Nevin Manimala

Quant Imaging Med Surg. 2024 Dec 5;14(12):9220-9233. doi: 10.21037/qims-24-318. Epub 2024 Nov 14.

ABSTRACT

BACKGROUND: Gut microbiota are associated with brain imaging-derived phenotypes (IDPs); however, the specific causal relationship between the gut microbiota and brain iron-related IDPs remains unclear. Thus, we sought to analyze the potential causal effects of gut microbiota on brain iron-related IDPs using Mendelian randomization (MR).

METHODS: We obtained the data of 196 gut microbiota from a genome-wide association study (GWAS) from the MiBioGen database, as well as the data of 18 quantitative susceptibility mapping (QSM) IDPs and 10 T2* IDPs from the United Kingdom Biobank (UKB). We then conducted one-way two-sample MR analyses to examine their causal interactions. To guarantee the robustness of the results, we performed two independent analysis processes by selecting statistically significant instrumental variables (IVs) with a distinct level of statistical strictness, and derived the intersection of these two analyses.

RESULTS: Our results showed that the genus Howardella was positively correlated with the median susceptibility in the right caudate [β: 0.0935, 95% confidence interval (CI): 0.0601, 0.1269, P_{inverse variance weighting (IVW)}=4.00E-08]; the genus Dialister was positively correlated with the median susceptibility in the right accumbens (β: 0.0949, 95% CI: 0.0575, 0.1324, P_IVW=6.90E-07); the genus Butyricicoccus was positively associated with the median T2* in the left hippocampus with the additional deconfounding of the background field gradient (β: 0.1543, 95% CI: 0.0959, 0.2127, P_IVW=2.20E-07); the genus Desulfovibrio was positively related to the T2* white matter hyperintensity (WMH) IDP with WMH volume regressed out (β: 0.1168, 95% CI: 0.0697, 0.1639, P_IVW=1.20E-06). Notably, both the family Defluviitaleaceae (β: -0.1215, 95% CI: -0.1604, -0.0827, P_IVW=8.40E-10) and genus DefluviitaleaceaeUCG011 (β: -0.1142, 95% CI: -0.1614, -0.0670, P_IVW=2.10E-06) were negatively correlated with the median T2* in the right accumbens with the additional deconfounding of the background field gradient.

CONCLUSIONS: This study found genetic evidence that gut microbiota dysbiosis has causal effects on brain iron-related IDPs. Our findings provide novel insights into the diagnosis and therapeutic management of central nervous system (CNS) diseases.

PMID:39698716 | PMC:PMC11652028 | DOI:10.21037/qims-24-318

Quant Imaging Med Surg. 2024 Dec 5;14(12):8629-8643. doi: 10.21037/qims-24-490. Epub 2024 Nov 11.

ABSTRACT

BACKGROUND: Anal fistula is a common anorectal disorder that significantly diminishes the quality of life for affected patients. Accurate preoperative evaluation of the fistula’s traits is essential for customizing surgical strategies, improving patient outcomes, and reducing the likelihood of the disease returning. This study aimed to evaluate the diagnostic accuracy of multi-phase contrast-enhanced fat-suppressed T1-weighted imaging using three-dimensional gradient echo sequence volumetric interpolated breath-hold examination (CE-FS-T1-3D-VIBE) and fat-suppressed T2-weighted imaging combined with diffusion-weighted imaging (FS-T2WI-DWI) sequence in delineating the characteristics of anal fistulas.

METHODS: A case-control study of 168 patients with anal fistula was conducted through the picture archiving and communication systems (PACS; diagnostic imaging workstation). Imaging evaluations were performed using both multi-phase CE-FS-T1-3D-VIBE and FS-T2WI-DWI imaging on a Siemens 3.0T magnetic resonance imaging system (Skyra 3.0T superconducting type). The efficacy of each imaging modality in depicting the clarity, number, and positioning of the internal openings, as well as the identification of primary and secondary fistulas and abscesses, was independently evaluated in a blinded manner by two senior diagnostic radiologists, each with over a decade of experience. Statistical analyses were performed using χ² test.

RESULTS: Comparative analysis of the FS-T2WI-DWI and multi-phase CE-FS-T1-3D-VIBE sequences for diagnosing internal and primary fistula tract clarity demonstrated a significant superiority of the multi-phase CE-FS-T1-3D-VIBE sequence in delineating internal clarity (P=0.013) and primary fistula tract clarity (P<0.001). The multi-phase CE-FS-T1-3D-VIBE sequence demonstrated superior accuracy over the FS-T2WI-DWI sequence in depicting localization of internal openings [86.31% vs. 77.38%, 95% confidence interval (CI): 0.307-0.959, P=0.034], as well as delineation of the secondary tracts (88.69% vs. 80.95%, 95% CI: 0.293-1.001, P=0.048). Despite the increased accuracy of the multi-phase CE-FS-T1-3D-VIBE sequence, no difference was observed between the two imaging techniques regarding the accuracy in determining the number of internal openings, the quantity of primary fistulas, and the classification of anal fistulas.

CONCLUSIONS: This study elucidates that the multi-phase CE-FS-T1-3D-VIBE imaging sequence potentially represents a more effective noninvasive alternative for the precise evaluation of the positioning and clarity of the internal opening, as well as the delineation of primary and secondary fistula tracts in anal fistula patients, compared to the FS-T2WI-DWI sequence. This enhanced diagnostic capability underscores the utility of multi-phase CE-FS-T1-3D-VIBE in improving the clinical management of anal fistulas.

PMID:39698714 | PMC:PMC11652061 | DOI:10.21037/qims-24-490

Quant Imaging Med Surg. 2024 Dec 5;14(12):8974-8987. doi: 10.21037/qims-24-1097. Epub 2024 Nov 29.

ABSTRACT

BACKGROUND: Preliminary small-sample studies suggest that silent magnetic resonance angiography (MRA) has an advantage over time-of-flight MRA (TOF MRA) in the characterization of brain arteriovenous malformation (BAVM), but did not examine whether the imaging performance of silent MRA was affected by the intrinsic features of BAVM or common clinical factors. This study sought to compare silent MRA and TOF MRA in terms of the visualization and grading of BAVMs in various clinical settings.

METHODS: In total, 85 participants (50 males, 35 females; mean age: 33.5±15.2 years) with BAVM who underwent both silent MRA and TOF MRA using a 3 Tesla (3T) magnetic resonance imaging (MRI) system were consecutively recruited from the Capital Medical University Xuanwu Hospital between April 2020 and October 2022 to participate in this cross-sectional retrospective study. The patients were divided into subgroups according to new hemorrhage presentation, embolization, size, and nidus compactness. Image quality scoring on a 4-point scale, and the accuracy of characteristic visulization and Spetzler-Martin grading were compared between the two MRA techniques and each MRA subgroup using the rank-sum Wilcoxon test and Fisher’s exact test with digital subtraction angiography (DSA) as the reference standard. A multivariable chi-square test was used to examine the interactions between the grouping factors. A P value <0.05 was considered statistically significant.

RESULTS: The average image quality scores were significantly higher for silent MRA than those for TOF MRA overall (2.83±0.42 versus 2.46±0.66, P<0.001) and in each subgroup (P<0.05). For silent MRA, the average image quality score for BAVM in each subgroup did not differ significantly (P>0.05). For TOF MRA, the image quality scores for the new hemorrhage, small nidus, and diffuse nidus groups was significantly reduced (P=0.001, <0.001, and 0.037, respectively). The accuracy of silent MRA was significantly better than that of TOF MRA in terms of nidus size and Spetzler-Martin grading (P<0.001), but did not differ significantly in terms of deep venous drainage and associated aneurysm (P=0.402, 0.098, respectively). In relation to silent MRA, the image quality, detection of BAVM characteristics, and grading were similar across the new hemorrhage, embolization, size, and compactness subgroups (P=0.066-0.959). In relation to TOF MRA, the accuracy of nidus size grading was significantly lower in the medium-size subgroup than the small-size subgroup (P<0.001).

CONCLUSIONS: Silent MRA performed well in imaging BAVM, and high performance in determining nidus size and Spetzler-Martin grading, but its ability to detect deep venous drainage was limited.

PMID:39698707 | PMC:PMC11651979 | DOI:10.21037/qims-24-1097

Quant Imaging Med Surg. 2024 Dec 5;14(12):8183-8195. doi: 10.21037/qims-24-278. Epub 2024 Oct 21.

ABSTRACT

BACKGROUND: Early recognition of sinus invasion for meningiomas matters the clinical intervention. Therefore, we retrospectively investigated the relationship between peritumoral vessel features on magnetic resonance venography (MRV) and sinus invasion status.

METHODS: Images of phase contrast MRV (PC-MRV, n=46) and contrast-enhanced MRV (CE-MRV, n=39) were independently assessed by four experienced neuroradiologists, including the adjacent sinus status, the peritumoral vessel count and diameter-associated parameters. The sinus invasion status confirmed based on Sindou’s criteria during surgery was taken as the gold standard. The relationship between these MRV-based vessel characteristics and sinus invasion status was further analyzed.

RESULTS: The judgment of sinus invasion based on PC-MRV (n=46) and CE-MRV (n=39) revealed a total accuracy of 63% and 74.4%, respectively. The MRV-based vessel count and associated diameter parameters demonstrated statistical differences between the non-invasion and the invasion group (P<0.05). Under the cutoff value of 3 vessels on PC-MRV and 5.5 vessels on CE-MRV, the prediction of sinus invasion status finally achieved the accuracy of 69.6% and 84.6%, respectively. Furthermore, the vessel count, the sum vascular diameter and the max vascular diameter remained significantly different in further subgroup analyses. A comprehensive generalized linear models (GLM) model based on MRV-related vascular features showed the best diagnostic performance on sinus invasion, with the area under the receiver operating characteristic curve of 0.859 for PC-MRV and 0.913 for CE-MRV.

CONCLUSIONS: For para-sinus meningioma, peritumoral vessel characteristics on MRV, especially the vessel count, exhibited close relationships with sinus status, and thus could be a novel tool to predict sinus invasion.

PMID:39698705 | PMC:PMC11652032 | DOI:10.21037/qims-24-278

Quant Imaging Med Surg. 2024 Dec 5;14(12):8479-8488. doi: 10.21037/qims-24-43. Epub 2024 Nov 29.

ABSTRACT

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) has been widely used for the resection of lung lesions. However, it is difficult to palpate or see small lesions, especially ground-glass opacities (GGOs) during VATS. Thoracoscopic ultrasound has definite value in locating pulmonary parenchymal nodules. However, due to the air in the lung parenchyma, its wide application is limited. This study investigated the value of thoracoscopic ultrasound for the localization of GGOs with incomplete lung collapse in VATS.

METHODS: A retrospective analysis was conducted on patients diagnosed with ground-glass nodules (GGNs) on computed tomography (CT) at Liaoning Province Tumor Hospital from November 2018 to August 2019, who underwent thoracoscopic ultrasound localization and VATS. Screening was conducted for patients who did not achieve complete collapse of the lungs after natural collapse during surgery, the success rate was calculated, and preoperative CT features and thoracoscopic ultrasound features of GGNs were summarized and analyzed.

RESULTS: The success rate of GGOs’ localization by thoracoscopic ultrasound in incomplete collapse lung was 56.67%. Of all preoperative CT features, only the distance between the nodule and the pleura was statistically different (P=0.001). The closer the GGO was to the pleura, the easier it was to be detected.

CONCLUSIONS: Thoracoscopic ultrasound could effectively locate GGO in the condition of incomplete lung collapse and not affect the surgical field, especially when the GGO is close to the pleura, which provides an alternative method for GGO localization in patients who cannot achieve complete lung collapse during VATS.

PMID:39698688 | PMC:PMC11652022 | DOI:10.21037/qims-24-43

Quant Imaging Med Surg. 2024 Dec 5;14(12):8927-8941. doi: 10.21037/qims-24-907. Epub 2024 Nov 29.

ABSTRACT

BACKGROUND: Deep learning has developed rapidly, and deep learning reconstruction (DLR) methods in magnetic resonance imaging (MRI) are gaining attention for their potential to improve efficacy in clinical work. The preoperative MRI assessment of rectal cancer is crucial for patient management, but the imaging quality is currently limited by a number of factors. DLR could be applied to the preoperative MRI assessment of primary rectal cancer, but research about its specific reliability is limited. Thus, this study aimed to evaluate the reliability of DLR in the preoperative MRI examination of primary rectal cancer.

METHODS: This cross-sectional study was conducted at Ruijin Hospital, Shanghai Jiaotong University School of Medicine from March 2022 to October 2022. Patients with primary rectal cancer underwent routine MRI scans on a 3.0T magnetic resonance scanner (SIGNA Architect, GE Healthcare, USA) with 32-channels flexible coil with conventional reconstruction (ConR) and DLR. The DLR method had three noise reduction levels: DLR-H: 75% noise reduction reconstruction; DLR-M: 50% noise reduction reconstruction; and DLR-L: 25% noise reduction reconstruction. Three components were evaluated: objective image quality; subjective image quality; and diagnostic performance. The objective image quality assessment included the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The subjective image quality assessment involved evaluating five subjective image quality parameters based on a 4-point Likert scale. The diagnostic performance assessment included tumour (T) staging, node (N) staging, as well as the circumferential resection margin and extramural vascular invasion evaluation. The images were evaluated in a blinded manner by two radiologists with different levels of experience. The paired sample Wilcoxon signed-rank test, Kappa test, interclass correlation coefficient, Chi-square test, Friedman test, and weighted kappa coefficients were used for the statistical analysis.

RESULTS: In total, 61 patients (mean age: 65±12 years; 38 men) were enrolled in the study. The DLR method improved the SNR and CNR values of the images relative to the ConR method, while the DLR-H produced the greatest improvement (P<0.040). The subjective image quality of the DLR-H images was superior to that of the ConR images (P<0.001), but there was no significant difference between the DLR-H and DLR-M images (P≥0.075). The evaluators showed good agreement in subjective scoring, and in the DLR image scoring, the evaluators have the best consistency in the DLR-H images scoring (kappa =0.921, P<0.001). The diagnostic efficacy of the DLR images was comparable to that of the ConR images in terms of T staging [Reader 1 (R1): P=0.603; Reader 2 (R2): P=0.206] and N staging (R1: P=0.990; R2: P=0.884).

CONCLUSIONS: The DLR method improved the quality of the images, and had comparable diagnostic efficacy without additional scanning time to that of the ConR method, and thus could be a feasible option for replacing the ConR method in the preoperative MRI examination of primary rectal cancer.

PMID:39698686 | PMC:PMC11651964 | DOI:10.21037/qims-24-907

Quant Imaging Med Surg. 2024 Dec 5;14(12):9506-9521. doi: 10.21037/qims-24-1138. Epub 2024 Nov 29.

ABSTRACT

BACKGROUND: Current medical image registration methods based on Transformer still encounter challenges, including significant local intensity differences and limited computational efficiency when dealing with three-dimensional (3D) computed tomography (CT) and cone beam CT (CBCT) images. These limitations hinder the precise alignment necessary for effective diagnosis and treatment planning. Therefore, the aim of this study is to develop a novel method that overcomes these challenges by enhancing feature interaction and computational efficiency in 3D medical image registration.

METHODS: This paper introduces a novel method that enhances feature interaction within Transformer by computing attention within resizable spatial perpendicular window (SPW). Additionally, it introduces a self-learning mapping control (SLMC) mechanism, which uses a mini convolutional neural network (CNN) to adaptively transform feature vectors into probability vectors. This approach is integrated into the UNet framework, resulting in the SPW-TransUNet. The effectiveness of the SPW-TransUNet is demonstrated through evaluations on two critical 3D medical imaging tasks: CT-CBCT registration and inter-CT registration. We utilized a range of evaluation metrics including Dice similarity coefficient (DICE), structural similarity index measure (SSIM), target registration error (TRE), and negative Jacobian percentage. The validation process involved comparative analysis against established baseline methods using statistical tests to ensure the robustness and reliability of our results.

RESULTS: The proposed method demonstrated outstanding performance in the registration of 124 pairs of CT-CBCT lung images from 20 patients, achieving the lowest TRE of 2.16 mm and a minimal negative Jacobian of 0.126. It also recorded the highest SSIM and Dice coefficient of 86.87% and 88.28%, respectively. For the liver CT task involving 150 patients, the method achieved peak SSIM and DICE scores of 76.92% and 85.77%, respectively. Furthermore, ablation studies confirmed the effectiveness of the designed structural components.

CONCLUSIONS: The SPW-TransUNet offers significant improvements in feature interaction and computational efficiency for medical image registration, providing an effective reference solution for patient and target localization in image-guided radiation therapy.

PMID:39698684 | PMC:PMC11651926 | DOI:10.21037/qims-24-1138

Quant Imaging Med Surg. 2024 Dec 5;14(12):8467-8478. doi: 10.21037/qims-24-389. Epub 2024 Nov 6.

ABSTRACT

BACKGROUND: Non-neoplastic ground-glass nodules (GGNs) generally decrease in size or density during follow-up; however, some exhibit the opposite effect (and show progressive changes), which can lead to unnecessary resection. This study sought to determine the progressive changes in non-neoplastic GGNs using follow-up computed tomography (CT).

METHODS: This cross-sectional study included 70 patients diagnosed with pathologically confirmed non-neoplastic GGNs from January 2017 to March 2023. Of the patients, 35 showed progressive changes and 35 showed no significant changes. The initial and preoperative chest CT images were reviewed to evaluate their changes. The progressive changes in the GGNs were classified into the following five types: type I: increasing density; type II: increasing size; type III: increasing density and solid component; type IV: increasing size and density/solid component; and type V: increasing size, density, and solid component. The T-test, Pearson chi-square test, Wilkinson sign test and Mann-Whitney U-test were used for the data analysis. A two-sided P value <0.05 was considered statistically significant.

RESULTS: Among the 35 GGNs with progressive changes, type II (14, 40.0%) was the most common, followed by types IV (9, 25.7%), I (5, 14.3%), V (5, 14.3%), and III (2, 5.3%). The number of lesions that changed in <6, ≥6 and <12, ≥12 and ≤24, >24 months was 22 (62.9%), 4 (11.4%), 5 (14.3%), and 4 (11.4%), respectively. Among the 28 GGNs with an increasing volume, the number of lesions with a volume doubling time (VDT) of <344 and >441 days was 20 (71.4%) and 8 (28.6%), respectively. Except for these progressive changes, the other features did not exhibit significant changes, especially the ill-defined boundary (74.3% vs. 71.4%, P>0.99).

CONCLUSIONS: GGNs with progressive changes are more likely to be non-neoplastic if the changes occur in a short period or the lesions maintain an ill-defined boundary.

PMID:39698674 | PMC:PMC11652038 | DOI:10.21037/qims-24-389

Quant Imaging Med Surg. 2024 Dec 5;14(12):9157-9168. doi: 10.21037/qims-24-1014. Epub 2024 Nov 29.

ABSTRACT

BACKGROUND: The detection of prostate cancer (PCa) via conventional magnetic resonance imaging (MRI) in patients with prostate-specific antigen (PSA) levels within the grey zone remains challenging. Whether synthetic MRI can provide supplementary benefits for the accurate diagnosis of PCa in this specific population is still unknown. This study aims to investigate the diagnostic performance of synthetic MRI for differentiating PCa lesions from noncancerous lesions in patients with PSA levels within the grey zone (4-10 ng/mL).

METHODS: Clinical and MRI data, including synthetic MRI data of patients suspected of having PCa between August 2020 and August 2022, were retrospectively collected from The First Affiliated Hospital of Sun Yat-sen University and Sun Yat-sen University Cancer Center. Patients with PSA levels ranging from 4-10 ng/mL were enrolled. Pathology was obtained either from transrectal ultrasound-guided biopsy or radical prostatectomy. Regions of interest were manually drawn by two independent radiologists, and the values of quantitative parameters, including longitudinal relaxation time (T1), transverse relaxation time (T2), proton density (PD), and apparent diffusion coefficient (ADC), were separately measured. Interobserver agreement was evaluated using the interclass correlation coefficient (ICC). The differences in quantitative parameter values between PCa and noncancerous lesions were assessed using an independent sample t-test or the Mann-Whitney U test. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic performance of each parameter (T1, T2, PD, and ADC values), as well as their combination. P<0.05 indicated statistical significance.

RESULTS: A total of 130 patients were enrolled in this study, with a mean age of 67.32±8.87 years. The interobserver agreement of all the T1, T2, PD, and ADC values was classified as good or above (ICC =0.60-1.00). The means of the T1, T2, PD, and ADC values were significantly different between PCa and noncancerous lesions (P=0.022, P<0.001, P=0.035, P<0.001, respectively). Notably, the ADC value demonstrated superior diagnostic performance compared to that of the other parameters, with an area under the curve (AUC) of 0.854 [95% confidence interval (CI): 0.781-0.909]. The combination of T1, T2, PD, and ADC values had a greater diagnostic performance (AUC =0.853, 95% CI: 0.781-0.909) than the T1 (AUC =0.622), T2 (AUC =0.721), or PD (AUC =0.608) values for differentiating PCa lesions from non-cancerous lesions. However, compared to the difference in the ADC value, no significant difference was found (P=0.982).

CONCLUSIONS: Quantitative parameters, including T1, T2, and PD, derived from synthetic MRI can be applied to differentiate PCa lesions from noncancerous lesions in patients with PSA levels within the grey zone. However, when these parameters were combined with the ADC, the diagnostic performance did not improve compared to that with the ADC value alone.

PMID:39698673 | PMC:PMC11651948 | DOI:10.21037/qims-24-1014

BMC Med Educ. 2024 Dec 18;24(1):1491. doi: 10.1186/s12909-024-06481-0.

ABSTRACT

BACKGROUND: Microaggressions, subtle and often unintentional acts of hostility, have been recognized as a significant issue in healthcare, adversely affecting learners’ emotional and physical well-being. Current strategies for addressing microaggressions are broad frameworks without empirical substantiation that leave learners without a clear direction for intervention. This study introduces a novel scripted, succinct, bystander intervention tool to combat microaggressions. The intervention tool developed by the research team, named I-RANT, follows the script of introduction, role naming, affirming the target, negating the microaggression, and transitioning within patient encounters. The study goal was to assess the ability of a training session to impact learners’ recognition of microaggressions, confidence in intervening, and competency in applying the I-RANT tool.

METHODS: A pre-experimental study was conducted with 97 second-year medical students at a large academic center in the Southeast United States. The I-RANT tool was taught through a 90-minute training session. The session included an introduction lecture, small group discussions, and role-play scenarios. Pre- and post-intervention surveys assessed microaggression recognition via a multiple-choice questionnaire (MCQ) and self-reported confidence in intervening on a Likert scale. Differences were compared via paired T-test. Role-play scenarios were observed by trained faculty and graded for competence using a rubric.

RESULTS: Participants showed significant improvement in microaggression identification with increase in MCQ score from 4.17 (SD 0.75) pre-intervention to 4.74 (SD 0.42) post-intervention (p < .001) and increased self-reported confidence from 3.2 (SD 1.0) to 4.2 (SD 0.63) (p < .001). Trained faculty evaluated a random sampling of students’ role-play scenarios (n = 30) revealing that 97% of sampled students demonstrated competence in utilizing the I-RANT tool.

DISCUSSION: The I-RANT training session empowered learners to address microaggressions. Learners demonstrated a statistically significant improvement in recognition of microaggressions and confidence in intervening. The majority of learners demonstrated competency in utilizing the I-RANT tool by the end of the training session.

CONCLUSIONS: This study supports the effectiveness of our training session in enhancing medical students’ ability to recognize and address microaggressions. I-RANT empowers learners with a tool to intervene against microaggressions within patient encounters.

PMID:39695515 | DOI:10.1186/s12909-024-06481-0