Petrous apex cephalocoele: contribution of coexisting intracranial pathologies to the aetiopathogenesis.

OBJECTIVE: The aim of this study was to show the MRI findings of petrous apex cephalocoele (PAC) and the other intracranial pathologies that coexist with PAC, and to discuss the contribution of the co-existing pathologies to aetiopathogenesis. METHODS: A retrospective analysis of our imaging archive for the period from January 2012 to October 2013 revealed 13 patients with PAC (12 females and 1 male; age range, 26-69 years). 11 patients underwent MRI examination of the cranium, and 2 patients underwent MRI examination of the sellar region. We evaluated the lesions for content, signal intensity, enhancement, relation to petrous apex and Meckel's cave. Images were also evaluated for coexisting pathologies. RESULTS: The presenting symptoms included headache, vertigo, cerebrospinal fluid (CSF) leak and trigeminal neuropathy. All patients had PAC. All lesions were located posterolateral to the Meckel's cave and were isointense with CSF signal on all pulse sequences. All lesions were continuous with Meckel's cave. Coexisting pathologies included intracranial aneurysmal dilatation, empty sella, mass in hypophysis, arachnoid cyst, inferior herniation of parahippocampal gyrus and optic nerve sheath CSF distension. CONCLUSION: Coexistence with other intracranial pathologies supports the possibility of CSF imbalance and/or intracranial hypertension in the aetiopathogenesis of PAC. ADVANCES IN KNOWLEDGE: This study examined the contribution of the co-existing intracranial pathologies to the aetiopathogenesis of PAC.

Persistent primitive hypoglossal artery and fenestration of posterior cerebral artery: CT and MR angiography.

Persistent primitive hypoglossal artery (PPHA) which is a persistent carotid-basilar anastomosis is a rare vascular anomaly. It is usually found incidentally. Fenestrations of cerebral arteries are uncommon. Herein we present a case of PPHA with fenestration of posterior cerebral artery. A 28 year old man was admitted to our hospital with complaints of dizziness and temporary loss of vision. Neurological examination revealed no abnormal findings. The patient was further evaluated with CT and MR angiography. To our knowledge, the case we reported is the first case in the literature with PPHA and fenestration of posterior cerebral artery. The detection of PPHA and associated vascular anomalies and diseases are important before surgical and interventional procedures. CT and MR angiography are much safer diagnostic alternatives in the detection of PPHA and fenestrations. When PPHA is detected, attention should be given to the coexistent posterior circulation anomalies.

Role of magnetic resonance imaging in evaluating sphenoid sinus and internal carotid artery.

OBJECTIVE: This study aimed to determine whether magnetic resonance imaging has a role in the evaluation of the sphenoid sinus and internal carotid artery. In addition, we aimed to establish reference measurements for the minimal distance between the internal carotid arteries. METHOD: The sphenoid sinuses and neighbouring internal carotid arteries of 90 patients were evaluated using sagittal T1-weighted and axial and coronal T2-weighted magnetic resonance images. RESULTS: Sphenoid sinus pneumatisation was categorised as occipitosphenoidal (0 per cent), conchal (3.3 per cent), presellar (14.4 per cent) or sellar (82.2 per cent). The internal carotid artery protruded into the sphenoid sinus in 32.8 per cent, with a septum in 9.4 per cent. The incidence of sellar-type sphenoid sinus pneumatisation was higher in patients with protrusion of the internal carotid artery into the sphenoid sinus (p < 0.001). The incidence of presellar pneumatisation was higher in patients without internal carotid artery protrusion (p < 0.001). The minimal distance between the internal carotid arteries varied between 9.04 and 24.26 mm (mean, 15.94 mm). CONCLUSION: Magnetic resonance imaging can provide useful information about the sphenoid sinus and internal carotid artery, prior to endoscopic sphenoidotomy and trans-sphenoidal hypophysectomy.

Lumbar epidural abscess caused by brucella species: report of two cases.

Spinal epidural abscess due to Brucella species is usually associated with spondylodiscitis. Urgent surgical decompression should be performed in cases with moderate to severe neurological deficits particularly if progressive. We report clinical features of two cases operated for lumbar epidural abscess caused by Brucella species. Early surgical decompression combined with medical treatment could decrease progression of neurological findings or the severity of complications. Iatrogenic dural tear at the operation should be repaired immediately with fine sutures and fibrin tissue glue to prevent further innoculation into the cerebrospinal axis. These cases should be cautiously followed for any recurrence or neurobrucellosis.

A misdiagnosis: duplication of the external auditory canal.

We present imaging and clinical findings of a case with a duplicated external auditory canal, which led to misdiagnosis secondary to lipomatous content on imaging studies prior to surgery. It is a very rare congenital anomaly. This entity is usually misdiagnosed not only clinically but also radiologically. This leads to a delay and failure in diagnosis and treatment. To the best of our knowledge, herein is the first case report of the duplication of the external auditory canal presenting with dominant lipomatous imaging features. In this report, we aim to draw attention to the atypical presentation.

Intradural cement leakage: a rare complication of percutaneous vertebroplasty.

Percutaneous vertebroplasty (PV) is one of the alternative treatments for vertebral fractures. Reported significant complications include pain, radiculopathy, spinal cord compression, pulmonary embolism, infection and rib fractures. In this report, we highlight intradural cement leakage which is a rare complication of the procedure. A 49 year old man with a T12 compression fracture due to multiple myeloma was referred to the neurosurgery department from the orthopaedics and traumatology clinic after developing a right lower limb weakness following percutaneous vertebroplasty with polymethylmethacrylate. An urgent thoraco-lumbar magnetic resonance imaging was performed. The T1 and T2-weighted images demonstrated intradural extramedullary and epidural cement leakages which were hypointense on both sequences. Total laminectomy was performed at T12 and L1 and two epidural cement collections were excised on the right. Then, a dural incision from T12 to the body of L1 was done and cement material seen in front of the rootlets excised without any nerve injury. The patient was discharged after a week and referred to the haematology clinic for additional therapy of multiple myeloma. Although the cement leakage was extensive, the right leg weakness improved significantly and he began to walk with assistance 3 months later. Good quality image monitoring and clear visualisation of cement are essential requirements for PV using polymethylmethacrylate to prevent this complication from the treatment.

Nasal septal deviation and concha bullosa coexistence: CT evaluation.

PROBLEMS/OBJECTIVES: The discussion of the incidence of sinusitis in patients with nasal septal deviation and concha bullosa has been accompanied by some controversy. In this study, we assess the incidence, in conjunction with concha bullosa and nasal septal deviation, of sinus, ostiomeatal and frontal recess disease on either side in the same patients. METHODOLOGY: We reviewed the CT studies conducted between 2003 and 2005 of the paranasal sinuses of 130 patients. All examinations were performed for the evaluation of a symptom referable to the sinonasal region. Fifty-eight patients had both nasal septal deviation and concha bullosa. We recorded the presence and degree of septal deviation, the direction of septal deviation, and sinus, ostiomeatal and frontal recess disease. RESULTS: Twenty-six patients had deviation to the right. Of these patients, nine had sinusitis on the left and ten had sinusitis on the right. Thirty-two patients had deviation to the left. Of these patients, 14 patients had sinusitis on the left and 17 had sinusitis on the right. No statistical difference was found (p > 0.05). Likewise, no correlation was found with frontal recess or ostiomeatal disease. CONCLUSIONS: The incidence of the coexistence of nasal septal deviation and concha bullosa is high (44.6%). There does not appear to be a statistically significant difference between the laterality of sinus, ostiomeatal and frontal recess disease (p > 0.05). The incidence of sinusitis in severe nasal septal deviation is higher when compared with mild (p = 0.001) and moderate groups (p < 0.001).

Quantitative and diffusion MR imaging as a new method to assess osteoporosis.

BACKGROUND AND PURPOSE: The role of advanced MR imaging techniques in demonstrating the microarchitectural changes in osteoporosis has been recently investigated. Our aim was to determine the role of quantitative and diffusion MR imaging in the diagnosis of osteoporosis compared with dual-energy x-ray absorptiometry (DEXA). MATERIALS AND METHODS: Fifty-one subjects underwent both DEXA and conventional MR imaging with diffusion and apparent diffusion coefficient (ADC) mapping. T1, T2, diffusion signal intensity, and ADC values were calculated and compared with bone mineral attenuation (BMD). Results were obtained from L1 to L4 of each patient with a total of 204 lumbar vertebrae. RESULTS: Both T1 and T2 signal intensities tended to increase when both diffusion and ADC values decreased with reducing BMD. CONCLUSIONS: An inverse relationship between BMD and T1 and T2 signal intensities and a direct relationship between diffusion and ADC values were present in this pilot group. The T1/diffusion signal-intensity ratio could be a reliable diagnostic indicator of osteoporosis.

Diffusion-weighted magnetic resonance imaging in rhombencephalitis due to Listeria monocytogenes.

We present diffusion-weighted imaging findings of a case of rhombencephalitis due to Listeria monocytogenes. It is a rare, life-threatening disorder. The diagnosis is difficult by clinical findings only. In this report, we aim to draw attention to the role of conventional and diffusion-weighted magnetic resonance imaging findings. To our knowledge, this is the first case report in the literature with apparent diffusion coefficient values of diseased brain parenchyma.

Bone marrow fat and bone mineral density on proton MR spectroscopy and dual-energy X-ray absorptiometry: their ratio as a new indicator of bone weakening.

OBJECTIVE: Bone weakening can be affected by agents other than bone mineral density (BMD). Increased bone marrow fat may have a direct link to bone loss. This pilot study analyzes the relationship between bone marrow fat and BMD in subjects with normal and structurally weakened vertebrae. SUBJECTS AND METHODS: Twenty-six subjects underwent both dual-energy X-ray absorptiometry and proton MR spectroscopy of 71 lumbar vertebrae. Fifteen subjects had normal-appearing vertebrae on MRI, and 11 had signs of bone weakening. RESULTS: We found that high bone marrow fat did not consistently equate with low BMD. Bone marrow fat can indicate bone weakening nearly as well as BMD, but neither parameter alone is suitable to be used independently as an indicator. The bone marrow fat/BMD ratio showed significant diagnostic power to detect bone weakening, even in this relatively small subject sample. CONCLUSION: An inverse relationship between bone marrow fat and BMD could not be confirmed. Bone marrow fat can be used to diagnose reduced bone strength nearly as well as BMD. The bone marrow fat/BMD ratio is a significant diagnostic indicator of bone weakening.

Potential value of vertebral proton MR spectroscopy in determining bone weakness.

BACKGROUND AND PURPOSE: Increased fat content in vertebrae may indicate bone weakness. Vertebral proton MR spectroscopy ((1)H MRS) quantitatively measures vertebral fat relative to water. Thus, (1)H MRS measurements of percent fat fraction (%FF) and spectral line width (LW) of vertebral bone marrow may differ between subjects with and those without MR imaging evidence of weakened bone. METHODS: We measured %FF and LW in 22 subjects with (15 men and 7 women, aged 26 to 80 years) and 72 control subjects without (33 male and 39 female subjects, aged 15 to 87 years) MR findings of weakened bone, including prominent Schmorl's nodes, endplate depression, vertebral wedging, and vertebral compression fractures. In those with bone weakness, (1)H MRS data were sampled from an intact vertebra, usually L2. Data were analyzed for differences by age and sex. We compared the mean %FF and LW in subjects with and in those without bone weakness by use of Student's t test. RESULTS: The %FF increased linearly with age in the control subjects, ranging from 20.5% in the second and third decades of life to 49.4% in eighth or ninth decades of life. Across all age groups, male control subjects had a higher aggregate %FF than did female control subjects. Male control subjects tended to have a greater LW than did female control subjects, but differences between the sexes within or across age groups were not significant. Contrary to expectations, LW was greatest in the oldest control subjects and lowest among younger control subjects, but there were insufficient data points to make definitive conclusions. Overall, %FF was a relative 45% higher in subjects with weakened bone compared with control subjects (48.8 vs 33.6 [P <.001]). The subjects with evidence of vertebral bone weakness also had a higher overall mean LW (37 vs 29 Hz [P <.002]), but this finding is of uncertain importance. CONCLUSION: The %FF was significantly higher within the L2 vertebral body in 22 subjects with weakened bone compared with the control group, suggesting that it could serve as a measure of bone quality. The LW measurements did not yield meaningful conclusions.