Acquisition Single-shot Turbo Spin-echo Research Articles

Quantification of Visceral Fat at the L5 Vertebral Body Level in Patients with Crohn's Disease Using T2-Weighted MRI.

The umbilical or L3 vertebral body level is often used for body fat quantification using computed tomography. To explore the feasibility of using clinically acquired pelvic magnetic resonance imaging (MRI) for visceral fat measurement, we examined the correlation of visceral fat parameters at the umbilical and L5 vertebral body levels. We retrospectively analyzed T2-weighted half-Fourier acquisition single-shot turbo spin echo (HASTE) MR axial images from Crohn's disease patients who underwent MRI enterography of the abdomen and pelvis over a three-year period. We determined the area/volume of subcutaneous and visceral fat from the umbilical and L5 levels and calculated the visceral fat ratio (VFR = visceral fat/subcutaneous fat) and visceral fat index (VFI = visceral fat/total fat). Statistical analyses involved correlation analysis between both levels, inter-rater analysis between two investigators, and inter-platform analysis between two image-analysis platforms. Correlational analysis of 32 patients yielded significant associations for VFI (r = 0.85; p < 0.0001) and VFR (r = 0.74; p < 0.0001). Intraclass coefficients for VFI and VFR were 0.846 and 0.875 (good agreement) between investigators and 0.831 and 0.728 (good and moderate agreement) between platforms. Our study suggests that the L5 level on clinically acquired pelvic MRIs may serve as a reference point for visceral fat quantification.

Interrelation Between Cerebrospinal Fluid Pressure, Intracranial Morphology and Venous Hemodynamics Studied by 4D Flow MRI.

To quantify the effects of CSF pressure alterations on intracranial venous morphology and hemodynamics in idiopathic intracranial hypertension (IIH) and spontaneous intracranial hypotension (SIH) and assess reversibility when the underlying cause is resolved. We prospectively examined venous volume, intracranial venous blood flow and velocity, including optic nerve sheath diameter (ONSD) as anoninvasive surrogate of CSF pressure changes in 11 patients with IIH, 11 age-matched and sex-matched healthy controls and 9 SIH patients, before and after neurosurgical closure of spinal dural leaks. We applied multiparametric MRI including 4D flow MRI, time-of-flight (TOF) and T2-weighted half-Fourier acquisition single-shot turbo-spin echo (HASTE). Sinus volume overlapped between groups at baseline but decreased after treatment of intracranial hypotension (p = 0.067) along with asignificant increase of ONSD (p = 0.003). Blood flow in the middle and dorsal superior sagittal sinus was remarkably lower in patients with higher CSF pressure (i.e., IIH versus controls and SIH after CSF leak closure) but blood flow velocity was comparable cross-sectionally between groups and longitudinally in SIH. We were able to demonstrate the interaction of CSF pressure, venous volumetry, venous hemodynamics and ONSD using multiparametric brain MRI. Closure of CSF leaks in SIH patients resulted in symptoms suggestive of increased intracranial pressure and caused asubsequent decrease of intracranial venous volume and of blood flow within the superior sagittal sinus while ONSD increased. In contrast, blood flow parameters from 4D flow MRI did not discriminate IIH, SIH and controls as hemodynamics at baseline overlapped at most vessel cross-sections.

Role of magnetic resonance imaging in the diagnosis of placenta accreta.

To analyze the value of magnetic resonance imaging (MRI) in suspicious cases for prenatal detection of placenta accreta (PA). A total of 50 placental MRI exams performed on a 1.5T scanner were retrospectively reviewed by two radiologists in consensus.HASTE(half-Fourier acquisition single-shot turbo spin echo)and True-FISP (true fast imaging with steady-state precession) sequences were acquired. Findings from MRI were compared with the final diagnosis, which was determined by clinical findings at delivery and pathological examination of specimens. Of 50 pregnant women in the analysis, 33 required cesarean hysterectomy, and 17 underwent cesarean delivery.MRI signs such as myometrial thinning, loss of T2 hypointense interface(loss of retroplacental clear space on US), heterogenous intraplacental sign, and intraplacental T2 dark bands were more likely to be seen in this group. In this group, the cases that were finally clinically and pathologically confirmed were 12, 16, and 22 cases of placenta accreta vera, placenta increta, and placenta percreta respectively. MRI is particularly useful in cases where US is inconclusive and to assess the extent to which the placenta penetrates the uterine serosa and invades outward into surrounding tissues.MRI has become a routine examination for patients with suspected PA in clinical practice.

Extended and weightbearing wrist 3-T MRI using a novel harness and flexible 24-channel glove coil to evaluate carpal kinematics: a pilot study in 10 volunteers.

Wrist pain in the extended or extended weightbearing positions may be incompletely evaluated using standard magnetic resonance imaging (MRI) with standard rigid clamshell coils in the neutral position. To evaluate a flexible 24-channel glove coil and harness when imaging the wrist in neutral, dorsally extended, and weightbearing positions. Ten wrists in 10 asymptomatic volunteers (mean age = 29 years) were scanned. Participants underwent 3-T MRI using the harness and flexible glove coil, acquiring sagittal turbo spin echo (TSE) and half-Fourier acquisition single-shot turbo spin echo (HASTE) pulse sequences. Static TSE images were obtained in neutral, extended, and weightbearing positions using proton density parameters and independently evaluated by two radiologists for: dorsal radiocarpal ligament thickness; radiocapitate, radiolunate, and capitatolunate angles; palmar translation of the lunate on the radius; angulation of the extensor tendons; and distance from the distal extensor retinaculum to Lister's tubercle. Cine HASTE images were dynamically acquired between neutral-maximum extension to measure the radiocapitate angle. Good reader agreement was observed (r > 0.73) for all measurements except palmar translation in the neutral position (r = 0.27). Significant increases in dorsal radiocarpal ligament thickness; radiocapitate, radiolunate and capitolunate angulation; and extensor tendon angulation were observed between the neutral and extended positions (P < 0.001). A further significant increase in these metrics between extended and weightbearing positions was also seen (P < 0.01). Significant increases in dorsal radiocarpal ligament thickness, articular and tendon angulations occur during wrist extension, that further increase with dorsal weightbearing.

Deep learning HASTE sequence compared with T2-weighted BLADE sequence for liver MRI at 3 Tesla: a qualitative and quantitative prospective study.

To qualitatively and quantitatively compare a single breath-hold fast half-Fourier single-shot turbo spin echo sequence with deep learning reconstruction (DL HASTE) with T2-weighted BLADE sequence for liver MRI at 3T. From December 2020 to January 2021, patients with liver MRI were prospectively included. For qualitative analysis, sequence quality, presence of artifacts, conspicuity, and presumed nature of the smallest lesion were assessed using the chi-squared and McNemar tests. For quantitative analysis, number of liver lesions, size of the smallest lesion, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in both sequences were assessed using the paired Wilcoxon signed-rank test. Intraclass correlation coefficients (ICCs) and kappa coefficients were used to assess agreement between the two readers. One hundred and twelve patients were evaluated. Overall image quality (p = .006), artifacts (p < .001), and conspicuity of the smallest lesion (p = .001) were significantly better for the DL HASTE sequence than for the T2-weighted BLADE sequence. Significantly more liver lesions were detected with the DL HASTE sequence (356 lesions) than with the T2-weighted BLADE sequence (320 lesions; p < .001). CNR was significantly higher for the DL HASTE sequence (p < .001). SNR was higher for the T2-weighted BLADE sequence (p < .001). Interreader agreement was moderate to excellent depending on the sequence. Of the 41 supernumerary lesions visible only on the DL HASTE sequence, 38 (93%) were true-positives. The DL HASTE sequence can be used to improve image quality and contrast and reduces artifacts, allowing the detection of more liver lesions than with the T2-weighted BLADE sequence. The DL HASTE sequence is superior to the T2-weighted BLADE sequence for the detection of focal liver lesions and can be used in daily practice as a standard sequence. • The half-Fourier acquisition single-shot turbo spin echo sequence with deep learning reconstruction (DL HASTE sequence) has better overall image quality, reduced artifacts (particularly motion artifacts), and improved contrast, allowing the detection of more liver lesions than with the T2-weighted BLADE sequence. • The acquisition time of the DL HASTE sequence is at least eight times faster (21s) than that of the T2-weighted BLADE sequence (3-5min). • The DL HASTE sequence could replace the conventional T2-weighted BLADE sequence to meet the growing indication for hepatic MRI in clinical practice, given its diagnostic and time-saving performance.

Diagnostic performance of multiparametric magnetic resonance imaging in the differentiation of clear cell renal cell cancer.

This study aimed to evaluate the diagnostic performance of multiparametric magnetic resonance imaging (mpMRI) in the differentiation of renal cell carcinoma (RCC) subtypes. This is a retrospective diagnostic performance study, in which the diagnostic performances of mpMRI features were evaluated to differentiate clear cell RCC (ccRCC) from non-clear cell RCC (non-ccRCC). Adult patients who were evaluated using a 3-Tesla dynamic contrast-enhanced mpMRI before undergoing partial or radical nephrectomy for possible malignant renal tumors were included in the study. Signal intensity change percentages (SICP) between contrast-enhanced phases and pre-administration period for both the tumor and normal renal cortex, and tumor-to-cortex enhancement index (TCEI); tumor apparent diffusion coefficient (ADC) values; tumor-to-cortex ADC ratio; and a scale which was developed according to the tumor signal intensities on the axial fat-suppressed T2-weighted Half-Fourier Acquisition Single-shot Turbo spin Echo (HASTE) images were used in ROC analysis to estimate the presence of ccRCC in the patients. The reference test positivity was the histopathologic examination of the surgical specimens. Ninety-eight tumors from 91 patients were included in the study, and 59 of them were ccRCC, 29 were pRCC, and 10 were chRCC. The mpMRI features that had the three highest sensitivity rates were excretory phase SICP, T2-weighted HASTE scale score, and corticomedullary phase TCEI (93.2%, 91.5%, and 86.4%, respectively). However, those with the three highest specificity rates were nephrographic phase TCEI, excretory phase TCEI, and tumor ADC value (94.9%, 94.9%, and 89.7%, respectively). Several parameters on mpMRI showed an acceptable performance to differentiate ccRCC from non-ccRCC.

Placental Area in the Lower Uterine Segment, Cervical Length, and Clinical Outcome in Pregnancies With Complete Placenta Previa.

Complete placenta previa is associated with a higher percentage of adverse clinical outcomes and magnetic resonance imaging (MRI) is widely used in the preoperative examination of patients with placenta previa. To evaluate the effectiveness of the placental area in the lower uterine segment and cervical length in identifying the adverse maternal-fetal outcomes in women with complete placenta previa. Retrospective. A total of 141 pregnant women (median age, 32; age range, 24-40 years) with complete placenta previa were examined by MRI to evaluate the uteroplacental condition. A 3 T with T1 -weighted imaging (T1 WI), T2 -weighted imaging (T2 WI), and half-Fourier acquisition single-shot turbo spin echo (HASTE) sequence. The association of the placental area in the lower uterine segment and cervical length measured using MRI with the risk of massive intraoperative hemorrhage (MIH) and maternal-fetal perinatal outcomes were determined. The adverse neonatal outcomes (preterm delivery, respiratory distress syndrome [RDS], admission to neonatal intensive care unit [NICU]) were analyzed in different groups. The t-test, Mann-Whitney U test, Chi-square, Fisher's exact test, and receiver operating characteristic (ROC) curve were used, and a P < 0.05 indicated a statistically significant difference. The mean operation time, intraoperative blood loss, and intraoperative blood transfusing were significantly higher in patients with large placental area and short cervix than in patients with the small placental area and long cervix, respectively. The incidence of adverse neonatal outcomes was significantly higher in the large placenta area group and short cervix group than in the small placenta group area and long cervix group, respectively, such as preterm delivery, RDS, and NICU. By combining placental area with cervical length sensitivity and specificity increased to 93% and 92%, respectively, for the identification of MIH > 2000 mL with area under the receiver operating curve (AUC) 0.941. Large placental area and short cervical length may be associated with a high risk of MIH and adverse maternal-fetal perinatal outcomes in patients with complete placenta previa. 2.

Simultaneous Highly Efficient Contrast-Free Lumen and Vessel Wall MR Imaging for Anatomical Assessment of Aortic Disease.

Bright-blood lumen and black-blood vessel wall imaging are required for the comprehensive assessment of aortic disease. These images are usually acquired separately, resulting in long examinations and potential misregistration between images. To characterize the performance of an accelerated and respiratory motion-compensated three-dimensional (3D) cardiac MRI technique for simultaneous contrast-free aortic lumen and vessel wall imaging with an interleaved T2 and inversion recovery prepared sequence (iT2Prep-BOOST). Prospective. A total of 30 consecutive patients with aortopathy referred for a clinically indicated cardiac MRI examination (9 females, mean age ± standard deviation: 32 ± 12 years). 1.5-T; bright-blood MR angiography (diaphragmatic navigator-gated T2-prepared 3D balanced steady-state free precession [bSSFP], T2Prep-bSSFP), breath-held black-blood two-dimensional (2D) half acquisition single-shot turbo spin echo (HASTE), and 3D bSSFP iT2Prep-BOOST. iT2Prep-BOOST bright-blood images were compared to T2prep-bSSFP images in terms of aortic vessel dimensions, lumen-to-myocardium contrast ratio (CR), and image quality (diagnostic confidence, vessel sharpness and presence of artifacts, assessed by three cardiologists on a 4-point scale, 1: nondiagnostic to 4: excellent). The iT2Prep-BOOST black-blood images were compared to 2D HASTE images for quantification of wall thickness. A visual comparison between computed tomography (CT) and iT2Prep-BOOST was performed in a patient with chronic aortic dissection. Paired t-tests, Wilcoxon signed-rank tests, intraclass correlation coefficient (ICC), Bland-Altman analysis. A P value < 0.05 was considered statistically significant. Bright-blood iT2Prep-BOOST resulted in significantly improved image quality (mean ± standard deviation 3.8 ± 0.5 vs. 3.3 ± 0.8) and CR (2.9 ± 0.8 vs. 1.8 ± 0.5) compared with T2Prep-bSSFP, with a shorter scan time (7.8 ± 1.7minutes vs. 12.9 ± 3.4minutes) while providing a complementary 3D black-blood image. Aortic lumen diameter and vessel wall thickness measurements in bright-blood and black-blood images were in good agreement with T2Prep-bSSFP and HASTE images (<0.02 cm and <0.005 cm bias, respectively) and good intrareader (ICC > 0.96) and interreader (ICC > 0.94) agreement was observed for all measurements. iT2Prep-BOOST might enable time-efficient simultaneous bright- and black-blood aortic imaging, with improved image quality compared to T2Prep-bSSFP and HASTE imaging, and comparable measurements for aortic wall and lumen dimensions. 2. Stage 2.

Association of MRI Features and Adverse Maternal Outcome in Patients With Placenta Accreta Spectrum Disorders After Abdominal Aortic Balloon Occlusion.

MRI features may be associated with adverse maternal outcome in patients with placenta accreta spectrum (PAS) disorders even with abdominal aortic balloon occlusion (AABO). This study aimed to identify risk factors of MRI for association with adverse maternal outcome in patients with PAS disorders after AABO. Retrospective. Clinical and MRI features of 80 patients were retrospectively reviewed from October 2016 to August 2021. A total of 40 patients had adverse maternal outcomes including intrapartum/peripartum bleeding >1000 mL and/or emergency hysterectomy after AABO. Half-Fourier acquisition single-shot turbo spin echo and gradient echo imaging True fast imaging with steady-state precession (True-FISP) at 1.5T MR scanner. MRI features were evaluated by three radiologists and were tested for any association with adverse maternal outcome. Interobserver agreement was calculated with kappa (k) statistics. Association between MRI features and adverse maternal outcomes were evaluated by univariate and multivariate analyses. A nomogram was constructed based on the logistic regression. The interobserver agreement ranged from fair to substantial (k=0.379-0.783). Multivariate analyses revealed that short cervical length (OR: 4.344), abnormal intraplacental vascularity (OR: 6.005), placental bulge (OR: 9.085), and myometrial interruption (OR: 9.550) were independent risk factors for adverse maternal outcomes. The combination of four risk factors together demonstrated the highest AUC of 0.851 (95% CI 0.769-0.933) with a sensitivity and specificity of 77.5% and 72.5%, respectively and then a nomogram composed of the above four risk factors was constructed to represent the probability of adverse maternal outcome. The nomogram demonstrated the association between MRI features and patient's poor outcome after undergoing AABO and C-section delivery for PAS. 4 TECHNICAL EFFICACY: Stage 3.

Accelerated three-dimensional susceptibility weighted imaging of the whole spine of fetus at 3T

ObjectivesTo investigate the image quality and capability of generalized auto-calibrating partially parallel acquisition (GRAPPA) accelerated Three-dimensional (3D) susceptibility weighted imaging (SWI) of the whole spine at 3T. MethodsA total of 37 pregnant women (gestation age 22 to 39 weeks, average 29 ± 3 weeks) with suspected fetal vertebral anomalies by ultrasound (US) screening underwent 3.0T MR imaging with 3D SWI, conventional two-dimensional (2D) half-flourier acquisition single-shot turbo spin-echo (HASTE) and 3D true fast imaging with steady-state precession (True FISP). The acquisition time of each protocol was recorded. Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were determined in representative interest regions of fetal thoracic vertebrae and compared among three pulse sequences. Two radiologists rated image quality independently in random order on a 5-point scale. Kappa coefficients were computed to assess inter-observer reliability. Receiver operating characteristic curves were generated, and the area under the curve (AUC) was used to compare the diagnostic performance of each protocol in vertebral deformities. ResultsThe acquisition time was 15 s for 3D-SWI and 17 s for 3D True FISP, significantly shorter than conventional HASTE (37 s; both P < 0.01).Of the three protocols, The SNR was highest on 3D True FISP, while the CNR was highest on 3D SWI. Visualization of all segments of the whole spine by 3D SWI was comparable with 3D True FISP. In contrast, 3D SWI and 3D True FISP depicted cervical and sacrococcygeal vertebrae better than HASTE. The weighted kappa statistic was 0.70–0.89 to evaluate the image quality of all segments of the whole spine, indicating good to excellent interobserver agreement. 3D SWI had the highest diagnostic performance for detecting fetal vertebral anomalies (AUC = 0.92). Conclusions3D-SWI is feasible for improved visualization of the whole fetal vertebral column and its congenital malformations with adequate image quality and high accuracy, thereby providing a supplementary method to conventional MR imaging.

Evaluation of HASTE T2 weighted image with reduced echo time for detecting focal liver lesions in patients at risk of developing hepatocellular carcinoma

PurposeTo compare the image quality and performance of half-Fourier acquisition single-shot turbo spin echo (HASTE) sequences, using compressed sensing (HASTE-CS) and deep-learning based reconstruction (HASTE-DL) in detecting focal liver lesions (FLLs), to those of T2-weighted image using BLADE sequence (T2WI) in patients at risk of developing hepatocellular carcinoma (HCC). Materials and methodsThis retrospective study included patients at risk of developing HCC who underwent liver MRI including HASTE-DL, HASTE-CS, T2WI and DWI between January and June 2020. Three radiologists independently reviewed the image quality along with FLL detection in the three T2-based sequences and DWI. Reference lesion characterization was done using the complete set of MRI sequences according to the Liver Imaging Reporting and Data System (LI-RADS) v2018. ResultsA total of 227 patients with 88 of whom had FLLs (n = 194, mean size 11.7 ± 10.9 mm) were included. HASTE-DL yielded the highest overall image quality, followed by HASTE-CS and T2WI (3.4 ± 0.5, 3.1 ± 0.6, 2.4 ± 0.5, respectively, P < 0.001 for all). In the detection of FLLs, HASTE-DL showed significantly higher sensitivity than T2WI (51.5 % vs 43.6 %, P = 0.007) whereas HASTE-CS and T2WI bore respectively little difference (P > 0.017) on per-patient basis. For LR-4, -5, -M lesions, HASTE-DL had significantly higher figure of merit than that of T2WI (0.58 vs 0.52, P < 0.001) in per-lesion basis. ConclusionHASTE-DL demonstrated better image quality and higher performance for FLL detection than conventional T2WI in patients at risk of developing HCC.

HASTE MRI sequence findings correlate with loss of deep pain perception in dogs with thoracolumbar disc extrusion.

Thoracolumbar intervertebral disc extrusion (TL IVDE) is a common reason for the veterinary hospital admission. Various imaging factors including degree and length of compression have been tested for correlation with clinical severity, but no reliable correlation has been found. Half-Fourier acquisition single-shot turbo spin echo (HASTE) magnetic resonance imaging (MRI) sequences highlight the dorsal and ventral cerebrospinal fluid (CSF) columns and have been used to demonstrate spinal cord swelling in dogs with TL IVDE. This has been used as a predictor of progressive ascending-descending myelomalacia but has not been correlated with neurological grade. This study aims to investigate the correlation between the attenuation of CSF HASTE signal and clinical severity in dogs suffering from TL disc extrusions. Dogs less than 15kg who were non-ambulatory due to suspected TL IVDE were prospectively recruited for a study into conservative management. MRI studies were undertaken under sedation including HASTE sequences. The ratio of the length of CSF attenuation to the length of the L2 vertebra was calculated and correlated with clinical severity. Twenty dogs met the inclusion criteria. No statistically significant difference was demonstrated between the mean CSF attenuation and neurological grade (p= 0.17 but there was a significant difference in the mean CSF attenuation in those who retained deep pain perception and those who did not (p= 0.02). Time to loss of ambulation was also found to not be correlated with CSF attenuation (p= 0.95). In conclusion, the length of CSF attenuation of HASTE MRI sequences in dogs less than 15kg suffering from IVDEs may be correlated with a loss of deep pain perception.

Susceptibility-weighted imaging to evaluate normal and abnormal vertebrae in fetuses: A preliminary study.

To evaluate the performance of susceptibility-weighted imaging (SWI) in visualizing normal and abnormal fetal vertebrae in vivo and in utero. Ninety-seven women with normal fetal vertebrae and 127 women suspected fetal vertebral anomalies on ultrasound were included in our study. SWI, true fast imaging with steady state precession (TrueFISP), and half-Fourier acquisition single-shot turbo spin-echo (HASTE) of the fetal spine were performed on 1.5-T magnetic resonance imaging. The image quality and diagnostic performance between HASTE/TrueFISP and SWI were compared. Pearson correlations to correlate the L1 centrum ossification center (COC) measurements with gestational age (GA) were performed. The visibility of the fetal vertebral structures on the SWI images (3.58±0.69) was significantly greater than those on the HASTE (1.98±0.51, p<0.001) and TrueFISP (2.63±0.52, p<0.001). The diagnostic accuracy of SWI (89.0%) was superior to HASTE/TrueFISP (48.0%) (p<0.001) and the area under the curve for SWI was 0.909 (p<0.001). The height, transverse, sagittal diameter, and area of L1 COC were linearly correlated with GA (all p<0.001). SWI proved to be a reliable method for depicting fetal vertebral structure and growth, which can significantly improve the diagnostic performance of vertebral anomalies in fetuses.

Radiomics analysis of T2 -weighted images for differentiating invasive placentas in women at high risks.

To develop and validate an MRI-based radiomics model for differentiating invasive placentas in patients with high risks. A total of 181 pregnant women suspected of placenta accreta spectrum (PAS) disorders and who underwent MRI for placenta evaluation were retrospectively enrolled. The data set was randomly divided into the training (n=125; invasive=63, noninvasive=62) and test (n=56; invasive=28, noninvasive=28) groups. Radiomics features were extracted from half-Fourier acquisition single-shot turbo spin echo (HASTE) and sagittal true fast imaging in steady-state precession (TRUFISP) sequences independently and mainly selected based on their correlations with invasive placentas to construct two radiomics signatures including HASTE-Radscore and TRUFISP-Radscore. Then, the predictive performance of radiomic signatures, clinical features, radiographic features, and their combination were evaluated. The model with the best predictive performance was validated with its discrimination ability, calibration, and clinical usefulness. Five radiomics features from HASTE and three radiomics features from TRUFISP were retained, respectively, for predicting invasive placentas. The combination of radiomics signatures and clinical features including prior cesarean delivery, placenta previa, and radiographic feature, the placental thickness resulted in the best discrimination ability, with area under the curve of 0.898 (95% confidence interval [CI] 0.844-0.9522) and 0.858 (95% confidence interval 0.7514-0.9655) in the training and test cohort, respectively. The combined model showed a significantly better area under the curve performance and clinical usefulness than independent clinical or radiographic model according to DeLong test (p < .05), net reclassification improvement and integrated discrimination improvement analysis (positive improvement) and decision curve analysis (higher net benefit). The T2 -weighted imaging MRI radiomics model could serve as a potential prenatal diagnosis tool for identifying invasive placentas in patients with high risks.

Abbreviated non-enhanced magnetic resonance imaging in patients with acute necrotizing pancreatitis.

To investigate the performance of T2-weighted abbreviated magnetic resonance imaging (T2W-AMRI) protocol in evaluating patients with acute necrotizing pancreatitis (ANP). A retrospective analysis of consecutive hospitalized patients with ANP who underwent MRI (contrast-enhanced, CE or non-contrast, NC) between January 2017 and November 2020was performed. The T2W-AMRI and complete MRI (cMRI) sequences were anonymized, and subsequently, two separate sets of data (AMRI and cMRI) were created for presentation to the radiologists involved in reading the data. The T2W-AMRI was based on a single-axial T2 half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence. The pancreatic and extrapancreatic findings were recorded and tabulated independently by two radiologists on T2W-AMRI and cMRI. In addition, the interobserver agreement and association of findings between T2W-AMRI and cMRI were analyzed. Twenty-eight patients (mean age 31.7 ± 12.2years, 17 females) were included. Thirteen patients had CE-cMRI, while the rest underwent NC-cMRI. There was no significant difference in the identification of pancreatic necrosis on T2W-AMRI vs. cMRI (p = 1.00). However, T2W-AMRI underestimated necrosis in one patient. Collections were accurately detected in all patients on T2W-AMRI. The mean size of the collection was larger on cMRI (6.5 ± 3.7cm) than T2W-AMRI (6 ± 3.7cm) with p = 0.006. cMRI detected more patients with disrupted pancreatic duct (n = 9) than T2W-AMRI (n = 6). However, the difference was not statistically significant (p = 0.375). There was a good to an excellent interobserver agreement between the readers for T2W-AMRI (k = 0.62-1). T2W-AMRI may offer a suitable alternative to cMRI in ANP, especially severe disease, as it can be acquired rapidly without the need for contrast injection.

Comprehensive Clinical Evaluation of a Deep Learning-Accelerated, Single-Breath-Hold Abdominal HASTE at 1.5 T and 3 T

To evaluate the clinical performance of a deep learning-accelerated single-breath-hold half-Fourier acquisition single-shot turbo spin echo (HASTEDL)-sequence for T2-weighted fat-suppressed MRI of the abdomen at 1.5 T and 3 T in comparison to standard T2-weighted fat-suppressed multi-shot turbo spin echo-sequence. A total of 320 patients who underwent a clinically indicated liver MRI at 1.5 T and 3 T between August 2020 and February 2021 were enrolled in this single-center, retrospective study. HASTEDL and standard sequences were assessed regarding overall and organ-based image quality, noise, contrast, sharpness, artifacts, diagnostic confidence, as well as lesion detectability using a Likert scale ranging from 1 to 4 (4=best). The number of visible lesions of each organ was counted and the largest diameter of the major lesion was measured. HASTEDL showed excellent image quality (median 4, interquartile range 3-4), although BLADE (median 4, interquartile range 4-4) was rated significantly higher for overall and organ-based image quality of the adrenal gland (P < .001), contrast (P < 0.001), sharpness (P < 0.001), artifacts (P < 0.001), as well as diagnostic confidence (P < .001). No significant differences were found concerning noise (P=0.886), organ-based image quality of the liver, pancreas, spleen, and kidneys (P=0.120-0.366), number and measured diameter of the detected lesions (ICC=0.972-1.0). Reduction of the aquisition time (TA) was at least 89% for 1.5 T images and 86% for 3 T images. HASTEDL provided excellent image quality, good diagnostic confidence and lesion detection compared to a standard T2-sequences, allowing an eminent reduction of the acquisition time.

Diagnostic accuracy of a fast MRI T2-sequence for the diagnosis of internal herniation after Roux-and-Y gastric bypass during pregnancy: A retrospective single center study

PurposeThe objective of this retrospective study was to evaluate the diagnostic accuracy of a fast sequence Magnetic Resonance Imaging (MRI) sequence, T2- half-Fourier acquisition single-shot turbo spin echo (HASTE) for the diagnosis of internal herniation (IH) in pregnant patients with a history of Roux-en-Y gastric bypass (RYGB). MethodsAbdominal MRI studies, performed for the clinical suspicion of IH of pregnant patients with a history of RYGB, were analyzed by two abdominal radiologists. Thirty-one cases were included and for each case both readers independently evaluated the T2 HASTE sequence in different planes (axial, coronal and sagittal) to determine the presence or absence of IH. Diagnostic performance of T2 HASTE MRI was evaluated by calculating sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy compared to the clinical diagnosis of IH as the gold standard. IH was diagnosed as the presence of herniated bowel through the mesenteric defect at the time of surgical exploration. IH was deemed absent if the surgical exploration showed no herniated bowel or if patients had no subsequent clinical symptoms of IH after 90 days of clinical follow-up. ResultsThe results in this study, with 16 patients with IH and 15 patients without IH, portray a high accuracy for the detection of IH, ranging from 87.9% to 90.3%. This fast T2 sequence shows a high NPV (86.7% - 100.0% 87.7), sensitivity (88.9% - 100.0%) and specificity (80.0% - 86.7%). This study also portrayed a substantial interobserver agreement (0.741) for the evaluation of IH. ConclusionT2 HASTE MRI shows an excellent sensitivity and NPV for the detection of IH in pregnant patients. The fast acquisition time makes this sequence useful in the emergency setting, and it can be used for the diagnosis or exclusion of IH in pregnant patients.

Perfusion Analysis of Kidney Injury in Rats With Cirrhosis Induced by Common Bile Duct Ligation Using Arterial Spin Labeling MRI.

Arterial spin labeling (ASL) has been proven to be effective in ischemia-induced acute kidney injury (AKI); however, validation of ASL magnetic resonance imaging (MRI) is limited in AKI in the presence of cirrhosis. To investigate the feasibility of ASL in revealing renal blood flow (RBF) changes in kidney injury in the presence of cirrhosis and to assess its value in the early diagnosis of disease. Longitudinal. Rats were randomized into baseline group (N = 3), sham surgery group (N = 18), and common bile duct ligation (BDL) group (N = 48). All groups were divided into six subgroups based on different sacrificed time points. 3 T scanner, prototypic pulsed ASL sequence using flow-sensitive alternating inversion recovery preparation, half-Fourier acquisition single-shot turbo spin echo sequence. RBF measurement was performed by ASL. Hematoxylin-eosin (HE) score, Hypoxia-inducible factor-1alpha (HIF-1α) score, peritubular capillar (PTC) density, alanine aminotransferase, aspartate aminotransferase, serum total bilirubin, total bile acids, serum creatinine (Scr), and blood urea nitrogen (BUN) were harvested. Analysis of variance, Pearson's correlation coefficient, and receiver operating characteristic curves were performed. P < 0.05 was considered statistically significant. RBF, HE score, HIF-1α score, and PTC density after BDL were significantly different from baseline. RBF was highly correlated with HE score, HIF-1α score, and PTC density (r = -0.7598, r = -0.7434, r = 0.6406, respectively). RBF and Scr began to differ significantly from baseline at day 3 and 7 after intervention, respectively. The areas under the curves of RBF, Scr, and BUN for distinguishing non-AKI from AKI in cirrhosis were 1.00, 0.888, and 0.911, while those for distinguishing mild from severe kidney injury were 0.961, 0.830, and 0.857, respectively. ASL allows the longitudinal assessment of the degree of AKI induced by cholestatic cirrhosis in rats and can serve as a noninvasive marker for the early and accurate diagnosis of AKI. 2 TECHNICAL EFFICACY STAGE: 2.

PD01-05 PROBING THE BLADDER WALL DIFFUSION OF INSTILLED GADOBUTROL BY MRI

You have accessJournal of UrologyInfections/Inflammation/Cystic Disease of the Genitourinary Tract: Interstitial Cystitis (PD01)1 Sep 2021PD01-05 PROBING THE BLADDER WALL DIFFUSION OF INSTILLED GADOBUTROL BY MRI Pradeep Tyagi, Chan-Hong Moon, Nishant Singh, Marc Connell, Jodi Maranchie, Christopher Chermansky, Naoki Yoshimura, and Jonathan Kaufman Pradeep TyagiPradeep Tyagi More articles by this author , Chan-Hong MoonChan-Hong Moon More articles by this author , Nishant SinghNishant Singh More articles by this author , Marc ConnellMarc Connell More articles by this author , Jodi MaranchieJodi Maranchie More articles by this author , Christopher ChermanskyChristopher Chermansky More articles by this author , Naoki YoshimuraNaoki Yoshimura More articles by this author , and Jonathan KaufmanJonathan Kaufman More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001965.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Intravesical therapy is critical for bladder cancer and a secondary option for interstitial cystitis and overactive bladder patient's refractory to oral treatment. Although paracellular diffusion of instilled drugs and radioactive agents from urine is suggested by ultrastructural studies and studies on diffusion across the excised whole bladder wall in Ussing chamber, the kinetics of diffusion across just the thickness of bladder mucosa is yet to be probed directly in a radiation-free manner with a non-invasive, non-tissue destructive method. Since MRI is capable of imaging the microscopic dimensions of bladder mucosa (Am J Physiol Renal Physiol 2020;319(3): F506-F514.), we investigated the diffusion kinetics of instilled Gadobutrol in a phantom constructed with 12% polyacrylamide (PLGA) gel, whose nanometer sized pores can partly mimic the nanometer gap of the apico-lateral tight junctions in mammalian urothelium. METHODS: PLGA gel was poured into a plastic jar while embedding 9 glass tubes which were removed upon setting of gel to create 9 cylindrical cavities for instilling ascending concentrations [0.5-20 mM] of Gadobutrol together with a fixed concentration of Ferumoxytol 0.1 mM. Phantom was wrapped by a 4 channel-flexible receiver coil for imaging in 3T scanner (Siemens, BioGraph) using T2 weighted Half-Fourier Acquisition Single-shot Turbo spin Echo imaging (HASTE) (repetition time 1000-1300 ms/echo time 80-90 ms). Gel diffusion of Gadobutrol was assessed by imaging at 30 min and at 5 h. RESULTS: The bright ring around the cavities demonstrates that molecular size of 0.8 nm permits easy diffusion of Gadobutrol into the >40 times bigger pores of 12% PLGA gel. The concentration gradient is the driving force for Gadobutrol diffusion is supported by the dependence of ring brightness on Gadobutrol concentration [0.5-20 mM] at room temperature and on the expansion of dark blob at 5 h in cavities filled with Gadobutrol 5-20 mM to recapitulate the classical pseudolayering effect of Gadobutrol accumulating into stored urine of bladder. CONCLUSIONS: MR imaging validated the linear relationship between Gadobutrol concentration in cavity and the signal gain in the surrounding gel, a surrogate for bladder mucosa. Findings support that MRI at clinical scanner can reliably assess the mucosal diffusion of instilled drugs and probes in bladder permeability assay. Source of Funding: DK 108397;CA252590 © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e32-e32 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Pradeep Tyagi More articles by this author Chan-Hong Moon More articles by this author Nishant Singh More articles by this author Marc Connell More articles by this author Jodi Maranchie More articles by this author Christopher Chermansky More articles by this author Naoki Yoshimura More articles by this author Jonathan Kaufman More articles by this author Expand All Advertisement Loading ...

Impact of rescanning and repositioning on radiomic features employing a multi-object phantom in magnetic resonance imaging

Our purpose was to analyze the robustness and reproducibility of magnetic resonance imaging (MRI) radiomic features. We constructed a multi-object fruit phantom to perform MRI acquisition as scan-rescan using a 3 Tesla MRI scanner. We applied T2-weighted (T2w) half-Fourier acquisition single-shot turbo spin-echo (HASTE), T2w turbo spin-echo (TSE), T2w fluid-attenuated inversion recovery (FLAIR), T2 map and T1-weighted (T1w) TSE. Images were resampled to isotropic voxels. Fruits were segmented. The workflow was repeated by a second reader and the first reader after a pause of one month. We applied PyRadiomics to extract 107 radiomic features per fruit and sequence from seven feature classes. We calculated concordance correlation coefficients (CCC) and dynamic range (DR) to obtain measurements of feature robustness. Intraclass correlation coefficient (ICC) was calculated to assess intra- and inter-observer reproducibility. We calculated Gini scores to test the pairwise discriminative power specific for the features and MRI sequences. We depict Bland Altmann plots of features with top discriminative power (Mann–Whitney U test). Shape features were the most robust feature class. T2 map was the most robust imaging technique (robust features (rf), n = 84). HASTE sequence led to the least amount of rf (n = 20). Intra-observer ICC was excellent (≥ 0.75) for nearly all features (max–min; 99.1–97.2%). Deterioration of ICC values was seen in the inter-observer analyses (max–min; 88.7–81.1%). Complete robustness across all sequences was found for 8 features. Shape features and T2 map yielded the highest pairwise discriminative performance. Radiomics validity depends on the MRI sequence and feature class. T2 map seems to be the most promising imaging technique with the highest feature robustness, high intra-/inter-observer reproducibility and most promising discriminative power.