Evolution of lumbar degenerative spondylolisthesis with key radiographic features.

Spondylolisthesis is a common finding in middle-aged and older adults with back pain. The pathophysiology of degenerative spondylolisthesis is a subject of controversy regarding not only its etiology but also the mechanisms of its progression. It is theorized that degeneration of the facets and discs can lead to segmental instability, leading to displacement over time. Kirkaldy-Willis divided degenerative spondylolisthesis into three phases: dysfunction, instability, and finally, restabilization. There is a paucity of literature on the unification of the radiological hallmarks seen in spondylolisthesis within these phases. The radiographic features include (1) facet morphology/arthropathy, (2) facet effusion, (3) facet vacuum, (4) synovial cyst, (5) interspinous ligament bursitis, and (6) vacuum disc as markers of dysfunction, instability, and/or restabilization. We discuss these features, which can be seen on X-ray, CT, and MRI, with the intention of establishing a timeline upon which they present clinically. Spondylolisthesis is initiated as either degeneration of the intervertebral disc or facet joints. Early degeneration can be seen as facet vacuum without considerable arthropathy. As the vertebral segment becomes increasingly dynamic, fluid accumulates within the facet joint space. Further degeneration will lead to the advancement of facet arthropathy, degenerative disc disease, and posterior ligamentous complex pathology. Facet effusion can eventually be replaced with a vacuum in severe facet osteoarthritis. Intervertebral disc vacuum continues to accumulate with further cleft formation and degeneration. Ultimately, autofusion of the vertebra at the facets and endplates can be observed. With this review, we hope to increase awareness of these radiographical markers and their timeline, thus placing them within the framework of the currently accepted model of degenerative spondylolisthesis, to help guide future research and to help refine management guidelines.

A meta-analysis of deep brain structural shape and asymmetry abnormalities in 2,833 individuals with schizophrenia compared with 3,929 healthy volunteers via the ENIGMA Consortium.

Schizophrenia is associated with widespread alterations in subcortical brain structure. While analytic methods have enabled more detailed morphometric characterization, findings are often equivocal. In this meta-analysis, we employed the harmonized ENIGMA shape analysis protocols to collaboratively investigate subcortical brain structure shape differences between individuals with schizophrenia and healthy control participants. The study analyzed data from 2,833 individuals with schizophrenia and 3,929 healthy control participants contributed by 21 worldwide research groups participating in the ENIGMA Schizophrenia Working Group. Harmonized shape analysis protocols were applied to each site's data independently for bilateral hippocampus, amygdala, caudate, accumbens, putamen, pallidum, and thalamus obtained from T1-weighted structural MRI scans. Mass univariate meta-analyses revealed more-concave-than-convex shape differences in the hippocampus, amygdala, accumbens, and thalamus in individuals with schizophrenia compared with control participants, more-convex-than-concave shape differences in the putamen and pallidum, and both concave and convex shape differences in the caudate. Patterns of exaggerated asymmetry were observed across the hippocampus, amygdala, and thalamus in individuals with schizophrenia compared to control participants, while diminished asymmetry encompassed ventral striatum and ventral and dorsal thalamus. Our analyses also revealed that higher chlorpromazine dose equivalents and increased positive symptom levels were associated with patterns of contiguous convex shape differences across multiple subcortical structures. Findings from our shape meta-analysis suggest that common neurobiological mechanisms may contribute to gray matter reduction across multiple subcortical regions, thus enhancing our understanding of the nature of network disorganization in schizophrenia.

Altered Cortical Brain Structure and Increased Risk for Disease Seen Decades After Perinatal Exposure to Maternal Smoking: A Study of 9000 Adults in the UK Biobank.

Secondhand smoke exposure is a major public health risk that is especially harmful to the developing brain, but it is unclear if early exposure affects brain structure during middle age and older adulthood. Here we analyzed brain MRI data from the UK Biobank in a population-based sample of individuals (ages 44-80) who were exposed (n = 2510) or unexposed (n = 6079) to smoking around birth. We used robust statistical models, including quantile regressions, to test the effect of perinatal smoke exposure (PSE) on cortical surface area (SA), thickness, and subcortical volumes. We hypothesized that PSE would be associated with cortical disruption in primary sensory areas compared to unexposed (PSE-) adults. After adjusting for multiple comparisons, SA was significantly lower in the pericalcarine (PCAL), inferior parietal (IPL), and regions of the temporal and frontal cortex of PSE+ adults; these abnormalities were associated with increased risk for several diseases, including circulatory and endocrine conditions. Sensitivity analyses conducted in a hold-out group of healthy participants (exposed, n = 109, unexposed, n = 315) replicated the effect of PSE on SA in the PCAL and IPL. Collectively our results show a negative, long term effect of PSE on sensory cortices that may increase risk for disease later in life.

Mapping abnormal subcortical neurodevelopment in a cohort of Thai children with HIV.

Alterations in subcortical brain structures have been reported in adults with HIV and, to a lesser extent, pediatric cohorts. The extent of longitudinal structural abnormalities in children with perinatal HIV infection (PaHIV) remains unclear. We modeled subcortical morphometry from whole brain structural magnetic resonance imaging (1.5 T) scans of 43 Thai children with PaHIV (baseline age = 11.09±2.36 years) and 50 HIV- children (11.26±2.80 years) using volumetric and surface-based shape analyses. The PaHIV sample were randomized to initiate combination antiretroviral treatment (cART) when CD4 counts were 15-24% (immediate: n = 22) or when CD4 < 15% (deferred: n = 21). Follow-up scans were acquired approximately 52 weeks after baseline. Volumetric and shape descriptors capturing local thickness and surface area dilation were defined for the bilateral accumbens, amygdala, putamen, pallidum, thalamus, caudate, and hippocampus. Regression models adjusting for clinical and demographic variables examined between and within group differences in morphometry associated with HIV. We assessed whether baseline CD4 count and cART status or timing associated with brain maturation within the PaHIV group. All models were adjusted for multiple comparisons using the false discovery rate. A pallidal subregion was significantly thinner in children with PaHIV. Regional thickness, surface area, and volume of the pallidum was associated with CD4 count in children with PaHIV. Longitudinal morphometry was not associated with HIV or cART status or timing, however, the trajectory of the left pallidum volume was positively associated with baseline CD4 count. Our findings corroborate reports in adult cohorts demonstrating a high predilection for HIV-mediated abnormalities in the basal ganglia, but suggest the effect of stable PaHIV infection on morphological aspects of brain development may be subtle.

Structural Neuroimaging and Neuropsychologic Signatures in Children With Vertically Acquired HIV.

BACKGROUND: Children with vertically acquired HIV exhibit persistent cognitive impairments, yet the corresponding neuroimaging signature of vertical infection remains unclear. METHODS: Fifty healthy control children and 51 vertically infected children were included in the study. The HIV-infected group consisted of survivors who had not received antiretroviral therapy at birth. The HIV-infected group averaged 11.4 (2.5) years of age, with a median CD4 count of 683 cells/mm(3). Most (71%) of the HIV-infected children were on antiretroviral therapy for a median of 34 months (range: 33-42) with HIV RNA <40 copies/mL in 89% of the sample. The HIV-uninfected group averaged 10.6 (2.6) years of age. Magnetic resonance imaging was acquired to determine volumes of the caudate, putamen, thalamus, pallidum, hippocampus, nucleus accumbens, total white matter, total gray matter and cortical gray matter. Correlational analyses examined the degree of shared variance between brain volumes and both cognitive performances and laboratory markers of disease activity (T cells and plasma viral load). RESULTS: HIV-infected children exhibited larger volumes of the caudate, nucleus accumbens, total gray matter and cortical gray matter when compared with the controls. Volumetric differences were predominately evident in children under 12 years of age. HIV-infected children performed worse than controls on most neuropsychologic tests, though neither cognitive performances nor laboratory markers corresponded to brain volumes in the HIV-infected children. CONCLUSIONS: Outcomes of the present study suggest abnormal brain maturation among HIV-infected pediatric survivors. Longitudinal studies of brain integrity and related resilience factors are needed to determine the impact of neuroimaging abnormalities on psychosocial function in pediatric HIV.

Computed Tomographic Diagnosis of Myocardial Fat Deposits in Sarcoidosis.

OBJECTIVE: Fat deposits in the left ventricle (LV) myocardium are uncommon and usually indicate scar due to chronic myocardial infarction. The purpose of this study was to determine the incidence of fatty lesions in the LV of patients with sarcoidosis. MATERIALS AND METHODS: Review of noncontrast computed tomographic images (2-mm thickness) in 133 patients with documented extracardiac sarcoidosis (age, 35-82 years, 55 ± 10 years, 67% female) with no history of significant coronary artery disease (clinical and coronary calcium) was performed. A control group included noncontrast computed tomographies with no coronary calcium in 133 patients with age/sex (59 ± 6 years, 73% female) similar to the sarcoid target group. Locations and morphology (linear vs bulky) of fat deposits (-30 to -180 Hounsfield units) and relevant intrathoracic findings were recorded. RESULTS: We found 35 fat deposits in 19 (14.3%) of sarcoid patients (target group: age, 59 ± 7 years, 78% female). Lesions were mainly at the LV apical level (n = 14). In the control group, 15 lesions in 13 (9.7%) patients were found. Numbers of fatty lesions in sarcoid targets were significantly higher than those in the control group (P = 0.015). The number of bulky lesions was significantly higher in sarcoid (n = 9) than in control (n = 1; P < 0.05). No significant difference was found for the rate of linear lesions. Interstitial lung disease was seen in 9 and enlarged lymph nodes in 9 of the sarcoid target group. There was no significant correlation between the severity of interstitial lung disease and the number of fatty lesions. CONCLUSIONS: Sarcoid patients demonstrate a higher chance of having LV fat deposits with a characteristic bulky morphology.

Incremental value of color coding in 3D volume rendered CT images for interpretation of complex cardiothoracic vascular malformations.

OBJECTIVES: To evaluate the benefit of color coding of CT angiography images for the assessment of complex cardiovascular malformations by comparing the quality of 3D (dimensional) volume rendered (VR) images before and after vessel color coding. METHODS: Cardiothoracic CT images of 34 patients with complex vascular malformations were retrospectively selected for post processing. 3D VR images were created without and after color coding of the target vessels. Source images as well as selected 3D VR images without and with color coding were reviewed independently by 4 observers and scores were recorded on a 4-point scale for overall image quality, visualization conspicuity of target vessels, and final interpretation of target structures. RESULTS: Overall diagnostic advantages of color coded VR images compared with non-color coded VR images included; improved visualization of the anatomical course of vessels, improved visualization of the extent of abnormality, better understanding of the spatial relationship of structures (i.e. to right ventricle outflow tract), and improved overall quality of the images. For all comparisons the color coded score was statistically significantly better than the non-color coded score (p<0.0001). A trend showed that review speed was faster for color coded images (p=0.06). Good inter-observer agreement was achieved for the target conspicuity and final interpretation scores with weighted Kappa score of 0.66 (95% CI: 0.54, 0.79) and 0.71 (95% CI: 0.60, 0.81) respectively. CONCLUSION: Color coded 3D VR images can optimize visualization of vascular structures and improve interpretation of complex vascular malformation in cardiothoracic CT studies.