Contact endoscopy as a novel technique for intra-operative identification of normal pituitary gland and adenoma

Intraoperative distinction of pituitary adenoma from normal gland is critical in maximizing tumor resection without compromising pituitary function. Contact endoscopy provides a noninvasive technique that allows for real-time in vivo visualization of differences in tissue vascularity. Two illustrative cases of endoscopic endonasal approaches (EEAs) for resection of pituitary adenoma illustrate the use of contact endoscopy in identifying tumor from gland and differentiating a thin section of normal gland draped over the underlying tumor, thereby allowing for safe extracapsular tumor resection. Contact endoscopy may be used as an adjunct for intraoperative, in vivo differentiation of pituitary gland and adenoma. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21199

A Novel Noninvasive Technique for Intracranial Pressure Waveform Monitoring in Critical Care

Background: We validated a new noninvasive tool (B4C) to assess intracranial pressure waveform (ICPW) morphology in a set of neurocritical patients, correlating the data with ICPW obtained from invasive catheter monitoring. Materials and Methods: Patients undergoing invasive intracranial pressure (ICP) monitoring were consecutively evaluated using the B4C sensor. Ultrasound-guided manual internal jugular vein (IJV) compression was performed to elevate ICP from the baseline. ICP values, amplitudes, and time intervals (P2/P1 ratio and time-to-peak [TTP]) between the ICP and B4C waveform peaks were analyzed. Results: Among 41 patients, the main causes for ICP monitoring included traumatic brain injury, subarachnoid hemorrhage, and stroke. Bland–Altman’s plot indicated agreement between the ICPW parameters obtained using both techniques. The strongest Pearson’s correlation for P2/P1 and TTP was observed among patients with no cranial damage (r = 0.72 and 0.85, respectively) to the detriment of those who have undergone craniotomies or craniectomies. P2/P1 values of 1 were equivalent between the two techniques (area under the receiver operator curve [AUROC], 0.9) whereas B4C cut-off 1.2 was predictive of intracranial hypertension (AUROC 0.9, p < 000.1 for ICP > 20 mmHg). Conclusion: B4C provided biometric amplitude ratios correlated with ICPW variation morphology and is useful for noninvasive critical care monitoring.

Musculoskeletal Applications of Magnetic Resonance-Guided Focused Ultrasound

Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel noninvasive therapy that uses focused sound energy to thermally ablate focal pathology within the body. In the United States, MRgFUS is approved by the Food and Drug Administration for the treatment of uterine fibroids, palliation of painful bone metastases, and thalamotomy for the treatment of essential tremor. However, it has also demonstrated utility for the treatment of a wide range of additional musculoskeletal (MSK) conditions that currently are treated as off-label indications. Advantages of the technology include the lack of ionizing radiation, the completely noninvasive technique, and the precise targeting that offer unprecedented control of the delivery of the thermal dose, as well as real-time monitoring capability with MR thermometry. In this review, we describe the most common MSK applications of MRgFUS: palliation of bone metastases, treatment of osteoid osteomas, desmoid tumors, facet arthropathy, and other developing indications.

Encapsulin Based Self-Assembling Iron-Containing Protein Nanoparticles for Stem Cells MRI Visualization

Over the past decade, cell therapy has found many applications in the treatment of different diseases. Some of the cells already used in clinical practice include stem cells and CAR-T cells. Compared with traditional drugs, living cells are much more complicated systems that must be strictly controlled to avoid undesirable migration, differentiation, or proliferation. One of the approaches used to prevent such side effects involves monitoring cell distribution in the human body by any noninvasive technique, such as magnetic resonance imaging (MRI). Long-term tracking of stem cells with artificial magnetic labels, such as magnetic nanoparticles, is quite problematic because such labels can affect the metabolic process and cell viability. Additionally, the concentration of exogenous labels will decrease during cell division, leading to a corresponding decrease in signal intensity. In the current work, we present a new type of genetically encoded label based on encapsulin from Myxococcus xanthus bacteria, stably expressed in human mesenchymal stem cells (MSCs) and coexpressed with ferroxidase as a cargo protein for nanoparticles’ synthesis inside encapsulin shells. mZip14 protein was expressed for the enhancement of iron transport into the cell. Together, these three proteins led to the synthesis of iron-containing nanoparticles in mesenchymal stem cells—without affecting cell viability—and increased contrast properties of MSCs in MRI.

The Role of Ultrasound as a Diagnostic and Therapeutic Tool in Experimental Animal Models of Stroke: A Review

Ultrasound is a noninvasive technique that provides real-time imaging with excellent resolution, and several studies demonstrated the potential of ultrasound in acute ischemic stroke monitoring. However, only a few studies were performed using animal models, of which many showed ultrasound to be a safe and effective tool also in therapeutic applications. The full potential of ultrasound application in experimental stroke is yet to be explored to further determine the limitations of this technique and to ensure the accuracy of translational research. This review covers the current status of ultrasound applied to monitoring and treatment in experimental animal models of stroke and examines the safety, limitations, and future perspectives.

Monitoring of the Reproductive Cycle in Captive-Bred Female Boa constrictor: Preliminary Ultrasound Observations

The Boa constrictor is one of the most common reptiles bred in captivity. To achieve a successful breeding season, thorough knowledge of the females’ reproductive activity is necessary. In this regard, information on the Boa constrictor is still rather scarce. The aim of the present study was to monitor the ovarian activity and the embryonic development of boas by ultrasound. We performed brief scans on thirty non-anaesthetized snakes using a portable ultrasound system and a 7.5–10 MHz linear array transducer (Esaote MyLab™ Classic). Ultrasound features, dimensions, and echogenicity of the preovulatory and postovulatory follicles were determined. As gestation progresses, the postovulatory follicle size increases, and the embryonic silhouette becomes increasingly recognizable. During the second month after ovulation, by using color Doppler, early embryos’ heart activity could be evaluated. It is possible to highlight vascular connections between the mother and the membrane covering the embryonic structures. Ultrasound also allows one to identify follicular regression or slugs (nonfertilized eggs) early. The present study suggests that ultrasound could be an excellent noninvasive technique to evaluate the reproductive activity of Boa constrictor, allowing us to precisely identify the correct time for mating, monitor embryo development and viability, and allow the early diagnosis of follicular regression.

Effect of Beach-Chair Position on Cerebral Blood Flow in Patients Undergoing Shoulder Surgery—A Preliminary Observational Study

Background Hypotension and cerebral hypoperfusion, commonly encountered in beach-chair position under general anesthesia, carry the risk of neurologic complications. There is a paucity of data on monitoring cerebral perfusion. Our objective was to compare the mean arterial pressure (MAP) and middle cerebral artery velocity (Vmca) in the supine and beach-chair position and estimate its correlation during hypotension. Materials and Methods Twenty ASA class I and II patients undergoing elective shoulder surgery in beach-chair position were included in the study. MAP was measured invasively with the pressure transducer leveled to the phlebostatic axis. Vmca was measured with a 2 MHz transcranial Doppler (TCD) probe through the temporal window. Both MAP and Vmca were measured at baseline after anesthetic induction in the supine position (BL), on assuming the beach-chair position (AP), at steady-state hemodynamics in beach-chair position (P1), whenever there was a drop in MAP > 20% (P2), and on the restoration of MAP (P3). Results A mean decrease in MAP and Vmca by 24.76% and 27.96%, respectively, from supine to beach-chair position with a significant linear correlation between MAP and Vmca along with a Pearsons’ coefficient of 0.77 was seen. A change in MAP of 1 mm of Hg resulted in a change in Vmca by 0.53 cm/sec (p < 0.05). Conclusion A significant decrease in MAP and Vmca was observed in the beach-chair position. TCD could be used as a point-of-care noninvasive technique to reliably assess cerebral perfusion.

A Novel Noninvasive Technique for Intracranial Pressure Waveform Monitoring in Critical Care

We validated a new noninvasive tool (B4C) to assess intracranial pressure waveform (ICPW) morphology in a set of neurocritical patients, correlating the data with ICPW obtained from invasive catheter monitoring. Materials and Methods: Patients undergoing invasive intracranial pressure (ICP) monitoring were consecutively evaluated using the B4C sensor. Ultrasound-guided manual internal jugular vein (IJV) compression was performed to elevate ICP from the baseline. ICP values, amplitudes, and time intervals (P2/P1 ratio and time-to-peak [TTP]) between the ICP and B4C waveform peaks were analyzed. Results: Among 41 patients, the main causes for ICP monitoring included traumatic brain injury, subarachnoid hemorrhage, and stroke. Bland-Altman&rsquo;s plot indicated agreement between the ICPW parameters obtained using both techniques. The strongest Pearson&rsquo;s correlation for P2/P1 and TTP was observed among patients with no cranial damage (r = 0.72 and 0.85, respectively) in detriment of those who have undergone craniotomies or craniectomies. P2/P1 values of 1 were equivalent between the two techniques (area under the receiver operator curve [AUROC], 0.9) whereas B4C cut-off 1.2 was predictive of intracranial hypertension (AUROC 0.9, p &lt; 000.1 for ICP &gt; 20 mmHg). Conclusion: B4C provided biometric amplitude ratios correlated with ICPW variation morphology and is useful for noninvasive critical care monitoring.

Simplified Guide to MR Elastography in Early Detection of Hepatic Fibrosis with Case Reports

The current unhealthy diets and sedentary lifestyle have led to increase in the prevalence of diabetes and metabolic syndrome globally. Fatty liver is a common occurrence in metabolic syndrome. The liver health is often ignored due to delayed warning signs. Fatty changes of the liver is one of the common findings in ultrasonography. Ultrasound does not detect fibrosis except when cirrhosis is developed. Early stages of fibrosis are asymptomatic with no significant laboratory or preliminary imaging findings. With fibrosis, the elasticity of the liver is reduced and becomes stiffer. Over the years, many techniques have developed to assess the stiffness of the liver, starting from palpation, ultrasonography, and recently developed magnetic resonance elastography (MRE). In this article, we have tried to simplify the concepts of MRE to detect fibrosis and present few case reports. The basic steps involved in generating elastograms and interpretation with some insight on how to incorporate it into the clinical workflow are discussed. MRE is superior to various other available techniques and even offers certain advantages over biopsy. MRE is FDA approved for liver fibrosis since 2009, yet it is hardly used in the Indian setting. MRE is a safe and noninvasive technique to evaluate a large volume of the liver and can be a new norm for the evaluation of fatty liver. Magnetic resonance imaging (MRI)-based elastography techniques hold an exciting future in providing mechanical properties of tissues in various organs like spleen, brain, kidney, and heart.

Role of Laryngeal Ultrasonography in screening for laryngeal diseases in symptomatic patients

Background Laryngoscopy is widely considered the most appropriate tool for evaluating the larynx, however, it is invasive and not all patients can tolerate it. Although laryngeal ultrasound has been proposed as a promising noninvasive technique that can play an important role in laryngeal imaging, there is lack of consensus regarding its role. Objective The aim of this study is to assess laryngeal ultrasound sensitivity compared to indirect laryngoscopy in screening for laryngeal diseases in symptomatic patients. Patients and methods 30 undiagnosed symptomatic patients underwent laryngeal ultrasound and indirect laryngoscopy. Their results were compared. Results Technical success rate of laryngeal ultrasound was (83%). It showed overall sensitivity of (78.9%) in detecting organic laryngeal diseases with high sensitivity in detecting laryngeal masses, reinke’s edema, vocal cord cysts and polyps (100%), vocal cord palsy (83.3%), intermediate sensitivity for vocal cord nodules (66.7%), and poor sensitivity for laryngitis and non organic voice disorders (0%). Conclusion Laryngeal ultrasound is a useful non invasive imaging tool that can be used with acceptable sensitivity in detecting organic laryngeal diseases excluding laryngitis, hindered mainly by complete thyroid cartilage calcification in older males. Consequently we recommend its use as complementary to clinical examination and mirror laryngoscopy, or as an alternative to indirect laryngoscopy when required and in routine neck ultrasound exams when appropriate.