Somatostatin Receptor-PET/CT/MRI of Head and Neck Neuroendocrine Tumors.

BACKGROUND AND PURPOSE: Due to its high sensitivity, somatostatin receptor-PET may detect smaller lesions and more extensive disease than contrast-enhanced MR imaging, while the superior spatial resolution of MR imaging enables lesions to be accurately localized. We compared results of somatostatin receptor-PET/MRI with those of MR imaging alone and assessed the added value of vertex-to-thigh imaging for head and neck neuroendocrine tumors. MATERIALS AND METHODS: Somatostatin receptor-PET/CT was acquired as limited brain or head and neck imaging, with optional vertex-to-thigh imaging, following administration of 64CU/68GA DOTATATE. Somatostatin receptor-PET was fused with separately acquired contrast-enhanced MR imaging. DOTATATE activity was classified as comparable, more extensive, and/or showing additional lesions compared with MR imaging. Vertex-to-thigh findings were classified as positive or negative for metastatic disease or incidental. RESULTS: Thirty patients (with 13 meningiomas, 11 paragangliomas, 1 metastatic papillary thyroid carcinoma, 1 middle ear neuroendocrine adenoma, 1 external auditory canal mass, 1 pituitary carcinoma, 1 olfactory neuroblastoma, 1 orbital mass) were imaged. Five had no evidence of somatostatin receptor-positive lesions and were excluded. In 11/25, somatostatin receptor-PET/MRI and MR imaging were comparable. In 7/25, somatostatin receptor-PET/MRI showed more extensive disease, while in 9/25, somatostatin receptor-PET/MRI identified additional lesions. On vertex-to-thigh imaging, 1 of 17 patients was positive for metastatic disease, 8 of 17 were negative, and 8 of 17 demonstrated incidental findings. CONCLUSIONS: Somatostatin receptor-PET detected additional lesions and more extensive disease than contrast-enhanced MR imaging alone, while vertex-to-thigh imaging showed a low incidence of metastatic disease. Somatostatin receptor-PET/MRI enabled superior anatomic delineation of tumor burden, while any discrepancies were readily addressed. Somatostatin receptor-PET/MRI has the potential to play an important role in presurgical and radiation therapy planning of head and neck neuroendocrine tumors.

Multimodality Imaging in Primary Progressive Aphasia.

Primary progressive aphasia is a clinically and neuropathologically heterogeneous group of progressive neurodegenerative disorders, characterized by language-predominant impairment and commonly associated with atrophy of the dominant language hemisphere. While this clinical entity has been recognized dating back to the 19th century, important advances have been made in defining our current understanding of primary progressive aphasia, with 3 recognized subtypes to date: logopenic variant, semantic variant, and nonfluent/agrammatic variant. Given the ongoing progress in our understanding of the neurobiology and genomics of these rare neurodegenerative conditions, accurate imaging diagnoses are of the utmost importance and carry implications for future therapeutic triaging. This review covers the diverse spectrum of primary progressive aphasia and its multimodal imaging features, including structural, functional, and molecular neuroimaging findings; it also highlights currently recognized diagnostic criteria, clinical presentations, histopathologic biomarkers, and treatment options of these 3 primary progressive aphasia subtypes.

PET/MRI in Pediatric Neuroimaging: Primer for Clinical Practice.

Modern pediatric imaging seeks to provide not only exceptional anatomic detail but also physiologic and metabolic information of the pathology in question with as little radiation penalty as possible. Hybrid PET/MR imaging combines exquisite soft-tissue information obtained by MR imaging with functional information provided by PET, including metabolic markers, receptor binding, perfusion, and neurotransmitter release data. In pediatric neuro-oncology, PET/MR imaging is, in many ways, ideal for follow-up compared with PET/CT, given the superiority of MR imaging in neuroimaging compared with CT and the lower radiation dose, which is relevant in serial imaging and long-term follow-up of pediatric patients. In addition, although MR imaging is the main imaging technique for the evaluation of spinal pathology, PET/MR imaging may provide useful information in several clinical scenarios, including tumor staging and follow-up, treatment response assessment of spinal malignancies, and vertebral osteomyelitis. This review article covers neuropediatric applications of PET/MR imaging in addition to considerations regarding radiopharmaceuticals, imaging protocols, and current challenges to clinical implementation.

Neurovascular Complications in COVID-19 Infection: Case Series.

We present a series of 10 hospitalized patients with confirmed coronavirus 2019 infections who developed severe neurovascular complications and discuss the possible reasons for these findings and their relationship to the novel Severe Acute Respiratory Syndrome coronavirus 2 infection.

Hemorrhagic Posterior Reversible Encephalopathy Syndrome as a Manifestation of COVID-19 Infection.

We describe 2 hospitalized patients with confirmed coronavirus 19 (COVID-19) infection in whom brain imaging showed hemorrhagic posterior reversible encephalopathy syndrome, and we discuss the possible reasons for these findings and their relationship to the infection.

A bicentric comparative and prospective study between classic photovaporization and anatomical GreenLight laser vaporization for large-volume prostatic adenomas.

OBJECTIVE: Long-term outcome after prostate photovaporization (PVP) remains largely unknown, especially when performed on enlarged prostates. However, new vaporisation techniques (e.g., laser enucleation) are increasingly used. Our aim was to compare postoperative results after standard PVP to those of an anatomical technique. MATERIALS AND METHODS: This bicentric prospective study included males treated for enlarged prostate caused by benign prostatic hyperplasia using a GreenLight laser. Patients were preoperatively assessed according to prostate volume, post-void residual volume (PVR), maximum urinary-flow rate (Qmax), prostatic specific antigens, and International prostate symptom score (IPSS). Peroperative data included vaporization time, energy delivered, and operative length. Postoperative data at 1, 3, 6 and 12 months were compared with initial data; all complications were recorded. Comparisons were made between the conventional vaporization technique versus anatomical vaporization, which initially differentiated the peripheral zone of the prostate using an enucleation technique but no morcellation. RESULTS: Records from 106 surgical patients between December 2012 and December 2013 were analyzed. Operative length, vaporisation time, and energy used were greater in the anatomical PVP group. The average length of hospital stay (2.0 vs. 2.5 days), time with a catheter (1.3 vs. 1.9 days), IPSS (5.0 vs. 6.4), PVR (15.5 vs. 11.7mL), and Qmax (19.9 vs. 19.7mL/s) were comparable between the two groups. However, more complications occurred (27% vs. 37%), including stress urinary incontinence (0% vs. 8%) when using anatomic vaporization. CONCLUSION: Despite comparable groups and similar functional results, anatomical PVP caused more stress incontinence. However, the learning curve between the two techniques may explain this difference. LEVEL OF EVIDENCE: 4.

Optimized, Minimal Specific Absorption Rate MRI for High-Resolution Imaging in Patients with Implanted Deep Brain Stimulation Electrodes.

BACKGROUND AND PURPOSE: Obtaining high-resolution brain MR imaging in patients with a previously implanted deep brain stimulator has been challenging and avoided by many centers due to safety concerns relating to implantable devices. We present our experience with a practical clinical protocol at 1.5T by using 2 magnet systems capable of achieving presurgical quality imaging in patients undergoing bilateral, staged deep brain stimulator insertion. MATERIALS AND METHODS: Protocol optimization was performed to minimize the specific absorption rate while providing image quality necessary for adequate surgical planning of the second electrode placement. We reviewed MR imaging studies performed with a minimal specific absorption rate protocol in patients with a deep brain stimulator in place at our institution between February 1, 2012, and August 1, 2015. Images were reviewed by a neuroradiologist and a functional neurosurgeon. Image quality was qualitatively graded, and the presence of artifacts was noted. RESULTS: Twenty-nine patients (22 with Parkinson disease, 6 with dystonia, 1 with essential tremor) were imaged with at least 1 neuromodulation implant in situ. All patients were imaged under general anesthesia. There were 25 subthalamic and 4 globus pallidus implants. Nineteen patients were preoperative for the second stage of bilateral deep brain stimulator placement; 10 patients had bilateral electrodes in situ and were being imaged for other neurologic indications, including lead positioning. No adverse events occurred during or after imaging. Mild device-related local susceptibility artifacts were present in all studies, but they were not judged to affect overall image quality. Minimal aliasing artifacts were seen in 7, and moderate motion, in 4 cases on T1WI only. All preoperative studies were adequate for guidance of a second deep brain stimulator placement. CONCLUSIONS: An optimized MR imaging protocol that minimizes the specific absorption rate can be used to safely obtain high-quality images in patients with previously implanted deep brain stimulators, and these images are adequate for surgical guidance.

Percentage insula ribbon infarction of >50% identifies patients likely to have poor clinical outcome despite small DWI infarct volume.

BACKGROUND AND PURPOSE: Large admission DWI infarct volume (>70 mL) is an established marker for poor clinical outcome in acute stroke. Outcome is more variable in patients with small infarcts (<70 mL). Percentage insula ribbon infarct correlates with infarct growth. We hypothesized that percentage insula ribbon infarct can help identify patients with stroke likely to have poor clinical outcome, despite small admission DWI lesion volumes. MATERIALS AND METHODS: We analyzed the admission NCCT, CTP, and DWI scans of 55 patients with proximal anterior circulation occlusions on CTA. Percentage insula ribbon infarct (>50%, ≤50%) on DWI, NCCT, CT-CBF, and CT-MTT were recorded. DWI infarct volume, percentage DWI motor strip infarct, NCCT-ASPECTS, and CTA collateral score were also recorded. Statistical analyses were performed to determine accuracy in predicting poor outcome (mRS >2 at 90 days). RESULTS: Admission DWI of >70 mL and DWI-percentage insula ribbon infarct of >50% were among significant univariate imaging markers of poor outcome (P < .001). In the multivariate analysis, DWI-percentage insula ribbon infarct of >50% (P = .045) and NIHSS score (P < .001) were the only independent predictors of poor outcome. In the subgroup with admission DWI infarct of <70 mL (n = 40), 90-day mRS was significantly worse in those with DWI-percentage insula ribbon infarct of >50% (n = 9, median mRS = 5, interquartile range = 2-5) compared with those with DWI-percentage insula ribbon infarct of ≤50% (n = 31, median mRS = 2, interquartile range = 0.25-4, P = .036). In patients with admission DWI infarct of >70 mL, DWI-percentage insula ribbon infarct did not have added predictive value for poor outcome (P = .931). CONCLUSIONS: DWI-percentage insula ribbon infarct of >50% independently predicts poor clinical outcome and can help identify patients with stroke likely to have poor outcome despite small admission DWI lesion volumes.

Errors in laparoscopic surgery: what surgeons should know.

Some two decades after its introduction, minimal access surgery (MAS) is still evolving. Undoubtedly, its significant uptake world wide is due to its clinical benefits to patient outcome. These benefits include reduced traumatic insult, reduction of pain, earlier return to bowel function, decrease disability, shorter hospitalization and better cosmetic results. Nonetheless complications due to the laparoscopic approach are not rare as documented by several studies on task specific or procedure related MAS morbidity. In all these instances, error analysis research has demonstrated that an understanding of the underlying causes of these complications requires a comprehensive approach addressing the entire system related to the procedure for identification and characterization of the errors ultimately responsible for the morbidity. The present review covers definition, taxonomy and incidence of errors in medicine with special reference to MAS. In addition, possible root causes of adverse events in laparoscopy are explored and existing methods to study errors are reviewed. Finally specific areas requiring further human factors research to enhance safety of patients undergoing laparoscopic operations are identified. The hope is that awareness of causes and mechanisms of errors may reduce incidence of errors in clinical practice for the final benefit of the patients.

Parental role in the Intensive Care Unit for children affected by Werdnig Hoffmann disease.

AIM: The aim of this study was to determine the role of parents after extubation of their children affected by Spinal Muscular Atrophy Type 1 (SMA1) in the Pediatric Intensive Care Unit. Currently, children affected by SMA1 are often treated with non-invasive mechanical ventilation and mechanical support of cough. During the first two or three years of life they frequently present severe respiratory failure requiring intubation. Extubation may be at severe risk of failure even because of inadequate care. METHODS: Parents of SMA1 children were offered an early education on the most critical aspects and a training in non-invasive respiratory support after diagnosis. They were asked and allowed to stay as longer as possible with their child after extubation. Quality and quantity of care given by parents during the first 24 hours after extubation were recorded. RESULTS: All parents participated to the success of the weaning procedure: they gave continuous care and all children could be extubated. CONCLUSION: The presence of parents after extubation of SMA1 patients is important for the success of the procedure; otherwise, the presence of a skilled nurse is needed, with a nurse-patient ratio of 1:1.

A simple duplex-PCR protocol for routine diagnosis and follow up of canine leishmaniasis.

The introduction of PCR has efficiently improved diagnosis of canine leishmaniasis. In order to provide a robust, efficient and reliable diagnostic method, a duplex PCR assay targeting the Leishmania infantum kDNA minicircle and the canine GAPDH gene as inner control was designed. Sensitivity of the assay reached 0.15 parasites/ml blood. Development, testing and application of this system on a group of 10 dogs during therapy administration (60 days) are also described. Six dogs (out of eight that have been showing a positive PCR result on peripheral blood during the study) were tested negative at day 62, indicating a reduction of parasitaemia at the end of the treatment period. All the animals had a positive PCR on lymph node aspirate both at the beginning and at the end of treatment. These findings seem to suggest that, in order to test therapy efficacy, PCR on whole blood could be a useful assay in dogs that have a positive PCR at the beginning of the treatment, while PCR positivity on lymph nodes lasts longer than the observation period during therapy administration. The presence of the GAPDH inner control band efficiently contributed to prevent false negatives, by highlighting samples affected by haemoglobin inhibition or inappropriate DNA isolation.

[Quantitative PCR in the diagnosis of Leishmania]. / PCR quantitativa nella diagnosi di Leishmania.

Polymerase chain reaction (PCR) is a sensitive and rapid method for the diagnosis of canine Leishmania infection and can be performed on a variety of biological samples, including peripheral blood, lymph node, bone marrow and skin. Standard PCR requires electrophoretic analysis of the amplification products and is usually not suitable for quantification of the template DNA (unless competitor-based or other methods are developed), being of reduced usefulness when accurate monitoring of target DNA is required. Quantitative real-time PCR allows the continuous monitoring of the accumulation of PCR products during the amplification reaction. This allows the identification of the cycle of near-logarithmic PCR product generation (threshold cycle) and, by inference, the relative quantification of the template DNA present at the start of the reaction. Since the amplification product are monitored in "real-time" as they form cycle-by-cycle, no post-amplification handling is required. The absolute quantification is performed according either to an internal standard co-amplified with the sample DNA, or to an external standard curve obtained by parallel amplification of serial known concentrations of a reference DNA sequence. From the quantification of the template DNA, an estimation of the relative load of parasites in the different samples can be obtained. The advantages compared to standard and semi-quantitative PCR techniques are reduction of the assay's time and contamination risks, and improved sensitivity. As for standard PCR, the minimal components of the quantitative PCR reaction mixture are the DNA target of the amplification, an oligonucleotide primer pair flanking the target sequence, a suitable DNA polymerase, deoxynucleotides, buffer and salts. Different technologies have been set up for the monitoring of amplification products, generally based on the use of fluorescent probes. For instance, SYBR Green technology is a non-specific detection system based on a fluorescent dsDNA intercalator and it is applicable to all potential targets. TaqMan technology is more specific since performs the direct assessment of the amount of amplified DNA using a fluorescent probe specific for the target sequence flanked by the primer pair. This probe is an oligonucleotide labelled with a reporter dye (fluorescent) and a quencher (which absorbs the fluorescent signal generated by the reporter). The thermic protocol of amplification allows the binding of the fluorescent probe to the target sequence before the binding of the primers and the starting of the polymerization by Taq polymerase. During polymerization, 5'-3' exonuclease activity of Taq polymerase digests the probe and in this way the reporter dye is released from the probe and a fluorescent signal is detected. The intensity of the signal accumulates at the end of each cycle and is related to the amount of the amplification product. In recent years, quantitative PCR methods based either on SYBR Green or TaqMan technology have been set up for the quantification of Leishmania in mouse liver, mouse skin and human peripheral blood, targeting either single-copy chromosomal or multi-copy minicircle sequences with high sensitivity and reproducibility. In particular, real-time PCR seems to be a reliable, rapid and noninvasive method for the diagnosis and follow up of visceral leishmaniasis in humans. At present, the application of real-time PCR for research and clinical diagnosis of Leishmania infection in dogs is still foreseable. As for standard PCR, the high sensitivity of real-time PCR could allow the use of blood sampling that is less invasive and easily performed for monitoring the status of the dogs. The development of a real-time PCR assay for Leishmania infantum infection in dogs could support the standard and optimized serological and PCR methods currenly in use for the diagnosis and follow-up of canine leishmaniasis, and perhaps prediction of recurrences associated with tissue loads of residual pathogens after treatment. At this regard, a TaqMan Real Time PCR method developed for the quantification of Leishmania infantum minicircle DNA in peripheral blood of naturally infected dogs sampled before and at different time points after the beginning of a standard antileishmanial therapy will be illustrated.

[Early postoperative hyperamylasemia after parathyroidectomy for primary hyperparathyroidism]. / Early postoperative hyperamylasemia after parathyroidectomy for primary hyperparathyroidism.

AIM: The postoperative pancreatitis was a classical complication in the historical series of primary hyperparathyroidism (HPT), but the causal association was never demonstrated and even recent studies denied it. The aim of this study was to determine the augmentation of postoperative amylasemia, and its possible clinical traduction in patients operated for primary HPT. MATERIAL AND METHODS: Fifty consecutive patients operated for cure of a primary HPT were included in this study. Total amylase, as well as isoenzyme fractions P (pancreatic) and S (salivary), calcium, phosphorus and intact PTH serum concentrations were determined on the days prior and after parathyroidectomy. Fifteen normocalcemic patients operated for secondary HPT constituted the control group. RESULTS: The study deals with 42 female and eight male patients, their mean age was 58.5 years (range 19-89 years). All patients underwent parathyroidectomy for adenoma or hyperplasia. No patient had pancreatitis before parathyroidectomy. Postoperative amylasemia developed in four patients (8%), one with increased total amylase and P fraction, one with only increased total amylase, and two with increased total amylase and S fraction. No patients exhibited abdominal symptoms suggesting acute pancreatitis in the postoperative period. There was no correlation between pre- and post-operative calcium serum levels and pre- and post-operative amylasemia. In the secondary HPT group no significant diminution of the total amylasemia or of P and S fractions were observed. CONCLUSIONS: These results indicate that acute pancreatitis is an exceptional postoperative complication of primary HPT nowadays. The 8% incidence reported in the present study matches the incidence of hyperamylasemia reported postoperatively in non-abdominal or non-parathyroid surgery.

A symbiont of the tick Ixodes ricinus invades and consumes mitochondria in a mode similar to that of the parasitic bacterium Bdellovibrio bacteriovorus.

We have recently performed molecular characterisation of an intracellular alpha-proteobacterium, named IricES1, which resides in the ovarian tissue of female Ixodes ricinus ticks from Italy. A unique characteristic of this bacterium is its ability to invade the mitochondria of the cells in which it resides. Although some ultrastructural studies have been performed on close relatives of this bacterium from I. ricinus in England and Switzerland, a number of questions remain about its movement within ovarian tissues and mitochondria. We have performed the first detailed ultrastructural examination of IricES1 in engorged female adult I. ricinus. Among our findings was that the bacterium enters mitochondria in a similar way to that employed by the 'predatory' bacterium Bdellovibro bacteriovorus, that is, between the inner and outer membranes. It then appears to multiply, with the new 'colony' consuming the mitochondrial matrix. Despite having many of their mitochondria consumed, oocytes appear to develop normally, and the bacteria are likely to be vertically transferred to all eggs.

Secondary migration of a central venous catheter: a rare complication.

The Authors describe a case of spontaneous migration in the right jugular vein of a central venous catheter tip, properly positioned in the right atrium through the right subclavian vein two days before.

Ultrastructural evidence of the degenerative events occurring during embryogenesis of the filarial nematode Brugia pahangi after tetracycline treatment.

Intracellular bacteria belonging to the genus Wolbachia have been described in filarial nematodes and these microorganisms appear to have evolved an obligatory mutualistic association with their filarial hosts. In fact, antibiotic treatment leads to the clearance of bacteria from worms resulting in a block in embryogenesis and, eventually, death of adult filariae. Currently, the antifilarial action of antibiotic treatment is interpreted as a secondary consequence of the bacteriostatic activity against Wolbachia endosymbionts. Here, we demonstrate by transmission electron microscopy the degenerative events occurring during embryogenesis of Brugia pahangi after tetracycline treatment. After 56 days of treatment the cytoplasm of hypodermal cords was totally void of Wolbachia and numerous vacuoles, residual of cytolitic activity, were observed. In the ovary, the morphology of the oocytes was well conserved 33 days after treatment, but the texture of symbiotic bacteria appeared altered. After 56 days of treatment embryogenesis was dramatically affected and the terminal portion of the ovary appeared totally empty. The authors suggest that the symbiotic bacteria play a direct role in worm metabolism and a long-term bacteriostatic effect may block bacterial activity involved in the active control of cytolysis. As a consequence, the bacteriophorous vacuole is transformed into a digestive vacuole and the whole symbiotic population is disrupted.