Pelvic imaging using a T1W fat-suppressed three-dimensional dual echo Dixon technique at 3T

Use of Dixon in magnetic resonance breast contrast-enhanced T1 weighted high-resolution imaging for mastectomy patients at 3T: A prospective study in single center

BACKGROUND

For patients with complete breast resection, conventional contrast-enhanced T1-weighted imaging (CE-T1WI) with frequency-selective spectral attenuated inversion recovery (SPAIR) provides limited fat suppression on the postoperative side due to the uneven skin surface, inhomogeneous tissue environment, and frequency-selective feature of the SPAIR scheme, leading to difficulties in precise diagnosis. This study aimed to investigate the image quality and performance of the Dixon method compared with SPAIR in breast high-resolution CE-T1WI for mastectomy patients.

MATERIALS AND METHODS

Sixty female patients who had not performed any breast surgeries were randomly selected retrospectively as the control group. Postmastectomy female patients were enrolled to undergone high-resolution CE-T1WI with SPAIR and Dixon breast scans. Subjective scores were rated using a 5-point scale. Objective parameters, including contrast-to-noise ratio (CNR), edge sharpness, and signal uniformity were measured and calculated. The Wilcoxon rank-sum test and Kappa statistic were used.

RESULTS

A total of 114 consecutive postmastectomy patients were included. Subjective scores of T1WI-SPAIR in the control group were all significantly better than those with SPAIR on the postoperative side of mastectomy patients (P < 0.01). Dixon outperformed SPAIR with significantly better subjective scores in regards to uniformity and degree of fat-suppression, anatomical structures depiction, lesion conspicuity, and axillary visibility (p < 0.05) in both post- and non-operative sides and bilateral axillary areas through the paired comparison. The objective parameters of Dixon were significantly better than those of SPAIR.

CONCLUSION

The Dixon method provided better image uniformity and higher fat suppression efficiency, and showed significant advantages in delineating the anatomical structures, with better axillary and lesion visibilities, especially on the completely removed breast side.

Can Dynamic Contrast-enhanced MRI Contribute to Improved Assessment of Rectosigmoid Involvement in Deep Infiltrating Endometriosis?

BACKGROUND/AIM

To determine whether a prototypical compressed-sensing volume-interpolated breath-hold (csVIBE) provides diagnostic value in detecting rectosigmoid infiltration in deep infiltrating endometriosis (DIE).

PATIENTS AND METHODS

csVIBE was employed in 151 women undergoing pelvic magnetic resonance imaging, of whom 43 had undergone surgery for suspected endometriosis. The accuracy of T2-weighted BLADE and BLADE/csVIBE, additional diagnostic value of csVIBE, and diagnostic confidence were rated by two readers. Additionally, the presence of the "mushroom cap sign" was assessed on BLADE and csVIBE.

RESULTS

The diagnostic accuracy, sensitivity, and specificity of BLADE and BLADE/csVIBE were not significantly different between Readers A and B. For both readers, the confidence in the diagnosis increased with csVIBE, but this increase in the odds ratio was not significant for both readers. Both readers preferred csVIBE over BLADE with regard to detection of the "mushroom cap sign."

CONCLUSION

csVIBE may provide a diagnostic benefit for surgical strategy selection through better delineation of the "mushroom cap sign."

Feasibility Study of Synthetic Diffusion-Weighted MRI in Patients with Breast Cancer in Comparison with Conventional Diffusion-Weighted MRI

OBJECTIVE

To investigate the clinical feasibility of synthetic diffusion-weighted imaging (sDWI) at different b-values in patients with breast cancer by assessing the diagnostic image quality and the quantitative measurements compared with conventional diffusion-weighted imaging (cDWI).

MATERIALS AND METHODS

Fifty patients with breast cancer were assessed using cDWI at b-values of 800 and 1500 s/mm² (cDWI₈₀₀ and cDWI₁₅₀₀) and sDWI at b-values of 1000 and 1500 s/mm² (sDWI₁₀₀₀ and sDWI₁₅₀₀). Qualitative analysis (normal glandular tissue suppression, overall image quality, and lesion conspicuity) was performed using a 4-point Likert-scale for all DWI sets and the cancer detection rate (CDR) was calculated. We also evaluated cancer-to-parenchyma contrast ratios for each DWI set in 45 patients with the lesion identified on any of the DWI sets. Statistical comparisons were performed using Friedman test, one-way analysis of variance, and Cochran's Q test.

RESULTS

All parameters of qualitative analysis, cancer-to-parenchyma contrast ratios, and CDR increased with increasing b-values, regardless of the type of imaging (synthetic or conventional) (p < 0.001). Additionally, sDWI₁₅₀₀ provided better lesion conspicuity than cDWI₁₅₀₀ (3.52 ± 0.92 vs. 3.39 ± 0.90, p < 0.05). Although cDWI₁₅₀₀ showed better normal glandular tissue suppression and overall image quality than sDWI₁₅₀₀ (3.66 ± 0.78 and 3.73 ± 0.62 vs. 3.32 ± 0.90 and 3.35 ± 0.81, respectively; p < 0.05), there was no significant difference in their CDR (90.0%). Cancer-to-parenchyma contrast ratios were greater in sDWI₁₅₀₀ than in cDWI₁₅₀₀ (0.63 ± 0.17 vs. 0.55 ± 0.18, p < 0.001).

CONCLUSION

sDWI₁₅₀₀ can be feasible for evaluating breast cancers in clinical practice. It provides higher tumor conspicuity, better cancer-to-parenchyma contrast ratio, and comparable CDR when compared with cDWI₁₅₀₀.

MRI for the diagnosis and staging of deeply infiltrating endometriosis: a national survey of BSGE accredited endometriosis centres and review of the literature

OBJECTIVES

Our objective was to establish the primary mode of imaging and MR protocols utilised in the preoperative staging of deeply infiltrating endometriosis in centres accredited by the British Society of Gynaecological Endoscopy (BSGE).

METHODS

The lead consultant radiologist in each centre was invited to complete an online survey detailing their protocols.

RESULTS

Out of 49 centres, 32 (65%) responded to the survey. Two centres performed transvaginal ultrasound as the primary method for preoperative staging of deeply infiltrating endometriosis and the remainder performed MRI. 21/25 centres did not recommend a period of fasting prior to MRI and 22/25 administered hyoscine butylbromide. None of the centres routinely offered bowel preparation or recommended a specific pre-procedure diet. 21/25 centres did not time imaging according to the woman's menstrual cycle, and instructions regarding bladder filling were varied. Rectal and vaginal opacification methods were infrequently utilised. All centres preferentially performed MRI in the supine position - six used an abdominal strap and four could facilitate prone imaging. Just under half of centres used pelvic-phased array coils and three centres used gadolinium contrast agents routinely. All centres performed T1W with fat-suppression and T2W without fat-suppression sequences. There was significant variation relating to other MR sequences depending on the unit.

CONCLUSIONS

There was significant inconsistency between centres in terms of MR protocols, patient preparation and the sequences performed. Many practices were out of line with current published evidence.

ADVANCES IN KNOWLEDGE

Our survey demonstrates a need for evidence-based standardisation of imaging in BSGE accredited endometriosis centres.

Recommendations for MRI technique in the evaluation of pelvic endometriosis: consensus statement from the Society of Abdominal Radiology endometriosis disease-focused panel

Endometriosis is a common entity causing chronic pain and infertility in women. The gold standard method for diagnosis is diagnostic laparoscopy, which is invasive and costly. MRI has shown promise in its ability to diagnose endometriosis and its efficacy for preoperative planning. The Society of Abdominal Radiology established a Disease-Focused Panel (DFP) to improve patient care for patients with endometriosis. In this article, the DFP performs a literature review and uses its own experience to provide technical recommendations on optimizing MRI Pelvis for the evaluation of endometriosis.

Quality comparison between three-dimensional T2-weighted SPACE and two-dimensional T2-weighted turbo spin echo magnetic resonance images for the brachytherapy planning evaluation of prostate and periprostatic anatomy

PURPOSE

The purpose of this study was to compare an isotropic three-dimensional (3D) T2-weighted sequence sampling perfection with application-optimized contrasts by using flip angle evolution (SPACE) with an axial two-dimensional T2-weighted turbo spin echo (TSE) sequence with regard to overall image quality and the delineation of normal prostate and periprostatic anatomy for low-dose-rate prostate cancer brachytherapy planning evaluation.

METHODS AND MATERIALS

Patients (n = 69) with prostate cancer who had pelvic magnetic resonance imaging (MRI) for low-dose-rate brachytherapy treatment planning were included. Three radiologists independently assessed the visibility of nine anatomic structures on each sequence by using a 5-point scale and overall image quality by using a 4-point scale. The significance of the differences in diagnostic performance was tested with a Wilcoxon signed rank test.

RESULTS

No significant intersequence differences were found for most (7/9) anatomical structures and overall image quality. The mean scores for visibility of anatomical structures on the 3D SPACE and 2D TSE sequences, respectively, were as follows: the zonal anatomy (3.7; 3.9, p = 0.05), prostate capsule (3.9; 4.0, p = 0.08), neurovascular bundle (2.9; 2.9, p = 0.9), rectoprostatic angle (3.8; 3.8, p = 0.35), rectum (4.2; 4.3, p = 0.26), urethra (3.8; 3.9, p = 0.12), urinary bladder (4.6; 4.6, p = 0.61), and overall image quality (2.9; 2.9, p = 0.33). 3D SPACE was superior for delineation of the genitourinary diaphragm (3.8; 3.6, p = 0.003), whereas 2D TSE was superior for delineation of the seminal vesicles (3.5; 4.0, p < 0.0001).

CONCLUSIONS

Anatomic delineation of the prostatic and periprostatic anatomy provided by the 3D SPACE sequence is as robust in quality as that provided by a conventional 2D TSE sequence with superior delineation of the genitourinary diaphragm. For MRI-based brachytherapy treatment planning, the 3D SPACE sequence with subcentimeter isotropic resolution can replace the 2D TSE sequence and be incorporated into standard MRI protocols.

Quantitative evaluation of computed and voxelwise computed diffusion-weighted imaging in breast cancer

OBJECTIVES

To assess the value of computed diffusion-weighted imaging (cDWI) and voxelwise computed diffusion-weighted imaging (vcDWI) in breast cancer.

METHODS

This retrospective study involved 130 patients (age range, 25-70 years; mean age ± standard deviation, 48.6 ± 10.5 years) with 130 malignant lesions, who underwent MRI examinations, including a DWI sequence, prior to needle biopsy or surgery. cDWIs with higher b-values of 1500, 2000, 2500, 3000, 3500, and 4000 s/mm², and vcDWI were generated from measured (m) DWI with two lower b-values of 0/600, 0/800, or 0/1000 s/mm². The signal-to-noise ratio (SNR) and contrast ratio (CR) of all image sets were computed and compared among different DWIs by two experienced radiologists independently. To better compare the CR with the SNR, the CR value was multiplied by 100 (CR100).

RESULTS

The CR of vcDWI, and cDWIs, except for cDWI₁₀₀₀, differed significantly from that of measured diffusion-weighted imaging (mDWI) (cDWI₁₀₀₀: CR = 0.4904, p = 0.394; cDWI₁₅₀₀: CR = 0.5503, p = 0.006; cDWI₂₀₀₀: CR = 0.5889, p < 0.001; cDWI₂₅₀₀: CR = 0.6109, p < 0.001; cDWI₃₀₀₀: mean = 0.6214, p < 0.001; cDWI₃₅₀₀: CR = 0.6245, p < 0.001; cDWI₄₀₀₀: CR = 0.6228, p < 0.001). The vcDWI provided the highest CR, while the CRs of all cDWI image sets improved with increased b-values. The SNR of neither cDWI₁₀₀₀ nor vcDWI differed significantly from that of mDWI, but the mean SNRs of the remaining cDWIs were significantly lower than that of mDWI. The SNRs of cDWIs declined with increasing b-values, and the initial decrease at low b-values was steeper than the gradual attenuation at higher b-values; the CR₁₀₀ rose gradually, and the two converged on the b-value interval of 1500-2000 s/mm² .

CONCLUSIONS

The highest CR was achieved with vcDWI; this could be a promising approach easier detection of breast cancer.

ADVANCES IN KNOWLEDGE

This study comprehensively compared and evaluated the value of the emerging post-processing DWI techniques (including a set of cDWIs and vcDWI) in breast cancer.

MRI for prostate cancer: can computed high b-value DWI replace native acquisitions?

OBJECTIVE

To compare computed high b-value diffusion-weighted images (c-DWI) derived from low b-value DWI images and acquired high b-value DWI (a-DWI), in overall image quality and prostate cancer detection rate.

MATERIALS AND METHODS

A total of 124 consecutive men with suspected prostate cancer (PCa) underwent diagnosis prostate MRI on a 3.0 T MR system using a 32-channel phased-array torso coil. Among them, 63 underwent prostate biopsy. MRI protocol included 3DT2w images, high resolution Fov Optimized and Constrained Undistorted Single-Shot (FOCUS™) DWI images with b-values of 100, 400, 800, and 2000 s/mm² and dynamic contrast enhanced images. C-DWI images (2000 and 2500 s/mm²) were derived from the three lower acquired b-value DWI images using a mono-exponential diffusion decay. C-DWI and acquired high b-value DWI (a-DWI) (2000 s/mm²) were compared for image quality (background signal suppression, anatomic clarity, ghosting, distortion) and tumor conspicuity by four radiologists.

RESULTS

C-DWIs demonstrated higher rating than a-DWIs for overall image quality despite worsened ghosting. In patients with a biopsy, similar detection rate was observed while conspicuity was better with c-DWI (p < 0.001). Non-acquisition of high b-value a-DWI reduced total acquisition time by 220 s per patient.

CONCLUSION

C-DWI provides a substantial reduction in acquisition time while maintaining comparable prostate cancer detection rate and improving global image quality.

KEY POINTS

• Computed DWI improves global quality of prostate MRI. • Computed DWI improves analysis of DWI images with decrease acquisition time. • Computed DWI provides greater background suppression of parenchyma and improves conspicuity of suspicious lesion.

Combined application of isotropic three-dimensional fast spin echo (3D-FSE-Cube) with 2-point Dixon fat/water separation (FLEX) and 3D-FSE-cube in MR dacryocystography

Objective:

To evaluate the image quality of magnetic resonance dacryocystography (MRD) using three-dimesional fast spin-echo -Cube (3D-FSE-Cube) and 3D-FSE-Cube-Flex sequences to examine the lacrimal drainage system (LDS).

Methods:

21 healthy volunteers underwent 3D-FSE-Cube and 3D-FSE-Cube-Flex MRD after topical administration of compound sodium chloride eye drops. Two radiologists assessed LDS images in a blinded fashion. The signal-to-noise ratio of fluid-filling and the contrast-to-noise ratio of fluid-turbinate were compared between the two sequences. Overall image quality, sharpness, artefacts, visualization of anatomical structures, and visibility of LDS segments were also compared.

Results:

Overall image quality, visualization of anatomic structures, and artefact were significantly better on 3D-FSE-Cube-Flex MRD (p < 0.001, respectively). when compared to 3D-FSE-Cube. 3D-FSE-Cube showed lower fluid-filling signal-to-noise ratio and fluid-inferior turbinate CNR (all p < 0.001). In comparison with 3D-FSE-Cube-Flex, 3D-FSE-Cube produced superior visibility of the upper drainage segments (superior canaliculi, p = 0.003; common canaliculus, p = 0.033; inferior canaliculi, p < 0.001), but inferior in lower-LDS visibility (lacrimal sac, p = 0.001; nasolacrimal duct, p < 0.001). There was no difference in the total number of segments visualized per LDS between the two sequences (p = 0.068).

Conclusions:

3D-FSE-Cube-Flex demonstrated superior image quality and visibility of the lower LDS segments. 3D-FSE-Cube showed an advantage in visualizing the upper LDS segments. The combination of these sequences can improve LDS visibility.

Advances in knowledge:

3D-FSE-Cube-Flex provides robust water & fat separation and mitigates lower LDS-associated inhomogeneity artefacts. 3D-FSE-Cube shows optimal upper LDS visualization. The combined application of these sequences is a non-invasive and effective method for assessing LDS disease.

The applied research of simultaneous image acquisition of T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) in the assessment of patients with prostate cancer

We aimed to evaluate the feasibility of simultaneous image acquisition of multiple instantaneous switchable scan (MISS) for prostate magnetic resonance imaging (MRI) on 3T. Fifty-three patients were scanned with MRI due to suspected prostate cancer. Twenty-eight of them got histological results. First, two readers assessed the structure delineation and image quality based on images of conventional T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) (CTD). Second, two readers identified the index lesion together, and then, reader one evaluated the contrast of index lesion on T2WI and signal ratio on apparent diffusion coefficient map. Third, they assigned Prostate Imaging Reporting and Data System (PI-RADS) score in consensus for the index lesion. After 4 weeks, the images of MISS were reviewed by the same readers following the same process. Finally, two readers gave preference for image interpretation, respectively. Kappa coefficient, Wilcoxon signed-rank test, paired-sample t-test, Bland–Altman analysis, and receiver operating characteristic (ROC) analysis were used for statistical analysis. The acquisition time of CTD was 6 min and 10 s, while the acquisition time of MISS was 4 min and 30 s. Interobserver agreements for image evaluation were κ = 0.65 and κ = 0.80 for CTD and MISS, respectively. MISS-T2WI showed better delineation for seminal vesicles than CTD-T2WI (reader 1: P < 0.001, reader 2: P = 0.001). The index lesion demonstrated higher contrast in MISS-T2WI (P < 0.001). The PI-RADS scores based on CTD and MISS exhibited high ability in predicting clinically significant cancer (area under curve [AUC] = 0.828 vs 0.854). Readers preferred to use MISS in 41.5%–47.2% of cases. MISS showed comparable performance to conventional technique with less acquisition time.

Fat suppression techniques for breast MRI: Dixon versus spectral fat saturation for 3D T1-weighted at 3 T

OBJECTIVE

To compare two fat suppression techniques used for 3D T1-weighted sequence in breast MRI (magnetic resonance imaging), namely Dixon versus spectral fat saturation (fat sat).

MATERIALS AND METHODS

All breast MRI examinations performed in a Philips 3 T unit between March 2013 and October 2015 including either a Dixon or a fat sat sequence were retrospectively analyzed. The examinations were subjectively evaluated by two independent experienced readers in a scale of 5 for overall quality of fat suppression, homogeneity of fat suppression, definition of anatomic structures and focal lesions, diagnostic confidence for axillary and internal mammary regions and the presence of artifacts, 1 corresponding to excellent and 5 to non-diagnostic quality. Contrast-to-noise-ratio (CNR) measurements for muscle and focal lesions were also performed.

RESULTS

Overall 161 women (mean age 51.6 ± 12.0 years) underwent 189 MR examinations, 113 with the fat saturation and 76 with the Dixon sequence. Interobserver variability was good (kappa = 0.757). In all subjectively evaluated parameters, the Dixon sequence was superior to the fat sat (p < 0.05). Mean values of CNR for muscle and focal lesions were 9.98 (±4.2), 17.9 (±7.53) for the fat sat and 18.3 (±10.4) and 29.3 (±14.1) for the Dixon sequence, respectively (p < 0.001).

CONCLUSION

3D T1 Dixon sequence is superior to fat sat for dedicated breast MRI at 3 T, in terms of efficiency of fat suppression and image quality with the added advantage of optimal exploration of the axillary areas.

Visualization, Quantification and Characterization of Caerulein-Induced Acute Pancreatitis in Rats by 3.0T Clinical MRI, Biochemistry and Histomorphology

Purpose: To investigate whether Caerulein-induced acute pancreatitis (AP) in rats could be noninvasively studied by clinical magnetic resonance imaging (MRI) techniques and validated by enzymatic biochemistry and histomorphology. Materials and Methods: The study was approved by the institutional animal ethical committee. The AP was induced in 26 rats by intraperitoneal injections of Caerulein, as compared to 6 normal rats. T2-weighted 3D MRI, T2 relaxation measurement and contrast enhanced T1-weighted MRI were performed at 3 Tesla. Pancreatic volume and contrast ratio of pancreas against surrounding tissues were measured by MRI. Animals were scarified at 3, 8, 24 and 48-hr respectively for analyses of serum lipase and amylase levels, and biliopancreatic perfusion-assisted histomorphology. Results: The AP could be observed on MRI 3-hr onwards after Caerulein-administration. T2 relaxation within the pancreas was prolonged due to high water content or edema. Increase of vascular permeability was indicated by T1 contrast enhancement. Both edema and vascular permeability gradually recovered afterwards (p<0.05/0.01), paralleled by declining serum enzyme levels (p<0.05). Microscopy revealed cell vacuolization and edema for early stage, and increased inflammatory cell infiltration and acinar cell loss after 24 and 48-hr. Conclusion: Multiparametric MRI techniques at 3.0T could facilitate noninvasive diagnosis and characterization of Caerulein induced AP in rats, as validated by a novel ex vivo method.

European society of urogenital radiology (ESUR) guidelines: MR imaging of pelvic endometriosis

Abstract

Endometriosis is a common gynaecological condition of unknown aetiology that primarily affects women of reproductive age. The accepted first-line imaging modality is pelvic ultrasound. However, magnetic resonance imaging (MRI) is increasingly performed as an additional investigation in complex cases and for surgical planning. There is currently no international consensus regarding patient preparation, MRI protocols or reporting criteria. Our aim was to develop clinical guidelines for MRI evaluation of pelvic endometriosis based on literature evidence and consensus expert opinion. This work was performed by a group of radiologists from the European Society of Urogenital Radiology (ESUR), experts in gynaecological imaging and a gynaecologist expert in methodology. The group discussed indications for MRI, technical requirements, patient preparation, MRI protocols and criteria for the diagnosis of pelvic endometriosis on MRI. The expert panel proposed a final recommendation for each criterion using Oxford Centre for Evidence Based Medicine (OCEBM) 2011 levels of evidence.

Key Points

• This report provides guidelines for MRI in endometriosis.

• Minimal and optimal MRI acquisition protocols are provided.

• Recommendations are proposed for patient preparation, best MRI sequences and reporting criteria.

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-016-4673-z) contains supplementary material, which is available to authorized users.

Liver acquisition with volume acceleration flex on 70-cm wide-bore and 60-cm conventional-bore 3.0-T MRI

This study aimed to compare the uniformity of fat suppression and image quality between liver acquisition with volume acceleration flex (LAVA-Flex) and LAVA on 60-cm conventional-bore and 70-cm wide-bore 3.0-T magnetic resonance imaging (MRI). The uniformity of fat suppression by LAVA-Flex and LAVA was assessed as the efficiency of suppression of superficial fat at the levels of the liver dome, porta, and renal hilum. Percentage standard deviation (%SD) was calculated using the following equation: %SD (%) = 100 × SD of the regions of interest (ROIs)/mean value of the signal intensity (SI) in the ROIs. Signal-to-noise ratio (SNR) and contrast ratio (CR) were calculated. In the LAVA sequence, the %SD in all slices on wide-bore 3.0-T MRI was significantly higher than that on conventional-bore 3.0-T MRI (P < 0.01). However, there was no significant difference in fat signal uniformity between the conventional and wide-bore scanners when LAVA-Flex was used. In the liver, there were no significant differences in SNR between the two sequences. However, the SNR in the pancreas was lower for the wide-bore scanner than for the conventional-bore scanner for both sequences (P < 0.05). There were no significant differences in CR for the liver and fat between LAVA-Flex and LAVA in both scanners. The CR in the LAVA-Flex images obtained by wide-bore MRI was significantly higher than that in the LAVA-Flex images recorded by conventional-bore MRI (P < 0.001). LAVA-Flex offers more homogenous fat suppression in the upper abdomen than LAVA for both conventional and wide-bore 3.0-T MRI.

Prostate Cancer Detection Using Computed Very High b-value Diffusion-weighted Imaging: How High Should We Go?

RATIONALE AND OBJECTIVES

The aim of this study was to assess prostate cancer detection using a broad range of computed b-values up to 5000 s/mm(2).

MATERIALS AND METHODS

This retrospective Health Insurance Portability and Accountability Act-compliant study was approved by an institutional review board with consent waiver. Forty-nine patients (63 ± 8 years) underwent 3T prostate magnetic resonance imaging before prostatectomy. Examinations included diffusion-weighted imaging (DWI) with b-values of 50 and 1000 s/mm(2). Seven computed DWI image sets (b-values: 1000, 1500, 2000, 2500, 3000, 4000, and 5000 s/mm(2)) were generated by mono-exponential fit. Two blinded radiologists (R1 [attending], R2 [fellow]) independently evaluated diffusion weighted image sets for image quality and dominant lesion location. A separate unblinded radiologist placed regions of interest to measure tumor-to-peripheral zone (PZ) contrast. Pathologic findings from prostatectomy served as reference standard. Measures were compared between b-values using the Jonckheere-Terpstra trend test, Spearman correlation coefficient, and generalized estimating equations based on logistic regression for correlated data.

RESULTS

As b-value increased, tumor-to-PZ contrast and benign prostate suppression for both readers increased (r = +0.65 to +0.71, P ≤ 0.001), whereas anatomic clarity, visualization of the capsule, and visualization of peripheral-transition zone edge decreased (r = -0.69 to -0.75, P ≤ 0.003). Sensitivity for tumor was highest for R1 at b1500-3000 (84%-88%) and for R2 at b1500-2500 (70%-76%). Sensitivities for both pathologic outcomes were lower for both readers at both b1000 and the highest computed b-values. Sensitivity for Gleason >6 tumor was highest for R1 at b1500-3000 (90%-93%) and for R2 at 1500-2500 (78%-80%). The positive predictive value for tumor for R1 was similar from b1000 to 4000 (93%-98%) and for R2 was similar from b1500 to 4000 (88%-94%).

CONCLUSIONS

Computed b-values in the range of 1500-2500 s/mm(2) (but not higher) were optimal for prostate cancer detection; b-values of 1000 or 3000-5000 exhibited overall lower performance.

[Evaluation of Image Quality in Three-dimensional Fat-suppressed T1-weighted Images with Fast Acquisition Mode for Upper Abdomen]

We compared the uniformity of fat-suppression and image quality using three-dimensional fat-suppressed T₁-weighted gradient-echo sequences that are liver acquisition with volume acceleration (LAVA) and Turbo-LAVA at 3.0T-MRI. The subjects were seven patients with liver disease (mean age, 66.7±8.2 years). The axial slices of two LAVA sequences were used for the comparison of the uniformity of fat-suppression and image quality at a region-of-interest (ROI) of the liver dome, the porta, and the renal hilum. To yield a quantitative measurement of the uniformity of fat suppression, the percentage standard deviation (%SD) was calculated by comparing two sequences. For image signal to noise ratio (SNR), the contrast between the liver and fat (C_liver-fat), and the liver and muscle (C_liver-muscle), the other ROIs were placed in the superficial fat, liver, spleen, pancreas, and muscle. The %SD in Turbo-LAVA (28.1±16.8%) was lower than that in LAVA (41.5±13.4%). The SNRs in Turbo-LAVA (17.8±4.1 [liver], 12.5±3.0 [pancreas], 14.7±1.6 [spleen], 8.2±3.5 [fat]) were lower than those in LAVA (20.9±6.1 [liver], 16.8±4.1 [pancreas], 17.4±2.4 [spleen], 12.0±4.5 [fat]). While, the C_liver-fat in the Turbo-LAVA (0.72±0.06) was significantly higher than that in LAVA (0.59±0.07). Turbo-LAVA sequence offers superior and more homogenous fat-suppression in comparison to LAVA sequence.

Advances in T1-weighted and T2-weighted imaging in the abdomen and pelvis

Utilization of abdominopelvic MR imaging continues to increase in volume and gain widespread clinical acceptance. Many factors such as diaphragmatic respiratory motion, bulk patient motion, and the need for large volumetric coverage while maintaining clinically feasible scan times have proven challenging for body applications of MRI. However, many advances in MR acquisition, including non-Cartesian T1-weighted and T2-weighted acquisitions, advanced Dixon sequences, and 3-dimensional volumetric T2-weighted imaging have helped to mitigate some of the issues which have hampered abdominopelvic MR. This article will summarize these advances in T1-weighted and T2-weighted imaging, with an emphasis on clinical applications and implementation.

Usefulness of two-point Dixon fat-water separation technique in gadoxetic acid-enhanced liver magnetic resonance imaging

AIM: To compare differences between volumetric interpolated breath-hold examination (VIBE) using two-point Dixon fat-water separation (Dixon-VIBE) and chemically selective fat saturation (FS-VIBE) with magnetic resonance imaging examination.

METHODS: Forty-nine patients were included, who were scanned with two VIBE sequences (Dixon-VIBE and FS-VIBE) in hepatobiliary phase after gadoxetic acid administration. Subjective evaluations including sharpness of tumor, sharpness of vessels, strength and homogeneity of fat suppression, and artifacts that were scored using a 4-point scale. The liver-to-lesion contrast was also calculated and compared.

RESULTS: Dixon-VIBE with water reconstruction had significantly higher subjective scores than FS-VIBE in strength and homogeneity of fat suppression (< 0.0001) but lower scores in sharpness of tumor (P < 0.0001), sharpness of vessels (P = 0.0001), and artifacts (P = 0.034). The liver-to-lesion contrast on Dixon-VIBE images was significantly lower than that on FS-VIBE (16.6% ± 9.4% vs 23.9% ± 12.1%, P = 0.0001).

CONCLUSION: Dixon-VIBE provides stronger and more homogenous fat suppression than FS-VIBE, while has lower clarity of focal liver lesions in hepatobiliary phase after gadoxetic acid administration.

Dynamic contrast-enhanced MRI of the prostate with high spatiotemporal resolution using compressed sensing, parallel imaging, and continuous golden-angle radial sampling: preliminary experience

PURPOSE

To demonstrate dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) of the prostate with both high spatial and temporal resolution via a combination of golden-angle radial k-space sampling, compressed sensing, and parallel-imaging reconstruction (GRASP), and to compare image quality and lesion depiction between GRASP and conventional DCE in prostate cancer patients.

MATERIALS AND METHODS

Twenty prostate cancer patients underwent two 3T prostate MRI examinations on separate dates, one using standard DCE (spatial resolution 3.0 × 1.9 × 1.9 mm, temporal resolution 5.5 sec) and the other using GRASP (spatial resolution 3.0 × 1.1 × 1.1 mm, temporal resolution 2.3 sec). Two radiologists assessed measures of image quality and dominant lesion size. The experienced reader recorded differences in contrast arrival times between the dominant lesion and benign prostate.

RESULTS

Compared with standard DCE, GRASP demonstrated significantly better clarity of the capsule, peripheral/transition zone boundary, urethra, and periprostatic vessels; image sharpness; and lesion conspicuity for both readers (P < 0.001-0.020). GRASP showed improved interreader correlation for lesion size (GRASP: r = 0.691-0.824, standard: r = 0.495-0.542). In 8/20 cases, only GRASP showed earlier contrast arrival in tumor than benign; in no case did only standard DCE show earlier contrast arrival in tumor.

CONCLUSION

High spatiotemporal resolution prostate DCE is possible with GRASP, which has the potential to improve image quality and lesion depiction as compared with standard DCE.

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

AIM

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.

MATERIALS AND METHODS

Thirteen patients with lumbar disease were studied on using 1.5 T 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.

RESULTS

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.

CONCLUSION

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.

Magnetic resonance imaging of pediatric muscular disorders: recent advances and clinical applications

This review describes various quantitative magnetic resonance imaging techniques that can be used to objectively analyze the composition (T2 relaxation time mapping, Dixon imaging, and diffusion-weighted imaging), architecture (diffusion tensor imaging), mechanical properties (magnetic resonance elastography), and function (magnetic resonance spectroscopy) of normal and pathologic skeletal muscle in the pediatric population.

Fat suppression strategies in MR imaging of breast cancer at 3.0 T: comparison of the two-point Dixon technique and the frequency selective inversion method

PURPOSE

To compare two fat suppression methods in contrast-enhanced MR imaging of breast cancer at 3.0 T: the two-point Dixon method and the frequency selective inversion method.

MATERIALS AND METHODS

Forty female patients with breast cancer underwent contrast-enhanced three-dimensional T1-weighted MR imaging at 3.0 T. Both the two-point Dixon method and the frequency selective inversion method were applied. Quantitative analyses of the residual fat signal-to-noise ratio and the contrast noise ratio (CNR) of lesion-to-breast parenchyma, lesion-to-fat, and parenchyma-to-fat were performed. Qualitative analyses of the uniformity of fat suppression, image contrast, and the visibility of breast lesions and axillary metastatic adenopathy were performed.

RESULTS

The signal-to-noise ratio was significantly lower in the two-point Dixon method (P < 0.001). All CNR values were significantly higher in the two-point Dixon method (P < 0.001 and P = 0.001, respectively). According to qualitative analysis, both the uniformity of fat suppression and image contrast with the two-point Dixon method were significantly higher (P < 0.001 and P = 0.002, respectively). Visibility of breast lesions and metastatic adenopathy was significantly better in the two-point Dixon method (P < 0.001 and P = 0.03, respectively).

CONCLUSION

The two-point Dixon method suppressed the fat signal more potently and improved contrast and visibility of the breast lesions and axillary adenopathy.

Computed diffusion-weighted imaging of the prostate at 3 T: impact on image quality and tumour detection

OBJECTIVES

To investigate the impact of prostate computed diffusion-weighted imaging (DWI) on image quality and tumour detection.

METHODS

Forty-nine patients underwent 3-T magnetic resonance imaging using a pelvic phased-array coil before prostatectomy, including DWI with b values of 50 and 1,000 s/mm(2). Computed DW images with b value 1,500 s/mm(2) were generated from the lower b-value images. Directly acquired b-1,500 DW images were obtained in 39 patients. Two radiologists independently assessed DWI for image quality measures and location of the dominant lesion. A third radiologist measured tumour-to-peripheral-zone (PZ) contrast. Pathological findings from prostatectomy served as the reference standard.

RESULTS

Direct and computed b-1,500 DWI showed better suppression of benign prostate tissue than direct b-1,000 DWI for both readers (P ≤ 0.024). However, computed b-1,500 DWI showed less distortion and ghosting than direct b-1,000 and direct b-1,500 DWI for both readers (P ≤ 0.067). Direct and computed b-1,500 images showed better sensitivity and positive predictive value (PPV) for tumour detection than direct b-1,000 images for both readers (P ≤ 0.062), with no difference in sensitivity or PPV between direct and computed b-1,500 images (P ≥ 0.180). Tumour-to-PZ contrast was greater on computed b-1,500 than on either direct DWI set (P < 0.001).

CONCLUSION

Computed DWI of the prostate using b value ≥1,000 s/mm(2) improves image quality and tumour detection compared with acquired standard b-value images.

KEY POINTS

• Diffusion weighted MRI is increasingly used for diagnosing and assessing prostate carcinoma. • Prostate computed DWI can extrapolate high b-value images from lower b values. • Computed DWI provides greater suppression of benign tissue than lower b-value images. • Computed DWI provides less distortion and artefacts than images using same b value. • Computed DWI provides better diagnostic performance than lower b-value images.

Liver T2-weighted MR imaging: assessment of a three-dimensional fast spin-echo with extended echo train acquisition sequence at 1.5 Tesla

PURPOSE

To retrospectively compare image quality and lesion detectability with two T2-weighted sequences at 1.5 Tesla (T): respiratory-triggered three-dimensional fat sat fast-spin-echo with extended echo-train acquisition (3D FSE-XETA) and respiratory-triggered two-dimensional fat-sat fast recovery fast-spin-echo (2D FRFSE).

MATERIALS AND METHODS

MR was performed at 1.5T in 53 consecutive patients. Two radiologists blinded to the sequence details reviewed the studies to determine: (i) signal and contrast to noise ratios, (ii) overall image quality, (iii) sensitivity for focal lesion detection.

RESULTS

Image assessment scores for the 2D FRFSE sequence were significantly higher than those for the 3D FSE-XETA sequence for overall image quality (P < 0.01) and artifacts (P < 0.001). Sensitivity for liver lesion detection was higher with the 3D FSE-XETA sequence (69.3% versus 57.3%; P < 0.05) compared with the 2D FRFSE sequence. The 3D FSE-XETA sequence improves the reader confidence score (P < 0.01) for liver lesions detection. Inter-observer correlation was higher with the 3D FSE-XETA sequence.

CONCLUSION

For T2-weighted liver imaging at 1.5T, the 3D FSE-XETA sequence improves sensitivity, reader confidence score and interobserver correlation for focal liver lesion detection, but it suffers from a lower overall image quality and higher artifacts.

Diagnosis of focal nodular hyperplasia with MRI: multicenter retrospective study comparing gadobenate dimeglumine to gadoxetate disodium

OBJECTIVE

The purpose of this article is to report the results from a multicenter retrospective MRI study comparing gadobenate dimeglumine and gadoxetate disodium for diagnosis of hepatic focal nodular hyperplasia (FNH).

MATERIALS AND METHODS

Thirty patients (28 women and two men; mean age, 37.1 years) with hepatic FNH who underwent both gadobenate dimeglumine- and gadoxetate disodium-enhanced MRI at 1.5 T were assessed. MRI was performed during the arterial, portal venous, late venous, and hepatobiliary contrast-enhanced phases (10 and 20 minutes or 1-3 hours after contrast administration, respectively, for gadoxetate disodium and gadobenate dimeglumine). Qualitative (lesion conspicuity score) and quantitative (lesion signal intensity [SI] ratio and lesion contrast ratio) assessments were performed.

RESULTS

In 30 patients, 51 FNHs were assessed (mean size 3.1 ± 1.5 cm). There was equivalent qualitative lesion conspicuity in the arterial phase between the two contrast agents and higher qualitative lesion conspicuity and SI ratio in the hepatobiliary phase with gadoxetate disodium (p < 0.002). Lesion contrast ratio was significantly higher in the arterial and late venous phases with gadobenate dimeglumine (p < 0.009), with no difference in the portal venous and hepatobiliary phases between the two contrast agents (p > 0.22).

CONCLUSION

These results indicate an advantage for gadobenate dimeglumine for detection of FNH at the dynamic phase and for gadoxetate disodium at the hepatobiliary phase. However, the equivalent or better qualitative lesion conspicuity coupled with the ability to obtain a comprehensive evaluation of the liver within a standard 30-minute imaging window suggests that gadoxetate disodium may be a better choice for diagnosis of FNH.

Prostate cancer: feasibility and preliminary experience of a diffusional kurtosis model for detection and assessment of aggressiveness of peripheral zone cancer

PURPOSE

To assess the feasibility of diffusional kurtosis (DK) imaging for distinguishing benign from malignant regions, as well as low- from high-grade malignant regions, within the peripheral zone (PZ) of the prostate in comparison with standard diffusion-weighted (DW) imaging.

MATERIALS AND METHODS

The institutional review board approved this retrospective HIPAA-compliant study and waived informed consent. Forty-seven patients with prostate cancer underwent 3-T magnetic resonance imaging by using a pelvic phased-array coil and DW imaging (maximum b value, 2000 sec/mm2). Parametric maps were obtained for apparent diffusion coefficient (ADC); the metric DK (K), which represents non-Gaussian diffusion behavior; and corrected diffusion (D) that accounts for this non-Gaussianity. Two radiologists reviewed these maps and measured ADC, D, and K in sextants positive for cancer at biopsy. Data were analyzed by using mixed-model analysis of variance and receiver operating characteristic curves.

RESULTS

Seventy sextants exhibited a Gleason score of 6; 51 exhibited a Gleason score of 7 or 8. K was significantly greater in cancerous sextants than in benign PZ (0.96±0.24 vs 0.57±0.07, P<.001), as well as in cancerous sextants with higher rather than lower Gleason score (1.05±0.26 vs 0.89±0.20, P<.001). K showed significantly greater sensitivity for differentiating cancerous sextants from benign PZ than ADC or D (93.3% vs 78.5% and 83.5%, respectively; P<.001), with equal specificity (95.7%, P>.99). K exhibited significantly greater sensitivity for differentiating sextants with low- and high-grade cancer than ADC or D (68.6% vs 51.0% and 49.0%, respectively; P≤.004) but with decreased specificity (70.0% vs 81.4% and 82.9%, respectively; P≤.023). K had significantly greater area under the curve for differentiating sextants with low- and high-grade cancer than ADC (0.70 vs 0.62, P=.010). Relative contrast between cancerous sextants and benign PZ was significantly greater for D or K than ADC (0.25±0.14 and 0.24±0.13, respectively, vs 0.18±0.10; P<.001).

CONCLUSION

Preliminary findings suggest increased value for DK imaging compared with standard DW imaging in prostate cancer assessment.

Preliminary clinical experience at 3 T with a 3D T2-weighted sequence compared with multiplanar 2D for evaluation of the female pelvis

OBJECTIVE

The purpose of this article is to compare 3D T2-weighted sampling perfection with application-optimized contrast with different flip-angle evolutions (SPACE) with three-plane 2D turbo-spin echo (TSE) sequences for female pelvic imaging at 3 T.

MATERIALS AND METHODS

Twenty women were imaged with 2D TSE and 3D SPACE sequences. Three radiologists independently assessed image quality, diagnostic quality, and artifacts; measured normal anatomic structures; evaluated pathologic abnormalities; and recorded interpretation time. Readers subsequently performed a side-by-side comparison, and their preferences were graded according to overall interpretation, sharpness of lesion edges, motion and other artifacts, uterine and cervical zonal anatomy distinction, identification of adnexal pathologic abnormalities, and distinction between fat and fluid. Quantitative comparison of relative signal intensity and relative tissue contrast was performed.

RESULTS

The mean acquisition time of 3D SPACE was significantly shorter than that of 2D TSE (6 minutes 35 seconds vs 8 minutes 50 seconds; p < 0.005). Intrareader agreement between interpretations of 2D and 3D sequences was excellent. There were no significant differences among readers in detecting artifacts, normal structures, and pathologic abnormalities or in determining endometrial thickness, image quality, or interpretation time (p > 0.05). Except for distinctions between fat and fluid, the average reader score indicated a slight preference for the 3D sequence. Three-dimensional multiplanar reconstructions were helpful but not considered essential. Relative agreement between readers was moderate (r ≥ 0.4) to strong (r ≥ 0.7). The relative signal intensity was higher for fat and bladder fluid on the 3D sequence than on the 2D sequence (p = 0.014 and p = 0.018, respectively). Relative tissue contrast was higher for the 3D sequence (p < 0.05), with no significant difference in bladder or fat contrast (p = 0.31) but a trend toward more superior contrast on the 2D sequence.

CONCLUSION

At 3 T, 3D SPACE has similar image quality and diagnostic quality with shorter scan time when compared with 2D TSE but with reduced contrast between fat and fluid.

Quantification of fat infiltration in oculopharyngeal muscular dystrophy: comparison of three MR imaging methods

PURPOSE

To analyze and compare three quantitative MRI methods to determine the degree of muscle involvement in oculopharyngeal muscular dystrophy (OPMD).

MATERIALS AND METHODS

Muscle fat content (MFC) was determined based on water-fat quantification using a 2-point Dixon (2PD) method and on a histogram analysis of the free induction decay (FID) signal of a gradient-spoiled steady-state free precession (SSFP) sequence. In addition, transverse relaxation times (T₂) of muscle tissue were calculated using a monoexponential decay model.

RESULTS

We observed an increased mean MFC in OPMD patients as compared to healthy controls with the adductor magnus and soleus muscles being the most involved muscles in the thigh and calf, respectively. Furthermore, strong correlations (0.78 < R² < 0.94) between different quantitative MR methods were observed. Fewer outliers, however, were obtained by the 2PD method and T₂ measurements, suggesting these methods being superior to the SSFP-FID method.

CONCLUSION

Quantitative MR techniques, such as fast multiecho Dixon methods and T₂ imaging, can reliably differentiate between healthy and dystrophic muscles in OPMD, even if muscles are only marginally affected. Quantitative methods thus represent a promising tool that may be able to monitor more objectively the individual disease progression and treatment response in future clinical trials in muscular dystrophies.

Feasibility of 3.0T pelvic MR imaging in the evaluation of endometriosis

INTRODUCTION

Endometriosis represents an important clinical problem in women of reproductive age with high impact on quality of life, work productivity and health care management. The aim of this study is to define the role of 3T magnetom system MRI in the evaluation of endometriosis.

MATERIALS AND METHODS

Forty-six women, with transvaginal (TV) ultrasound examination positive for endometriosis, with pelvic pain, or infertile underwent an MR 3.0T examination with the following protocol: T2 weighted FRFSE HR sequences, T2 weighted FRFSE HR CUBE 3D sequences, T1 w FSE sequences, LAVA-flex sequences. Pelvic anatomy, macroscopic endometriosis implants, deep endometriosis implants, fallopian tube involvement, adhesions presence, fluid effusion in Douglas pouch, uterus and kidney pathologies or anomalies associated and sacral nervous routes were considered by two radiologists in consensus. Laparoscopy was considered the gold standard.

RESULTS

MRI imaging diagnosed deep endometriosis in 22/46 patients, endometriomas not associated to deep implants in 9/46 patients, 15/46 patients resulted negative for endometriosis, 11 of 22 patients with deep endometriosis reported ovarian endometriosis cyst. We obtained high percentages of sensibility (96.97%), specificity (100.00%), VPP (100.00%), VPN (92.86%).

CONCLUSION

Pelvic MRI performed with 3T system guarantees high spatial and contrast resolution, providing accurate information about endometriosis implants, with a good pre-surgery mapping of the lesions involving both bowels and bladder surface and recto-uterine ligaments.

A method for automatic identification of water and fat images from a symmetrically sampled dual-echo Dixon technique

Sampling water and fat signals symmetrically (i.e., at 0 degrees and 180 degrees relative phase angles) in a dual-echo Dixon technique offers high intrinsic tolerance to phase fluctuations in postprocessing and maximum signal-to-noise performance for the separated water and fat images. However, identification of which image is water and which image is fat after their separation is not possible based on the phase information alone. In this work, we proposed a semiempirical automatic image identification method that is based on the intrinsic asymmetry between the water and fat chemical shift spectra. Specifically, the approximately bimodal feature of the fat spectra and the observation that most in vivo tissues are either predominantly water or predominantly fat are used to construct a spectrum-based algorithm. Additional refinement is accomplished by considering the spatial distribution of the tissues that may have a coexistence of water and fat. The final improved algorithm was tested on a total of 131 three-dimensional patient datasets collected from different scanners and found to yield correct water and fat identification in all datasets.

Fast dixon-based multisequence and multiplanar MRI for whole-body detection of cancer metastases

PURPOSE

To develop and demonstrate the feasibility of multisequence and multiplanar MRI for whole-body cancer detection.

MATERIALS AND METHODS

Two fast Dixon-based sequences and a diffusion-weighted sequence were used on a commercially available 1.5 T scanner for whole-body cancer detection. The study enrolled 19 breast cancer patients with known metastases and in multistations acquired whole-body axial diffusion-weighted, coronal T2-weighted, axial/sagittal pre- and postcontrast T1-weighted, as well as triphasic abdomen images. Three radiologists subjectively scored Dixon images of each series for overall image quality and fat suppression uniformity on a 4-point scale (1 = poor, 2 = fair, 3 = good, and 4 = excellent).

RESULTS

Eighteen of the 19 patients completed the whole-body MRI successfully. The mean acquisition time and overall patient table time were 46 +/- 3 and 69 +/- 5 minutes, respectively. The average radiologists' scores for overall image quality and fat suppression uniformity were both 3.4 +/- 0.5. The image quality was consistent between patients and all completed whole-body examinations were diagnostically adequate.

CONCLUSION

Whole-body MRI offering essentially all the most optimal tumor-imaging sequences in a typical 1-hour time slot can potentially become an appealing "one-stop-shop" for whole-body cancer imaging.