Artificial intelligence to predict T4 stage of pancreatic ductal adenocarcinoma using CT imaging.

BACKGROUND: The accurate assessment of T4 stage of pancreatic ductal adenocarcinoma (PDAC) has consistently presented a considerable difficulty for radiologists. This study aimed to develop and validate an automated artificial intelligence (AI) pipeline for the prediction of T4 stage of PDAC using contrast-enhanced CT imaging. METHODS: The data were obtained retrospectively from consecutive patients with surgically resected and pathologically proved PDAC at two institutions between July 2017 and June 2022. Initially, a deep learning (DL) model was developed to segment PDAC. Subsequently, radiomics features were extracted from the automatically segmented region of interest (ROI), which encompassed both the tumor region and a 3 mm surrounding area, to construct a predictive model for determining T4 stage of PDAC. The assessment of the models' performance involved the calculation of the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity. RESULTS: The study encompassed a cohort of 509 PDAC patients, with a median age of 62 years (interquartile range: 55-67). The proportion of patients in T4 stage within the model was 16.9%. The model achieved an AUC of 0.849 (95% CI: 0.753-0.940), a sensitivity of 0.875, and a specificity of 0.728 in predicting T4 stage of PDAC. The performance of the model was determined to be comparable to that of two experienced abdominal radiologists (AUCs: 0.849 vs. 0.834 and 0.857). CONCLUSION: The automated AI pipeline utilizing tumor and peritumor-related radiomics features demonstrated comparable performance to that of senior abdominal radiologists in predicting T4 stage of PDAC.

Quantitative Dixon and intravoxel incoherent motion diffusion magnetic resonance imaging parameters in lumbar vertebrae for differentiating aplastic anemia and acute myeloid leukemia.

Objective: We sought to evaluate the use of quantitative Dixon (Q-Dixon) and intravoxel incoherent motion diffusion imaging (IVIM) for the differential diagnosis of aplastic anemia (AA) and acute myeloid leukemia (AML). Methods: Between August 2021 and October 2023, we enrolled 68 diagnosed patients, including 36 patients with AA and 32 patients with AML, as well as 26 normal controls. All patients underwent 3-Tesla magnetic resonance imaging, which included IVIM and T2*-corrected Q-Dixon imaging at the L2-4 level. The iliac crest biopsy's pathology was used as the diagnostic criterion. The interobserver measurement repeatability was evaluated using the intraclass correlation coefficient (ICC). One-way analysis of variance, Spearman analysis, and receiver operating characteristic curve analysis were used. Results: The fat fraction (FF) and perfusion fraction (f) values were statistically significantly different between the three groups (p < 0.001 and p = 0.007). The FF and f values in the AA group were higher than those in the AML group. The true apparent diffusion coefficient (D) value was substantially negatively correlated to the FF and R2* values (r = -0.601, p < 0.001; r = -0.336, p = 0.002). The f value was positively correlated with both FF and pseudo-apparent diffusion coefficient (D*) values (r = 0.376, p < 0.001; r = 0.263, p = 0.017) and negatively correlated with the D value (r = -0.320, p = 0.003). The FF and f values were negatively correlated with the degree of myelodysplasia (r = -0.597, p < 0.001; r = -0.454, p = 0.004), and the D value was positively correlated with the degree of myelodysplasia (r = 0.395, p = 0.001). For the differential diagnosis of AA and AML, the Q-Dixon model's sensitivity (93.75%) and specificity (84%) confirmed that it outperformed the IVIM model. Conclusion: Q-Dixon parameters have the potential to be used as new biomarkers to differentiate AA from AML.

Segmental disturbance of white matter microstructure in predicting mild cognitive impairment in idiopathic Parkinson's disease: An individualized study based on automated fiber quantification tractography.

PURPOSE: The neurobiological mechanisms and an early identification of MCI in idiopathic Parkinson's disease (IPD) remain unclear. To investigate the abnormalities of types of white matter (WM) fiber tracts segmentally and establish reliable indicator in IPD-MCI. METHODS: Forty IPD with normal cognition (IPD-NCI), thirty IPD-MCI, and thirty healthy controls were included. Automated fiber quantification was applied to extract the fractional anisotropy (FA) and mean diffusivity (MD) values at 100 locations along the major fibers. Partial correlation was performed between diffusion values and cognitive performance. Furthermore, machine learning analyses were conducted to determine the imaging biomarker of MCI. Permutation tests were performed to evaluate the pointwise differences under the FWE correction. RESULTS: IPD-MCI had similar but more severe and widespread WM degeneration in the association, projection, and commissural fibers compared with IPD-NCI. Meanwhile, IPD-MCI showed distinct degeneration pattern in the association fibers. The FA of the anterior segment of right inferior fronto-occipital fasciculus (IFOF) was positively correlated with MoCA (P < 0.05) and executive function (P < 0.05). The MD of the middle and posterior segment of left superior longitudinal fasciculus (SLF) was negatively correlated with MoCA P < 0.05), executive (P < 0.05), visuospatial function (P < 0.05). Furthermore, the AUC of support vector machine model was 0.80 in the validation dataset. The FA of anterior segment of right IFOF contribute the most. CONCLUSION: This study demonstrated that regional tract-specific microstructural degeneration, especially the association fibers, can be used to predict MCI in IPD. Especially, the right IFOF may be a significant imaging biomarker in predicting IPD with MCI.

Multimodal striatal neuromarkers in distinguishing parkinsonian variant of multiple system atrophy from idiopathic Parkinson's disease.

AIMS: To develop an automatic method of classification for parkinsonian variant of multiple system atrophy (MSA-P) and Idiopathic Parkinson's disease (IPD) in early to moderately advanced stages based on multimodal striatal alterations and identify the striatal neuromarkers for distinction. METHODS: 77 IPD and 75 MSA-P patients underwent 3.0 T multimodal MRI comprising susceptibility-weighted imaging, resting-state functional magnetic resonance imaging, T1-weighted imaging, and diffusion tensor imaging. Iron-radiomic features, volumes, functional and diffusion scalars of bilateral 10 striatal subregions were calculated and provided to the support vector machine for classification RESULTS: A combination of iron-radiomic features, function, diffusion, and volumetric measures optimally distinguished IPD and MSA-P in the testing dataset (accuracy 0.911 and area under the receiver operating characteristic curves [AUC] 0.927). The diagnostic performance further improved when incorporating clinical variables into the multimodal model (accuracy 0.934 and AUC 0.953). The most crucial factor for classification was the functional activity of the left dorsolateral putamen. CONCLUSION: The machine learning algorithm applied to multimodal striatal dysfunction depicted dorsal striatum and supervening prefrontal lobe and cerebellar dysfunction through the frontostriatal and cerebello-striatal connections and facilitated accurate classification between IPD and MSA-P. The dorsolateral putamen was the most valuable neuromarker for the classification.

Identifying and validating subtypes of Parkinson's disease based on multimodal MRI data via hierarchical clustering analysis.

Objective: We wished to explore Parkinson's disease (PD) subtypes by clustering analysis based on the multimodal magnetic resonance imaging (MRI) indices amplitude of low-frequency fluctuation (ALFF) and gray matter volume (GMV). Then, we analyzed the differences between PD subtypes. Methods: Eighty-six PD patients and 44 healthy controls (HCs) were recruited. We extracted ALFF and GMV according to the Anatomical Automatic Labeling (AAL) partition using Data Processing and Analysis for Brain Imaging (DPABI) software. The Ward linkage method was used for hierarchical clustering analysis. DPABI was employed to compare differences in ALFF and GMV between groups. Results: Two subtypes of PD were identified. The "diffuse malignant subtype" was characterized by reduced ALFF in the visual-related cortex and extensive reduction of GMV with severe impairment in motor function and cognitive function. The "mild subtype" was characterized by increased ALFF in the frontal lobe, temporal lobe, and sensorimotor cortex, and a slight decrease in GMV with mild impairment of motor function and cognitive function. Conclusion: Hierarchical clustering analysis based on multimodal MRI indices could be employed to identify two PD subtypes. These two PD subtypes showed different neurodegenerative patterns upon imaging.

Rapid quantification of global brain volumetry and relaxometry in patients with multiple sclerosis using synthetic magnetic resonance imaging.

Background: Early pathologic studies have reported that focal areas of gray lesions in the cortex and other gray matter (GM) regions are important in multiple sclerosis (MS) patients. Quantitative magnetic resonance imaging (qMRI) can provide more specific insight into the disease process, progression, and therapeutic response of MS. The purpose of this study was to quantitatively assess the changes of global GM volumetry and relaxometry information simultaneously in MS patients using synthetic MRI. Methods: All MS patients and healthy controls (HCs) were recruited. The Expanded Disability Status Scale (EDSS) scores were obtained from all patients to evaluate the disability progression. Volumetry and relaxometry of the global brain and regional GM were obtained. The quantitative parameters between MS patients and HCs were compared using an analysis of covariance (ANCOVA). The Pearson correlation assessed the correlations between the quantitative parameters and EDSS, illness duration, education in MS patients. Results: Thirty-five MS patients and fifty-two age-matched HCs were enrolled in this prospective case-control study. The global volumetry including white matter volume (WMV), myelin volume (MYV), and brain parenchymal volume (BPV) were all significantly lower in MS patients (WMV: 613.120±65.388 vs. 579.903±68.432 mL; MYV: 151.883±22.766 vs. 192.457±27.381 mL; BPV: 1,136.771±106.126 vs. 1,276.712±107.368 mL), as well as a higher cerebral spinal fluid volume (CSFV) (241.294±81.805 vs. 177.017±39.729 mL) in MS patients than those in HCs. Similarly, brain parenchymal fraction (BPF) and myelin fraction (MYF) were significantly lower in MS patients (BPF: 82.623±5.368 vs. 87.85±2.392 mL; MYF: 11.034±1.529 vs. 13.231±1.465 mL). For regional GM volumetry, multiple regions of MS patients were significantly smaller than those of HCs (P<0.01, corrected). For regional GM relaxometry, the T1, T2, and PD values of multiple regions showed significant differences. Conclusions: These findings suggest that MS patients had global and regional brain volumetry and relaxometry alterations, and the synthetic MRI-derived parameters may be potentially used as specific quantitative markers for the clinic to improve the understanding of MS.

Unilaterally disrupted structural and functional connectivity of the fronto-limbic system in idiopathic hypogonadotropic hypogonadism.

OBJECTIVE: Idiopathic hypogonadotropic hypogonadism (IHH) is rare and can either be associated with normal or defective olfactory sensation, classified as normosmic IHH (nIHH) or Kallmann syndrome (KS). We do not yet understand the central processing pathways in the olfactory system. We aimed to compare the resting-state structural and functional connectivity (FC) of olfactory neural pathways in patients with IHH. We hypotheses that alterations of structural connectivity and FC may exist in the olfactory cortex pathways in IHH patients. DESIGN: STRUCTURAL AND FUNCTIONAL CONNECTIVITY DATA RESULTS BETWEEN TWO GROUPS WERE ANALYZED: Patients: Twenty-five IHH patients (13 nIHH patients and 12 KS patients) were recruited from the Department of Endocrinology and were assessed. A total of 25 age-matched healthy male controls were recruited from the community. MEASUREMENTS: All subjects underwent diffusion tensor imaging and functional magnetic resonance imaging (fMRI) scans. Structural and functional connectivity data analyses were then performed. Pearson's correlation analyses were performed to investigate the correlations between the fractional anisotropy (FA) value and FC strength, showing significant differences among the three groups separately. RESULTS: Compared with the HC group, FA value in the right uncinate fasciculus (UF) decreased significantly in the IHH group. The olfactory cortex FC values of the right gyrus rectus, orbitofrontal cortex (OFC) and right middle temporal gyrus in the IHH group were decreased compared with those in the HC group. Moreover, there were significant negative correlations between right UF FA and olfactory cortex-FC to both the gyrus rectus and OFC within the HC group (p < .05). CONCLUSION: Our findings suggest that alterations of structural and FC support the presence of neurobiological disruptions in IHH patients, particularly a specific structural-functional asymmetry disruption may exist in the olfactory cortex pathways in IHH patients.

Differentiation Between Lipomas and Atypical Lipomatous Tumors of the Extremities Using Radiomics.

BACKGROUND: The differentiation of soft tissue lipomas from atypical lipoma tumors (ALTs) of the extremities is important because of the distinction of the cytogenetic profiles and the treatment decisions. PURPOSE: To investigate a radiomics method to differentiate between lipomas and ALTs of the extremities. STUDY TYPE: Retrospective. POPULATION: Imaging data of 122 patients including 90 cases of lipomas and 32 cases of ALTs. FIELD STRENGTH/SEQUENCE: Axial T1-weighted imaging and fat suppressed T2-weighted imaging at 3.0T MRI. ASSESSMENT: Analysis of variance and the least absolute shrinkage and selection operator methods were used for feature selection and the random forest method was used to build three radiomics models based on T1WI, FS T2WI, and their combination (T1&T2WI). Three independent radiologists classified the tumors based on the subjective assessments. STATISTICAL TESTS: The area under the curve (AUC) of the receiver operating characteristic curve, accuracy, F1-score, specificity, and sensitivity were employed. The differences of the classifiers and discriminating ability of the radiologists and the radiomics model were compared by Delong test. A P value <0.05 was considered significant. Kappa test was used to determine the inter-reader agreements between the radiologists. RESULT: The AUCs were 0.952 (95% confidence interval [CI]: 0.785-0.998), 0.944 (95% CI: 0.774-0.997), and 0.968 (95% CI: 0.809-1) for T1WI, FS T2WI, and T1&T2WI models in testing sets respectively. Delong test showed there were no significant difference between the different radiomics models (P > 0.05). The AUCs of the radiologists were 0.893 (95% CI: 0.824-0.942), 0.831 (95% CI: 0.752-0.893), and 0.893 (95% CI: 0.824-0.94), respectively. There were significant difference between radiomics model and radiologists' model in the training and entire cohorts (P < 0.05) while there were no significant difference in the testing sets (P > 0.05). DATA CONCLUSION: Radiomics has the potential to distinguish between lipomas and ALTs of the extremities and their discrimination ability is no weaker than the senor radiologists. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 2.

Altered resting-state voxel-level whole-brain functional connectivity in multiple system atrophy patients with cognitive impairment.

OBJECTIVE: There is increasing evidence of cognitive impairment (CI) frequently occurring in patients with multiple system atrophy (MSA); however, the neurobiological mechanisms underlying CI in patients with MSA remain unclear. METHODS: We enrolled 61 patients with probable MSA and 33 healthy controls (HC). We used degree centrality (DC) analysis to assess changes in the centrality level of MSA-CI related brain nodes. We conducted a secondary seed-based functional connectivity (FC) analysis to investigate dysfunctions in cognitive networks related to MSA. Further, we analysed the correlation between clinical symptoms and acquired connectivity measures. RESULTS: Compared with HC, patients with MSA-CI and those with MSA with normal cognition (MSA-NCI) exhibited lower DC values in the left calcarine and right postcentral regions and higher DC values in the bilateral caudate and left precuneus. There were significant differences in the DC values in the right middle prefrontal gyrus between the MSA-CI and MSA-NCI groups. The mean DC values in the right middle prefrontal gyrus (RMPFG) were correlated with clinical cognitive severity. Consequently, we used this brain region as a seed in secondary seed-based FC analysis and observed FC changes within the right precuneus, inferior parietal lobe, and right insula. CONCLUSIONS: Decreased middle prefrontal cortex activity and its altered functional connectivity with the precuneus, inferior parietal lobe, and insula are possible biomarkers of cognitive dysfunction in patients with MSA-CI. SIGNIFICANCE: Cognitive impairment in MSA is associated with alterations in the dorsolateral prefrontal cortex network.

Prognostic value of pretreatment PET/CT lean body mass-corrected parameters in patients with hepatocellular carcinoma.

OBJECTIVE: This study was designed to investigate whether pretreatment fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) lean body mass-corrected parameters could predict the overall survival (OS) better than the established predictors in patients with hepatocellular carcinoma (HCC). PATIENTS AND METHODS: We retrospectively analyzed 61 patients with HCC with pretreatment F-FDG-PET/CT. Besides obtaining clinical factors, we measured both lean body mass-corrected and body weight-corrected PET/CT parameters, including metabolic tumor volume, maximal standardized uptake value of the tumor, total lesion glycolysis, tumor-to-normal liver uptake ratio, and so on. The prognostic value of those factors for OS was assessed by statistical software. RESULTS: In the univariate analysis, PET/CT parameters, ascites, serum α-fetoprotein, alkaline phosphatase, aspartate transaminase (AST), tumor number, tumor size of the maximal one, vascular invasion, TNM stage, Child-Pugh class, Barcelona Clinic Liver Cancer (BCLC) staging, and Okuda staging were significant predictors of OS. In multivariate and Kaplan-Meier analyses, lean body mass-corrected maximum standardized uptake value (lbmSUVmax) more than 3.35 g/ml, AST more than 42.00 U/l, and BCLC staging B-C were significant independent predictors of poor OS. When BCLC staging variable was stratified by four categories instead of two in the multivariate analysis, it was not the statistically significant independent predictor anymore, but lbmSUVmax and AST still were. CONCLUSION: Pretreatment F-FDG-PET/CT lean body mass-corrected parameters can predict the OS in patients with HCC. Moreover, lbmSUVmax and AST, as the independent predictors of OS, could supplement the prognostic value of the BCLC staging system.

Development of intraspinal ectopic endometrial tissue in connection with tethered cord syndrome.

We herein report a rare case of intraspinal ectopic endometrial tissue associated with tethered cord syndrome. The patient underwent MR imaging of the lumbar spine and CT spinal angiography. Asymptomatic dysraphism was also detected, including spinal bifida, low-lying conus medullaris, spinal meningocele and a lumbosacral lipoma. Venous reflux obstruction was also suggested. The patient underwent L2-S1 laminectomy and microdecompression of the lesion. The histological and immunohistochemical features were characteristic of ectopic endometrial tissue. Since the surgery, no neurological signs have been noted, either during or outside the patient's menstrual periods. The two-month follow-up MRI scans showed a regression of the lesion.

Cerebral radiation injury and changes in the brain tissues of rat models with glioma.

Cerebral radiation injury (CRI) is a crucial and common complication of radiotherapy for patients with glioma. In the study, we aimed to investigate the changes in the diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) and the histological changes in the brain tissues of mice models with glioma. After the tumor cell seeding, there was an obvious increase in the proportion of cellular nucleus in the brain tissues of rat models with glioma. There was also an obvious increase in the microvascular density (MVD) in the brain tissues of rat models with glioma. There was a linear correlation between the mean apparent diffusion coefficient value and the proportion of cellular nucleus in the brain tissues of rat models with glioma (P < 0.05). There was also a linear correlation between the maximal relative cerebral volume and MVD count in the brain tissues of rat models with glioma (P < 0.01). Therefore, the changes in the DWI and PWI are related with the histological changes in the brain tissues of glioma, and the finding may help us make a distinction between postoperative recurrent glioma and CRI.

Dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging noninvasive evaluation of vascular disrupting treatment on rabbit liver tumors.

Evaluation of vascular disrupting treatment (VDT) is generally based on tumor size and enhancement on conventional magnetic resonance imaging (MRI) which, unfortunately, may be limited in providing satisfactory information. The purpose of the study is to evaluate consecutive changes of 20 rabbit VX2 liver tumors after VDT by dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted imaging (DWI) at a 3.0 T MR unit. Twenty four hours after intravenous injection of Combretastatin A-4-phosphate (CA4P) at 20 mg/kg, DCE-MRI derived Maximum Slope of Increase (MSI) and Positive Enhancement Integral (PEI) decreased sharply due to sudden shutting down of tumor feeding vessels. DWI derived Apparent Diffusion Coefficient (ADC) in tumor periphery decreased because of ischemic cell edema. On day 4, an increase of MSI was probably caused by the recovery of blood supply. A remarkable increase of ADC represented a large scale of necrosis among tumors. On day 8, the blood perfusion further decreased and the extent of necrosis further increased, reflected by lower MSI and PEI values and higher ADC value. On day 12, a second decrease of ADC was noticed because the re-growth of periphery tumor. The experimental data indicate that the therapeutic effects of VDT may be noninvasively monitored with DCE-MRI (reflecting tumor blood perfusion) and DWI (reflecting the changes of histology), which provide powerful measures for assessment of anticancer treatments.

Quantitative assessment of iron deposition in the midbrain using 3D-enhanced T2 star weighted angiography (ESWAN): a preliminary cross-sectional study of 20 Parkinson's disease patients.

Conventional magnetic resonance imaging (MRI) assesses neurodegenerative structural changes in the cerebral anatomy of Parkinson's disease (PD) patients but cannot detect non-structural abnormalities; however, enhanced T2 star weighted angiography (ESWAN) can precisely indicate PD-related substantia nigra (SN) iron deposition. The differences in ESWAN-based parameters between different PD stages were assessed using midbrain iron deposits of 20 PD patients aged 64.3±12.7 (41-85) years grouped by Hoehn and Yahr staging into minimal (stages ≤2.5) or moderate to severe (stages ≥3.0) motor impairment groups and 14 healthy control subjects. Conventional MRI and ESWAN measurements of mean phase value (MPV) and midbrain dimensions (width and diameter) revealed similar anatomical characteristics; however, ESWAN revealed the presence of smaller MPVs and SN pars compacta (SNc) (P<0.01) and a negative correlation between reduction extent and motor impairment (P<0.01). SNc width to midbrain diameter was reduced in moderate to severe impairment patients versus control and minimal impairment patients (both P<0.01). A positive correlation was found between MPV and width or SNc width to midbrain diameter ratio (P<0.01 and P<0.05, respectively). Minimal impairment group mean MPV and substantia nigra pars reticulata (SNr) width evidenced no significant reduction, unlike significant reductions in the moderate to severe impairment group (P<0.01). No significant changes were observed in MPV or width in the RN region (P>0.05). ESWAN allows for early and accurate iron deposition determination in PD patients, particularly useful as a supplement to conventional MRI in early-stage PD patients.

Potential of diffusion tensor MR imaging in the assessment of cognitive impairments in children with periventricular leukomalacia born preterm.

PURPOSE: To investigate MR diffusion tensor imaging (DTI) and fiber tractography (FT) in the assessment of altered major white matter fibers correlated with cognitive functions in preterm infants with periventricular leukomalacia (PVL), to explore the neural foundation for PVL children's cognitive impairments. MATERIALS AND METHODS: Forty six preterm infants (16 ± 4.7 months) suffered from PVL and 16 age-matched normal controls were recruited. Developmental quotient (DQ) was recorded to evaluate PVL children's cognitive functions. According to the DQ scores, patients were divided into three groups: mild, moderate and severe cognitive impairment groups. DTI scan was performed. Fractional anisotropy (FA) values of major white matter fibers were measured and their correlation with cognitive levels was evaluated. RESULTS: Compared with the control group, the PVL group showed a significant mean FA reduction in bilateral corticospinal tract (CST), anterior/posterior limb of internal capsule (ICAL/ICPL), arcuate fasciculus (AF), corona radiate (CR), superior longitudinal fasciculus (SLF), splenium of corpus callosum (SCC) (p<0.05) and bilateral posterior thalamic radiation (PTR) (p<0.01). The FA values of left CST, bilateral AF, anterior cingulum (ACG), SLF, ICAL, ICPL, PTR, CR, genu of corpus callosum (GCC), SCC and middle cerebellar peduncle showed significant negative correlations with the cognitive levels. CONCLUSIONS: DTI can provide more information for understanding the pathophysiology of cognitive impairment in preterm infants with PVL.

Diffusion-weighted MR imaging allows monitoring the effect of combretastatin A4 phosphate on rabbit implanted VX2 tumor model: 12-day dynamic results.

OBJECTIVES: To investigate the 12-day dynamic characteristics of tumor response to intravenous administration of CA4P in rabbit VX2 tumor models. METHODS: Study protocol was approved by local ethical committee for animal care and use. Sixteen rabbits with 32 tumors on bilateral legs were randomly divided into treated and control groups. Conventional and DWI images were acquired before and 24 h, 4 days, 8 days and 12 days after treatment. The dynamic changes of tumor on images were correlated with histological results. ADCs were compared among and between groups at different time points. RESULTS: The tumors in treated group grew slower than those in control group. In treaded group, the mean ADC decreased slightly at 24 h point due to cell edema caused by ischemia. Then, it increased significantly at 4 days and 8 days because of progressive central necrosis. Finally, peripheral tumor proliferation caused a second decrease of ADC at 12 days. The significant difference of ΔADC% between the two groups at 24 h, 4 days and 8 days indicated that the change of ADC in treated group was really caused by CA4P. CONCLUSION: The dynamic histological changes of tumor caused by CA4P as reflected exactly by diffusion-weighted MR imaging indicate a noninvasive measure for monitoring tumor vascular targeting treatment.

Assessment of cortical visual impairment in infants with periventricular leukomalacia: a pilot event-related FMRI study.

OBJECTIVE: We wanted to investigate the usefulness of event-related (ER) functional MRI (fMRI) for the assessment of cortical visual impairment in infants with periventricular leukomalacia (PVL). MATERIALS AND METHODS: FMRI data were collected from 24 infants who suffered from PVL and from 12 age-matched normal controls. Slow ER fMRI was performed using a 3.0T MR scanner while visual stimuli were being presented. Data analysis was performed using Statistical Parametric Mapping software (SPM2), the SPM toolbox MarsBar was used to analyze the region of interest data, and the time to peak (TTP) of hemodynamic response functions (HRFs) was estimated for the surviving voxels. The number of activated voxels and the TTP values of HRFs were compared. Pearson correlation analysis was performed to compare visual impairment evaluated by using Teller Acuity Cards (TAC) with the number of activated voxels in the occipital lobes in all patients. RESULTS: In all 12 control infants, the blood oxygenation level-dependent (BOLD) signal was negative and the maximum response was located in the anterior and superior part of the calcarine fissure, and this might correspond to the anterior region of the primary visual cortex (PVC). In contrast, for the 24 cases of PVL, there were no activated pixels in the PVC in four subjects, small and weak activations in six subjects, deviated activations in seven subjects and both small and deviated activations in three subjects. The number of active voxels in the occipital lobe was significantly correlated with the TAC-evaluated visual impairment (p < 0.001). The mean TTP of the HRFs was significantly delayed in the cases of PVL as compared with that of the normal controls. CONCLUSION: Determining the characteristics of both the BOLD response and the ER fMRI activation may play an important role in the cortical visual assessment of infants with PVL.

[Early diagnosis of lingual thyroglossal duct cyst in newborns: analysis of 10 cases previously misdiagnosed as laryngomalacia].

OBJECTIVE: To distinguish lingual thyroglossal duct cyst (LTDC) from laryngomalacia in newborn infants. METHODS: Data of 10 newborn infants with laryngeal stridor and dyspnea, admitted to the department of neonatology in our hospital during December, 2004 to August, 2007, who were finally diagnosed with LTDC though previously diagnosed as congenital laryngeal stridor in other hospitals, were summarized and analyzed. RESULTS: Inspiratory stridor with chest wall retractions was cardinal symptom of newborn with LTDC. A slightly gray and round cyst with smooth surface at the base of the tongue was found with laryngoscopy. On computed tomography examination of larynx, a well-circumscribed lesion with low intensity was detected at the base of the tongue protruding into the air passage. Pathological examination demonstrated that the cyst wall was composed of tabular and columnar epithelium. CONCLUSIONS: LTDC is a common disease in newborns, which is similar to laryngomalacia. For neonates suspected of LTDC, laryngoscopic examination should be performed first, while laryngeal CT scan is an important diagnostic basis. Cyst puncture can ameliorate the symptoms of the patients, while surgical removal is the method of radical cure.

Studies on the value of diffusion-weighted MR imaging in the early prediction of periventricular leukomalacia.

OBJECTIVE: Periventricular leukomalacia (PVL) is the most common cerebral injury in premature infants. While cranial ultrasonography and conventional magnetic resonance imaging (MRI) offer little for its early diagnosis, still they are much favored at present. Based on the pathologic mechanism of ischemic cerebral injury in PVL, we attempt to elucidate the effects of diffusion-weighted MR imaging (DWI) for the early diagnosis of PVL. METHODS: Twelve cases of PVL in premature infants confirmed by MRI examinations were included in the current study. All cases underwent DWI in addition to conventional MR imaging (T1-weighted [T1W] and T2-weighted [T2W]) 7 days, 2 weeks, and 4 approximately 8 weeks after birth, respectively. RESULTS: Initial DWI examination (carried out at an average of 4.5 days after birth) revealed symmetrical and diffuse high signal in bilateral periventricular areas in all cases, while conventional MRI demonstrated normal signal. DWI examination of 2 weeks later showed irregular inhomogeneous signals in cerebral white matter, while conventional MRI revealed hyperintensity on T1WI and slight hypointensity on T2WI in corresponding areas. Four weeks later, DWI revealed various intensities of cystic low signals beside lateral ventricles, while conventional MRI showed hypointensity on T1WI and hyperintensity on T2WI in corresponding lesion, ie, change in cystic PVL. Four months later, conventional MRI evidenced gradual shrink and disappearance of cystic cavity, reduction in cerebral white matter, and ventricle enlargement. CONCLUSIONS: Symmetrical, diffuse hyperintensity in both lateral periventricular white matter on DWI was the earliest sign of PVL in premature infants. Imaging abnormalities provided by DWI had a close correlation with the results obtained by conventional MRI performed at the advanced stage of PVL, which suggests that DWI may be an important sequence for the early evaluation of cerebral white matter injury as well as for the prediction of PVL occurrence in premature infants.