A set of tissue-mimicking phantoms containing spherical negative contrast simulated lesions was employed to associate an automated method for determining detectability with human observers. Six alternative methods for computing the lesion signal-to-noise ratio (LSNR) were employed for quantifying automated detecting ability. The six methods differ regarding effective lesion area and ...

The variations in the stiffness or stiffness contrast of lesions resulting from radiofrequency (RF) ablation of canine liver tissue at different temperatures and for different ablation durations at a specified temperature are analyzed. Tissue stiffness, in general, increases with temperature; however, an anomaly exists around 80 degrees C, where the ...

Recent advances in contrast material-enhanced ultrasonography (US) mainly include (a) development of low-acoustic-pressure (low-mechanical-index) harmonic software, capable of obtaining real-time images without disrupting contrast material microbubbles, and (b) commercialization of new contrast media ("second-generation" contrast media), capable of producing intense echo signals in this low-mechanical-index setting. With use of low-mechanical-index ...

BACKGROUND: We assessed the potential usefulness of contrast-enhanced power Doppler ultrasonography (US) for differentiating pancreatic carcinoma from chronic focal pancreatitis. METHODS: Twenty-six consecutive patients with ductal carcinoma (n=16) and chronic focal pancreatitis (n=10) underwent power Doppler US examinations before and after intravenous injection of an air-based contrast agent (Levovist, Schering, ...

The prevalence of benign focal liver lesions (BFLL) is high both in the general population and in patients with known malignancies. The gray-scale ultrasound (US) technique is usually the first-line imaging modality used in the radiological workup of such lesions, but unfortunately it lacks specificity. Furthermore, Doppler examination may often ...

Two hundred and fifty-six (256) patients (72% preoperative, 28% pre-Mammotome) were prospectively examined with EIS using the TS 2000 (TransScan Research and Development Center, Israel; temporarily distributed by Siemens, Erlangen) with the "LOS"-software (level of suspicion). All exams were performed with the targeted scan probe, the observer knowing all clinical ...

Nasoalveolar cyst is a rare nonodontogenic cyst arising in the nasoalar region of the face. In this case, a 39-year-old female had a nontender, fluctuant, soft, round, and bluish lesion in the right anterior gingiva of the right maxilla. Panoramic and magnetic resonance imaging examinatioins were performed. No abnormality was ...

Lesion dimension of cryoablation. BACKGROUND: Transvenous catheter cryoablation is a novel technique for treating cardiac arrhythmias. However, the relative importance of temporal application parameters on lesion dimension and clinical efficacy has not been studied. METHODS AND RESULTS: We investigated the effects of (1) application duration: single 2.5 (2.5x1) versus single ...

OBJECTIVE: The utilization of diathermy (electrocautery) as an energy source in the treatment of chronic atrial fibrillation has generated positive early clinical results. Although this technology is available and affordable, it has not been well studied for this indication. The objectives of this study were: (1) to characterize atrial lesions ...

OBJECTIVE: The aim of this study was to evaluate the clinical feasibility of dynamic magnetic resonance (MR) imaging with a 3-dimensional (3D) gradient recalled echo (GRE) volumetric interpolated breath-hold examination (VIBE) sequence to differentiate between benign and malignant solitary pulmonary nodules (SPNs). METHODS: Dynamic 3D GRE VIBE was performed in ...

BACKGROUND: The differentiation of benign from malignant intraductal papillary mucinous tumors (IPMT) is often difficult even by various examination methods. We evaluated the qualitative and quantitative diagnostic ability of contrast-enhanced transabdominal ultrasonography (CE-US), mainly in differentiating benign from malignant tumors in patients with IPMT. PATIENTS AND METHODS: There were 21 ...

OBJECTIVES: The purpose of this study was to evaluate the safety and efficacy of cryoablation in a closed chest canine epicardial ablation model. BACKGROUND: Limitations of radiofrequency energy in the epicardial space warrants investigation of alternative energy sources. METHODS: A linear-tip catheter with a 3-cm freezing element and a 6-mm-tip ...

OBJECTIVE: The purpose of this study was to evaluate the appearance of primary peripheral soft tissue lymphoma on high-resolution ultrasonography. METHODS: We retrospectively studied the sonograms of 12 patients (5 female and 7 male; age range, 12-90 years; mean, 55 years) with soft tissue lymphoma. All lesions were palpable and ...

Segmental testicular infarction is described in 11-years-old-child presented with acute left hemiscrotal pain and swelling. Clinical examination suggested left testicular tenderness with no evidence of intratesticular mass and the rest of the scrotal contents were normal. Color doppler study suggested a well circumscribed avascular lesion in the upper pole of ...

To investigate the feasibility of combined dynamic contrast enhanced (DCE) and magnetic resonance spectroscopy (MRS) in evaluating breast lesions. Nine patients with positive mammograms scheduled for either biopsy or mastectomy were examined on a 1.5-T MR scanner. DCE was performed with administration of gadolinium-DTPA contrast using a two-dimensional spoiled gradient ...

This study attempted to evaluate the reliability of ultra-thin T2-weighted imaging with a constructive interference in steady state (CISS) sequence as a screening method for tumors in the cerebellopontine angle. A retrospective study of 200 CISS examinations was made by five investigators. The examinations were inspected on plain film supported ...

Three methods of creating large thermal lesions with cool-tip cluster electrodes were compared. Three cluster electrodes were arranged 4 cm apart in a triangular array. Eight lesions were created ex vivo in fresh bovine liver (from a butcher) with each method: sequential ablation (three electrodes, 12 minutes each); simultaneous activation ...

PURPOSE: Prospective evaluation of the 3- and 6-month results after atherectomy of below-knee arterial lesions with a reference diameter of at least 2.0 mm with use of the Silverhawk device. MATERIALS AND METHODS: Fifty-two below-knee lesions in 33 patients (61% men; mean age, 70 years +/- 11) with chronic peripheral ...

OBJECTIVE: We investigated the ability of contrast-enhanced sonography with SonoVue (Altana Pharma, Konstanz, Germany), a sulfur hexafluoride microbubble contrast agent, to reveal differences between benign and malignant focal hepatic lesions. METHODS: One hundred twenty-six lesions in 124 patients with focal hepatic lesions detected by B-mode sonography (hepatocellular carcinoma, n = ...

PURPOSE: To report the early and 6-month results after atherectomy of femoropopliteal lesions using a new atherectomy device compatible with a 7-F sheath. METHODS: Fifty-two patients (36 men; mean age 67+/-7 years) with stable, chronic lower limb occlusive disease were enrolled prospectively in a study of percutaneous directional atherectomy using ...

AIMS: To determine whether the presence of large intrahepatic blood vessels (>/=3 mm) affect radiofrequency (RF)-induced coagulation necrosis, the gross and histological characteristics of RF-ablated areas proximal to or around vessels were examined in normal pig livers. METHODS: An RF ablation treatment using a two-stepwise extension technique produced 12 lesions: ...

The purpose of this research was to evaluate the role of Echo Colour/Power Doppler and Magnetic Resonance Imaging (MRI) in the diagnosis of expansive parotid lesions, and to establish criteria for differential diagnosis between benign and malignant forms. Forty nine patients (23 males and 26 females), aging from 30 to ...

Since cadaveric donation is the main source of organs for transplantation in many countries, the diagnosis of brain death is an important issue. The cessation of cerebral circulation is one phenomenon closely related to brain death. Transcranial Doppler sonography is one of the accepted techniques to establish cessation of cerebral ...

OBJECTIVE: To investigate the potential efficacy of real-time contrast-enhanced power Doppler sonography in the differentiation of benign and malignant adnexal masses in a pilot study. METHODS: Before surgical treatment, adnexal masses were prospectively evaluated with power Doppler sonography before and after injection of a contrast agent. Real-time postinjection sequences were ...

Ultrasonography (US) of the thyroid gland has recently proved to be a useful clinical diagnostic method, and the newly developed high-resolution US with a color Doppler flow mapping function can reveal fine details of the thyroid gland and the hemodynamic features of a thyroid neoplasm. US can yield a diagnostic ...

OBJECTIVE: This study was performed to evaluate the role of diffusion-weighted imaging (DWI) in the diagnosis of Japanese encephalitis (JE) and to look for any relationship of the apparent diffusion coefficient (ADC) values with duration of the illness. METHODS: We performed DWI in fourteen patients of JE. T2 weighted (T2W) ...

OBJECTIVE: To investigate the relationship between size and whole lesion enhancement of breast neoplasms. MATERIALS AND METHODS: Fat-suppressed subtraction MRI was performed in 94 breast lesions (44 malignant, 50 benign) with pathologically confirmed diagnoses. Of these, all malignant lesions and 31 of the 50 benign lesions showed enhancement. The degree ...

Thermal ablation with radiofrequency (RF) is gaining increasing attention for the treatment of musculoskeletal lesions. This treatment offers several advantages compared to other methods: reduced invasiveness, low cost, and short hospitalisation time. In June 2001 we began using RF thermal ablation on osteoid osteomas (OO) in the appendicular and axial ...

OBJECTIVE: To determine the clinical usefulness of color duplex sonography in the diagnosis of giant cell arteritis as an alternative to temporal artery biopsy. METHODS: From May 1998 to November 2002, 68 consecutive patients seen in our hospital with a clinical suggestion of active temporal arteritis were included. Forty-eight patients ...

INTRODUCTION: The aim of this study was to assess the safety and feasibility of catheter-based cryothermal ablation lesions in the mid- and distal coronary sinus. METHODS AND RESULTS: Cryothermal ablation lesions were delivered using a 7-French catheter at the mid- (n = 13) and distal (n = 12) coronary sinus ...

BACKGROUND: Pulmonary vein isolation is a hallmark in current surgical ablation for atrial fibrillation. However, validation of isolation remains cumbersome. We evaluated electrophysiologic and not histologic means to test isolation. METHODS: In 16 mongrel dogs, robot-assisted epicardial beating-heart microwave ablation (FLEX 10) was performed around the pulmonary veins. Electrophysiologic isolation ...

INTRODUCTION: The inability to determine the extent and intramural depth of ablation lesions can hamper the success of catheter ablation. The study tested the feasibility of differentiating radiofrequency ablation lesions from normal myocardium and quantifying their dimensions by myocardial contrast echocardiography (MCE). METHODS AND RESULTS: In 11 normal dogs, we ...

OBJECTIVE: The aim of this prospective study was to investigate the accuracy of B-mode transvaginal sonography alone and combined with color Doppler imaging and cancer antigen 125 (CA 125) plasma concentrations in differentiating peritoneal cysts from other adnexal masses. METHODS: Between September 1999 and September 2003, 213 adnexal masses underwent ...

Transmural lesions are ensured with the cut and sew technique and with bipolar delivery of radiofrequency (RF) energy [Ann. Thorac. Surg. 74 (2002) 2210]. Unipolar sources of energy such as radiofrequency and microwave do not guarantee transmurality and may require intraoperative testing to evaluate complete lesion depth. Transmural lesions are ...

Choroid plexus carcinomas (CPC) are rare malignant intracranial neoplasms usually occurring in young children. The objectives of this study were to characterize the preoperative MRI features of CPC, determine the frequency of disseminated disease in the CNS at diagnosis, and assess patient outcomes. The preoperative cranial MR images of 11 ...

OBJECTIVE: The purpose of this study was to assess the value of multiarterial phase contrast-enhanced dynamic MRI of the whole liver obtained during a single breath-hold for small early enhancing hepatic lesions in patients with cirrhosis or chronic hepatitis, emphasizing the distinction between hypervascular hepatocellular carcinomas and pseudolesions. MATERIALS AND ...

BACKGROUND: Creating linear lesions is important for the treatment of arrhythmias such as atrial flutter and fibrillation. Making these lesions with standard radiofrequency catheters can be difficult and may result in charring and thrombosis. The purpose of this study was to evaluate beta-radiation as a novel energy source for creating ...

The objective of this paper is to compare the accuracy of standard, non-contrast endosonography (EAS) with contrast-enhanced endosonography (CE-EAS) in the diagnosis of anal fistulas. The group consisted of 126 patients (mean age: 43.1 years) with the clinical diagnosis of anal fistula. For anal endosonography, a Bruel & Kjaer unit ...

PURPOSE: To assess whether characterization of solid focal liver lesions could be improved by using ultrasonographic (US) contrast-specific modes after sulfur hexafluoride-filled microbubble contrast agent injection, as compared with lesion characterization achieved with preliminary baseline US. MATERIALS AND METHODS: Four hundred fifty-two solid focal hepatic lesions that were considered indeterminate ...

Epicardial radiofrequency ablation is increasingly being used for intraoperative treatment of atrial fibrillation. However, the effect of different parameters on the lesion characteristics has not been sufficiently characterized. We used a finite element model to calculate the temperature distribution in the atrial tissue under different conditions during a constant voltage ...

We report a rare case of bilateral pericallosal artery ectasia with stenosis in a 49-year-old man complaining of frontal headache. CT showed a serpiginous calcified interhemispheric fissure lesion with contrast enhancement. Imaging of this lesion was pursued with MR and MR angiography; however, conventional cerebral angiography was needed to make ...

Malignant gliomas arise from two distinct pathways, as de novo lesions or from secondary transformation from low-grade lesions. Herein, we describe the cases of two patients to illustrate the proposition that de novo malignant gliomas can originate as non-enhancing tumors and rapidly progress to a pattern of ring enhancement characteristic ...

Endocardial radiofrequency ablation of the left ventricle does not create transmural lesions reliably even with active electrode cooling. The authors developed a prototype catheter with an internally cooled needle electrode that could be advanced an adjustable distance into the myocardium. Freshly excised hearts from eight male sheep were perfused and ...

Diabetic fibrous mastopathy (DFM) is an uncommon lesion that may clinically mimic breast carcinoma. Routine mammographic and ultrasonographic features of this disease also mimic the those of malignant disease, making an accurate preoperative diagnosis difficult. Dynamic contrast-enhanced magnetic resonance imaging (MRI), however, reveals a homogeneous low-enhancement with a gradual and ...

The virtual electrode model predicts that pacing stimulus strength should reflect proximity of the pacing electrode to excitable myocardium, allowing pacing threshold to assess radiofrequency (RF) ablation lesions and unexcitable scar. The purpose of this study is to correlate RF lesion size with pacing threshold and electrogram (EG) amplitude change ...

AIM: To study the difference of microvessel density (MVD) between malignant and benign hepatic lesions and study the relationship between MVD and dynamic enhanced magnetic resonance imaging (MRI) for evaluation of microvessels within malignant and benign hepatic lesions. METHODS: A total of 265 specimens of hepatocellular carcinoma (HCC), 122 cirrhosis ...

Malignant gliomas of the brain typically exhibit on CT or MRI a strong peripheral contrast enhancement area with a variable central zone of necrosis. These tumours are not known to change their radiological appearance and contrast enhancement pattern under systemic steroid treatment--a feature usually associated with primary CNS lymphoma. We ...

BACKGROUND: Early diagnosis of hepatocellular carcinoma (HCC) is extremely important because surgical resection and local ablation therapy are undoubtfully the most effective treatment regiment. Recent advances in sonographic techniques have risen the question ofsonography utility. The scope of this investigation was to assess the detection accuracy of tumor vascularity in ...

The aim of this study was to investigate the feasibility of contrast-enhanced US (conE US) in differentiating pyogenic hepatic abscesses (PyHAs) from hypovascular hepatic malignancies. conE US images of 16 PyHAs in 12 patients were evaluated retrospectively and were compared with those of 22 hypovascular hepatic malignancies in 12 patients. ...

RF catheter ablation of ventricular tachycardia is sometimes limited by inadequate lesion depth. This study investigated the use of a retractable needle-tipped catheter to create deep RF lesions in vivo in porcine myocardium. An 8 Fr electrode catheter with an extendable 27-gauge needle at the tip was modified for RF ...