Multiparametric Magnetic Resonance Imaging Research Articles

Evaluating Biparametric Versus Multiparametric Magnetic Resonance Imaging for Diagnosing Clinically Significant Prostate Cancer: An International, Paired, Noninferiority, Confirmatory Observer Study

Background and objectiveBiparametric magnetic resonance imaging (bpMRI), excluding dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI), is a potential replacement for multiparametric MRI (mpMRI) in diagnosing clinically significant prostate cancer (csPCa). An extensive international multireader multicase observer study was conducted to assess the noninferiority of bpMRI to mpMRI in csPCa diagnosis. MethodsAn observer study was conducted with 400 mpMRI examinations from four European centers, excluding examinations with prior prostate treatment or csPCa (Gleason grade [GG] ≥2) findings. Readers assessed bpMRI and mpMRI sequentially, assigning lesion-specific Prostate Imaging Reporting and Data System (PI-RADS) scores (3–5) and a patient-level suspicion score (0–100). The noninferiority of patient-level bpMRI versus mpMRI csPCa diagnosis was evaluated using the area under the receiver operating curve (AUROC) alongside the sensitivity and specificity at PI-RADS ≥3 with a 5% margin. The secondary outcomes included insignificant prostate cancer (GG1) diagnosis, diagnostic evaluations at alternative risk thresholds, decision curve analyses (DCAs), and subgroup analyses considering reader expertise. Histopathology and ≥3 yr of follow-up were used for the reference standard. Key findings and limitationsSixty-two readers (45 centers and 20 countries) participated. The prevalence of csPCa was 33% (133/400); bpMRI and mpMRI showed similar AUROC values of 0.853 (95% confidence interval [CI], 0.819–0.887) and 0.859 (95% CI, 0.826–0.893), respectively, with a noninferior difference of –0.6% (95% CI, –1.2% to 0.1%, p < 0.001). At PI-RADS ≥3, bpMRI and mpMRI had sensitivities of 88.6% (95% CI, 84.8–92.3%) and 89.4% (95% CI, 85.8–93.1%), respectively, with a noninferior difference of –0.9% (95% CI, –1.7% to 0.0%, p < 0.001), and specificities of 58.6% (95% CI, 52.3–63.1%) and 57.7% (95% CI, 52.3–63.1%), respectively, with a noninferior difference of 0.9% (95% CI, 0.0–1.8%, p < 0.001). At alternative risk thresholds, mpMRI increased sensitivity at the expense of reduced specificity. DCA demonstrated the highest net benefit for an mpMRI pathway in cancer-averse scenarios, whereas a bpMRI pathway showed greater benefit for biopsy-averse scenarios. A subgroup analysis indicated limited additional benefit of DCE MRI for nonexperts. Limitations included that biopsies were conducted based on mpMRI imaging, and reading was performed in a sequential order. Conclusions and clinical implicationsIt has been found that bpMRI is noninferior to mpMRI in csPCa diagnosis at AUROC, along with the sensitivity and specificity at PI-RADS ≥3, showing its value in individuals without prior csPCa findings and prostate treatment. Additional randomized prospective studies are required to investigate the generalizability of outcomes.

Factors influencing urinary retention following freehand transperineal prostate biopsy: Insights from a tertiary care center study

ABSTRACT Objectives: In this study, we evaluated the risk factors for urinary retention after freehand transrectal ultrasound (TRUS) guided transperineal prostate biopsy (TPB). Patients and Methods: Data from 102 cases of freehand TPB at a single institution were retrospectively collected and analyzed. All patients underwent magnetic resonance imaging (MRI)-TRUS cognitive fusion TPB using a transperineal needle guide, with systematic biopsies from 10 prostate sectors and additional MRI-guided targeted biopsies. Exclusions comprised patients with coagulation abnormalities, prior prostate surgeries including biopsy, active urinary tract infection, or a lack of pre-biopsy multiparametric MRI. Results: 14/102 (13.72%) had urinary retention and required urethral catheterization for voiding difficulty or discomfort along with a bladder volume of ≥500 ml. Patients with retention exhibited significantly larger prostate volumes (median 75 cc vs. 40 cc; P &lt; 0.05). Receiver operating curve analysis revealed a prostate volume threshold of 57.5 cc and a core number cutoff of 23 for predicting post-TPB urinary retention, with sensitivities of 78.57% and 85.71%, specificities of 75% and 82.95%, positive predictive values of 33.33% and 44.44%, and negative predictive values of 95.75% and 97.33%, respectively, whereas the number of biopsy cores correlated positively with the development of urinary retention (median 25 vs. 22; P &lt; 0.05). Urinary retention was independent of the patient’s age, comorbidities, presenting prostate-specific antigen levels, prebiopsy severity of lower urinary tract symptoms, and use of alpha-blockers. Conclusion: Patients with larger prostates and higher number of biopsy cores are at a higher risk of postfreehand TPB urinary retention and should receive appropriate counselling. Targeted biopsies alone, rather than a full template, may help mitigate urinary retention in these high-risk groups.

Comparison between 18F-DCFPyL PET/MRI-guided ultrasound fusion targeted biopsy and systematic biopsy for tumor detection and grading in selected patients: A prospective randomized controlled trial

ObjectiveTo compare the upgrade rate and cancer detection rate between 18F-DCFPyL PET/MRI-guided ultrasound fusion targeted biopsy and systematic biopsy in selected patients with suspected prostate cancer (the multiparametric MRI prostate imaging reporting and data system score ≥4 and molecular imaging prostate-specific membrane antigen score of prostate-specific membrane antigen PET image ≥2). MethodsEighty-seven selected biopsy-naive patients were randomized into two groups: targeted biopsy (n=41) and systematic biopsy (control; n=46). Those with negative initial results underwent a repeat biopsy using the alternative method. Patients diagnosed with clinically significant prostate cancer proceed to radical prostatectomy. The primary outcome was the upgrade rate. Additional outcomes, including the cancer detection rate, incidence of repeat biopsy, positive surgical margin, complications, and prostate-specific antigen level at 6 weeks postoperatively, were compared between the groups using Pearson or Fisher's exact tests, as appropriate. ResultsIn the study, prostate cancer was ultimately detected in all patients. The targeted biopsy group successfully identified all tumors, whereas five patients in the control group initially missed their tumors. The pathological upgrade rates for the targeted biopsy and control groups were 31.7 % and 56.5 %, respectively. Overall, the detection rate for clinically significant prostate cancer (the International Society of Urological Pathology grade ≥2) was significantly higher in the targeted biopsy group (92.7 %) compared with the control group (76.1 %, p=0.035). However, no significant difference was found in the detection rate of all prostate cancer. Complications (Clavien–Dindo grade ≤2) occurred in both the targeted biopsy group (n=11) and the control group (n=13). No statistically significant difference was observed between the groups in terms of positive surgical margin, complications, and 6-week postoperative prostate-specific antigen level. The main limitation is the small population. Conclusion18F-DCFPyL PET/MRI-guided ultrasound fusion targeted biopsy alone was an efficient modality in diagnosing selected patients with prostate cancer.

Flourine-18 Prostate-Specific Membrane Antigen-1007 Positron Emission Tomography Imaging in Staging of Primary and Secondary Prostate Cancer—A Retrospective Observational Cohort Study

Background: Detection of metastatic disease is important to inform prostate cancer management. Objectives: Evaluate local and distant staging by initial 18F-PSMA-1007 PET in primary and secondary prostate cancer. Design, Setting, and Participants: We retrospectively identified a consecutive series of 18F-PSMA-1007 PET scans from the date of introduction of 18F-PSMA-1007 PET in September 2019 until April 2022 at a single UK tertiary referral center. Our protocol was registered in advance (OSF registration ID: KTE3R). Results: We identified 1335 PSMA-PET scans, from 1220 men. Across 623 initial scans for primary staging, we observed PSMA-PET avidity in 97.6% cases positive for local disease, 29.5% for nodal disease, and 26.5% for metastatic disease. PSMA-PET identified a 13.2% absolute increase in nodal lesions compared with MRI and a 24.0% absolute increase in metastatic lesions compared with MRI marrow. The sensitivity for detection of local disease among 79 patients who had radical prostatectomy was 96.2% for PSMA-PET vs 89.4% for multiparametric MRI. Across 612 scans for secondary staging, we observed PSMA-PET positive avidity in 51.2% of cases for local recurrence, 46.6% for nodal disease, and 43.0% for metastatic disease. When evaluated by the PSA range for patients receiving secondary staging, using the PSA values of 0.2 to 0.49, 0.5 to 0.99, 1 to 1.99, and ≥ 2 ng/mL, PSMA-PET scans were positive in 57.8%, 75.0%, 83.8%, and 95.5% of cases, respectively. PSMA-PET identified a 26.2% absolute increase in metastatic lesions compared with MRI marrow or other skeletal MRI (n = 61) and a 14.7% absolute increase in metastatic lesions compared with the bone scan (n = 42). Conclusion: 18F-PSMA-1007 PET identifies a higher number of nodal and metastatic lesions compared with conventional cross-sectional imaging. However, the high number of indeterminate lesions and stage migration necessitates discussion of 18F-PSMA-1007 PET imaging within a multidisciplinary team and places a higher burden on these teams.

Use of multiparametric MRI to noninvasively assess iodinated contrast-induced acute kidney injury

PurposeTo gauge the utility of multiparametric MRI in characterizing pathologic changes after iodinated contrast-induced acute kidney injury (CI-AKI) in rats. MethodsWe randomly grouped 24 rats injected with 8 g iodine/kg of body weight (n = 6 each) and 6 rats injected with saline as controls. All rats underwent T1, T2 mapping and diffusion kurtosis imaging (DKI) after contrast injection at 0 (control), 1, 3, 7, 13 days. T1, T2, and mean kurtosis (MK) values were performed in renal outer/inner stripes of outer medulla (OSOM and ISOM) and cortex (CO), and their diagnosis performance for CI-AKI also been evaluated. Serum creatinine (SCr), insulin-like growth factor-binding protein 7 (IGFBP7), tissue inhibitor metalloproteinase 2 (TIMP-2), aquaporin-1 (AQP1), α-smooth muscle actin (α-SMA), and histologic indices were examined. ResultsCompared with controls, urinary concentrations of both TIMP-2 and IGFBP7 were obviously elevated from Day 1 to Day 13 (all p < 0.05). T2 values were significantly higher than control group for Days 1 and 3, and T1 and MK increased were more remarkable at all time points (Days 1–13) in CI-AKI (all p < 0.05) than control group. Changes in T1 and MK strongly correlated with renal injury scores of all anatomical compartments and with expression levels of AQP1 and moderately correlated with α-SMA. Changes in T2 values correlating moderately with renal scores of CO, ISOM and OSOM and AQP1. The MK obtained the highest area under the receiver operating characteristic (ROC) curve of 0.846 with a sensitivity of 70.8 % and specificity of 88.9 %. ConclusionsCombined use of multiparametric MRI could be a valid noninvasive method for comprehensive monitoring of CI-AKI. Among these parameters, MK may achieve the best diagnostic performance for CI-AKI.

MRI-based Zero Echo Time and Black Bone Pseudo-CT Compared with Whole-Body CT to Detect Osteolytic Lesions in Multiple Myeloma.

Background MRI is highly sensitive for assessing bone marrow involvement in multiple myeloma (MM) but does not enable detection of osteolysis. Purpose To assess the diagnostic accuracy, repeatability, and reproducibility of pseudo-CT MRI sequences (zero echo time [ZTE], gradient-echo black bone [BB]) in detecting osteolytic lesions in MM using whole-body CT as the reference standard. Materials and Methods In this prospective study, consecutive patients were enrolled in our academic hospital between June 2021 and December 2022. Inclusion criteria were newly diagnosed MM, monoclonal gammopathy of undetermined significance at high risk for MM, or suspicion of progressive MM. Participants underwent ZTE and BB sequences covering the lumbar spine, pelvis, and proximal femurs as part of 3-T whole-body MRI examinations, as well as clinically indicated fluorine 18 fluorodeoxyglucose PET/CT examination within 1 month that included optimized whole-body CT. Ten bone regions and two scores (categorical score = presence/absence of osteolytic lesion; semiquantitative score = osteolytic lesion count) were assessed by three radiologists (two experienced and one unfamiliar with pseudo-CT reading) on the ZTE, BB, and whole-body CT images. The accuracy, repeatability, and reproducibility of categorical scores (according to Gwet agreement coefficients AC1 and AC2) and differences in semiquantitative scores were assessed at the per-sequence, per-region, and per-patient levels. Results A total of 47 participants (mean age, 67 years ± 11 [SD]; 27 male) were included. In experienced readers, BB and ZTE had the same high accuracy (98%) in the per-patient analysis, while BB accuracy ranged 83%-100% and ZTE accuracy ranged 74%-94% in the per-region analysis. An increase of false-negative (FN) findings in the spine ranging from +17% up to +23%, according to the lumbar vertebra, was observed using ZTE (P < .013). Regardless of the region (except coxal bones), differences in the BB score minus the ZTE score were positively skewed (P < .021). Regardless of the sequence or region, repeatability was very good (AC1 ≥0.87 for all), while reproducibility was at least good (AC2 ≥0.63 for all). Conclusion Both MRI-based ZTE and BB pseudo-CT sequences of the lumbar spine, pelvis, and femurs demonstrated high diagnostic accuracy in detecting osteolytic lesions in MM. Compared with BB, the ZTE sequence yielded more FN findings in the spine. ClinicalTrials.gov Identifier: NCT05381077 Published under a CC BY 4.0 license. Supplemental material is available for this article.

Neuronal current imaging of epileptic activity: An MRI study in patients with a first unprovoked epileptic seizure.

This study evaluates the performance of the novel MRI sequence stimulus-induced rotary saturation (SIRS) to map responses to interictal epileptic activity in the human cortex. Spin-lock pulses have been applied to indirectly detect neuronal activity through magnetic field perturbations. Following initial reports about the feasibility of the method in humans and animals with epilepsy, we aimed to investigate the diagnostic yield of spin-lock MR pulses in comparison with scalp-EEG in first seizure patients. We employed a novel method for measurements of neuronal activity through the detection of a resonant oscillating field, stimulus-induced rotary saturation contrast (SIRS) at spin-lock frequencies of 120 and 240 Hz acquired at a single 3T MRI system. Within a prospective observational study, we conducted SIRS experiments in 55 patients within 7 days after a suspected first unprovoked epileptic seizure and 61 healthy control subjects. In this study, we report on the analysis of data from a single 3T MRI system, encompassing 35 first seizure patients and 31 controls. The SIRS method was applicable in all patients and healthy controls at frequencies of 120 and 240 Hz. We did not observe any significant age- or sex-related differences. Specificity of SIRS at 120 Hz was 90.3% and 93.5% at 240 Hz. Sensitivity was 17.1% at 120 Hz and 40.0% at 240 Hz. SIRS targets neuronal oscillating magnetic fields in patients with epilepsy. The coupling of presaturated spins to epilepsy-related magnetic field perturbations may serve as a-at this stage experimental-diagnostic test in first seizure patients to complement EEG findings as a standard screening test. Routine diagnostic tests carry several limitations when applied after a suspected first seizure. SIRS is a noninvasive MRI method to enable time-sensitive diagnosis of image correlates of epileptic activity with increased sensitivity compared to routine EEG.

Head-to-head comparison of GA-68 PSMA PET/CT and multiparametric MRI findings with postoperative results in preoperative locoregional staging and localization of prostate cancer.

Accurate staging of prostate cancer (PCa) is essential for determining the appropriate treatment and predicting outcomes. This study is comparing the effectiveness of Gallium-68 Prostate-Specific Membrane Antigen Positron Emission Tomography/Computed Tomography (Ga-68 PSMA PET/CT) and multiparametric MRI (mpMRI) in preoperative locoregional staging and localizing PCa. A retrospective analysis was conducted on 78 patients who underwent both mpMRI and Ga-68 PSMA PET/CT scans before surgery. The imaging was reviewed by radiologists and nuclear medicine specialists and compared with the final histopathology, which was reviewed by an experienced uropathologist. mpMRI demonstrated higher sensitivity in detecting extraprostatic extension (EPE) and bladder neck invasion (BNI) compared to Ga-68 PSMA PET/CT (83% vs. 44% and 29% vs. 17%, respectively). Conversely, Ga-68 PSMA PET/CT showed higher sensitivity in detecting seminal vesicle invasion (SVI) and lymph node metastasis (LNM) (75% vs. 55% and 50% vs. 30%, respectively). When both methods were combined, sensitivity increased in detecting both EPE and SVI. The index tumor localization in mpMRI and Ga-68 PSMA PET/CT was found to be in complete agreement with histopathological findings at 36.4% and 41.8%, respectively. When both imaging methods were combined, the agreement with histopathology in predicting index tumor localization reached 72.1%. Both mpMRI and Ga-68 PSMA PET/CT provide valuable and complementary information for tumor localization and locoregional staging. While mpMRI showed higher sensitivity in detecting EPE, Ga-68 PSMA PET/CT demonstrated superior performance in detecting LNM and SVI. The combined use of these imaging modalities enhance accuracy of index tumor localizations.

Sorafenib plus memory-like natural killer cell immunochemotherapy boosts treatment response in liver cancer

BackgroundHeterogeneity of hepatocellular carcinoma (HCC) presents significant challenges for therapeutic strategies and necessitates combinatorial treatment approaches to counteract suppressive behavior of tumor microenvironment and achieve improved outcomes. Here, we employed cytokines to induce memory-like behavior in natural killer (NK) cells, thereby enhancing their cytotoxicity against HCC. Additionally, we evaluated the potential benefits of combining sorafenib with this newly developed memory-like NK cell (pNK) immunochemotherapy in a preclinical model.MethodsHCC tumors were grown in SD rats using subcapsular implantation. Interleukin 12/18 cytokines were supplemented to NK cells to enhance cytotoxicity through memory activation. Tumors were diagnosed using MRI, and animals were randomly assigned to control, pNK immunotherapy, sorafenib chemotherapy, or combination therapy groups. NK cells were delivered locally via the gastrointestinal tract, while sorafenib was administered systemically. Therapeutic responses were monitored with weekly multi-parametric MRI scans over three weeks. Afterward, tumor tissues were harvested for histopathological analysis. Structural and functional changes in tumors were evaluated by analyzing MRI and histopathology data using ANOVA and pairwise T-test analyses.ResultsThe tumors were allowed to grow for six days post-cell implantation before treatment commenced. At baseline, tumor diameter averaged 5.27 mm without significant difference between groups (p = 0.16). Both sorafenib and combination therapy imposed greater burden on tumor dimensions compared to immunotherapy alone in the first week. By the second week of treatment, combination therapy had markedly expanded its therapeutic efficacy, resulting in the most significant tumor regression observed (6.05 ± 1.99 vs. 13.99 ± 8.01 mm). Histological analysis demonstrated significantly improved cell destruction in the tumor microenvironment associated with combination treatment (63.79%). Interestingly, we observed fewer viable tumor regions in the sorafenib group (38.9%) compared to the immunotherapy group (45.6%). Notably, there was a significantly higher presence of NK cells in the tumor microenvironment with combination therapy (34.79%) compared to other groups (ranging from 2.21 to 26.50%). Although the tumor sizes in the monotherapy groups were similar, histological analysis revealed a stronger response in pNK cell immunotherapy group compared to the sorafenib group.ConclusionsExperimental results indicated that combination therapy significantly enhanced treatment response, resulting in substantial tumor growth reduction in alignment with histological analysis.

Impact of Susceptibility Weighted MRI Sequences in Cerebral Small Vessel Disease

Impact of Susceptibility Weighted MRI Sequences in Cerebral Small Vessel Disease

Enhancing organ and vascular contrast in preclinical ultra-low field MRI using superparamagnetic iron oxide nanoparticles

Superparamagnetic iron oxide nanoparticles (SPIONs) are characterized by their exceptional susceptibility and relaxivity at ultra-low field (ULF) regimes, make them a promising contrast agent (CA) for ULF MRI. Despite their distinct advantages, the translation of these properties into clinically valuable image contrast in ULF MRI remains underexplored. In this study, we investigate the use of SPIONs to generate in vivo MRI contrast at 6.5 mT within the organs and vascular system of rodents. This investigation includes comprehensive SPION characterization and phantom imaging experiments to validate the utility of SPIONs to produce positive image contrast and to facilitate phase-sensitive imaging at ULF. Optimized balanced steady-state free precession (bSSFP) and spoiled gradient echo (SPGR) MRI sequences are used to generate in vivo contrast by leveraging the distinctive properties of SPIONs at ULF. Imaging studies in rodents reveal positive organ contrast attainable in magnitude images, and MRI phase maps can be used to visualize the vascular system. This work demonstrates the effectiveness of SPIONs in enhancing preclinical organ and vascular imaging at ULF; it bridges the gap between the study of the distinctive physical properties of SPIONs and the demonstration of in vivo image contrast.

Stereotactic Radiosurgery for 1-10 Brain Metastases to avoid Whole-Brain Radiotherapy - Results of the CYBER-SPACE Randomized Phase 2 Trial.

Stereotactic Radiosurgery (SRS) is an emerging alternative to whole-brain radiotherapy (WBRT) for treating multiple brain metastases (BM), reducing toxicity and improving tumor control. The CYBER-SPACE trial compared SRS based on either SPACE or MPRAGE MRI sequence for avoiding or delaying WBRT in patients with 1-10 BM. Patients with 1-10 untreated BM were randomized 1:1 to receive SRS of all lesions based on either SPACE or MPRAGE MRI sequences. If subsequently new BM occurred, SRS was repeated. WBRT was indicated upon occurrence of >10 new BM, leptomeningeal disease or exhausted SRS-radiotolerance. The primary outcome was freedom from WBRT indication (WBRTi). Secondary outcomes included overall survival (OS), safety, and quality of life. 202 patients were randomized; SPACE n=99, MPRAGE n=103. 12-month WBRTi-free survival was 77.1% (95%-CI: 69.5%-83.1%) overall, 78.5% (95%-CI: 66.7%-86.5%) for SPACE, and 76.0% (95%-CI: 65.2%-83.9%) for MPRAGE (HR=0.84, 95%-CI: 0.43-1.63, p=0.590). Patients with 5-10 BM had shorter WBRTi-free survival (HR=3.13, 95%-CI: 1.53-6.40, p=0.002). Median OS was 13.1 months overall, 10.5 months for SPACE, and 15.2 months for MPRAGE (HR=1.10, 95%-CI: 0.78-1.56, p=0.585). Neurologic death rate was 10.1%. Predictors for longer OS included Karnofsky Performance Status >80% (HR=0.51, 95%-CI: 0.33-0.77, p=0.002) and concurrent immunotherapy (HR=0.34, 95%-CI: 0.23-0.52, p<0.001). The more sensitive SPACE sequence did not improve outcomes over MPRAGE. SRS with thorough monitoring and immediate re-treatment for new lesions decreases the need for WBRT and achieves low neurologic death rates. SRS should be considered a favorable alternative to WBRT for patients with 1-10 BM.

Quantitative evaluation of Scout Accelerated Motion Estimation and Reduction (SAMER) MPRAGE for morphometric analysis of brain tissue in patients undergoing evaluation for memory loss

BackgroundThree-dimensional (3D) T1-weighted MRI sequences such as the magnetization prepared rapid gradient echo (MPRAGE) sequence are important for assessing regional cortical atrophy in the clinical evaluation of dementia but have long acquisition times and are prone to motion artifact. The recently developed Scout Accelerated Motion Estimation and Reduction (SAMER) retrospective motion correction method addresses motion artifact within clinically-acceptable computation times and has been validated through qualitative evaluation in inpatient and emergency settings. MethodsWe evaluated the quantitative accuracy of morphometric analysis of SAMER motion-corrected compared to non-motion-corrected MPRAGE images by estimating cortical volume and thickness across neuroanatomical regions in two subject groups: (1) healthy volunteers and (2) patients undergoing evaluation for dementia. In part (1), we used a set of 108 MPRAGE reconstructed images derived from 12 healthy volunteers to systematically assess the effectiveness of SAMER in correcting varying degrees of motion corruption, ranging from mild to severe. In part (2), 29 patients who were scheduled for brain MRI with memory loss protocol and had motion corruption on their clinical MPRAGE scans were prospectively enrolled. ResultsIn part (1), SAMER resulted in effective correction of motion-induced cortical volume and thickness reductions. We observed systematic increases in the estimated cortical volume and thickness across all neuroanatomical regions and a relative reduction in percent error values compared to reference standard scans of up to 66 % for the cerebral white matter volume. In part (2), SAMER resulted in statistically significant volume increases across anatomical regions, with the most pronounced increases seen in the parietal and temporal lobes, and general reductions in percent error relative to reference standard clinical scans. ConclusionSAMER improves the accuracy of morphometry through systematic increases and recovery of the estimated cortical volume and cortical thickness following motion correction, which may affect the evaluation of regional cortical atrophy in patients undergoing evaluation for dementia.

Vessel wall MRI in giant cell arteritis: standardized protocol and scoring approach developed by an international working group.

There are an increasing number of centers performing research on high-resolution vessel wall magnetic resonance imaging (VW-MRI) in giant cell arteritis (GCA). However, harmonized approaches to VW-MRI in GCA are lacking and are essential to performing multicentre studies. Using a data-driven, consensus-based approach, an international expert group developed a standardized MRI protocol and scoring system to advance multi-centered research in cranial GCA. A targeted literature review of VW-MRI in cranial GCA was conducted. A working group comprised of radiologists, rheumatologists, and ophthalmologists with expertise in VW-MRI and GCA reviewed the results of the literature search, presented relevant data and images from their respective centers, and then reached consensus on recommendations related to key MRI structures, MRI sequences, scoring system, and other important considerations. A total of 21 relevant articles were identified and reviewed. Based on published literature, structures to be evaluated on MRI were categorized based on anatomic location (extradural cranial, intradural cranial, and orbits) and prioritization (core vs elective). Essential and elective sequences to comprehensively image cranial and orbital structures while minimizing scan time were determined along with scoring systems to grade contrast enhancement. This report describes a standardized approach to facilitate research of VW-MRI in cranial GCA that is the result of a multi-disciplinary, international collaboration of experts in VW-MRI and/or GCA.

Evaluating 4Kscore's role in predicting progression on active surveillance for prostate cancer independently of clinical information and PIRADS score.

4Kscore is used to aid the decision for prostate biopsy, however its role in active surveillance (AS) has not been investigated in a magnetic resonance imaging (MRI)-based protocol. Our objective was to assess the association between 4Kscore and progression in men undergoing AS on a prospective MRI-based protocol. This was a single-institution, single-arm, non-therapeutic, interventional trial of 166 men with biopsy-confirmed prostate cancer enrolled between 2014-2020. Patients were placed on a trial-mandated AS protocol including yearly multiparametric (mp)MRI, prostate biopsy, and 4Kscore followed for 48 months after diagnosis. We analyzed protocol-defined and grade progression at confirmatory and subsequent surveillance biopsies. Out of 166 patients, 83 (50%) men progressed per protocol and of them 41 (24.7% of whole cohort) progressed by grade. At confirmatory biopsy, men with a baseline 4Kscore ≥ 20% had a higher risk of grade progression compared to those with 4Kscore < 20% (OR = 4.04, 95% CI: 1.05-15.59, p = 0.043) after adjusting for National Comprehensive Cancer Network (NCCN) risk and baseline PIRADS score. At surveillance biopsies, most recent 4Kscore ≥ 20% significantly predicted per protocol (OR = 2.61, 95% CI: 1.03-6.63, p = 0.044) and grade progression (OR = 5.13, 95% CI: 1.63-16.11, p = 0.005). For patients on AS, baseline 4Kscore predicted grade progression at confirmatory biopsy, and most recent 4Kscore predicted per-protocol and grade progression at surveillance biopsy.

Elevating precision: A thorough investigation of multiparametric prostate MRI for prolonged insights into early continence prediction after robot-assisted laparoscopic prostatectomy

BackgroundWhile radical prostatectomy stands out as one of the most effective curative treatments for prostate cancer, it does come with annoying side effects, such as urinary incontinence (UI). We aimed to investigate the predictability of UI using MRI measurements, along with clinical and disease-related variables. MethodsWe included 191 patients who underwent robot-assisted laparoscopic radical prostatectomy between July 2020 and October 2022 in the study. Preoperative MRIs of the patients are re-evaluated by an experienced uroradiologist, and membranous urethral length (MUL), urethra wall thickness, levator ani thickness, outer levator distance, Lee's apex shape, intravesical prostate protrusion length, prostate apex depth, and pubic height measurements were made. Additionally, retrospective data on patients' age, BMI, PSA, PSA density, prostate volume, IPSS, clinical stage, and nerve-sparing status were collected. Patients were categorized into two groups based on continence status in the third postoperative month: continent or incontinent. The definition of UI was accepted as the use of one or more pads per day. ResultsUI was observed in 38.21 % of the patients in the postoperative third month. Among MRI measurements, only MUL showed a significant relationship with UI (p < 0.001). IPSS (p = 0.004) and Clinical Stage (p < 0.001) were also significantly associated with continence status. Logistic regression analysis identified BMI (p = 0.023; CI 0.73–0.97), IPSS (p = 0.002; CI 1.03–1.17), MUL (p = 0.001; CI 0.66–0.90), and Clinical Stage (p < 0.001; CI 1.53–2.71) as significant predictors. In Multivariable Regression analysis, Clinical Stage emerged as the most powerful predictor of UI (p < 0.001). ConclusionsExcept for MUL, MRI measurements may not predict postoperative UI. A combination of IPSS, clinical stage, and MUL effectively informs patients about postoperative outcomes. These findings contribute to enhancing preoperative counseling for patients undergoing radical prostatectomy.

Is fat quantification based on proton density fat fraction useful for differentiating renal tumor types?

This study retrospectively assessed the diagnostic accuracy of fat quantification based on proton density fat fraction (PDFF) for differentiating renal tumors. In this retrospective study, 98 histologically confirmed clear cell renal cell carcinomas (ccRCCs), 35 papillary renal cell carcinomas (pRCCs), 14 renal oncocytomas, 16 chromophobe renal cell carcinomas (chRCCs), 10 lymphomas, 19 uroepithelial tumors, 10 lipid-poor angiomyolipomas (AMLs), and 25 lipid-rich AMLs were identified in 226 patients (127 males and 99 females) over 5years. All patients underwent multiparametric kidney MRI. The MRI protocol included an axial plane and a volumetric 3D fat fraction sequence known as mDIXON-Quant for PDFF measurement. Demographic data were recorded, and PDFF values were independently reviewed by two radiologists blinded to pathologic results. MRI examinations were performed using a 1.5T system. MRI-PDFF measurements were obtained from the solid parts of all renal tumors. Fat quantification was performed using a standard region of interest for each tumor, compared to histopathological diagnoses. Sensitivity and specificity analyses were performed to calculate the diagnostic accuracy for each histopathological tumor type. Nonparametric variables were compared among the subgroups using the Kruskal-Wallis H test and Mann Whitney U test. P-values < 0.05 were considered statistically significant. In all, 102 patients underwent partial nephrectomy, 70 patients underwent radical nephrectomy, and the remaining 54 had biopsies. Patient age (mean: 58.11years; range: 18-87years) and tumor size (mean: 29.5mm; range: 14-147mm) did not significantly differ across groups. All measurements exhibited good interobserver agreement. The mean ccRCC MRI-PDFF was 12.6 ± 5.06% (range: 11.58-13.61%), the mean pRCC MRI-PDFF was 2.72 ± 2.42% (range: 2.12-3.32%), and the mean chRCC MRI-PDFF was 1.8 ± 1.4% (range: 1.09-2.5%). Clear cell RCCs presented a significantly higher fat ratio than other RCC types, uroepithelial tumors, lymphomas, and lipid-poor AMLs (p < 0.05). Lipid-rich AMLs demonstrated a very high fat ratio. MRI-PDFF facilitated accurate differentiation of ccRCCs from other renal tumors with high sensitivity and specificity.

Partial prostatectomy for localized prostate cancer.

Localized prostate cancer treatment aims to balance cancer control with preserving urinary and erectile function. While focal ablative therapies have emerged, their uncertain prognosis prompts exploration of partial prostatectomy. We systematically reviewed its efficacy as a primary treatment, particularly in low-to-intermediate-risk patients. Our review comprehensively analyzed existing studies on partial prostatectomy for localized cancer. We focused on patient selection, surgical techniques, and postoperative outcomes, emphasizing tumor control, continence, and erectile function. Studies involving multiparametric MRI and targeted biopsies for candidate selection were included. Partial prostatectomy, encompassing various techniques, demonstrates promising short-term outcomes in tumor control and functional preservation. Preoperative imaging and biopsy aid in candidate selection. However, longer-term data on cancer recurrence are limited, warranting further investigation. Heterogeneity among studies and the lack of standardized follow-up protocols are notable limitations. Partial prostatectomy offers a minimally invasive and effective treatment option for localized prostate cancer, particularly in selected patients. Preoperative imaging and biopsy play crucial roles in patient selection, while standardized follow-up protocols are needed to assess long-term outcomes. Future research should focus on elucidating its precise role and optimizing patient selection criteria, contributing to improved prostate cancer management strategies. Partial prostatectomy is explored for localized prostate cancer treatment, aiming to balance cancer control with preserving function. Short-term outcomes are promising, but long-term data on recurrence are lacking. Further research is needed to optimize patient selection and standardize follow-up protocols.

Multi-sequence MRI-based radiomics model to preoperatively predict the WHO/ISUP grade of clear Cell Renal Cell Carcinoma: a two-center study

ObjectivesTo develop radiomics models based on multi-sequence MRI from two centers for the preoperative prediction of the WHO/ISUP grade of Clear Cell Renal Cell Carcinoma (ccRCC).MethodsThis retrospective study included 334 ccRCC patients from two centers. Significant clinical factors were identified through univariate and multivariate analyses. MRI sequences included Dynamic contrast-enhanced MRI, axial fat-suppressed T2-weighted imaging, diffusion-weighted imaging, and in-phase/out-of-phase images. Feature selection methods and logistic regression (LR) were used to construct clinical and radiomics models, and a combined model was developed using the Rad-score and significant clinical factors. Additionally, seven classifiers were used to construct the combined model and different folds LR was used to construct the combined model to evaluate its performance. Models were evaluated using receiver operating characteristic (ROC) curves, area under the curve (AUC), and decision curve analysis (DCA). The Delong test compared ROC performance, with p < 0.050 considered significant.ResultsMultivariate analysis identified intra-tumoral vessels as an independent predictor of high-grade ccRCC. In the external validation set, the radiomics model (AUC = 0.834) outperformed the clinical model (AUC = 0.762), with the combined model achieving the highest AUC (0.855) and significantly outperforming the clinical model (p = 0.003). DCA showed that the combined model had a higher net benefit within the 0.04–0.54 risk threshold range than clinical model. Additionally, the combined model constructed using logistic regression has a higher priority compared to other classifiers. Additionally, 10-fold cross-validation with LR for the combined model showed consistent AUC values (0.849–0.856) across different folds.ConclusionThe radiomics models based on multi-sequence MRI might be a noninvasive and effective tool, demonstrating good efficacy in preoperatively predicting the WHO/ISUP grade of ccRCC.

Dermatofibrosarcoma Protuberans MRI: A Preliminary Comparison of Different Sequences

The purpose of this study was to compare the image quality of different MRI sequences regarding the presentation of Dermatofibrosarcoma Protuberans (DFSP). We retrospectively collected MRI images of 40 patients who had been pathologically diagnosed with DFSP, including 21 primary tumors and 19 recurrent tumors. The image quality of different MRI sequences was assessed subjectively by two radiologists, taking into account the display of the lesions, artifacts, and distortions, as well as the overall impact of the image quality. Among the 40 cases, 22 cases involved the trunk, 14 cases involved the shoulders and limbs, 2 cases involved the head and neck, 1 case involved the breast, and 1 case involved the groin. In terms of image quality, fat suppression T2-weighted images were superior to T1-weighted images and T2-weighted images (P<0.05). The difference between fat suppression T2-weighted images and contrast-enhanced images was not significant (P>0.05). As far as lesion contrast is concerned, diffusion-weighted images, fat suppression T2-weighted images, and contrast-enhanced images did not differ significantly (P>0.05). On the DWI images, there were severe magnetic artifacts and deformations. Fat suppression T2-weighted images and enhanced sequences produce the highest quality images, while diffusion-weighted images provide the best lesion contrast.