Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.59 (MIP)
 4,906 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three-dimensional gadolinium-enhanced dynamic MRI of whole liver using the spectrally selected enhanced fast gradient recall sequence (spec IR-efgre3d) was performed in five patients with HCC. Ten HCC nodules were confirmed by CTA, CTAP and Lipiodol CT, and all of them were detected with dynamic MRI. MIP images reconstructed from 3D gadolinium-enhanced dynamic MR studies clearly showed the main portal vein and its branches in all cases. Portal vein thrombosis was also demonstrated with the MIP images.
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PMID:[Three-dimensional gadolinium-enhanced dynamic MRI of whole liver using spectrally selected enhanced fast gradient recall sequence]. 955 53

To evaluate spiral-computed tomography (CT) angiography in primary diagnosis and/or in noninvasive follow-up after vascular intervention, we compared spiral-CT angiography and conventional angiography before and after vascular intervention. Helical-CT examinations before and after percutaneous transluminal angioplasty (PTA) or stent implantation were performed in 10 patients (mean age 63 years) with symptomatic peripheral arteriosclerotic disease. Stenoses were located in the iliac, femoral, or popliteal artery. CT examinations were done with a spiral-CT in double detector technique (CT Twin, Elscint). The parameters were as follows: slice thickness: 5.5 mm, increment: 2.7 mm, pitch: 1.5, contrast medium: 150 mL, flow rate: 2.5 mL/second, delay: 30 seconds. For evaluation, transverse planes as well as maximum intensity projections and 3-D reconstructions were used. The possible scan length reached from the aortic bifurcation down to about 10 cm below the ankle trifurcation. Preinterventional digital subtraction angiography (DSA) was superior to CT angiography (CTA: 94%, maximum intensity projection [MIP] alone: 65%), although high-grade stenoses were detected by both methods. After intervention, a resolved stenosis and improved peripheral flow could be detected by helical-CT as well as by intraarterial angiography in every patient (100%). In the primary diagnosis of vascular changes, intraarterial DSA remains the method of choice. Nevertheless, spiral-CT angiography shows comparable results after percutaneous intervention and becomes a noninvasive alternative in the postinterventional follow-up.
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PMID:Diagnostic value of spiral-CT angiography in comparison with digital subtraction angiography before and after peripheral vascular intervention. 971 88

The aim of the study was to investigate the use of 2D and 3D reconstructions in examinations of the aorta with CT and MRI. Postprocessing of 5 data sets including 2D MPR reconstructions, 3D MIP reconstructions and 3D volume rendering reconstructions acquired with contrast enhanced CTA and 5 data sets acquired with contrast enhanced MRA were performed. The luminal diameter, the length of the aneurysm and the detection of dissection was assessed for the reconstructions and the source images. Aneurysms and dissections of the aorta were correctly identified on source images. 2D MPR reconstructions and source images allow for a clear and easy image analysis including cases with high signal intensity or density of surrounding tissue and complex anatomical structures. The diameter and length of pathological findings can be determined correctly wit 2D MPR reconstructions, even when the vessel orientation is not exactly inplane or throughplane in relation to the source images. MIP reconstructions are suitable for contrast enhanced MRA data sets with high C/N ratio and volume rendering reconstructions are suitable for contrast enhanced CTA data sets, where calcifications and bone have also high density. For 3D visualization of large volumes MIP reconstructions are the method of choice for MRA and volume rendering reconstructions for CTA, respectively. In addition, 2D MPR can be necessary to determine the diameter and length of pathological findings.
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PMID:[Reconstruction methods in postprocessing of CT- and MR-angiography of the aorta]. 1155 84

With these two cases we want to demonstrate the additional impact of contrast enhanced multi-detector-row-CT angiography (MDR-CTA) compared to digital subtraction angiography (DSA) for planning of angiographic intervention. In selected cases a pre-interventional CTA can be useful to facilitate angiographic intervention. We selected two patients with different disease entities (bleeding caused by hepatic aneurysmosis; hepatocellular carcinoma (HCC) prior to transarterial chemoembolization (TACE) with aberrant arteries) from our collective who underwent CTA prior to angiographic intervention. The CT scans were performed using a 16 channel Multi-Detector-Row-CT (Philips Mx8000 IDT). Both multiplanar reconstructions (MPR) and slab maximum intensity projections (slab MIP) were performed. After CTA, patients underwent angiographic intervention (coil embolisation in the first case, TACE in the second case). MDR-CTA can not only find the cause of hemorrhage but also demonstrate the exact localization of the specific vascular pathology (first case). These findings facilitate the intervention, resulting in decreased table time in the angio suite and a reduction in radiation exposure. The second case illustrates the anatomic detail achievable with MDR-CTA. Even very small aberrant arteries (crucial to the success of TACE) are revealed. These arteries did not show in overview DSA and required superselective catheterization (only performed after MDR-CTA). These cases show that MDR-CTA can provide important informations in planning of interventional procedures.
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PMID:[Impact of a guiding CT prior to angiographic intervention]. 1511 38

With the development of MRI and MRA, many unruptured aneurysms have been detected and treated. Nevertheless, not a few false-positive and false-negative cases are found. We investigate aneurysms that were suspected after screening MRA at the neurosurgical outpatient clinic and the features of aneurysms detected not with MRA but with DSA were studied. Seventy-six patients (85 aneurysms) were suspected due to screening MRA and DSA was performed in 64 (71 aneurysms) of them. Correct diagnosis of cerebral aneurysms with MRA was obtained in 44 patients (45 aneurysms, 63.4%), while false-negative cases were found in 17 patients (plus 20 aneurysms) and false-positive cases in 7 patients (10 aneurysms). The accuracy was 97.2% in ACA, 93% in MCA, 94.4% in VA-BA, and 78.9% in IC, while the sensitivity 100%, 88.2%, 81.8%, 64.7% and the specificity 96.5%, 94.4%, 96.7%, 91.9%, respectively. The features of aneurysms correctly diagnosed with MRA were relatively large ACA, including AcoA, MCA and VA-BA aneurysms, whereas the features of aneurysms undetected with MRA were small IC aneurysms (1-3mm in diameter), especially at the C2-3 portion. These aneurysms at the C2-3 portion or at unusual portions tended to be difficult to detect even with 3D-CTA. Though most of the aneurysms detected with DSA but not with MRA tended to be small and not interventionally treated in the present study, we should pay attention to the fact that these aneurysms are overlooked despite the possibility that they may become enlarged or rupture. Though ruptured aneurysms were surgically treated with only MRA or 3D-CTA without conventional angiography in these days, we recommend the examination of the unruptured cases, which are usually asymptomatic and not hasty, with precise inspection by target MIP, high-performance 3D-CTA or DSA.
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PMID:[Unruptured cerebral aneurysms; the features of cases undetected with MR angiography]. 1535 28

With the introduction of MDCT with 16 or more detector rows, CTA of aortoiliac and peripheral run-off vessels has become a routine clinical tool. Rapid scan times of approximately 30 s for the entire peripheral vascular tree combined with thin slices (1-2 mm) allow high-resolution 3-D reconstruction. The short scan duration requires injection of a relatively small volume of contrast material. We recommend a monophasic contrast bolus of 100 mL Iomeprol 400 (Bracco, Italy) and 50 mL normal saline at a rate of 4 mL/s. This approach provides strong enhancement and adequate visualization of small peripheral vessels, including 93% of arteries below the knee and 84% of pedal arteries. The best synchronization of contrast bolus and scan acquisition is achieved with a table feed of 40-48 mm/s; this approach provides significantly stronger and more homogeneous enhancement along the z-axis than faster or slower approaches, and largely avoids problems associated with overriding of the bolus or venous overlay (<3%). Postprocessing of CTA datasets is crucial for adequate documentation and communication of anatomy and pathology. We prefer MIP reconstructions after bone removal and curved MPR. In a recent comparative study performed in 50 patients (958 lesions) to determine the accuracy of 16-slice CTA compared to DSA for detection of clinically relevant (>50%) stenoses, we obtained sensitivity and specificity values of 90.1-93.3% and 95.6-96.5%, respectively. Patient management decisions (conservative, intervention, or surgery) based on CTA were the same as after DSA in 49 of the 50 patients. CTA is an accurate, noninvasive alternative to DSA of the aorto-iliac and peripheral run-off arteries.
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PMID:MDCT angiography of peripheral arteries: technical considerations and impact on patient management. 1837 52

We evaluated quantification of calcified carotid stenosis by dual-energy (DE) CTA and dual-energy head bone and hard plaque removal (DE hard plaque removal) and compared the results to those of digital subtraction angiography (DSA). Eighteen vessels (13 patients) with densely calcified carotid stenosis were examined by dual-source CT in the dual-energy mode (tube voltages 140 kV and 80 kV). Head bone and hard plaques were removed from the dual-energy images by using commercial software. Carotid stenosis was quantified according to NASCET criteria on MIP images and DSA images at the same plane. Correlation between DE CTA and DSA was determined by cross tabulation. Accuracies for stenosis detection and grading were calculated. Stenosis could be evaluated in all vessels by DE CTA after applying DE hard plaque removal. In contrast, conventional CTA failed to show stenosis in 13 out of 18 vessels due to overlapping hard plaque. Good correlation between DE plaque removal images and DSA images was observed (r (2) = 0.9504) for stenosis grading. Sensitivity and specificity to detect hemodynamically relevant (>70%) stenosis was 100% and 92%, respectively. Dual-energy head bone and hard plaque removal is a promising tool for the evaluation of densely calcified carotid stenosis.
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PMID:Dual-energy CT head bone and hard plaque removal for quantification of calcified carotid stenosis: utility and comparison with digital subtraction angiography. 1927 72

The dysfunction of a vascular access for hemodialysis and its loss may depend on drainage difficulties of the superficial or deep venation due to hemodynamically significant stenosis or obstruction of a central vein, which generally involve the innominate-subclavian veins or superior vena cava. These alterations are often neglected due to their central and deep location; when there is hemodynamic compensation, they may remain asymptomatic. For these reasons every suspect clinical sign for central vein stenosis (gross arm syndrome or venous hypertension in an arteriovenous fistula) must not be ignored, as timely intervention is essential for functional recovery of the vessel and for the protection of the arteriovenous fistula. The modern imaging techniques ensure thorough diagnostic assessment, while the possibilities of endovascular treatment with interventional radiology allow, in a large proportion of cases, optimal minimally invasive treatment, but above all the recovery of venation in a hemodialyzed patient. We report our experience with multislice computed tomographic angiography (MS-CTA) and reconstruction software for treatment planning of central vein stenosis or obstruction. Forty-nine patients were studied with MS-CTA (GE 16). Images were acquired in the venous phase (120-180 seconds after contrast medium injection) followed by digital vascular reconstruction (AutoBone for bone removal, vessel analysis for caliber and length measurements, thin and curved MIP, MPR). Within a week control phlebography was performed. The venous tree was divided into seven segments and analyzed in a double-blind fashion with a distinction between patent segments, 50-70% stenosis, >70% stenosis, occlusion, and collateral vascular beds. There was excellent correspondence in all the examined segments for patency, >70% stenosis, and occlusion, with high sensitivity (98%), specificity (99.3%), and diagnostic accuracy (99.1%). The binomial test demonstrated a highly significant concordance (alpha=0.99) for all patients and in all vascular segments with the exception of 70% stenoses, in which MS-CTA gave a slight overestimate. In the central venous district, color Doppler ultrasonography may not be as effective as for the peripheral study of arteriovenous fistulae, and second-level imaging techniques such as MS-CTA are more useful. We suggest that endovascular treatment must be preceded by MS-CTA. This examination shows the lesions that may benefit from endovascular treatment and recognizes ''uncrossable'' lesions, ie, the ones that will not benefit from treatment. Moreover, it allows accurate planning of endovascular treatment by showing the lesion type (stenosis or obstruction), the position and extension of the involved vessels, the vessel caliber above and below the lesion, and the possible presence of a collateral vascular bed. MS-CTA with dedicated reconstruction software, if correctly performed and accurately reconstructed, is a precious tool for diagnosis and treatment planning.
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PMID:[Multislice computed tomographic angiography in the assessment of central veins for endovascular treatment planning: comparison with phlebography]. 2019 62

Introduction Existing stroke literature demonstrates that rapid recanalization of vessels improves long-term prognosis after acute ischemic stroke. However, further optimization of the speed of the thrombectomy procedure, used to recanalize a blocked vessel, is limited by our minimal knowledge of the clot dimensions pre-procedure. Knowing the clot dimensions would allow planning of the thrombectomy procedure with the appropriate size and length of stent retriever, and determination of the correct site of the stent deployment ensuring total coverage of the clot by the stent retriever. Methods We performed a feasibility study to assess if multiphase computed tomography angiography (mCTA) can be used to estimate clot length by comparing CTA imaging data with imaging data obtained from conventional digital subtraction angiography (DSA). A retrospective chart review was performed of patients with clots in the proximal middle cerebral artery and adequate collateral circulation, who underwent both mCTA and DSA. Results Clot length was not significantly different on 3D mCTA versus mCTA MIPs, nor was it significantly different on MIP mCTA versus DSA. Pathological evidence also supported our ability to measure clot length on mCTA. Conclusions We suggest that mCTA is a reliable and valid measure of clot length in acute ischemic stroke patients.
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PMID:Assessment of clot length with multiphase CT angiography in patients with acute ischemic stroke. 2906 54