Contrast-enhanced Magnetic Resonance Imaging Research Articles

Neuro-computational simulation of blood flow loaded with gold and maghemite nanoparticles inside an electromagnetic microchannel under rapid and unexpected change in pressure gradient.

In cardiovascular research, electromagnetic fields generated by Riga plates are utilized to study or manipulate blood flow dynamics, which is particularly crucial in developing treatments for conditions such as arterial plaque deposition and understanding blood behavior under varied flow conditions. This research predicts the flow patterns of blood enhanced with gold and maghemite nanoparticles (gold-maghemite/blood) in an electromagnetic microchannel influenced by Riga plates with a temperature gradient that decays exponentially, under sudden changes in pressure gradient. The flow modeling includes key physical influences like radiation heat emission and Darcy drag forces in porous media, with the flow mathematically represented through unsteady partial differential equations solved using the Laplace transform (LT) method. Results, including shear stress (SS) and rate of heat transfer (RHT), are graphically detailed, demonstrating changes in blood velocity profile with modifications in the Hartmann number and the width of electrodes, and differences in temperature and RHT between hybrid nano-blood (HNB) and nano-blood (NB). The key results indicate an increase in blood velocity distribution with higher modified Hartmann number, and a decrease with wider electrodes. Temperature is elevated in both hybrid nano-blood (HNB) and nano-blood (NB). Notably, HNB with gold and maghemite enhances heat transmission in the flow. Furthermore, an artificial intelligence-driven methodology employing an artificial neural network (ANN) has been incorporated to facilitate rapid and precise evaluations of SS and RHT, demonstrating remarkable predictive accuracy. The proposed algorithm exhibits outstanding accuracy, achieving 99.998% on the testing dataset and 96.843% during cross-validation for predicting SS, and 100% on the testing dataset, and 95.008% during cross-validation for predicting RHT. The implementation of nanotechnology with artificial intelligence promises new tools for doctors and surgeons, potentially transforming patient care in fields such as oncology, cardiology, and radiology. This model also facilitates the generation of precise electromagnetic fields to guide drug-loaded magnetic nanoparticles for applications in targeted drug delivery, hyperthermia treatment, MRI contrast enhancement, blood flow monitoring, cancer treatment, and controlled drug release.

Non-enhanced abbreviated MRI as a periodic surveillance protocol for colorectal liver metastases compared with contrast-enhanced CT: a prospective observational study.

Adopting appropriate noninvasive radiological method is crucial for periodic surveillance of liver metastases in colorectal cancer (CRC) patients after surgery, which is closely related to clinical management and prognosis. This study aimed to prospectively enroll stage II-III CRC patients for the surveillance of liver metastases, and compare the diagnostic performance of contrast-enhanced CT (CE-CT) and non-enhanced abbreviated MRI (NE-AMRI) during this process. 587 CRC patients undergoing radical resection of the primary tumor were evaluated by 1 to 3 rounds of surveillance tests, consisting of abdominal CE-CT and contrast-enhanced MRI (CE-MRI) within 7days at 6-month intervals. Subsequently, images of NE-AMRI were extracted from the CE-MRI examination, paired CE-CT and NE-AMRI analysis were performed. The lesion-based detection rates between two protocols were compared and a subgroup analysis was performed in lesions with the size of ≤ 10mm. The patient-based sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and the areas under the curves (AUCs) of CE-CT and NE-AMRI in each round were evaluated. Finally, the relationship between the diagnostic accuracy of two protocols and characteristics of patients was explored. The lesion-based detection rates of NE-AMRI in three rounds were all significantly higher than that of CE-CT (p < 0.001, p < 0.001, p=0.003, respectively). In the subgroup analysis of lesions ≤ 10mm, NE-AMRI also performed better than CE-CT (p < 0.001, p=0.002, p=0.005, respectively). The patient-based sensitivities, specificities, NPVs, PPVs of NE-AMRI were higher than those of CE-CT in three rounds of surveillance. The AUCs for NE-AMRI were all significantly better than that for CE-CT in each round (p=0.015, p=0.045, p=0.009, respectively). Furthermore, patient BMI and fatty liver disease had impacts on the diagnostic accuracy of CE-CT protocol, but not on NE-AMRI protocol. NE-AMRI may be a promising periodic surveillance tool for CRC patients after surgery to increase diagnostic accuracy of liver metastases, developing personalized clinical management and improving prognosis, simultaneously avoiding side-effects associated with ionizing radiation and contrast agents.

Preoperative MRI to Predict Upstaging of DCIS to Invasive Cancer at Surgery.

Ductal carcinoma in situ (DCIS) is overtreated, in part because of inability to predict which DCIS cases diagnosed at core needle biopsy (CNB) will be upstaged at excision. This study aimed to determine whether quantitative magnetic resonance imaging (MRI) features can identify DCIS at risk of upstaging to invasive cancer. This prospective observational clinical trial analyzed women with a diagnosis of DCIS on CNB. All the participantsunderwent preoperative 3T MRI. Quantitative MRI features from routine dynamic contrast-enhanced (DCE) MR images (e.g., peak percent enhancement [PE]) and from advanced high temporal-resolution DCE MR images (e.g., Ktrans) were measured. Clinical, pathologic, and mammographic features were reviewed. Associations with upstaging were summarized using the area under the receiver operating characteristic curve (AUC). Of 58 DCIS lesions at CNB, 15 (26%) were upstaged to invasive cancer at surgery. Of the 58 lesions, 46 (79%) enhanced on MRI, although enhancement alone was not significantly associated with upstaging (p = 0.71). Among the DCIS lesions that enhanced, higher PE was most strongly associated with upstaging (AUC, 0.81; adjusted p = 0.009) and outperformed MRI features acquired via high temporal resolution DCE-MRI (AUC, 0.50-0.73). Lesion span on MRI was not significantly associated with upstaging risk (AUC, 0.55; adjusted p = 0.61), nor were any clinical, pathologic, or mammographic features (p > 0.24). Quantitative features acquired from routine clinical breast MRI and advanced DCE-MRI demonstrated good performance in identifying which DCIS lesions were upstaged to invasive cancer at excision. These features may prove valuable for appropriate selection of active surveillance in future DCIS de-escalation trials.

P-03 NORMALIZATION OF THE DEXAMETHASONE SUPPRESSION TEST FOLLOWING PSYCHIATRIC TREATMENT IN A PATIENT WITH PSYCHOTIC DEPRESSION: A CASE REPORT

Abstract Introduction Cushing's syndrome (CS) is characterized by hypercortisolism and is typically diagnosed through clinical and laboratory evaluations. However, severe depression can lead to misleading results. In this case, a patient with severe depressive symptoms initially showed abnormal dexamethasone suppression test (DST) results, which normalized following psychiatric treatment. This case highlights the impact of psychiatric conditions on CS assessment and demonstrates how psychiatric intervention can influence test outcomes. Clinical Case A 67-year-old male patient with a known diagnosis of psychotic depression was referred to our outpatient clinic for hormonal evaluation after a left adrenal mass was detected. Physical examination revealed no signs of hypercortisolism. The patient's blood pressure was 100/70 mmHg, weight 50 kg, height 168 cm, and BMI 17 kg/m². Initial tests revealed that the nadir cortisol level after a 1 mg DST was not suppressed, with a value of 16 µg/dL. Additional tests for hypercortisolism were ordered. The patient’s 24-hour urinary free cortisol (UFC) was 97 µg/dL (normal: &amp;lt;130 µg/dL), and late-night salivary cortisol was 0.64 ng/mL (normal: &amp;lt;2.74 ng/mL), both within normal ranges. An ACTH level of 121 pg/mL was noted, leading to a planned evaluation for ACTH-dependent hypercortisolism. The laboratory results are presented in Table 1. The patient underwent dynamic contrast-enhanced 3-Tesla MRI to evaluate ACTH-dependent hypercortisolism. The sella MRI did not reveal any adenoma or other pathology. Due to the patient's agitation, bilateral inferior petrosal sinus sampling could not be performed. Given the absence of clinical signs of hypercortisolism, the patient’s psychiatric treatment was adjusted, and a re-evaluation from an endocrinological perspective was planned. Following nine sessions of inpatient electroconvulsive therapy, during which the patient was initiated on olanzapine 20 mg once daily and venlafaxine 150 mg once daily, he was discharged and continued these medications as part of his outpatient treatment. The patient was subsequently reassessed in the endocrinology clinic. With the adjusted psychiatric treatment, the patient’s nadir cortisol level after 1 mg DST decreased to 0.78 µg/dL. 24-hour UFC and late-night salivary cortisol levels were within normal ranges. It was concluded that the untreated psychiatric disorder had affected the DST results. The patient was placed under regular follow-up by the psychiatric unit. Conclusion This case underscores the potential impact of untreated psychiatric disorders on diagnostic tests for CS, such as the DST. The normalization of test results following effective psychiatric treatment highlights the importance of considering psychiatric conditions in the comprehensive laboratory evaluation of patients, particularly those without clinical signs of hypercortisolism.Table 1:The laboratory test resultsACTH=Adrenocorticotropic hormone; DST=Dexamethasone suppression test; HbA1c=Hemoglobin A1C; UFC=Urinary free cortisol

Diagnostic performance of contrast-enhanced T2-FLAIR MRI in the detection of meningitis

Background: The contrast-enhanced T2-FLAIR (CE-T2-FLAIR) sequence on MRI, through the suppression of CSF and vascular signals, can detect subtle meningeal enhancement in meningitis that may not be appreciable on the routinely used contrast-enhanced T1W (CE-T1W) sequence.Objectives: To assess CE-T2-FLAIR compared to CE-T1W in the diagnosis of meningitis, using CSF analysis as the gold standard, using both qualitative and quantitative approaches for assessment.Method: A retrospective study was conducted on 53 patients with clinically suspected meningitis referred for brain MRI. Twenty-seven patients, positive for meningitis on CSF analysis, were classified as the case group; the remaining patients were designated as controls. The pre-contrast, CE-T1W and CE-T2-FLAIR images were assessed and analysed, qualitatively for the detection of abnormal meningeal enhancement, and quantitatively by measuring single pixel signal intensities (SPSI) over the meninges and vessels.Results: Contrast-enhanced T2-FLAIR demonstrated significantly higher sensitivity (92.59% vs. 57.69%), negative predictive value (92.59% vs. 70.27%) and diagnostic accuracy (94.34% vs. 78.85%) compared to CE-T1W. Additionally, CE-T2-FLAIR showed significantly greater meningeal SPSI and enhancement than CE-T1W.Conclusion: Contrast-enhanced T2-FLAIR is better at detecting abnormal meningeal enhancement in meningitis than CE-T1W, because of significantly greater signal intensity and enhancement of the meninges compared to vessels.Contribution: This study reiterates the usefulness of CE-T2-FLAIR as an additional sequence for the detection of abnormal meningeal enhancement in cases of meningitis as confirmed both qualitatively and quantitatively.

P-46 A CASE OF PITUITARY APOPLEXY PRESENTING WITH OPHTHALMOPLEGIA

Abstract Introduction Pituitary apoplexy is a rare endocrinological emergency that may be life-threatening due to pituitary hormone deficiency or compression effect, if not treated appropriately. It usually develops secondary to acute ischemia or hemorrhage in the pituitary gland and presents with headache, vomiting, ophthalmoplegia, vision loss. In this case, we aim to present a case of pituitary apoplexy who applied to the emergency service with a complaint of vomiting, and developed ophthalmoplegia while hospitalized. Clinical Case A 76-year-old male patient applied to the emergency department with complaints of nausea and vomiting that had been continuing for the last week. At admission, physical examination, blood pressure and neurologic examination were normal. The laboratory tests were as follows: Glu:141 mg/dl, Cre:0,7 mg/dl, AST:25 U/L, ALT:13 IU/L, Na:118 mmol/L, K:3.0 mmol/L. He was admitted to the service in order to investigate hyponatremia and hypokalemia. On the first day of his hospitalization, restriction of upward sight in the right eye and ptosis developed. Cranial imaging with computerized tomography revealed a contrast-enhancing mass at the level of pituitary gland. A well-frameworked, 20 mm in diameter, hyperintens at T1-weighted images, with heterogeneous contrast enhancing lesion was reported in the contrast-enhanced pituitary MRI. Preliminary diagnosis were considered to be a bleeding cyst or pituitary apoplexy. Pituitary hormone tests were as follows: TSH:0.5 mIU/L (0.27-4.8), sT4: 1,38 ng/dL (0,79-1,59), sT3: 2.1 ng/L (2,04-4,4), FSH: 2.6 IU/L (1,5-12,4), LH: 0.87 IU/L (1,7-8,6), Total Testosterone: 0.4 ng/ml (2,8-8), PRL: 1 µg/dl (4,6-21,4), ACTH: 1,5 ng/L (7-63,2), Cortisol: 1.8 µg/dl (6-19), İGF-1: 53 mg/L (50-184). Hormone replacement with methylprednisolone 2x20 mg intravenous was started with the diagnosis of anterior pituitary insufficiency. The patient underwent to transphenoidal pituitary surgery for decompression, under a steroid cover. Hemodynamics remained stable following surgical intervention. Postop urinary output was also normal. But, right side ptosis continued after surgery. The patient was discharged with oral prednisolone 5 mg 1*1. Steroid was discontinued at the second week following surgery. The entire pituitary axis was determined to be intact at the first month. Pathology was reported as a large hemorrhagic infarction of the pituitary gland compatible with pituitary apoplexy. Consultations with Neurology and ophthalmology departments were done because of the persistence of right ptosis. No additional intervention was planned, follow-up was recommended. A significant improvement of ptosis was observed after a two months period. Conclusion Although the neurological signs and symptoms of pituitary apoplexy usually improves following accurate medical or surgical interventions in majority of patients, it should be kept in mind that it may take time for ptosis to recover after surgical decompression as in our case.Figure 1:Improvement in ptosis in the second month after surgery

O-01 A CASE OF LANGERHANS CELL HISTIOCYTOSIS WITH INVOLVEMENT OF THE HYPOTHALAMUS, BONE, AND LIVER

Abstract Introduction Langerhans cell histiocytosis (LCH) is a neoplastic disorder characterized by the abnormal infiltration of Langerhans cells, affecting multiple systems. Here, we report a rare case of LCH with involvement of the hypothalamus, liver, and bone. Clinical Case A 36-year-old female patient presented to the psychiatry department with complaints of anxiety, including sudden behavioral changes, headaches, increased forgetfulness, hypersomnia, and excessive thirst excessive eating, and memory lapses that persisted for three months. A contrast-enhanced pituitary MRI taken revealed a lobulated mass lesion, measuring 15x9x17 mm, extending into the interpeduncular cistern and anteriorly toward the optic chiasm, with cystic necrotic areas located at the base of the third ventricle (Figure 1A). Laboratory examinations indicated panhypopituitarism and central diabetes insipidus. Abdominal ultrasound revealed a hypoechoic area in liver segment 8.PET-CT showed a region of intense metabolic activity in the posterior section of the left mastoid bone (SUVmax: 12.4). In addition, a 14-mm focal area with increased fluorodeoxyglucose uptake was observed in liver segment 8 (SUVmax: 8.4) (Figure 1B).The temporal MRI showed a mass lesion extending to the petrous apex, filling the mastoid cells on the left side, with signal characteristics similar to the hypothalamic lesion (Figure 1C).Biopsy was performed on identified lesions. Both biopsy results were consistent with LCH. She was planned to administer two courses of cladribine therapy. Follow-up PET-CT after chemotherapy indicated that the liver and mastoid bone involvement had resolved. However, the patient’s neuropsychiatric symptoms did not improve following chemotherapy. Paraneoplastic autoimmune encephalitis was primarily suspected, and antibody testing was performed. Due to the progressive nature of the patient’s condition, intravenous immunoglobulin therapy was administered. On the fourth day of this treatment, the patient experienced increased agitation and delusions, and developed disorientation.50 mg of quetiapine was prescribed. Three days after starting quetiapine, the patient developed fever, tachypnea, muscle rigidity, increased confusion, and an acute increase in serum creatine kinase levels (29,000 U/L). The condition was evaluated as a neuroleptic malignant syndrome leading to the discontinuation of quetiapine. The patient was transferred to the intensive care unit (ICU).On the first day of ICU admission, the patient was intubated. Despite cardiac support, the patient died on the third day of ICU admission. Conclusion LCH is a rare but multisystemic inflammatory neoplasm. The absence of specific clinical features can lead to delays in diagnosis. Although LCH most commonly presents with bone and skin lesions, a multidisciplinary approach is crucial for an accurate diagnosis. Albeit rare, LCH should be considered in the differential diagnosis of patients presenting with hypothalamic masses.Figure 1:Magnetic resonance image of the hypothalamic mass (A), Magnetic resonance images revealing a mass lesion in the left mastoid bone (B) and a subcapsular lesion in liver segment 8 (C)

Dynamic Contrast-enhanced MRI Processing Comparison for Distinguishing True Progression From Pseudoprogression in High-grade Glioma.

Treatment-related changes may occur due to radiation and temozolomide in glioblastoma and can mimic tumor progression on conventional MRI. DCE-MRI enables quantification of the extent of blood-brain barrier (BBB) disruption, providing information about areas of suspicious postcontrast T1 enhancement. We compared DCE-MRI processing methods for distinguishing true disease progression from pseudoprogression in high-grade gliomas (HGGs). We identified 110 patients with HGG treated with surgery and chemoradiation who underwent DCE-MRI to further interrogate areas of new/increasing enhancement. All patients had confirmatory surgery/biopsy with pathology-confirmed progression or pseudoprogression. Scans were performed at 3T and analyzed using nordicICE. The MCA, SSS, and Parker models are three standardized processing methodologies used to create ktrans maps, a parameter that quantifies BBB permeability. Three equal regions of interest were placed at sites of peak contrast enhancement within each lesion. Data from each method was processed for mean and maximum ktrans. We conducted several rounds of analysis and finalized a strategy on penalized support vector machines based on engineered features with bootstrap sampling. The Parker method was significant for ktrans maximum in the combined pathology and clinical as well as the pathology-only data sets. MCA and SSS did not perform well under the SVM classifier for pathology only. For clinical follow-up subjects, the Parker method yielded statistically significant results for maximum and mean ktrans. The Parker method was effective in distinguishing PD and PsP for pathology and clinical data sets. MCA and SSS techniques were effective for the clinical data set.

CT and MR Imaging in Colorectal Carcinoma: A Tool for Diagnosis, Staging, Response Evaluation, and Follow-Up

The present review highlights the role of computed tomography (CT), CT colonography (CTC), and magnetic resonance imaging (MRI) in the diagnosis, staging, response evaluation, and follow-up of colorectal cancer. For a CT scan, prior bowel preparation is required. This is done to enhance imaging of the colon with the use of oral or rectal contrast agents. Negative contrast like air or carbon dioxide are helpful in detecting polyps and masses by distending the colon. Virtual colonoscopy offers a lower-radiation alternative for polyp and cancer detection. Intravenous contrast administration with arterial and venous phase CT images is also important in complete staging of a known case of colon cancer and for evaluation of residual/recurrent disease. With respect to MRI, high-resolution T2-weighted images in multiple planes are important, with diffusion-weighted imaging (DWI) sequences being important for restaging. Intravenous contrast is not generally recommended. Contrast-enhanced CT and MRI are used for nodal and distant metastasis staging, with special attention to the pelvic side wall nodes. Positron emission tomography (PET) CT is to be considered for further evaluation if the findings are unclear and recurrence is suspected.

Conditional diffusion-generated super-resolution for myocardial perfusion MRI

IntroductionMyocardial perfusion MRI is important for diagnosing coronary artery disease, but current clinical methods face challenges in balancing spatial resolution, temporal resolution, and slice coverage. Achieving broader slice coverage and higher temporal resolution is essential for accurately detecting abnormalities across different slice locations but remains difficult due to constraints in acquisition speed and heart rate variability. While techniques like parallel imaging and compressed sensing have significantly advanced perfusion imaging, they still suffer from noise amplification, residual artifacts, and potential temporal blurring due to the rapid transit of dynamic contrast vs. the temporal constraints of the reconstruction.MethodsThis study introduces a conditional diffusion-based generative model for myocardial perfusion MRI super resolution, addressing the trade-offs between spatiotemporal resolution and slice coverage. We adapted Denoising Diffusion Probabilistic Models (DDPM) to enhance low-resolution perfusion images into high-resolution outputs without requiring temporal regularization. The forward diffusion process introduces Gaussian noise incrementally, while the reverse process employs a U-Net architecture to progressively denoise the images, conditioned on the low-resolution input image.ResultsWe trained and validated the model on a retrospective dataset of dynamic contrast-enhanced (DCE) perfusion MRI, consisting of both stress and rest images from 47 patients with heart disease. Our results showed significant image quality improvements, with a 5.1% reduction in nRMSE, a 1.1% increase in PSNR, and a 2.2% boost in SSIM compared to GAN-based super-resolution method (P &amp;lt; 0.05 for all metrics using paired t-test) in retrospective study. For the 9 prospective subjects, we achieved a total nominal acceleration of 8.5-fold across 5–6 slices through a combination of low-resolution acquisition and GRAPPA. PerfGen outperformed GAN-based approach in sharpness (4.36 ± 0.38 vs. 4.89 ± 0.22) and overall image quality (4.14 ± 0.28 vs. 4.89 ± 0.22), as assessed by two experts in a blinded evaluation (P &amp;lt; 0.05) in prospective study.DiscussionThis work demonstrates the capability of diffusion-based generative models in generating high-resolution myocardial perfusion MRI from conditional low-resolution images. This approach has shown the potentials to accelerate myocardial perfusion MRI while enhancing slice coverage and temporal resolution, offering a promising alternative to existing methods.

Characteristics of In Vivo Lesion Formation With a Temperature-Controlled Diamond-Tip Radiofrequency Ablation Catheter in the Ventricle: A Preclinical Model.

Power-controlled radiofrequency ablation with irrigated-tip catheters has been the norm for ventricular ablation for almost 2 decades. New catheter technology has recently integrated more accurate tissue temperature sensing enabling temperature-controlled irrigated ablation. We aimed to investigate the in vivo ablation parameters and lesion formation characteristics in ventricular myocardium using a novel temperature-controlled radiofrequency catheter. Twenty canines were divided into 3 groups: 4 noninfarcted, acute (phase I); 8 noninfarcted, chronic (phase II); and 8 infarcted, chronic (phase III). Lesions were delivered with a temperature-controlled radiofrequency system utilizing a chemical vapor deposit diamond for efficient thermal diffusivity. In phase I, 17 ablation settings were tested (temperature set points, 50/60/70 °C; ablation duration, 15/30/60/90/120 s; and power limit, 30/50 W). Four and one of these sets of parameters were further tested in phases II and III, respectively. Lesions were assessed by ex vivo contrast-enhanced magnetic resonance imaging and gross pathology 5 weeks after ablation in phases II/III. Across all phases, 111 ablation lesions were delivered. Ablation with the power limit of 50 W, the temperature set point of 60 °C, and the duration of 60 s produced significantly larger and deeper lesions (mean, 569.2 mm3; mean maximal depth, 9.8 mm) compared with 50 W/60 °C/30 s (mean, 340.4 mm3; mean maximal depth, 8.3 mm) and 50 W/50 °C/60 s (mean, 227 mm3; mean maximal depth, 6.9 mm), with P<0.05 for all pairwise comparisons. Ablation of infarcted myocardium in phase III (50 W/60 °C/30 s) resulted in smaller impedance and bipolar electrogram amplitude changes and lesion size compared with ablation in normal myocardium with the same settings. No steam pop, myocardial perforation, or char formation was observed in any of the 111 ablations across all phases. In vivo radiofrequency ablation in a canine model with a diamond-tip temperature-controlled catheter using a temperature set point of 60 °C and a power limit of 50 W created large lesions without steam pop risk in both normal and infarcted ventricular myocardia.

Assessing blood flow in uterine fibroids using intravoxel incoherent motion imaging compared with dynamic contrast-enhanced MRI

To assess the utility of IVIM parameters in evaluating uterine fibroid blood flow compared to dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) derived blood flow. Sixteen premenopausal women with uterine fibroids were enrolled in this prospective study. Pelvic MRI scans were obtained for each subject, both with and without continuous intravenous infusion of oxytocin, known to decrease significantly uterine fibroid blood flow, to assess the changes in blood flow of uterine fibroids. IVIM and DCE analyses were conducted using separate dedicated software. The bi-exponential IVIM model was used to estimate perfusion fraction (f), pseudo-diffusion coefficient (D*), and diffusion coefficient (D). DCE blood flow values were derived via T1 perfusion deconvolution arithmetic, utilizing a first pass of an AIF curve. The correlation between the parameters were analyzed by Spearman’s rank correlation analysis due to small sample size. Means of the parameters were compared with a nonparametric Wilcoxon sign rank method for each pair. Statistically significant positive correlations were found between perfusion fraction values and DCE blood flow values with oxytocin (Spearson’s ρ = 0.78, p = 0.0004), and between fD* values and DCE blood flow values with oxytocin (Spearson’s ρ = 0.64, p = 0.0071). Significant differences in blood flow were detected across most IVIM parameters: f, D*, and fD* (p < 0.001, p = 0.0027, and p = 0.0002, respectively) when comparing the values without oxytocin and with oxytocin. IVIM imaging shows promise for assessing blood flow in uterine fibroids.

Brain Imaging in Patients with Non-Small Cell Lung Cancer—A Systematic Review

Background: Lung cancer frequently metastasizes to the brain, liver, and adrenal glands with a significant negative prognostic impact on overall survival and quality of life (QoL). To optimize treatment and prognosis, adequate staging with the detection of distant metastases is crucial. The incidence of brain metastases in potentially resectable early-stage non-small cell lung cancer (NSCLC) is as low as 3%; hence, the need for preoperative brain imaging has been a constant matter of debate, especially in stage II. In stages III and IV NSCLC, neuroimaging is an essential part of staging. Methods: A systematic literature search was performed. Publications from 1999 to 2024, focusing on preoperative brain imaging (BI) in the staging of stages I–IV NSCLC, were included. Data extraction included study population characteristics, the modality of BI, the incidence of brain metastases (BMs), and the main outcomes of the studies. The final included studies were selected according to the PRISMA criteria. In the second step, guidelines on BI in NSCLC staging of major importance were identified and compared. Results: A total of 530 articles were identified, of which 25 articles were selected. Four prospective studies and 21 retrospective investigations were included. Most of the investigations focused on BI in the early stages. The main imaging modality for BI was magnetic resonance imaging (MRI), followed by computed tomography (CT). Besides the identified 25 studies, the most important internationally applied guidelines on brain imaging in the staging of NSCLC were reviewed. While some guidelines agree on preoperative BI in NSCLC stage III (Union for International Cancer Control—UICC eighth edition) patients, other guidelines recommend earlier BI starting from clinical stage II. All mentioned guidelines homogenously recommend BI in patients with symptoms suggestive of brain pathologies. Conclusions: BI in NSCLC staging is recommended in neurologically symptomatic patients suggestive of brain metastases as well as NSCLC patients with stage III disease. Neuroimaging in stage IA patients, as well as in pure GGO (Ground-Glass Opacity) lesions, was considered unnecessary. The predominantly applied imaging modality was ce-MRI (contrast-enhanced magnetic resonance imaging). Inconsistency exists concerning BI in stage II. The identification of prognostic factors for developing BM in patients with early-stage NSCLC could help to clarify which subgroup might benefit from preoperative BI.

Prognosticating WHO/ISUP grade in clear cell renal cell carcinoma: Insights from amide proton transfer-weighted MRI.

Preoperative prediction of clear cell renal cell carcinoma (ccRCC) grade can support optimal selection of surgical resection strategies. Currently, there is no effective preoperative method for accurately assessing the histologic grade of ccRCC. More precise, non-invasive prediction methods are needed. To investigate the parameter of amide proton transfer-weighted (APTw) MRI for prediction of pathological ccRCC grade and whether the combination of the APTw, Diffusion-Weighted Imaging (DWI), and mDixon MRI techniques can improve the prediction performance. This prospective study included ccRCC patients who underwent multiparametric MRI examinations (including APTw, DWI, and mDixon) along with contrast-enhanced CT or MRI examinations from March 2021 to June 2024. The mean, maximum, minimum, and standard deviation (SD) values from APTw and apparent diffusion coefficient (ADC) imaging of the solid tumor portions and the fat fraction (FF) values from mDixon imaging were measured. The area under the receiver operating characteristic curve (AUC) values for the parameters were calculated to evaluate the diagnostic performance. A total of 48 ccRCC patients (mean age, 65 years; 32 males) were included, of whom 10 had high-grade ccRCC and 38 had low-grade ccRCC. Compared with low-grade ccRCC, high-grade ccRCC exhibited higher APTwmean (2.28 % vs. 4.17 %; P < .05), APTwmax (4.97 % vs. 8.48 %; P < .01), and APTwSD (1.10 vs. 1.75; P < .01) values as well as lower ADCmin values (1.23 × 10-3 mm2/s vs. 0.94 × 10-3 mm2/s; P < .05). The AUC values for the ability of APTwmean, APTwmax, APTwSD, ADCmin, and these factors combined to distinguish between low-grade and high-grade ccRCC were 0.728, 0.786, 0.832, 0.741, and 0.858, respectively. APTwmean, APTwmax, APTwSD, and ADCmin values are potential indicators for preoperative prediction of ccRCC pathologic grade. APTw parameters offer certain advantages for use alone or in combination with other parameters.

Differentiation of intrapancreatic accessory spleen from pancreatic neuroendocrine tumor using MRI R2.

To evaluate the performance of R2* in distinguishing intrapancreatic accessory spleens (IPASs) from pancreatic neuroendocrine tumors (PNETs). Two radiologists (R1 and R2) retrospectively reviewed the MRIs of 20 IPAS and 20 PNET patients. IPASs were diagnosed with uptake on 99mTc labeled heat-damaged red blood cell scintigraphy or characteristic findings on CT/MRI and ≥ 12 month-long-stability. PNETs were histopathologically diagnosed with resection. Using McNemar test, sensitivities and specificities of the diagnostic criterion based on R2* mass-to-spleen ratio (MSR) were compared with those of the other criteria using contrast-enhanced (CE) MRI and apparent diffusion coefficient (ADC) MSR. The study included 40 patients (median age, 54; interquartile range, 43-65; 24 men, 16 women). IPASs exhibited spleen-isointensity on T2WI, late arterial and portal phases, and diffusion-weighted images more frequently than PNETs (p <.05). ADC MSRs were lower (p <.001) and R2* MSRs were higher (p <.001) in IPASs compared to PNETs. For R1, sensitivity and specificity were 45.0% and 100.0% for criterion 1 (spleen-isointensity on CE-MRI); 45.0% and 85.0% for criterion 2 (ADC MSR ≤ 1.08); 90.0% and 95.0% for criterion 3 (0.9 ≤ R2* MSR ≤ 1.7). For R2, 75.0% and 100.0%; 45.0% and 90.0%; 90.0% and 100.0%. Criterion 3 showed higher sensitivity than criterion 1 for R1 (p =.004), and criterion 2 for R1 and R2 (p =.012). There was no difference in specificity. For differentiating IPAS from PNET, R2* showed higher sensitivity than, and similar specificity to CE-MRI and ADC.

Evaluating Suspicious Breast Lesions: A Head-to-Head Comparison of Contrast-Enhanced Mammography and Breast MRI

Evaluating Suspicious Breast Lesions: A Head-to-Head Comparison of Contrast-Enhanced Mammography and Breast MRI

Autoradiography of Intracerebral Tumours in the Chick Embryo Model: A Feasibility Study Using Different PET Tracers.

In addition to rodent models, the chick embryo model has gained attention for radiotracer evaluation. Previous studies have investigated tumours on the chorioallantoic membrane (CAM), but its value for radiotracer imaging of intracerebral tumours has yet to be demonstrated. Human U87 glioblastoma cells and U87-IDH1 mutant glioma cells were implanted into the brains of chick embryos at developmental day 5. After 12-14days of tumour growth, blood-brain-barrier integrity was evaluated in vivo using MRI contrast enhancement or ex vivo with Evans blue dye. The tracers O-(2-[18F]fluoroethyl)-L-tyrosine ([18F]FET) (n = 5), 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine ([18F]FDOPA) (n = 3), or [68Ga] labelled quinoline-based small molecule fibroblast activation protein inhibitor ([68Ga]FAPI-46) (n = 4) were injected intravenously if solid tumours were detected with MRI. For time-activity curves for [18F]FET, additional micro PET (µPET) was performed. The chick embryos were sacrificed 60min post-injection, and cryosections of the tumour-bearing brains were produced and evaluated with autoradiography and immunohistochemistry. Intracerebral tumours were produced with a 100% success rate in viable chick embryos at the experimental endpoint. However, 52% of chick embryos (n = 85) did not survive the procedure to embryonic development day 20. For the evaluated radiotracers, the tumour-to-brain ratios (TBR) derived from ex vivo autoradiography, as well as the tracer kinetics derived from µPET for intracerebral chick embryo tumours, were comparable to those previously reported in rodents and patients: the TBRmean for [18F]FET was 1.69 ± 0.54 (n = 5), and 3.8 for one hypermetabolic tumour and < 2.0 for two isometabolic tumors using [18F]FDOPA, with a TBRmean of 1.92 ± 1,11 (n = 3). The TBRmean of [68Ga]FAPI-46 for intracerebral chick embryo tumours was 19.13 ± 0.64 (n = 4). An intact blood-tumour barrier was observed in one U87-MG tumour (n = 5). Radiotracer imaging of intracerebral tumours in the chick embryo offers a fast model for the evaluation of radiotracer uptake, accumulation, and kinetics. Our results indicate a high comparability between intracerebral tumour imaging in chick embryos and xenograft rodent models or brain tumour patients.

Electrochemical Filtration of Gadolinium from Patient Urine after Magnetic Resonance Imaging.

The widespread use of gadolinium-based contrast agents for magnetic resonance imaging (MRI) in recent decades has led to a growing demand for Gd and raised environmental concerns due to their direct discharge into wastewater systems. In response, we developed an electrochemical filtration method to recover Gd from patient urine following contrast-enhanced MRI. This method involves modifying a conventional vacuum filtration apparatus by introducing electrodes into the filter membrane, creating a strong electric field of ∼5 kV/m and a steep three-zone pH gradient within the filter membrane. These electric and pH fields facilitate the dissociation of Gd-based contrast agents, releasing GdIII ions, electrophoretic separation of GdIII and its ligand, and eventually precipitation and trapping of GdIII as GdPO4 and Gd(OH)3 on the filter membrane. Using gadopentetate dimeglumine (GdDTPA) as a model Gd-based contrast agent, we achieved a Gd trapping efficiency of ∼70% for artificial and real urine samples. For macrocyclic Gd-based contrast agents such as gadoterate meglumine (GdDOTA), the Gd trapping efficiency decreased to 25.4% due to the slow dissociation kinetics of macrocyclic contrast agents. However, the trapping efficiency can be improved to ∼40% by allowing the macrocyclic contrast agent to predissociate in an acidic environment before electrochemical filtration. The Gd trapped on the filter membrane can be recovered by thermal treatment in a muffle furnace. After thermal treatment, the reclaimed Gd from the real urine sample was primarily identified as GdPO4. This electrochemical filtration design offers a straightforward and practical approach to recovering Gd from contrast-enhanced MRI scans, addressing the increasing demand for Gd and helping alleviate concerns about Gd contamination in surface water.

Incidental Detection of Choroid Plexus Metastasis From Neuroblastoma Demonstrated by 68Ga-DOTATATE PET/CT.

An 8-year-old girl with refractory high-risk neuroblastoma underwent 68Ga-DOTATATE PET/CT to evaluate the feasibility of potential 177Lu-DOTATATE therapy. The scan showed multiple foci of abnormal 68Ga-DOTATATE accumulation in the bone region, indicating the presence of bone metastases. Unexpectedly, an abnormal tracer uptake was noted in the left lateral ventricle area. The contrast-enhanced brain MRI showed obvious enhancement of this lesion, suggesting the diagnosis of choroid plexus metastasis. Our case shows that 68Ga-DOTATATE PET/CT might be useful in diagnosing choroid plexus metastasis.

Enhanced Detection of Residual Breast Cancer Post-Excisional Biopsy: Comparative Analysis of Contrast-Enhanced MRI with and Without Diffusion-Weighted Imaging.

To evaluate the effectiveness of breast MRI, including diffusion-weighted imaging (DWI), in detecting residual lesions in patients with malignancy after excisional biopsy. From January 2018 to December 2023, 3T breast MRI was performed to assess lesion morphology, residual size, and enhancement kinetics. The apparent diffusion coefficient (ADC) values were measured, and the diagnostic outcomes of CE-MRI, CE-MRI with DWI, mammography (MG), and ultrasound (US) were compared with clinical and histopathological data. A total of 152 lesions were analyzed, with 36.2% showing residual malignancy. Both CE-MRI and CE-MRI with DWI effectively identified residual lesions, with significant differences in morphology, size, kinetic patterns, and ADC values (all p < 0.001). CE-MRI with DWI showed a sensitivity of 90.9% and an NPV of 93.6%, compared with 89.1% sensitivity and 92.2% NPV for CE-MRI alone. Sensitivities for MG and US were 57.1% and 38.7%, with NPVs of 64.7% and 59.6%, respectively. Diagnostic accuracy was highest for CE-MRI with DWI (80.9%), followed by CE-MRI (79.0%), MG (60.3%), and US (59.7%). The AUC for CE-MRI with DWI (0.831) was slightly higher than CE-MRI alone (0.811), though not significant (p = 0.095). AUCs for MG and US were lower at 0.623 and 0.563, with no significant difference between MG and US (p = 0.234). CE-MRI with DWI and CE-MRI alone were comparable and demonstrated excellent performance in discriminating between women with and without residual disease. Integrating CE-MRI with DWI could become a standard protocol for patients with suspected residual malignancy after excisional biopsy.