scholarly journals Optimization of pulse sequences in ultrafast magnetic resonance imaging for the diagnosis of acute abdominal pain caused by gastrointestinal disease

2020 ◽  
Vol 9 (8) ◽  
pp. 205846012094924 ◽  
Author(s):  
Akitoshi Inoue ◽  
Akira Furukawa ◽  
Norihisa Nitta ◽  
Kai Takaki ◽  
Shinichi Ohta ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Abdominal Pain ◽  
Magnetic Resonance ◽  
Diagnostic Accuracy ◽  
Acute Abdominal Pain ◽  
Pulse Sequence ◽  
Pulse Sequences ◽  
Resonance Imaging ◽  
True Fisp ◽  
Significant Difference

Background Magnetic resonance imaging (MRI) is widely used to diagnose acute abdominal pain; however, it remains unclear which pulse sequence has priority in acute abdominal pain. Purpose To investigate the diagnostic accuracy of MRI and to assess the conspicuity of each pulse sequence for the diagnosis of acute abdominal pain due to gastrointestinal diseases Material and Methods We retrospectively enrolled 60 patients with acute abdominal pain who underwent MRI for axial and coronal T2-weighted (T2W) imaging, fat-suppressed (FS)-T2W imaging, and true-fast imaging with steady-state precession (True-FISP) and axial T1-weighted (T1W) imaging and investigated the diagnosis with endoscopy, surgery, histopathology, computed tomography, and clinical follow-up as standard references. Two radiologists determined the diagnosis with MRI and rated scores of the respective sequences in assessing intraluminal, intramural, and extramural abnormality using a 5-point scale after one month. Diagnostic accuracy was calculated and scores were compared by Wilcoxon-signed rank test with Bonferroni correction. Results Diagnostic accuracy was 90.0% and 93.3% for readers 1 and 2, respectively. Regarding intraluminal abnormality, T2W, FS-T2W, and True-FISP imaging were superior to T1W imaging in both readers. FS-T2W imaging was superior to True-FISP in reader 2 ( P < 0.0083). For intramural findings, there was no significant difference in reader 1, whereas T2W, FS-T2W, and True-FISP imaging were superior to T1W imaging in reader 2 ( P < 0.0083). For extramural findings, FS-T2W imaging was superior to T2W, T1W, and True-FISP imaging in both readers ( P < 0.0083). Conclusion T2W and FS-T2W imaging are pivotal pulse sequences and should be obtained before T1W and True-FISP imaging.

Magnetic Resonance Imaging of Maternal Diseases Causing Acute Abdominal Pain During Pregnancy

2005 ◽  
Vol 29 (3) ◽  
pp. 408-414 ◽  
Author(s):  
Aytekin Oto ◽  
Padmavathia N Srinivasan ◽  
Randy D Ernst ◽  
Gregory Chaljub ◽  
Alfred F Gei ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Abdominal Pain ◽  
Magnetic Resonance ◽  
Acute Abdominal Pain ◽  
Resonance Imaging

scholarly journals Performance of overnight on-call radiology residents in interpreting unenhanced abdominopelvic magnetic resonance imaging studies performed for pediatric right lower quadrant abdominal pain

2021 ◽  
Author(s):  
David M. Sawyer ◽  
Raza Mushtaq ◽  
Srinivasan Vedantham ◽  
Faryal Shareef ◽  
Sara M. Desoky ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Abdominal Pain ◽  
Magnetic Resonance ◽  
Acute Appendicitis ◽  
Surgical Pathology ◽  
Resonance Imaging ◽  
Radiology Reports ◽  
Significant Difference ◽  
Radiology Residents

Abstract Background Abdominopelvic magnetic resonance imaging (MRI) is increasingly being used to evaluate children with abdominal pain suspected of having acute appendicitis. At our institution, these examinations are preliminarily interpreted by radiology residents, especially when performed after hours. Objective To determine the accuracy of preliminary reports rendered by radiology residents in this setting. Materials and methods Three hundred seventy-seven pediatric abdominopelvic MRI examinations were included. The preliminary (resident) and final (attending) radiology reports were coded as diagnosing acute appendicitis or no acute appendicitis. The concordance between resident and attending radiologist interpretations was calculated. Additionally, both resident and attending reports were compared to available surgical pathology or clinical follow-up data. Results Overall concordance rate for the diagnosis of acute appendicitis was 97.1%. Concordance for verified cases of acute appendicitis was 93.4%. Concordance rates did not differ by residents’ postgraduate year levels. When compared against surgical pathology or clinical follow-up data, residents demonstrated 91.2% sensitivity and 97.6% specificity. There was no statistically significant difference in the sensitivity or specificity of resident or attending radiologist interpretations. Conclusion Radiology residents demonstrate high concordance with attending pediatric radiologists in their interpretations of pediatric abdominopelvic MRI for acute appendicitis. The diagnostic performances of residents and attendings were comparable.

OPTIMAL CONCENTRATIONS OF GADOVIST IN T1-WEIGHTED MAGNETIC RESONANCE IMAGING: PHANTOM STUDY AND COMPUTER SIMULATION

2011 ◽  
Vol 23 (03) ◽  
pp. 237-244 ◽  
Author(s):  
Chia-Chi Hsiao ◽  
Po-Chou Chen ◽  
Huay-Ben Pan ◽  
Jo-Chi Jao
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computer Simulation ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Pulse Sequence ◽  
Pulse Sequences ◽  
Phantom Study ◽  
Resonance Imaging ◽  
Gradient Echo ◽  
Spoiled Gradient Echo

Contrast-Enhanced Magnetic Resonance Imaging (CE-MRI) has been widely used in the diagnosis of lesions. Many contrast agents with various chemical and pharmacokinetic properties have been developed for clinical use. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) after the contrast agent administration depend on many factors, e.g. category and injected dosage of contrast agents, field strength of magnetic resonance (MR) scanner, slew rate of gradient, type of radiofrequency coil, reconstruction algorithm, pulse sequences, and so on. Gadovist is a newly developed contrast agent with high formulation of 1.0 M. It has been used in MR angiography and perfusion studies. The aim of this study is to investigate the optimal concentrations of Gadovist in MR T1-weighted (T1W) images from phantom study and computer simulation. A phantom made of 21 test tubes with various concentrations of Gadovist (0–160 mM) was investigated. All the studies were performed on a 1.5-T clinical whole-body scanner. Four T1W pulse sequences, including two-dimensional spoiled gradient echo (2DSPGR), three-dimensional fast spoiled gradient echo (3DFSPGR), conventional spin echo (CSE), and inversion recovery (IR) were employed to produce T1W images. The CNR values were calculated from regions of interest (ROIs) of all test tubes and the optimal concentration for each pulse sequence was determined. The T1 and T2 values of the phantom were also measured to obtain the relaxivities (r1 and r2). Afterward, the optimal concentration for each pulse sequence could be obtained from computer simulation by using the r1 and r2 values. The results showed that the measured optimal concentrations for 2DSPGR, 3DFSPGR, CSE and IR are 10, 20, 2.5, and 2.5 mM, respectively. The r1 and r2 values of the Gadovist phantom are 4.1 and 5.7 mM-1s-1, respectively. The optimal concentrations obtained from computer simulation are 13.5, 22.8, 2.0, and 2.7 mM for 2DSPGR, 3DFSPGR, CSE, and IR, respectively. The optimal concentrations obtained from computer simulation and phantom study are in good agreement.

INVERSION RECOVERY GRADIENT ECHO PULSE SEQUENCE PROGRAM ON A 0.7 TESLA OPEN SUPERCONDUCTING MAGNETIC RESONANCE IMAGING PLATFORM

2016 ◽  
Vol 16 (08) ◽  
pp. 1640020
Author(s):  
SHUO LI ◽  
YANCHUN ZHU ◽  
JIE YANG ◽  
YAOQIN XIE ◽  
SONG GAO
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Pulse Sequence ◽  
Pure Water ◽  
Pulse Sequences ◽  
Inversion Recovery ◽  
Resonance Imaging ◽  
Gradient Echo ◽  
Recovery Times ◽  
Magnetic Resonance Imaging Mri

The newly developed open superconducting magnetic resonance imaging (MRI) system, which combines the advantages of the high magnetic fields of superconducting MRI systems and open characteristics of permanent MRI systems, has great potential in clinical and research applications. However, few pulse sequences are applicable to this system. In addition, further testing on this system is needed. Therefore, in this paper, an inversion recovery gradient echo (IR-GE) pulse sequence was developed based on the features of the 0.7 Tesla open superconducting MRI system. An MR Solutions spectrometer was used to control the IR-GE pulse sequence. The developed IR-GE pulse sequence was applied to a pure water phantom using different inversion recovery times (TI). The results of the theoretical analysis and experiments indicate that the developed IR-GE pulse sequence could be effectively applied to the 0.7 Tesla open superconducting MRI system.

scholarly journals Values of Magnetic Resonance Imaging and Computed Tomography in the Diagnosis of Patients with Syndromes of Subacromial Impingement

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Xingfang Jiang ◽  
Zhiyan Guo ◽  
Linlin Hu ◽  
Pan Liu ◽  
Leiming Xu ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Rotator Cuff ◽  
Diagnostic Accuracy ◽  
Subacromial Impingement Syndrome ◽  
Subacromial Impingement ◽  
Resonance Imaging ◽  
Functional Disturbance ◽  
Significant Difference

Subacromial impingement syndrome (SIS) is defined as pressurization and impingement between the acromion, the bursa under the acromion, and the rotator cuff during the abduction and elevation of the shoulder joint, resulting in pain and a functional disturbance of elevation. It is the most common disorder of the shoulder, accounting for 44-65% of all complaints of shoulder pain during a physician’s office visit. The study was performed with the aim of valuing the magnetic resonance imaging (MRI) and computed tomography (CT) in diagnosing patients with SIS. A total of 68 patients with SIS were selected as study subjects and subjected to MRI and CT examinations. The diagnostic accuracy and sensitivity of MRI and CT were, respectively, 97.06 and 70.59% ( P < 0.05 ); the detection rates of SIS grade I, grade II, and grade III by MRI were 91.67%, 96.77%, and 100%, respectively, which were significantly higher than 50%, 80.65%, and 68% by CT, respectively ( P < 0.05 ). MRI and CT detection indicated that there was no significant difference in extensive rotator cuff tear, acromion stenosis, and normal acromion detected by MRI and CT ( P > 0.05 ). In conclusion, the diagnostic accuracy, sensitivity, and detection rate of acromion of MRI were higher compared with those of CT examination, and MRI is more suitable in the clinical diagnosis of SIS.

scholarly journals AB1086 POWER DOPPLER AND SPECTRAL DOPPLER ULTRASOUND IN SUSPECTED ACTIVE SACROILIITIS: A COMPARISON WITH MAGNETIC RESONANCE IMAGING AS GOLD STANDARD

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1832.1-1832
Author(s):  
P. Falsetti ◽  
E. Conticini ◽  
C. Baldi ◽  
M. Bardelli ◽  
S. Gentileschi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Diagnostic Accuracy ◽  
Doppler Ultrasound ◽  
Gold Standard ◽  
Clinical Characteristics ◽  
Power Doppler ◽  
Resonance Imaging ◽  
Asas Criteria ◽  
Spectral Doppler

Background:SIJ involvement is a characteristic feature of Spondylarthritis (SpA). Magnetic Resonance imaging (MRI) has been included in the new Assessment of SpA International Society (ASAS) criteria for the classification of Axial SpA. Gray scale US, Color Doppler ultrasound (CDUS), contrast-enhanced CDUS, and spectral Doppler (SD) US has been used in few works to evaluate the inflammatory activity of the SIJ with not conclusive results. Power Doppler ultrasound (PDUS) was not yet applied to the study of SIJ with active SI.Objectives:The aim of this work was to study with PDUS and SD US the SIJ of patients with suspected active SI, to describe inflammatory flows with spectral wave analysis (SWA) in duplex Doppler US, and to correlate US data with clinical characteristics and the presence of bone marrow edema (BME) in MRI.Methods:22 patients (18 females and 4 males, mean age 35 years) with new onset of inflammatory back pain (IBP), were included. Every patient underwent an US examination in prone position. The sonographers were blinded to the clinical data of the patient. A Esaote Twice US machine, equipped with a convex multifrequency 1-8 MHz probe, was used, with standardized parameters: 1-5 MHz for gray scale, 1.9-2.3 MHz frequency for Doppler with Pulse Repetition Frequency (PRF) of 1.0 KHz and a color gain just under the artifact limit. SIJ was located as the hypoechoic triangle delimited between the sacrum and iliac bone, and the posterior SI ligament as the upper margin. The first sacral foramen was always localized to avoid measurement of the normal pre-sacral arteries. The PDUS was applied, and if any signals were detected in the SIJ, they were scored with a 3-points scale: 0= absence of signals, 1= isolate vessels, 2= more than one vessel. The signals were also classified as intra-articular or peri-articular. The same vessels were also evaluated using quantitative SD calculating the Resistive Index (RI=peak of systolic flow- end diastolic flow/peak systolic flow), ranging between 0 and 1. Every patient underwent MRI of SIJ within the same week, before treatment. A statistical analysis was performed, estimating the sensitivity and specificity against the gold standard (presence of BME in the same SIJ according to ASAS criteria). The Spearman rank not-parametric test was applied to correlate the presence and grading of BME with PDUS grading and RI. A regression analysis was applied between PDUS results and clinical characteristics.Results:In 14/22 SIJ MRI revealed BME. In 13 of them, PDUS confirmed abnormal hypervascularisation in the intrarticular portion of SI, and in 3 in the periarticular site too. Two SIJ showed hypervascularisation at PD with no BME in MRI. A significant correlation was demonstrated between positivity and grading of PD and presence of BME in MRI (p=0.0005). SD analysis demonstrated low Resistance Index (RI) values in 14 SIJ (mean 0.57). An inverse correlation was demonstrated between RI and grading of BME in MRI (r= -0,6229, p= 0,044). The diagnostic accuracy of SD for detection of active SI varied on the basis of RI cut-off value. The best values of sensitivity (62,5%) and specificity (61,5%) were obtained with a RI cut-off values of 0.60. A multiple regression model demonstrated a significant relationship between PDUS signals and ASDAS (p=0.0382), but not with inflammatory reactants.Conclusion:PDUS and SD US of SIJ can be useful as first imaging assessment in suspected active SI, demonstrating a good diagnostic accuracy compared with MRI. Intra-articular low RI values (<0.60) on SD indicate active SI with good accuracy. Moreover, PDUS signals into the SIJ correlate with clinical symptoms but not with inflammation reactants.Figure 1.Doppler US in SI.Right SIJ with a Doppler signal along the posterior SIJ ligament, and another Doppler signal into the joint, where SD analysis gave a RI of 0,62.Disclosure of Interests:None declared

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