Fat-saturated T1 Research Articles

Optimizing functional MR urography: prime time for a 30-minutes-or-less fMRU.

Current protocols for functional MR urography (fMRU) require long scan times, limiting its widespread use. Our goal was to use pre-defined criteria to reduce the number of sequences and thus the examination time without compromising the morphological and functional results. The standard fMRU protocol in our department consists of eight sequences, including a 17-min dynamic post-contrast scan. Ninety-nine children and young adults (43 male, 56 female, mean age 7 years) were evaluated with this protocol. Each sequence was retrospectively analyzed for its utility and factors that affect its duration. Mean scan time to perform the eight sequences, without including the variable time between sequences, was 40.5 min. Five sequences were categorized as essential: (1) sagittal T2 for planning the oblique coronal plane, (2) axial T2 with fat saturation for the assessment of corticomedullary differentiation and parenchymal thickness, (3) coronal 3-D T2 with fat saturation for multiplanar and 3-D reconstructions, (4) pre-contrast coronal T1 with fat saturation to ensure an appropriate scan prior to injecting the contrast material and (5) the coronal post-contrast dynamic series. Functional information was obtained after 8 min of dynamic imaging in the majority of children. The coronal fat-saturated T2, coronal T1, and post-contrast sagittal fat-saturated T1 sequences did not provide additional information. Because of the effects of pelvicalyceal dilation and ureteropelvic angle on the renal transit time, prone position is recommended, at least in children with high-grade pelvicalyceal dilation. Comprehensive fMRU requires approximately 19 min for sequence acquisition. Allowing for time between sequences and motion correction, the total study time can be reduced to about 30 min. Four pre-contrast sequences and a shortened post-contrast dynamic scan, optimally with the child in prone position, are sufficient.

2066125 Acute Arm Muscle Injury Finding Correlation Between Us And Mr: Transient Compartment Syndrome In Arm

I showed the unusual muscle injury finding in arm. young patient come to practice for sudden developed arm pain and swelling after excercice. Reviw of the acute arm muscle pain complained patients by US and MRI. US finding was hyperechoic changed biceps ,brachialis and triceps. MR T2 FAT SAT finding was high signal intensity. 2 month after each patients clinical symptome and US finding was clearly improved . it is compatable with transient compartment syndrome . US is effective modality for diagnosis to acute arm musce pain patient.

Evaluation of shoulder pathology: three-dimensional enhanced T1 high-resolution isotropic volume excitation MR vs two-dimensional fast spin echo T2 fat saturation MR.

To evaluate the diagnostic accuracy of three-dimensional (3D) enhanced T1 high-resolution isotropic volume excitation (eTHRIVE) shoulder MR for the detection of rotator cuff tears, labral lesions and calcific tendonitis of the rotator cuff in comparison with two-dimensional (2D) fast spin echo T2 fat saturation (FS) MR. This retrospective study included 73 patients who underwent shoulder MRI using the eTHRIVE technique. Shoulder MR images were interpreted separately by two radiologists. They evaluated anatomic identification and image quality of the shoulder joint on routine MRI sequences (axial and oblique coronal T2 FS images) and compared them with the reformatted eTHRIVE images. The images were scored on a four-point scale (0, poor; 1, questionable; 2, adequate; 3, excellent) according to the degree of homogeneous and sufficient fat saturation to penetrate bone and soft tissue, visualization of the glenoid labrum and distinction of the supraspinatus tendon (SST). The diagnostic accuracy of eTHRIVE images compared with routine MRI sequences was evaluated in the setting of rotator cuff tears, glenoid labral injuries and calcific tendonitis of the SST. Fat saturation scores for eTHRIVE were significantly higher than those of the T2 FS for both radiologists. The sensitivity and accuracy of the T2 FS in diagnosing rotor cuff tears were >90%, whereas sensitivity and accuracy of the eTHRIVE method were significantly lower. The sensitivity, specificity and accuracy of both images in diagnosing labral injuries and calcific tendonitis were similar and showed no significant differences. The specificity of both images for the diagnosis of labral injuries and calcific tendonitis was higher than the sensitivities. The accuracy of 3D eTHRIVE imaging was comparable to that of 2D FSE T2 FS for the diagnosis of glenoid labral injury and calcific tendonitis of SST. The 3D eTHRIVE technique was superior to 2D FSE T2 FS in terms of fat saturation. Overall, 3D eTHRIVE was inferior to T2 FS in the evaluation of rotator cuff tears because of poor contrast between joint fluid and tendons. The accuracy of 3D eTHRIVE imaging is comparable to that of 2D FSE T2 FS for the diagnosis of glenoid labral injury and calcific tendonitis of SST.

Measurement of bone marrow lesions by MR imaging in knee osteoarthritis using quantitative segmentation methods--a reliability and sensitivity to change analysis.

BackgroundLongitudinal assessment of bone marrow lesions (BMLs) in knee osteoarthritis (KOA) by MRI is usually performed using semi-quantitative grading methods. Quantitative segmentation methods may be more sensitive to detect change over time. The purpose of this study was to evaluate and compare the validity and sensitivity to detect changes of two quantitative MR segmentation methods for measuring BMLs in KOA, one computer assisted (CAS) and one manual (MS) method.MethodsTwenty-two patients with KOA confined to the medial femoro-tibial compartment obtained MRI at baseline and follow-up (median 334 days in between). STIR, T1 and fat saturated T1 post-contrast sequences were obtained using a 1.5 T system. The 44 sagittal STIR sequences were assessed independently by two readers for quantification of BML. The signal intensities (SIs) of the normal bone marrow in the lateral femoral condyles and tibial plateaus were used as threshold values. The volume of bone marrow with SIs exceeding the threshold values (BML) was measured in the medial femoral condyle and tibial plateau and related to the total volume of the condyles/plateaus.The 95% limits of agreement at baseline were used to determine the sensitivity to change.ResultsThe mean threshold values of CAS and MS were almost identical but the absolute and relative BML volumes differed being 1319 mm3/10% and 1828 mm3/15% in the femur and 941 mm3/7% and 2097 mm3/18% in the tibia using CAS and MS, respectively. The BML volumes obtained by CAS and MS were significantly correlated but the tissue changes measured were different. The volume of voxels exceeding the threshold values was measured by CAS whereas MS included intervening voxels with normal SI.The 95% limits of agreement were narrower by CAS than by MS; a significant change of relative BML by CAS was outside the limits of -2.0%-4.7% whereas the limits by MS were -6.9%-8.2%. The BML changed significantly in 13 knees using CAS and in 10 knees by MS.ConclusionCAS was a reliable method for measuring BML and more sensitive to detect changes over time than MS. The BML volumes measured by the two methods differed but were significantly correlated.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2474-15-447) contains supplementary material, which is available to authorized users.

Magnetic resonance anatomy of the superior part of the rotator cuff in normal shoulders, assessment and practical implication.

The superior part of the rotator cuff consists of the anterior (SSa) and posterior (SSp) parts of the supraspinatus tendon, the infraspinatus (IS) tendon plus the articular capsule. An overlap of the distal SSp tendon by the anterior part of the IS one has been anatomically demonstrated; the insertion area of the IS is more anterior than currently believed. The aim of our study was to assess this complex architecture through standard MRI scans. Twenty-five healthy volunteers underwent a shoulder MRI. Three planes T2 fat saturation sequences were read in consensus by two radiologists. The SSa, the SSp, the IS tendons and the articular capsule were assessed for visibility. The patterns of demarcation of each structure from adjacent ones were assessed. The width and the thickness of each tendinous band were measured on sagittal images. The SSa, the SSp and the IS tendons were distinguishable in all patients. The anterior part of the IS tendon overlapped the SSp tendon to reach a quite anterior insertion into the greater tuberosity of the humerus. The SSa, the SSp and the IS tendons were 6.5-3.4, 15.1-2.8 and 26.8-2.2mm wide and thick, respectively. MR images of the normal superior rotator cuff are consistent with latest anatomical descriptions. The distal superposition of the IS over the SSp tendon should be considered regarding the linear increased signal areas and the commonly named "partial thickness ruptures" of the superior rotator cuff as well as the fatty infiltration of the IS muscle.

MRI-based 3D pelvic autonomous innervation: a first step towards image-guided pelvic surgery.

To analyse pelvic autonomous innervation with magnetic resonance imaging (MRI) in comparison with anatomical macroscopic dissection on cadavers. Pelvic MRI was performed in eight adult human cadavers (five men and three women) using a total of four sequences each: T1, T1 fat saturation, T2, diffusion weighed. Images were analysed with segmentation software in order to extract nervous tissue. Key height points of the pelvis autonomous innervation were located in every specimen. Standardised pelvis dissections were then performed. Distances between the same key points and the three anatomical references forming a coordinate system were measured on MRIs and dissections. Concordance (Lin's concordance correlation coefficient) between MRI and dissection was calculated. MRI acquisition allowed an adequate visualization of the autonomous innervation. Comparison between 3D MRI images and dissection showed concordant pictures. The statistical analysis showed a mean difference of less than 1 cm between MRI and dissection measures and a correct concordance correlation coefficient on at least two coordinates for each point. Our acquisition and post-processing method demonstrated that MRI is suitable for detection of autonomous pelvic innervations and can offer a preoperative nerve cartography. • Nerve preservation is a hot topic in pelvic surgery • High resolution MRI can show distal peripheral nerves • Anatomo-radiological comparison shows good correlation between MRI and dissection • 3D reconstructions of pelvic innervation were obtained with an original method • This is a first step towards image-guided pelvic surgery.

MRI IN SPINAL BONE MARROW REPLACEMENT DISORDERS

Objectives. The paper aims are: to present and illustrate the MRI aspects of the normal and pathological bone marrow involving the spine, focusing on MR techniques and interpretation in a precise clinico-biological context of each patient. Material and methods. The cases included in this study were explored using a 1.5 MRI system in T1-weighted, T2 FSE, STIR, FSE T2 Fat Sat sequences, in sagittal and or coronal plane. Sections made in the axial plane in T2 wi, were centered at the level of the lesion(s). In case of primitive or secondary tumoral lesions we have performed T1-weighted SE sequences Fat Sat pre-/ and post-iv. injection of Gd-BOPTA in multiple planes. In particular cases, we have used T1-weighted sections with a TE in and /out of phase. Imaging features. Normally, the bone marrow shows intermediate signal both on T1-/,T2 -/, Stir- weighted images in comparison to paravertebral muscle. Pathological aspects include: diffuse and focal tumor infiltration (leukemia, lymphoma, multiple myeloma, metastasis), that must be differentiate from hyperplasia (reconversion) of the red marrow, bone marrow depletion, supportive tissue pathology (primary and secondary myelofibrosis, Gaucher disease). Conclusions. MRI is the only imaging method that allows the analysis of the bone marrow. Knowledge of normal signal in different MRI sequences in correlation with the age and the clinico-biological context of the patient is essential for a correct interpretation and detection of different types of diseases involving bone marrow of the spine. In patients with a diffuse T1 hyposignal of the spinal bone marrow the differential diagnosis includes three main entities: conversion, myeloproliferative lesions and pathology of the support structures.

Magnetic resonance imaging as a non-invasive detection tool for extraovarian endometriosis – own experience

Endometriosis--due to its high incidence, associated pain and infertility--constitutes an important problem in gynecological practice. The Polish Gynecological Society Expert Panel recommends to perform magnetic resonance imaging (MRI) prior to laparoscopy The purpose of this study is to present the usefulness of MRI in the diagnosis of extraovarian endometriosis on the basis of own experience. The material consisted of 35 patients, aged 15-52 (mean 36.5 years), who were diagnosed with extraovarian endometriosis on MRI. MR examinations were performed with 1.5 T scanners according to a routine protocol, which incorporates the LAVA sequence of dynamic contrast studies protocol because of thin sections. Extraovarian endometriosis was isolated in 24 patients (68.6%), while in 11 (31.4%) it coexisted with ovarian endometriomas. In 23 cases (65.7%) extraovarian endometriosis was found in one place, in 12 (34.3%)--in two or more locations. Endometriosis was found in the following locations: abdominal wall--11 cases (37.4%), uterine body--9 (25.7%), posterior vaginal fornix--7 (20%), wall of the rectum and sigmoid colon--5 (14.3%), pararectal space--5, uterine cervix--4 (11.4%), Douglas pouch--3 (8.6%), Fallopian tube--2 (5.7%), wall of the small intestine--1 (2.8%), and urinary bladder--1. Adhesions were observed in 28.6% of the patients. MRI is an important addition to the non-invasive diagnosis of extraovarian endometriosis and should be performed before treatment, especially surgical one. The inclusion of fat saturated T1 sequence from the dynamic contrast examination in the study protocol increases the likelihood of detecting small endometrial implants.

Comparison of different magnetic resonance imaging sequences for assessment of fistula-in-ano.

To assess agreement between different forms of T2 weighted imaging (T2WI), and post-contrast T1WI in the depiction of fistula tracts, inflammation, and internal openings with that of a reference test. Thirty-nine consecutive prospective cases were enrolled. The following sequences were used for T2WI: 2D turbo-spin-echo (2D T2 TSE); 3D T2 TSE; short tau inversion recovery (STIR); 2D T2 TSE with fat saturation performed in all patients. T1WI were either a 3D T1-weighted prepared gradient echo sequence with fat saturation or a 2D T1 fat saturation [Spectral presaturation with inversion (SPIR)]. Agreement for each sequence for determination of fistula extension, internal openings, and the presence of active inflammation was assessed separately and blindly against a reference test comprised of follow-up, surgery, endoscopic ultrasound, and assessment by an independent experienced radiologist with access to all images. Fifty-six fistula tracts were found: 2 inter-sphincteric, 13 trans-sphincteric, and 24 with additional tracts. The best T2 weighted sequence for depiction of fistula tracts was 2D T2 TSE (Cohen's kappa = 1.0), followed by 3D T2 TSE (0.88), T2 with fat saturation (0.54), and STIR (0.19). Internal openings were best seen on 2D T2 TSE (Cohen's kappa = 0.88), followed by 3D T2 TSE (0.70), T2 with fat saturation (0.54), and STIR (0.31). Detection of inflammation showed Cohen's kappa of 0.88 with 2D T2 TSE, 0.62 with 3D T2 TSE, 0.63 with STIR, and 0.54 with T2 with fat saturation. STIR, 3D T2 TSE, and T2 with fat saturation did not make any contributions compared to 2D T2 TSE. Post-contrast 3D T1 weighted prepared gradient echo sequence with fat saturation showed better agreement in the depiction of fistulae (Cohen's kappa = 0.94), finding internal openings (Cohen's kappa = 0.97), and evaluating inflammation (Cohen's kappa = 0.94) compared to post-contrast 2D T1 fat saturation or SPIR where the corresponding figures were 0.71, 0.66, and 0.87, respectively. Comparing the best T1 and T2 sequences showed that, for best results, both sequences were necessary. 3D T1 weighted sequences were best for the depiction of internal openings and active inflammatory components, while 2D T2 TSE provided the best assessment of fistula extension.

Parenchymal Anaplastic Astrocytoma Presenting With Visual Symptoms Due to Bilateral Optic Nerve Sheath Involvement

A 23 year old man presented with transient visual obscurations and was found to have optic nerve edema and a thalamic lesion that did not enhance on magnetic resonance imaging. Lumbar puncture opening pressure was normal. Subsequent magnetic resonance images demonstrated optic nerve sheath enhancement. Pathological diagnosis of the thalamic mass was anaplastic astrocytoma (WHO grade III). Visual symptoms were attributed to spread of high grade parenchymal glioma to the optic nerve sheaths causing intraorbital optic nerve compression.

Comparing T1-weighted and T2-weighted three-point Dixon technique with conventional T1-weighted fat-saturation and short-tau inversion recovery (STIR) techniques for the study of the lumbar spine in a short-bore MRI machine

To compare T1-weighted (W) fat-water separation (Dixon's technique) with T1W fat-saturation (FS) and T2W Dixon with short-tau inversion recovery (STIR) images for fat suppression in a short-bore MRI machine. Thirteen patients with lumbar disease were studied on using 1.5T MRI machine. The protocol included T1 FS (with contrast medium administration) and/or STIR and T1W and/or T2W Dixon, for comparison. Three neuroradiologists scored the images from the two-pairs of techniques for fat suppression uniformity and lesion conspicuity. Clinical usefulness of fat-only images was also evaluated. Regarding uniformity of fat suppression, mean scores were 2.28 (±0.49), 3.06 (±0.49), 2.39 (±0.49), and 3.15 (±0.35) for T1W FS, T1W Dixon, STIR, and T2W Dixon sequences, respectively. For the same pulse sequences, lesion conspicuity scores were 2.78 (±0.50), 2.78 (±0.27), 2.76 (±0.47), and 2.91 (±0.4), respectively. Both T1W and T2W Dixon sequences showed more homogeneous fat-suppression when compared to T1W FS (p=0.026) and STIR (p=0.008) techniques, but no significant difference was found for lesion conspicuity. Mean scores for the diagnostic utility of fat-only maps were, respectively, 1.72 (±0.39) and 2.48 (±0.50) for T1W and T2W Dixon. Fat suppression quality was superior with Dixon when compared to the conventional sequences, but not lesion conspicuity, suggesting that both techniques are reliable for diagnosis. Dixon may be advantageous in cases where inhomogeneity artefacts are an issue. Water-only maps appear to be useful in the clinical setting.

THU0268 Local infliximab injection of sacroiliac joints in early axial spondyloarthropathies: Impact on parameters of disease activity

BackgroundSystemic administration of tumor necrosis factor-alpha (TNF-α) antagonists, such as infliximab, has been shown to be effective in the treatment of spondyloarthropathies (SpA). However, experience with the local use of...

SAT0335 Semi-quantitative assessment of bone marrow edema and synovitis-effusion in osteoarthritis with the knee inflammation MRI scoring system (KIMRISS): A target lesion based methodology

BackgroundCurrent MRI scoring methods for assessment of acute lesions such as bone marrow edema (BME) in the knee of patients with osteoarthritis rely on a complex subdivision of the knee...

SU-D-WAB-02: MRI-Based Treatment Planning in Brain Radiation Therapy: Validation of An Atlas-Based Pseudo-CT Generation Method

Purpose: To quantify the dosimetric accuracy of an atlas‐based pseudo‐CT (p‐CT) generation method in MRI‐based treatment planning, and to evaluate the influence of specific MRI sequences on p‐CT quality. Methods: For six brain IMRT patients, a p‐CT was generated from an MR image set previously used for target delineation. A research version of Advantage SIM™ software (GE Healthcare) was used to produce the p‐CT. The software uses body segmentation and bone enhancement on the input MRI, to produce a p‐CT image with a contrast similar to that of a bone atlas generated offline. The IMRT plan including the isocenter was copied on to the p‐CT and the dose was calculated in Pinnacle™. The two dose distributions were compared using (1) gamma analysis, and (2) differences between the average DVH for the target volume, and tissue contour. Results: The p‐CT visually co‐registered well with both the MRI and conventional CT in four cases where Axial T1 Spin Echo or Fast Spoiled Gradient‐Recalled Echo images were used. For these cases, the average Gamma Index 3%/3mm pass rates were 96.85%, 95.58% and 95.40%, in the axial, coronal and sagittal planes. On average, the absolute value difference between the average DVHs was 1.74 (max: 6.97) and 0.95 (max: 16.7) percentage points, for the tissue contour and target volume, respectively. Two of the MR image sequences (Axial T2 Flair and Axial T1 Fat Sat images) resulted in poor quality p‐CTs and were not used for dose comparison. Conclusion: A good agreement was seen between the p‐CT and CT dose distributions in this preliminary study, showing the potential for using MRI for both target delineation and dose calculation for brain treatments, with the clinical integration of an automated p‐CT generation method, and appropriate MRI sequences.

THU0413 Magnetic resonance imaging of hands and feet joints of ACPA positive persons without clinical arthritis

BackgroundUntil recently, the development of clinical detectable arthritis was considered as the start of Rheumatoid Arthritis (RA). Several studies have revealed that anti-citrullinated peptide antibodies (ACPA) can be present and...

AB1309 Differential diagnostic value of 1.5 TESLA extremity MRI in early arthritis

BackgroundMany studies have described the use of MRI in established rheumatoid arthritis (RA) and other rheumatic diseases. However there is a lack of studies determining its value in patients with...

Comparison of the effects of the CHESS sequence and the SPAIR sequence for fat saturation

This study compared the abilities of the chemical-shift selective saturation(CHESS) and the spectrally-adiabatic inversion recovery (SPAIR) fat-saturation techniques to resolve the recent problems in fat saturation caused by areas of changing volume such as the head and the neck and by metal artifacts when T1 fat-saturation techniques representing the anatomical images and T2 fat-saturation techniques representing pathological images are used. To compare the abilities of CHESS and SPAIR, we acquired images of the head and the neck and of the pelvis, and we compared the contrast-to-noise ratios (CNRs) and the signal-to-noise ratios (SNRs) of the signals from the flexed body parts. Images were taken of the abdomens, heads and necks, and pelvises of 15 men and 15 women (30 in total). In all scanning techniques, the SNRs and the CNRs were calculated based on a quantitative analysis method with a view to obtaining uniform data. According to the study results, the CNRs of the SPAIR and the CHESS techniques for the pelvis in the T1-weighted image were 55.10 and 67.23, respectively. The SNRs of the SPAIR technique were70.61 for muscle and 15.50 for fat whereas the SNRs of the CHESS technique were 79.23 for muscle and 12.00 for fat. For the pelvis in the T2-weighted image, the CNRs of the SPAIR and the CHESS technique were 12.50 and 16.66, respectively. The SNRs of the SPAIR technique were 16.98 for muscle and 5.14 for fat. In contrast, the SNRs of the CHESS technique were 27.90 for muscle and 11.23 for fat. Consequently, the signal intensity was higher in the CHESS than in the SPAIR technique. Nevertheless, with regard to the clinical usefulness, the image quality was higher in the SPAIR technique than in the CHESS technique.

3D fat-saturated T1 SPACE sequence for the diagnosis of cervical artery dissection

This study aims to demonstrate the added value of a 3D fat-saturated (FS) T1 sampling perfection with application-optimised contrast using different flip angle evolutions (SPACE) sequence compared to 2D FS T1 spin echo (SE) for the diagnosis of cervical artery dissection. Thirty-one patients were prospectively evaluated on a 1.5-T MR system for a clinical suspicion of acute or subacute cervical artery dissection with 3D T1 SPACE sequence. In 23 cases, the axial 2D FS T1 SE sequence was also used; only these cases were subsequently analysed. Two neuroradiologists independently and blindly assessed the 2D and 3D T1 sequences. The presence of recent dissection (defined as a T1 hyperintensity in the vessel wall) and the quality of fat suppression were assessed. The final diagnosis was established in consensus, after reviewing all the imaging and clinical data. Overall sensitivity and specificity were 0.929 and 1 for axial T1 SE, and 0.965 and 0.945 for T1 SPACE (P > 0.05), respectively. The two readers had excellent agreement for both sequences (k = 1 and 0.8175 for T1 SE and T1 SPACE, respectively; P > 0.05). The quality of the fat saturation was similar. Very good fat saturation was obtained in the upper neck. Multiplanar reconstructions were very useful in tortuous regions, such as the atlas loop of the vertebral artery or the carotid petrous entry. 3D T1 SPACE sequence has a shorter acquisition time (3min 25s versus 5min 32s for one T1 SE sequence) and a larger coverage area. 3D T1 SPACE sequence offers similar information with its 2D counterpart, in a shorter acquisition time and larger coverage area.

Normal paediatric bone marrow: Magnetic resonance imaging appearances from birth to 5 years

Bone marrow (BM) assessment is an important aspect of paediatric MRI, with the marrow cavity visible on almost every clinical MR examination. In practice, however, assessment for marrow infiltration in paediatric patients can be challenging. Our aim was to review the MRI appearance of normal BM from 0 to 5 years. Consecutive body MR examinations over 7 years were retrospectively reviewed in patients aged 0-5 years. Patients with anticipated BM abnormality were excluded. All patients had imaging of the spine and/or pelvis with T1-weighted (T1) ± T2 with fat saturation, post-contrast T1-weighted, diffusion-weighted or out-of-phase sequences. Nineteen patients were included: nine (47%) infants, 11 (58%) boys, mean age 18.2 months (range 1 day to 3 years and 10 months). On T1 imaging, 69% infant marrow sites and 24% in children >1 year were isointense, the remainder were hyperintense. One hundred per cent BM was T2 fat saturation hyperintense. Enhancement following contrast was seen in 16% of BM sites. Restricted diffusion was seen in 100% infant BM and 50% BM in children >1 year. On out-of-phase imaging, no signal loss was seen in infants, and 21% BM in children >1 year showed signal loss. Due to normal age-related differences in BM histology, MRI for marrow assessment in infants and young children can be misleading and may mimic marrow infiltration.

Conspicuity of bone metastases on fast Dixon-based multisequence whole-body MRI: Clinical utility per sequence

PurposeThe purpose of the study was to evaluate the conspicuity of bone metastases on each of the numerous sequences produced by fast Dixon-based multisequence whole-body (WB) magnetic resonance imaging (MRI) scanning in order to determine the most clinically useful sequences overall and per anatomic region. Materials and MethodsTwenty-seven breast cancer patients with bone metastases were prospectively studied with fast Dixon-based WB MRI including head/neck, chest, abdominal, pelvic, thigh, calf/feet and either cervical, thoracic and lumbar or cervical/thoracic and thoracic/lumbar regions. Sequences included coronal T2, axial T1 without and with intravenous gadolinium (+C), sagittal T1 spine+C, each associated fat-only (FO) and fat-saturated (FS) sequence, axial diffusion-weighted imaging (DWI) and short tau inversion recovery (STIR). Blinded reviewers evaluated lesion conspicuity, a surrogate of clinical utility, on a five-point scale per anatomic region. Sequences were compared using analysis of variance, differences were detected with Tukey's honestly significant difference test, and the four sequences with highest mean conspicuity were compared to the remainder overall and per anatomic region. ResultsOverall, a significant lesion conspicuity difference was found (P<.0001), and lesion conspicuity was significantly higher on FS T1+C, FO T1+C, T1+C sagittal and FS T1+C axial sequences (P<.0001). Per-region results were the same in the head/neck. Other sequences overlapped with these and included the following: chest/abdomen — FO T2, DWI; pelvis — DWI, FO T2; thigh — FS T2, FO T2, FO T1+C; calf/feet — FS T2, DWI, FO T2, STIR. ConclusionOverall, bone lesions were most conspicuous on FS T1+C sagittal, FO T1+C sagittal, T1+C sagittal and FS T1+C axial fast Dixon WB MRI sequences.