Discriminatory power of 3.5 MHz convex and 7.5 MHz linear ultrasound probes for the imaging of traumatic splenic lesions: a feasibility study

Diagnostic performance of contrast-enhanced ultrasound in traumatic solid organ injuries in children: a systematic review and meta-analysis

BACKGROUND

Blunt abdominal trauma (BAT) is a significant contributor to pediatric mortality, often causing liver and spleen injuries. Contrast-enhanced computed tomography (CT), the gold standard for diagnosing solid organ injury, poses radiation risks to children. Contrast-enhanced ultrasound (CEUS) may be a promising alternative imaging modality.

OBJECTIVES

To evaluate the diagnostic utility of CEUS for detecting solid organ injuries following BAT in the pediatric population.

METHODS

A systematic review and meta-analysis were conducted through a thorough literature search in PubMed, Scopus, Web of Science, and Embase databases up to October 1, 2023. Diagnostic accuracy metrics were aggregated using a bivariate model, and subgroup meta-analysis compared CEUS accuracy across various organs.

RESULTS

Meta-analysis from four studies, including 364 pediatric patients, revealed a pooled sensitivity of 88.5% (95%CI 82.5-92.6%) and specificity of 98.5% (95%CI 94.9-99.6%), with an area under the curve of 96% (95%CI 88 - 99%). Splenic injuries showed higher sensitivity than liver injuries (P-value < 0.01), while kidney assessments demonstrated higher specificity (P-value < 0.05).

CONCLUSION

This study highlights the diagnostic potential of CEUS for pediatric solid organ injuries caused by BAT. Further large-scale studies are needed due to the limited number and sample size of the included studies.

Point-of-Care Ultrasound for Extrapulmonary Tuberculosis in India: A Prospective Cohort Study in HIV-Positive and HIV-Negative Presumptive Tuberculosis Patients

Diagnosing extrapulmonary tuberculosis (EPTB) is challenging. Point-of-care ultrasound (POCUS) for human immunodeficiency virus (HIV)-associated EPTB is applied in sub-Saharan Africa. This study aimed at evaluating the applicability of POCUS for diagnosing EPTB in HIV-positive and HIV-negative presumptive tuberculosis (TB) patients in India, a country of moderate relative TB and HIV burden. Presumptive TB patients at Kasturba Hospital, Manipal, India, prospectively underwent POCUS evaluating for pericardial, pleural and ascitic effusion, abdominal lymphadenopathy, and hepatic and splenic microabscesses. Findings were correlated with TB category (confirmed TB, clinical TB, unlikely TB), HIV status, and discharge diagnoses. A total of 425 patients underwent POCUS; 81 (20%) were HIV-positive. POCUS findings were more common in HIV/TB coinfected patients than in HIV-positive patients with unlikely TB (24/40 (60%) versus 9/41 (22%), P < 0.001). Abdominal lymphadenopathy and splenic microabscesses were strongly associated with TB in HIV-positive patients (P = 0.002 and P = 0.001). POCUS findings did not correlate with TB in HIV-negative patients; a third of HIV-negative patients with unlikely TB and POCUS findings had cancer, another third other infectious diseases. Sonographic findings were common in HIV-positive and HIV-negative presumptive TB patients. POCUS was a useful bedside test for the detection of HIV-associated EPTB. In HIV-negative patients, POCUS detected features associated with EPTB but also of malignancy and other infectious diseases.

Screening Ultrasound in Blunt Abdominal Trauma

Ultrasound is used worldwide to evaluate patients with blunt abdominal trauma. Sometimes referred to as an extension of the physical exam, ultrasound can rapidly help distinguish patients with injury requiring computerized tomography (CT) or surgery (typically 5%-10%) from those with no abdominal injury (> 90%). Ultrasound has several advantages in the setting of trauma. It is portable, integrates easily into the resuscitation of trauma victims without causing delay in therapy, is noninvasive, and has no associated morbidity. Limitations of ultrasound include its dependence on operator skill and technique, poor image quality in patients with morbid obesity or extensive subcutaneous gas, limited visualization of the retroperitoneum, and less reliable localization of visceral injury compared to CT. Successful use of abdominal ultrasound in the setting of trauma can be maximized with adequate sonographer training, appreciation of technical limitations, and adherence to an appropriate trauma ultrasound protocol.

Radiation-free percutaneous nephrostomy performed on neonates, infants, and preschool-age children

AIM

The aim of this study was to evaluate the effectiveness and safety of high-frequency linear probe ultrasonographic (US) guidance percutaneous nephrostomy (PN) in terms of diagnostic and therapeutic approach in preschool-age children with urological problems.

MATERIALS AND METHODS

PN was performed on 40 kidneys in 33 patients (13 girls, 20 boys) aged 3 days - 7 years (mean 4.1 years). All procedures were performed with US guidance utilizing a Shimadzu SDU 2200 Xplus 5-10 mHz probe. Complete blood count, urinalysis, bladder urine culture, blood urea, and creatinine values were obtained before PN placement on the same day. Urine cultures were obtained by nephrostomy tube and compared to bladder urine culture.

RESULTS

PN procedures were technically successful in 39 kidney units (97.5%). Two major complications were macroscopic hematuria requiring blood transfusions (1 case) and sepsis (1 case). Minor complications were displacement of the catheter (4), urinary tract infection (4), urine extravasation (1), early dislocation of the catheter (1). In three cases, the catheter was replaced. Analysis of bladder urine showed that 13 patients (39.4%) had positive cultures, but analysis of PN urine showed that 25 patients (78.1%) had positive cultures.

CONCLUSIONS

PN is an easy, safe and efficient diagnostic and therapeutic procedure with few complications even in preschool-age children. The antibiotic regimen should be revised in order to avoid sepsis and urinary tract infection.

CEUS in abdominal trauma: multi-center study

The objective of this study was to evaluate the concordance of US and contrast-enhanced US (CEUS) with CT in the assessment of solid organ injury following blunt trauma. Patients underwent complete US examination, including free fluid search and solid organ analysis. CEUS followed, using low-mechanical index techniques and SonoVue. CT was performed within 1 h. Among 156 enrolled patients, 91 had one or more abnormalities (n = 107) at CT: 26 renal, 38 liver, 43 spleen. Sensitivity, specificity, and accuracy for renal trauma at baseline US were 36%, 98%, and 88%, respectively, after CEUS values increased to 69%, 99%, and 94%. For liver baseline US values were 68%, 97%, and 90%; after CEUS were 84%, 99%, and 96%. For spleen, results were 77%, 96%, and 91% at baseline US and 93%, 99%, and 97% after CEUS. Per patient evaluation gave the following results in terms of sensitivity, specificity and accuracy: 79%, 82%, 80% at baseline US; 94%, 89%, and 92% following CEUS. CEUS is more sensitive than US in the detection of solid organ injury, potentially reducing the need for further imaging. False negatives from CEUS are due to minor injuries, without relevant consequences for patient management and prognosis.

Focused assessment with sonography for trauma: the FAST scan

Focused assessment with sonography for trauma or focused abdominal sonography for trauma — the FAST scan, has become a useful modality for the initial evaluation of patients with blunt abdominal trauma. The technique is used to identify free fluid in the abdomen and pelvis and to detect the presence of a pericardial effusion. FAST can be performed by any trained individual, not necessarily a sonographer or radiologist, aiding in the immediate availability of this technique in the emergency situation. We will discuss the applications and sensitivity of this technique in trauma and review the potential pitfalls and limitations which need to be understood if this technique is to be safely applied. The use of FAST for the detection of pneumothoraces in trauma and other advances in FAST scanning, such as scoring systems and paediatric FAST are also reviewed.

Clinician-performed focused sonography for the resuscitation of trauma

Traumatic death remains pandemic. The majority of preventable deaths occur early and are due to injuries or physiologic derangements in the airway, thoracoabdominal cavities, or brain. Ultrasound is a noninvasive and portable imaging modality that spans a spectrum between the physical examination and diagnostic imaging. It allows trained examiners to immediately confirm important syndromes and answer clinical questions. Newer technologies greatly increase the fidelity, accessibility, ease of use, and informatic manipulation of the results. The early bedside use of focused ultrasound as the initial imaging modality used to detect hemoperitoneum and hemopericardium in the resuscitation of the injured patient has become an accepted standard of care. Widespread dissemination of basic ultrasound skills and technology to facilitate this brings ultrasound to many resuscitative and critical care areas. Although not as widely appreciated, the focused use of ultrasound may also have a role in detecting hemothoraces and pneumothoraces, guiding airway management, and detecting increased intracranial pressure. Intensivists generally utilize a treating philosophy that requires the real-time integration of many divergent sources of information regarding their patients' anatomy and physiology. They are therefore positioned to take advantage of focused resuscitative ultrasound, which offers immediate diagnostic information in the early care of the critically injured.

High-Frequency Sonographic Patterns of the Spleen in Children

PURPOSE

To retrospectively evaluate the normal sonographic appearance of splenic parenchyma in children of various ages with high-frequency transducer sonography.

MATERIALS AND METHODS

Research ethics committee board approval was obtained, with waiver of informed consent. We evaluated in vivo sagittal and transverse sonograms of spleens obtained with 13-MHz linear-array transducers in 100 children (age range, 1 day to 17 years) with clinically diagnosed disease that did not affect the lymphoid system. Three radiologists working in consensus defined the grading system for the splenic parenchyma. Thereafter, these same radiologists graded the sonographic reticulonodular pattern independently as granular, mild, or marked. These grades were cross correlated with clinical data by using logistic regression analysis and chi(2) tests. Sonographic measurements of the splenic parenchyma in nine pediatric cadavers separate from the in vivo cohort of the study were compared with those of corresponding histologic slices by means of linear correlation.

RESULTS

Both grade 2 and grade 3 patterns occurred more frequently in children older than 1 year but no older than 5 years, whereas grade 1 pattern occurred most frequently in neonates (P < .001). As patients' age (odds ratio, 1.6; P < .001) and splenic dimensions (odds ratio, 3.1; P < .001) increased, the frequency with which the reticulonodular pattern was classified as either grade 2 or grade 3 increased. No association was noted between sonographic patterns and body mass index (P = .85) or sex (P = .07). The parenchymal nodules graded as 2 or 3 on sonograms correlated well with the presence of lymphoid follicles (white pulp) at histologic analysis (r = .71, P = .03).

CONCLUSION

High-frequency transducer sonography of the spleen in children can demonstrate normal echo patterns that should not be misinterpreted as indicative of disease.

Ultrasound detection of blunt urological trauma: a 6-year study

The objective of this study was to assess the utility of emergency ultrasonography in the detection of blunt urological injury. A retrospective review was conducted of all consecutive emergency blunt trauma ultrasonograms (US) obtained at a level I trauma centre from January 1995 to January 2001. Among the 4320 emergency ultrasonograms performed, 596 patients (14%) had intraabdominal injury and, of these, 99 patients (17%) had urological injuries. The sensitivity of ultrasound for all urological injuries was 67%, and specificity was 99.8%. For isolated urological injuries, sensitivity and specificity were 55.6 and 99.8%, respectively. Ultrasound was most accurate in the detection of grade III renal injuries, identifying 14/15 (93%), and 13 underwent laparotomy. For isolated urological injuries, 15 of 25 (60%) patients with a true-positive US underwent laparotomy compared to 3 of 20 (15%) with a false-negative US. Isolated urological injury was significantly associated with an ultrasonographic pattern of free fluid in the left upper quadrant and the left pericolic gutter (odds ratio=55.1; P<0.001), followed by isolated fluid in the left pericolic gutter (odds ratio=8.6; P=0.04). Although emergency ultrasonography is useful in the triage of patients with blunt urological trauma, it may miss significant urological injury requiring further intervention. As most renal injuries may be managed non-operatively, further studies such as contrast-enhanced CT or angiography should be obtained in the stable patient with suspected blunt urological injury.

Ultrasound in abdominal trauma

This article reviews current issues regarding the Focused Assessment with Sonography for Trauma (FAST) examination. Technical performance issues, decision-making and practice algorithms, fluid volume and scoring systems, proficiency and training, and the role of the FAST in pediatric trauma are covered. This article examines the FAST examination from a practical, evidenced-based stand-point.

Emergency ultrasound in trauma patients

US will be used more frequently in the future for the evaluation of traumatized patients. Previously,the main focus of the sonographic examination was for the detection of free fluid. Unstable patients with free fluid often can be triaged to the operation room without further imaging tests. In patients who are more stable or in whom US results are negative, CT is required. Based on recent studies, sonography has a sensitivity rate of approximately 40% in direct detection of solid organ injuries. In the future, however, with the use of contrast-enhanced agents, sonography may more reliably detect solid organ injuries. Within the chest, US has been shown to be helpful in detecting pleural effusions and may be useful in detecting pericardial effusions. US has been shown to be sensitive in detecting pneumothoraces in traumatized patients.

Sonographic patterns of intraperitoneal hemorrhage associated with blunt splenic injury

OBJECTIVE

To determine the correlation between sonographic detection of free fluid in the left upper quadrant and blunt splenic injury.

METHODS

A retrospective review was conducted of all consecutive emergency blunt trauma sonograms obtained at a level I trauma center from January 1995 to January 2001. Data were collected on demographics, free fluid location, and patient outcome. Injuries were determined from computed tomography, diagnostic peritoneal lavage, laparotomy, or a combination thereof.

RESULTS

A total of 4320 blunt trauma sonograms were obtained, and 596 patients (14%) had intra-abdominal injuries. The mean age was 33.7 +/- 19.1 years (range, 1-95 years), with 294 (49%) male and 302 (51%) female. There was no statistical difference between age, sex, or mechanism for all subgroups. There were 409 true-positive, 187 false-negative, 88 false-positive, and 3636 true-negative findings. Sensitivity of sonography for detecting all intra-abdominal injuries was 68%, and specificity was 97.6%; sensitivity for detecting isolated splenic injuries was 73.8%. Locations of free fluid in patients with nonsplenic injuries were compared with those in patients with splenic injuries. Isolated left upper quadrant free fluid was significantly associated with splenic injury (odds ratio = 3.0; P = .002), followed by diffuse free fluid (odds ratio = 2.1; P = .005). A subanalysis of isolated splenic injuries also revealed a significant association with left upper quadrant free fluid (odds ratio = 3.1; P = .007) and diffuse free fluid (odds ratio = 2.7; P = .0007).

CONCLUSIONS

Free fluid in the left upper quadrant is significantly associated with splenic injury. This finding should triage patients more rapidly to computed tomography, angiography, embolization, and laparotomy.

Doppler sonography and color duplex imaging for planning a perforator flap

The most critical factor to predict viability for any muscle perforator flap is an adequate circulation. Therefore, it is advantageous during preoperative planning to have the capability to localize the requisite cutaneous perforator. Color duplex imaging fulfills this requirement and permits the identification of additional characteristics, including caliber, course, and flow velocity of essential perforators and any source vessel. Nevertheless, with the current state of technology, Doppler sonography remains a more rapid, convenient, and simpler method for perforator localization.

Splenic trauma: evaluation with contrast-specific sonography and a second-generation contrast medium: preliminary experience

OBJECTIVE

To report our experience in the assessment of splenic trauma with contrast-coded sonography and a second-generation contrast medium.

METHODS

From January to May 2002, 120 patients were studied with sonography for suspected splenic trauma. Twenty-five were selected for further imaging because of sonographic findings positive for splenic injury, findings positive for peritoneal fluid only, indeterminate findings, and negative findings with high clinical or laboratory suspicion. These patients underwent contrast-enhanced harmonic sonography and contrast-enhanced helical computed tomography.

RESULTS

Among the 25 patients studied, 6 had no spleen trauma at initial and follow-up evaluation. One patient had a hypoperfused spleen without parenchymal damage, and 18 had splenic injuries; these 19 patients were considered positive. Hemoperitoneum was identified by sonography, contrast-enhanced sonography, and contrast-enhanced computed tomography in 74% of the 19 positive cases. Perisplenic clots were recognized in 58% of the cases by computed tomography and in 42% by baseline and enhanced sonography. Splenic infarctions were found in 11% of cases by contrast-enhanced sonography and computed tomography; none was found by unenhanced sonography. Parenchymal traumatic lesions were identified in 12 of 18 patients with splenic injuries by unenhanced sonography, in 17 cases by contrast-enhanced sonography, and in all 18 cases by contrast-enhanced computed tomography. A minimal splenic lesion was found in the single patient with a false-negative contrast-enhanced sonographic finding. Contrast-enhanced sonography correlated appreciably better than unenhanced sonography in detecting injuries and in estimating their extent. Findings undetectable on unenhanced sonography were also noted: splenic hypoperfusion in 11% of positive cases on both contrast-enhanced sonography and contrast-enhanced computed tomography, contrast medium pooling in 21% of cases on both contrast-enhanced sonography and computed tomography, and contrast extravasation in 11% of cases on computed tomography and 5% on contrast-enhanced sonography.

CONCLUSIONS

Contrast-enhanced sonography is a promising tool in the assessment of splenic trauma. In institutions where sonography is used as the initial procedure, this technique may increase its effectiveness.

The focused abdominal sonography for trauma scan: pearls and pitfalls

OBJECTIVE

To review the state-of-the-art use of sonography in evaluating the patient with trauma.

METHODS

We reviewed our experience in performing more than 5000 sonographic examinations in the patient with trauma. The recent experience of other publications advocating newer applications of sonography in the patient with trauma are discussed and presented in a pictorial fashion.

RESULTS

The main focus of sonography in the patient with trauma has been in performance of the focused abdominal sonography for trauma scan. The focused abdominal sonography for trauma scan is usually performed in the patient with blunt abdominal trauma and is used to check for free fluid in the abdomen or pelvis. There are certain pitfalls that need to be avoided and certain limitations of the focused abdominal sonography for trauma scan that need to be recognized. These pitfalls and limitations are reviewed. More recently, sonography has been used to detect certain solid-organ injuries that have a variety of appearances. Thus, sonography may be used to localize the specific site of injury in these patients. More recently, sonography has been used to evaluate thoracic abnormalities in patients with trauma, including pleural effusions, pneumothoraces, and pericardial effusions.

CONCLUSIONS

The use of sonography in evaluating the patient with trauma has rapidly expanded in the past decade. Those using sonography in this group of patients should be aware of its many uses but also its potential pitfalls and limitations.

The hand-held FAST: experience with hand-held trauma sonography in a level-I urban trauma center

AIMS

To describe the effectiveness of a portable hand-held ultrasound machine when used by clinicians in the early evaluation and resuscitation of trauma victims.

METHODS

The study was a prospective evaluation in a level-I urban trauma center. The focussed assessment with sonography for trauma is a specifically defined examination for free fluid known as the focused assessment with sonography for trauma (FAST) exam. Seventy-one patients had a hand-held FAST (HHFAST) examination performed with a Sonosite 180, 2.4 kg ultrasound machine. Sixty-seven examinations were immediately repeated with a Toshiba SSH 140A portable floor-based machine. This repeat scan (formal FAST or FFAST) was used as a comparison standard between the devices for study purposes. Four patients had a HHFAST only, all with positive result, two being taken for immediate laparotomy, and two having a follow-up computed tomographic (CT) scan. Patient follow-up from other imaging studies, operative intervention, and clinical outcomes were also compared to the performance of each device.

RESULTS

There were 58 victims of blunt, and 13 of penetrating abdominal trauma. One examination was indeterminate using both machines. The apparent HHFAST performance yielded; sensitivity, specificity, positive predictive value, negative predictable value, and accuracy (S, S, PPV, NPV, A) of 83, 100, 100, 98, 98%. Upon review, a CT scan finding and benign clinical course found the HHFAST diagnosis to be correct rather than the FFAST in one case. Considering the ultimate clinical course of the patients, yielded a (S, S, PPV, NPV, A) of 78, 100, 100, 97, and 97% for the HHFAST and 75, 98, 86, 97, and 96% for the FFAST. Statistically, there was no significant difference in the actual performance of the HHFAST compared to the FFAST in this clinical setting.

DISCUSSION

Hand-held portable sonography can simplify early and accurate performance of FAST exams in victims of abdominal trauma.

[Second hemorrhage in patients with splenic injuries]

Although the diagnosis of spleen injuries is not a considerable clinical problem today, subsequent ruptures of this organ may occur in a smaller number of patients (2-5% of total proportion of spleen injuries) following the so-called "free interval". Such injuries are most commonly explained by present hematoma localized in the central spleen, which becomes larger in time, and eventually causes its rupture. This form of lesion may be found both in isolated blunt abdominal injuries and in associated injuries. When it is the question of delayed hemorrhage, our results as well as data obtained from foreign literature, suggest three basic rise factors of the etiology of this type of injury. These are as follows: a) spleen injuries in severe trauma or polytrauma, b) older patients (over 65 years of age), and c) in cases when more than a single blood unit had to be administered for the initial hemodynamic stabilization of a patient. Delayed hemorrhage, which is occult in polytraumatized patients since it is frequently "disguised" by severity of clinical picture and traumatic shock, may subsequently cause sudden fall of hemogram and hemodynamic parameter values, and if immediate surgery is not performed, it may lead to heavy bleeding and lethal outcome of the patient.