Neurological prognosis in surgically treated acute aortic dissection with brain computed tomography perfusion.

OBJECTIVES: The aim of this study was to explore the prognostic value of brain computed tomography perfusion (CTP) for postoperative new stroke in acute type A aortic dissection (ATAAD) patients. METHODS: Patients with ATAAD and suspected cerebral malperfusion who underwent brain CTP and surgical repair were retrospectively analysed. Brain perfusion was quantified mainly with the averaged cerebral blood flow. Significant clinical and imaging findings were identified through univariable and multivariable regression analysis. Furthermore, the added prognostic benefit of perfusion parameters was confirmed with the receiver operating characteristic curves in the entire cohort and subgroup analysis. RESULTS: The incidence of postoperative new stroke was 30.8% (44/143). The independent adjusted predictors of postoperative new stroke included an impaired averaged cerebral blood flow (ml/100 ml/min) (odds ratio: 0.889; P < 0.001), severe stenosis (odds ratio: 5.218; P = 0.011) or occlusion (odds ratio: 14.697; P = 0.048) of the true lumen in common carotid artery (CCA), hypotension on admission (odds ratio: 9.644; P = 0.016) and a longer surgery time (odds ratio: 1.593; P = 0.021). The area under the receiver operating characteristic curves significantly improved after adding perfusion parameters to clinical and computed tomography angiography characteristics (P = 0.048). This benefit was more pronounced in patients with severe stenosis or occlusion in CCA true lumen (P = 0.004). CONCLUSIONS: Brain CTP could be a useful prognostic tool for surgically treated ATAAD patients and especially beneficial in patients with severe stenosis or occlusion of the CCA true lumen.

The restoration ability of a short nap after sleep deprivation on the brain cognitive function: A dynamic functional connectivity analysis.

AIMS: The brain function impairment induced by sleep deprivation (SD) is temporary and can be fully reversed with sufficient sleep. However, in many cases, long-duration recovery sleep is not feasible. Thus, this study aimed to investigate whether a short nap after SD is sufficient to restore brain function. METHODS: The data of 38 subjects, including resting state functional magnetic resonance imaging data collected at three timepoints (before SD, after 30 h of SD, and after a short nap following SD) and psychomotor vigilance task (PVT) data, were collected. Dynamic functional connectivity (DFC) analysis was used to evaluate changes in brain states among three timepoints, and four DFC states were distinguished across the three timepoints. RESULTS: Before SD, state 2 (a resting-like FC matrix) was dominant (48.26%). However, after 30 h SD, the proportion of state 2 dramatically decreased, and state 3 (still resting-like, but FCs were weakened) became dominant (40.92%). The increased proportion of state 3 positively correlated with a larger PVT "lapse" time. After a nap, the proportions of states 2 and 3 significantly increased and decreased, respectively, and the change in proportion of state 2 negatively correlated with the change in PVT "lapse" time. CONCLUSIONS: Taken together, the results indicated that, after a nap, the cognitive function impairment caused by SD may be reversed to some extent. Additionally, DFC differed among timepoints, which was also associated with the extent of cognitive function impairment after SD (state 3) and the extent of recovery therefrom after a nap (state 2).

White matter structural topologic efficiency predicts individual resistance to sleep deprivation.

BACKGROUND: Sleep deprivation (SD) is commonplace in modern society and there are large individual differences in the vulnerability to SD. We aim to identify the structural network differences based on diffusion tensor imaging (DTI) that contribute to the individual different vulnerability to SD. METHODS: The number of psychomotor vigilance task (PVT) lapses was used to classify 49 healthy subjects on the basis of whether they were vulnerable or resistant to SD. DTI and graph theory approaches were used to investigate the topologic organization differences of the brain structural connectome between SD-vulnerable and -resistant individuals. We measured the level of global efficiency and clustering in rich club and non-rich club organizations. RESULTS: We demonstrated that participants vulnerable to SD had less global efficiency, network strength, and local efficiency but longer shortest path length compared with participants resistant to SD. Lower efficiency was mainly distributed in the right insula, bilateral thalamus, bilateral frontal, temporal, and temporal lobes. Furthermore, a disrupted subnetwork was observed that consisted of widespread connections. Moreover, the vulnerable group showed significantly decreased strength of the rich club compared with the resistant group. The strength of rich club connectivity was found to be correlated negatively with PVT performance (r = -0.395, p = 0.005). We further tested the reliability of the results. CONCLUSION: The findings revealed that individual differences in resistance to SD are related to disrupted topologic efficiency connectome pattern, and our study may provide potential connectome-based biomarkers for the early detection of the vulnerable degree to SD.

Prognostic Value of Non-alcoholic Fatty Liver Disease and RCA Pericoronary Adipose Tissue CT Attenuation in Patients with Acute Chest Pain.

RATIONALE AND OBJECTIVES: Pericoronary adipose tissue (PCAT) CT attenuation of right coronary artery (RCA) and non-alcoholic fatty liver disease (NAFLD) have prognostic value for major adverse cardiovascular events (MACE) in patients with coronary artery disease. However, the superior prognostic value between RCA PCAT CT attenuation and NAFLD remains unclear in patients with acute chest pain. This study is to evaluate the prognostic value of NAFLD for MACE, and further assess the incremental prognostic value of NAFLD over PCAT CT attenuation. MATERIALS AND METHODS: Between January 2011 and December 2021, all consecutive emergency patients with acute chest pain referred for coronary CT angiography (CCTA) were retrospectively enrolled. MACE included unstable angina requiring hospitalization, coronary revascularization, non-fatal myocardial infarction, and all-cause death. Patients' baseline and CCTA characteristics, RCA PCAT CT attenuation, and the presence of NAFLD were used to evaluate risk factors of MACE using multivariable Cox regression analysis. The prognostic value of NAFLD compared to RCA PCAT CT attenuation was analyzed. RESULTS: A total of 514 patients were enrolled (mean age, 58.36 ± 13.05 years; 310 men). During a median follow-up of 31 months, 60 patients (11.67%) experienced MACE. NAFLD (HR = 2.599, 95% CI: 1.207, 5.598, P = 0.015) and RCA PCAT CT attenuation (HR = 1.026, 95% CI: 1.001, 1.051, P = 0.038) were independent predictors of MACE. The global Chi-square analysis showed that NAFLD improved the risk of MACE more than that using clinical risk factors and CCTA metrics (59.51 vs 54.44, P = 0.024) or combined with RCA PCAT CT attenuation (63.75 vs 59.51, P = 0.040). CONCLUSION: NAFLD and RCA PCAT CT attenuation were predictors of MACE. NAFLD had an incremental prognostic value beyond RCA PCAT CT attenuation for MACE in patients with acute chest pain. Adding CT-FFR into the risk prediction of patients with acute chest pain is worth considering.

Structural abnormalities in the Fronto-Parietal Network: Linking white matter integrity to sustained attention deficits in Schizophrenia.

Schizophrenia is associated with a range of cognitive deficits, among which impairments in sustained attention are particularly significant. Previous research has investigated functional changes in the fronto-parietal network (FPN) related to attentional control in schizophrenia. However, the role of structural connectivity within the FPN in sustained attention deficits remains under-explored. Utilizing diffusion tensor imaging (DTI), this study investigated white matter integrity in 75 participants, comprising 37 individuals with schizophrenia (SZ) and 38 healthy controls (HC). Psychomotor vigilance task (PVT) performance was assessed to gauge sustained attention. The SZ group showed a significant reduction in fractional anisotropy (FA) and streamline counts within white matter tracts connecting frontal and parietal regions, compared to the HC group. Further, significant negative correlations were found between PVT performance and white matter integrity measures within the SZ group, specifically in the left FPN. Our findings indicate that structural abnormalities in the FPN are associated with sustained attention deficits in schizophrenia. These results contribute to our understanding of the neurobiological mechanisms underlying cognitive impairments in schizophrenia and offer potential avenues for targeted therapeutic interventions. Further research is warranted to validate these outcomes and explore their clinical implications.

Association of Objective Sleep Characteristics and Incident Angina Pectoris: A Longitudinal Analysis from the Sleep Heart Health Study.

Purpose: While prior research has highlighted a significant association between sleep characteristics and angina pectoris (AP) incidence, the link between sleep efficiency (SE) and angina remains unexplored. This study seeks to elucidate the relationship between AP and objectively quantified SE. Patients and Methods: We examined a cohort of 2990 participants (1320 males and 1670 females; mean age 63.69 ± 13.2 years) from the Sleep Heart Health Study. The main exposure variable was SE, as determined by baseline home polysomnography, while the primary outcome was the first incidence of angina pectoris (AP) during the period between the baseline polysomnography and the end of follow-up. A multivariate Cox regression model was utilized, controlling for factors such as age, gender, BMI, smoking and alcohol consumption habits, diabetes, hypertension, sleep duration, triglycerides, cholesterol, high-density lipoprotein, apnea-hypopnea index, nocturnal oxygen saturation, to analyze the relationship between SE and AP. Results: During an average follow-up of 11 years, 284 patients developed AP. The unadjusted Kaplan-Meier analysis identified the 2nd quartile of SE as having the lowest AP risk. The multivariate Cox proportional hazards model demonstrated a higher risk of AP in quartile 1 (HR, 1.679; 95% CI, 1.109-2.542; P <0.014) and quartile 3 (HR, 1.503; 95% CI, 1.037-2.179; P <0.031), compared to quartile 2 of SE. Upon stratified analysis, this relationship was particularly pronounced in hypertensive individuals. Conclusion: Our results highlight the critical role of optimal sleep efficiency in mitigating the risk of angina pectoris, especially among hypertensive individuals.

Cognitive impairment after sleep deprivation: The role of precuneus related connectivity on the intra-individual variability changes.

OBJECTIVE: Intra-individual variability (IIV) in cognitive performance is thought to reflect the efficiency with which attentional resources are allocated in different circumstances requiring cognitive control. IIV in cognitive performance is associated with the strength of the negative correlation between task-positive network and default mode network (DMN) activity. In this study, we investigated the impact of sleep deprivation (SD) on functional connectivity (FC) between the DMN and psychomotor vigilance task-related network (PVT-RN), and its relationship with IIV in cognitive performance. METHODS: Two analyses, network-level independent component analysis (NL-ICA) and region-level (RL)-ICA, were employed to compare the coefficient of variation (CV) of the PVT between normal sleep and SD conditions across 67 healthy participants. RESULTS: After SD, in NL-ICA, the FC between the PVT-RN and DMN was positively correlated with the CV of the PVT, as well as the changes therein, compared with normal sleep. Using a mask derived from the DMN and PVT-RN, the RL-ICA revealed that 12 edges/connections between DMN and PVT independent components were associated with the CV of the PVT, with nine of these connections involving the precuneus. CONCLUSIONS: These findings suggest that the precuneus may play a crucial role in the interactions of various brain functions during the PVT, with the connections between the precuneus and frontoparietal and somatosensory networks being significantly altered after SD. Moreover, following SD, weakened negative FC between the precuneus and bilateral inferior parietal lobule may disrupt the balance between cognitive and executive control functions, leading to a decline in cognitive performance.

Risk prediction of preoperative acute ischemic stroke in acute type A aortic dissection.

OBJECTIVES: To predict preoperative acute ischemic stroke (AIS) in acute type A aortic dissection (ATAAD). METHODS: In this multi-center retrospective study, 508 consecutive patients diagnosed as ATAAD between April 2020 and March 2021 were considered for inclusion. The patients were divided into a development cohort and two validation cohorts based on time periods and centers. Clinical data and imaging findings obtained were analyzed. Univariable and multivariable logistic regression analyses were performed to identify predictors associated with preoperative AIS. The performance of resulting nomogram was evaluated in discrimination and calibration on all cohorts. RESULTS: A total of 224 patients were in the development cohort, 94 in the temporal validation cohort, and 118 in the geographical validation cohort. Six predictors were identified: age, syncope, D-dimer, moderate to severe aortic valve insufficiency, diameter ratio of true lumen in ascending aorta < 0.33, and common carotid artery dissection. The nomogram established showed good discrimination (area under the receiver operating characteristic curve [AUC], 0.803; 95% CI: 0.742, 0.864) and calibration (Hosmer-Lemeshow test p = 0.300) in the development cohort. External validation showed good discrimination and calibration abilities in both temporal (AUC, 0.778; 95% CI: 0.671, 0.885; Hosmer-Lemeshow test p = 0.161) and geographical cohort (AUC, 0.806; 95% CI: 0.717, 0.895; Hosmer-Lemeshow test p = 0.100). CONCLUSIONS: A nomogram, based on simple imaging and clinical variables collected on admission, showed good discrimination and calibration abilities in predicting preoperative AIS for ATAAD patients. KEY POINTS: • A nomogram based on simple imaging and clinical findings may predict preoperative acute ischemic stroke in patients with acute type A aortic dissection in emergencies. • The nomogram showed good discrimination and calibration abilities in validation cohorts.

Functional Connectivity Alterations During Sleep Deprivation: Investigating Key Brain Regions and Networks.

BACKGROUND: Sleep deprivation (SD) has emerged as a significant public health concern because of its adverse effects on cognition and behavior. However, the influence of circadian rhythms on SD and brain activities has been less studied. This study employed functional magnetic resonance imaging (fMRI) and functional connectivity density (FCD) metrics to investigate the interaction between sleep pressure and circadian rhythms during SD. METHODS: Thirty-six volunteers with good sleep habits underwent a sleep deprivation trial. Sleepiness was assessed using the Stanford Sleepiness Scale (SSS) at multiple time points, and fMRI scans were conducted to derive global and local FCD (gFCD and iFCD) values. This study focused on specific brain regions and networks, including the thalamus, the frontoparietal network (FPN), and the default mode network (DMN). RESULTS: Analysis indicated significant changes in gFCD and iFCD values in several key brain regions. A strong correlation was found between sleepiness and both gFCD and iFCD values in certain areas, such as the left superior temporal gyrus and left thalamus. The gFCD values in these regions showed a gradual increase across sessions, while iFCD values in the right superior frontal gyrus decreased. CONCLUSIONS: This study revealed that SD leads to enhanced functional activities in the DMN and thalamus and decreased activity in the FPN. These changes in brain activity were significantly correlated with increases in sleepiness, as measured by the SSS. Our findings underscore the importance of understanding the neural underpinnings of SD and could guide future clinical interventions aimed at mitigating its effects.

Predicting Attentional Vulnerability to Sleep Deprivation: A Multivariate Pattern Analysis of DTI Data.

Background: Large individual differences exist in sleep deprivation (SD) induced sustained attention deterioration. Several brain imaging studies have suggested that the activities within frontal-parietal network, cortico-thalamic connections, and inter-hemispheric connectivity might underlie the neural correlates of vulnerability/resistance to SD. However, those traditional approaches are based on average estimates of differences at the group level. Currently, a neuroimaging marker that can reliably predict this vulnerability at the individual level is lacking. Methods: Efficient transfer of information relies on the integrity of white matter (WM) tracts in the human brain, we therefore applied machine learning approach to investigate whether the WM diffusion metrics can predict vulnerability to SD. Forty-nine participants completed the psychomotor vigilance task (PVT) both after resting wakefulness (RW) and after 24 h of sleep deprivation (SD). The number of PVT lapse (reaction time > 500 ms) was calculated for both RW condition and SD condition and participants were categorized as vulnerable (24 participants) or resistant (25 participants) to SD according to the change in the number of PVT lapses between the two conditions. Diffusion tensor imaging were acquired to extract four multitype WM features at a regional level: fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity. A linear support vector machine (LSVM) learning approach using leave-one-out cross-validation (LOOCV) was performed to assess the discriminative power of WM features in SD-vulnerable and SD-resistant participants. Results: LSVM analysis achieved a correct classification rate of 83.67% (sensitivity: 87.50%; specificity: 80.00%; and area under the receiver operating characteristic curve: 0.85) for differentiating SD-vulnerable from SD-resistant participants. WM fiber tracts that contributed most to the classification model were primarily commissural pathways (superior longitudinal fasciculus), projection pathways (posterior corona radiata, anterior limb of internal capsule) and association pathways (body and genu of corpus callosum). Furthermore, we found a significantly negative correlation between changes in PVT lapses and the LSVM decision value. Conclusion: These findings suggest that WM fibers connecting (1) regions within frontal-parietal attention network, (2) the thalamus to the prefrontal cortex, and (3) the left and right hemispheres contributed the most to classification accuracy.

Application value of magnetic resonance hydrography of the inner ear in cochlear implantation.

OBJECTIVE: This study aims to investigate the application value of magnetic resonance (MR) hydrography of the inner ear in cochlear implantation. METHODS: 146 patients were enrolled. MR hydrography and spiral CT examinations for the intracranial auditory canal were performed before surgery, and all imaging results were statistically analyzed in order to explore the application value of MR hydrography of the inner ear in cochlear implantation. RESULTS: 146 patients (292 ears) were examined. Among these patients, 13 were diagnosed with abnormal vestibular aqueducts (20 ears) by MR hydrography, while five were diagnosed with this disease by CT; 15 patients were diagnosed with inner ear malformation (19 ears) by MR hydrography, while 11 were diagnosed by CT (four were misdiagnosed); five patients were diagnosed with internal acoustic canal stenosis (eight ears) by MR hydrography, while two were diagnosed by CT (three were misdiagnosed); and four patients were diagnosed with cochlear fibrosis (five ears) by MR hydrography, while four were diagnosed by CT (four ears). The correct rate of diagnosis was 77.40% (113/146) based on CT, while the rate was 93.84% (137/146) based on MR hydrography. CONCLUSIONS: MR hydrography imaging technique can be applied to the preoperative evaluation of cochlear implantation, providing accurate and reliable anatomic information on the inner membranous labyrinth and nerves in the internal acoustic canal and an accurate basis for the diagnosis of cochlear fibrosis and nerve development. This has a guiding significance for the selection of treatment schemes.

Application value of magnetic resonance hydrography of the inner ear in cochlear implantation

SUMMARY OBJECTIVE This study aims to investigate the application value of magnetic resonance (MR) hydrography of the inner ear in cochlear implantation. METHODS 146 patients were enrolled. MR hydrography and spiral CT examinations for the intracranial auditory canal were performed before surgery, and all imaging results were statistically analyzed in order to explore the application value of MR hydrography of the inner ear in cochlear implantation. RESULTS 146 patients (292 ears) were examined. Among these patients, 13 were diagnosed with abnormal vestibular aqueducts (20 ears) by MR hydrography, while five were diagnosed with this disease by CT; 15 patients were diagnosed with inner ear malformation (19 ears) by MR hydrography, while 11 were diagnosed by CT (four were misdiagnosed); five patients were diagnosed with internal acoustic canal stenosis (eight ears) by MR hydrography, while two were diagnosed by CT (three were misdiagnosed); and four patients were diagnosed with cochlear fibrosis (five ears) by MR hydrography, while four were diagnosed by CT (four ears). The correct rate of diagnosis was 77.40% (113/146) based on CT, while the rate was 93.84% (137/146) based on MR hydrography. CONCLUSIONS MR hydrography imaging technique can be applied to the preoperative evaluation of cochlear implantation, providing accurate and reliable anatomic information on the inner membranous labyrinth and nerves in the internal acoustic canal and an accurate basis for the diagnosis of cochlear fibrosis and nerve development. This has a guiding significance for the selection of treatment schemes.

RESUMO OBJETIVO Este estudo visa investigar o valor da aplicação da hidrografia por ressonância magnética (RM) do ouvido interno no implante coclear. MÉTODOS Cento e quarenta e seis pacientes foram inscritos. Os exames da hidrografia por RM e do CT espiral para o canal auditivo intracraniano foram executados antes da cirurgia, e todos os resultados da imagem foram analisados estatisticamente, a fim de explorar o valor da aplicação da hidrografia por RM do ouvido interno no implante coclear. RESULTADOS Centro e quarenta e seis pacientes (292 ouvidos) foram examinados. Dentre esses pacientes, 13 foram diagnosticados com aquedutos vestibulares anormais (20 ouvidos) pela hidrografia por RM, enquanto cinco pacientes foram diagnosticados com esta doença pelo CT; 15 pacientes foram diagnosticados com malformação do ouvido interno (19 ouvidos) pela hidrografia por RM, enquanto 11 pacientes foram diagnosticados por CT (quatro foram diagnosticados erroneamente); cinco pacientes foram diagnosticados com estenose de canal acústico interno (oito ouvidos) pela hidrografia por RM, enquanto dois pacientes foram diagnosticados por CT (três foram diagnosticados erroneamente); e quatro pacientes foram diagnosticados com fibrose coclear (cinco ouvidos) pela hidrografia por RM, enquanto quatro foram diagnosticados por CT (quatro ouvidos). A taxa correta de diagnóstico foi de 77,40% (113/146) com base no CT, enquanto a taxa foi de 93,84% (137/146) com base na hidrografia por RM. CONCLUSÕES A técnica de imagem da hidrografia por RM pode ser aplicada à avaliação pré-operatória do implante coclear, que pode fornecer informações anatômicas precisas e confiáveis sobre o labirinto membranoso interno e os nervos no canal acústico interno, além de uma base exata para o diagnóstico da fibrose coclear e do desenvolvimento do nervo. Isso tem um significado orientador para a seleção de esquemas de tratamento.

Decreased Regional Cerebral Perfusion at Resting State in Acute Posttraumatic Stress Disorder Resulting From a Single, Prolonged Stress Event.

RATIONALE AND OBJECTIVES: This study evaluated the altered regional cerebral blood flow (rCBF) in resting state in patients with acute posttraumatic stress disorder (PTSD) 3 months after trauma. MATERIALS AND METHODS: The rCBF was measured in 30 patients with acute PTSD and 36 healthy controls. RESULTS: Survivors with acute PTSD showed decreased rCBF, the Clinician-Administered PTSD Scale score correlated negatively with the rCBF, and rCBF at resting state decreased in acute PTSD. CONCLUSIONS: PTSD symptom severity was associated with diminished cerebral blood flow in the right insular cortex and right orbital medial frontal gyrus. The rCBF may predict PTSD symptom severity.

Rosette-forming glioneuronal tumor in the pineal gland and the third ventricle: a case with radiological and clinical implications.

A 39-year-old man presented with more than 20 years history of episodic headache and one year history of dizziness, impaired vision and memory disorders. Computed tomography and Magnetic resonance imaging revealed a cystic mass involving the pineal gland, tectum and the third ventricle and obstruction of the aqueduct. Interestingly, the fourth ventricle was not involved in this case. The pathological diagnosis was rosette forming glioneuronal tumor (RGNT). These lesions are considered low-grade tumors (WHO grade I). We describe here the fifth reported patient with a pineal gland RGNT and the eighth reported patient with a RGNT outside the fourth ventricle.

Association of TAP1 and TAP2 polymorphisms with the outcome of persistent HBV infection in a northeast Han Chinese population.

OBJECTIVE: Transporter associated with antigen processing (TAP) plays a central role in a cellular immune response against HBV. Polymorphisms exist at the coding region of TAP and alter its structure and function. The aim of this study was to evaluate the potential relationship between polymorphisms of TAP and different outcomes of persistent HBV infection in a Han population in northeastern China. MATERIAL AND METHODS: 189 HBV spontaneously recovered (SR) subjects, 571 HBV-infected patients including 180 chronic hepatitis B (CHB), 196 liver cirrhosis (LC) and 195 hepatocellular carcinoma (HCC) individuals were included in this study. TAP1-333 Ile/Val and -637 Asp/Gly, TAP2-651 Arg/Cys and -687 Stop/Gln were genotyped in all the samples by using a PCR-RFLP method. RESULTS: The frequency of TAP1-637-Gly (allele G) was significantly higher in persistently HBV-infected individuals (CHB and LC) than that of SR subjects (OR = 1.58, 95% CI 1.12-2.45, p = 0.024; OR = 1.78, 95% CI 1.27-2.68, p = 0.002) by a logistic regression analysis. In addition, the statistically significant difference in the distribution of TAP2-651-Cys (allele T) was observed between HCC cases and SR controls (OR = 2.30, 95% CI 1.51-3.72, p < 0.001), and TAP2-687-Gln (allele C) in CHB patients was more common than that in SR subjects (OR = 1.41, 95% CI 1.13-1.97, p = 0.021). The data also revealed that haplotype 687 Gln-651 Cys-637 Gly-333 Ile was strongly associated with persistent HBV infection (CHB, LC and HCC) (p < 0.001, < 0.05 and < 0.001, respectively). CONCLUSION: These results suggested that TAP variants were likely to play a substantial role in different outcomes of persistent HBV infection in the studied population.

Combined T2-weighted and diffusion-weighted MRI for diagnosis of urinary bladder invasion in patients with prostate carcinoma.

PURPOSE: To retrospectively determine the diffusion-weighted imaging (DWI) characteristics and apparent diffusion coefficient (ADC) values of prostate carcinoma (PCa) with urinary bladder invasion, and to compare the accuracy of T2-weighted MRI alone and T2 combined with DWI for predicting urinary bladder invasion. MATERIALS AND METHODS: Sixty-eight patients with proven PCa were diagnosed with urinary bladder invasion after conventional magnetic resonance imaging (MRI) and DWI (b value = 750 sec/mm(2)) examinations. All the 68 cases underwent cystoscopy examination. DWI appearances of all urinary bladder invasion and a normal urinary bladder wall were analyzed, and their ADC values were measured. T2 images alone and then T2 images combined with DWI were scored for the likelihood of urinary bladder invasion on the basis of radiologists' written reports. The area under the receiver operating characteristic curve (AUC) was used to assess accuracy. Statistical significance was inferred at P < 0.05. RESULTS: After cystoscopy examination, 45 (66%) of 68 cases were pathologically proven urinary bladder invasion. The mean ADCs for urinary bladder invasion and normal urinary bladder wall were (0.963 +/- 0.155) x 10(-3)mm(2)/sec and (1.517 +/- 0.103) x 10(-3)mm(2)/sec, respectively. The ADC values of urinary bladder invasion were significantly lower than those of normal urinary bladder wall (P = 0.000). The AUC for T2-weighted imaging plus DW imaging (0.861) was significantly larger than that for T2-weighted imaging alone (0.734) or for DW imaging alone (0.703) (P < 0.001). CONCLUSION: Urinary bladder invasion had lower ADC values compared with normal urinary bladder wall. T2 images plus DWI is significantly better than T2-weighted imaging alone in the detection of urinary bladder invasion in patients with PCa.

Seminal vesicle invasion in prostate cancer: prediction with combined T2-weighted and diffusion-weighted MR imaging.

The aim of this study was to evaluate the usefulness of diffusion-weighted imaging (DWI) in detecting seminal vesicle invasion (SVI). A total of 283 patients underwent conventional MRI and DWI before prostate cancer surgery. The apparent diffusion coefficient (ADC) values of all PCa foci, SVI and seminal vesicle were measured. T2 images alone and then T2 images combined with DWI were scored for the likelihood of SVI. The area under the receiver operating characteristic curve (AUC) was used to assess accuracy. Statistical significance was inferred at P < 0.05. On pathological analysis, 39 patients had SVI. The ADC values of SVI were significantly lower than those of SV. The AUC for T2-weighted imaging plus DW imaging (0.897) was significantly larger (P < 0.05) than that for T2-weighted imaging alone (0.779). T2 images combined with DWI shows significantly higher accuracy than T2-weighted imaging alone in the detection of SVI.

Normalized upper cervical spinal cord atrophy in multiple sclerosis.

BACKGROUND AND PURPOSE: To find an optimal normalizing factor for upper cervical spinal cord area (UCCA) and to establish whether, in a cross-sectional study, the normalized UCCA correlates better with the neurological disability than the absolute measurement in multiple sclerosis patients. METHODS: UCCA and three potential normalizing factors were estimated from magnetic resonance imaging data in 51 control subjects. Their reliability was assessed and the linear relationships between UCCA and three potential correction factors were investigated. UCCA was then normalized by these factors respectively. On the basis of these results, an optimal factor was selected and applied to 29 MS subjects. RESULTS: An extremely strong correlation between UCCA and LECA was seen (r= .88, P < .01). The coefficient of variation (COV) of UCCA was reduced to 4.4% from 9.3% after correction by LECA. The normalized measurement of UCCA correlated better with the expanded disability status scale (EDSS) than the absolute measurement especially in relapsing-remitting multiple sclerosis patients. Moreover, more spinal cord atrophy was identified in corrected data than uncorrected data. CONCLUSION: Our findings suggest that LECA is an optimal correction factor for UCCA and normalized UCCA is preferable to absolute measurement in cross-sectional study.

Diffusion-weighted imaging in normal prostate and differential diagnosis of prostate diseases.

BACKGROUND: During the past several years, the morbidities of prostate diseases have increased sharply all over the world. Diffusion-weighted imaging (DWI) is an MR-based technique that probes the function of tissues. We attempt to investigate the diagnostic value of DWI and apparent diffusion coefficient (ADC) in normal prostate gland and prostate diseases. MATERIALS AND METHODS: A total of 16 healthy volunteers, 9 prostate cysts, 29 benign prostatic hyperplasia (BPH), and 21 prostatic carcinoma (Pca) underwent DWI, respectively. Their DWI and ADC characteristics were analyzed, and the diagnostic and differential diagnostic values of DWI and ADC were summarized. All of the BPH and Pca received a histological diagnosis. RESULTS: In DWI, the signal intensity of BPH nodule was nonhomogeneous and lower than that of the peripheral zone (PZ). Pca showed high signal intensity while the prostate cyst showed low intensity. The mean ADCs for the normal central gland, PZ, prostate cyst, BPH nodules, and Pca foci were (1.352 +/- 0.052) x 10(-3 )mm(2)/s, (1.829 +/- 0.071) x 10(-3 )mm(2)/s, (2.557 +/- 0.084) x 10(-3 )mm(2)/s, (1.576 +/- 0.101) x 10(-3 )mm(2)/s, and (0.934 +/- 0.166) x 10(-3 )mm(2)/s, respectively (P = 0.000). CONCLUSIONS: Diffusion-weighted imaging and ADCs for the normal central gland, PZ, prostate cyst, BPH nodules, and Pca demonstrate significant differences, and those can be used in the diagnosis and differential diagnosis of the diseases of prostate.