Pneumatic Distension of Ventricular Mural Architecture Validated Histologically

Purpose: There are ongoing arguments as to how cardiomyocytes are aggregated together within the ventricular walls. We used pneumatic distension through the coronary arteries to exaggerate the gaps between the aggregated cardiomyocytes, analyzing the pattern revealed using computed tomography, and validating our findings by histology. Methods: We distended 10 porcine hearts, arresting 4 in diastole by infusion of cardioplegic solutions, and 4 in systole by injection of barium chloride. Mural architecture was revealed by computed tomography, measuring also the angulations of the long chains of cardiomyocytes. We prepared the remaining 2 hearts for histology by perfusion with formaldehyde. Results: Increasing pressures of pneumatic distension elongated the ventricular walls, but produced insignificant changes in mural thickness. The distension exaggerated the spaces between the aggregated cardiomyocytes, compartmenting the walls into epicardial, central, and endocardial regions, with a feathered arrangement of transitions between them. Marked variation was noted in the thicknesses of the parts in the different ventricular segments, with no visible anatomical boundaries between them. Measurements of angulations revealed intruding and extruding populations of cardiomyocytes that deviated from a surface-parallel alignment. Scrolling through the stacks of tomographic images revealed marked spiraling of the aggregated cardiomyocytes when traced from base to apex. Conclusion: Our findings call into question the current assumption that cardiomyocytes are uniformly aggregated together in a tangential fashion. There is marked heterogeneity in the architecture of the different ventricular segments, with the aggregated units never extending in a fully transmural fashion. Key Points: • Pneumographic computed tomography reveals an organized structure of the ventricular walls.• Aggregated cardiomyocytes form a structured continuum, with marked regional heterogeneity.• Global ventricular function results from antagonistic forces generated by aggregated cardiomyocytes. Citation Format: • Burg MC, Lunkenheimer P, Niederer P et al. Pneumatic Distension of Ventricular Mural Architecture Validated Histologically. Fortschr Röntgenstr 2016; 188: 1045 - 1053.

TNF receptors 1 and 2 exert distinct region-specific effects on striatal and hippocampal grey matter volumes (VBM) in healthy adults

Tumour necrosis factor alpha (TNFα) has been implicated in the pathophysiology of neurodegenerative and neuropsychiatric disease, with research highlighting a role for TNFα in hippocampal and striatal regulation. TNFα signals are primarily transduced by TNF receptors 1 and 2 (TNFR1 and TNFR2), encoded by TNFRSF1A and TNFRSF1B, which exert opposing effects on cell survival (TNFR1, neurodegenerative; TNFR2, neuroprotective). We therefore sought to explore the respective roles of TNFR1 and TNFR2 in the regulation of hippocampal and striatal morphology in an imaging genetics study. Voxel-based morphometry was used to analyse the associations between TNFRSF1A (rs4149576 and rs4149577) and TNFRSF1B (rs1061624) genotypes and grey matter structure. The final samples comprised a total of 505 subjects (mean age = 33.29, SD = 11.55 years; 285 females and 220 males) for morphometric analyses of rs1061624 and rs4149576, and 493 subjects for rs4149577 (mean age = 33.20, SD = 11.56 years; 281 females and 212 males). Analyses of TNFRSF1A single nucleotide polymorphisms (SNPs) rs4149576 and rs4149577 showed highly significant genotypic associations with striatal volume but not the hippocampus. Specifically, for rs4149576, G homozygotes were associated with reduced caudate nucleus volumes relative to A homozygotes and heterozygotes, whereas for rs4149577, reduced caudate volumes were observed in C homozygotes relative to T homozygotes and heterozygotes. Analysis of the TNFRSF1B SNP rs1061624 yielded a significant association with hippocampal but not with striatal volume, whereby G homozygotes were associated with increased volumes relative to A homozygotes and heterozygotes. Our findings indicate a role for TNFR1 in regulating striatal but not hippocampal morphology, as well as a complementary role for TNFR2 in hippocampal but not in striatal morphology.

Cine Phase Contrast Angiography of Normal and Diseased Peripheral Arteries

Cine phase contrast angiography (PCA) is a modified MR phase contrast sequence that acquires up to 22 coronal phase images per mean cardiac cycle. The ability of the sequence to visualise local haemodynamics was investigated in 7 normal volunteers and 9 patients with flow disturbances of the peripheral arteries using a 1.5 T imager. Functional flow information provided by coronal cine PCA was correlated with quantitative data obtained by MR flow measurements and vessel morphology confirmed by conventional angiograms. Due to the yet suboptimal image quality, an aortic dissection and 1 of 4 aneurysms could not be depicted morphologically. The temporal pattern of arterial perfusion in cine PCA corresponded with flow velocity versus time data provided by quantitative MR flow measurements. Accuracy and time resolution of cine PCA was thus sufficient to provide functional information on the severity of occlusive vascular disease.

Assessment of coronary arterial stents by multislice-CT angiography

Purpose: To assess patency and lumen visibility of coronary artery stents by multislice-CT angiography (MSCTA) in comparison with conventional coronary angiography as the standard of reference.

Material and Methods: 47 stents of 13 different types were evaluated in 29 patients. MSCTA was performed on a 4-slice scanner with a standard coronary protocol (detector collimation 4 × 1 mm; table feed 1.5 mm/rotation, 400 mAs, 120 kV). Image evaluation was performed by two readers who were blinded to the reports from the catheter angiography. MIP reconstructions were evaluated for image quality on a 4-point scale (1 = poor, 4 = excellent) and stent patency (contrast distal to the stent as an indirect patency sign). Axial images and multiplanar reformations through the stents were used for assessment of stent lumen visibility (measurement of the visible stent lumen diameter) and detection of relevant in-stent stenosis (≥50%).

Results: Image quality was fair to good on average (score 2.64 ± 1.0) and depended on the heart rate (heart rate 45–60: average score 3.2, heart rate 61–70: average score 2.8, heart rate >71: average score 1.4). Thirty-seven stents were correctly classified as patent, 1 was correctly classified as occluded and 9 stents were not assessible due to insufficient image quality because of triggering artifacts. Parts of the stent lumen could be visualized in 30 cases. On average, 20–40% of the stent lumen diameter was visible. Twenty-five stents were correctly classified as having no stenosis, 1 was falsely classified as stenosed, 1 was correctly classified as occluded. In 20 stents lumen visibility was not sufficient for stenosis evaluation.

Conclusion: Although the stent lumen may be partly visualized in most stents, a reliable evaluation of in-stent stenoses does not seem practical by 4-slice MSCT. Nevertheless, for stent patency evaluation, MS-CTA might provide valuable clinical information. With submillimeter MSCT (e.g., 16-slice scanners) and more sophisticated reconstruction algorithms, further improvements may be expected.

Undetected Dural Leaks Complicated by Accidental Drainage of Cerebrospinal Fluid (CSF) can Lead to Severe Neurological Deficits

PURPOSE

Intracranial hypotension has been reported as a complication of accidental drainage after surgical treatment in several cases. Application of negative pressure systems (wound drains, VAC(®)-therapy, chest tube drainage) had typically led to severe intracranial hypotension including intracranial hemorrhage and tonsillar herniation. In the last year the authors observed 2 cases of accidental spinal drainage of CSF in patients with neurological deficits, regressing after reduction of the device suction.

MATERIAL AND METHODS

We conducted a systematic PubMed-based research of the literature to study the variety and frequency of the reported symptoms from 1st of January 1980 until 1st of October 2015.

RESULTS

Reviewing the literature 24 relevant citations including 27 reported cases of posttraumatic or postoperative loss of CSF leading to neurological symptoms were identified. All 15 reported cases in which a negative pressure suction device had been applied showed severe neurological and radiological symptoms such as coma or brain herniation and intracranial hemorrhage. In all cases patients recovered rapidly after removal of the suction device. Milder symptoms were observed in the patients without negative pressure suction, mainly only presenting with headaches or cranial nerve involvement.Additionally, we give an overview about current recommendations regarding cranial and spinal imaging to rule out dural laceration and cranial hypotension.

CONCLUSION

Patients with dural laceration complicated by accidental drainage of CSF can present with life-threatening conditions. Increasing use of negative pressure suction devices makes the reported condition an important differential diagnosis. A precise radiological examination can help to rule out dural laceration and intracranial hypotension.

KEY POINTS

• Undetected dural laceration complicated by negative pressure suction drains can induce life-threatening symptoms.• Increasing use of negative pressure suction devices makes the reported condition an important differential diagnosis for radiologists Citation Format: • Sporns PB, Schwindt W, Cnyrim CD et al. Undetected Dural Leaks Complicated by Accidental Drainage of Cerebrospinal Fluid (CSF) can Lead to Severe Neurological Deficits. Fortschr Röntgenstr 2016; 188: 451 - 458.

Differing brain structural correlates of familial and environmental risk for major depressive disorder revealed by a combined VBM/pattern recognition approach

BACKGROUND

Neuroimaging traits of either familial or environmental risk for major depressive disorder (MDD) have been interpreted as possibly useful vulnerability markers. However, the simultaneous occurrence of familial and environmental risk might prove to be a major obstacle in the attempt of recent studies to confine the precise impact of each of these conditions on brain structure. Moreover, the exclusive use of group-level analyses does not permit prediction of individual illness risk which would be the basic requirement for the clinical application of imaging vulnerability markers. Hence, we aimed to distinguish between brain structural characteristics of familial predisposition and environmental stress by using both group- and individual-level analyses.

METHOD

We investigated grey matter alterations between 20 healthy control subjects (HC) and 20 MDD patients; 16 healthy first-degree relatives of MDD patients (FH+) and 20 healthy subjects exposed to former childhood maltreatment (CM+) by using a combined VBM/pattern recognition approach.

RESULTS

We found similar grey matter reductions in the insula and the orbitofrontal cortex in patients and FH+ subjects and in the hippocampus in patients and CM+ subjects. No direct overlap in grey matter alterations was found between FH+ and CM+ subjects. Pattern classification successfully detected subjects at risk for the disease even by strictly focusing on morphological traits of MDD.

CONCLUSIONS

Familial and environmental risk factors for MDD are associated with differing morphometric anomalies. Pattern recognition might be a promising instrument in the search for and future application of vulnerability markers for MDD.

Selective arterial Embolisation of Aneurysmal Bone Cysts of the Sacrum: a promising Alternative to Surgery

PURPOSE

The sacrum is a rare but unfavourable location for Aneurysmal Bone Cysts (ABCs), surgical procedures aiming to achieve local tumour control can be mutilating. Aim of this study was to evaluate whether selective arterial embolisation (AE) of ABC of the sacrum is an effective treatment and might be an alternative to surgical treatment options.

MATERIALS AND METHODS

Between 2007 and 2011 six patients (mean age 13.7 years, range 8 - 18 years) with an ABC of the sacrum were treated by AE. Follow-up was performed by MRI-scans as well as clinical examination (mean 36.5 months, range 14 - 56 months).

RESULTS

No treatment related complications have been observed. AE resulted in devascularisation of ABC and led to local tumour control in all patients. A partial consolidation was noticed in three patients. Pain relief was achieved in five of six patients, neurological deficits dissolved. In two patients more than one embolization was necessary. In one of these patients due to exacerbation of pain a surgical decompression was performed.

CONCLUSION

AE of sacral ABCs can serve as an effective and safe treatment option. Thus it might be an alternative to potentially harmful surgical procedures. In case of ongoing tumour growth or pain recurrence AE can be repeated. In case of treatment failure surgical interventions are still possible.

KEY POINTS

• transarterial embolisation enables local tumour control in sacral ABCs. • transarterial embolisation of sacral ABCs is a safe procedure. • in case of tumour progression repetitive embolisations are possible and effective.

Reduction of Advanced Breast Cancer Stages at Subsequent Participation in Mammography Screening

PURPOSE

The decline in advanced breast cancer stages is presumably the most relevant surrogate parameter in mammography screening. It represents the last step in the causal cascade that is expected to affect breast cancer-related mortality. To assess the effectiveness of population-based screening, we analyzed the 2-year incidence rates of advanced breast cancers between women participating in the initial and in the first subsequent round.

MATERIALS AND METHODS

The study included data from 19,563 initial and 18,034 subsequent examinations of one digital screening unit (2008 - 2010). Data on tumor stages, detected by screening or within the following interval of two years (2-year incidence), were provided by the epidemiological cancer registry. Rates of all and combined UICC stages 2, 3 and 4 (advanced stages) were reported for a two-year period. Proportions were tested for significance by using chi-square tests (p < 0.001).

RESULTS

The 2-year incidence rate of all stages was significantly lower in participants in subsequent screening than in initial screening (0.85 vs. 1.29 per 100 women (%); p < 0.0001). A significantly lower 2-year incidence of advanced stages was observed for subsequent screening compared to initial screening (0.26 % vs. 0.48 %; p = 0.0007). Among women aged 50 to 59 years, the incidence of advanced stages was less clearly different (0.21 % vs. 0.35 %; p = 0.07) than in women aged 60 to 69 years (0.31 % vs. 0.70 %; p = 0.0008).

CONCLUSION

During the change from prevalent to incident phase mammography screening, a program impact is seen by a lower 2-year incidence of advanced breast cancers within subsequent compared to initial participants, predominately in women aged 60 to 69 years.

KEY POINTS

• The incidence of advanced tumor stages represents the most relevant surrogate parameter for screening effectiveness. • For the first time the 2-year incidence of advanced breast cancer stages after subsequent mammography screening was analyzed. • We observed a significant effect of screening on the 2-year incidence of advanced stages, predominately in the age group 60 to 69 years.

xPIPE--Reception of DICOM Data from any Sender via the Internet

PURPOSE

Various technologies have been established for DICOM data exchange in radiology. In addition to the patient CD, online transfers via VPN (virtual private network) or DICOM email are common practice. However, dedicated network solutions are generally not appropriate for data exchange with occasional and spontaneous partners due to missing infrastructure at the partner institutions and/or complex setup procedures. The purpose was to develop a practical solution to complement the established technologies to allow users worldwide to transfer images without registration.

MATERIALS AND METHODS

The development of the xPIPE system is based on Java and various software libraries. A client hosted on a website enables sending DICOM data to a receiving system of the hospital.

RESULTS

The new xPIPE system creates a gateway to a receiving hospital which is accessible from any point worldwide, giving other hospitals, clinics and patients a simple and secure method to transmit DICOM data without intermediate storage on external servers.

CONCLUSION

The system was deployed at the University Hospital Münster and subsequently widely used even without information events and training. Data protection during transfer is ensured by the use of signatures and encryption. From the user's perspective the system has only minor technical requirements and can be used with minimal setup effort.

CTP-Based Tissue Outcome: Promising Tool to Prove the Beneficial Effect of Mechanical Recanalization in Acute Ischemic Stroke

PURPOSE

To prove the tissue-protecting effect of mechanical recanalization, we assessed the CT perfusion-based tissue outcome ("TO") and correlated this imaging parameter with the 3-month clinical outcome ("CO").

MATERIALS AND METHODS

159 patients with large intracranial artery occlusions revealing mechanical recanalization were investigated by CCT, CT angiography (CTA) and CT perfusion (CTP) upon admission. For the final infarct volume, native CCT was repeated after 24 h. The "TO" ("percentage mismatch loss" = %ML) was defined as the difference between initial penumbral tissue on CTP and final infarct volume on follow-up CCT. We monitored the three-month modified Rankin Scale (mRS), age, bleeding occurrence, time to recanalization, TICI score and collateralization grade, infarct growth and final infarct volume. Spearman's correlation and nominal regression analysis were used to evaluate the impact of these parameters on mRS. 

RESULTS

Significant correlations were found for %ML and mRS (c = 0.48, p < 0.001), for final infarct volume and mRS (c = 0.52, p < 0.001), for TICI score and mRS (c = - 0.35, p < 0.001), for initial infarct core and mRS (c = 0.14, p = 0.039) as well as for age and mRS (c = 0.37, p < 0.001). According to the regression analysis, %ML predicted the classification of mRS correctly in 38.5 % of cases. The subclasses mRS 1 and 6 could be predicted by %ML with 86.4 % and 60.9 % reliability, respectively. No correlations were found for time to recanalization and mRS, for collateralization grade and mRS, and for post-interventional bleeding and mRS. 

CONCLUSION

Better than the TICI score, CT-based TO predicts the clinical success of mechanical recanalization, showing that not recanalization, but reperfusion should be regarded as a surrogate parameter for stroke therapy.

KEY POINTS

• %ML as well as the final infarct volume can make a direct point about the immediate effect of successful mechanical recanalization.• The clinical outcomes after mechanical recanalization are reliably predicted by %ML, reflecting the benefit of escalation therapy including interventional reopening of parent vessel occlusions.• Not recanalization but rather reperfusion should be regarded as a surrogate parameter for successful stroke therapy.