Imaging Guidance for Transcatheter Mitral Valve Intervention on Prosthetic Valves,Rings, and Annular Calcification

Catheter-based interventions to improve mitral valve function are dependent on anatomic and functional information provided by noninvasive imaging to plan, perform, and evaluate each intervention. In this review we highlight the importance of imaging guidance for catheter-based interventions on prosthetic mitral valves, surgical rings, and native valve annular calcification. Both repair and replacement procedures are discussed. We review the general features common to this collection of procedures and discuss specific imaging issues and concerns for each procedure. Figures and intraprocedural videos emphasize central messages using case examples.     

Impact of intravascular ultrasound for the treatment of calcified infrarenal aortic stenosis: A case report study

We report two cases of heavily calcified infrarenal aortic stenosis that were successfully treated by Intravascular ultrasound‐ (IVUS)‐guided stenting. Two middle‐aged women visited our hospital due to intermittent claudication. Diagnostic arteriography revealed possible infrarenal aortic stenosis even though the findings were equivocal. IVUS demonstrated heavily calcified atherosclerotic lesions and allowed the accurate assessment of the types and extents of the lesions to be treated in both cases. The patients successfully underwent stent implantation according to the findings of IVUS. IVUS significantly contributed to the interventional successes. © 2008 Wiley‐Liss, Inc.     

Mitral annular calcification as a marker of complex aortic atheroma in patients with stroke of uncertain etiology

The aim of this study was to evaluate the presence of dense mitral annular calcification as a marker of complex aortic atherosclerosis in patients with stroke of uncertain etiology. One hundred twenty-one patients with stroke of uncertain etiology were evaluated for complex aortic atherosclerotic plaques; their presence and severity were correlated with transthoracic echocardiographic findings, demographic data, and cardiovascular risk factors. Complex plaques in the ascending aorta or aortic arch were found in 72 of the 121 patients (59.5%). The only difference seen in patients with or without plaques was the presence of dense mitral annular calcification (58.3 vs 16.3%; P < 0.001). Dense mitral annular calcification (n = 50) was associated with higher prevalence of complex aortic plaques (84.0% vs 42.3%; P < 0.001), mobile components (28.0% vs 9.9%; P < 0.01), and protruding (80.0% vs 36.6%; P < 0.001), ulcerated (16.0% vs 1.4%; P < 0.01), and multisite complex plaques (46.0% vs 9.0%; P < 0.001). Therefore, in patients with stroke of uncertain etiology dense mitral annular calcification is an important marker of aortic atherosclerosis with high risk of embolism, and this association may explain in part the high prevalence of stroke and peripheral embolism in patients with mitral annular calcification.     

Nanobacteria May Be Linked to Calcification in Placenta

Aims: Placental calcification is a common pathologic condition in obstetrics. To detect the bacteria infection mechanisms for calcification, an experiment was performed to isolate, culture, and identify the nanobacteria in placental calcification.

Method: Sixteen cases of placental calcification of pregnant women were collected for the purpose of the isolation of nanobacteria, cultivation, and identification of 16S rDNA sequence.

Result: Under transmission electron microscope, novel oval-shape nanobacteria-like particles (NLP) in extracellular matrix of calcified placenta tissues were found with 50–500?nm in diameter, and among hydroxyapatite crystals aggregation existed. After about 4 weeks of culturing and isolating NLP from these calcified tissues, all calcified placental tissue samples and one adjacent tissue of calcified placental tissue samples showed white granular depositions, which were firmly attached to the bottom of the culture tubes and visible to the naked eyes. In the control group they could not be seen. After PCR was amplified a 1407-bp fragment was obtained and submitted to GenBank after sequencing with accession number JN029830. The 16S rDNA sequence homology between the isolation strain and strain nanobacteria (X98418) was 92% in GenBank.

Conclusion: For the first time isolated, cultured, and identified nanobacteria in placental calcification indicated that nanobacteria infection is related to placental calcification.     

Nanobacteria and Psammoma Bodies: Ultrastructural Observations in a Case of Pathological Placental Calcification

Nanobacteria are controversial infectious agents with nanometric size, the capacity to nucleate hydroxyapatite and grow in culture, and present in human diseases associated with calcification and psammoma bodies. The authors report a case of pathological placental calcifications associated with nanobacteria. Electron microscopy and electron energy loss spectroscopy imaging were used to recognize 160-nm-sized calcium-free bodies mainly presenting as extracellular fibrillary tangles and 500-nm-sized calcified bodies; they encrusted the syncito-trophoblast basal membrane and aggregated into miniaturized psammoma bodies. Nanobacteria may be composed of a prionoid protein with self-assembling and self-propagating abilities whose growth is associated with the formation of psammoma bodies.     

Hepatocellular Calcification in Severe Ischemia–Reperfusion Injury in a Liver Allograft

Ischemia–reperfusion injury (IR) of solid organ allografts is a consequence of ischemia resulting from disruption of blood flow during organ harvest and transportation. Histologically, this manifests as variable necrosis in a pattern similar to that seen in systemic hypoperfusion. Calcification of hepatocytes has been rarely observed in ischemic injury due to systemic shock and in two cases of severe IR, both of which were associated with graft loss and death. The authors present another case of dystrophic calcification within hepatocytes occurring in a liver allograft affected by severe IR. Biochemical stains revealed that the mineralized material was calcium phosphate (likely hydroxyapatite). By electron microscopy, the hepatocyte cytoplasm was filled with variably calcified vacuoles, a subset of which likely represented swollen mitochondria. When encountered in hepatic allograft biopsies, hepatocellular calcification is associated with ischemic injury and a poor prognosis.     

Characterization of the Apatite Crystals of Bone and their Maturation in Osteoblast Cell Culture: Comparison with Native Bone Crystals

Calcium phosphate crystals deposited in the organic matrix synthesized by chick bone osteoblasts in culture were studied by x-ray and electron diffraction, Fourier transform infrared spectroscopy and chemical composition. The amounts of mineral phase deposited with time and the extent of calcification (% of mineral phase in the tissue) were also determined as a function of time, as were the nature of the changes in the short range order of the crystals. The amount of mineral deposited and the extent of calcification increased with time; the tissue not only contained more crystals of apatite, but the extent of calcification also increased with time as it does in vivo. After 30 days of culture the extent of calcification in the cell culture matrix was similar to that in late chick embryonic and early postnatal chick tibiae. The nature of the CO₃ and HPD₄ environments were similar to those found in vivo although the concentrations of these ions and the changes in their concentrations with time appeared to develop more slowly in cell culture than they do in vivo. However, the general overall pathway of maturation was similar in cell culture to that observed in vivo.     

Risk factors for calcification of the vertebrobasilar arteries in cardiovascular patients referred for a head CT,the SMART study

Background and purposeVertebrobasilar artery calcification (VBAC) has been associated with increased stroke occurrence. Little is known on VBAC risk factors, especially for patients with cardiovascular disease. We aimed to assess risk factors associated with VBAC in a cohort of cardiovascular patients referred for a head computed tomography (CT) scan.Materials and methodsAll patients who underwent a clinically indicated, unenhanced, thin slice head CT 6 months before or after inclusion in the SMART study were included. CTs were assessed for presence of VBAC (dichotomously). Relative risks of the associations of age, sex, diabetes mellitus (DM), obesity, body mass index, estimated glomerular filtration rate, hypertension, hyperlipidemia, use of lipid lowering medication, smoking status, high sensitivity C-reactive protein, ankle-brachial index (ABI; ≤ 0.90, ≥ 1.30, continuous), internal carotid artery stenosis ≥ 70%, and carotid intima-media thickness (IMT) with VBAC were estimated using Poisson regression analysis with robust standard errors, adjusted for age and sex.ResultsOf the 471 patients included (57% male, median age 58 [interquartile range 47–63]), 117 (24.8%) showed VBAC. Presence of VBAC was associated with older age (RR per 10 years = 1.70 [95%CI 1.46–1.99]), DM (RR = 1.45 [95%CI 1.03–2.06]), obesity (RR = 1.53 [95%CI 1.10–2.12]), ABI ≤ 0.90 (RR = 1.57 [95%CI 1.02–2.41]), and an increased carotid IMT (RR = 2.60 per mm [95%CI 1.20–5.62]). Other measurements were not associated with VBAC.ConclusionsWe identified several markers associated with VBAC in patients with cardiovascular disease referred for a head CT. Future investigation into the relationship between VBAC and stroke is warranted to determine the potential of VBAC in stroke prevention.     

Polymicrogyria with calcification in Pallister-Killian syndrome detected by microarray analysis

BackgroundPallister-Killian syndrome (PKS) is a rare disorder caused by the mosaic tetrasomy of chromosome 12p, and is characterized by facial dysmorphism, developmental delay, hypotonia and seizures.ResultsWe report a patient with PKS showing unique polymicrogyria with calcification. He had delayed development and dysmorphic facial features including frontal bossing, hypertelorism, and high arched palate at 6 months of age. Neuroimaging revealed unilateral polymicrogyria with spot calcifications, which predominantly affected the right perisylvian region. Chromosome G-banding showed the karyotype 46,XY, however, array-based comparative genomic hybridization analysis showed mosaic duplication of chromosome 12p, in which CCND2, which encodes cyclin D2 and is a downstream mediator of PI3K-AKT pathway, is located. Supernumerary chromosome of 12p was detected in 58% of buccal mucosa cells by the interphase fluorescence in situ hybridization analysis using chromosome 12 centromere-specific D12Z3 probe. The diagnosis of PKS was made based on distinctive clinical features of our patient and the results of cytogenetic analyses.ConclusionThis report is, to our knowledge, the first case of a patient with PKS who clearly demonstrates polymicrogyria colocalized with calcifications, as shown by CT scans and MRI, and suggests that a patient with PKS could show structural brain anomalies with calcification. We assume that somatic mosaicism of tetrasomy could cause asymmetrical polymicrogyria in our patient, and speculate that increased dosages of CCND2 at chromosome 12p might be involved in the abnormal neuronal migration in PKS.     

双源CT评估冠状动脉钙化与病理诊断符合度

目的　以病理诊断为标准评价双源CT增强扫描定性和定量冠状动脉钙化斑块的准确性。 方法　采用双源CT对离体冠状动脉进行0.6 mm层厚横断面增强扫描,将CT值＞130 HU的斑块定性为钙化斑块,依据钙化斑块在管壁横断面上的弧度将其分为3型：轻度钙化、中度钙化和重度钙化。计算钙化斑块导致的冠状动脉狭窄,并与病理分型和所测冠状动脉狭窄进行对比。 结果　病理切片发现钙化斑块69个,DSCT发现57个,双源CT检测轻度、中度和重度钙化斑块的敏感性分别为88.3%、100%和100%。与病理诊断结果相比,双源CT高估了轻度、中度和重度钙化斑块导致的冠状动脉狭窄程度,分别相差（3.2±2.0）%、（4.9±4.7）%和（14.7±8.2）%,P<0.05。 结论　双源CT增强扫描能够检测定性不同类型的冠状动脉钙化;与病理对比,双源CT高估了钙化斑块导致的冠状动脉狭窄程度较严重。