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The use of nanoparticles in tumor imaging, molecular imaging, and drug delivery has significantly expanded in the last few years. The relatively new field of “theranostics” combines their capacity for drug delivery with their potential as contrast agents. Depending on the imaging modality used, several types of nanoparticles are available, such as gold for optical imaging or superparamagnetic iron oxide for magnetic resonance imaging. This review will give a short overview of the different types of nanoparticles as well as their development and potential application in recent years. Furthermore, it describes the research on classic imaging modalities as well as on new techniques to image nanoparticles in vivo and focuses on magnetic-based imaging modalities.

Single-center comparison of postinterventional multislice computed tomography (MS-CT) and flat-detector computed tomography (FD-CT) in patients with subarachnoid haemorrhage (SAH) and endovascularly treated cerebral aneurysms with a focus on detection of posttherapeutical complications. Patients with endovascularly treated aneurysmal SAH undergoing both MS-CT and FD-CT within 24 h after intervention were included. Datasets were compared regarding image quality (IQ) as well as qualitative (detection of SAH, intracerebral haemorrhage [ICH], intraventricular haemorrhage [IVH], external ventricular drain [EVD] position, acute obstructive hydrocephalus [AOH]) and quantitative (cella media distance [CMD], modified Graeb score [GS]) parameters. 410 patients with endovascularly treated aneurysmal SAH were included. IQ was equal between MS-CT and FD-CT. FD-CT allowed equal detection of SAH and ICH in comparison to MS-CT. FD-CT allowed excellent detection of IVH and delineation of EVD position with strong agreement to MS-CT findings. FD-CT allowed equal detection of AOH in comparison to MS-CT. There was no significant difference of CMD and GS between FD-CT and MS-CT. Postinterventional FD-CT yields equivalent diagnostic value in patients with endovascular treated SAH as MS-CT. Enabling reliable detection of SAH-associated complications within the angiosuite, FD-CT might be an efficient and safe imaging modality in these clinical emergencies. [ABSTRACT FROM AUTHOR]

Treated cerebral aneurysms (IA) require follow-up imaging to ensure occlusion. Metal artifacts complicate radiologic assessment. Our aim was to evaluate an innovative metal-artifact-reduction (iMAR) algorithm for flat-detector computed tomography angiography (FD-CTA) regarding image quality (IQ) and detection of aneurysm residua/reperfusion in comparison to 2D digital subtraction angiography (DSA). Patients with IAs treated by endovascular coiling or clipping underwent both FD-CTA and DSA. FD-CTA datasets were postprocessed with/without iMAR algorithm (MAR+/MAR−). Evaluation of all FD-CTA and DSA datasets regarding qualitative (IQ, MAR) and quantitative (coil package diameter/CPD) parameters was performed. Aneurysm occlusion was assessed for each dataset and compared to DSA findings. In total, 40 IAs were analyzed (ncoiling = 24; nclipping = 16). All iMAR+ datasets demonstrated significantly better IQ (pIQ coiling < 0.0001; pIQ clipping < 0.0001). iMAR significantly reduced the metal-artifact burden but did not affect the CPD. iMAR significantly improved the detection of aneurysm residua/reperfusion with excellent agreement with DSA (naneurysm detection MAR+/MAR−/DSA = 22/1/26). The iMAR algorithm significantly improves IQ by effective reduction of metal artifacts in FD-CTA datasets. The proposed algorithm enables reliable detection of aneurysm residua/reperfusion with good agreement to DSA. Thus, iMAR can help to reduce the need for invasive follow-up in treated IAs. [ABSTRACT FROM AUTHOR]

We present two cases of ChAdOx1 nCov-19 (AstraZeneca)-associated thrombotic thrombocytopenia syndrome (TTS) and cerebral venous sinus thrombosis (CVST). At the time of emergency room presentation due to persistent headache, blood serum levels revealed reduced platelet counts. Yet, 1 or 4 days after the onset of the symptom, the first MR-angiography provided no evidence of CVST. Follow-up imaging, performed upon headache refractory to nonsteroidal pain medication verified CVST 2–10 days after initial negative MRI. Both the patients received combined treatment with intravenous immunoglobulins and parenteral anticoagulation leading to an increase of platelet concentration in both the individuals and resolution of the occluded cerebral sinus in one patient. [ABSTRACT FROM AUTHOR]

Introduction: Sarcoidosis is a rare, systemic inflammatory disease and can involve multiple organs, especially the lungs and lymph nodes. The nervous system is affected in <10 percent of patients, which is called neurosarcoidosis. Neurosarcoidosis can cause a multitude of symptoms and can mimic various diseases. A rare manifestation is bone marrow involvement. We describe a case of spinal cord syndrome due to myelopathy that was caused by sarcoidosis of the bone marrow. Case Presentation: A male patient presented to our hospital with incomplete spinal cord syndrome. He suffered from numbness of the legs which had progressed to severe paraparesis. Magnetic resonance imaging revealed thoracic myelopathy without contrast enhancement. Thorough diagnostics found no explanation for the myelopathy, and the patient was treated symptomatically with high-dose steroids. When the patient developed non-resolving leukopenia, a bone marrow biopsy was performed. The bone marrow showed changes due to sarcoidosis. Further testing revealed myocardial involvement of the sarcoidosis. The patient was started on oral prednisolone and methotrexate. Over the course of time, his symptoms improved, but he still suffers from spastic leg paresis and needs aids to walk farther than 1 kilometre. Conclusion: In patients presenting with neurological deficits of unknown cause, neurosarcoidosis is a potential explanation. If it manifests primarily in the bone marrow, the diagnosis can be easily overlooked. Abnormalities in a full blood count should make the treating physician consider this diagnosis, and a bone marrow biopsy should be performed. [ABSTRACT FROM AUTHOR]

Background: Flat detector computed tomography angiography (FDCTA) can be reconstructed from volume perfusion flat detector computed tomography (VP-FDCT). Thus, CTA equivalent stroke imaging might be feasible within the angio suite. Purpose: To evaluate the diagnostic accuracy of FDCTA in detecting large vessel occlusion (LVO) and collateral supply in acute stroke patients. Material and Methods: Sixteen patients with LVO of the anterior circulation were analyzed retrospectively. Each patient underwent a multimodal CT stroke protocol, subsequent VP-FDCT, and digital subtraction angiography (DSA) for endovascular stroke therapy. Angiographic images reconstructed secondarily from VP-FDCT were evaluated with regard to visualization of LVO, Collateral Score (CS), Clot Burden Score (CBS), and image quality. Results: Image quality of FDCTA was sufficient for diagnosis with a strong correlation between CTA and FDCTA (median score: CTA = 4 ± 0.447; FDCTA = 4 ± 0.5). Detection of LVO could be achieved with high sensitivity and specificity for FDCTA and CTA (97.9%, 95% confidence interval [CI] = 96.0–99.9; 92.6%, 95% CI = 84.3–100.0 vs. 96.8%, 95% CI = 93.2–100.0; 86.3%, 95% CI = 88.2–95.2). CBS and CS assessment showed no significant difference between FDCTA and CTA for both readers (reader1CBS: P = 0.751, reader1CS: P = 0.718; reader2CBS: P = 0.164; reader2CS: P = 0.582) and an excellent interrater agreement (CTACBSICC = 0.984, FDCTACBSICC = 0.951; CTACSICC = 0.754, FDCTACSICC = 0.789). Conclusion: FDCTA, reconstructed from VP-FDCT data, allows reliable detection of ICA or MCA M1 segment occlusion comparable to CTA and may provide information concerning the clot extent with sufficient image quality. [ABSTRACT FROM AUTHOR]

Background and purpose The purpose of this study was to assess the initial post-market experience of the device and how it is compared with the Penumbra Pivotal trial used to support the 510k application. Methods A retrospective case review of 157 consecutive patients treated with the Penumbra system at seven international centers was performed. Primary endpoints were revascularization of the target vessel (TIMI score of 2 or 3), good functional outcome as defined by a modified Rankin scale (mRS) score of ≤2 and incidence of procedural serious adverse events. Results were compared with those of the Penumbra pivotal trial. Results A total of 157 vessels were treated. Mean baseline values at enrollment were: age 65 years, NIHSS score 16. After use of the Penumbra system, 87% of the treated vessels were revascularized to TIMI 2 (54%) or 3 (33%) as compared with 82% reported in the Pivotal trial. Nine procedural serious adverse events were reported in 157 patients (5.7%). All-cause mortality was 20% (32/157), and 41% had a mRS of ≤2 at 90-day follow-up as compared with only 25% in the Pivotal trial. Patients who were successfully revascularized by the Penumbra system had significantly better outcomes than those who were not. Conclusion Initial post-market experience of the Penumbra system revealed that the revascularization rate and safety profile of the device are comparable to those reported in the Pivotal trial. However, the proportion of patients who had good functional outcome was higher than expected. [ABSTRACT FROM AUTHOR]

Background: Data on clinical characteristics and outcome of patients with intracerebral hemorrhage (ICH) and concomitant systemic cancer disease are very limited. Methods: Nine hundred and seventy three consecutive primary ICH patients were analyzed using our prospective institutional registry over a period of 9 years (2006-2014). We compared clinical and radiological parameters as well as outcome -- scored using the modified Rankin Scale (mRS) and analyzed in a dichotomized fashion as favorable outcome (mRS = 0-3) and unfavorable outcome (mRS = 4-6) -- of ICH patients with and without cancer. Relevant imbalances in baseline clinical and radiological characteristics were adjusted using propensity score (PS) matching. Results: Prevalence of systemic cancer among patients with ICH was 8.5% (83/973). ICH patients with cancer were older (77 [70-82] vs. 72 [63-80] years; p = 0.002), had more often prior renal dysfunction (19/83 [22.9%] vs.107/890 [12.0%]; p = 0.005), and smaller hemorrhage volumes (10.1 [4.8-24.3] vs. 15.3 [5.4-42.9] mL; p = 0.017). After PS-matching there were no significant differences neither in mortality nor in functional outcome both at 3 months (mortality: 33/81 [40.7%] vs. 55/158 [34.8%]; p = 0.368; mRS = 0-3: 28/81 [34.6%] vs. 52/158 [32.9%]; p = 0.797) and 12 months (mortality: 39/78 [50.0%] vs. 70/150 [46.7%]; p = 0.633; mRS = 0-3: 25/78 [32.1%] vs. 53/150 [35.3%]; p = 0.620) among patients with and without concomitant systemic cancer. ICH volume tended to be highest in patients with hematooncologic malignancy and smallest in urothelial cancer. Conclusions: Patients with ICH and concomitant systemic cancer on average are older; however, they show smaller ICH volumes compared to patients without cancer. Yet, mortality and functional outcome is not different in ICH patients with and without cancer. Thus, the clinical history or the de novo diagnosis of concomitant malignancies in ICH patients should not lead to unjustified treatment restrictions. [ABSTRACT FROM AUTHOR]

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