Novel quantitative software for automatically excluding red bone marrow on whole-body magnetic resonance imaging in patients with metastatic prostate cancer: A pilot study.

OBJECTIVES: To establish a novel quantitative method that automatically excludes the red bone marrow and accurately quantifies the tumor volume on whole-body magnetic resonance imaging using updated imaging software. To also evaluate the association between the quantified tumor volume and the prognosis of patients with metastatic prostate cancer. METHODS: This prospective analysis included patients diagnosed with metastatic hormone-sensitive or metastatic castration-resistant prostate cancer between 2017 and 2022. We developed an imaging software (Attractive BD_Score) that analyzed whole-body diffusion-weighted and in-phase and opposed-phase T1-weighted images to automatically exclude the red bone marrow. The quantified tumor volume was compared with that quantified by traditional whole-body diffusion-weighted imaging without red bone marrow exclusion. Prostate-specific antigen progression-free survival, time-to-pain progression, and overall survival were evaluated to assess the prognostic value of the quantified tumor volume. RESULTS: The quantified tumor volume was significantly smaller than that quantified by the traditional method in metastatic hormone-sensitive (median: 81.0 ml vs. 149.4 ml) and metastatic castration-resistant (median: 29.4 ml vs. 63.5 ml) prostate cancer. A highly quantified tumor volume was associated with prostate-specific antigen progression-free survival (p = 0.030), time-to-pain progression (p = 0.003), and overall survival (p = 0.005) in patients with metastatic hormone-sensitive prostate cancer and with poor prostate-specific antigen progression-free survival (p = 0.001) and time-to-pain progression (p = 0.005) in patients with metastatic castration-resistant prostate cancer. CONCLUSIONS: Our imaging method could accurately quantify the tumor volume in patients with metastatic prostate cancer. The quantified tumor volume can be clinically applied as a new prognostic biomarker for metastatic prostate cancer.

Potential of Perfusion Magnetic Resonance Imaging to Predict Residual Renal Function after Radical Nephroureterectomy.

INTRODUCTION: The diffusion-weighted imaging (DWI) technique with intravoxel incoherent motion model enables the estimation of capillary blood volume as a perfusion-related parameter- (PP-) value. Therefore, the PP-value of the kidney theoretically reflects renal capillary blood volume. We analyzed the usefulness of the PP-value in estimating postoperative renal function in upper-tract urothelial carcinoma (UTUC) patients. METHODS: Forty-eight consecutive patients who underwent magnetic resonance imaging before radical nephroureterectomy from 2011 to 2018 were analyzed. A PP-map displaying PP-values on a pixel-by-pixel basis was created from DWI signals (b-values of 0, 500, and 1,000 s/mm2). Two readers independently analyzed the renal PP-value. DWI-based split renal function (SRF) of the intact kidney was calculated by splitting serum Cr-based preoperative estimated glomerular filtration rates (eGFRs). The predictive accuracy of the method was evaluated using renography as the reference standard. RESULTS: Interobserver analysis revealed an excellent correlation value of 0.97. The SRF value showed a good linear correlation with the observed postoperative eGFR (r = 0.76, p < 0.001). The predictive accuracy of the DWI-based method was similar to that of the nuclear-based method. CONCLUSION: This DWI-based evaluation of capillary blood volume provides a noninvasive tool for predicting the postoperative renal function, thereby facilitating the management of UTUC patients.

Quantification of the myocardial area at risk using coronary CT angiography and Voronoi algorithm-based myocardial segmentation.

OBJECTIVES: The purpose of this study was to estimate the myocardial area at risk (MAAR) using coronary computed tomography angiography (CTA) and Voronoi algorithm-based myocardial segmentation in comparison with single-photon emission computed tomography (SPECT). METHODS: Thirty-four patients with coronary artery disease underwent 128-slice coronary CTA, stress/rest thallium-201 SPECT, and coronary angiography (CAG). CTA-based MAAR was defined as the sum of all CAG stenosis (>50%) related territories (the ratio of the left ventricular volume). Using automated quantification software (17-segment model, 5-point scale), SPECT-based MAAR was defined as the number of segments with a score above zero as compared to the total 17 segments by summed stress score (SSS), difference (SDS) score map, and comprehensive SPECT interpretation with either SSS or SDS best correlating CAG findings (SSS/SDS). Results were compared using Pearson's correlation coefficient. RESULTS: Forty-nine stenoses were observed in 102 major coronary territories. Mean value of CTA-based MAAR was 28.3 ± 14.0%. SSS-based, SDS-based, and SSS/SDS-based MAAR was 30.1 ± 6.1%, 20.1 ± 15.8%, and 26.8 ± 15.7%, respectively. CTA-based MAAR was significantly related to SPECT-based MAAR (r = 0.531 for SSS; r = 0.494 for SDS; r = 0.814 for SSS/SDS; P < 0.05 in each). CONCLUSIONS: CTA-based Voronoi algorithm myocardial segmentation reliably quantifies SPECT-based MAAR. KEY POINTS: • Voronoi algorithm allows for three-dimensional myocardial segmentation of coronary CT angiography • Stenosis-related CT myocardial territories correlate to SPECT based area at risk • CT angiography myocardial segmentation may assist in clinical decision-making.

Volume ratio and distribution rate in patients with orthostatic vertigo/dizziness using MR imaging: a comparison with vertiginous diseases.

BACKGROUND: Orthostatic dizziness/vertigo (ODV) is characterized by lightheadedness owing to postural changes. AIMS/OBJECTIVES: To measure the endolymphatic space (ELS)/total fluid space (TFS) volume ratio and the distribution rate of endolymphatic fluid (ELF) of patients with ODV and compare them with those of control subjects (CS). MATERIALS AND METHODS: This study included 22 patients (44 ears) with ODV and 52 controls (104 ears, CS). The ELS/TFS volume ratio (%) and distribution rate (%) of the inner ear components were measured using 3-dimensional magnetic resonance imaging. RESULTS: In the ODV group, the mean ELS/TFS volume ratios of the cochlea, vestibule, and semi-circular canals (SCCs) were 12.1%, 18.6%, and 18.1%, respectively; the mean ELS distribution rates for the cochlea, vestibule, and SCCs were 27.3%, 26.2%, and 46.6%, respectively. The ELS distribution rate of the vestibule was significantly lower (p < .01) and the ELS distribution rate of the SCCs was significantly higher in the ODV than in the CS group (p < .01). CONCLUSIONS AND SIGNIFICANCE: The ELS distribution rate in the vestibule + SCCs among patients with ODV did not differ from that in the CS; ELF in the vestibule moved to the SCCs, and a large amount of ELF was distributed only in the SCCs.

Magnetic resonance imaging of the endolymphatic space in patients with benign paroxysmal positional vertigo: volume ratio and distribution rate of the endolymphatic space.

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular disease. It is characterised by sudden onset short lived vertigo triggered by sudden changes in head position relative to gravity. AIMS/OBJECTIVES: We aimed to perform a quantitative volumetric analysis of the inner ear endolymphatic space in patients with BPPV. MATERIAL AND METHODS: This study included 67 patients with BPPV and 50 control subjects (CS). The endolymphatic space/total fluid space volume ratio (%) and the distribution rate of the inner ear components in the endolymphatic space (%) were measured using three-dimensional magnetic resonance imaging. RESULTS: Differences in the endolymphatic space/total fluid space volume ratio of the inner ear, cochlea, vestibule, and semi-circular canals (SCCs) between the CS and BPPV groups were not significant. The endolymphatic space distribution rate of the vestibule in the BPPV group was significantly lower than that in the CS group, and the endolymphatic space distribution rate of SCCs in the BPPV group was significantly higher than that in the CS group. CONCLUSIONS AND SIGNIFICANCE: Extended endolymphatic space in patients with BPPV did not exist. The otoconia released from the damaged utricles were considered to move with the endolymphatic flow toward SCCs.

Magnetic resonance imaging of endolymphatic hydrops in patients with unilateral Meniere's disease: volume ratio and distribution rate of the endolymphatic space.

BACKGROUND: Endolymphatic hydrops (ELH), which is a pathological feature of Meniere's disease (MD), is characterized by an extended endolymphatic space (ELS). AIMS/OBJECTIVES: We aimed to perform a quantitative volumetric analysis of inner-ear ELH in patients with unilateral MD (uMD). MATERIAL AND METHODS: This study included 97 patients with definite uMD and 49 control subjects (CS). The ELS/total fluid space (TFS) volume ratio (%) and the distribution rate of the inner-ear components in the ELS (%) were measured using 3D magnetic resonance imaging and compared between patients with uMD and CS. RESULTS: Compared to CS, patients with uMD had significantly higher mean ELS/TFS volume ratios for inner-ear components. The mean distribution rate of the inner-ear components in the ELS was not significantly different between the two groups. CONCLUSIONS AND SIGNIFICANCE: In patients with uMD, ELH was noted to be spread throughout the entire inner ear and the endolymph was evenly distributed in the total ELS. These findings should be useful as a standard reference for further research.

Magnetic Resonance 3D Measurement of the Endolymphatic Space in 100 Control Human Subjects.

Three Dimensional-magnetic resonance imaging of the inner ear endolymphatic space was performed in 100 control human subjects. Ear endolymphatic space was visualized using contrast-enhanced magnetic resonance imaging with intravenous gadolinium injection. The images were acquired on a 3-tesla magnetic resonance scanner using a 32-channel array head coil for all patients. The ear endolymphatic space and total fluid space volumes of the inner ear, cochlea, and vestibule were measured, and the ear endolymphatic space in the cochlea and vestibule was classified into four categories. The cochlea categories were: c-1, no ear endolymphatic space; c-2, ear endolymphatic space visualized only until the upper turn; c-3, ear endolymphatic space visualized from the upper turn to the second turn; and c-4, ear endolymphatic space visualized up to the basal turn. The vestibule categories were: v-1, no ear endolymphatic space; v-2, ear endolymphatic space visualized only in the utriculus; v-3, ear endolymphatic space visualized in the utriculus and sacculus separately; and v-4, ear endolymphatic space visualized in the utriculus and sacculus together. The mean TFS volumes of the inner ear, cochlea, and vestibule were 282.1 ± 33.2 µL, 112.9 ± 15.9 µL, and 69.1 ± 9.9 µL, respectively, and that of the ampulla of the posterior semicircular canal was 7.8 ± 1.7 µL. The mean ear endolymphatic space/total fluid space volume ratio in the cochlea was 10.3 ± 6.7% and that in the vestibule was 17.3 ± 12.2%. This ratio in the cochlea was between the results of categories c-1 and c-2 and that in the vestibule between those of categories v-2 and v-3. Two subjects had ear endolymphatic space extending from the vestibule to the posterior non-ampullated crus of the lateral semicircular canal. These findings can be applied as standard reference values for further research.

Magnetic resonance imaging of endolymphatic hydrops in patients with unilateral Meniere's disease: a comparison between with and without herniation into the posterior and lateral semi-circular canals.

BACKGROUND: The presence of endolymphatic hydrops (ELH) in patients with Meniere's disease (MD) is considered a pathological hallmark. AIMS/OBJECTIVES: We aimed to conduct a quantitative volumetric measurement of inner ear ELH in patients with unilateral MD (uMD). The values of uMD with and without herniation into the posterior semi-circular canal (h-PSC) and the lateral semi-circular canal (h-LSC) were compared using 3 D magnetic resonance imaging. MATERIAL AND METHODS: This study included 130 individuals (47 controls and 83 patients with uMD). We measured the total fluid space (TFS) and endolymphatic space (ELS) volumes. We also evaluated the ELS/TFS volume ratios (%). RESULTS: The ELS/TFS volume ratios in the inner ear, cochlea, and vestibule were significantly different between the affected and contralateral sides in patients with h-PSC. Moreover, the ELS/TFS volume ratios of the inner ear, vestibule, and semi-circular canals in the affected ear were significantly higher in patients with h-PSC than in those without h-PSC. The vestibular ELS/TFS volume ratio in the affected ear was significantly higher in patients with h-LSC than in those without h-LSC. CONCLUSIONS AND SIGNIFICANCE: H-LSC is present in extended vestibular ELH. However, this is a result of ELH progression in the inner ear.

Magnetic resonance imaging of endolymphatic space in patients with sensorineural hearing loss: comparison between fluctuating and idiopathic sudden sensorineural hearing loss.

Background: Recently, 3-Tesla magnetic resonance imaging (MRI) after an intravenous gadolinium injection has been used to describe the endolymphatic space (ELS).Objectives: This study described the histopathological differences between idiopathic sudden sensorineural hearing loss (ISSNHL) and fluctuating sensorineural hearing loss (FSNHL) by examining the ELS. Additionally, the relationship between the affected cochlear and vestibular ELS/total fluid space (TFS) volume ratio and the duration from the onset to MRI in patients with FSNHL were evaluated.Material and methods: This study included 205 individuals without vertigo: 47 controls, 94 with ISSNHL, and 64 with FSNHL. The TFS and ELS volumes were measured and the ELS/TFS volume ratios (%) were evaluated.Results: The cochlear and vestibular ELS/TFS volume ratios of the affected ear in patients with FSNHL were significantly higher than that in those with ISSNHL. There was no correlation between the duration from FSNHL onset to the MRI scan in the affected cochlea and vestibule.Conclusion and significance: There were differences in the form of hearing fluctuation and the extended ELS volume between ISSNHL and FSNHL. ISSNHL cases with severe ELS extension were likely to change to FSNHL.

Spinal cord biopsy findings of anti-aquaporin-4 antibody-negative recurrent longitudinal myelitis in a patient with sicca symptoms and hepatitis C viral infection.

We describe the pathological features of a spinal cord biopsy from a 69-year-old woman with anti-aquaporin-4 antibody-negative recurrent longitudinal myelitis. Spinal cord MRI showed T2 high-intensity lesions with strong gadolinium enhancement, when episodes of sensory-motor impairment were repeated. The radiological abnormality was corrected by corticosteroid administration, but improvement of the symptoms was minimal. Although the patient had sicca symptoms and fulfilled four of the diagnostic criteria for Sjögren syndrome, the diagnosis was excluded, because of infection with hepatitis C virus, an exclusion criterion of Sjögren syndrome. In the spinal cord lesions, necrotic changes affected both myelin and axons. Infiltrating lymphocytes were predominantly T-cells. The proliferation of small vessels with hyalinization and concomitant occlusive change was remarkable. These pathological findings resembled those previously reported in Sjögren syndrome. Ultrastructurally, the endothelial cells of the small vessels showed features of activated cells and contained vesiculo-tubular structures in the cytoplasm, indicating that increased blood-brain barrier (BBB) permeability might contribute to pathogenesis. We speculated that increased BBB permeability and T-cell entry in the spinal parenchyma triggered pathological reactions resulting in necrotic changes in the spinal cord. Obstruction of small vessels might add ischemic damage to the lesions. The clinical course and pathological findings indicated that damage progressed rapidly in the spinal cord and was irreversible. The lesions apparently differed from typical demyelination plaques. Faced with such spinal cord lesions, a preventive therapeutic approach is necessary to avoid attack-associated disability.