Contrast-Enhanced Ultrasound

Heterotopic ossification (HO) is the formation of bone in soft tissues. The purpose of the present study was to evaluate the magnetic resonance imaging (MRI) findings on clinical suspicion of HO in the knee joint of patients hospitalised in the intensive care unit (ICU). This was a case series of 11 patients requiring prolonged ventilation in the ICU who had the following diagnoses: head trauma (nine), necrotising pancreatitis (one), and fat embolism (one). On clinical suspicion of HO, x-rays and MRI of the knee joint were performed. Follow-up x-rays and MRI were also performed. First x-rays were negative, whereas MRI (20.2 +/- 6.6 days after admission) showed joint effusion and in fast spin-echo short time inversion-recovery (STIR) images a 'lacy pattern' of the muscles vastus lateralis and medialis. The innermost part of the vastus medialis exhibited homogeneous high signal. Contrast-enhanced fat-suppressed T1-weighted images also showed a 'lacy pattern.' On follow...

estimate the performance of those. Our hydrothermally synthesized lead zirconate titanate (PZT) poly-crystalline film can be deposited on a tiny or complex-shaped titanium (Ti) substrate. Furthermore, it is thought that ultrasound probes with ultrawide frequency characteristics of their receiving sensitivity can be fabricated with the hydrothermally synthesized PZT film. We fabricated the miniature needle-type hydrophones with a small aperture by deposition of a hydrothermally synthesized PZT film on thin Ti wires and measured their performance. However, unnecessary back echo from the end of Ti wire was observed in our needle-type hydrophones and unnecessary peaks and dips appeared in the frequency characteristics of receiving sensitivities of our needle-type hydrophones. We think that such peaks and dips were caused by the resonance of the radial vibration mode. Miniature membrane-type hydrophones with disk type unimorph piezoelectric element were fabricated by deposition of a hydrothermally synthesized PZT film on Ti foil in order to avoid from back echo and peaks and dips in the frequency characteristics of receiving sensitivities. As a result, back echo was not observed in the membrane-type hydrophone. And received ultrasound waveform with our membrane-type hydrophone were similar to the applied electrical pulse waveform. Therefore, it is expected that our membrane-type hydrophone has smooth and wide frequency characteristics of receiving sensitivity without unnecessary peaks and dips. We will report the manufacturing process and measured results of their performance in this paper.

An improved fuzzy relaxation algorithm for image contrast enhancement is introduced, the relationship between the convergence regions and the parameters in the transformations defined by the algorithm is shown, which is essential to the successful application of this algorithm. Furthermore, in order to measure the quality of an enhanced image, an index of fuzziness is used in this paper to evaluate the performance of the fuzzy relaxation scheme. This extended index of fuzziness is used as a criterion for automatically stopping the fuzzy relaxation process. The analytical result is tested by experiments of image contrast enhancement.

Magnetic resonance-guided focused ultrasound surgery (MRgFUS) is a non-invasive treatment approach for symptomatic uterine fibroids. One imaging characteristic considered in selecting patients who may benefit from MRgFUS of their uterine fibroids is the signal intensity of the fibroid compared with surrounding myometrium on T2-weighted MR images. Previous reports suggest that hyper-intense fibroids are less amenable to MRgFUS compared with iso- or hypo-intense fibroids. In this case study, we utilized contrast-enhanced dynamic MR imaging to further characterize the vascularity of a hyper-intense fibroid. Based on the results of dynamic T1-weighted contrast-enhanced images, we assumed that the hyper-intense appearance resulted from high fluid content rather than high vascularity and predicted that the fibroid would respond to MRgFUS. The patient underwent the MRgFUS without complication and reported significant decrease in fibroid symptoms at 3 and 12 months post-treatment. This case...

Purpose: Three databases were pooled and analyzed to determine which groupings of prognostic factors best predicted overall survival for patients with low-grade gliomas treated with surgery and immediate or delayed radiotherapy. Methods and Materials: Databases of patients with low-grade gliomas compiled at the London Regional Cancer Centre (LRCC), the Norwegian Radium Hospital (NRH), and the University of California, San Francisco (UCSF) were merged. Inclusion criteria for the pooled analysis included: age > 18 years and histologically confirmed low-grade (World Health Organization Grade II) supratentorial fibrillary astrocytoma, oligodendroglioma or mixed oligoastrocytoma. Factors analyzed for prognostic significance included: age at diagnosis, gender, seizures at presentation, presence of enhancement on computed tomography (CT) or magnetic resonance imaging (MRI), Karnofsky Performance Status (KPS) at diagnosis, histology, extent of surgical resection, timing of radiotherapy, and treating institution. Univariate and multivariate analysis of overall survival for these factors was performed. Recursive partitioning was performed to generate prognostic groups using these factors.

Purpose: Three databases were pooled and analyzed to determine which groupings of prognostic factors best predicted overall survival for patients with low-grade gliomas treated with surgery and immediate or delayed radiotherapy. Methods and Materials: Databases of patients with low-grade gliomas compiled at the London Regional Cancer Centre (LRCC), the Norwegian Radium Hospital (NRH), and the University of California, San Francisco (UCSF) were merged. Inclusion criteria for the pooled analysis included: age > 18 years and histologically confirmed low-grade (World Health Organization Grade II) supratentorial fibrillary astrocytoma, oligodendroglioma or mixed oligoastrocytoma. Factors analyzed for prognostic significance included: age at diagnosis, gender, seizures at presentation, presence of enhancement on computed tomography (CT) or magnetic resonance imaging (MRI), Karnofsky Performance Status (KPS) at diagnosis, histology, extent of surgical resection, timing of radiotherapy, and treating institution. Univariate and multivariate analysis of overall survival for these factors was performed. Recursive partitioning was performed to generate prognostic groups using these factors.

Objectives: The purpose of this study is to evaluate the feasibility of contrast-enhanced ultrasonography (CE-US) to differentiate between benign and malignant intraductal papillary mucinous neoplasms (IPMN). Patients and methods: Contrast-enhanced ultrasonography with a contrast agent was performed on 22 consecutive patients with IPMN suspected of being malignant. This revealed 10 carcinomas, 1 borderline lesion and 11 adenomas. All patients underwent surgery, and the histological diagnosis was confirmed by examination of resected specimens. CE-US was performed using a contrast agent. The detection rates of mural nodules were compared between CE-US and contrast-enhanced computed tomography (CE-CT), and the imaging of mural nodules depicted under CE-US was analyzed. Results: Seventeen of 22 resected specimens (77.3%) had mural nodules. There was no significant difference in the detection rate between CE-US (n = 15; 88.2%) and CE-CT (n = 12; 70.6%). In 12 (80.0%) of these patients, CE-US revealed small vessels in the mural nodule. The spotty or linear-shaped pattern was detected in 4 patients and the branch-shaped pattern in 8. The branch-shaped pattern lesion was associated with carcinoma. These mural nodules were 10 mm or more in height. In the perfusion image phase, cystic walls and mural nodules were also enhanced in all cases. Conclusion: The vessel shapes of the mural nodules depicted under CE-US were associated with size and pathological findings. These results suggested that CE-US with a contrast agent is a powerful modality with which to evaluate the malignant potential of IPMN.

Objective: The purpose of this study was to clarify the usefulness of contrast-enhanced endoscopic ultrasonography in pancreatic diseases. Methods: The subjects comprised 37 patients with pancreatic diseases: 11 with ductal cell carcinoma, 10 with mucin-producing tumor, five with pseudo-cyst, four with islet cell tumor, four with chronic pancreatitis, and three with serous cystadenoma. After endoscopic ultrasonography, Albunex (0.22 ml/kg) was

Background Contrast enhanced multi-slice computed tomography (MSCT) is the leading modality in non-invasive coronary angiography (CTA) today. We investigated MSCT based assessment of coronary artery bypass grafts (CABG) by analyzing assets and drawbacks of CTA in order to define demands on latest technology. Methods In a clinical setting 39 CABG patients (69.2 ± 1.4 years; male n = 36) underwent CTA (collimation 16 9 0.75 mm, contrast medium 100 ml; 320 mAs, 120 KV). Ninety-seven CABG (61 venous, 36 arterial grafts) were evaluated. A subgroup of 18 patients underwent additional invasive coronary angiography (CA). Results CTA for CABG assessment resulted in an overall sensitivity (sens.) of 100%, specificity (spec.) of 92.4% and positive and negative predictive values (PPV, NPV) of 60% and 100%, respectively. CABG anastomoses showed slightly inferior diagnostic accuracy than other CABG segments. Limitations in imaging quality caused 21% unevaluable segments of the CABG anastomoses. Evaluation of native vessel segments proximal and distal to the anastomoses resulted in a sens, spec, PPV and NPV of 57.5, 94.6, 92 and 67.3%, respectively. With 28.5% unevaluable segments, the native vessel segments showed serious limitations in imaging quality. Radiation exposure was 9.88 ± 3.20 mSv (9.69 ± 3.25 mSv male; 12.08 ± 1.35 mSv female). Conclusion 16-slice MSCT based CABG assessment offers sufficient diagnostic accuracy. However, focussing on the bypass anastomoses and the native revascularized coronary arteries, clinical value is limited.

Aim: To evaluate the role of CT colonography (CTC) in the follow-up of patients having received partial colectomy for colorectal cancer. Methods and materials: CTC was performed in 72 subjects with history of partial colectomy for colorectal cancer. Colectomy had been performed in the right colon (n = 18), descending colon (n = 15), sigmoid colon (n = 21), and rectum (n = 18). Patients underwent CTC following incomplete conventional colonoscopy due to intolerance to endoscope insertion or luminal stenosis. In 70 cases pneumocolon was obtained through a rectal tube, and in 2 cases through a cutaneous anastomosis. CTC datasets were analyzed in combined 2D and 3D mode. All patients in whom CTC was suggestive for or raised the suspicion of disease recurrence underwent colonoscopy in sedation for confirmation of CTC findings. Results: CTC detected 7 cases of anastomotic stenosis. In 6/7 patients the stenosis was located in the sigmoid colon and in 1/7 patients at the level of the ileo-colic junction in the transverse colon. Out of these cases, four were fibrotic and three were neoplastic stenoses. In none of these cases was the CT appearance of the stenoses specific for disease recurrence, and conventional colonoscopy together with biopsy was necessary in order to characterize such findings. However, sensitivity of CTC in detecting anastomotic stenosis was 100% (7/7). One colonic mass (5 cm largest diameter) was detected in one case at the level of the proximal transverse colon in a patient with left colectomy performed 2 years before. The study of the residual colon showed 3 polyps in three patients (8, 6, and 5 mm, respectively). All CT findings were confirmed and characterized by conventional colonoscopy. In all cases the residual colon was entirely visualized by CTC with a completion rate of 100%. Conclusions: CTC is a feasible and minimally invasive method for full exploration of the colon after surgical resection allowing detection of cancer recurrence, metachronous disease, and distant metastases in one single study, and represents a valid alternative to conventional colonoscopy in this patient population.

The purpose of this study was to compare optimized whole-body (WB) and dedicated high-resolution contrast-enhanced PET/CT protocols and contrast enhanced CT in the preoperative staging of primary squamous cell carcinoma of the head and neck. Methods: A total of 44 patients with clinically M0 squamous cell carcinoma of the head and neck underwent primary tumor resection and neck dissection within 6 wk of diagnostic imaging. Imaging consisted of a standard WB PET/CT protocol without intravenous contrast enhancement, followed by a high-resolution dedicated head and neck (HN) PET/CT protocol, which included diagnostic-quality contrast-enhanced CT (CECT). Imaging results were compared with histopathology. A 5-point scale was used to designate primary tumor localization and the presence of lymph node metastasis on a per-patient and per-level basis. For cervical nodes, receiver-operating-characteristic curves were generated to determine the differences in performance between the WB and HN PET/CT protocols and CECT. Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated for primary tumor and cervical nodes. Results: No statistical difference was observed between WB and HN PET/CT protocols, both of which significantly outperformed CECT, in the evaluation of the primary tumor. The performance of the HN PET/CT protocol was superior to that of the WB PET/CT in the detection of cervical node metastases, achieving statistical significance on a per-level basis and approaching significance on a per-patient basis, with the greatest advantage in the detection of small positive lymph nodes (,15 mm). No significant difference was observed between the WB PET/CT protocol and CECT in nodal staging, either on a per-patient or on a per-level basis. Conclusion: The primary advantage of the dedicated HN PET/CT protocol over the WB protocol or CECT in the staging of head and neck cancer is in the detection of small lymph node metastases.

Objective: To integrate CT-perfusion into a routine, clinical contrast-enhanced (ce) PET/CT protocol for the evaluation of liver metastases and to compare functional CT and PET parameters. Materials and methods: Forty-six consecutive patients (mean age: 60 (34-82) years; 20 f, 26 m) with known liver lesions (colorectal metastases (n = 34), primary liver cancer (n = 4), breast cancer (n = 3), anal cancer, gastric cancer, esophageal cancer, GIST, duodenal cancer (all: n = 1) who were referred for staging or therapy follow-up by [18F]-Fluoro-2-deoxy-D-glucose-positron-emissiontomography/computed-tomography imaging (FDG-PET/ CT) were included. After acquisition of a low-dose PET/ CT, a split-injection (70-90 mL) ce-CT-protocol, including a 35-s CT-perfusion scan of the liver and a diagnostic ce-CT of the thorax and/or abdomen (70 s delay, iv-contrast volume: 90 mL, 4 mL/s) was performed. CT-perfusion parameters (BF, BV, MTT,) and semi-quantitative PETparameters (SUVmax, SUVmean, TLG, PETvol) were analyzed and compared. Results: CT-perfusion data could be obtained in all but one patient with shallow breathing. In all patients, diagnostic ce-PET/CT quality was adequate without the use of additional contrast media. Significant correlations (P < 0.05) were found for each of BF, BV, MTT, and SUVmax, further, BF and MTT correlated with TLG. Several other correlations were seen for other perfusion and PET-parameters. Conclusion: Combined CT-perfusion/PET/CT-protocol without the use of additional contrast media is feasible and can be easily integrated in clinical routine. Perfusion parameters and PET-parameters are only partly correlating and therefore have to be investigated further at fixed time points during the course of disease and therapy.

The purpose of this review is to describe the spectrum of sonographic findings in rheumatic diseases with respect to the diagnostic potential using US contrast media which prove activity or inactivity in synovial tissue where new treatment regimes target. Synovial activity can be found in non-erosive and erosive forms of primary and secondary osteoarthritis, and in inflammatory forms of joint diseases like rheumatoid arthritis and peripheral manifestations of spondyloarthritis including, ankylosing spondylitis, Reiter's syndrome, psoriatic arthritis and enteropathic arthritis. It can also be present in metabolic and endocrine forms of arthritis, in connective tissue arthropathies like systemic lupus erythematosus or scleroderma and in infectious arthritis. Ultrasound should be used as first-line imaging modality in suspected early cases of RA and other forms of arthritis, whereas contrast-enhanced ultrasound (CEUS) can further enable for sensitive assessment of vascularity which correlates with disease activity.

AIM: To quantify MRI enhancement characteristics of normal and abnormal prostatic tissues and to correlate these with tumour stage, histological grade and tumour markers. MATERIALS AND METHODS: Quantitative gradient recalled echo MR images were obtained following bolus injection of gadopentetate dimeglumine in 48 patients with prostate cancer. Turbo spin-echo T2-weighted images at the same anatomical position were reviewed for the presence of tumours (45 regions), normal peripheral zone (33 regions), and normal appearing central gland (30 regions). Time-signal intensity parameters (onset time, mean gradient and maximal amplitude of enhancement and wash-out score) and modelling parameters (permeability surface area product, lesion leakage space and maximum gadolinium concentration) were correlated with tumour stage, histological grade (Gleason score) and serum prostatic specific antigen (PSA) levels. RESULTS: Significant differences were noted between peripheral zone and tumour with respect to signal intensity and modelling parameters (P ¼ 0.0001), except onset time. No differences between central gland and tumour enhancement values were seen. There was weak correlation between MRI tumour stage and tumour vascular permeability (r 2 ¼ 12%; P ¼ 0.02) and maximum tumour gadolinium concentration (r 2 ¼ 14%; P ¼ 0.015). However, no significant correlations were seen with Gleason score or PSA levels. CONCLUSION: Quantification of MR contrast enhancement characteristics allows tissue discrimination in prostate cancer consistent with known variations in microvessel density estimates. Padhani, A. R. et al. (2000). Clinical Radiology 55, 99-109.

Three-dimensional micro computed tomography (microCT) offers the opportunity to capture images liver structures and lesions in mice with a high spatial resolution. Non-invasive microCT allows for accurate calculation of vessel tortuosity and density, as well as liver lesion volume and distribution. Longitudinal monitoring of liver lesions is also possible. However, distinguishing liver lesions from variations within a normal liver is impossible by microCT without the use of liver-or tumor-specific contrast-enhancing agents. The combination of microCT for morphologic imaging with functional imaging, such as positron emission tomography (PET) or single photon emission tomography (SPECT), offers the opportunity for better abdominal imaging and assessment of structure discrepancies visible by functional imaging.

The purpose of this study was to evaluate the usefulness of a new ultrashort contrast-enhanced (CE) MR angiography (MRA) for the morphologic evaluation of cerebral arteriovenous malformations (AVMs). The method was compared with conventional X-ray digital subtraction angiography (DSA) and time-of-flight (TOF) MRA in 22 patients to assess the angioarchitecture of the malformations which is essential for treatment planning and follow-up. Two experienced MR readers independently evaluated both techniques with regard to the assessment of feeding arteries, AVM nidus, and venous drainage patterns. Contrast-enhanced MRA was able to detect all AVMs seen on DSA, whereas the TOF MRA failed in 1 patient with a very small AVM. In the assessment of the different vessel components of the AVM there was no difference for the detection and delineation of feeding arteries and the AVM. The venous drainage patterns could always be clearly delineated in the CE MRA, whereas TOF MRA could demonstrate the ...

Aims Global angiographic scores have been developed to determine the extent of myocardium jeopardized by significant coronary stenosis. We adapted these scores to quantify the anatomic area at risk during acute myocardial infarction. We used contrast-enhanced magnetic resonance (CMR) infarct imaging to measure the portion of myocardium that developed necrosis within the so defined angiographic area at risk. Methods and results In 83 subjects presenting for primary percutaneous intervention, the myocardium at risk was estimated angiographically using the Myocardial Jeopardy Index (BARI) and a modified version of the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) scores. CMR was performed within a week to measure infarct size, infarct endocardial surface area (infarct-ESA), and infarct transmurality. As infarct transmurality increased, the infarct size closely approximated the myocardium at risk by angiography. In 35 subjects with transmural infarcts, the area at risk by BARI and APPROACH scores matched the infarct size (r ¼ 0.90 and r ¼ 0.92, P , 0.001). Additionally, BARI and APPROACH scores matched the infarct-ESA in all subjects independently of collateral flow and time to reperfusion (r ¼ 0.90 and r ¼ 0.87, P , 0.001). The presence of early reperfusion, collaterals, or both was associated with a progressive decrease in infarct transmurality (P , 0.001 for trend) with no difference in the infarct-ESA. Conclusion The myocardium at risk of infarction can be determined angiographically as validated in subjects with transmural myocardial infarcts. Salvage provided by early reperfusion or collaterals occurs by limiting infarct transmurality, thereby the extent of endocardial infarct involved also allows estimation of the myocardium at risk in patients presenting with STEMI.

In patients with multiple sclerosis (MS), we assessed the short-and long-term effects of a weekly low dose of recombinant human interferon beta 1a (rh-IFN beta 1a) on the development of new magnetic resonance imaging (MRI) lesions enhancing at different gadolinium-DTPA (Gd) doses. Every 4 weeks, standard dose (SD) (0.1 mmol / kg of Gd) and triple dose (TD) (0.3 mmol / kg of Gd) Gd-enhanced brain MRI scans were obtained from 18 patients with relapsing-remitting MS for 3 months before treatment, 4 months after treatment initiation (treatment period [TP] I) and 4 months after 1 year of treatment (TP II) with 44 mg of rh-IFN beta 1a subcutaneously, once a week. The mean numbers of new enhancing lesions / patient / month were 1.4 (baseline), 1.1 (TP I) and 0.7 (TP II) on SD scans and 2.4 (baseline), 1.3 (TP I) and 0.8 (TP II) on TD scans. On average, treatment decreased the rate of new enhancing lesion appearance by 24% (SD scans) and 45% (TD scans) during TP I and by 52% (SD scans) and 66% (TD scans) during TP II. This study indicates that the effect of 44 mg of rh-IFN beta 1a given once a week on MRI-monitored MS activity increases over time. It also suggests that TD MRI is useful in detecting early treatment effect, that would otherwise be missed.

The purpose of this study was to investigate the correspondence between the coronary arterial anatomy and supplied myocardium based on the proposed American Heart Association 17-segment model. B A C K G R O U N D Standardized assignment of coronary arteries to specific myocardial segments is currently based on empirical assumptions.

Purpose: The role of radiotherapy (RT) seems established for patients with low-grade gliomas with poor prognostic factors. Three-dimensional (3D) magnetic resonance spectroscopy imaging (MRSI) has been reported to be of value in defining the extent of glioma infiltration. We performed a study examining the impact MRSI would have on the routine addition of 2-3-cm margins around MRI T2-weighted hyperintensity to generate the treatment planning clinical target volume (CTV) for low-grade gliomas. Methods and Materials: Twenty patients with supratentorial gliomas WHO Grade II (7 astrocytomas, 6 oligoastrocytomas, 7 oligodendrogliomas) underwent MRI and MRSI before surgery. The MRI was contoured manually; the regions of interest included T2 hyperintensity and, if present, regions of contrast enhancement on T1-weighted images. The 3D-MRSI peak parameters for choline and N-acetyl-aspartate, acquired voxel-by-voxel, were categorized using a choline/N-acetyl-aspartate index (CNI), a tool for quantitative assessment of tissue metabolite levels, with CNI 2 being the lowest value corresponding to tumor. CNI data were aligned to MRI and displayed as 3D contours. The relationship between the anatomic and metabolic information on tumor extent was assessed by comparing the CNI contours and other MRSI-derived metabolites to the MRI T2 volume. Results: The limitations in the size of the region "excited" meant that MRSI could be used to evaluate only a median 68% of the T2 volume (range 38 -100%), leaving the volume T2c. The CNI 2 volume (median 29 cm 3 , range 10 -73) was contained totally within the T2c in 55% of patients. In the remaining patients, the volume of CNI 2 extending beyond the T2c was quite small (median 2.3 cm 3 , range 1.4 -5.2), but was not distributed uniformly about the T2c, extending up to 22 mm beyond it. Two patients demonstrated small regions of contrast enhancement corresponding to the regions of highest CNI. Other metabolites, such as creatine and lactate, seem useful for determining less and more radioresistant areas, respectively. Conclusion: Metabolically active tumor, as detected by MRSI, is restricted mainly to the T2 hyperintensity in low-grade gliomas, but can extend outside it in a limited and nonuniform fashion up to 2 cm. Therefore, a CTV including T2 and areas of CNI extension beyond the T2 hyperintensity would result in a reduction in the size and a change in the shape of the standard clinical target volumes generated by adding uniform margins of 2-3 cm to the T2 hyperintensity.

We compared contrast-enhanced T1-weighted and 3D constructive interference in steady state (CISS) sequences for demonstrating possible prognostic factors in hearing-preservation surgery for vestibular schwannoma. We studied 22 patients with vestibular schwannomas having hearing-preservation surgery. Postoperatively six (27%) had a facial palsy and eight (36%) had hearing loss. There was a significant correlation between the size of the tumour and facial palsy (r=-0.72). Both techniques adequately demonstrated all tumours. Involvement of the fundus of the internal auditory canal (IAC) and a small distance between the lateral border of the tumour and the fundus were correlated significantly with hearing loss (r=-0.81 and -0.75, respectively). The 3D-CISS sequence, by virtue of its high contrast resolution was superior to T1-weighted images ( P&lt;0.05) for detection of the fundal involvement. The direction of displacement of the facial nerve did not correlate with facial palsy or hear...

To delineate the cardiac magnetic resonance (MR) appearances of cardiovascular disease (CVD) in patients with systemic lupus erythematosus (SLE), in comparison with transthoracic echocardiographs. Cardiac MR was performed on 22 patients with SLE-11 with previous CVD and 11 matched controls-using late gadolinium contrast enhancement (LGE) to identify areas of myocardial scarring; Transthoracic echocardiography (TTE) was performed on the same day. Twenty female and two male patients participated. LGE was seen in 5/11 subjects in the CVD group (4/5 with previous myocardial infarction) and 1/11 in the control group. TTE detected myocardial abnormalities in 2/6 patients with LGE. The cardiac MR appearance of CVD in these patients with SLE was suggestive of coronary disease, rather than cumulative inflammatory muscle damage. Cardiac MR detected more abnormalities than TTE. Further studies of cardiac MR in patients with SLE are warranted to investigate these preliminary findings.

BACKGROUND AND PURPOSE: The use of a high-resolution T2-weighted MR sequence, which suppresses signal from both fat and water, has been shown to be highly effective for depicting areas of inflammatory damage within the optic nerve. The ability of this sequence to show neoplastic and inflammatory orbital lesions, which may mimic neuritis, is unknown. This study was designed to examine

The purpose of this study was to determine the feasibility of using an ultrasound contrast agent test bolus to determine optimum bolus timing for three-dimensional (3D) gadolinium (Gd)-enhanced magnetic resonance angiography (MRA). Small test doses of ultrasound contrast agent (0.3 ml Optison) were injected intravenously followed immediately by a 20 ml saline flush. Arrival of the contrast agent was detected by spectral Doppler ultrasound (US). This technique was implemented in patients undergoing peripheral vascular MRA and carotid MRA. Arrival of the US contrast agent test bolus was readily detected by the change in amplitude of the Doppler spectrum and by a huge increase in the audio signal amplitude. This contrast travel time measurement accurately guided bolus timing for 3D Gd MRA. Bolus timing for 3D contrast-enhanced MRA can be performed using US, thereby eliminating the problems and MR scanner time required for injecting a test bolus of Gd contrast. J. Magn. Reson. Imaging 1999;10:389-394.

Christian P. Behrenbruch 1 , Kostas Marias 1,2 , Paul A. Armitage 1 , J. Michael Brady 1 , ... 1 Medical Vision Laboratory (Robotics), Oxford University, Parks Rd, Oxford OX1 3PJ, United Kingdom: {cpb,jmb}@robots.ox.ac.uk ... 2 Department of Surgery, Royal Free and ...

In real world machine vision problems, numerous issues such as variable scene illumination make edge and object detection difficult. There exists no universal edge detection method which works well under all conditions. In this paper, we propose a logarithmic edge detection method based on Parameterized Logarithmic Image Processing (PLIP) and a four-directional Sobel method, achieving a higher level of independence from scene illumination. We present experimental results for this method, and compare results of the algorithms against several leading edge detection methods, such as Sobel and Canny. To compare results objectively, we use Pratt's Figure of Merit. We demonstrate the application of the algorithm in conjunction with Edge Preserving Contrast Enhancement (EPCE), which is an image enhancement method dependent on the raw output of an edge detection kernel. This shows that the use of this edge detection algorithm results in better image enhancement, as quantified by the Logarithmic AME.

Recording coronary arteries&#39; flow by transthoracic Doppler echocardiography (TTDE) is a new task. Despite several studies concerning the left anterior descending artery (LAD) exist, the same for posterior descending coronary artery (PD) do not. Reported feasibility is not more than 76%. The aim of the study was to try to improve feasibility by using an additional two-dimensional view as a guide. PD flow recording was performed in 35 consecutive unselected patients under the guidance of the usual two-dimensional modified view [a two-chamber view (2-C)], and with a new four-chamber modified view (4-C). A semi-quantitative growing-quality score (from 0 to 3 points) to the trace was given. Contrast enhancement was used if PD was not visualized without it. The overall feasibility was 80%. A good or very good velocity signal (TTDE score &gt; or = 2) was observed in 48% of patients without contrast enhancement. Time for first visualization of PD was short and significantly lower in 2-C...

Background: Echocardiographic assessment of LV wall motion is still most frequently done visually. This study was designed to validate a new system for semi-automatic quantification of global and regional LV systolic function from contrast-enhanced cross-sectional echocardiograms. Methods: Measurements of LV volumes were validated in 50 patients using magnetic resonance (MR) as reference. The regional identification of the endocardial boundary was validated frame-by-frame against the visually identified border in another 27 patients. Finally, the applicability of the system for quantifying stress-echocardiographic exams was assessed in 52 patients undergoing dobutamine interventions. Echocardiographic sequences were digitally processed using custom-built algorithms, based on local phase feature descriptors, deformable contour fitting, and prospective training. Results: Compared to MR, the tracing system showed reasonable accuracy, with relative errors for end-diastolic volume, end-systolic volume, and EF of 21 ± 20%, 27 ± 33%, and − 4 ± 18%, respectively. Regional agreement of the instantaneous contours with visually traced borders was within the limits of visual reproducibility. The system was suitable for tracking stress-echo studies from all patients except two (96%). Quantification of regional radial shortening allowed to discriminate segments showing an abnormal regional wall motion with an overall area under the ROC curve of 0.87. Conclusions: A reliable and accurate quantification of LV systolic function can be obtained by processing contrast echocardiograms. Values of LV volumes, ejection fraction, and regional endocardial shortening adequately correlate with currently available reference methods. Readily applicable to baseline and stress studies, endocardial tracking techniques increase the reliability of echocardiography for the assessment of global and regional systolic function.