Lateral Decubitus Views Research Articles

Yield of abdominal radiographs in children with suspected intussusception; rate of pneumoperitoneum and other abdominal pathology

ObjectivesUltrasound is the criterion standard imaging modality for the diagnosis of intussusception. However, to our knowledge the utility of abdominal radiographs to concurrently screen for pneumoperitoneum or other abdominal pathology that could have a similar presentation has not been studied. Our institutional protocol requires the performance of AP supine and left lateral decubitus views of the abdomen prior to ultrasound evaluation for intussusception, providing an opportunity to examine the yield of abdominal radiographs in this setting.Our primary objective was to determine the rate of pneumoperitoneum on screening abdominal radiographs in children undergoing evaluation for intussusception. Our secondary objective was to determine the rate that other clinically significant pathology is found on these screening abdominal radiographs. MethodsWe performed a retrospective chart review of all patients under 6 years of age who had any imaging ordered in our large urban pediatric emergency department to evaluate for suspected intussusception during the calendar years 2018–2020. Results1115 patient encounters met our inclusion criteria. Among 1090 who had screening abdominal radiographs, 82 (8%) had findings concerning for intussusception. Of those not concerning for intussusception, 635 (58%) were read as normal, 263 (24%) showed moderate to large stool burden, 107 (10%) showed generalized bowel distention, and 22 (2%) showed abnormal gastric distention. Individually the remainder of all other findings compromised <1% of encounters and included radiopaque foreign body (8), intraabdominal calcification (4), pneumonia/effusion (3), pneumatosis intestinalis, abdominal mass (2), diaphragmatic hernia (1), rib fracture (1), appendicolith (1), feeding tube malposition (1), and bowel wall thickening (1). In one encounter the patient had a bowel perforation with pneumoperitoneum present secondary to ingestion of multiple magnets. ConclusionsOur study indicates that radiograph-detected pneumoperitoneum is rare in children with suspected intussusception. Constipation is the most common abnormal finding on screening radiographs. Other findings occur in approximately 15% of total cases, some of which require further workup.

A review of plain radiographic methods for measuring femoral version after total hip arthroplasty and validation of modified Budin’s method in Indian population

BackgroundMultiple plain radiographic methods; cross table radiographic method, modified Budin method, projected neck-shaft angle method, and trans lateral decubitus view method using Ogata-Goldsand formula, have been described in literature for measurement of femoral stem version (FSV) after total hip arthroplasty (THA). PurposeTo review these multiple radiographic methods and also determine validity and accuracy of modified Budin method in Indian population. Patients and methodsA literature search for different methods described for FSV measurement was performed and these methods were reviewed. In addition, for validation of modified Budin method in Indian population, data was collected for 36 THAs prospectively. A posteroanterior radiograph with patient sitting in 90° hip flexion and 30° abduction was taken 3 weeks and 6 weeks after surgery for calculating the FSV using modified Budin method. At 3 weeks, a CT scan was also done for version measurement. Intra and interobserver reliability, and reproducibility of radiographic FSV measurement, and the correlation between CT scan and radiographic FSV measurement were statistically calculated. ResultsAll the reviewed studies demonstrated that their method is comparable to CT method for FSV measurement, except FSV measured on cross table radiographic view. However, there were only one or at most two studies of every method described except for modified Budin technique. The mean FSV in our prospective case series using ‘modified Budin’ method was 11.6° which was comparable to the mean of CT scan version measurement (12.3°). The mean difference was 0.7° which was not statistically significant (p value > 0.05). In addition, there was high intra-class correlation coefficient in radiographic FSV for both intra- and inter-observer reliability. ConclusionMultiple methods have been described and validated in literature, however, the ‘modified Budin’ view have proved multiple times to have excellent reliability and validity for easy measurement of FSV.

Chest radiographs and computed tomography scans in children with airway foreign body

Purpose: This study aimed to evaluate the diagnostic value of radiologic findings in children with suspected foreign body aspira tion. Methods: A retrospective medical chart review was done on 32 children with suspected foreign bodies in terms of age, sex, symp toms, signs, bronchographic findings, and type and location of foreign bodies. The diagnostic value of radiography was analyzed: 29 with chest anteroposterior (AP) or posteroanterior (PA) view, 23 with chest lateral decubitus view, 27 with chest computed tomogra phy (CT), 29 with chest AP, PA or chest lateral decubitus view, and 25 with bronchoscopy. Results: As a measure for detecting foreign body aspiration, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of radiologic findings were: chest AP or PA view, 50%, 100%, 100%, 29.4%, and 58.6%, respectively; chest lateral decubitus view, 57.9%, 50.0%, 84.6%, 20.0%, and 56.5%, respectively; chest AP, PA or chest lateral decubitus view, 69.6%, 66.7%, 88.8%, 36.4%, and 69.0%, respectively; and chest CT, 100.0%, 85.7%, 95.2%, 100.0%, and 96.2%, respectively. Conclusion: There is clinical benefit to take chest radiographs to diagnose foreign body aspiration. However, based on the results of this study, it may be not necessary to take chest lateral decubitus to diagnose foreign body aspiration. If chest radiographs show unilateral hyperinflation, foreign body aspiration can be diagnosed. In cases of normal chest radiography and history of a witnessed choking episode combined with positive signs, the diagnosis of airway foreign body aspiration should be made by using chest CT. (Allergy Asthma Respir Dis 2018;6:241-247)

Are bilateral decubitus views necessary in assessing for vertebral compression fractures using DXA vertebral fracture assessment?

The diagnostic accuracy of vertebral fracture assessment (VFA) can be influenced by poor patient position and scoliosis. This study aims to assess the differences in VFA diagnostic accuracy for right and left lateral decubitus views and the effect of scoliosis. One hundred fourteen postmenopausal women received right and left lateral thoracolumbar spine dual-energy VFA and radiography. Cobb angles were measured from the posteroanterior absorptiometry image, and lumbar spine radiography was the standard reference for vertebral fracture and also provides the levels investigated. McNemar's test was used to compare accuracy between the two decubitus position and Fisher's exact test was used for patients with and without scoliosis. Forty-two vertebral fractures (VFs) were identified. There was no significant difference in sensitivity (p=0.125) or specificity (p=0.866) between the left lateral decubitus (64.3, 97.2%) and right lateral decubitus (76.2, 91.1%), respectively, views. Scoliotic patients had a significantly worse specificity (92.7 vs 98.1%, p=0.003) than patients without scoliosis; however, a combination of both decubitus positions significantly improved specificity (p<0.001). Right and left side lateral decubitus views have excellent agreement with radiography and similar diagnostic accuracy in the detection of VFs. Thus, the current practice of performing only one side is valid. With scoliosis, bilateral decubitus views can improve the specificity of detecting VF; however, this would increase radiation dose.

Infant with Respiratory Distress

Subxiphoid chest ultrasonography is performed in an infant with respiratory distress. See video below to review. Video. Click here to view the video. Of the following chest radiographs shown on the next page, the most likely chest radiograph in this infant is: 1. 2. 3. 4. Correct Response: Radiograph C. The focused subxiphoid chest ultrasonogram of this infant was obtained in the transverse plane to assess for diaphragmatic movement. The video shows decreased excursion of the left hemidiaphragm during both inspiration and expiration (still image shown in the Figure). The right hemidiaphragm has normal movements. There is no evidence of a pleural effusion or extrapleural air. These ultrasonographic findings are most consistent with a left diaphragmatic paresis. Figure. Still image of subxiphoid chest ultrasonography in a neonate with respiratory distress. The left diaphragm remains flaccid throughout the breathing cycle. Radiograph C is the most likely chest radiograph of the infant in the video. This image shows an elevated left hemidiaphragm, corresponding to a unilateral left diaphragmatic paresis. The lateral decubitus view in Radiograph A shows a left pleural effusion that layers out when the infant …

Within Normal Limits

Figure: Radiographs are not reliable to evaluate for ileocolic intussusception, but can be a helpful preliminary study to exclude worrisome findings such as free air. Ileocolic intussusception appears as a soft tissue mass on abdominal radiographs, sometimes with a targetoid appearance. The left lateral decubitus view is also important because it evaluates for free intraperitoneal air, which is a contraindication for an air enema.FigureFigureFigureA 3-year-old girl presented to the emergency department with two days of worsening abdominal pain occurring every 60 to 90 minutes that is now increasing to every 20 minutes. She has had no vomiting or diarrhea, and her father reported no fever. Initial imaging should include a left lateral decubitus radiograph of the abdomen to evaluate for more worrisome etiologies of acute abdomen such as obstruction or free air. Ileocolic intussusception appears as a soft tissue mass in the right upper or lower quadrants. Left lateral decubitus views excludes free intraperitoneal air, which is a contraindication to air enema.Figure: Ultrasound of the abdomen shows a targetoid lesion in the right upper quadrant, shown here in transverse view, which is compatible with an ileocolic intussusception. The color Doppler image shows that the soft tissue mass is hyperemic, suggesting the bowel is still viable.Figure: This fluoroscopic image was taken during an air enema. There is a soft tissue mass, the ileocolic intussusception, in the right upper quadrant. This is displaced proximally with air during the procedure. Post-procedural radiograph showed no soft tissue mass in the right upper or lower quadrants. Gas was also seen in the region of the terminal ileum, confirming reduction of the intussusception.A dedicated ultrasound of the abdomen to evaluate for intussusception should be performed next. It appears as a targetoid soft tissue mass with increased blood flow, which is evaluated by color Doppler. Air enema should be performed to reduce the ileocolic intussusception if it's positive on ultrasound. Several attempts should be made to reduce the intussusception. The likelihood of successful reduction, however, decreases with increasing length of symptoms. The mean duration of symptoms for successful reduction was 1.6 days versus 2.8 days in unsuccessful reductions in one study. Surgical reduction of the intussusception is necessary if air enema is unsuccessful. Ileocolic intussusception is a common cause of acute abdomen in infancy and early childhood. It occurs when the terminal ileum telescopes into the adjacent cecum and proximal colon. This can cause obstruction and eventually ischemia of the bowel. Ileocolic intussusception usually occurs in children from 6 months to 2 years. The common clinical presentation includes the triad of intermittent abdominal pain with currant-jelly stool and a palpable abdominal mass. Lead points of an ileocolic intussusception are most commonly lymph nodes, which can occur in post-viral syndrome or, less commonly, Meckel's diverticulum. The patient may be discharged after: Excluding an acute abdomen before ultrasound imaging. Using ultrasound of the abdomen to confirm the diagnosis without any radiation exposure. Treating with an air or contrast enema, the first line for an ileocolic intussusception. Opting for surgical reduction of the ileocolic intussusception if an air or contrast enema is unsuccessful. Share this article on Twitter and Facebook. Access the links in EMN by reading this on our website or in our free iPad app, both available at www.EM-News.com. Comments? Write to us at [email protected].

Inverted V sign.

Despite the ever-increasing utilization of CT, a supine abdominal radiograph can still be the ‘‘presenting’’ imaging study for patients with acute abdominal pain. Although less sensitive than upright or left lateral decubitus views, a supine frontal abdomen view thus can present the initial opportunity to detect pneumoperitoneum [1]. Among the many described radiographic signs is an ‘‘inverted V’’ visible in the pelvis (Fig. 1). Superomedially directed oblique lines are thought to represent gas outlining peritoneal folds that overlie either the obliterated umbilical arteries [2], or the inferior epigastric arteries [3]. As with any imaging evidence of pneumoperitoneum, the inverted V should prompt a search for perforated viscus.

Transient serosal enhancement mimicking pneumoperitoneum

Sir, In a prior issue of this journal, we reported two cases of a novel enhancement pattern involving the pericardium, peritoneum and soft tissues seen on radiographs in the early post-cardiac catheterization period [1]. Knowledge of this phenomenon is clinically important because the enhancement pattern renders a relative lucency over the liver. We report a third case of this radiographic phenomenon that mimicked the appearance of pneumoperitoneum and led to an exploratory laparotomy. A baby girl with hypoplastic left heart variant including a double-outlet right ventricle and restrictive atrial septum was born by cesarean section at 37 2/7 weeks to a gravida I para I woman. Cardiac catheterization was performed on the day the child was born for stent placement into veins decompressing into the left atrium. At 5 days old, the newborn was taken for a Norwood/Sano procedure and atrial septectomy. A complicated post-operative course followed, including renal insufficiency, respiratory failure, poor cardiac function, acidosis and delayed sternotomy closure. The infant was taken back to the cardiac catheterization lab to evaluate the pulmonary veins. A radiograph of the chest and abdomen obtained within 24 h of completion of the cardiac catheterization suggested the presence of free intraperitoneal air, characterized by a conspicuous relative lucency over the right upper quadrant (Fig. 1). A left lateral decubitus view did not confirm the presence of pneumoperitoneum. However, given the suggestive findings of pneumoperitoneum on the supine radiograph and the infant’s clinical condition, the child was taken to the operating room. Findings during the exploratory laparotomy were negative. The classic findings of pneumoperitoneum on supine abdominal radiography include radiolucency over the liver [2].

Konventionelle Abdomenübersichtsaufnahmen – welchen klinischen Nutzen hat die Aufnahme in Rückenlage?

To assess the diagnostic value of an additionally acquired plain abdominal radiograph in supine position. Two experienced radiologists evaluated retrospectively 2148 consecutive patients having plain abdominal radiographs acquired in a tertiary care center. There were 1385 patients having an erect view and 763 patients with a left lateral decubitus view. All patients had a second examination in supine position. First the radiographs in erect or decubitus view were evaluated regarding the presence and details of pathological changes. After 4 weeks all radiographs including the supine view were evaluated again. Next to pathological changes the additional value of the supine projection was assessed. The results were compared and the additional diagnostic value using the supine view was noted. We evaluated 2148 patients having a plain abdominal radiograph (1325 men, 823 women, mean 58.9 years, range 15-96 years). The average age within the group acquired with left decubitus view was 61.1 years, while patients having an erect view had a mean age of 57.0 years. For the first evaluation we found pathological changes in 10.5% (decubitus view: 13.1%, erect view 9.5%; p = 0.01). The most frequent diagnosis was ileus (7.7%) followed by abdominal free air (2.4%). The results were confirmed during the second reading in 99.2%. In 3.5% (decubitus view 5.8%, erect view 2.2%) more anatomical structures were depicted considering the supine projection and the decubitus/erect projections. The anatomical information was in no case relevant for the diagnosis. Having the information of an supine view additionally to an decubitus/erect view increases the depiction of anatomical structures up to 5.8%. Nevertheless there was no additional diagnostic relevant information based on the supine view.

The Differential Diagnosis of Right Lower Quadrant Pain: Radiological Clarification

The authors deserve a compliment for their excellent presentation, but a further clarification should be made concerning the necessary radiological studies. The patient with an acute abdomen (the subject of the article) should be studied not with abdominal plain films, but rather with an erect abdominal or left lateral decubitus view, and always with a horizontal beam projection. The patient must maintain this position for five to ten minutes. Only in this way can a perforation of the intestinal tract – e.g., in diverticulitis – be detected by the presence of air under the diaphragm on the right side, and only in this way can fluid levels be seen whose differing heights convey useful information about peristaltic activity. A chest x-ray should always be performed as well, with the patient standing, if possible. Urinary calculi should be sought with a non-contrast-enhanced CT scan as the imaging method of choice; a contrast-enhanced scan can be performed immediately afterward, of course, to answer other questions. Excretion urography is of secondary importance.

Is the Lateral Decubitus Radiograph Necessary for the Management of a Parapneumonic Pleural Effusion?

A pproximately 50% of patients who are admitted to the hospital with community-acquired pneumonia will develop a pleural effusion.1,2 While most parapneumonic effusions will resolve without specific therapy, approximately 10% will become complicated or progress to empyema.3 Because delays in the drainage of these clinically significant effusions have been associated with increased morbidity and mortality,4 prompt detection and accurate characterization of a parapneumonic effusion are important. Guidelines5 based on a consensus conference have comprehensively summarized the literature regarding parapneumonic effusions and have made specific recommendations for their management. Although this document reflects the “state of the art,” as the authors noted, most studies of parapneumonic effusions have been observational, often with a limited numbers of patients. One of the recommendations in the guidelines was that all patients with a parapneumonic effusion should have a chest radiograph performed with a lateral decubitus view.5 This recommendation also was incorporated into the American Thoracic Society guidelines6 for the care of adults with communityacquired pneumonia. The rationale is that if the thickness of the effusion on the lateral decubitus view is 1 cm, the effusion is small enough so that no further intervention is needed.1 While there is good evidence that small effusions resolve without specific therapy,1 the suggestion that a lateral decubitus radiograph is required to determine the appropriate course of action with respect to a parapneumonic effusion appears to have been made without sufficient supporting data. The purpose of this article is to review the indications and usage of the lateral decubitus chest radiograph and demonstrate its limited value in the setting of parapneumonic pleural effusions. Radiographs of the chest made with the patient in the standard erect position usually will not reveal the presence of a pleural effusion 300 to 500 mL in size, as the fluid usually pools in the posterior costophrenic sulcus.7,8 The varying volumes reported may be due to differences in patient size, as a larger individual probably can “hide” a larger volume of fluid than can a smaller individual. The lateral decubitus view was first described by Merlo Gomez and Heidenreich,9 in 1924, as a technique to identify the presence of small pleural effusions. Its first English-language description was by Rigler,7 in 1931, who used this technique to confirm the presence of pleural effusions in a small series of patients despite the absence of a visible effusion using the standard erect views. Subsequently, other investigators demonstrated that the sensitivity of this view can be increased by placing a pillow under the patient’s pelvis, so that the thorax slopes downward away from the lung base.10 By injecting known amounts of fluid into cadavers, in 1973 Moskowitz et al8 demonstrated that effusions as small as 5 to 10 mL could be detected using the lateral decubitus view.

Rapid Pleurodesis for Malignant Pleural Effusions

To determine the feasibility of rapid pleurodesis in patients with malignant pleural effusions in order to reduce hospital length of stay in patients with a limited life expectancy. Prospective case series. Two university hospital programs. Thirty-eight patients with symptomatic pleural effusions associated with malignancy. A 14F catheter was inserted percutaneously into the pleural space after radiographic confirmation of free fluid by lateral decubitus views. Following radiographic confirmation of complete fluid evacuation, a sclerosing agent (ie, talc slurry or bleomycin) was instilled into the pleural space. This was accomplished within 2 h of chest tube insertion, unless the tube was inserted in the evening or if the lung was trapped. After clamping the tube for 90 min, the pleural space was drained for 2 h, after which the chest tube was removed. The intervention was scored as "successful" if no radiographic evidence of fluid reaccumulation was noted at 4 weeks. A "partial successful" score indicated reaccumulation of fluid that did not produce symptoms and did not require repeat pleural drainage of any sort. All other outcomes were scored as "unsuccessful." Forty chest tubes were inserted into 38 patients. Four procedures revealed the presence of a trapped lung and did not result in any attempt at pleurodesis. Five patients who received pleurodesis died in less than 1 month and therefore were not evaluable. Two patients had technical problems with the chest tube and were not evaluable. Of the remaining 29 procedures, drainage procedures with pleurodesis were performed in 27 patients, a complete response was seen in 14 patients (48%), a partial response was seen in 9 patients (31%), and 6 patients (21%) did not respond to pleurodesis. Chemical pleurodesis was completed as an outpatient procedure in only two patients. In one of these, the outcome was unsuccessful. In the remainder, insertion of the chest tube in the evening or additional medical problems necessitated hospital admission, but the entire procedure was completed within 24 h. Chemical pleurodesis can be accomplished with good results in < 24 h in the majority of patients with malignant pleural effusions.

Overview of emergency radiological management of the pregnant patient, especially the traumatized pregnant patient

Both traumatic and nontraumatic acute emergencies are seen in hospitals in women of childbearing age. The effects of radiation are theoretically most deleterious from 10 days after conception until roughly the end of the first trimester. However, there should be no hesitation about performing appropriate emergency imaging studies at any time during pregnancy. If time permits, the presence and age of the fetus should be determined through physical examination, appropriate laboratory studies, and the obtaining of adequate medical historical information. Imaging studies can be roughly classified into two main categories, those with minimal radiation effect and those that may expose the fetus to significant potential ionizing energy. The radiologist must be responsible for the determination of the most appropriate studies needed and in what sequence. Traumatized pregnant patients especially require maternal and fetal monitoring prior to arrival at the hospital and throughout the hospital stay. Fetal demise is a significant risk in case of both minor and major trauma. Maternal survival is the most significant factor in fetal well-being, with a fetal death approaching 80 % in cases of maternal shock and almost 100 % where there is partial or complete abruptio placentae. Properly performed imaging of the pregnant female, where the uterus is not likely to be exposed to ionizing radiation, should be cause little concern. Depending on the clinical presentation, appropriate first images might include a cervical spine, a portable chest film, an abdominal film, and a lateral decubitus view to check for suspected bowel perforation. This should be rapidly followed by fetal and then maternal ultrasonography. Overall, CT may be the best single abdominal study for severe abdominal problems where multiple organ damage is suspected. MRI for neurological disease and carefully monitored of selective vascular embolization for life-threatening abdominal bleeding are other important legitimate imaging studies.

The value of inspiratory-expiratory lateral decubitus views in the diagnosis of small pleural effusions

AIM: To evaluate the usefulness of expiratory lateral decubitus views in the radiological diagnosis of small pleural effusions. MATERIALS AND METHODS: Patients referred for abdominal sonography for various reasons were examined for ultrasonographic features of pleural effusion. From November 1994 until May 1996,36 patients were found to have pleural effusion not exceeding 15 mm in depth and were included in the study. Erect posteroanterior, lateral, and lateral decubitus (in inspiration and expiration) ragiographs were performed in all patients. RESULTS: The mean thickness of fluid was 4.3 mm on inspiratory lateral decubitus radiographs and 7.9mm on expiratory lateral decubitus views ( P<0.005). In 31 of 36 patients (86%) there was a difference in the thickness of the fluid layer as measured in expiratory vs. inspiratory lateral decubitus radiographs. In 16% of patients, the fluid was not visible on inspiratory lateral decubitus projections. CONCLUSIONS: Expiratory lateral decubitus views may be useful for demonstrating small pleural effusions.

A Case of Pulmonary Gangrene Associated with Obstructive Pneumonia Due to Non-small Cell Lung Carcinoma

저자들은 비소세포폐암으로 인한 폐쇄성폐렴에 동반된 림프절종대의 혈관압박에 의해서 발생한 폐괴저를 수술적 치료로 호전시킨 1예를 경험하였기에 문헌고찰과 함께 보고하는 바이다. 【Pulmonary gangrene is a rare complication of severe pulmonary infection in which a pulmonary segment or lobe is sloughed. It is a part of a spectrum of disease in which lung tissue is devitalized(such as necrotizing pneumonia, pulmonary abscess), but apart from them, pulmonary gangrene has more extensive area of necrosis and thrombosis of large vessels plays a prominent role in the pathogenesis. We experienced a case of pulmonary gangrene in 71 year old female obstructive pneumonia patient with non-small cell lung carcinoma. She complained high fever, chill and despite treatment with antibiotics, pneumonia progressed to empyema. At that time chest radiograph showed a large cavity including sloughed lung tissue, freely moving to dependent position at both lateral decubitus view. RML and RLL were resected and compression of pulmonary vessels by enlarged lymph nodes was observed. Defervescence was obtained immediate postoperative period and the patient was discharged after infection control with antibiotics, chest tube drainage. The perivascular lymph nodes dissected during lobectomy were proved to be reactive hyperplasias. We speculated that the carcinoma caused obstructive pneumonia, in turn, resulted in reactive hyperplasia of the draining lymph nodes surrounding the large vessels and finally the lung tissues supplied by them necrotized and sloughed.】

Colonic pseudo-obstruction: value of prone lateral view of the rectum.

Collection of fluid within the rectum of patients with gas-distended bowel can simulate as obstructive lesion. In 12 patients with suspected distal colonic obstruction on plain radiographs, we obtained 2 additional films comprising a right lateral decubitus view of the abdomen followed by a prone lateral view of the pelvis. Significant gaseous distension of the rectum was achieved in 75% of the 8 patients with pseudo-obstruction. Gaseous filling of the rectum did not occur in any patient with a structural obstructive lesion. In the appropriate clinical setting this approach could exclude the presence of obstruction and avoid unnecessary barium enemas in the majority of patients with colonic pseudo-obstruction.

Delayed tension penumothorax complicating central venous catheterization and positive pressure ventilation

Pneumothorax is the most common complication after central venous catheterization. The diagnosis of pneumothorax may be delayed for hours or days, in some instances because of minimal clinical symptoms or radiographic signs on initial evaluation, or in other instances because of late presentation precipitated by positive pressure ventilation. A case is presented in which a patient developed a tension pneumothorax while under general anesthesia 10 days after central venous line placement. A review of the literature suggests that delayed pneumothorax has an incidence of approximately 0.4% of all central venous access attempts, is much more common after subclavian than internal jugular approaches, especially in difficult or multiple attempts, is asymptomatic in 22%, and results in tension pneumothorax in 22%. End-expiratory upright chest radiographs, the optimal radiographic technique for detection of small pneumothoraces, were obtained in only 19% of reviewed cases. Supine views, the least sensitive radiographic technique, should be carefully reviewed for evidence of basilar hyperlucency, a deep sulcus sign, or a double diaphragm sign. In patients unable to tolerate the upright position, supine views should be supplemented with lateral decubitus, oblique, or cross-table lateral views. Emergency physicians should be aware of the possibility of delayed pneumothorax, as well as optimal radiographic technique for demonstration of small pneumothoraces, and subtle radiographic findings in supine or semirecumbent patients.

Plain and computed radiography for detecting experimentally induced pneumothorax in cadavers: implications for detection in patients.

Pneumothorax was induced in cadavers to determine the effects of patient positioning and imaging modality (conventional screen-film and computed radiography) on radiographic findings. Chest radiography, with cadavers in the supine frontal, erect frontal, and left lateral decubitus positions, was performed at baseline and after injection of incremental quantities of air into the pleural space. Five radiologists independently interpreted each radiograph. The ability of the radiologists to diagnose pneumothorax varied by cadaver position and depended on volume of air. Overall, the left lateral decubitus view was most sensitive (88%) for diagnosis of pneumothorax, followed by the erect (59%) and supine (37%) views. Receiver operating characteristic curves and multiple repeated measures analysis of variance revealed no statistically significant difference between diagnostic proficiency with conventional screen-film radiography and that with computed radiography. The authors conclude that the lateral decubitus view is superior to the erect and supine views for pneumothorax detection and that conventional and computed radiography perform similarly in pneumothorax detection.

Left lateral decubitus sonography of gallstones in the contracted gallbladder.

A prospective study of the accuracy in diagnosing gallstones using ultrasonography in the absence of a fluid-filled gallbladder was done over a 20 month period; 91 patients were studied. A focal echo complex with acoustic shadowing was shown to be a highly reliable criterion for diagnosing gallstones in a contracted gallbladder when (1) it was demonstrated on longitudinal, transverse, and left lateral decubitus views, and (2) the configuration of the echo complex remained the same.

The Incidence and Clinical Correlates of Parapneumonic Effusions in Pneumococcal Pneumonia

Pneumococcal parapneumonic effusions are thought to be uncommon. Considering the frequency off pleuritic pain and the proposed pathogenesis off pneumococcal pneumonia, a higher incidence was suspected. Thirty-five consecutive patients with pneumonia due to Streptococcus pneumoniae were studied prospectively utilizing frequent chest x-ray films, including lateral decubitus views. Twenty (57 percent) of the 35 patients had parapneumonic effusions. The presence of parapneumonic effusions correlated significantly with the duration of symptoms before admission, bacteremia, and prolonged fever after therapy (P