Standard Magnetic Resonance Imaging Protocol Research Articles

Magnetic Resonance Imaging Diagnosis of Spinal Longitudinal Epidural Collections in a Spontaneous Spinal Dural Breach and Successful Surgical Treatment

Spontaneous intracranial hypotension is generally secondary to cerebrospinal fluid leaks. Spinal magnetic resonance imaging is an important part of the diagnostic workup, especially to display spinal longitudinal epidural collections. Other causes of leaks include nerve root sleeve tear and cerebrospinal fluid-venous fistula. We propose a standard magnetic resonance imaging protocol including sagittal T1, T2-weighted, and T2 fat-saturated sequences, with addition of high-resolution three-dimensional T2 images to improve detection of spinal longitudinal epidural collections and help locate the dural breach level. Spine computed tomography may prove useful in detecting a bony spur that may cause the dural breach. Treatment of identified dural breaches includes targeted epidural blood patch or neurosurgery in case of blood patch inefficacy. Few cases of successful surgical treatments of dural breaches have been reported with complete regression of spinal longitudinal epidural collections; thus more studies will be valuable to help establish guidelines in this pathology.

MFFE CT-like MRI Sequences for the Assessment of Vertebral Fractures.

The aim of this study was to evaluate the diagnostic performance, image quality, and inter- and intra-observer agreement of the 3D T1 multi-echo fast field echo (mFFE) sequence in cervico-thoraco-lumbar vertebral fractures compared with conventional computed tomography (CT) as the gold standard. We conducted a prospective single-centre study including 29 patients who underwent spinal magnetic resonance imaging (MRI) at the surgeon's request, in addition to CT for vertebral fracture assessment and classification. A 3D T1 mFFE sequence was added to the standard MRI protocol. Consecutively, two readers analyzed the 3D mFFE sequence alone, the 3D mFFE sequence with the entire MRI protocol, including the STIR and T1 sequences, and, finally, the CT images in random order and 1 month apart. A standardized assessment was performed to determine the presence or absence of a fracture, its location, its classification according to the Genant and AO classifications for traumatic and osteoporotic fractures, respectively, the loss of height of the anterior and posterior walls of the vertebral body, and the presence of concomitant disco-ligamentous lesions. Contingency tables, intraclass correlation coefficients, and Cohen's kappa tests were used for statistical analysis. A total of 25 fractures were recorded (48% cervical, 20% thoracic, and 32% lumbar), of which 52% were classified A, according to the AO classification system. The quality of the 3D mFFE image was good or excellent in 72% of cases. Inter-observer agreement was near perfect (0.81-1) for vertebral body height and for AO and Genant classifications for all modalities. Intra-observer agreement was strong-to-near perfect between CT and the 3D mFFE sequence. Regarding the diagnostic performance of the 3D mFFE sequence, the sensitivity was 0.9200 and 0.9600, the specificity was 0.9843 and 0.9895, and the accuracy was 0.9861 and 0.9769 for Readers 1 and 2, respectively. In addition, up to 40% of intervertebral disc lesions and 33% of ligamentous lesions were detected by the 3D mFFE sequence compared to CT, allowing four AO type A fractures to be reclassified as type B. The 3D mFFE sequence allows accurate diagnosis of vertebral fractures, with superiority over CT in detecting disco-ligamentous lesions and a more precise classification of fractures, which can prompt clinicians to adapt their management despite an image quality that still requires improvement in some cases. Vertebral fractures and disco-ligamentous lesions can be assessed using CT-like MRI sequences, with 3D T1 mFFE being superior to CT for the detection of disco-ligamentous lesions. CT-like images using the 3D T1 mFFE sequence improve the diagnostic accuracy of bone structures in MRI.

Feasibility of knee magnetic resonance imaging protocol using artificial intelligence-assisted iterative algorithm protocols: comparison with standard MRI protocols.

To evaluate the image quality and diagnostic performance of AI-assisted iterative algorithm protocols (AIIA) in accelerated fast spin-echo magnetic resonance imaging (MRI) versus standard (SD) fast spin-echo MRI for clinical 3.0 T rapid knee scans. The accelerated sequence, which includes fat-suppression proton density-weighted imaging (FS-PDWI), T2-weighted imaging (T2WI), and T1-weighted imaging (T1WI), was used in conjunction with the SD sequence in 61 patients who underwent MRI scans. SD images were processed using standard reconstruction techniques, while accelerated images utilized AIIA reconstruction. Quantitative assessments of image quality were conducted, measuring noise levels, signal-to-noise ratio (SNR) and contrast signal-to-noise ratio (CNR). Additionally, subjective evaluations were performed using a Likert five-point scale to assess image quality. The SD group completed the entire knee scan in 466 s, while the AIIA group completed the scan in 312 s. Compared to the SD group, the AIIA group had a noticeably higher SNR of T1WI in the femur and subpatellar fat pad (p = 0.04, 0.001). On the other hand, T2WI femur SNR was noticeably higher in the SD group (p = 0.004). Measurements of SNR, CNR and other noise levels showed no statistically significant changes. Compared to the SD group, the AIIA group had significantly higher subjective image quality scores for every sequence (p < 0.05). There was a modest to large intraclass correlation value (ICC = 0.65-0.90) for the anomalies that were examined among readers. Both the AIIA and SD procedures were shown to have comparable diagnostic performance for meniscal and cruciate ligament rupture (p > 0.05). Images processed using AIIA reconstruction were acquired faster while maintaining comparable image quality and diagnostic capability, meeting the requirements for clinical diagnosis.

Prevalence of Asymptomatic Changes in the Groin Region Among Adult Professional Soccer Players and Their Association With Limb Dominance.

To investigate the prevalence of asymptomatic radiologic groin region findings in adult professional soccer players using magnetic resonance imaging (MRI) and examine the influence of age and limb dominance on their occurrences. Cross-sectional trial. Soccer club medical service, private practice. Forty-seven male professional soccer players. Players underwent a groin presigning MRI scan with a magnetic field induction of 1.5 Tesla. Image analysis of their pubic bones was performed according to The Copenhagen Standardized MRI protocol to assess the pubic symphysis and adductor regions of players. The prevalence of various changes in the symphysis, pubic bone, and adjacent areas. Fifty images of pubic bones and adjacent regions (53.2%) highlighted 1 to 4 changes, while another 44 images (46.8%) demonstrated 5 or more changes. The most frequent changes observed in the pubic bone were joint surface irregularities (100%), symphyseal sclerosis (93.6%), pubic bone swelling (56.3%), parasymphyseal high-intensity line (55.3%), fatty infiltration in bone marrow (38.3%), and adductor tendinopathy (34%). When comparing the prevalence of different changes in the dominant and nondominant limbs, no statistically significant differences were found. In adult professional soccer players with no prior groin pain complaints in recent history (12 months), asymptomatic changes are extremely common in the pubic joint and adjacent areas, including those that are very likely to be considered the main cause of pain when investigated in soccer players with groin pain. None of these changes were associated with limb dominance.

Ultrafast Brain MRI at 3 T for MS: Evaluation of a 51-Second Deep Learning-Enhanced T2-EPI-FLAIR Sequence.

In neuroimaging, there is no equivalent alternative to magnetic resonance imaging (MRI). However, image acquisitions are generally time-consuming, which may limit utilization in some cases, e.g., in patients who cannot remain motionless for long or suffer from claustrophobia, or in the event of extensive waiting times. For multiple sclerosis (MS) patients, MRI plays a major role in drug therapy decision-making. The purpose of this study was to evaluate whether an ultrafast, T2-weighted (T2w), deep learning-enhanced (DL), echo-planar-imaging-based (EPI) fluid-attenuated inversion recovery (FLAIR) sequence (FLAIRUF) that has targeted neurological emergencies so far might even be an option to detect MS lesions of the brain compared to conventional FLAIR sequences. Therefore, 17 MS patients were enrolled prospectively in this exploratory study. Standard MRI protocols and ultrafast acquisitions were conducted at 3 tesla (T), including three-dimensional (3D)-FLAIR, turbo/fast spin-echo (TSE)-FLAIR, and FLAIRUF. Inflammatory lesions were grouped by size and location. Lesion conspicuity and image quality were rated on an ordinal five-point Likert scale, and lesion detection rates were calculated. Statistical analyses were performed to compare results. Altogether, 568 different lesions were found. Data indicated no significant differences in lesion detection (sensitivity and positive predictive value [PPV]) between FLAIRUF and axially reconstructed 3D-FLAIR (lesion size ≥3 mm × ≥2 mm) and no differences in sensitivity between FLAIRUF and TSE-FLAIR (lesion size ≥3 mm total). Lesion conspicuity in FLAIRUF was similar in all brain regions except for superior conspicuity in the occipital lobe and inferior conspicuity in the central brain regions. Further findings include location-dependent limitations of signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) as well as artifacts such as spatial distortions in FLAIRUF. In conclusion, FLAIRUF could potentially be an expedient alternative to conventional methods for brain imaging in MS patients since the acquisition can be performed in a fraction of time while maintaining good image quality.

Typical and Emerging Diagnostic MRI Features in Multiple Sclerosis.

Magnetic resonance imaging (MRI) stands as the most sensitive paraclinical technique for detecting the demyelinating lesions characteristic of multiple sclerosis (MS). Consequently, MRI plays a pivotal role in establishing an accurate and timely diagnosis of the disease, ultimately based on the application of the McDonald criteria. Early diagnosis is particularly important as it facilitates the prompt initiation of disease-modifying treatments, deemed most effective during the initial phases of MS. This review article examines the recommended standardized MRI protocol, as well as the classic imaging features of MS in the brain, optic nerve, and spinal cord, capable of discriminating, in most cases, MS from other disorders that can mimic this disease. Additionally, novel MR imaging findings, such as the central vein sign and paramagnetic rim lesion, which have been proposed as new imaging biomarkers to enhance diagnostic specificity for MS, are also discussed. These emerging features are likely to be incorporated in the future iterations of the McDonald criteria, and therefore, radiologists should be familiar with their appearance and with the optimal MRI protocols required for their detection.

Dynamic Magnetic Resonance Imaging Protocol: An Effective and Useful Tool to Assess Discoid Lateral Meniscus Instability in Children.

One of the most common symptoms in cases of discoid lateral meniscus (DLM) in children is a "snapping" knee. The clock in extension, followed by a pop in flexion, perceived by the clinician, reflects the meniscal displacement caused by the peripheral meniscocapsular detachment. Standard magnetic resonance imaging (MRI) results in a 40% false-negative rate for detecting this instability. The hypothesis was that a dynamic MRI protocol could reduce the false negative rate and improve the efficiency of the MRI in detecting the direction of instability. Eight DLM knees (8 patients) with snapping knees (grade 2 of Lyon's classification) were included in this monocentric prospective preliminary study in a referral center of pediatric orthopaedic surgery. Every patient underwent a dynamic MRI protocol with both T2-Fat-Sat sagittal and coronal slices, performed "after the clock" and again "after the pop" in a knee with standard 20 degrees of flexion during acquisition. All the MRI data were correlated with an arthroscopic description of the peripheral tear of the DLM according to Ahn's classification to assess for diagnostic accuracy. The standard MRI protocol resulted in a false-negative rate of 50% for detecting the direction of instability. The dynamic MRI protocol allowed the identification of, and classification of the meniscal instability, meniscal shift, and meniscocapsular tear in 8 of 8 patients (0% false-negative rate), perfectly correlated with arthroscopic findings. This preliminary series, although short, allowed us to understand all the types of movements and lesions associated with the child's discoid meniscus. The detailed case analysis showed a strong benefit of such a protocol for planning the surgical suture procedure. The functionality and reliability of the dynamic MRI protocol is a good and method relatively simple method which does not require specific equipment, minimizing any additional cost compared with standard MRI. Level IV.

Radiology diagnostics of spinal corel injury in early children: a prospective study

INTRODUCTION: Spinal cord injury (SCI) in young children includes a relatively higher prevalence of cervical spine injury, multiple thoracic vertebral compression fractures, and spinal cord injury. Spinal cord injuries without radiological changes/signs of fractures or dislocations (SCIWORA) also occur in young children. X-ray assessment of damage to immature vertebrae and cartilage in young children is difficult, since incompletely formed vertebral bodies can be confused with fractures. Accordingly, an MRI is required, which provides a detailed anatomical image of all structures of the spinal column and also diagnoses damage to the spinal cord, ligaments and muscles.OBJECTIVE: To investigate the possibilities of methods of radiation diagnosis of spinal cord injury in young children (up to 3 years).MATERIAL AND METHODS: 20 children aged from 11 months up to 3 years old were studied with spinal cord injury. X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) were performed. The standard MRI protocol for SCI in children under 3 years of age included: MR myelography in the coronary and sagittal projections, sagittal projection STIR, DTI and T2WI FS SE, axial projection T2WI FS SE or T2*WI FS GE; coronary projection T2WI SE; 3D T1WI FS GE before and after contrast enhancement.RESULTS: An analysis of the data of patients included in the category of polytrauma was carried out. The causes of SCI in these patients were road accidents and falls from various heights. X-ray and CT scans were uninformative, and had large discrepancies with MRI results. All anatomical and morphological changes revealed by MRI correlated well with clinical manifestations and corresponded to the classification of the level and severity of spinal cord injury (ASIA). An increase in the volume and change in the signal of the spinal cord due to edema and / or hemorrhage in the spinal cord is the main sign of damage to the spinal cord, and is best indicated on T2WI and STIR, as a hyperintense signal.DISCUSSION: MRI is critical in the emergency assessment of spinal cord injury or compression to predict the outcome of SCI. There is currently no spinal cord imaging technique that can compete with MRI. Increased volume and signal changes in the spinal cord due to edema and/or hemorrhage are a sign of spinal cord injury and are best demonstrated on T2WI and STIR as a hyperintense signal. Incomplete spinal cord injury is also manifested by a hyperintense signal on T2WI and/or FLAIR, which in intensity and extent correlates with the degree of injury. Hemorrhagic injuries are better detected using T2*GRE or SWI, and spinal cord edema is better detected using T2WI SE and STIR. In addition, STIR can identify bone marrow edema in injured vertebrae, even when the injury is not detected on CT.CONCLUSION: When performing MRI in patients with SCI, three quantitative parameters should be assessed: the maximum damage to the spinal cord, the maximum compression of the spinal cord, and the length of the affected area. In addition to the results of quantitative parameters, potential predictive qualitative MRI findings should be evaluated such as intramedullary hemorrhage, focal and diffuse spinal cord edema, soft tissue injury, probable stenosis before injury, and disc herniation.

Magnetic resonance imaging relevance in diagnosis and prognosis of early postoperative period following pancreatic cancer surgical treatment

Purpose of the study. Improvement of the prognostic outcomes for the pancreatic fistula development in surgical treatment for pancreatic cancer by implementation of new diagnostic algorithms for magnetic resonance imaging (MRI) assessment of supposed pancreatic stump.Materials and methods. We performed a retrospective analysis of MRI results of 1136 patients from the medical data base of National Medical Research Centre for Oncology for 2009–2020. An original scanning technique, trans- and cross-pancreatic imaging and MR spectroscopy of the pancreas in patients with pancreatic cancer, was developed and applied. Preoperative examinations were compared retrospectively: a standard MRI protocol without anatomical orientation of the series; MRI protocol using the developed technology.Results. 717 patients were diagnosed with advanced pancreatic cancer. Lymph nodes were affected in 302 patients among 419 patients with radical surgeries. All cases were confirmed morphologically. In the group of 419 patients with pancreatic resections, based on the analysis of morphological and clinical data and preoperative MRI data, we developed an original preoperative scale for assessing the risk of pancreatic fistula development and compared its accuracy with other intraoperative scales, FRS and modified FRS. Lactate and lipid complex were selected from a wide range of metabolites. The surgical protocols and results of histological examination of the surgical material were used to prove the accuracy of the study. The overall accuracy of the technique in predicting fistula development was 97.5 %. New visual predictors («domino» and «white on white» symptoms) based on MRI data were used to improve the scale accuracy.Conclusion. The developed method of using a modified scale for risk assessment of pancreatic fistula development allows predicting the onset of early postoperative complications already at the preoperative stage. When comparing the calculated risks of pancreatic fistula according to the developed scale with the results by the known scales (FRS and modified FRS), statistical analysis showed a significant difference for the better when compared with FRS (p = 0.0477), and a tendency when compared with modified FRS (p = 0.0544).

Review of standard paediatric neuroradiology MRI protocols from 12 UK tertiary paediatric hospitals: is there much variation between centres?

To investigate how magnetic resonance imaging (MRI) examinations are protocolled in tertiary paediatric neuroradiology centres around the UK for some of the more common presentations encountered in paediatric neuroradiology, and to identify any variations of note. All 19 UK tertiary paediatric neuroradiology centres registered with the British Society of Neuroradiologists-Paediatric Group were contacted and asked if they could provide a copy of their standard MRI protocols. Twelve responded (63%) and 10 of the more common presentations were selected and the standard acquired sequences obtained at each participating centre were compared. Where available the collated protocols were also compared against current published guidance. The basic sequences carried out by centres around the UK are similar; however, there are lots of variations overall. The only standardised protocol currently being implemented nationally in paediatric imaging is that for brain tumours. Otherwise, chosen protocols are generally dependent on the preferences and technical capabilities of individual centres. Suggested published protocols also exist for non-accidental injury (NAI), multiple sclerosis, epilepsy, and head and neck imaging. The differences in MRI protocolling depend in part on technical capabilities and in part on the experience and preferences of the paediatric neuroradiologists at each centre. For most presentations, there is no consensus as to what constitutes the perfect protocol. The present results will be useful for specialist centres who may wish to review their current protocols, and for more generalist centres to use as a reference to guide their MRI protocolling.

Comparison of a Routine Magnetic Resonance Imaging &amp; T2* Mapping of Articular Cartilage in Knee Osteoarthritis

Purpose To detect the knee articular cartilage lesions in T2* mapping as compared to a routine standard magnetic resonance imaging (MRI) at 3T. Material and Methods Twenty-five patients, complaining of knee pain and trauma, underwent knee MRI and were imaged with a standard knee MRI protocol (proton-density-weighted Fat Sat sagittal and axial series, T2weighted sagittal and axial series, and T1-weighted coronal series) and Proton density 3D sagittal and axial sequences are added, then images of T2* relaxation time is generated with color-coded mapping representing the relaxation time. The detected lesions were evaluated for lesion width (mm), lesion depth (1/3, 2/3, or 3/3 of cartilage thickness), and T2 values (20–40 ms, 40–60 ms, or 60– 80 ms). Results The study was conducted on 25 patients (13 female &amp; 12 male with a mean of 44.92 ± 11.74 years). 87 lesions were detected both on MRI and T2 maps, while 41 lesions were visible only on T2* maps. The cartilage lesions’ width and depth measurements showed no statistically significant difference on T2 maps as compared to standard knee MRI. Many lesions (45) had moderately (T2 40–60 ms) increased T2 values, while 29 lesions had slightly (T2 20–40 ms) and 13 lesions with remarkably (T2 60– 80 ms) increased T2 relaxation times. Conclusion T2 mapping of articular cartilage is efficient in cartilage evaluation and may reveal early cartilage lesions not visible on standard clinical MRI.

Consensus recommendations on regional interdisciplinary standardization of MRI diagnostics for multiple sclerosis in the metropolitan area of Essen

Magnetic resonance imaging (MRI) is of exceptional importance in the diagnostics and monitoring of multiple sclerosis (MS); however, a close interdisciplinary cooperation between neurologists in private practice, (neuro)radiological practices, hospitals or specialized MS centers is only rarely established. In particular, there is a lack of standardized MRI protocols for image acquisition as well as established quality parameters, which guarantee the comparability of MRI records; however, this is a fundamental prerequisite for an effective application of MRI in the treatment of MS patients, e.g., for making the diagnosis or treatment monitoring. To address these challenges a group of neurologists and (neuro)radiologists developed a consensus proposal for standardization of image acquisition, interpretation and transmission of results and for improvement in interdisciplinary cooperation. This pilot project in the metropolitan area of Essen used a modified Delphi process and was based on the most up to date scientific knowledge. The recommendation takes the medical, economic, temporal and practical aspects of MRI in MS into consideration. The model of interdisciplinary cooperation between radiologists and neurologists with the aim of a regional standardization of MRI could serve as an example for other regions of Germany in order to optimize MRI for MS.

Shortening Acquisition Time and Improving Image Quality for Pelvic MRI Using Deep Learning Reconstruction for Diffusion-Weighted Imaging at 1.5 T

To determine the impact on acquisition time reduction and image quality of a deep learning (DL) reconstruction for accelerated diffusion-weighted imaging (DWI) of the pelvis at 1.5 Tcompared to standard DWI. A total of 55 patients (mean age, 61±13 years; range, 27-89; 20 men, 35 women) were consecutively included in this retrospective, monocentric study between February and November 2022. Inclusion criteria were (1) standard DWI (DWIS) in clinically indicated magnetic resonance imaging (MRI) at 1.5 Tand (2) DL-reconstructed DWI (DWIDL). All patients were examined using the institution's standard MRI protocol according to their diagnosis including DWI with two different b-values (0and 800s/mm2) and calculation of apparent diffusion coefficient (ADC) maps. Image quality was qualitatively assessed by four radiologists using a visual 5-point Likert scale (5= best) for the following criteria: overall image quality, noise level, extent of artifacts, sharpness, and diagnostic confidence. The qualitative scores for DWIS and DWIDL were compared with the Wilcoxon signed-rank test. The overall image quality was evaluated to be significantly superior in DWIDL compared to DWIS for b =0s/mm2, b =800s/mm2, and ADC maps by all readers (P<.05). The extent of noise was evaluated to be significantly less in DWIDL compared to DWIS for b =0s/mm2, b=800s/mm2, and ADC maps by all readers (P<.001). No significant differences were found regarding artifacts, lesion detectability, sharpness of organs, and diagnostic confidence (P>.05). Acquisition time for DWIS was 2:06minutes, and simulated acquisition time for DWIDL was 1:12minutes. DL image reconstruction improves image quality, and simulation results suggest that a reduction in acquisition time for diffusion-weighted MRI of the pelvis at 1.5 Tis possible.

Systemic transit time correlates with renal cortical perfusion: a preliminary study

Abstract Funding Acknowledgements Type of funding sources: None. Introduction We sought to measure systemic transit time (STT) on MRI dynamic sequences of images in patients based on the recirculation time. In a subset of patients, using the same images, when the abdominal aorta and at least part of one kidney was available, we used a 2-compartment filtration model to approximate renal cortical plasma perfusion (RCPF). Methods This is a retrospective study in a single site MR unit. 218 patients underwent a standard myocardial MR imaging protocol on a 1.5 Tesla MRI system including a pulse-gated, free breathing, dynamic first-pass perfusion scan of 100 phases using a saturation recovery turbo-FLASH pulse sequence (TR = 172 ms / TE = 1.1 ms / flip angle = 5°). Motion correction was applied. All patients were injected intravenously with a bolus dose of gadoteratemeglumine followed by a 20 ml saline flush. On the 218 patients studied, 20 patients were excluded due to shunts:n=5, inadequate first pass perfusion signal:n=8, fitting script did not converge on a solution:n=7. Circular ROIs were placed in the RV (Right Ventricle) and LV (Left Ventricle)cavities. The time curves for each cavity’s signals were fitted to a time-sliding 3 component-LogNormal function using an in-house python script based on the lmfit package (Levenberg-Marquardt method) to determine systemic (STT) and pulmonary transit times (PTT). In a subset of 61 patients, an attempt to measure RCPF was undertaken. An elliptic ROI was drawn in the aorta to follow arterial input. A spline polygon ROI was placed on the visible renal cortical tissue. 14 sets of images were rejected for plasma perfusion analysis for different reasons (absence of suitable abdominal aorta image, absence of suitable renal cortical image, motion artifact, …). Plasma perfusion measurements were made using a 2-compartment filtration model. Results We studied 198 sets of MRI dynamic perfusion images. Our population consists of 65,7% men aged 53,0±16,9 (mean± SD) and 34,3% women aged 55,9 ± 14,1 (mean ± SD). Fitting of the experimental data was very good in most cases (mean R² for RV:0.981, max:0.997, min: 0.907, SD:0.014) (mean R² for LV: 0.994, max:0.999, min: 0.975, SD: 0.004). An example of experimental data fitting can be seen in fig. 1. STT values were as follows: mean = 14.3 s, SD = 3.0s, max = 27.1 s, min = 8.7 s. Measures of recirculation time were highly correlated on the RV and LV side (Pearson’s R =0,975; p &amp;lt; 0,001). We found a significant correlation between STT and PTT (Pearson’s R = 0,521; p &amp;lt; 0,001). In the 47 patients where RCPF could be calculated, a significant negative correlation was found between STT and RCPF (Pearson’s R = -0,578; p &amp;lt; 0,001) (fig. 2). Conclusions Systemic transit time can be accurately measured on standard MRI perfusion scans and is negatively correlated with cortical renal plasma perfusion. Assessing systemic transit time using MRI dynamic perfusion imaging of the heart could be a usable surrogate for end-organ perfusion.

Introducing 3D modelling of MRI in the preoperative mapping of perianal fistula: How it could help the surgeons?

BackgroundSurgeons find treating perianal fistula difficult because insufficient drainage and failure to eradicate perianal sepsis could increase the risk of recurrence and postoperative complications. For better planning of the most suitable surgical technique, surgeons must consider the risk factors of recurrence with an accurate pre-operative assessment of perianal fistulae.The most common imaging method for grading primary perianal fistulas, identifying their complications, and locating occult extensions is magnetic resonance imaging (MRI). However, surgeons may find it challenging to read the lengthy reports of complex tracts, particularly for complicated patients. The creation of three-dimensional (3D) models has gained traction recently as a genuinely useful diagnostic tool for pre-operative planning. The authors evaluated the value of these surgical models. Inspecting the 3D models in addition to the routine two-dimensional study caused four out of five skilled colorectal surgeons to re-evaluate how far the fistulae extended. This made promise that 3D models would be helpful, simple to understand, and quick to interpret for colorectal surgeons. The purpose of the study is to assess the value of adding 3D modelling of MRI to standard two-dimensional MRI protocol for more accurate delineation of perianal fistula and its complications aiming at better surgical outcomes.ResultsRegarding 3D models, the highest degree of accuracy was in detecting supra-levator extension (100%) by both the third radiologist and the surgeon. There was a statistically high diagnostic inter-observer agreement between both, with a p-value < 0.0001. The highest inter-observer agreement was in the supra-levator extension (50/50, 100%), and the lowest agreement was in the side branches detection (44/50, 88%).ConclusionsPre-operative 3D MRI modelling provided the surgeon with a pre- and intra-operative road map that improved the surgeon’s orientation and ability to see complex perianal fistulas and their consequences, especially those with supra levator extension, thus helping the surgeon achieve better surgical results and decrease the preoperative risk factors of recurrence. Surgeons should utilise it in complex and recurrent cases reducing preoperative risk factors and improving outcomes. Although this technique is expensive, its cost–benefit ratio is low relative to recurrent hospitalisation and complications.

Physiological alterations of pineal recess crowding in symptomatic non-hydrocephalic pineal cysts.

Pineal cysts are prevalent in the population. Due to more widespread use of magnetic resonance imaging, an increasing number of symptomatic patients with non-hydrocephalic pineal cysts are referred to neurologists and neurosurgeons. Currently, there is no generally accepted theoretical framework for linking symptoms to a pineal cyst. We have previously suggested that cyst-induced crowding of the pineal recess may affect venous runoff from the deep cerebral veins crossing the cyst. However, evidence underpinning this hypothesis is sparse. In the present study, we asked whether crowding of the pineal recess without imaging signs of hydrocephalus may be accompanied with alterations in blood flow of the internal cerebral veins, cerebrospinal fluid flow in the Sylvian aqueduct and cerebrospinal fluid-mediated tracer clearance from the brain along extravascular pathways (referred to as glymphatic function). This prospective, observational study included symptomatic individuals with non-hydrocephalic pineal cysts who underwent a standardized magnetic resonance imaging protocol (n = 25): Eleven patients were treated surgically with craniotomy and cyst extirpation and 14 individuals were managed conservatively without surgery. Our findings suggest that cyst-induced crowding of the pineal recess may have brain-wide effects: (i) There was a significant negative correlation between degree of crowding within the pineal recess and change in maximum venous flow velocity at the cyst, and a significant positive correlation between maximum venous flow velocity change at the cyst and net cerebrospinal fluid flow in the Sylvian aqueduct; (ii) increased degree of crowding in the pineal recess was accompanied by significantly impaired glymphatic enrichment in the cerebral cortex and subcortical white matter, indicative of a brain-wide effect in this cohort who also reported markedly impaired subjective sleep quality; (iii) there was a significant negative correlation between the apparent diffusion coefficient (suggestive of interstitial water content) within the thalamus and glymphatic enrichment of tracer and (iv) pineal recess crowding associated with symptoms. Comparison of the surgical cases [in whom 10/11 (91%) reported marked clinical improvement at follow-up] and the conservatively managed cases [in whom 1/14 (7%) reported marked clinical improvement at follow-up] showed differences in pre-treatment glymphatic tracer enrichment as well as differences in tracer enrichment in subarachnoid cerebrospinal fluid spaces. Taken together, we interpret these observations to support the hypothesis that cyst-induced crowding of the pineal recess without hydrocephalus may alter blood flow of the internal cerebral veins and cerebrospinal fluid flow and even cause brain-wide impairment of glymphatic transport with possible implications for cerebrospinal fluid transport of trophic factors such as melatonin.

Diagnostic performance of abbreviated gadoxetic acid-enhanced magnetic resonance protocols with contrast-enhanced computed tomography for detection of colorectal liver metastases.

Although contrast-enhanced magnetic resonance imaging (MRI) using gadoxetic acid has been shown to have higher accuracy, sensitivity, and specificity for the detection and characterization of hepatic metastases compared with other modalities, the long examination time would limit the broad indication. Several abbreviated enhanced MRI (Ab-MRI) protocols without dynamic phases have been proposed to achieve equivalent diagnostic performance for the detection of colorectal liver metastases. However, an optimal protocol has not been established, and no studies have assessed the diagnostic performance of Ab-MRI combined with contrast-enhanced computed tomography (CE-CT), which is the preoperative imaging of colorectal cancer staging in clinical settings, to determine the best therapeutic strategy. To compare the diagnostic performance of two kinds of Ab-MRI protocol with the standard MRI protocol and a combination of the Ab-MRI protocol and CE-CT for the detection of colorectal liver metastases. Study participants comprised 87 patients (51 males, 36 females; mean age, 67.2 ± 10.8 years) who had undergone gadoxetic acid-enhanced MRI and CE-CT during the initial work-up for colorectal cancer from 2010 to 2021. Each exam was independently reviewed by two readers in three reading sessions: (1) Only single-shot fast spin echo (FSE) T2-weighted or fat-suppressed-FSE-T2-weighted, diffusion-weighted, and hepatobiliary-phase images (Ab-MRI protocol 1 or 2); (2) all acquired MRI sequences (standard protocol); and (3) a combination of an Ab-MRI protocol (1 or 2) and CE-CT. Diagnostic performance was then statistically analyzed. A total of 380 Lesions were analyzed, including 195 metastases (51.4%). Results from the two Ab-MRI protocols were similar. The sensitivity, specificity, and positive and negative predictive values from Ab-MRI were non-inferior to those from standard MRI (P > 0.05), while those from the combination of Ab-MRI protocol and CE-CT tended to be higher than those from Ab-MRI alone, although the difference was not significant (P > 0.05), and were quite similar to those from standard MRI (P > 0.05). The diagnostic performances of two Ab-MRI protocols were non-inferior to that of the standard protocol. Combining Ab-MRI with CE-CT provided better diagnostic performance than Ab-MRI alone.

Retinal and optic nerve magnetic resonance diffusion-weighted imaging in acute non-arteritic central retinal artery occlusion

ObjectivesDiffusion weighted imaging hyperintensity (DWI-H) has been described in the retina and optic nerve during acute central retinal artery occlusion (CRAO). We aimed to determine whether DWI-H can be accurately identified on standard brain magnetic resonance imaging (MRI) in non-arteritic CRAO patients at two tertiary academic centers. Materials and methodsRetrospective cross-sectional study that included all consecutive adult patients with confirmed acute non-arteritic CRAO and brain MRI performed within 14 days of CRAO. At each center, two neuroradiologists masked to patient clinical data reviewed each MRI for DWI-H in the retina and optic nerve, first independently then together. Statistical analysis for inter-rater reliability and correlation with clinical data was performed. ResultsWe included 204 patients [mean age 67.9±14.6 years; 47.5% females; median time from CRAO to MRI 1 day (IQR 1-4.3); 1.5 T in 127/204 (62.3%) and 3.0 T in 77/204 (37.7%)]. Inter-rater reliability varied between centers (κ = 0.27 vs. κ = 0.65) and was better for retinal DWI-H. Miss and error rates significantly differed between neuroradiologists at each center. After consensus review, DWI-H was identified in 87/204 (42.6%) patients [miss rate 117/204 (57.4%) and error rate 11/87 (12.6%)]. Significantly more patients without DWI-H had good visual acuity at follow-up (p = 0.038). ConclusionsIn this real-world case series, differences in agreement and interpretation accuracy among neuroradiologists limited the role of DWI-H in diagnosing acute CRAO on standard MRI. DWI-H was identified in 42.6% of patients and was more accurately detected in the retina than in the optic nerve. Further studies are needed with standardized novel MRI protocols.

Harmonizing Magnetic Resonance Imaging Protocols for Veterans With Multiple Sclerosis.

Magnetic resonance imaging (MRI) assists with the diagnosis of multiple sclerosis (MS), allows for timely therapeutic intervention, and for the evaluation of disease progression, treatment effect, and safety. An international task force including representatives from the Veterans Health Administration worked together to update guidelines for imaging the brain, spinal cord, and optic nerve in people with MS. This commentary communicates the core message of the 2021 MAGNIMS-CMSC-NAIMS Consensus Recommendations on the Use of MRI in Patients With Multiple Sclerosis as part of the MS Center of Excellence effort to align with contemporary guidelines, apply the highest scientific standards, and achieve consistent outcomes for veterans with MS. To implement and disseminate these proposed recommendations within the Veterans Health Administration, a workgroup was formed at the end of 2020, which discussed a modified version of the 2021 MRI Guidelines to accommodate US Department of Veterans Affairs medical centers that had fewer imaging resources as well as veterans' needs. Standardized MRI protocols are fundamental for the care of veterans with MS. Mitigating interscan variabilities is recognized as a priority by scientific and clinical expert committees.

Pelvic CT in addition to MRI to differentiate between rectal and sigmoid cancer on imaging using the sigmoid take-off as a landmark.

The sigmoid take-off (STO) is a recently established landmark to discern rectal from sigmoid cancer on imaging. STO-assessment can be challenging on magnetic resonance imaging (MRI) due to varying axial planes. To establish the benefit of using computed tomography (CT; with consistent axial planes), in addition to MRI, to anatomically classify rectal versus sigmoid cancer using the STO. A senior and junior radiologist retrospectively classified 40 patients with rectal/rectosigmoid cancers using the STO, first on MRI-only (sagittal and oblique-axial views) and then using a combination of MRI and axial CT. Tumors were classified as rectal/rectosigmoid/sigmoid (according to published STO definitions) and then dichotomized into rectal versus sigmoid. Diagnostic confidence was documented using a 5-point scale. Adding CT resulted in a change in anatomical tumor classification in 4/40 cases (10%) for the junior reader and in 6/40 cases (15%) for the senior reader. Diagnostic confidence increased significantly after adding CT for the junior reader (mean score 3.85 vs. 4.27; P < 0.001); confidence of the senior reader was not affected (4.28 vs. 4.25; P = 0.80). Inter-observer agreement was similarly good for MRI only (κ=0.77) and MRI + CT (κ=0.76). Readers reached consensus on the classification of rectal versus sigmoid cancer in 78%-85% of cases. Availability of a consistent axial imaging plane - in the case of this study provided by CT - in addition to a standard MRI protocol with sagittal and oblique-axial imaging views can be helpful to more confidently localize tumors using the STO as a landmark, especially for more junior readers.