Nonenhanced Magnetic Resonance Imaging Research Articles

Paper 41: Does MR Arthrography Improve Evaluation of Patients with Posterior Shoulder Instability? An Analysis from the MOON Shoulder Instability Group

Objectives: Posterior shoulder instability is an uncommon injury, accounting for 2-12% of shoulder instability patients. Magnetic resonance imaging (MRI) is often utilized to non-invasively evaluate the joint for labral, cartilage, and bony injury. MR arthrography (MRA) may improve the evaluation of these intra-articular structures, but requires additional cost, time, and an invasive procedure. Moreover, its benefits for patients with posterior shoulder instability are unclear. Accurate imaging is critical in patients undergoing surgery because certain findings may influence the surgical approach. Thus, the purpose of this study is to compare the accuracy of MRA and non-enhanced MRI in detecting labral, chondral, and osseous lesions in patients with posterior shoulder instability. Methods: There were 291 patients with unilateral posterior shoulder instability who had preoperative MRA or MRI between 2006 and 2021 in the MOON database. Images were reviewed by a fellowship-trained musculoskeletal radiologist with 10+ years of experience and an orthopaedic surgeon. Evaluators were blinded to age, gender, medical history, MR report, and arthroscopic findings, but were aware of the patient's history of posterior shoulder instability. Examinations were evaluated for presence, location, morphology, and length of glenoid labral tears. Tear length and localization were noted using a standard clock face. The presence and size of humeral/glenoid osseous and cartilage lesions was also noted.Intraoperative findings from arthroscopic evaluation were documented by the surgeon using a standard response questionnaire. Diagnostic performance of standard MRA and MRI were evaluated using sensitivity and specificity with arthroscopic evaluation as the gold-standard. Chi-squared or Fisher’s exact tests were used to compare the sensitivities and specificities of MRA and MRI. Significance was defined as P < 0.05. Results: 200 patients (69%) had MRA, while 91 patients had non-contrast MRIs of the shoulder. On imaging evaluation, 273 (94%) patients had labral tears with a mean tear size of 156º. 39 (13%) patients had humeral cartilage lesions, whereas 40 (14%) patients had glenoid cartilage lesions. 34 (12%) patients had glenoid bone loss greater than 5%. The mean glenoid bone loss was 12% (range, 5% - 26%). A reverse Hill-Sachs lesion was present in 35 (12%) patients. 16 (6%) patients had bipolar bone loss. The sensitivity for detection of labral tears was high for both MRA (0.95) and standard MRI (0.98) (Tables 1 and 2), though the specificity was low for both modalities (0.25 and 0.40, respectively). There was no difference in the sensitivities or specificities of the two imaging modalities in the detection of labral tears. MRA had a lower sensitivity than MRI in the detection of glenoid cartilage lesions (0.31 vs 0.88, p < 0.001), but no difference was observed for specificity. There was no difference in the sensitivities and specificities of MRA and MRI for humeral cartilage lesions (p = 0.354).MRA had a higher sensitivity than MRI in assessing glenoid bone loss (0.78 vs 0.50, p < 0.001), though there was no difference in specificity. There was no difference between imaging modalities in the evaluation of humeral bone loss (p = 1.000). Conclusions: In this multicenter study, MRA was the most commonly utilized preoperative advanced imaging study for patients with posterior shoulder instability. MRA had a higher sensitivity in detecting glenoid bone loss but lower sensitivity in detecting glenoid cartilage lesions compared to standard non-contrast MRI. There was no difference in diagnostic performance between MRA and MRI in the diagnosis of labral tears and humeral chondral and osseous lesions. MRA may provide an advantage over standard MRI in the evaluation of glenoid bone loss, which can influence the treatment plan for patients undergoing surgical management of posterior shoulder instability.

A comparison of conventional 3.0-Tesla nonenhanced magnetic resonance imaging and arthroscopic findings of the anteroinferior capsulolabral complex in patients with traumatic anterior shoulder instability

This study aimed to evaluate the association between specific, reproducible findings of an anteroinferior capsulolabral complex obtained using conventional 3.0-Tesla nonenhanced magnetic resonance imaging (MRI) and pathologic arthroscopic findings and to assess the confidence level of the findings. Of 125 cases of traumatic anterior instability surgery from January 2017 to November 2019, 66 patients (52 men, 14 women; 23.5±7.9 year old) who underwent conventional 3.0-Tesla MRI at our hospital were reviewed. The following anteroinferior capsulolabral complex features were observed on the T2-star axial image: size difference of the labrum (swelling, diminished), difference in marginal and internal signals (irregularity), and capsule edema image (capsular thickening). We also reviewed fraying, flattening, cracking, and capsular hypertrophy as pathologic arthroscopic findings of the capsulolabral complex. These findings allowed for the simultaneous description of the MRI and arthroscopic evaluations. Three orthopedic surgeons and one radiologist measured the interobserver reliability. We investigated the correlation between the MRI and arthroscopic findings. The interobserver reliability of MRI irregularities was low (κ=-0.16), whereas reliability was moderate (κ=0.554-0.595) for swelling in 22 cases (33%), diminished in 34 cases (52%), and capsular thickness in 40 cases (59%). Labral detachment was found in 26 patients (39%) and fluid collection in 24 patients (36%). The agreement of MRI findings with arthroscopic findings was κ=0.46 (95% confidence interval [CI]: 0.268-0.654) for swelling to fraying; κ=0.42 (95% CI: 0.202-0.638) for swelling to capsular hypertrophy; and 0.46 (95% CI: 0.268-0.654) for flattening to diminished. The swelling and diminished findings of the anteroinferior capsulolabral complex on conventional MRI were moderately related to pathologic arthroscopic findings in patients with traumatic anterior shoulder instability. These findings contribute to achieving an accurate clinical diagnosis.

The value of the dermal rim sign on nonenhanced magnetic resonance imaging for predicting dermal backflow in patients with primary lower extremity lymphedema

PurposeThe dermal rim sign (DRS) on nonenhanced magnetic resonance imaging has been shown to predict dermal backflow (DBF) in patients with secondary upper limb lymphedema. However, whether the DRS has the same effects on primary lower extremity lymphedema (PLEL) has not been clearly reported. Therefore, this study aimed to explore whether the DRS can be used to diagnose DBF on lymphoscintigraphy in patients with PLEL. MethodsA total of 94 patients who were diagnosed with PLEL were recruited for this retrospective study from January 2022 to December 2023. All the patients were divided into two groups according to the lymphoscintigraphy findings: no DBF and DBF. The magnetic resonance imaging data of the two groups were recorded and statistically compared for the following indicators: range of lymphedema involvement (left, right, whole lower limbs, only thigh, only calf and ankle), signs of lymphedema (notable thickening of skin, parallel line sign, grid sign, honeycomb sign, band sign, lymph lake sign, crescent sign, DRS), and lymphedema measurement (skin thickness, band width). The DRS is characterized by notable thickening of the skin plus the grid sign and/or honeycomb sign, plus the band sign. ResultsThe following statistically significant differences in the following indicators were found between the two groups (P < .05): notable skin thickening, parallel line sign, grid sign, honeycomb sign, band sign, DRS, skin thickness, and band width. The sensitivity, specificity, and accuracy for predicting for DBF with the DRS was 82%, 64%, and 77%, respectively. ConclusionsThis study confirmed good consistency between the DRS and DBF from the perspective of imaging. This tool is suitable for children, adolescents, and patients with contraindications to lymphoscintigraphy. The DRS has important value in assessing the severity of PLEL. The DRS is suggested for the clinical use of combined surgical treatment of PLEL.

Differentiating gallbladder cancer from polyps using non-enhanced magnetic resonance imaging.

This retrospective cohort study assessed the efficiency of non-enhanced magnetic resonance imaging (MRI) for differentiating gallbladder cancer (GBC) from gallbladder polyps (GBPs) measuring ≥ 10 mm. Patients diagnosed with GBCs or GBPs ≥ 10 mm and GBC ≤ T2 stage were eligible for inclusion. Two independent blinded readers assessed the continuity of the mucosal and muscular layers (CMML; present or absent) and normalised signal intensity ratio (NIR) on the apparent diffusion coefficient map (NIR-ADC), T1-weighted image (NIR-T1WI), and T2-weighted half-Fourier acquisition single-shot turbo spin-echo image. Univariate and multivariate logistic regression analyses and interobserver agreement analyses were performed to detect predictive variables differentiating GBCs from GBPs. Receiver operating characteristic (ROC) analysis was performed to evaluate diagnostic performance. A reproducibility test was performed to verify the predictive variables. Multivariate analysis showed significant differences in CMML, NIR-ADC, and NIR-T1WI (p < 0.001). The positive predictive value (PPV) and specificity of the absence of CMML were approximately 100%. The CMML showed the best specificity, accuracy, and PPV in the reproducibility study. The sensitivity of CMML alone was approximately 50%, whereas it increased to approximately 70% when combined with NIR-ADC. The diagnostic performance of the combination, including sensitivity, was almost like that of tumour size. The combined tumour size and CMML assessment showed higher diagnostic performance than tumour size alone. The absence of CMML and NIR-ADC ≤ 1.86 helped in differentiating GBCs from GBPs. Evaluation of the absence of CMML and measurement of tumour size could better aid in determining between the two than measurement of tumour size alone.

Inoperable Optic Pathway Glioma: A Seven-Year-Old Male with &gt;35 Years Overall Survival Following Treatment with Antineoplastons

Optic pathway glioma (OPG) is a low-grade tumor developing along the pre-cortical optic pathways and can involve the optic nerve, optic chiasm, optic tracts, and hypothalamus. Objective: A male child with newly diagnosed and unresectable OPG is presented to 1) review the earliest use of Antineoplastons A10 and AS2-1 for the treatment of brain tumors and 2) demonstrate the efficacy of Antineoplastons in the treatment of OPG. On April 18, 1988, a seven-year-old male child presented to the Burzynski Clinic (BC) with headaches. Based on prior, non-enhanced MRIs and biopsy, an unresectable suprasellar OPG was diagnosed. Antineoplaston therapy was started on a “proof of principle” basis. Tumor response was measured by magnetic resonance imaging (MRI) scans of the brain. Results: A brain MRI, performed on May 31, 1989, demonstrated an enhancing suprasellar nodule measuring 4.37 cm2. On August 24, 1990, brain MRI demonstrated a 0.96 cm2 enhancing nodule, indicating the achievement of a partial response (PR). Following higher dose intravenous (IV) and oral Antineoplastons, brain MRI performed on January 24, 1997, demonstrated a residual 0.4 cm2 enhancing nodule, indicating an enduring PR. All Antineoplaston therapy was discontinued on August 21, 2000. At last follow-up, &gt; 35 years since the start of Antineoplaston therapy, the patient was healthy and showed no evidence of tumor progression. “Proof of principle” Antineoplaston therapy utilized in a seven-year-old male with unresectable OPG produced an objective response (OR) and prolonged overall survival. Antineoplaston therapy is an attractive therapeutic option for children with OPG.

Gastrointestinal tumor-related perihepatic fluorouracil encapsulated lesions and liver metastases: a diagnostic imaging study based on contrast-enhanced computed tomography and magnetic resonance imaging.

Perihepatic fluorouracil encapsulated lesions (FELs) can result in potentially confusing computed tomography (CT) and magnetic resonance imaging (MRI) features in postoperative examinations of gastrointestinal tumors. This retrospective study aimed to summarize the typical imaging features of FELs and determine the best imaging modality to distinguish FELs from liver metastases for junior residents. Patients with FELs who had undergone gastrointestinal tumor surgery in Tongji Hospital from January 2016 to June 2022 were evaluated. The imaging features of FELs were summarized by two senior radiologists. Contrast-enhanced CT (CECT) was used as the primary follow-up tool for postoperative gastrointestinal tumor patients. Patients with FELs and available CECT and MRI examinations were matched with patients with liver metastases based on gender and age and presented in chronological order in a 2:1 ratio. Different imaging modality combinations were used for further evaluation, including a CECT group (modality Ⅰ), CECT and nonenhanced MRI group (modality Ⅱ) and CECT with all MRI sequences group (modality Ⅲ). Subsequently, two junior residents blindly evaluated three groups following a 4-week interval based on a 5-point scale (1= definite benign lesion, 2= probable benign lesion, 3= indeterminate, 4= probable liver metastasis, 5= definite liver metastasis). Imaging features of 33 patients with 36 FELs were analyzed. CECT and dynamic contrast-enhanced MRI (DCE-MRI) showed no enhancement in most lesions. Additionally, 20 patients with FELs meeting the requirements were matched with 40 patients with liver metastases. The highest sensitivity, specificity, and consistency for identifying liver metastases were achieved using a combination of CECT and MRI encompassing all sequences yielded, including modality Ⅰ (reader 1: 72.0% and 17.4%; reader 2: 62.0% and 17.4%; kappa value 0.295), modality Ⅱ (reader 1: 88.0% and 8.7%; reader 2: 92.0% and 34.8%; kappa value 0.259), and modality Ⅲ (reader 1: 98.0% and 34.8%; reader 2: 92.0% and 39.1%; kappa value 0.680). FELs are typically non-enhancing lesions. In our study, two junior residents could best distinguish FELs from liver metastases using CECT with all MRI sequences.

Noninvasive prediction of insufficient biochemical response after ursodeoxycholic acid treatment in patients with primary biliary cholangitis based on pretreatment nonenhanced MRI

ObjectivesTo explore the feasibility of pretreatment nonenhanced magnetic resonance imaging (MRI) in predicting insufficient biochemical response to ursodeoxycholic acid (UDCA) in patients with primary biliary cholangitis (PBC).MethodsFrom January 2009 to April 2022, consecutive PBC patients who were treated with UDCA and underwent nonenhanced MRI within 30 days before treatment were retrospectively enrolled. All MR images were independently evaluated by two blinded radiologists. Uni- and multivariable logistic regression analyses were performed to develop a predictive model for 12-month insufficient biochemical response. Model performances were evaluated by computing the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity.ResultsA total of 74 patients (50.6 ± 11.9 years; 62 females) were included. Three pretreatment MRI features, including hepatomegaly (odds ratio [OR]: 4.580; p = 0.011), periportal hyperintensity on T2-weighted imaging (T2WI) (OR: 4.795, p = 0.008), and narrowing of the bile ducts (OR: 3.491; p = 0.027) were associated with 12-month insufficient biochemical response in the multivariable analysis. A predictive model based on the above indicators had an AUC of 0.781, sensitivity of 85.4%, and specificity of 61.5% for predicting insufficient biochemical response.ConclusionsA noninvasive model based on three pretreatment MRI features could accurately predict 12-month insufficient biochemical response to UDCA in patients with PBC. Early identification of PBC patients at increased risk for insufficient response can facilitate the timely initiation of additional treatment.Clinical relevance statementA noninvasive predictive model constructed by incorporating three pretreatment MRI features may help identify patients with primary biliary cholangitis at high risk of insufficient biochemical response to ursodeoxycholic acid and facilitate the timely initiation of additional treatment.Key Points• Noninvasive imaging features based on nonenhanced pretreatment MRI may predict an insufficient biochemical response to UDCA in PBC patients.• A combined model based on three MRI features (hepatomegaly, periportal hyperintensity on T2-weighted imaging, and narrowing of the bile ducts) further improved the predictive efficacy for an insufficient biochemical response to UDCA in PBC patients, with high sensitivity and specificity.• The nomogram of the combined model showed good calibration and predictive efficacy for an insufficient biochemical response to UDCA in PBC patients. In particular, the calibration curve visualised the clinical applicability of the prediction model.

Radiomics Features in Contrast‐Enhanced and Nonenhanced Magnetic Resonance Imaging Images Are Associated With High Intracranial Aneurysmal Risk

Background Aneurysm wall enhancement is a potential imaging biomarker for risk stratification of intracranial aneurysms (IAs). Variations in the texture of the magnetic resonance imaging (MRI) signal could shed light on the underlying pathobiology of the aneurysm wall. Radiomics can help quantify the textural complexity in MRI images, which could lead to better understanding and risk stratification of IAs. Herein, we investigated the potential use of radiomics derived from nonenhanced and contrast‐enhanced MRI to identify high‐risk IAs and evaluated their performance on different data sets. Methods We obtained 126 IAs from different centers and extracted radiomics features from nonenhanced and contrast‐enhanced MRI for each aneurysm. We then built a random forest model from a part of the 3‐T data set to identify high‐risk IAs based on the 5‐year population, hypertension, age, size of aneurysm, earlier SAH from another aneurysm, site of aneurysm (PHASES) score. We then tested the performance of this model on a part of the same 3‐T data set, a 7‐T data set, and an external 3‐T data set. We also performed multivariate analysis to understand the significance of radiomics features. Results We found that 75 radiomics features were significantly different between high‐ and low‐risk IAs. The radiomics model had good performance when tested on the 3‐T data set (accuracy, 90%; sensitivity, 86%; and specificity, 92%); however, when tested on external data sets, it had a moderate performance (accuracy, 88%; sensitivity, 50%; and specificity, 95% for external 3‐T data set; and accuracy, 62%; sensitivity, 27%; and specificity, 100% for 7‐T data set). Conclusions Radiomics derived from nonenhanced and contrast‐enhanced MRI show high accuracy in identifying high‐risk aneurysms from the same data set and could be used as a tool for quantifying aneurysm wall enhancement.

Pregnancy-Associated Renal Cortical Necrosis and Nonenhanced Functional Magnetic Resonance Imaging: A Case Series

Pregnancy-associated renal cortical necrosis is a critical illness with a poor prognosis. We aimed to describe the clinical and magnetic resonance imaging (MRI) characteristics of a case series of patients with acute kidney injury in the setting of pregnancy-associated renal cortical necrosis. Case series. Seventeen patients from a single center diagnosed by nonenhanced functional MRI and/or kidney pathology. All patients presented with postpartum acute kidney injury stage 3. Of the 17 patients, 15 (88%) had pregnancy-associated atypical hemolytic uremic syndrome, 11 (65%) had postpartum hemorrhage, 7 (41%) had preeclampsia/hemolysis elevated liver enzymes low platelet count syndrome, and 4 (24%) had disseminated intravascular coagulation. On T2-weighted MRI, the diffuse phenotype showed outer cortex swelling in the early phase, with a dark signal rim involving the inner cortex and Bertin column, which became more apparent over time along with cortical thinning, substantially decreasing T2 signal intensity. The focal phenotype showed focally distributed hypointense signals in the cortex. After 8-101 (median: 60) months of follow-up, 4 individuals had estimated glomerular filtration rates≥60mL/min/1.73m2, 6 had estimated glomerular filtration rates of 15-60mL/min/1.73m2, and 7 had kidney failure requiring kidney replacement therapy. The diffuse phenotype was present in all of the individuals who remained kidney replacement therapy dependent. Retrospective study; small sample size. Different forms of pregnancy-associated thrombotic microangiopathy were the major causative diseases in our pregnancy-associated renal cortical necrosis case series. Nonenhanced functional MRI may provide valuable data for establishing diagnosis and kidney prognosis.

Heuristic multi-modal integration framework for liver tumor detection from multi-modal non-enhanced MRIs

The detection of liver tumors from non-enhanced Magnetic Resonance Imaging (MRI) has become crucial for current diagnosis and treatment due to the avoidance of contrast-agent injection and associated health risks. A recent study, based on Deep Reinforcement Learning (DRL), validated the feasibility of detecting liver tumors from non-enhanced MRIs for the first time. However, this study only employed single-modal MRIs, where malignant tumors are often invisible, leading to the detection of only benign tumors. This paper proposes the Heuristic Multi-modal Integration (HMI) framework to detect both benign and malignant tumors from multi-modal non-enhanced MRIs. The HMI utilizes individual DRL modules on each modality to extract specific features and then integrates these modules into a collective DRL module, utilizing the comprehensive information from multiple modalities to detect the desired tumors. Compared to existing liver tumor detection methods, the HMI is the first study without contrast agents in both training and testing, expanding the reach of non-enhanced detection technology. Furthermore, the HMI successfully employs DRL in a multi-modal environment, offering a solution to the difficulties of DRL convergence with complex inputs and high computational requirements. The experimental results show that the HMI outperforms current state-of-the-art methods, making it an accurate and contrast-agent-free alternative for liver tumor detection in clinical settings.

Non-enhanced magnetic resonance imaging-based radiomics model for the differentiation of pancreatic adenosquamous carcinoma from pancreatic ductal adenocarcinoma.

To evaluate the diagnostic performance of radiomics model based on fully automatic segmentation of pancreatic tumors from non-enhanced magnetic resonance imaging (MRI) for differentiating pancreatic adenosquamous carcinoma (PASC) from pancreatic ductal adenocarcinoma (PDAC). In this retrospective study, patients with surgically resected histopathologically confirmed PASC and PDAC who underwent MRI scans between January 2011 and December 2020 were included in the study. Multivariable logistic regression analysis was conducted to develop a clinical and radiomics model based on non-enhanced T1-weighted and T2-weighted images. The model performances were determined based on their discrimination and clinical utility. Kaplan-Meier and log-rank tests were used for survival analysis. A total of 510 consecutive patients including 387 patients (age: 61 ± 9 years; range: 28-86 years; 250 males) with PDAC and 123 patients (age: 62 ± 10 years; range: 36-84 years; 78 males) with PASC were included in the study. All patients were split into training (n=382) and validation (n=128) sets according to time. The radiomics model showed good discrimination in the validation (AUC, 0.87) set and outperformed the MRI model (validation set AUC, 0.80) and the ring-enhancement (validation set AUC, 0.74). The radiomics model based on non-enhanced MRI outperformed the MRI model and ring-enhancement to differentiate PASC from PDAC; it can, thus, provide important information for decision-making towards precise management and treatment of PASC.

Symptom: Runny Nose Six Years After Acoustic Neuroma Surgery

Symptom: Runny Nose Six Years After Acoustic Neuroma Surgery

Detection of cerebral aneurysm and intracranial vertebral dissection using non-enhanced magnetic resonance imaging in emergency setting: Emphasis on magnitude image of susceptibility-weighted image.

To evaluate image features and diagnostic performance of susceptibility-weighted image (SWI) in detection of intracranial vertebral artery dissection (VAD) and unruptured intracranial aneurysm (UIA). From January 2015 to December 2021, symptomatic patients who underwent 3.0 T MR SWI were recruited. For study group, transfemoral cerebral angiography-proven lesions were included, while 1:1 matched control group with MR angiography were included. Image features of SWI were evaluated. Diagnostic performance and interobserver agreements were calculated for detecting VAD with stenosis and UIA greater than 7 mm. Total of 110 patients (mean age: 60.92 years, female: 60/110) were included. In the study group (N = 55), 21 patients (38.2%) had VAD, while 34 patients (61.8%) had UIA. For SWI-detectable VAD, larger parent artery (PA)-dilatation ratio was observed (1.36 vs. 1.84, p = 0.034). For SWI-detectable UIA, larger PA-dome ratio (1.32 vs. 1.90, p = 0.020) and larger PA-height ratio (1.25 vs. 1.77, p = 0.005) were observed. The diagnostic performance and kappa values for VAD with stenosis were as follow: sensitivity: 91.7 (95% CI: 61.5-99.8); specificity: 93.9 (95% CI: 87.2-97.7); к: 0.80. The diagnostic performance for UIA larger than 7 mm were as follow: sensitivity: 87.5 (95% CI: 47.4-99.7); specificity: 95.1 (95% CI: 88.9-98.4); к: 0.73. SWI-detectable lesions were VAD with larger PA-dilatation ratio, and UIA with larger PA-dome ratio, and PA-height ratio. SWI was able to accurately detect VAD with stenosis and UIA larger than 7 mm with substantial interobserver agreements.

Correlation between renal ablation zone in contrast-enhanced CT and non-enhanced MRI during the early period following percutaneous cryoablation

PurposeTo retrospectively evaluate and correlate the contrast-enhanced computed tomography (CECT) and non-enhanced magnetic resonance imaging (MRI) during the early period following renal cryoablation.Materials and methodsBoth dynamic CECT and non-enhanced MRI were performed within 4 days following cryoablation in 34 renal tumors in 33 patients. The renal volumes of the unenhanced regions on dynamic CECT (nephrogenic phase, 4 mm thickness) and the regions with signal intensity changes on non-enhanced MRI (fat-suppressed T2-weighted image, 4 mm thickness) were evaluated. Fusion images of the axial, coronal, and sagittal sections of CECT and MRI images were created from the maximum cross-section of the renal tumor, and the match score of each image was visually evaluated on a 5-point scale.ResultsThe mean renal volume of the unenhanced regions on CECT and those with signal intensity changes on non-enhanced MRI following cryoablation were 29.5 ± 19.9 cm3 (range, 4.3–97.4 cm3) and 30.7 ± 19.8 cm3 (range, 6.7–94.0 cm3), respectively; the difference between them was –1.17 cm3 (95% confidence interval [CI] –2.74, 0.40, P = 0.139). The Pearson’s product-moment correlation coefficient (r = 0.975; 95% CI, 0.951, 0.988; P < 0.0001) showed a strong correlation between the volumes. The average match score between CECT and non-enhanced MRI was as high as 4.5 ± 0.5 points (radiologist 1, 4.3 ± 0.5; radiologist 2, 4.7 ± 0.5). Local tumor control rate was 94.1% (32/34 tumors) and recurrence-free survival rate was 82.0% (95% CI: 64.2%, 91.5%) at 5 years.ConclusionsThe region with signal intensity changes on non-enhanced MRI was strongly correlated with the unenhanced region on CECT during the early period following renal cryoablation.

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

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

Transvaginal Aspiration for Management of Huge Ovarian Endometrioma in Pregnancy

Study Objective To demonstrate a minimally invasive approach of a huge ovarian cyst during pregnancy. Design A step-by-step explanation of the patient's condition, diagnosis, surgical technique, and post-operative results. Setting The patient underwent transvaginal procedure in the lithotomy position and under intravenous sedation and ventilation by face mask. Patients or Participants A 34-year-old woman, gravida 1 at 12 weeks 5 days’ gestation, presented with huge ovarian cyst. A transvaginal ultrasound demonstrated ovarian cyst measuring 10.4 × 8.2 cm with no evidence of malignancy, no free fluid, and a normal-appearing contralateral ovary. The crown-rump length measured 5.92 cm. On non-enhanced magnetic resonance imaging (MRI), 11 × 7 cm sized cystic lesion with high signal intensity in T1-weighted image (WI) and T1-weighted fat suppressed image, low signal intensity in T2 WI suggesting endometrioma, located in cul-de-sac was noted. Because the cyst was huge and deeply located in cul-de-sac, and the uterus was enlarged to 13 weeks size, approach through laparoscopy or even laparotomy was thought to be difficult and the risk of manipulation for uterus was high. So, we decided to aspirate the ovarian cyst through the vaginal route. Interventions Ultrasound-guided transvaginal aspiration was performed using an 18-G needle. Measurements and Main Results The operation time was 4 hours and 35 minutes with 305 mL dark brownish fluid drained. The patient recovered well and was discharged 2days after the procedure. There was no intraoperative or postoperative complication. Postoperative ultrasound revealed neither recurrence nor fetal abnormality. Until delivery, the patient was free of symptom and ultrasound revealed neither recurrence nor fetal abnormality. Conclusion In select pregnant woman with endometrioma requiringintervention, the risks of surgery may be minimized with aspiration. Transvaginal ultrasound-guided aspiration is a safe, feasible, and effective minimally invasive procedure for huge ovarian endometrioma in pregnancy. To demonstrate a minimally invasive approach of a huge ovarian cyst during pregnancy. A step-by-step explanation of the patient's condition, diagnosis, surgical technique, and post-operative results. The patient underwent transvaginal procedure in the lithotomy position and under intravenous sedation and ventilation by face mask. A 34-year-old woman, gravida 1 at 12 weeks 5 days’ gestation, presented with huge ovarian cyst. A transvaginal ultrasound demonstrated ovarian cyst measuring 10.4 × 8.2 cm with no evidence of malignancy, no free fluid, and a normal-appearing contralateral ovary. The crown-rump length measured 5.92 cm. On non-enhanced magnetic resonance imaging (MRI), 11 × 7 cm sized cystic lesion with high signal intensity in T1-weighted image (WI) and T1-weighted fat suppressed image, low signal intensity in T2 WI suggesting endometrioma, located in cul-de-sac was noted. Because the cyst was huge and deeply located in cul-de-sac, and the uterus was enlarged to 13 weeks size, approach through laparoscopy or even laparotomy was thought to be difficult and the risk of manipulation for uterus was high. So, we decided to aspirate the ovarian cyst through the vaginal route. Ultrasound-guided transvaginal aspiration was performed using an 18-G needle. The operation time was 4 hours and 35 minutes with 305 mL dark brownish fluid drained. The patient recovered well and was discharged 2days after the procedure. There was no intraoperative or postoperative complication. Postoperative ultrasound revealed neither recurrence nor fetal abnormality. Until delivery, the patient was free of symptom and ultrasound revealed neither recurrence nor fetal abnormality. In select pregnant woman with endometrioma requiringintervention, the risks of surgery may be minimized with aspiration. Transvaginal ultrasound-guided aspiration is a safe, feasible, and effective minimally invasive procedure for huge ovarian endometrioma in pregnancy.

Evaluation of the Effect of Multiple Linear Gadolinium-Based Contrast Agent Exposures on the Signal Intensity of the Dentate Nucleus in Multiple Sclerosis Patients

Background: Magnetic resonance imaging (MRI) with gadolinium (GAD)-based contrast agents has been the imaging modality of choice for early detection and monitoring of multiple sclerosis (MS) patients. Objectives: This study aimed to assess the effect of multiple injections of linear GAD-based contrast agents on the signal intensity of the dentate nucleus (DN) in MS patients. Patients and Methods: A cohort of 122 MS patients with GAD-enhanced MRI scans and 61 healthy controls were enrolled in this study. The final standard GAD-enhanced MRI scans were acquired using 1.5T MRI systems. Non-enhanced T1-weighted MRI was performed to assess the DN hyperintensity. The signal intensity ratio (SIR) was also calculated by setting the regions of interest (ROIs) on the DN and pons and dividing the signal intensity of DN to that of pons. The patients were also divided into two subgroups, based on the total number of MRI exposures (&gt; 4 times vs. others), and the subgroups were compared in terms of the mean SIR and hyperintensity. Results: Overall, 68% (n = 83) of the patients were exposed to a contrast agent more than four times. Of these patients, 31.3% (n = 26) showed DN hyperintensity, while no hyperintensity was found in other patients or healthy controls (P &lt; 0.02 for both). The mean SIRs were 1.10 ± 0.07 and 1.04 ± 0.02 in the patients and healthy controls, respectively (P &lt; 0.001). Besides, the mean SIR was 1.14 ± 0.04 in patients with DN hyperintensity and 1.09 ± 0.07 in other patients (P &lt; 0.001). Based on the results, the mean SIR was 1.12 ± 0.7 in patients with &gt; 4 contrast injections, while it was 1.06 ± 0.04 in patients with ≤ 4 contrast injections (P &lt; 0.001). Conclusion: The SIR and visible DN hyperintensity increased by increasing the number of GAD injections, which could be due to the tissue deposition of GAD.

Magnetically guided theranostics: montmorillonite-based iron/platinum nanoparticles for enhancing in situ MRI contrast and hepatocellular carcinoma treatment

In Asia, including Taiwan, malignant tumors such as Hepatocellular carcinoma (HCC) one of the liver cancer is the most diagnosed subtype. Magnetic resonance imaging (MRI) has been a typical diagnostic method for accurately diagnosing HCC. When it is difficult to demonstrate non-enhanced MRI of tumors, radiologists can use contrast agents (such as Gd3+, Fe3O4, or FePt) for T1-weighted and T2-weighted imaging remain in the liver for a long time to facilitate diagnosis via MRI. However, it is sometimes difficult for T2-weighted imaging to detect small tumor lesions because the liver tissue may absorb iron ions. This makes early cancer detection a challenging goal. This challenge has prompted current research to create novel nanocomposites for enhancing the noise-to-signal ratio of MRI. To develop a method that can more efficiently diagnose and simultaneously treat HCC during MRI examination, we designed a functionalized montmorillonite (MMT) material with a porous structure to benefit related drugs, such as mitoxantrone (MIT) delivery or as a carrier for the FePt nanoparticles (FePt NPs) to introduce cancer therapy. Multifunctional FePt@MMT can simultaneously visualize HCC by enhancing MRI signals, treating various diseases, and being used as an inducer of magnetic fluid hyperthermia (MFH). After loading the drug MIT, FePt@MMT-MIT provides both MFH treatment and chemotherapy in one nanosystem. These results ultimately prove that functionalized FePt@MMT-MIT could be integrated as a versatile drugs delivery system by combining with MRI, chemotheraeutic drugs, and magnetic guide targeting.

Non-Hemorrhagic Adrenal Infarction during Pregnancy: The Diagnostic Imaging Keys.

Background: non-hemorrhagic adrenal infarction (NHAI) is a rare cause of acute abdominal/flank pain during pregnancy; in order to ensure prompt and appropriate treatment, this diagnosis should not be overlooked. This case series highlights pertinent imaging findings, including ultrasounds (USs), computed tomography (CT), and magnetic resonance imaging (MRI) of recent NHAI cases. Methods: we compiled all consecutive NHAI cases from two university hospitals over a two-year period and checked the relevant clinical, laboratory, and imaging findings. Relevant articles on NHAI published from January 2010 to March 2021 were analyzed. Results: six cases were found in our database. CT-scans typically showed enlarged, hypodense, and non-enhanced adrenal glands. Unenhanced MRIs allowed for diagnoses and showed enlarged adrenal glands in the signal hyperintensity on T2 and diffusion-weighted imaging, without any signal hyperintensity on T1. In two of our six cases, USs showed swollen adrenal glands with fluid collection. Conclusion: NHAI and its differential diagnosis—in cases of acute pain during pregnancy—highlight the crucial roles of integrated radiological examination and cooperation between obstetricians and radiologists, both of whom should consider the location of the pain, the accessibility and tolerance of MRI, and the radiation exposure of CT. Despite its supposed poor sensitivity, an US performed because the patient reports pain should also be used to examine the adrenal gland regions. Non-enhanced MRI is clearly of value and access to it in emergencies is important to avoid radiation exposure

Reliability and agreement of proton density-weighted vs. gadolinium-enhanced T1-weighted MRI in hand osteoarthritis. An OMERACT MRI special interest group reliability exercise

ObjectivesTo compare reliabilities of assessing synovitis in hand osteoarthritis (OA) using Magnetic Resonance Imaging (MRI) with/without gadolinium (Gd). MethodsThree readers scored synovitis on non-enhanced two-dimensional (2D) proton density (PD)-weighted MRI and Gd-enhanced (3D) MRI of hand joints in 20 patients. Inter-reader reliabilities were examined. ResultsReliability was good for Gd-enhanced MRI, but poor for non-enhanced PD-weighted MRI (intraclass correlation coefficient 0.83 and 0.21, respectively). Agreement between the two sequences was poor (weighted kappa 0.18). ConclusionGd-enhanced MRI was more reliable than PD-weighted MRI for assessing synovitis. Gd-enhancement, but also resolution and tissue contrast, might have contributed to this.