Multinodular and Vacuolating Posterior Fossa Lesions of Unknown Significance

Multinodular and vacuolating neuronal tumor of the cerebrum is a rare supratentorial brain tumor described for the first time in 2013. Here, we report 11 cases of infratentorial lesions showing similar striking imaging features consisting of a cluster of low T1-weighted imaging and high T2-FLAIR signal intensity nodules, which we referred to as multinodular and vacuolating posterior fossa lesions of unknown significance. No relationship was found between the location of the lesion and clinical symptoms. A T2-FLAIR hypointense central dot sign was present in images of 9/11 (82%) patients. Cortical involvement was present in 2/11 (18%) of patients. Only 1 nodule of 1 multinodular and vacuolating posterior fossa lesion of unknown significance showed enhancement on postcontrast T1WI. DWI, SWI, MRS, and PWI showed no malignant pattern. Lesions did not change in size or signal during a median follow-up of 3 years, suggesting that multinodular and vacuolating posterior fossa lesions of unknown significance are benign malformative lesions that do not require surgical intervention or removal.

A 3T Phase-Sensitive Inversion Recovery MRI Sequence Improves Detection of Cervical Spinal Cord Lesions and Shows Active Lesions in Patients with Multiple Sclerosis

BACKGROUND AND PURPOSE

Magnetic Resonance Imaging is the modality of choice to detect spinal cord lesions in patients with Multiple Sclerosis (MS). However, this imaging is challenging. New sequences such as phase-sensitive inversion recovery have been developed to improve detection. Our aim was to compare a 3D phase-sensitive inversion recovery and a conventional imaging dataset including postcontrast T2WI and T1WI to detect MS spinal cord lesions.

MATERIALS AND METHODS

This retrospective single-center study included 100 consecutive patients with MS (mean age, 41 years) from January 2015 to June 2016. One senior neuroradiologist and 1 junior radiologist blinded to clinical data checked for new spinal cord lesions, individually analyzing conventional and 3D phase-sensitive inversion recovery datasets separately, placing a 3-week delay between the 2 readings. A consensus reading was done with a third senior neuroradiologist. A Wilcoxon test was used to compare the 2 imaging datasets. Intra- and interobserver agreement was assessed by the κ coefficient.

RESULTS

3D phase-sensitive inversion recovery detected significantly more lesions than conventional imaging (480 versus 168, P < .001). Eleven patients had no detected lesions on T2WI, whereas 3D phase-sensitive inversion recovery detected at least 1 lesion. All postcontrast T1WI enhancing lesions were also visible on 3D phase-sensitive inversion recovery. The signal-to-noise ratio was significantly higher using 3D phase-sensitive inversion recovery (0.63 versus 0.46, P = .03). Mean reading confidence was significantly higher using 3D phase-sensitive inversion recovery. Inter- and intraobserver agreement was good for both datasets.

CONCLUSIONS

Our study showed that 3D phase-sensitive inversion recovery significantly improved detection of cervical spinal cord lesions, including both enhancing and nonenhancing lesions in patients with MS.

Improved Detection of New MS Lesions during Follow-Up Using an Automated MR Coregistration-Fusion Method

BACKGROUND AND PURPOSE

MR imaging is the key examination in the follow-up of patients with MS, by identification of new high-signal T2 brain lesions. However, identifying new lesions when scrolling through 2 follow-up MR images can be difficult and time-consuming. Our aim was to compare an automated coregistration-fusion reading approach with the standard approach by identifying new high-signal T2 brain lesions in patients with multiple sclerosis during follow-up MR imaging.

MATERIALS AND METHODS

This prospective monocenter study included 94 patients (mean age, 38.9 years) treated for MS with dimethyl fumarate from January 2014 to August 2016. One senior neuroradiologist and 1 junior radiologist checked for new high-signal T2 brain lesions, independently analyzing blinded image datasets with automated coregistration-fusion or the standard scroll-through approach with a 3-week delay between the 2 readings. A consensus reading with a second senior neuroradiologist served as a criterion standard for analyses. A Poisson regression and logistic and γ regressions were used to compare the 2 methods. Intra- and interobserver agreement was assessed by the κ coefficient.

RESULTS

There were significantly more new high-signal T2 lesions per patient detected with the coregistration-fusion method (7 versus 4, P < .001). The coregistration-fusion method detected significantly more patients with at least 1 new high-signal T2 lesion (59% versus 46%, P = .02) and was associated with significantly faster overall reading time (86 seconds faster, P < .001) and higher reader confidence (91% versus 40%, P < 1 × 10^-4). Inter- and intraobserver agreement was excellent for counting new high-signal T2 lesions.

CONCLUSIONS

Our study showed that an automated coregistration-fusion method was more sensitive for detecting new high-signal T2 lesions in patients with MS and reducing reading time. This method could help to improve follow-up care.

TIPIC Syndrome: Beyond the Myth of Carotidynia, a New Distinct Unclassified Entity

BACKGROUND AND PURPOSE

The differential diagnosis of acute cervical pain includes nonvascular and vascular causes such as carotid dissection, carotid occlusion, or vasculitis. However, some patients present with unclassified vascular and perivascular changes on imaging previously reported as carotidynia. The aim of our study was to improve the description of this as yet unclassified clinico-radiologic entity.

MATERIALS AND METHODS

From January 2009 through April 2016, 47 patients from 10 centers presenting with acute neck pain or tenderness and at least 1 cervical image showing unclassified carotid abnormalities were included. We conducted a systematic, retrospective study of their medical charts and diagnostic and follow-up imaging. Two neuroradiologists independently analyzed the blinded image datasets.

RESULTS

The median patient age was 48 years. All patients presented with acute neck pain, and 8 presented with transient neurologic symptoms. Imaging showed an eccentric pericarotidian infiltration in all patients. An intimal soft plaque was noted in 16 patients, and a mild luminal narrowing was noted in 16 patients. Interreader reproducibility was excellent. All patients had complete pain resolution within a median of 13 days. At 3-month follow-up, imaging showed complete disappearance of vascular abnormalities in 8 patients, and a marked decrease in all others.

CONCLUSIONS

Our study improved the description of an unclassified, clinico-radiologic entity, which could be described by the proposed acronym: TransIent Perivascular Inflammation of the Carotid artery (TIPIC) syndrome.

Usefulness of colour Doppler flow imaging in the management of lacrimal gland lesions

OBJECTIVE

To assess the role of colour Doppler flow imaging (CDFI) in the diagnosis and management of lacrimal fossa lesions.

METHODS

Institutional ethical committee approval was obtained. Fifty-one patients with 62 lacrimal fossa lesions were retrospectively included from 2003-2015. All patients underwent conventional ultrasonography and CDFI, with a qualitative and quantitative analysis of the vascularization. All patients had lacrimal gland surgery. Definitive diagnosis was based on pathological examination.

RESULTS

The study included 47 non-epithelial lesions (NEL) and 15 epithelial lesions (EL), with 24 (39 %) malignant lesions and 38 (61 %) benign lesions. NEL were significantly more likely to present with septa (p < 0.001), hypoechogenicity (p < 0.001), high vascular intensity (p < 0.001), both central and peripheral vascularization (p < 0.001), tree-shape vascularization (p < 0.05) and a low resistance index (RI) (p < 0.0001). EL were significantly more likely to present with the presence of cysts (p < 0.001), and a higher RI. Receiver operating characteristic curves identified a RI value of 0.72 as the best cut-off to differentiate NEL from EL, with a sensitivity and specificity of 100 %.

CONCLUSION

CDFI is a valuable tool in the differential diagnosis of lacrimal fossa lesions. Resistance index measurement enables substantial distinction between EL and NEL, thus providing crucial data for surgical management.

KEY POINTS

• CDFI is a valuable tool in lacrimal fossa lesions. • Resistance Index measurement enables substantial distinction between epithelial and non-epithelial lesions. • Management of patients becomes more appropriate.

Tumor pathology of the orbit

The term orbital tumor covers a wide range of benign and malignant diseases affecting specific component of the orbit or developing in contact with them. They are found incidentally or may be investigated as part of the assessment of a systemic disorder or because of orbital signs (exophthalmos, pain, etc.). Computed tomography, MRI and Color Doppler Ultrasound (CDU), play a varying role depending on the clinical presentation and the disease being investigated. This article reflects long experience in a reference center but does not claim to be exhaustive. We have chosen to consider these tumors from the perspective of their usual presentation, emphasizing the most common causes and suggestive radiological and clinical presentations (progressive or sudden-onset exophthalmos, children or adults, lacrimal gland lesions, periorbital lesions and enophthalmos). We will describe in particular muscle involvement (thyrotoxicosis and tumors), vascular lesions (cavernous sinus hemangioma, orbital varix, cystic lymphangioma), childhood lesions and orbital hematomas. We offer straightforward useful protocols for simple investigation and differential diagnosis. Readers who wish to go further to extend their knowledge in this fascinating area can refer to the references in the bibliography.

[Transcranial Doppler imaging: state of the art]

Initially introduced in the early 1980's, transcranial Doppler followed by transcranial Doppler sonography were used in neurosurgical units for management and follow-up of intracranial vasospasm in patients with subarachnoid hemorrhage. This imaging technique, more sensitive and less invasive than catheter angiography, also proved to be of value for diagnosis of intracranial atherosclerosis, management of patients with head trauma, and evaluation of collateral flow through the circle of Willis. Doppler US would also allow prediction of the risk of symptomatic embolic events through monitoring of HITS. Evaluation of the middle cerebral arteries during carotid occlusion testing is useful for evaluating the need for particular revascularization techniques. Finally, Doppler imaging is useful to assess patients with possible brain death. A recent advance in Doppler imaging is the ability to provide a three-dimensional projection (3D Doppler) of the intracranial arteries enabling improved detection and evaluation of stenoses involving the circle of Willis and improved characterization of intracranial aneurysms. These new applications benefit from the use of US contrast agents and harmonic US imaging.

[Imagery of human immunodeficiency virus (HIV) encephalitis]

The authors present the different aspects of HIV encephalitis in CT and MR in a series of 15 patients with anatomopathological proof. Atrophy was the most commonly found lesion (12 patients) and could rapidly be evolutive. White matter lesions (9 patients) were more of ten nodular than diffuse. They were better demonstrated by MRI and did not enhance after intra-venous injection of DOTA-gadolinium. A frequent association with opportunistic infections (toxoplasmosis: 10 patients, CMV:2 patients), lymphoma (4 patients), or PML (3 patients) was observed which emphasized the low specificity of brain imaging in patients with HIV encephalitis.

MR imaging of posteromedial and posterolateral stabilisers of the knee: anatomic basis and patterns of lesions in knee injuries

The angular points are the ligamentous and tendinous structures that reinforce the posteromedial and posterolateral capsule of the knee and share in fixation of the posterior horns of the menisci. They are often damaged in acute injuries and this is usually associated with ruptures of the cruciate and collateral ligaments and may add to the degree of laxity. We describe the normal appearance of these structures in terms of the sectional anatomy, correlated with the lesional appearances of complete and incomplete ruptures and associated meniscal detachments as shown by clinical testing and arthrotomy findings.

Periventricular leukomalacia: correlation between MR imaging and autopsy findings during the first 2 months of life

PURPOSE

To correlate magnetic resonance (MR) imaging and pathologic findings in premature infants with periventricular leukomalacia (PVL).

MATERIALS AND METHODS

Eight premature infants with PVL who died after 3-7 weeks of life were studied with in vivo T1-weighted MR imaging, and imaging patterns were compared with hypoxic-ischemic injuries at pathologic analysis.

RESULTS

Cavities were seen as zones of absent or weak signal intensity. Translucent sparsely cellular zones appeared as areas of intermediate intensity, and cellular reactions were seen as limited linear or punctate zones of increased intensity, usually less intense than the cortex. MR imaging provided reliable depiction of these lesions, with adequate estimation of their volume and topography. However, the extent of periventricular cellular lesions was underestimated. In one case, blood seen as hyperintense or isointense zones masked portions of cystic lesions, and in three cases small thalamic lesions were overlooked.

CONCLUSION

With the above limitations, T1-weighted MR imaging offers precise evaluation of PVL.