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Biomedical subjects

R Campani

Publications and source records attributed to R Campani.

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↗
PubMed2000

Serum liver enzymes in Turner syndrome.

UNLABELLED: Increased serum concentrations of liver enzymes are sometimes observed, in the absence of clinical symptoms of liver disease, in patients with Turner syndrome. The purpose of this study was to evaluate, in our Turner patients, serum liver enzyme levels and to find a cause for their increase. In 70 Turner patients, serum AST, ALT, GGT levels were evaluated every 6 months during a period of 0. 8-21.9 years. In patients in whom increased values of liver enzymes were found, serological markers for infectious hepatitis, serum hepatitis C virus RNA and virus genotype, IgG and IgA antibodies to gliadin and endomysium, coeruloplasmin, copper, alpha(1)-antitrypsin, total proteins and electrophoresis, IgG, IgA, IgM, fibrinogen, prothrombin, alkaline phosphatase, creatine kinase and total and direct bilirubin were also determined. Antinuclear, anti-smooth muscle and anti-liver-kidney microsome antibodies together with antithyroglobulin and anti-thyroid peroxidase antibodies were determined in all patients and in 166 age-matched female controls. In 22 patients, increased liver enzymes were observed, not related to karyotype. Follow-up showed that the hepatic disorder did not worsen with the time. Serological markers of hepatitis C virus were positive in three patients. When the serum liver enzyme increase was first observed in the other 19 patients with high enzyme levels (group A), 14 patients had never been submitted to hormonal treatment, 4 were on oestrogen/gestagen treatment and 1 was being treated with both growth hormone and oestrogen. Coeliac disease, alpha(1)-antitrypsin deficiency and Wilson disease were ruled out by appropriate investigations. In 8/19 group A patients, antinuclear and/or anti-smooth muscle antibodies were present versus 6/48 of patients with normal liver enzymes (group B). Thyroid antibodies were found in 8/19 patients in group A and in 13/48 in group B. Weight excess SDS was significantly higher in Turner girls with liver enzyme increase. Ultrasonography, performed in 17 patients of group A, showed mild hepatomegaly in 4 and increased echogenicity with fatty infiltration in 6. CONCLUSION: Hepatic abnormalities in Turner syndrome are not progressive. Oestrogen should not be considered the main cause of increased liver enzymes in Turner syndrome since most of our patients with this finding had not been previously treated with oestrogens. An auto-immune pathogenesis might be considered in some cases, whereas the association with weight excess seems the most frequent cause of liver disorder in Turner syndrome.

Adolescent↗
PubMed2000

MR imaging of CNS involvement in children affected by chronic liver disease.

BACKGROUND AND PURPOSE: MR imaging sheds new light on CNS involvement in the course of acquired chronic liver disease; however, the exact pathogenetic mechanisms of hepatic encephalopathy and associated MR abnormalities remain unclear. Our purpose was to relate MR signal intensity abnormalities of the CNS to clinical, biochemical, and pathologic features of childhood-onset chronic liver disease. METHODS: Twenty-one patients (12 male and nine female patients) were included in the study; two had Crigler-Najjar disease type 2, 17 had chronic liver disease of different causes, and two had idiopathic copper toxicosis. Twelve patients had histologically proved liver cirrhosis, with a median disease duration of 175 months at the time of MR study. None had clinical symptoms of hepatic encephalopathy. MR imaging was performed using spin-echo T1- and T2-weighted sequences. RESULTS: Eleven patients had abnormal MR imaging findings of the brain revealed by T1-weighted MR sequences; two of the 11 had idiopathic copper toxicosis. The affected sites were the hypothalamus and globus pallidus, presenting symmetrical and bilateral high signal intensities, or the pituitary gland, which appeared homogeneously hyperintense, or both findings. Eight of the 12 patients with cirrhosis had abnormal MR signals of the brain. In these, the median cirrhosis duration was shorter (169 months) than in the remaining four patients with normal MR signals (177 months). A significant correlation was found between abnormal MR signals of the brain and cirrhosis (P = .008) and factor V activity (P = .008). CONCLUSION: MR imaging confirms the presence of abnormal brain signals in the globus pallidus, hypothalamus, and pituitary gland in patients with childhood-onset liver disease in the absence of clinical symptoms of encephalopathy. Signal intensity abnormalities are likely caused by an as yet unidentified metabolic process partially correlated with the severity of liver disease.

Adolescent↗
PubMed2000

[The larynx: an anatomical and functional echographic study].

PURPOSE: To investigate the capabilities of US in morphological and functional studies of laryngeal structures. MATERIALS AND METHODS: We examined 50 healthy subjects (30 women and 20 men) ranging in age 23 to 74 years; 17 of them were professional opera singers. The patient was laid supine, with his/her neck in marked hypertension, and images were acquired with the vocal cords at rest, and during quiet breathing inspiratory and expiratory standstill, Valsalva, and wording of "e" and "o". We used 7.5-12.0 MHz probes to perform (para)median axial scans with anteroposterior and caudocranial US beam incidence. RESULTS: All the anatomical structures that could be measured were clearly demonstrated. The length of the true vocal cords was 16-28 mm in women and 20-23 mm in men and their wideness 7-15 mm to the dorsal end 2-4 mm to the ventral and; maximum thickness ranged 2-10 mm. The respiratory space varies 2-8 mm in the different phases of respiration and speech. In the 17 opera singers we found agreement between length of the vocal cord compass: basses had 30-33 mm and tenors 21-25 mm. DISCUSSION AND CONCLUSIONS: In addition to the advantages US is known to provide, it can also permit accurate measurements of the anatomical structures of the larynx and respiratory space at rest and in the dynamic phase, which are important data in some conditions (e.g., cord paralysis) or follow-up of drug or rehabilitation treatment. Finally US can permit to detect atypical situations such as those in false/true vocal cords hypertrophy and abnormal cord growth.

Adult↗
PubMed2000

[Calcified renal metastases: their etiology, pathogenesis, computed tomographic aspects and differential diagnosis].

PURPOSE: To describe CT findings of calcified renal metastases focusing on differential diagnosis problems. MATERIAL AND METHODS: We retrospectively reviewed abdominal CT scans of 8000 patients with tumor, performed from 1984 to 1998. Among the 58 renal metastases, 9 showed a calcific component. We evaluated the location, morphostructural pattern, histology of the primary lesion, the synchronous or metachronous character and the type of treatment. All the lesions were pathologically proved. RESULTS: The primary histotype of the 9 metastases was as follows: 4 mucin-producing adenocarcinomas of the large bowel, 1 gastric mucinous adenocarcinoma, 1 chondrosarcoma, 1 osteosarcoma, 1 melanoma, 1 papillary thyroid carcinoma. In all the cases the renal metastasis was unilateral and unifocal. Granular multiple calcifications were demonstrated within the metastases of mucin-producing adenocarcinoma of the large bowel (3), within the metastasis of chondrosarcoma (1) and of melanoma (1). Diffuse "star-like" calcifications were demonstrated in renal metastases of mucin-producing adenocarcinoma of the large bowel and of gastric mucinous adenocarcinoma (1). Peripheral "egg-shell" calcifications were demonstrated in renal metastasis from papillary thyroid carcinoma (1). Completely calcified monofocal calcification was demonstrated in renal metastasis from osteosarcoma (1). DISCUSSION AND CONCLUSIONS: Calcified renal metastases are rare lesions related to specific oncotypes. The differential diagnosis (carcinoma with calcifications, osteosarcoma, chondrosarcoma, nephrocalcinosis, granulomatosis, hydatidosis etc.) is particularly difficult because of the aspecificity of the morphostructural pattern. Diagnosis is based on a history of specific oncotypes (papillary and mucin-secreting carcinomas, osteosarcoma and chondrosarcoma), but in most cases it requires pathologic confirmation.

Aged↗
PubMed2000

Correlation between pretreatment prognostic factors and lymph node metastases in endometrial adenocarcinoma. Clinical application.

PURPOSE: To evaluate the prognosis of stage I endometrial adenocarcinoma, which differs by various prognostic factors. Some of them (tumor grading, histotype, myometrial infiltration, the latter evaluated with Magnetic Resonance Imaging) can be assessed before surgery. These prognostic factors correlate with patient survival and the presence of lymph node metastases. MATERIAL AND METHODS: We used tumor grading, histotype, myometrial infiltration for the preoperative and prospective classification into a low- and a high-risk group of 80 patients with endometrial adenocarcinomas stage I. Low-risk patient [group A: G1-G2, pure adenocarcinoma involving the inner portion of the myometrium (M0-M1)] underwent surgery without lymph node resection, while high-risk patients [group B: G3, pure adenocarcinoma with deep infiltration of the myometrium (M2) and/or clear cell, serous papillary, adenosquamous carcinomas] had pelvic and lumboaortic lymphadenectomy. The minimum 36 months' follow-up (median: 61 months) was requested for all patients. RESULTS: Histotype evaluated by dilatation and curettage and hysteroscopic and/or office biopsy, had 100% agreement with tumor histotype. Tumor grading was in agreement in 72/80 patients (81%). The grade of myometrial infiltration was confirmed in 72/80 cases (81%). Eight misdiagnoses were divided in over--(4 cases) and under--(4 cases) estimated infiltration. All 16 mistakes resulted in 10 inclusion in the wrong risk group (8 in the low-risk and two in the high-risk group). Surgical-pathological staging did not change the prognosis but only staging in 6 preoperatively high-risk group. CONCLUSIONS: This initial study confirms the importance of prognostic factors in the treatment of endometrial adenocarcinoma, as well as that of the different surgical choices which can be made after correct pretreatment prognosis.

Adenocarcinoma↗
PubMed1999

Magnetic resonance appearance of endometrial sarcoma: report of a case with unusual findings.

We report the MR findings of an endometrial stromal sarcoma. The uterus was enlarged and completely replaced by neoplastic tissue, with full-thickness myometrial infiltration. It had isointense signal on T1- and irregularly hyperintense signal on T2-weighted images and the dynamic study with intravenous gadoteridol showed centripetal enhancement. This sarcomatous-like pattern correlates well with the pathologic and CT findings reported in the literature.

Endometrial Neoplasms↗
PubMed1999

The role of computed tomography in the preoperative assessment and follow-up of oromandibular reconstruction with microvascular osteomyocutaneous free flaps.

OBJECTIVE: To investigate the capacity of helical CT in the pre- and post-operative management of oromandibular reconstruction of patients with oropharyngeal carcinoma using microvascular composite free flaps. MATERIALS/METHODS: Thirty-four patients with oropharyngeal cancer were examined by helical CT and nine (six men and three women) submitted to oromandibular reconstruction. The osteomyocutaneous flaps used for reconstruction were taken from the iliac crest in six cases and from the fibula in three cases. All patients were examined by CT 1 - 4 days postoperatively and then at 6 monthly intervals. Double helical scans were performed in all cases, with slices of 2 - 3 mm for primary lesion studies and 5 mm for lymph node staging, pitch >/=1 and RI=1. Multiplanar (MPR) and 3D reconstructions were obtained from pre- and postoperative CT examinations. RESULTS: Preoperative CT showed massive bone infiltration in six of the nine surgical patients and marginal infiltration in three. These findings were confirmed histologically. There were no false negatives. The immediate postoperative examination showed correct flap positioning in eight of nine cases. The flap underwent ischemic necrosis in two cases; CT showed very early signs of bone ischemia in both. CT detected two cases of recurrence after about 1 year. CONCLUSIONS: Axial CT permitted adequate assessment of the extent of mandibular infiltration and detected early ischemic complications and distant recurrences. Integration with MPR and 3D reconstructions simplified the choice of flap type and size and enabled the postoperative assessment of correct flap positioning. This helped the surgeon plan subsequent rehabilitation with osseo-integrated implants.

Aged↗
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↗
PubMed1999

[An assessment of abdominal fatty tissue distribution in obese children. A comparison between echography and computed tomography].

PURPOSE: Computed tomography (CT) and, more recently, ultrasound (US), have proved excellent tools for quantifying adipose tissue distribution. Body fat distribution is an important factor in the treatment of obesity and its complications. We investigated the correlation between CT and US measurements in pediatric obesity. MATERIAL AND METHODS: Forty obese children and adolescents aged 4.1-14.8 years were submitted to CT and US. Intra-abdominal, subcutaneous and total body fat were calculated (in cm2), with the CT image analysis software. The rectus muscle-spine and rectus muscle-aorta distances, as indicative of visceral fat thickness, were measured on US images with(out) compression. The distance between skin-fat and fat-rectus muscle interfaces was measured as subcutaneous fat thickness. We also compared US-CT findings with other morphometric variables--i.e., patient's (ideal) body weight and skin fold measures. RESULTS: At US, the rectus muscle-aorta and rectus muscle-spine distances ranged 2.4-7.5 cm (mean: 4.47 cm) and 3.6-8.9 cm (mean: 5.79 cm), respectively. The skin-rectus muscle distance ranged 1.2-7.5 cm (mean: 3.14 cm). A statistically significant correlation was found between the CT measurement of visceral fat and the aorta-rectus muscle and rectus muscle-spine distances (r = 0.80 and 0.74, respectively). The US measurements of subcutaneous fat were correlated with CT subcutaneous fat area (r = 0.82). No correlation was found between overweight, as calculated by body mass index, and CT or US fat. CONCLUSION: Our findings indicate that US is as useful as CT in evaluating body fat distribution in pediatric obesity.

Abdomen↗
PubMed1998

Spiral CT angiography and surgical correlations in the evaluation of intracranial aneurysms.

We investigated the accuracy of spiral computed tomography angiography (CTA) in the detection and study of intracranial aneurysms by comparing CTA with selective angiograms and surgical findings. Twenty-six patients (9 men and 17 women; mean age 53.1 +/- 1.8 years) with suspected intracranial aneurysms were submitted to CTA (1- to 2-mm slices, pitch 1:1, 24 s, RI = 1) after a conventional CT examination showing subarachnoid hemorrhage (SAH) in 19 cases and during neuroradiological investigations performed for other reasons in 7 cases. One hundred twenty to 150 ml iodate contrast agent (0.3-0.4 gI/ml) were injected intravenously at 5 ml/s rate and with 12- to 25-s delay calculated with a preliminary test bolus. Three-dimensional shaded surface display (3D SSD) and maximum intensity projection (MIP) reconstructions were obtained from axial images. Then, within 48 h, all patients were submitted to digital subtraction angiography (DSA), with separate assessment of CTA and DSA findings. Twenty-two aneurysms shown by CTA were confirmed at DSA and surgery (true positives), whereas the vascular lesion was not confirmed at DSA in 2 cases (false positives). The presence of intracranial aneurysms was excluded at both CTA and subsequent DSA in 7 cases (true negatives) and there were no false negatives; sensitivity was 100 %, specificity 77.8 %, and diagnostic accuracy 93.5 %. Computed tomography angiography aneurysm location was confirmed at surgery in all cases, with very high accuracy in assessing the presence of an aneurysm neck (100 %). Computed tomography angiography accurately depicted the aneurysm shape in 20 of 22 cases, but failed to depict its multilobed nature in 2 cases. The mean aneurysm diameter calculated at CTA was 0.99 +/- 0.12 cm vs 1.09 +/- 0.11 cm at surgery (p < 0.01). The present results suggest that the high sensitivity of CTA, if confirmed by further studies, might help in avoiding having to resort to arteriography after negative CTA in SAH patients.

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

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↗