Narrative review of the utility of magnetic resonance imaging in radiotherapy for cervical cancer.

BACKGROUND AND OBJECTIVE: In radiotherapy (RT) for locally advanced cervical cancer, high soft tissue contrast on magnetic resonance imaging (MRI) can ensure accurate delineation of target volumes (TVs) and optimal dose distribution to the RT target and organs at risk (OAR). MRI-guided adaptive RT (MRIgART) is a novel technology that revises RT plans according to anatomical changes occurring throughout the treatment to improve target coverage and minimise OAR toxicity. This review aims to assess the evidence and gaps of MRI use in RT planning and MRIgART in the treatment of cervical cancer, as well as challenges in its clinical implementation. METHODS: Ovid Medline and PubMed were searched using keywords for MRI in RT for cervical cancer. After applying the inclusion and exclusion criteria, the initial search was deduced to 32 studies. A total of 37 final studies were reviewed, including eight additional articles from references. KEY CONTENT AND FINDINGS: In the primary studies, TVs and organ motion were assessed before, during, and after treatment. MRI was used to investigate dose distribution and therapeutic response to the treatment in association with its outcome. Lastly, rationales for MRIgART were evaluated. CONCLUSIONS: It was concluded that MRI enables accurate target delineation, assessment of organ motion and interfraction changes, and monitoring of treatment response through dynamic parameters. Enhanced target coverage and reduced OAR irradiation through MRIgART can improve local control and the overall outcome, although its rationales against the logistical challenges need to be evaluated on further research.

Using gamma-band transcranial alternating current stimulation (tACS) to improve sleep quality and cognition in patients with mild neurocognitive disorders due to Alzheimer's disease: A study protocol for a randomized controlled trial.

BACKGROUND: Sleep disturbances are highly prevalent in patients with age-related neurodegenerative diseases, which severely affect cognition and even lead to accumulated ß-amyloid. Encouraging results from recent studies on transcranial direct current stimulation (tDCS) showed moderate positive effects on sleep quality in preclinical Alzheimer's disease (AD). Compared to tDCS, transcranial alternating current stimulation (tACS) enables the entrainment of neuronal activity with optimized focality through injecting electric current with a specific frequency and has significant enhancement effects on slow wave activities. METHODS AND DESIGN: This is a randomized, double-blind, sham-controlled clinical trial comparing 40 Hz tACS with tDCS in mild neurocognitive disorders due to AD with sleep disturbances. Magnetic resonance imaging (MRI) data is used to construct personalized realistic head model. Treatment outcomes, including sleep quality, cognitive performance and saliva Aß levels will be conducted at baseline, 4th week, 8th week, 12th week and 24th week. CONCLUSIONS: It is expected that the repeated gamma-band tACS will show significant improvements in sleep quality and cognitive functions compared to tDCS and sham tDCS. The findings will provide high-level evidence and guide further advanced studies in the field of neurodegenerative diseases and sleep medicine. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05544201.

Subsegmental pulmonary embolism and anticoagulant therapy: the impact of clinical context.

BACKGROUND: Anticoagulation for subsegmental pulmonary embolism (SSPE) is controversial. AIM: To assess the impact of clinical context on anticoagulation and outcomes of SSPE. METHODS: We electronically searched computed tomography pulmonary angiogram reports to identify SSPE. We extracted demographic, risk factor, investigations and outcome data from the electronic medical record. We stratified patients according to anticoagulation and no anticoagulation. RESULTS: From 1 January 2017 to 31 December 2019, we identified 166 patients with SSPE in 5827 pulmonary angiogram reports. Of these, 123 (74%) received anticoagulation. Compared with non-anticoagulated patients, such patients had a different clinical context: higher rates of previous venous thromboembolism (11% vs 0%; P = 0.019), more recent surgery (26% vs 9%; P = 0.015), more elevated serum D-dimer (22% vs 5%; P = 0.004), more lung parenchymal abnormalities (76% vs 61%; P = 0.037) and were almost twice as likely to require inpatient care (76% vs 42%; P < 0.001). Such patients also had twice the all-cause mortality at 1 year (32% vs 16%). CONCLUSIONS: SSPE is diagnosed in almost 3% of pulmonary angiograms and is associated with high mortality, regardless of anticoagulation, due to coexistent disease processes rather than SSPE. Anticoagulation appears dominant but markedly affected by the clinical context of risk factors, alternative indications and illness severity. Thus, the controversy is partly artificial because anticoagulation after SSPE is clinically contextual with SSPE as only one of several factors.

Endometriosis: A multimodal imaging review.

Endometriosis is a chronic inflammatory disorder characterized endometrial-like tissue present outside of the uterus, affecting approximately 10% of reproductive age women. It is associated with abdomino-pelvic pain, infertility and other non - gynecologic symptoms, making it a challenging diagnosis. Several guidelines have been developed by different international societies to diagnose and classify endometriosis, yet areas of controversy and uncertainty remains. Transvaginal ultrasound (TV-US) is the first-line imaging modality used to identify endometriosis due to its accessibility and cost-efficacy. Enhanced sonographic techniques are emerging as a dedicated technique to evaluate deep infiltrating endometriosis (DIE), depending on the expertise of the sonographer as well as the location of the lesions. MRI is an ideal complementary modality to ultrasonography for pre-operative planning as it allows for a larger field-of-view when required and it has high levels of reproducibility and tolerability. Typically, endometriotic lesions appear hypoechoic on ultrasonography. On MRI, classical features include DIE T2 hypointensity, endometrioma T2 hypointensity and T1 hyperintensity, while superficial peritoneal endometriosis (SPE) is described as a small focus of T1 hyperintensity. Imaging has become a critical tool in the diagnosis, surveillance and surgical planning of endometriosis. This literature review is based mostly on studies from the last two decades and aims to provide a detailed overview of the imaging features of endometriosis as well as the advances and usefulness of different imaging modalities for this condition.

Temporal processing deficit in children with attention-deficit/hyperactivity disorder: An online assessment.

Objective: Temporal processing deficits were found among children with attention-deficit/hyperactivity disorder (ADHD). The present study aims to develop an online temporal processing assessment that can be conducted remotely, and the sensitivity of the test was assessed on a group of children with ADHD. Methods: A total of 188 children were recruited, including 94 typically developing (TD) children, and 94 children with ADHD. The online assessment consists of two temporal-order judgment (TOJ) tasks. One task used tone pairs presented with two interstimulus intervals (ISIs) (305ms and 40ms). Another task used pairs of consonant-vowel (CV) syllables with 20 varying ISI levels. Participants were asked to determine the sequence of the sound pairs. Results: The results showed that ADHD children were less accurate (ISI 305ms: M = 83.90%; ISI 40ms: M = 66.28%) than TD children (ISI 305ms: M = 89.36%; ISI 40ms: M = 77.16%) in the tone task. Similarly, ADHD children showed a higher ISI passing threshold (M = 283.64ms) than TD children (M = 199.76ms) and higher accuracy in the CV task. Hierarchical binary logistic regression suggested a model to predict ADHD children using accuracy in ISI 40ms in the tone task and ISI passing threshold in the CV task. Receiver operating characteristic (ROC) analysis yielded a sensitivity of 75.58% and a specificity of 51.11%. Conclusion: ADHD children showed temporal processing deficits of both tones and CVs. The online assessment may be a valid tool for differentiating ADHD children from TD children.

Eye-tracking training improves the learning and memory of children with learning difficulty.

Children who experience difficulty in learning at mainstream schools usually are provided with remediation classes after school to facilitate their learning. The present study aims to evaluate an innovative eye-tracking training as possible alternative remediation. Our previous findings showed that children who received eye-tracking training demonstrated improved attention and inhibitory control, and the present randomized controlled study aims to evaluate if eye-tracking training can also enhance the learning and memory of children. Fifty-three primary school students with learning difficulty (including autism spectrum disorder, attention-deficit/hyperactivity disorder, specific learning disorder, specific language impairment and borderline intellectual functioning) were recruited and randomly assigned to either the Eye-tracking Training group or the after-school remediation class. They were assessed on their learning and memory using the Hong Kong List Learning Test before and after 8-month training. Twenty weekly parallel sessions of training, 50 min per session, were provided to each group. Children who received the eye-tracking training, not those in the control group, showed a significant improvement in memory as measured by the delayed recall. In addition, the Eye-Tracking Training group showed significantly faster learning than the control group. Also, the two groups showed a significant improvement in their reading abilities. In sum, eye-tracking training may be effective training for enhancing the learning and memory of children with learning difficulties.

Preoperative Imaging in Patients with Deep Infiltrating Endometriosis: An Important Aid in Predicting Depth of Infiltration in Rectosigmoid Disease.

STUDY OBJECTIVE: To determine the diagnostic accuracy of specialist-performed transvaginal ultrasound (TVUS) and pelvic magnetic resonance imaging (MRI) modalities in predicting depth of deep infiltrating endometriosis (DIE) of the rectosigmoid by comparison with histologic specimens obtained at surgery. DESIGN: A retrospective analysis, which met the Standards for Reporting of Diagnostic Accuracy Studies (2015) guidelines for a diagnostic accuracy study. SETTING: Tertiary teaching hospital. PATIENTS: A total of 194 cases who underwent preoperative discussion at the gynecologic endosurgery unit multidisciplinary meeting between January 2012 and December 2019 were eligible for inclusion. INTERVENTIONS: Retrospective assessment of the accuracy of TVUS and MRI in predicting histologic depth of rectosigmoid DIE after operative management. MEASUREMENTS AND MAIN RESULTS: Al total of 135 surgeries were performed for DIE; 20 underwent a rectal shave, 14 had a disc/wedge resection, 38 an anterior/segmental resection, and 63 had no rectosigmoid surgery. Of the 52 patients with full-thickness rectal wall excision, all patients had at least one imaging modality available for review; 42 (81%) had both. At least one imaging modality was in agreement with histologic depth in 48 cases (92%) (sensitivity, 94%; specificity, 50%; positive predictive value [PPV], 97.9%; negative predictive value [NPV], 25.0%; area under the receiver operating curve, 0.720; 95% confidence interval, 0.229-1.000). When TVUS was assessed in isolation, the test remained sensitive for any rectal wall involvement (sensitivity, 93.6%; specificity, 50.0%; PPV, 97.8%; NPV, 25.0%; area under the receiver operating curve, 0.718; 95% confidence interval, 0.227-1.000). When only MRI was assessed, the test demonstrated both high sensitivity and specificity for rectal wall disease (sensitivity, 86.4%; specificity, 100%; PPV, 100%; NPV, 14.2). CONCLUSION: Specialist-performed TVUS and MRI are accurate in predicting depth of disease in rectosigmoid endometriosis. These modalities were similar in their diagnostic performance at assessing depth of rectal wall involvement, and their use is justified in the preoperative planning of these gynecologic surgeries.

Diagnostic Utility of MRI Features of Placental Adhesion Disorder for Abnormal Placentation and Massive Postpartum Hemorrhage.

OBJECTIVE. The study's aim was to assess MRI, in cases in which MRI was deemed clinically necessary, to determine its diagnostic accuracy for placental adhesion disorder (PAD) and prognostic accuracy for massive postpartum hemorrhage (PPH). Additionally, we investigated the diagnostic utility of MRI in the antenatal workup of PAD as an adjunct to clinical assessment and ultrasound. MATERIALS AND METHODS. We retrospectively identified patients who underwent antenatal MRI for suspicion of PAD. Images were reviewed by two radiologists who were blinded to surgical and pathologic outcomes. Diagnostic utility of various clinical, ultrasound, and MRI features of PAD were estimated by ROC analysis. Logistic regression analysis was performed to assess various diagnostic models for PAD and prognostic models for massive PPH, with model selection based on Bayesian information criterion. RESULTS. Fifty-six patients met the inclusion criteria. Sensitivity and specificity of MRI in the diagnosis of PAD were 93% and 81%, respectively. The most accurate MRI features for PAD were myometrial thinning (AUC = 0.881), heterogeneous placenta (AUC = 0.864), and placental bulge (AUC = 0.845). The most accurate MRI features for massive PPH were heterogeneous placenta (AUC = 0.872) and dark intraplacental bands (AUC = 0.736). The addition of MRI to a model based on clinical and ultrasound features was preferred for both diagnosis of PAD and prognosis of massive PPH. CONCLUSION. This study shows the utility of certain MRI features for identification of PAD and massive PPH. Furthermore, our data show a substantial incremental benefit of the addition of MRI in the antenatal workup for PAD compared with clinical assessment and ultrasound alone.

Radiologically and clinically diagnosed acute pulmonary oedema in critically ill patients: prevalence, patient characteristics, treatments and outcomes.

Background: Acute pulmonary oedema is a life-threatening syndrome diagnosed based on radiological and clinical findings. However, to our knowledge, no studies have investigated this syndrome in critically ill patients. Objective: To describe the prevalence of radiologically and clinically diagnosed pulmonary oedema (RCDPO) in critically ill patients, characteristics of diagnosed patients, and treatments and outcomes in this patient population. Methods: We conducted a retrospective study using natural language processing to identify all radiological reports of pulmonary oedema among patients who had been admitted to single tertiary intensive care unit (ICU) over a 1-year period (January 2015 to January 2016). We reviewed clinical data, discharge diagnosis, treatment and outcomes for such patients, and used multivariable logistic regression analysis to identify the association of RCDPO with various outcomes. Results: Out of 2001 ICU patients, we identified 238 patients (11.9%) with RCDPO. Patients with RCDPO were more acutely ill, had more chronic liver disease and had more chronic renal failure than critically ill patients who did not have RCDPO. They were typically admitted with acute cardiovascular disease; were more likely to receive invasive mechanical ventilation and continuous renal replacement therapy; had longer duration of ICU and hospital stay; were more likely to die in hospital; and, if discharged alive, were more likely to be admitted to a chronic care facility. In total, 46 RCDPO patients (19.3%) died in hospital. On multivariable analysis, only age and continuous renal replacement therapy were independently associated with mortality. In contrast, invasive mechanical ventilation was associated with a 2.5 times greater odds of radiological resolution. Conclusion: RCDPO affected about one in eight ICU patients. Such patients were sicker and had more comorbidities. The presence of RCDPO was independently associated with higher risk of death. Invasive mechanical ventilation was the only intervention independently associated with greater odds of radiological resolution.

Prevalence, characteristics, drainage and outcome of radiologically diagnosed pleural effusions in critically ill patients.

OBJECTIVE: Pleural effusions in the intensive care unit (ICU) are clinically important. However, there is limited information regarding effusions in such patients. We aimed to estimate the prevalence, patient characteristics, mortality, effusion duration, radiological resolution, drainage, and reaccumulation rates of pleural effusions in ICU patients. METHODS: This retrospective cohort study assessed all patients admitted to a tertiary hospital ICU from 1 January to 31 December 2015 with a chest x-ray report of pleural effusion. All chest x-ray reports were reviewed and data were combined with an established clinical ICU database. Statistical analysis of the combined dataset was performed. RESULTS: Among 2094 patients admitted to the ICU, 566 (27%) had pleural effusions diagnosed by chest x-ray. The effusion median duration was 3 days (IQR, 1-5 days). Radiologically documented clearance of the effusion occurred in 243 patients (43%) and drainage was performed in 52 patients (9%). Among patients with effusion clearance, 80 (33%) reaccumulated the effusion. Drainage was more common in patients who experienced reaccumulation (19% v 7%; P = 0.004). Overall, 89 patients (16%) died, with 20% mortality among those with reaccumulation versus 9% among patients without reaccumulation (P = 0.037). CONCLUSION: Pleural effusions are common in ICU patients and drainage is infrequent. One-third of effusions reaccumulate, even after drainage, and one in six patients with an effusion die in hospital. This information helps clinicians estimate resolution rates, advantages and disadvantages of effusion drainage, and overall prognosis.

Deep infiltrating endometriosis: Can magnetic resonance imaging anticipate the need for colorectal surgeon intervention?

OBJECTIVE: To identify magnetic resonance imaging (MRI) features associated with colorectal surgical bowel resection for treatment of deep infiltrating endometriosis (DIE). MATERIALS AND METHODS: 122 preoperative pelvic MRIs in women with laparoscopically-proven DIE and subsequent surgery (2006-2015) were identified, and retrospective cohort analysis performed. MRIs were reviewed independently by two radiologists blinded to surgical/histopathological outcomes. Associations between MRI characteristics of middle/posterior compartment endometriosis and surgical outcomes were investigated to identify MRI features associated with colorectal surgical bowel resection. RESULTS: MRI features associated with colorectal surgical intervention were: presence of an MRI bowel lesion (sensitivity 95.3%, specificity 63.3%, ROC-AUC 0.79); MRI bowel lesions ≥20 mm in length (sensitivity 91%, specificity 77%, ROC-AUC 0.84); MRI bowel lesions invading the muscularis or submucosa/mucosa layers (sensitivity 95.3%, specificity 63.3%, ROC-AUC 0.90). CONCLUSION: This study identifies MRI features that have potential diagnostic utility in identifying the need for colorectal surgical intervention in patients with DIE.

Invisible cortex sign: A highly accurate feature to localize the inferolateral central sulcus.

INTRODUCTION: The central sulcus is a key landmark on MRI of the brain, but its inferolateral portion is difficult to identify if unable to trace the sulcus superoinferiorly. The authors observed that the cortex abutting the central sulcus appears isointense to the adjacent white matter on DWI, we named this the 'invisible cortex sign' and our study evaluates whether it could be used to identify the inferolateral central sulcus. METHODS: Observational study of 108 consecutive 'normal' MRI studies performed from May 2016 to January 2017. A single axial DWI image - obtained in the anterior commissure-posterior commissure plane - was selected from each scan just above the subcentral gyrus such that it included the most inferolateral portion of the central sulcus. These single images were given to 10 readers (neuroradiologists, a neuroradiology fellow and radiology trainees) who marked the central sulcus based on the presence of the 'invisible cortex sign'. Their accuracy in identifying the central sulcus was compared with that of the principal investigators, who used tri-planar T1 volumetric MRI sequences. RESULTS: One hundred and eight consecutive patients (55 female, 53 male) were selected, ranging from 18 to 81 years old (mean = 40.5, σ = 18.2). The central sulcus was correctly identified in 95.5% of cases (σ = 3.7%; range 89.4-99.1%). CONCLUSION: The 'invisible cortex sign' is a highly accurate method of identifying the inferolateral central sulcus on a single axial DWI slice without relying on the more superior aspects of the sulcus.

Magnetic resonance imaging features of gemistocytic astrocytoma.

INTRODUCTION: Gemistocytic astrocytoma is the second most common subtype of World Health Organization grade 2 astrocytoma, but has a worse prognosis than other grade 2 lesions. We aim to describe the MR imaging features of histopathologically proven gemistocytic tumours. METHODS: Ethics approval was obtained from both institutions. Patient consent was not required for this retrospective study. We reviewed MR imaging findings of 16 consecutive cases of histopathologically proven gemistocytic astrocytoma and anaplastic astrocytoma with gemistocytic features. RESULTS: Average patient age was 48 years, with a 3:1 male to female ratio. Based on our series, the typical appearance of a gemistocytic astrocytoma is a large, heterogeneous mass most commonly supratentorial and lobar. Regions of cyst formation, partial signal suppression on FLAIR images and contrast enhancement are all common features. Additionally, contrary to previous literature that describes gemistocytic astrocytoma as a purely supratentorial lesion, we present two cases of gemistocytic astrocytoma involving the brainstem. CONCLUSIONS: The possibility of gemistocytic astrocytoma should be considered in patients presenting with large heterogeneous tumours that have regions of cyst formation, partial FLAIR suppression and contrast enhancement. This may be especially useful in reconciling a lesion with high-grade MR imaging features with low-grade histopathology. An infratentorial location does not preclude the diagnosis of gemistocytic astrocytoma.

Endometriosis: Does the menstrual cycle affect magnetic resonance (MR) imaging evaluation?

PURPOSE: To determine if the menstrual cycle affects MR interpretation in patients with pelvic endometriosis. MATERIALS AND METHODS: Thirty-one patients with either laparoscopically proven endometriosis, or a high clinical suspicion of deep infiltrative endometriosis, were prospectively recruited from May 2008 to October 2009 and January to June 2012. Two pelvic MR scans were performed for pre-operative planning; during menses and the other mid-cycle. Two experienced radiologists independently assessed image quality and disease extent. Both were blinded to patient identity, previous imaging and menstrual status. Interobserver agreement was assessed using the Kappa (k) test. Descriptive statistics were prepared using chi-squared (or Fishers' exact) tests and Mann-Whitney (rank sum) tests to assess for significant differences between menstrual and non-menstrual imaging. RESULTS: Interobserver agreement for image quality was moderate for T2 weighted imaging (k=0.475, p-value <0.001) and substantial for T1 fat saturated imaging (k=0.733, p-value<0.001), with no significant difference in image quality between menstrual and non-menstrual scans (all p-values>0.255). Readers demonstrated at least moderate interobserver agreement for certainty level of endometriosis at site-specific locations, with median k 0.599 (IQR 0.488-0.807). No significant difference in disease extent was observed between menstruating and non-menstruating scans (all p-values>0.05). CONCLUSION: Findings suggest no significant differences in image quality, disease extent or disease severity between menstruating and non-menstruating MR; thus, timing of pelvic MR for assessment of endometriosis need not be influenced by the menstrual cycle.

Diffusion-weighted imaging properties of uterine fibroids pre- and post-uterine fibroid embolisation.

OBJECTIVE: To determine the change in apparent diffusion coefficient (ADC) of uterine fibroids following uterine fibroid embolisation (UFE), and if the ADC change correlates with either volume loss or degree of contrast enhancement post-UFE. MATERIALS AND METHODS: This study was approved by our institutional review board with waiver of consent. The pelvic MRI examinations, including diffusion-weighted MRI (DWI) using 4 b-values, of 50 consecutive patients prior to and 6 months post-UFE were analyzed. The volume, ADC and amount of enhancement were calculated for each fibroid both pre- and post-UFE. The percent residual enhancement for each fibroid was categorized as either: no (0-1%) residual enhancement or residual (>1%) enhancement. Statistical analysis compared ADC, enhancement and volume for each fibroid pre- and post-UFE using paired t-tests and Pearson correlation coefficients. RESULTS: The mean ADC of all (n=88) fibroids pre-UFE was 1.30±0.20×10(-3)mm(2)/s, and increased to 1.68±0.24×10(-3)mm(2)/s post-UFE (p<0.0001). Lower pre-UFE ADC correlated with greater ADC change post-UFE (r=-0.50; p<0.0001). There was no correlation between ADC change and volume change post-UFE (r=0.07; p=0.59). However, fibroids with no residual enhancement post-UFE had larger ADC change than those with residual enhancement (p=0.003). CONCLUSION: The ADC of fibroids rises post-UFE. ADC change post-UFE is associated with the degree of loss of enhancement and may therefore be valuable in predicting response to treatment in pre-procedural counseling.

Impact of butylscopolamine on image quality of magnetic resonance cholangiopancreatography.

PURPOSE: To assess the effect of parenteral butylscopolamine on magnetic resonance cholangiopancreatography (MRCP) image quality. MATERIALS AND METHODS: The 3D free-breathing respiratory-compensated MRCP images (mean acquisition time 7min) of 94 consecutive non-paired patients (47 with and 47 without 20mg intramuscular butylscopolamine) were analysed retrospectively. Two experienced abdominal radiologists scored the image quality of five predefined pancreaticobiliary ductal segments on the MRCP images in a blinded fashion in both cohorts using a 5 point validated scale, ranging from perfect visualization of the entire ductal structure to the ductal structure being not visible. Interobserver agreement was determined. RESULTS: Parenteral butylscopolamine injection significantly reduced bowel peristalsis-related artefacts of the inferior common bile duct (CBD; p=0.031) and the pancreatic duct (PD; p=0.034) for reader 1 and the inferior CBD (p=0.041) for reader 2. The difference in visualization of all remaining ductal segments, and of the overall pancreaticobiliary tree, was not statistically significant between the two cohorts. Interobserver agreement between the two readers was substantial for the superior CBD, common hepatic duct (CHD) and PD, was moderate for the inferior CBD, and was fair for the peripheral intrahepatic ducts. CONCLUSION: On free-breathing 3D MRCP images, parenteral butylscopolamine improves only the visualization of the inferior CBD and the PD. However, no significant improvement in visualization of other ductal segments was demonstrated.

The augmented breast: a pictorial review of the abnormal and unusual.

OBJECTIVE: This article reviews the multimodality imaging features of breast augmentation complications as well as appearances of unusual breast augmentation techniques. CONCLUSION: Cosmetic breast augmentation is an increasingly common procedure performed in our society. Although breast prosthesis implantation is the most common technique, other unusual techniques such as autologous fat implantation as well as direct liquid silicone and paraffin injections have also been used.