Sagittal T1-weighted Sequences Research Articles

Five-minute knee MRI: An AI-based super resolution reconstruction approach for compressed sensing. A validation study on healthy volunteers

PurposeTo investigate the potential of combining Compressed Sensing (CS) and a newly developed AI-based super resolution reconstruction prototype consisting of a series of convolutional neural networks (CNN) for a complete five-minute 2D knee MRI protocol. MethodsIn this prospective study, 20 volunteers were examined using a 3T-MRI-scanner (Ingenia Elition X, Philips). Similar to clinical practice, the protocol consists of a fat-saturated 2D-proton-density-sequence in coronal, sagittal and transversal orientation as well as a sagittal T1-weighted sequence. The sequences were acquired with two different resolutions (standard and low resolution) and the raw data reconstructed with two different reconstruction algorithms: a conventional Compressed SENSE (CS) and a new CNN-based algorithm for denoising and subsequently to interpolate and therewith increase the sharpness of the image (CS-SuperRes). Subjective image quality was evaluated by two blinded radiologists reviewing 8 criteria on a 5-point Likert scale and signal-to-noise ratio calculated as an objective parameter. ResultsThe protocol reconstructed with CS-SuperRes received higher ratings than the time-equivalent CS reconstructions, statistically significant especially for low resolution acquisitions (e.g., overall image impression: 4.3 ± 0.4 vs. 3.4 ± 0.4, p < 0.05). CS-SuperRes reconstructions for the low resolution acquisition were comparable to traditional CS reconstructions with standard resolution for all parameters, achieving a scan time reduction from 11:01 min to 4:46 min (57 %) for the complete protocol (e.g. overall image impression: 4.3 ± 0.4 vs. 4.0 ± 0.5, p < 0.05). ConclusionThe newly-developed AI-based reconstruction algorithm CS-SuperRes allows to reduce scan time by 57% while maintaining unchanged image quality compared to the conventional CS reconstruction.

Multiple sclerosis imaging in clinical practice: a European-wide survey of 428 centers and conclusions by the ESNR Working Group.

To evaluate compliance with the available recommendations, we assessed the current clinical practice of imaging in the evaluation of multiple sclerosis (MS). An online questionnaire was emailed to all members and affiliates. Information was gathered on applied MR imaging protocols, gadolinium-based contrast agents (GBCA) use and image analysis. We compared the survey results with the Magnetic Resonance Imaging in MS (MAGNIMS) recommendations considered as the reference standard. A total of 428 entries were received from 44 countries. Of these, 82% of responders were neuroradiologists. 55% performed more than ten scans per week for MS imaging. The systematic use of 3T is rare (18%). Over 90% follow specific protocol recommendations with 3D FLAIR, T2-weighted and DWI being the most frequently used sequences. Over 50% use SWI at initial diagnosis and 3D gradient-echo T1-weighted imaging is the most used MRI sequence for pre- and post-contrast imaging. Mismatches with recommendations were identified including the use of only one sagittal T2-weighted sequence for spinal cord imaging, the systematic use of GBCA at follow-up (over 30% of institutions), a delay time shorter than 5min after GBCA administration (25%) and an inadequate follow-up duration in pediatric acute disseminated encephalomyelitis (80%). There is scarce use of automated software to compare images or to assess atrophy (13% and 7%). The proportions do not differ significantly between academic and non-academic institutions. While current practice in MS imaging is rather homogeneous across Europe, our survey suggests that recommendations are only partially followed. Hurdles were identified, mainly in the areas of GBCA use, spinal cord imaging, underuse of specific MRI sequences and monitoring strategies. This work will help radiologists to identify the mismatches between their own practices and the recommendations and act upon them. • While current practice in MS imaging is rather homogeneous across Europe, our survey suggests that available recommendations are only partially followed. • Several hurdles have been identified through the survey that mainly lies in the areas of GBCA use, spinal cord imaging, underuse of specific MRI sequences and monitoring strategies.

Enhancing Annular Fissures and High-Intensity Zones: Pain, Internal Derangement, and Anesthetic Response at Provocation Lumbar Discography.

A high-intensity zone identified on preprocedural MR imaging is known to correlate with pain at provocation lumbar discography. The correlation between enhancing annular fissures and pain at provocation lumbar discography has not been comprehensively evaluated. The purpose of this study was to assess the pain response and imaging features at enhancing annular fissure nonoperated disc levels identified on preprocedural MR imaging with comparison with the high-intensity zone and nonenhancing disc levels in patients referred for provocation lumbar discography. One-hundred nonoperated discs in 44 patients were retrospectively evaluated for an enhancing annular fissure on sagittal postcontrast T1-weighted pre-discogram MR imaging. Enhancing annular fissure discs were graded on the sagittal T2-weighted sequence (Grade 4: like CSF to Grade 1: negative/barely visible) for high-intensity-zone conspicuity. High-intensity-zone detection was performed independently. In the primary assessment, enhancing annular fissure and high-intensity zones were associated with pain response at provocation lumbar discography. Additional analysis included intradiscal anesthetic response and postdiscogram CT appearance. Thirty-nine discs demonstrated an enhancing annular fissure, with 23/39 demonstrating a high-intensity zone. The presence of a high-intensity zone predicted severe pain (concordant + nonconcordant; P = .005, sensitivity of 40%, specificity of 94%) and concordant pain (P = .007, sensitivity of 39%, specificity of 86%) at provocation lumbar discography. Enhancing annular fissures without a detected high-intensity zone were more frequently observed among severely painful (50%) and concordant (36%) discs than among discs negative for pain (9%; P = .01). This finding resulted in a substantially greater overall sensitivity of enhancing annular fissures for severe (P < .001, 64%) and concordant pain (P = .008, 61%), significantly improving the overall predictive ability of a high-intensity zone alone. A high-intensity zone went undetected in 9/11 Grade 1 disc levels with concordant pain present in 7/9. Consideration of enhancing annular fissures on preprocedural MR imaging substantially improves the prediction of severe/concordant pain in provocation lumbar discography.

Assessment of the normal pediatric pineal gland - MR findings of a single centre; A retrospective study.

To analyse the size and morphology of the normal pineal gland in the paediatric age group using magnetic resonance imaging. The retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised data of patients aged <18 years who had magnetic resonance imaging done between 2007 and 2017. Pineal size was estimated measuring its largest anteroposterior and supero-inferior diameters on sagittal T2-weighted sequences on any slice with maximal diameter. The width of pineal gland was measured on axial or coronal T2 sequences. The volume, morphology and enhancement patterns of the gland were also assessed. Data was analysed using SPSS 21. Of the 200 patients, 116(58%) were males and 84(42%) were females. The overall mean age was 7.8±5.5 years. The mean anteroposterior dimension was 4.85±1.46mm, height 3.31±0.95mm, width 4.16±1.19, and volume 39.54±38.12 mm3. Mean size of cyst was 2.77±1.4mm (range: 1.2-7.5mm). No significant differences in the pattern of enhancement were found in different age groups (p>0.05). Comprehensive knowledge of the size of the typical pineal organ is useful for radiologists in the identification of pineal gland anomalies and the exclusion of neoplastic lesions.

Can T2-weighted Dixon fat-only images replace T1-weighted images in degenerative disc disease with Modic changes on lumbar spine MRI?

To evaluate the diagnostic performance and interobserver agreement of a magnetic resonance imaging (MRI) protocol that only includes sagittal T2-weighted Dixon fat and water images as an alternative to a standard protocol that includes both sagittal T1-weighted sequence and T2-weighted Dixon water images as reference standard in lumbar degenerative disc disease with Modic changes. From February 2017 to March 2019, 114 patients who underwent lumbar spine MRI for low back pain were included in this retrospective study. All MRI showed Modic changes at least at one vertebral level. Two radiologists read the standard protocol and 1 month later the alternative protocol. All MRI were assessed for Modic changes (types, location, extension) as well as structural changes (endplate defects, facet arthropathy, spinal stenosis, foraminal stenosis, Schmorl nodes, spondylolisthesis, disc bulges, and degeneration). Interobserver agreement was assessed, as well as diagnostic performance using the standard protocol as reference standard. Interobserver agreement was moderate to excellent (kappa ranging from 0.51 to 0.92). Diagnostic performance of the alternative protocol was good for detection of any Modic change (sensitivity = 100.00% [95% CI, 99.03-100.00]; specificity = 98.89% [95% CI, 98.02-99.44]), as well as for detection of each Modic subtype and structural variables (sensitivity respectively 100% and ranging from 88.43 to 99.75% ; specificity ranging respectively from 97.62 to 100% and 99.58 to 99.91% ). Combined with T2-weighted Dixon water images, T2-weighted Dixon fat images provide good diagnostic performance compared to T1-weighted images in lumbar degenerative disc disease with Modic changes, and could therefore allow for a shortened protocol. • Combined with T2-weighted Dixon water images, T2-weighted Dixon fat images (in comparison to T1-weighted sequence) can provide good diagnostic performance in lumbar degenerative disc disease with Modic changes. • Interobserver agreement of the alternative protocol including sagittal T2-weighted Dixon fat and water images was substantial to excellent for every studied variable exceptfor facet arthropathy. • A shortened MRI protocol including T2-weighted Dixon sequence without T1-weighted sequence could be proposed in this clinical setting.

Implementation of a sagittal T2-weighted DIXON turbo spin-echo sequence may shorten MRI acquisitions in the emergency setting of suspected spinal bleeding

BackgroundMagnetic resonance imaging (MRI) is the modality of choice for evaluating soft tissue damage along the spine in the emergency setting, yet access and fast protocol availability are limited. We assessed the performance of a sagittal T2-weighted DIXON turbo spin-echo sequence and investigated whether additional standard sagittal T1-weighted sequences are necessary in suspected spinal fluid collections/bleedings.MethodsSeventy-four patients aged 62.9 ± 19.3 years (mean ± standard deviation) with MRI including a sagittal T2-weighted DIXON sequence and a T1-weighted sequence were retrospectively included. Thirty-four patients (45.9%) showed a spinal fluid collection/bleeding. Two layouts (layout 1: fat-only and water-only and in-phase images of the DIXON sequence and T1-weighted images; layout 2: fat-only and water-only and in-phase images of the DIXON sequence) were evaluated by three readers (R1, R2, and R3) concerning presence of spinal fluid collections/bleedings and diagnostic confidence from 1 (very low confidence) to 5 (very high confidence). χ2 and κ statistics were used.ResultsThere was no difference in detecting spinal fluid collections/bleedings between the layouts (R1 and R2 detected all, R3 missed one spinal fluid collection/bleeding in the same patient in both layouts). Confidence was high (layout 1, R1 4.26 ± 0.81, R2 4.28 ± 0.81, R3 4.32 ± 0.79; layout 2, R1 3.93 ± 0.70, R2 4.09 ± 0.86, R3 3.97 ± 0.73), with higher inter-reader agreement for layout 1 (κ 0.691–0.780) than for layout 2 (κ 0.441–0.674).ConclusionsA sagittal T2-weighted DIXON sequence provides diagnostic performance similar to a protocol including standard T1-weighted sequences.

Imaging of the degenerative spine using a sagittal T2-weighted DIXON turbo spin-echo sequence

PurposeTo evaluate the diagnostic performance of a sagittal T2-weighted DIXON turbo spin-echo (TSE) sequence and to assess whether fat-only images could replace dedicated sagittal T1-weighted sequences for magnetic resonance imaging (MRI) of the degenerative spine. Method35 patients (56.5 ± 19.8 years, 62.9 % males) with lumbar back pain (LBP) who underwent MRI of the lumbar spine including a sagittal T2-weighted DIXON sequence (acquisition time: 3:25 min) and T1-weighted sequence (acquisition time: 3:03 min) were included. Two image layouts (layout 1: fat-only AND water-only AND in-phase images of the DIXON sequence; layout 2: water-only AND in-phase images of the DIXON sequence AND T1-weighted images) were evaluated by two readers (R1 and R2) concerning degenerative changes including diagnostic confidence (1 – low, 2 – intermediate, and 3 – high) and signal changes of vertebral bone marrow (BM). Results were compared between readers and layouts. ResultsNo differences were observed in the number of detected pathologies on a segment-wise level, nor in the number of segments affected by degenerative changes when comparing evaluations of layout 1 and layout 2 for each reader. Diagnostic confidence was high without a statistically significant difference between the readings of both layouts (R1: layout 1: 2.79 ± 0.41, layout 2: 2.81 ± 0.39, p = 0.53; R2: layout 1: 2.99 ± 0.07, layout 2: 2.99 ± 0.07, p = 0.99). ConclusionsIn patients with LBP, MRI using a sagittal T2-weighted DIXON sequence and no separate T1-weighted sequence might be sufficient to accurately detect common degenerative changes with high diagnostic confidence. Sparing dedicated T1-weighted sequences can considerably reduce overall scan time.

Magnetic resonance imaging of the spine in a pediatric population: incidental findings.

ObjectiveTo determine the prevalence of incidental findings on magnetic resonance imaging (MRI) scans of the cervical, thoracic and lumbar spine in a paediatric population.Materials and MethodsWe evaluated 190 spinal MRI examinations of patients aged ≤ 18 years of age. The study included only patients for whom complete medical records were available and who underwent complete MRI examination of the cervical, thoracic or lumbar spine, including whole-spine sagittal T2-weighted sequences. Imaging findings not related to the symptom or indication for MRI were considered incidental findings.ResultsOf the 190 MRI examinations evaluated, 110 were in women and 80 were in men. The mean age of the study population was 12.46 ± 3.68 years. The main clinical indications for MRI in the sample were lumbago, scoliosis, dorsalgia and cervicalgia. Incidental findings were detected in the cervical, thoracic and lumbar spine in 40 (21.05%), 26 (13.83%) and 43 (22.63%) of the patients, respectively. The most common were (in the cervical spine) reversal/correction of the normal curvature; (in the thoracic spine) intravertebral disc herniation (Schmorl’s node) and disc dehydration; and (in the lumbar spine) disc protrusion (12 cases), Schmorl’s node (5 cases) and spondylolysis (4 cases).ConclusionIncidental findings on MRI of the spine are less common in the paediatric population than in the adult population. Nevertheless, careful clinical evaluation of paediatric patients with complaints of axial and radiating pain is necessary in order to determine the correlation between symptoms and imaging findings.

Should Spinal MRI Be Routinely Performed in Patients With Clinically Isolated Optic Neuritis?

Should Spinal MRI Be Routinely Performed in Patients With Clinically Isolated Optic Neuritis?

Dorsal and ventral horn atrophy is associated with clinical outcome after spinal cord injury.

ObjectiveTo investigate whether gray matter pathology above the level of injury, alongside white matter changes, also contributes to sensorimotor impairments after spinal cord injury.MethodsA 3T MRI protocol was acquired in 17 tetraplegic patients and 21 controls. A sagittal T2-weighted sequence was used to characterize lesion severity. At the C2-3 level, a high-resolution T2*-weighted sequence was used to assess cross-sectional areas of gray and white matter, including their subcompartments; a diffusion-weighted sequence was used to compute voxel-based diffusion indices. Regression models determined associations between lesion severity and tissue-specific neurodegeneration and associations between the latter with neurophysiologic and clinical outcome.ResultsNeurodegeneration was evident within the dorsal and ventral horns and white matter above the level of injury. Tract-specific neurodegeneration was associated with prolonged conduction of appropriate electrophysiologic recordings. Dorsal horn atrophy was associated with sensory outcome, while ventral horn atrophy was associated with motor outcome. White matter integrity of dorsal columns and corticospinal tracts was associated with daily-life independence.ConclusionOur results suggest that, next to anterograde and retrograde degeneration of white matter tracts, neuronal circuits within the spinal cord far above the level of injury undergo transsynaptic neurodegeneration, resulting in specific gray matter changes. Such improved understanding of tissue-specific cord pathology offers potential biomarkers with more efficient targeting and monitoring of neuroregenerative (i.e., white matter) and neuroprotective (i.e., gray matter) agents.

The quadriceps active ratio: a dynamic MRI-based assessment of patellar height.

Patella alta (PA) is one of the primary correctable risk factors for patellofemoral instability (PFI). Both an accurate diagnosis of PA and a clinically relevant target for correction are necessary for optimal treatment. An ideal test for PA should relate the position of the patella to the femur rather than tibia, should do so with the quadriceps contracted and the patellar tendon under tension and should have good sensitivity and specificity. None of the currently used radiographic tests PA meet these criteria, most of which are based on the position of the patella relative to the tibia with diagnostic cutoffs based on 2 standard deviations from the mean rather than optimal sensitivity and specificity. The authors describe the quadriceps active ratio (Q+R), an MRI-based assessment of PA based on patellofemoral contact under quadriceps activated with a cutoff based on optimal sensitivity a specificity for PFI. Ninety-four participants investigated for knee pain or instability with a clinically indicated MRI were recruited. Routine MRI sequences were obtained, with the addition of a quadriceps contracted sagittal T1-weighted sequence. Participants presenting with PFI were identified. Those with trochlear dysplasia were identified and excluded from analysis so that patellar height could be assessed against PFI without being confounded by trochlear dysplasia. Q+R and patellotrochlear index (PTI) were calculated from the remaining 78 scans by 3 consultant orthopaedic surgeons at three time points. In 54 of these cases, a lateral radiograph was available from which the Insall-Salvati, modified Insall-Salvati, Caton-Deschamps and Blackburn-Peel ratios were also calculated. Intra- and inter-observer reliability was assessed for the Q+R. A cutoff value for the Q+R based on optimal sensitivity and specificity for the diagnosis of PFI was calculated from receiver-operator characteristic (ROC) curves and compared to the PTI. The cutoff for the Q+R was compared for sensitivity and specificity for the diagnosis of PFI against the radiographic ratios. The Q+R had satisfactory or better ICC values across time points and surgeons. The Q+R was superior to the PTI on area under curve ROC analysis (0.76 vs 0.74). A cutoff value of 0.12 for the Q+R gave sensitivity of 79% and specificity of 55% for the diagnosis of PFI. The radiographic indices were generally insensitive for this diagnosis of PFI with sensitivities ranging from 0-66%. TheQ+R is a reliable diagnostic test for patellar height assessment, showing good intra- and inter-rater consistency, and greater diagnostic accuracy than the PTI. A Q+R value of 0.12 is a good test for clinically significant PA. Of the radiographic indices, the Insall-Salvati ratio had the best diagnostic accuracy.

Evaluation of T2-weighted versus short-tau inversion recovery sagittal sequences in the identification and localization of canine intervertebral disc extrusion with low-field magnetic resonance imaging.

Sagittal T2-weighted sequences (T2-SAG) are the foundation of spinal protocols when screening for the presence of intervertebral disc extrusion. We often utilize sagittal short-tau inversion recovery sequences (STIR-SAG) as an adjunctive screening series, and experience suggests that this combined approach provides superior detection rates. We hypothesized that STIR-SAG would provide higher sensitivity than T2-SAG in the identification and localization of intervertebral disc extrusion. We further hypothesized that the parallel evaluation of paired T2-SAG and STIR-SAG series would provide a higher sensitivity than could be achieved with either independent sagittal series when viewed in isolation. This retrospective diagnostic accuracy study blindly reviewed T2-SAG and STIR-SAG sequences from dogs (n = 110) with surgically confirmed intervertebral disc extrusion. A consensus between two radiologists found no significant difference in sensitivity between T2-SAG and STIR-SAG during the identification of intervertebral disc extrusion (T2-SAG: 92.7%, STIR-SAG: 94.5%, P = 0.752). Nevertheless, STIR-SAG accurately identified intervertebral disc extrusion in 66.7% of cases where the evaluation of T2-SAG in isolation had provided a false negative diagnosis. Additionally, one radiologist found that the parallel evaluation of paired T2-SAG and STIR-SAG series provided a significantly higher sensitivity than T2-SAG in isolation, during the identification of intervertebral disc extrusion (T2-SAG: 78.2%, paired T2-SAG, and STIR-SAG: 90.9%, P = 0.017). A similar nonsignificant trend was observed when the consensus of both radiologists was taken into consideration (T2-SAG: 92.7%, paired T2-SAG, and STIR-SAG= 97.3%, P = 0.392). We therefore conclude that STIR-SAG is capable of identifying intervertebral disc extrusion that is inconspicuous in T2-SAG, and that STIR-SAG should be considered a useful adjunctive sequence during preliminary sagittal screening for intervertebral disc extrusion in low-field magnetic resonance.

High-resolution heavily T2-weighted magnetic resonance imaging for evaluation of the pituitary stalk in children with ectopic neurohypophysis.

In anterior pituitary deficiency, patients with non visible pituitary stalk have more often multiple deficiencies and persistent deficiency than patients with visible pituitary stalk. To compare the diagnostic value of a high-resolution heavily T2-weighted sequence to 1.5-mm-thick unenhanced and contrast-enhanced sagittal T1-weighted sequences to assess the presence of the pituitary stalk in children with ectopic posterior pituitary gland. We retrospectively evaluated the MRI data of 14 children diagnosed with ectopic posterior pituitary gland between 2010 and 2014. We evaluated the presence of a pituitary stalk using a sagittal high-resolution heavily T2-weighted sequence and a 1.5-mm sagittal T1-weighted turbo spin-echo sequence before and after contrast medium administration. A pituitary stalk was present on at least one of the sequences in 10 of the 14 children (71%). T2-weighted sequence depicted the pituitary stalk in all 10 children, whereas the 1.5-mm-thick T1-weighted sequence depicted 2/10 (20%) before contrast injection and 8/10 (80%) after contrast injection (P=0.007). Compared with 1.5-mm-thick contrast-enhanced T1-weighted sequences, high-resolution heavily T2-weighted sequence demonstrates better sensitivity in detecting the pituitary stalk in children with ectopic posterior pituitary gland, suggesting that contrast injection is unnecessary to assess the presence of a pituitary stalk in this setting.

Hirayama's disease: an Italian single center experience and review of the literature.

Hirayama's disease (HD), is a benign, self-limited, motor neuron disease, characterized by asymmetric weakness and atrophy of one or both distal upper extremities. In the present study we report the clinical, electrophysiological and MRI features of a group of Italian patients, with review of the literature. Moreover we propose an optimized MRI protocol for patients with suspected or diagnosed HD in order to make an early diagnosis and a standardized follow up. Eight patients with clinical suspicion of Hirayama disease underwent evaluation between January 2007 and November 2013. All patients underwent standard nerve conduction studies (NCS), electromyography (EMG) and motor/sensory evoked potentials (MEP/SEP). Cervical spine MRI studies were conducted with a 1.5 Tesla MRI scanner in neutral and flexion position, including sagittal T1-weighted sequences and sagittal and axial T2-weighted sequences. The following diagnostic features were evaluated: abnormal cervical curvature, localized cervical cord atrophy in the lower tract (C4-C7), presence of cord flattening (CF), intramedullary signal hyperintensity on T2 weighted sequences, anterior shifting of the posterior wall of the cervical dural sac (ASD) and presence of flow voids (EFV) in the posterior epidural space during flexion. All patients complained of weakness in hand muscles as initial symptoms, associated with hand tremor in three of them and abnormal sweating of the hand palm in two of them. No sensory deficits and weakness at lower limbs were reported by any patients. Distal deep tendon reflexes at upper limbs were absent in all patients with the absence of the right tricipital reflex in one of them. Deep tendon reflexes at lower limbs were normal and no signs of pyramidal tract involvement were present. The clinical involvement at onset was unilateral in six patients (three left-sided and three right-sided) and bilateral asymmetric in two of them, with the right side more affected. With the progression of the disease all patients but one experienced weakness and wasting of hand muscles and forearm bilaterally, but still asymmetric. The duration of the progression phase of the disease ranged from eight months to three years. In all patients, NCS and EMG findings were consistent with a spinal metameric disorder involving the C7-T1 myotomes bilaterally; sensory conduction and electrophysiologic features at lower limbs were normal. MEP and SEP were normal and we did not observe the disappearance of the spinal potential during the neck flexion in any of the patients. MRI is the best diagnostic tool in the diagnosis of HD; it can confirm clinical diagnosis and exclude other conditions responsible for the neurological deficits leading to a correct patient management and therapy, limiting arm impairment. On MRI all patients had loss of the normal cervical lordosis (100%). Five patients had loss of attachment of posterior dural sac and anterior dural shift on flexion MRI with presence of flow voids from venous plexus congestion (62.5%); three patients had no anterior dislocation of the dural sac and no epidural vein congestion. Two patients showed localized cord atrophy, one at C5-C6 and the other at C6-C7 level (25%). Three patients had T2 intramedullary hyperintensities (37.5%) and cord flattening (CF) was present in 5 patients of 8 (62.5%). HD is a rare entity and a self-limited condition, but it has to be early differentiated from other diseases that may determine myelopathy and amyotrophy to establish a correct therapy and limit arm impairment. MRI is very important to confirm the clinical suspect of HD and a standardized MRI protocol using axial and sagittal images in both neutral and flexing position is needed, in order to diagnose and follow up affected patients.

Pituitary siderosis: the dark side of the pituitary

A 23-year-old woman with persistent secondary amenorrhoea, 2 years after completion of non-ovarian toxic chemotherapy for osteosarcoma, was referred from the oncologist for investigation. She had severe sicklecell disease, diagnosed at age 18 months, requiring frequent red blood cells, exchange transfusion treatments, and a splenectomy. Despite oral chelation treatment, ferritin and transferrin saturation levels were raised (7000 μg/L and 121%, respectively). Pituitary investigations showed anterior hypopituitarism with several pituitary defi ciencies, including low concentrations of luteinising hormone (0·2 IU/L [normal range 0·8–10·4 IU/L]), follicle-stimulating hormone (0·8 IU/L [normal range 1·8–9·4 IU/L]), and oestradiol (<13 pmol/L [normal range 92–367 pmol/L]); normal concentrations of thyroid-stimulating hormone (2 mIU/L [normal range 0·17–4·05 mIU/L]); low free thyroxine (9·6 pmol/L [normal range 11·5–23·0 pmol/L]); and low morning cortisol concentrations on two successive days (133 nmol/L and 174 nmol/L [normal range 263–724 nmol/L]). An insulin tolerance test was contraindicated by the renal insuffi ciency secondary to chemotherapy. On MRI examination, coronal and sagittal T1-weighted sequences showed a normal pituitary and stalk, without evidence of pituitary tumour or infl ammation that could account for pituitary insuffi ciency (fi gure A, B). Coronal and sagittal T2-weighted sequences showed a normal posterior pituitary signal and a mainly homogeneous hypointense signal from the anterior pituitary, which was pathognomonic of pituitary siderosis (fi gure C, D). Haemosiderin deposition secondary to pituitary tumour apoplexy was excluded by the absence of clinical symptoms or indirect MRI signs of pituitary adenoma (eg, sella turcica deformation, pituitary stalk deviation, and pituitary mass). The MRI fi ndings led us to conclude that the patient had a rare hypopituitarism secondary to iron overload, caused by sickle-cell disease transfusion therapy. In severe thalassaemia requiring repeated transfusions, pituitary hypointense T2-weighted signal has been shown to be independently predictive of hypogonadism. Although such cases are rare, we suggest that pituitary MRI should be done in patients with sickle-cell disease who require frequent transfusions to assess the potential risk of hypopituitarism.

MRI appearance of the superior transverse scapular ligament.

The superior transverse scapular ligament (STSL) forms the roof of the suprascapular notch, which is the most common location of entrapment of the suprascapular nerve, a cause of shoulder pain and weakness. The purpose of this study is to determine the frequency of visualization of the STSL on routine shoulder MRIs, to identify the sequences and imaging planes on which it is visualized most frequently, and to describe its typical MRI appearance, none of which have been previously addressed in the radiologic literature. One hundred twenty-one consecutive shoulder MRIs were reviewed for the presence or absence of the STSL, including the imaging plane and sequence that best depicted the ligament. Dimensions of the ligament were recorded. Fifty four of 121 shoulder MRIs were technically adequate for visualization of the STSL, and it was identified on 51 of these studies (94%). There was no statistically significant difference between 1.5-T and 3-T systems. The best individual sequence for visualizing the STSL was the sagittal T1-weighted sequence, in which the STSL was visible on 75/80 technically adequate sequences (94%). The sagittal plane was the best plane for visualizing the STSL, in which it was visible on 65/69 technically adequate studies (94%). The STSL on average measured 12.8 ± 1.5 mm in transverse dimension. The STSL can be visualized on the majority of shoulder MRIs and is best seen on sagittal T1-weighted images on our imaging protocol. Evaluation of the STSL can potentially help in identifying pathologic conditions affecting the suprascapular nerve.

Radiological findings in Behçet disease.

Between 5 and 30% of patients with Behçet's disease will present neurological signs during the course of their illness. In order to evaluate the radiological signs on neuro-behçet disease, we studied consecutive patients in whom the diagnosis of this disease was retained, and who referred from January 2004 to December 2011 to the neurology and internal medicine departments in Mohammed VI universitary hospital in Marrakesh. Using 1.5T magnetic resonance imaging (MRI) with axial and coronal T2- weighted, axial Fluid Attenuated Inversion Recovery (FLAIR), pre- and post-contrast axial, coronal and sagittal T1-weighted sequences. The final number of patients in whom the diagnosis criteria of behçet disease were fulfilled and in whom an MRI was performed was 68 cases. Among these patients, 52 had parenchymal form of neuro-behçet with abnormalities in the MRI, 12 had vascular form and 4 patients had normal MRI. The brainstem, cerebral white matter, basal ganglia, internal capsule, thalamus and spinal cord were involved in forty four, thirty one, thirty, twenty nine, seventeen and four patients, respectively. The cerebral peduncle was the brainstem structure mainly involved with thirty cases followed by the pons with, twenty cases. Midbrain involvement interested forty patients. Brainstem atrophy was seen in eighteen cases. Finally, control MRI were obtained in four cases only, and showed changes in lesions size and shape.

Traumatic Brown-Sequard syndrome – clinico-radiological correlation on MRI

A 34-year-old man presented with a history of a stab wound to the left side of the neck. Physical examination revealed an ipsilateral left-sided hemiplegia and contralateral loss of sensation. A clinical diagnosis of Brown-Sequard syndrome was made. Magnetic resonance imaging (MRI) findings demonstrated hyperintensity at C4 and C5 levels on sagittal T2-weighted sequence of the cervical spine (Fig. 1) with limitation to the left hemicord demonstrated in the axial plane (Fig. 2), accounting for the Brown-Sequard syndrome. The patient was managed with supportive treatment.

The Presence of Fatty Infiltration in the Infraspinatus: Its Relation With the Condition of the Supraspinatus Tendon

We aim to determine the prevalence of fatty infiltration and tears in the infraspinatus and to identify any associated risk factors. Shoulder magnetic resonance imaging scans from 2006 to 2009 were reviewed. Arthrograms, inflammatory arthropathies, neoplasms, and fractures were excluded. Rotator cuff tears were graded in 4 categories: no tear, partial tear, and complete tear with and without retraction. Fatty infiltration was graded by radiologists using the modified Goutallier classification. Supraspinatus muscle atrophy (size) was measured by use of the ratio of the cross-sectional area of the muscle to the supraspinatus fossa on a sagittal T1-weighted sequence. Three hundred seventy-seven scans were included. The prevalence of infraspinatus tears was as follows: no tear, 74.8%; partial tear, 17.5%; complete tear, 3.2%; and complete tear with retraction, 4.5%. Fatty infiltration of grade 2 or higher was found in 18.1% of the infraspinatus without tears, 39.4% with partial tears, 66.7% with a complete tear, and 82.4% with a complete tear with retraction. In the infraspinatus without tears, increasing fatty infiltration was correlated with the severity of a concomitant supraspinatus tear. Fatty infiltration of grade 2 or higher in the infraspinatus without tears was found in 7.8% of shoulders with an intact supraspinatus, 18.6% with a partial supraspinatus tear, 23.5% with a complete supraspinatus tear, and 54.6% with a retracted complete supraspinatus tear. Supraspinatus muscle atrophy was correlated with infraspinatus fatty infiltration. Increased infraspinatus fatty infiltration was correlated with the severity of an infraspinatus tear. However, substantial fatty infiltration of the infraspinatus was seen even in the absence of a tear, and it was correlated with a worsening severity of a concomitant supraspinatus tear and atrophy. Concern over tear progression and increasing fatty infiltration of the infraspinatus may impact the management of isolated supraspinatus tendon tears. Level IV, prognostic case series.

3-T MRI of Rectal Carcinoma: Preoperative Diagnosis, Staging, and Planning of Sphincter-Sparing Surgery

The purpose of this study was to assess the accuracy of 3-T MRI in the preoperative diagnosis, staging, and planning of surgical management of rectal carcinoma. Thirty-eight patients (23 men, 15 women) with clinically suspected rectal carcinoma underwent 3-T MRI. Coronal, axial, and sagittal T2-weighted sequences with and without fat suppression; axial T1-weighted spin-echo sequences; axial T1-weighted gradient-echo sequences with and without fat suppression; oblique 2D MR hydrography; and 3D fat-suppressed dynamic contrast-enhanced MRI were performed. Image quality with these sequences was evaluated by three radiologists experienced in body MRI. The significance of difference in results with the sequences was tested. The manner in which MRI staging and feasibility of sphincter-sparing surgery agreed with operative and pathologic findings was evaluated with kappa statistics. Rectal carcinoma was identified on MRI and confirmed histologically in all 38 patients. MRI findings were correctly predictive of T category in 35 cases (accuracy, 92.1%). In 31 (96.9%) of 32 resectable cases,sphincter-sparing surgical approaches were accurately chosen on the basis of MRI findings. Among the 11 sequences, 3D fat-suppressed dynamic contrast-enhanced MRI best delineated tumor margins. Coronal and axial T2-weighted images also well depicted tumor margins with minimal artifact. T2-weighted images were superior to unenhanced T1-weighted images. MRI of rectal cancer at 3 T is accurate for prediction of T category and the feasibility of sphincter-sparing surgery. The best images were obtained with coronal, sagittal, and axial T2-weighted sequences and 3D fat-suppressed dynamic contrast-enhanced MRI.