RESUMO
This study investigates age and gender differences of normative values of spleen diffusion MRI parameters.We recruited 124 volunteers with MRI conducted at 1.5T. Diffusion imaging had b-values of 0, 2, 4, 7, 10, 15, 20, 30, 46, 60, 72, 100, 150, 200, 400, 600 s/mm2. ADC, IVIM-Dslow, IVIM-PF, IVIM-Dfast, and DDVD (diffusion-derived vessel density) were computed. DDVD is the signal difference between the b=0 s/mm2 image and b=2, 4 s/mm2 image. Only images without apparent artifacts and with good curving fitting were included in the analysis. Finally, 34 females (age: 20-71 years) and 69 males (22-70 years) were measured with ADC; 20 females (20-71 years) and 48 males (22-67 years) were measured with IVIM; 32 females (20-71 years) and 65 males (22-70 years) were measured with DDVD parameter.An age-related decrease in ADC was noted for females, while such a trend was not noted for males. A very high level of heterogeneity was noted for the data for the males, with the highest ADC value being 1.710 × 10-3mm 2/s and the lowest ADC value being 0.705 × 10-3 mm2/s when b=0 and 600 s/mm 2 were used for ADC calculation. A male-female data comparison did not show a statistically significant difference between the ADC median value. However, ADCs > 1.3 × 10-3 mm2/s were only seen among males. A very high level of heterogeneity was also noted for males' Dslow, with the highest value being 1.468 × 10-3 mm2/s and the lowest value being 0.600 × 10-3 mm2/s. Both PF and Dfast demonstrated a trend of age-related increase for older subjects. PF values were higher among males than females. However, no difference was noted for Dfast between males and females. DDVD did not show an age-related trend both for females and males. No difference was noted in DDVD values between males and females.Interpreting normal spleen diffusion MRI parameters should consider age and gender factors. · An age-related decrease in spleen ADC and IVIM-Dslow was seen for healthy females.. · There is a high level of heterogeneity for spleen ADC and IVIM-Dslow data for healthy males.. · IVIM modelled perfusion fraction and Dfast demonstrate an artificial trend of age-related increase for older subjects.. · Vessel density measured on diffusion imaging does not show an age-related trend.. · Yu W, Ma FZ, Huang H et al. Age and gender differences of normative values of spleen diffusion MRI parameters. Fortschr Röntgenstr 2024; DOI 10.1055/a-2357-9741.
RESUMO
It has been frequently cited that 'the majority of fragility fractures (FF) occur at non-osteoporotic bone mineral density (BMD)'. For the reports with T-score measured around the time of a hip fracture, we conducted a systematic literature search in December 2022, and resulted in 10 studies with five for Caucasian women and five for East Asian women. Femoral neck (FN) T-score was reported in five Caucasian studies and three East Asian studies, three of five Caucasian studies had a mean T-score ≤-2.5, and one study had the majority of their patients measuring a mean T-score ≤-2.5. All three East Asian studies reported a mean FN T-score ≤-2.7. Total hip T-score was reported in two Caucasian studies and three East Asian studies, the two Caucasian studies both had a mean T-score ≤-2.5, and all three East Asian studies had a mean T-score ≤-2.6. A new literature search conducted in April 2024 results in additional three studies, with results being consistent with the data described above. A trend was noted that 'younger' patients suffer from hip fractures at a 'higher' T-score. For the highly cited articles where the notion the majority of FF occur at non-osteoporotic BMD was derived from, authors reported prospective epidemiological studies where BMD was not measured at the timepoint of hip fracture, instead, BMD was measured at the study baseline. These epidemiological studies suggest that >50% of hip fractures likely occur in women with an osteoporotic FN or hip T-score. However, a pattern was seen that older men suffer from hip fracture at a notably higher T-score than older women. For the cases of radiographic vertebral FF, despite varying criteria being used to classify these FFs, the majority of female patients had spine densitometric osteoporosis. Literature shows, compared with the cases of hip fracture, distal forearm fracture occurs at a 'younger' age and 'higher' BMD, suggesting distal forearm fracture is more likely associated with a 'higher' trauma energy level.
RESUMO
For older Caucasian women and men, the QCT (quantitative CT) lumbar spine (LS) bone mineral density (BMD) threshold for classifying osteoporosis is 80 mg/ml. It was recently proposed that, for older East Asian women, the QCT LS BMD value equivalent to the Caucasian women's threshold of 80 mg/mL is about 45â¼50 mg/ml. For a data of 328 cases of Chinese men (age: 73.6 ± 4.4 years) who had QCT LS BMD and DXA LS BMD at the same time and with the DXA BMD value of ≤ 0.613 g/cm2 to classify osteoporosis, the corresponding QCT LS BMD threshold is 53 mg/ml. Osteoporotic-like vertebral fracture sum score (OLVFss) ≤ -2.5 has been proposed to diagnose osteoporosis. For 316 cases of Chinese men (age:73.7±4.5 years), OLVFss ≤ -2.5 defines an osteoporosis prevalence of 4.4%; to achieve this osteoporosis prevalence, the corresponding QCT LS BMD value is < 47.5 mg/ml. In the China Action on Spine and Hip Status study, a Genant grades 2/3 radiographic 'osteoporotic vertebral fracture' prevalence was 2.84% for Chinese men (total n = 1267, age: 62.77 ± 9.20 years); to achieve this osteoporosis prevalence, the corresponding BMD value was < 42.5 mg/ml. In a study of 357 Beijing older men, according to the clinical fragility fracture prevalence and femoral neck DXA T-score, the QCT LS BMD value to classify osteoporosis was between 39.45 mg/ml and 51.38 mg/ml. For older Chinese men (≥ 50 years), we recommend the cutpoint for the QCT LS BMD definition of osteoporosis to be 45â¼50 mg/ml which is the same as the value for Chinese women.
RESUMO
Background: Diffusion-derived vessel density (DDVD) is a physiological surrogate of the area of micro-vessels per unit tissue area. DDVD is calculated according to: DDVD(b0b5) = Sb0/ROIarea0 - Sb5/ROIarea5, where Sb0 and Sb5 refer to the tissue signal when b is 0 or 5 s/mm2. This study applied DDVD to assess the perfusion of rectal carcinoma (RC). Methods: MRI was performed with a 3.0-T magnet. Diffusion weighted image with b-values of 0, 5 s/mm2 were acquired in 113 patients with non-mucinous RC and 15 patients with mucinous RC. Diffusion-derived vessel density ratio [DDVDr(b0b5)] was DDVD(b0b5) of RC divided by DDVD(b0b5) of tumor-free rectal wall. Results: The median value of the DDVDr(b0b5) for non-mucinous RCs was 1.430, with the majority of RCs showing a higher DDVD than the adjacent tumor-free wall [i.e., with DDVDr(b0b5) >1]. 90.3% (102/113) of non-mucinous RCs were hypervascular, 1.77% (2/113) were iso-vascular, and 7.96% (9/113) were hypovascular. The median value of the DDVDr(b0b5) for mucinous RCs was 1.660. 73.3% (11/15) of mucinous RCs were hypervascular, and 26.7% (4/15) were hypovascular. A trend (P=0.09) was noted that earlier clinical grades non-mucinous RCs had a higher DDVDr(b0b5) than those of the advanced clinical grades (2.245 for grade 0&I, 1.460 for grade II, 1.430 for grade III, 1.130 for grade IV). A non-significant trend was noted with well and moderately differentiated non-mucinous RCs had a higher DDVDr(b0b5)than that of poorly differentiated non-mucinous RCs (median: 1.460 vs. 1.320). A non-significant trend was noted with MRI-detected extramural vascular invasion (mrEMVI) positive non-mucinous RCs had a higher DDVDr(b0b5) than that of mrEMVI negative non-mucinous RCs (1.630 vs. 1.370). Conclusions: DDVD results in this study approximately agree with contrast agent dynamically enhanced CT literature data.
RESUMO
When a low-energy trauma induces an acute vertebral fracture (VF) with clinical symptoms, a definitive diagnosis of osteoporotic vertebral fracture (OVF) can be made. Beyond that, a "gold" radiographic standard to distinguish osteoporotic from non-osteoporotic VFs does not exist. Fracture-shaped vertebral deformity (FSVD) is defined as a deformity radiographically indistinguishable from vertebral fracture according to the best of the reading radiologist's knowledge. FSVD is not uncommon among young populations with normal bone strength. FSVD among an older population is called osteoporotic-like vertebral fracture (OLVF) when the FSVD is likely to be associated with compromised bone strength. In more severe grade deformities or when a vertebra is collapsed, OVF diagnosis can be made with a relatively high degree of certainty by experienced readers. In "milder" cases, OVF is often diagnosed based on a high probability rather than an absolute diagnosis. After excluding known mimickers, singular vertebral wedging in older women is statistically most likely an OLVF. For older women, three non-adjacent minimal grade OLVF (< 20% height loss), one minimal grade OLVF and one mild OLVF (20-25% height loss), or one OLVF with ≥ 25% height loss, meet the diagnosis of osteoporosis. For older men, a single OLVF with < 40% height loss may be insufficient to suggest the subject is osteoporotic. Common OLVF differential diagnoses include X-ray projection artifacts and scoliosis, acquired and developmental short vertebrae, osteoarthritic wedging, oncological deformities, deformity due to high-energy trauma VF, lateral hyperosteogeny of a vertebral body, Cupid's bow, and expansive endplate, among others.
RESUMO
OBJECTIVES: Increasing trend of PAS (placenta accreta spectrum disorders) incidence is a major health concern as PAS is associated with high maternal morbidity and mortality during cesarean section. Prenatal identification of PAS is crucial for delivery planning and patients management. This study aims to explore whether diffusion-derived vessel density (DDVD) computed from a simple diffusion MRI protocol differs in PAS from normal placenta. METHODS: We enrolled 86 patients with PAS disorders and 40 pregnant women without PAS disorders. Each patient underwent intravoxel incoherent motion (IVIM) MRI sequence with 11 b-values. Placenta diffusion-derived vessel density (DDVD-b0b50) was the signal difference between b = 0 and b = 50 s/mm2 images. DDVD(b0b50) A/N was calculated as [accreta lesion DDVD(b0b50)]/ [normal placenta DDVD(b0b50)]. The correlation between DDVD and gestational age was explored using Spearman rank correlation. Differences of DDVD(b0b50) A/N in patients with normal placentas and with PAS, and in patients with different subtypes of PAS were explored. RESULTS: DDVD was negatively correlated with gestational age (p = 0.023, r = -0.359) in patients with normal placentas. DDVD(b0b50) A/N was significantly higher in patients with PAS (median:1.16, mean: 1.261) than normal placenta (median:1.02, mean: 1.032, p < 0.001) and especially higher in patients with placenta increta (median:1.14, mean: 1.278) and percreta (median: 1.20, mean: 1.396, p < 0.001). CONCLUSION: As a higher DDVD indicates higher physiological volume of micro-vessels in PAS, this study suggests DDVD can be a potential biomarker to evaluate the placenta perfusion.
Assuntos
Placenta Acreta , Placenta , Gravidez , Humanos , Feminino , Placenta/diagnóstico por imagem , Placenta Acreta/diagnóstico por imagem , Cesárea , Imagem de Difusão por Ressonância Magnética , Biomarcadores , Estudos RetrospectivosRESUMO
Background: The use of segmentation architectures in medical imaging, particularly for glioma diagnosis, marks a significant advancement in the field. Traditional methods often rely on post-processed images; however, key details can be lost during the fast Fourier transformation (FFT) process. Given the limitations of these techniques, there is a growing interest in exploring more direct approaches. The adaption of segmentation architectures originally designed for road extraction for medical imaging represents an innovative step in this direction. By employing K-space data as the modal input, this method completely eliminates the information loss inherent in FFT, thereby potentially enhancing the precision and effectiveness of glioma diagnosis. Methods: In the study, a novel architecture based on a deep-residual U-net was developed to accomplish the challenging task of automatically segmenting brain tumors from K-space data. Brain tumors from K-space data with different under-sampling rates were also segmented to verify the clinical application of our method. Results: Compared to the benchmarks set in the 2018 Brain Tumor Segmentation (BraTS) Challenge, our proposed architecture had superior performance, achieving Dice scores of 0.8573, 0.8789, and 0.7765 for the whole tumor (WT), tumor core (TC), and enhanced tumor (ET) regions, respectively. The corresponding Hausdorff distances were 2.5649, 1.6146, and 2.7187 for the WT, TC, and ET regions, respectively. Notably, compared to traditional image-based approaches, the architecture also exhibited an improvement of approximately 10% in segmentation accuracy on the K-space data at different under-sampling rates. Conclusions: These results show the superiority of our method compared to previous methods. The direct performance of lesion segmentation based on K-space data eliminates the time-consuming and tedious image reconstruction process, thus enabling the segmentation task to be accomplished more efficiently.
RESUMO
Diffusion-derived vessel density (DVDD) is a physiological surrogate of the area of microvessels per unit tissue area. DDVD is calculated according to DDVD(b0b2) = Sb0/ROIarea0 - Sb2/ROIarea2, where Sb0 and Sb2 refer to the liver signal when b is 0 or 2 s/mm2. Pathohistological studies and contrast-enhanced CT/MRI data showed higher blood volume in hepatocellular carcinoma (HCC) relative to native liver tissue. With intravoxel incoherent motion (IVIM) imaging, most authors paradoxically reported a decreased perfusion fraction of HCC relative to the adjacent liver. This study applied DDVD to assess the perfusion of HCC. MRI was performed with a 3.0-T magnet. Diffusion-weighted images with b-values of 0 and 2 s/mm2 were acquired in 72 HCC patients. Thirty-two patients had microvascular invasion (MVI(+)) and 40 patients did not have microvascular invasion (MVI(-)). Fifty-eight patients had Edmondson-Steiner grade I or II HCC, and 14 patients had Edmondson-Steiner grade III or IV HCC. DDVD measurement was conducted on the axial slice that showed the largest HCC size. DDVD(b0b2) T/L = HCC DDVD(b0b2)/liver DDVD(b0b2). DDVD(b0b2) T/L median (95% confidence interval) of all HCCs was 2.942 (2.419-3.522), of MVI(-) HCCs was 2.699 (2.030-3.522), of MVI(+) HCCs was 2.988 (2.423-3.990), of Edmondson-Steiner grade I/II HCCs was 2.873 (2.277-3.465), and of Edmondson-Steiner grade III/IV HCCs was 3.403 (2.008-4.485). DDVD(b0b2) T/L approximately agrees with contrast agent dynamically enhanced CT/MRI literature data, whereas it differs from earlier IVIM study results, where HCC perfusion fraction was paradoxically lower relative to native liver tissue. A weak trend was noted with MIV(+) HCCs had a higher DDVD(b0b2) T/L than that of MVI(-) HCCs, and a weak trend was noted with the poorly differentiated group of HCCs (Edmondson-Steiner grade III and IV) had a higher DDVD(b0b2) T/L than that of the better differentiated group of HCCs (Edmondson-Steiner grade I and II).
Assuntos
Carcinoma Hepatocelular , Imagem de Difusão por Ressonância Magnética , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/irrigação sanguínea , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Adulto , Movimento (Física)RESUMO
For Caucasian women, the QCT (quantitative CT) lumbar spine (LS) bone mineral density (BMD) cutpoint value for classifying osteoporosis is 80 mg/ml. At the age of approximate 78 years, US Caucasian women QCT LS BMD population mean is 80 mg/ml, while that of Chinese women and Japanese women is around 50 mg/ml. Correlation analyses show, for Chinese women and Japanese women, QCT LS BMD of 45 mg/ml corresponds to the dual-energy X-ray absorptiometry cutpoint value for classifying osteoporosis. For Chinese and Japanese women, if QCT LS BMD 80 mg/ml is used as the threshold to classify osteoporosis, then the specificity of classifying subjects with vertebral fragility fracture into the osteoporotic group is low, whereas threshold of 45 mg/ml approximately achieve a similar separation for women with and without vertebral fragility fracture as the reports for Caucasian women. Moreover, by using 80mg/ml as the cutpoint value, LS QCT leads to excessively high prevalence of osteoporosis for Chinese women, with the discordance between hip dual-energy X-ray absorptiometry and LS QCT measures far exceeding expectation. Considering the different bone properties and the much lower prevalence of fragility fractures in the East Asian women compared with Caucasians, we argue that the QCT cutpoint value for classifying osteoporosis among older East Asian women will be close to and no more than 50 mg/ml LS BMD. We suggest that it is also imperative the QCT osteoporosis classification criterion for East Asian male LS, and male and female hips be re-examined.
Assuntos
Densidade Óssea , População do Leste Asiático , Vértebras Lombares , População Branca , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Absorciometria de Fóton , Vértebras Lombares/diagnóstico por imagem , Osteoporose/diagnóstico por imagem , Prevalência , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios XRESUMO
Background: Pulmonary nodular consolidation (PN) and pulmonary cavity (PC) may represent the two most promising imaging signs in differentiating multidrug-resistant (MDR)-pulmonary tuberculosis (PTB) from drug-sensitive (DS)-PTB. However, there have been concerns that literature described radiological feature differences between DS-PTB and MDR-PTB were confounded by that MDR-PTB cases tend to have a longer history. This study seeks to further clarify this point. Methods: All cases were from the Guangzhou Chest Hospital, Guangzhou, China. We retrieved data of consecutive new MDR cases [n=46, inclusive of rifampicin-resistant (RR) cases] treated during the period of July 2020 and December 2021, and according to the electronic case archiving system records, the main PTB-related symptoms/signs history was ≤3 months till the first computed tomography (CT) scan in Guangzhou Chest Hospital was taken. To pair the MDR-PTB cases with assumed equal disease history length, we additionally retrieved data of 46 cases of DS-PTB patients. Twenty-two of the DS patients and 30 of the MDR patients were from rural communities. The first CT in Guangzhou Chest Hospital was analysed in this study. When the CT was taken, most cases had anti-TB drug treatment for less than 2 weeks, and none had been treated for more than 3 weeks. Results: Apparent CT signs associated with chronicity were noted in 10 cases in the DS group (10/46) and 9 cases in the MDR group (10/46). Thus, the overall disease history would have been longer than the assumed <3 months. Still, the history length difference between DS patients and MDR patients in the current study might not be substantial. The lung volume involvement was 11.3%±8.3% for DS cases and 8.4%±6.6% for MDR cases (P=0.022). There was no statistical difference between DS cases and MDR cases both in PN prevalence and in PC prevalence. For positive cases, MDR cases had more PN number (mean of positive cases: 2.63 vs. 2.28, P=0.38) and PC number (mean of positive cases: 2.14 vs. 1.38, P=0.001) than DS cases. Receiver operating characteristic curve analysis shows, PN ≥4 and PC ≥3 had a specificity of 86% (sensitivity 25%) and 93% (sensitivity 36%), respectively, in suggesting the patient being a MDR cases. Conclusions: A combination of PN and PC features allows statistical separation of DS and MDR cases.
RESUMO
For liver intravoxel incoherent motion (IVIM) data acquisition, respiratory-triggering (RT) MRI is commonly used, and there are strong motivations to shorten the scan duration. For the same scan duration, more b values or higher numbers of excitations can be allowed for free-breathing (FB) imaging than for RT. We studied whether FB can be used to replace RT when careful IVIM image acquisition and image processing are conducted. MRI data of 22 healthy participants were acquired using a 3.0 T scanner. Diffusion imaging was based on a single-shot spin-echo-type echo-planar sequence and 16 b values of 0, 2, 4, 7, 10, 15, 20, 30, 46, 60, 72, 100, 150, 200, 400, and 600 s/mm2 . Each subject attended two scan sessions with an interval of 10-20 days. For each scan session, a subject was scanned twice, first with RT and then with FB. The mean image acquisition time was 5.4 min for FB and 10.8 min for RT. IVIM parameters were calculated with bi-exponential model segmented fitting with a threshold b value of 60 s/mm2 , and fitting started from b = 2 s/mm2 . There was no statistically significant difference between IVIM parameters measured with FB imaging or RT imaging. Perfusion fraction ICC (intraclass correlation coefficient) for FB imaging and RT imaging in the same scan session was 0.824. For perfusion fraction, wSD (within-subject standard deviation), BA (Bland-Altman) difference, BA 95% limit, and ICC were 0.022, 0.0001, -0.0635~0.0637, and 0.687 for FB and 0.031, 0.0122, -0.0723~0.0967, and 0.611 for RT. For Dslow (×10-3 s/mm2 ), wSD, BA difference, BA 95% limit, and ICC were 0.057, 0.0268, -0.1258~0.1793, and 0.471 for FB and 0.073, -0.0078, -0.2170-0.2014, and <0.4 for RT. The Dfast coefficient of variation was 0.20 for FB imaging and 0.28 for RT imaging. All reproducibility indicators slightly favored FB imaging.