MRI of the liver with the new contrast medium Gd-BOPTA

International Nuclear Information System (INIS)

Vogl, T.J.; Pegios, W.; Balzer, J.; Lissner, J.; Pirovano, G.

1992-01-01

A phase 1 study on 8 normals has been carried out to determine the effectiveness and safety during MRI of a new hepatobiliary contrast medium Gd-BOPTA for causing enhancement of the upper abdominal organs. Gradient echo sequences (flash), T 1 and T 2 -weighted spin echo sequences and turbo-flash sequences were used. The contrast medium was given as a single infusion in various concentrations (0.005, 0.05, 0.1 and 0.2 mmol/kg body weight). Optimal contrast of liver parenchyma was obtained with a dose of 0.05-0.1 mmol/kg body weight, resulting in contrast increase of 149.1% during gradient echo sequences and 107.8% during T 1 spin echo sequences. In general, the increased contrast lasted for about two hours. Because of the biliary and renal excretion there was an enormous increase in signal intensity of the bile ducts and a significant increase in the kidneys and ureters. The results of the first in-vivo-trial of Gd-BOPTA encourages the performance of further clinical studies of this new hepatobiliary contrast medium. (orig.) [de

Incompatibility of Contrast Medium and Trisodium Citrate

International Nuclear Information System (INIS)

Delcour, Christian; Bruninx, Guy

2013-01-01

To test the compatibility of trisodium citrate, a catheter lock solution, with iodinated contrast medium. Iohexol, iobitridol, iodixanol, ioxaglate, ioxithalamate, iomeprol, and iopromide were tested. In all tests, 2 ml of contrast medium were mixed with 2 ml of trisodium citrate solution. Iodixanol and ioxaglate provoked a highly viscous gluelike precipitation when mixed with trisodium citrate. A brief transient precipitate was observed with iohexol, iomeprol, and ioxithalamate. Permanent precipitation occurred with iobitridol and iopromide. One must be aware of the potential for precipitation when contrast medium is mixed with trisodium citrate solution. Before trisodium citrate solution is injected, the catheter should be thoroughly flushed with saline if a contrast medium has previously been injected through it.

Computed tomography of the cervical spine with iv injection of contrast medium

International Nuclear Information System (INIS)

Magnaldi, S.; Pozzi-Mucelli, R.S.; Cova, M.A.; De Morpurgo, P.

1989-01-01

Computed Tomography (CT) without contrast medium is largely applied to the study of intervertebral disk pathology in the lumbar spine, but has not been widely accepted in cervical spine, due to technical and anatomical limitations. For these reasons many neuroradiologists still prefer myelography or myelo-CT. CT may yield better results if combined with iv contrast medium injection, which allows a better visualization of disk herniation. This technique is aimed at enhancing the density of the venous plexus which is located close to the intervertebral disk the vertebral bodies and the neural foramina. A better contrast enhancement is thus obtained between the disk and the spinal cord. The authors' experience is based on 61 patients who underwent contrast enhanced CT; in 22 cases myelography and myelo-CT were also performed. The authors describe their technique and the most frequent CT findings of disk hernation: the typical finding includes a focal hypodensity surrounded by a linear blush, due to a posteriorly dislocated epidural vein. The posterior linear blush alone may be present in few cases. Contrast enhanced CT is very useful in the study of disk pathology of the cervical spine, even when compared with myelography and myelo-CT, due the increase in the density of epidural plexus it allows. However, the technique must be very accurate if the same results as those of myelo-CT are to be obtained

Roentgen contrast medium

International Nuclear Information System (INIS)

Tamborski, C.

1989-01-01

The patent deals with a roentgen contrast medium containing a perfluorinebrominealkylether of the formula C m F 2m+1 OC n F 2n Br dispersed in water, preferentially in the presence of a non-ionic dispersing agent such as a fluorinated amidoaminoxide. 2 tabs

Magnetic resonance tomography of the orbit: First experiences with the paramagnetic contrast medium gadolinium-DTPA

International Nuclear Information System (INIS)

Markl, A.; Vogl, T.; Scheidhauer, K.; Riedel, K.G.; Oeckler, R.

1986-01-01

In 21 patients with orbital mass lesions MRI was performed before and after administration of paramagnetic contrast medium, gadolinium-DPTA. In comparison to the plain scan the differentiation of the tumorous tissue against the surrounding structures was improved after application of contrast medium despite a partially moderate increase in signal intensity. Especially highly vascular tumors and vessel diseases show a significant contrast enhancement. With increasing experience in larger number of patients a tissue differentiation seems to be possible. (orig.) [de

Influence of hyperosmotic agent (glycerol) in contrast enhancement

International Nuclear Information System (INIS)

Moriyama, Takashi; Suzuki, Shigeharu; Nakaoka, Tsutomu

1981-01-01

For getting a better contrast enhancement (CE) of computed tomography (CT) in brain tumors, we tried to increase the extravascular iodine concentration. A vailing ourselves of the period of returning water following intravenously administered glycerol, a drip injection of the contrast medium gave a better CE effect than the usual CE. In two benign gliomas, CE with glycerol was much better than CE without glycerol, and in two malignant gliomas and two metastatic tumors, CE with glycerol was better, but not so much better as with the benign tumors. In general, the CE effect in primary brain tumors showed a decreasing pattern, whereas in metastatic brain tumors the best time was 60 minutes after the injection of the contrast material (increasing and decreasing pattern), suggesting an increase in the extravascular iodine and a severe failure of the blood brain barrier. Two cystic malignant gliomas allowed the intravenously injected contrast medium to enter the cysts. It appears that the contrast medium passes through and/or is secreted from the wall of the cyst. (author)

Contrast-enhanced ultrasound imaging of active bleeding associated with hepatic and splenic trauma.

Science.gov (United States)

Lv, F; Tang, J; Luo, Y; Li, Z; Meng, X; Zhu, Z; Li, T

2011-10-01

The aim of this study was to evaluate contrast-enhanced ultrasound (CEUS) imaging of active bleeding from hepatic and splenic trauma. Three hundred and ninety-two patients with liver or/and spleen trauma (179 liver and 217 spleen injuries), who underwent CEUS examinations following contrast-enhanced computed tomography (CT), were enrolled in this retrospective study over a period of >4 years. CEUS detected contrast medium extravasation or pooling in 16% (63/396) of liver or spleen lesions in 61 patients, which was confirmed by contrast-enhanced CT. Special attention was paid to observing the presence, location, and characteristics of the extravasated or pooled contrast medium. The CEUS detection rate for active bleeding was not different from that of contrast-enhanced CT (p=0.333). Information from surgery, minimally invasive treatment and conservative treatment was used as reference standard, and the sensitivities of the two techniques were not different (p=0.122). Of 63 lesions in 61 patients, CEUS showed that 74.6% (47/63) (21 liver lesions and 26 spleen lesions) presented contrast medium extravasation or pooling, both in the organ and out the capsule, in 14.3% (9/63) and only outside the capsule in 11.1% (7/63). CEUS imaging of active bleeding from hepatic and splenic trauma presented various characteristics, and the sizes and shapes of the active bleeding due to contrast medium extravasation or pooling were variable. CEUS can show the active bleeding associated with hepatic and splenic trauma with various imaging characteristics, thus making it possible to diagnose active bleeding using CEUS.

Risk of application of contrast medium in computed tomography

Energy Technology Data Exchange (ETDEWEB)

Wende, S.; Speck, U.

1981-06-01

The paper deals with the risk associated with the application of contrast medium in CT. The risk is to be seen in intolerance reactions, such as allergic or circulatory reactions and neurotoxic side-effects. In this paper the problems of renal failure caused by the injection of contrast medium are given special attention. Furthermore an iodine-induced hyperthyreosis might result. Especially the possible disturbance of the kidney function means that contrast medium should not be applied arbitrarily and that the examination should be done only by experienced staff. Furthermore the indication for the application of contrast medium in CT should be strictly qualified.

A method to evaluate the dose increase in CT with iodinated contrast medium

International Nuclear Information System (INIS)

Amato, Ernesto; Lizio, Domenico; Settineri, Nicola; Di Pasquale, Andrea; Salamone, Ignazio; Pandolfo, Ignazio

2010-01-01

Purpose: The objective of this study is to develop a method to calculate the relative dose increase when a computerized tomography scan (CT) is carried out after administration of iodinated contrast medium, with respect to the same CT scan in absence of contrast medium. Methods: A Monte Carlo simulation in GEANT4 of anthropomorphic neck and abdomen phantoms exposed to a simplified model of CT scanner was set up in order to calculate the increase of dose to thyroid, liver, spleen, kidneys, and pancreas as a function of the quantity of iodine accumulated; a series of experimental measurements of Hounsfield unit (HU) increment for known concentrations of iodinated contrast medium was carried out on a Siemens Sensation 16 CT scanner in order to obtain a relationship between the increment in HU and the relative dose increase in the organs studied. The authors applied such a method to calculate the average dose increase in three patients who underwent standard CT protocols consisting of one native scan in absence of contrast, followed by a contrast-enhanced scan in venous phase. Results: The authors validated their GEANT4 Monte Carlo simulation by comparing the resulting dose increases for iodine solutions in water with the ones presented in literature and with their experimental data obtained through a Roentgen therapy unit. The relative dose increases as a function of the iodine mass fraction accumulated and as a function of the Hounsfield unit increment between the contrast-enhanced scan and the native scan are presented. The data shown for the three patients exhibit an average relative dose increase between 22% for liver and 74% for kidneys; also, spleen (34%), pancreas (28%), and thyroid (48%) show a remarkable average increase. Conclusions: The method developed allows a simple evaluation of the dose increase when iodinated contrast medium is used in CT scans, basing on the increment in Hounsfield units observed on the patients' organs. Since many clinical protocols

A method to evaluate the dose increase in CT with iodinated contrast medium

Energy Technology Data Exchange (ETDEWEB)

Amato, Ernesto; Lizio, Domenico; Settineri, Nicola; Di Pasquale, Andrea; Salamone, Ignazio; Pandolfo, Ignazio [Department of Radiological Sciences, University of Messina, Messina 98125 (Italy); Department of Physics, University of Messina, Messina 98166 (Italy); University Hospital ' ' G. Martino' ' , Messina 98125 (Italy); Department of Radiological Sciences, University of Messina, Messina 98125 (Italy) and University Hospital ' ' G. Martino' ' , Messina 98125 (Italy)

2010-08-15

Purpose: The objective of this study is to develop a method to calculate the relative dose increase when a computerized tomography scan (CT) is carried out after administration of iodinated contrast medium, with respect to the same CT scan in absence of contrast medium. Methods: A Monte Carlo simulation in GEANT4 of anthropomorphic neck and abdomen phantoms exposed to a simplified model of CT scanner was set up in order to calculate the increase of dose to thyroid, liver, spleen, kidneys, and pancreas as a function of the quantity of iodine accumulated; a series of experimental measurements of Hounsfield unit (HU) increment for known concentrations of iodinated contrast medium was carried out on a Siemens Sensation 16 CT scanner in order to obtain a relationship between the increment in HU and the relative dose increase in the organs studied. The authors applied such a method to calculate the average dose increase in three patients who underwent standard CT protocols consisting of one native scan in absence of contrast, followed by a contrast-enhanced scan in venous phase. Results: The authors validated their GEANT4 Monte Carlo simulation by comparing the resulting dose increases for iodine solutions in water with the ones presented in literature and with their experimental data obtained through a Roentgen therapy unit. The relative dose increases as a function of the iodine mass fraction accumulated and as a function of the Hounsfield unit increment between the contrast-enhanced scan and the native scan are presented. The data shown for the three patients exhibit an average relative dose increase between 22% for liver and 74% for kidneys; also, spleen (34%), pancreas (28%), and thyroid (48%) show a remarkable average increase. Conclusions: The method developed allows a simple evaluation of the dose increase when iodinated contrast medium is used in CT scans, basing on the increment in Hounsfield units observed on the patients' organs. Since many clinical

Contrast enhancement of cranial lesions in computed tomography

Energy Technology Data Exchange (ETDEWEB)

Lewander, R; Bergstroem, M; Bergvall, U [Kungliga Karolinska Mediko-Kirurgiska Inst., Stockholm (Sweden)

1978-01-01

The time course of enhancement in apparently normal brain tissue, edema and focal lesions during 30 to 60 min after intravenous injection of vascular contrast medium was evaluated in a series of 41 pateints with differnt intracranial lesions. The attenuation of apparently normal unenhanced brain tissue varied with the level of the scan, mainly an effect of beam hardening. Different types of enhancement response are discussed in terms of a 3-compartment model. The differential diagnostic potential of contrast enhancement in the early phase needs further evaluation using instruments with short scanning time, while the late phase of enhancement must be recorded with the use of a reliable head fixation to provide reproducibility of repeat measurements.

Risk of application of contrast medium in computed tomography

International Nuclear Information System (INIS)

Wende, S.; Speck, U.; Schering A.G., Berlin

1981-01-01

The paper deals with the risk associated with the application of contrast medium in CT. The risk is to be seen in intolerance reactions, such as allergic or circulatory reactions and neurotoxic side-effects. In this paper the problems of renal failure caused by the injection of contrast medium are given special attention. Furthermore an iodine-induced hyperthyreosis might result. Especially the possible disturbance of the kidney function means that contrast medium should not be applied arbitrarily and that the examination should be done only by experienced staff. Furthermore the indication for the application of contrast medium in CT should be strictly qualified. (orig.) [de

Oral contrast medium in PET/CT: should you or shouldn't you?

International Nuclear Information System (INIS)

Groves, Ashley M.; Kayani, Irfan; Dickson, John C.; Townsend, Caroline; Croasdale, Ian; Syed, Rizwan; Nagabushan, Nagesh; Hain, Sharon F.; Ell, Peter J.; Bomanji, Jamshed B.

2005-01-01

It has been suggested that the use of computed tomography (CT) positive contrast agents has led to attenuation-induced artefacts on 18 F-fluorodeoxyglucose positron emission tomography ( 18 F-FDG PET/CT) systems. Consequently, centres may withhold the use of such agents. Whilst there is theoretical evidence to support the aforementioned claim, the clinical relevance of the induced artefacts has not been widely established. Moreover, the potential benefits of bowel enhancement on PET/CT have yet to be formally evaluated. We therefore prospectively examined PET/CT studies to assess whether the use of oral contrast medium induces clinically relevant artefacts and whether the use of these agents is diagnostically helpful. Over a 2-month period, 18 F-FDG PET/CT images were prospectively reviewed from 200 patients following Gastrografin administration 2 h prior to examination. Both a radiologist and a nuclear medicine physician reviewed the images for contrast medium-mediated clinically relevant artefacts. Artefacts were sought on the CT attenuation-corrected images and were compared with the appearance on non-attenuated-corrected images. The number of examinations in which the oral contrast aided image interpretation was also noted. There were no oral contrast medium-induced clinically significant artefacts. In 38 of the 200 patients, oral contrast aided image interpretation (owing to differentiation of mass/node from bowel, discrimination of intestinal wall from lumen or definition of the anatomy of a relevant site). In 33 of these 38 patients, the anatomical site of interest was the abdomen/pelvis. The use of oral contrast medium in 18 F-FDG PET studies should not be withheld as it improves image interpretation and does not produce clinically significant artefacts. (orig.)

Abdominal multi-detector row CT: Effectiveness of determining contrast medium dose on basis of body surface area

International Nuclear Information System (INIS)

Onishi, Hiromitsu; Murakami, Takamichi; Kim, Tonsok; Hori, Masatoshi; Osuga, Keigo; Tatsumi, Mitsuaki; Higashihara, Hiroki; Maeda, Noboru; Tsuboyama, Takahiro; Nakamoto, Atsushi; Tomoda, Kaname; Tomiyama, Noriyuki

2011-01-01

Purpose: To investigate the validity of determining the contrast medium dose based on body surface area (BSA) for the abdominal contrast-enhanced multi-detector row CT comparing with determining based on body weight (BW). Materials and methods: Institutional review committee approval was obtained. In this retrospective study, 191 patients those underwent abdominal contrast-enhanced multi-detector row CT were enrolled. All patients received 96 mL of 320 mg I/mL contrast medium at the rate of 3.2 mL. The iodine dose required to enhance 1 HU of the aorta at the arterial phase and that of liver parenchyma at portal venous phase per BSA were calculated (EU BSA ) and evaluated the relationship with BSA. Those per BW were also calculated (EU BW ) and evaluated. Estimated enhancement values (EEVs) of the aorta and liver parenchyma with two protocols for dose decision based on BSA and BW were calculated and patient-to-patient variability was compared between two protocols using the Levene test. Results: The mean of EU BSA and EU BW were 0.0621 g I/m 2 /HU and 0.00178 g I/kg/HU for the aorta, and 0.342 g I/m 2 /HU and 0.00978 g I/kg/HU for the liver parenchyma, respectively. In the aortic enhancement, EU BSA was almost constant regardless of BSA, and the mean absolute deviation of the EEV with the BSA protocol was significantly lower than that with the BW protocol (P < .001), although there was no significant difference between two protocols in the hepatic parenchymal enhancement (P = .92). Conclusion: For the aortic enhancement, determining the contrast medium dose based on BSA was considered to improve patient-to-patient enhancement variability.

Contrast enhancement of the gyri in herpes simplex encephalitis

International Nuclear Information System (INIS)

Schumacher, K.A.; Langer, M.; Langer, R.

1982-01-01

A case of herpes simplex encephalitis was examined by computer tomography. Both cerebral hemispheres showed contrast enhancement of the gyri. The cause of this is considered. The increased contrast medium accumulation in the affected areas is probably due to the marked vascular proliferation which can be demonstrated anatomically, and to the rapid escape of contrast from the capillaries into the interstitial spaces. The findings of other authors, which differ somewhat, are discussed. (orig.) [de

Transient partial amnesia complicating cardiac and peripheral arteriography with nonionic contrast medium

International Nuclear Information System (INIS)

Yildiz, A.; Yencilek, E.; Apaydin, F.D.; Duce, M.N.; Oezer, C.; Atalay, A.

2003-01-01

The aim of this study was to present a case of disruption of the blood-brain barrier during the coronary and lower extremity angiographies with radiological and clinical findings. This condition was secondary to intraarterial use of a nonionic, monomeric contrast medium. A total of 450 cc contrast media was used. Computed tomography examination showed contrast enhancement of the right occipital and frontoparietal cortical regions, which returned to normal one day after. The patient also fully recovered from the neurological symptoms within 24 h. We discussed the possible mechanism for blood-brain barrier disruption in this case. (orig.)

Transient partial amnesia complicating cardiac and peripheral arteriography with nonionic contrast medium

Energy Technology Data Exchange (ETDEWEB)

Yildiz, A.; Yencilek, E.; Apaydin, F.D.; Duce, M.N.; Oezer, C. [Dept. of Radiology, Mersin Ueniv. Tip Fakueltesi Sokak Mersin (Turkey); Atalay, A. [Dept. of Cardiology, Mersin Ueniv. Tip Fakueltesi Sokak Mersin (Turkey)

2003-12-01

The aim of this study was to present a case of disruption of the blood-brain barrier during the coronary and lower extremity angiographies with radiological and clinical findings. This condition was secondary to intraarterial use of a nonionic, monomeric contrast medium. A total of 450 cc contrast media was used. Computed tomography examination showed contrast enhancement of the right occipital and frontoparietal cortical regions, which returned to normal one day after. The patient also fully recovered from the neurological symptoms within 24 h. We discussed the possible mechanism for blood-brain barrier disruption in this case. (orig.)

Clinical experience with a non-ionic contrast medium (ultravist) in left ventriculography

International Nuclear Information System (INIS)

Lee, Ghi Jai; Park, Jae Hyung; Soe, Gwy Suk; Hong, Ju Hee; Han, Man Chung

1988-01-01

Non-ionic contrast medium, iopromide (Ultravist), was compared with ionic contrast medium, ioxitalamate (Telebrix), for efficacy and safety in 63 patients undergoing left ventriculography. In all patients, adverse symptoms and signs including pain, heat sense, nausea, vomiting, etc., were checked during and shortly after the injection. Blood pressure, heart rate, EKG and left ventricular pressure were also monitored during the study, and CBC, UA, BUN and creatinine were checked before and 24 hours after the study. The cineangiographic films were analysed and compared by 2 radiologists for the quality. Serious adverse effect did not occur in any case. Minor effects, especially nausea, were lee frequently caused by non-ionic contrast medium than by ionic contrast medium, and heat sense to non-ionic contrast medium was less severe than to ionic contrast medium. Except slightly elevated LVEDP at 1,5 minutes after the study in patients given ionic contrast medium, there was no significant change of electrophysiologic parameters and laboratory findings in both groups. In regard to image quality, there was no significant difference between ionic and non-ionic contrast medium. Thus non-ionic contrast medium, iopromide, appears to be safer for use in left ventriculography than the conventional ionic contrast medium, particularly in those patients at high risk of adverse effects.

Hepatic contrast medium enhancement at computed tomography and its correlation with various body size measures

Energy Technology Data Exchange (ETDEWEB)

Svensson, Anders; Nouhad, Jallo; Cederlund, Kerstin; Aspelin, Peter; Torkel, Brismar B., E-mail: anders.svensson@karolinska.se [Dept. of Clinical Science, Intervention and Technology at Karolinska Inst., Div. of Medical Imaging and Technology, Stockholm (Sweden); (Dept. of Radiology, Karolinska Univ. Hospital, Huddinge, Stockholm (Sweden)); Nyman, Ulf (Dept. of Diagnostic Radiology, Lasarettet Trelleborg, Univ. of Lund, Trelleborg (Sweden)); Bjoerk, Jonas (Competence Centre for Clinical Research, Skaane Univ. Hospital, Lund (Sweden)

2012-07-15

Background. When the same dose of iodine is given to all patients when performing abdominal computed tomography (CT) there may be a wide inter-individual variation in contrast medium (CM) enhancement of the liver. Purpose. To evaluate if any of the measures body height (BH), body mass index (BMI), lean body mass (LBM), ideal body weight (IBW), and body surface area (BSA) correlated better than body weight (BW) with hepatic enhancement, and to compare the enhancement when using iodixanol and iomeprol. Material and Methods. One hundred patients referred for standard three-phase CT examination of abdomen were enrolled. Body weight and height were measured at the time of the CT examination. Forty grams of iodine (iodixanol 320 mg I/mL or iomeprol 400 mg I/mL) was injected at a rate of 1.6 g-I/s, followed by a 50 mL saline flush. The late arterial phase was determined by using a semi-automatic smart prep technique with a scan delay of 20 s. The hepatic parenchymal phase started automatically 25 s after the late arterial phase. CM concentration was estimated by placement of regions of interest in aorta (native and late arterial phase) and in liver (native and parenchymal phase). Results. BW (r -0.51 and -0.64), LBM (r = -0.54 and -0.59), and BSA (r -0.54 and -0.65) showed the best correlation coefficients with aortic and hepatic parenchymal enhancement, respectively, without any significant differences between the measures. Comparing iodixanol and iomeprol there was no significant difference in aortic enhancement. The liver enhancement was significantly higher (P < 0.05) using iodixanol than iomeprol. Conclusion. To achieve a consistent hepatic enhancement, CM dose may simply be adjusted to body weight instead of using more complicated calculated parameters based on both weight and height.

Independent component analysis of dynamic contrast-enhanced computed tomography images

Energy Technology Data Exchange (ETDEWEB)

Koh, T S [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Ave, Singapore 639798 (Singapore); Yang, X [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Ave, Singapore 639798 (Singapore); Bisdas, S [Department of Diagnostic and Interventional Radiology, Johann Wolfgang Goethe University Hospital, Theodor-Stern-Kai 7, D-60590 Frankfurt (Germany); Lim, C C T [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore)

2006-10-07

Independent component analysis (ICA) was applied on dynamic contrast-enhanced computed tomography images of cerebral tumours to extract spatial component maps of the underlying vascular structures, which correspond to different haemodynamic phases as depicted by the passage of the contrast medium. The locations of arteries, veins and tumours can be separately identified on these spatial component maps. As the contrast enhancement behaviour of the cerebral tumour differs from the normal tissues, ICA yields a tumour component map that reveals the location and extent of the tumour. Tumour outlines can be generated using the tumour component maps, with relatively simple segmentation methods. (note)

Contrast enhancement of mail piece images

Science.gov (United States)

Shin, Yong-Chul; Sridhar, Ramalingam; Demjanenko, Victor; Palumbo, Paul W.; Hull, Jonathan J.

1992-08-01

A New approach to contrast enhancement of mail piece images is presented. The contrast enhancement is used as a preprocessing step in the real-time address block location (RT-ABL) system. The RT-ABL system processes a stream of mail piece images and locates destination address blocks. Most of the mail pieces (classified into letters) show high contrast between background and foreground. As an extreme case, however, the seasonal greeting cards usually use colored envelopes which results in reduced contrast osured by an error rate by using a linear distributed associative memory (DAM). The DAM is trained to recognize the spectra of three classes of images: with high, medium, and low OCR error rates. The DAM is not forced to make a classification every time. It is allowed to reject as unknown a spectrum presented that does not closely resemble any that has been stored in the DAM. The DAM was fairly accurate with noisy images but conservative (i.e., rejected several text images as unknowns) when there was little ground and foreground degradations without affecting the nondegraded images. This approach provides local enhancement which adapts to local features. In order to simplify the computation of A and (sigma) , dynamic programming technique is used. Implementation details, performance, and the results on test images are presented in this paper.

Contrast induced nephropathy in patients undergoing intravenous (IV) contrast enhanced computed tomography (CECT) and the relationship with risk factors: a meta-analysis

NARCIS (Netherlands)

Moos, Shira I.; van Vemde, David N. H.; Stoker, Jaap; Bipat, Shandra

2013-01-01

To summarize the incidence of contrast-induced nephropathy (CIN) and associations between CIN incidence and risk factors in patients undergoing intravenous contrast-enhanced computed tomography (CECT) with low- or iso-osmolar iodinated contrast medium. This review is performed in accordance with the

B-mode and contrast-enhanced sonographic assessment of accessory spleen in the dog.

Science.gov (United States)

Rossi, Federica; Rabba, Silvia; Vignoli, Massimo; Haers, Hendrik; Terragni, Rossella; Saunders, Jimmy H

2010-01-01

Four dogs with an accessory spleen are described. The accessory spleens appeared as a round-to-triangular structure located in the perisplenic area. They were homogeneous and isoechoic with the adjacent spleen. Contrast-enhanced ultrasound was performed using a second generation microbubble contrast medium (sulfur hexafluoride). The type and timing of enhancement of the accessory spleen was similar to that of the parent spleen. Contrast-enhanced ultrasound is a noninvasive modality useful in distinguishing an accessory spleen from a mass of another origin.

Intravenous contrast medium application in elderly patients - evaluation of Iopentol (Imagopaque trademark 300)

International Nuclear Information System (INIS)

Rathsmann, P.; Jacobs, G.F.; Mueller, R.D.

2004-01-01

Purpose: We examined the subjective compatibility of elderly patients who received the intravenous contrast medium Iopentol (Imagopaque trademark 300). In addition, objective data were acquired to show possible interactions between contrast media and organ systems in old patients. Methods and materials: A CT scan with intravenous application of contrast media was performed on 132 patients ranging in age from 75 to 96 years. The patients were questioned about their individual sensations. In addition, blood pressure, creatinine and CT-densitometry were acquired as objective date. Results: The patients' individual sensations and clinical data show a very low rate of complications. Mild allergic reactions were noticed in two patients. No severe anaphylactic reactions were encountered. Statistically significant changes in blood pressure before and after administration of the contrast medium were not observed. The serum creatinine concentration was unchanged after application of contrast media. For CT-densitometry, the patients were divided into two groups, one group with patients 75-84 years and the other group with patients 85-96 years of age. CT-densitometry showed no age-related differences. The protocol of contrast administration resulted in excellent opacification of the examined regions, only the liver did not enhance in some cases before the opacification of the portal vein. Conclusion: It is shown that old age alone is no reason to withhold contrast media containing iodine when performing CT. For the evaluation of the liver, however, the peculiarities of old age have to be taken into account and the interval between injection of the contrast medium and beginning of the spiral-CT has to be extended. (orig.)

Visualization of endolymphatic hydrops in meniere's disease after single-dose intravenous gadolinium-based contrast medium. Timing of optimal enhancement

International Nuclear Information System (INIS)

Naganawa, Shinji; Yamazaki, Masahiro; Kawai, Hisashi; Bokura, Kiminori; Sone, Michihiko; Nakashima, Tsutomu

2012-01-01

Visualization of endolymphatic hydrops (EH) in patients with Meniere's disease (MD) is now possible by heavily T 2 -weighted 3-dimensional fluid-attenuated inversion recovery (h T 2 W-3D-FLAIR) obtained 4 hours after intravenous (IV) administration of single dose gadolinium-based contrast medium (GBCM). Although maximum enhancement has been reported 4 hours after contrast administration in healthy volunteers, the timing of optimal enhancement in patients with MD is not reported. We investigated if that optimal timing is earlier or later than 4 hours. We evaluated 10 consecutive patients with suspected MD whom we randomly divided into 2 groups. We obtained h T 2 W-3D-FLAIR before GBCM administration and 10 min, 3.5 hours, and 4 hours after GBCM administration in Group A and before and 10 min, 4 hours, and 4.5 hours after GBCM administration in Group B. We compared signal intensity ratio (SIR) values of the perilymph and pons between 3.5 and 4 hours in Group A and between 4 and 4.5 hours in Group B and evaluated grades of EH at 3.5 and 4 hours in Group A and at 4 and 4.5 hours in Group B. SIR values did not differ significantly between 3.5 and 4 hours in Group A and between 4 and 4.5 hours in Group B. However, SIR values at 4 hours were significantly higher in Group A than Group B. Grades of EH agreed between 3.5 and 4 hours in Group A and between 4 and 4.5 hours in Group B. The optimal timing of contrast enhancement in patients with suspected MD remains unclear, but evaluation of EH may be possible from 3.5 to 4.5 hours after contrast administration. (author)

The influence of different contrast medium concentrations and injection protocols on quantitative and clinical assessment of FDG–PET/CT in lung cancer

Energy Technology Data Exchange (ETDEWEB)

Verburg, Frederik A., E-mail: fverburg@ukaachen.de [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Maastricht University Medical Center, Department of Nuclear Medicine, P. Debyelaan 25, 6229 HX Maastricht (Netherlands); Kuhl, Christiane K. [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology, Pauwelsstraße 30, 52074 Aachen (Germany); Pietsch, Hubertus [Bayer Pharma AG, Berlin, Müllerstrasse 178, 13353 Berlin (Germany); Palmowski, Moritz [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Mottaghy, Felix M. [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Maastricht University Medical Center, Department of Nuclear Medicine, P. Debyelaan 25, 6229 HX Maastricht (Netherlands); Behrendt, Florian F. [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany)

2013-10-01

Objectives: To compare the effects of two different contrast medium concentrations for use in computed X-ray tomography (CT) employing two different injection protocols on positron emission tomography (PET) reconstruction in combined 2-{sup 18}F-desoxyglucose (FDG) PET/CT in patients with a suspicion of lung cancer. Methods: 120 patients with a suspicion of lung cancer were enrolled prospectively. PET images were reconstructed with the non-enhanced and venous phase contrast CT obtained after injection of iopromide 300 mg/ml or 370 mg/ml using either a fixed-dose or a body surface area adapted injection protocol. Maximum and mean standardized uptake values (SUVmax and SUVmean) and contrast enhancement (HU) were determined in the subclavian vein, ascending aorta, abdominal aorta, inferior vena cava, portal vein, liver and kidney and in the suspicious lung lesion. PET data were evaluated visually for the presence of malignancy and image quality. Results: At none of the sites a significant difference in the extent of the contrast enhancement between the four different protocols was found. However, the variability of the contrast enhancement at several anatomical sites was significantly greater in the fixed dose groups than in the BSA groups for both contrast medium concentrations. At none of the sites a significant difference was found in the extent of the SUVmax and SUVmean increase as a result of the use of the venous phase contrast enhanced CT for attenuation. Visual clinical evaluation of lesions showed no differences between contrast and non-contrast PET/CT (P = 0.32). Conclusions: Contrast enhanced CT for attenuation correction in combined PET/CT in lung cancer affects neither the clinical assessment nor image quality of the PET-images. A body surface adapted contrast medium protocol reduces the interpatient variability in contrast enhancement.

Evaluation of liver parenchyma and perfusion using dynamic contrast-enhanced computed tomography and contrast-enhanced ultrasonography in captive green iguanas (Iguana iguana) under general anesthesia.

Science.gov (United States)

Nardini, Giordano; Di Girolamo, Nicola; Leopardi, Stefania; Paganelli, Irene; Zaghini, Anna; Origgi, Francesco C; Vignoli, Massimo

2014-05-13

Contrast-enhanced diagnostic imaging techniques are considered useful in veterinary and human medicine to evaluate liver perfusion and focal hepatic lesions. Although hepatic diseases are a common occurrence in reptile medicine, there is no reference to the use of contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT) to evaluate the liver in lizards. Therefore, the aim of this study was to evaluate the pattern of change in echogenicity and attenuation of the liver in green iguanas (Iguana iguana) after administration of specific contrast media. An increase in liver echogenicity and density was evident during CEUS and CECT, respectively. In CEUS, the mean ± SD (median; range) peak enhancement was 19.9% ± 7.5 (18.3; 11.7-34.6). Time to peak enhancement was 134.0 ± 125.1 (68.4; 59.6-364.5) seconds. During CECT, first visualization of the contrast medium was at 3.6 ± 0.5 (4; 3-4) seconds in the aorta, 10.7 ± 2.2 (10.5; 7-14) seconds in the hepatic arteries, and 15 ± 4.5 (14.5; 10-24) seconds in the liver parenchyma. Time to peak was 14.1 ± 3.4 (13; 11-21) and 31 ± 9.6 (29; 23-45) seconds in the aorta and the liver parenchyma, respectively. CEUS and dynamic CECT are practical means to determine liver hemodynamics in green iguanas. Distribution of contrast medium in iguana differed from mammals. Specific reference ranges of hepatic perfusion for diagnostic evaluation of the liver in iguanas are necessary since the use of mammalian references may lead the clinician to formulate incorrect diagnostic suspicions.

Comparison of neutral oral contrast versus positive oral contrast medium in abdominal multidetector CT

International Nuclear Information System (INIS)

Berther, Ralph; Eckhardt, Boris; Zollikofer, Christoph L.; Patak, Michael A.; Erturk, Sukru M.

2008-01-01

To determine whether neutral contrast agents with water-equivalent intraluminal attenuation can improve delineation of the bowel wall and increase overall image quality for a non-selected patient population, a neutral oral contrast agent (3% mannitol) was administered to 100 patients referred for abdominal multidetector row computed tomography (MDCT). Their results were compared with those of 100 patients given a positive oral contrast agent. Qualitative and quantitative measurements were done on different levels of the gastrointestinal tract by three experienced readers. Patients given the neutral oral contrast agent showed significant better qualitative results for bowel distension (P<0.001), homogeneity of the luminal content (P<0.001), delineation of the bowel-wall to the lumen (P<0.001) and to the mesentery (P<0.001) and artifacts (P<0.001), leading to a significant better overall image quality (P<0.001) than patients receiving positive oral contrast medium. The quantitative measurements revealed significant better distension (P<0.001) and wall to lumen delineation (P<0.001) for the patients receiving neutral oral contrast medium. The present results show that the neutral oral contrast agent (mannitol) produced better distension, better homogeneity and better delineation of the bowel wall leading to a higher overall image quality than the positive oral contrast medium in a non-selected patient population. (orig.)

Radiculography with water-soluble contraste medium

International Nuclear Information System (INIS)

Araujo Pinheiro, R.S. de

1987-01-01

The etiologic diagnosis of the lumbar pain is discussed. The radiculography with water-soluble contrast medium is used and 250 cases are studied. Some practical criteria of indication executation and interpretation of the examination are reported. (M.A.C.) [pt

Comparison of renal toxicity after injection of CT contrast medium and MR contrast medium: change of renal function in acute renal failure rat models

International Nuclear Information System (INIS)

Han, Young min; Lee, Young Hwan; Kim, Sang Won; Jin, Kong Young; Kim, Won; Chung, Gyung Ho

2002-01-01

To determine renal toxicity through changes in renal function after the injection of CT and MRI contrast media into rats in which acute renal failure (ARF) was induced. To cause acute renal failure, the abdominal cavity of 110 male rats each weighing 250-300 gm was opened via a midline incision under anesthesia. Microvascular clamps were placed on both renal arteries and veins to completely block renal blood flow for 45 minutes, and were then removed, allowing blood flow to return to the kidneys. ARF, defined as a two-fold difference in the creatinine level before ARF and 48 hours after, was successfully induced in 60 of the rats. These were divided into two groups: one was injected with CT contrast medium and the other with MRI contrast medium. Each CT and MRI group was divided into a low dose (0.5 cc/kg, 0.2 ml/kg), standard dose (2 cc/kg, 0.8 ml/kg), and high dose (8 cc/kg, 3.2 ml/kg) sub-group; thus, there was a total of six groups with ten rats in each. Blood samples were obtained before ARF, 48 hours after, and 48 hours after contrast injection, and CT scanning and MRI were performed after blood sampling at 48 hours. In each group, creatinine levels 48 hours after contrast injection were compared by means of the ANOVA test. There were no significant differences in creatinine levels between the CT and MRI contrast medium groups (p=0.116), nor between the animals to which different doses of CT and MRI contrast medium, were administered. After both standard and high doses, CT and MRI provided good images. In rats in which acute renal failure was induced, renal function did not change according to whether CT or MRI contrast medium was injected. Thus, the two media induce similar levels of toxicity

MR mammography: influence of menstrual cycle on the dynamic contrast enhancement of fibrocystic disease

International Nuclear Information System (INIS)

Rieber, A.; Nuessle, K.; Merkle, E.; Tomczak, R.; Brambs, H.J.; Kreienberg, R.

1999-01-01

Magnetic resonance mammography (MRM) provides data regarding the nature of tumours based on contrast medium dynamics; fibrocystic changes in the breast, however, may lead to false-positive results. This study investigated whether the contrast medium dynamics of fibrocystic changes are dependent on the menstrual cycle. Twenty-four patients with palpable lumps but normal mammographies and ultrasound studies were examined. The MRM technique was performed during the first and second part of the menstrual cycle using a FLASH 3D sequence, both native and at 1, 2, 3 and 8 min after intravenous application of 0.15 mmol/kg body weight of gadodiamide. The calculated time-intensity curves were evaluated based on the following criteria: early percentage of contrast medium uptake in relation to the native value; formation of a plateau phenomenon after the second minute; the point of maximal contrast medium uptake; and calculation of the contrast enhancing index. During the second half of the menstrual cycle, a generally greater contrast medium uptake was observed. Nevertheless, when further diagnostic criteria, such as continuous contrast medium increase as a function of time, were considered, there was no increased rate of false-positive findings. The phase of the menstrual cycle may affect the specificity of the examination, if only the quantitative contrast medium uptake and the percentage of contrast medium uptake in the first 2 min are considered. A control MRM during the other half of the cycle may then be indicated and additional diagnostic criteria may improve specificity. (orig.)

MR mammography: influence of menstrual cycle on the dynamic contrast enhancement of fibrocystic disease

Energy Technology Data Exchange (ETDEWEB)

Rieber, A.; Nuessle, K.; Merkle, E.; Tomczak, R.; Brambs, H.J. [Ulm Univ. (Germany). Abt. Radiologie 1 (Roentgendiagnostik); Kreienberg, R. [Ulm Univ. (Germany). Dept. of Gynecology

1999-08-01

Magnetic resonance mammography (MRM) provides data regarding the nature of tumours based on contrast medium dynamics; fibrocystic changes in the breast, however, may lead to false-positive results. This study investigated whether the contrast medium dynamics of fibrocystic changes are dependent on the menstrual cycle. Twenty-four patients with palpable lumps but normal mammographies and ultrasound studies were examined. The MRM technique was performed during the first and second part of the menstrual cycle using a FLASH 3D sequence, both native and at 1, 2, 3 and 8 min after intravenous application of 0.15 mmol/kg body weight of gadodiamide. The calculated time-intensity curves were evaluated based on the following criteria: early percentage of contrast medium uptake in relation to the native value; formation of a plateau phenomenon after the second minute; the point of maximal contrast medium uptake; and calculation of the contrast enhancing index. During the second half of the menstrual cycle, a generally greater contrast medium uptake was observed. Nevertheless, when further diagnostic criteria, such as continuous contrast medium increase as a function of time, were considered, there was no increased rate of false-positive findings. The phase of the menstrual cycle may affect the specificity of the examination, if only the quantitative contrast medium uptake and the percentage of contrast medium uptake in the first 2 min are considered. A control MRM during the other half of the cycle may then be indicated and additional diagnostic criteria may improve specificity. (orig.) With 2 figs., 2 tabs., 24 refs.

Local blood-brain barrier penetration following systemic contrast medium administration

International Nuclear Information System (INIS)

Utz, R.; Ekholm, S.E.; Isaac, L.; Sands, M.; Fonte, D.

1988-01-01

The present study was initiated by a severe complication in a patient with renal dysfunction who developed cortical blindness and weakness of her left extremities 30 hours following renal and abdominal angiography. To evaluate the impact of prolonged high serum concentrations of contrast medium (CM) this clinical situation was simulated in a laboratory model using sheep with elevated serum levels of contrast medium maintained for 48 hours. The experimental data did not support the theory that the prolonged exposure to high circulating levels of contrast medium (4 ml/kg body weight of meglumine diatrizoate 60%) is sufficient alone to cause penetration of the blood-brain barrier. (orig.)

The cerebral intravascular enhancement sign is not specific: a contrast-enhanced MRI study

Energy Technology Data Exchange (ETDEWEB)

Bakshi, R.; Kinkel, W.R.; Bates, V.E.; Mechtler, L.L.; Kinkel, P.R. [Lucy Dent Imaging Center, University at Buffalo, NY (United States)

1999-02-01

The intravascular enhancement (IVE) sign, also known as the ``arterial enhancement sign``, is an abnormal finding in the brain on contrast-enhanced MRI studies. IVE has been described in arterial cerebrovascular disorders, most commonly in acute or subacute arterial ischemic infarcts. However, the specificity of this sign has not been established. We describe four patients with disorders other than arterial strokes in whom gadolinium-enhanced high-field (1.5 T) MRI suggested IVE. The conditions were herpes simplex viral encephalitis, idiopathic cerebellitis, pneumococcal meningitis, and superior sagittal sinus thrombosis with venous infarction. IVE in these cases may be due to multiple factors, including arterial, venous, perivascular, and leptomeningeal or sulcal contrast medium accumulation. Our observations suggest that arterial ischemia, previously described as the cardinal cause of IVE, probably does not explain all instances, and urge caution in interpreting this sign as a specific MRI manifestation of acute arterial infarction or ischemia. (orig.) With 4 figs., 1 tab., 44 refs.

Risk of contrast-medium-induced nephropathy in high-risk patients undergoing MDCT--a pooled analysis of two randomized trials

DEFF Research Database (Denmark)

Thomsen, Henrik S; Morcos, Sameh K

2009-01-01

of the LOCM were also observed in patients with GFR contrast agents in patients with moderate-to-severe renal insufficiency, the risk of significant CIN seems to be low. The IOCM iodixanol caused a higher rate of CIN than the LOCM......The incidence of contrast-medium-induced nephropathy (CIN) following intravenous (IV) CM administration of contrast media to renally impaired patients undergoing multidetector computed tomography (MDCT) is not well characterized. Our objective was to investigate the incidence of CIN in patients...... with glomerular filtration rate (GFR) contrast-enhanced MDCT examinations and to compare the rates of CIN following the IV administration of low-osmolar contrast media (LOCM, iopamidol and iomeprol) and an iso-osmolar contrast medium (IOCM, iodixanol). A total of 301 adult patients...

Automated contrast medium monitoring system for computed tomography--Intra-institutional audit.

Science.gov (United States)

Lauretti, Dario Luca; Neri, Emanuele; Faggioni, Lorenzo; Paolicchi, Fabio; Caramella, Davide; Bartolozzi, Carlo

2015-12-01

The aim of this study was to analyze the usage and the data recorded by a RIS-PACS-connected contrast medium (CM) monitoring system (Certegra(®), Bayer Healthcare, Leverkusen, Germany) over 19 months of CT activity. The system used was connected to two dual syringe power injectors (each associated with a 16-row and a high definition 64-row multidetector CT scanner, respectively), allowing to manage contrast medium injection parameters and to send and retrieve CT study-related information via RIS/PACS for any scheduled contrast-enhanced CT examination. The system can handle up to 64 variables and can be accessed via touchscreen by CT operators as well as via a web interface by registered users with three different hierarchy levels. Data related to CM injection parameters (i.e. iodine concentration, volume and flow rate of CM, iodine delivery rate and iodine dose, CM injection pressure, and volume and flow rate of saline), patient weight and height, and type of CT study over a testing period spanning from 1 June 2013 to 10 January 2015 were retrieved from the system. Technical alerts occurred for each injection event (such as system disarm due to technical failure, disarm due to operator's stop, incomplete filling of patient data fields, or excessively high injection pressure), as well as interoperability issues related to data sending and receiving to/from the RIS/PACS were also recorded. During the testing period, the CM monitoring system generated a total of 8609 reports, of which 7629 relative to successful injection events (88.6%). 331 alerts were generated, of which 40 resulted in injection interruption and 291 in CM flow rate limitation due to excessively high injection pressure (>325 psi). Average CM volume and flow rate were 93.73 ± 17.58 mL and 3.53 ± 0.89 mL/s, and contrast injection pressure ranged between 5 and 167 psi. A statistically significant correlation was found between iodine concentration and peak IDR (rs=0.2744, psystems can provide a full

Recommendation to use iso-osmotic contrast medium in interventional treatment

International Nuclear Information System (INIS)

Zhou Bing; Cheng Yongde

2012-01-01

With the rapid development of imaging diagnostic and interventional therapeutic techniques, the contrast medium (CM) has been used more and more common in clinical practice, and meanwhile more and more attention has been paid to the CM-related adverse events. Contrast induced nephropathy (CN) is the most common CM-related adverse event, and CM-related neurotoxicity has already attracted the physicians' attention. The osmotic pressure of the iso-osmotic contrast medium (IOCM) is quite the same as that of the plasma, and therefore its safety is higher than that of low-osmotic contrast medium (LOCM), the patient's tolerance to IOCM is better than that to LOCM. For this reason, the use of IOCM should be strongly recommended in interventional procedures, which is of great significance to the reduction of the occurrence of CM-related adverse events. (authors)

A prolapsed cervical disc with diffuse contrast enhancement on CT

International Nuclear Information System (INIS)

Goto, Jun; Shinpo, Tomoyuki; Inoue, Kiyoharu; Shigeno, Taku; Ochiai, Chikayuki

1985-01-01

A 48-year-old woman with the C5/6 disc herniation was reported. She had noticed vague pains in the left shoulder a half year earlier. Neurological examination showed left lower cervical radicular pains and incomplete Brown-Sequard syndrome of the same side. The disc herniation was diagnosed by myelography and discography. On the CT examination, surprisingly, the prolapsed disc was homogenously enhanced after the administration of intravenous contrast medium. The vertebral angiography showed increased vascularity behind the C5/6 intervertebral space. At operation, a prolapsed nucleus pulposus with proliferated connective tissue was found and curetted. The etiology of contrast enhancement was discussed. (author)

Magnetic Resonance Imaging in degenerative disease of the lumbar spine: Fat Saturation technique and contrast medium.

Science.gov (United States)

D'Aprile, Paola; Nasuto, Michelangelo; Tarantino, Alfredo; Cornacchia, Samantha; Guglielmi, Giuseppe; Jinkins, J Randy

2018-01-19

To examine both anterior and posterior elements of the lumbar spine in patients with low back pain using MRI T2-weighted sequences with Fat Saturation (FS) and contrast enhanced T1-weighted sequences with FS. Two thousand eight hundred and twenty (2820) patients (1628 male, 1192 female, mean age 54) presenting low back pain underwent MRI standard examination (Sagittal T1w TSE and T2w TSE, axial T1 SE) with the addition of sagittal and axial T2w Fat Sat (FS) sequences. Among all the patients, 987 (35%) have been studied adding Contrast Enhanced (CE) T1w FS sequences after administration of contrast medium. Among 987 patients studied with contrast medium, we found: active-inflammatory intervertebral osteochondrosis in 646 (65%) patients; degenerative-inflammatory changes in facet joints (facet joint effusion, synovitis, synovial cysts) in 462 (47%); spondylolysis in 69 (7%); degenerative-inflammatory changes of the flava, interspinous and supraspinous ligaments in 245 (25%); inflammatory changes of posterior perispinal muscles in 84 (8%) patients. In patients with suspected no-disc-related low back pain, the implementation of T2w FS and CE T1w FS sequences to the standard MR protocol could allow a better identification of degenerative-inflammatory changes more likely associated to the pain.

Radiculography with reduced amounts of contrast medium

International Nuclear Information System (INIS)

Signorini, E.; Caputo, N.; Chiurulla, C.; Ciorba, E.; Pelliccioli, G.P.; Cianciulli, E.

1984-01-01

Because of the frequency and seriousness of side effects observed after radiculography, due to, among the other things, the amount of contrast medium, the authors describe a method that gives diagnostically satisfactory results using a low dose of contrast and a tangent-beam technique. Among 106 patients undergoing radiculography with a tangent-beam technique and Iopamidol, only 4 developed mild side effects, namely headache in three cases and headache with nausea in one. (Author)

Targeting cancer chemotherapeutic agents by use of lipiodol contrast medium

International Nuclear Information System (INIS)

Konno, T.

1990-01-01

Arterially administered Lipiodol Ultrafluid contrast medium selectively remained in various malignant solid tumors because of the difference in time required for the removal of Lipiodol contrast medium from normal capillaries and tumor neovasculature. Although blood flow was maintained in the tumor, even immediately after injection Lipiodol contrast medium remained in the neovasculature of the tumor. To target anti-cancer agents to tumors by using Lipiodol contrast medium as a carrier, the characteristics of the agents were examined. Anti-cancer agents had to be soluble in Lipiodol, be stable in it, and separate gradually from it so that the anti-cancer agents would selectively remain in the tumor. These conditions were found to be necessary on the basis of the measurement of radioactivity in VX2 tumors implanted in the liver of 16 rabbits that received arterial injections of 14C-labeled doxorubicin. Antitumor activities and side effects of arterial injections of two types of anti-cancer agents were compared in 76 rabbits with VX2 tumors. Oily anti-cancer agents that had characteristics essential for targeting were compared with simple mixtures of anti-cancer agents with Lipiodol contrast medium that did not have these essential characteristics. Groups of rabbits that received oily anti-cancer agents responded significantly better than groups that received simple mixtures, and side effects were observed more frequently in the groups that received the simple mixtures. These results suggest that targeting of the anti-cancer agent to the tumor is important for treatment of solid malignant tumors

Clinical evaluation of contrast-enhanced digital mammography and contrast enhanced tomosynthesis--Comparison to contrast-enhanced breast MRI.

Science.gov (United States)

Chou, Chen-Pin; Lewin, John M; Chiang, Chia-Ling; Hung, Bao-Hui; Yang, Tsung-Lung; Huang, Jer-Shyung; Liao, Jia-Bin; Pan, Huay-Ben

2015-12-01

To compare the diagnostic accuracy of contrast-enhanced digital mammography (CEDM) and contrast-enhanced tomosynthesis (CET) to dynamic contrast enhanced breast MRI (DCE-MRI) using a multireader-multicase study. Institutional review board approval and informed consents were obtained. Total 185 patients (mean age 51.3) with BI-RADS 4 or 5 lesions were evaluated before biopsy with mammography, tomosynthesis, CEDM, CET and DCE-MRI. Mediolateral-oblique and cranio-caudal views of the target breast CEDM and CET were acquired at 2 and 4 min after contrast agent injection. A mediolateral-oblique view of the non-target breast was taken at 6 min. Each lesion was scored with forced BI-RADS categories by three readers. Each reader interpreted lesions in the following order: mammography, tomosynthesis, CEDM, CET, and DCE-MRI during a single reading session. Histology showed 81 cancers and 144 benign lesions in the study. Of the 81 malignant lesions, 44% (36/81) were invasive and 56% (45/81) were non-invasive. Areas under the ROC curve, averaged for the 3 readers, were as follows: 0.897 for DCE-MRI, 0.892 for CET, 0.878 for CEDM, 0.784 for tomosynthesis and 0.740 for mammography. Significant differences in AUC were found between the group of contrast enhanced modalities (CEDM, CET, DCE-MRI) and the unenhanced modalities (all p0.05). CET and CEDM may be considered as an alternative modality to MRI for following up women with abnormal mammography. All three contrast modalities were superior in accuracy to conventional digital mammography with or without tomosynthesis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Use of subvoxel registration and subtraction to improve demonstration of contrast enhancement in MRI of the brain

International Nuclear Information System (INIS)

Curati, W.L.; Williams, E.J.; Oatridge, A.; Hajnal, J.V.; Saeed, N.; Bydder, G.M.

1996-01-01

To assess the potential of registration of images before and after contrast medium for improving the demonstration of contrast enhancement, we compared conventional 2 D T 1-weighted spin-echo images with precisely registered 3 D volume images and subtraction images derived from them in 2 normal subjects and 30 patients with a variety of brain disease. The volume images were registered to subvoxel accuracy using a rigid body translation and rotation, sinc interpolation and a least-squares fit; subtraction images were obtained from these. Normal contrast enhancement was demonstrated better with positionally registered volume and subtraction images than with conventional images in the meninges, ependyma, diploic veins, scalp, skin, orbit and sinuses. Abnormal enhancement was seen better in meningeal disease, multiple sclerosis and tumours as well as on follow-up studies. Subvoxel registration of images before and after contrast medium may be of considerable value in the recognition of contrast enhancement where there are small changes, or where the changes affect tissues with high or low baseline signal values. The technique also appears likely to be of value in demonstrating contrast enhancement in tissues at inferfaces and at other areas of complex anatomy, and in follow-up studies. (orig.). With 4 figs., 4 tabs

MO-E-17A-02: Incorporation of Contrast Medium Dynamics in Anthropomorphic Phantoms: The Advent of 5D XCAT Models

Energy Technology Data Exchange (ETDEWEB)

Sahbaee, P [NC State University, Raleigh, NC (United States); Samei, E [Duke University Medical Center, Durham, NC (United States); Segars, W [Duke University, Durham, NC (United States)

2014-06-15

Purpose: To develop a unique method to incorporate the dynamics of contrast-medium propagation into the anthropomorphic phantom, to generate a five-dimensional (5D) patient model for multimodality imaging studies. Methods: A compartmental model of blood circulation network within the body was embodied into an extended cardiac-torso (4D-XCAT) patient model. To do so, a computational physiologic model of the human cardiovascular system was developed which includes a series of compartments representing heart, vessels, and organs. Patient-specific cardiac output and blood volume were used as inputs influenced by the weight, height, age, and gender of the patient's model. For a given injection protocol and given XCAT model, the contrast-medium transmission within the body was described by a series of mass balance differential equations, the solutions to which provided the contrast enhancement-time curves for each organ; thereby defining the tissue materials including the contrastmedium within the XCAT model. A library of time-dependent organ materials was then defined. Each organ in each voxelized 4D-XCAT phantom was assigned to a corresponding time-varying material to create the 5D-XCAT phantom in which the fifth dimension is blood/contrast-medium within the temporal domain. Results: The model effectively predicts the time-varying concentration behavior of various contrast-medium administration in each organ for different patient models as function of patient size (weight/height) and different injection protocol factors (injection rate and pattern, iodine concentration or volume). The contrast enhanced XCAT patient models was developed based on the concentration of iodine as a function of time after injection. Conclusion: Majority of medical imaging systems take advantage of contrast-medium administration in terms of better image quality, the effect of which was ignored in previous optimization studies. The study enables a comprehensive optimization of contrast

Computed tomography using contrast medium in disorders of the patello-femoral joint

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Kenji; Chiba, Mitsuho; Morita, Hiromi; Kikuchi, Toshihiko; Shimada, Yoichi; Yamamoto, Masahiro; Tozawa, Kazuma

1985-01-01

The morphology and alignment of the articular cartilage of the patello-femoral joint were examined by computed tomography (CT) using a contrast medium in 15 patients with a chief complaint of patellar pain. CT was undertaken immediately after injecting a contrast medium and air into the knee joint. Retention and irregularity of the contrast medium in the joint estimated the expansion and depth of lesions in patients with osteomalacia of the auricular joint or osteoarthritis of the knee, and the thickness of the auricular cartilage. Considering the individual differences of the patella itself and specificity of the form of the auricular cartilage, the auricular joint should also be examined in terms of alignment of the cartilage surface. CT using a contrast medium is a simple, less invasive method for evaluating disorders of the patello-femoral joint.

Magnetic resonance tomography for focal lesions in the liver using the para-magnetic contrast medium gadolinium DTPA

International Nuclear Information System (INIS)

Hamm, B.; Roemer, T.; Felix, R.; Wolf, K.J.; Klinikum Charlottenburg, Berlin

1986-01-01

The use of the para-magnetic contrast medium gadolinium DTPA for magnetic resonance tomography of focal lesions in the liver was investigated in 31 patients. Two dosage schedules of the contrast medium (0.1 and 0.2 mmol/kg body weight) were used with field strengths of 0.35 and 0.5 Tesla. Using T 1 sequences, gadolinium DTPA showed increased signal intensity in the liver and in tumours, but this was significantly more marked in the tumour. On T 1 spin-echo sequences, previously iso-intense lesions became visible after administration of contrast. On the other hand, contrast-enhanced lesions were less well seen on inversion recovery sequences because of a reduction in the contrast between tumour and liver tissue. The contrast between tumour and liver tissue was not improved by gadolinium DTPA in comparison with precontrast inversion recovery sequences and T 2 spin-echo sequences. The perfusion of intra-hepatic tumours could be elucidated by magnetic resonance tomography after the administration of gadolinium DTPA. (orig.) [de

Contrast-enhanced turbo spin-echo(TSE) T1-weighted imaging: improved contrast of enhancing lesions

International Nuclear Information System (INIS)

Choi, Sung Wook; Lee, Ghi Jai; Shim, Jae Chan; Lee, Young Ju; Jeong, Se Hyung; Kim, Ho kyun

1997-01-01

The purpose of this study was to evaluate the effect of contrast improvement of enhancing brain lesions by inherent magnetization transfer effect in turbo spin-echo(TSE)T1-weighted MR imaging. Twenty-six enhancing lesions of 19 patients were included in this study. Using a 1.0T superconductive MR unit, contrast-enhanced SE T1-weighted images(TR=3D600 msec, TE=3D12 msec, NEX=3D2, acquistition time=3D4min 27sec) and contrast-enhanced TSE T1-weighted images(TR=3D600 msec, TE=3D12, acquistition time=3D1min 44sec) were obtained. Signal intensities at enhancing lesions and adjacent white matter were measured in the same regions of both images. Signal-to-noise ratio(SNR) of enhancing lesions and adjacent white matter, and con-trast-to-noise ratio(CNR) and lesion-to-background contrast (LBC) of enhancing lesions were calculated and statistically analysed using the paired t-test. On contrast-enhanced TSE T1-weighted images, SNR of enhancing lesions and adjacent white matter decreased by 18%(p<0.01) and 32%(p<0.01), respectively, compared to contrast-enhanced SE T1-weighted images. CNR and LBC of enhancing lesions increased by 16%(p<0.05) and 66%(p<0.01), respectively. Due to the proposed inherent magnetization transfer effects in TSE imaging, con-trast-enhanced T1-weighted TSE images demonstrated a statistically significant improvement in CNR and LBC, compared to conventional contrast-enhanced T1-weighted SE images, and scan time was much shorter

Potential mechanisms behind contrast medium-induced nephropathy

African Journals Online (AJOL)

How contrast medium-induced nephropathy (CIN) comes about is poorly understood, although CIN is a common cause of acute renal failure. Hitherto, the various studies performed have led to different interpretations and partially contradictory conclusions. This article aimed to review the mechanisms underlying CIN and to ...

Quantitative analysis of contrast enhancement of transplanted kidneys under computed tomography

International Nuclear Information System (INIS)

Fujita, Tamio; Asano, Haruyoshi; Yanaoka, Masanori; Moriguchi, Ryuichiro; Okishio, Norihiko

1981-01-01

Using Hitachi CT-3, the changes in CT numbers of the kidney were calculated in 10 normal and 12 transplanted kidneys. Two mililiters per kg of meglumine diatrizoate (Angiografin) was given intravenously in bolus fashion. Kidneys were scanned before injection, at termination of injection and correctly 10 minutes after injection. In control group, the CT numbers of the cortex, the medulla and the aorta showed rapid increase after contrast administration. Ten minutes after administration of medium, the CT numbers of the medulla remained a little higher than the cortex, though that of the aorta showed rapid decrease. In contrast to control group, in transplanted kidneys the CT numbers of the cortex and medulla showed less increase than the control group just after contrast administration. Moreover, in the recipients who have had good graft function the CT numbers of the cortex and medulla showed gradual increase, in the recipients who have had poor graft function the CT numbers showed gradual decrease 10 minutes after injection. Enhancing indices calculated from the formula: CT numbers 10 minutes after contrast enhancement CT numbers before contrast enhancement were inversely proportional to the serum creatinine. These results lead to the conclusion that the CT scans employing contrast enhancement method after kidney transplantation has the diagnostic value of graft function in addition to diagnostic usefulness for post-transplantation complications such as hematoma, urinoma or lymphocele. (author)

Effects of use of the lodine contrast medium on gamma camera imaging

Energy Technology Data Exchange (ETDEWEB)

Pyo, Sung Jae; Cho, Yun Ho [Dept. of Nuclear Medicine, Inha University hospital, Incheon (Korea, Republic of); Choi, Jae Ho [Dept. of Radiological Technology, Ansan College, Ansan (Korea, Republic of)

2016-12-15

Effects of Gamma camera imaging on gamma ray counting rates as a function of use and density of the iodine contrast medium currently in primary use for clinics, and changes in gamma ray counting rates as a function of the contrast medium status upon attenuation correction using a CT absorption coefficientin an SPECT/CT attenuation correction will be considered herein. For experimental materials used 99mTcO4 370 MBq and Pamiray 370 mg, Iomeron 350 mg, Visipaque 320 mg, Bonorex 300 mg of iodine contrast medium. For image acquisition, planar imaging was consecutively filmed for 1, 2, 3, 4, 5 min, respectively, 30 min after administration of 99mTcO4. while 60 views were filmed per frame for 20 min at 55 min for the SPECT/CT imaging. In planar imaging, the gamma ray counting rates as a function of filming time were reduced showing a statistically significant difference when mixed according to the type of contrast medium density rather than when the radioactive isotope 99mTcO4 and the saline solution were mixed. In the tomography for mixing of the radioactive isotope 99mTcO4 and saline solution, the mean counting rate without correction by the CT absorption coefficient is 182±26 counts, while the counting rate with correction by the CT absorption coefficient is 531.3±34 counts. In the tomography for mixing of the radioactive isotope 99mTcO4 and the saline solution with the contrast medium, the mean values before attenuation correction by CT absorption coefficient were 166±29, 158.3±17, 154±36, and 150±33 counts depending on the densities of the contrast medium, while the mean values after attenuation correction were 515±03, 503±10, 496±31, and 488.7±33 counts, showing significant differences in both cases when comparatively evaluated with the imaging for no mixing of the contrast medium. Iodine contrast medium affects the rate of gamma ray. Therefore, You should always be preceded before another test on the day of diagnosis.

Examination of hepatic contrast-enhanced CT monitored by Smart Prep

International Nuclear Information System (INIS)

Kakizaki, Dai; Saito, Kazuhiro; Sakurada, Toru; Abe, Kimihiko; Suzuki, Kenji

1999-01-01

The aim of the present study is to obtain the time density curves of the contrast-enhanced CT of hepatic portal vein, hepatic and splenic parenchyma, and to examine the relation with age, body weight, type of liver dysfunction. Subjects were 32 patients with liver tumors or liver diseases. For this purpose, the procedure of hepatic CT was monitored by Smart Prep and the images of whole liver was taken when the level of the contrast at the hepatic portal vein reached to the enhancement threshold. The contrast medium used was Iomeprol 300. The adverse reactions by Iomeprol 300 were mild and any treatment did not need. There was no correlation age and weight with enhancement threshold at the hepatic portal vein and peak time at the splenic parenchyma. The enhancement threshold at the hepatic portal vein was various in patients with chrrhosis and chronic hepatitis, and tended to be delayed in patients with chrrhosis. The peak time of the splenic parenchyma was up to 52 seconds in all patients with chronic hepatitis. The shortage of the enhancement threshold and the increase in blood flow at arterial early phase were observed in the patients with advanced acute hepatitis. This method should be examined more cases with various hepatic diseases. (K.H.)

Renal clearance of an ionic high-osmolar and a nonionic low-osmolar contrast medium

International Nuclear Information System (INIS)

Thomsen, H.S.; Vestergaard, A.; Nielsen, S.L.; Fogh-Andersen, N.; Golman, K.; Dorph, S.

1991-01-01

One hundred patients with normal serum creatinine concentration underwent intravenous urography with either an ionic high-osmolar (diatrizoate) or a nonionic low-osmolar (iopamidol) contrast medium after randomization. Before injection of the contrast medium, a blood sample was drawn for determinating serum creatinine concentration, and a urine sample for measurement of urine osmolality. Using x-ray fluorescence, the plasma concentration of iodine (contrast medium) was determined on blood samples drawn approximately 3 and 4 hours after injection of the contrast medium. The glomerular filtration rate was calculated by two different formulas: one requiring only a single sample and one requiring at least two samples (standard). There were poor correlations between the standard contrast medium clearance and the serum creatinine concentration, the estimated creatinine clearance (calculated from a nomogram), as well as the urine osmolality. The 3-hour and the 4-hour single-sample values correlated well with the two-sample values for both contrast media. In patients with normal serum creatinine, the glomerular filtration rate determined by measuring the contrast medium concentration in a single plasma sample obtained at 3 hours, is almost identical to the value determined from two samples. Consequently, two samples are unnecessary

Quantitative analysis of enhanced malignant and benign lesions on contrast-enhanced spectral mammography.

Science.gov (United States)

Deng, Chih-Ying; Juan, Yu-Hsiang; Cheung, Yun-Chung; Lin, Yu-Ching; Lo, Yung-Feng; Lin, GiGin; Chen, Shin-Cheh; Ng, Shu-Hang

2018-02-27

To retrospectively analyze the quantitative measurement and kinetic enhancement among pathologically proven benign and malignant lesions using contrast-enhanced spectral mammography (CESM). We investigated the differences in enhancement between 44 benign and 108 malignant breast lesions in CESM, quantifying the extent of enhancements and the relative enhancements between early (between 2-3 min after contrast medium injection) and late (3-6 min) phases. The enhancement was statistically stronger in malignancies compared to benign lesions, with good performance by the receiver operating characteristic curve [0.877, 95% confidence interval (0.813-0.941)]. Using optimal cut-off value at 220.94 according to Youden index, the sensitivity was 75.9%, specificity 88.6%, positive likelihood ratio 6.681, negative likelihood ratio 0.272 and accuracy 82.3%. The relative enhancement patterns of benign and malignant lesions, showing 29.92 vs 73.08% in the elevated pattern, 7.14 vs 92.86% in the steady pattern, 5.71 vs 94.29% in the depressed pattern, and 80.00 vs 20.00% in non-enhanced lesions (p < 0.0001), respectively. Despite variations in the degree of tumour angiogenesis, quantitative analysis of the breast lesions on CESM documented the malignancies had distinctive stronger enhancement and depressed relative enhancement patterns than benign lesions. Advances in knowledge: To our knowledge, this is the first study evaluating the feasibility of quantifying lesion enhancement on CESM. The quantities of enhancement were informative for assessing breast lesions in which the malignancies had stronger enhancement and more relative depressed enhancement than the benign lesions.

2D and 3D parameter images for analysis of contrast medium enhancement based on dynamic CT and MR

International Nuclear Information System (INIS)

Beier, J.; Stroszczynski, C.; Oellinger, H.; Felix, R.; Buege, T.; Fleck, E.

1998-01-01

Aim: For dynamic contrast medium (CM) studies, parameter images exploit specific features of the time/intensity curve (TIC) of each pixel and represent these values in a new image. Existing concepts of two-dimensional CM analysis are extended for three-dimensional applications using adequate computer graphic visualization. Results: In first-pass analyses, TMIP and TG allowed the simultaneous or separted presentation of different temporal phases of the CM bolus. Correlation images emphasized regions with similarities to given TIC patterns. Three-dimensional computer graphic techniques enabled (1) anatomical/function mapping of original image and CM accumulation and (2) fused display of both spatial CM enhancement and color-encoded time of TIC peak in one common image. Conclusions: The quantifiction of presence, magnitude, and time-of-peak of CM accumulation in local image regions supports the assessment of vascularization and of ischemic or necrotic areas. (orig./AJ) [de

Contrast-enhanced harmonic endoscopic ultrasound

DEFF Research Database (Denmark)

Săftoiu, A; Dietrich, C F; Vilmann, P

2012-01-01

Second-generation intravenous blood-pool ultrasound contrast agents are increasingly used in endoscopic ultrasound (EUS) for characterization of microvascularization, differential diagnosis of benign and malignant focal lesions, and improving staging and guidance of therapeutic procedures. Although...... initially used as Doppler signal enhancers, second-generation microbubble contrast agents are now used with specific contrast harmonic imaging techniques, which benefit from the highly nonlinear behavior of the microbubbles. Contrast-specific modes based on multi-pulse technology are used to perform...... contrast-enhanced harmonic EUS based on a very low mechanical index (0.08 - 0.12). Quantification techniques based on dynamic contrast-enhanced ultrasound have been recommended for perfusion imaging and monitoring of anti-angiogenic treatment, mainly based on time-intensity curve analysis. Most...

Adverse effects in coronary angiography: a comparative study of different temperature contrast medium

International Nuclear Information System (INIS)

Zhou Peng; Wang Qiulin; Cai Guocai; Li Lu; Jiang Licheng; Yang Zhen; Huang Xiuping

2011-01-01

Objective: To investigate the correlation between different temperature contrast medium and the occurrence of adverse effects, including the chest discomfort, the changes of heart rate, ST segment and T wave, the operating time and the used dosage of contrast medium, in performing coronary angiography. Methods: According to the contrast medium temperature used in coronary angiography, the patients were randomly divided into two groups: room temperature group (n=521) and warm temperature group (n=522). The contrast medium used in warm temperature group was bathed in 37 ℃ water for 60 minutes when the coronary angiography was carried out. The T Wave amplitude changes ≥ 0.01 mv, ST segment depression ≥ 0.05 mv, changes in heart rate ≥ 10 times/min were brought into the positive accounting. The occurrence of adverse effects, such as palpitation, chest distress and pectoralgia, the operative time and the used dosage of contrast medium were recorded. The results were analyzed and compared between the two groups. Results: Statistically significant differences in the changes of heart rate, ST segment deviation, T wave change and operating time existed between the two groups (P<0.05). And the difference in the occurrence of adverse effects between the two groups was also statistically significant (P<0.05). Conclusion: When performing coronary angiography, warming of the contrast medium with water bath is greatly conducive to the prevention of cardiac adverse effects. (authors)

Contrast Enhanced US in the Abdomen

International Nuclear Information System (INIS)

Chung, Yong Eun; Kim, Ki Whang

2012-01-01

Contrast enhanced ultrasound, which was introduced in 1996, has been widely used in Europe and Eastern Asia. Ultrasound contrast agent can be classified as first generation and second generation, depending on the gas within the microbubble. With the first generation contrast agent, the high MI technique was used, and only intermittent scanning was possible due to destruction of the microbubble during scanning. Use of the second generation contrast agent with the low MI technique makes continuous scanning possible. Contrast enhanced US can be used in detection and differentiation of focal liver lesions. It is also helpful for monitoring of radiofrequency ablation and for targeting of US guided biopsy. Currently, because morphologic criteria alone may not reflect the response of the tumor to treatment, new criteria are needed for treatment evaluation after administration of anti-angiogenic agents. Contrast enhanced US could provide quantitative markers for evaluation of the response to treatment via use of dynamic contrast enhanced US. Due to cost-effectiveness, contrast enhanced US is not yet widely used in Korea; however, considering recent issues regarding contrast agent related adverse reaction, such as contrast induced nephropathy and nephrogenic systemic fibrosis, and radiation exposure, contrast enhanced US might be more widely used in Korea, as an alternative imaging modality in the future.

Dynamic Contrast-Enhanced Magnetic Resonance Enterography and Dynamic Contrast-Enhanced Ultrasonography in Crohn's Disease

DEFF Research Database (Denmark)

Wilkens, Rune; Peters, David A; Nielsen, Agnete Hedemann

2017-01-01

Purpose e Cross-sectional imaging methods are important for objective evaluationof small intestinal inflammationinCrohn'sdisease(CD).The primary aim was to compare relative parameters of intestinal perfusion between contrast-enhanced ultrasonography (CEUS) and dynamic contrast-enhanced magnetic...

The affects of contrast medium on renal function in selective coronary angiography and intervention

International Nuclear Information System (INIS)

Chen Yueguang; Lv Baojing

2006-01-01

Selective coronary angiography and intervention with injection of contrast medium into the coronary arteries has become very common in dealing with coronary cardiac diseases. The excretion of contrast medium through kidneys may lead to acute renal functional insufficiency, especially for those suffering from chronic nephropathy, diabetes and cardiac functional disorder to form the so called 'contrast medium nephropathy' which is considered as the number second drug induced acute renal functional failure. Although routine preventive measure including low osmotic contrast medium and fine hydrotherapy have been taken, 14% incidences still occur with renal functional damage. The majority could be reversible but the minority needs emergent hemodialysis or even with persistent renal functional damage in a few ones. (authors)

Extravasation of contrast medium during CT examination: An ...

African Journals Online (AJOL)

2013-03-31

Extravasation of contrast medium during CT examination: An observational casecontrol study. ... Methods: every incident of extravasation which occurred between March 2012 and March 31, 2013 was recorded in an extravasation form. Ethics Committee approval was obtained and the patients gave their consent to ...

Dual Energy CT Angiography of Peripheral Arterial Disease: Feasibility of Using Lower Contrast Medium Volume.

Directory of Open Access Journals (Sweden)

Abdulrahman Almutairi

Full Text Available One of the main drawbacks associated with Dual Energy Computed Tomography Angiography (DECTA is the risk of developing contrast medium-induced nephropathy (CIN. The aim of the present study was firstly, to design an optimal CT imaging protocol by determining the feasibility of using a reduced contrast medium volume in peripheral arterial DECTA, and secondly, to compare the results with those obtained from using routine contrast medium volume.Thirty four patients underwent DECTA for the diagnosis of peripheral arterial disease. They were randomly divided into two groups: Group 1 (routine contrast volume group with n = 17, injection rate 4-5 ml/s, and 1.5 ml/kg of contrast medium, and Group 2 ((low contrast volume group, with n = 17, injection rate 4-5ml/s, and contrast medium volume 0.75 ml/kg. A fast kilovoltage-switching 64-slice CT scanner in the dual-energy mode was employed for the study. A total of 6 datasets of monochromatic images at 50, 55, 60, 65, 70 and 75 keV levels were reconstructed with adaptive statistical iterative reconstruction (ASIR at 50%. A 4-point scale was the tool for qualitative analysis of results. The two groups were compared and assessed quantitatively for image quality on the basis of signal-to-noise ratio (SNR and contrast-to-noise-ratio (CNR. Radiation and contrast medium doses were also compared.The overall mean CT attenuation and mean noise for all lower extremity body parts was significantly lower for the low volume contrast group (p<0.001, and varied significantly between groups (p = 0.001, body parts (p<0.001 and keVs (p<0.001. The interaction between group body parts was significant with CT attenuation and CNR (p = 0.002 and 0.003 respectively, and marginally significant with SNR (p = 0.047, with minimal changes noticed between the two groups. Group 2 (low contrast volume group displayed the lowest image noise between 65 and 70 keV, recorded the highest SNR and CNR at 65 keV, and produced significantly lower

Power port contrast medium flushing and trapping: impact of temperature, an in vitro experimental study.

Science.gov (United States)

Guiffant, Gérard; Durussel, Jean Jacques; Flaud, Patrice; Royon, Laurent; Marcy, Pierre Yves; Merckx, Jacques

2013-01-01

The use of totally implantable venous access devices (TIVADs) certified as "high pressure resistant" or "power port" has begun to spread worldwide as a safe procedure for power contrast injection. Owing to the thermo-rheological properties of the contrast media, the primary aim of this work is to present an in vitro experimental impact study concerning the impact of the temperature level on flushing efficiency after contrast medium injection. Moreover, we report experimental data that confirms the role of needle bevel orientation. The secondary aim is to answer the following questions: Is there significant device contrast medium trapping after contrast medium injection? Is saline flushing efficient? And, finally, is it safe to inject contrast medium through an indwelled port catheter? The experimental results show that in addition to hydrodynamics, temperature is a key parameter for the efficiency of device flushing after contrast medium injection. It appears that this is the case when the cavity is incompletely rinsed after three calibrated flushing volumes of 10 mL saline solution, even by using the Huber needle bevel opposite to the port exit. This leads to a potentially important trapped volume of contrast medium in the port, and consequently to the possibility of subsequent salt precipitates and long term trisubstituted benzene nuclei delivery that might impair the solute properties, which may be further injected via the power port later on. We thus suggest, in TIVADS patients, the use of a temporary supplementary intravenous line rather than the port to perform contrast medium injections in daily radiology routine practice.

Prevalence and characteristics of intravertebral enhancement on contrast-enhanced CT scans in cancer patients

Energy Technology Data Exchange (ETDEWEB)

Rasselet, Benjamin [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Larbi, Ahmed; Viala, Pierre [Medical Imaging Department, Nimes University Hospital, 4 rue du Professeur Robert Debré, 30029 Nîmes (France); Molinari, Nicolas [Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Tetreau, Raphael [Medical Imaging Department, Montpellier Cancer Institute (ICM), 208 Avenue des Apothicaires, 34298 Montpellier Cedex 5 (France); Faruch-Bilfeld, Marie [Medical Imaging Department, Toulouse University Hospital, Place du Docteur Baylac, 31059 Toulouse Cedex 9 (France); Taourel, Patrice [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France); Cyteval, Catherine, E-mail: c-cyteval@chu-montpellier.fr [Medical Imaging Department and Biostatistics Department, Montpellier University Hospital, 191 Avenue du Doyen Gaston Giraud, 34 295 Montpellier Cedex 5 (France)

2017-01-15

Highlights: • 2.8% of collateral venous circulation seen on CT scan in a cancer population. • 37% of intravertebral enhancement in this population with collateral venous circulation. • 80.8% of intravertebral enhancements are located between C6 and. • 73% of intravertebral enhancements are located ipsilateral to the injection side. -  Abstract: Study design: This was a single center, retrospective observational study. Objective: to investigate—in a cancer population—the prevalence and hallmarks of intravertebral enhancement (IVE) detected on contrast-enhanced CT. Summary of background data: Intravertebral enhancements secondary to iodinated contrast stagnation have been described. Cancer patients have an increased risk of perivertebral venous thrombosis or stenosis secondary to several risk factors (cancer or drug induced hypercoagulability, deterioration of venous flow linked to catheter insertion, prolonged immobilization). In case of a high density lesion identified on CT, the diagnostic choice between metastasis and contrast media within bone marrow vessels may be an issue, especially as oncologic follow-up CT scans are usually performed with contrast medium injection. Methods: 2572 contrast-enhanced body CT scans performed in cancer patients over 3 months in the medical imaging department of a university hospital were retrospectively reviewed. IVE was sought when paravertebral venous collateral circulation was detected and bone metastasis ruled out and classified as linear or nodular. Their locations within vertebra, their relation to the injection side and the predominant collateral venous network side were evaluated. Results: Sixty-seven (2.8%) patients had a collateral paravertebral venous system and among them 21 had IVE (37%). There were 208 IVE locations involving 75 vertebrae. 199 IVE were linear-shaped (95.7%) and 9 nodular-shaped (4.3%). 80.8% were located between C6 and T4. 88.9% were localized in the vertebral body. 73.1% were located

Prevalence and characteristics of intravertebral enhancement on contrast-enhanced CT scans in cancer patients

International Nuclear Information System (INIS)

Rasselet, Benjamin; Larbi, Ahmed; Viala, Pierre; Molinari, Nicolas; Tetreau, Raphael; Faruch-Bilfeld, Marie; Taourel, Patrice; Cyteval, Catherine

2017-01-01

Highlights: • 2.8% of collateral venous circulation seen on CT scan in a cancer population. • 37% of intravertebral enhancement in this population with collateral venous circulation. • 80.8% of intravertebral enhancements are located between C6 and. • 73% of intravertebral enhancements are located ipsilateral to the injection side. -  Abstract: Study design: This was a single center, retrospective observational study. Objective: to investigate—in a cancer population—the prevalence and hallmarks of intravertebral enhancement (IVE) detected on contrast-enhanced CT. Summary of background data: Intravertebral enhancements secondary to iodinated contrast stagnation have been described. Cancer patients have an increased risk of perivertebral venous thrombosis or stenosis secondary to several risk factors (cancer or drug induced hypercoagulability, deterioration of venous flow linked to catheter insertion, prolonged immobilization). In case of a high density lesion identified on CT, the diagnostic choice between metastasis and contrast media within bone marrow vessels may be an issue, especially as oncologic follow-up CT scans are usually performed with contrast medium injection. Methods: 2572 contrast-enhanced body CT scans performed in cancer patients over 3 months in the medical imaging department of a university hospital were retrospectively reviewed. IVE was sought when paravertebral venous collateral circulation was detected and bone metastasis ruled out and classified as linear or nodular. Their locations within vertebra, their relation to the injection side and the predominant collateral venous network side were evaluated. Results: Sixty-seven (2.8%) patients had a collateral paravertebral venous system and among them 21 had IVE (37%). There were 208 IVE locations involving 75 vertebrae. 199 IVE were linear-shaped (95.7%) and 9 nodular-shaped (4.3%). 80.8% were located between C6 and T4. 88.9% were localized in the vertebral body. 73.1% were located

Kinetics of intravenous radiographic contrast medium injections as used on CT: simulation with time delay differential equations in a basic human cardiovascular multicompartment model.

Science.gov (United States)

Violon, D

2012-12-01

To develop a multicompartment model of only essential human body components that predicts the contrast medium concentration vs time curve in a chosen compartment after an intravenous injection. Also to show that the model can be used to time adequately contrast-enhanced CT series. A system of linked time delay instead of ordinary differential equations described the model and was solved with a Matlab program (Matlab v. 6.5; The Mathworks, Inc., Natick, MA). All the injection and physiological parameters were modified to cope with normal or pathological situations. In vivo time-concentration curves from the literature were recalculated to validate the model. The recalculated contrast medium time-concentration curves and parameters are given. The results of the statistical analysis of the study findings are expressed as the median prediction error and the median absolute prediction error values for both the time delay and ordinary differential equation systems; these are situated well below the generally accepted maximum 20% limit. The presented program correctly predicts the time-concentration curve of an intravenous contrast medium injection and, consequently, allows an individually tailored approach of CT examinations with optimised use of the injected contrast medium volume, as long as time delay instead of ordinary differential equations are used. The presented program offers good preliminary knowledge of the time-contrast medium concentration curve after any intravenous injection, allowing adequate timing of a CT examination, required by the short scan time of present-day scanners. The injected volume of contrast medium can be tailored to the individual patient with no more contrast medium than is strictly needed.

Studies on the consistency of internally taken contrast medium for pancreas CT

Energy Technology Data Exchange (ETDEWEB)

Matsushima, Kishio; Mimura, Seiichi; Tahara, Seiji; Kitayama, Takuichi; Inamura, Keiji; Mikami, Yasutaka; Hashimoto, Keiji; Hiraki, Yoshio; Aono, Kaname

1985-02-01

A problem of Pancreatic CT scanning is the discrimination between the pancreas and the adjacent gastrointestinal tract. Generally we administer a dilution of gastrografin internally to make the discrimination. The degree of dilution has been decided by experience at each hospital. When the consistency of the contrast medium is low in density, an enhancement effect cannot be expected, but when the consistency is high, artifacts appear. We have experimented on the degree of the dilution and CT-No to decide the optimum consistency of gastrografin for the diagnosis of pancreatic disease. Statistical analysis of the results show the optimum dilution of gastrografin to be 1.5%.

Experience with contrast-enhanced CT in delayed traumatic intracerebral hematoma

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Shiro; Nakazawa, Shozo; Yokota, Hiroyuki; Isayama, Kazuo; Yajima, Kouzo; Otsuka, Toshibumi [Nippon Medical School, Tokyo

1984-02-01

During the four-and-a-half-year period from April, 1976, to September, 1980, out of 257 patients with severe head injuries graded 8 or less by the Glasgow Coma Scale in the Department of Neurosurgery and Critical Care Medicine of the Nippon Medical School, Tokyo, Japan, 33 cases showed the development of delayed traumatic intracerebral hematoma (DTICH) upon the serial computerized tomography (CT). Contrast-enhanced CT was performed in 20 cases of the 33 patients demonstrating DTICH. Among these, 8 cases (40%) indicated the development of DTICH in the lesions of cerebral contusion (a salt-and-pepper appearance in the initial plain CT) which showed a remarkable enhancement, sustaining the extravasation of the contrast medium into the contused brain tissue. The authors discuss the pathogenesis of DTICH and suggest that vasoparalysis in the cerebral contusion might be a factor in the development of DTICH in patients with servere head injuries.

Body surface area adapted iopromide 300 mg/ml versus 370 mg/ml contrast medium injection protocol: Influence on quantitative and clinical assessment in combined PET/CT

Energy Technology Data Exchange (ETDEWEB)

Verburg, Frederik A., E-mail: fverburg@ukaachen.de [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Maastricht University Medical Center, Department of Nuclear Medicine, P. Debyelaan 25, 6229 HX Maastricht (Netherlands); Apitzsch, Jonas [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology, Pauwelsstraße 30, 52074 Aachen (Germany); Lensing, Carina [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Kuhl, Christiane K. [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology, Pauwelsstraße 30, 52074 Aachen (Germany); Pietsch, Hubertus [Bayer Pharma AG, Müllerstrasse 178, 13353 Berlin (Germany); Mottaghy, Felix M. [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany); Maastricht University Medical Center, Department of Nuclear Medicine, P. Debyelaan 25, 6229 HX Maastricht (Netherlands); Behrendt, Florian F. [RWTH Aachen University Hospital, Department of Nuclear Medicine, Pauwelsstraße 30, 52074 Aachen (Germany)

2013-12-01

Purpose: To investigate the quantitative and qualitative differences between combined positron emission tomography and computed X-ray tomography (PET/CT) enhanced with contrast medium with either an iodine concentration 300 mg/ml or 370 mg/ml. Materials and methods: 120 consecutive patients scheduled for F-18-Fluorodeoxyglucose (FDG) PET/CT were included. The first (second) 60 patients received contrast medium with 300 (370) mg iodine/ml. Intravenous injection protocols were adapted for an identical iodine delivery rate (1.3 mg/s) and body surface area (BSA) adapted iodine dose (22.26 g I/m{sup 2}). Maximum and mean standardized uptake values (SUV{sub max}; SUV{sub mean}) and contrast enhancement (HU) were determined in the ascending aorta, the abdominal aorta, the inferior vena cava, the portal vein, the liver and the right kidney in the venous contrast medium phase. PET data were evaluated visually for the presence of malignancy and image quality. Results: Both media caused significantly higher values for HU, SUV{sub mean} and SUV{sub max} for the enhanced PET/CT than the non-enhanced one (all p < 0.01). There were no significant differences in the degree of increase of HU, SUV{sub mean} and SUV{sub max} between the two contrast media at any anatomic site (all p > 0.05). Visual evaluation of lesions showed no differences between contrast and non-contrast PET/CT or between the two different contrast media (p = 0.77). Conclusion: When using a constant iodine delivery rate and total iodine dose in a BSA adapted injection protocol, there are no quantitative or qualitative differences in either CT or PET between contrast media with an iodine concentration of 300 mg/ml and 370 mg/ml, respectively.

CT enhancement of acute cerebral infarction following long-term continuous contrast infusion

International Nuclear Information System (INIS)

Ito, Umeo; Seida, Mitsuru; Tomida, Shuichi; Inaba, Yutaka.

1985-01-01

In this experimental study, we employed a long-term (3 hours) continuous-drip infusion of the contrast medium (200 ml of meglumine amidtrizoate) rather than the conventional bolus injection. On admission, four-vessel angiography was performed on all 14 patients. Within 3 days after the onset of the disease, CT scan was carried out repeatedly just prior to contrast infusion, immediately after the end of the continuous-contrast infusion, and additionally, in 4 cases, 3 hours after the end of the contrast infusion. The Haunsfield number was calculated in 3 regions of interest (Radius 5) in the infarction. Positive enhancement was observed in 10 out of the 14 patients (71 %). Among them, 4 out of 5 patients in whom no vascular obstraction on angiography, but marked low-density areas with a mass effect on CT were observed, showed moderate to marked enhancement. In these 4 patients, a temporary cerebral ischemia due to vascular embolization was considered. From the other 4 patients in whom the additional CT scan was performed 3 hours after the end of the contrast infusion, a blood sample was obtained at each of the 3 CT scannings. The iodine concentrations of the blood samples were measured, and their Haunsfield numbers were calculated in the water phantom. The above two parameters were well correlated in a linear function. Among the 4 patients, Gado's tissue-blood ratio (the Haunsfield number of the CT lesion is divided by that of the blood sample) was more than 17.2 % immediately after, and more than 54.7 % 3 hours after, the contrast infusion. Thus, we could conclude that the break-down of the BBB which was demonstrated by a long-term high-blood-concentration level of the contrast medium is an earlier event in human cerebral infarction than is usually accepted. The findings are compatible with our results in animal experiments. (author)

Power port contrast medium flushing and trapping: impact of temperature, an in vitro experimental study

Directory of Open Access Journals (Sweden)

Guiffant G

2013-09-01

Full Text Available Gérard Guiffant,1 Jean Jacques Durussel,1 Patrice Flaud,1 Laurent Royon,1 Pierre Yves Marcy,2 Jacques Merckx1,31University Paris Diderot, Paris, France; 2Radiodiagnosis and Interventional Radiology Department, Caen, France; 3University Teaching Hospital Necker-Enfants Malades, Paris, FrancePurpose: The use of totally implantable venous access devices (TIVADs certified as "high pressure resistant" or "power port" has begun to spread worldwide as a safe procedure for power contrast injection. Owing to the thermo-rheological properties of the contrast media, the primary aim of this work is to present an in vitro experimental impact study concerning the impact of the temperature level on flushing efficiency after contrast medium injection. Moreover, we report experimental data that confirms the role of needle bevel orientation. The secondary aim is to answer the following questions: Is there significant device contrast medium trapping after contrast medium injection? Is saline flushing efficient? And, finally, is it safe to inject contrast medium through an indwelled port catheter?Results: The experimental results show that in addition to hydrodynamics, temperature is a key parameter for the efficiency of device flushing after contrast medium injection. It appears that this is the case when the cavity is incompletely rinsed after three calibrated flushing volumes of 10 mL saline solution, even by using the Huber needle bevel opposite to the port exit. This leads to a potentially important trapped volume of contrast medium in the port, and consequently to the possibility of subsequent salt precipitates and long term trisubstituted benzene nuclei delivery that might impair the solute properties, which may be further injected via the power port later on.Conclusion: We thus suggest, in TIVADS patients, the use of a temporary supplementary intravenous line rather than the port to perform contrast medium injections in daily radiology routine practice

Contrast-enhanced magnetic resonance imaging of tumours of the central nervous systems: a clinical review

International Nuclear Information System (INIS)

Graif, M.; Steiner, R.E.

1986-01-01

The clinical application of the intravascular paramagnetic contrast agent gadolinium-DTPA for magnetic resonance imaging (MRI) imaging of tumours of the central nervous system (CNS) has been assessed over the past 3 years. Various patterns of contrast enhancement were observed, and situations in MRI where the administration of contrast medium may be useful have been defined. These include lesions which are isointense with normal brain matter, the separation of tumour from surrounding oedema, evaluation of the degree of blood-brain barrier breakdown, delineation of tumours obscured by overlying calcification on computed tomography (CT) and in the investigation of lesions in anatomical areas where CT has known limitations (brain, stem, cervical spine). Changes in relaxation times in normal and abnormal tissues following contrast medium, toxicity and dosage of gadolinium-DTPA, and MRI pulse sequence techniques are reviewed. (author)

CT colonography: Diagnostic role of contrast enhancement of benign polyps and colorectal carcinoma

International Nuclear Information System (INIS)

Stoinova, V.; Nedevska, M.

2006-01-01

Full text: The aim of this study was to compare pre- and postcontrast CT attenuation values of benign colorectal polyps and carcinoma lesions detected by CT colonography, and to investigate whether contrast enhancement of these lesions can be potentially used for differentiation from residual fluid and feces. We retrospectively reviewed CT colonographic dataset of 120 patients. 35 benign polyps and 22 colorectal carcinomas were included in our study. All lesions were confirmed by colonoscopic biopsy or surgery. The difference in attenuation value between precontrast and postcontrast studies of polyps was statistically significant; the same was true for colorectal cancers. In the precontrast phase no statistically significant difference was observed between stool, polyps and cancers. The mean attenuation value of solid fecal residuals was 37 HU before and after contrast enhancement. Residual fluid do not take up contrast and the density does not change in the contrast-enhanced phase. The difference between postcontrast density of polyps and cancers with respect to density of stools and residual fluid was significant. The use of contrast medium could be helpful in CT colonography for discriminating polypoid benign lesions and colorectal cancer from fecal and fluid residuals

Attenuation changes of the normal and ischemic canine kidney. Dynamic CT scanning after intravenous contrast medium bolus

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Jaschke, W.; Lipton, M.J.; Boyd, D.P.; Cann, C.; Strauss, L.; Sievers, R.S.

The potential of CT scanning to explore total and regional renal blood flow was evaluated in a dog model with unilateral renal artery stenosis (n=7, reduction of renal blood flow: 32-75% of base line flow). Attenuation versus time curves were generated for the renal cortex and medulla, as well as for the aorta and renal vein. A fast CT scanner was used which allowed for up to 24 scans/minute at the same level (slice thickness: 10 mm). A total of 10 ml contrast medim was injected into a peripheral vein for each scan series taken. During baseline conditions, the curve of the renal cortex and medulla demonstrated 2 peaks. The first peak was mainly related to early vascular enhancement, whereas the second peak corresponded mainly to the appearance of contrast medium in the distal convolutes and collecting ducts. Ischemia of the kidney resulted in a reduction of the first peak and a flattening of the leading edge slope. Transport of contrast medium through the extravascular compartments of the kidney was delayed during ischemia. Relative renal blood flow was obtained from the CT data by dividing peak enhancement by rise-time as assessed from the cortical curve. All measurements were related to baseline flow and validated by flow measurements using radioactive labeled microspheres (n=5). Correlation was found to be r=0.97. (orig.).

Contrast enhanced CT of spinal cord angioma

International Nuclear Information System (INIS)

Nakamura, Takahiko; Ebitani, Tsutomu; Honma, Takao; Sofue, Muroto; Nakamura, Shigeru

1982-01-01

Contrast enhanced CT on 6 patients with spinal cord angioma showed enhancement in 2 of them. The conditions to produce contrast enhancement were the window width of 100 - 200, and the window level of 0 - 50. In spinal cord angioma, contrast enhanced CT is presently only an adjunct to angiography and myelography. Nevertheless, contrast enhanced CT is useful in the screening test for spinal cord angioma, in the patients who are nonindicated to angiography, and in the postoperative follow-up. (Ueda, J.)

Abdominal vascular and visceral parenchymal contrast enhancement in MDCT: Effects of injection duration

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Tsuge, Yusuke, E-mail: tsugeu@cup.ocn.ne.jp [Department of Radiology, Kizawa Memorial Hospital, 590 Kobityo Shimokobi, Minokamo City, Gifu 505-8503 (Japan); Kanematsu, Masayuki [Department of Radiology, Gifu University Hospital, Gifu (Japan); Department of Radiology Services, Gifu University Hospital, Gifu (Japan); Goshima, Satoshi; Kondo, Hiroshi [Department of Radiology, Gifu University Hospital, Gifu (Japan); Yokoyama, Ryujiro; Miyoshi, Toshiharu [Department of Radiology Services, Gifu University Hospital, Gifu (Japan); Onozuka, Minoru [Department of Physiology and Neuroscience, Kanagawa Dental College, Yokosuka (Japan); Moriyama, Noriyuki [Research Center for Cancer Prevention and Screening, National Cancer Center Hospital, Tsukiji (Japan); Bae, Kyongtae T. [Radiology and Biomedical Engineering, University of Pittsburgh, Pittsburgh, PA (United States)

2011-11-15

Purpose: To evaluate and compare the effect of short and long injection durations on aortic, pancreatic and hepatic enhancement in abdominal MDCT. Methods and materials: Triphasic contrast-enhanced CT images (16-MDCT, 1.25-mm collimation, 5-mm thickness, 6.1-s acquisition time for each phase) were obtained with 2 mL/kg injection of 300 mgI/mL iodine contrast material in 116 patients. Patients were prospectively randomized into two groups: one receiving contrast medium for 25-s injection duration and the other for 35-s injection duration. In both groups, triphasic scans were initiated 5, 15, and 40 s after the completion of contrast injection for the first, second and third phases, respectively. CT values (HU) in the abdominal aorta, liver, spleen, pancreas, splenic and superior mesenteric arteries, and veins (splenic, superior mesenteric, portal, and hepatic) were measured. Quantitative and qualitative analysis for the degree of contrast enhancement between the two groups in various organs was compared at each scan phase. Results: The aortic and arterial enhancements in the first-phase scan were higher for the 25-s group than those of the 35-s group (P < .001). Hepatic enhancement was higher for the 35-s group in the first (P < .001) and second (P < .01) phases, but no difference in the third-phase. No difference was found between the groups for the pancreatic enhancement at any phases. Qualitative results were in good agreement with quantitative results. Conclusion: Contrast administration with shorter injection duration increased peak aortic and arterial enhancement and contributed to improvement in the quality of CT angiograms, but for the solid abdominal organs 35-s protocol is recommended.

Development of low-dose photon-counting contrast-enhanced tomosynthesis with spectral imaging.

Science.gov (United States)

Schmitzberger, Florian F; Fallenberg, Eva Maria; Lawaczeck, Rüdiger; Hemmendorff, Magnus; Moa, Elin; Danielsson, Mats; Bick, Ulrich; Diekmann, Susanne; Pöllinger, Alexander; Engelken, Florian J; Diekmann, Felix

2011-05-01

To demonstrate the feasibility of low-dose photon-counting tomosynthesis in combination with a contrast agent (contrast material-enhanced tomographic mammography) for the differentiation of breast cancer. All studies were approved by the institutional review board, and all patients provided written informed consent. A phantom model with wells of iodinated contrast material (3 mg of iodine per milliliter) 1, 2, 5, 10, and 15 mm in diameter was assessed. Nine patients with malignant lesions and one with a high-risk lesion (atypical papilloma) were included (all women; mean age, 60.7 years). A multislit photon-counting tomosynthesis system was utilized (spectral imaging) to produce both low- and high-energy tomographic data (below and above the k edge of iodine, respectively) in a single scan, which allowed for dual-energy visualization of iodine. Images were obtained prior to contrast material administration and 120 and 480 seconds after contrast material administration. Four readers independently assessed the images along with conventional mammograms, ultrasonographic images, and magnetic resonance images. Glandular dose was estimated. Contrast agent was visible in the phantom model with simulated spherical tumor diameters as small as 5 mm. The average glandular dose was measured as 0.42 mGy per complete spectral imaging tomosynthesis scan of one breast. Because there were three time points (prior to contrast medium administration and 120 and 480 seconds after contrast medium administration), this resulted in a total dose of 1.26 mGy for the whole procedure in the breast with the abnormality. Seven of 10 cases were categorized as Breast Imaging Reporting and Data System score of 4 or higher by all four readers when reviewing spectral images in combination with mammograms. One lesion near the chest wall was not captured on the spectral image because of a positioning problem. The use of contrast-enhanced tomographic mammography has been demonstrated successfully in

Experience with contrast-enhanced CT in delayed traumatic intracerebral hematoma

International Nuclear Information System (INIS)

Kobayashi, Shiro; Nakazawa, Shozo; Yokota, Hiroyuki; Isayama, Kazuo; Yajima, Kouzo; Otsuka, Toshibumi

1984-01-01

During the four-and-a-half-year period from April, 1976, to September, 1980, out of 257 patients with severe head injuries graded 8 or less by the Glasgow Coma Scale in the Department of Neurosurgery and Critical Care Medicine of the Nippon Medical School, Tokyo, Japan, 33 cases showed the development of delayed traumatic intracerebral hematoma (DTICH) upon the serial computerized tomography (CT). Contrast-enhanced CT was performed in 20 cases of the 33 patients demonstrating DTICH. Among these, 8 cases (40%) indicated the development of DTICH in the lesions of cerebral contusion (a salt-and-pepper appearance in the initial plain CT) which showed a remarkable enhancement, sustaining the extravasation of the contrast medium into the contused brain tissue. The authors discuss the pathogenesis of DTICH and suggest that vasoparalysis in the cerebral contusion might be a factor in the development of DTICH in patients with servere head injuries. (author)

Contrast enhanced magnetic resonance imaging of the brain using gadolinium-DTPA

International Nuclear Information System (INIS)

Valk, J.; Slegte, R.G.M. de; Crezee, F.C.; Hazenberg, G.J.; Thjaha, S.I.; Nauta, J.J.P.; Vrije Univ., Amsterdam; Vrije Univ., Amsterdam; Vrije Univ., Amsterdam

1987-01-01

This report concerns a clinical trial with gadolinium-DTPA (Gd-DTPA) as an intravenous contrast medium for magnetic resonance imaging (MRI) in patients with disorders of the central nervous system. Fifty patients, 30 females and 20 males, were examined without and with Gd-GTPA. The contrast medium was well tolerated by all patients. The results of MRI scanning without and with Gd-DTPA and those obtained with computed tomography (CT) using intravenous contrast enhancement were compared. This investigation comprised mainly patients with intracranial tumors, multiple sclerosis, and nasopharyngeal tumors. The results may be summarized as follows: 1) MRI with Gd-DTPA (MRI+) gave better results than MRI without Gd as regards delineation of the lesion, blood vessels and edema in cerebral tumors, pituitary adenomas and acute forms of multiple sclerosis (MS). MRI+ was better than CT in 32 of the 50 cases examined; with intracerebral tumors it was better in 15 out of 18 cases. 3) MRI+ was always better than CT in patients with MS. In 3 out of 7 cases MRI demonstrated the acute MS lesions. 4) MRI+ seemed to have advantages also in nasopharyngeal tumors as ascertained from this limited experience. (orig.)

Contrast enhanced ultrasound in liver imaging

International Nuclear Information System (INIS)

Nielsen, Michael Bachmann; Bang, Nanna

2004-01-01

Ultrasound contrast agents were originally introduced to enhance the Doppler signals when detecting vessels with low velocity flow or when imaging conditions were sub-optimal. Contrast agents showed additional properties, it was discovered that a parenchymal enhancement phase in the liver followed the enhancement of the blood pool. Contrast agents have made ultrasound scanning more accurate in detection and characterization of focal hepatic lesions and the sensitivity is now comparable with CT and MRI scanning. Further, analysis of the transit time of contrast agent through the liver seems to give information on possible hepatic involvement, not only from focal lesions but also from diffuse benign parenchymal disease. The first ultrasound contrast agents were easily destroyed by the energy from the sound waves but newer agents have proved to last for longer time and hereby enable real-time scanning and make contrast enhancement suitable for interventional procedures such as biopsies and tissue ablation. Also, in monitoring the effect of tumour treatment contrast agents have been useful. A brief overview is given on some possible applications and on different techniques using ultrasound contrast agents in liver imaging. At present, the use of an ultrasound contrast agent that allows real-time scanning with low mechanical index is to be preferred

Contrast-medium-induced nephropathy: is there a new consensus? A review of published guidelines

International Nuclear Information System (INIS)

Thomsen, Henrik S.; Morcos, Sameh K.

2006-01-01

The interest in contrast-medium-induced nephropathy has increased considerably during the last few years. Various guidelines regarding identifying patients at risk and measures to reduce the incidence of this complication have been proposed. The aim of this review was to analyse whether there is some consistency amongst these guidelines. A Medline search for the keyword ''contrast medium induced nephropathy'' during the period from the beginning of 2003 through the end of September 2005 was carried out. Only papers in English were reviewed. Thirteen guidelines were identified. Inconsistency was observed regarding advise on the prophylactic use of drugs and the isoosmolar dimer to reduce the incidence of contrast-medium-induced nephropathy. Consistency was found in relation to the importance of hydration, cessation of intake of nephrotoxic drugs and administration of the lowest possible dose of contrast medium. No new consensus has been observed in comparison to the European Society for Urogenital Radiology (ESUR) guidelines, which were published in 1999. (orig.)

Use of iohexol as a gastrointestinal contrast medium in the dog

International Nuclear Information System (INIS)

Agut, A.; Sanchez-Valverde, M.A.; Lasaosa, J.M.; Murciano, J.; Molina, F.

1993-01-01

Iohexol was administered orally in five dogs. The dose, gastrointestinal (GI) transit time, appearance of mucosal patterns and side effects were studied. Three different doses (525, 700, 875 mgI/kg) were used in each dog at 1-week intervals. GI transit time was rapid. In each dose, gastric emptying commenced immediately after administration of the contrast medium, and was completed within 30–60 min with doses of 525–700 mgI/kg and 90–120 min with 875 mgI/kg. Large intestinal filling was observed within 60-90 min. In the majority of studies, the mucosal border appeared as a thin homogeneous halo of lucency surrounding the more opaque bowel lumen contents. The contrast intensity was not adequate with the lowest dose. The image quality did not deteriorate along the GI tract. No adverse reactions were found. Iohexol is an alternative GI contrast medium in the dog when contrast media are contraindicated

CT of hepatocellular carcinoma. Analysis of contrast-enhanced CT using CT arteriography

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Nakamura, H; Tanaka, T; Hori, S; Tokunaga, K; Yoshioka, H [Osaka Univ. (Japan). Faculty of Medicine

1981-02-01

Although changes in the CT appearance resulting from contrast enhancement (CE) for hepatocellular carcinoma have been considered in association with vascularity of tumors, no detailed studies have yet been made. We analyzed changes in the CT appearance following CE by comparing with hepatic arteriogram and CT arteriogram (CTA) performed during intraarterial infusion of contrast medium. When tumors showing low density in the plain CT were enhanced by contrast, the results were variable, ranging from intensification of the low density to replacement by high density, and the results were classified into L/sub 0/ to L/sub 3/ according to vascularity of tumors. The results after CE could also be classified into I/sub 0/ to I/sub 3/ when tumors showed isodensity in the plain CT. There was a correlation between vascularity presumed from CE and vascularity by CTA. It may be concluded that tumor vascularity could be estimated by the findings of CE which might indicate a possibility of qualitative diagnosis of tumors.

Contrast-enhanced MR angiography in Leriche's syndrome

International Nuclear Information System (INIS)

Link, J.; Steffens, J.C.; Brossmann, J.; Heller, M.; Loose, R.

1998-01-01

Purpose: To determine the usefulness of contrast-enhanced MR angiography for the diagnosis of Leriche's syndrome. Material and methods: Leriche's syndrome was seen in 7 patients via DSA. In [dition, contrast-enhanced MR angiography was performed (T R 7.8 ms/T E 2.1 ms, flip angle 30 , slab thickness 116 mm, slice thickness 1.82 mm, 64 partitions, FOV 500x438 mm, matrix 224x512). Results: Diagnosis of Leriche's syndrome was possible by contrast-enhanced MR angiography in each case. Visualisation of the femoral arteries was not possible in two patients by intraarterial DSA, in three other patients there was an insufficient contrast in the femoral arteries with DSA. Contrast-enhanced MR angiography revealed good visualisation of the femoral arteries in these patients. In [dition, contrast-enhanced MR angiography allowed complete visualisation of the patent lower limb arteries. In intraarterial DSA visualisation of the lower limb arteries was achieved reached in only one patient, but was incomplete. Conclusion: Contrast-enhanced MR angiography yielded the correct diagnosis of Leriche's syndrome in all 7 patients. Contrast-enhanced MR angiography was superior to DSA in the assessment of the distal run-off vessels in five of seven patients. (orig.) [de

Comparison of Oral Contrast-Enhanced Transabdominal Ultrasound Imaging With Transverse Contrast-Enhanced Computed Tomography in Preoperative Tumor Staging of Advanced Gastric Carcinoma.

Science.gov (United States)

He, Xuemei; Sun, Jing; Huang, Xiaoling; Zeng, Chun; Ge, Yinggang; Zhang, Jun; Wu, Jingxian

2017-12-01

This study assessed the diagnostic performance of transabdominal oral contrast-enhanced ultrasound (US) imaging for preoperative tumor staging of advanced gastric carcinoma by comparing it with transverse contrast-enhanced computed tomography (CT). This retrospective study included 42 patients with advanced gastric cancer who underwent laparoscopy, radical surgery, or palliative surgery because of serious complications and had a body mass index of less than 25 kg/m 2 . A cereal-based oral contrast agent was used for transabdominal oral contrast-enhanced US. Retrospective analyses were conducted using preoperative tumor staging data acquired by either transabdominal oral contrast-enhanced US or transverse contrast-enhanced CT. Both contrast-enhanced US and contrast-enhanced CT examinations were reviewed by 2 experienced radiologists independently for preoperative tumor staging according to the seventh edition of the TNM classification. The accuracy, sensitivity, and specificity were calculated by comparing the results of contrast-enhanced US and contrast-enhanced CT with pathologic findings. The overall accuracies of the imaging modalities were compared by the McNemar test. No significant difference was noted in the overall accuracy of transabdominal oral contrast-enhanced US (86% [36 of 42]) and transverse contrast-enhanced CT (83% [35 of 42] P > .999). For stage T2 to T4 gastric cancer, the accuracies of transabdominal oral contrast-enhanced US were 88%, 86%, and 98%, respectively, and those of transverse contrast-enhanced CT were 93%, 83%, and 90%. The overall accuracy of transabdominal oral contrast-enhanced US was comparable with that of transverse contrast-enhanced CT for preoperative tumor staging of advanced gastric cancer. © 2017 by the American Institute of Ultrasound in Medicine.

Evaluation of residual hepatocellular carcinoma after transcatheter arterial chemoembolization: Comparison between contrast-enhanced helical CT and contrast-enhanced power doppler ultrasonography

International Nuclear Information System (INIS)

Kim, Seung Hoon; Lim, Hyo Keun; Lee, Won Jae

2001-01-01

To evaluate the effectiveness of contrast-enhanced helical CT and contrast-enhanced power doppler ultrasonography (PDUS) in assessing the therapeutic effect of transcatheter arterial chemoembolization (TACE) in hepatocellular carcinomas (HCCs). The follow-up contrast-enhanced helical CT and contrast-enhanced PDUS were performed for twenty-nine nodular HCCs from twelve patients previously treated with TACE. We defined the residual HCCs as intratumoral enhancing area on contrast-enhanced helical CT and color signal on contrast-enhanced PDUS. The interval between two examinations was less than 2 weeks (mean, 9 days). Two radiologists evaluated two examinations by consensus, and the results of these two examination were compared with the findings of other examinations including CT, angiography, and/or pathology to calculate the sensitivity, specificity and accuracy of two examinations. Of the 29 HCCs, 20 had residual HCCs whereas no residual HCCs in 9 HCCs on pathologic examination and/or follow-up radiologic study. The sensitivity, sensitivity and accuracy of contrast-enhanced helical CT were 65 (13/20), 89 (8/9), and 72% (21/29) while those of contrast-enhanced PDUS were 100 (20/20), 89 (8/9) and 97% (28/29), respectively. A microbubble contrast-enhanced PDUS was more effective in the detection of residual tumor in HCCs following TACE than contrast-enhanced helical CT.

CT contrasting theory. Effects of the concentration, volume and infusion rate of iodine contrast medium on TDC

International Nuclear Information System (INIS)

Yamachi, Jun

2007-01-01

This study was performed to evaluate the effects in the title on TDC (time-density curve) using a phantom. CT machine used was Toshiba Aquilion Multi 64, TDC phantom was the product of Nemoto-Kyorindo Co., and the contrast medium was Eisai iomeprol, in syringe-sealed formulations of 300 and 350 mg I/mL. The medium was infused at 1-5 mL/sec in the phantom equivalent to body weight of 78 kg (total water volume=1 min circulation=6,000 mL, 800 mL/heart) to obtain 30 TDCs. Evaluated were the relationships of the infusion rate (mL/sec), volume (mL) or time (sec) with TDC parameters of the detection time of the medium, slope, time to reach the maximum CT value, the maximum CT value, time to keep the CT concentration and its actual concentration. Results revealed that, regardless to the difference of formulations of the contrast medium, TDC with high reproducibility can be obtainable by making the infusion rate of I per unit time and body weight (mgI/sec/kg) constant when the infusion time is made identical for CT of the same diagnostic purpose. (R.T.)

Use of cystatin C and serum creatinine for the diagnosis of contrast-induced nephropathy in patients undergoing contrast-enhanced computed tomography at an oncology centre.

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Joao Italo Fortalesa Melo

Full Text Available Our aim was to assess renal function using as laboratory measurements serum creatinine and cystatin C concentrations before and after administration of low-osmolarity (nonionic iodinated contrast medium in patients with cancer undergoing computed tomography (CT.This prospective study included 400 oncologic outpatients. Serum creatinine and cystatin C concentrations were measured before and 72 h after contrast administration. Glomerular filtration rates (GFRs were estimated using serum creatinine-based [Modification of Diet in Renal Disease (MDRD and Cockroft-Gault and cystatin C based (Larsson equations. Exploratory data analysis was performed. The nonparametric Wilcoxon test was used to compare pre and post contrast of test results and estimated clearance. The confidence interval used in the analysis was 95%.Compared with the pre-contrast values, the mean serum creatinine concentration was significantly higher and average GFRs estimated using MDRD and Cockcroft-Gault equations were significantly lower after the administration of contrast (p <0.001. It was also observed a significant increase after contrast in the concentration of Cystatin C (p = 0.015. In addition, a decrease in GFR estimated using the average Larsson (p = 0.021 was observed between time points. However, none of the patients presented clinically significant nephropathy.Assessment using serum creatinine and cystatin C concentrations showed changes in renal function among patients with cancer undergoing contrast-enhanced CT examination in this study. No significant renal damage related to the use of low-osmolarity iodinated contrast medium of the type and dosage employed in this study was observed. This contrast medium is thus safe for use in patients with cancer.

Nanoparticles generated by laser in liquids as contrast medium and radiotherapy intensifiers

Science.gov (United States)

Restuccia, Nancy; Torrisi, Lorenzo

2018-01-01

The synthesis of Au and Ag nanoparticles (NP) though laser ablation in liquids as a function the laser parameters is presented. Spherical NPs with diameter distribution within 1 and 100 nm were prepared by laser ablation in water. The nanoparticles characterization was performed using optical spectroscopy and electronic microscopy (SEM and TEM) measurements. Studies of the possible use of metallic nanoparticles as intensifier of diagnostics imaging contrast medium and absorbing dose from ionizing radiations in traditional radiotherapy and protontherapy are presented. Examples of in vitro (in tissue equivalent materials) and in vivo (in mice), were conducted thank to simulation programs permitting to evaluate the enhancement of efficiency in imaging and therapy as a function of the NPs concentrations and irradiation conditions.

Nanoparticles generated by laser in liquids as contrast medium and radiotherapy intensifiers

Directory of Open Access Journals (Sweden)

Restuccia Nancy

2018-01-01

Full Text Available The synthesis of Au and Ag nanoparticles (NP though laser ablation in liquids as a function the laser parameters is presented. Spherical NPs with diameter distribution within 1 and 100 nm were prepared by laser ablation in water. The nanoparticles characterization was performed using optical spectroscopy and electronic microscopy (SEM and TEM measurements. Studies of the possible use of metallic nanoparticles as intensifier of diagnostics imaging contrast medium and absorbing dose from ionizing radiations in traditional radiotherapy and protontherapy are presented. Examples of in vitro (in tissue equivalent materials and in vivo (in mice, were conducted thank to simulation programs permitting to evaluate the enhancement of efficiency in imaging and therapy as a function of the NPs concentrations and irradiation conditions.

In which patients should serum creatinine be measured before iodinated contrast medium administration?

International Nuclear Information System (INIS)

Thomsen, Henrik S.

2005-01-01

Routine measurement of serum creatinine before injection of intravascular iodinated contrast material in all patients would be cumbersome and have an associated cost. There is doubt about whether serum creatinine should be measured routinely in all patients or selectively. The Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and draw up guidelines on this important practical issue. A literature search was carried out and summarized in a report. Based on the available information and discussions amongst the members of the Committee, guidelines were produced. The report and guidelines were discussed at the 11th European Symposium on Urogenital Radiology in Santiago de Compostela, Spain. The practice for identifying patients at risk of contrast medium induced nephropathy varies considerably from one institution to another. Patients at risk constitute only a small percentage of all cases referred for contrast enhanced imaging examination. However, it is important to identify them and take the necessary precautions. Recent serum creatinine level should be available in patients with an increased probability of a raised serum creatinine level (renal disease, renal surgery, proteinuria, diabetes mellitus, hypertension, gout, current intake of nephrotoxic drugs). A simple guideline has been produced. (orig.)

In which patients should serum creatinine be measured before iodinated contrast medium administration?

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Thomsen, Henrik S. [Copenhagen University Hospital, Herlev (Denmark). Department of Diagnostic Radiology; Morcos, Sameh K. [Northern General Hospital, Department of Diagnostic Imaging, Sheffield Teaching Hospitals NHS Trust, Sheffield (United Kingdom)

2005-04-01

Routine measurement of serum creatinine before injection of intravascular iodinated contrast material in all patients would be cumbersome and have an associated cost. There is doubt about whether serum creatinine should be measured routinely in all patients or selectively. The Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and draw up guidelines on this important practical issue. A literature search was carried out and summarized in a report. Based on the available information and discussions amongst the members of the Committee, guidelines were produced. The report and guidelines were discussed at the 11th European Symposium on Urogenital Radiology in Santiago de Compostela, Spain. The practice for identifying patients at risk of contrast medium induced nephropathy varies considerably from one institution to another. Patients at risk constitute only a small percentage of all cases referred for contrast enhanced imaging examination. However, it is important to identify them and take the necessary precautions. Recent serum creatinine level should be available in patients with an increased probability of a raised serum creatinine level (renal disease, renal surgery, proteinuria, diabetes mellitus, hypertension, gout, current intake of nephrotoxic drugs). A simple guideline has been produced. (orig.)

Analytical optimization of digital subtraction mammography with contrast medium using a commercial unit.

Science.gov (United States)

Rosado-Méndez, I; Palma, B A; Brandan, M E

2008-12-01

Contrast-medium-enhanced digital mammography (CEDM) is an image subtraction technique which might help unmasking lesions embedded in very dense breasts. Previous works have stated the feasibility of CEDM and the imperative need of radiological optimization. This work presents an extension of a former analytical formalism to predict contrast-to-noise ratio (CNR) in subtracted mammograms. The goal is to optimize radiological parameters available in a clinical mammographic unit (x-ray tube anode/filter combination, voltage, and loading) by maximizing CNR and minimizing total mean glandular dose (D(gT)), simulating the experimental application of an iodine-based contrast medium and the image subtraction under dual-energy nontemporal, and single- or dual-energy temporal modalities. Total breast-entrance air kerma is limited to a fixed 8.76 mGy (1 R, similar to screening studies). Mathematical expressions obtained from the formalism are evaluated using computed mammographic x-ray spectra attenuated by an adipose/glandular breast containing an elongated structure filled with an iodinated solution in various concentrations. A systematic study of contrast, its associated variance, and CNR for different spectral combinations is performed, concluding in the proposal of optimum x-ray spectra. The linearity between contrast in subtracted images and iodine mass thickness is proven, including the determination of iodine visualization limits based on Rose's detection criterion. Finally, total breast-entrance air kerma is distributed between both images in various proportions in order to maximize the figure of merit CNR2/D(gT). Predicted results indicate the advantage of temporal subtraction (either single- or dual-energy modalities) with optimum parameters corresponding to high-voltage, strongly hardened Rh/Rh spectra. For temporal techniques, CNR was found to depend mostly on the energy of the iodinated image, and thus reduction in D(gT) could be achieved if the spectral energy

Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

International Nuclear Information System (INIS)

Xu Huixiong; Chen Lida; Xie Xiaoyan; Xie Xiaohua; Xu Zuofeng; Liu Guangjian; Lin Manxia; Wang Zhu; Lu Mingde

2010-01-01

Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125). Conclusion: The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

Enhancement pattern of hilar cholangiocarcinoma: Contrast-enhanced ultrasound versus contrast-enhanced computed tomography

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Xu Huixiong, E-mail: xuhuixiong@hotmail.co [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Chen Lida; Xie Xiaoyan; Xie Xiaohua; Xu Zuofeng; Liu Guangjian; Lin Manxia; Wang Zhu [Department of Medical Ultrasonics, The First Affiliated Hospital, Institute of Diagnostic and Interventional Ultrasound, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China); Lu Mingde, E-mail: lumd@21cn.co [Department of Hepatobiliary Surgery, First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan Road 2, Guangzhou 510080 (China)

2010-08-15

Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P > 0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P = 0.125). Conclusion: The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

Quantitative 2- and 3-dimensional analysis of pharmacokinetic model-derived variables for breast lesions in dynamic, contrast-enhanced MR mammography

International Nuclear Information System (INIS)

Hauth, E.A.M.; Jaeger, H.J.; Maderwald, S.; Muehler, A.; Kimmig, R.; Forsting, M.

2008-01-01

Purpose: 2- and 3-dimensional evaluation of quantitative pharmacokinetic parameters derived from the Tofts model modeling dynamic contrast enhancement of lesions in MR mammography. Materials and methods: In 95 patients, MR mammography revealed 127 suspicious lesions. The initial rate of enhancement was coded by color intensity, the post-initial enhancement change is coded by color hue. 2D and 3D analysis of distribution of color hue and intensity, vascular permeability and extracellular volume were performed. Results: In 2D, malignant lesions showed significant higher number of bright red, medium red, dark red, bright green, medium green, dark green and bright blue pixels than benign lesions. In 3D, statistical significant differences between malignant and benign lesions was found for all this parameters. Vascular permeability was significant higher in malignant lesions than in benign lesions. Regression model using the 3D data found that the best discriminator between malignant and benign lesions was combined number of voxels and medium green pixels, with a sensitivity of 79.4% and a specificity of 83.1%. Conclusions: Quantitative analysis of pharmacokinetic variables of contrast kinetics showed significant differences between malignant and benign lesions. 3D analysis showed superior diagnostic differentiation between malignant and benign lesions than 2D analysis. The parametric analysis using a pharmacokinetic model allows objective analysis of contrast enhancement in breast lesions

Contrast-enhanced endoscopic ultrasonography

DEFF Research Database (Denmark)

Reddy, Nischita K; Ioncica, Ana Maria; Saftoiu, Adrian

2011-01-01

Contrast agents are increasingly being used to characterize the vasculature in an organ of interest, to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures. We review the mechanisms of action of first, second and third generation contrast...... agents and their use in various endoscopic procedures in the gastrointestinal tract. Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy, assessment of depth of invasion of esophageal, gastric and gall bladder...

Soft-tissue tumor differentiation using 3D power Doppler ultrasonography with echo-contrast medium injection.

Science.gov (United States)

Chiou, Hong-Jen; Chou, Yi-Hong; Chen, Wei-Ming; Chen, Winby; Wang, Hsin-Kai; Chang, Cheng-Yen

2010-12-01

We aimed to evaluate the ability of 3-dimensional power Doppler ultrasonography to differentiate soft-tissue masses from blood flow and vascularization with contrast medium. Twenty-five patients (mean age, 44.1 years; range, 12-77 years) with a palpable mass were enrolled in this study. Volume data were acquired using linear and convex 3-dimensional probes and contrast medium injected manually by bolus. Data were stored and traced slice by slice for 12 slices. All patients were scanned by the same senior sonologist. The vascular index (VI), flow index (FI), and vascular-flow index (VFI) were automatically calculated after the tumor was completely traced. All tumors were later confirmed by pathology. The study included 8 benign (mean, 36.5 mL; range, 2.4-124 mL) and 17 malignant (mean, 319.4 mL; range, 9.9-1,179.6 mL) tumors. Before contrast medium injection, mean VI, FI and VFI were, respectively, 3.22, 32.26 and 1.07 in benign tumors, and 1.97, 29.33 and 0.67 in malignant tumors. After contrast medium injection, they were, respectively, 20.85, 37.33 and 8.52 in benign tumors, and 40.12, 41.21 and 17.77 in malignant tumors. The mean differences between with and without contrast injection for VI, FI and VFI were, respectively, 17.63, 5.07 and 7.45 in benign tumors, and 38.15, 11.88 and 16.55 in malignant tumors. Tumor volume, VI, FI and VFI were not significantly different between benign and malignant tumors before and after echo-contrast medium injection. However, VI, FI and VFI under self-differentiation (differences between with and without contrast injection) were significantly different between malignant and benign tumors. Three-dimensional power Doppler ultrasound is a valuable tool for differential diagnosis of soft-tissue tumors, especially with the injection of an echo-contrast medium. Copyright © 2010 Elsevier. Published by Elsevier B.V. All rights reserved.

Contrast enhancement CT by iopamidol

International Nuclear Information System (INIS)

Mori, Masaki; Makita, Nobue; Yanai, Kyoko

1984-01-01

In order to evaluate the contrast enhancement effect and safety of iopamidol (IOP) in CT examination, IOP was compared with angiographin (AG). In the liver and abdominal aorta, peak CT values were obtained earlier and were higher in the group with AG than in the group with IOP. However, CT values in the group with IOP decreased a little more slowly than those in the group with AG. There was no significant difference in the effect on contrast enhancement between the groups. Intravenous injection of IOP caused lower degree of burning sensation than that of AG, and some of the patients with IOP did not feel burning sensation at all. Changes in clinical laboratory values were slight before and after intravenous injection of IOP. These results suggest that IOP is satisfactory in terms of safety and effect on contrast enhancement in CT examination. (Namekawa, K.)

Contrast-enhanced dynamic MR imaging in rheumatoid arthritis

International Nuclear Information System (INIS)

Koenig, H.; Sieper, J.; Wolf, K.J.

1989-01-01

This paper reports on a study for the identification of different pannus formations. Twenty patients with advanced rheumatoid arthritis of the knee joint were examined with MR imaging primary to surgery. The authors used a 1.5-T Magnetom unit, a circular surface coil for signal detection, 0.1 mmol/kg of Gd-DTPA given as a bolus injection, fast low-angle shot (FLASH) sequence (TR, 30 msec; TE, 10 msec; 128 x 128 matrix; excitation angle, 70 degrees) repeated 30 times within 120 seconds, and a T1-weighted spin-echo sequence (Tr, 500 msec; TE, 22 msec) before and 2 minutes after contrast medium injection. Enhancement of pannus and joint effusion has been measured and standardized to muscle tissue

Utility of gadolinium as a contrast medium in endovascular therapeutic procedures; Utilidad del gadolinio como medio de contraste en procedimientos terapeuticos endovasculares

Energy Technology Data Exchange (ETDEWEB)

Reyes, R.; Pardo, M. D.; Gorriz, E.; Gallardo, L. (Hospital de Gran Canaria Dr. Negrin); Carreira, J. M. (Universidad de Santiago de Compostela)

2001-07-01

To assess the utility of gadolinium associated with CO{sub 2}, as a contrast medium in angiographic studies related to endovascular therapeutic procedures in patients with suboptimal renal function. Between January 2000 and June 2001, endovascular treatments using CO{sub 2} and gadolinium as contrast medium were performed in 10 patients presenting renal function deterioration (creatinine>1.5 mg/ml). A mean dose of 42 ml of gadolinium was administered. The images acquired in diagnostic and therapeutic studied were satisfactory in every case. There was no evidence of significant increases in the previous urea and creatine levels when measured 24, 48 and 72 hours after the procedure. In combination with CO{sub 2} gadolinium is a useful contrast medium for endovascular therapeutic procedures in patients with suboptimal renal function. (Author) 21 refs.

Field strength and dose dependence of contrast enhancement by gadolinium-based MR contrast agents

International Nuclear Information System (INIS)

Rinck, P.A.; Muller, R.N.

1999-01-01

The relaxivities r 1 and r 2 of magnetic resonance contrast agents and the T 1 relaxation time values of tissues are strongly field dependent. We present quantitative data and simulations of different gadolinium-based extracellular fluid contrast agents and the modulation of their contrast enhancement by the magnetic field to be able to answer the following questions: How are the dose and field dependences of their contrast enhancement? Is there an interrelationship between dose and field dependence? Should one increase or decrease doses at specific fields? Nuclear magnetic relaxation dispersion data were acquired for the following contrast agents: gadopentetate dimeglumine, gadoterate meglumine, gadodiamide injection, and gadoteridol injection, as well as for several normal and pathological human tissue samples. The magnetic field range stretched from 0.0002 to 4.7 T, including the entire clinical imaging range. The data acquired were then fitted with the appropriate theoretical models. The combination of the diamagnetic relaxation rates (R 1 = 1/T 1 and R 2 = 1/T 2 ) of tissues with the respective paramagnetic contributions of the contrast agents allowed the prediction of image contrast at any magnetic field. The results revealed a nearly identical field and dose-dependent increase of contrast enhancement induced by these contrast agents within a certain dose range. The target tissue concentration (TTC) was an important though nonlinear factor for enhancement. The currently recommended dose of 0.1 mmol/kg body weight seems to be a compromise close to the lower limits of diagnostically sufficient contrast enhancement for clinical imaging at all field strengths. At low field contrast enhancement might be insufficient. Adjustment of dose or concentration, or a new class of contrast agents with optimized relaxivity, would be a valuable contribution to a better diagnostic yield of contrast enhancement at all fields. (orig.)

Effect of different saline chaser volumes and flow rates on intravascular contrast enhancement in CT using a circulation phantom

International Nuclear Information System (INIS)

Behrendt, Florian F.; Bruners, Philipp; Keil, Sebastian; Plumhans, Cedric; Mahnken, Andreas H.; Das, Marco; Ackermann, Diana; Guenther, Rolf W.; Muehlenbruch, Georg

2010-01-01

Purpose: To evaluate the influence of different saline chaser volumes and different saline chaser flow rates on the intravascular contrast enhancement in MDCT. Materials and methods: In a physiological flow phantom contrast medium (120 ml, 300 mgI/ml, Ultravist 300) was administered at a flow rate of 6 ml/s followed by different saline chaser volumes (0, 30, 60 and 90 ml) at the same injection rate or followed by a 30-ml saline chaser at different injection rates (2, 4, 6 and 8 ml/s). Serial CT-scans at a level covering the pulmonary artery, the ascending and the descending aorta replica were obtained. Time-enhancement curves were computed and both pulmonary and aortic peak enhancement and peak time were determined. Results: Compared to contrast medium injection without a saline chaser the pushing with a saline chaser (30, 60, and 90 ml) resulted in a statistically significant increased pulmonary peak enhancement (all p = 0.008) and prolonged peak time (p = 0.032, p = 0.024 and p = 0.008, respectively). Highest aortic peak enhancement values were detected for a saline chaser volume of 30 ml. A saline chaser flow rate of 8 ml/s resulted in the highest pulmonary peak enhancement values compared to flow rates of 2, 4 and 6 ml/s (all p = 0.008). Aortic peak enhancement showed the highest values for a flow rate of 6 ml/s. Conclusion: A saline chaser volume of 30 ml and an injection rate of 6 ml/s are sufficient to best improve vascular contrast enhancement in the pulmonary artery and the aorta in MDCT.

Aspiration of barium contrast medium in an elderly man with disordered swallowing

OpenAIRE

Bağcı Ceyhan, B.; Çelikel, T.; Koç, M.; Ahıskalı, R.; Biren, T.; Ataizi Çelikel, Ç.

1995-01-01

The aspiration of contrast medium during the investigation of gastrointestinal diseases is a well recognized hazard, particularly in patients with swallowing disorders. A case is reported in which accidental aspiration of contrast barium occurred owing to disordered swallowing in an elderly man. The infiltration on chest x-ray persisted 2 years after barium contrast aspiration. Inflammatory reaction and retractile, granular material observed in lung biopsy specimens suggested barium-induced p...

Extravasation of contrast medium into the gastrointestinal tract following lymphangiography

International Nuclear Information System (INIS)

Mihara, K.; Koga, K.; Tsurudome, H.; Nakano, T.; Hoshi, H.; Yamada, H.; Kawahira, K.; Inakura, M.; Watanabe, K.; Haraguchi, Y.

1981-01-01

Two cases with roentgenologic findings of extravasation of contrast medium into the stomach and colon following lymphangiography are presented. One is clinically diagnosed as primary intestinal lymphangiectasia; the other as retroperitoneal spread from uterine cancer. The significance of lymphangiography in gastrointestinal or retroperitoneal disorders is discussed. (orig.)

Extravasation of contrast medium into the gastrointestinal tract following lymphangiography

Energy Technology Data Exchange (ETDEWEB)

Mihara, K.; Koga, K.; Tsurudome, H.; Nakano, T.; Hoshi, H.; Yamada, H.; Kawahira, K.; Inakura, M.; Watanabe, K.; Haraguchi, Y.

1981-07-15

Two cases with roentgenologic findings of extravasation of contrast medium into the stomach and colon following lymphangiography are presented. One is clinically diagnosed as primary intestinal lymphangiectasia; the other as retroperitoneal spread from uterine cancer. The significance of lymphangiography in gastrointestinal or retroperitoneal disorders is discussed.

Angiogenesis and dynamic contrast enhanced MRI of benign and malignant breast lesions: preliminary results

International Nuclear Information System (INIS)

Liu Peifang; Bao Runxian; Niu Yun; Yu Yong

2002-01-01

amplitude and MVD or VEGF expression. Regarding the distribution of MVD, the study showed that the greater MVD was most frequently observed at the marginal region of breast cancer, although the distribution of MVD was heterogeneous in each lesion. Conclusion: MVD and VEGF affect the contrast medium enhancement of breast lesions. The early phase enhancement rate and time-SI curve types of benign and malignant breast lesions are closely related to MVD and VEGF. As a noninvasive method, contrast enhanced MRI has a potential role in estimating the degree of angiogenesis of breast neoplasm

Local recurrence of rectal cancer: MR imaging before and after oral superparamagnetic particles vs contrast-enhanced computed tomography

International Nuclear Information System (INIS)

Blomqvist, L.; Ohlsen, H.; Holm, T.

2000-01-01

The aim of this study was to compare three imaging strategies for the diagnosis of local recurrence of rectal cancer: (a) MR imaging; (b) MR imaging after administration of enteral superparamagnetic particles (Ferristene); and (c) contrast-enhanced CT. Seventeen patients with previous surgery for rectal cancer were examined, 12 patients with local tumour recurrence in the pelvis and 5 patients with postoperative changes. Pelvic multi-coil MR imaging before and after oral administration of superparamagnetic contrast medium [Abdoscan (Ferristene USAN), Nycomed-Amersham, Lidingoe, Sweden] as well as abdominal and pelvic CT was performed in all patients. The examinations were independently evaluated by three different radiologists. The general effect of the oral MR contrast medium, the delineation of normal and pathological structures as well as confidence in the diagnosis were registered on a visual analog scale (VAS). The diagnosis according to MR before and after oral contrast medium, and CT, was compared, in 16 patients, with the final diagnosis which was verified by biopsy (n = 3), surgery (n = 6), clinical follow-up (n = 4) and by follow-up with MR or CT (n = 3). No significant improvement in MR image quality was found after enteral contrast medium. The post-contrast MR diagnosis was not changed in any of the patients. The diagnosis on MR correlated with the final diagnosis in 12 of 16 patients (sensitivity 91 %, accuracy 62 %) and the diagnosis on CT in 11 of 16 patients (sensitivity 82 %, accuracy 56 %). The radiologists' ''confidence'' in the diagnosis and the degree of accordance with the final diagnosis did not score higher on MR after than before oral contrast administration; however, the accordance with the final diagnosis scored better on MR than on CT. No advantages of orally administered superparamagnetic contrast medium were observed in the examined patient group. Magnetic resonance is preferable to CT in diagnosing local tumour recurrence. (orig.)

Evaluation of the minimum iodine concentration for contrast-enhanced subtraction mammography

International Nuclear Information System (INIS)

Baldelli, P; Bravin, A; Maggio, C Di; Gennaro, G; Sarnelli, A; Taibi, A; Gambaccini, M

2006-01-01

Early manifestation of breast cancer is often very subtle and is displayed in a complex and variable pattern of normal anatomy that may obscure the disease. The use of dual-energy techniques, that can remove the structural noise, and contrast media, that enhance the region surrounding the tumour, could help us to improve the detectability of the lesions. The aim of this work is to investigate the use of an iodine-based contrast medium in mammography with two different double exposure techniques: K-edge subtraction mammography and temporal subtraction mammography. Both techniques have been investigated by using an ideal source, like monochromatic beams produced at a synchrotron radiation facility and a clinical digital mammography system. A dedicated three-component phantom containing cavities filled with different iodine concentrations has been developed and used for measurements. For each technique, information about the minimum iodine concentration, which provides a significant enhancement of the detectability of the pathology by minimizing the risk due to high dose and high concentration of contrast medium, has been obtained. In particular, for cavities of 5 and 8 mm in diameter filled with iodine solutions, the minimum concentration needed to obtain a contrast-to-noise ratio of 5 with a mean glandular dose of 2 mGy has been calculated. The minimum concentrations estimated with monochromatic beams and K-edge subtraction mammography are 0.9 mg ml -1 and 1.34 mg ml -1 for the biggest and smallest details, respectively, while for temporal subtraction mammography they are 0.84 mg ml -1 and 1.31 mg ml -1 . With the conventional clinical system the minimum concentrations for the K-edge subtraction mammography are 4.13 mg ml -1 (8 mm diameter) and 5.75 mg ml -1 (5 mm diameter), while for the temporal subtraction mammography they are 1.01 mg ml -1 (8 mm diameter) and 1.57 mg ml -1 (5 mm diameter)

How to reduce nephropathy following contrast-enhanced CT: A lesson in policy implementation

International Nuclear Information System (INIS)

Richenberg, J.

2012-01-01

In excess of 50 contrast-enhanced computed tomography (CT) examinations are typically undertaken in our tertiary hospital NHS Trust each weekday, approximately 13,000 each year. In the Department of Radiology alone, we inject more than 1300 l of iodinated contrast medium per annum. There is a real need to devise a policy to anticipate contrast medium-induced nephropathy (CIN) and minimize its effects, without disrupting the high-intensity CT service. Having written a comprehensive yet pragmatic policy to reduce the incidence of this iatrogenic condition, it seemed sensible to share it with the wider radiology community and share the experience and lessons learnt in engaging all the stakeholders, ushering in the change with as little fuss as possible. The ramifications on primary and secondary care had to be anticipated, resource implications managed, and staff trained. This review is therefore presented in four sections: framing the problem, assessing its size and nature; a succeeding section on the available guidelines and their uptake; the policy itself to reduce CIN in CT is presented in the third section; and crucially, a description of the policy introduction process in the last section.

Can contrast-enhanced ultrasonography improve Zone III REBOA placement for prehospital care?

Science.gov (United States)

Chaudery, Muzzafer; Clark, James; Morrison, Jonathan J; Wilson, Mark H; Bew, Duncan; Darzi, Ara

2016-01-01

Torso hemorrhage is the primary cause of potentially preventable mortality in trauma. Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been advocated as an adjunct to bridge patients to definitive hemorrhage control. The primary aim of this study was to assess whether contrast-enhanced ultrasonography can improve the accuracy of REBOA placement in the infrarenal aorta (Zone III). A fluoroscopy-free "enhanced" Zone III REBOA technique was developed using a porcine cadaver model. A "standard" over-the-wire Seldinger technique was used, which was enhanced with the addition of a microbubble contrast medium to inflate the balloon, observed with ultrasonography. Following this, attending- and resident-level physicians were randomized into two groups. They were taught either the enhanced with ultrasonography guidance (Group A) or the standard measuring length of catheter insertion (Group B) technique as part of a human cadaver trauma skills course. Outcomes assessed included time (seconds) from insertion to inflation, accuracy, and missed targets. All results were benchmarked against three endovascular experts. There were 20 participants who performed REBOA with Group A (51 [31]) being significantly faster than Group B (90 [63]) (p = 0.003) and more accurate (p = 0.023) with no missed targets. Group B had five missed targets, the most common error being inflation within Zone II. For Zone III REBOA, contrast-enhanced ultrasonography technique is faster and more accurate than the standard technique. This may have value in time-critical and austere environments. Clinical studies are now required to evaluate this approach further.

Contrast-enhanced endoscopic ultrasonography

DEFF Research Database (Denmark)

Reddy, Nischita K; Ioncică, Ana Maria; Săftoiu, Adrian

2011-01-01

Contrast agents are increasingly being used to characterize the vasculature in an organ of interest, to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures. We review the mechanisms of action of first, second and third generation contrast...... agents and their use in various endoscopic procedures in the gastrointestinal tract. Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy, assessment of depth of invasion of esophageal, gastric and gall bladder...... cancers and visualization of the portal venous system and esophageal varices. In addition, contrast agents can be used to differentiate pancreatic lesions. The use of color Doppler further increases the ability to diagnose and differentiate various pancreatic malignancies. The sensitivity of power Doppler...

Radiologic diagnosis of gastro-oesophageal reflux. Comparison of barium and low-density contrast medium

Energy Technology Data Exchange (ETDEWEB)

Fransson, S.G.; Soekjer, H.; Johansson, K.E.; Tibbling, L.

It has been proposed that the high density of ordinary barium suspension may complicate the radiologic diagnosis of gastro-oesophageal reflux. For this reason P-contrast was developed (Ferring AB); a contrast medium with the same density as water (1 g/cm/sup 3/). A comparison of P-contrast and barium (Mixobar Ventrikel 400 mg/ml) was performed in 82 patients. All patients were examined with both contrast media and the findings were compared with those at reflux test at manometry, endoscopy and 24-hour pH monitoring. Another 40 patients and 15 symptom-free controls were examined with two different amounts of barium, 100 ml and 200 ml, to study if the radiologic diagnosis of reflux varied with the volume of contrast medium administered. P-contrast was found to have no advantages over barium for the diagnosis of gastro-oesophageal reflux. The outcome of the radiologic examination was not influenced by the different volumes of barium used.

Evaluation of the acute adverse reaction of contrast medium with high and moderate iodine concentration in patients undergoing computed tomography

International Nuclear Information System (INIS)

Nagamoto, Masashi; Gomi, Tatsuya; Terada, Hitoshi; Terada, Shigehiko; Kohda, Eiichi

2006-01-01

The aim of this prospective study was to evaluate and compare acute adverse reactions between contrast medium containing moderate and high concentrations of iodine in patients undergoing computed tomography (CT). A total of 945 patients undergoing enhanced CT were randomly assigned to receive one of two doses of contrast medium. We then prospectively investigated the incidence of adverse reactions. Iopamidol was used as the contrast medium, with a high concentration of 370 mgI/ml and a moderate concentration of 300 mgI/ml. The frequency of adverse reactions, such as pain at the injection site and heat sensation, were determined. Acute adverse reactions were observed in 2.4% (11/458) of the moderate-concentration group compared to 3.11% (15/482) of the high-concentration group; there was no significant difference in incidence between the two groups. Most adverse reactions were mild, and there was no significant difference in severity. One patient in the high-concentration group was seen to have a moderate adverse reaction. No correlation existed between the incidence of adverse reactions and patient characteristics such as sex, age, weight, flow amount, and flow rate. The incidence of pain was not significantly different between the two groups. In contrast, the incidence of heat sensation was significantly higher in the high-concentration group. The incidence and severity of acute adverse reactions were not significantly different between the two groups, and there were no severe adverse reactions in either group. (author)

The forgotten organ: Contrast enhanced sonography of the spleen

International Nuclear Information System (INIS)

Goerg, Christian

2007-01-01

Objective: Ultrasound contrast agents in conjunction with contrast specific imaging techniques, are increasingly accepted in clinical use for diagnostic imaging in several organs. Contrast enhanced sonography (CES) of second-generation contrast media have shown a spleen-specific uptake of the microbubble contrast agent. The aim of this review is to illustrate indications for the use of CES in patients with suspected (peri-)splenic pathology. Methods: This review based on the experience of transcutaneous CES in 200 patients with (peri-)splenic pathology diagnosed by B-mode sonography at an internal medicine center. CES studies were performed with a contrast-devoted unit (Acuson, Sequoia, Siemens medical solution) that had contrast-specific, continuous-mode software. A low mechanical index was used. A sulfur hexafluoride-based microbubble contrast medium (Sonovue, Bracco SpA, Milan, Italy) was injected. Results: On our experience, there are several clinical conditions which may show an diagnostic advantage of CES in comparison to B-mode US. CES should be performed to investigate: (1) the perisplenic tumor to diagnose or exclude accessory spleen, (2) the small-sized spleen to diagnose functional asplenia/hyposplenia, (3) the inhomogenous spleen of unknown cause to diagnose focal lesions within the spleen, (4) the incidentally found hypoechoic splenic tumor to diagnose high vascular splenic hemangioma, (5) focal lesions suspect for splenic abscess, hematoma, infarction to confirme diagnosis, and (6) patients with abdominal trauma to diagnose or exclude splenic injuriy. Conclusion: CES is of diagnostic value in several clinical circumstances to diagnose accessory spleen, functional asplenia, small-sized splenic involvement, high vascular splenic hemangioma, and vascular splenic pathology like splenic infarction, splenic abscess, and splenic laceration

The forgotten organ: Contrast enhanced sonography of the spleen

Energy Technology Data Exchange (ETDEWEB)

Goerg, Christian [Medizinische Universitaetsklinik, Baldingerstrasse, 35043 Marburg/Lahn (Germany)], E-mail: goergc@med.uni-marburg.de

2007-11-15

Objective: Ultrasound contrast agents in conjunction with contrast specific imaging techniques, are increasingly accepted in clinical use for diagnostic imaging in several organs. Contrast enhanced sonography (CES) of second-generation contrast media have shown a spleen-specific uptake of the microbubble contrast agent. The aim of this review is to illustrate indications for the use of CES in patients with suspected (peri-)splenic pathology. Methods: This review based on the experience of transcutaneous CES in 200 patients with (peri-)splenic pathology diagnosed by B-mode sonography at an internal medicine center. CES studies were performed with a contrast-devoted unit (Acuson, Sequoia, Siemens medical solution) that had contrast-specific, continuous-mode software. A low mechanical index was used. A sulfur hexafluoride-based microbubble contrast medium (Sonovue, Bracco SpA, Milan, Italy) was injected. Results: On our experience, there are several clinical conditions which may show an diagnostic advantage of CES in comparison to B-mode US. CES should be performed to investigate: (1) the perisplenic tumor to diagnose or exclude accessory spleen, (2) the small-sized spleen to diagnose functional asplenia/hyposplenia, (3) the inhomogenous spleen of unknown cause to diagnose focal lesions within the spleen, (4) the incidentally found hypoechoic splenic tumor to diagnose high vascular splenic hemangioma, (5) focal lesions suspect for splenic abscess, hematoma, infarction to confirme diagnosis, and (6) patients with abdominal trauma to diagnose or exclude splenic injuriy. Conclusion: CES is of diagnostic value in several clinical circumstances to diagnose accessory spleen, functional asplenia, small-sized splenic involvement, high vascular splenic hemangioma, and vascular splenic pathology like splenic infarction, splenic abscess, and splenic laceration.

Visual Contrast Enhancement Algorithm Based on Histogram Equalization

Science.gov (United States)

Ting, Chih-Chung; Wu, Bing-Fei; Chung, Meng-Liang; Chiu, Chung-Cheng; Wu, Ya-Ching

2015-01-01

Image enhancement techniques primarily improve the contrast of an image to lend it a better appearance. One of the popular enhancement methods is histogram equalization (HE) because of its simplicity and effectiveness. However, it is rarely applied to consumer electronics products because it can cause excessive contrast enhancement and feature loss problems. These problems make the images processed by HE look unnatural and introduce unwanted artifacts in them. In this study, a visual contrast enhancement algorithm (VCEA) based on HE is proposed. VCEA considers the requirements of the human visual perception in order to address the drawbacks of HE. It effectively solves the excessive contrast enhancement problem by adjusting the spaces between two adjacent gray values of the HE histogram. In addition, VCEA reduces the effects of the feature loss problem by using the obtained spaces. Furthermore, VCEA enhances the detailed textures of an image to generate an enhanced image with better visual quality. Experimental results show that images obtained by applying VCEA have higher contrast and are more suited to human visual perception than those processed by HE and other HE-based methods. PMID:26184219

Visual Contrast Enhancement Algorithm Based on Histogram Equalization

Directory of Open Access Journals (Sweden)

Chih-Chung Ting

2015-07-01

Full Text Available Image enhancement techniques primarily improve the contrast of an image to lend it a better appearance. One of the popular enhancement methods is histogram equalization (HE because of its simplicity and effectiveness. However, it is rarely applied to consumer electronics products because it can cause excessive contrast enhancement and feature loss problems. These problems make the images processed by HE look unnatural and introduce unwanted artifacts in them. In this study, a visual contrast enhancement algorithm (VCEA based on HE is proposed. VCEA considers the requirements of the human visual perception in order to address the drawbacks of HE. It effectively solves the excessive contrast enhancement problem by adjusting the spaces between two adjacent gray values of the HE histogram. In addition, VCEA reduces the effects of the feature loss problem by using the obtained spaces. Furthermore, VCEA enhances the detailed textures of an image to generate an enhanced image with better visual quality. Experimental results show that images obtained by applying VCEA have higher contrast and are more suited to human visual perception than those processed by HE and other HE-based methods.

Gadolinium-DTPA (Magnevist) as a contrast medium for arterial DSA

International Nuclear Information System (INIS)

Schild, H.H.; Weber, W.; Boeck, E.; Mildenberger, P.; Strunk, H.; Dueber, C.; Grebe, P.; Schadmand-Fischer, S.; Thelen, M.

1994-01-01

16 DSA investigations using intra-arterial Gd-DTPA were performed on 12 patients. The contrast medium was administered either as a 0.5 molar gadolinium solution (commercially available) or diluted with distilled water to a 0.2 -0.4 molar gadolinium solution. The injection was made either by pressure injector or by hand. The aortic arch, abdominal aorta and pelvic and lower limb arteries were examined. 14 of the 16 procedures were diagnostically adequate, but compared with iodinated contrast materials, contrast was less marked. There were no cardiovascular, neurological or allergic side effects. Three patients suffered a feeling of heat and one patient had mild pain during the injection. Even large volumes rapidly injected (up to 20 ml/s of the commercially available solution) were well tolerated. DSA with intra-arterial Gd-DTPA seems to be a suitable alternative for vascular imaging if iodine-containing contrast materials are contraindicated. (orig.) [de

Contrast media on abdominal computed tomography

International Nuclear Information System (INIS)

Skalpe, I.O.; Oestensen, H.M.

1984-01-01

Abdominal computed tomography was performed in 55 patients before and after intravenous injection of 60 ml of a non-ionic (iohexol) or an ionic (metrizoate) contrast medium. The adverse effects were recorded and a series of measurements of attenuation values before and after the contrast medium injection was performed in the aorta and in hepatic and renal parenchyma. Only minor adverse effects were seen with both contrast media, but iohexol was clearly better tolerated than metrizoate. No difference in the enhancement properties was found between the two contrast media. (orig.)

FDG-PET/contrast-enhanced CT as a post-treatment tool in head and neck squamous cell carcinoma: comparison with FDG-PET/non-contrast-enhanced CT and contrast-enhanced CT

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Suenaga, Yuko; Kitajima, Kazuhiro; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Ishihara, Takeaki; Sasaki, Ryohei [Kobe University Graduate, School of Medicine, Department of Radiology, Division of Radiation Oncology, Kobe (Japan); Otsuki, Naoki; Nibu, Ken-ichi [Kobe University Graduate, School of Medicine, Department of Otolaryngology-Head and Neck Surgery, Kobe (Japan); Minamikawa, Tsutomu [Kobe University Graduate School of Medicine, Department of Oral and Maxillofacial Surgery, Kobe (Japan); Kiyota, Naomi [Kobe University Hospital, Department of Medical Oncology and Hematology, Kobe (Japan)

2016-04-15

To evaluate the accuracy of PET/CT using {sup 18}F-fluorodeoxyglucose (FDG) with IV contrast for suspected recurrent head and neck squamous cell carcinoma (HNSCC). One hundred and seventy patients previously treated for HNSCC underwent PET/CT, consisting of non-contrast-enhanced and contrast-enhanced CT, to investigate suspected recurrence. Diagnostic performance of PET/contrast-enhanced CT (PET/ceCT), PET/non-contrast-enhanced CT (PET/ncCT) and contrast-enhanced CT (ceCT) for local or regional recurrence, distant metastasis, overall recurrence and second primary cancer was evaluated. The reference standard included histopathology, treatment change and imaging follow-up. The patient-based areas under the receiver operating characteristic curves (AUC) for ceCT, PET/ncCT and PET/ceCT were 0.82, 0.96 and 0.98 for local recurrence, 0.73, 0.86 and 0.86 for regional recurrence, 0.86, 0.91 and 0.92 for distant metastasis, 0.72, 0.86 and 0.87 for overall recurrence, and 0.86, 0.89 and 0.91 for a second primary cancer. Both PET/ceCT and PET/ncCT statistically showed larger AUC than ceCT for recurrence, and the difference between PET/ceCT and PET/ncCT for local recurrence reached a significant level (p = 0.039). The accuracy of PET/ceCT for diagnosing overall recurrence was high, irrespective of the time interval after the last treatment (83.3-94.1 %). FDG-PET/CT was a more accurate HNSCC restaging tool than ceCT. The added value of ceCT at FDG-PET/CT is minimal. (orig.)

Human pharmacokinetics of iohexol. A new nonionic contrast medium

International Nuclear Information System (INIS)

Olsson, B.; Aulie, A.; Sveen, K.; Andrew, E.

1983-01-01

The pharmacokinetics of iohexol, a new nonionic, water-soluble contrast medium, have been determined after intravenous injection in 20 healthy volunteers, at four different dose levels (125-500 mg I/kg). The apparent volume of distribution was 0.27 1/kg, indicating distribution in the extracellular water. The biologic half-life was 121 minutes, comparable with that of other intravascular contrast media. Iohexol was excreted completely unmetabolized in the urine, with a 100% recovery 24 hours after injection. A comparison of iohexol and chromium-51 ( 51 Cr)-EDTA clearances indicates that iohexol is mainly excreted by glomerular filtration. The 51 Cr-EDTA clearance was the same when injected separately and concomitantly with iohexol, indicating that glomerular filtration rate is not affected by iohexol. No dose dependency was observed in the investigated parameters t1/2 alpha, t1/2 beta, Vd, ClT or ClR. Iohexol pharmacokinetics are in correspondence with previously reported data on intravascular contrast media

Diagnostic capabilities of the contrast medium verografin in liposomes (animal experiments)

International Nuclear Information System (INIS)

Rozenberg, O.A.; Khason, K.P.; Aliyakparov, M.T.; Davidenkova, E.F.; Zherbin, E.A.; Akademiya Meditsinskikh Nauk SSSR, Leningrad. Inst. Ehksperimental'noj Meditsiny)

1985-01-01

Some examples for the diagnosis of various diseases of liver and spleen after intravenous (cats, dogs) or intraportal (rodents) injection of lecithin-cholesterol liposomes containing the water soluble contrast medium verografin are described. Tumors of 1 mm were found in the spleen of mice with lymphogranulomatosis, hepatomas of 3-5 mm in rats and lesions of 10 mm in cats with turpentine abscesses. The application of liposomes containing radiographic contrast media offers good possibilities for the diagnosis of liver and spleen. (author)

A Novel Contrast Enhancement Technique on Palm Bone Images

Directory of Open Access Journals (Sweden)

Yung-Tsang Chang

2014-09-01

Full Text Available Contrast enhancement plays a fundamental role in image processing. Many histogram-based techniques are widely used for contrast enhancement of given images, due to their simple function and effectiveness. However, the conventional histogram equalization (HE methods result in excessive contrast enhancement, which causes natural looking and satisfactory results for a variety of low contrast images. To solve such problems, a novel multi-histogram equalization technique is proposed to enhance the contrast of the palm bone X-ray radiographs in this paper. For images, the mean-variance analysis method is employed to partition the histogram of the original grey scale image into multiple sub-histograms. These histograms are independently equalized. By using this mean-variance partition method, a proposed multi-histogram equalization technique is employed to achieve the contrast enhancement of the palm bone X-ray radiographs. Experimental results show that the multi-histogram equalization technique achieves a lower average absolute mean brightness error (AMBE value. The multi-histogram equalization technique simultaneously preserved the mean brightness and enhanced the local contrast of the original image.

Dual-energy contrast-enhanced mammography.

Science.gov (United States)

Travieso Aja, M M; Rodríguez Rodríguez, M; Alayón Hernández, S; Vega Benítez, V; Luzardo, O P

2014-01-01

The degree of vascularization in breast lesions is related to their malignancy. For this reason, functional diagnostic imaging techniques have become important in recent years. Dual-energy contrast-enhanced mammography is a new, apparently promising technique in breast cancer that provides information about the degree of vascularization of the lesion in addition to the morphological information provided by conventional mammography. This article describes the state of the art for dual-energy contrast-enhanced mammography. Based on 15 months' clinical experience, we illustrate this review with clinical cases that allow us to discuss the advantages and limitations of this technique. Copyright © 2014 SERAM. Published by Elsevier Espana. All rights reserved.

CT angiography. Abdominal CT using intravenous aortography for contrast enhancement

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Nagai, J; Nakauma, Y; Egawa, J; Kawamura, M [Teikyo Univ., Tokyo (Japan). Faculty of Medicine

1980-04-01

To obtain imaging effects close to those of abdominal aortography and investigate a technique with little invasion to patients, intravenous aortography was applied to contrast enhancement (CE) in abdominal CT, and its usefulness was discussed. Intravenous aortography could clearly visualize lesions with rich neovascularity such as hepatocellular carcinoma and renal cell carcinoma. Differing from a drip infusion method, this method has complexities in its technique that contrast medium is injected at once, blood circulation time which is represented by the time between the injection and the time when the patients feel bitterness (10 - 12 seconds) must be measured before CE, and scanning begins 2 seconds before the patients feel bitterness. However, the invasion to patients due to this method is slight, and the capacity of this method to visualize neovascularity is superior to CE by a drip infusion method. Therefore, qualitative diagnosis by CT will be improved by using this method together with a drip infusion method.

Dual-energy contrast-enhanced spectral mammography (CESM).

Science.gov (United States)

Daniaux, Martin; De Zordo, Tobias; Santner, Wolfram; Amort, Birgit; Koppelstätter, Florian; Jaschke, Werner; Dromain, Clarisse; Oberaigner, Willi; Hubalek, Michael; Marth, Christian

2015-10-01

Dual-energy contrast-enhanced mammography is one of the latest developments in breast care. Imaging with contrast agents in breast cancer was already known from previous magnetic resonance imaging and computed tomography studies. However, high costs, limited availability-or high radiation dose-led to the development of contrast-enhanced spectral mammography (CESM). We reviewed the current literature, present our experience, discuss the advantages and drawbacks of CESM and look at the future of this innovative technique.

Morphological rational operator for contrast enhancement.

Science.gov (United States)

Peregrina-Barreto, Hayde; Herrera-Navarro, Ana M; Morales-Hernández, Luis A; Terol-Villalobos, Iván R

2011-03-01

Contrast enhancement is an important task in image processing that is commonly used as a preprocessing step to improve the images for other tasks such as segmentation. However, some methods for contrast improvement that work well in low-contrast regions affect good contrast regions as well. This occurs due to the fact that some elements may vanish. A method focused on images with different luminance conditions is introduced in the present work. The proposed method is based on morphological transformations by reconstruction and rational operations, which, altogether, allow a more accurate contrast enhancement resulting in regions that are in harmony with their environment. Furthermore, due to the properties of these morphological transformations, the creation of new elements on the image is avoided. The processing is carried out on luminance values in the u'v'Y color space, which avoids the creation of new colors. As a result of the previous considerations, the proposed method keeps the natural color appearance of the image.

The Future of Contrast-Enhanced Mammography.

Science.gov (United States)

Covington, Matthew F; Pizzitola, Victor J; Lorans, Roxanne; Pockaj, Barbara A; Northfelt, Donald W; Appleton, Catherine M; Patel, Bhavika K

2018-02-01

The purpose of this article is to discuss facilitators of and barriers to future implementation of contrast-enhanced mammography (CEM) in the United States. CEM provides low-energy 2D mammographic images analogous to digital mammography and contrast-enhanced recombined images that allow assessment of neovascularity similar to that offered by MRI. The utilization of CEM in the United States is currently low but could increase rapidly given the many potential indications for its clinical use.

The association between use of metformin and change in serum CO_2 level after administration of contrast medium

International Nuclear Information System (INIS)

Kim, S.K.; Jung, J.; Jung, J.H.; Kim, K.Y.; Baek, J.-H.; Hahm, J.R.

2016-01-01

Aim: To evaluate the changes in serum creatinine and total CO_2 levels in patients receiving metformin during administration of contrast medium. Materials and methods: Patient records from January 2012 to December 2012 after the administration of contrast medium were reviewed retrospectively. A total of 924 patients were included for the final analysis. Of them, 105 received metformin during contrast medium administration, 112 were taking other oral hypoglycaemic agents, and 707 patients were not diabetic (controls). Results: No significant change in total CO_2 levels was detected (p=0.678). Metabolic acidosis was present in 33 (31.4%) metformin users, 31 (28.6%) other oral hypoglycaemic agent users, and 153 (21.6%) control patients. In the present logistic regression analysis, age, baseline levels of creatinine, and total CO_2 levels were associated with metabolic acidosis after contrast medium exposure. Conclusion: These data indicate the presence of a coexisting risk factor, other than metformin use, associated with metabolic acidosis after contrast medium exposure. No relationship was found between the use of metformin and metabolic acidosis during contrast medium exposure. - Highlights: • The use of metformin was not associated with metabolic acidosis after contrast exposure. • The coexisting risk factors for metabolic acidosis were present in patient with metabolic acidosis after contrast exposure. • There is a need to consider the maintenance of metformin during a CT scan in patients with a low risk for lactic acidosis.

Contrast-enhanced power Doppler US of hepatocellular carcinomas: Quantitative analysis

International Nuclear Information System (INIS)

Kim, Ah Young; Choi, Byung Ihn; Kim, Tae Kyoung; Lee, Kyoung Ho; Han, Joon Koo

1999-01-01

To determine peak time and duration of contrast enhancement of nodular hepatocellular carcinoma (HCC) on contrast-enhancement power Doppler ultrasound (US) with Levovist by quantitative analysis. Twenty eight patients with nodular HCC were prospectively evaluated with power Doppler US by one examiner. Serial images were obtained before and after injection of 300 mg/mL US contrast agent (SH U 508 A, Levovist, Schering) with the injection rate of 0.2 mL/sec. Power Doppler signals on obtained digital images were quantified using 'Ultrasound Imaging Tool Version 1.0' (Seoul, Korea). The grade, peak time and duration of contrast enhancement of the tumors were analyzed. For nodular HCCs, mean peak enhancement time was 60 seconds after injection of Levovist (mean enhanced area 41.6 ± 28.6 %). These tumoral enhancement decreased from 90 seconds and returned to near baseline state at 5 minutes after injection of Levovist. Maximum enhanced areas (%) were variable at a range of 8-98.5% and mean maximum enhanced area was 46.4 ± 28.6%. On contrast-enhanced power Doppler US with Levovist, nodular HCCs showed peak contrast enhancement (41.6± 28.6) at 60 seconds after injection of contrast agent. This tumoral enhancement nearly disappeared at 5 minutes after injection of contrast agent.

GE-145, a new low-osmolar dimeric radiographic contrast medium

International Nuclear Information System (INIS)

Wistrand, Lars-G.; Rogstad, Astri; Hagelin, Gunnar

2010-01-01

Background: Contrast-induced nephrotoxicity is a significant risk when using radiographic contrast media clinically, especially in high risk patients. Consequently, there is a need for a new contrast agent with improved clinical safety with regards to nephrotoxicity. Purpose: To evaluate the physicochemical properties as well as the preclinical safety and biodistribution parameters of the newly developed radiographic contrast medium GE-145. Material and Methods: Standard methods for radiographic contrast media were used for evaluation of physicochemical properties. The acute toxicity in rats was studied at 8, 10, and 12.5 gI/kg, the clinical chemistry parameters were determined, and histology of the kidneys was performed. Biodistribution was studied in rats using 123 I-labeled GE-145. Results: GE-145 is more hydrophilic than iodixanol and has a considerably lower osmolality. The viscosity is similar to that of iodixanol and the protein binding is low. The acute toxicity is similar to that of iodixanol and the biodistribution is similar to that of other radiographic contrast media, showing mainly renal excretion. Kidney histology showed a moderate reversible vacuolization, similar to that of iodixanol. Conclusion: GE-145 exhibits similar preclinical properties to other dimeric radiographic contrast media. In addition, the low osmolality enables an iso-osmolar formulation containing a significantly higher concentration of electrolytes than Visipaque

Contrast-enhanced computed tomography of the primary tumor in muscle invasive carcinoma of the urinary bladder

International Nuclear Information System (INIS)

Sager, E.M.

1991-01-01

Patients with muscle invasive carcinoma of the urinary bladder were examined with contrast-enhanced CT of the primary tumor. A specially designed technique was developed to increase the diagnostic potential of CT. The most important points about the technique were controlled filling of the bladder, the use of thin slices, series of scans before and after intravenous injection of contrast medium, and long scanning times in the precontrast series. The absorbed dose to the patient resulting from the new technique was found to be within the range of the dose from urography or barium enema. This dose was considered to be acceptable given the diagnostic gain of the procedure. Features of irradiated bladder tumors were analysed to find which parameter correlated with persistent malignancy. High contrast enhancement of a tumor relative to the bladder wall was found to be the best indicator of a malignant tumour after irradiation. 127 refs

Bladder transitional cell carcinoma: correlation of contrast enhancement on computed tomography with histological grade and tumour angiogenesis

International Nuclear Information System (INIS)

Xie, Q.; Zhang, J.; Wu, P.-H.; Jiang, X.-Q.; Chen, S.-L.; Wang, Q.-L.; Xu, J.; Chen, G.-D.; Deng, J.-H.

2005-01-01

AIM: To investigate the correlation between the degree of contrast enhancement of bladder cancer in the early enhanced phase of helical computed tomography (CT) and microvessel density (MVD), vascular endothelial growth factor (VEGF) and histological grade. MATERIALS AND METHODS: Sixty-five patients with transitional cell carcinoma of the bladder were examined by incremental unenhanced CT and helical CT at 40-45 s after initiation of intravenous administration of contrast medium before surgery. The CT density in Hounsfield units of bladder carcinomas were measured in the middle of the maximum diameter section of the cancer lesions on unenhanced and enhanced CT. The degree of contrast enhancement of the tumour was determined as the absolute increase in Hounsfield units. Histological grade, VEGF and MVD were analysed for each cancer. The Pearson and Spearman correlation tests were used to determine the strength of the relationships between CT enhancement and histological grade, VEGF expression and MVD. RESULTS: Different degrees of enhancement were observed in 91 cancers during the early enhanced phase of helical CT. Mean MVDs and mean CT enhancing values of different histological grade groups were statistically different (p<0.001). A positive correlation was found in the CT-enhancing value of bladder cancer and MVD (Pearson correlation test; r=0.938, p<0.001) and histological grade (Spearman rank correlation; r=0.734, p<0.001). VEGF of bladder cancer did not correlate with the change in CT attenuation (Spearman rank correlation; r=0.087, p=0.410) and MVD (Spearman rank correlation, r=0.103, p=0.330). CONCLUSION: In bladder cancer, the degree of contrast enhancement during the early enhanced helical CT is correlated with the MVD and histological grade of tumour. It is possible that MVD is the histopathological basis of early contrast enhancement of bladder cancer

Clinical experience with a commercially available negative oral contrast medium in PET/CT

International Nuclear Information System (INIS)

Hausegger, K.; Reinprecht, P.; Kau, T.; Igerc, I.; Lind, P.

2005-01-01

Purpose: to evaluate a commercially available negative oral contrast material for PET/CT. Material and methods: in a prospective series of 49 patients, Mukofalk registered , which is a vegetarian-based substance, was used as a negative oral contrast medium in whole body PET/CT studies. Mukofalk was administered during a time period of 1.5 hours before the examination. Quality of small bowl distension and eventual pathological tracer uptake in the intestine were evaluated. Results: distension of the small bowel was excellent or good in 41 (85%) and poor in 8 (15%) patients. Mild tracer uptake in the small bowel was observed in 5 patients (10.2%) and moderate uptake in another 2 patients (4%). In none of these patients did the F-18 FDG uptake interfere with image interpretation. Conclusion: Mukofalk registered can be used as a negative oral contrast medium in PET/CT studies. (orig.)

Clinical experience with a commercially available negative oral contrast medium in PET/CT

Energy Technology Data Exchange (ETDEWEB)

Hausegger, K.; Reinprecht, P. [Roentgendiagnostisches Zentralinstitut, LKH Klagenfurt (Austria); Kau, T. [Roentgendiagnostisches Zentral Inst., Klagenfurt (Austria); Igerc, I.; Lind, P. [Abt. fuer Nuklearmedizin und Spezielle Endokrinologie, LKH Klagenfurt (Austria)

2005-06-01

Purpose: to evaluate a commercially available negative oral contrast material for PET/CT. Material and methods: in a prospective series of 49 patients, Mukofalk {sup registered}, which is a vegetarian-based substance, was used as a negative oral contrast medium in whole body PET/CT studies. Mukofalk was administered during a time period of 1.5 hours before the examination. Quality of small bowl distension and eventual pathological tracer uptake in the intestine were evaluated. Results: distension of the small bowel was excellent or good in 41 (85%) and poor in 8 (15%) patients. Mild tracer uptake in the small bowel was observed in 5 patients (10.2%) and moderate uptake in another 2 patients (4%). In none of these patients did the F-18 FDG uptake interfere with image interpretation. Conclusion: Mukofalk {sup registered} can be used as a negative oral contrast medium in PET/CT studies. (orig.)

Water as a contrast medium: a re-evaluation using the multidetector-row computed tomography.

Science.gov (United States)

Makarawo, Tafadzwa P; Negussie, Edsa; Malde, Sachit; Tilak, Jacqueline; Gayagoy, Jennifer; Watson, Jenna; Francis, Faiz; Lincoln, Denis; Jacobs, Michael J

2013-07-01

Water as an intraluminal negative contrast medium produces improved image quality with reduced artefact. However, rapid absorption of oral water in the bowel relative to speed and timing of image capturing has limited its clinical application. These findings predate advances in multidetector-row computed tomography (CT). To re-evaluate differences in image quality, we studied image clarity and luminal distention between the same group of patients who received both a pancreas protocol CT (PPCT) that uses oral water and a conventional positive oral contrast scan. We reviewed 66 patients who had previously undergone both a PPCT and an oral contrast abdominal CT. CT images were independently reviewed by two board-certified radiologists who scored degree of hollow viscus distention and visualization of mural detail using a Likert 5-point scale. Results were evaluated by using the Wilcoxon-signed rank test. Student's t test was applied to evaluate the differences in radiation dosage and Spearman's correlational test was used to evaluate interrater correlation between the radiologists. In comparing the mean radiation dosage, there was no statistical difference between the two protocols, and there was good interrater association with ratios of 0.595 and 0.51 achieved for the PPCT and conventional oral scan, respectively. The Wilcoxon signed-rank test showed statistical differences in the stomach (P contrast medium causing better or equal distention in the bowel and better or equal clarity than routine barium contrast. This calls for a need to reconsider the use of water as a contrast medium in clinical practice.

Quantitative evaluation of contrast-enhanced ultrasound after intravenous administration of a microbubble contrast agent for differentiation of benign and malignant thyroid nodules: assessment of diagnostic accuracy.

Science.gov (United States)

Nemec, Ursula; Nemec, Stefan F; Novotny, Clemens; Weber, Michael; Czerny, Christian; Krestan, Christian R

2012-06-01

To investigate the diagnostic accuracy, through quantitative analysis, of contrast-enhanced ultrasound (CEUS), using a microbubble contrast agent, in the differentiation of thyroid nodules. This prospective study enrolled 46 patients with solitary, scintigraphically non-functional thyroid nodules. These patients were scheduled for surgery and underwent preoperative CEUS with pulse-inversion harmonic imaging after intravenous microbubble contrast medium administration. Using histology as a standard of reference, time-intensity curves of benign and malignant nodules were compared by means of peak enhancement and wash-out enhancement relative to the baseline intensity using a mixed model ANOVA. ROC analysis was performed to assess the diagnostic accuracy in the differentiation of benign and malignant nodules on CEUS. The complete CEUS data of 42 patients (31/42 [73.8%] benign and 11/42 [26.2%] malignant nodules) revealed a significant difference (P benign and malignant nodules. Furthermore, based on ROC analysis, CEUS demonstrated sensitivity of 76.9%, specificity of 84.8% and accuracy of 82.6%. Quantitative analysis of CEUS using a microbubble contrast agent allows the differentiation of benign and malignant thyroid nodules and may potentially serve, in addition to grey-scale and Doppler ultrasound, as an adjunctive tool in the assessment of patients with thyroid nodules. • Contrast-enhanced ultrasound (CEUS) helps differentiate between benign and malignant thyroid nodules. • Quantitative CEUS analysis yields sensitivity of 76.9% and specificity of 84.8%. • CEUS may be a potentially useful adjunct in assessing thyroid nodules.

Radiochromic film dosimetry of contrast-enhanced radiotherapy (CERT)

International Nuclear Information System (INIS)

Morris, Kevin N; Weil, Michael D; Malzbender, Rainer

2006-01-01

Contrast-enhanced radiotherapy (CERT) employs elevated concentrations of high-Z contrast media in targets to dramatically increase the absorbed dose of radiation relative to the surrounding tissues. However, it is difficult to measure the dose enhancement with routine clinical instruments because the photoelectrons and Auger electrons produced by the interaction of kilovoltage x-rays with the contrast agent travel extremely short distances. We have developed a technique utilizing unlaminated radiochromic film to measure the maximum dose enhancement factor attainable in solutions of contrast agent with iodine concentrations ranging from 0% to 37% (w/v). The films were also used to simultaneously measure the dose enhancement and beam attenuation through solutions containing 0%, 5% and 10% iodine (w/v). These depth-dose measurements were made in phantoms representing 3 cm targets located 0 and 4.8 cm deep in acrylic. Higher concentrations of contrast yielded greater dose enhancement and target-to-surface dose ratios, but caused more rapid attenuation of the beam as it traversed the target. The dose distribution across the entire target could be improved by employing multiple beams. These results, using concentrations of contrast that are clinically achievable by intratumoural injection, illustrate the potential of CERT for the specific delivery of high doses of radiation to targets at depth

Contrast-enhanced CISS imaging of cerebellopontine angle tumors

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Tozaki, Mitsuhiro; Toyoda, Keiko; Hata, Yuichi; Fukuda, Yasushi; Fukuda, Kunihiko [Jikei Univ., Tokyo (Japan). School of Medicine; Katano, Shuichi

1999-10-01

Our purpose of this study was to evaluate the clinical usefulness of contrast-enhanced CISS-3DFT MR imaging for the diagnosis of CP angle tumors. CISS-3DFT MR imaging is expected for screening procedure of acoustic schwannoma because of excellent spatial resolution. Recently, we discovered contrast enhancement effect on CISS sequence in spite of heavily T{sub 2}-weighted images. Fourteen patients with CP angle tumors were performed on a 1.0 T MR unit. Transaxial CISS-3DFT MRI was obtained both before and after intravenous injections of Gd-DTPA. Multiplanar reconstructions (MPRs) were performed in all cases. Contrast enhancement effect of CP angle tumors, and the relationship between tumors and the adjacent cranial nerves were evaluated. Contrast enhancement effect of the tumors was present in all cases in spite of heavily T{sub 2}-weighted images of CISS sequences. In the internal auditory canal, relationship between the tumors and the cranial nerves was demonstrated in 6 cases (6/9). In the cerebellopontine cistern, all cases were demonstrated (11/11). Contrast-enhanced CISS-3DFT MR imaging with a good contrast resolution and an excellent spatial resolution is useful for the diagnosis of CP angle tumors. (author)

Abducens nerve enhancement demonstrated by multiplanar reconstruction of contrast-enhanced three-dimensional MRI

International Nuclear Information System (INIS)

Hosoya, T.; Adachi, M.; Sugai, Y.; Yamaguchi, K.; Yamaguchi, K.; Kato, T.

2001-01-01

We describe contrast enhancement of the cisternal portion of the abducens nerve and discuss its clinical significance. We examined 67 patients with ophthalmoplegia using contrast-enhanced 3-dimensional (3D) MRI with multiplanar reconstruction along the nerves and found 16 patients (ten men, six women), aged 10-73 years (mean 34.4 years), with contrast enhancement of the abducens nerve. Of the 36 patients who had an abducens palsy, 14 (39 %) showed contrast enhancement. In the 16 patients, 23 abducens nerves enhanced; 13 were symptomatic and 10 asymptomatic at the time. The causes were disseminated tumour (1), an inflammatory process (3), trauma (2), ischaemia (2) and autoimmune diseases (8), such as the Miller Fisher syndrome, acute ophthalmoparesis, polyneuropathy and multiple sclerosis. Abducens and/or oculomotor nerve enhancement was the only abnormality on MRI in the patients with traumatic or ischaemic neuropathy or autoimmune diseases. There were 14 patients who recovered fully within 1-6 months after treatment, and resolution of the enhancement correlated well with recovery. (orig.)

Abducens nerve enhancement demonstrated by multiplanar reconstruction of contrast-enhanced three-dimensional MRI

Energy Technology Data Exchange (ETDEWEB)

Hosoya, T.; Adachi, M.; Sugai, Y. [Dept. of Radiology, Yamagata University School of Medicine (Japan); Yamaguchi, K.; Yamaguchi, K. [Dept. of Ophthalmology, Yamagata University School of Medicine (Japan); Kato, T. [3. Dept. of Internal Medicine, Yamagata University School of Medicine (Japan)

2001-04-01

We describe contrast enhancement of the cisternal portion of the abducens nerve and discuss its clinical significance. We examined 67 patients with ophthalmoplegia using contrast-enhanced 3-dimensional (3D) MRI with multiplanar reconstruction along the nerves and found 16 patients (ten men, six women), aged 10-73 years (mean 34.4 years), with contrast enhancement of the abducens nerve. Of the 36 patients who had an abducens palsy, 14 (39 %) showed contrast enhancement. In the 16 patients, 23 abducens nerves enhanced; 13 were symptomatic and 10 asymptomatic at the time. The causes were disseminated tumour (1), an inflammatory process (3), trauma (2), ischaemia (2) and autoimmune diseases (8), such as the Miller Fisher syndrome, acute ophthalmoparesis, polyneuropathy and multiple sclerosis. Abducens and/or oculomotor nerve enhancement was the only abnormality on MRI in the patients with traumatic or ischaemic neuropathy or autoimmune diseases. There were 14 patients who recovered fully within 1-6 months after treatment, and resolution of the enhancement correlated well with recovery. (orig.)

Is hepatotropic contrast enhanced MR a more effective method in differential diagnosis of hemangioma than multi-phase CT and unenhanced MR?

Directory of Open Access Journals (Sweden)

Markiet Karolina

2011-04-01

Full Text Available Abstract Background Cavernous hemangiomas are the most frequent neoplasms of the liver and in routine clinical practice they often need to be differentiated from malignant tumors and other benign focal lesions. The purpose of this study is to evaluate whether diagnostic accuracy of magnetic resonance imaging (MRI of hepatic hemangiomas, showing atypical pattern on US, improves with the use of Gd-BOPTA in comparison with contrast-enhanced multi-phase computed tomography (CT. Methods 178 consecutive patients with ambiguous hepatic masses showing atypical hyperechoic pattern on grey-scale US, underwent unenhanced and contrast-enhanced multi-phase multi-detector CT and MR (1.5T with the use of liver-specific contrast medium gadobenate dimeglumine (Gd-BOPTA. After intravenous contrast administration arterial (HAP, venous-portal (PVP, equilibrium phases (EP both in CT and MR and additionally hepatobiliary phase (HBP in MR were obtained. 398 lesions have been detected including 99 hemangiomas and 299 other lesions. Results In non-enhanced MDCT examination detection of hemangiomas was characterized by sensitivity of 76%, specificity of 90%, PPV of 71%, NPV of 92% and accuracy of 86%. Non-enhanced MR examination showed sensitivity of 98%, specificity of 99%, PPV of 99%, NPV of 99% and accuracy of 99%. After intravenous administration of contrast medium in MR the mentioned above parameters did not increase significantly. Conclusion Gd-BOPTA-enhanced MR in comparison with unenhanced MRI does not improve diagnostic accuracy in discriminating hemangiomas that show non-specific appearance in ultrasound examination. Unenhanced MR as a method of choice should directly follow US in course of diagnostic algorithm in differentiation of hemangiomas from other liver tumors.

Generalized image contrast enhancement technique based on Heinemann contrast discrimination model

Science.gov (United States)

Liu, Hong; Nodine, Calvin F.

1994-03-01

This paper presents a generalized image contrast enhancement technique which equalizes perceived brightness based on the Heinemann contrast discrimination model. This is a modified algorithm which presents an improvement over the previous study by Mokrane in its mathematically proven existence of a unique solution and in its easily tunable parameterization. The model uses a log-log representation of contrast luminosity between targets and the surround in a fixed luminosity background setting. The algorithm consists of two nonlinear gray-scale mapping functions which have seven parameters, two of which are adjustable Heinemann constants. Another parameter is the background gray level. The remaining four parameters are nonlinear functions of gray scale distribution of the image, and can be uniquely determined once the previous three are given. Tests have been carried out to examine the effectiveness of the algorithm for increasing the overall contrast of images. It can be demonstrated that the generalized algorithm provides better contrast enhancement than histogram equalization. In fact, the histogram equalization technique is a special case of the proposed mapping.

Pure and diluted contrast medium in the evaluation of portal venous system with digital subtraction angiography

International Nuclear Information System (INIS)

Gattoni, F.; Baldini, V.; Pozzato, C.; Nessi, R.; Raiteri, R.; Uscenghi, C.; Opocher, E.; Santambrogio, R.

1990-01-01

We report the results of intra-arterial digital subtraction angiography (DSA) in 100 patients with portal hypertension. The portal venous system was evaluated; all patients underwent angiography of the celiac and superior mesenteric arteries before surgery. Forty-four of them were also examined after Warren splenorenal shunts. Therefore, a total of 144 exams was evaluated. The authors always employed low-osmolality ionic and non-ionic contrast media (iodine concentration: 300-350 mg/ml). In 70 cases pure contrast medium was injected (20/25 ml): in the extant 74 cases it was diluted with an equal volume of saline solution (osmolality and iodine concentration reduced by 50%). Intra-arterial DSA always visualized portal venous system, collateral circulation, shunt location and postoperative changes. The mayor advantage of intra-arterial DSA is the smaller amount of contrast medium injected, so that local and systemic side effects are rare. According to our experience, it is best to dilute the contrast medium and inject the same amount as in conventional angiography, at the same rate. Other well-known advantages of intra-arterial DSA are quicker execution, less injury to arteries using smaller caliber catheters, and low cost. The major disadvantage of intra-arterial DSA, as it appeared also in our study, is the field size of the intensifier, which in our case was limited to 6-9 inches. This is an insufficient coverage for the whole portal system to be studied, and some contrast medium injections become therefore necessary. An average of 3 injections were given to each patient. This problem reduces the advantage of less contrast medium per injection. At any rate, even though intra-arterial DSA exhibits this limitation, it can nevertheless yield important information in the pre- and postoperative evaluation of patients with portal hypertension

The 'humble' bubble: Contrast-enhanced ultrasound

International Nuclear Information System (INIS)

Marshall, Gill; Sykes, Anne; Berry, Jonathan; Jonker, Leon

2011-01-01

The use of contrast-enhanced ultrasound (CEUS) is increasing within the field of medical imaging. Ultrasonic contrast agent (UCA) contain gas microbubbles similar in size to red corpuscles which provide highly reflective interfaces, enabling dynamic demonstration of echogenic streams of the contrast within the anatomical area of interest on real-time grey scale ultrasound. Longevity of the microbubbles has been improved by changing their composition. The application of CEUS in the UK continues to grow, bringing it into territories historically occupied by computerised tomography (CT) scanning and magnetic resonance imaging (MRI). Hence, the role of CEUS may be of interest to all diagnostic imaging practitioners. Here we summarise the mode of action and use of CEUS, and its role within a range of applications. The potential risks of CEUS are compared to other contrast-enhanced imaging techniques. The benefits of CEUS and its implications for diagnostic imaging practice are also covered.

Analysis on the entrance surface dose and contrast medium dose at computed tomography and angiography in cardiovascular examination

Energy Technology Data Exchange (ETDEWEB)

Seo, Young Hyun [Dept. of Cardiovascular Center, Yeocheon Jeonnam Hospital, Yeosu (Korea, Republic of); Han, Jae Bok; Choi, Nam Gil; Song, Jong Nam [Dept. of Radiological Science, Dongshin University, Naju (Korea, Republic of)

2016-12-15

This study aimed to identify dose reduction measures by retrospectively analyzing the entrance surface dose at computed tomography and angiography in cardiovascular examination and to contribute the patients with renal impairmend and a high probability of side effects to determine the inspection's direction by measuring the contrast usages actually to active actions for the dose by actually measuring the contrast medium dose. The CTDIvol value and air kerma value, which are the entrance surface doses of the two examinations, and the contrast medium dose depending on the number of slides were compared and analyzed. This study was conducted in 21 subjects (11 males; 10 females) who underwent Cardiac Computed Tomographic Angiography (CCTA) and Coronary Angiography (CAG) in this hospital during the period from May 2014 to May 2016. The subject's age was 48-85 years old (mean 65±10 years old), and the weight was 37.6~83.3 kg (mean 63±6 kg). Dose reduction could be expected in the cardiovascular examination using CCTA rather than in the examination using CAG. In terms of contrast medium dose, CAG used a smaller dose than CCTA. In particular, as the number of slides increases at CAG, the contrast medium dose increases. Therefore, in order to reduce the contrast medium dose, the number of slides suitable for the scan range must be selected.

Sequential contrast-enhanced MR imaging of the penis.

Science.gov (United States)

Kaneko, K; De Mouy, E H; Lee, B E

1994-04-01

To determine the enhancement patterns of the penis at magnetic resonance (MR) imaging. Sequential contrast material-enhanced MR images of the penis in a flaccid state were obtained in 16 volunteers (12 with normal penile function and four with erectile dysfunction). Subjects with normal erectile function showed gradual and centrifugal enhancement of the corpora cavernosa, while those with erectile dysfunction showed poor enhancement with abnormal progression. Sequential contrast-enhanced MR imaging provides additional morphologic information for the evaluation of erectile dysfunction.

Characterisation of urinary stones in the presence of iodinated contrast medium using dual-energy CT: a phantom study

Energy Technology Data Exchange (ETDEWEB)

Wang, Jia; Qu, Mingliang; Duan, Xinhui; Takahashi, Naoki; Kawashima, Akira; Leng, Shuai; McCollough, Cynthia H. [Mayo Clinic, Department of Radiology, Rochester, MN (United States)

2012-12-15

To develop a dual-energy CT (DECT) method for differentiating uric acid (UA) from non-UA stones in the presence of iodinated contrast medium. Thirty UA and 45 non-UA stones were selected after infra-red spectroscopic analysis and independently placed in a 1.5-ml vial, which was filled first with saline and then with increasing concentrations of iodine. For each condition, tubes were put in a 35-cm water phantom and examined using a dual-source CT system at 100 and 140 kV. Virtual unenhanced images created from CT data sets of the stones in iodine-containing solutions provided position and volume information. This map was used to calculate a CT number ratio to differentiate stone type. A region-growing method was developed to improve the ability to differentiate between UA and non-UA stones with iodinated contrast medium. The sensitivity for detecting UA stones was 100 % for unenhanced images but fell to 18 % with 20 mgI/ml iodine solution and 0 % for higher concentrations. With region growing, the sensitivity for detecting UA stones was increased to 100 %, 82 %, 57 %, 50 % and 21 % for iodine solutions of 20, 40, 60, 80 and 100 mgI/ml. The region-growing method improves differentiation of UA from non-UA stones on contrast-enhanced DECT urograms. (orig.)

Nonlinear image blending for dual-energy MDCT of the abdomen: can image quality be preserved if the contrast medium dose is reduced?

Science.gov (United States)

Mileto, Achille; Ramirez-Giraldo, Juan Carlos; Marin, Daniele; Alfaro-Cordoba, Marcela; Eusemann, Christian D; Scribano, Emanuele; Blandino, Alfredo; Mazziotti, Silvio; Ascenti, Giorgio

2014-10-01

The objective of this study was to compare the image quality of a dual-energy nonlinear image blending technique at reduced load of contrast medium with a simulated 120-kVp linear blending technique at a full dose during portal venous phase MDCT of the abdomen. Forty-five patients (25 men, 20 women; mean age, 65.6 ± 9.7 [SD] years; mean body weight, 74.9 ± 12.4 kg) underwent contrast-enhanced single-phase dual-energy CT of the abdomen by a random assignment to one of three different contrast medium (iomeprol 400) dose injection protocols: 1.3, 1.0, or 0.65 mL/kg of body weight. The contrast-to-noise ratio (CNR) and noise at the portal vein, liver, aorta, and kidney were compared among the different datasets using the ANOVA. Three readers qualitatively assessed all datasets in a blinded and independent fashion. Nonlinear blended images at a 25% reduced dose allowed a significant improvement in CNR (p < 0.05 for all comparisons), compared with simulated 120-kVp linear blended images at a full dose. No statistically significant difference existed in CNR and noise between the nonlinear blended images at a 50% reduced dose and the simulated 120-kVp linear blended images at a full dose. Nonlinear blended images at a 50% reduced dose were considered in all cases to have acceptable image quality. The dual-energy nonlinear image blending technique allows reducing the dose of contrast medium up to 50% during portal venous phase imaging of the abdomen while preserving image quality.

Contrast-enhanced flair imaging in the evaluation of infectious leptomeningeal diseases

International Nuclear Information System (INIS)

Parmar, Hemant; Sitoh, Y.-Y.; Anand, Pooja; Chua, Violet; Hui, Francis

2006-01-01

Purpose: The purpose of our study was to compare contrast-enhanced fluid-attenuated inversion recovery (FLAIR) images with contrast-enhanced T1 weighted images for infectious leptomeningitis. Materials and methods: We studied twenty-four patients with a clinical suspicion of infectious meningitis with unenhanced FLAIR, contrast-enhanced T1 weighted and contrast-enhanced FLAIR MR sequences. Twelve patients had cytologic and biochemical diagnosis of meningitis on cerebrospinal fluid (CSF) examination obtained 48 h before or after the MR study. Sequences were considered positive if abnormal signal was seen in the subarachnoid space (cistern or sulci) or along pial surface. Results: Twenty-seven examinations in 24 patients were performed. Of the 12 patients (thirteen studies) in whom cytology was positive, unenhanced FLAIR images were positive in six cases (sensitivity 46%), contrast-enhanced FLAIR images were positive in 11 (sensitivity 85%), and contrast-enhanced T1 weighted MR images were positive in 11 patients (sensitivity 85%). Of the 12 patients (14 studies) in whom cerebrospinal fluid study was negative, unenhanced FLAIR images were negative in 13, contrast-enhanced FLAIR images were negative in 11, and contrast-enhanced T1 weighted MR images were negative in eight. Thus, the specificity of unenhanced FLAIR, contrast-enhanced FLAIR and contrast-enhanced T1 weighted images was 93, 79 and 57%, respectively. Conclusion: Our results suggest that post-contrast FLAIR images have similar sensitivity but a higher specificity compared to contrast-enhanced T1 weighted images for detection of leptomeningeal enhancement. It can be a useful adjunct to post-contrast T1 weighted images in evaluation of infectious leptomeningitis

Contrast-enhanced flair imaging in the evaluation of infectious leptomeningeal diseases

Energy Technology Data Exchange (ETDEWEB)

Parmar, Hemant [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore) and Department of Diagnostic Imaging, Hospital for Sick Children, Toronto (Canada)]. E-mail: parurad@hotmail.com; Sitoh, Y.-Y. [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore); Anand, Pooja [Department of Neurology, National Neuroscience Institute, 11 Jalan Tan Tock Seng (Singapore); Chua, Violet [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore); Hui, Francis [Department of Neuroradiology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433 (Singapore)

2006-04-15

Purpose: The purpose of our study was to compare contrast-enhanced fluid-attenuated inversion recovery (FLAIR) images with contrast-enhanced T1 weighted images for infectious leptomeningitis. Materials and methods: We studied twenty-four patients with a clinical suspicion of infectious meningitis with unenhanced FLAIR, contrast-enhanced T1 weighted and contrast-enhanced FLAIR MR sequences. Twelve patients had cytologic and biochemical diagnosis of meningitis on cerebrospinal fluid (CSF) examination obtained 48 h before or after the MR study. Sequences were considered positive if abnormal signal was seen in the subarachnoid space (cistern or sulci) or along pial surface. Results: Twenty-seven examinations in 24 patients were performed. Of the 12 patients (thirteen studies) in whom cytology was positive, unenhanced FLAIR images were positive in six cases (sensitivity 46%), contrast-enhanced FLAIR images were positive in 11 (sensitivity 85%), and contrast-enhanced T1 weighted MR images were positive in 11 patients (sensitivity 85%). Of the 12 patients (14 studies) in whom cerebrospinal fluid study was negative, unenhanced FLAIR images were negative in 13, contrast-enhanced FLAIR images were negative in 11, and contrast-enhanced T1 weighted MR images were negative in eight. Thus, the specificity of unenhanced FLAIR, contrast-enhanced FLAIR and contrast-enhanced T1 weighted images was 93, 79 and 57%, respectively. Conclusion: Our results suggest that post-contrast FLAIR images have similar sensitivity but a higher specificity compared to contrast-enhanced T1 weighted images for detection of leptomeningeal enhancement. It can be a useful adjunct to post-contrast T1 weighted images in evaluation of infectious leptomeningitis.

MR-imaging of the breast at 0.5 Tesla: menstrual-cycle dependency of parenchymal contrast enhancement in healthy volunteers with oral contraceptive use?

International Nuclear Information System (INIS)

Lorenzen, J.; Welger, J.; Krupski, G.; Adam, G.; Lisboa, B.W.

2003-01-01

Introduction: To evaluate changes of contrast medium enhancement of the breast parenchyma due to menstrual cycle in healthy volunteers with oral contraceptive use in MR-imaging of the breast. Material and Methods: 15 healthy volunteers (age: 22 - 36, mean 28,2) without breast disease were examined two times during one menstrual cycle (days 7 - 14 and days 21 - 2). Two volunteers were examined only in the second part of the cycle (days 21 - 2). All volunteers used oral contraceptives for more than 6 month continuously. Examinations were performed with a 0,5 T magnet (dynamic 3D-gradient echo protocol with subtraction postprocessing). We evaluated the number of enhancing foci and the parenchymal contrast medium enhancement during the different phases of the cycle by region of interest. Results: Only a total of two enhancing foci were found in 2 of 17 volunteers. Time/signal intensity diagrams in these both cases were not suspicious ( [de

Adaptive multiscale processing for contrast enhancement

Science.gov (United States)

Laine, Andrew F.; Song, Shuwu; Fan, Jian; Huda, Walter; Honeyman, Janice C.; Steinbach, Barbara G.

1993-07-01

This paper introduces a novel approach for accomplishing mammographic feature analysis through overcomplete multiresolution representations. We show that efficient representations may be identified from digital mammograms within a continuum of scale space and used to enhance features of importance to mammography. Choosing analyzing functions that are well localized in both space and frequency, results in a powerful methodology for image analysis. We describe methods of contrast enhancement based on two overcomplete (redundant) multiscale representations: (1) Dyadic wavelet transform (2) (phi) -transform. Mammograms are reconstructed from transform coefficients modified at one or more levels by non-linear, logarithmic and constant scale-space weight functions. Multiscale edges identified within distinct levels of transform space provide a local support for enhancement throughout each decomposition. We demonstrate that features extracted from wavelet spaces can provide an adaptive mechanism for accomplishing local contrast enhancement. We suggest that multiscale detection and local enhancement of singularities may be effectively employed for the visualization of breast pathology without excessive noise amplification.

Correlation of contrast agent kinetics between iodinated contrast-enhanced spectral tomosynthesis and gadolinium-enhanced MRI of breast lesions

International Nuclear Information System (INIS)

Froeling, Vera; Diekmann, Felix; Renz, Diane M.; Fallenberg, Eva M.; Steffen, Ingo G.; Diekmann, Susanne; Schmitzberger, Florian F.; Lawaczeck, Ruediger

2013-01-01

Assessment of contrast agent kinetics in contrast-enhanced MRI (CE-MRI) with gadolinium-containing contrast agents offers the opportunity to predict breast lesion malignancy. The goal of our study was to determine if similar patterns exist for spectral contrast-enhanced digital breast tomosynthesis (CE-DBT) using an iodinated contrast agent. The protocol of our prospective study was approved by the relevant institutional review board and the German Federal Office for Radiation Protection. All patients provided written informed consent. We included 21 women with a mean age of 62.4 years. All underwent ultrasound-guided biopsy of a suspect breast lesion, spectral CE-DBT and CE-MRI. For every breast lesion, contrast agent kinetics was assessed by signal intensity-time curves for spectral CE-DBT and CE-MRI. Statistical comparison used Cohen's kappa and Spearman's rho test. Spearman's rho of 0.49 showed significant (P = 0.036) correlation regarding the contrast agent kinetics in signal intensity-time curves for spectral CE-DBT and CE-MRI. Cohen's kappa indicated moderate agreement (kappa = 0.438). There is a statistically significant correlation between contrast agent kinetics in the signal intensity-time curves for spectral CE-DBT and CE-MRI. Observing intralesional contrast agent kinetics in spectral CE-DBT may aid evaluation of malignant breast lesions. (orig.)

Fibroadenomas of the breast: histopathological/dynamic contrast-enhanced MR correlation

Energy Technology Data Exchange (ETDEWEB)

Gilles, R. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Garnier, C. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Meingan, P. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Zemoura, L. [Dept. of Histopathology C, Inst. Gustave Roussy, 94 - Villejuif (France); Lucidarme, O. [Dept. of Radiology, Hopital Salpetriere, 75 - Paris (France); Guinebretiere, J.M. [Dept. of Histopathology C, Inst. Gustave Roussy, 94 - Villejuif (France); Tardivon, A.A. [Dept. of Radiology, Inst. Gustave Roussy, 94 - Villejuif (France)]|[CIERM, Hopital Bicetre, 94 - Le Kremin-Bicetre (France); Arriagada, R. [Breast Cancer Study Group, Inst. Gustave Roussy, 94 - Villejuif, (France)

1995-12-31

A total of 22 women with fibroadenomas had preoperative dynamic MR study (T1-weighted images every 47 s after injection of Gd-DOTA). Their age, hormonal status, breast MR studies and histopathological slides were retrospectively reviewed. Eleven pre- (n = 2) or post-menopausal (n = 9) women showed no early contrast enhancement. The absence of early contrast enhancement correlated with hyalin stromal component. Eleven pre- (n = 7) or post-menopausal (n = 4) women showed focal (n = 9) or diffuse (n = 2) early contrast enhancement. Early focal contrast enhancement correlated with myxoid (n = 9), mixed hyalin/myxoid (n = 1) or hyalin (n = 1) fibroadenomas. Early diffuse contrast enhancement of the breast correlated with myxoid (n = 1) or hyalin (n = 1) stromal component associated with proliferative fibrocystic disease of the breast parenchyma. The presence of contrast enhancement correlated with myxoid fibroadenomas, whereas absence of contrast enhancement correlated with hyalin fibroadenomas. As hyalin fibroadenomas occurs in post-menopausal women, the diagnostic accuracy of dynamic MRI may be improved in this age group. (orig.)

Fibroadenomas of the breast: histopathological/dynamic contrast-enhanced MR correlation

International Nuclear Information System (INIS)

Gilles, R.; Garnier, C.; Meingan, P.; Zemoura, L.; Lucidarme, O.; Guinebretiere, J.M.; Tardivon, A.A.; Arriagada, R.

1995-01-01

A total of 22 women with fibroadenomas had preoperative dynamic MR study (T1-weighted images every 47 s after injection of Gd-DOTA). Their age, hormonal status, breast MR studies and histopathological slides were retrospectively reviewed. Eleven pre- (n = 2) or post-menopausal (n = 9) women showed no early contrast enhancement. The absence of early contrast enhancement correlated with hyalin stromal component. Eleven pre- (n = 7) or post-menopausal (n = 4) women showed focal (n = 9) or diffuse (n = 2) early contrast enhancement. Early focal contrast enhancement correlated with myxoid (n = 9), mixed hyalin/myxoid (n 1) or hyalin (n = 1) fibroadenomas. Early diffuse contrast enhancement of the breast correlated with myxoid (n = 1) or hyalin (n = 1) stromal component associated with proliferative fibrocystic disease of the breast parenchyma. The presence of contrast enhancement correlated with myxoid fibroadenomas, whereas absence of contrast enhancement correlated with hyalin fibroadenomas. As hyalin fibroadenomas occurs in post-menopausal women, the diagnostic accuracy of dynamic MRI may be improved in this age group. (orig.)

Contrast-enhanced dynamic MR imaging of parasellar tumor using fast spin-echo sequence

International Nuclear Information System (INIS)

Kusunoki, Katsusuke; Ohue, Shiro; Ichikawa, Haruhisa; Saito, Masahiro; Sadamoto, Kazuhiko; Sakaki, Saburo; Miki, Hitoshi.

1995-01-01

We have applied a new dynamic MRI technique that uses a fast spin-echo sequence to parasellar tumors. This sequence has less susceptible effect and better spatial resolution than a gradient echo sequence, providing faster images than a short spin-echo sequence does. Image was obtained in the coronal or sagittal plane using a 1.5T clinical MRI system, and then, dynamic MR images were acquired every 10 to 20 sec after administration of Gd-DTPA (0.1 mmol/kg). The subjects were 12 patients (5 microadenomas, 5 macroadenomas and 2 Rathke's cleft cysts) and 5 normal volunteers. As for volunteers, the cavernous sinus, pituitary stalk and posterior pituitary gland were contrasted on the first image, followed by visualization of the proximal portion adjacent to the junction of the infundibulum and the anterior pituitary gland, and finally by contrasting the distal portion of the anterior pituitary gland. There was a difference with respect to tumor contrast between microadenomas and macroadenomas. In the case of the macroadenomas, the tumor was contrasted at the same time as, or faster than the anterior pituitary gland, while with the microadenomas the tumor was enhanced later than the anterior pituitary gland. No enhancement with contrast medium was seen in Rathke's cleft cysts. In addition, it was possible to differentiate a recurrent tumor from a piece of muscle placed at surgery since the images obtained by the fast spin-echo sequence were clearer than those obtained by gradient echo sequence. (author)

Evaluation of changes in vertebral body density following administration of contrast medium during routine CT examination

International Nuclear Information System (INIS)

Janicek, M.; Bruna, J.; Stenhova, H.

1984-01-01

The possibility is discussed of depicting changes in the density of spongiosis of the vertebral body in normal patients after intravenous administration of a bolus of 40 ml 60% Diazetrizoate in the course of a routine CT examination. The average increase in density immediately after the administration of the contrast medium is 12 H (8%), in the course of 10 minutes is reduced to 5 H (4%) against the initial values in native examination. These average changes are statistically significant, in individual patients, however, the increase in density following the administration of a contrast medium fluctuates considerably (from 0.7% to 10%). Only systematic comparison with various pathological conditions will make it possible to assess the possibilities of the evaluation of the structure of the vertebral body in routine CT with the administration of a contrast medium into the blood flow. (author)

Ultrasonographic contrast-enhanced study of sicca syndrome

International Nuclear Information System (INIS)

Giuseppetti, Gian Marco; Argalia, Giulio; Salera, Diego; Ranaldi, Roberto; Danieli, Giovanna; Cappelli, Marida

2005-01-01

Objective: To assess the ability of US contrast-enhanced time-intensity curves to depict the changes connected with sicca syndrome, a fairly common condition that is often associated with autoimmune disorders such as Sjogren's syndrome or other diseases. Diagnostic criteria are complex and controversial and although no single test can be considered the gold standard, salivary gland scintigraphy and biopsy are reliable diagnostic methods. Materials and methods: Sixty consecutive patients with sicca syndrome, 40 of whom had primary (n = 23) or secondary (n = 17) Sjogren's syndrome and 20 had non-Sjogren's sicca syndrome, selected according to European Community Study Group diagnostic criteria for Sjogren's syndrome and subjected to contrast-enhanced US imaging of the parotids using a second-generation contrast agent with analysis of time-intensity curves at rest and during salivary stimulation, Tc99m salivary gland scintigraphy and labial gland biopsy. Results: In the 40 Sjogren's patients, US enhancement values were significantly lower (P < 0.0001 and P < 0.00003, respectively) than in the 20 non-Sjogren's patients both at rest and during stimulation. In the 23 subjects with the primary syndrome, values during stimulation were significantly lower than in the 17 subjects with the secondary syndrome (P < 0.0006), whereas at rest differences were not significant. Contrast-enhanced US imaging allowed to discriminate Sjogren's from non-Sjogren's sicca patients with 87.5% sensitivity, 85% specificity and 86.7% accuracy and the primary from the secondary syndrome with 78.2% sensitivity, 70.5% specificity and 75% accuracy. Interestingly, in eight patients with the primary syndrome, i.e. those with the more severe gland involvement, enhancement values were lower during stimulation than at rest. Conclusion: Preliminary results indicate that contrast-enhanced US imaging can provide useful information on sicca characterisation and severity

Ultrasonographic contrast-enhanced study of sicca syndrome

Energy Technology Data Exchange (ETDEWEB)

Giuseppetti, Gian Marco [Institute of Radiology, University School of Medicine, Umberto I Hospital, Via Conca 1, Ancona (Italy)]. E-mail: gm.giuseppetti@ao-umbertoprimo.marche.it; Argalia, Giulio [Institute of Radiology, University School of Medicine, Umberto I Hospital, Via Conca 1, Ancona (Italy); Salera, Diego [Institute of Radiology, University School of Medicine, Umberto I Hospital, Via Conca 1, Ancona (Italy); Ranaldi, Roberto [Institute of Pathological Anatomy and Histopathology, University School of Medicine, Umberto I Hospital, Ancona (Italy); Danieli, Giovanna [Institute of Internal Medicine, University School of Medicine, Umberto I Hospital, Ancona (Italy); Cappelli, Marida [Institute of Internal Medicine, University School of Medicine, Umberto I Hospital, Ancona (Italy)

2005-05-01

Objective: To assess the ability of US contrast-enhanced time-intensity curves to depict the changes connected with sicca syndrome, a fairly common condition that is often associated with autoimmune disorders such as Sjogren's syndrome or other diseases. Diagnostic criteria are complex and controversial and although no single test can be considered the gold standard, salivary gland scintigraphy and biopsy are reliable diagnostic methods. Materials and methods: Sixty consecutive patients with sicca syndrome, 40 of whom had primary (n = 23) or secondary (n = 17) Sjogren's syndrome and 20 had non-Sjogren's sicca syndrome, selected according to European Community Study Group diagnostic criteria for Sjogren's syndrome and subjected to contrast-enhanced US imaging of the parotids using a second-generation contrast agent with analysis of time-intensity curves at rest and during salivary stimulation, Tc99m salivary gland scintigraphy and labial gland biopsy. Results: In the 40 Sjogren's patients, US enhancement values were significantly lower (P < 0.0001 and P < 0.00003, respectively) than in the 20 non-Sjogren's patients both at rest and during stimulation. In the 23 subjects with the primary syndrome, values during stimulation were significantly lower than in the 17 subjects with the secondary syndrome (P < 0.0006), whereas at rest differences were not significant. Contrast-enhanced US imaging allowed to discriminate Sjogren's from non-Sjogren's sicca patients with 87.5% sensitivity, 85% specificity and 86.7% accuracy and the primary from the secondary syndrome with 78.2% sensitivity, 70.5% specificity and 75% accuracy. Interestingly, in eight patients with the primary syndrome, i.e. those with the more severe gland involvement, enhancement values were lower during stimulation than at rest. Conclusion: Preliminary results indicate that contrast-enhanced US imaging can provide useful information on sicca characterisation and

Risk of contrast-medium-induced nephropathy in high-risk patients undergoing MDCT - A pooled analysis of two randomized trials

Energy Technology Data Exchange (ETDEWEB)

Thomsen, Henrik S. [University of Copenhagen, Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, and Department of Diagnostic Sciences, Faculty of Health Sciences, Herlev (Denmark); Morcos, Sameh K. [University of Sheffield, Department of Diagnostic Imaging, Northern General Hospital, Sheffield (United Kingdom)

2009-04-15

The incidence of contrast-medium-induced nephropathy (CIN) following intravenous (IV) CM administration of contrast media to renally impaired patients undergoing multidetector computed tomography (MDCT) is not well characterized. Our objective was to investigate the incidence of CIN in patients with glomerular filtration rate (GFR) <60 ml/min undergoing contrast-enhanced MDCT examinations and to compare the rates of CIN following the IV administration of low-osmolar contrast media (LOCM, iopamidol and iomeprol) and an iso-osmolar contrast medium (IOCM, iodixanol). A total of 301 adult patients with moderate-to-severe renal failure received a similar IV contrast dose (40 gI). Serum creatinine (SCr) was measured at screening, baseline and 48-72 {+-} 6 h after the MDCT examination. Primary CIN outcome was an increase in SCr {>=}0.5 mg/dl ({>=}44.2 {mu}mol/l) from baseline. The CIN rates were 2.3% in the total population, 0.6% when GFR >40 ml/min, 4.6% when GFR <40 ml/min and 7.8% in patients with GFR <30 ml/min. The incidence of CIN was significantly higher after iodixanol than after LOCM (seven patients, 4.7% following IOCM, no CIN cases following the LOCM; p = 0.007). Significant differences in favor of the LOCM were also observed in patients with GFR <40 ml/min and GFR <30 ml/min. Following the IV administration of nonionic contrast agents in patients with moderate-to-severe renal insufficiency, the risk of significant CIN seems to be low. The IOCM iodixanol caused a higher rate of CIN than the LOCM iopamidol and iomeprol, especially in high-risk patients. Differences in osmolality between these LOCM and iodixanol do not play a role in the genesis of CIN. (orig.)

Post-traumatic contrast enhancing brain lesion

International Nuclear Information System (INIS)

Kim, Dae Jung; Kim, Hyun Sook; Jeong, Min Sun; Kim, Deok Ryeong; Cho, Young Kwon; Choi, Yun Sun

2014-01-01

Only a few studies have been reported on the MR contrast enhancement and the apparent diffusion coefficient (ADC) findings of the post-traumatic lesion of the brain. We report a case of the venous ischemia in the left frontal lobe observed in the MRI obtained one day after the incidence of trauma. Considering the presented slight increase in the ADC, the vasogenic edema was thought to be the major mechanism of the venous ischemia and excitotoxic injury. In spite of a slight increase in the ADC, the hyperintensity in the diffusion weighted imaging and contrast-enhanced areas eventually changed into hemorrhagic lesions.

Post-traumatic contrast enhancing brain lesion

Energy Technology Data Exchange (ETDEWEB)

Kim, Dae Jung; Kim, Hyun Sook; Jeong, Min Sun; Kim, Deok Ryeong; Cho, Young Kwon; Choi, Yun Sun [Eulji Hospital, Eulji University College of Medicine, Seoul (Korea, Republic of)

2014-10-15

Only a few studies have been reported on the MR contrast enhancement and the apparent diffusion coefficient (ADC) findings of the post-traumatic lesion of the brain. We report a case of the venous ischemia in the left frontal lobe observed in the MRI obtained one day after the incidence of trauma. Considering the presented slight increase in the ADC, the vasogenic edema was thought to be the major mechanism of the venous ischemia and excitotoxic injury. In spite of a slight increase in the ADC, the hyperintensity in the diffusion weighted imaging and contrast-enhanced areas eventually changed into hemorrhagic lesions.

Contrast-enhanced endoscopic ultrasonography in digestive diseases.

Science.gov (United States)

Hirooka, Yoshiki; Itoh, Akihiro; Kawashima, Hiroki; Ohno, Eizaburo; Itoh, Yuya; Nakamura, Yosuke; Hiramatsu, Takeshi; Sugimoto, Hiroyuki; Sumi, Hajime; Hayashi, Daijiro; Ohmiya, Naoki; Miyahara, Ryoji; Nakamura, Masanao; Funasaka, Kohei; Ishigami, Masatoshi; Katano, Yoshiaki; Goto, Hidemi

2012-10-01

Contrast-enhanced endoscopic ultrasonography (CE-EUS) was introduced in the early 1990s. The concept of the injection of carbon dioxide microbubbles into the hepatic artery as a contrast material (enhanced ultrasonography) led to "endoscopic ultrasonographic angiography". After the arrival of the first-generation contrast agent, high-frequency (12 MHz) EUS brought about the enhancement of EUS images in the diagnosis of pancreatico-biliary diseases, upper gastrointestinal (GI) cancer, and submucosal tumors. The electronic scanning endosonoscope with both radial and linear probes enabled the use of high-end ultrasound machines and depicted the enhancement of both color/power Doppler flow-based imaging and harmonic-based imaging using second-generation contrast agents. Many reports have described the usefulness of the differential diagnosis of pancreatic diseases and other abdominal lesions. Quantitative evaluation of CE-EUS images was an objective method of diagnosis using the time-intensity curve (TIC), but it was limited to the region of interest. Recently developed Inflow Time Mapping™ can be generated from stored clips and used to display the pattern of signal enhancement with time after injection, offering temporal difference of contrast agents and improved tumor characterization. On the other hand, three-dimensional CE-EUS images added new information to the literature, but lacked positional information. Three-dimensional CE-EUS with accurate positional information is awaited. To date, most reports have been related to pancreatic lesions or lymph nodes. Hemodynamic analysis might be of use for diseases in other organs: upper GI cancer diagnosis, submucosal tumors, and biliary disorders, and it might also provide functional information. Studies of CE-EUS in diseases in many other organs will increase in the near future.

Contrast-enhanced fluorodeoxyglucose positron emission tomography/contrast-enhanced computed tomography in mediastinal T-cell lymphoma with superior vena cava syndrome

International Nuclear Information System (INIS)

Santhosh, Sampath; Gorla, Arun Kumar Reddy; Bhattacharya, Anish; Varma, Subhash Chander; Mittal, Bhagwant Rai

2016-01-01

Positron emission tomography-computed tomography (PET/CT) is a routine investigation for the staging of lymphomas. Contrast-enhanced computed tomography is mandatory whenever parenchymal lesions, especially in the liver and spleen are suspected. We report a rare case of primary mediastinal T-cell lymphoma evaluated with contrast-enhanced PET/CT that showed features of superior vena cava syndrome

Can low-dose CT with iterative reconstruction reduce both the radiation dose and the amount of iodine contrast medium in a dynamic CT study of the liver?

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Hiroto; Okada, Masahiro; Hyodo, Tomoko; Hidaka, Syojiro; Kagawa, Yuki; Matsuki, Mitsuru; Tsurusaki, Masakatsu; Murakami, Takamichi, E-mail: murakami@med.kindai.ac.jp

2014-04-15

Purpose: To investigate whether low-dose dynamic CT of the liver with iterative reconstruction can reduce both the radiation dose and the amount of contrast medium. Materials and methods: This study was approved by our institutional review board. 113 patients were randomly assigned to one of two groups. Group A/group B (fifty-eight/fifty-five patients) underwent liver dynamic CT at 120/100 kV, with 0/40% adaptive statistical iterative reconstruction (ASIR), with a contrast dose of 600/480 mg I/kg, respectively. Radiation exposure was estimated based on the manufacturer's phantom data. The enhancement value of the hepatic parenchyma, vessels and the tumor-to-liver contrast of hepatocellular carcinomas (HCCs) were compared between two groups. Two readers independently assessed the CT images of the hepatic parenchyma and HCCs. Results: The mean CT dose indices: 6.38/4.04 mGy, the dose-length products: 194.54/124.57 mGy cm, for group A/group B. The mean enhancement value of the hepatic parenchyma and the tumor-to-liver contrast of HCCs with diameters greater than 1 cm in the post-contrast all phases did not differ significantly between two groups (P > 0.05). The enhancement values of vessels in group B were significantly higher than that in group A in the delayed phases (P < 0.05). Two reader's confidence levels for the hepatic parenchyma in the delayed phases and HCCs did not differ significantly between the groups (P > 0.05). Conclusions: Low-dose dynamic CT with ASIR can reduce both the radiation dose and the amount of contrast medium without image quality degradation, compared to conventional dynamic CT without ASIR.

Contrast Enhanced Spectral Mammography: A Review.

Science.gov (United States)

Patel, Bhavika K; Lobbes, M B I; Lewin, John

2018-02-01

Contrast-enhanced spectral mammography (CESM) provides low-energy 2D mammographic images comparable to standard digital mammography and a post-contrast recombined image to assess tumor neovascularity similar to magnetic resonance imaging (MRI). The utilization of CESM in the United States is currently low but could increase rapidly given many potential indications for clinical use. This article discusses historical background and literature review of indications and diagnostic accuracy of CESM to date. CESM is a growing technique for breast cancer detection and diagnosis that has levels of sensitivity and specificity on par with contrast-enhanced breast MRI. Because of its similar performance and ease of implementation, CESM is being adopted for multiple indications previously reserved for MRI, such as problem-solving, disease extent in newly diagnosed patients, and evaluating the treatment response of neoadjuvant chemotherapy. Copyright © 2018 Elsevier Inc. All rights reserved.

Generalized image contrast enhancement technique based on the Heinemann contrast discrimination model

Science.gov (United States)

Liu, Hong; Nodine, Calvin F.

1996-07-01

This paper presents a generalized image contrast enhancement technique, which equalizes the perceived brightness distribution based on the Heinemann contrast discrimination model. It is based on the mathematically proven existence of a unique solution to a nonlinear equation, and is formulated with easily tunable parameters. The model uses a two-step log-log representation of luminance contrast between targets and surround in a luminous background setting. The algorithm consists of two nonlinear gray scale mapping functions that have seven parameters, two of which are adjustable Heinemann constants. Another parameter is the background gray level. The remaining four parameters are nonlinear functions of the gray-level distribution of the given image, and can be uniquely determined once the previous three are set. Tests have been carried out to demonstrate the effectiveness of the algorithm for increasing the overall contrast of radiology images. The traditional histogram equalization can be reinterpreted as an image enhancement technique based on the knowledge of human contrast perception. In fact, it is a special case of the proposed algorithm.

Duplex-assisted carotid artery stenting without administration of contrast medium for patients with chronic kidney disease or allergic reaction.

Science.gov (United States)

Mizowaki, Takashi; Fujita, Atsushi; Imahori, Taichiro; Uyama, Atsushi; Inoue, Satoshi; Kohta, Masaaki; Hamaguchi, Hirotoshi; Sasayama, Takashi; Hosoda, Kohkichi; Kohmura, Eiji

2016-07-01

We aimed to investigate the safety and feasibility of duplex-assisted carotid artery stenting (CAS) without administration of contrast medium for the prevention of adverse reactions. Fifteen patients (9 % of all CASs) with severe carotid stenosis (≥70 %) associated with chronic kidney disease (CKD) (stage ≥3) or allergy to contrast medium underwent duplex-assisted CAS without administration of contrast medium over 4 years. The procedural success rate and perioperative complication rates were compared between the duplex-assisted CAS (n = 15) and conventional CAS (n = 153) groups. The technical success rate was 100 % in both groups. Combined stroke or death rates during the post-procedural period did not differ significantly between the duplex-assisted CAS group (0/15, 0 %) and conventional CAS group (4/153, 2.6 %). None of the 14 patients with CKD in the duplex-assisted CAS group experienced further deterioration of renal function. The mean surface radiation dose of participants in the duplex-assisted CAS group (n = 13, 312 ± 131 mGy) was significantly lower than that of the conventional CAS group (n = 31, 1036 ± 571 mGy) (p duplex-assisted CAS group (156 ± 39.7 min) and the conventional CAS group (156 ± 37.4 min). Duplex-assisted CAS without administration of contrast medium could be an alternative option in selected patients deemed to be at high risk for renal failure from nephrotoxic contrast medium or who have an allergy to contrast medium.

Digital subtraction angiography and intraarterial contrast medium injection for coronary examinations

Energy Technology Data Exchange (ETDEWEB)

Tobio, R; Kallmeyer, C; Castello, J

1985-01-01

Digital subtraction angiography (DSA) is an established method of vasography, most extensively used as i.v. DSA. Intraarterial injection, however, applying selective or non-selective contrast medium injection, seems to be at least as important a technique although it has not yet met with corresponding interest. The article explains advantages of the technique for angiographic examinations, in particular of coronary angiography.

Complex cystic renal masses: characterization with contrast-enhanced US.

Science.gov (United States)

Ascenti, Giorgio; Mazziotti, Silvio; Zimbaro, Giovanni; Settineri, Nicola; Magno, Carlo; Melloni, Darwin; Caruso, Rosario; Scribano, Emanuele

2007-04-01

To prospectively compare contrast material-enhanced ultrasonography (US) with computed tomography (CT) in the classification of complex cystic renal masses with the Bosniak system. Ethics committee approval and written informed consent were obtained. Forty patients (17 women, 23 men; age range, 31-77 years) with 44 complex cystic renal masses detected with conventional US were prospectively examined by using second-harmonic US with a second-generation contrast agent and multiphasic helical CT. Thirty-six patients had one lesion, and four patients had two lesions. Surgical resection in nine patients and imaging follow-up in 31 patients were used to determine the outcome. On contrast-enhanced US images, masses were classified as Bosniak category II (n = 18), IIF (ie, lesions were classified as category II and follow-up was needed) (n = 16), III (n = 7), or IV (n = 3) lesions. On CT images, masses were classified as Bosniak category II (n = 24), IIF (n = 10), III (n = 7), or IV (n = 3) lesions. Interobserver agreement was high (kappa = 0.86, P < .001) for classification with US. Complete concordance between the readers was found for classification with CT. Complete concordance between contrast-enhanced US and CT was observed in the differentiation of surgical and nonsurgical complex cysts. Complete concordance among the three readers in the assessment of vascularity with contrast-enhanced US was found. Interobserver agreement in the evaluation of enhancement on CT images was high (kappa = 0.88, P < .001). Concordance between contrast-enhanced US and CT in the evaluation of vascularization was high (kappa = 0.77, P < .001). The study data suggest that contrast-enhanced second-harmonic US is appropriate for renal cyst classification with the Bosniak system.

Sentinel node detection in melanomas using contrast-enhanced ultrasound

DEFF Research Database (Denmark)

Nielsen, K. Rue; Klyver, H.; Chakera, A. Hougaard

2009-01-01

in humans. PURPOSE: To investigate the possible use of CEUS in detecting SN in patients with malignant melanomas (MM), and to improve the method by using different concentrations of contrast agent and various positions of the extremity. MATERIAL AND METHODS: Ten patients with MM on an extremity and one...... healthy volunteer were included. One milliliter of a contrast agent (Sonovue; Bracco, Milan, Italy) was injected subcutaneously on both sides of the scar from the excised tumor. Contrast-enhanced lymph channels and lymph nodes (LNs) were searched for using low-mechanical-index CEUS and by stimulated...... tissue damage, as the contrast agent was not registered for subcutaneous administration. RESULTS: In one patient, two contrast-enhanced inguinal LNs were visualized by CEUS, corresponding to two inguinal SNs found by scintigraphic imaging. No contrast-enhanced lymph channels or LNs were visualized in any...

Contrast enhanced CT-scans are not comparable to non-enhanced scans in emphysema quantification

International Nuclear Information System (INIS)

Heussel, C.P.; Kappes, J.; Hantusch, R.; Hartlieb, S.; Weinheimer, O.; Kauczor, H.-U.; Eberhardt, R.

2010-01-01

Systemic, interventional and surgical treatments have gone new ways in treatment of emphysema. For longitudinal therapy monitoring and as end-points for clinical trials, quantification of the disease is necessary. Sensitive, easy to measure, as well as stable and reproducible parameters have to be characterized. One parameter that might affect emphysema quantification is IV contrast enhancement, which might also be indicated. Whether or not the contrast enhanced scan is also suited for emphysema quantification or an additional scan is necessary, a retrospective analysis of 12 adult patients undergoing clinically indicated both, a non-enhanced and enhanced thin section MSCT within a week (median 0 days, range 0-4 days) was done. The in-house YACTA software was used for automatic quantification of lung and emphysema volume, emphysema index, mean lung density, and 5th, 10th, 15th percentile. After IV contrast administration, the median CT derived lung volume decreased mild by 1.1%, while median emphysema volume decreased by relevant 11%. This results in a decrease of median emphysema index by 9%. The median lung density (15th percentile) increased after contrast application by 18 HU (9 HU). CT quantification delivers emphysema values that are clearly affected by IV contrast application. The detected changes after contrast application show the results of higher density in the lung parenchyma. Therefore the amount of quantified emphysema is reduced and the lung density increased after contrast enhancement. In longitudinal analyses, non-enhanced scans should be the reference, while enhanced scans cannot be used.

Intravenous contrast medium application in elderly patients - evaluation of Iopentol (Imagopaque trademark 300); Intravenoese Kontrastmittel-Applikation bei aelteren Patienten - Anwendungsbeobachtung von Iopentol (Imagopaque trademark 300)

Energy Technology Data Exchange (ETDEWEB)

Rathsmann, P.; Jacobs, G.F.; Mueller, R.D. [Zentrum fuer Klinische Radiologie, Kliniken Essen-Sued (Germany)

2004-12-01

Purpose: We examined the subjective compatibility of elderly patients who received the intravenous contrast medium Iopentol (Imagopaque trademark 300). In addition, objective data were acquired to show possible interactions between contrast media and organ systems in old patients. Methods and materials: A CT scan with intravenous application of contrast media was performed on 132 patients ranging in age from 75 to 96 years. The patients were questioned about their individual sensations. In addition, blood pressure, creatinine and CT-densitometry were acquired as objective date. Results: The patients' individual sensations and clinical data show a very low rate of complications. Mild allergic reactions were noticed in two patients. No severe anaphylactic reactions were encountered. Statistically significant changes in blood pressure before and after administration of the contrast medium were not observed. The serum creatinine concentration was unchanged after application of contrast media. For CT-densitometry, the patients were divided into two groups, one group with patients 75-84 years and the other group with patients 85-96 years of age. CT-densitometry showed no age-related differences. The protocol of contrast administration resulted in excellent opacification of the examined regions, only the liver did not enhance in some cases before the opacification of the portal vein. Conclusion: It is shown that old age alone is no reason to withhold contrast media containing iodine when performing CT. For the evaluation of the liver, however, the peculiarities of old age have to be taken into account and the interval between injection of the contrast medium and beginning of the spiral-CT has to be extended. (orig.)

Contrast enhancement by lipid-based MRI contrast agents in mouse atherosclerotic plaques; a longitudinal study

NARCIS (Netherlands)

den Adel, Brigit; van der Graaf, Linda M.; Que, Ivo; Strijkers, Gustav J.; Löwik, Clemens W.; Poelmann, Robert E.; van der Weerd, Louise

2013-01-01

The use of contrast-enhanced MRI to enable in vivo specific characterization of atherosclerotic plaques is increasing. In this study the intrinsic ability of two differently sized gadolinium-based contrast agents to enhance atherosclerotic plaques in ApoE(-/-) mice was evaluated with MRI. We

Development and validation of Monte Carlo dose computations for contrast-enhanced stereotactic synchrotron radiation therapy

International Nuclear Information System (INIS)

Vautrin, M.

2011-01-01

Contrast-enhanced stereotactic synchrotron radiation therapy (SSRT) is an innovative technique based on localized dose-enhancement effects obtained by reinforced photoelectric absorption in the tumor. Medium energy monochromatic X-rays (50 - 100 keV) are used for irradiating tumors previously loaded with a high-Z element. Clinical trials of SSRT are being prepared at the European Synchrotron Radiation Facility (ESRF), an iodinated contrast agent will be used. In order to compute the energy deposited in the patient (dose), a dedicated treatment planning system (TPS) has been developed for the clinical trials, based on the ISOgray TPS. This work focuses on the SSRT specific modifications of the TPS, especially to the PENELOPE-based Monte Carlo dose engine. The TPS uses a dedicated Monte Carlo simulation of medium energy polarized photons to compute the deposited energy in the patient. Simulations are performed considering the synchrotron source, the modeled beamline geometry and finally the patient. Specific materials were also implemented in the voxelized geometry of the patient, to consider iodine concentrations in the tumor. The computation process has been optimized and parallelized. Finally a specific computation of absolute doses and associated irradiation times (instead of monitor units) was implemented. The dedicated TPS was validated with depth dose curves, dose profiles and absolute dose measurements performed at the ESRF in a water tank and solid water phantoms with or without bone slabs. (author) [fr

Analysis of factors influencing the integrated bolus peak timing in contrast-enhanced brain computed tomographic angiography

International Nuclear Information System (INIS)

Son, Soon Yong; Choi, Kwan Woo; Jeong, Hoi Woun; Jang, Seo Goo; Jung, Jae Young; Yun, Jung Soo; Kim, Ki Won; Lee, Young Ah; Son, Jin Hyun; Min, Jung Whan

2016-01-01

The objective of this study was to analyze the factors influencing integrated bolus peak timing in contrast- enhanced computed tomographic angiography (CTA) and to determine a method of calculating personal peak time. The optimal time was calculated by performing multiple linear regression analysis, after finding the influence factors through correlation analysis between integrated peak time of contrast medium and personal measured value by monitoring CTA scans. The radiation exposure dose in CTA was 716.53 mGy·cm and the radiation exposure dose in monitoring scan was 15.52 mGy (2 - 34 mGy). The results were statistically significant (p < .01). Regression analysis revealed, a -0.160 times decrease with a one-step increase in heart rate in male, and -0.004, -0.174, and 0.006 times decrease with one-step in DBP, heart rate, and blood sugar, respectively, in female. In a consistency test of peak time by calculating measured peak time and peak time by using the regression equation, the consistency was determined to be very high for male and female. This study could prevent unnecessary dose exposure by encouraging in clinic calculation of personal integrated peak time of contrast medium prior to examination

Use of high concentration contrast media: principles and rationale--vascular district

International Nuclear Information System (INIS)

Fleischmann, Dominik.

2003-01-01

Optimal contrast medium delivery remains a crucial issue in CT angiography and it will become even more critical with continuously evolving, faster CT scanner technology. This review article first explains the fundamentals of arterial enhancement using mathematical models of early contrast medium dynamics. The relationship of contrast medium volume, injection flow rates and injection duration are explicitly illustrated. Next, current techniques of contrast medium application are reviewed, with particular attention to methods of accurate timing of the scanning delay (test-bolus and automated bolus triggering), tools for automated saline-flushing of the veins (double-syringe power injectors) and the use of high-concentration contrast medium. From there, rational CT angiographic injection protocols for a wide range of selectable acquisition times for 4-, 8- and 16-channel MDCT are proposed

Contrast enhancement by arterial perfusion during computed tomography (computed tomographic arteriography) of the pancreatic disease

International Nuclear Information System (INIS)

Takaki, Yukiari

1983-01-01

Computed tomographic arteriography (CTA) was performed on 52 cases of pancreatic disease in which was suspected clinically, and in which other method failed to yield a definitive diagnosis. For CTA, 65% meglumine diatrizoate 20 ml, diluted 1:3, was injected via a catherter inserted in an artery connected with the pancreas and the change with time of the pacreas CT number was studied. The normal pancreas stains deeply and the best contrast enhancement was obtained between 17 to 21 seconds after instillation of contrast medium. In the CTA findings in pancreatic cancer, low density areas with irregular internal structures are characteristic, and these characteristics were seen even in minute pancreatic cancers which could not be recognized by CT or the intravenous bolus injection method. On the other hand, in chronic pancreatitis, even when differentiation from pancreatic cancer is difficult with arterial and venous encasement in angiography, as long as the chronic pancreatitis is not very advanced ischemic changes are not seen, and this permits differentiation form normal pancreas. This also facilitates differentiation between pancreatitis and pancreatic cancer. In the intravenous bolus injection method, the chronological change of contrast enhancement in the pancreas was studied and the best contrast enhancement was obtained after 60 to 120 seconds. This method revealed no findings peculiar to pancreatic cancer. Based on the above, CTA was found to be useful for making in contributing to establishing a definitive diagnosis, detecting minute pancreatic cancer and to differentiate pancreatic cancer from chronic pancreatitis. (author)

Contrast-enhanced peripheral MRA. Technique and contrast agents

International Nuclear Information System (INIS)

Nielsen, Yousef W.; Thomsen, Henrik S.

2012-01-01

In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast agents. Peripheral CE-MRA is defined as an MR angiogram of the arteries from the aortic bifurcation to the feet. Advantages of CE-MRA include minimal invasiveness and lack of ionizing radiation. The basic technique employed for peripheral CE-MRA is the bolus-chase method. With this method a paramagnetic MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic field strength of the MRI system, receiver coil configuration, use of parallel imaging, contrast bolus timing technique, and k-space filling strategies. Furthermore, it is possible to optimize peripheral CE-MRA using venous compression techniques, hybrid scan protocols, time-resolved imaging, and steady-state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged intravascular stay, due to macromolecular structure or protein binding. These agents can be used for first-pass, as well as steady-state MRA. Some Gd-based contrast agents with low thermodynamic stability have been linked to development of nephrogenic systemic fibrosis in patients with severe renal insufficiency. Using optimized technique and a stable MRI contrast agent, peripheral CE-MRA is a safe procedure with diagnostic accuracy close to that of conventional catheter X

Evaluation of sacroiliitis: contrast-enhanced MRI with subtraction technique

Energy Technology Data Exchange (ETDEWEB)

Algin, Oktay; Gokalp, Gokhan; Baran, Bulent; Ocakoglu, Gokhan; Yazici, Zeynep [Uludag University, Medical Faculty, Department of Radiology, Gorukle, Bursa (Turkey)

2009-10-15

The purpose of the study was to investigate the diagnostic value of contrast-enhanced MRI using the subtraction technique in the detection of active sacroiliitis. Magnetic resonance imaging was performed in 8 asymptomatic volunteers and 50 patients with clinically suspected active sacroiliitis. On precontrast MR images, T1-weighted spin-echo images with and without fat saturation (T1WFS and T1W), STIR and 3D-FLASH images with fat saturation were obtained in the semicoronal plane using a 1.5 Tesla imager. Postcontrast MRI was performed using the same T1WFS sequence as before contrast injection for all volunteers and patients. Postcontrast images were subtracted from fat-suppressed precontrast images. Enhancement within the joint space and bone marrow was considered to demonstrate active sacroiliitis. In 50 patients (100 sacroiliac joints [SIJs]), 40 (76 SIJs) were considered to have active sacroiliitis based on MR images. Bone marrow edema was present in 33 patients (62 SIJs) on STIR images. Routine MRI allowed identification of contrast enhancement in SIJs on postcontrast T1WFS images in 31 patients (49 SIJs). Contrast enhancement was observed in 40 patients (76 SIJs) who were examined by MRI using the subtraction technique. Contrast enhancement was significantly more conspicuous on subtraction images than on non-subtracted postcontrast T1WFS images (Mann-Whitney U test, p<0.001). Contrast-enhanced MRI with subtraction technique may be useful for early detection of active sacroiliitis. (orig.)

The effect of iodine uptake on radiation dose absorbed by patient tissues in contrast enhanced CT imaging. Implications for CT dosimetry

Energy Technology Data Exchange (ETDEWEB)

Perisinakis, Kostas; Damilakis, John [University of Crete, Department of Medical Physics, Medical School, Heraklion, Crete (Greece); University Hospital of Heraklion, Department of Medical Physics, Heraklion, Crete (Greece); Tzedakis, Antonis; Papadakis, Antonios E. [University Hospital of Heraklion, Department of Medical Physics, Heraklion, Crete (Greece); Spanakis, Kostas [University Hospital of Heraklion, Department of Radiology, Heraklion, Crete (Greece); Hatzidakis, Adam [University Hospital of Heraklion, Department of Radiology, Heraklion, Crete (Greece); University of Crete, Department of Radiology, Medical School, Heraklion, Crete (Greece)

2018-01-15

To investigate the effect of iodine uptake on tissue/organ absorbed doses from CT exposure and its implications in CT dosimetry. The contrast-induced CT number increase of several radiosensitive tissues was retrospectively determined in 120 CT examinations involving both non-enhanced and contrast-enhanced CT imaging. CT images of a phantom containing aqueous solutions of varying iodine concentration were obtained. Plots of the CT number increase against iodine concentration were produced. The clinically occurring iodine tissue uptake was quantified by attributing recorded CT number increase to a certain concentration of aqueous iodine solution. Clinically occurring iodine uptake was represented in mathematical anthropomorphic phantoms. Standard 120 kV CT exposures were simulated using Monte Carlo methods and resulting organ doses were derived for non-enhanced and iodine contrast-enhanced CT imaging. The mean iodine uptake range during contrast-enhanced CT imaging was found to be 0.02-0.46% w/w for the investigated tissues, while the maximum value recorded was 0.82% w/w. For the same CT exposure, iodinated tissues were found to receive higher radiation dose than non-iodinated tissues, with dose increase exceeding 100% for tissues with high iodine uptake. Administration of iodinated contrast medium considerably increases radiation dose to tissues from CT exposure. (orig.)

Potential Cost Savings of Contrast-Enhanced Digital Mammography.

Science.gov (United States)

Patel, Bhavika K; Gray, Richard J; Pockaj, Barbara A

2017-06-01

The purpose of this article is to discuss whether the sensitivity and specificity of contrast-enhanced digital mammography (CEDM) render it a viable diagnostic alternative to breast MRI. That CEDM couples low-energy images (comparable to the diagnostic quality of standard mammography) and subtracted contrast-enhanced mammograms make it a cost-effective modality and a realistic substitute for the more costly breast MRI.

Contrast media in computed tomography of the pelvic organs

International Nuclear Information System (INIS)

Husband, J.E.

1981-01-01

The use of various contrast media is essential for examination of the pelvis with computed tomography (CT) because there is little fat between the organs and structures and because bowel may be misinterpreted as mass. Routine opacification of the distal small bowel and colon is achieved using dilute oral and rectal contrast medium, and all patients are scanned with a full bladder. A tampon is used to outline the vaginal vault. Intravenous contrast medium may be required to opacify the urinary tract or to distinguish vessels from a suspected space-occupying lesion. Pelvic masses may show tissue enhancement following injection of intravenous contrast medium but further studies are required to determine the diagnostic value of the information obtained. (Auth.)

Lecithine as an adjuvant in resorption of contrast medium in oral cholecystography

International Nuclear Information System (INIS)

Lindgren, I.

1978-01-01

No or poor filling of the gallbladder was obtained in 21 patients at cholecystography. They were re-examined after 10 days or later with the addition of lecithine to the contrast medium. The filling of the gallbladder, which was without abnormality, was improved in all cases. The mechanism of this effect is discussed. (Auth.)

Contrast-enhanced spectral mammography (CESM) and contrast enhanced MRI (CEMRI): Patient preferences and tolerance.

Science.gov (United States)

Hobbs, Max M; Taylor, Donna B; Buzynski, Sebastian; Peake, Rachel E

2015-06-01

Contrast-enhanced spectral mammography (CESM) may have similar diagnostic performance to Contrast-enhanced MRI (CEMRI) in the diagnosis and staging of breast cancer. To date, research has focused exclusively on diagnostic performance when comparing these two techniques. Patient experience is also an important factor when comparing and deciding on which of these modalities is preferable. The aim of this study is to compare patient experience of CESM against CEMRI during preoperative breast cancer staging. Forty-nine participants who underwent both CESM and CEMRI, as part of a larger trial, completed a Likert questionnaire about their preference for each modality according to the following criteria: comfort of breast compression, comfort of intravenous (IV) contrast injection, anxiety and overall preference. Participants also reported reasons for preferring one modality to the other. Quantitative data were analysed using a Wilcoxon sign-rank test and chi-squared test. Qualitative data are reported descriptively. A significantly higher overall preference towards CESM was demonstrated (n = 49, P < 0.001), with faster procedure time, greater comfort and lower noise level cited as the commonest reasons. Participants also reported significantly lower rates of anxiety during CESM compared with CEMRI (n = 36, P = 0.009). A significantly higher rate of comfort was reported during CEMRI for measures of breast compression (n = 49, P = 0.001) and the sensation of IV contrast injection (n = 49, P = 0.003). Our data suggest that overall, patients prefer the experience of CESM to CEMRI, adding support for the role of CESM as a possible alternative to CEMRI for breast cancer staging. © 2015 The Royal Australian and New Zealand College of Radiologists.

Contrast-enhanced spectral mammography (CESM) and contrast enhanced MRI (CEMRI): Patient preferences and tolerance

International Nuclear Information System (INIS)

Hobbs, Max; Buzynski, Sebastian; Taylor, Donna B.; Peake, Rachel E.

2015-01-01

Contrast-enhanced spectral mammography (CESM) may have similar diagnostic performance to Contrast-enhanced MRI (CEMRI) in the diagnosis and staging of breast cancer. To date, research has focused exclusively on diagnostic performance when comparing these two techniques. Patient experience is also an important factor when comparing and deciding on which of these modalities is preferable. The aim of this study is to compare patient experience of CESM against CEMRI during preoperative breast cancer staging. Forty-nine participants who underwent both CESM and CEMRI, as part of a larger trial, completed a Likert questionnaire about their preference for each modality according to the following criteria: comfort of breast compression, comfort of intravenous (IV) contrast injection, anxiety and overall preference. Participants also reported reasons for preferring one modality to the other. Quantitative data were analysed using a Wilcoxon sign-rank test and chi-squared test. Qualitative data are reported descriptively. A significantly higher overall preference towards CESM was demonstrated (n = 49, P < 0.001), with faster procedure time, greater comfort and lower noise level cited as the commonest reasons. Participants also reported significantly lower rates of anxiety during CESM compared with CEMRI (n = 36, P = 0.009). A significantly higher rate of comfort was reported during CEMRI for measures of breast compression (n = 49, P = 0.001) and the sensation of IV contrast injection (n = 49, P = 0.003). Our data suggest that overall, patients prefer the experience of CESM to CEMRI, adding support for the role of CESM as a possible alternative to CEMRI for breast cancer staging.

A contrast-enhanced ultrasound study of benign and malignant ...

African Journals Online (AJOL)

A contrast-enhanced ultrasound study of benign and malignant breast tissue. S Barnard, E Leen, T Cooke, W Angerson. Abstract. Objective. To determine the diagnostic value of haemodynamic contrast-enhanced ultrasound assessment in benign and malignant breast tissue, using histological examination as the reference ...

The role of contrast-enhanced endoscopic ultrasound in pancreatic adenocarcinoma

DEFF Research Database (Denmark)

Saftoiu, Adrian; Vilmann, Peter; Bhutani, Manoop S

2016-01-01

contrast agents for early detection, tridimensional and fusion techniques for enhanced staging and resectability assessment but also novel applications of perfusion imaging for monitoring ablative therapy, improved local detection through EUS-guided sampling of portal vein flow or enhanced drug delivery......Contrast-enhanced endoscopic ultrasound (CE-EUS) allows characterization, differentiation, and staging of focal pancreatic masses. The method has a high sensitivity and specificity for the diagnosis of pancreatic adenocarcinoma which is visualized as hypo-enhanced as compared to the rest...... of the parenchyma while chronic pancreatitis and neuroendocrine tumors are generally either iso-enhanced or hyper-enhanced. The development of contrast-enhanced low mechanical index harmonic imaging techniques used in real time during endoscopic ultrasound (EUS) allowed perfusion imaging and the quantification...

In Vivo Differentiation of Complementary Contrast Media at Dual-Energy CT

Science.gov (United States)

Mongan, John; Rathnayake, Samira; Fu, Yanjun; Wang, Runtang; Jones, Ella F.; Gao, Dong-Wei

2012-01-01

Purpose: To evaluate the feasibility of using a commercially available clinical dual-energy computed tomographic (CT) scanner to differentiate the in vivo enhancement due to two simultaneously administered contrast media with complementary x-ray attenuation ratios. Materials and Methods: Approval from the institutional animal care and use committee was obtained, and National Institutes of Health guidelines for the care and use of laboratory animals were observed. Dual-energy CT was performed in a set of iodine and tungsten solution phantoms and in a rabbit in which iodinated intravenous and bismuth subsalicylate oral contrast media were administered. In addition, a second rabbit was studied after intravenous administration of iodinated and tungsten cluster contrast media. Images were processed to produce virtual monochromatic images that simulated the appearance of conventional single-energy scans, as well as material decomposition images that separate the attenuation due to each contrast medium. Results: Clear separation of each of the contrast media pairs was seen in the phantom and in both in vivo animal models. Separation of bowel lumen from vascular contrast medium allowed visualization of bowel wall enhancement that was obscured by intraluminal bowel contrast medium on conventional CT scans. Separation of two vascular contrast media in different vascular phases enabled acquisition of a perfectly coregistered CT angiogram and venous phase–enhanced CT scan simultaneously in a single examination. Conclusion: Commercially available clinical dual-energy CT scanners can help differentiate the enhancement of selected pairs of complementary contrast media in vivo. © RSNA, 2012 PMID:22778447

A novel approach to background subtraction in contrast-enhanced dual-energy digital mammography with commercially available mammography devices: Polychromaticity correction

Energy Technology Data Exchange (ETDEWEB)

Contillo, Adriano, E-mail: contillo@fe.infn.it; Di Domenico, Giovanni; Cardarelli, Paolo; Gambaccini, Mauro; Taibi, Angelo [Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, Via Saragat 1, Ferrara I-44122 (Italy)

2015-11-15

Purpose: Contrast-enhanced digital mammography is an image subtraction technique that is able to improve the detectability of lesions in dense breasts. One of the main sources of error, when the technique is performed by means of commercial mammography devices, is represented by the intrinsic polychromaticity of the x-ray beams. The aim of the work is to propose an iterative procedure, which only assumes the knowledge of a small set of universal quantities, to take into account the polychromaticity and correct the subtraction results accordingly. Methods: In order to verify the procedure, it has been applied to an analytical simulation of a target containing a contrast medium and to actual radiographs of a breast phantom containing cavities filled with a solution of the same medium. Results: The reconstructed densities of contrast medium were compared, showing very good agreement between the theoretical predictions and the experimental results already after the first iteration. Furthermore, the convergence of the iterative procedure was studied, showing that only a small number of iterations is necessary to reach limiting values. Conclusions: The proposed procedure represents an efficient solution to the polychromaticity issue, qualifying therefore as a viable alternative to inverse-map functions.

Is contrast-enhanced CT indicated in acute head injury

International Nuclear Information System (INIS)

Mauser, H.W.; Nieuwenhuizen, O. van; Veiga-Pires, J.A.

1984-01-01

The authors discuss the value of intravenous contrast enhancement in CT scanning in acute head injury. In a series of seventy consecutive patients they conclude that no incremental information was obtained by performing contrast-enhanced CT scans in the acute phase of the head injury. (orig.)

Medial tibial pain: a dynamic contrast-enhanced MRI study.

Science.gov (United States)

Mattila, K T; Komu, M E; Dahlström, S; Koskinen, S K; Heikkilä, J

1999-09-01

The purpose of this study was to compare the sensitivity of different magnetic resonance imaging (MRI) sequences to depict periosteal edema in patients with medial tibial pain. Additionally, we evaluated the ability of dynamic contrast-enhanced imaging (DCES) to depict possible temporal alterations in muscular perfusion within compartments of the leg. Fifteen patients with medial tibial pain were examined with MRI. T1-, T2-weighted, proton density axial images and dynamic and static phase post-contrast images were compared in ability to depict periosteal edema. STIR was used in seven cases to depict bone marrow edema. Images were analyzed to detect signs of compartment edema. Region-of-interest measurements in compartments were performed during DCES and compared with controls. In detecting periosteal edema, post-contrast T1-weighted images were better than spin echo T2-weighted and proton density images or STIR images, but STIR depicted the bone marrow edema best. DCES best demonstrated the gradually enhancing periostitis. Four subjects with severe periosteal edema had visually detectable pathologic enhancement during DCES in the deep posterior compartment of the leg. Percentage enhancement in the deep posterior compartment of the leg was greater in patients than in controls. The fast enhancement phase in the deep posterior compartment began slightly slower in patients than in controls, but it continued longer. We believe that periosteal edema in bone stress reaction can cause impairment of venous flow in the deep posterior compartment. MRI can depict both these conditions. In patients with medial tibial pain, MR imaging protocol should include axial STIR images (to depict bone pathology) with T1-weighted axial pre and post-contrast images, and dynamic contrast enhanced imaging to show periosteal edema and abnormal contrast enhancement within a compartment.

Contrast enhanced MRI findings of ductal carcinoma in situ

International Nuclear Information System (INIS)

Kang, Bong Joo; Cha, Eun Suk; Kim, Hyeon Sook; Suh, Young Jin; Choi, Hyun Joo

2006-01-01

The purpose of this study is to describe characteristic contrast enhanced MR mammographic findings of ductal carcinoma in situ (DCIS) and also DCIS with microinvasion. From January 2000 to July 2005, 32 women with 33 lesions affected by DCIS or DCIS with microinvasion underwent contrast enhanced MRI, and they were then retrospectively evaluated. All the patients had previously undergone mammography and ultrasonography. All the findings of mammography, ultrasonography (US), and MRI were analyzed by using an ACR BI-RADS lexicon. All 33 cases were enhanced on the enhanced MR images. A smooth margined homogeneous enhanced mass was seen in the two (2/33) cases, and nonmass enhancement was seen in 31 (31/33) cases. Among the non-mass enhancement, focal enhancement (7/31), ductal enhancement (5/31), segmental enhancement (9/31), and regional enhancement (10/31) were observed. On the kinetic study, a wash-out pattern (10/33), a plateau pattern (20/33), and a persistent pattern (3/33) were demonstrated. No significant differences were noted between the pure and microinvasive DCIS. There is no significant difference between pure and microinvasive DCIS. However, contrast enhanced MR images can demonstrate occult foci, multifocal lesion and the tumor extent of DCIS on mammogram or ultrasonogram

Contrast-enhanced dedicated breast CT detection of invasive breast cancer preceding mammographic diagnosis

Directory of Open Access Journals (Sweden)

Nicolas D. Prionas, MD, PhD

2015-01-01

Full Text Available Dedicated breast computed tomography (bCT generates high-resolution, three-dimensional images of the pendent uncompressed breast. Intravenous iodinated contrast during bCT provides additional physiologic information. In this case, a 10.0-mm invasive ductal carcinoma was visualized using contrast-enhanced breast CT one year before mammographic detection. Mammography four months before bCT was negative. The bCT contrast enhancement pattern closely matched the dynamic contrast-enhanced MRI obtained after diagnosis. Lesion enhancement at contrast-enhanced breast CT matched previously published enhancement values of breast cancer. Contrast-enhanced dedicated bCT provided high-resolution tomographic images and physiologic contrast enhancement data that facilitated the detection of an early breast cancer.

Contrast Enhancement Algorithm Based on Gap Adjustment for Histogram Equalization

Science.gov (United States)

Chiu, Chung-Cheng; Ting, Chih-Chung

2016-01-01

Image enhancement methods have been widely used to improve the visual effects of images. Owing to its simplicity and effectiveness histogram equalization (HE) is one of the methods used for enhancing image contrast. However, HE may result in over-enhancement and feature loss problems that lead to unnatural look and loss of details in the processed images. Researchers have proposed various HE-based methods to solve the over-enhancement problem; however, they have largely ignored the feature loss problem. Therefore, a contrast enhancement algorithm based on gap adjustment for histogram equalization (CegaHE) is proposed. It refers to a visual contrast enhancement algorithm based on histogram equalization (VCEA), which generates visually pleasing enhanced images, and improves the enhancement effects of VCEA. CegaHE adjusts the gaps between two gray values based on the adjustment equation, which takes the properties of human visual perception into consideration, to solve the over-enhancement problem. Besides, it also alleviates the feature loss problem and further enhances the textures in the dark regions of the images to improve the quality of the processed images for human visual perception. Experimental results demonstrate that CegaHE is a reliable method for contrast enhancement and that it significantly outperforms VCEA and other methods. PMID:27338412

Contrast Enhancement Algorithm Based on Gap Adjustment for Histogram Equalization

Directory of Open Access Journals (Sweden)

Chung-Cheng Chiu

2016-06-01

Full Text Available Image enhancement methods have been widely used to improve the visual effects of images. Owing to its simplicity and effectiveness histogram equalization (HE is one of the methods used for enhancing image contrast. However, HE may result in over-enhancement and feature loss problems that lead to unnatural look and loss of details in the processed images. Researchers have proposed various HE-based methods to solve the over-enhancement problem; however, they have largely ignored the feature loss problem. Therefore, a contrast enhancement algorithm based on gap adjustment for histogram equalization (CegaHE is proposed. It refers to a visual contrast enhancement algorithm based on histogram equalization (VCEA, which generates visually pleasing enhanced images, and improves the enhancement effects of VCEA. CegaHE adjusts the gaps between two gray values based on the adjustment equation, which takes the properties of human visual perception into consideration, to solve the over-enhancement problem. Besides, it also alleviates the feature loss problem and further enhances the textures in the dark regions of the images to improve the quality of the processed images for human visual perception. Experimental results demonstrate that CegaHE is a reliable method for contrast enhancement and that it significantly outperforms VCEA and other methods.

Facial nerve palsy: Evaluation by contrast-enhanced MR imaging

International Nuclear Information System (INIS)

Kinoshita, T.; Ishii, K.; Okitsu, T.; Okudera, T.; Ogawa, T.

2001-01-01

AIM: The purpose of this study was to investigate the value of contrast-enhanced magnetic resonance (MR) imaging in patients with peripheral facial nerve palsy. MATERIALS AND METHODS: MR imaging was performed in 147 patients with facial nerve palsy, using a 1.0 T unit. All of 147 patients were evaluated by contrast-enhanced MR imaging and the pattern of enhancement was compared with that in 300 control subjects evaluated for suspected acoustic neurinoma. RESULTS: The intrameatal and labyrinthine segments of the normal facial nerve did not show enhancement, whereas enhancement of the distal intrameatal segment and the labyrinthine segment was respectively found in 67% and 43% of patients with Bell's palsy. The geniculate ganglion or the tympanic-mastoid segment was enhanced in 21% of normal controls versus 91% of patients with Bell's palsy. Abnormal enhancement of the non-paralyzed facial nerve was found in a patient with bilateral temporal bone fracture. CONCLUSION: Enhancement of the distal intrameatal and labyrinthine segments is specific for facial nerve palsy. Contrast-enhanced MR imaging can reveal inflammatory facial nerve lesions and traumatic nerve injury, including clinically silent damage in trauma. Kinoshita T. et al. (2001)

Facial nerve palsy: Evaluation by contrast-enhanced MR imaging

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, T.; Ishii, K.; Okitsu, T.; Okudera, T.; Ogawa, T

2001-11-01

AIM: The purpose of this study was to investigate the value of contrast-enhanced magnetic resonance (MR) imaging in patients with peripheral facial nerve palsy. MATERIALS AND METHODS: MR imaging was performed in 147 patients with facial nerve palsy, using a 1.0 T unit. All of 147 patients were evaluated by contrast-enhanced MR imaging and the pattern of enhancement was compared with that in 300 control subjects evaluated for suspected acoustic neurinoma. RESULTS: The intrameatal and labyrinthine segments of the normal facial nerve did not show enhancement, whereas enhancement of the distal intrameatal segment and the labyrinthine segment was respectively found in 67% and 43% of patients with Bell's palsy. The geniculate ganglion or the tympanic-mastoid segment was enhanced in 21% of normal controls versus 91% of patients with Bell's palsy. Abnormal enhancement of the non-paralyzed facial nerve was found in a patient with bilateral temporal bone fracture. CONCLUSION: Enhancement of the distal intrameatal and labyrinthine segments is specific for facial nerve palsy. Contrast-enhanced MR imaging can reveal inflammatory facial nerve lesions and traumatic nerve injury, including clinically silent damage in trauma. Kinoshita T. et al. (2001)

Centrifugal (inside-out) enhancement of liver hemangiomas: A possible atypical appearance on contrast-enhanced US

International Nuclear Information System (INIS)

Bartolotta, Tommaso Vincenzo; Taibbi, Adele; Galia, Massimo; Lo Re, Giuseppe; La Grutta, Ludovico; Grassi, Roberto; Midiri, Massimo

2007-01-01

Objective: To report the prevalence and to describe the atypical centrifugal (inside-out) appearance of contrast-enhancement of liver hemangiomas on contrast-enhanced sonography. Materials and methods: Baseline and SonoVue-enhanced ultrasonography of 92 patients with 158 liver hemangiomas - considered atypical at grey-scale examination and confirmed by computed tomography, magnetic resonance imaging and ultrasound follow-up - were reviewed in consensus by two experienced radiologists, who evaluated baseline echogenicity and the dynamic enhancement pattern of each lesion looking for the presence of central enhancing foci in the arterial phase followed by a centrifugal (inside-out) enhancement in the portal-venous and late phases. Results: After administration of SonoVue, 12/158 hemangiomas (7.6%) (size range: 1-7 cm; mean: 3.2 cm) in seven patients (5 women, 2 men; age range: 34-71 years, mean: 50.8 years) showed a central enhancing focus in the arterial phase followed by a centrifugal enhancement in the portal-venous and late phases. In all cases centrifugal enhancement was incomplete at contrast-enhanced sonography, whereas computed tomography and/or magnetic resonance imaging were able to depict a complete and homogeneous fill-in. Conclusion: Radiologist should be aware that centrifugal (inside-out) appearance on contrast-enhanced sonography is a rare but possible feature of liver hemangioma

Centrifugal (inside-out) enhancement of liver hemangiomas: A possible atypical appearance on contrast-enhanced US

Energy Technology Data Exchange (ETDEWEB)

Bartolotta, Tommaso Vincenzo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: tv.bartolotta@unipa.it; Taibbi, Adele [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: taibbi_adele@yahoo.it; Galia, Massimo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: mgalia@yahoo.com; Lo Re, Giuseppe [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: giuseppe.lore12@tin.it; La Grutta, Ludovico [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: lagrutta@mbox.infcom.it; Grassi, Roberto [Institute of Radiology, Second University of Naples, Piazza Miraglia, 80138 Naples (Italy)], E-mail: roberto.grassi@libero.it; Midiri, Massimo [Department of Radiology, University of Palermo, Via Del Vespro 127, 90127 Palermo (Italy)], E-mail: mmidiri@hotmail.com

2007-12-15

Objective: To report the prevalence and to describe the atypical centrifugal (inside-out) appearance of contrast-enhancement of liver hemangiomas on contrast-enhanced sonography. Materials and methods: Baseline and SonoVue-enhanced ultrasonography of 92 patients with 158 liver hemangiomas - considered atypical at grey-scale examination and confirmed by computed tomography, magnetic resonance imaging and ultrasound follow-up - were reviewed in consensus by two experienced radiologists, who evaluated baseline echogenicity and the dynamic enhancement pattern of each lesion looking for the presence of central enhancing foci in the arterial phase followed by a centrifugal (inside-out) enhancement in the portal-venous and late phases. Results: After administration of SonoVue, 12/158 hemangiomas (7.6%) (size range: 1-7 cm; mean: 3.2 cm) in seven patients (5 women, 2 men; age range: 34-71 years, mean: 50.8 years) showed a central enhancing focus in the arterial phase followed by a centrifugal enhancement in the portal-venous and late phases. In all cases centrifugal enhancement was incomplete at contrast-enhanced sonography, whereas computed tomography and/or magnetic resonance imaging were able to depict a complete and homogeneous fill-in. Conclusion: Radiologist should be aware that centrifugal (inside-out) appearance on contrast-enhanced sonography is a rare but possible feature of liver hemangioma.

Contrast agent enhanced pQCT of articular cartilage

Energy Technology Data Exchange (ETDEWEB)

Kallioniemi, A S [Department of Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Jurvelin, J S [Department of Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Nieminen, M T [Department of Diagnostic Radiology, POB 50, 90029 OYS, Oulu University Hospital, Oulu (Finland); Lammi, M J [Department of Anatomy, Institute of Biomedicine, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Toeyraes, J [Department of Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland)

2007-02-21

The delayed gadolinium enhanced MRI of cartilage (dGEMRIC) technique is the only non-invasive means to estimate proteoglycan (PG) content in articular cartilage. In dGEMRIC, the anionic paramagnetic contrast agent gadopentetate distributes in inverse relation to negatively charged PGs, leading to a linear relation between T{sub 1,Gd} and spatial PG content in tissue. In the present study, for the first time, contrast agent enhanced peripheral quantitative computed tomography (pQCT) was applied, analogously to dGEMRIC, for the quantitative detection of spatial PG content in cartilage. The suitability of two anionic radiographic contrast agents, gadopentetate and ioxaglate, to detect enzymatically induced PG depletion in articular cartilage was investigated. First, the interrelationships of x-ray absorption, as measured with pQCT, and the contrast agent solution concentration were investigated. Optimal contrast agent concentrations for the following experiments were selected. Second, diffusion rates for both contrast agents were investigated in intact (n = 3) and trypsin-degraded (n 3) bovine patellar cartilage. The contrast agent concentration of the cartilaginous layer was measured prior to and 2-27 h after immersion. Optimal immersion time for the further experiments was selected. Third, the suitability of gadopentetate and ioxaglate enhanced pQCT to detect the enzymatically induced specific PG depletion was investigated by determining the contrast agent concentrations and uronic acid and water contents in digested and intact osteochondral samples (n = 16). After trypsin-induced PG loss (-70%, p < 0.05) the penetration of gadopentetate and ioxaglate increased (p < 0.05) by 34% and 48%, respectively. Gadopentetate and ioxaglate concentrations both showed strong correlation (r = -0.95, r -0.94, p < 0.01, respectively) with the uronic acid content. To conclude, contrast agent enhanced pQCT provides a technique to quantify PG content in normal and experimentally

Contrast agent enhanced pQCT of articular cartilage

Science.gov (United States)

Kallioniemi, A. S.; Jurvelin, J. S.; Nieminen, M. T.; Lammi, M. J.; Töyräs, J.

2007-02-01

The delayed gadolinium enhanced MRI of cartilage (dGEMRIC) technique is the only non-invasive means to estimate proteoglycan (PG) content in articular cartilage. In dGEMRIC, the anionic paramagnetic contrast agent gadopentetate distributes in inverse relation to negatively charged PGs, leading to a linear relation between T1,Gd and spatial PG content in tissue. In the present study, for the first time, contrast agent enhanced peripheral quantitative computed tomography (pQCT) was applied, analogously to dGEMRIC, for the quantitative detection of spatial PG content in cartilage. The suitability of two anionic radiographic contrast agents, gadopentetate and ioxaglate, to detect enzymatically induced PG depletion in articular cartilage was investigated. First, the interrelationships of x-ray absorption, as measured with pQCT, and the contrast agent solution concentration were investigated. Optimal contrast agent concentrations for the following experiments were selected. Second, diffusion rates for both contrast agents were investigated in intact (n = 3) and trypsin-degraded (n = 3) bovine patellar cartilage. The contrast agent concentration of the cartilaginous layer was measured prior to and 2-27 h after immersion. Optimal immersion time for the further experiments was selected. Third, the suitability of gadopentetate and ioxaglate enhanced pQCT to detect the enzymatically induced specific PG depletion was investigated by determining the contrast agent concentrations and uronic acid and water contents in digested and intact osteochondral samples (n = 16). After trypsin-induced PG loss (-70%, p < 0.05) the penetration of gadopentetate and ioxaglate increased (p < 0.05) by 34% and 48%, respectively. Gadopentetate and ioxaglate concentrations both showed strong correlation (r = -0.95, r = -0.94, p < 0.01, respectively) with the uronic acid content. To conclude, contrast agent enhanced pQCT provides a technique to quantify PG content in normal and experimentally

Contrast agent enhanced pQCT of articular cartilage

International Nuclear Information System (INIS)

Kallioniemi, A S; Jurvelin, J S; Nieminen, M T; Lammi, M J; Toeyraes, J

2007-01-01

The delayed gadolinium enhanced MRI of cartilage (dGEMRIC) technique is the only non-invasive means to estimate proteoglycan (PG) content in articular cartilage. In dGEMRIC, the anionic paramagnetic contrast agent gadopentetate distributes in inverse relation to negatively charged PGs, leading to a linear relation between T 1,Gd and spatial PG content in tissue. In the present study, for the first time, contrast agent enhanced peripheral quantitative computed tomography (pQCT) was applied, analogously to dGEMRIC, for the quantitative detection of spatial PG content in cartilage. The suitability of two anionic radiographic contrast agents, gadopentetate and ioxaglate, to detect enzymatically induced PG depletion in articular cartilage was investigated. First, the interrelationships of x-ray absorption, as measured with pQCT, and the contrast agent solution concentration were investigated. Optimal contrast agent concentrations for the following experiments were selected. Second, diffusion rates for both contrast agents were investigated in intact (n = 3) and trypsin-degraded (n 3) bovine patellar cartilage. The contrast agent concentration of the cartilaginous layer was measured prior to and 2-27 h after immersion. Optimal immersion time for the further experiments was selected. Third, the suitability of gadopentetate and ioxaglate enhanced pQCT to detect the enzymatically induced specific PG depletion was investigated by determining the contrast agent concentrations and uronic acid and water contents in digested and intact osteochondral samples (n = 16). After trypsin-induced PG loss (-70%, p < 0.05) the penetration of gadopentetate and ioxaglate increased (p < 0.05) by 34% and 48%, respectively. Gadopentetate and ioxaglate concentrations both showed strong correlation (r = -0.95, r -0.94, p < 0.01, respectively) with the uronic acid content. To conclude, contrast agent enhanced pQCT provides a technique to quantify PG content in normal and experimentally degraded

Estimation of aortic time-enhancement curve in pharmacokinetic analysis. Dynamic study by multi-detector row computed tomography

International Nuclear Information System (INIS)

Yamaguchi, Isao; Kidoya, Eiji; Higashimura, Kyoji; Hayashi, Hiroyuki; Suzuki, Masayuki

2007-01-01

This paper presents an introduction to the development of software that provides a physiologic model of contrast medium enhancement by incorporating available physiologic data and contrast medium pharmacokinetics to predict an organ-specific aortic time-enhancement curve (TEC) in computed tomography (CT) with various contrast medium injection protocols in patients of various heights, weights, cardiac output levels, and so on. The physiologic model of contrast medium enhancement was composed of six compartments for early contrast enhancement pharmacokinetics. Contrast medium is injected via the antecubital vein and distributed to the right side of the heart, the pulmonary compartment, the left side of the heart, and the aorta. It then circulates back to the right side of the heart via the systemic circulation. A computer-based, compartmental model of the aortic system was generated using human physiologic parameters and six differential equations to describe the transport of contrast medium. Aortic TEC generated by the computer-based physiologic model of contrast medium enhancement showed validity and agreement with clinical data and findings published previously. A computer-based physiologic model that may help predict organ-specific CT contrast medium enhancement for different injection protocols was developed. Such a physiologic model may have multiple clinical applications. (author)

Iopamidol, a new non-ionic X-ray contrast medium

International Nuclear Information System (INIS)

Hagen, B.

1982-01-01

Iopamidol, a new non-ionic, monomeric contrast medium with low osmolality has been well established in our angiographic routine procedures according to the favourable results obtained in more than 300 controlled trials. The general tolerance (demonstrated by the rate of systemic adverse reactions) of the lower concentrated solution (300 mg iodine/ml is a little bit better than that of the higher concentrated one (370 mg iodine/ml). We could demonstrate a significant difference between the two preparations related to local side effects such as pain and heat sensations. The results of 100 intraindividual double blind studies (only peripheral angiography) specially referred to local side effects showed the high significant decrease of pain and heat sensations after application of Iopamidol compared to the results gained by the ionic Ioxitalamate and Ioglicinate. There was no remarkable difference between Iopamidol and Ioxaglate which is a dimeric but likewise low osmolar substance. The role of osmolality in the generation of side effects is pointed out. In consequence the advantages of using contrast media of reducted osmolality particularly in peripheral angiography must be emphasized. (orig.)

Low concentration contrast medium for dual-source computed tomography coronary angiography by a combination of iterative reconstruction and low-tube-voltage technique: Feasibility study

Energy Technology Data Exchange (ETDEWEB)

Zheng, Minwen, E-mail: zhengmw2007@163.com; Liu, Ying, E-mail: yingyinglyly@126.com; Wei, Mengqi, E-mail: weimengqi2008@163.com; Wu, Yongjie, E-mail: wu18291988526@163.com; Zhao, Hongliang, E-mail: zhaohl1980@163.com; Li, Jian, E-mail: xjyylj@yeah.net

2014-02-15

Objectives: To assess the impact of low-concentration contrast medium on vascular enhancement, image quality and radiation dose of coronary CT angiography (cCTA) by using a combination of iterative reconstruction (IR) and low-tube-voltage technique. Materials and methods: One hundred patients were prospectively randomized to two types of contrast medium and underwent prospective electrocardiogram-triggering cCTA (Definition Flash, Siemens Healthcare; collimation: 128 mm × 0.6 mm; tube current: 300 mA s). Fifty patients received Iopromide 370 were scanned using the conventional tube setting (100 kVp or 120 kVp if BMI ≥ 25 kg/m{sup 2}) and reconstructed with filtered back projection (FBP). Fifty patients received Iodixanol 270 were scanned using the low-tube-voltage (80 kVp or 100 kVp if BMI ≥ 25 kg/m{sup 2}) technique and reconstructed with IR. CT attenuation was measured in coronary artery and other anatomical regions. Noise, image quality and radiation dose were compared. Results: Compared with two Iopromide 370 subgroups, Iomeprol 270 subgroups showed no significant difference in CT attenuation (576.63 ± 95.50 vs. 569.51 ± 118.93 for BMI < 25 kg/m{sup 2}, p = 0.647 and 394.19 ± 68.09 vs. 383.72 ± 63.11 for BMI ≥ 25 kg/m{sup 2}, p = 0.212), noise (in various anatomical regions of interest) and image quality (3.5 vs. 4.0, p = 0.13), but significantly (0.41 ± 0.17 vs. 0.94 ± 0.45 for BMI < 25 kg/m{sup 2}, p < 0.001 and 1.14 ± 0.24 vs. 2.37 ± 0.69 for BMI ≥ 25 kg/m{sup 2}, p < 0.001) lower radiation dose, which reflects dose saving of 56.4% and 51.9%, respectively. Conclusions: Combined IR with low-tube-voltage technique, a low-concentration contrast medium of 270 mg I/ml can still maintain the contrast enhancement without impairing image quality, as well as significantly lower the radiation dose.

Semi-quantitative assessment of tricuspid regurgitation on contrast-enhanced multidetector CT

International Nuclear Information System (INIS)

Groves, A.M.; Win, T.; Charman, S.C.; Wisbey, C.; Pepke-Zaba, J.; Coulden, R.A.

2004-01-01

AIM: To assess whether the early regurgitation of intravenous contrast medium into the inferior vena cava (IVC) and/or hepatic veins on computed tomography (CT), indicates tricuspid regurgitation (TR), and if so, whether it be used to grade severity. MATERIALS AND METHODS: We identified 86 consecutive patients that had been investigated for possible pulmonary endarterectomy at Papworth Hospital. From these, 61 patients were selected in whom CT, transthoracic echocardiography, and right heart catheterization (RHC) had been performed within 6 weeks. Using an arbitrary visual scale, the degree of TR assessed by intravenous contrast-enhanced CT was compared with echocardiography. Results were analysed using a kappa weighted statistical test. In addition, CT and echocardiographic assessments of TR severity were correlated with pulmonary artery pressure measurements obtained by RHC (Spearman's rank correlation coefficient). RESULTS: CT assessment of TR had a sensitivity of 90.4% and a specificity of 100% in detecting echocardiographic TR. For TR graded as more than trivial by echocardiography, sensitivity of CT was 100%. With respect to RHC data, the correlation between severity assessment of TR between CT and echocardiography using the Kappa weighted coefficient was 0.56 (moderately good agreement). With respect to RHC data, the correlation between mean pulmonary pressure and TR grading on CT and echocardiography was r=0.685 (p<0.001) and r=0.727 (p<0.001), respectively. CONCLUSION: Early opacification of the IVC or hepatic veins on first-pass contrast-enhanced CT almost invariably indicates TR. There is moderately good agreement between CT and echocardiographic assessment of the severity of TR. Both CT and echocardiographic grading of TR correlate well with RHC measurements of pulmonary artery pressure

Effect of barium sulfate contrast medium on rheology and sensory texture attributes in a model food.

Science.gov (United States)

Ekberg, O; Bulow, M; Ekman, S; Hall, G; Stading, M; Wendin, K

2009-03-01

The swallowing process can be visualized using videoradiography, by mixing food with contrast medium, e.g., barium sulfate (BaSO(4)), making it radiopaque. The sensory properties of foods may be affected by adding this medium. To evaluate if and to what extent sensory and rheological characteristics of mango purée were altered by adding barium sulfate to the food. This study evaluated four food samples based on mango purée, with no or added barium sulfate contrast medium (0%, 12.5%, 25.0%, and 37.5%), by a radiographic method, and measured sensory texture properties and rheological characteristics. The sensory evaluation was performed by an external trained panel using quantitative descriptive analysis. The ease of swallowing the foods was also evaluated. The sensory texture properties of mango purée were significantly affected by the added barium in all evaluated attributes, as was the perception of particles. Moreover, ease of swallowing was significantly higher in the sample without added contrast medium. All samples decreased in extensional viscosity with increasing extension rate, i.e., all samples were tension thinning. Shear viscosity was not as dependent on the concentration of BaSO(4) as extensional viscosity. Addition of barium sulfate to a model food of mango purée has a major impact on perceived sensory texture attributes as well as on rheological parameters.

Algorithms for contrast enhancement of electronic portal images

International Nuclear Information System (INIS)

Díez, S.; Sánchez, S.

2015-01-01

An implementation of two new automatized image processing algorithms for contrast enhancement of portal images is presented as suitable tools which facilitate the setup verification and visualization of patients during radiotherapy treatments. In the first algorithm, called Automatic Segmentation and Histogram Stretching (ASHS), the portal image is automatically segmented in two sub-images delimited by the conformed treatment beam: one image consisting of the imaged patient obtained directly from the radiation treatment field, and the second one is composed of the imaged patient outside it. By segmenting the original image, a histogram stretching can be independently performed and improved in both regions. The second algorithm involves a two-step process. In the first step, a Normalization to Local Mean (NLM), an inverse restoration filter is applied by dividing pixel by pixel a portal image by its blurred version. In the second step, named Lineally Combined Local Histogram Equalization (LCLHE), the contrast of the original image is strongly improved by a Local Contrast Enhancement (LCE) algorithm, revealing the anatomical structures of patients. The output image is lineally combined with a portal image of the patient. Finally the output images of the previous algorithms (NLM and LCLHE) are lineally combined, once again, in order to obtain a contrast enhanced image. These two algorithms have been tested on several portal images with great results. - Highlights: • Two Algorithms are implemented to improve the contrast of Electronic Portal Images. • The multi-leaf and conformed beam are automatically segmented into Portal Images. • Hidden anatomical and bony structures in portal images are revealed. • The task related to the patient setup verification is facilitated by the contrast enhancement then achieved.

Applications of contrast enhanced CT through external jugular access

International Nuclear Information System (INIS)

Xu Qiaolan; Zou Wenxing; Chen Meixia; Xie Hongbo

2005-01-01

Objective: A retrospective analysis and evaluation for the effects of contrast enhanced computed tomography through external jugular access. Methods: 1250 cases (male 692 and female 558) underwent CT contrast enhanced examination were retrospectively reviewed from May, 2002 to Oct, 2002. The patients aged from 12 to 86 years, averagely 49 years. Contrast agent (Ultravist) was given through an intravenous catheter placed in the cubital vein. Precise injection rates were ensured by a power injector (Medrad MCT310, USA). Excellent enhancement was achieved with this protocol in most of the patients, while external jugular access was established in 96 cases because it was unable to setup a cubital venous access. Results: Good enhancement were acquired when 96 cases of contrast agent injected through external jugular vein. And the external jugular access was setup successfully with a single puncture. Conclusion: It is a common occasion when patient undergoing contrast enhanced CT scan is in poor conditions: debility, cachexia, or with complication of chemotherapy or radiation therapy, which often results in invalidity of cabital venous access, and consequently, making bolus injection impossible. The external jugular vein is a large and central blood vessel, which is easy to setup an access. In our experience, an external jugular access should be recommended as a substitution if the cubital venous access is not available. (authors)

Applications of contrast enhanced CT through external jugular access

Energy Technology Data Exchange (ETDEWEB)

Qiaolan, Xu; Wenxing, Zou; Meixia, Chen; Hongbo, Xie [The First Affiliated Hospital of Sun Yat-sen University, Guangzhou (China). Dept. of Radiology

2005-09-15

Objective: A retrospective analysis and evaluation for the effects of contrast enhanced computed tomography through external jugular access. Methods: 1250 cases (male 692 and female 558) underwent CT contrast enhanced examination were retrospectively reviewed from May, 2002 to Oct, 2002. The patients aged from 12 to 86 years, averagely 49 years. Contrast agent (Ultravist) was given through an intravenous catheter placed in the cubital vein. Precise injection rates were ensured by a power injector (Medrad MCT310, USA). Excellent enhancement was achieved with this protocol in most of the patients, while external jugular access was established in 96 cases because it was unable to setup a cubital venous access. Results: Good enhancement were acquired when 96 cases of contrast agent injected through external jugular vein. And the external jugular access was setup successfully with a single puncture. Conclusion: It is a common occasion when patient undergoing contrast enhanced CT scan is in poor conditions: debility, cachexia, or with complication of chemotherapy or radiation therapy, which often results in invalidity of cabital venous access, and consequently, making bolus injection impossible. The external jugular vein is a large and central blood vessel, which is easy to setup an access. In our experience, an external jugular access should be recommended as a substitution if the cubital venous access is not available. (authors)

Contrast-enhanced ultrasound for extrahepatic lesions: preliminary experience

Energy Technology Data Exchange (ETDEWEB)

Thorelius, Lars E-mail: lars@thorelius.com

2004-06-01

Ultrasound imaging (US) is a convenient, inexpensive and non-invasive investigation. Its use is limited by low sensitivity in the detection of a number of parenchymal lesions, especially those produced by trauma, such as infarctions. Contrast enhancement with SonoVue{sup [reg]} improves the sensitivity of ultrasound in the detection and characterization of focal liver lesions to such an extent, that it may replace computed tomography (CT) and magnetic resonance imaging (MRI). Preliminary experience suggests that SonoVue-enhanced sonography may be useful in the detection of lesions in which blood flow is severely reduced as compared to surrounding parenchyma, such as infarctions, lacerations, hematomas, necrotic tissue and non-vascular cysts, especially in the spleen, kidney and pancreas. This technique can also rule out occlusion of the superior mesenteric, splenic and portal veins, and dilation of the biliary tree. Clinical trials comparing contrast-enhanced sonography with contrast-enhanced computed tomography are warranted to establish the role of this inexpensive and non-invasive technique in the routine work-up of patients with abdominal trauma or presenting with sudden flank pain.

3D CT cerebral angiography technique using a 320-detector machine with a time–density curve and low contrast medium volume: Comparison with fixed time delay technique

International Nuclear Information System (INIS)

Das, K.; Biswas, S.; Roughley, S.; Bhojak, M.; Niven, S.

2014-01-01

Aim: To describe a cerebral computed tomography angiography (CTA) technique using a 320-detector CT machine and a small contrast medium volume (35 ml, 15 ml for test bolus). Also, to compare the quality of these images with that of the images acquired using a larger contrast medium volume (90 or 120 ml) and a fixed time delay (FTD) of 18 s using a 16-detector CT machine. Materials and methods: Cerebral CTA images were acquired using a 320-detector machine by synchronizing the scanning time with the time of peak enhancement as determined from the time–density curve (TDC) using a test bolus dose. The quality of CTA images acquired using this technique was compared with that obtained using a FTD of 18 s (by 16-detector CT), retrospectively. Average densities in four different intracranial arteries, overall opacification of arteries, and the degree of venous contamination were graded and compared. Results: Thirty-eight patients were scanned using the TDC technique and 40 patients using the FTD technique. The arterial densities achieved by the TDC technique were higher (significant for supraclinoid and basilar arteries, p < 0.05). The proportion of images deemed as having “good” arterial opacification was 95% for TDC and 90% for FTD. The degree of venous contamination was significantly higher in images produced by the FTD technique (p < 0.001%). Conclusion: Good diagnostic quality CTA images with significant reduction of venous contamination can be achieved with a low contrast medium dose using a 320-detector machine by coupling the time of data acquisition with the time of peak enhancement

In vivo magnetic resonance imaging of atherosclerotic lesions with a newly developed Evans blue-DTPA-gadolinium contrast medium in apolipoprotein-E-deficient mice.

Science.gov (United States)

Yasuda, Satoshi; Ikuta, Kenjiro; Uwatoku, Toyokazu; Oi, Keiji; Abe, Kohtaro; Hyodo, Fuminori; Yoshimitsu, Kengo; Sugimura, Kohtaro; Utsumi, Hideo; Katayama, Yoshiki; Shimokawa, Hiroaki

2008-01-01

Magnetic resonance imaging (MRI) contrast agents that specifically detect atherosclerotic plaque may be useful for the noninvasive detection of the plaque. We have recently developed a new contrast agent, Evans blue-DTPA-gadolinium (EB-DTPA-Gd), which selectively accumulates vascular lesions with endothelial removal. In this study, we examined whether EB-DTPA-Gd is also useful for in vivo imaging of atherosclerotic plaques. We used male apolipoprotein-E-deficient (ApoE-/-) mice of different ages (3, 6 and 12 months old) and age-matched male wild-type mice. After a single intravenous administration of EB-DTPA-Gd (160 microM/kg body weight), MRI T(1) signal was obtained in vivo. Increased signal intensity in the aortic wall was noted within 10-20 min after intravenous injection of EB-DTPA-Gd and was maintained for 30 min. The MRI enhancement in the aorta of ApoE-/- mice was increased in accordance with age, whereas no such enhancement was noted in wild-type mice. Histological examination demonstrated that there was a topological correlation between the site of MRI enhancement and that of atherosclerotic plaque. These results indicate that EB-DTPA-Gd is a useful MRI contrast medium for the in vivo detection of atherosclerotic plaques. Copyright (c) 2007 S. Karger AG, Basel.

Automatic Time Sequence Alignment in Contrast Enhanced MRI by Maximization of Mutual Information

National Research Council Canada - National Science Library

Positano, Vicenzo

2001-01-01

The use of contrast medium allows joining the high-resolution anatomical information provided by standard magnetic resonance with functional information obtained by means of the diffusion of contrast...

Confident Diagnosis of Bronchobiliary Fistula Using Contrast-Enhanced Magnetic Resonance Cholangiography

Energy Technology Data Exchange (ETDEWEB)

Karabulut, Nevzat; Cakmak, Vefa; Kiter, Go ksel [Pamukkale University Medical Center, Denizli (Turkmenistan)

2010-08-15

We report the utility of contrast-enhanced magnetic resonance cholangiography (MRC) using gadoxetic acid (Gd-EOB-DTPA) in the diagnosis of bronchobiliary fistula associated with liver hydatid cyst. Contrast-enhanced MRC clearly delineated the leakage of contrast agent from the biliary duct and its communication with the bronchial tree. Providing functional information about physiologic or pathologic biliary flow in addition to the display of biliary anatomy, contrast enhanced MRC stands as a robust technique in confidently detecting bronchobiliary fistula and bile leaks

Cranial CT revisited: do we really need contrast enhancement?

International Nuclear Information System (INIS)

Demaerel, P.; Buelens, C.; Wilms, G.; Baert, A.L.

1998-01-01

The aim of this study was to define guidelines for intravenous contrast administration in cranial CT, as currently there are no recent guidelines based on a large series of patients. In 1900 consecutive patients (1480 adults and 420 children) pre- and post-contrast scan was analysed in order to assess the contribution of contrast enhancement to the diagnosis. The findings were grouped according to whether abnormalities were seen on the pre- and/or post-contrast scan, or whether no abnormalities were seen at all. Sensitivity, specificity, positive predictive value, negative predictive value and accurracy of a pre-contrast scan were used to determine validity. Intravenous contrast enhancement only contributes to the diagnosis if a suspicious abnormality is seen on the unenhanced scan or in the appropriate clinical setting (33.6 %). In the remaining patients (65.6 %) there is no diagnostic contribution, except for a small number of abnormalities (0.8 %). These are often anatomical variants and have no therapeutic impact. The number of contrast-enhanced cranial CT examinations can significantly be reduced by using four general guidelines for contrast administration resulting in considerable cost savings without affecting the quality of service to the patient. These guidelines are defined by the clinical findings/presentation or by the findings on the unenhanced scan. The number of contrast-related complications will be reduced, which may have medicolegal implications. These guidelines can be applied in any radiology department. (orig.) (orig.)

Contrast-enhanced ultra-high-field liver MRI: A feasibility trial

Energy Technology Data Exchange (ETDEWEB)

Umutlu, Lale, E-mail: Lale.Umutlu@uk-essen.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Bitz, Andreas K.; Maderwald, Stefan; Orzada, Stephan; Kinner, Sonja; Kraff, Oliver; Brote, Irina; Ladd, Susanne C.; Schroeder, Tobias; Forsting, Michael; Antoch, Gerald; Ladd, Mark E. [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Quick, Harald H. [Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Institute of Medical Physics, University Nuernberg-Erlangen (Germany); Lauenstein, Thomas C. [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany)

2013-05-15

The aim of this study was to investigate the feasibility of dynamic contrast-enhanced 7 T MRI of the liver using an eight-channel radiofrequency (RF) transmit/receive body-coil. 16 healthy subjects were examined on a 7 T MR system utilizing a custom-built eight-channel RF body-coil suitable for RF-shimming. The following data were acquired: (1) steady state free precession imaging, (2) T2w turbo spin echo imaging, (3) T1w in and opposed-phase imaging, (4) T1w 3D FLASH images pre-contrast and in arterial, portal-venous and venous phase and (5) a fat-saturated pre- and post-contrast 2D FLASH sequence. Visual evaluation of (1) the delineation of liver vasculature, (2) the overall image quality, and (3) artifact presence and consequent image impairment was performed. SNR of the liver parenchyma was measured for the contrast-enhanced 2D and 3D FLASH sequences. For statistical analysis, a Wilcoxon-Rank Test was used. Best delineation of non-enhanced liver vasculature and overall image quality was found for 2D FLASH MRI, with only slight improvement in vessel conspicuity after the application of contrast media. T2-weighted TSE imaging remained strongly impaired, falling short of diagnostic relevance and precluding a clinical application. Our results demonstrate the feasibility and diagnostic potential of dedicated contrast-enhanced 7 T liver MRI as well as the potential for non-contrast-enhanced angiographic application.

The predictive value of the product of contrast medium volume and urinary albumin/creatinine ratio in contrast-induced acute kidney injury.

Science.gov (United States)

Wang, Chunrui; Ma, Shuai; Deng, Bo; Lu, Jianxin; Shen, Wei; Jin, Bo; Shi, Haiming; Ding, Feng

2017-11-01

Preexisting renal impairment and the amount of contrast media are the most important risk factors for contrast-induced acute kidney injury (CI-AKI). We aimed to investigate whether the product of contrast medium volume and urinary albumin/creatinine ratio (CMV × UACR) would be a better predictor of CI-AKI in patients undergoing nonemergency coronary interventions. This was a prospective single-center observational study, and 912 consecutive patients who were exposed to contrast media during coronary interventions were investigated prospectively. CI-AKI is defined as a 44.2 μmol/L rise in serum creatinine or a 25% increase, assessed within 48 h after administration of contrast media in the absence of other causes. Fifty patients (5.48%) developed CI-AKI. The urinary albumin/creatinine ratio (UACR) (OR = 1.002, 95% CI = 1.000-1.003, p = .012) and contrast medium volume (CMV) (OR = 1.008, 95% CI = 1.001-1.014, p = .017) were independent risk factors for the development of CI-AKI. The area under the ROC curve of CMV, UACR and CMV × UACR were 0.662 (95% CI = 0.584-0.741, p < .001), 0.761 (95% CI = 0.674-0.847, p < .001) and 0.808 (95% CI = 0.747-0.896, p < .001), respectively. The cutoff value of CMV × UACR to predict CI-AKI was 1186.2, with 80.0% sensitivity and 62.2% specificity. The product of CMV and UACR (CMV × UACR) might be a predictor of CI-AKI in patients undergoing nonemergency coronary interventions, which was superior to CMV or UACR alone.

Computed tomography of kidney with diuretics. A method for avoiding artifact due to nonionic contrast medium

Energy Technology Data Exchange (ETDEWEB)

Hiromura, Tadao; Terae, Satoshi; Takamura, Akio; Mizoe, Junetsu (Obihiro Kosei Hospital, Hokkaido (Japan)); Morita, Yutaka; Irie, Goro

1989-07-01

We devised a method for avoiding beam-hardening artifacts, which interfere with enhanced CT images of kidney due to nonionic contrast medium. The radiographic effect and the frequency of beam-hardening artifacts on enhanced CT of kidney were studied by prospective comparison among three groups: a group of 20 patients examined with furosemide (f-d.CT), a group of 20 patients examined without diuretics (non-d.CT) and a group of 20 patients examined after water intake (w-d.CT). In all patients of f-d.CT group, the renal parenchyma from the cortex to the papilla was almost evently enhanced, free from artifacts. The density of the renal papilla and pelvis in non-d.CT and w-d.CT groups was significantly higher than that in f-d.CT group, and artifacts were also observed in 14 (70%) of non-d.CT group and 12 (60%) of w.d.CT group, respectively. Satisfactory CT of kidney free from artifacts was obtained by f-d.CT, providing easy evaluation of renal pelvic or peripelvic lesions. In conclusion, this technique can be used in those pathologic cases of renal pelvis or peripelvic region, that are not clear on routine CT because of artifacts. (author).

Contrast enhancement pattern in MR imaging of acute cerebral infarction

International Nuclear Information System (INIS)

Kim, Jong Deok; Cho, Mee Young; Lee, Chae Guk; Song, Dong Hoon

1994-01-01

To present the enhancement pattern of acute cerebral or cerebellar cortical infarctions aged 1-3 days on MR. Contrast-enhanced MR images of 26 patients with acute cerebral or cerebellar ischemic events were retrospectively reviewed. MR was performed within 3 days after ictus. Contrast enhancement in the area of infarction was observed in 61.5% (16/26) on MR. Of these 50% (13/26) showed non-parenchymal enhancement (NPE) representing either vascular or leptomeningeal enhancement, 7.7% (2/26) showed parenchymal enhancement (PE), and 2.8% (1/26) showed both NPE and PE. The earliest enhancement was seen in images obtained 12 hours after the onset of symptoms and appeared as NPE. One patient showed NPE without apparent high signal intensity at the corresponding area on T2-weighted images. In 38.5% (10/26), there was no enhancement. Contrast-enhanced MR imaging may be needed in acute ischemic infarction, because NPE may be seen as the earliest MR finding of acute cortical infraction aged 1-3 days

Contrast enhancement pattern in MR imaging of acute cerebral infarction

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Deok; Cho, Mee Young; Lee, Chae Guk; Song, Dong Hoon [Inje University College of Medicine, Pusan (Korea, Republic of)

1994-08-15

To present the enhancement pattern of acute cerebral or cerebellar cortical infarctions aged 1-3 days on MR. Contrast-enhanced MR images of 26 patients with acute cerebral or cerebellar ischemic events were retrospectively reviewed. MR was performed within 3 days after ictus. Contrast enhancement in the area of infarction was observed in 61.5% (16/26) on MR. Of these 50% (13/26) showed non-parenchymal enhancement (NPE) representing either vascular or leptomeningeal enhancement, 7.7% (2/26) showed parenchymal enhancement (PE), and 2.8% (1/26) showed both NPE and PE. The earliest enhancement was seen in images obtained 12 hours after the onset of symptoms and appeared as NPE. One patient showed NPE without apparent high signal intensity at the corresponding area on T2-weighted images. In 38.5% (10/26), there was no enhancement. Contrast-enhanced MR imaging may be needed in acute ischemic infarction, because NPE may be seen as the earliest MR finding of acute cortical infraction aged 1-3 days.

Non-enhanced CT versus contrast-enhanced CT in integrated PET/CT studies for nodal staging of rectal cancer

International Nuclear Information System (INIS)

Tateishi, Ukihide; Maeda, Tetsuo; Morimoto, Tsuyoshi; Miyake, Mototaka; Arai, Yasuaki; Kim, E.E.

2007-01-01

The purpose of the present study was to determine the diagnostic accuracy of non-enhanced CT and contrast-enhanced CT in integrated PET/CT studies for preoperative nodal staging of rectal cancer. Retrospective analysis was performed in 53 patients with pathologically proven rectal cancer who had been referred for preoperative staging. All patients underwent integrated PET/CT consisting of non-enhanced and contrast-enhanced CT followed by whole-body fluorine-18-fluorodeoxyglucose ([ 18 F]FDG) PET. Both non-enhanced and contrast-enhanced PET/CT images were evaluated separately by two observers in consensus. The reference standard was histopathologic results. For nodal staging of rectal cancer, we compared diagnostic accuracy on a per-patient basis between the two modalities. Nodal staging was correctly determined with non-enhanced studies in 37 patients (70%) and with contrast-enhanced studies in 42 patients (79%). On a per-patient basis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of regional lymph node staging were 85%, 68%, 83%, 72%, and 79%, respectively, with contrast-enhanced studies, and 85%, 42%, 73%, 62%, and 70%, respectively, with non-enhanced studies. The difference in the accuracy of nodal staging between the two modalities was not significant (p = 0.063). Compared with non-enhanced studies, contrast-enhanced studies determined more correctly the status of pararectal lymph nodes (p 0.002), internal iliac lymph nodes (p = 0.004), and obturator lymph nodes (p < 0.0001). Contrast-enhanced PET/CT is superior to non-enhanced PET/CT for precise definition of regional nodal status in rectal cancer. (orig.)

Contrast-Enhanced Ultrasound in Vascular Surgery

DEFF Research Database (Denmark)

Bredahl, Kim; Mestre, Xavier Marti; Coll, Ramon Vila

2017-01-01

modalities. Ultrasound has only challenged these methods in assessment of carotid disease, aortic aneurysms, venous insufficiency, and thromboembolism and in surveillance of in situ bypasses. These practice patterns may change with the introduction of second-generation ultrasound contrast agents which...... are easy to use, manageable, and safe. This topical review attempts to summarize and highlight the current evidence and future prospects for contrast-enhanced ultrasound in vascular surgery, with a particular focus on opportunities in carotid and lower limb arteriosclerotic disease and surveillance after...

Comparison between two positive and one negative oral contrast medium for abdominal CT diagnosis

International Nuclear Information System (INIS)

Zwaan, M.; Gmelin, E.

1989-01-01

In a prospective randomised study three groups of 30 patients each were subjected to CT of the entire abdomen. The oral intestinal contrast media used were iodine solution (2%), barium suspension (1.5%) and paraffin emulsion (25%). The results were evaluated according to imaging, artifacts, assessability of the intestinal wall, taste and side effects. All three contrast media are suitable for marking the gastrointestinal tract; paraffin shows advantages in the upper part of the tract and is the only medium that enables assessment of the wall, while causing the lowest rate of artifacts. Barium has a high acceptance and the best tolerance of all contrast agents. (orig.) [de

Comparison of neutral and positive enteral contrast media for MDCT enteroclysis

International Nuclear Information System (INIS)

Aiyappan, Senthil Kumar; Kalra, Naveen; Sandhu, Manavjit Singh; Kochhar, Rakesh; Wig, Jai Dev; Khandelwal, Niranjan

2012-01-01

Objective: To compare neutral and positive enteral contrast media for MDCT enteroclysis (MDCTE) in various small bowel diseases. Materials and methods: 40 patients with suspicion of small bowel diseases were divided randomly into two equal groups. In one group, water was used as neutral enteral contrast and in other group, 2% water soluble iodinated contrast was used as positive enteral contrast. All MDCTE were done on a 16-slice multidetector row CT unit. The findings of MDCTE were compared with the standards of reference. Results: There were 12 cases of abdominal tuberculosis (30%), 5 cases of bowel masses (12%), 4 cases of Crohn's disease (10%), 3 cases of small bowel adhesions (7%), 2 cases of midgut volvulus (5%), 2 cases of segmental enteritis (5%) and 12 of all cases (30%) were normal. There was no statistically significant difference between neutral and positive enteral contrast with regards to bowel distention, contrast reflux and evaluation of duodenum. Abnormal bowel wall enhancement was appreciated only with use of neutral enteral contrast (n = 12). Evaluation of ileocaecal junction was possible in all 20 patients (100%) with positive enteral contrast but in only 17 patients (85%) with neutral enteral contrast. Overall sensitivity and specificity of MDCTE with use of neutral contrast medium (100 and 88% respectively) was greater for evaluation of small bowel diseases, when compared to MDCTE using positive enteral contrast medium (92.8 and 83.3% respectively). Conclusions: Water is a good enteral contrast medium for MDCT enteroclysis examination and allows better evaluation of abnormal bowel wall enhancement. Ileocaecal junction evaluation is better with positive enteral contrast medium.

Improvement of observer performance during fluoroscopy by local adaptive contrast enhancement

International Nuclear Information System (INIS)

Gould, R.G.; Demas, B.E.; Maroney, T.P.

1988-01-01

The ability of a video processor (FluoroVision FV-1), which performs two-dimensional locally adaptive contrast enhancement, to improve the detection of a low-contrast object was evaluated by means of receiver operating characteristic (ROC) curves. Three independent observers viewed a videotape of 50 fluoroscopic images of a varied background, in which a test object was present in 25. Each observer viewed the tape under four conditions: (1) no processing, (2) temporal noise reduction (gaussian weighted time averaging, (3) contrast enhancement, and (4) both noise reduction and contrast enhancement. The results were that detection was significantly improved by the locally adaptive contrast enhancement. Noise reduction did not significantly improve performance, probably because washer detection was limited by background contrast variations as well as noise and because only a small amount of noise reduction was used. The authors conclude that the processing device is potentially valuable in improving the quality of clinical fluoroscopic images

Feasibility of opportunistic osteoporosis screening in routine contrast-enhanced multi detector computed tomography (MDCT) using texture analysis.

Science.gov (United States)

Mookiah, M R K; Rohrmeier, A; Dieckmeyer, M; Mei, K; Kopp, F K; Noel, P B; Kirschke, J S; Baum, T; Subburaj, K

2018-04-01

This study investigated the feasibility of opportunistic osteoporosis screening in routine contrast-enhanced MDCT exams using texture analysis. The results showed an acceptable reproducibility of texture features, and these features could discriminate healthy/osteoporotic fracture cohort with an accuracy of 83%. This aim of this study is to investigate the feasibility of opportunistic osteoporosis screening in routine contrast-enhanced MDCT exams using texture analysis. We performed texture analysis at the spine in routine MDCT exams and investigated the effect of intravenous contrast medium (IVCM) (n = 7), slice thickness (n = 7), the long-term reproducibility (n = 9), and the ability to differentiate healthy/osteoporotic fracture cohort (n = 9 age and gender matched pairs). Eight texture features were extracted using gray level co-occurrence matrix (GLCM). The independent sample t test was used to rank the features of healthy/fracture cohort and classification was performed using support vector machine (SVM). The results revealed significant correlations between texture parameters derived from MDCT scans with and without IVCM (r up to 0.91) slice thickness of 1 mm versus 2 and 3 mm (r up to 0.96) and scan-rescan (r up to 0.59). The performance of the SVM classifier was evaluated using 10-fold cross-validation and revealed an average classification accuracy of 83%. Opportunistic osteoporosis screening at the spine using specific texture parameters (energy, entropy, and homogeneity) and SVM can be performed in routine contrast-enhanced MDCT exams.

Recent advances in contrast-enhanced magnetic resonance angiography

International Nuclear Information System (INIS)

Meaney, J.F.M.; Goyen, M.

2007-01-01

Magnetic resonance angiography (MRA) provides a means of visualizing vascular structures noninvasively and is increasingly replacing conventional X-ray angiography in routine use. Contrast-enhanced MRA (CE-MRA), in which gadolinium contrast agents are used to shorten the T1 relaxation, offers increased resolution and higher signal-to-noise ratio compared with earlier flow-dependent [time-of-flight (TOF) or phase-contrast (PC)] techniques. Currently available contrast agents differ in their ability to lower T1 values, and hence the choice of contrast agent is an important consideration in the successful use of CE-MRA. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first of a new class of intravascular contrast agents. This agent is extensively (approximately 85%) and reversibly bound to human serum albumin and is retained within the vasculature thus allowing steady-state imaging to be perform-ed. An additional benefit is that gado0fosveset offers higher relaxivity compared with other contrast agents, thus giving a lower blood T1 values which also makes it ideal for first-pass imaging. Clinical trials have consistently shown that gadofosveset enhanced MRA is more sensitive, specific and accurate than time-of-flight MRA, gives fewer uninterpretable scans and affords greater diagnostic confidence. Intravascular contrast agents such as gadofosveset, therefore, offer the potential for improved vascular imaging. (orig.)

Contrast-enhanced fast fluid-attenuated inversion recovery MR imaging in patients with brain tumors

International Nuclear Information System (INIS)

Kim, Chan Kyo; Na, Dong Gyu; Ryoo, Wook Jae; Byun Hong Sik; Yoon, Hye Kyung; Kim, Jong hyun

2000-01-01

To assess the feasibility of contrast-enhanced fast fluid-attenuated inversion recovery (fast FLAIR) MR imaging in patients with brain tumors. This study involved 31 patients with pathologically proven brain tumors and nine with clinically diagnosed metastases. In all patients, T2-weighted, fast FLAIR, images were visual contrast-enhanced T1-weighted MR images were obtained. Contrast-enhanced fast FLAIR images were visually compared with other MR sequences in terms of tumor conspicuity. In order to distinguish tumor and surrounding edema, contrast-enhanced fast FLAIR images were compared with fast FLAIR and T2-weighted images. The tumor-to- white matter contrast-to-noise ratios (CNRs), as demonstrated by T2-weighted, fast FLAIR, contrast-enhanced fast FLAIR and contrast-enhanced T1-weighted imaging, were quantitatively assessed and compared. For the visual assessment of tumor conspicuity, contrast-enhanced fast FLAIR image imaging superior to fast FLAIR in 60% of cases (24/40), and superior to T2-weighted in 70% (28/40). Contrast-enhanced fast FLAIR imaging was inferior to contrast-enhanced T1-weighted in 58% of cases (23/40). For distinguishing between tumor and surrounding edema, contrast-enhanced fast FLAIR imaging was superior to fast FLAIR or T2-weighted in 22 of 27 tumors with peritumoral edema (81%). Quantitatively, CNR was the highest on contrast-enhanced fast FLAIR image and the lowest on fast FLAIR. For the detection of leptomeningeal metastases, contrast-enhanced fast FLAIR was partially superior to contrast-enhanced T1-weighted imaging in two of three high-grade gliomas. Although contrast-enhanced fast FLAIR imaging should not be seen as a replacement for conventional modalities, it provides additional informaton for assessment of the extent of glial cell tumors and leptomeningeal metastases in patients with brain tumors. (author)

Use of Iodine-based contrast media in digital full-field mammography - initial experience

International Nuclear Information System (INIS)

Diekmann, F.; Diekmann, S.; Taupitz, M.; Bick, U.; Winzer, K.-J.; Huettner, C.; Muller, S.; Jeunehomme, F.; Hamm, B.

2003-01-01

Aim: To investigate the use of iodine-based contrast media in digital full-field mammography. Methods: After performing initial phantom studies, seven patients underwent digital mammography (Senographe 2000D, GE Medical Systems, Milwaukee, USA) using a specially filtered beam before as well as 60, 120, and 180 seconds after injection of 80 ml of iodine contrast medium (Ultravist 370, Schering AG, Germany). The precontrast mammograms were then subtracted from the postcontrast mammograms and the resulting images compared with a contrast-enhanced dynamic MRI study, performed on all women. Results: Contrast medium accumulation within the tumors was visualized with a good quality in all cases. The conditions under which successful contrast-enhanced digital mammography can be performed were determined in phantom studies. Conclusions: Contrast-enhanced digital mammography has a potential for improving the visualization of breast tumors in mammography using special beam filtering, adjusted X-ray parameters, proper timing, and suitable subtraction software. (orig.) [de

Physical experiments on the utility of non-iodine-containing contrast media

International Nuclear Information System (INIS)

Kirschner, H.; Burmester, U.; Stringaris, K.; Jentsch, F.

1979-01-01

Because of the excellent ability of the CT scanner in analyzing absorption, the use of non-iodine-containing contrast media will be discussed. Experimental studies of the chemical elements with the atomic number Z = 1-83 with a scan tension of 120 kV were made to determine how many atoms of a given element are necessary to replace one iodine atom in an iodine-containing contrast medium, whereby the same contrast enhancement in the scan picture as with the iodine-containing contrast medium is produced. (orig.) 891 ORU/orig. 892 MB [de

Patterns of contrast enhancement in the brain and meninges.

Science.gov (United States)

Smirniotopoulos, James G; Murphy, Frances M; Rushing, Elizabeth J; Rees, John H; Schroeder, Jason W

2007-01-01

Contrast material enhancement for cross-sectional imaging has been used since the mid 1970s for computed tomography and the mid 1980s for magnetic resonance imaging. Knowledge of the patterns and mechanisms of contrast enhancement facilitate radiologic differential diagnosis. Brain and spinal cord enhancement is related to both intravascular and extravascular contrast material. Extraaxial enhancing lesions include primary neoplasms (meningioma), granulomatous disease (sarcoid), and metastases (which often manifest as mass lesions). Linear pachymeningeal (dura-arachnoid) enhancement occurs after surgery and with spontaneous intracranial hypotension. Leptomeningeal (pia-arachnoid) enhancement is present in meningitis and meningoencephalitis. Superficial gyral enhancement is seen after reperfusion in cerebral ischemia, during the healing phase of cerebral infarction, and with encephalitis. Nodular subcortical lesions are typical for hematogenous dissemination and may be neoplastic (metastases) or infectious (septic emboli). Deeper lesions may form rings or affect the ventricular margins. Ring enhancement that is smooth and thin is typical of an organizing abscess, whereas thick irregular rings suggest a necrotic neoplasm. Some low-grade neoplasms are "fluid-secreting," and they may form heterogeneously enhancing lesions with an incomplete ring sign as well as the classic "cyst-with-nodule" morphology. Demyelinating lesions, including both classic multiple sclerosis and tumefactive demyelination, may also create an open ring or incomplete ring sign. Thick and irregular periventricular enhancement is typical for primary central nervous system lymphoma. Thin enhancement of the ventricular margin occurs with infectious ependymitis. Understanding the classic patterns of lesion enhancement--and the radiologic-pathologic mechanisms that produce them--can improve image assessment and differential diagnosis.

Contrast-enhanced ultrasound and computed tomography findings of granulomatosis with polyangiitis presenting with multiple intrarenal microaneurysms: A case report.

Science.gov (United States)

Kim, Youe Ree; Lee, Young Hwan; Lee, Jong-Ho; Yoon, Kwon-Ha

Granulomatosis with polyangiitis (GPA) is a systemic disorder that affects small- and medium- sized vessels in many organs. Although the kidneys are the second most commonly involved organ in patients with GPA, its manifestation as multiple intrarenal aneurysms is rare. We report an unusual manifestation of GPA with multiple intrarenal microaneurysms, as demonstrated by contrast-enhanced ultrasound and computed tomography. Copyright © 2017 Elsevier Inc. All rights reserved.

Is the transport of a gadolinium-based contrast agent decreased in a degenerated or aged disc? A post contrast MRI study.

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Marta Tibiletti

Full Text Available A post contrast magnetic resonance imaging study has been performed in a wide population of low back pain patients to investigate which radiological and phenotypic characteristics influence the penetration of the contrast agent in lumbar discs in vivo. 37 patients affected by different pathologies (disc herniation, spondylolisthesis, foraminal stenosis, central canal stenosis were enrolled in the study. The selected population included 26 male and 11 female subjects, with a mean age of 42.4 ± 9.3 years (range 18-60. Magnetic resonance images of the lumbar spine were obtained with a 1.5 T scanner (Avanto, Siemens, Erlangen, Germany with a phased-array back coil. A paramagnetic non-ionic contrast agent was injected with a dose of 0.4 ml/kg. T1-weighted magnetic resonance images were subsequently acquired at 5 time points, 5 and 10 minutes, 2, 4 and 6 hours after injection. Endplates presented clear enhancement already 5 minutes after injection, and showed an increase in the next 2 hours followed by a decrease. At 5 and 10 minutes, virtually no contrast medium was present inside the intervertebral disc; afterwards, enhancement significantly increased. Highly degenerated discs showed higher enhancement in comparison with low and medium degenerated discs. Discs classified as Pfirrmann 5 showed a statistically significant higher enhancement than Pfirrmann 1, 2 and 3 at all time points but the first one, possibly due to vascularization. Disc height collapse and Modic changes significantly increased enhancement. Presence of endplate defects did not show any significant influence on post contrast enhancement, but the lack of a clear classification of endplate defects as seen on magnetic resonance scans may be shadowing some effects. In conclusion, disc height, high level of degeneration and presence of Modic changes are factors which increase post contrast enhancement in the intervertebral disc. The effect of age could not be demonstrated.

Contrast enhanced ultrasound of sentinel lymph nodes

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XinWu Cui

2013-03-01

Full Text Available Sentinel lymph nodes are the first lymph nodes in the region that receive lymphatic drainage from a primary tumor. The detection or exclusion of sentinel lymph node micrometastases is critical in the staging of cancer, especially breast cancer and melanoma because it directly affects patient’s prognosis and surgical management. Currently, intraoperative sentinel lymph node biopsies using blue dye and radioisotopes are the method of choice for the detection of sentinel lymph node with high identification rate. In contrast, conventional ultrasound is not capable of detecting sentinel lymph nodes in most cases. Contrast enhanced ultrasound with contrast specific imaging modes has been used for the evaluation and diagnostic work-up of peripherally located suspected lymphadenopathy. The method allows for real-time analysis of all vascular phases and the visualization of intranodal focal “avascular” areas that represent necrosis or deposits of neoplastic cells. In recent years, a number of animal and human studies showed that contrast enhanced ultrasound can be also used for the detection of sentinel lymph node, and may become a potential application in clinical routine. Several contrast agents have been used in those studies, including albumin solution, hydroxyethylated starch, SonoVue®, Sonazoid® and Definity®. This review summarizes the current knowledge about the use of ultrasound techniques in detection and evaluation of sentinel lymph node.

Contrast induced nephropathy

DEFF Research Database (Denmark)

Stacul, Fulvio; van der Molen, Aart J; Reimer, Peter

2011-01-01

PURPOSE: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN). AREAS COVERED: Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic me....../min/1.73 m (2) is CIN risk threshold for intravenous contrast medium. • Hydration with either saline or sodium bicarbonate reduces CIN incidence. • Patients with eGFR = 60 ml/min/1.73 m (2) receiving contrast medium can continue metformin normally....

Avascular necrosis of femoral head: findings of contrast-enhanced MR imaging

International Nuclear Information System (INIS)

Shin, Yong Moon; Kang, Heung Sik; Kim, Chu Wan; Kim, Hee Joong; Kim, Young Min

1995-01-01

To evaluate the findings and the role of contrast enhanced magnetic resonance imaging in avascular necrosis of femoral head. Sixteen patients with avascular necorsis of femoral head were examined with MRI. T1-weighted and T2-weighted image and contrast-enhanced T1-weighted images were obtained. Enhancing characteristics of the necrotic area and synovium were determined. Also a change of the disease extent after enhancement was assessed. Twenty seven avascular necrosis of the femoral head including 11 cases of bilateral lesion were detected. Fifteen cases revealed collapse of the femoral head. The portions of the lesion with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images showed contrast enhancement in 15 cases. However, the potions with low signal intensities both on T1 and T2-weighted images showed enhancement in one case. There was no significant change of the disease extent after enhancement. Synovium showed enhancement in 18 cases, and joint effusion was detected in 23 cases. Contrast enhanced MR images may be helpful in predicting histopathologic findings of avascular necrosis of the femoral head, but not useful for evaluating the extent of disease

Avascular necrosis of femoral head: findings of contrast-enhanced MR imaging

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Shin, Yong Moon; Kang, Heung Sik; Kim, Chu Wan; Kim, Hee Joong; Kim, Young Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1995-06-15

To evaluate the findings and the role of contrast enhanced magnetic resonance imaging in avascular necrosis of femoral head. Sixteen patients with avascular necorsis of femoral head were examined with MRI. T1-weighted and T2-weighted image and contrast-enhanced T1-weighted images were obtained. Enhancing characteristics of the necrotic area and synovium were determined. Also a change of the disease extent after enhancement was assessed. Twenty seven avascular necrosis of the femoral head including 11 cases of bilateral lesion were detected. Fifteen cases revealed collapse of the femoral head. The portions of the lesion with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images showed contrast enhancement in 15 cases. However, the potions with low signal intensities both on T1 and T2-weighted images showed enhancement in one case. There was no significant change of the disease extent after enhancement. Synovium showed enhancement in 18 cases, and joint effusion was detected in 23 cases. Contrast enhanced MR images may be helpful in predicting histopathologic findings of avascular necrosis of the femoral head, but not useful for evaluating the extent of disease.

Contrast-enhanced NMR imaging: animal studies using gadolinium-DTPA complex

International Nuclear Information System (INIS)

Brasch, R.C.; Weinmann, H.J.; Wesbey, G.E.

1984-01-01

Gadolinium (Gd)-DTPA complex was assessed as a nuclear magnetic resonance (NMR) contrast-enhancing agent by experimentally imaging normal and diseased animals. After intravenous injection, Gd-DTPA, a strongly paramagnetic complex by virtue of unpaired electrons, was rapidly excreted into the urine of rats, producing an easily observable contrast enhancement on NMR images in kidney parenchyma and urine. Sterile soft-tissue abscesses demonstrated an obvious rim pattern of enhancement. A focus of radiation-induced brain damage in a canine model was only faintly detectable on spin-echo NMR images before contrast administration; after 0.5 mmol/kg Gd-DTPA administration, the lesion intensity increased from 3867 to 5590. In comparison, the normal brain with an intact blood-brain barrier remained unchanged in NMR characterization. Gd-DTPA is a promising new NMR contrast enhancer for the clinical assessment of renal function, of inflammatory lesions, and of focal disruption of the blood-brain barrier

Enhanced renal image contrast by ethanol fixation in phase-contrast X-ray computed tomography.

Science.gov (United States)

Shirai, Ryota; Kunii, Takuya; Yoneyama, Akio; Ooizumi, Takahito; Maruyama, Hiroko; Lwin, Thet Thet; Hyodo, Kazuyuki; Takeda, Tohoru

2014-07-01

Phase-contrast X-ray imaging using a crystal X-ray interferometer can depict the fine structures of biological objects without the use of a contrast agent. To obtain higher image contrast, fixation techniques have been examined with 100% ethanol and the commonly used 10% formalin, since ethanol causes increased density differences against background due to its physical properties and greater dehydration of soft tissue. Histological comparison was also performed. A phase-contrast X-ray system was used, fitted with a two-crystal X-ray interferometer at 35 keV X-ray energy. Fine structures, including cortex, tubules in the medulla, and the vessels of ethanol-fixed kidney could be visualized more clearly than that of formalin-fixed tissues. In the optical microscopic images, shrinkage of soft tissue and decreased luminal space were observed in ethanol-fixed kidney; and this change was significantly shown in the cortex and outer stripe of the outer medulla. The ethanol fixation technique enhances image contrast by approximately 2.7-3.2 times in the cortex and the outer stripe of the outer medulla; the effect of shrinkage and the physical effect of ethanol cause an increment of approximately 78% and 22%, respectively. Thus, the ethanol-fixation technique enables the image contrast to be enhanced in phase-contrast X-ray imaging.

Focal hepatic lesions: contrast-enhancement patterns at pulse-inversion harmonic US using a microbubble contrast agent

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Kim, Eun-A; Yoon, Kwon-Ha; Lee, Young-Hwan; Kim, Hye-Won; Juhng, Seon-Kwan; Won, Jong-Jin [Wonkwang University, Iksan (Korea, Republic of)

2003-12-15

To analyze the contrast-enhancement patterns obtained at pulse-inversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect. We reviewed pulse-inversion images in 90 consecutive patients with focal hepatic lesions, namely hepatocellular carcinoma (HHC) (n=43), metastases (n=30), and hemangioma (n=17). Vascular and delayed phase images were obtained immediately and five minutes following the injection of a microbubble contrast agent. Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns. Vascular phase images depicted internal vessels in 93% of HCCs, marginal vessels in 83% of metastases, and peripheral enhancement in 71% of hemangiomas. Delayed phase images showed inhomogeneous enhancement in 86% of HCCs; hypoechoic, decreased enhancement in 93% of metastases; and hypoechoic and reversed echogenicity in 65% of hemangiomas. Vascular and delayed phase enhancement patterns were associated with a specificity of 91% or greater, and 92% or greater, respectively, and with positive predictive values of 71% or greater, and 85% or greater, respectively. Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

The analysis of the contrast enhanced lesions on cerebro-vascular diseases

International Nuclear Information System (INIS)

Terada, Tomoaki; Nishiguchi, Takashi; Hyoutani, Genhachi; Miyamoto, Kazuki; Komai, Norihiko

1989-01-01

The contrast enhancement of cerebro-vascular diseases on CT is thought to be due to the increase of the cerebral blood volume (CBV) and/or the disruption of the blood brain barrier (BBB). However, it is difficult to differentiate these two conditions only by contrast enhanced CT. We employed dynamic CT (DCT) to analyse these lesions with respect to the patterns of time-density curve and peak height (PH) of the curve upon the theoretical basis that flattening of the latter part of the time-density curve reflected the degree of BBB disruption and PH reflected the CBV. In all cases of hypertensive intracerebral hemorrhage (11 cases), the contrast enhanced lesion around the hematoma showed marked BBB disruption according to the results of DCT. In 11 cases of cerebral infarction, patterns of BBB disruption and CBV varied at the contrast enhanced lesions according to the result of DCT. However, all contrast enhanced lesions with increased PH were associated with hemorrhagic infarction. Thus, the precise analysis of DCT provides appropriate therapeutic schedules by predicting the occurrence of hemorrhagic infarction. (author)

Contrast-enhanced power Doppler ultrasonography of the metacarpophalangeal joints in rheumatoid arthritis

DEFF Research Database (Denmark)

Szkudlarek, Marcin; Court-Payen, Michel; Strandberg, Charlotte

2003-01-01

The aim of this study was to examine, with dynamic contrast-enhanced MRI as the reference, if contrast-enhanced power Doppler ultrasonography (CE PDUS) of rheumatoid arthritis (RA) metacarpophalangeal (MCP) joints provides additional information for evaluation of synovial inflammation compared...... with PDUS. One MCP joint in each of 15 RA patients and 3 healthy control persons were examined with PDUS before and after intravenous bolus Levovist contrast injection. Corresponding rates of early synovial enhancement (RESE), previously shown to be closely related to histopathological synovitis, were...... calculated from dynamic contrast-enhanced MR images obtained the same day. Prior to ultrasonography, the joint was evaluated clinically. Levovist increased the flow signal in 7 of 9 joints with pre-contrast flow-signal and in 0 of 9 without pre-contrast signal. No healthy controls showed CE PDUS signal...

Contrast-enhanced ultrasonography depicts small tumor vessels for the evaluation of pancreatic tumors

International Nuclear Information System (INIS)

Okamoto, Yuko; Kawamoto, Hirofumi; Takaki, Akinobu; Ishida, Etsuji; Ogawa, Tsuneyoshi; Kuwaki, Kenji; Kobayashi, Yoshiyuki; Sakaguchi, Kohsaku; Shiratori, Yasushi

2007-01-01

Objective: The aim of this study is to evaluate the efficacy of contrast-enhanced ultrasonography for the diagnosis of pancreatic tumors. Materials and methods: Contrast-enhanced ultrasonography with Levovist was performed on 62 consecutive patients (53 with pancreatic cancer, 4 with islet cell tumor, 3 with inflammatory pancreatic tumor, and 2 with metastatic tumor). The vascular and perfusion image phases of the tumors were evaluated and compared with the findings of contrast-enhanced computed tomography. Results: Contrast-enhanced ultrasonography showed tumor vessels around and/or in the tumor at the vascular image phase in 79% of pancreatic cancer patients (42/53). At the perfusion image phase, 96% of pancreatic cancers (51/53) were classified as hypo-enhancement type. However, tiny spotty or irregular heterogeneous enhanced lesions were found in 84% of hypo-enhanced pancreatic cancer patients (43/51). The presence of small vessels at the vascular image phase was closely correlated with the presence of these intratumor regional enhanced lesions at the perfusion image phase (κ coefficient = 0.42). The sensitivity of contrast-enhanced ultrasonography (100%) for pancreatic cancer was superior to that of contrast-enhanced computed tomography (91%), but no significant difference was observed between the two (McNemar test: p = 0.063). Conclusion: Contrast-enhanced ultrasonography with Levovist successfully visualizes fine vessels and enhancement in pancreatic tumors, and is useful for evaluating pancreatic tumors

Gray-scale contrast-enhanced utrasonography in detecting sentinel lymph nodes: An animal study

International Nuclear Information System (INIS)

Wang Yuexiang; Cheng Zhigang; Li Junlai; Tang Jie

2010-01-01

Objective: To investigate the usefulness of gray-scale contrast-enhanced ultrasonography for detecting sentinel lymph nodes. Methods: Contrast-enhanced ultrasonography was performed in five normal dogs (four female and one male) after subcutaneous administration of a sonographic contrast agent (Sonovue, Bracco, Milan, Italy). Four distinct regions in each animal were examined. After contrast-enhanced ultrasonography, 0.8 ml of blue dye was injected into the same location as Sonovue and the sentinel lymph nodes were detected by surgical dissection. The findings of contrast-enhanced ultrasonography were compared with those of the blue dye. Results: Twenty-one sentinel lymph nodes were detected by contrast-enhanced ultrasonography while 23 were identified by blue dye with surgical dissection. Compared with the blue dye, the detection rate of enhanced ultrasonography for the sentinel lymph nodes is 91.3% (21/23). Two patterns of enhancement in the sentinel lymph nodes were observed: complete enhancement (5 sentinel lymph nodes) and partial enhancement (16 sentinel lymph nodes). The lymphatic channels were demonstrated as hyperechoic linear structures leading from the injection site and could be readily followed to their sentinel lymph nodes. Histopathologic examination showed proliferation of lymphatic follicles or lymphatic sinus in partial enhanced sentinel lymph nodes while normal lymphatic tissue was demonstrated in completely enhanced sentinel lymph nodes. Conclusions: Sonovue combined with gray-scale contrast-enhanced ultrasonography may provide a feasible method for detecting sentinel lymph nodes.

International guidelines for contrast-enhanced ultrasonography

DEFF Research Database (Denmark)

Nolsøe, Christian Pállson; Lorentzen, Torben

2016-01-01

The intent of this review is to discuss and comment on common clinical scenarios in which contrast-enhanced ultrasonography (CEUS) may play a decisive role and to illustrate important points with typical cases. With the advent of CEUS, the scope of indications for ultrasonography has been dramati...

Exogenous attention enhances 2nd-order contrast sensitivity

Science.gov (United States)

Barbot, Antoine; Landy, Michael S.; Carrasco, Marisa

2011-01-01

Natural scenes contain a rich variety of contours that the visual system extracts to segregrate the retinal image into perceptually coherent regions. Covert spatial attention helps extract contours by enhancing contrast sensitivity for 1st-order, luminance-defined patterns at attended locations, while reducing sensitivity at unattended locations, relative to neutral attention allocation. However, humans are also sensitive to 2nd-order patterns such as spatial variations of texture, which are predominant in natural scenes and cannot be detected by linear mechanisms. We assess whether and how exogenous attention—the involuntary and transient capture of spatial attention—affects the contrast sensitivity of channels sensitive to 2nd-order, texture-defined patterns. Using 2nd-order, texture-defined stimuli, we demonstrate that exogenous attention increases 2nd-order contrast sensitivity at the attended location, while decreasing it at unattended locations, relative to a neutral condition. By manipulating both 1st- and 2nd-order spatial frequency, we find that the effects of attention depend both on 2nd-order spatial frequency of the stimulus and the observer’s 2nd-order spatial resolution at the target location. At parafoveal locations, attention enhances 2nd-order contrast sensitivity to high, but not to low 2nd-order spatial frequencies; at peripheral locations attention also enhances sensitivity to low 2nd-order spatial frequencies. Control experiments rule out the possibility that these effects might be due to an increase in contrast sensitivity at the 1st-order stage of visual processing. Thus, exogenous attention affects 2nd-order contrast sensitivity at both attended and unattended locations. PMID:21356228

Effects of changes in analytic variables and contrast medium on estimation of glomerular filtration rates by computed tomography in healthy dogs.

Science.gov (United States)

Matsuda, Yuri; Kishimoto, Miori; Kushida, Kazuya; Yamada, Kazutaka; Shimizu, Miki; Itoh, Hiroshi

2017-09-01

OBJECTIVE To investigate effects of changes in analytic variables and contrast medium osmolality on glomerular filtration rate estimated by CT (CT-GFR) in dogs. ANIMALS 4 healthy anesthetized Beagles. PROCEDURES GFR was estimated by inulin clearance, and dogs underwent CT-GFR with iodinated contrast medium (iohexol or iodixanol) in a crossover-design study. Dynamic renal CT scanning was performed. Patlak plot analysis was used to calculate GFR with the renal cortex or whole kidney selected as the region of interest. The renal cortex was analyzed just prior to time of the second cortical attenuation peak. The whole kidney was analyzed 60, 80, 100, and 120 seconds after the appearance of contrast medium. Automated GFR calculations were performed with preinstalled perfusion software including 2 noise reduction levels (medium and strong). The CT-GFRs were compared with GFR estimated by inulin clearance. RESULTS There was no significant difference in CT-GFR with iohexol versus iodixanol in any analyses. The CT-GFR at the renal cortex, CT-GFR for the whole kidney 60 seconds after appearance of contrast medium, and CT-GFR calculated by perfusion software with medium noise reduction did not differ significantly from GFR estimated by inulin clearance. The CT-GFR was underestimated at ≥ 80 seconds after contrast medium appearance (whole kidney) and when strong noise reduction was used with perfusion CT software. CONCLUSIONS AND CLINICAL RELEVANCE Selection of the renal cortex as region of interest or use of the 60-second time point for whole-kidney evaluation yielded the best CT-GFR results. The perfusion software used produced good results with appropriate noise reduction. IMPACT FOR HUMAN MEDICINE The finding that excessive noise reduction caused underestimation of CT-GFR suggests that this factor should also be considered in CT-GFR examination of human patients.

Diagnosis of hepatic steatosis by contrast-enhanced abdominal computed tomography

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Rodrigo da Fonseca Monjardim

2013-06-01

Full Text Available Objective To evaluate the diagnostic capacity of abdominal computed tomography in the assessment of hepatic steatosis using the portal phase with a simplified calculation method as compared with the non-contrast-enhanced phase. Materials and Methods In the present study, 150 patients were retrospectively evaluated by means of non-contrast-enhanced and contrast-enhanced computed tomography. One hundred patients had hepatic steatosis and 50 were control subjects. For the diagnosis of hepatic steatosis in the portal phase, the authors considered a result of < 104 HU calculated by the formula [L - 0.3 × (0.75 × P + 0.25 × A] / 0.7, where L, P and A represent the attenuation of the liver, of the main portal vein and abdominal aorta, respectively. Sensitivity, specificity, positive and negative predictive values were calculated, using non-contrast-enhanced computed tomography as the reference standard. Results The simplified calculation method with portal phase for the diagnosis of hepatic steatosis showed 100% sensitivity, 36% specificity, negative predictive value of 100% and positive predictive value of 75.8%. The rate of false positive results was 64%. False negative results were not observed. Conclusion The portal phase presents an excellent sensitivity in the diagnosis of hepatic steatosis, as compared with the non-contrast-enhanced phase of abdominal computed tomography. However, the method has low specificity.

Diagnosis of hepatic steatosis by contrast-enhanced abdominal computed tomography

International Nuclear Information System (INIS)

Monjardim, Rodrigo da Fonseca; Costa, Danilo Manuel Cerqueira; Romano, Ricardo Francisco Tavares; Salvadori, Priscila Silveira; Santos, Jaime de Vargas Conde dos; Atzingen, Augusto Castelli Von; Shigueoka, David Carlos; D'Ippolito, Giuseppe

2013-01-01

Objective: to evaluate the diagnostic capacity of abdominal computed tomography in the assessment of hepatic steatosis using the portal phase with a simplified calculation method as compared with the non-contrast-enhanced phase. Materials and methods: in the present study, 150 patients were retrospectively evaluated by means of non-contrast-enhanced and contrast-enhanced computed tomography. One hundred patients had hepatic steatosis and 50 were control subjects. For the diagnosis of hepatic steatosis in the portal phase, the authors considered a result of < 104 HU calculated by the formula [L - 0.3 × (0.75 × P + 0.25 × A)] / 0.7, where L, P and A represent the attenuation of the liver, of the main portal vein and abdominal aorta, respectively. Sensitivity, specificity, positive and negative predictive values were calculated, using non-contrast-enhanced computed tomography as the reference standard. Results: the simplified calculation method with portal phase for the diagnosis of hepatic steatosis showed 100% sensitivity, 36% specificity, negative predictive value of 100% and positive predictive value of 75.8%. The rate of false positive results was 64%. False negative results were not observed. Conclusion: The portal phase presents an excellent sensitivity in the diagnosis of hepatic steatosis, as compared with the non-contrast-enhanced phase of abdominal computed tomography. However, the method has low specificity. (author)

Appropriate Contrast Enhancement Measures for Brain and Breast Cancer Images

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Suneet Gupta

2016-01-01

Full Text Available Medical imaging systems often produce images that require enhancement, such as improving the image contrast as they are poor in contrast. Therefore, they must be enhanced before they are examined by medical professionals. This is necessary for proper diagnosis and subsequent treatment. We do have various enhancement algorithms which enhance the medical images to different extents. We also have various quantitative metrics or measures which evaluate the quality of an image. This paper suggests the most appropriate measures for two of the medical images, namely, brain cancer images and breast cancer images.

Nanodiamond-Manganese dual mode MRI contrast agents for enhanced liver tumor detection.

Science.gov (United States)

Hou, Weixin; Toh, Tan Boon; Abdullah, Lissa Nurrul; Yvonne, Tay Wei Zheng; Lee, Kuan J; Guenther, Ilonka; Chow, Edward Kai-Hua

2017-04-01

Contrast agent-enhanced magnetic resonance (MR) imaging is critical for the diagnosis and monitoring of a number of diseases, including cancer. Certain clinical applications, including the detection of liver tumors, rely on both T1 and T2-weighted images even though contrast agent-enhanced MR imaging is not always reliable. Thus, there is a need for improved dual mode contrast agents with enhanced sensitivity. We report the development of a nanodiamond-manganese dual mode contrast agent that enhanced both T1 and T2-weighted MR imaging. Conjugation of manganese to nanodiamonds resulted in improved longitudinal and transverse relaxivity efficacy over unmodified MnCl 2 as well as clinical contrast agents. Following intravenous administration, nanodiamond-manganese complexes outperformed current clinical contrast agents in an orthotopic liver cancer mouse model while also reducing blood serum concentration of toxic free Mn 2+ ions. Thus, nanodiamond-manganese complexes may serve as more effective dual mode MRI contrast agent, particularly in cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

Arterial and venous blood pressure and blood flow following femoral angiography with a new non-ionic contrast medium

International Nuclear Information System (INIS)

Nyman, U.; Almen, T.

1978-01-01

At femoral angiography in dogs the effects of a new non-ionic contrast medium (C29) were compared with those of one non-ionic medium (metrizamide) and one ionic medium (meglumine/sodium diatrizoate) in current use. In the leg subjected to angiography the pressure gradient over the peripheral vessels decreased and the femoral blood flow increased. The changes induced by the ionic medium were significantly greater than those induced by metrizamide and C29, whereas no significant difference between the two non-ionic media was recorded. (Auth.)

The significance of delayed contrast-enhanced CT in chronic subdural hematomas

International Nuclear Information System (INIS)

Karasawa, Hideharu; Ohya, Shigeru; Ueno, Junji; Watanabe, Saburo; Mikabe, Toshio

1983-01-01

We have previously, reported our delayed contrast-enhanced CT (DCECT) findings in traumatic subdural hygromas and chronic subdural hematomas. The purpose of this report is to clarify the relationship between the contrast media within subdural hematomas and the delayed enhancement. The clinical subjects were 35 cases of traumatic subdural hematomas. DCECT examinations were performed in all cases. The concentrations of the contrast media within the hematoma were measured during the operations. DCECT showed that the density of the hematomas increased 3 to 6 hours after the injection of the contrast media. The contrast media were detected within the hematomas a few hours after the injection. The contrast media were still present 24 hours after the injection, but disappeared in 48 hours. These findings suggest that contrast media go in and then come out of the subdural hematomas and that the main factor related to delayed enhancement is the concentration of the contrast media within the hematomas. DCECT examination may be most helpful in evaluating the dynamic changes in subdural collections. (author)

A fundamental study of non-contrast enhanced MR angiography using ECG gated-3D fast spin echo at 3.0 T

International Nuclear Information System (INIS)

Nakato, Kengo; Hiai, Yasuhiro; Tomiguchi, Seiji

2010-01-01

Contrast-enhanced magnetic resonance angiography (CE-MRA) is frequently performed in body and extremity studies because of its superior ability to detect the vascular stenosis. However, nephrotoxicity of the contrast medium has been emphasized in recent years. Non-contrast MRA using the three-dimensional electrocardiogram-synchronized fast spin echo method (fresh blood imaging (FBI), non-contrast MRA of arteries and veins (NATIVE) and triggered acquisition non contrast enhancement MRA (TRANCE)) is recommended as a substitute for CE-MRA. There are a few reports in the literature that evaluate the detectability of vascular stenosis using non-contrast MRA on 3.0 T MRI. The purpose of this study was to evaluate the detectability of vascular stenosis using non-contrast MRA at 3.0 T with an original vascular phantom. The vascular phantom consisted of silicon tubes. 30% and 70% stenosis of luminal diameter were made. Each silicon tube connected a pump producing a pulsatile flow. A flowing material to was used in this study to show the similarity of the intensity to blood on MRI. MRA without a contrast medium (NATIVE sequence) were performed in the vascular phantom by changing the image matrix, static magnetic field strength and flow velocity. In addition, the NATIVE sequence was used with or without flow compensation. Vascular stenosis was quantitatively estimated by measurement of the signal intensities in non-contrast MRA images. MRA with NATIVE sequence demonstrated an accurate estimation of 30% vascular stenosis at slow flow velocity. However, 30% stenosis was overestimated in cases of high flow velocity. Estimation was improved by using a flow compensation sequence. 70% stenosis was overestimated on MRA with NATIVE sequence. Estimation of 70% stenosis was improved by using a flow compensation sequence. Accurate estimation of vascular stenosis in MRA with a NATIVE sequence is improved by using the flow compensation technique. MRA with NATIVE sequence is considered to

Intravenous contrast-enhanced sonography in children and adolescents – a single center experience

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Martin Stenzel

2013-06-01

Full Text Available Compared to adult patients, ultrasonography in children and adolescents is much more common, due to lack of ionizing radiation, and its wide availability. With the introduction of contrast-media for use in ultrasonography, one major drawback of the method could be overcome. In Europe, SonoVue® is the only widely available agent, which due to improved stability makes it possible to image normal and diseased tissue perfusion and vascularization with high accuracy. Inability to hold the breath and voluntary body movement of the patient is less of an obstacle compared to color Doppler techniques and makes the method very attractive for use in children, which, depending on age, may not be very cooperative. Use of intravenous contrast-medium in minors is currently very limited for several reasons: availability, lack of recommendation in national and international guidelines, and lack of official licensing. The article will touch medical indications, technique, safety considerations, and perspective of intravenous use of contrast-media in children and adolescents, including data from a 6-year period in 37 patients. Purpose: The purpose of the study was to collect data on ultrasonographic examinations, expanded by intravenous administration of the contrast agent SonoVue® in children and adolescents. Besides assessing diagnostic yield, data on adverse medication effects was collected. Materials and methods: The study includes contrast-enhanced ultrasound examinations in 37 children at a single institution. Indications for the examinations were tumor lesions, infections, traumatic organ injuries, and parenchymal organ ischemia. Parents of the patients and adolescent patients were informed about the off-label use of the contrast agent. Thirty-nine examinations were performed, the average age of the patient was 11.1 years (range 1 7/ 12 to 17 11/ 12 years. Results: All of the examinations yielded additional diagnostic value, always expanding results

Effect of duration of contrast material injection on peak enhancement times and values of the aorta, main portal vein, and liver at dynamic MDCT with the dose of contrast medium tailored to patient weight

International Nuclear Information System (INIS)

Erturk, S.M.; Ichikawa, T.; Sou, H.; Tsukamoto, T.; Motosugi, U.; Araki, T.

2008-01-01

Aim: To investigate the effects of contrast material injection duration on peak enhancement times and attenuation values of the aorta, main portal vein, and liver at MDCT when the dose of contrast material is adjusted to patient weight. Material and methods: Seventy-five patients were randomly assigned to one of five groups, with durations of injection of 25, 30, 35, 40, or 45 s. All patients were injected with 2 ml/kg iodine (300 mg/ml). Attenuation values and peak enhancement times for the aorta, main portal vein, and liver were determined. The relationship between patient weight and enhancement times and values, the differences regarding peak enhancement times, and the relationship between injection duration and enhancement values were investigated using Pearson correlation, analysis of variance (ANOVA), and Spearman rank correlation, respectively. Results: No significant correlations were seen between patient weight and peak enhancement times or values. Mean peak enhancement times for the aorta, main portal vein, and liver were 9-11 s, 18-22 s, and 30-34 s, respectively (p > 0.05). The correlations between injection duration and peak enhancement values were significant and negative. Conclusions: Regardless of patient weight and injection duration, peak enhancement times of aorta, main portal vein and liver were approximately 10, 20, and 30 s, respectively. The enhancement values tended to be higher for shorter injection durations

A developed unsharp masking method for images contrast enhancement

International Nuclear Information System (INIS)

Zaafouri, A.; Sayadi, M.; Fnaiech, F.

2011-01-01

In this paper, we propose a developed unsharp masking process for contrast image enhancement. The main idea here is to enhance the dark and bright area in the same way which matches the response of human visual system well. Then in order to reduce the noise effect, a mean weighted high pass filter is used for edge extraction. The proposed method gives satisfactory results for wide range of low contrast images compared with others known approaches.

Microwave ablation of liver metastases guided by contrast-enhanced ultrasound

DEFF Research Database (Denmark)

Lorentzen, T; Skjoldbye, B O; Nolsoe, C P

2011-01-01

The aim of our study was to evaluate the efficacy of microwave (MW) ablation of liver metastases guided by B-mode ultrasound (US) and contrast-enhanced US (CEUS).......The aim of our study was to evaluate the efficacy of microwave (MW) ablation of liver metastases guided by B-mode ultrasound (US) and contrast-enhanced US (CEUS)....

Diagnositc value of 3D-gradient echo dynamic contrast enhanced MRI in breast cancer

Energy Technology Data Exchange (ETDEWEB)

Yang, Ik; Chung, Soo Young; Park, Hai Jung; Lee, Yul; Chung, Bong Wha; Shim, Jeong Won [Hallym Univ. College of Medicine, Seoul (Korea, Republic of)

1997-10-01

To assess the usefulness of 3D-gradient echo dynamic contrast enhanced MRI (3D-DMRI) in the diagnosis of breast cancer and to determine the most useful parameter for this diagnosis. Using a 1.0T MR unit, (Magnetom, Siemens, Erlaugen, Germany), 3D-DMRI (TR/TE=3D30/12) with Gd-DTPA was performed in 38 cases of breast cancer, 22 of fibroadenoma, and in three normal volunteers. We retrospectively evaluated the findings according to the speed on dynamic study and maximal amount of contrast enhancement during the delayed phase;we calculated the contrast index and morphology of the cancers and compared diagnostic accuracy among these three diagnostic parameters. On conventional spin-echo T1-and T2-weighted images, there was no significant difference of signal intensity between benign fibroadenoma and breast carcinoma. Rapid contrast enhancement (within one minute) was noted in 35 breast cancer lesions (92.1%), but relatively low and slow contrast enhancement (after five minutes) was noted in three such lesions (7.9%). Gradual contrast enhancement was noted in 21 lesions of fibroadenoma(95.5%), but a moderate degree of rapid contrast enhancement (from three to five minutes) was noted in the other case (7.9%). of On the delayed enhanced phase of 3D-DMRI, the maximal amount of contrast enhancement showed no significant difference between fibroadenoma and cancer. On 3D-DMRI, an irregular, spiculated border, with high contrast enhancement was noted in all cases of breast cancer, in particular, irregular thick peripheral contrast enhancement with central necrosis was noted 11cases(28.9%). For the diagnosis of breast cancer, 3D-DMRI is a useful technique. Among the diagnostic criteria of speed, maximal amount of contrast enhancement and morphology, morphologic change after contrast enhancement study was the most useful diagnostic parameter.=20.

Diagnositc value of 3D-gradient echo dynamic contrast enhanced MRI in breast cancer

International Nuclear Information System (INIS)

Yang, Ik; Chung, Soo Young; Park, Hai Jung; Lee, Yul; Chung, Bong Wha; Shim, Jeong Won

1997-01-01

To assess the usefulness of 3D-gradient echo dynamic contrast enhanced MRI (3D-DMRI) in the diagnosis of breast cancer and to determine the most useful parameter for this diagnosis. Using a 1.0T MR unit, (Magnetom, Siemens, Erlaugen, Germany), 3D-DMRI (TR/TE=3D30/12) with Gd-DTPA was performed in 38 cases of breast cancer, 22 of fibroadenoma, and in three normal volunteers. We retrospectively evaluated the findings according to the speed on dynamic study and maximal amount of contrast enhancement during the delayed phase;we calculated the contrast index and morphology of the cancers and compared diagnostic accuracy among these three diagnostic parameters. On conventional spin-echo T1-and T2-weighted images, there was no significant difference of signal intensity between benign fibroadenoma and breast carcinoma. Rapid contrast enhancement (within one minute) was noted in 35 breast cancer lesions (92.1%), but relatively low and slow contrast enhancement (after five minutes) was noted in three such lesions (7.9%). Gradual contrast enhancement was noted in 21 lesions of fibroadenoma(95.5%), but a moderate degree of rapid contrast enhancement (from three to five minutes) was noted in the other case (7.9%). of On the delayed enhanced phase of 3D-DMRI, the maximal amount of contrast enhancement showed no significant difference between fibroadenoma and cancer. On 3D-DMRI, an irregular, spiculated border, with high contrast enhancement was noted in all cases of breast cancer, in particular, irregular thick peripheral contrast enhancement with central necrosis was noted 11cases(28.9%). For the diagnosis of breast cancer, 3D-DMRI is a useful technique. Among the diagnostic criteria of speed, maximal amount of contrast enhancement and morphology, morphologic change after contrast enhancement study was the most useful diagnostic parameter.=20

Attention enhances contrast appearance via increased input baseline of neural responses.

Science.gov (United States)

Cutrone, Elizabeth K; Heeger, David J; Carrasco, Marisa

2014-12-30

Covert spatial attention increases the perceived contrast of stimuli at attended locations, presumably via enhancement of visual neural responses. However, the relation between perceived contrast and the underlying neural responses has not been characterized. In this study, we systematically varied stimulus contrast, using a two-alternative, forced-choice comparison task to probe the effect of attention on appearance across the contrast range. We modeled performance in the task as a function of underlying neural contrast-response functions. Fitting this model to the observed data revealed that an increased input baseline in the neural responses accounted for the enhancement of apparent contrast with spatial attention. © 2014 ARVO.

Contrast-enhanced ultrasound features of histologically proven focal nodular hyperplasia: diagnostic performance compared with contrast-enhanced CT

International Nuclear Information System (INIS)

Wang, Wei; Chen, Li-Da; Liu, Guang-Jian; Xu, Zuo-Feng; Xie, Xiao-Yan; Wang, Yan; Zhou, Lu-Yao; Lu, Ming-De; Shen, Shun-Li

2013-01-01

To investigate and compare contrast-enhanced ultrasound (CEUS) in the characterisation of histologically proven focal nodular hyperplasia (FNH) with contrast-enhanced computed tomography (CECT). CEUS was performed in 85 patients with 85 histologically proven FNHs. Enhancement, centrifugal filling, spoke-wheel arteries, feeding artery and central scarring were reviewed and correlated with lesion size or liver background. Independent factors for predicting FNH from other focal liver lesions (FLLs) were evaluated. Forty-seven FLLs with CECT were randomly selected for comparison of diagnostic performance with CEUS. Centrifugal filling was more common (P = 0.002) and the significant predictor (P = 0.003) in FNHs ≤3 cm. Lesion size or liver background has no significant influence on the detection rate of the spoke-wheel arteries and feeding artery (P > 0.05). Central scarring was found in 42.6 % of FNHs ≥3 cm (P = 0.000). The area under the ROC curve, sensitivity and specificity showed no significant differences between CEUS and CECT (P > 0.05), except that the sensitivity of CEUS was better for reader 1 (P = 0.041). CEUS is valuable in characterising centrifugal filling signs or spoke wheels in small FNHs and should be employed as the first-line imaging technique for diagnosis of FNH. (orig.)

Elevated arousal levels enhance contrast perception.

Science.gov (United States)

Kim, Dongho; Lokey, Savannah; Ling, Sam

2017-02-01

Our state of arousal fluctuates from moment to moment-fluctuations that can have profound impacts on behavior. Arousal has been proposed to play a powerful, widespread role in the brain, influencing processes as far ranging as perception, memory, learning, and decision making. Although arousal clearly plays a critical role in modulating behavior, the mechanisms underlying this modulation remain poorly understood. To address this knowledge gap, we examined the modulatory role of arousal on one of the cornerstones of visual perception: contrast perception. Using a reward-driven paradigm to manipulate arousal state, we discovered that elevated arousal state substantially enhances visual sensitivity, incurring a multiplicative modulation of contrast response. Contrast defines vision, determining whether objects appear visible or invisible to us, and these results indicate that one of the consequences of decreased arousal state is an impaired ability to visually process our environment.

MRI contrast enhancement using Magnetic Carbon Nanoparticles

Science.gov (United States)

Chaudhary, Rakesh P.; Kangasniemi, Kim; Takahashi, Masaya; Mohanty, Samarendra K.; Koymen, Ali R.; Department of Physics, University of Texas at Arlington Team; University of Texas Southwestern Medical Center Team

2014-03-01

In recent years, nanotechnology has become one of the most exciting forefront fields in cancer diagnosis and therapeutics such as drug delivery, thermal therapy and detection of cancer. Here, we report development of core (Fe)-shell (carbon) nanoparticles with enhanced magnetic properties for contrast enhancement in MRI imaging. These new classes of magnetic carbon nanoparticles (MCNPs) are synthesized using a bottom-up approach in various organic solvents, using the electric plasma discharge generated in the cavitation field of an ultrasonic horn. Gradient echo MRI images of well-dispersed MCNP-solutions (in tube) were acquired. For T2 measurements, a multi echo spin echo sequence was performed. From the slope of the 1/T2 versus concentration plot, the R2 value for different CMCNP-samples was measured. Since MCNPs were found to be extremely non-reactive, and highly absorbing in NIR regime, development of carbon-based MRI contrast enhancement will allow its simultaneous use in biomedical applications. We aim to localize the MCNPs in targeted tissue regions by external DC magnetic field, followed by MRI imaging and subsequent photothermal therapy.

TMJ disorders and pain: Assessment by contrast-enhanced MRI

International Nuclear Information System (INIS)

Farina, Davide; Bodin, Christiane; Gandolfi, Silvia; De Gasperi, Werner; Borghesi, Andrea; Maroldi, Roberto

2009-01-01

Though magnetic resonance (MRI) is a widely accepted standard for the assessment of patients with temporomandibular joint (TMJ) disorders, efforts to correlate symptoms to MRI findings have often given controversial results. Aim of this study was to investigate the correlation between TMJ pain and findings of contrast-enhanced MRI. Thirty-eight consecutive patients with TMJ dysfunction syndrome (study group) were examined with MRI. Protocol included T2 turbo spin-echo sequence, T1 spin-echo sequence, and T2 gradient-echo (acquired with closed jaw, at intermediate and maximal opening). Post-contrast phase was obtained through a fat sat 3D T1 gradient-echo sequence (VIBE). Post-contrast findings in the study group were matched with those obtained in a control group of 33 patients submitted to MRI of the paranasal sinuses. Statistically significant difference was found between condylar medullary bone enhancement in painful TMJ, in painless TMJ and control group. In addition the average thickness of joint soft tissue enhancement in painful TMJ was superior to painless TMJ (p < 0.0001) and to control group. On multivariate logistic regression analysis, the odds ratio that a painful TMJ showed disk displacement, osteoarthrosis, effusion and JST enhancement were 3.05, 3.18, 1.2 and 11.36, respectively. Though not histologically proven, TMJ enhancement could reflect the presence of inflammation in painful joints. Furthermore, the administration of contrast could be of help for the assessment of patients with orofacial pain, particularly when clinical exploration is insufficient to ascribe the pain to TMJ.

TMJ disorders and pain: Assessment by contrast-enhanced MRI

Energy Technology Data Exchange (ETDEWEB)

Farina, Davide [Department of Radiology (School of Medicine), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy); Bodin, Christiane [Division of Gnathology (School of Dentistry), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy); Gandolfi, Silvia [Department of Radiology (School of Medicine), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy); De Gasperi, Werner [Division of Gnathology (School of Dentistry), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy); Borghesi, Andrea; Maroldi, Roberto [Department of Radiology (School of Medicine), University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia (Italy)

2009-04-15

Though magnetic resonance (MRI) is a widely accepted standard for the assessment of patients with temporomandibular joint (TMJ) disorders, efforts to correlate symptoms to MRI findings have often given controversial results. Aim of this study was to investigate the correlation between TMJ pain and findings of contrast-enhanced MRI. Thirty-eight consecutive patients with TMJ dysfunction syndrome (study group) were examined with MRI. Protocol included T2 turbo spin-echo sequence, T1 spin-echo sequence, and T2 gradient-echo (acquired with closed jaw, at intermediate and maximal opening). Post-contrast phase was obtained through a fat sat 3D T1 gradient-echo sequence (VIBE). Post-contrast findings in the study group were matched with those obtained in a control group of 33 patients submitted to MRI of the paranasal sinuses. Statistically significant difference was found between condylar medullary bone enhancement in painful TMJ, in painless TMJ and control group. In addition the average thickness of joint soft tissue enhancement in painful TMJ was superior to painless TMJ (p < 0.0001) and to control group. On multivariate logistic regression analysis, the odds ratio that a painful TMJ showed disk displacement, osteoarthrosis, effusion and JST enhancement were 3.05, 3.18, 1.2 and 11.36, respectively. Though not histologically proven, TMJ enhancement could reflect the presence of inflammation in painful joints. Furthermore, the administration of contrast could be of help for the assessment of patients with orofacial pain, particularly when clinical exploration is insufficient to ascribe the pain to TMJ.

Could parenchymal enhancement on contrast-enhanced spectral mammography (CESM) represent a new breast cancer risk factor? Correlation with known radiology risk factors.

Science.gov (United States)

Savaridas, S L; Taylor, D B; Gunawardana, D; Phillips, M

2017-12-01

To compare background parenchymal enhancement (BPE) on contrast-enhanced (CE) spectral mammography (CESM) with CE magnetic resonance imaging (MRI), and evaluate how these relate to hormonal status, mammographic breast density (MBD) and MRI fibroglandular tissue volume (FGTV). Between June 2012 to October 2015, participants in a cancer staging study underwent full-field digital mammography (FFDM), CEMRI, and CESM. Two readers independently rated FGTV, MBD, and BPE using the Breast Imaging-Reporting and Data System (BI-RADS) criteria. Inter-reader reliability was estimated using weighted kappa (k) and correlations between BPE, MBD, and FGTV calculated using Spearman's correlation coefficient. Associations with hormonal status were evaluated using multilevel ordinal regression analysis. Of the 96 eligible participants, 66 women (35-77 years) underwent CESM and CEMRI. Reasons for exclusion were declined or withdrawn consent (n=18), inadequate renal function (n=2), claustrophobia (n=2), previous reaction to contrast medium (n=2), mild reaction to contrast medium following CESM (n=2), lack of vascular access (n=1), neoadjuvant chemotherapy (n=1), CESM equipment failure (n=1), and unclear in one case. Inter-reader agreement was substantial (k=0.67) for CESM BPE, slight (k=0.19) for CEMRI BPE, moderate (k=0.57) for MRI FGTV and fair (k=0.35) for MBD. CESM BPE showed significant correlation with MBD (rho=0.36, p<0.0001), FGTV (rho=0.52, p<0.0001), and MRI BPE (rho=0.49, p<0.0001). BPE was significantly reduced in the post-menopausal group for CEMRI and CESM (p<0.05). CESM BPE did not significantly fluctuate during the menstrual cycle. CESM BPE is correlated with MBD, FGTV, and CEMRI BPE, has better inter-reader reliability than CEMRI, and is not influenced by the menstrual cycle. Grading the degree of BPE on CESM could be a useful addition to breast cancer risk assessment tools. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights

Clinical validation of semi-automated software for volumetric and dynamic contrast enhancement analysis of soft tissue venous malformations on magnetic resonance imaging examination

Energy Technology Data Exchange (ETDEWEB)

Caty, Veronique [Hopital Maisonneuve-Rosemont, Universite de Montreal, Department of Radiology, Montreal, QC (Canada); Kauffmann, Claude; Giroux, Marie-France; Oliva, Vincent; Therasse, Eric [Centre Hospitalier de l' Universite de Montreal (CHUM), Universite de Montreal and Research Centre, CHUM (CRCHUM), Department of Radiology, Montreal, QC (Canada); Dubois, Josee [Centre Hospitalier Universitaire Sainte-Justine et Universite de Montreal, Department of Radiology, Montreal, QC (Canada); Mansour, Asmaa [Institut de Cardiologie de Montreal, Heart Institute Coordinating Centre, Montreal, QC (Canada); Piche, Nicolas [Object Research System, Montreal, QC (Canada); Soulez, Gilles [Centre Hospitalier de l' Universite de Montreal (CHUM), Universite de Montreal and Research Centre, CHUM (CRCHUM), Department of Radiology, Montreal, QC (Canada); CHUM - Hopital Notre-Dame, Department of Radiology, Montreal, Quebec (Canada)

2014-02-15

To evaluate venous malformation (VM) volume and contrast-enhancement analysis on magnetic resonance imaging (MRI) compared with diameter evaluation. Baseline MRI was undertaken in 44 patients, 20 of whom were followed by MRI after sclerotherapy. All patients underwent short-tau inversion recovery (STIR) acquisitions and dynamic contrast assessment. VM diameters in three orthogonal directions were measured to obtain the largest and mean diameters. Volumetric reconstruction of VM was generated from two orthogonal STIR sequences and fused with acquisitions after contrast medium injection. Reproducibility (interclass correlation coefficients [ICCs]) of diameter and volume measurements was estimated. VM size variations in diameter and volume after sclerotherapy and contrast enhancement before sclerotherapy were compared in patients with clinical success or failure. Inter-observer ICCs were similar for diameter and volume measurements at baseline and follow-up (range 0.87-0.99). Higher percentages of size reduction after sclerotherapy were observed with volume (32.6 ± 30.7 %) than with diameter measurements (14.4 ± 21.4 %; P = 0.037). Contrast enhancement values were estimated at 65.3 ± 27.5 % and 84 ± 13 % in patients with clinical failure and success respectively (P = 0.056). Venous malformation volume was as reproducible as diameter measurement and more sensitive in detecting therapeutic responses. Patients with better clinical outcome tend to have stronger malformation enhancement. (orig.)

Subtraction MR venography acquired from time-resolved contrast-enhanced MR angiography: Comparison with phase-contrast MR venography and single-phase contrast-enhanced MR venography

International Nuclear Information System (INIS)

Jang, Jin Hee; Kim, Bum Soo; KIm, Bom Yi; Choi, Hyun Seok; Jung, So Lyung; Ahn, Kook Jin; Sung, Ji Kyeong

2015-01-01

To evaluate the image characteristics of subtraction magnetic resonance venography (SMRV) from time-resolved contrast-enhanced MR angiography (TRMRA) compared with phase-contrast MR venography (PCMRV) and single-phase contrast-enhanced MR venography (CEMRV). Twenty-one patients who underwent brain MR venography (MRV) using standard protocols (PCMRV, CEMRV, and TRMRA) were included. SMRV was made by subtracting the arterial phase data from the venous phase data in TRMRA. Co-registration and subtraction of the two volume data was done using commercially available software. Image quality and the degree of arterial contamination of the three MRVs were compared. In the three MRVs, 19 pre-defined venous structures (14 dural sinuses and 5 cerebral veins) were evaluated. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the three MRVs were also compared. Single-phase contrast-enhanced MR venography showed better image quality (median score 4 in both reviewers) than did the other two MRVs (p < 0.001), whereas SMRV (median score 3 in both reviewers) and PCMRV (median score 3 in both reviewers) had similar image quality (p ≥ 0.951). SMRV (median score 0 in both reviewers) suppressed arterial signal better than did the other MRVs (median score 1 in CEMRV, median score 2 in PCMRV, both reviewers) (p < 0.001). The dural sinus score of SMRV (median and interquartile range [IQR] 48, 43-50 for reviewer 1, 47, 43-49 for reviewer 2) was significantly higher than for PCMRV (median and IQR 31, 25-34 for reviewer 1, 30, 23-32 for reviewer 2) (p < 0.01) and did not differ from that of CEMRV (median and IQR 50, 47-52 for reviewer 1, 49, 45-51 for reviewer 2) (p = 0.146 in reviewer 1 and 0.123 in reviewer 2). The SNR and CNR of SMRV (median and IQR 104.5, 83.1-121.2 and 104.1, 74.9-120.5, respectively) were between those of CEMRV (median and IQR 150.3, 111-182.6 and 148.4, 108-178.2) and PCMRV (median and IQR 59.4, 49.2-74.9 and 53.6, 43.8-69.2). Subtraction magnetic

Characteristics of hypertrophic cardiomyopathy on delayed contrast-enhanced MRI

International Nuclear Information System (INIS)

Yan Chaowu; Zhao Shihua; Li Hua; Jiang Shiliang; Lu Minjie; Zhang Yan; Wei Yunqing; Ling Jian; Fang Wei

2010-01-01

Objective: To analyze the characteristics of hypertrophic cardiomyopathy (HCM) on delayed contrast-enhanced cardiac magnetic resonance imaging (CMRI). Methods: All patients underwent delayed contrast-enhanced CMRI. The left ventricle was divided into 9 segments to assess the location, extent and function of the hypertrophic segments. The t test was applied for the statistics. Results: Of 154 patients, delayed enhancement of' hypertrophic segment was found in 95 cases and non-delayed enhancement in 59 cases. The thickness and number of hypertrophic segment in patients with delayed enhancement were larger than those with non-delayed enhancement [(24.8±5.5) mm vs (20.4± 3.8) mm, t=3.82, P<0.05; (3.3±1.9) vs (2.4±1.7), t=2.26, P<0.05], and the age was younger [(46.0±15.2) years vs (55.0±11.9) years, t=-3.67, P<0.05]. The diffuse enhancement was found in 62 patients, and confluent enhancement in 33 patients. Confluent enhancement was found in all 14 patients after the alcohol ablation procedure. Conclusion: The age, thickness and number of hypertrophic segments in patients with delayed enhancement are different from those with non-delayed enhancement. (authors)

Reproducibility of contrast-enhanced transrectal ultrasound of the prostate

NARCIS (Netherlands)

Sedelaar, J. P.; Goossen, T. E.; Wijkstra, H.; de la Rosette, J. J.

2001-01-01

Transrectal three-dimensional (3-D) contrast-enhanced power Doppler ultrasound (US) is a novel technique for studying possible prostate malignancy. Before studies can be performed to investigate the clinical validity of the technique, reproducibility of the contrast US studies must be proven.

Contrast enhancement of focal hepatic lesions in CT: effect of size and histology

International Nuclear Information System (INIS)

Burgener, F.A.; Hamlin, D.J.

1983-01-01

The effect of size and histology on the contrast enhancement of hepatic lesions has been analyzed in this clinical and experimental investigation yielding the following results: (1) The attenuation values of hepatic cysts in patients increase significantly and inversely with their size after contrast enhancement when the cysts measure less than twice the CT-slice thickness. This seems to be caused by partial-volume effect. (2) Experimental tumors of identical sizes and originating from the same cell line can demonstrate different contrast-enhancement patterns. (3) Peak contrast uptake in both experimental and human tumors seems to be inversely related to their size. (4) Compared to liver, contrast washout from experimental and human tumors (presumably the extravascular space) is delayed. The delay in the contrast washout from a tumor seems to correlate with tumor size. These findings suggest that in general, it is not possible to differentiate reliably among various hepatic neoplasms on the basis of their contrast enhancement patterns for the following reasons: (1) Attenuation values of small hepatic neoplasms are distorted by partial volume effect. (2) Tumors of different histologies can demonstrate the same enhancement pattern. (3) Tumors of identical histology and size can demonstrate different enhancement patterns. (4) The enhancement pattern of a tumor changes with growth or size

Contrast enhanced ultrasound in the assessment of urogenital pathology

Directory of Open Access Journals (Sweden)

Libero Barozzi

2014-12-01

Full Text Available Contrast enhanced ultrasound (CEUS is an innovative technique that employs microbubble contrast agents to demonstrate parenchymal perfusion. Although initial clinical application was focused on the liver pathology, a wide variety of clinical conditions can be assessed now with CEUS. CEUS is a well-tolerated technique and is acquiring an increasing role in the assessment of renal pathology because contrast agents are not excreted by the kidney and do not affect the renal function. CEUS demonstrated an accuracy similar to contrast enhanced multi-detector computed tomography (CEMDCT in detecting focal lesions, with the advantage of the real-time assessment of microvascular perfusion by using time-intensity curves. The aim of this paper is to review the main indications of CEUS in the assessment of renal and urogenital pathology. Imaging examples are presented and described. Advantages and limitations of CEUS with reference to conventional US and CE-MDCT are discussed.

A case of pulmonary edema developed after intraarterial injection of iodinated contrast medium

International Nuclear Information System (INIS)

Min, Byoung Chol; Chun, Kang Woo; Koh, Jae Hyu; Yoon, Jong Sup

1982-01-01

Pulmonary edema is a rare adverse reaction to the iodinated contrast medium. Complaining of huge abdominal mass, a 52 years old female was admitted to the Hangang Sungsim Hospital. On physical examination, the patient appeared to be healthy. She had stable vital signs, i.e. BP: 120/80 mmHg, pulse rate: 80/min.etc. An adult head sized mass was palpated in the left mid and lower abdomen. Otherwise nonspecific. On laboratory studies the positive findings were 8-10 WBC/HPF in urine, 25.6 mg/dl for BUN and PVC in EKG. It was negative for urine protein, serum creatinline and liver function test. We injected 100 ml and 30 ml of Urografin 60 through the abdominal aorta dividing 3 times and major branches of the abdominal aorta, respectively. Immediately after complicating angiography, interstitial pulmonary edema was found, showing blurring of the vascular margins, perivascular haziness and thickening of the interlobular septal lines in the both lower lung fields. The blood pressure was dropped to 80/60 mmHg, but pulse rate was normal. She did not complain of dyspnea, and cyanosis was not developed. The urine volume was normally maintained. She was treated for pulmonary edema, which was completely absorbed after 20 hours. And the blood pressure was also normalized. We have experienced a case of pulmonary edema developed after intraarterial injection of the iodinated contrast medium without underlying cardiac, renal and hepatic problems, and reviewed the literatures on mechanisms of pulmonary edema caused by intravascular injection of the iodinated contrast materials

Contrast-enhanced near-infrared laser mammography with a prototype breast scanner: feasibility study with tissue phantoms and preliminary results of imaging experimental tumors.

Science.gov (United States)

Boehm, T; Hochmuth, A; Malich, A; Reichenbach, J R; Fleck, M; Kaiser, W A

2001-10-01

Near-infrared (NIR) optical mammography without contrast has a low specificity. The application of optical contrast medium may improve the performance. The concentration-dependent detectability of a new NIR contrast medium was determined with a prototype optical breast scanner. In vivo imaging of experimental tumors was performed. The NIR contrast agent NIR96010 is a newly synthesized, hydrophilic contrast agent for NIR mammography. A concentration-dependent contrast resolution was determined for tissue phantoms consisting of whole milk powder and gelatin. A central part of the phantoms measuring 2 x 2 cm2 without contrast was replaced with phantom material containing 1 micromol/L to 25 nmol/L NIR96010. The composite phantoms were measured with a prototype NIR breast scanner with lasers of lambda1 = 785 nm and lambda2 = 850 nm wavelength. Intensity profiles and standard deviations of the transmission signal in areas with and without contrast were determined by linear fit procedures. Signal-to-noise ratios and spatial resolution as a function of contrast concentration were determined. Near-infrared imaging of five tumor-bearing SCID mice (MX1 breast adenocarcinoma, tumor diameter 5-10 mm) was performed before and after intravenous application of 2 micromol/kg NIR96010. Spectrometry showed an absorption maximum of the contrast agent at 755 nm. No spectral shifts occurred in protein-containing solution. Signal-to-noise ratio in the transmission intensity profiles ranged from 1.1 at 25 nmol/L contrast to 28 at 1 micromol/L. At concentrations contrast-enhanced images, with better delineation after contrast administration. In postcontrast absorption profiles, a 44.1% +/- 11.3% greater absorption increase was seen in tumor tissue compared with normal tissue. The laser wavelength lambda1 of the prototype laser mammography device was not situated at maximum absorption of the contrast agent NIR96010 but on the descending shoulder of the absorption spectrum. This implies a 20

Abnormal contrast enhancement after the removal of meningioma

Energy Technology Data Exchange (ETDEWEB)

Soutsu, M; Hashimoto, T; Yamaguchi, Y; Sekino, H; Nakamura, N [Jikei Univ., Tokyo (Japan). School of Medicine

1980-12-01

Since the introduction of Computerized Tomography (CT) in August, 1976, we have had experience with 20 patients with meningioma. In 10 patients out of the 20, the tumors were removed totally and examined by contrast-enhanced CT pre- and postoperatively. In spite of the total removal of the tumor, however, 5 patients showed an unexpected abnormal enhancement at the operated site after the infusion of a contrast material. These changes were relatively intense, so it was suspected that there were residual tumors. Comparing these 5 cases with the remaining 5 that had no postoperative enhancement, the former cases were shown by operative and angiographical findings to have more adhesion and connecting vessels between tumor and cortex. Since such a postoperative abnormal enhancement is seen along the corticotomy or retracted area after operations for and aneurysm or another lesion, damaged brain tissue was though to be the probable reason for this enhancement. Moreover, the circulatory change caused by cutting the connecting vessels between tumor and cortex was considered to be another reason for the enhancement. This mechanism was also considered to be one reason for the post-meningioma syndrome by El-Banhawy. These postoperative enhancements decreased in density and became obscure within 4 or 8 weeks. Any reappearance of such changes after that period should be examined, carefully to determine whether or not it marks a recurrent tumor.

Clinical cardiovascular experiences with iopamidol: a new non-ionic contrast medium

International Nuclear Information System (INIS)

Partridge, J.B.; Robinson, P.J.; Turnbull, C.M.; Stoker, J.B.; Morrison, G.W.; Boyle, R.M.

1981-01-01

Iopamidol, a new non-ionic water-soluble contrast medium, has been compared with standard ionic media in a number of cardiovascular applications. It is stable in aqueous solution, is much less viscous and only slightly more osmolar than metrizamide. Compared to sodium meglumine diatrizoate in a series of 40 coronary arteriograms, it produced a consistent and highly significant decrease in the incidence and severity of hypotension and bradycardia following intracoronary injection. In the same group and in 62 children undergoing ventricular or great vessel angiocardiography, a subjective assessment of patient reaction showed that iopamidol was better tolerated than the ionic medium. There was a very strong patient preference for iopamidol in a group of 10 of the adult patients who had also consented to femoral artery injections of both media. Throughout these series there was no detectable difference in arterial image quality between the media. Venous phase opacification during arterioportography was assessed in 11 cases comparing iopamidol with sodium meglumine iothalamate. No significant difference was found. We conclude that iopamidol is clearly preferable to ionic media for routine cardiovascular applications. (author)

Dynamic contrast-enhanced MR imaging of endometrial cancer. Optimizing the imaging delay for tumour-myometrium contrast

International Nuclear Information System (INIS)

Park, Sung Bin; Moon, Min Hoan; Sung, Chang Kyu; Oh, Sohee; Lee, Young Ho

2014-01-01

To investigate the optimal imaging delay time of dynamic contrast-enhanced magnetic resonance (MR) imaging in women with endometrial cancer. This prospective single-institution study was approved by the institutional review board, and informed consent was obtained from the participants. Thirty-five women (mean age, 54 years; age range, 29-66 years) underwent dynamic contrast-enhanced MR imaging with a temporal resolution of 25-40 seconds. The signal intensity difference ratios between the myometrium and endometrial cancer were analyzed to investigate the optimal imaging delay time using single change-point analysis. The optimal imaging delay time for appropriate tumour-myometrium contrast ranged from 31.7 to 268.1 seconds. The median optimal imaging delay time was 91.3 seconds, with an interquartile range of 46.2 to 119.5 seconds. The median signal intensity difference ratios between the myometrium and endometrial cancer were 0.03, with an interquartile range of -0.01 to 0.06, on the pre-contrast MR imaging and 0.20, with an interquartile range of 0.15 to 0.25, on the post-contrast MR imaging. An imaging delay of approximately 90 seconds after initiating contrast material injection may be optimal for obtaining appropriate tumour-myometrium contrast in women with endometrial cancer. (orig.)

Multiphase contrast-enhanced CT with highly concentrated contrast agent can be used for PET attenuation correction in integrated PET/CT imaging

International Nuclear Information System (INIS)

Aschoff, Philip; Plathow, Christian; Lichy, Matthias P.; Claussen, Claus D.; Pfannenberg, Christina; Beyer, Thomas; Erb, Gunter; Oeksuez, Mehmet Oe.

2012-01-01

State-of-the-art positron emission tomography/computed tomography (PET/CT) systems incorporate multislice CT technology, thus facilitating the acquisition of multiphase, contrast-enhanced CT data as part of integrated PET/CT imaging protocols. We assess the influence of a highly concentrated iodinated contrast medium (CM) on quantification and image quality following CT-based attenuation correction (CT-AC) in PET/CT. Twenty-eight patients with suspected malignant liver lesions were enrolled prospectively. PET/CT was performed 60 min after injection of 400 MBq of 18 F-fluorodeoxyglucose (FDG) and following the biphasic administration of an intravenous CM (400 mg iodine/ml, Iomeron 400). PET images were reconstructed with CT-AC using any of four acquired CT image sets: non-enhanced, pre-contrast (n-PET), arterial phase (art-PET), portal venous phase (pv-PET) and late phase (late-PET). Normal tissue activity and liver lesions were assessed visually and quantitatively on each PET/CT image set. Visual assessment of PET following CT-AC revealed no noticeable difference in image appearance or quality when using any of the four CT data sets for CT-AC. A total of 44 PET-positive liver lesions was identified in 21 of 28 patients. There were no false-negative or false-positive lesions on PET. Mean standardized uptake values (SUV) in 36 evaluable lesions were: 5.5 (n-PET), 5.8 (art-PET), 5.8 (pv-PET) and 5.8 (late-PET), with the highest mean increase in mean SUV of 6%. Mean SUV changes in liver background increased by up to 10% from n-PET to pv-PET. Multiphase CT data acquired with the use of highly concentrated CM can be used for qualitative assessment of liver lesions in torso FDG PET/CT. The influence on quantification of FDG uptake is small and negligible for most clinical applications. (orig.)

MRI contrast enhancement of the lung using a Gd-DTPA aerosol

International Nuclear Information System (INIS)

Bockisch, A.; Harvey, R.C.; Davis, M.A.; Kabalka, G.W.

1993-01-01

A MR imaging study was performed in anesthetized female beagle dogs to investigate the effectiveness of Gd-DTPA aerosol for contrast enhancement in ventilated lungs. Ventilation was performed using a commercially available atomizer to administer Gd-DTPA solution. MR imaging was performed with a 1.9 T whole body imager using respiratory gated acquisition. To define the amount of Gd-DTPA being trapped in the lungs identical experiments were performed with 99m Tc-DTPA. MR imaging confirmed at 70% contrast enhancement following inhalation of Gd-DTPA. Because of the inherently low signal intensity of lung parenchyma the degree of contrast enhancement is not sufficient for clinical application. (orig.) [de

Radiofrequency ablation of liver cancer: early evaluation of therapeutic response with contrast-enhanced ultrasonography

International Nuclear Information System (INIS)

Choi, Dong Gil; Lim, Hyo K.; Lee, Won Jae; Kim, Seung Hoon; Kim, Min Ju; Kim, Seung Kwon; Jang, Kyung Mi; Lee, Ji Yeon; Lim, Jae Hoon

2004-01-01

The early assessment of the therapeutic response after percutaneous radiofrequency (RF) ablation is important, in order to correctly decide whether further treatment is necessary. The residual unablated tumor is usually depicted on contrast-enhanced multiphase helical computed tomography (CT) as a focal enhancing structure during the arterial and portal venous phases. Contrast-enhanced color Doppler and power Doppler ultrasonography (US) have also been used to detect residual tumors. Contrast-enhanced gray-scale US, using a harmonic technology which has recently been introduced, allows for the detection of residual tumors after ablation, without any of the blooming or motion artifacts usually seen on contrast-enhanced color or power Doppler US. Based on our experience and reports in the literature, we consider that contrast-enhanced gray-scale harmonic US constitutes a reliable alternative to contrast-enhanced multiphase CT for the early evaluation of the therapeutic response to RF ablation for liver cancer. This technique was also useful in targeting any residual unablated tumors encountered during additional ablation

Cytogenetic effects of cardioangiography on blood lymphocytes in children and in vitro effects of contrast medium and low dose radiation

International Nuclear Information System (INIS)

Nikula, E.; Kiviniitty, K.

1987-01-01

Structural chromosome aberrations were analysed in the peripheral blood lymphocytes of 15 children, aged 1 to 13 years, before, immediately after, 24 hours after and 6 to 8 months after cardioangiographic examination. Statistically significant increases were only demonstrated in the frequency of gaps and, consequently, in the frequency of aberrant cells immediately after cardioangiography. Most of the chromosome damage clearly disappeared within 24 hours. In addition, whole blood cultures were exposed in vitro to low dose radiation, a contrast medium, and radiation together with the contrast medium. No statistically significant differences could be observed in the chromosome aberration frequencies. It was concluded that the modern radiographic procedure, which uses very low radiation doses and less contrast medium, does not cause a consistent, permanent increase of chromosomal damage in the lymphocytes of children. However, the situation may be different if the child undergoes many radiography examinations or the radiation doses are high. (orig./MG)

SU-E-T-56: Brain Metastasis Treatment Plans for Contrast-Enhanced Synchrotron Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Obeid, L; Adam, J [Grenoble Institut des Neurosciences, La Tronche, Rhone-Alpes (France); Tessier, A [Centre Hospitalier Universitaire, La Tronche, Rhone-Alpes (France); Vautrin, M; Benkebil, M [DOSIsoft, Cachan, Ile de France (France); Sihanath, R [Centre Hospitalier Universitaire, La Tronche, Rhone- Alpes (France)

2014-06-01

Purpose: Iodine-enhanced radiotherapy is an innovative treatment combining the selective accumulation of an iodinated contrast agent in brain tumors with irradiations using monochromatic medium energy x-rays. The aim of this study is to compare dynamic stereotactic arc-therapy and iodineenhanced SSRT. Methods: Five patients bearing brain metastasis received a standard helical 3D-scan without iodine. A second scan was acquired 13 min after an 80 g iodine infusion. Two SSRT treatment plans (with/without iodine) were performed for each patient using a dedicated Monte Carlo (MC) treatment planning system (TPS) based on the ISOgray TPS. Ten coplanar beams (6×6 cm2, shaped with collimator) were simulated. MC statistical error objective was less than 5% in the 50% isodose. The dynamic arc-therapy plan was achieved on the Iplan Brainlab TPS. The treatment plan validation criteria were fixed such that 100% of the prescribed dose is delivered at the beam isocentre and the 70% isodose contains the whole target volume. The comparison elements were the 70% isodose volume, the average and maximum doses delivered to organs at risk (OAR): brainstem, optical nerves, chiasma, eyes, skull bone and healthy brain parenchyma. Results: The stereotactic dynamic arc-therapy remains the best technique in terms of dose conformation. Iodine-enhanced SSRT presents similar performances to dynamic arc-therapy with increased brainstem and brain parenchyma sparing. One disadvantage of SSRT is the high dose to the skull bone. Iodine accumulation in metastasis may increase the dose by 20–30%, allowing a normal tissue sparing effect at constant prescribed dose. Treatment without any iodine enhancement (medium-energy stereotactic radiotherapy) is not relevant with degraded HDVs (brain, parenchyma and skull bone) comparing to stereotactic dynamic arc-therapy. Conclusion: Iodine-enhanced SSRT exhibits a good potential for brain metastasis treatment regarding the dose distribution and OAR criteria.

Analysis of peritumoral edema and contrast enhancement by computerized axial tomography

International Nuclear Information System (INIS)

Oi, Shizuo; Szper, I.; Wetzel, N.; Kim, Kwang-S.

1980-01-01

For the purpose of treating brain tumors satisfactorily with steroids, CT findings of brain tumors were analyzed, and pathogenesis of peritumoral edema and supposed effects of steroids were investigated. The degree of peritumoral edema and contrast enhancement and their relationship were analyzed in total 201 patients with brain tumors (gliomas, meningiomas, and metastatic brain tumors). As a result, significant peritumoral edema was recognized in 59% of patients with metastatic brain tumors, 46% of patients with glioma, and 34% of patients with meningioma. As a rule, there was a relationship between peritumoral edema and malignancy or localization of braiin tumors. Severe peritumoral edema was observed in malignant supratentorial tumors (over 60%), but peritumoral edema which was found in infratentorial tumors benign gliomas was mild. The degree of contrast enhancement differed according to tumors, and there was not always a relationship between the degree of contrast enhancement and malignancy or localization of brain tumors. CT findings of brain tumors after the administration of steroids showed decrease in the degree of contrast enhancement. Judging from the effect of steroids to inhibit increased vascular permeability associated with brain edema, like CT findings of peritumoral edema, the degree of contrast enhancement which probably expressed vascularity or vascular permeability seemed to be important in deciding the indications for steroid administration. (Tsunoda, M.)

Evaluation of delayed contrast-enhanced CT scan in diagnosing hilar cholangiocarcinoma

International Nuclear Information System (INIS)

Li Jianding; Liang Chenyang; Zhang Hua; Zhang Yuezhen; Li Rui

2001-01-01

Objective: To assess the diagnostic value of delayed CT contrast enhancement patterns in hilar cholangiocarcinoma based on two-phased dynamic incremental CT scanning. Methods: Fifty-two patients with suspected hilar tumor and bile duct obstruction underwent spiral CT scan. The scan time for one revolution of the X-ray tube was 1 second. To elucidate the delay time for optimal imaging, all proved cholangiocarcinoma with delayed (6, 8, 10, 15, 20, 30 minutes) post-equilibrium-phase contrast-enhanced CT scans were acquired with unenhanced, dynamic contrast-enhanced, and delayed images. Degree of delayed enhancement was compared with that of surrounding liver parenchyma. Results: (1) 8-15 minutes after IV injection of contrast material was the delay time for optimal imaging. (2) Of 29 cholangiocarcinomas, the early CT showed hypo-attenuating (lower than that of liver parenchyma) in 23 tumors, iso-attenuating (equal to that of the liver) in 4 tumors, and hyper-attenuating (higher than that of liver) in 2 tumors. The delayed CT scan showed iso-attenuating in 8 tumors, hyper-attenuating in 21 tumors, and no hypo-attenuating. Most of delay imaging of hilar cholangiocarcinoma may appear hyper-attenuating (U = -4.3073, P 2 = 9.09, P < 0.01). Conclusion: When assessing hilar tumor, delayed CT contrast enhancement patterns based on two-phase dynamic incremental CT scans is useful in the detection and characterization of hilar cholangiocarcinoma

Feature and Contrast Enhancement of Mammographic Image Based on Multiscale Analysis and Morphology

Directory of Open Access Journals (Sweden)

Shibin Wu

2013-01-01

Full Text Available A new algorithm for feature and contrast enhancement of mammographic images is proposed in this paper. The approach bases on multiscale transform and mathematical morphology. First of all, the Laplacian Gaussian pyramid operator is applied to transform the mammography into different scale subband images. In addition, the detail or high frequency subimages are equalized by contrast limited adaptive histogram equalization (CLAHE and low-pass subimages are processed by mathematical morphology. Finally, the enhanced image of feature and contrast is reconstructed from the Laplacian Gaussian pyramid coefficients modified at one or more levels by contrast limited adaptive histogram equalization and mathematical morphology, respectively. The enhanced image is processed by global nonlinear operator. The experimental results show that the presented algorithm is effective for feature and contrast enhancement of mammogram. The performance evaluation of the proposed algorithm is measured by contrast evaluation criterion for image, signal-noise-ratio (SNR, and contrast improvement index (CII.

Polysorbate 80 and low-osmolality water-soluble contrast medium enema in diagnosis and treatment of faecal obstruction in malignant phaeochromocytoma

International Nuclear Information System (INIS)

Ratcliffe, J.F.

1986-01-01

Stercoral obstruction in a young woman with disseminated phaeochromocytoma was diagnosed and treated successfully using an enema of isosmolar iohexol (Omnipaque) and 1% polysorbate 80 (Tween 80) without complication. Surgical intervention was thus avoided. A low osmolality water-soluble contrast medium (iohexol 150 mg I/ml) with a wetting agent (1% Tween 80) was used because a barium suspension would have inspissated, exacerbating the constipation and a hyperosmolar contrast medium might have precipitated a hypertensive crisis and destablished her critical salt and water balance. (orig.)

Dynamic contrast-enhanced subtraction MR angiography in intracranial vascular abnormalities

International Nuclear Information System (INIS)

Takano, K.; Ono, H.; Utsunomiya, H.; Okazaki, M.; Tanaka, A.

1999-01-01

We present our clinical experience with dynamic contrast-enhanced MR angiography (MRA) with subtraction for assessing intracranial vascular abnormalities. Ten patients with various cerebrovascular disorders underwent dynamic contrast-enhanced MRA on a 1.0-T system. Thirty sections (2 mm) were acquired in 29-30 s. Maximum intensity projection images and subtracted source images were compared with those obtained by conventional angiography. In all cases, the presence or absence of abnormalities in the targeted vessels, as well as the morphology of the sagittal sinuses, was clearly visualized as in conventional angiography, without any obstructions such as hyperintense hematomas or thrombi, or intraluminal turbulence. Although the temporal and spatial resolutions with current hardware are insufficient, these preliminary results suggest that dynamic contrast-enhanced MRA with subtraction may be useful for assessing vascular lesions with hemorrhage or thrombus, and the dural sinuses. (orig.)

A contrast enhancement method for improving the segmentation of breast lesions on ultrasonography.

Science.gov (United States)

Flores, Wilfrido Gómez; Pereira, Wagner Coelho de Albuquerque

2017-01-01

This paper presents an adaptive contrast enhancement method based on sigmoidal mapping function (SACE) used for improving the computerized segmentation of breast lesions on ultrasound. First, from the original ultrasound image an intensity variation map is obtained, which is used to generate local sigmoidal mapping functions related to distinct contextual regions. Then, a bilinear interpolation scheme is used to transform every original pixel to a new gray level value. Also, four contrast enhancement techniques widely used in breast ultrasound enhancement are implemented: histogram equalization (HEQ), contrast limited adaptive histogram equalization (CLAHE), fuzzy enhancement (FEN), and sigmoid based enhancement (SEN). In addition, these contrast enhancement techniques are considered in a computerized lesion segmentation scheme based on watershed transformation. The performance comparison among techniques is assessed in terms of both the quality of contrast enhancement and the segmentation accuracy. The former is quantified by the measure, where the greater the value, the better the contrast enhancement, whereas the latter is calculated by the Jaccard index, which should tend towards unity to indicate adequate segmentation. The experiments consider a data set with 500 breast ultrasound images. The results show that SACE outperforms its counterparts, where the median values for the measure are: SACE: 139.4, SEN: 68.2, HEQ: 64.1, CLAHE: 62.8, and FEN: 7.9. Considering the segmentation performance results, the SACE method presents the largest accuracy, where the median values for the Jaccard index are: SACE: 0.81, FEN: 0.80, CLAHE: 0.79, HEQ: 77, and SEN: 0.63. The SACE method performs well due to the combination of three elements: (1) the intensity variation map reduces intensity variations that could distort the real response of the mapping function, (2) the sigmoidal mapping function enhances the gray level range where the transition between lesion and background

Perforations during contrast enema

International Nuclear Information System (INIS)

Vogel, H.; Steinkamp, U.; Grabbe, E.; Allgemeines Krankenhaus Ochsenzoll, Hamburg

1983-01-01

During contrast enema, perforation into the retroperitoneal space can be differentiated from perforation into the peritoneum and perforation into the intestinal wall associated with formation of barium granulomas or submucosal spreading of the contrast medium. Other special forms are perforation with contrast medium embolism of diverticula; of the processus vermiformis; penetration of contrast medium into fistulous systems and from the operated areas. Risk factors are: balloon catheter, intestinal tubes with a hard tip, preternatural anus, excessive enema pressure, contrast medium additions, preceding manipulations, intestinal diseases, advanced age and delegation of manipulations to assistants and unskilled staff. Children are particularly at risk. (orig.) [de

Intravenous contrast media application using cone-beam computed tomography in a rabbit model

Energy Technology Data Exchange (ETDEWEB)

Kim, Min Sung; Kim, Bok Yeol; Choi, Hwa Young [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University, Seoul (Korea, Republic of); and others

2015-03-15

This study was performed to evaluate the feasibility of visualizing soft tissue lesions and vascular structures using contrast-enhanced cone-beam computed tomography (CE-CBCT) after the intravenous administration of a contrast medium in an animal model. CBCT was performed on six rabbits after a contrast medium was administered using an injection dose of 2 mL/kg body weight and an injection rate of 1 mL/s via the ear vein or femoral vein under general anesthesia. Artificial soft tissue lesions were created through the transplantation of autologous fatty tissue into the salivary gland. Volume rendering reconstruction, maximum intensity projection, and multiplanar reconstruction images were reconstructed and evaluated in order to visualize soft tissue contrast and vascular structures. The contrast enhancement of soft tissue was possible using all contrast medium injection parameters. An adequate contrast medium injection parameter for facilitating effective CE-CBCT was a 5-mL injection before exposure combined with a continuous 5-mL injection during scanning. Artificial soft tissue lesions were successfully created in the animals. The CE-CBCT images demonstrated adequate opacification of the soft tissues and vascular structures. Despite limited soft tissue resolution, the opacification of vascular structures was observed and artificial soft tissue lesions were visualized with sufficient contrast to the surrounding structures. The vascular structures and soft tissue lesions appeared well delineated in the CE-CBCT images, which was probably due to the superior spatial resolution of CE-CBCT compared to other techniques, such as multislice computed tomography.

Intravenous contrast media application using cone-beam computed tomography in a rabbit model

International Nuclear Information System (INIS)

Kim, Min Sung; Kim, Bok Yeol; Choi, Hwa Young

2015-01-01

This study was performed to evaluate the feasibility of visualizing soft tissue lesions and vascular structures using contrast-enhanced cone-beam computed tomography (CE-CBCT) after the intravenous administration of a contrast medium in an animal model. CBCT was performed on six rabbits after a contrast medium was administered using an injection dose of 2 mL/kg body weight and an injection rate of 1 mL/s via the ear vein or femoral vein under general anesthesia. Artificial soft tissue lesions were created through the transplantation of autologous fatty tissue into the salivary gland. Volume rendering reconstruction, maximum intensity projection, and multiplanar reconstruction images were reconstructed and evaluated in order to visualize soft tissue contrast and vascular structures. The contrast enhancement of soft tissue was possible using all contrast medium injection parameters. An adequate contrast medium injection parameter for facilitating effective CE-CBCT was a 5-mL injection before exposure combined with a continuous 5-mL injection during scanning. Artificial soft tissue lesions were successfully created in the animals. The CE-CBCT images demonstrated adequate opacification of the soft tissues and vascular structures. Despite limited soft tissue resolution, the opacification of vascular structures was observed and artificial soft tissue lesions were visualized with sufficient contrast to the surrounding structures. The vascular structures and soft tissue lesions appeared well delineated in the CE-CBCT images, which was probably due to the superior spatial resolution of CE-CBCT compared to other techniques, such as multislice computed tomography.

Renal streaky artifact during contrast-enhanced abdominal and pelvic CT: Comparison of high versus low osmolality contrast media

International Nuclear Information System (INIS)

Kim, Dae Hong; Kim, Jong Chul; Lee, Chung Keun; Shin, Kyoung Suk

1994-01-01

Introduction of low osmolality contrast agent(LOCA) has allowed safer, more comfortable contrast-enhanced CT examination, but there has been significant increase in image degradation when evaluating the kidneys due to streaky artifact. The authors reviewed findings of contrast- enhanced abdominal and pelvic computed tomography(CT) to know the difference of renal streaky artifact between a high osmolality contrast agent (HOCA) and LOCA. This study included two hundred contrast-enhanced CT in 200 patients, 100 performed with HOCA(meglumine ioglicate, 150 ml) and 100 performed with LOCA (iopromide,150 ml). The severity of renal streaky artifact was compared between HOCA and LOCA groups. Of the scans performed with HOCA, 40 had no artifact, 52 had grade I artifact, 6 had grade II artifact, and 2 had grade III artifact. Of the scans preformed with LOCA, 23 had no artifact, 44 had grade I artifact, 29 had grade II artifact, and 4 had grade III artifact. There was significant difference in the degree of the streaky artifact depending upon the osmolality of the contrast media used(by χ 2 -test, P=.0001). The results of this study revealed a statistically significant increased incidence of artifacts and distortions of renal image with LOCA when compared with HOCA

Contrast Enhancement in Poor Visibility Conditions Using Guided Filtering

Directory of Open Access Journals (Sweden)

D

2013-06-01

Full Text Available In this paper, extraction of atmospheric veil is proposed to enhance the contrast of the images captured under poor visibility conditions. The method based on guided filtering can accurately recover hidden edges, maintain structural similarity (SSIM to input image and it is effective for both color and gray level images. The proposed algorithm works without prior information about the scene and its complexity is linear function of the input image size. Experimental comparisons with state of the art algorithms demonstrate that our approach can significantly enhance the contrast and restore the visibility in fine details.

Contrast-enhanced thoracic 3D-MR angiography in infants and children

International Nuclear Information System (INIS)

Holmqvist, C.; Larsson, E.M.; Staahlberg, F.; Laurin, S.

2000-01-01

To optimise breath-hold contrast-enhanced MR angiography (MRA) in infants and children with suspected congenital heart or thoracic vessel malformation. Thirty-nine children (median age 1 year) were examined, using five different ultrafast MRA sequences with a TR between 3.2 and 5.0 ms and the contrast agent meglumine gadoterate. A test injection was used to determine contrast travel time. Different parameters for contrast injection were evaluated. Signal-to-noise ratio (SNR) measurements were performed and image quality and injection timing were evaluated. MRA was successful in all patients and image quality was considered very good in 52%. Adequate SNR was achieved with no significant differences between the MR sequences. SNR decreased only 25 - 30% between subsequent scans. The mean contrast dose was 0.23 mmol/kg. The mean scan time was 12.5±3.8 s; the shorter scan times made dynamic examinations possible with high temporal resolution. Highest spatial resolution was obtained with TR 4.6/5.0 sequences. A contrast dose of 0.2 mmol/kg b.w. is recommended with an injection rate of 0.5 to 1.2 ml/s, depending on patient size and scan time. The scan delay time should equal the contrast travel time for optimal vessel enhancement. In the future, contrast-enhanced MRA may be a potential alternative to angiocardiography in infants and children

Contrast induced nephropathy

DEFF Research Database (Denmark)

Stacul, Fulvio; van der Molen, Aart J; Reimer, Peter

2011-01-01

PURPOSE: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN). AREAS COVERED: Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic me...

Contrast-enhanced ultrasound study of primary hepatic angiosarcoma: A pitfall of non-enhancement

International Nuclear Information System (INIS)

Wang, Liang; Lv, Ke; Chang, Xiao-Yan; Xia, Yu; Yang, Zhi-Ying; Jiang, Yu-Xin; Dai, Qing; Tan, Li; Li, Jian-Chu

2012-01-01

Highlights: ► The contrast-enhanced ultrasound (CEUS) characteristics of primary hepatic angiosarcoma (PHA) in three patients were retrospectively analyzed. ► PHA appeared similar peripheral enhancement pattern in our series. ► Non-necrotic tumor tissue of PHA unexpectedly demonstrated non-enhancement on CEUS. ► It may be associated with the very low velocity of blood flow in the central region of tumors. ► This interesting finding warrants further investigations, particularly on intratumoral hemodynamics. -- Abstract: Objective: To investigate the contrast-enhanced ultrasound (CEUS) characteristics of primary hepatic angiosarcoma (PHA). Methods: The sonographic findings and CEUS images of PHA in three patients were retrospectively analyzed. Results: In our study, 3 cases of PHA (2 multiple nodules and 1 solitary mass) showed similar enhancement pattern on CEUS, characterized by remarkable central non-enhancement and peripheral irregular enhancement in the arterial and portal phase, and complete wash-out in the late phase. Furthermore, we unexpectedly found that abundant neoplastic tissues were present in the central area of non-enhancement on pathological evaluation. Based on literature review, we supposed that the unusual finding may be associated with the very low velocity of blood flow in the central region of tumors. Conclusion: CEUS could well depict PHA with some common features, which may provide valuable clues in diagnosis of this rare disease. And non-necrotic tumor tissue of PHA could also demonstrate non-enhancement on CEUS, which warrant further investigations

Nuclear magnetic resonance diagnosis of cerebral tumours with the use of the contrast medium gadolinium-DTPA

International Nuclear Information System (INIS)

Schoerner, W.; Felix, R.; Claussen, C.; Fiegler, W.; Kazner, E.; Speck, U.; Niendorf, H.P.

1984-01-01

This study examines the effect of the NMR contrast medium gadolinium-DTPA on image contrast in cerebral tumours. Sixteen patients with space-occupying cerebral lesions were examined on a 0.35 Tesla superconducting scanner, using a T1-weighted spinecho sequence prior to and after the intravenous application of gadolinium-DTPA. In 8 patients T2-weighted spinecho-sequences were obtained before the administration of contrast. The tomograms were evaluated visually and according to quantitative criteria. The use of gadolinium-DTPA helps to evaluate the blood-brain barrier and improves diagnosis by differentiating tumour tissue from edema and from normal brain tissue. (orig.) [de

Morphological image processing for quantitative shape analysis of biomedical structures: effective contrast enhancement

International Nuclear Information System (INIS)

Kimori, Yoshitaka

2013-01-01

A contrast enhancement approach utilizing a new type of mathematical morphology called rotational morphological processing is introduced. The method is quantitatively evaluated and then applied to some medical images. Image processing methods significantly contribute to visualization of images captured by biomedical modalities (such as mammography, X-ray computed tomography, magnetic resonance imaging, and light and electron microscopy). Quantitative interpretation of the deluge of complicated biomedical images, however, poses many research challenges, one of which is to enhance structural features that are scarcely perceptible to the human eye. This study introduces a contrast enhancement approach based on a new type of mathematical morphology called rotational morphological processing. The proposed method is applied to medical images for the enhancement of structural features. The effectiveness of the method is evaluated quantitatively by the contrast improvement ratio (CIR). The CIR of the proposed method is 12.1, versus 4.7 and 0.1 for two conventional contrast enhancement methods, clearly indicating the high contrasting capability of the method

An improved contrast enhancement algorithm for infrared images based on adaptive double plateaus histogram equalization

Science.gov (United States)

Li, Shuo; Jin, Weiqi; Li, Li; Li, Yiyang

2018-05-01

Infrared thermal images can reflect the thermal-radiation distribution of a particular scene. However, the contrast of the infrared images is usually low. Hence, it is generally necessary to enhance the contrast of infrared images in advance to facilitate subsequent recognition and analysis. Based on the adaptive double plateaus histogram equalization, this paper presents an improved contrast enhancement algorithm for infrared thermal images. In the proposed algorithm, the normalized coefficient of variation of the histogram, which characterizes the level of contrast enhancement, is introduced as feedback information to adjust the upper and lower plateau thresholds. The experiments on actual infrared images show that compared to the three typical contrast-enhancement algorithms, the proposed algorithm has better scene adaptability and yields better contrast-enhancement results for infrared images with more dark areas or a higher dynamic range. Hence, it has high application value in contrast enhancement, dynamic range compression, and digital detail enhancement for infrared thermal images.

MR imaging of spine and spinal canal neoplasms: value of Gd-DTPA contrast enhancement

International Nuclear Information System (INIS)

Paprzycki, W.; Gradzki, J.; Sosnowski, P.; Stajgis, M.

1994-01-01

Value of Gadolinium-DTPA contrast enhancement in diagnosis of neoplastic diseases of spinal canal was estimated on the basis of retrospective analysis of MR examinations performed in 75 patients. The analyzed material consisted of 15 cases of intramedullary tumors (group 1.), 38 of subdural extramedullary (group 2.) and 22 extradural ones (group 3.). Contrast enhanced MR contributed significant information to the final diagnosis in all groups. The utmost significance of Gd-DTPA contrast enhancement was ascertained in group 1. Authors conclude that contrast enhancement with Gd-DTPA is indispensable in all these cases of spinal canal neoplasms, where non-contrast MR did not reveal pathologic changes in optimal manner. (author)

Contrast-enhanced breast MRI: factors affecting sensitivity and specificity

Energy Technology Data Exchange (ETDEWEB)

Piccoli, C.W. [Department of Radiology, Jefferson Medical College, Thomas Jefferson University Hospital, 132 South 10th Street, 7th floor, Philadelphia, PA 19107-5244 (United States)

1997-12-31

Contrast-enhanced MRI (CE-MRI) of the breast has been investigated for over 10 years. The reports of sensitivity for cancer detection have generally been greater than 90 %. However, estimates of specificity have varied greatly. Differing results are due to differences in study populations, technical methods and criteria for interpretation. Early and marked signal rise, detected using dynamic imaging technique following contrast administration, is the MRI hallmark of cancer. However, some malignant lesions may enhance slowly or minimally, and a variety of benign lesions may enhance rapidly with marked signal intensity. High resolution techniques generally requiring longer acquisition times are more likely to depict the slowly enhancing malignancies at the cost of a decrease in specificity due to lack of temporal resolution. This disadvantage may be offset by the improved visualization of lesion morphology with high resolution images. This report reviews the methods and results of the leading investigators of breast MRI. (orig.) With 3 figs., 70 refs.

Contrast-enhanced breast MRI: factors affecting sensitivity and specificity

International Nuclear Information System (INIS)

Piccoli, C.W.

1997-01-01

Contrast-enhanced MRI (CE-MRI) of the breast has been investigated for over 10 years. The reports of sensitivity for cancer detection have generally been greater than 90 %. However, estimates of specificity have varied greatly. Differing results are due to differences in study populations, technical methods and criteria for interpretation. Early and marked signal rise, detected using dynamic imaging technique following contrast administration, is the MRI hallmark of cancer. However, some malignant lesions may enhance slowly or minimally, and a variety of benign lesions may enhance rapidly with marked signal intensity. High resolution techniques generally requiring longer acquisition times are more likely to depict the slowly enhancing malignancies at the cost of a decrease in specificity due to lack of temporal resolution. This disadvantage may be offset by the improved visualization of lesion morphology with high resolution images. This report reviews the methods and results of the leading investigators of breast MRI. (orig.)

Experimental investigations on the influence of the contrast medium Iopamiro 300 mixed with vegetal mucus on the nasolacrimal system and external eye tissues

International Nuclear Information System (INIS)

Rubaj, B.; Koper, S.; Wolski, T.; Toczowski, J.; Wolski, J.; Langwinska-Wosko, E.

1994-01-01

Using low osmolality, nonionized contrast medium Iopamiro-300, Bracco mixed with the mucus prepared from the seed flax (''Linum usitatissimum, L.''), a dacryocistorhinography was performed experimentally on 8 healthy mongrel dogs. Assessing the occurrence of local and general complications was the aim of the investigation. On the basis of a radiographic examination it has been shown that the mixture of the contrast medium and seed flax mucus appeared to be a very useful compound for dacryocistorhinography, especially for the evaluation of nasolacrimal duct system course and its patency. Clinical observations and a histological examination proved that this compound of the contrast medium was well tolerated by the mucous membrane of the nasolacrimal system and the external eye tissues. (author). 21 refs, 4 figs

Diagnostic accuracy of magnetic resonance, computed tomography and contrast enhanced ultrasound in radiological multimodality assessment of peribiliary liver metastases.

Directory of Open Access Journals (Sweden)

Vincenza Granata

Full Text Available We compared diagnostic performance of Magnetic Resonance (MR, Computed Tomography (CT and Ultrasound (US with (CEUS and without contrast medium to identify peribiliary metastasis.We identified 35 subjects with histological proven peribiliary metastases who underwent CEUS, CT and MR study. Four radiologists evaluated the presence of peribiliary lesions, using a 4-point confidence scale. Echogenicity, density and T1-Weigthed (T1-W, T2-W and Diffusion Weighted Imaging (DWI signal intensity as well as the enhancement pattern during contrast studies on CEUS, CT and MR so as hepatobiliary-phase on MRI was assessed.All lesions were detected by MR. CT detected 8 lesions, while US/CEUS detected one lesion. According to the site of the lesion, respect to the bile duct and hepatic parenchyma: 19 (54.3% were periductal, 15 (42.8% were intra-periductal and 1 (2.8% was periductal-intrahepatic. According to the confidence scale MRI had the best diagnostic performance to assess the lesion. CT obtained lower diagnostic performance. There was no significant difference in MR signal intensity and contrast enhancement among all metastases (p>0.05. There was no significant difference in CT density and contrast enhancement among all metastases (p>0.05.MRI is the method of choice for biliary tract tumors but it does not allow a correct differential diagnosis among different histological types of metastasis. The presence of biliary tree dilatation without hepatic lesions on CT and US/CEUS study may be an indirect sign of peribiliary metastases and for this reason the patient should be evaluated by MRI.

MRI cisternography with gadolinium-containing contrast medium: its role, advantages and limitations in the investigation of rhinorrhoea.

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Aydin, K; Guven, K; Sencer, S; Jinkins, J R; Minareci, O

2004-01-01

Our purpose was to evaluate the utility of intrathecal gadopentetate dimeglumine -enhanced magnetic resonance cisternography (GdMRC). We injected 0.5 ml contrast medium into the subarachnoid space via lumbar puncture in 20 patients with suspected cerebrospinal fluid (CSF) rhinorrhoea. MRC showed CSF leakage in 14 patients with rhinorrhoea at the time of the examination, into the ethmoid air cells in nine, the sphenoid sinus in three and the frontal sinus in two cases. In 12 of these the site leakage was confirmed during surgical repair of the fistula. No leakage was observed in four patients with intermittent rhinorrhoea, not present at the time of the examination. GdMRC showed leakage in two patients with negative CT cisternography. GdMRC may prove better than CT cisternography, especially with slow CSF flow. We also showed low-dose GdMRC to be a feasible and relative safe way of confirming the presence of and localising active CSF leaks prior to surgical repair.

MRI cisternography with gadolinium-containing contrast medium: its role, advantages and limitations in the investigation of rhinorrhoea

International Nuclear Information System (INIS)

Aydin, K.; Guven, K.; Sencer, S.; Minareci, O.; Jinkins, J.R.

2004-01-01

Our purpose was to evaluate the utility of intrathecal gadopentetate dimeglumine -enhanced magnetic resonance cisternography (GdMRC). We injected 0.5 ml contrast medium into the subarachnoid space via lumbar puncture in 20 patients with suspected cerebrospinal fluid (CSF) rhinorrhoea. MRC showed CSF leakage in 14 patients with rhinorrhoea at the time of the examination, into the ethmoid air cells in nine, the sphenoid sinus in three and the frontal sinus in two cases. In 12 of these the site leakage was confirmed during surgical repair of the fistula. No leakage was observed in four patients with intermittent rhinorrhoea, not present at the time of the examination. GdMRC showed leakage in two patients with negative CT cisternography. GdMRC may prove better than CT cisternography, especially with slow CSF flow. We also showed low-dose GdMRC to be a feasible and relative safe way of confirming the presence of and localising active CSF leaks prior to surgical repair. (orig.)

Contrast enhancement of the cochlear aqueduct in MR imaging: its frequency and clinical significance

International Nuclear Information System (INIS)

Nakamura, T.; Naganawa, S.; Fukatsu, H.; Sakurai, Y.; Ishigaki, T.; Aoki, I.; Ninomiya, A.; Nakashima, T.

2003-01-01

There have been no previous reports on contrast enhancement of the cochlear aqueduct in magnetic resonance imaging. The purpose of the present study was to evaluate the frequency and significance of this finding. Thirty-one patients (15 men and 16 women; age range 18-81 years) with otologic symptoms (sudden sensorineural hearing loss, vertigo, or tinnitus) were examined using contrast-enhanced imaging on a 1.5-T MR scanner. The normal ear served as the control. Two radiologists evaluated contrast enhancement in the area of the cochlear aqueduct. Forty-eight of 62 ears (77.4%) showed contrast enhancement of the cochlear aqueduct, but no significant differences in the frequency of contrast enhancement were observed between patients with and patients without vertigo, tinnitus, sensorineural hearing loss, cerebellopontine angle tumors, or a high-riding jugular bulb. In addition, no gender- or age-related differences were noted. Contrast enhancement of the cochlear aqueduct was frequently observed, but the frequency of enhancement in symptomatic ears was not significantly higher than in control ears. The results of this study may prove helpful in avoiding unnecessary examinations and potential diagnostic confusion. (orig.)

Contrast enhancement of the cochlear aqueduct in MR imaging: its frequency and clinical significance

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Nakamura, T; Naganawa, S; Fukatsu, H; Sakurai, Y; Ishigaki, T [Department of Radiology, Nagoya University School of Medicine, 65 Tsurumai-cho, 466-8550, Shouwa-ku, Nagoya (Japan); Aoki, I; Ninomiya, A [Medical Systems Company, Toshiba Corporation, Nasu Operations, Otawara-shi, Tochigi (Japan); Nakashima, T [Department of Otorhinolaryngology, Nagoya University School of Medicine, Shouwa-ku, Nagoya (Japan)

2003-09-01

There have been no previous reports on contrast enhancement of the cochlear aqueduct in magnetic resonance imaging. The purpose of the present study was to evaluate the frequency and significance of this finding. Thirty-one patients (15 men and 16 women; age range 18-81 years) with otologic symptoms (sudden sensorineural hearing loss, vertigo, or tinnitus) were examined using contrast-enhanced imaging on a 1.5-T MR scanner. The normal ear served as the control. Two radiologists evaluated contrast enhancement in the area of the cochlear aqueduct. Forty-eight of 62 ears (77.4%) showed contrast enhancement of the cochlear aqueduct, but no significant differences in the frequency of contrast enhancement were observed between patients with and patients without vertigo, tinnitus, sensorineural hearing loss, cerebellopontine angle tumors, or a high-riding jugular bulb. In addition, no gender- or age-related differences were noted. Contrast enhancement of the cochlear aqueduct was frequently observed, but the frequency of enhancement in symptomatic ears was not significantly higher than in control ears. The results of this study may prove helpful in avoiding unnecessary examinations and potential diagnostic confusion. (orig.)

Myths and misconceptions concerning contrast media-induced anaphylaxis: a narrative review.

Science.gov (United States)

Böhm, Ingrid; Morelli, John; Nairz, Knud; Silva Hasembank Keller, Patricia; Heverhagen, Johannes T

2017-03-01

Contrast-enhanced radiological examinations are an increasingly important diagnostic tool in modern medicine. All approved and available contrast media (iodinated and gadolinium-based) are safe compounds that are well-tolerated by most patients. However, a small percentage of patients exhibit contrast medium-induced adverse drug reactions that are dose-dependent and predictable (type A) or an even smaller cohort experience so-called type B (dose-independent, non-predictable). To increase patients' safety, recommendations/guidelines have been put forth in the literature and advice passed down informally by radiologists in practice to ensure contrast media safety. Through these, both reasonable suggestions as well as misinterpretations and myths (such as the misleading terms "allergy-like" reactions, and "iodine-allergy", the wrong assumption that the initial contact to a contrast medium could not induce an allergy, the estimation that an anti-allergy premedication could suppress all possible adverse reactions, and interleukin-2 as a risk/trigger for contrast medium adverse events) have arisen. Since the latter are not only unhelpful but also potentially reduce patients' safety, such myths and misconceptions are the focus of this review.

Meta-analysis: Serum creatinine changes following contrast enhanced CT imaging

International Nuclear Information System (INIS)

Kooiman, Judith; Pasha, Sharif M.; Zondag, Wendy; Sijpkens, Yvo W.J.; Molen, Aart J. van der; Huisman, Menno V.; Dekkers, Olaf M.

2012-01-01

Purpose: Contrast induced nephropathy (CIN) is defined as a decrease in renal function following administration of contrast media. The aim of this meta-analysis was to asses the overall risk of CIN, chronic loss of kidney function and the need for renal replacement therapy (RRT) after intravenous contrast enhanced CT-scan. Secondly, we aimed to identify subgroups at increased risk for CIN. Materials and methods: A literature search in Pubmed, Medline, Embase and Cochrane databases was performed. Data extraction was carried out independently by two reviewers. Meta-analysis and meta-regression were performed using an exact likelihood approach. Results: Forty studies evaluating the incidence of CIN after CT were included. The pooled incidence of CIN was 6.4% (95% CI 5.0–8.1). The risk of RRT after CIN was low, 0.06% (95% CI 0.01–0.4). The decline in renal function persisted in 1.1% of patients (95% CI 0.6–2.1%). Patients with chronic kidney disease (odds ratio 2.26, p < 0.001) or diabetes mellitus (odds ratio 3.10, p < 0.001) were at increased risk for the development of CIN. Conclusion: CIN occurred in 6% of patients after contrast enhanced CT. In 1% of all patients undergoing contrast enhanced CT the decline in renal function persisted

Meta-analysis: Serum creatinine changes following contrast enhanced CT imaging

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Kooiman, Judith, E-mail: j.kooiman@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Pasha, Sharif M., E-mail: s.m.pasha@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Zondag, Wendy, E-mail: w.zondag@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Sijpkens, Yvo W.J., E-mail: ysijpens@bronovo.nl [Department of Nephrology, Bronovo Hospital, The Hague (Netherlands); Molen, Aart J. van der, E-mail: molen@lumc.nl [Department of Radiology, LUMC, Leiden (Netherlands); Huisman, Menno V., E-mail: m.v.huisman@lumc.nl [Department of Thrombosis and Haemostasis, LUMC, Leiden (Netherlands); Dekkers, Olaf M., E-mail: o.m.dekkers@lumc.nl [Department of Clinical Epidemiology and Department of Endocrinology, LUMC, Leiden (Netherlands)

2012-10-15

Purpose: Contrast induced nephropathy (CIN) is defined as a decrease in renal function following administration of contrast media. The aim of this meta-analysis was to asses the overall risk of CIN, chronic loss of kidney function and the need for renal replacement therapy (RRT) after intravenous contrast enhanced CT-scan. Secondly, we aimed to identify subgroups at increased risk for CIN. Materials and methods: A literature search in Pubmed, Medline, Embase and Cochrane databases was performed. Data extraction was carried out independently by two reviewers. Meta-analysis and meta-regression were performed using an exact likelihood approach. Results: Forty studies evaluating the incidence of CIN after CT were included. The pooled incidence of CIN was 6.4% (95% CI 5.0–8.1). The risk of RRT after CIN was low, 0.06% (95% CI 0.01–0.4). The decline in renal function persisted in 1.1% of patients (95% CI 0.6–2.1%). Patients with chronic kidney disease (odds ratio 2.26, p < 0.001) or diabetes mellitus (odds ratio 3.10, p < 0.001) were at increased risk for the development of CIN. Conclusion: CIN occurred in 6% of patients after contrast enhanced CT. In 1% of all patients undergoing contrast enhanced CT the decline in renal function persisted.

Value of contrast-enhanced MRI of breast after silicone implant

International Nuclear Information System (INIS)

Heinig, A.; Heywang-Koebrunner, S.H.; Viehweg, P.; Spielmann, R.P.; Lampe, D.; Buchmann, J.

1997-01-01

Early recognition of recurrence and work-up of clinically indeterminate lesions may be impaired after reconstruction with silicone implants due to superimposition of the implant or to scarring. This study was undertaken to evaluate the use of contrast-enhanced MRI in patients with silicone implant after breast cancer. Contrast-enhanded MRI was offered to 169 patients. Comparative two- to three-view mammography was also performed in 169 patients, as well as comparative sonography in 144 patients. Conventional imaging and clinical examination detected only 8/13 recurrences, whereas 12/13 were detected by MRI. One recurrence had been visible as a strongly enhancing 2-mm dot in a previous examination (2 years before), but was not called. It was therefore counted as false negative. In addition, multicentricity was detected by MRI alone in two of three cases. MRI correctly diagnosed scar tissue in all cases with indeterminate findings. However, due to false-positive calls caused by enhancing granulomas specificity could not be improved. Contrast-enhanded MRI allowed decisive additional information in our study group and improved the sensitivity significantly (concerning all diagnoses). Contrast-enhanded MRI allowed decisive additional information in our study group and improved the sensitivity significantly (concerning all diagnoses). Contrast-enhanded MRI is recommended in patients with diagnostic problems or high risk of recurrence after silicone implants. (orig.) [de

Indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced computed tomography: Assessment of the additional diagnostic value of contrast-enhanced ultrasound in the non-cirrhotic liver

International Nuclear Information System (INIS)

Quaia, Emilio; De Paoli, Luca; Angileri, Roberta; Cabibbo, Biagio; Cova, Maria Assunta

2014-01-01

Objective: To assess the additional diagnostic value of contrast-enhanced ultrasound (CEUS) in the characterization of indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced computed tomography (CT). Methods: Fifty-five solid hepatic lesions (1–4 cm in diameter) in 46 non-cirrhotic patients (26 female, 20 male; age ± SD, 55 ± 10 years) underwent CEUS after being detected on contrast-enhanced CT which was considered as non-diagnostic after on-site analysis. Two blinded independent readers assessed CT and CEUS scans and were asked to classify retrospectively each lesion as a malignant or benign based on reference diagnostic criteria for the different hepatic lesion histotypes. Diagnostic accuracy and confidence (area – A z – under ROC curve) were assessed by using gadobenate dimeglumine-enhanced magnetic resonance (MR) imaging (n = 30 lesions), histology (n = 7 lesions), or US follow-up (n = 18 lesions) as the reference standards. Results: Final diagnoses included 29 hemangiomas, 3 focal nodular hyperplasias, 1 hepatocellular adenoma, and 22 metastases. The additional review of CEUS after CT images improved significantly (P < .05) the diagnostic accuracy (before vs after CEUS review = 49% [20/55] vs 89% [49/55] – reader 1 and 43% [24/55] vs 92% [51/55] – reader 2) and confidence (A z , 95% Confidence Intervals before vs after CEUS review = .773 [.652–.895] vs .997 [.987–1] – reader 1 and .831 [.724–.938] vs .998 [.992–1] – reader 2). Conclusions: CEUS improved the characterization of indeterminate solid hepatic lesions identified on non-diagnostic contrast-enhanced CT by identifying some specific contrast enhancement patterns.

64-section multidetector CT of the upper abdomen: optimization of a saline chaser injection protocol for improved vascular and parenchymal contrast enhancement

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Marin, Daniele [Duke University Medical Center, Department of Radiology, Durham, NC (United States); University of Rome Sapienza, Department of Radiological Sciences, Rome (Italy); Nelson, Rendon C. [Duke University Medical Center, Department of Radiology, Durham, NC (United States); Guerrisi, Antonino; Passariello, Roberto; Catalano, Carlo [University of Rome Sapienza, Department of Radiological Sciences, Rome (Italy); Barnhart, Huiman [Duke University Medical Center, Department of Biostatistics and Bioinformatics, Durham, NC (United States); Schindera, Sebastian T. [University Hospital of Bern, Institute for Diagnostic, Interventional and Pediatric Radiology, Bern (Switzerland)

2011-09-15

To prospectively investigate the effect of varying the injection flow rates of a saline chaser on vascular and parenchymal contrast enhancement during abdominal MDCT. 100 consecutive patients were randomly assigned to four injection protocols. A fixed dose of contrast medium was administered followed by no saline (Protocol A) or 50 mL of saline at 2, 4, or 8 mL/s (Protocols B, C, and D). Peak, time-to-peak, and duration of 90% peak enhancement were determined for aorta, pancreas, and liver. Aortic peak enhancement was significantly higher for Protocol D (369.5 HU) compared with Protocols A and B (332.9 HU and 326.0 HU, respectively; P < 0.05). Pancreatic peak enhancement was significantly higher for Protocols C and D (110.6 HU and 110.9 HU, respectively) compared to Protocol A (92.5 HU; P < 0.05). Aortic and pancreatic time-to-peak enhancement occurred significantly later for Protocol D compared with Protocol A (42.8 s vs. 36.1 s [P < 0.001] and 49.7 s vs. 45.3 s [P = 0.003]). Injecting a saline chaser at high flow rates yields significantly higher peak aortic and pancreatic enhancement, with a slight longer time-to-peak enhancement. (orig.)

Contrast-enhanced ultrasound in diagnosis and characterization of focal hepatic lesions.

Science.gov (United States)

Molins, Inés Gómez; Font, Juan Manuel Fernández; Alvaro, Juan Carrero; Navarro, Jose Luís Lledó; Gil, Marta Fernández; Rodríguez, Conrado M Fernández

2010-12-28

The extensive use of imaging techniques in differential diagnosis of abdominal conditions and screening of hepatocellular carcinoma in patients with chronic hepatic diseases, has led to an important increase in identification of focal liver lesions. The development of contrast-enhanced ultrasound (CEUS) opens a new window in the diagnosis and follow-up of these lesions. This technique offers obvious advantages over the computed tomography and magnetic resonance, without a decrease in its sensitivity and specificity. The new second generation contrast agents, due to their intravascular distribution, allow a continuous evaluation of the enhancement pattern, which is crucial in characterization of liver lesions. The dual blood supply in the liver shows three different phases, namely arterial, portal and late phases. The enhancement during portal and late phases can give important information about the lesion's behavior. Each liver lesion has a different enhancement pattern that makes possible an accurate approach to their diagnosis. The role of emerging techniques as a contrast-enhanced three-dimensional US is also discussed. In this article, the advantages, indications and technique employed during CEUS and the different enhancement patterns of most benign and malignant focal liver lesions are discussed.

Magnetic iron oxide for contrast-enhanced MR imaging

International Nuclear Information System (INIS)

Fahlvik, A.K.

1991-05-01

The main objective of this experimental work has been to study the biological fate and the contrast enhancing potential of a model preparation of magnetic iron oxide (MSM) after intravenous injection to rodents. This was achieved by: Studying in vitro contrast efficacy of various magnetic iron oxide preparations by relaxation analysis. Studying in vivo contrast efficacy of MSM by relaxation analysis and NMR imaging. Studying the biodistribution and bioelimination of MSM in independent experiments using relaxation analysis, radioactivity studies and histological techniques. Studying interactions of MSM with target cells and target organelles using ex vivo techniques. Based on the presented experimental study, the MSM model preparation of magnetic iron oxide seems to fulfill basic requirements of NMR contrast agents: efficient proton relaxation, specific in vivo distribution, and biological tolerance. 177 refs., 5 figs., 2 tabs

Contrast medium-induced nephropathy: the pathophysiology

DEFF Research Database (Denmark)

Persson, P B; Tepel, Martin

2006-01-01

A widespread, rather general, definition of contrast-induced nephropathy (CIN) is an impairment in renal function occurring within 3 days following the intravascular administration of contrast media (CM) and the absence of an alternative aetiology. In spite of the vast clinical importance of CIN...... haemodynamics, regional hypoxia, auto-, and paracrine factors (adenosine, endothelin, reactive oxygen species) to direct cytotoxic effects. Although these potential mediators of CIN will be discussed separately, several factors may act in concert to perturb kidney function after exposure to contrast media. From...... the current knowledge of the mechanisms causing CIN, it is not possible to recommend a certain class of contrast media, except to avoid large doses of CM of the first generation. From a pathophysiological perspective, volume expansion is effective in avoiding CIN, since water permeability of the collecting...

Contrast enhancement by differently sized paramagnetic MRI contrast agents in mice with two phenotypes of atherosclerotic plaque

NARCIS (Netherlands)

van Bochove, Glenda S.; Paulis, Leonie E. M.; Segers, Dolf; Mulder, Willem J. M.; Krams, Rob; Nicolay, Klaas; Strijkers, Gustav J.

2011-01-01

Interest in the use of contrast-enhanced MRI to enable in vivo specific characterization of atherosclerotic plaques is increasing. In this study the intrinsic ability of three differently sized gadolinium-based contrast agents to permeate different mouse plaque phenotypes was evaluated with MRI. A

Dynamic contrast-enhanced MRI in patients with luminal Crohn's disease

NARCIS (Netherlands)

Ziech, M. L. W.; Lavini, C.; Caan, M. W. A.; Nio, C. Y.; Stokkers, P. C. F.; Bipat, S.; Ponsioen, C. Y.; Nederveen, A. J.; Stoker, J.

2012-01-01

Objectives: To prospectively assess dynamic contrast-enhanced (DCE-)MRI as compared to conventional sequences in patients with luminal Crohn's disease. Methods: Patients with Crohn's disease undergoing MRI and ileocolonoscopy within 1 month had DCE-MRI (3T) during intravenous contrast injection of

The role of contrast-enhanced ultrasound in risk assessment of carotid atheroma

Directory of Open Access Journals (Sweden)

Silviu Stanciu

2016-07-01

Full Text Available Background and objective: Contrast-enhanced ultrasound, used to assess atherosclerotic carotid plaques, improves visualization of vessel wall irregularities and depicts intraplaque neovascularization. This article illustrates the use of contrast-enhanced ultrasound in the risk assessment of carotid atherosclerotic lesions, especially in challenging plaques evaluation. Materials and methods: For 23 patients with difficult duplex ultrasound examination due to carotid tortuosity or calcifications we assessed plaque morphology (contour, echogenicity and stenosis degree using contrast substance (Sonovue, Braco with dedicated vascular low mechanical index CPC software. Conclusion: Contrast-enhanced ultrasound is a new, noninvasive, and safe procedure for imaging carotid atherosclerotic lesions. It is a valuable tool for evaluating the vulnerable plaque at risk for rupture and for the diagnostic of the development and severity of systemic atherosclerotic disease

Technical aspects of contrast-enhanced magnetic resonance imaging of the breast: literature review

International Nuclear Information System (INIS)

Leopoldino, Denise de Deus; Gracio, Tatiana Schiller; D'Ippolito, Giuseppe; Bezerra, Alexandre Sergio de Araujo; Gracio, Tatiana Schiller

2005-01-01

With the advances in surface coil technology and the development of new imaging protocols in addition to the increase of the use of contrast agents, contrast enhanced magnetic resonance imaging (MRI) has emerged as a promising modality for detection, diagnosis and staging of breast cancer. Despite these advances, there are some unresolved issues, including no defined standard technique for contrast-enhanced breast MRI and no standard criteria of interpretation for the evaluation of such studies. In this article, we review the literature and discuss the general requirements and recommendations for contrast agent-enhanced breast MRI, including image interpretation criteria, MR equipment, dedicated radiofrequency coils, use of paramagnetic contrast agents, fat-suppression techniques, planes of acquisition, pulse sequence specifications and artifact sources. (author)

High contrast enhancement aspect of dynamic computed tomography with arterial infusion - DCT-AI

International Nuclear Information System (INIS)

Kato, Seishi; Iwasaki, Naoya; Matsumura, Yoshimitsu; Kuramae, Shigeru; Mishiro, Tadashi

1983-01-01

Dynamic computed tomography was performed on 112 cases possibly having hepatic tumors with intraarterial infusion of undiluted contrast into a selectively placed catheter following angiographies. Our dynamic program could evaluate not only early phase of enhancement but also late phase up to 120 sec. Reconstructed views from early scans and magnified views were very useful to evaluate minute sequential changes. Hepatic masses less than 5 cm in size were found in thirty-one cases. Patterns of tumor enhancement and time-density curves have been analysed to correlate them with histology. Four types of tumor enhancement were noted: (1) homogeneous (2) patchy (3) mottled (4) ringed. Characteristic changes were observed in hepatocellular carcinoma - HCC - (mostly mottled) and haemangioma (mostly patchy). The former was divided in two groups reflecting the cellular maturity. The metastatic tumor could be enhanced in a ringed form with dendritic pattern of supplying vascularities in some cases. To support the use of undiluted contrast and to investigate the diagnostic efficacy of high contrast enhancement, experiments were performed by taking transaxial views of an acrylic phantom immersed in different concentrations of contrast. Analysis of CT images taken at different HU values ranging from 0 to 450 demonstrated that the higher the concentration of contrast, the better the spatial resolution was. Also larger magnification could be expected by using higher concentration of contrast. Although our Dynamic Computed Tomography with Arterial Infusion of Contrast still has drawbacks and limited indications, we advocate it as a better way of enhancement to detect and evaluate the hepatic masses, which sometimes elude the examiner's grasp with conventional way of enhancement. (author)

Apparition of iodinated contrast agents in twin neonatal gastrointestinal tracts after maternal contrast-enhanced computed tomography

International Nuclear Information System (INIS)

Kato, Hiroki; Kanematsu, Masayuki; Kato, Zenichiro; Kondo, Naomi; Orii, Kenji E.; Morimoto, Masahiro

2011-01-01

We describe a case of the appearance of iodinated contrast agents in the same locations of twins' neonatal gastrointestinal tracts 1 day after maternal contrast-enhanced computed tomography (CT). The CT examination had been performed on the expectant mother for suspected deep venous thrombosis on the day previous to the twin delivery. At 23 h after the CT examination and after cesarean section, iodinated contrast agents appeared in the same place in the twins' neonatal gastrointestinal tracts, mainly in the ascending colon, on plain abdominal radiographs. Radiologists, obstetricians, and pediatricians should understand the mechanism of appearance of iodinated contrast agents in fetal gastrointestinal tracts when the expectant mother had been given iodinated contrast agents intravenously shortly before delivery. (author)

A review on brightness preserving contrast enhancement methods for digital image

Science.gov (United States)

Rahman, Md Arifur; Liu, Shilong; Li, Ruowei; Wu, Hongkun; Liu, San Chi; Jahan, Mahmuda Rawnak; Kwok, Ngaiming

2018-04-01

Image enhancement is an imperative step for many vision based applications. For image contrast enhancement, popular methods adopt the principle of spreading the captured intensities throughout the allowed dynamic range according to predefined distributions. However, these algorithms take little or no consideration into account of maintaining the mean brightness of the original scene, which is of paramount importance to carry the true scene illumination characteristics to the viewer. Though there have been significant amount of reviews on contrast enhancement methods published, updated review on overall brightness preserving image enhancement methods is still scarce. In this paper, a detailed survey is performed on those particular methods that specifically aims to maintain the overall scene illumination characteristics while enhancing the digital image.

Morphological rational multi-scale algorithm for color contrast enhancement

Science.gov (United States)

Peregrina-Barreto, Hayde; Terol-Villalobos, Iván R.

2010-01-01

Contrast enhancement main goal consists on improving the image visual appearance but also it is used for providing a transformed image in order to segment it. In mathematical morphology several works have been derived from the framework theory for contrast enhancement proposed by Meyer and Serra. However, when working with images with a wide range of scene brightness, as for example when strong highlights and deep shadows appear in the same image, the proposed morphological methods do not allow the enhancement. In this work, a rational multi-scale method, which uses a class of morphological connected filters called filters by reconstruction, is proposed. Granulometry is used by finding the more accurate scales for filters and with the aim of avoiding the use of other little significant scales. The CIE-u'v'Y' space was used to introduce our results since it takes into account the Weber's Law and by avoiding the creation of new colors it permits to modify the luminance values without affecting the hue. The luminance component ('Y) is enhanced separately using the proposed method, next it is used for enhancing the chromatic components (u', v') by means of the center of gravity law of color mixing.

Diagnostic value of dynamic contrast-enhanced MRI for submucosal palatal tumors

International Nuclear Information System (INIS)

Matsuzaki, Hidenobu; Yanagi, Yoshinobu; Hara, Marina; Katase, Naoki; Hisatomi, Miki; Unetsubo, Teruhisa; Konouchi, Hironobu; Takenobu, Toshihiko

2012-01-01

Objectives: To evaluate the diagnostic value of dynamic contrast-enhanced MRI (DCE-MRI) for differentiating between benign and malignant tumors in the palate. Materials and methods: 26 patients with submucosal palatal tumors were preoperatively examined using DCE-MRI. Their maximum contrast index (CImax), time of CImax (Tmax), and washout ratios (WR300 and WR600) were determined from contrast index curves. The submucosal palatal tumors were divided into two groups according to their Tmax values: the early enhancement group (Tmax 2 = 0.92, P < 0.001). Conclusions: Tmax is a useful parameter for distinguishing between benign and malignant submucosal palatal tumors.

Pulmonary CT angiography: optimization of contrast enhancement technique

International Nuclear Information System (INIS)

Ma Lianju; Tang Guangjian; Fu Jiazhen

2012-01-01

Objective: To derive and evaluate the formula of exactly calculating the contrast dosage used during pulmonary CT angiography (CTPA). Methods: Time density curves in 27 patients who underwent CTPA were collected and analyzed,the formula for calculating contrast dosage during CTPA was derived. 68 patients suspected of pulmonary embolism (PE) clinically but no PE on CTPA were divided randomly into group A, with bolus tracing technique (n=26), and group B, with small dose injection contrast test (SDCT) (n=42). The CT values of the right main pulmonary artery (RMPA), right upper pulmonary vein (RUPV), right posterior basal PA, right lower PV (RLPV) and the aorta were calculated. The total contrast dosage and the hard beam artifact in the SVC were compared between the two groups.Student's t test, Chi-square test and Mann-Whitney U test were used. Results: The ratio of the time from starting injection to enhancement peak of caudal end of SVC and the time to enhancement peak of the main pulmonary trunk was 0.65 ±0.09 (about 2/3), the formula for contrast dosage calculation was derived as (DTs/3 + STs/2) FR ml/s. The CT values of RMPA and RLPA between the two groups [(301 ±117), (329 ± 122) and (283 ±95), (277 ±98) HU respectively] were not significantly different (t=1.060, P=0.292; t=2.056, P=0.044), but the differences of CT values in the paired PA and PV between the two groups (median were 22.5, 58.0 and 170.5, 166.5 HU respectively) were significant (U=292, P=0.001 and U=325, P=0.005), contrast artifact of the SVC (grade 1-3) in group B (n=34, 7, 1 respectively) was significantly less than in group A (n=11, 10, 5 respectively, χ 2 =10.714, P=0.002), the contrast dosage injected in group A was ( 87.6 ± 7.3) ml, and in group B was (40.0 ±5.4) ml (P<0.01). Conclusion: CTPA with SDCT technique is superior to that with conventional bolus tracing technique regarding contrast dosage and contrast artifact in the SVC. (authors)

A multi-slice gradient sequence for contrast enhanced MR diagnosis of intracranial tumours

International Nuclear Information System (INIS)

Schoerner, W.; Sander, B.; Kornmesser, W.; Laniado, M.; Nakamura, T.; Felix, R.

1988-01-01

A multi-slice gradient echo sequence (FLASH) was compared with a conventional spin-echo (SE) technique with regard to its value for contrast enhanced MR diagnosis. In 28 patients with cerebral tumours, SE images (SE 400/30; four images/3.4 minutes) and FLASH images (FLASH 315/14; 15 images/1.4 minutes) were obtained before and after gadolinium DTPA. After gadolinium-DTPA results were comparable for both techniques with respect to contrast enhancement, tumor contrast and delineation. Because of the higher efficiency of the FLASH 315/14 technique, this sequence is the method of choice for contrast enhanced cerebral MR imaging. (orig.) [de

Delayed contrast-enhanced MRI: use in myocardial viability assessment and other cardiac pathology

International Nuclear Information System (INIS)

Bogaert, J.; Dymarkowski, S.

2005-01-01

As in other organs, tissue characterization is important for many cardiac diseases. For example, in ischemic heart disease, differentiation between reversibly and irreversibly damaged myocardium in patients with a prior myocardial infarction is crucial in determining disease severity, functional recovery and patient outcome. With the recent advent of the single inversion-recovery contrast-enhanced magnetic resonance imaging (MRI) sequence (delayed contrast-enhanced MRI), contrast between normal and abnormal tissues could be significantly enhanced compared with the conventional cardiac MRI sequences, enabling even subtle abnormalities to be visualized. Together with other advances in cardiac MRI (e.g. functional imaging, coronary artery imaging), MRI has become one of the preferred non-invasive modalities to study cardiac diseases. In this paper an overview of the versatility of delayed contrast-enhanced MRI for investigating cardiac diseases is given. (orig.)

Dynamic contrast enhanced ultrasound for therapy monitoring

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Hudson, John M. [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Williams, Ross [Imaging Research, Sunnybrook Research Institute, Toronto, ON (Canada); Tremblay-Darveau, Charles; Sheeran, Paul S. [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Milot, Laurent [Department of Medical Imaging, University of Toronto, Toronto, ON (Canada); Bjarnason, Georg A. [Department of Medical Oncology, University of Toronto, and Sunnybrook Odette Cancer Centre, Toronto, ON (Canada); Burns, Peter N., E-mail: burns@sri.utoronto.ca [Department of Medical Biophysics, University of Toronto, Toronto, ON (Canada); Imaging Research, Sunnybrook Research Institute, Toronto, ON (Canada); Department of Medical Imaging, University of Toronto, Toronto, ON (Canada)

2015-09-15

Quantitative imaging is a crucial component of the assessment of therapies that target the vasculature of angiogenic or inflamed tissue. Dynamic contrast-enhanced ultrasound (DCE-US) using microbubble contrast offers the advantages of being sensitive to perfusion, non-invasive, cost effective and well suited to repeated use at the bedside. Uniquely, it employs an agent that is truly intravascular. This papers reviews the principles and methodology of DCE-US, especially as applied to anti-angiogenic cancer therapies. Reproducibility is an important attribute of such a monitoring method: results are discussed. More recent technical advances in parametric and 3D DCE-US imaging are also summarised and illustrated.

Fast mutual-information-based contrast enhancement

Science.gov (United States)

Cao, Gang; Yu, Lifang; Tian, Huawei; Huang, Xianglin; Wang, Yongbin

2017-07-01

Recently, T. Celik proposed an effective image contrast enhancement (CE) method based on spatial mutual information and PageRank (SMIRANK). According to the state-of-the-art evaluation criteria, it achieves the best visual enhancement quality among existing global CE methods. However, SMIRANK runs much slower than the other counterparts, such as histogram equalization (HE) and adaptive gamma correction. Low computational complexity is also required for good CE algorithms. In this paper, we novelly propose a fast SMIRANK algorithm, called FastSMIRANK. It integrates both spatial and gray-level downsampling into the generation of pixel value mapping function. Moreover, the computation of rank vectors is speeded up by replacing PageRank with a simple yet efficient row-based operation of mutual information matrix. Extensive experimental results show that the proposed FastSMIRANK could accelerate the processing speed of SMIRANK by about 20 times, and is even faster than HE. Comparable enhancement quality is preserved simultaneously.

Osteoblastic Metastases Mimickers on Contrast Enhanced CT

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Fahad Al-Lhedan

2017-01-01

Full Text Available Secondary osseous involvement in lymphoma is more common compared to primary bone lymphoma. The finding of osseous lesion can be incidentally discovered during the course of the disease. However, osseous metastases are infrequently silent. Detection of osseous metastases is crucial for accurate staging and optimal treatment planning of lymphoma. The aim of imaging is to identify the presence and extent of osseous disease and to assess for possible complications such as pathological fracture of the load-bearing bones and cord compression if the lesion is spinal. We are presenting two patients with treated lymphoma who were in complete remission. On routine follow-up contrast enhanced CT, there were new osteoblastic lesions in the spine worrisome for metastases. Additional studies were performed for further evaluation of both of them which did not demonstrate any corresponding suspicious osseous lesion. The patients have a prior history of chronic venous occlusive thrombosis that resulted in collaterals formation. Contrast enhancement of the vertebral body marrow secondary to collaterals formation and venous flow through the vertebral venous plexus can mimic the appearance of spinal osteoblastic metastases.

The role of contrast-enhanced ultrasonography in image-guided liver ablations

International Nuclear Information System (INIS)

Pescatori, Lorenzo Carlo; Sconfienza, Luca Maria; Mauri, Giovanni

2016-01-01

We read with great interest the paper by Kim et al. entitled “Local ablation therapy with contrast enhanced ultrasonography for hepatocellular carcinoma: a practical review,” recently published in Ultrasonography. We think that contrast-enhanced ultrasonography (CEUS), together with the development of reliable navigation systems, is likely to represent one of the most important advances in image-guided ablations in recent years. Thus, we offer some considerations on the topic

Value of the Gd-DTPA contrast enhanced MR in patients with failed back surgery syndrome

International Nuclear Information System (INIS)

Paprzycki, W.; Gradzki, J.; Sosnowski, P.; Stajgis, M.

1994-01-01

Gd-DTPA contrast - enhanced MR enables differentiation between postoperative scar and recurrent prolapse of nucleus pulposus (RPNP). Pre- and post-contrast MR studies in 40 patients with failed back surgery syndrome, previously treated surgically on 54 intervertebral levels, were evaluated. Presence of RPNP was confirmed on 4, postoperative scars on 35 and both condition on 15 invertebral levels. Correct interpretation of pathologic changes on 15 invertebral levels (28%) was only possible after contrast enhancement. Contrast enhancement of scar excluded the diagnosis of coexistence of RPNP and scar, based on pre-contrast MR studies. MR with Gd-DTPA contrast enhancement is the best diagnostic method in patients with failed back surgery syndrome (author)

Effects of high iodine doses given parenterally as contrast medium on parameter of the pro/antioxidative balance

International Nuclear Information System (INIS)

Winkler, R.; Griebenow, S.; Scheidleder, B.; Bailer, H.

2002-01-01

The aim of this study was to investigate effects of high iodine doses given parenterally as contrast medium on parameters of lipid status and thyroid hormone status as well as on parameters of the pro/antioxidative balance of spa patients. 29 patients with a comparable indication who had to undergo an angiography were chosen. The blood parameters of these patients were determined before and after the angiographic treatment. No provable changes of the thyroid parameters f-T 3 , f-T 4 and TSH were found after the angiography. In case of enzyme activities, the protective enzymes SOD and GSHPX showed no changes, while the concentrations of peroxides and MDA were increased significantly. Corresponding to this, the total antioxidative status and the vitamin E level decreased significantly. Altogether these results stand for a moderate deterioration of the antioxidative protective potential by the highly iodine containing contrast medium. (author)

The use of dilute calogen[reg] as a fat density oral contrast medium in upper abdominal computed tomography, compared with the use of water and positive oral contrast media

International Nuclear Information System (INIS)

Ramsay, Duncan W.; Markham, Derrian H.; Morgan, Bruno; Rodgers, Peter M.; Liddicoat, Amanda J.

2001-01-01

AIM: Oral contrast media are commonly given prior to computed tomography (CT) examination of the upper abdomen. Although positive oral contrast media are normally used, there is increasing interest in using negative agents such as water and less commonly fat density products. The aim of this study was to compare a positive oral contrast medium, water, and a diluted emulsion of arachis oil (Calogen[reg], a fat density food supplement) for assessment of the upper abdomen. MATERIALS AND METHODS: Seventy-one patients referred for upper abdominal CT were randomized to receive either 500 ml water, 2% sodium diatrizoate or a dilute suspension of Calogen[reg]. The CT images were scored independently by three radiologists. Distension and anatomical identification was assessed for the stomach, duodenum and jejunum; with anatomical identification recorded for the pancreas, retroperitoneum, liver, gallbladder and spleen. RESULTS: Dilute Calogen[reg] produced a significant improvement (P < 0.01) in distension and anatomical visualization of the stomach and proximal duodenum. Only minimal differences were demonstrated between the three contrast media for visualization of more distal small bowel or identification of the other upper abdominal viscera. Significantly more artifacts were caused by positive contrast media than with the Calogen[reg] mixture. CONCLUSION: A dilute suspension of Calogen[reg] as an oral contrast medium is recommended when disease is suspected within the stomach or proximal duodenum. Ramsay, D.W. et al. (2001)

Utility of intravenous nonionic contrast media for abdominal CT in patients with renal dysfunction

International Nuclear Information System (INIS)

Craig, B.M.; Alpern, M.B.; Sandler, M.A.; Pearlberg, J.L.; Swanson, D.P.

1987-01-01

The safety and efficacy of a nonionic contrast medium (NICM) for CT enhancements in patients with renal dysfunction were evaluated. Thirty consecutive patients referred for abdominal CT with a serum creatinine (SCr) level over 5 mg/dL or a SCr level of 2-5 mg/dL and another risk factor (e.g., diabetes, single kidney) received NICM. Each was matched with a control who received the same 150-mL bolus of a conventional medium. No adverse reactions or significant alterations in SCr values were found in the NICM patients. No significant differences between the patient groups were found in blinded subjective image quality ratings or measured attenuation values of a parenchymal organs and vascular structures (with the exception of less renal enhancement in the NICM patients, reflecting their renal dysfunction). Use of an NICM is a safe and effective method for contrast medium-enhanced CT in patients with renal dysfunction

Contrast-enhanced color Doppler US in breast cancer: Tumoral vascularity correlated with angiogenesis

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Kim, Eun A; Yoon, Kwon Ha; Yun, Ki Jung; Lee, Kwang Man; Park, Ki Han; Juhng, Seon Kwan; Won, Jong Jin [Wonkwang University School of Medicine, Seoul (Korea, Republic of)

2000-12-15

To evaluate the effects of contrast-enhanced color Doppler ultrasonography (CDUS) on the depiction of vascularity and flow pattern in breast cancer and to determine the relationship between tumoral vascularity and angiogenesis. Twenty-one patients with breast cancer were prospectively evaluated with CDUS before and after injection of the contrast agent (SH U 508A, 2.5g, 300 mg/ml ). The tumoral vascularity was expressed as percentage of color Doppler area, which was measured quantitatively by a computerized program (Ultrasonic Imaging Tool; Soongsil University, Seoul, Korea). The flow pattern (four-patterns; spotty, linear, branching, marginal) of the vascularity was analyzed. After surgery, tumor angiogenesis was assessed by microvessel density. The relationship between the vascularity on CDUS and microvessel density was statistically analyzed. At unenhanced CDUS, tumoral flow signals were detected in 12 lesions (48%); at contrast-enhanced CDUS, 18 lesions (86%). All These 18 lesions showed increased signals, compared with those at unenhanced CDUS. The percentage color Doppler area was 1.86 {+-} 0.48% at unenhanced CDUS and 5.23 {+-} 1.18% at contrast-enhanced CDUS. The flow patterns before contrast injection were spotty pattern in 11 tumors and linear pattern in one; after contrast injection, spotty in 8, linear in 4, branching in 5, and marginal in one. The tumoral vascularity at contrast-enhanced CDUS showed no significant correlation with microvessel density. Contrast-enhanced CDUS seems to be a valuable tool in the depiction of vascularity and characterization of flow pattern in breast cancer. However, tumoral vascularity on CDUS may not reflect tumoral angiogenesis.

Breast dynamic contrast enhanced MRI: fibrocystic changes presenting as a non-mass enhancement mimicking malignancy

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Milosevic Zorica C.

2017-06-01

Full Text Available We aimed to analyse the morphokinetic features of breast fibrocystic changes (nonproliferative lesions, proliferative lesions without atypia and proliferative lesions with atypia presenting as a non-mass enhancement (NMEin dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI examination.

Evaluation of the early enhancement of coronary atherosclerotic plaque by contrast-enhanced MR angiography

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Li Tao [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Zhao Xihai [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Liu Xin [Paul C. Lauterbur Biomedical Imaging Center, Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Science, Shenzhen 518067 (China); Gao Jianhua [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Zhao Shaohong [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Li Xin; Zhou Weihua [Department of Radiology, The General Hospital of Chinese People' s Armed Police Forces, Number 69, Yong Ding Road, Hai Dian District, Beijing (China); Cai Zulong [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China); Zhang Weiguo [Cardiovascular and Neurological Consulting Institute, 6771 San Fernando, Irving, TX 75039 (United States); Yang Li, E-mail: Yangli301@yahoo.com [Department of Radiology, Chinese People' s Liberation Army General Hospital, Number 28, Fu Xing Road, Hai Dian District, Beijing (China)

2011-10-15

Purpose: To evaluate the early enhancement of coronary atherosclerotic plaque using contrast-enhanced MR angiography (CE-MRA) and investigate the association between unstable angina pectoris (UAP) and early enhancement of the plaque. Methods: Forty-one patients presenting with angina pectoris and demonstrating single-vessel disease with non-calcified plaque and significant coronary stenosis ({>=}50%) on CTA were consecutively recruited for coronary CE-MRA. Contrast-to-noise ratio of the culprit plaque guided by CTA was measured on a cross-sectional multi-planar reconstruction image of the plaque on both pre- and post-CE-MRA. A 50% increasing of CNR was defined as plaque enhancement. The association between early enhancement of the plaques and UAP was analyzed. Results: Thirty-seven non-calcified plaques with significant coronary stenosis were detected in the 37 patients on MRA. 4 subjects were excluded because coronary atherosclerotic plaques were inadequate for identification on MRA. Of the 37 patients, 18 patients had UAP and other 19 patients presented stable angina pectoris (SAP). Of the 37 plaques on CE-MRA, 13 and 24 plaques presented early enhancement and no enhancement, respectively. Of the 13 early-enhanced plaques, 11 (85%) and 2 (15%) were found in the patients with UAP and SAP, respectively (p < 0.01). Of the 37 patients, 11 (61%) with UAP and 2 (11%) with SAP had early-enhanced plaques, respectively (p < 0.01). Conclusion: CE-MRA allows detection of early enhancement of coronary atherosclerotic plaque. The early enhancement is common in unstable angina and could be a sign of vulnerability.

Estimation of shear velocity contrast for dipping or anisotropic medium from transmitted Ps amplitude variation with ray-parameter

Science.gov (United States)

Kumar, Prakash

2015-12-01

Amplitude versus offset analysis of P to P reflection is often used in exploration seismology for hydrocarbon exploration. In the present work, the feasibility to estimate crustal velocity structure from transmitted P to S wave amplitude variation with ray-parameter has been investigated separately for dipping layer and anisotropy medium. First, for horizontal and isotropic medium, the approximation of P-to-s conversion is used that is expressed as a linear form in terms of slowness. Next, the intercept of the linear regression has been used to estimate the shear wave velocity contrast (δβ) across an interface. The formulation holds good for isotropic and horizontal layer medium. Application of such formula to anisotropic medium or dipping layer data may lead to erroneous estimation of δβ. In order to overcome this problem, a method has been proposed to compensate the SV-amplitude using shifted version of SH-amplitude, and subsequently transforming SV amplitudes equivalent to that from isotropic or horizontal layer medium as the case may be. Once this transformation has been done, δβ can be estimated using isotropic horizontal layer formula. The shifts required in SH for the compensation are π/2 and π/4 for dipping layer and anisotropic medium, respectively. The effectiveness of the approach has been reported using various synthetic data sets. The methodology is also tested on real data from HI-CLIMB network in Himalaya, where the presence of dipping Moho has already been reported. The result reveals that the average shear wave velocity contrast across the Moho is larger towards the Indian side compared to the higher Himalayan and Tibetan regions.

Multipeak Mean Based Optimized Histogram Modification Framework Using Swarm Intelligence for Image Contrast Enhancement

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P. Babu

2015-01-01

Full Text Available A novel approach, Multipeak mean based optimized histogram modification framework (MMOHM is introduced for the purpose of enhancing the contrast as well as preserving essential details for any given gray scale and colour images. The basic idea of this technique is the calculation of multiple peaks (local maxima from the original histogram. The mean value of multiple peaks is computed and the input image’s histogram is segmented into two subhistograms based on this multipeak mean (mmean value. Then, a bicriteria optimization problem is formulated and the subhistograms are modified by selecting optimal contrast enhancement parameters. While formulating the enhancement parameters, particle swarm optimization is employed to find optimal values of them. Finally, the union of the modified subhistograms produces a contrast enhanced and details preserved output image. This mechanism enhances the contrast of the input image better than the existing contemporary HE methods. The performance of the proposed method is well supported by the contrast enhancement quantitative metrics such as discrete entropy, natural image quality evaluator, and absolute mean brightness error.

Contrast enhanced MR imaging of postoperative medulloblastoma in childhood: emphasis on meningeal enhancement

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Choi, Choong Gon; Kim, In One; Kim, Woo Sun; Kim, Ho Chul; Yeon, Kyung Mo [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

1993-03-15

To differentiate the postoperative changes from the recurrence of tumor and to evaluate MR imaging of early postoperative leptomeningeal seeding in medulloblastoma, We have retrospectively analysed 34 cases of MR images of 17 patients who were confirmed as medulloblastoma by histopathology. Noncontrast and postcontrast T1 weighted MR images were obtained in all patients. In 11 patients follow-up MR was done more than once (average: 1.5 times) and average interval of MR imaging was 6 months. The timing of 34 MR images was as follow: 6 case within 2 months, 9 cases between 2 months and 1 year, 19 cases more than 1 year after surgery respectively. MR images within 2 month after surgery revealed contrast enhancement at operation site and adjacent meninges, hemorrhage, residual tumor. In patients who had no evidence of tumor recurrence, these early postoperative changes were markedly decreased within 6 month after surgery. MR images obtained more than 1 year after surgery showed no abnormal contrast enhancement or mild focal dural enhancement at operation site. Diffuse moderate dural enhancement was noted in one patient who had the history of post-surgical subdural hemorrhage. In six patients with tumor recurrences which were detected from as early as 9 months to 6 years after surgery, the findings of recurrence included leptomeningeal enhancement of brain stem and cerebellar surface at early stage, variable sized enhancing leptomeningeal nodules, linear or irregular sulcus obliterating enhancing lesions, enhancing mass at primary or metastatic site. We have concluded that leptomeningeal enhancement detected after 6 months of surgery is an important MR finding suggesting the possibility of tumor recurrence. Small nodular and linear enhancement of leptomeninges at brainstem or cerebellar surface is considered as the early manifestation of intracranial tumor seeding.

Contrast enhanced MR imaging of postoperative medulloblastoma in childhood: emphasis on meningeal enhancement

International Nuclear Information System (INIS)

Choi, Choong Gon; Kim, In One; Kim, Woo Sun; Kim, Ho Chul; Yeon, Kyung Mo

1993-01-01

To differentiate the postoperative changes from the recurrence of tumor and to evaluate MR imaging of early postoperative leptomeningeal seeding in medulloblastoma, We have retrospectively analysed 34 cases of MR images of 17 patients who were confirmed as medulloblastoma by histopathology. Noncontrast and postcontrast T1 weighted MR images were obtained in all patients. In 11 patients follow-up MR was done more than once (average: 1.5 times) and average interval of MR imaging was 6 months. The timing of 34 MR images was as follow: 6 case within 2 months, 9 cases between 2 months and 1 year, 19 cases more than 1 year after surgery respectively. MR images within 2 month after surgery revealed contrast enhancement at operation site and adjacent meninges, hemorrhage, residual tumor. In patients who had no evidence of tumor recurrence, these early postoperative changes were markedly decreased within 6 month after surgery. MR images obtained more than 1 year after surgery showed no abnormal contrast enhancement or mild focal dural enhancement at operation site. Diffuse moderate dural enhancement was noted in one patient who had the history of post-surgical subdural hemorrhage. In six patients with tumor recurrences which were detected from as early as 9 months to 6 years after surgery, the findings of recurrence included leptomeningeal enhancement of brain stem and cerebellar surface at early stage, variable sized enhancing leptomeningeal nodules, linear or irregular sulcus obliterating enhancing lesions, enhancing mass at primary or metastatic site. We have concluded that leptomeningeal enhancement detected after 6 months of surgery is an important MR finding suggesting the possibility of tumor recurrence. Small nodular and linear enhancement of leptomeninges at brainstem or cerebellar surface is considered as the early manifestation of intracranial tumor seeding

A feasibility study of projection-based energy weighting based on a photon-counting detector in contrast-enhanced digital subtraction mammography: a simulation study

International Nuclear Information System (INIS)

Choi, Sunghoon; Lee, Seungwan; Choi, Yuna; Kim, Heejoung

2014-01-01

Contrast media, such as iodine and gadolinium, are generally used in digital subtraction mammography to enhance the contrast between target and background materials. In digital subtraction mammography, where one image (with contrast medium) is subtracted from another (anatomical background) to facilitate visualization of the tumor structure, tumors can be more easily distinguished after the injection of a contrast medium. In order to have more an effective method to increase the contrast-to-noise ratio (CNR), we applied a projection-based energy-weighting method. The purpose of this study is to demonstrate the feasibility of using the projection-based energy-weighting method in digital subtraction mammography. Unlike some other previous studies, we applied the projection-based energy-weighting method to more practical mammography conditions by using the Monte Carlo method to simulate four different iodine solutions embedded in a breast phantom comprised of 50% adipose and 50% glandular tissues. We also considered an optimal tube voltage and anode/filter combination in digital iodine contrast media mammography in order to maximize the figure-of-merit (FOM). The simulated source energy was from 20 to 45 keV to prevent electronic noise and include the k-edge energy of iodine (33.2 keV). The results showed that the projection-based energy-weighting improved the CNR by factors of 1.05 - 1.86 compared to the conventionally integrated images. Consequently, the CNR of digital subtraction mammography images can be improved by using projection-based energy-weighting with photon-counting detectors.

A feasibility study of projection-based energy weighting based on a photon-counting detector in contrast-enhanced digital subtraction mammography: a simulation study

Energy Technology Data Exchange (ETDEWEB)

Choi, Sunghoon; Lee, Seungwan; Choi, Yuna; Kim, Heejoung [Yonsei University, Wonju (Korea, Republic of)

2014-06-15

Contrast media, such as iodine and gadolinium, are generally used in digital subtraction mammography to enhance the contrast between target and background materials. In digital subtraction mammography, where one image (with contrast medium) is subtracted from another (anatomical background) to facilitate visualization of the tumor structure, tumors can be more easily distinguished after the injection of a contrast medium. In order to have more an effective method to increase the contrast-to-noise ratio (CNR), we applied a projection-based energy-weighting method. The purpose of this study is to demonstrate the feasibility of using the projection-based energy-weighting method in digital subtraction mammography. Unlike some other previous studies, we applied the projection-based energy-weighting method to more practical mammography conditions by using the Monte Carlo method to simulate four different iodine solutions embedded in a breast phantom comprised of 50% adipose and 50% glandular tissues. We also considered an optimal tube voltage and anode/filter combination in digital iodine contrast media mammography in order to maximize the figure-of-merit (FOM). The simulated source energy was from 20 to 45 keV to prevent electronic noise and include the k-edge energy of iodine (33.2 keV). The results showed that the projection-based energy-weighting improved the CNR by factors of 1.05 - 1.86 compared to the conventionally integrated images. Consequently, the CNR of digital subtraction mammography images can be improved by using projection-based energy-weighting with photon-counting detectors.

Local Contrast Enhancement Utilizing Bidirectional Switching Equalization of Separated and Clipped Subhistograms

Directory of Open Access Journals (Sweden)

Haidi Ibrahim

2014-01-01

Full Text Available Digital image contrast enhancement methods that are based on histogram equalization technique are still useful for the use in consumer electronic products due to their simple implementation. However, almost all the suggested enhancement methods are using global processing technique, which does not emphasize local contents. Therefore, this paper proposes a new local image contrast enhancement method, based on histogram equalization technique, which not only enhances the contrast, but also increases the sharpness of the image. Besides, this method is also able to preserve the mean brightness of the image. In order to limit the noise amplification, this newly proposed method utilizes local mean-separation, and clipped histogram bins methodologies. Based on nine test color images and the benchmark with other three histogram equalization based methods, the proposed technique shows the best overall performance.

Quantitative contrast-enhanced optical coherence tomography

Energy Technology Data Exchange (ETDEWEB)

Winetraub, Yonatan; SoRelle, Elliott D. [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Liba, Orly [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Zerda, Adam de la [Molecular Imaging Program at Stanford, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Bio-X Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Biophysics Program, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Structural Biology, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States); Department of Electrical Engineering, Stanford University, 299 Campus Drive, Stanford, California 94305 (United States)

2016-01-11

We have developed a model to accurately quantify the signals produced by exogenous scattering agents used for contrast-enhanced Optical Coherence Tomography (OCT). This model predicts distinct concentration-dependent signal trends that arise from the underlying physics of OCT detection. Accordingly, we show that real scattering particles can be described as simplified ideal scatterers with modified scattering intensity and concentration. The relation between OCT signal and particle concentration is approximately linear at concentrations lower than 0.8 particle per imaging voxel. However, at higher concentrations, interference effects cause signal to increase with a square root dependence on the number of particles within a voxel. Finally, high particle concentrations cause enough light attenuation to saturate the detected signal. Predictions were validated by comparison with measured OCT signals from gold nanorods (GNRs) prepared in water at concentrations ranging over five orders of magnitude (50 fM to 5 nM). In addition, we validated that our model accurately predicts the signal responses of GNRs in highly heterogeneous scattering environments including whole blood and living animals. By enabling particle quantification, this work provides a valuable tool for current and future contrast-enhanced in vivo OCT studies. More generally, the model described herein may inform the interpretation of detected signals in modalities that rely on coherence-based detection or are susceptible to interference effects.

A Case of Contiguous Primary Hepatic Marginal Zone B-Cell Lymphoma and Hemangioma Ultimately Diagnosed Using Contrast-Enhanced Ultrasonography

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Kazue Shiozawa

2015-02-01

Full Text Available Primary hepatic marginal zone B-cell malignant lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma is extremely rare. We present a case in which a lesion was diagnosed as 2 contiguous tumors (MALT lymphoma and hemangioma using contrast-enhanced ultrasonography (US with sonazoid. There has been no previous case of contiguous hepatic MALT lymphoma and hemangioma. The present case was a female with no medical history. We detected a snowman-like appearance, which was a tumor of 15 mm in diameter with hypo- and hyper-echogenicities in the lateral and medial parts, respectively, in the Couinaud's segment (S6 of the liver on US. The tumor appeared as a single lesion with a low-density area in the unenhanced phase and prolonged enhancement in the equilibrium phases on dynamic CT. On MRI, the whole lesion showed a low-intensity signal on T1-weighted imaging, but isointensity in the lateral part and high intensity in the medial part were seen on T2-weighted imaging. On contrast-enhanced US, the lateral hypoechoic region was homogenously hyperenhanced in the early vascular phase, and the contrast medium was washed out after about 30 s; in contrast, the medial hyperechoic region was gradually stained from the margin toward the central region. The tumor showed a defect in both hypo- and hyperechoic regions in the postvascular phase. Hemangioma was suspected for the medial part based on the typical image findings, but the lateral part was not given a diagnosis. Thus, surgical resection was performed. The medial part was a hemangioma, and the lateral part was a MALT lymphoma by histopathological findings.

MR-imaging of the breast at 0.5 Tesla: menstrual-cycle dependency of parenchymal contrast enhancement in healthy volunteers with oral contraceptive use?; MR-Mammographie bei 0,5 Tesla: Menstruationszyklusabhaengigkeit der Kontrastmittelanreicherung unter hormoneller Kontrazeption?

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Lorenzen, J.; Welger, J.; Krupski, G.; Adam, G. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Lisboa, B.W. [Klinik und Poliklinik fuer Frauenheilkunde und Geburtshilfe, Universitaetsklinikum Hamburg-Eppendorf (Germany)

2003-04-01

Introduction: To evaluate changes of contrast medium enhancement of the breast parenchyma due to menstrual cycle in healthy volunteers with oral contraceptive use in MR-imaging of the breast. Material and Methods: 15 healthy volunteers (age: 22 - 36, mean 28,2) without breast disease were examined two times during one menstrual cycle (days 7 - 14 and days 21 - 2). Two volunteers were examined only in the second part of the cycle (days 21 - 2). All volunteers used oral contraceptives for more than 6 month continuously. Examinations were performed with a 0,5 T magnet (dynamic 3D-gradient echo protocol with subtraction postprocessing). We evaluated the number of enhancing foci and the parenchymal contrast medium enhancement during the different phases of the cycle by region of interest. Results: Only a total of two enhancing foci were found in 2 of 17 volunteers. Time/signal intensity diagrams in these both cases were not suspicious (< 80% initial signal increase after of contrast medium injection, no wash-out phenomenon) and sonography of the breast in these two cases was inconspicuous. Contrast medium enhancement of breast parenchyma in cycle days 7 - 14 (mean enhancement: 0.12 - 0.26, minutes 1 - 9 p.i.) was not significantly different (p = 0.2209; Wilcoxon signed rank test) from cycle days 21 - 2 (mean: 0.13 - 0.32). Conclusion: Menstrual cycle dependency of parenchymal contrast medium enhancement seems to be of minor relevance for premenopausal women with use of oral contraceptives. (orig.) [German] Fragestellung: Untersuchung der Kontrastmittelaufnahme des Brustparenchyms in Abhaengigkeit vom Menstruationszyklus bei gesunden Probandinnen unter oraler Kontrazeption. Material und Methode: Bei 15 gesunden Probandinnen ohne Brusterkrankung in der Anamnese wurde eine MR-Mammographie zweimal waehrend eines Menstruationszyklus durchgefuehrt (Zyklustag: 7 - 14 und 21 - 2). Bei zwei weiteren Probandinnen erfolgte die MR-Mammographie nur in der zweiten Zyklushaelfte

Real-time 3-dimensional contrast-enhanced ultrasound in detecting hemorrhage of blunt renal trauma.

Science.gov (United States)

Xu, Rui-Xue; Li, Ye-Kuo; Li, Ting; Wang, Sha-Sha; Yuan, Gui-Zhong; Zhou, Qun-Fang; Zheng, Hai-Rong; Yan, Fei

2013-10-01

The objective of this study is to evaluate the diagnostic value of real-time 3-dimensional contrast-enhanced ultrasound in the hemorrhage of blunt renal trauma. Eighteen healthy New Zealand white rabbits were randomly divided into 3 groups. Blunt renal trauma was performed on each group by using minitype striker. Ultrasonography, color Doppler flow imaging, and contrast-enhanced 2-dimensional and real-time 3-dimensional ultrasound were applied before and after the strike. The time to shock and blood pressure were subjected to statistical analysis. Then, a comparative study of ultrasound and pathology was carried out. All the struck kidneys were traumatic. In the ultrasonography, free fluid was found under the renal capsule. In the color Doppler flow imaging, active hemorrhage was not identified. In 2-dimensional contrast-enhanced ultrasound, active hemorrhage of the damaged kidney was characterized. Real-time 3-dimensional contrast-enhanced ultrasound showed a real-time and stereoscopic ongoing bleeding of the injured kidney. The wider the hemorrhage area in 4-dimensional contrast-enhanced ultrasound was, the faster the blood pressure decreased. Real-time 3-dimensional contrast-enhanced ultrasound is a promising noninvasive tool for stereoscopically and vividly detecting ongoing hemorrhage of blunt renal trauma in real time. © 2013.

Value of fat suppression and dynamic contrast-enhanced MRI in the diagnosis of insulinoma

International Nuclear Information System (INIS)

Xu Zengbin; Ruan Lingxiang; Peng Zhiyi; Zhang Minming; Xu Shunliang; Zhang Xidao

2003-01-01

Objective: To evaluate the value of fat suppression and dynamic contrast-enhanced MRI in the preoperative localization of insulinoma. Methods: Twelve cases with pathologically proven insulinoma were evaluated with MRI. SE T 1 WI, FSE T 2 WI, T 1 WI and T 2 WI with fat suppression, dynamic contrast-enhanced FMPSPGR sequences were used in MR scanning. Results: On SE T 1 WI, the lesions displayed hypointense in 4, isointense in 8 cases. Lesions showed hyperintense in 4, isointense in 8 cases on FSE T 2 WI. In contrast, 7 cases appeared as hypointense on T 1 WI with fat suppression and 6 cases appeared as hyperintense on T 2 WI with fat suppression. With dynamic contrast-enhanced FMPSPGR sequence 11 of 12 insulinomas were detected. In the arterial phase, the lesions presented as hyperintense with different degrees in 11 cases and isointense in 1 case. 6 cases remained hyperintense and 6 cases were isointense in pancreatic parenchymal and portal phase. 4 lesions were identified only in dynamic enhancement images. The diagnostic accuracy of insulinoma by dynamic contrast-enhanced MRI was 91.7% (11/12) as compared with histological study. Conclusion: The results indicate that dynamic contrast-enhanced MRI is an sensitive and accurate method for the preoperative localization of insulinoma