Negative spot sign in primary intracerebral hemorrhage: potential impact in reducing imaging.

Intracerebral hemorrhage (ICH) is one of the most devastating and costly diagnoses in the USA. ICH is a common diagnosis, accounting for 10-15 % of all strokes and affecting 20 out of 100,000 people. The CT angiography (CTA) spot sign, or contrast extravasation into the hematoma, is a reliable predictor of hematoma expansion, clinical deterioration, and increased mortality. Multiple studies have demonstrated a high negative predictive value (NPV) for ICH expansion in patients without spot sign. Our aim is to determine the absolute NPV of the spot sign and clinical characteristics of patients who had ICH expansion despite the absence of a spot sign. This information may be helpful in the development of a cost effective imaging protocol of patients with ICH. During a 3-year period, 204 patients with a CTA with primary intracerebral hemorrhage were evaluated for subsequent hematoma expansion during their hospitalization. Patients with intraventricular hemorrhage were excluded. Clinical characteristics and antithrombotic treatment on admission were noted. The number of follow-up NCCT was recorded. Of the resulting 123 patients, 108 had a negative spot sign and 7 of those patients subsequently had significant hematoma expansion, 6 of which were on antithrombotic therapy. The NPV of the CTA spot sign was calculated at 0.93. In patients without antithrombotic therapy, the NPV was 0.98. In summary, the negative predictive value of the CTA spot sign for expansion of ICH, in the absence of antithrombotic therapy and intraventricular hemorrhage (IVH) on admission, is very high. These results have the potential to redirect follow-up imaging protocols and reduce cost.

The "O" sign, a simple and helpful tool in the diagnosis of laparoscopic adjustable gastric band slippage.

OBJECTIVE: The purpose of this article is to describe a sign on radiography for gastric band slippage, a complication of adjustable gastric banding surgery, and to emphasize the importance of this finding to radiologists and clinicians. MATERIALS AND METHODS: We reviewed the radiologic findings in 55 consecutive patients who underwent laparoscopic gastric banding. Between January 2007 and September 2008, gastric band slippage was diagnosed in four patients at our institution. All patients underwent an upper gastrointestinal examination at the time of presentation. On the basis of either radiographic findings or clinical presentation, all patients underwent exploratory surgery. RESULTS: In all four patients with surgically proven gastric band slippage, the initial abdominal radiograph showed an O-shaped configuration of the gastric band, which we have termed the "O" sign. Baseline upper gastrointestinal examinations were available for comparison in all patients. In each case, the O-shaped configuration of the band was a change from its rectangular appearance when in the proper position. CONCLUSION: As laparoscopic adjustable gastric banding is increasingly used, more patients will present to the emergency department with complications of the procedure, particularly complications from band slippage. Because the consequences of slippage may require acute surgical intervention, it is imperative that the radiologist is familiar with the surgical technique to correctly position the band and the appearances of a gastric band when correctly and incorrectly positioned. Identification of the O sign on radiography can potentially aid the radiologist, surgeon, or emergency department physician in the early detection of gastric band slippage and appropriate patient triage.

Amyloidosis in the head and neck: CT findings with clinicopathological correlation.

PURPOSE: To characterize the CT imaging features of head and neck amyloidosis and correlate with extent of disease and clinical outcomes. MATERIALS AND METHODS: This retrospective study included 80 patients with head and neck amyloidosis who underwent soft tissue neck CT imaging between November 2003 and April 2018. The CT imaging features including lesion distribution, morphology (focal, diffuse/circumferential, or combined), presence and pattern of calcification, (punctate or diffuse), and thickness of airway lesion were evaluated and compared with the extent of amyloidosis (localized or systemic), and clinical course (stable, no recurrence, or progression requiring repeated surgical treatment). RESULTS: Localized disease (83.8%, 67/80) was most common with AL type (97.6%, 41/42) representing nearly all cases of head and neck amyloidosis. The larynx was the most frequently affected organ (60.0%, 48/80), specifically the glottis (43.8%, 35/80). Calcification was seen in 65.0% of cases (52/80). Non-airway or tongue lesions were significantly associated with systemic (92.3%, 12/13) as opposed to localized amyloidosis (4.5%, 3/67; P < 0.001). Repeated surgical treatment was significantly associated with laryngeal amyloidosis (35.3%, 12/34; P = 0.002) and multi-centric disease (33.3%, 10/30; P = 0.048). Airway wall thickness in patients who required repeated surgical treatment was significantly greater than in patients with stable or no recurrent disease (P = 0.016). CONCLUSION: Knowledge of the imaging features of head and neck amyloidosis can aid the diagnosis, disease monitoring, and prediction of patients requiring repeated surgical intervention.

The measurement of blood and plasma nitrite by chemiluminescence: pitfalls and solutions.

There are a number of difficulties involved in the quantification of nitrite in biological systems. These difficulties result from oxidation of nitrite (within minutes) by heme proteins, such as hemoglobin, myoglobin, cytoglobin, and neuroglobin; its low levels in vivo; and its ubiquitous presence in laboratory buffers and glassware. The goal of this review is to present an assay suitable for the sensitive and specific measurement of intravascular nitrite in mammals using the chemiluminescence-based nitric oxide analyzer and to inform the reader on how to evade the pitfalls pertinent to nitrite determination in biological matrices.

Imaging of penetrating injuries of the head and neck:current practice at a level I trauma center in the United States.

Penetrating neck injuries are commonly related to stab wounds and gunshot wounds in the United States. The injuries are classified by penetration site in terms of the three anatomical zones of the neck. Based on this zonal classification system, penetrating injuries to the head and neck have traditionally been evaluated by conventional angiography and/or surgical exploration. In recent years, multidetector-row computed tomography (CT) angiography has significantly improved detectability of vascular injuries and extravascular injuries in the setting of penetrating injuries. CT angiography is a fast and minimally invasive imaging modality to evaluate penetrating injuries of the head and neck for stable patients. The spectrum of penetrating neck injuries includes vascular injury (extravasation, pseudoaneurysm, dissection, occlusion, and arteriovenous fistula), aerodigestive injury (esophageal and tracheal injuries), salivary gland injury, neurologic injury (spinal canal and cerebral injuries), and osseous injury, all of which can be evaluated using CT angiography. Familiarity with the complications and imaging characteristics of penetrating injuries of the head and neck is essential for accurate diagnosis and optimal treatment.