Ultra-sensitive broadband "AWESOME" electric field receiver for nanovolt low-frequency signals.

Longwave (defined here as 500 Hz-500 kHz) radio science drives many scientific and engineering applications, including lightning detection and geolocation, subsea and subsurface sensing and communications, navigation and timing, and ionospheric and magnetospheric remote sensing. The hardware performance (i.e., sensitivity and bandwidth) of the receivers that detect long waves determines the maximum amount of information that can be extracted from the acquired data. In this paper, we present and describe an ultra-sensitive electric field receiver that enables broadband radio reception from near-DC up to 470 kHz, augmenting the legacy of the "Atmospheric Weather Electromagnetic System for Observation Modeling and Education" (AWESOME), a state-of-the-art magnetic field receiver completed previously. The AWESOME electric field receiver uses capacitive coupling with a dipole antenna to detect the electric field components of long waves and attains a sensitivity of 0.677 nV/(mHz). This sensitivity allows the detection of natural radio atmospherics and man-made beacon emissions at a global range. The AWESOME electric field receiver can also be integrated with a magnetic field sensor for simultaneous electric and magnetic field reception. In this paper, we detail the design of the receiver, including the receiver architecture, its working principles, design methodology, and trade-offs. We showcase the receiver performance characterized through both numerical models and empirical measurements. We demonstrate a novel calibration method that is quick and straightforward, suitable for deployments in the field. Finally, we demonstrate some novel applications enabled by this receiver's excellent sensitivity and simultaneous reception capability of electric and magnetic field components of long waves.

Intraductal papillary mucinous neoplasm of the pancreas associated with neuroendocrine tumor: A case report.

INTRODUCTION: Intraductal papillary mucinous neoplasm is an uncommon cystic tumor of pancreas that can be associated with ductal adenocarcinoma. Coexistence of pancreatic IPMN and neuroendocrine tumor is very rare. Here, we report the imaging features of mixed type intraductal papillary mucinous neoplasia of the pancreas with high grade dysplasia together with neuroendocrine carcinoma and perform review of the literature. PRESENTATION: A 68-year old patient has been evaluated for possible IPMN that was suspected during ultrasound. MRI revealed main and side branch duct dilatations. At the head, a contrast enhancing nodular lesion was identified. Due to the presence of high risk stigmata according to guidelines, surgery was performed. Histopathological examination revealed an unusual association, including mixed type IPMN and neuroendocrine carcinoma. DISCUSSION: The concomitant occurrence of pancreatic IPMN and neuroendocrine tumor has been reported in case studies and brief reviews. Yet, the imaging findings and underlying molecular mechanisms of this entity has not been fully understood. In addition to this unusual association, pancreatic intraepithelial neoplasia was also detected in the present case. Although majority of neuroendocrine tumor associated IPMNs were reported to be having low grade dysplasia, our patient had high grade dysplasia. Further studies and reviews with larger groups are needed to establish imaging features and underlying molecular mechanisms of this rare association. CONCLUSION: Although the major concern during work-up of IPMN is presence of associated pancreatic ductal adenocarcinoma, the possibility of neuroendocrine tumor, in the presence of a hypervascular solid foci on imaging studies should be kept in mind.

A new parameter in the diagnosis of vascular erectile dysfunction with penile Doppler ultrasound: cavernous artery ondulation index.

AIM: Our aim is to introduce the cavernous artery ondulation index (CA-OI) as a new parameter that could be accepted as an indirect indicator of vascular hemodynamics and also gives us information about the efficiency of erection. PATIENTS AND METHODS: A total of 27 patients with erectile dysfunction were evaluated with penile Doppler ultrasonography (PDUS). After injection of papaverine intracavernously, arterial diameter and peak-systolic and end-diastolic velocities were measured. For measuring at a standart time, five minutes after injection, bilateral cavernosal arteries were examined and gray scale and color Doppler US images through the long axis were recorded at the mentioned phases. Cavernosal artery ondulation index (CA-OI) showing the amount of ondulation was calculated for each subject using these images. RESULTS: In 9 of total 27 patients, erection could not pass the tumescence phase with 3 flaccid phases, while the remaining 18 had full erection. Mean CA-OI values were measured as 2.51±0.37 mm, 3.15±0.38 mm, and 2.68±0.09 mm in normal, arterial insufficiency and venous insufficiency groups, respectively. CONCLUSIONS: It is possible to differentiate the arterial insufficiency by using the cut-off value of CA-OI ≥ 2.5 values as a criteria.

Indirect measurement of the temporomandibular joint disc elasticity with magnetic resonance imaging.

OBJECTIVES: The radiological evaluation of the temporomandibular joint (TMJ) consists of demonstrating the morphological features of the disc and the condyle in closed and open mouth positions using MRI. We aimed to determine elasticity of the disc by measuring the amount of elongation during mouth opening. METHODS: The study population included 49 patients. Coronal T(1) and multiplane oblique T(2) weighted gradient recalled echo sequences were acquired in open and closed mouth positions. Biconcave TMJ disc lengths were measured on sagittal oblique images in both positions. Elongation ratio (ER) was calculated for each patient. According to the findings, TMJs are classified into subgroups: normal (N), dislocated with reduction (DWR), pure DWR (p-DWR), DWR with additional findings (DWR-a) and dislocated without reduction (DWOR). Statistical analysis was performed using the χ(2) test and receiver operating characteristic analysis. RESULTS: Out of 98 discs, 22 of them were evaluated as N, 60 as DWR (28 p-DWR, 32 DWR-a) and 16 as DWOR. There was no significant difference among the disc lengths in three subgroups at the closed mouth position (P = 0.15), whereas there was significant difference in the open mouth position (P = 0.0001). There was significant difference among subgroups as far as ER is concerned (P < 0.05). CONCLUSIONS: ER is a strong indicator of elasticity. Compared with the N group, elasticity of the disc was not significantly different in the p-DWR group but the disc elasticity was very degraded in DWR-a and in DWOR. A negative conversion or one smaller than 1.4 mm means a compromised disc, although sometimes it will possess normal anatomical configurations or signal characteristics.

Evaluation of the gastro-oesophageal junction: defining the incompetent cardio-oeosophageal angle non-invasively with ultrasound and computerized tomography.

This study aimed to demonstrate the presence of gastro-oesophageal reflux disease (GORD) non-invasively using ultrasound (US) and computerized tomography (CT). Intra-abdominal oesophageal length (IAOL) and cardio-oesophageal angle (COA) were measured by US in 25 patients with known reflux and in 25 healthy subjects (control group). CT images of 42 patients with reflux disease and 44 controls were reviewed retrospectively, and IAOL and COA were measured on curved multiplanar format images. Using a cut-off value for IAOL of 20.5 mm, the sensitivity to detect GORD with US was 96% and the specificity was 80% and, with CT, the sensitivity was 95% and the specificity was 78%. A cut-off value of 138.5° for COA yielded sensitivity and specificity values for GORD detection of 76% and 72% with US and 83% and 80% with CT, respectively. In conclusion, with equivocal diagnostic findings, IAOL and COA are useful parameters that can be determined non-invasively by US or CT and may aid diagnosis and treatment choices for patients with suspected GORD.

Nodule or pseudonodule? Differentiation in Hashimoto's thyroiditis with sonoelastography.

Fine needle aspiration biopsy (FNAB) is the gold standard for the diagnosis of lymphoma in Hashimoto's thyroiditis and is able to differentiate between benign, inflammatory or malignant nodules, classifying them as either true nodules or pseudonodules. This technique is, however, invasive. The present study aimed to differentiate pseudonodules from true nodules by sonoelastography, a non-invasive technique, in 54 patients with Hashimoto's thyroiditis. The accuracy of sonoelastography to differentiate between true or pseudonodules was compared with the gold standard FNAB and with grey scale ultrasonography. The nodules were categorized into three groups: non-demarcated hypoechogenic, demarcated hyperecho genic, and demarcated hypoechogenic. Sono elastography findings were concordant with the cytopathological results and demonstrated that sono elastography was able to detect true thyroid nodules often misdiagnosed by conventional grey scale ultrasonography. Sonoelastography was found to have increased sensitivity for true nodule diagnosis compared with conventional grey scale ultrasonography and may eliminate unnecessary FNABs being carried out.

Imaging features of a cecal lipoma as a lead point for colo-colonic intussusception.

Intussusception is a rare occurrence in the adult population with most of the cases seen during the childhood period. Compared with the pediatric intussusceptions, there is more often an underlying cause in adults. Lipoma as a lead point for colonic intussusception is rare. Ultrasound may be helpful in the diagnosis, but computed tomography is more reliably used for differential diagnosis. An adult patient with colo-colonic intussusception diganosed with ultrasound and confirmed with computed tomography is presented.

Primary epiploic appendagitis: the role of computed tomography in diagnosis.

Primary epiploic appendagitis is a rare entity that occurs due to torsion and inflammation of the epiploic appendages. Clinically, this entity may be mistaken for acute abdomen with resultant unnecessary surgery. In contrast to acute surgical abdomen, epiploic appendagitis usually does not require surgical treatment; most of the patients resolve with conservative management. Diagnosis can be achieved with imaging modalities of which computed tomography is the gold standard procedure. Herein, a patient who presented with acute abdomen like clinical picture, with the computed tomography demonstration of primary epiploic appendagitis, is presented.

Cystic splenosis mimicking a renal mass: a case report and review of the literature.

Splenosis is a well-known entity, caused by autotransplantation of splenic tissue as a result of trauma or splenectomy. Patients are generally asymptomatic, and this entity is diagnosed during routine diagnostic imaging. Cystic changes in splenic implants have been defined before but, as to our knowledge, radiological demonstration of cystic components has not been published in the literature. It is well-known that unusual locations of the splenic implants create diagnostic problems, sometimes leading to unnecessary surgical interventions. In this report splenosis, mimicking a renal tumour, with cystic changes in the biggest splenule, and diagnosis with ferrumoxide-enhanced MRI is presented.

Vasculopathic changes in the cerebral arterial system with neurobrucellosis.

Brucellosis is a zoonotic disease characterized by multisystem involvement. Nervous system involvement is rare, with a reported incidence of 3%-13%. Brucellosis can also be manifested in the form of vasculopathy. Cerebral vasculopathy due to brucellosis is a very rare entity, with only a few cases reported in the literature. We present a patient with neurobrucellosis who had involvement of cerebral vasculature demonstrated by angiography.