Fat Stripe Research Articles

THE ROLE OF CHEST RADIOGRAPHY TO DIAGNOSE LARGE PERICARDIAL EFFUSION IN WOMAN 66 YEARS OLD WITH MALIGNANCY : HIDING PERICARDIAL EFFUSION

Introduction: Pericardial effusion refers to an increase in fluid accumulation in the pericardial cavity. This pericardial fluid acts as a lubricant between the layers of the pericardium. We report a case of pericardial effusion, which was significant but not detectable on conventional chest radiographs.Case: A 66-year-old woman with lung adenocarcinoma accompanied by large pericardial effusion without sign of impending tamponade. The diagnosis of pericardial effusion was mainly based on echocardiography, where there is a large pericardial effusion but without signs of cardiac tamponade, and the patient then underwent pericardiocentesis. Previously, the patient had undergone two examinations with two different imaging modalities, namely CXR and chest CT scan, where on the CXR results, the patient only showed cardiomegaly.Discussion: There are four parameters suggestive for assessing a pericardial effusion, namely enlargement of the heart silhouette, pericardial fat stripe, left dominant pleural effusion, and an increase in the transverse diameter of the heart compared to the previous chest X-ray. This parameter is obtained not only based on the position of the photo taken but requires another position, whereas, in this patient, only CXR was performed with the posteroanterior position.Conclusion: When there are complaints of progressive shortness of breath in individuals with an underlying disease that may cause pericardial effusion, then the CXR examination cannot be used as a reference when there are no radiographic signs that point to pericardial effusion because CXR has a low diagnostic value in assessing the presence of pericardial effusion.

The Intergluteal Fat Stripe in Patients With Hip Abductor Tears.

Background:With a hip abductor tendon tear, widening of the intergluteal space, or “fat stripe,” is a characteristic change seen in and around the gluteus medius and minimus.Purpose:To determine the relationship of the intergluteal fat stripe in hips with pathologic abductor tears compared with the contralateral side and to evaluate the association of fat stripe size with hip-specific patient-reported outcome measures.Study Design:Case series; Level of evidence, 4.Methods:Of the 43 patients (42 female, 1 male; mean age, 56.6 years; range, 38-85 years) who underwent endoscopic gluteus medius repair, 19 met inclusion criteria of preoperative bilateral hip magnetic resonance imaging (MRI) scans and 2-year follow up. A single board-certified fellowship-trained orthopaedic surgeon (J.F.), who was blinded to outcomes, evaluated the MRI scans to measure the intergluteal fat stripe on the operative and nonoperative sides. The 2-year postoperative International Hip Outcome Tool (iHOT-12) and modified Harris Hip Score (mHHS) values were analyzed to determine their relationship to the size of the fat stripe. Statistical analysis was performed using a paired t test, and associations were determined using Pearson product correlation as well as nonparametric measurements.Results:The size of the intergluteal fat stripe differed significantly between the operative and nonoperative sides. The area of the fat stripe on the operative side was 645.73 ± 513.09 mm2, and on the nonoperative side it was 313.47 ± 360.71 mm2, an average of 332.36 mm2 greater than the nonoperative side (P = .02). The width of the fat stripe was 9.10 ± 4.60 mm on the operative side and 5.15 ± 3.87 mm on the nonoperative side, 3.95 mm greater than the nonoperative side (P < .01). There was no correlation between the width or area of the fat stripe on the operative side and iHOT-12 or mHHS values at 2-year follow-up.Conclusion:The study findings indicated that the intergluteal fat stripe is significantly wider and has a significantly larger area in hips with abductor tears compared with unaffected hips. This did not correlate with 2-year patient-reported outcomes.

Extrapleural Hematoma: A Complication of Jugular Vein Cannulation

SESSION TITLE: Disorders of the Pleura SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: For centuries, central venous catheters (CVC) have been used as a means of assessing a patients cardiovascular hemodynamics and administering noxious medications. While the role of CVC in managing critically ill patients is indispensable, we must be cognizant of its complications. In this case report, hemodynamic instability complicates a surgical procedure, and the need for central venous access inadvertently leads to the development of an extrapleural hematoma (EPH). CASE PRESENTATION: We present a case of a 78 year old female, whose medical history of atrial fibrillation and transient ischemic attacks placed her at high risk of an ischemic cerebral event (CHA2DS2-VASc scoring). Her recurrent episodes of severe epistaxis precluded her from receiving anticoagulation therapy, and a left atrial appendage closure device (Watchman) was pursued as an alternative for stroke prevention. Sustained intraoperative hypotension necessitated the placement of a right-sided internal jugular CVC for the delivery of norepinephrine to regain hemodynamic stability. Without the availability of ultrasound guidance, anatomic landmarks led to successful cannulation after a failed first attempt. Post procedural chest x-ray (CXR) revealed a near complete opacification of the right hemithorax and CT scan of the chest confirmed a large apical hematoma (Image 1). Thoracoscopic surgery was performed for clot evacuation due to persistence of the EPH despite the placement of chest tubes and conservative medical management. Subsequent CXR revealed a complete resolution of the EPH (Image 2), and she was liberated from mechanical ventilation and vasopressor support. DISCUSSION: The lung parenchyma is surrounded by a physiologic visceral and parietal pleura which lies deep to the endothoracic fascia (ETF). The ETF is the outermost layer of the thoracic cavity and extends from the most inferior portions of the lung to the superior thoracic aperture to encase the lung apices. When diagnosed, the inciting event that precipitates an EPH is typically a penetrating injury to the chest or blunt trauma with injury to the ribs. Damage to the intercostal vasculature leads to the extravasation of blood into the physiologic space that lies between the ETF and the innermost intercostal musculature. This space occupying lesion displaces the ETF centrally, leading to a characteristic “fat stripe” seen on CT scans. CONCLUSIONS: EPH are a pleural space disease and a potential complication of CVC placement. Although a rare occurrence, the disruption in cardiopulmonary physiology can lead to life-threatening complications unless detected early. Reference #1: Chung, JH, Carr RB, Stern EJ. Extrapleural hematomas: imaging appearance, classification, and clinical significance. Journal of Thoracic Imaging. 2011:26:218-223 Reference #2: Aquino, S., Chiles, C., Oaks, T. Displaced extrapleural fat as revealed by CT scanning: evidence of extrapleural hematoma. American Journal of Radiology, 1997. DISCLOSURE: The following authors have nothing to disclose: Christopher Lee, Reenal Patel, Christian Castaneda, Olumayowa Abe, Samarth Beri No Product/Research Disclosure Information

Sonographic swelling of pronator quadratus muscle in patients with occult bone injury.

BackgroundThe disarranged fat stripe of the pronator quadratus muscle (PQ) on radiographs (the PQ sign) is reported to be predictive of subtle bone fractures. This study aimed to report the results of magnetic resonance imaging (MRI) study in the patients in whom bone injury was not radiographically detected around the wrist joint, and the PQ was sonographically swollen following acute trauma.MethodsWe evaluated sonographically the PQ of 55 patients who showed normal radiographs following acute trauma. The sonographic appearance of the PQ was checked on both longitudinal and transverse images. On the longitudinal image, the probe was positioned along the flexor carpi radialis tendon. For the transverse image, we adopted the image of the same level in which the PQ of the unaffected hand showed maximal thickness. The PQ was considered to be swollen with disproportionate hyperechogenicity and/or thickening compared with the unaffected side at least in one of the two images. Of the 55 patients, 25 patients whose PQ was considered to be swollen underwent MRI study. PQ thickness in millimeters was retrospectively measured on longitudinal and transverse sonographic images.ResultsTwenty-three patients (92.0%) had occult bone injury, and two adult patients (8.0%) showed only wrist joint effusion on MRI. Among these 23, the distal radius was the most frequent location of the occult bone injury (20 patients; 9 [36.0%] with an occult fracture line and 11 [44.0%] with bone bruising). In longitudinal image, the mean value of the PQ thickness of affected hands was 6.2 (3.7–9.6 mm; standard deviation [SD], 1.5) and that of unaffected hands was 4.5 (2.3–6.7 mm; SD, 1.2), respectively. In transverse image, that of dominant and nondominant hands was 7.6 (4.6–13.2 mm; SD, 2.0) and 5.5 (3.6–7.5 mm; SD, 1.1), respectively. The mean difference in PQ thickness between affected and unaffected hands was 1.7 (0.1–5.0 mm; SD, 1.1) in longitudinal image and 2.0 (0.3–6.8 mm; SD, 1.7) in transverse image.ConclusionsSonographic swelling of the PQ might be indicative of occult bone injury in patients with normal radiographs following acute trauma.

Computer Vision and Stereoscopy for Estimating Firmness in the Salmon (Salmon salar) Fillets

The computer vision and a stereoscopy technique were used to characterize and detect changes in the capacity of the salmon fillet surface to recover its original form after a constant weight was applied. A curvature index (associated to fillet firmness) calculated by means of 3D information data obtained with the stereoscopy technique from the fat stripe on the fillets was estimated over 6 months and was suggested as a characteristic of the recovery property of the fresh salmon fillet surface. Simultaneously, instrumental firmness using a LFRA1500 texture was measured. The values for the fresh salmon fillet measurement curvature index during a period of 6 months were established in the range of 0.05 and 0.10 (dimensionless), and this value was used in the experiments to represent fresh salmon fillets. Changes in the curvature index (associated with similar changes in firmness) for salmon fillet surface treated with enzymes (pepsin and papain) were registered on the second day during storage at 2 °C. In general, stereoscopy is a technique that can be used on salmon fillets to detect changes in the recovery properties of the salmon fillet surface and to determine when salmon fillets can be classified as a fillet that has not been processed with enzymes.

The annular fat stripe as a fluoroscopic guide to anatomic sites during diagnostic and interventional electrophysiology studies.

Few radiographic landmarks are visible during electrophysiology procedures to aid in catheter positioning other than the catheters themselves. In the 35 degrees -45 degrees RAO projection, a linear radio-opacity corresponding to the rings of fat surrounding both annuli can be easily identified. This "fat stripe" can serve as a useful landmark for several important anatomic sites. Intracardiac catheters positioned left of (posterior) the fat stripe lie within an atrial cavity while those positioned to the right (anterior) lie within a ventricular cavity. The superior third of the stripe corresponds to the region of the right and left atrial appendages while the inferior end identifies the site of the coronary sinus os. The middle third serves as a reference for the fast AV nodal pathway and compact AV node. The region corresponding to the slow AV nodal pathway superimposes on the lower third of the fat stripe. Electrophysiological recordings from catheters positioned along the fat stripe always exhibit both an atrial and ventricular component consistent with an annular recording, whether the catheter is septal or free wall in its location. Coronary sinus os engagement and catheterization can be simplified by using the fat stripe as an anatomic guide. In addition to facilitating catheter positioning for evaluating normal AV conduction, the fat stripe can serve as an excellent guide for targeting the majority of structures intended for ablation because of their annular location. These include the compact AV node, the slow AV nodal pathway, the subeustachian isthmus and any accessory pathway. Good ablation catheter tip contact with annular structures is confirmed by observing its movement in unison with the fat stripe.

Scaphoid and Pronator Fat Stripes are Unreliable Soft Tissue Signs in the Detection of Radiographically Occult Fractures

AIM: To determine the clinical value of scaphoid and pronator fat stripes in identifying occult underlying scaphoid and distal radius fractures, respectively. MATERIALS AND METHODS: In our department, all patients with clinically suspected scaphoid fractures and normal scaphoid series of radiographs undergo magnetic resonance imaging (MRI) of the wrist. We selected 50 cases with unequivocal MRI evidence of scaphoid fracture, 50 cases with distal radius fracture and 50 cases with no MRI evidence of bony injury. All 150 initial plain radiographs were examined retrospectively in random order without knowledge of the MRI findings and the scaphoid and pronator fat stripes scrutinized. RESULTS: The scaphoid fat stripe was abnormal in only 25 cases (50%) with confirmed scaphoid fracture on MRI. The pronator fat stripe was abnormal in 13 cases (26%) with confirmed distal radius fracture. In the 50 cases with no MRI evidence of bony injury, the scaphoid fat stripe and pronator fat stripe were abnormal in 25 (50%) and 15 (30%) cases, respectively. The sensitivity and specificity for an abnormal scaphoid fat stripe was 50%. The sensitivity and specificity for an abnormal pronator fat stripe was 26 and 70%, respectively. CONCLUSION: Scaphoid and pronator fat stripes are poor predictors of the presence or absence of underlying occult fractures.

Abnormal paraspinal fat stripe on plain radiograph

Abnormal paraspinal fat stripe on plain radiograph

Intra-articular entrapment of the medial collateral ligament: radiographic and MRI findings

Displacement of the medial collateral ligament (MCL) into the medial knee joint is an extremely rare finding associated with MCL tears, and is easily diagnosed on magnetic resonance imaging. A case of intra-articular interposition of the MCL during a severe knee injury is presented. A radiolucent "fat stripe" sign and adjacent skin dimpling on radiographs may be relatively specific indicators of this injury.

Suspected scaphoid fractures in skeletally immature patients: application of MRI.

The purpose of our study was to evaluate the MR findings in the wrists of pediatric patients who have sustained acute wrist injuries and to determine if this imaging method yields more information than combined serial radiographs and physical examinations. Eighteen skeletally immature patients (11 boys and 7 girls, age range 8-15 years) who had presented to the emergency room within 2 days following acute wrist trauma underwent serial clinical, radiographic, and MR examinations if there was a suspicion of a scaphoid fracture. Ten patients had a scaphoid abnormality on MR images. Six had fractures and four had regional bone marrow edema. Initially, all but two fractures were radiographically occult, although the other fractures eventually became evident on later studies. Those with marrow edema did not progress to fractures. Obliteration of the scaphoid fat stripe occurred in five patients with a scaphoid fracture and in six patients who did not have a fracture. Dorsal soft tissue swelling occurred in eight patients, five of whom had scaphoid fractures. Seven patients had evidence of extensor tenosynovitis on MRI. A normal initial MR image had a negative predictive value of 100%. Persistent snuffbox pain may represent injury to the scaphoid, extensor tendons, or dorsal soft tissues. An outcome study evaluating the benefits of early application of MR in the pediatric population is warranted.

Effect of varying kVp on visibility of epicardial fat stripe in pericardial effusions.

Effect of varying kVp on visibility of epicardial fat stripe in pericardial effusions.

Diagnostic value of chest radiography for pericardial effusion

Objectives. This study was designed to determine the diagnostic valve of chest radiography for pericardial effusion.Background. Pericardial effusions may cause life-threatening cardiac complications, yet they are often difficult to diagnose.Methods. In a blinded manner, we reviewed the chest radiographs of 83 ptients with echocardiographicaily diagnosed pericardial effusions (5 large, 18 moderate, 60 small) and those of 17 control subjects without effusions. We examined four radiographic signs: an enlarged cardiac silhouette, a pericardial fat stripe, a predominant left-sided pleural effusion and an increase in transverse cardiac diameter compared with the diameter on a previous chest radiograph.Results. An enlarged cardiac silhouette was moderately sensitive (71%) but not specific (41%) for pericardial effusion. a pricardial fat stripe, a predominant left-sided pleural effusion and an increase in transverse cardiac diameter were all specific (94%, 100% and 80%, respectively) but not sensitive (12%, 20% and 46%, respectively). A predominait left-sided pleural effusion was associated with pericardial effusions of all sizes (odds ratio = 1.3, 9S% confidence interval [CI] = 1.0–1.6, p = 0.04) and with large and moderate pericardial efftisions alone (odds ratio = 7.7, 95% CI = 2.5–34.0, p = 0.0004). In contrast, a pericardial fat stripe was associated only with large and moderate pericardial effusions (odds ratio = 3.3, 95% CI = 0.9–12.0, p = 0.07), and an enlarged cardiac silhouette and an increase in cardiac diameter were not associated with pericardial effusion it all.Conclusions. A predominant left-sided pleural effusion and a pericardial fat stripe are chest radiographic signs that are suggestive, but not diagnostic, of pericardial effusion. Because these signs cannot reliably Confirm or exclude the presence of pericardial effusion, we conclude that chest radiography is poorly diagnostic of this condition.

Shoulder after surgery: MR imaging with surgical validation.

To assess the accuracy of magnetic resonance (MR) imaging in the evaluation of the shoulder after surgery, MR examinations were performed in 31 patients before repeated surgery, and MR findings were correlated with the subsequent operative findings. In addition, the MR findings associated with prior surgery were reviewed, including altered structure of the acromion, soft-tissue metal artifacts, a surgical trough in the humeral head, nonvisualization of the subacromial-subdeltoid fat stripe, and intermediate signal intensity within the substance of the rotator cuff on images obtained with all pulse sequences. The MR criteria for full-thickness tears in the shoulder after surgery are the presence of fluidlike signal intensity on T2-weighted images that extends through an area of the rotator cuff or the nonvisualization of a portion of the rotator cuff. With use of these criteria, six of seven full-thickness rotator cuff tears were identified at MR imaging, with an accuracy of 90%. Partial cuff tears were indistinguishable from repaired tendons. Findings at MR imaging were 74% accurate concerning the presence of impingement.

The normal shoulder: common variations that simulate pathologic conditions at MR imaging.

The appearance of the supraspinatus tendon and anterior capsular mechanism was analyzed in 60 asymptomatic shoulders with magnetic resonance (MR) imaging. The images were reviewed with special attention to findings that simulate pathologic conditions, as defined by means of currently accepted criteria. On T1-weighted and proton-density (PD) spin-echo (SE) images, intermediate signal intensity was present within the supraspinatus tendon in most shoulders. Focal signal intensity within the distal tendon was particularly common finding, being present in 95% (57 of 60) of shoulders on PD images. Focal obliteration of the subacromial-subdeltoid fat stripe and acromioclavicular joint arthrosis were seen in 95% (57 of 60) and 48% (29 of 60) of the subjects, respectively. There was considerable variation in the shape of the anterior glenoid labrum-glenohumeral ligament (GHL) complex. The labrum may appear triangular, round, crescentic, or absent. The middle and inferior GHLs lie in proximity to the upper half of the anterior labrum; the cleavage plane between the ligaments and the labrum can mimic a tear at MR imaging.

Shoulder MRI: the subacromial/subdeltoid bursa fat stripe in healthy and pathologic conditions

The MRI appearance of the subacromial/subdeltoid (SA-SD) bursa is described here in both healthy and pathological conditions. Based on one case of rotator cuff tear and intrabursal fluid outlined by two adjacent fat stripes we reviewed 20 shoulder MR examinations to define the normal and abnormal appearance of the peribursal fat. We found four pathological patterns: lateral displacement, tear-drop configuration, obliteration and double fat stripe.

CT diagnosis of strangulated diaphragmatic hernia

Strangulated diaphragmatic hernia is a surgical emergency which on occasions can be a diagnostic dilemma. We report of a 2-year-old-male child with strangulated diaphragmatic hernia in whom a correct preoperative diagnosis was made with progression of illness. CT depicted a curvilinear fat stripe in a fluid filled hemithorax.

The validity and reliability of the navicular fat stripe as a screening test for detection of navicular fractures

The purpose of this study was to determine if the navicular fat stripe (NFS) is a valid and reliable screening tool in assessing potential navicular fractures. Retrospective analysis. Minor trauma section of the Los Angeles County-University of Southern California Medical Center emergency department. Study population included patients seen for wrist injury between January 1987 and December 1988. The individuals who interpreted the radiographs included eight observers with varying degrees of radiographic experience. None The positive predictive value averaged 12% or 15% depending on how we counted a straight NFS, and the negative predictive value averaged 93% or 95%, again depending on how we counted a straight NFS. A straight NFS was ten times as likely to occur among normal wrists than among those with navicular fractures. Interobserver reliability was found to be high with a Hoyt reliability coefficient of .79. An abnormal NFS is a poor predictor of a navicular fracture while both a straight and a normal NFS are good predictors of no navicular fracture. A normal NFS may allow less stringent treatment by the emergency physician. Extremes of radiographic experience were found to have no significant effect on NFS interpretation.

Cervical prevertebral fat stripe: a normal variant simulating prevertebral hemorrhage.

We present a rare case of marked cervical prevertebral soft-tissue thickening detected on plain films in a patient being examined for acute cervical spine trauma in whom subsequent CT examination showed a large prevertebral fat stripe but no acute injuries. To our knowledge this finding, which has not been previously reported, is a normal variant that should be recognized in order to avoid further unnecessary diagnostic workup and treatment.

The anatomical fat pad and the radiological “scaphoid fat stripe”

The diagnostic value of the “scaphoid fat stripe” seen on X-rays in association with fractures of the scaphoid bone in the wrist is reviewed. The anatomical basis for these soft tissue radiological changes was investigated by dissection of the anatomical snuff-box and by injection studies. It is concluded that the snuffbox fat is part of a major fat-pad located in a recess radio-dorsally on the wrist. However the radiological structure named the “scaphoid fat stripe” was found to be the highly radiolucent common tendon sheath of the extensor pollicis brevis and the abductor pollicis longus muscles. Limitations in diagnostic sensitivity and specificity are discussed.

The anatomical fat pad and the radiological "scaphoid fat stripe".

The diagnostic value of the "scaphoid fat stripe" seen on X-rays in association with fractures of the scaphoid bone in the wrist is reviewed. The anatomical basis for these soft tissue radiological changes was investigated by dissection of the anatomical snuff-box and by injection studies. It is concluded that the snuffbox fat is part of a major fat-pad located in a recess radio-dorsally on the wrist. However the radiological structure named the "scaphoid fat stripe" was found to be the highly radiolucent common tendon sheath of the extensor pollicis brevis and the abductor pollicis longus muscles. Limitations in diagnostic sensitivity and specificity are discussed.