Diffusion-weighted Magnetic Resonance Imaging Findings Research Articles

Cerebral Embolic Protection Device protects against stroke during Transcatheter Aortic Valve Replacement (TAVR): An Updated Meta-Analysis

Abstract Background Cerebral Embolic Protection Device (CEPD) is used to capture emboli during Transcatheter Aortic Valve Replacement (TAVR). Previous meta-analyses have yielded conflicting results regarding efficacy and safety of CEPD in TAVR. With recently published pivotal trial and multiple Cohort studies reporting new data, there is a need of re-calibration of available statistical evidence. Aims The aim of our study was to explore the effects of using CEPD on TAVR outcomes. Methods A systematic literature search was conducted across Pubmed, Cochrane, Embase, and clinicaltrials.gov from inception till February 2023. Dichotomous outcomes were pooled using Odds Ratio (OR) while continuous outcomes were pooled using Standardized Mean Difference (SMD). Revman 5.4 was used to pool the data using random effects model With Mantel-Haenszel method. Subgroup analysis for study type (RCT vs NRS) was conducted. Sensitivity analysis using leave one out method and multiple exit method was conducted to find out, if unadjusted cohort studies had an impact on the pooled outcomes. Results The initial search revealed 870 articles. After primary and secondary screening, data was included from 17 studies (6 RCTs, 11 cohorts, n= 180187). Use of CEPD was associated with 50% reduced odds of stroke (OR=0.50, 95% CI=0.03-0.75, p=<0.01, I2=32%). There was no significant difference in 30 days mortality between the two groups (OR=0.76, 95% CI=0.44-1.31, p=0.33, I2=18%). On Diffusion Weighted Magnetic Resonance Imaging (DW-MRI), the two groups did not have any significant differences in volume per lesion (SMD=-0.07,CI=-0.28-0.14, p=0.52,I2=71%), Total volume of lesions (SMD=-0.08, p=0.73, CI=-0.53,0.17, I2=84%) and Number of lesions per patient (SMD=-0.15, p=0.45, CI=-0.23,0.10, I2=84%). On subgroup analysis, RCTs were found to have high heterogeneity while NRS had zero heterogeneity. The pooled analysis revealed no significant association with either of the group regarding Acute Kidney Injury (OR=0.84, p=0.43,I2=0%), risk of pacemaker implantation (OR=1.17,p=0.35,I2=0%), major bleed (OR=0.97,p=0.94,I2=62%), Worsening National Institute of Health Stroke Scale (NIHSS) (OR=0.46,p=0.36,I2=76%), and Vascular complications VC (OR=0.85,p=0.35,I2=0%). The results remained insignificant for subgroup analysis for study type and sensitivity analysis using leave one out and exit multiple methods for unadjusted cohort studies. Conclusion The use of CEPD during TAVR was found to be associated with reduced risk of stroke, however, there was no significant association with mortality, DW-MRI findings, AKI, major bleed, minor bleed, risk of pacemaker implantation, worsening NIHSS score and vascular complications. Further, large scale prospective trials are needed to provide definitive evidenceFig 1:Plots for mortality and strokeFig 2:Plots for VC and AKI

Dynamic susceptibility contrast perfusion-weighted and diffusion-weighted magnetic resonance imaging findings in pilocytic astrocytoma and H3.3 and H3.1 variant diffuse midline glioma, H3K27-altered.

This study compared the dynamic susceptibility contrast (DSC) magnetic resonance imaging parameters and apparent diffusion coefficient (ADC) between pilocytic astrocytoma (PA) and diffuse midline glioma, H3K27-altered (DMG) variants. The normalized relative cerebral blood volume (nrCBV), normalized relative flow (nrCBF), percentile signal recovery (PSR), and normalized mean ADC (nADCmean) of 23 patients with midline PAs (median age, 13 years [range, 1-71 years]; 13 female patients) and 40 patients with DMG (8.5 years [1-35 years]; 19 female patients), including 35 patients with H3.3- and five patients with H3.1-mutant tumors, treated between January 2016 and May 2022 were statistically compared. DMG had a significantly lower nADCmean (median: 1.48 vs. 1.96; p = 0.00075) and lower PSR (0.97 vs. 1.23, p = 0.13) but higher nrCBV and nrCBF (1.66 vs. 1.17, p = 0.058, respectively, and 1.87 vs. 1.19, p = 0.028, respectively) than PA. The H3.3 variant had a lower nADCmean than the H3.1 variant (1.46 vs. 1.80, p = 0.10). DMG had lower ADC and PSR and higher rCBV and rCBF than PA. The H3.3 variant had a lower ADC than the H3.1 variant. Recognizing the differences and similarities in the DSC parameters and ADC between these tumors may help presurgical diagnosis.

Retina and optic nerve diffusion restriction in acute central retinal artery occlusion (P2-9.007)

<h3>Objective:</h3> To determine whether diffusion restriction (DR) of the retina and/or optic nerve (ON) in acute central retinal artery occlusion (CRAO) can be accurately identified on brain diffusion-weighted magnetic resonance imaging (DW-MRI) by junior versus senior neurology residents and vascular neurologists. <h3>Background:</h3> Retina and/or ON DR in CRAO was described with various accuracies and fair inter-rater reliability even between experienced neuroradiologists. The identification of these subtle DW-MRI findings by the forefront neurology residents or vascular neurologists was not previously investigated. <h3>Design/Methods:</h3> Retrospective cohort study of consecutive acute CRAO patients that had stroke-protocol DW-MRI at our tertiary academic center (2013–2020). Two neurology residents (junior and senior), vascular neurologist, and two neuroradiologists blinded to the CRAO site independently reviewed the DW-MRI for retina and/or ON DR. Their inter-rater reliability was calculated using kappa statistics. The neuroradiologists’ consensus agreement was the reference for the non-radiologists. <h3>Results:</h3> We included 128 patients (mean age 68 years; 55% right eye, median time from CRAO to DW-MRI 2 days (IQR 1–4). 28/128 (21.8%) had a discrepancy between the neuroradiologists. After neuroradiologist consensus, DR was correctly identified in the retina or ON in 51/128 (39.8%), retina alone 35/128 (27.3%), ON alone 31/128 (24.2%), both retina and ON 15/128 (11.7%). Upon comparing the neurology trainees and vascular neurologist, the positive agreement was low (22.2% to 43.9%) but the negative agreement was high (88.0% to 92.9%). The senior resident had the highest observer agreement. Overall substantial agreement (P-B adjusted Kappa &gt; 0.6) between the readings, excepting for moderate (P-B adjusted kappa= 0.59) for ON DR for the junior resident. <h3>Conclusions:</h3> Incongruities in identifying retina and/or ON DR in CRAO are encountered by various specialists. When compared to experienced neuroradiologists, neurology trainees and attending have substantial agreement on the negative findings but low agreement for the positive findings. <b>Disclosure:</b> Dr. Gomez Ramos has nothing to disclose. Dr. Harahsheh has nothing to disclose. Nan Zhang has nothing to disclose. Mr. Parikh has nothing to disclose. Mr. Elshaigi has nothing to disclose. Tanya Rath has nothing to disclose. Dr. Hoxworth has nothing to disclose. Dr. Dumitrascu has nothing to disclose.

Vacuoles related to tissue neuron-astrocyte ratio and infiltration of macrophages/monocytes contribute to hyperintense brain signals on diffusion-weighted magnetic resonance imaging in sporadic Creutzfeldt-Jakob disease

BackgroundRadiological features in patients with sporadic Creutzfeldt-Jakob disease (sCJD) are hyperintensity of the cerebral cortex and the basal ganglia displayed by diffusion-weighted magnetic resonance imaging (DW-MRI). We performed a quantitative study on neuropathological and radiological findings. MethodsPatient 1 received a definite diagnosis of MM1-type sCJD, while patient 2 received a definite diagnosis of MM1 + 2-type sCJD. Two DW-MRI scans were performed on each patient. DW-MRI was either taken the day before or on the day of the patient's death, and several hyperintense or isointense areas were marked as a region of interest (ROI). Mean signal intensity of the ROI was measured. Pathological quantitative assessments of the vacuoles, astrocytosis, infiltration of monocytes/macrophages, and proliferation of microglia was performed. Vacuole load (% area vacuole), glial fibrillary acidic protein (GFAP), CD68, and Iba-1 load were calculated. We defined spongiform change index (SCI) to indicate vacuoles related to a tissue neuron-astrocyte ratio. We assessed the correlation of intensity of the last DW-MRI and the pathological findings as well as association of changes of the signal intensity on the sequential images and the pathological findings. ResultWe observed a strong positive correlation between SCI and DW-MRI intensity. In the analysis using serial DW-MRI and pathological findings, we found that CD68 load was significantly larger in areas where signal intensity decreased, as compared to those areas where hyperintensity remained unchanged. ConclusionDW-MRI intensity in sCJD is associated with the ratio of neuron to astrocyte in the vacuoles and the infiltration of macrophages and/or monocytes.

Current state of management of struma ovarii and preoperative imaging features: A retrospective case series study of 18 patients at a single institution.

Even though 95% of struma ovarii are benign, it is often overtreated because of the difficulty to distinguish it from malignancy. In this study, our aim was to evaluate the current state of the preoperative diagnosis and the selection of the surgical procedure, and to improve preoperative diagnostic accuracy by retrospectively reviewing imaging findings. We retrospectively reviewed the clinical course and imaging characteristics of 18 patients who were diagnosed postoperatively with struma ovarii, pathologically, at our institution between 2015 and 2021. The preoperative diagnoses included benign ovarian tumor in eight cases, borderline in four cases, and malignant in six cases. None of the cases were diagnosed as struma ovarii preoperatively. Of the seven patients who had confirmed a desire for future childbearing, four patients were suspected for borderline or malignant tumor preoperatively, and underwent abdominal adnexectomy. In patients without a desire for childbearing, laparoscopic surgery was performed in only 45% of the patients whose preoperative diagnosis was benign. On magnetic resonance imaging (MRI), 54% of the cases showed enhanced solid components, which is characteristic of malignant tumors, but diffusion restriction was observed in only 11%. On computed tomography (CT), 78% of the cases showed a high attenuation lesion reflecting thyroid tissue. Struma ovarii is difficult to distinguish from malignancy preoperatively, making the choice of surgical approach complicated. A comprehensive evaluation of diffusion-weighted MRI and CT findings may improve the accuracy of preoperative diagnosis of struma ovarii.

Utility of standard diffusion-weighted magnetic resonance imaging for the identification of ischemic optic neuropathy in giant cell arteritis

This study assessed diffusion abnormalities of the optic nerve (ON) in giant cell arteritis (GCA) patients with acute onset of visual impairment (VI) using diffusion-weighted magnetic resonance imaging (DWI). DWI scans of GCA patients with acute VI were evaluated in a case-control study. Two blinded neuroradiologists assessed randomized DWI scans of GCA and controls for ON restricted diffusion. Statistical quality criteria and inter-rater reliability (IRR) were calculated. DWI findings were compared to ophthalmological assessments. 35 GCA patients (76.2 ± 6.4 years; 37 scans) and 35 controls (75.7 ± 7.6 years; 38 scans) were included. ON restricted diffusion was detected in 81.1% (Reader 1) of GCA scans. Localization of ON restricted diffusion was at the optic nerve head in 80.6%, intraorbital in 11.1% and affecting both segments in 8.3%. DWI discerned affected from unaffected ON with a sensitivity, specificity, positive and negative predictive value of 87%/99%/96%/96%. IRR for ON restricted diffusion was κinter = 0.72 (95% CI 0.59–0.86). DWI findings challenged ophthalmologic diagnoses in 4 cases (11.4%). DWI visualizes anterior and posterior ON ischemia in GCA patients with high sensitivity and specificity, as well as substantial IRR. DWI may complement the ophthalmological assessment in patients with acute VI.

Diffusion weighted magnetic resonance imaging for diagnosis of post-operative paediatric cholesteatoma.

High rates of recidivism are reported after paediatric cholesteatoma surgery. Our practice has adapted to include non-echoplanar diffusion-weighted magnetic resonance imaging for the diagnosis of residual or recurrent cholesteatoma. This audit aimed to evaluate the performance of non-echoplanar diffusion-weighted magnetic resonance imaging in our paediatric population. A retrospective review was conducted of non-echoplanar diffusion-weighted magnetic resonance imaging scans performed to detect residual disease or recurrence after surgery for cholesteatoma in children from 1 January 2012 to 30 November 2017 in our centre. Follow-up diffusion-weighted magnetic resonance imaging scans were reviewed to 16 August 2019. Thirty-four diffusion-weighted magnetic resonance imaging scans were included. The sensitivity and specificity values of diffusion-weighted magnetic resonance imaging for detecting post-operative cholesteatoma were 81 per cent and 72 per cent, respectively. Positive predictive and negative predictive values were 72 per cent and 81 per cent, respectively. Use of diffusion-weighted magnetic resonance imaging is recommended as a replacement for routine second-look surgical procedures in the paediatric population. However, we would caution that patients require close follow up after negative diffusion-weighted magnetic resonance imaging findings.

Quantification of New Intracerebral Lesions on Diffusion-weighted Magnetic Resonance Imaging After Transcarotid Artery Revascularization for Treatment of Carotid Stenosis

Quantification of New Intracerebral Lesions on Diffusion-weighted Magnetic Resonance Imaging After Transcarotid Artery Revascularization for Treatment of Carotid Stenosis

An observational study of the demographic, clinical, and diffusion-weighted magnetic resonance imaging characteristics of patients with musculoskeletal infections

Introduction: Musculoskeletal infections have been emerging nowadays. Its early diagnosis is warranted as it may lead to disabling sequelae. Recently, the use of diffusion-weighted magnetic resonance imaging (DWMRI) provided additional pulse sequences enabling better diagnosis and needs to be explored for diagnosing musculoskeletal infections. Thus, we conducted this study with an aim to discuss demographic, clinical, and DWMRI findings of the spectrum of musculoskeletal infections, emphasizing the apparent diffusion coefficient (ADC) map for this domain of infections. Methods: A retrospective observational study was carried out in the department of radiodiagnosis of a tertiary care hospital. The study was performed on 50 patients who were suspected cases of musculoskeletal infections. All the patients underwent basic investigations, ultrasound, magnetic resonance imaging, and diffusion-weighted imaging with ADC mapping. The data were entered into MS EXCEL spreadsheet and analysis was done using Statistical Package for Social Sciences (SPSS) version 21.0. Results: Maximum patients were in the age group of 11–20 years (40%) with 58% males and 42% females. Lower limb infections were common, especially the involvement of the hip joint. Pain and swelling were the most common symptoms as seen in 96% and 88% of the patients respectively. DWMRI was able to diagnose and lay down significantly different ADC values for different musculoskeletal infections. The mean ADC values were higher for acute infections and lower for chronic infections. Conclusions: DWMRI holds an important role in the investigation profile for musculoskeletal infections and must be used wherever deemed necessary to avoid unnecessary referrals and treatments.

To determine the sensitivity, specificity, and diagnostic accuracy of diffusion-weighted MRI in localization of non-palpable undescended testes taking laparoscopic findings as the gold standard: A cross-sectional study from Pakistan

BackgroundCryptorchidism, undescended testes, is a pathological condition that is due to failure of descent of testes in the scrotum. This study was aimed to determine the diagnostic accuracy of diffusion-weighted magnetic resonance imaging (DW-MRI) in localization of undescended testes taking laparoscopic findings as the gold standard. MethodsA cross-sectional study was conducted in the radiology department of a tertiary care hospital from September 27, 2018 to September 26, 2019. A total of 416 patients were included. Abdomen-pelvic and scrotal ultrasound were performed. Preoperative abdominal and pelvic DW-MRI was performed with a 1.5-T MRI system using a body coil. All study patients underwent laparoscopic exploration. Intra-abdominal atrophic testes were treated with laparoscopic orchiectomy and orchiectomy samples were taken for histopathologic examination. DW-MRI findings were correlated with laparoscopic findings. A 2 x 2 table was used to calculate the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of DW-MRI taking laparoscopy as the gold standard. ResultsThe mean age was 17.08 ± 7.99 years and the mean BMI was 19.36 ± 4.96 kg/m2. In our study, 34.1% of cases were diagnosed as undescended testes localized by DWI-MRI and 51% of cases were diagnosed as undescended testes localized via laparoscopy. Sensitivity, specificity, PPV, NPV and accuracy were 65.1%, 98%, 97.2%, 73% and 81.3% respectively. ConclusionDW-MRI improves the detection of undescended testes. DW-MRI can be a recommended imaging tool to increase the preoperative diagnostic accuracy of MRI in localizing nonpalpable undescended testes.

Diffusion-weighted magnetic resonance imaging instead of contrast-enhanced imaging for evaluating immediate therapeutic efficacy of high-intensity focused ultrasound ablation of adenomyosis

To explore the feasibility of diffusion-weighted magnetic resonance imaging (DWI) instead of contrast-enhanced (CE) imaging for evaluation of the immediate therapeutic efficacy of high-intensity focused ultrasound (HIFU) ablation for treatment of adenomyosis. We retrospectively analyzed the data of 29 patients aged 40.5 ± 5.4 years under going HIFU treatment for adenomyosis in our hospital between December, 2017 and July, 2020. The patients received MRI examination both before and within 24 h after the operation. Two observers analyzed the morphology of the ablation area on DWI and classified the lesions into type 1 (spot-like or no obvious signal intensity changes), type 2 (patchy signal intensity changes) and type 3 (ring-like signal intensity changes). The inter- and intra-observer reliability of morphological assessment was assessed using kappa test. The volume of necrotic tissues following the ablation was measured with both DWI and CE imaging, and the consistency of the measurements and the inter- and intra-observer reliability of DWI-based measurements were evaluated using Bland-Altman plot tests. The median volume of necrotic tissues was 36.9 cm3 (range 16.4-65.5 cm3) following ablation of the 29 lesions. DWI findings identified 24-25 (82.8%-86.2%) lesions with type 2 or 3 signal changes following the ablation with measurable necrotic tissue volume. On DW images, the Kappa value of intra- and inter-observer reliability for morphological classification of the ablation area reached 0.798 (P=0.000) and 0.933 (P= 0.000), respectively. Bland-Altman plots showed a good consistency of the necrotic volumes measured by CE and at DWI with a strong inter- and intra-observer reliability of DWI-based volume measurements (with only one point outside the range of 95% limits of agreement). The remaining 4 or 5 lesions, which presented with type 1 signal changes following ablation, were all small in size (the largest was only 18.61 cm3) and showed poor therapeutic responses to the ablation. DWI-based morphological assessment and necrotic tissue volume measurement can replace CE imaging for assessment of the immediate therapeutic efficacy of HIFU ablation for treatment of adenomyosis.

Shear Wave Ultrasound Elastography and Diffusion-Weighted Magnetic Resonance Imaging Findings of Pleural-Based Masses with Histopathologic Correlation

Objective: The study aims to evaluate the usefulness of non-invasive diagnostic methods, shear wave elastography (SWE), and diffusion-weighted magnetic resonance imaging (DWI) to differentiate benign and malignant lesions in the thoracic pleural based masses by comparing them with histopathological findings.Materials and Methods: Sixty-three patients having a pleural-based peripheral mass on CT, admitted to the interventional radiology department for transthoracic biopsy, were included in the study. All patients underwent DWI, and ADC values of the groups were measured. Transthoracic biopsy was performed with the guidance of US from the area where the highest shear wave velocity (SWV) value was calculated. ADC and SWV values of histopathologically proven benign and malignant lesions were statistically compared.Results: Fifty-six patients were male, and seven were female. The mean age was 64.68±10.13 years (41-85 years). Fourty-four patients were malignant, and 19 were benign. The maximum SWV was found to be 4.13±0.59 m/s in malignant cases and 3.55±0.71 m/s in benign cases, and the difference was significant (p = 0.001). Mean ADC value was measured as 1.04±0.30 x 10-3 mm2/s in malignant cases and 1.32±0.33 x 10-3 mm2/s in benign cases on DWI and the difference was significant (p = 0.002). In malignant cases, the minimum ADC was 0.73±0.29 x 10-3 mm2/s, and 0.99±0.44 x 10-3 mm2/s in benign cases, the difference was significant (p = 0.024). ROC analysis revealed a cut-off value of ≥4.08 m/s for SWVmax, ≤1.01x10-3 mm2/s for mean ADC, and ≤0.8x10-3 mm2/s for minimum ADC showed a significant performance in distinguishing malignant and benign lesions. Conclusions: Transthoracic US elastography and DWI are useful in differentiating malignant and benign lesions in appropriate cases. Both SWE and DWI are useful in routine use because they are non-invasive and do not contain radiation. In particular, SWE is suitable for biopsy guidance and may prevent the possibility of insufficient material.

Role of Diffusion-Weighted Magnetic Resonance Imaging in Laryngeal and Hypopharyngeal Cancer in Comparison to Histopathological Finding

Background: Diffusion-weighted magnetic resonance imaging (DW-MRI) has the ability of tissue characterization and can differentiate between benign and malignant tissues, including differentiation between benign post-radiotherapy changes and residual or recurrent malignancy. Objective: This study aimed to assess the role of diffusion-weighted magnetic resonance imaging in the evaluation of laryngeal and hypopharyngeal cancer as an initial diagnosis and the post-treatment surveillance protocol. Patients and methods: This study was a cross-sectional analytical study including twenty-five patients who presented with laryngeal or hypopharyngeal masses, thirteen cases were pretreatment cases, and twelve cases were post-treatment cases after completion of treatment. Seven cases had a hypopharyngeal origin, and eighteen cases had a laryngeal origin. The patients were assessed using history taking, a telescopic examination of the larynx and hypopharynx, computed tomography scanning, and diffusion-weighted magnetic resonance imaging on the neck. Direct laryngoscopic examination and biopsy taking from suspicious lesions were done. Biopsies were subjected to histopathological examination with a correlation between pathological and DW- MRI radiological results. Results: DW-MRI had a 100% sensitivity, 82.4 % specificity, and 88% accuracy compared to histopathological findings of biopsies from the studied group. There was a non-significant difference between DW-MRI and biopsy findings for either pretreatment or post-treatment cases of both laryngeal and hypopharyngeal origin of the lesions (p-value > 0.05 for all). Conclusion: DW-MRI is a sensitive tool for detecting laryngeal and hypopharyngeal cancers in new cases and excluding tumor residual after chemo-radiotherapy in cases with suspicious lesions after completion of treatment.

Relationships and Qualitative Evaluation Between Diffusion-Weighted Imaging and Pathologic Findings of Resected Lung Cancers.

For detecting malignant tumors, diffusion-weighted magnetic resonance imaging (DWI) as well as fluoro-2-deoxy-glucose positron emission tomography/computed tomography (FDG-PET/CT) are available. It is not definitive how DWI correlates the pathological findings of lung cancer. The aim of this study is to evaluate the relationships between DWI findings and pathologic findings. In this study, 226 patients with resected lung cancers were enrolled. DWI was performed on each patient before surgery. There were 167 patients with adenocarcinoma, 44 patients with squamous cell carcinoma, and 15 patients with other cell types. Relationships between the apparent diffusion coefficient (ADC) of DWI and the pathology were analyzed. When the optimal cutoff value (OCV) of ADC for diagnosing malignancy was 1.70 × 10−3 mm2/s, the sensitivity of DWI was 92.0% (208/226). The sensitivity was 33.3% (3/9) in mucinous adenocarcinoma. The ADC value (1.31 ± 0.32 × 10−3 mm2/s) of adenocarcinoma was significantly higher than that (1.17 ± 0.29 × 10−3 mm2/s) of squamous cell carcinoma (p = 0.012), or (0.93 ± 0.14 × 10−3 mm2/s) of small cell carcinoma (p = 0.0095). The ADC value (1.91 ± 0.36 × 10−3 mm2/s) of mucinous adenocarcinoma was significantly higher than that (1.25 ± 0.25 × 10−3 mm2/s) of adenocarcinoma with mucin and that (1.24 ± 0.30 × 10−3 mm2/s) of other cell types. The ADC (1.11 ± 0.26 × 10−3 mm2/s) of lung cancer with necrosis was significantly lower than that (1.32 ± 0.33 × 10−3 mm2/s) of lung cancer without necrosis. The ADC of mucinous adenocarcinoma was significantly higher than those of adenocarcinoma of other cell types. The ADC of lung cancer was likely to decrease according to cell differentiation decreasing. The sensitivity of DWI for lung cancer was 92% and this result shows that DWI is valuable for the evaluation of lung cancer. Lung cancer could be evaluated qualitatively using DWI.

Renal epithelioid angiomyolipoma: Incidence in a Japanese cohort and diagnostic utility of diffusion-weighted magnetic resonance imaging.

To show the epidemiological characteristics of epithelioid angiomyolipoma in a Japanese population, and to establish the preoperative diagnosis method of epithelioid angiomyolipoma. Among the 855 tumors of patients who underwent partial/radical nephrectomy or renal biopsy for presumed renal cell carcinoma between 2007 and 2018, 39 renal tumors were diagnosed as nonclassical angiomyolipoma, including epithelioid angiomyolipoma and fat-poor angiomyolipoma. We retrospectively evaluated the incidence of epithelioid angiomyolipoma. Furthermore, we analyzed computed tomography and magnetic resonance imaging results, including diffusion-weighted magnetic resonance imaging findings of epithelioid angiomyolipoma and fat-poor angiomyolipoma. The incidence of epithelioid angiomyolipoma (n=7) was 17.9% of surgically resected non-classical angiomyolipoma. The radiological appearance of epithelioid angiomyolipoma was hyperattenuating on unenhanced computed tomography images with iso or low intensity on T2-weighted magnetic resonance imaging. The mean apparent diffusion coefficient value of the solid component in epithelioid angiomyolipoma was significantly lower than that in fat-poor angiomyolipoma (median 0.79×10-3 vs 1.07×10-3 mm2 /s, P=0.0019). The proportion of epithelioid angiomyolipoma in our Japanese cohort was equivalent to that of the reported series in the USA. The apparent diffusion coefficient value is potentially useful to differentiate between epithelioid angiomyolipoma and fat-poor angiomyolipoma. Further research is required to establish the imaging diagnostic criteria for epithelioid angiomyolipoma.

Diffusion weighted imaging is a promising method to detect acute pyelonephritis in non-sedated free breathing infants

Urinary tract infection (UTI) is a common disease in infants. The initial evaluation includes imaging to identify risk factors for permanent renal damage, such as malformation and renal parenchymal involvement of the infection i.e. pyelonephritis. 99mTc-Dimercaptosuccinic acid (DMSA) scintigraphy is a well-established method for detection of pyelonephritis and renal damage, but has limitations in availability, spatial resolution, and detection of congenital malformations. Diffusion weighted magnetic resonance imaging (DWI) has been shown to have a high sensitivity for detection of pyelonephritis in children without the use of invasive procedures, contrast agents or ionizing radiation. How this method performs in young infants during non-sedated free breathing remains, however, to be investigated. To prospectively assess the feasibility and performance of DWI for detection of pyelonephritis in non-sedated free breathing infants. 32 children <6 months of age with first-time symptomatic UTI were examined with DWI and DMSA scintigraphy. The DWI examination was performed using a free breathing protocol without the use of sedation. Pyelonephritic lesions were registered for both methods by independent observers. Agreement between DWI and DMSA was evaluated. Consensus diagnosis was determined and compared to the DWI findings. The MRI and DMSA examinations were completed in 25 infants, with a median age of 1.7 (0.7-5.5) months. Focal uptake reductions were detected on the DMSA images in 12 (24%) of the 50 kidneys. The DWI method demonstrated a fair to good agreement with DMSA, k=0.50 (p<0.0001). The consensus diagnosis was pyelonephritis in eight (16%) of the 50 kidneys. DWI detected seven of the eight kidneys with pyelonephritis. No false positive findings were detected with DWI compared to consensus diagnosis. This study has shown an agreement between DWI and DMSA scintigraphy in the detection of pyelonephritis. Further validation of the performance of DWI, using a consensus diagnosis as a reference, confirmed the potential of the method. This feasibility study included a limited number of patients and the results need to be confirmed in a prospective study of a larger cohort. Free breathing DWI is a promising method for detection of pyelonephritic lesions in non-sedated infants.

Neurovascular changes in magnetic resonance imagining and single-photon emission computed tomography during migraine attack in patients with FHM2 mutations

The aim of this article is to provide neuroimaging data on cases with familial hemiplegic migraine (FHM). A 14-year-old male presented normal diffusion-weighted magnetic resonance imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) findings during his first hemiplegic migraine attack. However, magnetic resonance angiography (MRA) showed diffuse narrowing of the right middle cerebral artery. Cerebral blood flow–single-photon emission computed tomography showed right hypoperfusion. A follow-up study showed no abnormal findings. His mother had normal DWI, FLAIR, and MRA findings during her migraine attack. Both patients were diagnosed with FHM2 (p.R763H mutation in ATP1A2). This study highlights the importance of neurovascular examinations during the FHM2 headache phase. Further cases are required to clarify the pathophysiology of migraine.

Investigation of the Value of T peak to T end and QTc Intervals as Electrocardiographic Arrhythmia Susceptibility Markers in Acute Ischemic Stroke.

Arrhythmias are one of the most common causes of mortality in patients with acute ischemic stroke (AIS). This study aimed to investigate the relationships of arrhythmia susceptibility markers (QT, QTc, Tpe, Tpe-D, Tpe/QT, and Tpe/QTc) with the localization and volume of the ischemic area, the National Institutes of Health Stroke Scale (NIHSS) scores, and troponin levels in AIS. Patients diagnosed with AIS in the emergency department in the period from 01 November 2016 to 31 March 2019 were retrospectively reviewed. Patients admitted to the emergency department with no pathological ECG findings were included. The measurements of QT, QTc, Tpe, Tpe-D, Tpe/QTc, and Tpe/QT were performed under a digital microscope. The NIHSS scores, troponin values, and the ischemic area volume based on the diffusion-weighted magnetic resonance imaging findings at the time of admission were found. A total of 135 patients, comprising 70 AIS patients and 65 individuals as controls, were included in the study. The male/female ratio was 73/62 and the mean age was 68.51±10.80 years. All of the ECG parameters in the AIS group and the control group were statistically significantly different between the groups except Tpe-D (p=0.454) (For QT, QTc, Tpe, Tpe/QTc, and Tpe/QT; p=0.003, 0.022, <0.001, 0.001, 0.001; respectively). QT, QTc, Tpe, Tpe/QTc, and Tpe/QT values were not significantly different between the groups with a NIHSS score of ≤5 and >5 (p=0.480, 0.688, 0.663, 0.512, 0.333, respectively). Arrhythmia susceptibility markers including QT, QTc, Tpe, the values of Tpe-D, Tpe/QT, and Tpe/QTc are different in AIS patients compared to the individuals in the control group; therefore, these parameters can be included among the other parameters of close cardiac monitoring.

Diagnostic Accuracy of Echo-planar Diffusion-weighted Imaging in the Diagnosis of Intra-cerebral Abscess by Taking Histopathological Findings as the Gold Standard.

ObjectiveTo determine the diagnostic accuracy of echo-planar diffusion-weighted imaging (DWI) in the diagnosis of intra-cerebral abscesses by taking histopathological findings as the gold standard.Subject and methodsA retrospective cross-sectional study was performed from July 2014 to June 2015 at a tertiary care hospital in Karachi. A total of 462 patients, who were referred for magnetic resonance imaging (MRI) brain, presenting with clinical suspicion of an intra-cerebral abscess on the basis of clinical signs and symptoms, were included in this study. MR imaging was performed. All patients subsequently underwent surgery. The histopathological findings of these patients were collected and compared with echo-planar diffusion-weighted MRI findings. A proforma was used to record the findings.ResultsThe mean age of the patients was 47.39±13.54 years. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of echo-planar diffusion-weighted MRI in the diagnosis of intra-cerebral abscesses was 85.64%, 95.88%, 93.82%, 90.14%, and 91.56%, respectively.ConclusionBrain abscesses and necrotic tumors are, most of the time, difficult to differentiate on routine conventional imaging, and prompt diagnosis is important, as an untreated brain abscess could be lethal. Diffusion imaging can aid in the diagnosis and further management plan so as to help in improved patient care. Although this sequence has high sensitivity and specificity, it should be used in addition to conventional imaging and not as a replacement of histopathology.

MR imaging features of pancreatic acinar cell carcinoma.

This study aimed to report the magnetic resonance imaging (MRI) features of acinar cell carcinoma (ACC) of the pancreas including diffusion-weighted MRI findings. The MRI examinations of five patients (3 men, 2 women; median age, 61years) with histopathologically proven ACC of the pancreas were retrospectively reviewed. MR images were analyzed qualitatively (location, shape, homogeneity, signal intensity, vascular involvement and extrapancreatic extent of ACC) and quantitatively (tumor size, apparent diffusion coefficient [ADC] and normalized ADC of ACC). All ACC were visible on MRI, presenting as an oval pancreatic mass (5/5; 100%), with moderate and heterogeneous enhancement (5/5; 100%), with a median transverse diameter of 43mm (Q1, 35; Q3, 82mm; range: 30-91mm). Tumor capsule was visible in 4/5 ACC (80%) and Wirsung duct enlargement in 2/5 ACC (40%). On diffusion-weighted MRI, all ACC (5/5; 100%) were hyperintense on the 3 b value images. Median ADC value of ACC was 1.061×10-3mm2/s (Q1, 0.870×10-3mm2/s; Q3, 1.138×10-3mm2/s; range: 0.834-1.195×10-3mm2/s). Median normalized ADC ratio of ACC was 1.127 (Q1, 1.071; Q3, 1.237; range: 1.054-1.244). On MRI, ACC of the pancreas presents as a large, oval pancreatic mass with moderate and heterogeneous enhancement after intravenous administration of a gadolinium chelate, with restricted diffusion and a median ADC value of 1.061×10-3mm2/s on diffusion-weighted MRI. Further studies however are needed to confirm our findings obtained in a limited number of patients.