gallbladder), peripheral vessels (supra-aortic trunks and limb vessels) and central (the aorta and iliac arteries) or cerebral vessels. Moreover, tumoral vessels in parenchymatous organs can be reconstructed, and even the fetus in the uterine cavity, with excellent detailing. The recent introduction of echocontrast agents and second harmonic imaging has permitted to study normal and abnormal peripheral, central and parenchymatous vessels, with similar patterns to those obtained with digital angiography. The spatial relationships between the vascular structures of the liver, kidney and placenta were studied with 3D ultrasound angiograms. The applications of this new technique include the analysis of vascular anatomy and the potential assessment of organ perfusion. THE LATEST APPLICATIONS--INTRAVASCULAR STUDIES: Some catheters with an ultrasound transducer in the tip have been tested for intravascular studies. Just like conventional transducers, they provide two-dimensional (2D) images which are then postprocessed into longitudinal 3D or volume reconstructions. The former resemble angiographic images and can be viewed 3D rotating the image along its longitudinal axis. Volume images, which are more complex and slower to obtain, can be rotated on any spatial plane and provide rich detailing of the internal vascular lumen. The clinical importance of intravascular ultrasound with 3D volume reconstructions lies in the diagnosis of vascular conditions and the assessment and monitoring of intravascular interventional procedures--e.g. to detect inaccurate deployment of intravascular stents and endoluminal grafts during the maneuver. Three-dimensional reconstructions involve geometric data assembly and volumetric interpolation of a spatially related sequence of tomographic cross sections generated by an ultrasound catheter withdrawn at a constant rate through a vascular segment of interest, resulting in the display of a straight segment. Therefore particular care is needed and there are some useful hints to avoid mistakes. CONCLUSIONS: Three dimensional reconstructions of B-mode and color Doppler images are no longer a work in progress and their clinical importance and possible applications are both established and ever-increasing. On the other hand, independent of the different types of energy used, also computed tomography and magnetic resonance 3D reconstructions are very useful from a clinical viewpoint and they have become an established routine technique for both these methods. It is very likely that 3D volume reconstructions in ultrasound will find numerous applications in the near future. They may help to increase the diagnostic confidence and to facilitate diagnosis, intraprocedure monitoring in interventional radiology and follow-up and also to reduce the number of invasive examinations with iodinated contrast agents. This could result in cutting the cost and duration of the most expensive examinations. New, although invasive, applications can be hypothesized for intravascular or intraluminal catheters with an ultrasound transducer inside.

Blood Vessels↗
PubMed1997

[Assessment of varicocele recurrence with ultrasonography, color and power Doppler].

To study the postoperative recurrences of varicocele and the relationship between recurrences and sperm variables, we reexamined postoperatively 48 patients aged 14-56 years (mean: 25 years); the patients returned within a time range of 4 to 36 months. All the patients underwent physical examination, B-mode, color and power Doppler sonography (US); the images were acquired with the patient both supine and upright, both at rest and during Valsalva maneuver. We studied the incidence of recurrences and their bilaterality, the presence of reflux with or without functional maneuvers, associated conditions, surgical complications and the improvement of sperm variables; color and power Doppler findings were compared. The incidence of recurrences (28) and that of major complications (2) were related to the type of surgery: thus, no complications but 26 recurrences were found in the patients with spermatic vein ligation, versus only 2 recurrences but also 2 major complications (1 testicular ischemia and 1 hydrocele) in the patients with ligation of the spermatic cord venous channels. A right varicocele was found in 12 patients, which confirmed the frequent bilaterality of this condition; 8 patients with recurrences had improved sperm variables and 6 presented associated conditions. Our trial confirms that B-mode US, combined with color and power Doppler, can show recurrences, bilaterality, surgical complications and associated conditions and emphasize the role of these exams in the postoperative follow-up of varicocele. However, no method alone, without the evaluation of sperm variables, permits to select the patients to be reoperated on.

Adolescent↗
PubMed1996

Long-term effects of intravenous calcitriol therapy on the control of secondary hyperparathyroidism.

Although high-dose intravenous calcitriol has been shown to be effective in suppressing parathyroid hormone (PTH) secretion in dialysis patients with secondary hyperparathyroidism, an increasing number of patients is refractory to treatment. Only a few studies have evaluated the factors that can predict a favorable response to calcitriol, but contrasting results have been reported. This study was performed to evaluate the effect of high-dose intravenous calcitriol on parathyroid function and to investigate the factors that can predict a favorable response to treatment. Thirty-five dialysis patients were selected for intravenous calcitriol treatment (2 microg after dialysis for 12 months) because of increased PTH levels (>325 pg/mL). Before starting the treatment, the set point of calcium and the PTH-ionized calcium (ICa) curve was evaluated in each patient by inducing hypocalcemia and, 1 week later, hypercalcemia to maximally stimulate or inhibit PTH secretion. Parathyroid glands were assessed by high-resolution color Doppler ultrasonography. Throughout the study, calcium carbonate or acetate dosage was modified to maintain serum phosphate less than 5.5 mg/dL. Hypercalcemia was managed by reducing dialysate calcium to 5 mg/dL and, if necessary, calcitriol dose. The therapeutic goal was to reduce PTH levels below 260 pg/mL while maintaining normocalcemia. The patients who achieved the therapeutic goal were considered responders. Taking the data from the 35 patients together, we observed a significant decrease (P < 0.01) in alkaline phosphatase (from 252 +/- 106 IU/L to 194 +/- 81 IU/L) and PTH (from 578 +/- 231 pg/mL to 408 +/- 291 pg/mL), and a significant increase in serum ICa (from 5.1 +/- 0.2 mg/dL to 5.3 +/- 0.2 mg/dL; P < 0.001) after calcitriol therapy. PTH changes after therapy were not correlated to serum ICa changes, serum phosphate levels during treatment, and calcitriol dose. The response to therapy was heterogeneous because PTH levels markedly decreased over the treatment period in 18 responsive patients, whereas they increased or remained unchanged in 14 of 17 nonresponders. In three additional refractory patients, there was a decline in PTH of 20% to 35%, but this decline was associated with hypercalcemia. Pretreatment parathyroid gland size, serum ICa, PTH, maximal PTH induced by hypocalcemia, minimal PTH induced by hypercalcemia, the set point of ICa, and the ICa levels at which maximal PTH secretion and inhibition occurred were higher in the 17 refractory patients than in the 18 responsive patients. However, logistic regression analysis showed that among these parathyroid function parameters, the only significant predictors of a favorable response to calcitriol therapy were the parathyroid gland size and the set point of ICa. Throughout the study, serum phosphate and calcitriol dose were comparable in the two groups. In conclusion, the response to intravenous calcitriol therapy in dialysis patients with secondary hyperparathyroidism is heterogeneous, consisting of patients who are either responsive or refractory to treatment; refractoriness can be predicted by parathyroid volume and calcium set point.

Calcitriol↗
PubMed1996

[Bone callus: possible assessment with color Doppler ultrasonography. Normal bone healing process].

Conventional US demonstrates bone callus dimensions and structure, which permits to monitor the bone healing process. January, 1993, through May, 1995, we examined 108 patients with simple fractures of humerus, femur and tibia; all the fractures had been treated with an external or intramedullary metallic fixator. All the patients were submitted to conventional and color-Doppler US of the fracture focus on all possible scanning planes. We considered morphological parameters (the presence/absence of vessels, their number and shape) and functional parameters (the resistive index and the presence of a telesystolic notch). Color-Doppler US and the spectral analysis allowed us to add functional data, on bone callus and newly formed bone vascularization, to morphological studies. In the patients with positive fracture evolution, the caliber of afferent vessels progressively increased, their number decreased and branches appeared. The RI progressively increased, up to similar values to those of nutrient vessels (.36 to .90). Within the second month of fracture, a telesystolic notch appears: this indicates a muscular tunic in the vessel wall, meaning a mature, and no longer a newly formed, vessel. The normal evolution of bone healing may be interrupted by several mechanical and biohumoral factors which reportedly act in a similar way by reducing the number of vessels and increasing peripheral resistance in residual vessels because of fibrosclerotic involution of bone healing. Color-Doppler US permits noninvasive, repeatable and nearly real-time monitoring of bone fracture healing, which suggests this technique could be used: -to assess the results of treatment changes (e.g., loading, external fixator adjustments); -to study the definitive callus; -for the medicolegal assessment of delayed bone healing and of pseudoarthrosis; -for real-time treatment planning, according to color-Doppler findings, and to monitor treatment results.

Bony Callus↗
PubMed1994

Color Doppler imaging of liver metastases. The value phase-III of a US contrast agent: SH U 508 A (Levovist) Schering.

In a phase-III multicenter clinical trial, the color Doppler vascular patterns were studied of 34 liver metastases in 18 patients before and after the i.v. injection of SH U 508 A (Levovist), with different US units and probes. The patients were selected as having poor color Doppler signals at unenhanced examinations. Lesion size ranged .8 to 9 cm (mean: 3.5 cm). The primary lesion site was the colon in 14 cases, the breast in 8 cases, the lung in 4, the stomach in 4 cases, the ovary in 3 and finally unknown in 4 cases. Each patient received two to four contrast agent injections, with suggested doses and concentrations (10 ml x 300 mg/ml, 8 ml x 400 mgr/ml). No adverse reactions were observed. Thirteen of 34 lesions exhibited no vascular signals at baseline examinations, 10 exhibited some perilesional color spots or small vessel branches, 5 some internal color spots or vessels and 4 small internal and peripheral vessels. After contrast agent infusion, the vascular patterns were better demonstrated in 28/34 lesions and the signal-to-noise ratio was markedly improved, in a concentration-dependent manner, from 40 to 240s. Five lesions remained avascular, 11 exhibited "basket"-like vascular patterns, 10 "internal flow" patterns and finally 10 lesions exhibited both. No major correlation was observed between vascular pattern and lesion size. To conclude, the use of the intravenous contrast agent SH U 508 A (Levovist) appears to be a promising technique to improve the color Doppler demonstration of focal metastatic liver lesions. Nonetheless, further studies on larger series of cases are needed to differentiate the different primary sites of the metastases.

Aged↗
PubMed1993

[Echo-color Doppler in the study of hypothyroidism in the adult].

Color-Doppler US was performed on 20 patients with sub-clinic hypothyroidism which had been confirmed by laboratory tests. In all cases, color-Doppler US showed increased parenchymal flow, whose semiology was similar to the one known as "thyroid inferno" and currently associated, in the literature, with diffuse hyperfunction conditions. Quantitative measurements yielded no further element for differential diagnosis, while showing high flow speeds which were similar to those in hyperfunction. On the basis of consequent physiopathologic considerations, hypervascularization, as observed in hypothyroidism, is likely to be referred to the hypertrophic action of TSH, which was reported as high in all patients. In conclusion, the color-Doppler "thyroid inferno" pattern, which has been to date considered as specific of thyroid hyperfunction, has lost part of its diagnostic specificity, and further investigation--e.g. hormonal titers, scintigraphy--is needed for an unquestionable diagnosis to be made.

Adult↗
PubMed1993

[Clinical applications of color-Doppler: the parathyroid glands].

The high-resolution appearance of enlarged parathyroid glands is well known. Thus, real-time gray-scale US alone fails to provide, in ENT surgery, adequate sensitivity and specificity rates to differentiate between parathyroid glands, hypoechoic thyroid adenomas and other hypoechoic neck masses. Since parathyroid tissue, in both normal and enlarged glands, is hypervascular, color-Doppler US is used as a sort of non-invasive angiography to identify parathyroid glands. The combined use of B-mode and color-Doppler US allows the vascular features of thyroid masses to be satisfactorily demonstrated, with easy differentiation between enlarged parathyroid glands, featuring diffuse internal vascularization, and thyroid adenomas characterized by rounded peripheral vessels and also lymph nodes and cysts exhibiting different vascular patterns. We studied 25 patients with clinical and biochemical signs of hyperparathyroidism (19 primary and 6 secondary) submitted to surgery in the last 20 months. Every patient was scanned with both B-mode and color-Doppler US. At surgery, 19 parathyroid adenomas were found--16 of them correctly identified preoperatively with color-Doppler US and 3 false negatives (retrotracheal glands). Moreover, 1 false positive was observed due to a small Plummer's adenoma misdiagnosed as an intrathyroid parathyroid adenoma: both lesions had the same vascular pattern on US images. Sensitivity was 84.5% and specificity 93.7%. In secondary HPT patients, 23 hyperplastic glands were found at surgery--21 of them correctly identified preoperatively by color-Doppler US, with 2 false negatives. No false positive was found. Sensitivity was 87.5% and specificity 100%. Sensitivity does not differ very much from what reported in literature. Specificity is clearly increased by the use of color-Doppler US. The possible source of error represented by Plummer's adenomas lead us to investigate pulsed Doppler capabilities in differentiating Plummer's adenomas from PT glands, since color-Doppler findings were similar in the two conditions. Peak velocities recorded with both color and pulsed Doppler showed velocity to range 6 to 40 cm/s in parathyroid glands (mean +/- SD: 14.6 +/- 11.7) and 38 to 120 cm/s in thyrotoxic nodules (mean +/- SD: 78.4 +/- 23). The statistical analysis of the results showed a highly significant difference between the two groups of velocities. Peak velocities as recorded in the main, vessels of the parathyroid glands with color and pulsed Doppler were correlated with the activity of the parathyroid glands.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenoma↗