Diagnostic Magnetic Resonance Imaging Research Articles

Preoperative MRI for oral tongue squamous cell carcinoma: timing and correlation to histopathology

Magnetic resonance imaging (MRI) is an integral part of the evaluation of local and regional disease in tongue squamous cell carcinoma prior to surgery. The aim of this study was to evaluate the accuracy of MRI in assessing tumour dimensions, as well as the impact of the time-lag from diagnostic biopsy on the accuracy of MRI. The medical records of 64 patients with tongue carcinoma were reviewed retrospectively. Tumour maximum diameter and tumour depth of invasion were compared between pathology and MRI (T1- and T2-weighted). MRI-derived maximum tumour diameter and depth of invasion correlated strongly with histopathology: T1-weighted (r = 0.700 and r = 0.813, respectively) and T2-weighted (r = 0.734 and r = 0.834, respectively). A significant correlation was found between measurements on T1 and T2 MRI for both parameters (P = 0.955 and P = 0.984, respectively). The accuracy rate of MRI for T-staging of early tumours was low: 10% for T1 tumours; 39.3% for T2 tumours. A time-lag of less than 2 weeks between the diagnostic biopsy and MRI adversely affected the correlation of tumour dimensions. MRI is a reliable tool for evaluating tongue carcinoma; however, it overestimates early tumours. A 2-week delay after diagnostic biopsy is desired before completing an MRI. Alternatively, if logistics allow, a pre-biopsy MRI is preferred, especially for T1–T2 tumours.

Implementation of abbreviated breast MRI in diagnostic and screening settings.

Abbreviated magnetic resonance imaging (MRI) includes fewer sequences than standard MRI, which could be utilized for breast cancer detection. To evaluate the diagnostic accuracy of abbreviated MRI protocol in screening and diagnostic settings. All women with screening and diagnostic (problem-solving and preoperative staging) MRI examination were recruited from 2017 to 2020. Two expert radiologists assessed designed abbreviated protocol (fat-saturated T1-weighted [T1W] pre-contrast and two first fat-saturated T1W post-contrast series with reconstruction of their subtraction) including maximum intensity projection (MIP) and then evaluated standard protocol of breast MRI. Associated findings, including axillary lymphadenopathy and invasion to nipple, skin, or pectoralis muscle were also evaluated. The concordance rate of abbreviated with standard protocol in screening and diagnostic settings were also compared, based on BI-RADS classification. Diagnostic accuracy, sensitivity, specificity, and positive and negative predictive value were calculated. A total of 108 (26.5%) of 408 patients (mean age = 43 ± 9 years) were classified as BI-RADS 4-5 and considered positive findings based on suspicious enhancement (mass or non-mass enhancement). Compared to standard protocol, abbreviated protocol revealed >98% accuracy in the diagnostic setting as well as 100% accuracy in the screening setting. Concordance rates in screening and diagnostic settings were 99.6% and 98.1%, respectively. There was no discordance between abbreviated and standard protocol in the evaluation of associated findings. Abbreviated MRI protocol possesses substantial diagnostic accuracy in both screening and diagnostic settings. Additional information provided by standard protocol might not require for cancer detection.

Identification of Diagnostic Magnetic Resonance Imaging Findings in 47 Shoulders with Subcoracoid Impingement Syndrome by Comparison with 100 Normal Shoulders.

BACKGROUND The aim of this study was to identify the diagnostic magnetic resonance imaging (MRI) findings in 47 shoulders with subcoracoid impingement syndrome by comparison with 100 normal shoulders. MATERIAL AND METHODS The subcoracoid impingement syndrome group consisted of 47 shoulders with subcoracoid impingement syndrome and the normal group consisted of 100 normal shoulders. The MRI parameters - coracoids-humeral distance (CHD), coracoid index (CI), height of the lesser tuberosity (HLT), coracoid obliquity (CO), coracoglenoid angle (CGA), coracohumeral angle (CHA), width of the subscapular tendon (WST), and contact distance between subscapular tendon and coracoid process (CD) - were compared between the subcoracoid impingement syndrome group and the normal group. The areas under the curves (AUCs) from the receiver operating characteristic (ROC) for single MRI parameters were recorded, in which the MRI parameters with AUC exceeding 0.70 were included in the analysis of combined parameters. Comparisons of ROC were made among single parameters and combined parameters. RESULTS For diagnosing subcoracoid impingement syndrome by using single MRI parameters (CHD, CI, HLT, CGA, CHA, WST, and CD), the AUCs were 0.963, 0.806, 0.745, 0.691, 0.613, 0.685, and 0.614, respectively, of which CHD had the largest AUC. CHD, CI, and HLT (AUC exceeding 0.70) were included in the study of the combined parameters. The AUC of combined CHD and HLT showed a significantly larger AUC than that of CHD (0.986 vs 0.963, P=0.036), and showed no significant difference compared with that of combined CHD, CI, and HLT (0.986 vs 0.987, P=0.882). CONCLUSIONS Measurement of the coracoid-humeral distance and height of the lesser tuberosity were key MRI diagnostic findings for subcoracoid impingement syndrome.

Changes in Measures of Vestibular and Balance Function and Hippocampus Volume in Alzheimer's Disease and Mild Cognitive Impairment.

To test the hypotheses that people with Alzheimer's disease and mild cognitive impairment have increased frequency of vestibular impairments and decreased hippocampal volume compared with healthy age-matched controls. Retrospective, with some historical controls. Out-patient, tertiary care center. People with mild to moderate dementia diagnosed with Alzheimer's disease and with mild cognitive impairment. Main Outcome Measures: A standard clinical battery of objective tests of the vestibular system, and screening for balance; available clinical diagnostic magnetic resonance imaging (MRIs) were reviewed and postprocessed to quantify the left and right hippocampal volumes utilizing both manual segmentation and computer automated segmentation. Study subjects (N = 26) had significantly more vestibular impairments, especially on Dix-Hallpike maneuvers and cervical vestibular evoked myogenic potentials (cVEMP), than historical controls. No differences were found between mild and moderate dementia subjects. Independence on instrumental activities of daily living in subjects with age-normal balance approached statistical differences from subjects with age-abnormal balance. MRI data were available for 11 subjects. Subjects with abnormal cVEMP had significantly reduced left hippocampal MRIs using manual segmentation compared with subjects with normal cVEMP. The data from this small sample support and extend previous evidence for vestibular impairments in this population. The small MRI sample set should be considered preliminary evidence, and suggests the need for further research, with a more robust sample and high-resolution MRIs performed for the purpose of hippocampal analysis.

A review of high-intensity focused ultrasound as a novel and non-invasive interventional radiology technique

High-intensity focused ultrasound (HIFU) is a non-invasive interventional radiology technology, which has been generally accepted in clinical practice for the treatment of benign and malignant tumors. HIFU can cause targeted tissue coagulative necrosis and protein denaturation by thermal or non-thermal effects, guided by diagnostic ultrasound or magnetic resonance imaging, without destruction of the normal adjacent tissue, under sedation or general anesthesia. HIFU has become an important alternative to standard treatments of solid tumors, including surgery, radiation, and medications. The aim of this review is to describe the development, principle, devices, and clinical applications of HIFU.

CT and MRI diagnostics of desmoid fibroids in familial colon adenomatosis

Objective: to study the features of CT and MRI diagnostics of desmoid fibroids (DF) in familial colon adenomatosis (SATC). Patients and methods: the study included 35 patients with desmoid fibroids (DF) in familial colon adenomatosis (SATC). All patients were examined using computed tomography (CT) and magnetic resonance imaging (MRI) with intravenous contrast. Localization, size, growth pattern, prevalence of DF, features of contrast and intensity of the MR signal on T2-VI and post-contrast T1-VI were evaluated. Twenty-five (71.4%) patients were observed in dynamics, including during systemic therapy. Results: in 21 (60.0 %) patients, a lesion of only one anatomical area was detected, and in 14 (40.0%) cases, a combined lesion of different anatomical zones was noted. In the majority of observations (33/35, 94.4 %) desmoid fibroids were detected in the mesentery and mesentery root of the small intestine, including with a combined lesion. The majority of patients (24/35, 68.6%) were diagnosed with a diffuse nodular form of growth; 13 (37.1%) had a nodular form and 6 (17.1%) had a diffuse form. Twenty-five patients (25/35, 71.4%) were repeatedly re-examined using CT (13/35, 37.1%) and MRI (12/35, 34.3%), in particular during systemic therapy. Conclusion: CT and MRI are the basic methods for detecting DF in SATC, allowing to determine the nature of tumor growth, to assess the prevalence of the tumor process and the degree of involvement of adjacent organs and structures. In dynamic observation and evaluation of the response of a desmoid tumor to systemic therapy, MRI has greater diagnostic capabilities compared to CT, since it takes into account not only the size of the desmoid, but also the intensity of the MR signal on T2-VI and the nature of the accumulation of contrast agent on post-contrast T1-VI with fat suppression.

Quantitative analysis of diffusion weighted imaging in rectal cancer during radiotherapy using a magnetic resonance imaging integrated linear accelerator.

Magnetic resonance imaging integrated linear accelerator (MR-Linac) platforms enable acquisition of diffusion weighted imaging (DWI) during treatment providing potential information about treatment response. Obtaining DWI on these platforms is technically different from diagnostic magnetic resonance imaging (MRI) scanners. The aim of this project was to determine feasibility of obtaining DWI and calculating apparent diffusion coefficient (ADC) parameters longitudinally in rectal cancer patients on the MR-Linac. Nine patients undergoing treatment on MR-Linac had DWI acquired using b-values 0, 30, 150, 500s/mm2. Gross tumour volume (GTV) and normal tissue was delineated on DWI throughout treatment and median ADC was calculated using an in-house tool (pyOsirix ®). Seven out of nine patients were included in the analysis; all demonstrated downstaging at follow-up. A total of 63 out of 70 DWI were analysed (7 excluded due to poor image quality). An increasing trend of ADC median for GTV (1.15×10-3 mm2/s interquartile range (IQ): 1.05-1.17 vs 1.59×10-3 mm2/s IQ: 1.37 - 1.64; p=0.0156), correlating to treatment response. In comparison ADC median for normal tissue remained the same between first and last fraction (1.61×10-3 mm2/s IQ: 1.56-1.71 vs 1.67×10-3 mm2/s IQ: 1.37-2.00; p=0.9375). DWI assessment in rectal cancer patients on MR-Linac is feasible. Initial results provide foundations for further studies to determine DWI use for treatment adaptation in rectal cancer.

Deep learning-based 3D MRI contrast-enhanced synthesis from a 2D noncontrast T2Flair sequence.

Gadolinium-based contrast agents (GBCAs) have been successfully applied in magnetic resonance (MR) imaging to facilitate better lesion visualization. However, gadolinium deposition in the human brain raised widespread concerns recently. On the other hand, although high-resolution three-dimensional (3D) MR images are more desired for most existing medical image processing algorithms, their long scan duration and high acquiring costs make 2D MR images still much more common clinically. Therefore, developing alternative solutions for 3D contrast-enhanced MR image synthesis to replace GBCAs injection becomes an urgent requirement. This study proposed a deep learning framework that produces 3D isotropic full-contrast T2Flair images from 2D anisotropic noncontrast T2Flair image stacks. The super-resolution (SR) and contrast-enhanced (CE) synthesis tasks are completed in sequence by using an identical generative adversarial network (GAN) with the same techniques. To solve the problem that intramodality datasets from different scanners have specific combinations of orientations, contrasts, and resolutions, we conducted a region-based data augmentation technique on the fly during training to simulate various imaging protocols in the clinic. We further improved our network by introducing atrous spatial pyramid pooling, enhanced residual blocks, and deep supervision for better quantitative and qualitative results. Our proposed method achieved superior CE-synthesized performance in quantitative metrics and perceptual evaluation. In detail, the PSNR, structural-similarity-index, and AUC are 32.25dB, 0.932, and 0.991 in the whole brain and 24.93dB, 0.851, and 0.929 in tumor regions. The radiologists' evaluations confirmed that our proposed method has high confidence in the diagnosis. Analysis of the generalization ability showed that benefiting from the proposed data augmentation technique, our network can be applied to "unseen" datasets with slight drops in quantitative and qualitative results. Our work demonstrates the clinical potential of synthesizing diagnostic 3D isotropic CE brain MR images from a single 2D anisotropic noncontrast sequence.

Conservative Treatment of Didelphyc Uterus with Obstructed Hemivagina and Ipsilateral Renal Agenesis

To show a conservative surgical treatment for a female adolescent affected by Wunderlich syndrome with didelphys uterus and obstructed hemivagina. Stepwise demonstration of the technique with narrated video footage. In the context of obstructive congenital müllerian anomalies, involving a stagnation of menstrual blood, the Wunderlich syndrome is the most common and constantly characterized by the duplicity of the uterine body, by the presence of an imperforate hemivagina, and by renal agenesis ipsilateral to the obstructed hemivagina. The imperforate hemivagina leads to dysmenorrhea and abdominal pain, owing to the hematocolpos and the hematometra, which arose immediately after the menarche. This is the case of a 14-year-old female adolescent affected by Wunderlich syndrome referred to the San Raffaele Hospital adolescent center (Milan, Italy) for dysmenorrhea and abdominal pain. At vaginal exploration, a right imperforated hemivagina and hematocolpos were highlighted. A diagnostic magnetic resonance imaging (MRI) found the duplicity of the uterine body, the hematometra, and the right renal agenesis. A combination of explorative laparoscopy and surgical vaginal time leads to the excision of the vaginal septum that allows the drainage of the hematocolpos and of the hematometra. Three surgical steps are described: 1. First laparoscopic step: exploration of the abdominal cavity with the detection of a double uterine body, an enlarged hemiuterus, and an enlarged hemivagina caused by the hematometra and the hematocolpos. Careful evaluation of adnexa for eventual presence of hematosalpinx. 2. Vaginal step divided into the following: (A) puncture of the vaginal tumescence (corresponding to the imperforated hemivagina) with a 19-gauge needle mounted on a syringe. Aspiration results in thick creamy black material (old menstrual blood). (B) In correspondence with the needle puncture, a full-thickness incision of the vaginal wall widely opening the second uterine cervix and (C) stabilization of the opening by the marsupialization of the edge of the obstructed hemivagina were performed. 3. Second laparoscopic step: having emptied the hematocolpos of the left hemiuterus, the didelphys uterus and the disappearance of the hematocolpos can be clearly seen. Here, we demonstrate a conservative surgical approach for the treatment of Wunderlich syndrome. This rare malformation is characterized by an extreme variability of the anatomic presentation, and the precise identification of the variety together with the early diagnosis is of fundamental importance for the surgical correction.

Giant sacrococcygeal teratoma in a neonate: illustrative case

BACKGROUNDSacrococcygeal teratomas (SCTs) are tumors that emerge in the sacrococcygeal area and contain tissue from all three germ layers. SCT affects about 1 in every 35,000–40,000 live births, with malignant transformation becoming more common as the patient gets older. Ultrasound helps in prenatal diagnosis. Surgical resection is the mainstay of treatment.OBSERVATIONSA couple gave birth to a neonate with a small mass over his sacral region that progressively increased in size. Diagnostic magnetic resonance imaging was performed, and a diagnosis of giant SCT was established. Complete resection with flap reconstruction was performed. In regular follow-up, he is in a good state of health.LESSONSOne of the most common tumors in infancy, SCT should be carefully diagnosed. SCT is often confused with neural tube defects such as myelocystocele or myelomeningocele. Complete resection with appropriate reconstruction can ensure better treatment, and close follow-up until adulthood is recommended to keep a close view on its possible recurrence and to improve prognosis. Postoperative complications such as infection, bleeding, and urethral complications should be carefully watched.

Retrospective and integrative analyses of molecular characteristics and their specific imaging parameters in pediatric grade 1 gliomas.

Pediatric low-grade gliomas (PLGG) are the most common brain tumors diagnosed during childhood and represent a heterogeneous group associating variable molecular abnormalities. To go further and develop specific statistical patterns between tumor molecular background, imaging features, and patient outcome, a retrospective study was performed in a group of non-neurofibromatosis type 1 (non-NF1) grade 1 PLGGs. Seventy-eight children, followed from 2004 to 2017, were retrospectively reported. In this population, we analyzed radiological and molecular parameters. Their therapeutic management comprised surgery or surgery plus chemotherapies. Considering all 78 patients, 59 had only a surgical removal and 19 patients were treated with postoperative chemotherapy. Twelve progressions were reported in the partially resected and chemotherapeutic groups, whereas four deaths occurred only in the highly treated patients. As expected, in the global cohort, PLGG with BRAF p.V600E and/or CDKN2A loss exhibited poor outcomes and we evidenced significant associations between those molecular characteristics and their imaging presentation. In the chemo-treated patients, when associating initial and 6-month magnetic resonance imaging (MRI) parameters to the molecular features, the good risk situations were significantly linked to the presence of a large tumor cyst at diagnosis and the appearance during treatment of a higher cystic proportion that we called cystic conversion. So, additionally to the presence of BRAF p.V600E or CDKN2A deletion in grade 1 PLGGs, the absence on diagnostic MRI of cystic parts and/or cystic conversion at 6-month chemotherapy were significantly linked to a worst prognosis and response to treatment. These imaging features should be considered as prognostic markers in future PLGG studies.

Breast MRI: Simplifying Protocol and BI-RADS Categories

BackgroundBreast magnetic resonance imaging (MRI) is a useful imaging method, and studies have proven abbreviated protocols may reduce its time and costs with comparable accuracy. To assess the agreement of the abbreviated and full MRI protocols for breast cancer. Patients and MethodsThis retrospective cross-sectional study included consecutive women who underwent breast MRI from June 2019 to May 2020. Breast MRIs were performed in 2 hospitals, and 3 board-certified radiologists conducted its evaluations. The abbreviated breast MRI was assessed in the following order: MIP; subtraction; and T1W pre- and post-contrast. Findings were categorized according Breast Imaging - Reporting and Data System (BI-RADS 5th edition). The groups were named simplified BI-RADS and were adapted from BI-RADS 5-point scoring system. ResultsFour hundred and nineteen women (838 BI-RADS), with mean age of 49.5 ± 12.3 years were evaluated. A very good agreement was found between the protocols for total population (weighted kappa: 0.95; P <.001) and for MRI indication subgroups (weighted kappa: 0.86-1.00; P <.001). A high accuracy was also observed comparing abbreviated breast MRI compared to a full diagnostic MRI (97.6%). ConclusionAbbreviated breast MRI has demonstrated performance comparable to full diagnostic MRI protocols for breast cancer screening and diagnostic. In addition, the present study proposes the use of the simplified BI-RADS as a new classification, in order to assist physicians in clinical management.

Leptomeningeal enhancement in magnetic resonance imaging predicts poor prognosis in lung adenocarcinoma patients with leptomeningeal metastasis.

BackgroundTo investigate the prognostic value of magnetic resonance imaging (MRI) findings in the prognosis of patients with leptomeningeal metastasis from lung adenocarcinoma.MethodsPatients with lung adenocarcinoma complicated with cytologically confirmed leptomeningeal metastasis who visited Peking Union Medical College Hospital (blinded for review) between January 2012 and July 2019 were retrospectively reviewed. We collected the patients' clinical and neuroimaging findings and pathological data. The presence of leptomeningeal enhancement on initial contrast MRI was used to divide patients into MRI‐positive and MRI‐negative groups. Univariate and multivariate analyses were performed to evaluate prognostic factors.ResultsEighty‐six patients (38 men and 48 women; median age = 56 [range, 25–80]) were included. Seventy‐three patients (84.9%) had targetable genetic alterations. Only 30 patients (34.88%) had leptomeningeal enhancement on initial contrast MRI. No significant differences were observed in the distribution of demographics, driver gene status, intracranial pressure, complicated brain/spinal metastasis, or treatment strategies between the two groups. The median overall survival of patients in the MRI‐positive group was significantly shorter than that in the negative group (182 days vs. 352 days, p = 0.036). Cox regression analysis indicated that the presence of leptomeningeal enhancement on the initial diagnostic magnetic resonance imaging was an independent predictor of an unfavourable prognosis of leptomeningeal metastasis (hazard ratio = 1.707, p = 0.044).ConclusionsThis is the first time that positive initial contrast‐enhanced magnetic resonance imaging of the neuroaxis has been proposed as a risk factor for the prognosis of leptomeningeal metastasis from lung adenocarcinoma with contemporary survival data.

Post-Acquisition Hyperpolarized 29Silicon Magnetic Resonance Image Processing for Visualization of Colorectal Lesions Using a User-Friendly Graphical Interface.

Medical imaging devices often use automated processing that creates and displays a self-normalized image. When improperly executed, normalization can misrepresent information or result in an inaccurate analysis. In the case of diagnostic imaging, a false positive in the absence of disease, or a negative finding when disease is present, can produce a detrimental experience for the patient and diminish their health prospects and prognosis. In many clinical settings, a medical technical specialist is trained to operate an imaging device without sufficient background information or understanding of the fundamental theory and processes involved in image creation and signal processing. Here, we describe a user-friendly image processing algorithm that mitigates user bias and allows for true signal to be distinguished from background. For proof-of-principle, we used antibody-targeted molecular imaging of colorectal cancer (CRC) in a mouse model, expressing human MUC1 at tumor sites. Lesion detection was performed using targeted magnetic resonance imaging (MRI) of hyperpolarized silicon particles. Resulting images containing high background and artifacts were then subjected to individualized image post-processing and comparative analysis. Post-acquisition image processing allowed for co-registration of the targeted silicon signal with the anatomical proton magnetic resonance (MR) image. This new methodology allows users to calibrate a set of images, acquired with MRI, and reliably locate CRC tumors in the lower gastrointestinal tract of living mice. The method is expected to be generally useful for distinguishing true signal from background for other cancer types, improving the reliability of diagnostic MRI.

Magnetic resonance imaging evaluation of the effectiveness of FemiCushion in pelvic organ prolapse.

AimsFemiCushion (FC) is a supportive device for pelvic organ prolapse (POP), but its effectiveness has not been evaluated with imaging studies. This study utilized magnetic resonance imaging (MRI) to evaluate the anatomic changes induced by FC use in patients with severe POP.MethodsThis prospective study examined patients with stage 3 or 4 POP who underwent treatment with FC and received a diagnostic MRI. Measurements were made in the midsagittal plane at rest and during straining with and without FC. The vertical distances from the lowest points of the anterior and posterior vaginal wall (A; P), uterine cervix or vaginal stump (C), and perineal body (PB) to the Pelvic Inclination Correction System line were measured, along with the lengths of the urogenital (UGH) and levator hiatus (LH).ResultsTwelve patients were included in the study. The median age was 72 (range, 56–84) years. All reference points were positioned significantly higher with the FC than without the FC (median ΔA: 11 mm, p = 0.005; ΔC: 14 mm, p = 0.011; ΔP: 6 mm, p = 0.008; ΔPB: 7 mm, p = 0.002). Median UGH and LH lengths during straining were significantly shorter with the FC than without the FC (UGH: 44 mm vs. 53 mm, p = 0.002; LH: 60 vs. 65 mm, p = 0.021).ConclusionsThis is the first report on the use of MRI to measure the performance of FC. Our study demonstrates that FC effectively repositioned the organs involved in POP.

A retrospective study of small-pelvis radiotherapy plus image-guided brachytherapy in stage I-II non-bulky cervical squamous cell carcinoma.

We herein report a retrospective analysis of the efficacy of a combination therapy of pelvic irradiation that excluded the common iliac lymph nodes region and image-guided brachytherapy (IGBT) for non-bulky (≤4 cm) cervical cancer. Thirty-three patients with stage I–II cervical squamous cell carcinoma (≤4 cm) and without pelvic/para-aortic lymphadenopathy who were treated with definitive radiotherapy alone between February 2009 and September 2016 were included. The radiotherapy consisted of CT-based small-pelvis irradiation (whole pelvis minus common iliac lymph node area) of 20 Gy/10 fractions followed by pelvic irradiation with a midline block of 30 Gy/15 fractions and IGBT of 24 Gy/4 fractions (6 Gy/fraction for high-risk [HR] clinical target volume [CTV] D90%). In-room computed tomography (CT) imaging with applicator insertion was used for brachytherapy planning, with physical examinations and diagnostic magnetic resonance imaging (MRI) also being referred to for determination of HR CTV. Over a median follow-up of 60.5 months (range, 7–89), two patients developed distant recurrence and one developed local and distant recurrence. Two patients died from cervical cancer, one from hepatocellular carcinoma and one from non-cancerous disease. The 2/5-year local control (LC), progression-free survival (PFS) and overall survival (OS) rates were 100%/96.7%, 93.8%/90.6% and 93.9%/93.9%, respectively. No pelvic/para-aortic lymph node recurrence was observed. There were no late complications of grade 3 or higher in the small bowel, large bowel/rectum, or bladder. Our results suggest that a combination therapy of IGBT plus small-pelvis irradiation excluding common iliac lymph nodes provides reasonable clinical outcomes and can be a treatment option in non-bulky (≤4 cm) cervical squamous cell carcinoma.

Comparison of artefact reduction possibilities with the new active transcutaneous bone conduction implant (Bonebridge).

This study aimed to evaluate the possibilities of artefact reduction using different anatomical implant positions with the Bonebridge bone-conduction hearing implant 602 for a patient with an acoustic neuroma requiring regular diagnostic magnetic resonance imaging of the tumour position. Three implant positions and magnetic resonance imaging examinations with and without customised sequences for metal artefact suppression were investigated. The diagnostic usefulness was rated by a radiologist (qualitative evaluation), and the relation between the area of artefact and the total head area was calculated (quantitative evaluation). Following the qualitative analysis, the radiologist rated the superior to middle fossa implant placement significantly better for diagnostic purposes, which is in agreement with the calculated artefact ratio (p < 0.0001). The customised slice-encoding metal artifact correction view-angle tilting metal artifact reduction technique sequences significantly decreased the relative artefact area between 5.13 per cent and 25.02 per cent. The smallest mean artefact diameter was found for the superior to middle fossa position with 6.80 ± 1.30 cm (range: 5.42-9.74 cm; reduction of 18.65 per cent). The application of artefact reduction sequencing and special anatomical implant positioning allows regular magnetic resonance imaging in patients with the bone-conduction hearing implant 602 without sacrificing diagnostic imaging quality for tumour diagnosis.

Left-Right Intensity Asymmetries Vary Depending on Scanner Model for FLAIR and T1 Weighted MRI Images.

BackgroundLocalized regions of left–right image intensity asymmetry (LRIA) were incidentally observed on T2‐weighted (T2‐w) and T1‐weighted (T1‐w) diagnostic magnetic resonance imaging (MRI) images. Suspicion of herpes encephalitis resulted in unnecessary follow‐up imaging. A nonbiological imaging artifact that can lead to diagnostic uncertainty was identified.PurposeTo investigate whether systematic LRIA exist for a range of scanner models and to determine if LRIA can introduce diagnostic uncertainty.Study TypeA retrospective study using the Alzheimer's Disease Neuroimaging Initiative (ADNI) data base.SubjectsOne thousand seven hundred fifty‐three (median age: 72, males/females: 878/875) unique participants with longitudinal data were included.Field Strength3T.SequencesT1‐w three‐dimensional inversion‐recovery spoiled gradient‐echo (IR‐SPGR) or magnetization‐prepared rapid gradient‐echo (MP‐RAGE) and T2‐w fluid‐attenuated inversion recovery (FLAIR) long tau fast spin echo inversion recovery (LT‐FSE‐IR). Only General Electric, Philips, and Siemens' product sequences were used.AssessmentLRIA was calculated as the left–right percent difference with respect to the mean intensity from automated anatomical atlas segmented regions. Three neuroradiologists with 37 (**), 32 (**), and 3 (**) years of experience rated the clinical impact of 30 T2‐w three‐dimensional FLAIR exams with LRIA to determine the diagnostic uncertainty. Statistical comparisons between retrospective intensity normalized T1m and original T1‐w images were made.Statistical TestsFor each image type, a linear mixed effects model was fit using LRIA scores from all scanners, regions, and participants as the outcome and age and sex as predictors. Statistical significance was defined as having a P‐value <0.05.ResultsLRIA scores were significantly different from zero on most scanners. All clinicians were uncertain or recommended definite diagnostic follow‐up in 62.5% of cases with LRIA >10%. Individuals with acute brain pathology or focal neurologic deficits are not enrolled in ADNI; therefore, focal signal abnormalities were considered false positives.Data ConclusionLRIA is system specific, systematic, creates diagnostic uncertainty, and impacts IR‐SPGR, MP‐RAGE, and LT‐FSE‐IR product sequences.Level of Evidence: 2Technical Efficacy Stage: 3

Automatic segmentation of high-risk clinical target volume for tandem-and-ovoids brachytherapy patients using an asymmetric dual-path convolutional neural network.

Preimplant diagnostic magnetic resonance imaging is the gold standard for image-guided tandem-and-ovoids (T&O) brachytherapy for cervical cancer. However, high dose rate brachytherapy planning is typically done on postimplant CT-based high-risk clinical target volume (HR-CTVCT ) because the transfer of preimplant Magnetic resonance (MR)-based HR-CTV (HR-CTVMR ) to the postimplant planning CT is difficult due to anatomical changes caused by applicator insertion, vaginal packing, and the filling status of the bladder and rectum. This study aims to train a dual-path convolutional neural network (CNN) for automatic segmentation of HR-CTVCT on postimplant planning CT with guidance from preimplant diagnostic MR. Preimplant T2-weighted MR and postimplant CT images for 65 (48 for training, eight for validation, and nine for testing) patients were retrospectively solicited from our institutional database. MR was aligned to the corresponding CT using rigid registration. HR-CTVCT and HR-CTVMR were manually contoured on CT and MR by an experienced radiation oncologist. All images were then resampled to a spatial resolution of 0.5× 0.5 × 1.25mm. A dual-path 3D asymmetric CNN architecture with two encoding paths was built to extract CT and MR image features. The MR was masked by HR-CTVMR contour while the entire CT volume was included. The network put an asymmetric weighting of 18:6 for CT: MR. Voxel-based dice similarity coefficient (DSCV ), sensitivity, precision, and 95% Hausdorff distance (95-HD) were used to evaluate model performance. Cross-validation was performed to assess model stability. The study cohort was divided into a small tumor group(<20 cc), medium tumor group (20-40cc), and large tumor group(>40cc) based on the HR-CTVCT for model evaluation. Single-path CNN models were trained with the same parameters as those in dual-path models. For this patient cohort, the dual-path CNN model improved each of our objective findings, including DSCV , sensitivity, and precision, with an average improvement of 8%, 7%, and 12%, respectively. The 95-HD was improved by an average of 1.65mm compared to the single-path model with only CT images as input. In addition, the area under the curve for different networks was 0.86 (dual-path with CT and MR) and 0.80 (single-path with CT), respectively. The dual-path CNN model with asymmetric weighting achieved the best performance with DSCV of 0.65 ± 0.03 (0.61-0.70), 0.79 ± 0.02 (0.74-0.85), and 0.75 ± 0.04 (0.68-0.79) for small, medium, and large group. 95-HD were 7.34 (5.35-10.45) mm, 5.48 (3.21-8.43) mm, and 6.21 (5.34-9.32) mm for the three size groups, respectively. An asymmetric CNN model with two encoding paths from preimplant MR (masked by HR-CTVMR ) and postimplant CT images was successfully developed for automatic segmentation of HR-CTVCT for T&O brachytherapy patients.

Cost-Effectiveness of Prostate Cancer Detection in Biopsy-Naïve Men: Ultrasound Shear Wave Elastography vs. Multiparametric Diagnostic Magnetic Resonance Imaging.

This exploratory study investigates the cost-effectiveness of ultrasound shear wave elastography (SWE) imaging in comparison to pre-biopsy multiparametric magnetic resonance imaging (mpMRI) in men with suspected prostate cancer. This research is motivated by the early evidence of the good performance of SWE in distinguishing cancerous from benign prostate tissues. We used a decision analysis model representing the care-pathways of men referred with a high prostate specific antigen (PSA) and/or abnormal digital rectal examination (DRE) in a UK setting from the payer’s perspective with results reported in 2016 GBP. We then appraised the cost-effectiveness of a novel approach based on SWE compared to the more conventional and widely practiced mpMRI-based approaches using data reported in the literature. Deterministic and probabilistic sensitivity analyses were used to address uncertainty regarding the parameter values utilised. Our exploratory results implied that SWE approach yielded an additional quality-adjusted life year (QALY) at the cost of GBP 10,048 compared to the standard mpMRI-based approach in the UK. This is lower than the official willingness to pay threshold of GBP 20,000 (the UK healthcare system guidelines) and is therefore a suitable replacement for the current practice. Sensitivity analyses confirmed the robustness of our results.