Age and gender dependence of liver diffusion parameters and the possibility that intravoxel incoherent motion modeling of the perfusion component is constrained by the diffusion component.

The aim of this study was to establish reference values for middle-aged subjects and to investigate the age and gender dependence of liver diffusion MRI parameters. The IVIM type of liver diffusion scan was based on a single-shot spin-echo-type echo-planar sequence using a 1.5 T magnet with 16 b-values. Diffusion-derived vessel density (DDVD)(b0b2) or DDVD(b0b10) was the signal difference between b = 0 and b = 2 (or b = 10) s/mm2 images after removing visible vessels. IVIM analysis was performed with full fitting and segmented fitting, and with a threshold b-value of 60 or 200 s/mm2 , and fitting started from b = 2 s/mm2 . Thirty-one men (age range: 25-71 years) and 26 men (age: 22-69 years) had DDVD and IVIM analysis, respectively, while 37 women (age: 20-71 years) and 36 women (age: 20-71 years) had DDVD and IVIM analysis, respectively. DDVD results showed a significant age-related reduction for women. IVIM results for full fitting showed excellent agreement with those for segmented fitting using a threshold b of 60 s/mm2 , but this was less good for results with a threshold b of 200 s/mm2 . As age increased, female subjects' Dslow measure showed a significant reduction, while their PF and Dfast measures showed a significant increase. For the age group of 40-55 years, DDVD(b0b2), DDVD(b0b10), Dslow , PF and Dfast were 12.26 ± 3.90 au/pixel, 16.95 ± 5.45 au/pixel, 1.072 ± 0.067 (10-3 mm2 /s), 0.141 ± 0.025 and 61.0 ± 14.0 (10-3 mm2 /s) for men, and 13.35 ± 3.6 au/pixel, 17.20 ± 3.62 au/pixel, 1.069 ± 0.074 (10-3 mm2 /s), 0.119 ± 0.014 and 57.1 ± 13.2 (10-3 mm2 /s) for women, respectively. DDVD measure of this study suggest that aging is associated with a reduction in liver perfusion. There is a possibility that a lower Dslow measure is associated with artificially higher PF and Dfast measures, and that IVIM modeling of the perfusion component is constrained by the diffusion component.

Elderly men have much lower vertebral fracture risk than elderly women even at advanced age: the MrOS and MsOS (Hong Kong) year 14 follow-up radiology results.

MrOS MsOS (Hong Kong) studies year 14 follow-up shows for subjects without baseline osteoporotic vertebral deformity, women's incident vertebral fracture (VF) rate was twice that of men. For subjects with vertebral deformity of baseline ≥ 20% height loss, counting subject, women's incident VF rate was three times higher than that of men. INTRODUCTION: For MrOS MsOS (Hong Kong) baseline (BL) studies, 2000 men and 2000 women ≥ 65 years were recruited during 2001 to 2003. This study presents the year 14 follow-up (FU). MATERIALS: Whole spine MRI was performed in 271 males (mean, 82.8 ± 3.6 years) and 150 females (mean, 82.0 ± 4.29 years). Osteoporotic vertebral deformity (OVD) classification included no OVD (grade 0), and OVDs with < 20%, 20~25%, > 25%~1/3, > 1/3~40%, > 40%~2/3, and > 2/3 height loss (grade 1~6). With an existing VD, a further height loss of ≥ 15% was a VD progression. A new incident VD was a change from grade 0 to ≥ grade 2 or to grade 1 with ≥ 10% height loss. OVD progression and new incident OVD were considered incident VF. RESULTS: The proportion of osteoporotic subjects only slightly increased during FU for men but doubled for women. Groupwise, OVD was not associated with back pain in men; but OVD with > 1/3 height loss was associated with back pain in women. For subjects without BL OVD, 7.9% of men and 14.6% of women had incident VF. For subjects with BL OVD of ≥ 20% height loss, men's and women's incident VF were 17.6% and 52.6%, respectively, counting subject and 1.68% and 7.89%, respectively, counting vertebra. CONCLUSION: Elderly men with or without existing osteoporotic VD have much lower future VF risk than elderly women.

Diagnosis and grading of radiographic osteoporotic vertebral deformity by general radiologists after a brief self-learning period.

BACKGROUND: The expanded semi-quantitative (eSQ) osteoporotic vertebral deformity (OVD) classification has minimal, mild, moderate, moderately-severe, severe, and collapsed grades with <20%, 20-25%, >25%-1/3, >1/3-40%, >40%-2/3, >2/3 vertebral height loss respectively. This study evaluates the performance of using this grading criterion by radiology readers who did not have former training in OVD assessment. METHODS: Spine radiographs of 44 elderly women with 278 normal appearing vertebrae and 65 OVDs were selected, with two senior readers agreed the reference reading. Three readers from Italy and three readers from China were invited to evaluate these radiographs after reading five reference articles including one detailing eSQ criteria with illustrative examples. Before the second round of reading, the readers were asked to read an additional explanatory document. For the readers in Italy an additional on-line demonstration was given on how to measure vertebral height loss in another five cases of OVD. Two Chinese readers had a third round of reading after a 90 minutes' on-line lecture. RESULTS: The final absolute agreement rate with the reference reading (i.e., exactly the same grading as the reference) ranged between 46.2% to 68.2% for the six readers, and the final relative agreement (with one eSQ grade difference allowed) ranged between 78.5% to 92.5%. The >1 grade disagreement rate was all below 11%, and mostly below 7%. The missed OVD were mostly minimal grade. The rate for missing a ≥ mild OVD was <4.5%, and false positive rate was generally <1.4% among the final reading. If the minimal grade was removed and the remaining gradings were converted to Genant's semi-quantitative (GSQ) grading, the mean kappa values against the reference reading for SQ grades-1,2,3 were 0.813, 0.814, and 0.916 respectively. CONCLUSIONS: This study demonstrates good performance of the six learner readers for assessing radiographic after a brief self-learning period.

Underreporting characteristics of osteoporotic vertebral fracture in back pain clinic patients of a tertiary hospital in China.

AIM: Osteoporotic vertebral compressive fractures (VCFs) â€‹are known to be commonly missed in X-rays indicated for pulmonary or heart diseases. In this study, we investigated the underreporting status of VCF in back pain clinic patients when the spine was the focus of interest. MATERIALS AND METHODS: This is a retrospective analysis of 105 female cases (mean: 72 years, range: 55-93 years) from a tertiary hospital in China (facility A, FA). The patients with back and/or leg pain were referred for a spine X-ray. The images were retrieved and transferred to a central reading facility (facility B, FB), where images were double-read by two readers experienced in evaluating osteoporotic vertebral compressive deformity (VCD)/VCF. A qualitative VCD with <20%, 20-25%, 25-40%, and >40% vertebral body height loss was recorded as minimal, mild, moderate, and severe grades, respectively. A â€‹VCD coexisted with endplate/cortex fracture (ECF) was VCF. FB readings were considered as the reference. RESULTS: There were 34 true negative cases where FA and FB had a consensus. In 7 cases with minimal VCD, 3 cases with ECF, and 7 cases with minimal or mild VCFs, the FA readings were false negative. No standalone singular moderate or severe VCD/VCF in a patient was missed in FA's reports. In 25 FA reading positive cases with multiple VCFs, one VCF was missed in 8 cases, more than one VCF was missed in 15 cases, and one additional ECF was missed in 2 cases. In 14 cases, FA and FB had VCF number agreement, with the term 'vertebral fracture' was used appropriately in FA reports. In 15 cases, FA and FB had agreement in VCF number; however, the appropriate term 'vertebral fracture' was not used in FA reports; instead the terms of 'compressive change' or 'wedging change' were used. In most VCFs, severity grading was not given in FA. In 13 VCFs where grading was reported, all were marked as 'mild', including seven mild VCFs, five moderate VCFs, and even one severe VCF. CONCLUSION: Among the patients with VCD/VCF, the false negative rate among was 23.9% (17/71), but the missed cases were all minimal or mild grades. One or more VCFs were missed in 32.4% (23/71) of the cases with multiple VCFs. Appropriate severity grading was not reported for most cases. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: The underreporting rate of osteoporotic vertebral compressive fracture in back pain clinic patients in a typical tertiary hospital setting in China compared favorably with literature reports. However, there is a general lack of awareness of vertebral endplate/cortex fracture sign and vertebral fracture severity grading, while minimal and mild VCD with endplate/cortex fracture may have clinical significance. Moreover, after one VCF is spotted in a patient, it is highly advisable to carefully check the whole spine so that multiple VCFs will not be missed.

Semi-quantitative grading and extended semi-quantitative grading for osteoporotic vertebral deformity: a radiographic image database for education and calibration.

The Genant's semi-quantitative (GSQ) criteria is currently the most used approach in epidemiology studies and clinical trials for osteoporotic vertebral deformity (OVD) evaluation with radiograph. The qualitative diagnosis with radiological knowledge helps to minimize false positive readings. However, unless there is a face-to-face training with experienced readers, it can be difficult to apply GSQ criteria by only reading the text description of Genant et al. (in 1993), even for a musculoskeletal radiologist. We propose an expanded semi-quantitative (eSQ) OVD classification with the following features: (I) GSQ grade-0.5 is noted as minimal grade (eSQ grade-1) for OVDs with height loss <20%; (II) GSQ mild grade (grade-1) is the same as eSQ mild grade (grade-2); (III) GSQ moderate grade (grade-2) is subdivided into eSQ grade-3 (moderate, >25%-1/3 height loss) and eSQ grade-4 (moderately-severe, >1/3-40% height loss); (IV) GSQ severe grade is subdivided into eSQ grade-5 (severe, >40%-2/3 height loss) and eSQ grade-6 (collapsed, with >2/3 height loss). We advocate to estimate vertebral height loss with adjacent vertebral heights as the reference (rather than using individual vertebra's posterior height as the reference). This article presents radiographs of 36 cases with OVD, together with gradings using GSQ criteria and eSQ criteria. The examples in this article can serve as teaching material or calibration database for readers who will use GSQ criteria or eSQ criteria. Our approach for quantitative measurement is explained graphically.

Recognizing osteoporotic vertebral deformity on frontal view radiograph: a cohort analysis and a pictorial review.

PURPOSE: Opportunities exist to detect osteoporotic vertebral deformities (VDs) on frontal radiograph (FR) indicated for lung or abdominal diseases, while literature have been mostly based on lateral radiograph (LR). This study analyzed the detectability of moderate and severe grades VD on FR. METHODS: There were 105 female cases (mean 72 years, range 55~93 year), who were referred for digital spine FR and LR with back and/or leg pain. The LR and FR were read, osteoporotic VDs with < 20%, 20-25%, 25-40%, and > 40% vertebral body height loss were recorded as minimal, mild, moderate, and severe grades, respectively. After a 10-month interval, only FRs were read again, and each vertebra was classified as (1) no notable VD, (2) with notable VD, and (3) ambiguous. The first reading was the reference, while the second reading was allowed to miss minimal/mild VCD and endplate/cortex fracture. RESULTS: Counting by subjects, for 98 cases, the two reading sessions had agreement, including 43 "true negative" cases and 55 true positive cases. There were two false positive cases, and five ambiguous cases. In total, 1286 vertebra were assessed, FR reading had 1126 vertebrae "true negative," 130 vertebrae true positive, one vertebra false negative, 3 vertebrae false positive, and 26 ambiguous vertebrae (65.4% being true negative and 34.6% being true positive). Most of the disagreements were associated with kyphosis or poor X-ray projection. Nineteen illustrative cases are presented graphically. CONCLUSION: Moderate and severe grades of VD are identifiable on FR as long as the involved vertebrae are clearly filmed.

Intravoxel incoherent motion derived liver perfusion/diffusion readouts can be reliable biomarker for the detection of viral hepatitis B induced liver fibrosis.

BACKGROUND: Recent two studies reported that intravoxel incoherent motion (IVIM) analysis can separate healthy livers and viral hepatitis B (VHB) induced liver fibrosis. However, in these two studies the starting b value for bi-exponential decay analysis was b =10 and 15 s/mm2 respectively. The current study has two primary aims. The first is to further confirm the diagnostic value of IVIM in detecting liver fibrosis. The second is to test whether by sampling very low b value densely, then b =0 s/mm2 image could be included to improve IVIM's diagnostic performance. METHODS: This was a prospective study with data acquired at the Third Xiangya Hospital of Central South University, Changsha, China. Healthy volunteers and patients suspected of VHB induced liver fibrosis with liver biopsy performed, as well as hepatocellular carcinoma patients scheduled for surgery, were recruited. All the hepatocellular carcinoma patients had liver fibrosis. After exclusions based on pre-defined criteria for image data quality, for IVIM analysis this study included 20 healthy volunteers; 4 chronic VHB patients with biopsy showing no liver fibrosis; 11 stage-1 liver fibrosis patients, 10 stage-2 liver fibrosis patients, 2 stage-3 liver fibrosis patients, and 5 stage-4 liver fibrosis patients. In the liver fibrosis patients, 1, 19, and 8 cases had inflammation grade-0, grade-1, and grade-2 respectively. The reference IVIM bi-exponential decay curve fitting analysis was segmented fitting performed with b =2 s/mm2 image as the starting point and a threshold-b of 60 s/mm2. This reference fitting method was compared with threshold-b of 40 s/mm2, full fitting, fitting starting from b =0, 5, and 10 s/mm2 respectively. The potential correlation between IVIM readouts and liver function was assessed for the liver fibrosis patients. RESULTS: Based on the smaller coefficient of variation (CoV) for the volunteer group and the smaller patient/volunteer ratios [= (mean measurement for patient groups)/(mean measurement for healthy volunteers)], the comparison of fitting methods favored the reference approach starting from b =2 s/mm2 with a threshold-b of 60 s/mm2. The IVIM measures of four patients without liver fibrosis resembled those of healthy subjects. PF offered the best diagnostic value for separating healthy livers and fibrotic livers, and a threshold of PF =0.1406 separated all fibrotic livers and healthy livers with an exception of one hepatocellular carcinoma patient (fibrosis grade-2/inflammation grade-2). The correlation between fibrosis grading and inflammation grading was weakly positive; while compared with fibrotic livers with inflammation grade-1, fibrotic livers with inflammation grade-2 showed a trend of higher Dfast. A weak correlation is shown with lower PF and lower Dfast associated with lower total protein, lower albumin; higher alanine transaminase, higher aspartate transaminase; higher total bilirubin, and higher direct bilirubin. CONCLUSIONS: Segmented-fitting with threshold-b =60 s/mm2 and starting from non-zero very low b value outperforms other methods. IVIM has high sensitivity in detecting liver fibrosis, and PF and Dfast have potential correlation with serum liver function biomarkers. IVIM measures and liver fibrosis grading are not in a linear relationship.

High performance of intravoxel incoherent motion diffusion MRI in detecting viral hepatitis-b induced liver fibrosis.

BACKGROUND: Recently a small cohort study demonstrated that intravoxel incoherent motion (IVIM) diffusion MRI can detect early stage liver fibrosis. Using modified IVIM data acquisition parameters, the current study aims to confirm this finding. METHODS: Twenty-six healthy volunteers, three patients of chronic viral hepatitis-b but without fibrosis and one mild liver steatosis subject, and 12 viral hepatitis-b patients with fibrosis (stage 1-2=7, stage 3-4=5) were included in this study. With a 1.5-T MR scanner and respiration-gating, IVIM diffusion imaging was acquired using a single-shot echo-planar sequence with a b-value series of 2, 0, 1, 15, 20, 30, 45, 50, 60, 80, 100, 200, 300, 600, 800 s/mm2. Signal measurement was performed on right liver parenchyma. The first three very low b-values were excluded to improve the curve fitting stability, and bi-exponential segmented fitting was performed using the 12 b-values of 15~800 s/mm2. Both threshold b-values of 60 s/mm2 and 200 s/mm2 were tested. With a 3-dimensional tool, Dslow (D), PF (f) and Dfast (D*) values were placed along the x-axis, y-axis, and z-axis, and a plane was defined to separate healthy volunteers from liver fibrosis patients. RESULTS: Threshold b-value of 60 s/mm2 was preferred over 200 s/mm2 for separating healthy volunteers and liver fibrosis patients. The IVIM measures of the four patients without fibrosis resembled those of healthy volunteers. When threshold b-value =60 s/mm2 was applied, PF (PF <6.49%) could differentiate healthy livers and all fibrotic livers with 100% sensitivity and specificity. For the patients' measurement, PF and Dfast were highly correlated with a Pearson correlation coefficient r of 0.865 (P<0.001); while the correlations between slow diffusion compartment (Dslow) and fast diffusion compartment (Dfast or PF) were not statistically significant. CONCLUSIONS: This study confirms previous report that IVIM diffusion MRI has high diagnostic performance in detecting viral hepatitis-b induced liver fibrosis.

Osteoporotic vertebral endplate and cortex fractures: A pictorial review.

Despite years' research, the radiographic criteria for osteoporotic vertebral fracture and its grading remain debated. The importance of identifying vertebral endplate/cortex fracture (ECF) is being recognised; however, evaluation of osteoporotic ECF requires training and experience. This article aims to serve as a teaching material for radiologists/physicians or researchers to evaluate osteoporotic ECF. Emphasis is particularly dedicated to identifying ECF that may not be associated with apparent vertebral body collapse. We suggest a combined approach based on standardised radiologic evaluation by experts and morphometry measurement is the most appropriate approach to detect and classify osteoporotic vertebral fractures. THE TRANSLATIONAL POTENTIAL: A good understanding of radiologic anatomy of vertebrae and fracture signs of endplate/cortex are essential for spine fragility fracture assessment.

Prevalent osteoporotic vertebral fractures more likely involve the upper endplate than the lower endplate and even more so in males.

BACKGROUND: While the importance of identifying osteoporotic vertebral endplate fracture (EPF) is being recognized; the pathophysiological understanding of EPF till now remain insufficient. In this population-based cross-sectional radiograph study, we aim to investigate the anatomic location characteristics of osteoporotic EPF. METHODS: This study analyzed the anatomical location of osteoporotic EPFs in elderly Chinese population (age ≥65 years). The T4-L4 radiographs of 1,954 elderly Chinese men (mean: 72.3 years) and 1,953 elderly Chinese women (mean: 72.5 years) were evaluated to identify EPF, and vertebral bodies were graded according to Genant's vertebral deformity criteria. RESULTS: Of the 101,582 endplates analyzed, there were 505 EPFs (males: 27.7%; females: 72.3%). Excluding those with both upper endplate and lower endplate involvements, the ratio of upper EPF to lower EPF was 9.63 for males and 4.3 for females (P<0.05). Thoracolumbar junction, particularly L1 (26.4% for males and 24.1% for females) and followed by T12 (20.7% for males and 19.7% for females), had highest prevalence of EPF. With an endplate divided into 5 segments of equal length in the anteroposterior direction and grade 0.5 & 1, grade 2 vertebral deformities analyzed, fractures occurred mostly at the middle segment (70.1% for upper endplates in males and 78.6% for upper endplates in females), followed by second anterior segment (20.9% for upper endplates in males and 14.4% for upper endplates in females). The most anterior and most posterior segments were not primarily involved in EPF. CONCLUSIONS: Osteoporotic EPFs more likely involve the upper endplate rather than lower endplate, with a trend for this effect to be greater in men than in women. These characteristics may help radiographic differential diagnosis for osteoporotic EPF.