A. Banco

Reversible MRI abnormalities in an unusual paediatric presentation of Wernicke's encephalopathy.

Background. We report an unusual paediatric presentation of acute Wernickes encephalopathy in a 12-year-old boy affected by chronic gastrointestinal disease. MRI demonstrated, in addition to the typical diencephalic and mesencephalic signal abnormalities on T2-weighted images, enhancement of the mammillary bodies and the floor of the hypothalamus. Materials and methods. Following parenteral administration of thiamine for 4 days, the patient recovered from his neurological deficits and on follow-up enhanced MRI 1 month later, no signal abnormalities were found nor was there diencephalic or mesencephalic atrophy, as is usual in the chronic phase of the disease. Results. MRI provides crucial information in the diagnosis of Wernickes encephalopathy, either in the acute or chronic phases of the disease. Conclusion. Our report provides an additional clue for recognition of the acute phase of the disease; enhancement of the floor of the hypothalamus has not previously been described despite its recorded involvement at autopsy.

Magnetic resonance findings in scuba diving-related spinal cord decompression sickness

Scuba diving is associated with risk of severe decompression sickness (DCS type II), which results from rapid reduction of the environmental pressure sufficient to cause the formation into tissue or blood of inert gas bubbles previously loaded within tissues as a soluble phase. DCS type II constitutes a unique subset of ischemic insults to the central nervous system (CNS) with primarily involvement of the spinal cord. Ten patients with diving-related barotrauma underwent neurologic examination. Two of them presented progressive sensory and motor loss in the extremities at admission and were presumed affected by spinal cord DCS. Magnetic resonance imaging (MRI) demonstrated abnormalities in the white-matter tracts of the spinal cord in these patients, in each case corresponding to an area of the cord believed to be clinically involved. After a course of therapeutic recompressions, one patient was able to stand and walk a short distance,and MRI revealed a decreased extension of areas of spinal cord abnormalities. MRI has proved to be reliable in the detection of pathologic changes of spinal cord decompression sickness that were previously undetectable by other neuroimaging methods and also has proved to be useful in the follow-up during therapeutic hyperbaric recompressions.

Imaging processing for CT angiography of the cervicocranial arteries: evaluation of reformatting technique

Purpose.The aim of this study was to compare computed tomography angiography (CTA) sliding-thin-slab (STS) multiplanar reformatting (MPR), STS maximum intensity projection (MIP) and three-dimensional (3D) volume rendering (VR) reformatting techniques in the evaluation of cervicocranial arteries.Materials and methods.Twenty patients examined with multislice CT were included in this study. CTA images were reformatted as STS-MIP, STS-MPR and 3DVR in orthogonal planes and in the oblique-coronal plane. Images were evaluated in consensus by two radiologists, with a third radiologist to resolve discordances in grading image quality parameters. The Spearman correlation analysis was performed to compare results and to obtain the correlation between scores resulting from the evaluation of parameters considered with the different techniques used (STSMIP, STS-MPR and 3DVR).Results.STS-MIP images were significantly superior to STSMPR images for all parameters considered (p<0.05). Obliquecoronal 3DVR images were significantly superior to obliquecoronal STS-MIP images in the evaluation of vertebrobasilar vessels (p<0.05); in all other cases, 3DVR images were equivalent to STS-MIP images.Conclusion.STS-MIP images should be the primary reformatting technique for CTA of the cervicocranial arteries in addition to viewing the source images; 3DVR images can play an important role after a previsional diagnosis is made on the STS-MIP images.

Accuracy of SWI sequences compared to T2*-weighted gradient echo sequences in the detection of cerebral cavernous malformations in the familial form

Purpose The purpose of this study was to assess the accuracy of susceptibility-weighted imaging (SWI), compared with T2*-weighted gradient echo (GRE) imaging in assessing cerebral cavernous malformations. Materials and methods We retrospectively evaluated 21 patients with a familial form of cavernous malformation. Magnetic resonance (MR) protocol included non-enhanced and contrast-enhanced fast-spin echo (FSE) T1-weighted sequences, FSE T2-weighted sequences, fluid-attenuated inversion-recovery (FLAIR), GRE T2*-weighted and SWI sequences. Images were reviewed in consensus by two expert neuroradiologists to assess the location, number, size and conspicuity of the lesions on T2*-weighted GRE and SWI sequences. Statistical differences in the number, size and conspicuity of the lesions seen on the SWI images and the T2*-weighted GRE images were assessed with the nonparametric Wilcoxon signed rank test. Results The number of cavernous malformations was significantly higher (p < .001) on the SWI images (n = 152) than on T2*-weighted GRE images (n = 56). Lesion size was significantly higher (p < .001) on SWI images (mean: 0.4 cm, SD ± 0.55) than on T2*-weighted GRE sequences (mean: 0.2 cm, SD ± 0.51) and the differences were statistically significant (p < .001). Lesion conspicuity was significant higher (p < .001) on SWI than on T2*-weighted GRE images. In one patient who underwent a 2-month follow-up for the onset of neurologic symptoms related to cerebral hemorrhage, a cerebral hematoma was identified at the site of a cerebral cavernous malformation that was demonstrated only on the SWI images in the previous MR examination. Conclusions The SWI sequence, being more sensitive to substances which distort the local magnetic field than the GRE T2*W sequence, showed a higher sensitivity in identifying cerebral cavernous malformations. Thus, routine clinical neuroimaging protocol should contain SWI sequences to evaluate patients with (or suspected) cerebral cavernous malformations.

Magnetic resonance imaging in the assessment of brain involvement in alcoholic and nonalcoholic Wernicke's encephalopathy

AIM To present the typical and atypical magnetic resonance (MR) imaging findings of alcoholic and non-alcoholic Wernicke’s encephalopathy. METHODS This study included 7 patients with Wernicke’s encephalopathy (2 men, 5 women; mean age, 52.3 years) that underwent brain MR examination between January 2012 and March 2016 in a single institution. Three patients were alcoholics and 4 patients were non-alcoholics. MR protocol included a T2-weighted sequence, a fluid attenuation inversion recovery (FLAIR) sequence, a diffusion-weighted sequence (b = 0 and 1000 s/mm2), and a contrast-enhanced MR sequence. All MR images were retrospectively reviewed at baseline and follow-up by two radiologists. RESULTS All patients with Wernicke’s encephalopathy had bilateral areas showing high signal intensity on both T2-weighted and FLAIR MR images in the typical sites (i.e., the periaqueductal region and the tectal plate). Signal intensity abnormalities in the atypical sites (i.e., the cerebellum and the cerebellar vermis) were seen in 4 patients, all of which had no history of alcohol abuse. Six patients had areas with restricted diffusion in the typical and atypical sites. Four patients had areas showing contrast-enhancement in the typical and atypical sites. Follow-up MR imaging within 6 mo after therapy (intravenous administration of thiamine) was performed in 4 patients, and demonstrated a complete resolution of all the signal intensities abnormalities previously seen in all patients. CONCLUSION MR imaging is valuable in the diagnosis of Wernicke’s encephalopathy particularly in patients presenting with atypical clinical symptoms, or with no history of alcohol abuse.

Value of serial magnetic resonance imaging in the assessment of brain metastases volume control during stereotactic radiosurgery

AIM To evaluate brain metastases volume control capabilities of stereotactic radiosurgery (SRS) through serial magnetic resonance (MR) imaging follow-up. METHODS MR examinations of 54 brain metastases in 31 patients before and after SRS were reviewed. Patients were included in this study if they had a pre-treatment MR examination and serial follow-up MR examinations at 6 wk, 9 wk, 12 wk, and 12 mo after SRS. The metastasis volume change was categorized at each follow-up as increased (> 20% of the initial volume), stable (± 20% of the initial volume) or decreased (< 20% of the initial volume). RESULTS A local tumor control with a significant (P < 0.05) volume decrease was observed in 25 metastases at 6-wk follow-up. Not significant volume change was observed in 23 metastases and a significant volume increase was observed in 6 metastases. At 9-wk follow-up, 15 out of 25 metastases that decreased in size at 6 wk had a transient tumor volume increase, followed by tumor regression at 12 wk. At 12-wk follow-up there was a significant reduction in volume in 45 metastases, and a significant volume increase in 4 metastases. At 12-mo follow-up, 19 metastases increased significantly in size (up to 41% of the initial volume). Volume tumor reduction was correlated to histopathologic subtype. CONCLUSION SRS provided an effective local brain metastases volume control that was demonstrated at follow-up MR imaging.

Late-onset Sheehan’s syndrome presenting with rhabdomyolysis and hyponatremia: a case report

IntroductionHyponatremia associated with rhabdomyolysis is a rare event and a correct diagnostic approach is required to rule out this or other diseases as a primary cause and to avoid other complications resulting from a lack of appropriate treatment.Case presentationA 64-year-old Caucasian woman presented to our facility with worsening fatigue, slurred speech, nausea and vomiting, and high serum levels of creatine kinase and myoglobin together with hyponatremia. Normal arterial blood gas analysis results, normal serum potassium levels, increased urine sodium levels, urine specific gravity of >1003N/m3 and low urine volume suggested an endocrine etiology. Her low cortisol and thyroid hormone serum levels suggested a pituitary disorder. A magnetic resonance imaging study showed atrophy of her pituitary gland. A more detailed study of our patient’s obstetric history revealed a post-partum hemorrhage 30 years earlier. She was diagnosed as having late-onset Sheehan’s syndrome and treated with hormone replacement therapy, which normalized her clinical picture.ConclusionsThis case report shows that, in hyponatremia-associated rhabdomyolysis, an endocrinological origin should always be considered. This should include Sheehan’s syndrome as it can occur with late onset.

Percutaneous Pedicle-Lengthening Osteotomy in Minimal Invasive Spinal Surgery to Treat Degenerative Lumbar Spinal Stenosis: A Single-Center Preliminary Experience

Abstract Background Lumbar spinal stenosis (LSS) is a narrowing of the spinal canal due to spinal degeneration, and its main clinical symptom is neurogenic claudication. Surgical treatment is pursued for patients who do not improve with conservative care. Patients with symptomatic LSS who also have significant medical comorbidities, although clearly in need of intervention, are unattractive candidates for traditional open lumbar decompressive procedures. Thus it is important to explore minimally invasive surgical techniques to treat select patients with LSS. Methods This retrospective case series evaluated the clinical and radiographic outcomes of a new minimally invasive procedure to treat LSS: pedicle‐lengthening osteotomy using the ALTUM system ((Innovative Surgical Designs, Inc., Bloomington, Indiana, United States). Peri‐ and postoperative demographic and radiographic data were collected from a clinical series of seven patients with moderate LSS who were > 60 years of age. Clinical outcome was evaluated using visual analog scale (VAS) scores and the spinal canal area on computed tomography scans. Results Twelve months after the procedure, scoring revealed a median improvement of 3.7 on the VAS for the back and 6.3 on the VAS for the leg, compared with the preoperative baseline (p < 0.05). The postoperative central area of the lumbar canal was significantly increased, by 0.39 cm2; the right and left neural foramina were enlarged by 0.29 cm2 and 0.47 cm2, respectively (p < 0.05). Conclusions In this preliminary study, the ALTUM system showed a good clinical and radiologic outcome 1 year after surgery. In an older or high‐risk population, a short minimally invasive procedure may be beneficial for treating LSS.

Hypogonadotrophic Pituitary Insufficiency in Transfusional Hemochromatosis Complicating Thalassemia Major: MR Imaging

To identify pituitary iron overload in patients with transfusion-dependent thalassemia major causing secondary hypogonadism, we prospectively evaluated signal intensity abnormalities of the anterior lobe of the pituitary gland of 30 patients comparing spin-echo, gradient-echo imaging and pituitary T2 relaxation times measurement. We found that pituitary iron overload can best be assessed by MR imaging using gradient-echo T2*-weighted technique to establish signal reduction in the anterior lobe of the pituitary gland. This finding is correlated to increasing serum ferritin level — a parameter that reflects the severity of iron overload, and is more evident in patients with secondary hypogonadism. This finding is consistent with the hypothesis of hypogonadotrophic pituitary insufficiency due to iron-induced cellular damage.

Comparison of Single-Echo T2-weighted Fast Spin-Echo and Conventional Spin-Echo MR Sequences In the detection of Brain Lesions of Multiple Sclerosis

We compared single-echo T2-weighted fast spin-echo (FSE) magnetic resonance imaging and conventional spin-echo (CSE) T2-weighted imaging in the detection of brain lesions of multiple sclerosis (MS). 16 patients with clinically definite MS underwent brain imaging at 0.5 T with T2-weighted single-echo fast spin-echo (FSE) and conventional spin-echo (CSE) sequences. Image analysis was performed by three of the investigators who worked together to reduce interobserver variability. Statistical analysis was performed using Students t test to assess the difference in the contrast-to-noise (C/N) ratio of MS lesions between CSE and FSE sequences. The Wilcoxon signed rank test was used to evaluate the difference in the number of lesions between the two sequences. There was no significant difference in the overall total number of lesions detected on FSE vs CSE (964 vs 1009, P >.05). However significantly (P = .02) more posterior fossa lesions were detected using FSE than CSE, whereas significantly (P = .002) more periventricular lesions were detected using CSE than FSE. The difference in the number of lesions in the other sites was not significant (P > .05). There was no significant difference in the overall total C/N ratio of MS lesions between FSE and CSE sequences (11.7 ± 3.9 vs 12.6 ± 4). Considerable time savings can be made when substituting FSE for CSE sequences in T2-weighted imaging, and this is a compelling reason to employ such sequences in clinical practice. Our results suggest that for single-echo T2-weighted imaging, FSE can replace CSE in long term monitoring especially when patient movement prevents a useful investigation and when optional scanning planes are required.