Tumor-mimicking primary angiitis of the central nervous system: initial and follow-up MR features

Introduction

Primary angiitis of the central nervous system (PACNS) is an extremely rare vasculitis of unknown etiology. The purpose of this study was to describe the initial and follow-up magnetic resonance (MR) imaging features of the tumor-mimicking PACNS.

Methods

We retrospectively reviewed a total of 21 initial and follow-up brain MR images obtained in four patients with biopsy-proven PACNS mimicking brain tumor on MR images during the periods from 1 to 8.1 years. In the initial study, diffusion-weighted imaging (DWI; n?=?4), MR angiogram (n?=?4), conventional catheter angiogram (n?=?3), perfusion MR (n?=?1), and computed tomography (n?=?1) and proton MR spectroscopy (MRS; n?=?2) were included. The lesions of the brain were qualitatively assessed in terms of location, number, size, shape, signal intensity, absence or presence of hemorrhage, enhancement pattern, and changes on the follow-up studies.

Results

Initially, the lesion manifested as single suprasellar (n?=?1) and frontal hemispheric (n?=?1) mass and as multiple-enhancing lesions in the unilateral supratentorial hemisphere (n?=?2). A patient showed steno-occlusive lesions in the internal carotid and middle cerebral arteries. DWI, perfusion imaging, and MRS revealed inconsistent findings among the patients. On the follow-up studies, a patient had two relapses but there was either significant decrease in size and extent or disappearance of the lesions with immunosuppressive therapy in all patients.

Conclusion

Tumor-mimicking PACNS shows variable features on initial MR images but shows good responses to appropriate immunosuppressive therapy on follow-up MR images.     

Fetal liver iron overload: the role of MR imaging

Objective

To assess the potential role of MR imaging in the diagnosis of fetal liver iron overload.

Methods

We reviewed seven cases of abnormal liver signal in fetuses referred to MR imaging in a context of suspected congenital infection (n?=?2), digestive tract anomalies (n?=?3) and hydrops fetalis (n?=?2). The average GA of the fetuses was 31?weeks. The antenatal diagnoses were compared with histological data (n?=?6) and postnatal work-up (n?=?1).

Results

Magnetic resonance imaging demonstrated unexpected abnormal fetal liver signal suggestive of iron overload in all cases. The iron overload was confirmed on postnatal biopsy (n?=?2) and fetopathology (n?=?4). The final diagnosis was hepatic hemosiderosis (haemolytic anaemia (n?=?2) and syndromal anomalies (n?=?2)) and congenital haemochromatosis (n?=?3). In all cases, the liver appeared normal on US.

Conclusions

Magnetic resonance is the only imaging technique able to demonstrate liver iron overload in utero. Yet, the study outlines the fundamental role of MR imaging in cases of congenital haemochromatosis. The antenatal diagnosis of such a condition may prompt ante??(in the case of recurrence) or neonatal treatment, which might improve the prognosis.     

Reflux venous flow in dural sinus and internal jugular vein on 3D time-of-flight MR angiography

Introduction

Reflux venous signal on the brain and neck time-of-flight magnetic resonance angiography (TOF MRA) is thought to be related to a compressed left brachiocephalic vein. This study is aimed to assess the prevalence of venous reflux flow in internal jugular vein (IJV), sigmoid sinus/transverse sinus (SS/TS), and inferior petrosal sinus (IPS) on the brain and neck TOF MRA and its pattern.

Methods

From the radiology database, 3,475 patients (1,526 men, 1,949 women, age range 19–94, median age 62 years) with brain and neck standard 3D TOF MRA at 3 T and 1.5 T were identified. Rotational maximal intensity projection images of 3D TOF MRA were assessed for the presence of reflux flow in IJV, IPS, and SS/TS.

Results

Fifty-five patients (1.6 %) had reflux flow, all in the left side. It was more prevalent in females (n?=?43/1,949, 2.2 %) than in males (n?=?12/1,526, 0.8 %) (p?=?0.001). The mean age of patients with reflux flow (66 years old) was older than those (60 years old) without reflux flow (p?=?0.001). Three patients had arteriovenous shunt in the left arm for hemodialysis. Of the remaining 52 patients, reflux was seen on IJV in 35 patients (67.3 %). There were more patients with reflux flow seen on SS/TS (n?=?34) than on IPS (n?=?25).

Conclusion

Venous reflux flow on TOF MRA is infrequently observed, and reflux pattern is variable. Because it is exclusively located in the left side, the reflux signal on TOF MRA could be an alarm for an undesirable candidate for a contrast injection on the left side for contrast-enhanced imaging study.     

Salivary duct carcinomas: clinical and CT and MR imaging features in 20 patients

Introduction

Salivary duct carcinoma (SDC) is an uncommon high grade adenocarcinoma of the salivary gland with a grave prognosis. The aim of this study was to investigate the clinical and CT and MR imaging features of SDC.

Methods

We retrospectively evaluated the clinical and CT and MR imaging findings in 20 patients (14 men and six women; mean age, 59?years) with histologically proved SDC. We also tried to correlate clinicoradiological tumor staging with pathologic tumor staging in 17 patients who underwent surgery.

Results

The tumor originated in the parotid gland (n?=?11; 55%), the submandibular gland (n?=?7; 35%) and the buccal space along the distal Stensen's duct (n?=?2; 10%). Locoregional recurrence occurred in 41% and distant metastasis in 47%. Fifty-eight percent died of the disease with a mean survival period of 32?months after diagnosis. On CT and MR images, SDC was mostly seen as an ill-defined (85%) and infiltrative (60%) mass with frequent calcification (50%) and necrosis (80%). Although various signal intensities were seen on MR images, six of nine tumors contained the areas of marked hypointensity on T2-weighted images. Clinicoradiological tumor staging correlated well with pathologic tumor staging in 82% of the patients.

Conclusion

Ill-defined, infiltrative mass with calcification on CT scans and the areas of marked hypointensity on T2-weighted MR images may be useful radiologic features to suggest the diagnosis of SDC. CT and MR imaging are useful for staging of SDC.     

Cervicofacial tissue infarction in patients with acute invasive fungal sinusitis: prevalence and characteristic MR imaging findings

Introduction

Tissue infarction is known as one of the characteristic features of invasive fungal sinusitis (IFS). The purpose of this study was to investigate the prevalence and characteristic MR imaging findings of cervicofacial tissue infarction (CFTI) associated with acute IFS.

Methods

We retrospectively reviewed MR images in 23 patients with histologically or microbiologically proven acute IFS. CFTI was defined as an area of lack of enhancement in and around the sinonasal tract on contrast-enhanced T1-weighted images. We divided CFTI into two groups, i.e., intrasinonasal and extrasinonasal. Particular attention was paid to the location of extrasinonasal CFTI and the signal intensity of CFTI on T1- and T2-weighted images. The presence of bone destruction on CT scans was also recorded.

Results

CFTI was found in 17 (74 %) of 23 patients. All of these 17 patients had intrasinonasal CFTI, and 13 patients also had extrasinonasal CFTI. All 13 patients with extrasinonasal CFTI died of disease directly related to IFS. Various locations were involved in the 13 patients with extrasinonasal CFTI, including the orbit (n?=?8), infratemporal fossa (n?=?7), intracranial cavity (n?=?3), and oral cavity and/or facial soft tissue (n?=?4). Various signal intensities were noted at the area of CFTI on T1- and T2-weighted images. Bone destruction was found on CT scans in only 3 of 17 patients with CFTI.

Conclusion

CFTI with preservation of the bony wall of the involved sinonasal tract may be a characteristic MR imaging finding of acute IFS. The mortality is very high once the lesion extends beyond the sinonasal tract.     

Spindle cell lipoma of the head and neck: CT and MR imaging findings

Introduction

Spindle cell lipoma (SCL) is an uncommon benign lipomatous tumor, most commonly occurring in the posterior neck and shoulder. The purpose of this study was to investigate the CT and MR imaging features of SCL in the head and neck.

Methods

CT (n?=?5) and MR (n?=?3) images of seven patients (five men and two women; mean age, 54 years) with surgically proven SCL in the head and neck were retrospectively reviewed. The location and morphologic characteristics of SCL were documented as well.

Results

Six lesions were well-defined and located in the subcutaneous fat of the posterior neck (n?=?4), anterior neck (n?=?1), and buccal space (n?=?1). One lesion was ill-defined and located deeply in the supraclavicular fossa, infiltrating the adjacent shoulder muscles. Intratumoral fat was identified in five lesions in various amounts. Compared with the adjacent subcutaneous fat, intratumoral fat was slightly hyperattenuated on CT scans and slightly hypointense on T1-weighted MR images. In five of six lesions in which postcontrast CT and/or MR images were obtained, significant enhancement was seen in the nonadipose component of the lesion.

Conclusion

Various components of the adipose and nonadipose tissues may cause difficulty differentiating between SCL and other adipocytic tumors including liposarcoma radiologically. Although nonspecific, the radiologist should know the various imaging features of SCL, because the tumor can be cured by simple excision.     

Inter- and intraobserver variability of MR arthrography in the detection and classification of superior labral anterior posterior (SLAP) lesions: evaluation in 78 cases with arthroscopic correlation

Purpose

The purpose of this study was to determine inter- and intraobserver variability of MR arthrography of the shoulder in the detection and classification of superior labral anterior posterior (SLAP) lesions.

Methods

MR arthrograms of 78 patients who underwent MR arthrography before arthroscopy were retrospectively analysed by three blinded readers for the presence and type of SLAP lesions. MR arthrograms were reviewed twice by each reader with a time interval of 4 months between the two readings. Inter- and intraobserver agreement for detection and classification of SLAP lesions were calculated using κ coefficients.

Results

Arthroscopy confirmed 48 SLAP lesions: type I (n?=?4), type II (n?=?37), type III (n?=?3), type IV (n?=?4). Sensitivity and specificity for detecting SLAP lesions with MR arthrography for each reader were 88.6%/93.3%, 90.9%/80.0% and 86.4%/76.7%. MR arthrographic and arthroscopic grading were concurrent for 72.7%, 68.2% and 70.5% of SLAP lesions for readers 1–3, respectively. Interobserver agreement was excellent (κ?=?0.82) for detection and substantial (κ?=?0.63) for classification of SLAP lesions. For each reader intraobserver agreement was excellent for detection (κ?=?0.93, κ?=?0.97, κ?=?0.97) and classification (κ?=?0.94, κ?=?0.84, κ?=?0.93) of SLAP lesions.

Conclusion

MR arthrography allows reliable and accurate detection of SLAP lesions. In addition, SLAP lesions can be diagnosed and classified with substantial to excellent inter- and intraobserver agreement.     

Triple-negative invasive breast cancer on dynamic contrast-enhanced and diffusion-weighted MR imaging: comparison with other breast cancer subtypes

Objectives

To determine the MRI features of triple-negative invasive breast cancer (TNBC) on dynamic contrast-enhanced MR imaging (DCE-MRI) and diffusion-weighted MR imaging (DWI) in comparison with ER-positive/HER2-negative (ER+) and HER2-positive cancer (HER2+).

Methods

A total of 271 invasive cancers in 269 patients undergoing preoperative MRI and surgery were included. Two radiologists retrospectively assessed morphological and kinetic characteristics on DCE-MRI and tumour detectability on DWI. Apparent diffusion coefficient (ADC) values of lesions were measured. Clinical and MRI features of the three subtypes were compared.

Results

Compared with ER+ (n?=?119) and HER2+ (n?=?94), larger size, round/oval mass shape, smooth mass margin, and rim enhancement on DCE-MRI were significantly associated with TNBC (n?=?58; P??3?mm²/s) of TNBC (1.03) was higher than the mean ADC values for ER+ and HER2+ (0.89 and 0.84; P?P?=?0.099). Tumour size (P?=?0.009), mass margin (smooth, P?P?=?0.020), and ADC values (P?=?0.002) on DCE-MRI and DWI were independent features of TNBC.

Conclusions

In addition to the morphological features, higher ADC values on DWI were independently associated with TNBC and could be useful in differentiating TNBC from ER+ and HER2+.

Key Points

? Triple-negative breast cancers (TNBC) lack oestrogen/progesterone receptors and HER2 expression/amplification. ? TNBCs are larger, better defined and more necrotic than conventional cancers. ? On MRI, necrosis yields high T2-weighted signal intensity and ADCs. ? High ADC values can be useful in diagnosing TNBC.     

MR findings of steatotic focal nodular hyperplasia and comparison with other fatty tumours

Objectives

To correlate MR findings with pathology in steatotic FNHs and to compare the MR findings with those of other fatty tumours developed on noncirrhotic liver in a consecutive series of resected lesions.

Methods

Our population included resected FNH with intralesional steatosis (n?=?25) and other resected fatty tumours selected as controls (hepatocellular adenomas and angiomyolipomas, n?=?34). Lesions were classified into three groups: those with typical FNH without (group 1) or with (group 2) fat on MR and those with atypical lesions (group 3). In group 3, diagnostic criteria for other fatty tumours were applied.

Results

There were 9 lesions in group 1 (15.3 %), 4 in group 2 (16.8 %) and 46 in group 3 (77.9 %). Group 3 contained 12 FNHs (26 %) and all the other fatty tumours. In group 3, the association of lesion homogeneity, signal intensity similar to or slightly different from adjacent liver on in-phase T1- and T2-weighted sequences, and strong arterial enhancement was observed in 7/12 (58 %) of steatotic FNHs and 3/34 (9 %) of other tumours.

Conclusion

On MR, fat within a typical FNH should not reduce the diagnostic confidence. We recommend further investigations including liver biopsy if necessary when fatty tumours exhibit atypical MR findings.

Key Points

? MRI is increasingly used to assess hepatic lesions containing fat. ? Nodules of focal nodular hyperplasia often contain foci of fat. ? However, steatotic FNH does not always demonstrate typical fatty features on MRI. ? The main mimickers of steatotic FNHs are telangiectatic/inflammatory hepatocellular adenomas. ? We recommend liver biopsy when fatty tumours exhibit atypical MR findings.     

Detection and treatment of spinal CSF leaks in idiopathic intracranial hypotension

Introduction

This study aimed to evaluate the diagnostic imaging findings and treatment results of patients with idiopathic intracranial hypotension (IIH) due to cerebrospinal fluid (CSF) leaks.

Methods

Between February 2009 and April 2012, 26 IIH patients (15 men, median age 49?years) presenting with orthostatic headache (n?=?20) and/or with spontaneous subdural effusions or subarachnoid hemorrhage (n?=?19) were enrolled. Twenty-three patients underwent a whole spine CT and MRI myelography, starting 45?min after the intrathecal injection of 9?cc of iomeprol (Imeron 300 M) and 1?cc of gadobutrolum (Gadovist). Three patients only underwent MR myelography after intrathecal gadobutrolum injection. Adjacent to the level(s) of the detected CSF leak(s) along the nerve roots, 20?cc of fresh venous blood with 0.5?cc Gadovist was injected epidurally (blood patch, BP). The distribution of the BP was visualized by MRI the following day. Treatment results were evaluated clinically and by myelography 2?weeks after the application of the BP. Retreatment was offered to patients with persistent symptoms and continued CSF leakage.

Results

CSF leaks were detected at the cervical (n?=?12), thoracic (n?=?25), or lumbar (n?=?21) spine. In 23 patients, more than one spinal segment was affected. One patient refused treatment. BP were applied in one (n?=?9) or several (n?=?16) levels. Clinical and/or radiological improvement was achieved after one (n?=?16), two (n?=?5), three (n?=?3), or five (n?=?1) BPs.

Conclusion

CT and MRI myelography allow the reliable detection of spinal CSF leaks. The targeted and eventually repeated epidural BP procedure is a safe and efficacious treatment.     

Non-invasive tracking of human haemopoietic CD34+ stem cells in vivo in immunodeficient mice by using magnetic resonance imaging

Objective

To assess migration of CD34⁺ human stem cells to the bone marrow of athymic mice by using magnetic resonance (MR) imaging and Resovist, a contrast agent containing superparamagnetic iron oxide (SPIO) particles.

Methods

All animal and human procedures were approved by our institution’s ethics committee, and women had given consent to donate umbilical cord blood (UCB). Balb/c-AnN Foxn1^nu/Crl mice received intravenous injection of 1?×?10⁶ (n?=?3), 5?×?10⁶ (n?=?3) or 1?×?10⁷ (n?=?3) human Resovist-labelled CD34⁺ cells; control mice received Resovist (n?=?3). MR imaging was performed before, 2 and 24 h after transplantation. Signal intensities of liver, muscle and bone marrow were measured and analysed by ANOVA and post hoc Student’s t tests. MR imaging data were verified by histological and immunological detection of both human cell surface markers and carboxydextran-coating of the contrast agent.

Results

CD34⁺ cells were efficiently labelled by Resovist without impairment of functionality. Twenty-four hours after administration of labelled cells, MR imaging revealed a significant signal decline in the bone marrow, and histological and immunological analyses confirmed the presence of transplanted human CD34⁺ cells.

Conclusion

Intravenously administered Resovist-labelled CD34⁺ cells home to bone marrow of mice. Homing can be tracked in vivo by using clinical 1.5-T MR imaging technology.     

Magnetic resonance imaging to assess the effect of exercise training on pulmonary perfusion and blood flow in patients with pulmonary hypertension

Objectives

To evaluate whether careful exercise training improves pulmonary perfusion and blood flow in patients with pulmonary hypertension (PH), as assessed by magnetic resonance imaging (MR).

Methods

Twenty patients with pulmonary arterial hypertension or inoperable chronic thromboembolic PH on stable medication were randomly assigned to control (n?=?10) or training groups (n?=?10). Training group patients received in-hospital exercise training; patients of the sedentary control group received conventional rehabilitation. Medication remained unchanged during the study period. Changes of 6-min walking distance (6MWD), MR pulmonary flow (peak velocity) and MR perfusion (pulmonary blood volume) were assessed from baseline to week 3.

Results

After 3 weeks of training, increases in mean 6MWD (P?=?0.004) and mean MR flow peak velocity (P?=?0.012) were significantly greater in the training group. Training group patients had significantly improved 6MWD (P?=?0.008), MR flow (peak velocity ?9.7?±?8.6 cm/s, P?=?0.007) and MR perfusion (pulmonary blood volume +2.2?±?2.7 mL/100 mL, P?=?0.017), whereas the control group showed no significant changes.

Conclusion

The study indicates that respiratory and physical exercise may improve pulmonary perfusion in patients with PH. Measurement of MR parameters of pulmonary perfusion might be an interesting new method to assess therapy effects in PH. The results of this initial study should be confirmed in a larger study group.

Key Points

? Quantification of magnetic resonance perfusion is feasible in patients with pulmonary hypertension. ? Quantified magnetic resonance perfusion may become useful for non-invasive monitoring of treatment. ? Quantification of lung perfusion allows new insights into lung (patho-)physiology of PH. ? Careful exercise training improves pulmonary perfusion and blood flow in patients with PH.     

Subfascial involvement in glomuvenous malformation

Objective

Glomuvenous malformation (GVM) is an inherited autosomal dominant trait. The lesions, which appear as bluish nodules or plaque-like cutaneous elevations, are usually tender and more firm than sporadic venous malformations. Conventionally, the lesions are thought to be limited to the cutaneous and subcutaneous tissue planes. The objective was to characterize the depth of involvement of GVM lesions.

Materials and Methods

Magnetic resonance imaging (MRI) findings in GVM were retrospectively evaluated by two radiologists. The signal characteristics, tissue distribution, pattern of contrast enhancement of the lesions in GVM were documented.

Results

Thirty patients (19 female) aged 1–35 years (mean 18 years) were diagnosed with GVM based on clinical features (n?=?20) and/or histopathological findings (n?=?10). The lesions were present in the lower extremity (n?=?15), upper extremity (n?=?6), cervico-facial region (n?=?6), pelvis (n?=?2), and chest wall (n?=?1). All patients had skin and subcutaneous lesions. Fifty percent of the patients (n?=?15) demonstrated subfascial intramuscular (n?=?15), intra-osseous (n?=?1), and intra-articular involvement (n?=?1).

Conclusion

Contrary to the conventional belief that GVMs are generally limited to the skin and subcutaneous tissue, deep subfascial extension of the lesions is common.     

Contrast enhancement kinetics of normal breast parenchyma in dynamic MR mammography: effects of menopausal status, oral contraceptives, and postmenopausal hormone therapy

Objectives

To investigate effects of menopausal status, oral contraceptives (OC), and postmenopausal hormone therapy (HT) on normal breast parenchymal contrast enhancement (CE) and non-mass-like enhancing areas in magnetic resonance mammography (MRM).

Methods

A total of 459 female volunteers (mean age 49.1?±?12.5?years) underwent T1-weighted 3D MRM 1–5?min after bolus injection of gadobutrol. Quantitative analysis was performed in normal breast parenchyma by manually tracing regions of interest and calculating percentage CE. Semiquantitative analysis was performed in non-mass-like enhancing areas, and signal intensity changes were characterised by five predefined kinetic curve types. The influence of OC (n?=?69) and HT (n?=?24) on CE was studied using random effects models.

Results

Breast parenchymal enhancement was significantly higher in premenopausal than in postmenopausal women (P?<?0.001). CE decreased significantly with the use of OC (P?=?0.01), while HT had negligible effects (P?=?0.52). Prevalence of kinetic curve types of non-mass-like enhancement differed strongly between pre- and postmenopausal women (P?<?0.0001), but was similar in OC users and non-OC users (P?=?0.61) as well as HT users and non-HT users (P?=?0.77).

Conclusions

Normal breast parenchymal enhancement and non-mass-like enhancing areas were strongly affected by menopausal status, while they were not affected by HT use and only moderately by OC use.

Key Points

? Breast parenchymal enhancement at MR mammography is stronger in premenopausal than postmenopausal women. ? The prevalence of strong enhancing non-mass-like areas is greater before menopause. ? Such enhancing non-mass-like areas may impair lesion detection in premenopausal women. ? Breast parenchymal enhancement is only marginally affected by hormone use. ? Discontinuation of hormone use before MR mammography may be unnecessary.     

Do more MRI findings imply worse disability or more intense low back pain? A cross-sectional study of candidates for lumbar disc prosthesis

Objective

To examine whether combined magnetic resonance imaging (MRI) findings are related to the degree of disability and low back pain (LBP) in candidates for lumbar disc prosthesis surgery.

Materials and methods

This cross-sectional study included 170 disc prosthesis candidates (mean age 41 years; 88 women) with chronic non-radicular LBP and localized disc degeneration. Experienced radiologists rated Modic changes and disc findings at L4-S1 on pre-treatment MRIs. An MRI total score (0–10) for findings at L4/L5 plus L5/S1 was calculated for Modic type I and/or II changes, a posterior high intensity zone (HIZ) in the disc, dark/black nucleus pulposus signal, and ≥40 % disc height decrease. We analyzed the relationship of the MRI total score to the Oswestry Disability Index (ODI) (n?=?170) and LBP intensity scores (0–100 visual analogue scale, n?=?165) using multiple linear regression and adjusting for age, gender, body mass index, smoking, and anxiety/depression.

Results

The MRI total score was not related to ODI (regression coefficient 0.12, p?=?0.79) or LBP intensity (regression coefficient 0.64, p?=?0.37). When individual MRI findings were analyzed, patients with HIZ at L5/S1 had slightly lower ODI scores (4.7 points, p?=?0.02). In post hoc analyses, results remained unchanged after adding facet arthropathy to the MRI total score and adjusting also for physical workload and physical leisure-time activity.

Conclusions

The combined MRI findings were not related to the degree of disability or the intensity of LBP. These degenerative MRI findings cannot explain variation in pre-treatment disability and pain in patients with chronic LBP accepted for disc prosthesis surgery.     

MR perfusion-weighted imaging may help in differentiating between nonenhancing gliomas and nonneoplastic lesions in the cervicomedullary junction

Purpose:

To evaluate the ability of dynamic susceptibility‐weighted contrast‐enhanced magnetic resonance (MR) perfusion imaging (DSC‐PWI) in distinguishing between nonenhancing gliomas and nonenhancing, nonneoplastic lesions in the cervicomedullary junction region.

Materials and Methods:

This retrospective study involved eight patients with nonenhancing gliomas in the medulla oblongata and eight patients with nonenhancing nonneoplastic lesions. The relative cerebral blood volume (rCBV) ratios, peak heights, and percentage of signal intensity recovery derived from time‐signal intensity curves of these nonenhancing lesions were compared.

Results:

The mean peak height of nonenhancing gliomas was significantly higher than the value of their reference regions of interest (ROIs). In contrast, mean peak height of nonneoplastic lesions was significantly lower than their reference ROIs. The mean peak height and mean maximal rCBV ratio of nonenhancing gliomas were significantly higher than those of nonenhancing, nonneoplastic lesions (P<0.05). There was no significant difference with regard to percentage of signal intensity recovery between the two groups.

Conclusion:

DSC‐PWI could be a useful adjuvant tool to differentiate between nonenhancing gliomas and nonenhancing, nonneoplastic lesions in the cervicomedullary junction region. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.     

Sporadic meningioangiomatosis: imaging findings with histopathologic correlations in seven patients

Introduction

Meningioangiomatosis (MA) is a rare benign cerebral lesion. We aimed to evaluate the CT and MR features of sporadic MA, with a focus on the correlation between imaging and histopathologic findings.

Methods

CT (n?=?7) and MR (n?=?8) images of eight patients (6 men and 2 women; mean age, 12.8 years; range, 4–22 years) with pathologically proven MA were retrospectively reviewed. After dividing the MA lesions according to their distribution into cortical and subcortical white matter components, the morphologic characteristics were analyzed and correlated with histopathologic findings in seven patients.

Results

CT and MR images showed cortical (n?=?4, 50 %) and subcortical white matter (n?=?7, 88 %) components of MA. All four cortical components revealed hyperattenuation on CT scan and T1 isointensity/T2 hypointensity on MR images, whereas subcortical white matter components showed hypoattenuation on CT scan and T1 hypointensity/T2 hyperintensity on MR images. Two cortical components (25 %) demonstrated enhancement and one subcortical white matter component demonstrated cystic change. Seven cases were available for imaging-histopathologic correlation. In all seven cases, the cortex was involved by MA and six patients (86 %) showed subcortical white matter involvement by MA. There were excellent correlations between the imaging and histopathologic findings in subcortical white matter components, and the accuracy was 100 % (seven of seven); whereas there were poor correlations in cortical components, and the accuracy was 43 % (three of seven).

Conclusions

The cerebral cortex and subcortical white matter were concomitantly involved by MA. Subcortical white matter components of MA were more apparent than cortical components on CT and MR imaging.     

Does obesity preclude lumbar puncture with a standard spinal needle? The use of computed tomography to measure the skin to lumbar subarachnoid space distance in the general hospital population

Objectives

Failed lumbar puncture (LP) is a common indication for referral for radiologically guided LP. This study aims to evaluate what percentage of the hospital population would fail an LP using a standard 9-cm needle because of obesity and a skin to subarachnoid space distance greater than 9 cm.

Methods

Images of 402 consecutive patients undergoing computed tomography of the abdomen and pelvis were reviewed. Skin to subarachnoid space distance was calculated using sagittal images. A survey was conducted among junior hospital doctors to assess their experience of performing lumbar puncture in obese patients.

Results

Four hundred patients were included. Fifty-five patients (13.8 %) had a skin to subarachnoid space distance greater than 9 cm. Intra-abdominal fat, subcutaneous fat and abdominal girth correlated with distance between the skin and subarachnoid space. Among junior doctors, 68.3 % (n?=?41) reported LP failure on an obese patient; 78.4 % (n?=?47) were unaware of the existence of a longer needle and 13.3 % (n?=?8) had experience using a longer needle.

Conclusions

A significant proportion of the hospital population will fail LP with a standard length spinal needle. Selecting a longer needle may be sufficient to successfully complete LP in obese patients.

Key Points

? Lumbar puncture failure commonly leads to referral for an image-guided procedure ? Standard lumbar puncture may fail in 13.8 % of patients due to obesity ? 78.4 % of trainee doctors are unaware of the existence of longer spinal-needles ? Using longer spinal needles may allow successful LP in obese patients     

Imaging characterization of benign and malignant pheochromocytoma or paraganglioma: comparison between MIBG uptake and MR signal intensity ratio

Objective

We compared metaiodobenzylguanidine (MIBG) uptake and magnetic resonance (MR) signal intensity ratio in differentiating benign and malignant disease in patients with pheochromocytoma or paraganglioma.

Methods

Eighteen patients (9 men, mean age 37?±?8?years) with pheochromocytoma or paraganglioma underwent MR imaging and iodine-131 MIBG scintigraphy. MR signal intensity ratio was measured on T1 and T2-weighted images using region of interest analysis and intensity ratio of MIBG uptake was calculated for each tumor lesion on 48?h images.

Results

A total of 28 tumor lesions was analyzed of which 12 were benign and 16 malignant. MIBG uptake intensity ratio was significantly higher in malignant lesions compared to benign (5.2?±?2.4 and 2.9?±?1.4, respectively, p?<?0.01). On the contrary, no significant difference in tumor size and MR signal intensity ratio between malignant and benign tumor lesions was observed.

Conclusions

In patients with pheochromocytoma or paraganglioma, iodine-131 MIBG uptake is able to differentiate between benign and malignant disease, while MR imaging is not useful for this purpose. The higher MIBG uptake observed in malignant lesions could reflect major tumor storage of catecholamines compared to benign lesions.     

Minimal hepatic encephalopathy in children with liver cirrhosis: diffusion-weighted MR imaging and proton MR spectroscopy of the brain

Introduction

The aim of this work was to detect minimal hepatic encephalopathy (minHE) in children with diffusion-weighted MR imaging (DWI) and proton magnetic resonance spectroscopy (¹H-MRS) of the brain.

Methods

Prospective study conducted upon 30 consecutive children (age range 6–16 years, 21 boys and 9 girls) with liver cirrhosis and 15 age- and sex-matched healthy control children. Patients with minHE (n?=?17) and with no minHE (n?=?13) groups and control group underwent DWI, ¹H-MRS, and neuropsychological tests (NPTs). The glutamate or glutamine (Glx), myoinositol (mI), choline (Cho), and creatine (Cr) at the right ganglionic region were determined at ¹H-MRS. The apparent diffusion coefficient (ADC) value and metabolic ratios of Glx/Cr, mI/Cr, and Cho/Cr were calculated.

Results

There was elevated ADC value and Glx/Cr and decreased mI/CI and Ch/Cr in patients with minHE compared to no minHE and control group. There was significant difference between minHE, no minHE, and control group in the ADC value (P?=?0.001 for all groups), GLx/Cr (P?=?0.001 for all groups), mI/Cr (P?=?0.004, 0.001, and 0.001, respectively), Ch/Cr (P?=?0.001 for all groups), and full-scale IQ of NPT (P?=?0.001, 0.001, and 0.143, respectively). The NPT of minHE had negative correlation with ADC value (r?=??0.872, P?=?0.001) and GLx/Cr (r?=??0.812, P?=?0.001) and positive correlation with mI/Cr (r?=?0.732, P?=?0.001).

Conclusion

DWI and ¹H-MRS are imaging modalities that can detect minHE in children with liver cirrhosis and correlate well with parameters of NPT.