Imaging of total colonic Hirschsprung disease

BACKGROUND: Hirschsprung disease (HD) is a functional obstruction of the bowel caused by the absence of intrinsic enteric ganglion cells. The diagnosis of total colonic HD (TCHD) based on contrast enemas is difficult in newborns because radiological findings vary. OBJECTIVE: To evaluate the radiographic and contrast enema findings in patients with pathologically proven TCHD. MATERIALS AND METHODS: From 1966 to 2007, 17 records from a total of 31 patients with TCHD were retrospectively evaluated for diameter and shape of the colon, diameter of the small bowel, bowel wall contour, ileal reflux, abdominal calcifications, pneumoperitoneum, filling defects, transitional zones and rectosigmoid index. RESULTS: Three colonic patterns of TCHD were found: microcolon, question-mark-shape colon and normal caliber colon. Additional findings included spasmodic colon, ileal reflux, delayed evacuation and abdominal calcifications. Colonic transitional zones were found in eight patients with TCHD. CONCLUSION: The diagnosis of TCHD is difficult to establish by contrast enema studies. The length of the aganglionic small bowel and the age of the patient can influence the radiological findings in TCHD. The transitional zone and the rectosigmoid index can be false-positive in TCHD. The colon can appear normal. Consider TCHD if the contrast enema study is normal but the patient remains symptomatic and other causes of distal bowel obstruction have been excluded.

Inheritance of ectopic ureters in Entlebucher Mountain Dogs

To test the hypothesis of a heritable base of ectopic ureters (EU) in Entlebucher Mountain Dogs (EMD) and to elucidate associated risk factors and mode of inheritance of the disease, 565 EMD were clinically investigated and population genetic analyses performed. Based on the location of the most caudal termination of the ureteral openings, 552 EMD were classified into three phenotype groups trigone, intravesically and extravesically ectopic based on results of abdominal sonography, urethra-cystoscopy and/or contrast-enhanced computed tomography. One-third (32.9%) of the phenotyped animals had normal terminations of both ureters in the bladder trigone, 47.3% had at least one intravesicular ectopic termination and 19.8% had at least one extravesicular ectopic termination. Multivariate mixed logistic regression revealed gender as a risk factor associated with EU as males were more often affected than females. Complex segregation analysis indicated a hereditary basis for EU in EMD and the involvement of a major gene in the occurrence of the extravesicular EU phenotype.

Effect of Acute Administration of Angiopoietin-1 in Experimental Traumatic Spinal Cord Injury: Magnetic Resonance Imaging and Neurobehavioral Studies

Spinal cord injury (SCI) is a devastating condition that affects people in the prime of their lives. A myriad of vascular events occur after SCI, each of which contributes to the evolving pathology. The primary trauma causes mechanical damage to blood vessels, resulting in hemorrhage. The blood-spinal cord barrier (BSCB), a neurovascular unit that limits passage of most agents from systemic circulation to the central nervous system, breaks down, resulting in inflammation, scar formation, and other sequelae. Protracted BSCB disruption may exacerbate cellular injury and hinder neurobehavioral recovery in SCI. In these studies, angiopoietin-1 (Ang1), an agent known to reduce vascular permeability, was hypothesized to attenuate the severity of secondary injuries of SCI. Using longitudinal magnetic resonance imaging (MRI) studies (dynamic contrast-enhanced [DCE]-MRI for quantification of BSCB permeability, highresolution anatomical MRI for calculation of lesion size, and diffusion tensor imaging for assessment of axonal integrity), the acute, subacute, and chronic effects of Ang1 administration after SCI were evaluated. Neurobehavioral assessments were also performed. These non-invasive techniques have applicability to the monitoring of therapies in patients with SCI. In the acute phase of injury, Ang1 was found to reduce BSCB permeability and improve neuromotor recovery. Dynamic contrast-enhanced MRI revealed a persistent compromise of the BSCB up to two months post-injury. In the subacute phase of injury, Ang1’s effect on reducing BSCB permeability was maintained and it was found to transiently reduce axonal integrity. The SCI lesion burden was assessed with an objective method that compared favorably with segmentations from human raters. In the chronic phase of injury, Ang1 resulted in maintained reduction in BSCB permeability, a decrease in lesion size, and improved axonal integrity. Finally, longitudinal correlations among data from the MRI modalities and neurobehavioral assays were evaluated. Locomotor recovery was negatively correlated with lesion size in the Ang1 cohort and positively correlated with diffusion measures in the vehicle cohort. In summary, the results demonstrate a possible role for Ang1 in mitigating the secondary pathologies of SCI during the acute and chronic phases of injury.

State-of-the-art aortic imaging: Part II - applications in transcatheter aortic valve replacement and endovascular aortic aneurysm repair.

Transcatheter aortic valve replacement (TAVR) as well as thoracic and abdominal endovascular aortic repair (TEVAR and EVAR) rely on accurate pre- and postprocedural imaging. This review article discusses the application of imaging, including preprocedural assessment and measurements as well as postprocedural imaging of complications. Furthermore, the exciting perspective of computational fluid dynamics (CFD) based on cross-sectional imaging is presented. TAVR is a minimally invasive alternative for treatment of aortic valve stenosis in patients with high age and multiple comorbidities who cannot undergo traditional open surgical repair. Given the lack of direct visualization during the procedure, pre- and peri-procedural imaging forms an essential part of the intervention. Computed tomography angiography (CTA) is the imaging modality of choice for preprocedural planning. Routine postprocedural follow-up is performed by echocardiography to confirm treatment success and detect complications. EVAR and TEVAR are minimally invasive alternatives to open surgical repair of aortic pathologies. CTA constitutes the preferred imaging modality for both preoperative planning and postoperative follow-up including detection of endoleaks. Magnetic resonance imaging is an excellent alternative to CT for postoperative follow-up, and is especially beneficial for younger patients given the lack of radiation. Ultrasound is applied in screening and postoperative follow-up of abdominal aortic aneurysms, but cross-sectional imaging is required once abnormalities are detected. Contrast-enhanced ultrasound may be as sensitive as CTA in detecting endoleaks.

State-of-the-art of imaging detecting endoleaks post-EVAR with special focus on low-flow endoleaks.

Endovascular aortic repair (EVAR) necessitates lifelong surveillance for the patient, in order to detect complications timely. Endoleaks (ELs) are among the most common complications of EVAR. Especially type II ELs can have a very unpredictable clinical course and this can range from spontaneous sealing to aortic rupture. Subgroups of this type of EL need to be identified in order to make a proper risk stratification. Aim of this review is to describe the existing imaging techniques, including their advantages and disadvantages in the context of post-EVAR surveillance with a particular emphasis on low-flow ELs. Low flow ELs cause pressurization of the aortic aneurysm sac with a low velocity filling, leading to difficulty of detection by routine imaging protocols for EVAR surveillance, e.g. bi- or triphasic multislice computed tomographic angiography, magnetic resonance imaging and contrast enhanced ultrasound. In this article, we review the imaging possibilities of ELs and discuss the different imaging strategies available for depicting low flow ELs.

Diagnosis of cardiac metastasis from cervical cancer in a 33-year-old patient using multimodal imaging studies: a case report and literature review.

We report a case of a 33-year-old woman with emergency admission due to dyspnoea and fever. History included squamous cell carcinoma of the cervix in complete remission. Contrast-enhanced computed tomography (CT) scanning of the chest, which was indicated to rule out pneumonia, revealed an infiltrative cardiac mass. Further assessment of the tumour by echocardiography and cardiac magnetic resonance imaging (MRI) showed transmural infiltration of the apical interventricular septum with a mass extending into the left and right ventricle cavities. The mass was highly suspicious for a cardiac metastasis. Cardiac metastases from cervical cancer are extremely rare. Recurrence of cervical carcinoma involving the heart should be considered even after a curative therapy approach. Non-invasive imaging plays a paramount role in investigating cardiac masses. Echocardiography, CT and MRI are complementary imaging modalities for complete work-up of intracardiac lesions.

Dissecting abdominal aortic aneurysm in Ang II-infused mice: suprarenal branch ruptures and apparent luminal dilatation.

AIMS In this work, we provide novel insight into the morphology of dissecting abdominal aortic aneurysms in angiotensin II-infused mice. We demonstrate why they exhibit a large variation in shape and, unlike their human counterparts, are located suprarenally rather than infrarenally. METHODS AND RESULTS We combined synchrotron-based, ultra-high resolution ex vivo imaging (phase contrast X-Ray tomographic microscopy) with in vivo imaging (high-frequency ultrasound and contrast-enhanced micro-CT) and image-guided histology. In all mice, we observed a tear in the tunica media of the abdominal aorta near the ostium of the celiac artery. Independently we found that, unlike the gradual luminal expansion typical for human aneurysms, the outer diameter increase of angiotensin II-induced dissecting aneurysms in mice was related to one or several intramural haematomas. These were caused by ruptures of the tunica media near the ostium of small suprarenal side branches, which had never been detected by the established small animal imaging techniques. The tear near the celiac artery led to apparent luminal dilatation, while the intramural haematoma led to a dissection of the tunica adventitia on the left suprarenal side of the aorta. The number of ruptured branches was higher in those aneurysms that extended into the thoracic aorta, which explained the observed variability in aneurysm shape. CONCLUSION Our results are the first to describe apparent luminal dilatation, suprarenal branch ruptures, and intramural haematoma formation in dissecting abdominal aortic aneurysms in mice. Moreover, we validate and demonstrate the vast potential of phase contrast X-ray tomographic microscopy in cardiovascular small animal applications.

Magnetic resonance imaging features of sinonasal disorders in horses.

Diseases of paranasal sinuses and nasal passages in horses can be a diagnostic challenge because of the complex anatomy of the head and limitations of many diagnostic modalities. Our hypothesis was that magnetic resonance (MR) imaging would provide excellent anatomical detail and soft tissue resolution, and would be accurate in the diagnosis of diseases of the paranasal sinuses and nasal passages in horses. Fourteen horses were imaged. Inclusion criteria were lesions located to the sinuses or nasal passages that underwent MR imaging and subsequent surgical intervention and/or histopathologic examination. A low field, 0.3 tesla open magnet was used. Sequences in the standard protocol were fast spin echo T2 sagittal and transverse, spin echo T1 transverse, short-tau inversion recovery (STIR) dorsal, gradient echo 3D T1 MPR dorsal (plain and contrast enhanced), spin echo T1 fatsat (contrast enhanced). Mean scan time to complete the examination was 53 min (range 39-99 min). Lesions identified were primary or secondary sinusitis (six horses), paranasal sinus cyst (four horses), progressive ethmoid hematoma (two horses), and neoplasia (two horses). The most useful sequences were fast spin echo T2 transverse and sagittal, STIR dorsal and FE3D MPR (survey and contrast enhanced). Fluid accumulation, mucosal thickening, presence of encapsulated contents, bone deformation, and thickening were common findings observed in MR imaging. In selected horses, magnetic resonance imaging is a useful tool in diagnosing lesions of the paranasal sinuses and nasal passages.

Fusion of fundus images and MRI data of the human eye

Purpose Ophthalmologists are confronted with a set of different image modalities to diagnose eye tumors e.g., fundus photography, CT and MRI. However, these images are often complementary and represent pathologies differently. Some aspects of tumors can only be seen in a particular modality. A fusion of modalities would improve the contextual information for diagnosis. The presented work attempts to register color fundus photography with MRI volumes. This would complement the low resolution 3D information in the MRI with high resolution 2D fundus images. Methods MRI volumes were acquired from 12 infants under the age of 5 with unilateral retinoblastoma. The contrast-enhanced T1-FLAIR sequence was performed with an isotropic resolution of less than 0.5mm. Fundus images were acquired with a RetCam camera. For healthy eyes, two landmarks were used: the optic disk and the fovea. The eyes were detected and extracted from the MRI volume using a 3D adaption of the Fast Radial Symmetry Transform (FRST). The cropped volume was automatically segmented using the Split Bregman algorithm. The optic nerve was enhanced by a Frangi vessel filter. By intersection the nerve with the retina the optic disk was found. The fovea position was estimated by constraining the position with the angle between the optic and the visual axis as well as the distance from the optic disk. The optical axis was detected automatically by fitting a parable on to the lens surface. On the fundus, the optic disk and the fovea were detected by using the method of Budai et al. Finally, the image was projected on to the segmented surface using the lens position as the camera center. In tumor affected eyes, the manually segmented tumors were used instead of the optic disk and macula for the registration. Results In all of the 12 MRI volumes that were tested the 24 eyes were found correctly, including healthy and pathological cases. In healthy eyes the optic nerve head was found in all of the tested eyes with an error of 1.08 +/- 0.37mm. A successful registration can be seen in figure 1. Conclusions The presented method is a step toward automatic fusion of modalities in ophthalmology. The combination enhances the MRI volume with higher resolution from the color fundus on the retina. Tumor treatment planning is improved by avoiding critical structures and disease progression monitoring is made easier.

Spinal Spot Sign.

INTRODUCTION A marker predictive of hematoma expansion in the central nervous system could aid the selection of patients for hemostatic or surgical treatment. CASE REPORT Here, we present a 83-year-old patient with acute spinal subdural hematoma with paraparesis progressing to paraplegia. A contrast extravasation within the intraspinal hematoma was visualized on spinal MR indicating active bleeding (spinal spot sign). A second acquisition of contrast-enhanced MR images showed progression of contrast extravasation helping to different active bleeding from spinal arteriovenous malformations/fistula. CONCLUSIONS A "spinal spot sign" may be important for treatment decisions, notably in patients with incomplete neurological deficits at the time of imaging.

Copper-64 Labeled Macrobicyclic Sarcophagine Coupled to a GRP Receptor Antagonist Shows Great Promise for PET Imaging of Prostate Cancer

The gastrin-releasing peptide receptor (GRPr) is an important molecular target for the visualization and therapy of tumors and can be targeted with radiolabeled bombesin derivatives. The present study aims to develop statine-based bombesin receptor antagonists suitable for labeling with 64Cu for imaging by positron emission tomography (PET). The potent GRPr antagonist D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2 was conjugated to the sarcophagine (3,6,10,13,16,19-hexaazabicyclo[6.6.6] icosane=Sar) derivative 5-(8-methyl-3,6,10,13,16,19-hexaaza-bicyclo[6.6.6]icosan-1-ylamino)-5-oxopentanoic acid (MeCOSar) via PEG4 (LE1) and PEG2 (LE2) spacers and radiolabeled with 64Cu2+ with >95% yield and specific activities of about 100 MBq/nmol. Both Cu(II) conjugates have high affinity for GRPr (IC50: natCu-LE1, 1.4±0.1 nM; natCu-LE2, 3.8±0.6 nM). The antagonistic properties of both conjugates were confirmed by Ca2+-flux measurements. Biodistribution studies of Cu-64-LE1 exhibited specific targeting of the tumor (19.6±4.7% IA/g at 1 h p.i.) and GRPr-positive organs. Biodistribution and PET images at 4 and 24 h postinjection showed increasing tumor-to-background ratios with time. This was illustrated by the acquisition of PET images showing high tumor-to-normal tissue contrast. This study demonstrates the high affinity of the MeCOSar-PEGx-bombesin conjugates to GRPr. The stability of 64Cu complexes of MeCOSar, the long half-life of 64Cu, and the suitable biodistribution profile of the 64Cu-labeled peptides lead to PET images of high contrast suitable for potential translation into the clinic.

New diagnostic and therapeutic approaches to treat ventricular tachycardias originating at the summit of the left ventricle role of merged hemodynamic-MRI and alternative ablation sources

The left ventricular (LV) summit is the most common site of idiopathic epicardial LV arrhythmias and frequently represents a diagnostic and a therapeutic challenge.1 We present a case of sustained monomorphic ventricular tachycardia (SMVT) originating at the LV summit that underwent failed cryosurgical epicardial ablation and was successfully treated with the aid of merged hemodynamic and contrast-enhanced MRI (CE-MRI).

Intracerebral injection of human immunodeficiency virus type 1 coat protein gp120 differentially affects the expression of nerve growth factor and nitric oxide synthase in the hippocampus of rat.

We have studied the neuropathological characteristics of the brain of rats receiving daily intracerebroventricular administration of freshly dissolved human immunodeficiency virus type 1 recombinant protein gp120 (100 ng per rat per day) given for up to 14 days. Histological examination of serial brain sections revealed no apparent gross damage to the cortex or hippocampus, nor did cell counting yield significant neuronal cell loss. However, the viral protein caused after 7 and 14 days of treatment DNA fragmentation in 10% of brain cortical neurons. Interestingly, reduced neuronal nitric oxide synthase (NOS) expression along with significant increases in nerve growth factor (NGF) were observed in the hippocampus, where gp120 did not cause neuronal damage. No changes in NGF and NOS expression were seen in the cortex, where cell death is likely to be of the apoptotic type. The present data demonstrate that gp120-induced cortical cell death is associated with the lack of increase of NGF in the cerebral cortex and suggest that the latter may be important for the expression of neuropathology in the rat brain. By contrast, enhanced levels of NGF may prevent or delay neuronal death in the hippocampus, where reduced NOS expression may be a reflection of a subcellular insult inflicted by the viral protein.

Susac's syndrome: Leptomeningeal enhancement on 3D FLAIR MRI

BACKGROUND Contrast-enhanced (ce) fluid-attenuated inversion recovery magnetic resonance imaging (FLAIR MRI) has recently been shown to identify leptomeningeal pathology in multiple sclerosis. OBJECTIVE To demonstrate leptomeningeal enhancement on three-dimensional (3D) FLAIR in a case of Susac's syndrome. METHODS Leptomeningeal enhancement was correlated with clinical activity over 20 months and compared to retinal fluorescein angiography. RESULTS The size, number, and location of leptomeningeal enhancement varied over time and generally correlated with symptom severity. The appearance was remarkably similar to that of retinal vasculopathy. CONCLUSION Ce 3D FLAIR may aid in diagnosis and understanding of pathophysiology in Susac's syndrome and may serve as a biomarker for disease activity.

Comparison between myocardial integrated backscatter and strain rate imaging in the quantitative assessment of subepicardial function post-myocardial infarction

Transmural extent of infarction (TME) may be an important determinant of functional recovery and remodeling. Recent animal data suggest that strain rate imaging (SRI) maybe able to identify subendocardial ischemia.We compared SRI and cyclic variation of integrated backscatter (CVIB) for predicting TME in the quantitative assessment of regional subepicardial function. Forty-nine (n = 49) postmyocardial infarct patients (61±10 years, EF 41±10%) underwent tissue Doppler echocardiography (TDE) and contrast enhanced magnetic resonance imaging (CMR). A15 mm×2mm sampling volume (tracked to wall motion) was placed over the long axis subepicardial region of each segment during TDE offline analysis to measure peak longitudinal systolic strain rate (SR), peak longitudinal systolic strain (PS), and CVIB. Findingswere compared with TME classified into two categories of scar thickness by CMR: Non-transmural (TME≤50%), and transmural (TME > 50%). Of 213 segments identified with resting wall motion abnormalities, 145 segments showed delayed hyperenhancement on CMR. SR, PS and CVIB were similar with no significant differences between transmural and non-transmural infarcts regardless of the echo modality.