Increased Contrast Enhancement Research Articles

Dynamic contrast enhanced magnetic resonance imaging in chronic Achilles tendinosis

BackgroundChronic Achilles tendinosis is a common problem. When evaluating and comparing different therapies there is a need for reliable imaging methods. Our aim was to evaluate if chronic Achilles tendinosis affects the dynamic contrast-enhancement in the tendon and its surroundings and if short-term eccentric calf-muscle training normalizes the dynamic contrast-enhancement.Methods20 patients with chronic Achilles tendinopathy were included. Median duration of symptoms was 31 months (range 6 to 120 months). Both Achilles tendons were examined with dynamic contrast enhanced MRI before and after a 12- week exercise programme of eccentric calf-muscle training. The dynamic MRI was evaluated in tendon, vessel and in fat ventrally of tendon. Area under the curve (AUC), time to peak of signal, signal increase per second (SI/s) and increase in signal between start and peak as a percentage (SI%) was calculated. Pain and performance were evaluated using a questionnaire.ResultsIn the fat ventrally of the tendon, dynamic contrast enhancement was significantly higher in the symptomatic leg compared to the contralateral non-symptomatic leg before but not after treatment. Despite decreased pain and improved performance there was no significant change of dynamic contrast enhancement in symptomatic tendons after treatment.ConclusionIn Achilles tendinosis there is an increased contrast enhancement in the fat ventrally of the tendon. The lack of correlation with symptoms and the lack of significant changes in tendon contrast enhancement parameters do however indicate that dynamic enhanced MRI is currently not a useful method to evaluate chronic Achilles tendinosis.

Gadolinium-Based CuInS2/ZnS Nanoprobe for Dual-Modality Magnetic Resonance/Optical Imaging

A new magnetic resonance/optical nanoprobe with specific cellular targeting capabilities based on nontoxic CuInS2/ZnS quantum dots (QDs) with direct covalent attachment of a Gd(III)-complex for tumor-specific imaging is reported. We introduce amphiphilic poly(maleic anhydride-alt-1-octadecene) to interdigitate with hydrophobic, protective agents on the surface of CuInS2/ZnS QDs that allows phase transfer of hydrophobic QDs from the organic into aqueous phase. Carbodiimide chemistry is used to covalently couple the Gd(III) complex on the surface of CuInS2/ZnS QDs, and then folic acid is further utilized to functionalize this dual-modality nanoprobe for active tumor targeting based on the fact that the membrane-associated folate receptor is overexpressed in many tumor cells. The longitudinal relaxivity value is 3.72 mM(-1) s(-1) for the dual-modality nanoprobe and a clear, positive, and increasing contrast enhancement of magnetic resonance signals concurrently with increasing Gd(III) concentration is observed. The dual-modality nanoprobe exhibits negligible cytotoxicity with >80% cell viability at a concentration of up to 100 μg/mL in human cervical (HeLa), human liver carcinoma (HepG2), and human breast (MCF-7) cells after 24 h. The specificity of folic-acid-conjugated nanoprobe cellular uptake has been investigated by confocal scanning laser imaging, which revealed that HeLa cells, expressing the folate receptor, internalized a higher level of dual-modality nanoprobes than HepG2 and MCF-7 cells.

Abstract B84: Activated c-Src enhances hypoxia in human glioblastoma multiforme and promotes tumor angiogenesis

Abstract Exhibiting substantial vascularization and propensity to infiltrate surrounding brain tissue, glioblastoma multiforme (GBM) is the most aggressive primary brain tumor. Even with aggressive intervention afflicted individuals uniformly receive poor prognosis. Growth factor receptor tyrosine kinases (RTKs) are frequently amplified, overexpressed, and constitutively activated in malignant gliomas, and because targeting these molecules has produced promising results in the treatment of several human neoplasms, RTKs are emerging as increasingly viable targets in effective treatment of GBM. Functional ambiguity between normal and constitutively activated RTK signalling compounds the challenges of identifying suitable targets, however. Likewise, the functions of many reported downstream signalling molecules, namely Src family non-receptor tyrosine kinases (SFKs), remain cryptic. Our lab has previously developed a clinically relevant in vivo model that reliably maintains the genomic profiles of corresponding patient tumors, and employing this model, we are able to accurately investigate mechanisms of RTK signalling in human GBM. Ongoing studies suggest that tumor overexpression and activation of the epidermal growth factor receptor (EGFR) promotes the invasive phenotype in human GBM potentially via c-Src dependent signal transduction. In fact, we have observed SFK activation downstream of EGFR. To further investigate this, we implanted GBM patient tumor cells from two individuals with distinct EGFR protein expression, tumor phenotype, and c-Src activity into the brains of nude rats. Minimally expressing EGFR tumor cells from a patient displaying an angiogenic in vivo phenotype were transduced to stably overexpress activated c-Src. Likewise, EGFR-overexpressing tumor cells from a patient displaying an invasive, non angiogenic in vivo phenotype were transduced to stably overexpress kinase-inactive-dominant-negative c-Src. To our surprise, compared with corresponding xenograft control tumors, xenograft tumors overexpressing constitutively activated c-Src showed substantially increased contrast enhancement on MRI, enhanced histological features of angiogenesis, and revealed marked increases in molecular markers of tumor hypoxia and angiogenesis on western blot. Meanwhile, compared with corresponding xenograft control tumors, xenograft tumors overexpressing kinase-inactive-dominant-negative c-Src did not show increased contrast enhancement on MRI, showed no histological evidence of angiogenesis, and maintained a non-angiogenic molecular profile on western blot. We hereby report that activation of the SFK c-Src enhances tumor hypoxia, promotes the aggressive angiogenic tumor phenotype, and is subsequently not likely a primary downstream SFK substrate of overexpressed EGFR in human GBM. Overexpression of wild type EGFR may, instead, signal through a different SFK to promote the invasive phenotype. These results suggest that, more so than invasion, c-Src activation may be a valuable diagnostic and prognostic indicator of malignant progression. Furthermore, these results indicate that c-Src activation may be a strategic target in the therapeutic intervention of human malignant glioma. Citation Format: Eskil Eskilsson, Krishna M. Talasila, Gro V. Røsland, Lina Leiss, Narve Brekkå, Per Øystein Sakariassen, Per Øyvind Enger, Rolf Bjerkvig, Hrvoje Miletic. Activated c-Src enhances hypoxia in human glioblastoma multiforme and promotes tumor angiogenesis. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr B84.

Clear Cell Adenocarcinoma Arising from Clear Cell Adenofibroma of the Ovary: Value of DWI and DCE-MRI

Clear cell adenofibroma (CCAF) is a rare surface epithelial-stromal tumor of the ovary and recently considered another precursor of clear cell adenocarcinoma (CCA) other than endometrioma. We report magnetic resonance (MR) findings of a borderline CCAF that contained a small CCA focus. The tumor manifested a characteristic "black sponge" appearance. The CCA focus showed high signal intensity on diffusion-weighted imaging (DWI) and early enhancement on dynamic contrast-enhanced (DCE) MR imaging (DCE-MRI), and the CCAF components showed low signal intensity on DWI and gradually increasing contrast enhancement on DCE-MRI.

Maximizing the Relaxivity of Gd-Complex by Synergistic Effect of HSA and Carboxylfullerene

Macromolecular magnetic resonance imaging (MRI) contrast agent Gd-DTPA-HSA (DTPA, diethylene triamine pentacetate acid; HSA, human serum albumin) as a model has been successfully conjugated with trimalonic acid modified C60 for contrast enhancement at clinically used magnetic field strength. The Gd-DTPA-HSA-C60 conjugate exhibit maximal relaxivity (r1 = 86 mM(-1) s(-1) at 0.5 T, 300 K) reported so far, which is much superior to that of the control Gd-DTPA-HSA (r1 = 38 mM(-1)s(-1)) under the same condition and comparable to the theoretical maximum (r1 = 80-120 mM(-1) s(-1), at 20 MHz and 298 K), indicating the synergistic effect of HSA and carboxylfullerene on the increased contrast enhancement. TEM characterization reveals that both Gd-DTPA-HSA-C60 and Gd-DTPA-HSA can penetrate the cells via endocytosis and trans-membrane, respectively, suggesting the potential to sensitively image the events at the cellular and subcellular levels. In addition, the fusion of fullerene with Gd-DTPA-HSA will further endow the resulting complex with photodynamic therapy (PDT) property and thus combine the modalities of therapy (PDT) and diagnostic imaging (MRI) into one entity. More importantly, the payloaded Gd-DTPA may substitute for other more stable Gd-DOTA and HSA as a theranostic package can further work as a drug delivery carrier and effectively control drug release through proteolysis.

Evaluation of Clear Corneal Wound Dynamics With Contrast-Enhanced Spectral-Domain Optical Coherence Tomography

To evaluate wound morphology and integrity using contrast-enhanced spectral-domain optical coherence tomography (SD-OCT). Eighteen patients (18 eyes) undergoing unilateral routine cataract surgery were enrolled. SD-OCT imaging of the corneal wound was performed immediately following cataract surgery and on postoperative day 1. A topical contrast agent, prednisolone acetate 1%, was used to help evaluate wound integrity. OCT features of the corneal incision and changes in wound interface reflectivity after administration of topical prednisolone acetate 1% were analyzed. Main outcome measures were quantitative and qualitative description of wound morphology and contrast enhancement of the wound interface. Internal wound gape was found in 89% of eyes. Gape area decreased by 43% from days 0 to 1 (462 vs 273 μm(2); P < .01). Contrast enhancement at the wound interface was seen in 56% of eyes on day 0 compared to 17% on day 1 following application of prednisolone acetate 1% (P < .05). Decreased intraocular pressure correlated with increased contrast enhancement (P < .05). Wound morphology evolves during the early postoperative period. Wound gape and ingress of a topical contrast agent decrease during the first 24 hours following surgery. Contrast enhancement at the wound interface increases as the intraocular pressure decreases.

Detection of Hepatocellular Carcinoma and Liver Metastases with BR14: A Multicenter Phase IIA Study

The study was designed primarily to find the optimal dosage range of BR14 contrast-enhanced ultrasonography (CEUS) to detect malignant focal liver lesions. Secondary objectives were the evaluation of the safety profile and comparison with contrast-enhanced MRI (CE MRI). We studied 25 patients (9 females, 16 males, mean age, 66 years) with known hepatocellular carcinoma or liver metastases at 3 centers over a 3-month period. Each patient underwent a baseline examination and at least 3 CEUS examinations with ascending dose levels (0.25 mL; 1.0 mL; 4.0 mL) of BR14. CE MRI was performed 4 weeks before or after the CEUS examination. Dedicated liver maps were used to record the location, size, and type of detected lesions. Examination quality was documented and safety parameters were assessed. The number of lesions detected by BR14 CEUS increased with dosage, whereas the number of missed lesions and the lesion sizes decreased. Despite the increasing contrast enhancement, substantial differences among dosages were not seen for other image quality parameters. No significant changes were noted in safety parameters and no serious adverse events were reported. We conclude that the recommended dose level of BR14 is between 1 mL and 4 mL; at this dosage, lesion detection is comparable to that of CE MRI.

Clinical and diagnostic imaging findings in dogs with zygomatic sialadenitis: 11 cases (1990–2009)

To describe clinical and diagnostic imaging features of zygomatic sialadenitis in dogs. Retrospective case series. 11 dogs with zygomatic sialadenitis and 20 control dogs without evidence of retrobulbar disease. Medical records were searched for dogs with zygomatic sialadenitis that underwent some combination of magnetic resonance imaging (MRI), computed tomography (CT), and ultrasonography. Signalment, clinical signs, results of clinicopathologic tests, cytologic and histologic diagnosis, treatment, qualitative disease features, and disease course were recorded. Images obtained via MRI or CT were analyzed for pre- and postcontrast signal intensity or density, respectively; zygomatic salivary gland area was determined. Results were compared with those of control dogs that underwent the same imaging procedures (n = 10/method). Ultrasonographic images of affected dogs were assessed qualitatively. Most (9/11) affected dogs were medium- or large-breed males (mean age, 8 years) with unilateral disease. Affected dogs had clinical signs of retrobulbar disease and cytologic or histologic evidence of zygomatic sialadenitis. Sialoceles were detected in 7 affected glands. Compared with values for control dogs, MRI findings in affected dogs (n = 7) included gland enlargement, T1-weighted hypointensity, T2-weighted hyperintensity, and increased contrast enhancement; CT features in affected dogs (2) included gland enlargement and hypodensity on unenhanced images. Retrobulbar masses were identified via ultrasonography in 9 of 10 orbits examined, and zygomatic salivary gland origin was detected in 4. Visualization of anatomic structures for diagnosis of zygomatic sialadenitis and evaluation of adjacent structures was excellent via MRI and CT Ultrasonography was less definitive but useful for sample collection.

MRI Features of Stromal Fibrosis of the Breast With Histopathologic Correlation

The purpose of this article is to present the MRI features of stromal fibrosis of the breast, thus enabling radiologists to better determine radiologic-pathologic concordance of biopsy results and appropriate patient management. A retrospective review of radiology records between 2003 and 2009 identified 123 MRI-detected lesions with the histologic diagnosis of stromal fibrosis. Of these, 83 cases were excluded either because stromal fibrosis was not the primary histologic diagnosis, or because there were associated pathologic abnormalities that may have contributed to contrast enhancement. The remaining 40 lesions with a primary histologic diagnosis of stromal fibrosis were included in our study. Their MRI and histopathologic features were examined and categorized. The lesions included five foci, 23 masses, and 12 areas of nonmasslike enhancements. The prevalent features of the masses were size smaller than 1 cm (20/23 [87%]), round or oval shape (16/23 [70%]), irregular or spiculated margins (15/23 [65%]), rapid or medium rate of initial contrast uptake (21/23 [91%]), and plateau or washout curves (16/23 [70%]). Most nonmass lesions showed clumped enhancement (9/12) and linear distribution (7/12). Many of these features were suggestive of malignancy. Twenty-seven of 40 cases (68%) had histologic confirmation by excision or MRI confirmation of benignancy. No false-negative cases have been identified to date. Histopathologic correlation showed the presence of masslike septal fibrosis associated with ectatic vascular channels in 60-67% of cases, which may lead to increased contrast enhancement on MRI. Stromal fibrosis has widely variable MRI features, often mimicking breast carcinoma. It may represent an acceptable benign concordant diagnosis on vacuum-assisted large-core needle biopsy for the described MRI findings.

Perfusion CT Assessment of Tissue Hemodynamics Following Hepatic Arterial Infusion of Increasing Doses of Angiotensin II in a Rabbit Liver Tumor Model

To investigate the effects of increasing doses of angiotensin II on hepatic hemodynamics in the normal rabbit liver and in hepatic VX2 tumors by using dynamic contrast material-enhanced perfusion computed tomography (CT). This study was approved by the institutional animal care and use committee. Solitary hepatic VX2 tumors were implanted into 12 rabbits. In each animal, perfusion CT of the liver was performed before (at baseline) and after hepatic arterial infusion of varying doses (0.1-50.0 μg/mL) of angiotensin II. Images were acquired continuously for 80 seconds after the start of the intravenous contrast material administration. Blood flow (BF), blood volume (BV), mean transit time (MTT), and capillary permeability-surface area product were calculated for the tumor and the adjacent and distant normal liver tissue. Generalized linear mixed models were used to estimate the effects of angiotensin II dose on outcome measures. Angiotensin II infusion increased contrast enhancement of the tumor and distal liver vessels. Tumor BF increased in a dose-dependent manner after administration of 0.5-25.0 μg/mL angiotensin II, but only the 2.5 μg/mL dose induced a significant increase in tumor BF compared with BF in the adjacent (68.0 vs 26.3 mL/min/100 g, P < .0001) and distant (68.0 vs 28.3 mL/min/100 g, P = .02) normal liver tissue. Tumor BV varied with angiotensin II dose but was greater than the BV of the adjacent and distant liver tissue at only the 2.5 μg/mL (4.8 vs 3.5 mL/100 g for adjacent liver [P < .0001], 4.8 vs 3.3 mL/100 g for distant liver [P = .0006]) and 10.0 μg/mL (4.9 vs 4.4 mL/100 g for adjacent liver [P = .007], 4.9 vs 4.3 mL/100 g for distant liver [P = .04]) doses. Tumor MTT was significantly shorter than the adjacent liver tissue MTT at angiotensin II doses of 2.5 μg/mL (9.7 vs 15.8 sec, P = .001) and 10.0 μg/mL (5.1 vs 13.2 sec, P = .007) and significantly shorter than the distant liver tissue MTT at 2.5 μg/mL only (9.7 vs 15.3 sec, P = .0006). The capillary permeability-surface area product for the tumor was higher than that for the adjacent liver tissue at the 2.5 μg/mL angiotensin II dose only (11.5 vs 8.1 mL/min/100 g, P = .01). Perfusion CT enables a mechanistic understanding of angiotensin II infusion in the liver and derivation of the optimal effective dose. The 2.5 μg/mL angiotensin II dose increases perfusion in hepatic VX2 tumors versus that in adjacent and distant normal liver tissue primarily by constricting normal distal liver vessels and in turn increasing tumor BF and BV.

Manifestations of small bowel disease in pediatric Crohnʼs disease on magnetic resonance enterography

We report the manifestations of Crohn's disease (CD) observed on magnetic resonance enterography (MRE) in a pediatric population at the time of CD diagnosis. MRE of 95 consecutive pediatric patients with inflammatory bowel disease (IBD) examined in 2006-2009 were retrospectively analyzed, with documentation of findings based on type and location of the small bowel (SB) disease. In all, 51 were boys and 44 girls. 54 had CD, 31 non-CD IBD, and 10 no IBD. The most common site of SB involvement in CD was the terminal ileum seen in 29 (53.7%) patients, followed by ileum in 10 (18.5%) and jejunum in 9 (16.7%) patients. Solitary jejunal inflammation (3.7%), SB stenoses (1.9%), fistula formation (0.95%), and abscess (0.95%) were much less common. Perienteric lymphadenopathy was seen in 30 (55.6%) patients and fatty proliferation in 9 (16.7%). The most common manifestation of SB inflammation was increased contrast enhancement of bowel wall (93.5%), thickening of the bowel wall (90.3%), and derangement of bowel shape with saccular formations (25.8%). MRE in the pediatric population often demonstrates increased contrast uptake, bowel wall thickening, and perienteral lymphadenopathy in CD. More chronic small bowel changes seen commonly in adults and solitary jejunal involvements are less commonly seen.

Ischemia‐reperfusion injury in rat skeletal muscle assessed with T2‐weighted and dynamic contrast‐enhanced MRI

Pressure ulcers are localized areas of soft tissue breakdown due to mechanical loading. Susceptible individuals are subjected to pressure relief strategies to prevent long loading periods. Therefore, ischemia-reperfusion injury may play an important role in the etiology of pressure ulcers. To investigate the inter-relation between postischemic perfusion and changes in skeletal muscle integrity, the hindlimbs of Brown Norway rats were subjected to 4-h ischemia followed by 2-h reperfusion. Dynamic contrast-enhanced MRI was used to examine perfusion, and changes in skeletal muscle integrity were monitored with T2-weighted MRI. The dynamic contrast-enhanced MRI data showed a heterogeneous postischemic profile in the hindlimb, consisting of areas with increased contrast enhancement (14-76% of the hindlimb) and regions with no-reflow (5-77%). For T2, a gradual increase in the complete leg was observed during the 4-h ischemic period (from 34 to 41 msec). During the reperfusion phase, a heterogeneous distribution of T2 was observed. Areas with increased contrast enhancement were associated with a decrease in T2 (to 38 msec) toward preischemic levels, whereas no-reflow areas exhibited a further increase in T2 (to 42 msec). These results show that reperfusion after prolonged ischemia may not be complete, thereby continuing the ischemic condition and aggravating tissue damage.

Contrast-Enhanced Ultrasound Imaging Detects Intraplaque Neovascularization in an Experimental Model of Atherosclerosis

The aims of this study were to investigate the feasibility of contrast-enhanced ultrasound (CEU) imaging for in vivo visualization of intraplaque neovascularization and to correlate the in vivo observations with histological assessment of neovessel density and plaque composition in an experimental animal model of advanced atherosclerosis. Recent evidence has linked plaque angiogenesis with enhanced atherosclerotic plaque progression and vulnerability. Increased neovascularization has been detected in ruptured human lesions and is associated with clinical manifestations of plaque rupture. Advanced aortic atherosclerosis was induced in New Zealand white rabbits (n = 21; high cholesterol-rich diet/double-balloon aortic denudation). Animals underwent standard and CEU imaging at the end of the atherosclerosis induction period. Six age-matched animals served as control subjects. Within 24 h, animals were euthanized and aortas processed for histopathological evaluation of plaque composition and neovascularization. Imaged plaques were classified as contrast enhanced (CE) positive or CE negative, according to their contrast enhancement on CEU imaging. The lesions were also classified as class III (predominantly echogenic) or class II (predominantly echolucent), according to their echogenicity on non-CEU images. No contrast enhancement was observed in control animals. In atherosclerotic animals, class III lesions showed an increased contrast enhancement compared with class II lesions and CE-positive lesions showed greater neovascularization than CE-negative plaques. Macrophage density, but not smooth muscle cell density, was significantly higher in CE-positive than CE-negative lesions. As expected, class III lesions showed increased macrophage density compared with class II plaques. Intraplaque neovessel density at histology was significantly higher in CE-positive than in CE-negative lesions. Class III plaques showed a significantly higher neovessel density compared with class II lesions. A strong correlation between intraplaque neovessels and contrast enhancement was found. CEU imaging is a feasible noninvasive imaging modality to evaluate intraplaque neovascularization. A noninvasive imaging modality to assess lesion neovascularization could be of great importance to identify vascularized, "high-risk" lesions before rupture.

Improvement of Image Quality of Low Radiation Dose Abdominal CT by Increasing Contrast Enhancement

The purpose of this study was to evaluate the effects of noise index and contrast material dose on radiation dose, contrast enhancement, image noise, and image quality in abdominal CT. Contrast-enhanced abdominal CT with tube current modulation was performed on 195 patients. The patients were prospectively randomized into three groups of equal size (protocol A, noise index of 12 HU and 521 mg I/kg; protocol B, 15 HU and 521 mg I/kg; protocol C, 15 HU and 600 mg I/kg). Scanning was initiated 5 and 45 seconds after aortic enhancement reached 100 HU. Attenuation was measured in the aorta, portal vein, and liver. Transverse CT images were qualitatively graded for diagnostic acceptability and image noise. Arterial phase volume-rendered and multiplanar reformatted (MPR) images and portal venous phase MPR CT angiograms were qualitatively graded for depiction of vessels. Contrast enhancement, objective image noise, radiation dose, and qualitative grades were analyzed and compared among the three groups. The contrast enhancement values of the aorta, portal vein, and liver were higher in protocol C than in protocols A and B (p < 0.05). Objective image noise was greater in protocols B and C than in protocol A (p < 0.05). The radiation dose in protocols B and C was 31-32% lower than in protocol A (p < 0.001). Depiction of vessels, diagnostic acceptability, and subjective image noise were comparable in protocols A and C. Use of higher contrast enhancement can compensate for the degradation of image quality resulting from use of a low radiation dose for CT.

İdiopatik Granülomatöz Mastitin Radyolojik Bulguları

Idiopathic granulomatous mastitis (IGM) is a rarely seen benign chronic inflammatory breast disease. Etiology is still unknown, many factors mainly including hormonal factors are proposed. Clinical findings include inflammation of the breast, induration, palpation of a mass galactorrhea and retraction of the nipple. Unilateral, usually right sided involvement is encountered. IGM may mimic fibroadenoma, fibrocystic changes, abscess and especially malignancy both clinically and radiologically. Although definite diagnosis is made by cytologic or histopathologic evaluation, radiological evaluation plays an important role in diagnosis and differentiating it from malignancy. Mammography (MG) and ultrasonography (US) are used basically for the diagnosis, but due to wide spectrum and low sensitivity, the findings are challenging. The most common finding of MG is ill-defined asymmetrical density that does not cause mass effect. On US, the radiological finding spectrum is quite wide. On conventional magnetic resonance imaging (MRI) lesion may demonstrate irregular or spiculated contours which may lead to misdiagnosis. However dynamic contrast-enhanced MRI plays an important role in differentiating the lesion from malignancy if a benign type (increasing contrast enhancement) Type 1 signal intensity time curve is obtained. On the other hand, sometimes Type 2 (plateau type) or even malignant type (early washout) Type 3 curve can be obtained. In these cases differentiation from malignancy by radiological means is quite difficult. New MRI techniques including diffusion MRI and MR spectroscopy (MRS), to our knowledge, are not reported yet. In this report MG, US, dynamic contrast-enhanced MRI,diffusion MRI and MR spectroscopy findings of IGM will be presented and the differential diagnosis will be discussed

Evaluation of the microcirculatory disturbance of biliary ischemia after liver transplantation with contrast-enhanced ultrasound: Preliminary experience

The aim of this study was to determine the efficacy of contrast-enhanced ultrasound for depicting the perfusion of hilar bile ducts in ischemic-type biliary lesions after orthotopic liver transplantation. Thirteen transplant recipients with ischemic-type biliary lesions and 12 patients without ischemic-type biliary lesions underwent ultrasound examinations after the injection of 1.5 mL of an intravenous contrast agent. The enhancement of the hilar bile duct wall in the arterial, portal venous, and late phases was qualitatively graded as higher, equal, lower, or none with respect to that of the adjacent liver parenchyma. No or low contrast enhancement was seen in 10 of 13 patients (76.90%) with biliary ischemia, whereas increased contrast enhancement with respect to the normal liver parenchyma was found in all 12 patients without biliary ischemia. The difference in the enhancement patterns between the 2 groups was significant (P = 0.0001). In conclusion, contrast-enhanced ultrasound is a new imaging modality to depict perfusion of the hilar bile duct. No or low contrast enhancement of the bile duct wall in the arterial phase may reflect the microcirculatory disturbance of biliary ischemia and may contribute to its early diagnosis.

MR imaging in Duchenne muscular dystrophy: Quantification of T1‐weighted signal, contrast uptake, and the effects of exercise

To quantify the differences between normal and corticosteroid-treated Duchenne muscular dystrophy (DMD) lower limb muscle using signal intensity measurements on T(1)-weighted and gadolinium contrast-enhanced images and by measurement of muscle T(2) values, and to investigate the effect of exercise. Eleven ambulant boys with DMD were imaged at 3 Tesla (T(1)-weighted, gadolinium enhancement and T(2) measurement) before stepping exercise and again (gadolinium, T(2) measurement) 4 days later and were compared with five healthy controls imaged 4 days before and after stepping exercise. Muscle region-of-interest signal intensities were referenced to external oil and gadolinium phantoms. DMD thigh muscle T(2) values were significantly higher than normal values with the exception of the gracilis muscle. Eight of nine muscles studied showed a significant increase in T(1)-w signal intensity in DMD as compared to normal muscle, suggestive of increased fat infiltration in DMD muscle. In the DMD boys, an exercise effect (increased contrast enhancement) was only seen for the tibialis anterior muscle. Referenced signal intensity measurements may be used to quantify differences between dystrophic and normal muscle without T(1) mapping. Stepping exercise does not have a large impact on subsequent MR imaging of dystrophic muscle.

Early diagnosis of temporomandibular joint involvement in juvenile idiopathic arthritis: a pilot study comparing clinical examination and ultrasound to magnetic resonance imaging

Objectives. To study the validity of both rheumatological and orthodontic examinations and ultrasound (US) as screening methods for early diagnosis of TMJ arthritis against the gold standard MRI.Methods. Thirty consecutive juvenile idiopathic arthritis (JIA) patients were included in this pilot study. Rheumatological and orthodontic examinations as well as US were performed within 1 month of the MRI in a blinded fashion. Joint effusion and/or increased contrast enhancement of synovium or bone were considered signs of active arthritis on MRI.Results. A total of 19/30 (63%) patients and 33/60 (55%) joints had signs of TMJ involvement on MRI. This was associated with condylar deformity in 9/19 (47%) patients and 15/33 (45%) joints. Rheumatological, orthodontic and US examinations correctly diagnosed 11 (58%), 9 (47%) and 6 (33%) patients, respectively, with active TMJ arthritis, but misdiagnosed 8 (42%), 10 (53%) and 12 (67%) patients, respectively, as having no signs of inflammation. The best predictor for active arthritis on MRI was a reduced maximum mouth opening.Conclusion. None of the methods tested was able to reliably predict the presence or absence of MRI-proven inflammation in the TMJ in our cohort of JIA patients. US was the least useful of all methods tested to exclude active TMJ arthritis.

Effect of adding temozolomide to radiation therapy on the incidence of pseudo-progression

Recently, there has been greater awareness that combination radiation and temozolomide used to treat glioblastomas may cause increased contrast enhancement on the first post radiation MRI scan. However, this increased enhancement may stabilize or decrease over time and represent pseudo-progression (psPD) rather than true progressive disease. It has never been shown that this phenomenon is greater with combination therapy than radiation alone. To address this question, we reviewed MRI scans in glioblastoma patients treated with radiation alone versus patients treated with radiation and concomitant temozolomide and compared the frequency of psPD in the two groups. Eighteen of 47 patients (38%) treated with radiation alone demonstrated enlargement on their first post-radiation MRI scan and 11 of these 18 (61%) proved to have psPD as defined by no further enlargement on stable therapy for 3 months following radiation. Twenty-four of 45 patients (53%) treated with radiation and temozolomide had enlargement on their first post-radiation MRI scan and 13 of these 24 (54%) had psPD. Median overall survival (OS) in patients with psPD treated with radiation alone was 15.6 versus 12.8 months in those without psPD. Median OS in patients treated with radiation and concomitant temozolomide who had psPD was 24.4 versus 15.9 months in those who did not have psPD. We were unable to detect a difference in OS between the four groups. Presence of psPD, independent of treatment, was associated with prolonged progression-free survival (P = 0.05) but not OS. psPD may be more common in combination therapy but most likely by a small margin.

Contrast‐enhanced ultrasonography using cadence‐contrast pulse sequencing technology for targeted biopsy of the prostate

To evaluate contrast-enhanced ultrasonography (US) using cadence-contrast pulse sequencing (CPS) technology, compared with systematic biopsy for detecting prostate cancer, as grey-scale US has low sensitivity and specificity for detecting prostate cancer. In all, 44 men with suspicious prostate-specific antigen (PSA) levels and CPS findings were assessed; all had CPS-targeted and systematic biopsy. Transrectal CPS images were taken with a low mechanical index (0.14). A microbubble contrast agent (SonoVue, Bracco International BV, Amsterdam, the Netherlands) was administered as a bolus, with a maximum dose of 4.8 mL. CPS was used to assess prostatic vascularity. Areas with a rapid and increased contrast enhancement within the peripheral zone were defined as suspicious for prostate cancer. Up to five CPS targeted biopsies were taken and subsequently a 10-core systematic biopsy was taken. Cancer detection rates for the two techniques were compared. Overall, cancer was detected in 35 of 44 patients (80%), with a mean PSA level of 3.8 ng/mL. Lesions suspicious on CPS showed cancer in 35 of 44 patients (80%) and systematic biopsy detected cancer in 15 of 44 patients (34%). CPS-targeted cores were positive in 105 of 220 cores (47.7%) and in 41 of 440 systematic biopsy cores (9.3%) (P < 0.001). Lesions suspicious on CPS were false-positive in nine of 44 patients (20%). The mean Gleason score for systematic biopsy was 6.7 and for CPS-targeted biopsy 6.8 (P > 0.05). The sensitivity of CPS for detecting cancer was 100% (confidence interval, 95%). However, limitations in the series included that only CPS-positive cases were investigated, and CPS-targeted biopsy should be evaluated in a more extended biopsy scheme. Contrast-enhanced US using CPS enables excellent visualization of the microvasculature associated with prostate cancer, and can improve the detection of prostate cancer compared with systematic biopsy.