Normal Ultrasonography Research Articles

Evaluation of a thoracic ultrasound training module for the detection of pneumothorax and pulmonary edema by prehospital physician care providers

BackgroundWhile ultrasound (US) has continued to expedite diagnosis and therapy for critical care physicians inside the hospital system, the technology has been slow to diffuse into the pre-hospital system. Given the diagnostic benefits of thoracic ultrasound (TUS), we sought to evaluate image recognition skills for two important TUS applications; the identification of B-lines (used in the US diagnosis of pulmonary edema) and the identification of lung sliding and comet tails (used in the US diagnosis of pneumothorax). In particular we evaluated the impact of a focused training module in a pre-hospital system that utilizes physicians as pre-hospital providers.Methods27 Paris Service D'Aide Médicale Urgente (SAMU) physicians at the Hôpital Necker with varying levels of US experience were given two twenty-five image recognition pre-tests; the first test had examples of both normal and pneumothorax lung US and the second had examples of both normal and pulmonary edema lung US. All 27 physicians then underwent the same didactic training modules. A post-test was administered upon completing the training module and results were recorded.ResultsPre and post-test scores were compared for both the pneumothorax and the pulmonary edema modules. For the pneumothorax module, mean test scores increased from 10.3 +/- 4.1 before the training to 20.1 +/- 3.5 after (p < 0.0001), out of 25 possible points. The standard deviation decreased as well, indicating a collective improvement. For the pulmonary edema module, mean test scores increased from 14.1 +/- 5.2 before the training to 20.9 +/- 2.4 after (p < 0.0001), out of 25 possible points. The standard deviation decreased again by more than half, indicating a collective improvement.ConclusionThis brief training module resulted in significant improvement of image recognition skills for physicians both with and without previous ultrasound experience. Given that rapid diagnosis of these conditions in the pre-hospital system can change therapy, especially in systems where physicians can integrate this information into treatment decisions, the further diffusion of this technology would seem to be beneficial and deserves further study.

Natural History of Mild Subclinical Hypothyroidism: Prognostic Value of Ultrasound

Clinical repercussions, progression to overt hypothyroidism, and treatment benefits have been well established in patients with subclinical hypothyroidism (SCH) and TSH >10 mIU/L. In contrast, these aspects of the disease are poorly understood in patients with even milder SCH as defined by TSH < or = 10 mIU/L and normal thyroid hormone levels. Therefore, we sought to evaluate the natural history of this milder form of SCH (TSH < or =10 mIU/L with normal thyroid hormone levels) in adult women patients. One hundred seventeen patients with TSH levels ranging from 5 to 10 mIU/L and normal free T4, without a previously known history of thyroid disease, were followed for a period of 3 years and had two consecutive assessments. Sixty patients tested positive for antithyroperoxidase antibodies (TPOAb) and 36 were TPOAb negative but had diffuse hypoechogenicity on thyroid ultrasound (US). Twenty-one patients were TPOAb negative and had normal US. During follow-up, 20.5% of the patients had spontaneous normalization of their TSH, 27.3% required replacement therapy with levothyroxine (L-T4) because of progression to overt hypothyroidism or persistence of serum TSH >10 mIU/L, and 52.1% continued to meet the criteria for mild SCH (persistence of TSH < or =10 mIU/L). If the patients were classified into two groups, one with positive TPOAb and/or US alteration and the other with testing negative for TPOAb and not having US alteration, the first group had a greater progression toward overt hypothyroidism (31.2% vs. 9.5%, respectively) and a lower rate of normalization of TSH (15.6% vs. 43% respectively). These rates were similar in TPOAb-positive patients and patients with negative TPOAb but with positive US. Most patients with SCH and TSH < or = 10 mIU/L do not progress to overt hypothyroidism. The presence of chronic thyroiditis as demonstrated by US increases the evolution of SH to overt hypothyroidism or more severe SCH and thus the need for L-T4 treatment. US findings are important in determining the prognosis of mild SCH.

Comment on: Clinical examination versus ultrasonography in detecting developmental dysplasia of the hip

Dear Editor, We read the article by Dogruel et al. [2], on the clinical examination versus ultrasonography in detecting developmental dysplasia of the hip, with interest. The purpose of this prospective study was to investigate the usefulness of clinical examination in detecting developmental dysplasia of the hip in infants, as defined by hip ultrasonography. This article is important because developmental dysplasia of the hip is a common, treatable disease, in which the most accurate screening procedure is still debatable. The authors concluded that clinical examination did not reliably detect developmental dysplasia of the hip. Ultrasonography is frequently used as a screening tool in clinical practice, but this method can result in false positive results [3]. The American Academy of Pediatrics (AAP) guideline [1] recommends routine screening for developmental dysplasia of the hip through clinical examination by skilled personnel. In doubtful cases referral to an orthopaedic surgeon is useful. In infants with risk factors, irrespective of the results of clinical examination, ultrasonography should be considered. Although ultrasonography is not the gold standard for the diagnosis of developmental dysplasia of the hip, we understand that it was used in this study to compare the results of ultrasonography with clinical examination. However, when we recalculated sensitivity and specificity in the study by Dogruel et al., we found different values (see Table 1). Table 1 Clinical examination versus ultrasonography in terms of numbers of hips defined as normal or pathological (results Dogruel et al. [2]) The sensitivity is 59/208 = 28%, which is the proportion of hips in which a pathological clinical examination was found in infants with pathological ultrasonography (true-positives). The specificity is 6502/6874 = 95%, which is the proportion of hips in which a normal clinical examination and normal ultrasonography were found (true-negatives). The reported 13.68% (59/431), in the article by Dogruel et al. cited as the specificity, is in fact, the predictive value of a positive test, i.e. the percentage of infants with ultrasonography defined dysplasia of the hip with a positive clinical examination. The percentage reported by the authors as sensitivity is, in fact, the prevalence of non-disease (6874/7082 = 97%). These different values may influence the conclusions reached by the study. From the results of the study described by Dogruel et al., we concluded that the sensitivity of clinical examination of the hip in diagnosing congenital hip dysplasia was very low. The question is whether this is due to the index test (the sensitivity of clinical examination is too low) or because of the reference test (ultrasonography used as the gold standard, but known to show false positive results). The specificity of clinical examination (95%) seems quite high. However, this study was performed on healthy infants, with a low a priori chance of 2.9% (208/7082). This percentage however is consistent with other study results. Because of the high negative predictive value (6502/6651 = 97.8%) we conclude that screening by physical examination is useful.

Letters to the Editor

Letters to the Editor

Ultrasound of enthesopathy in rheumatic diseases

Enthesopathy is the pathologic change of the insertion of tendons, ligaments and joint capsules on the bone. It is a cardinal feature of spondyloarthropathies (SpA), but it can occur in other rheumatic disease. Recent studies using magnetic resonance imaging (MRI) and ultrasonography (US) have demonstrated that enthesopathy can often be asymptomatic, in both the axial and peripheral skeleton. Therefore, a systematic US study of peripheral entheses could be useful in the diagnostic process of patients with rheumatic diseases, in particular SpA. Recently, power Doppler US (PDUS) has been proved to be useful for differentiating mechanical/degenerative and inflammatory enthesopathy and for monitoring the efficacy of therapy. This article reviews the main histopathologic aspects of enthesopathy and describes the normal US features of enthesis and the basic US features of enthesopathy, in its various stages. The usefulness of US and PDUS in the diagnosis and assessment of enthesopathy is discussed on the basis of the literature and our experience.

Scrotal Ultrasound: A Pictorial Review

Ultrasound (US) is now the accepted modality of choice for imaging the scrotal contents, in particular for evaluation of suspected testicular pathology. There are numerous scrotal pathologies which present with pain, swelling and/or a mass. Testicular lesions vary from the benign to the malignant and also include surgical emergencies and infections. Using 'colour' and applying 'power' Doppler assist in making the diagnosis. However, differentiating between lesions requires a highly skilled US examiner, a sound knowledge of the normal US anatomy and knowledge of the US appearance of numerous conditions. This article reviews the US appearances of many common scrotal pathologies.

Antenatal hydronephrosis: infants with minor postnatal dilatation do not need prophylaxis

The aim of this study was to determine the occurrence of urinary tract infection (UTI) in infants with antenatal renal pelvis dilatation (ARPD). Consecutive ultrasound (US) screening of 14,000 pregnant women detected ARPD >or=5 mm in 106 foetuses. After birth, two US examinations were performed: on the fifth to seventh day and during the third week of life. The findings were considered normal when renal pelvis dilatation (RPD) was <or=7 mm on both examinations and no other signs of abnormality were present. Voiding cystourethrography (VCUG) was done in all infants 6-8 weeks after birth. One hundred and three infants were followed for 2 years. Antibacterial prophylaxis (trimethoprim 1 mg/kg per day) was given to those with RPD >or=15 mm, vesicoureteric reflux (VUR) grades III-V and suspected obstruction. In 53/103 babies, both US examinations were normal, three had VUR grade I. Two girls had UTI at 18 and 24 months of age, respectively. Among the 50 infants with abnormal initial US, six had VUR, of which four were high grade (IV-V). All four developed UTI. We conclude that UTI is uncommon in infants with two normal postnatal US examinations. Routine use of antibacterial prophylaxis in these infants therefore cannot be recommended.

Supernumerary marker chromosomes management in prenatal diagnosis

To assess the practical usefulness of array-comparative genomic hybridization (a-CGH) when supernumerary marker chromosomes (SMCs) are detected during prenatal diagnosis, we retrospectively studied SMC management in our laboratory before a-CGH availability. In this 11-year study, SMCs were observed in 20/16,810 routine karyotypes (0.12%). Their chromosomal origin, ascertained in 13 cases, remained elusive in seven using conventional cytogenetics and FISH. In the literature, most of SMCs (2/3) are easily identified through conventional cytogenetics and targeted FISH, and in these cases a-CGH would have been unneeded. This technique would have been less helpful in nine cases, that is, bisatellited SMC, isochromosomes and translocation derivatives. On the other hand, a-CGH would have been helpful for the 11 remaining cases. It would have improved diagnostic accuracy of six SMC whom chromosomal origin was ascertained by cytogenetics and FISH and for which prognosis was only based on literature and ultrasonographic data. Among five unidentified SMCs, a-CGH would have been more reassuring for four heterochromatic SMCs than normal ultrasonography alone and would have characterized the unidentified case associated with malformations that was interrupted. However potential pitfalls should be outlined. Using high level resolution chip expose to polymorphism detection and misinterpretation, a very sensitive problem in prenatal diagnosis. Moreover, low grade mosaicism could remain undetectable with this technique, leading to erroneous conclusions. Wisest use of a-CGH should be a complementary approach in prenatal management of SMC. It is specifically appropriate when SMC interpretation remains equivocal and only indirectly based on mode of inheritance, literature data and ultrasonography.

Screening for Deep Vein Thrombosis in Asymptomatic High-risk Patients: A Comparison between Digital Photoplethysmography and Venous Ultrasonography

To determine the role of digital photoplethysmography in screening asymptomatic patients who are susceptible for developing deep vein thrombosis. Three hundred and thirty-seven limbs in 169 patients who were high risk for development of deep vein thrombosis were assessed by ultrasonography digital photoplethysmography and the results were compared. Thirteen limbs were found to have deep vein thrombosis as demonstrated by ultrasonography. All limbs with a venous refilling time greater than 12 seconds had a normal ultrasonography. Compared with ultrasonography and using refilling time less than 12 seconds as the cutoff point, digital photoplethysmography achieved a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 73.8%, 13.3%, and 100% respectively, for detecting deep vein thrombosis in asymptomatic high-risk patients. Digital photoplethysmography is a simple, noninvasive, and highly sensitive test for screening of deep vein thrombosis.

OP07.06: Hysteroscopy in patients with abnormal uterine bleeding and normal transvaginal sonography

Background: Abnormal uterine bleeding (AUB) is one of the most common clinical problems in gynecology. Transvaginal sonography (TVS) and hysteroscopy are two diagnostic methods for patients with AUB. For most of the patients with AUB, diagnostic hysteroscopy can be done in clinic with minimal discomfort and much lower expense than operative room. Materials and Methods: In our clinical trial study, from March 21, 2005 to March 20, 2007, patients with AUB in Ahwaz Imam Khomayni hospital, after history and physical examinations underwent TVS. Of those, 147 patients with normal TVS entered the study and were considered for outpatient hysteroscopy. Patients with endometrial cavity lesion were scheduled for operation room, and those with empty endometrial cavity aspiration biopsy were done outpatiently. Specimens were sent to pathologist for examination. Results: All the patients were divided into three groups: group 1 or minority was under 30 years old (7 women), group 2 was 30-40 years, and group 3 or majority was over 40 years old (96 women). 115 patients (78.2%) had normal and 32 patients (21.8%) had abnormal hysteroscopic results. 116 patients (78.8%) had normal and 31 patients (21.2%) had abnormal pathologic results; moreover, cervical canal polyp was the most common lesion hysteroscopically and pathologically in all groups. Conclusion: Of 147 patients (100%) with AUB and normal TVS, 32 patients (21.8%) were abnormal hysteroscopically. Cervical canal polyps may be missed by transvaginal sonography, but can be diagnosed by hysteroscopy. In patients with AUB and normal TVS, hysteroscopy can be used as the second step.

What is the value of magnetic resonance venography in children before renal transplantation?

Radiological evaluation before renal transplantation includes imaging of vascular anatomy, as thrombosis, narrowing and anomalies of the inferior vena cava (IVC) and/or iliac veins (IV) can influence the surgical technique. Most cases only require investigation with Doppler vessel ultrasonography (US), with magnetic resonance venography (MRV) reserved to clarify US findings and investigate high-risk patients. The purpose of this study was to compare these modalities in evaluating IVC and IV and correlate imaging and operative findings of patients at RTx surgery. Twenty-nine children, 21 (72%) of whom had subsequent RTx surgery, were investigated over 5 years with correlation of US and MRV in 62% (18 of 29). Technically difficult US examinations needing MRV for clarification occurred in six (21%), and normal US with anatomical variations on MRV was seen in three (10%). The anatomical variations consisted of left-sided IVC, aberrant right common femoral vein and a left IV partly draining into the azygos and renal veins. US is an excellent screening tool for evaluating vascular anatomy patency in children. MRV infrequently contributes beneficial information, is difficult to justify as a screening tool, and due to the risks of gadolinium in uraemia, should only be used on an individual patient basis.

Use of ultrasound exam as an objective tool in therapeutic triaged of patients with billiary and pancreatic disease in emergency department

Aim: Correct and rapid diagnosis is a pivotal to practice of emergency medicine. Bedside ultrasonography (US) could be useful to diagnosis the real billiary and pancreatic emergency. The retrospective clinical study analyzes the accuracy of US exam and the ratio of delayed/missing diagnosis. Material and methods: The prospective study (December 2005– July 2006) is an analytical clinical research. The inclusion criterion in the study at emergency department being clinical: billiary dyskinesia, billiary colic, acute pancreatitis, jaudice syndrome. The abdominal US exam was performing using a portable device (PICO SONOACE) with convex (3–5MHz) probe. Results: There were 305 patients examined in the first hour of emergency department admission. The clinical sort of patients showed us: 176 patients with billiary colic, 34 with billiary dyskinesia, 18 with acute pancreatitis and 77 with jaudice syndrome. After US examination: 188 were hospitalized, 117 needed surgery intervention, 94 had normal US and discharged, 15 were send to Infectious Disease Clinic, 38 patients had billiary stone without complication and discharge (13 return with acute colecistitis), 9 patients with normal US had high level of pancreatic enzimes and were hospitalized. We observed that was not a linear correlation between clinical simptoms and US results. US could depict severe complication wihtout alarm clinical simptom especially at older patients. Conclusions: 1. In emergency department US is the better tool for diagnosis triage of billiary emergency. 2. US exam depicts precocious the cases who needed surgical treatment. 3. US are useful to detect severe complication in case of equivocally clinical symptoms.

Proinflammatory Cytokine-Receptor Interaction Model Improves the Predictability of Cerebral White Matter Injury in Preterm Infants

Proinflammatory cytokines have been variably linked to development of cerebral white matter injury (WMI) in preterm infants. Because soluble receptors tightly control cytokine bioactivity, we modeled cytokine-receptor interaction as a predictor of WMI. Plasma from 100 preterm infants was assayed for cytokines (tumor necrosis factor alpha, interleukin (IL-1beta, IL-6) and their soluble receptors (sTNF-RI), sTNF-RII, sIL-1RA, and sIL-6R). Cranial ultrasound (US) results were correlated with cytokine and receptor concentrations individually and with cytokine-receptor interaction models (PROC LOGISTIC; SAS Software). Receiver operating characteristic curves were constructed to determine the predictability of WMI. Fifty-two infants with normal US exams were compared with 21 infants with evidence of WMI. There was no association between individual cytokine or receptor concentrations and the development of WMI. However, modeling cytokines with their soluble receptors significantly improved the predictability of WMI. We concluded that consideration of cytokine-receptor interaction may be more important than individual cytokine concentrations alone in determining the role of inflammation in the pathogenesis of WMI in preterm infants.

Vertebral artery decompression in a patient with rotational occlusion

We report a patient who suffered drop attacks during head reclination. Computer tomography of the cervical spine demonstrated a stenotic right vertebral artery at C4/5. However, Doppler ultrasonography of the vertebral artery showed no abnormality. Angiography confirmed complete occlusion of the left vertebral and a stenosis of the right vertebral artery. Dynamic angiography indicated occlusion of the stenotic region on the right side during reclination of the head. Surgery using a posterior approach with decompression of the vertebral artery, lead to an excellent outcome and the patient left the hospital without any symptoms. Therefore, in patients with drop attacks and normal ultrasonography, a stenosis of the vertebral artery caused by a spondylophytic compression could still be the cause. At worst, the stenosis could lead to brain infarction if left untreated. Dynamic angiography is crucial for the diagnosis and surgical decompression has excellent results.

The relation between composite ultrasound measures and the DAS28 score, its components and acute phase markers in adult RA

Ultrasound (US) provides measurements of synovial morphology and vascularity. However, on an individual joint basis in RA, US measures do not relate well to clinical signs. This study investigates the relationship between composite US measures and the 28-joint disease activity score (DAS28), its components and acute phase markers in adult RA. RA synovial disease activity was recorded in 50 patients by: (i) the DAS28 score; (ii) ESR and CRP; and (iii) US using Grey scale (GS) and power Doppler (PD) measures of PIP and MCP joints to derive composite US scores based on abnormal counts and severity. A total of 25 control subjects were studied to define normal US appearances. The relation between each measure of synovial disease was determined by Spearman correlation analysis. There was a significant relation between the DAS28 and the GS joint count (GSJC, Spearman's r = 0.4; P = 0.004) and severity score (GSJS, r = 0.34; P = 0.016) and the PD joint count (PDJC, r = 0.32; P = 0.028). There was a significant relation between the ESR and PDJC (r = 0.37; P = 0.007) and PD joint severity score (PDJS, r = 0.38; P = 0.006) and between the CRP and PDJS (r = 0.29; P = 0.04). The remaining components of the DAS28 related poorly to all US measures, except the tender joint count, which related significantly to the GS but not the PD measures. Composite US markers of synovial disease relate significantly to the DAS28 score and ESR/CRP in adult RA, but not as well with individual clinical joint counts and the patient's global assessment.

Knee joint ultrasonography of the ACLT rabbit experimental model of osteoarthritis: relevance and effectiveness in detecting meniscal lesions

To develop a protocol for rabbit knee joint ultrasonography (US); to grade ultrasonographically the meniscal injuries of the anterior cruciate ligament transection (ACLT) rabbit model of osteoarthritis (OA); to assess with US the effectiveness of the ACLT; to compare final US with macroscopy for the evaluation of medial and lateral meniscal injuries depending on the age and weight when ACLT is performed. Twenty-two skeletally mature and adolescent New Zealand white rabbits were housed during the same period at the Institut Claude-Bourgelat, Lyon, France. Surgical ACLT was performed in the left knee of nine adolescent and five adult rabbits. Final US and macroscopic semi-quantitative grading of the meniscal injuries were compared 5 months after ACLT. A standardised protocol was developed to evaluate the rabbit knee joint. US was performed in both control and ACLT knees. Normal and abnormal meniscal US appearances were described. A semi-quantitative scale to grade US meniscal injuries was created. Macroscopic and US total meniscal scores were significantly positively correlated (P<0.001, r=0.70). US detection of meniscal injuries was 92% sensitive and 87.5% specific compared to macroscopy. Positive and negative predictive values of US were, respectively, 92% and 87.5%. US detection of the ACLT effectiveness was 100% specific and 78.5% sensitive. A significant relationship was found between ultrasonographic and macroscopic grading of meniscal injuries. US was both specific and sensitive in detecting meniscal lesions. We propose US as a non-invasive, non-expensive, in vivo imaging technique for preclinical studies in the ACLT rabbit OA model.

CT in the Evaluation of Nontraumatic Abdominal Pain in Pregnant Women

To retrospectively determine sensitivity and specificity of computed tomography (CT) for the diagnosis of appendicitis in pregnant women with nontraumatic abdominal pain and retrospectively compare findings at CT and ultrasonography (US) in patients who underwent both examinations, with surgery or clinical follow-up as a reference standard. Institutional review board approval was obtained, and the study was HIPAA compliant. Informed consent was waived. Findings of 80 consecutive CT examinations performed in 78 pregnant women (mean age, 25.9 years; range, 17-43 years) for abdominal pain between September 2000 and October 2004 were compared with findings at prior US (n=52), surgery, and clinical follow-up. Sensitivity and specificity were calculated for the diagnosis of appendicitis. The average fetal radiation dose was 16 mGy (1.6 rad) (range, 4-45 mGy [4-4.5 rad]). CT findings were normal in 51 examinations (64%) and abnormal in 29 (36%). Abnormal findings were appendicitis (n=13), urinary tract calculi (n=6), small-bowel obstruction (n=2), cholelithiasis (n=2), pyelonephritis (n=2), diaphragmatic hernia (n=1), cecal bascule (n=1), ileus (n=1), and metastatic lymphadenopathy (n=1). One surgically confirmed case of appendicitis was not detected at CT. For diagnosis of appendicitis, sensitivity of CT was 92% (12 of 13 examinations), specificity was 99% (66 of 67), and negative predictive value was 99% (66 of 67). Fifty-two CT studies were performed after US. US findings were normal in 46 patients (88%) and abnormal in six (12%). Abnormal findings were cholelithiasis (n=3), obstructive hydronephrosis (n=1), small-bowel dilatation (n=1), and appendicitis (n=1). Among 46 patients with normal US findings, CT findings were abnormal in 14, nine of whom required surgery. CT added important diagnostic information in 14 of 46 patients (30%). CT findings established the diagnosis in 35% of examinations in pregnant women with abdominal pain (28 of 80), with a negative predictive value of 99% for appendicitis; when CT followed negative US findings, CT findings established the diagnosis in 30% of patients.

Ultrasound Diagnosis of Fatty Liver in Patients With Chronic Liver Disease

Hepatic ultrasound (US) is readily available and physicians usually trust the results of an US report suggesting fatty liver, but there are conflicting reports on its accuracy, especially in patients with chronic liver disease (CLD). Therefore, we retrospectively examined liver biopsies in patients with CLD and compared the histologic results to the hepatic US findings. Liver biopsies were graded for fat (grades 0 to 3), inflammation (grades 0 to 4), and fibrosis (stages 0 to 4) in 131 patients with CLD (89% had chronic hepatitis C). Hepatic US interpretations were grouped into 3 categories-"normal," "fatty liver," and "nonspecific." A secondary analysis was performed using 3 sonographic categories based on the echogenicity: normal, "increased echogenicity," and "heterogenous." The US results were then compared with the liver biopsy results. A normal US report was associated with many false negatives, as 25% of these patients had fat (grades 1 to 3) on biopsy; furthermore, 46% had "significant fibrosis" (stages 2 to 4) or "significant inflammation" (grades 2 to 4). A "fatty liver" interpretation correctly identified fat on biopsy in 36.4% and "significant fat" (grades 2 to 3) in 11.4%, but 66% had significant fibrosis or significant inflammation. An US with increased echogenicity correctly identified fat in 43.5% and significant fat in 19.4%, but 69.4% had significant fibrosis or significant inflammation. The sensitivity of an US ranged from 11.4% to 88.2% and the specificity ranged from 40.4% to 86.2%, depending on the degree of steatosis on biopsy and the sonographic interpretation being considered. US is inaccurate for diagnosing hepatic steatosis in patients with CLD. Echogenic abnormalities are more likely to be the result of fibrosis or inflammation in this setting.

Ultrasound of the nerves of the knee region: Technique of examination and normal US appearance

The diagnosis of disorders of the peripheral nerves (PN) has traditionally been based on clinical and electrophysiological data since nerve tissue cannot be visualized on standard radiographs. More recently, however, nerve structures have been evaluated with magnetic resonance imaging (MRI) and ultrasound (US). The former modality is expensive and not available in all institutions. There are also some contraindications to its use, and the assessment of long nerves can be time-consuming since different coils must be used. Thanks to recent advances in sonographic software and hardware, US can now be used for in-depth assessment of the PN of the upper and lower limbs. Most knee disorders involve lesions to the cruciate ligaments and/or the menisci, which are difficult to evaluate with US. However, similar symptoms may be caused by compression of one or more nerves in the knee region or intrinsic disorders involving these structures. Because of their superficial positions, the nerves around the knee can be clearly visualized with US. A thorough knowledge of the normal anatomy of this region and a careful scanning technique are essential for a successful diagnostic US examination. In this article, we will review the normal gross and microscopic anatomy of the nerves in the knee region, the US technique used for their examination, and their normal US appearance.

Diagnostic Utility of Cholescintigraphy in Emergency Department Patients with Suspected Acute Cholecystitis: Comparison with Bedside RUQ Ultrasonography

Tc-99m-HIDA cholescintigraphy studies of gallbladder (GB) emptying are considered to be the most accurate method to diagnose acute cholecystitis (AC). With increasing use of bedside ultrasound (US) by emergency physicians for the evaluation of GB pathology, it is important to determine the role of cholescintigraphy as an adjunct to emergency ultrasound of the gallbladder. The objective of this study was to determine the utility of cholescintigraphy as an adjunct to bedside ultrasound in the evaluation of Emergency Department (ED) patients with suspected acute cholecystitis. We retrospectively reviewed US studies of 102 patients being evaluated for AC at a large community ED with a residency program. All patients over 18 years of age presenting to the ED over a 1-year period who received an ED US of the GB followed by a cholescintigraphy were enrolled. Bedside ultrasonography was performed after an initial physical examination by a hospital-credentialed emergency sonologist. Criteria used to diagnose AC include the finding of gallstones with a sonographic Murphy sign, significant wall thickening over 5 mm, pericholecystic fluid, impacted stone, or a combination of these. US reports were compared to cholescintigraphy results, final diagnosis, disposition, and pathology results when applicable. Statistical analysis included descriptive statistics calculated using StatsDirect software. A total of 102 patients fit criteria for this study over a 1-year period. Three patients were dropped from data analysis due to incomplete data. ED US and cholescintigraphy examinations agreed for presence or absence of AC in 76 of 99 patients (77%; 95% confidence interval [CI] 68–84%) resulting in a correlation value of rs = 0.74. A total of 38 of 99 (38%; 95% CI 30–49%) patients were diagnosed with AC on cholescintigraphy and ED US agreed in 20 patients. ED US diagnosed 25 (25%; 95% CI 18–34%) patients with AC and cholescintigraphy agreed in 20 patients. Of 99 patients enrolled, 63 were admitted to the hospital (63%; 95% CI 53–72%). Of the admitted patients, 36 (36%; 95% CI 27–46%) went to the operating room (OR) for presumed AC. Of the 31 (79%; 95% CI 64–89%) with AC on cholescintigraphy who went to the OR, only 13 (42%; 95% CI 26–59%) had pathology-based diagnosis of AC; 15 (48%; 95% CI 32–65%) had chronic inflammation only and 3 (10%; 95% CI 4–25%) had a diagnosis of cholelithiasis only. In 12 of 15 OR cases (80%; 95% CI 62–98%), where cholescintigraphy diagnosed AC but ED US did not, operative diagnosis agreed with US. Five patients with normal cholescintigraphy but ED US diagnosis of AC were taken to OR; pathology agreed with ultrasonography in all. Three other patients diagnosed with AC on cholescintigraphy, but not on ED US, never required operative intervention based on consulting surgeon evaluation. Our study demonstrates that the utility of cholescintigraphy in the evaluation of ED patients with suspected acute cholecysitis after a negative ultrasound examination is very limited.