Rejection evaluation after renal transplantation using MR diffusion tensor imaging.

Background Renal allograft dysfunction monitoring is mainly performed using the serum creatinine (SC) level, Doppler ultrasound (US), or renal biopsy. Recently proposed diffusion-based magnetic resonance imaging (MRI) methods have been explored as new, non-invasive tools for assessing renal function after transplantation. Purpose To investigate the value of fractional anisotropy (FA) measurements in the evaluation of acute rejection cases after renal transplant. Material and Methods Doppler US and MRI diffusion tensor imaging (DTI) were performed in 21 patients with graft dysfunction requiring graft biopsy after renal transplantation and in 21 patients with normal graft function. The MR examinations were performed on a 1.5-T MRI using two b-values (0 and 800 s/mm2). FA values were measured from the cortex and medulla of the transplanted kidney at the upper, middle, and lower poles. Results Twenty-one transplant patients diagnosed with acute rejection (Group 1) were compared to the control group of 21 transplant patients with normal graft function (Group 2). The measured FA values of the medulla were 0.19 ± 0.02 and 0.22 ± 0.05 ( P = 0.017) for Groups 1 and 2, respectively. On the other hand, the measured FA values of the renal cortex were 0.18 ± 0.04 and 0.18 ± 0.04 ( P = 0.97) for Groups 1 and 2, respectively. Conclusion The good correlation between the renal medulla FA values and allograft function shows that MR DTI has potential for non-invasive functional assessment of transplanted kidneys. On the other hand, the renal cortex FA values had no correlation with the allograft function.

Ossifying fibroma of the inferior turbinate.

Hypertrophy of inferior turbinate is a common condition, especially with nasal septum deviation. Sometimes, the cause of hypertrophy of inferior turbinate can be fibro-osseous lesions. Benign, rare, and non-aggressive fibro-osseous neoplasms such as ossifying fibroma can affect paranasal sinuses. Isolated inferior turbinate involvement is extremely rare in ossifying fibroma. In this article, we present a 28-year-old female suffering from nasal obstruction due to septal deviation and hypertrophy of inferior turbinate. Preoperative and postoperative investigation show that cause of hypertrophy of inferior turbinate is ossifying fibroma. To our knowledge, that this is the second case of ossifying fibroma reported in the English-language literature due to its isolated localization. However, if the patients with inferior turbinate hypertrophy are examined carefully, we can prevent unnecessary medical treatment and surgery for inferior turbinate hypertrophy.

Autonomic dysreflexia in a man with multiple sclerosis.

BACKGROUND/OBJECTIVE: To report manifestation of autonomic dysreflexia (AD) in a man with multiple sclerosis (MS). DESIGN: Case report. FINDINGS: A young man presented with a history of several admissions to the emergency department with complaints of hypertensive attacks, palpitations, difficulty in breathing, headaches, and flushing. The attacks were attributed to a previously diagnosed anxiety disorder. Onset of numbness of the left leg numbness prompted a more thorough study, which showed evidence of MS. AD was suspected as the cause of his recurrent attacks of hypertension. Bladder distension was identified as the cause of AD, and his hypertensive attacks were controlled by management of neurogenic bladder. CONCLUSIONS: This report emphasizes that AD can occur in MS. Somatic symptoms warrant thorough investigation before attributing them to psychosomatic causes.

Diffusion-weighted imaging of adnexal torsion.

We report the diffusion-weighted imaging findings (DWI) of a case with ovarian torsion. Magnetic resonance imaging revealed a large cyst within a non-enhancing ovary. DWI depicted restricted diffusion which in turn was found to be related with the infarction of the ovary in the laparoscopic salpingo-oophorectomy performed.

Assessment of Doppler waveform patterns and flow velocities of hepatic veins in children with acute viral hepatitis.

PURPOSE: To evaluate hepatic vein flow patterns and velocities in children with acute viral hepatitis and to compare the findings to a group of healthy children, with duplex sonography. MATERIALS AND METHODS: Forty children with acute viral hepatitis were enrolled in group 1 and forty healthy children were enrolled in group 2 (control group). Both groups underwent gray scale and duplex sonography. Hepatic venous Doppler flow patterns were categorized as triphasic, biphasic, or monophasic. Peak systolic velocities of hepatic veins were recorded. RESULTS: In group 1, hepatic venous flow was triphasic in 61.6%, monophasic in 26.6%, and biphasic in 11.6% of the patients. These figures were 88.3%, 8.3%, and 3.3%, respectively, for the controls in group 2. Group 1 had fewer patients with only a triphasic flow pattern, but had a higher percentage of monophasic and biphasic flow patterns. There was a triphasic flow pattern in all three hepatic veins in 50% of group 1 and in 80% of group 2. Differences in flow patterns of hepatic veins between the groups were found to be significant according to the student t-test (p < 0.01), and this was independent of age, gender, feeding status, and activity. CONCLUSION: Similar to reports of chronic liver disease or diffuse liver disease, significant differences in the flow patterns of hepatic veins were found in children with acute viral hepatitis. Hepatic vein flow patterns were frequently monophasic or biphasic in group 1, especially when accompanied by change in hepatic echogenicity. There was no significant difference in the flow velocities of the hepatic veins between group 1 and group 2.

Laryngeal neurofibroma associated with neurofibromatosis type 2.

We present a case of laryngeal neurofibroma associated with neurofibromatosis type 2. Although laryngeal neurofibromas have previously been reported in cases of neurofibromatosis type 1, their presence has never been described in a patient with neurofibromatosis type 2.

Brain injury: analysis of imaging modalities.

Advances in imaging have had a significant impact not only on the diagnosis of but also on the management of patients with brain injury. Various modalities are available to image the brain; however, it is not always clear which imaging modality (CT, MRI, SPECT, PET, etc.) is optimal for a specific aspect of traumatized brain. The purpose of this paper is to analyze the over 20,000 imaging studies done in brain injury and to compare the results with the experience in the literature. A detailed comparison has been done relative to CT, MRI, SPECT and PET in traumatic brain injury.

Isolated septum pellucidum agenesis in an adult.

Septum pellucidum agenesis is frequently associated with other cerebral malformations. Its isolated agenesis is quite rare. In the literature, all reported cases were diagnosed in early childhood. The authors present an unusual case of isolated septum pellucidum agenesis detected in adulthood with computed tomography and magnetic resonance imaging.

Transverse sinus air after cranial trauma.

Air in vascular compartments has been rarely reported. We report a case in whom air within transverse sinus and sinus confluence through ruptured superior sagittal sinus (SSS) due to fractures of parietal and frontal bones was disclosed by computed tomography (CT). Although air in transverse sinus has been reported rarely this could be the first case with air in transverse sinus through the SSS after cranial trauma.

Iatrogenic vertebral artery pseudoaneurysm: US, CT and MRI findings.

Vertebral artery pseudoaneurysm (VAP) is the result of the penetrating neck trauma, chiropractic manipulation, vasculopathies and rarely iatrogenic due to internal jugular vein (IJV) catheterization. It should be identified and treated immediately because of its potential risk of rupture. We present a case of a right VAP resulting from jugular vein catheterization, with the Doppler ultrasonography (US), Computed tomography (CT) and magnetic resonance imaging (MRI) findings. Although angiography is a well known gold standard modality, Doppler US, CT and MRI findings can be sufficient to demonstrate VAP.

Observer variability based on the strength of MR scanners in the assessment of lumbar degenerative disc disease.

OBJECT: aim of this study was to analyse the observer variability in the diagnosis and definition of disc pathologies with low and high-field strength MR scanners. MATERIAL AND METHODS: 95 patients with low back pain or radicular pain who were referred from two different centers were included in the study. Fifty-seven patients were scanned with 0.3 T MR (group 1) and 38 patients with 1.5 T (group 2). The intraobserver and interobserver reliability were assessed with the cappa coefficient which was characterised as follows: values less than 0.0 = 'poor' agreement, values 0.01-0.2 = 'slight' agreement beyond chance, 0.21-0.4 = 'fair' agreement, 0.41-0.60 = 'moderate' agreement, 0.61-0.80 = 'substantial' agreement and 0.81-1.00 = 'almost perfect' agreement. RESULTS: intraobserver agreement in group 1 and group 2 for both readers was 'almost perfect' in differentiating normal and pathological discs; 'substantial-almost perfect' in defining the disc pathologies, 'moderate-substantial' in root compression, and 'moderate-substantial' in spinal stenosis. Interobserver agreement was 'almost perfect' in differentiating normal and pathological discs, 'substantial' in defining disc pathologies, 'moderate' in root compression and 'moderate' in spinal stenosis in the group 1, whereas in group 2, it was 'almost perfect' in differentiating normal and pathological discs, 'almost perfect' in defining disc pathologies, 'slight-substantial' in root compression and 'moderate' in spinal stenosis. CONCLUSION: in the diagnosis of root compression and spinal stenosis, the intra and interobserver agreements were relatively poor with both high and low-strength field MRIs, indicating a need for more objective criteria. In differentiating normal and pathologic appearance of disc, the interobserver agreement was considerably better with high-field compared to low-field strength MRI. In cases where this definition is important, high-field strength scanners should be preferred.

Giant aneurysm of the azygos pericallosal artery: case report and review of the literature.

BACKGROUND: Pericallosal aneurysms are encountered less than 6.7%, and giant aneurysms among them even less. Giant azygos pericallosal artery aneurysm at the callosomarginal bifurcation is extremely rare, and our case presented herein is the second one. The case is discussed with thorough review of the literature. METHODS: A 65-year-old woman presented with an extremely rare giant aneurysm on the azygos pericallosal artery manifesting as subarachnoid hemorrhage in World Federation of Neurosurgical Societies Grade 3. Computed tomography (CT), magnetic resonance angiography (MRA), and four vessel angiography revealed a giant azygos pericallosal artery aneurysm associated with a second aneurysm at the left M1. RESULTS: After recovery to Grade 2, she underwent surgery via the right frontal interhemispheric approach for the azygos artery aneurysm on the 17th day after bleeding. The true dimensions of the aneurysm were greater than indicated by angiography because of partial thrombosis. Trilobulate aneurysm was carefully dissected from the surrounding structures. Postoperative cerebral angiography showed no filling of the clipped aneurysm and preservation of circulation. CONCLUSIONS: The treatment of distal anterior cerebral artery aneurysms is often difficult, because of their broad-based irregular configurations and adherence to surrounding tissue, tendency to bleed irrespective of size and the coexistence of other cerebral aneurysms. However, excellent outcomes can be obtained based on thorough preoperative radiologic evaluation, including magnetic resonance imaging (MRI), and correct selection of surgical approach.

Complete superior and inferior sagittal sinus thromboses with multiple cranial nerve pareses and transient ischemic attack--case report.

A 27-year-old woman with headache and right peripheral facial nerve paresis persisting for over 25 days, and left hemiparesis for 2 days, which had all been gradually improving, was admitted to our hospital as she suddenly developed horizontal and vertical diplopia. She had right fourth and sixth cranial nerve pareses, papilledema, and right orbital venous congestion, and also experienced a seizure on the day of admission. Magnetic resonance (MR) imaging and MR venography revealed complete superior and inferior sagittal sinus thromboses and significant collateral venous channels, but no parenchymal lesion. Fourth and seventh cranial nerve pareses and the left hemiparesis resolved completely within 2 days, but she concurrently developed an episode of right hemiparesis, which lasted for 30 minutes. The patient recovered with medical therapy. MR venography showed recanalization of both sinuses. She was neurologically intact except for minimal right abducens nerve paresis at discharge, 40 days after admission. Multiple cranial nerve pareses with transient ischemic attack is an extremely rare manifestation of superior sagittal sinus thrombosis. Transient functional disturbance due to temporary reduction of tissue perfusion caused by overload of the collateral channels is more likely to be responsible for the transient ischemic attack and reversible ischemic neurological deficit.

Short term effects of valsartan on portal blood flow in cirrhotic patients.

BACKGROUND/AIMS: Portal hypertension is a common syndrome characterized by a chronic increase of the portal pressure and is the most frequent clinical manifestation of cirrhosis. In this study short term effects of Valsartan, an angiotensin II receptor antagonist, upon portal blood flow in 36 cirrhotic patients was determined by Doppler ultrasonography. METHODS: Patients were divided into three groups of 12 according to Child-Pugh classification. They (18 women and 18 men with a mean age of 50+/-14 years) received a daily dose of 80 mg valsartan for one week after which the effects upon hemodynamic changes were evaluated by colored Doppler ultrasonography. Hemodynamic measurements were performed 24 hours prior to valsartan administration and then four and eight days after adiministration. The following parameters were evaluated: for hemodynamic changes: peak systolic flow velocity, diastolic flow velocity, peak systolic flow velocity/diastolic flow velocity ratio, resistive index and pulsatility index were evaluated in hepatic, superior mesenteric and right and left renal arteries. In the portal vein, diameter, mean flow velocity and flow volume were evaluated. Results are expressed as means+/-SD. RESULTS: Hemodynamic parameters showed no significant change during the measurement in hepatic, superior and right and left renal arteries. Valsartan induced a significant decrease (p<0.05) in portal vein diameter, in portal vein maximal flow velocity and in portal vein flow volume. The decrease in portal vein flow volume was 11.7% on day four and 24.4% on day eight. In two patients, a symptomatic hypotensive attack occurred. Serum potassium levels were increased significantly (p<0.05). CONCLUSIONS: These results indicate that valsartan can be used in portal hypertension safely.

Working memory dysfunction in delusional disorders: an fMRI investigation.

BACKGROUND: Delusional disorder (DD) is a rare and understudied psychiatric disorder. There is limited number of studies concerning cognitive characteristics in DD. Using an established working memory paradigm with variable levels of memory load, we investigated alterations in functional magnetic resonance imaging (fMRI) of brain regions in patients with DD. METHODS: This case control study included 9 patients with DD and 9 healthy control subjects matched for age, sex, and education level. Diagnosis of DD was confirmed using the Structured Clinical Interview for DSM-IV Axis I. The severity of the symptoms was evaluated using the Positive and Negative Syndrome Scale. All patients were asked to perform 0-back and 2-back tasks during fMRI experiments. Functional imaging was performed using the 3.0 T Philips whole-body scanner using an 8-channel head coil. RESULTS: Participants with DD had less neural activation of the left dorsolateral prefrontal cortex in fMRI scans obtained during performance tasks. On the other hand, neural activation of the left and right superior temporal gyrus, left middle and inferior temporal gyrus, right and left posterior cingulate gyrus, right amygdala, left and right fusiform gyrus was more prominent in patients with DD in comparison with the control group. DISCUSSION: Patients with DD had dysfunction in the prefrontal, temporal and limbic regions of the brain in particular, during performance tasks of working memory. Our findings were in line with the findings of the early reports on deficient functioning in temporal or limbic regions of the brain. Further, patients with DD displayed prefrontal dysfunction as seen in patients with schizophrenia.

The utility of high b-value DWI in evaluation of ischemic stroke at 3T.

PURPOSE: The utility of DWI with high b-value in ischemic stroke is still unsettled. The purpose of this study is to compare high b-value (3000) and standard b-value (1000) diffusion-weighted images in patients with ischemic stroke at 3T. MATERIALS AND METHODS: 27 patients with acute stroke who were admitted to the hospital during the first 24h after symptom onset were included in this study. All patients had a brain MRI study with stroke protocol including standard (b=1000) DWI and high b-value (b=3000) DWI sequences at 3T MR scanner. Number and localization of the lesions were assessed MR signal intensities (SI), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), contrast ratio (CR) and apparent diffusion coefficient (ADC) values of the lesions and normal parenchyma on DWI with b=1000 and b=3000 sequences were measured. RESULTS: All patients with acute stroke revealed hyperintense lesions due to restricted diffusion on DWI with both b-values. However, lesions of restricted diffusion were more conspicuous in b=3000 value DWI than b=1000, and additional 4 ischemic lesions were detected on b=3000 DWI. SNR, CNR, SI and also ADC values in both stroke area and normal parenchyma were lower at b=3000 than the value at b=1000. At b=3000, CR was significantly greater than b=1000 images. CONCLUSIONS: Although quantitative analysis shows higher SI, SNR and CNR values with standard b-value (b=1000) diffusion-weighted imaging, using higher b-value may still be beneficial in detecting additional subtle lesions in patients whose clinical findings are not correlated with standard b-value DWI in stroke.

High b-value diffusion-weighted MR imaging of normal brain at 3T.

INTRODUCTION: The purpose of this study was to determine the normative apparent diffusion coefficient (ADC) values at 3T using high b-value (3000 s/mm(2)) diffusion-weighted images (DWI) and compare the signal characteristics of the high b value with standard b-value (1000 s/mm(2)) DWI. METHODS: Institutional review board approval was obtained for this prospective study which included 20 volunteers (10 M, 10 F, mean age: 38.7+/-14.9) without any known clinical disease or radiological findings. All brain examinations were performed with 3T MR by using similar parameters of b1000 and b3000 DWI sequences. DWI and ADC maps were obtained. Signal intensity, noise, signal to noise ratio (SNR), contrast to noise (CNR), contrast ratio (CR), and ADC values of bilateral posterior limb of internal capsule, frontal white matter, parietal gray matter, pons, thalamus, splenium of corpus callosum were measured on b1000 and b3000 DW images. RESULTS: In all anatomic locations, MR signal intensity, SNR and ADC values of b3000 images were significantly lower than MR signal intensity, SNR and ADC values of b1000 images (p<0.001). The CNR and CR values at the posterior limb of internal capsule and pons were significantly increased on b3000 images (p<0.001) and decreased in the other regions measured. CONCLUSION: The ADC values calculated from standard b-value DWI were significantly higher than those calculated from high b-value DWI. These results agree with the previous studies. In the regions where CNR values increase with high b value, b3000 DWI images may provide additional clinical information.

Pseudoaneurysm and renal arteriovenous fistula after nephrectomy: two cases treated by transcatheter coil embolization.

Pseudoaneurysms and arteriovenous fistulas of renal arteries are rare clinical lesions. Invasive renal procedures may lead to pseudoaneurysm or arteriovenous fistulas (AVFs). We report two pseudoaneurysms and arteriovenous fistula cases that were treated by transcatheter embolization with metallic coils. The first case is left main renal artery pseudoaneurysm after nephrectomy in a patient with a solid renal tumor. The second case is right main renal artery AVF with giant pseudoaneurysm after both gunshot injury and nephrectomy. On the basis of color Doppler sonography and computed tomography (CT) findings, cases were diagnosed as pseudoaneurysm after nefrectomy. Contrast-enhanced CT scans showed a hyperdense area within the hematoma consistent with pseudoaneurysm. Endovascular treatment with coil embolization succeeds to total occlusion in renal artery pseudoaneurysm. Delayed hemorrhage related to postnephrectomy may be life-threatening conditions because of diagnostic difficulties. AVF and pseudoaneurysm can be treated safely and successfully by transcatheter arterial embolization.

Reversal of ergotamine-induced vasospasm following methylprednisolone.

INTRODUCTION: Ergotamine, an ergot alkaloid with partial agonist effects on alpha1 receptors and serotonin receptors, is widely used in the treatment of migraine. Ergotamine may cause severe vasospasm. CASE REPORT: A 25-year-old man was admitted to the emergency department with complaints of sudden coldness, pallor, and pain in his hands and feet for 2 days. He had been using a drug containing ergotamine for his migraine headaches for 1 week. On examination, the pulses of the radial, ulnar, popliteal, and tibial arteries were bilaterally undetectable. Treatment consisted of sodium nitroprusside and heparin. On the third day of the admission, bilateral brachial and femoral artery pulses were lost and his complaints exacerbated. Angiography revealed diffuse vasospasm of the arteries in the both lower extremities (Fig. 1A and C). Because of the lack of response to the ongoing therapy, a single dose of methylprednisolone sodium succinate (1 mg/kg) was given intravenously; the nitroprusside infusion was terminated because of the development of hypotension. The pulses were palpable 2 h after the methylprednisolone dose. Angiography done 12 h after the methylprednisolone dose showed improvement of the vasospasm in the lower extremities. Recovery was uneventful and follow-up evaluation found no abnormalities. DISCUSSION: Although vasodilator agents are first-line therapy in the treatment of ergotism, corticosteroids may be considered as an alternative therapy, especially for intractable cases. The mechanism by which corticosteroids dilate arteries is not clear. CONCLUSIONS: Ischemia in an extremity secondary to ergotamine-induced vasospasm unresponsive to sodium nitroprusside may be treated successfully with methylprednisolone.

Hemorrhage into the brain abscess cavity with Fallot's tetralogy.

Hemorrhage into the abscess cavity is a complication of brain abscess. It has been reported to be due to inflammation which results in the damage of the fragile neovasculature of the abscess wall. Hypoxia caused by Fallot's tetralogy or other congenital heart diseases facilitates the damage of these vessels with the lacking supportive tissues, and in turn intracavital bleeding.