Vito Antonio Caiulo

Lung Ultrasound Characteristics of Community-Acquired Pneumonia in Hospitalized Children

The diagnosis of community‐acquired pneumonia (CAP) is based mainly on the patients medical history and physical examination. However, in severe cases a further evaluation including chest X‐ray (CXR) may be necessary. At present, lung ultrasound (LUS) is not included in the diagnostic work‐up of pneumonia.

Lung ultrasound in bronchiolitis: comparison with chest X-ray

The diagnosis of bronchiolitis is based mainly on the patient’s medical history and physical examination. However, in severe cases, a further evaluation including chest X-ray (CXR) may be necessary. At present, lung ultrasound (LUS) is not included in the diagnostic work-up of bronchiolitis. This study aimed to compare the diagnostic accuracy of LUS and CXR in children with bronchiolitis, and to evaluate the correlation between clinical and ultrasound findings. Only patients with a diagnosis of bronchiolitis, who had undergone a CXR, were enrolled in the study. Fifty-two infants underwent LUS and CXR. LUS was also performed in 52 infants without clinical signs of bronchiolitis. LUS was positive for the diagnosis of bronchiolitis in 47/52 patients, whereas CXR was positive in 38/52. All patients with normal LUS examination had a normal CXR, whereas nine patients with normal CXR had abnormal LUS. In these patients, the clinical course was consistent with bronchiolitis. We found that LUS is a simple and reliable tool for the diagnosis and follow-up of bronchiolitis. It is more reliable than CXR, can be easily repeated at the patient’s bedside, and carries no risk of irradiation. In some patients with bronchiolitis, LUS is able to identify lung abnormalities not revealed by CXR. Furthermore, there is a good correlation between clinical and ultrasound findings. Given the short time needed to get a US report, this technique could become the routine imaging modality for patients with bronchiolitis.

Incidental detection of neuroblastoma and “wait and see” strategy

To the Editor: We read with great interest the paper by Peter Fritsch et al. [1] entitled ‘‘Wait and See’’ strategy in localized neuroblastoma in infants: An option not only for cases detected by mass screening. We fully agree with the Authors’ conclusion that a ‘‘Wait and See’’ strategy is beneficial in the management of neuroblastoma (NB) found by urinary mass screening or detected incidentally, as these tumors may spontaneously regress or turn out to be benign lesions. Since 1992, we have been performing a ultrasound mass screening for urinary tract malformations between 2 and 4 months of age (approximately a total of 15,000 infants screened to date). Three clinical cases were incidentally diagnosed with abdominal NB in the course of the screening. Median age at diagnosis was 3 months (range 2–4 months). All patients met the following criteria: localized tumors, tumor size less than 5 cm in diameter, absence of invasive growth, vanillylmandelic acid (VMA) and homovanillic acid (HVA) less than 50 mg/mg creatinine, and informed consent of parents. Monitoring was performed by monthly ultrasound examinations and urine catecholamine analysis. Median follow-up is 21 months (5–38 months). In one patient, the tumor rapidly increased in size and was resected after 5 months of observation displaying unfavorable histology. At 5 years of age, the child is in good health, with no signs of NB recurrence. The two other tumors spontaneously regressed. Our clinical observations indicate the possibility of successfully detecting NB at an early stage as an incidental ultrasonic finding during a mass screening for urinary tract malformations. A ‘‘Wait and See’’ strategy may be successfully applied in incidentally detected cases of localized neuroblastoma.

Nephrogenic rests: their frequency and their fate.

Nephrogenic rests (NRs) are considered to be precursor lesions of Wilms tumor, the most common malignant neoplasm of the urinary tract in children. We have previously reported on 2 cases of NRs, incidentally diagnosed at 2 to 3 months of age during an ultrasound mass screening for urinary tract malformations between 1992 and 2006. As the screened population consisted of 17,065 infants, the observed prevalence of NRs in our area in the examined time period was of 1.17/10,000. This is the first reliable estimate of the frequency of clinically appreciable NRs in infants. Microscopic NRs have been found at autopsy in about 1% of infants. Our data are, therefore, helpful in the assessment of the proportion of NRs that disappear spontaneously in the childhood age group. To the best of our knowledge, no false-negative cases were found. Our observations indicate that our policy of “wait and see” is appropriate when NRs are identified incidentally during ultrasonographic screening done for whatever purpose.

Re: Incidental detection of nephroblastoma and “wait and see” strategy—response

To the Editor: We read with great interest the Letter by D’Angio [1]. It is well known that nephrogenic rests (NRs) are foci of metanephric blastema that persist beyond 36 weeks’ gestation and have the potential for malignant transformation into Wilms tumor. They may be difficult to diagnose on ultrasonography, as may have a mixed appearance, manifesting themselves as hypo-, hyper-, or isoechogenic nodules [2]. In the ultrasound mass screening for urinary tract malformations we performed [3], two cases were incidentally diagnosed with NRs in the course of the screening and were monitored by 6-monthly ultrasound examinations for an early detection of malignant transformation. Case 1: A.G., 2-month-old asymptomatic male. The NR appeared in the superior pole of right kidney, as a spherical hyperechogenic nodule of 7.5 mm in diameter, with a well-defined, homogeneous perimeter. At 8 years of age, the child is in good health, while the nodular lesion remains unchanged. Case 2: M.F., 3-month-old male. The NR appeared as spherical, hypochogenic mass of 19 mm in diameter in the superior pole of the left kidney. A sonographic check carried out 1 month later and the abdominal computed tomography scan confirmed the presence of a spherical mass of about 20 mm in diameter. The lesion underwent a very slow growth up to 6 years of age. Between the 6th and the 7th year of age, the nodule rapidly increased in size. The lesion was resected and displayed a favorable histology. At 10 years of age, the child is in good health, and there have been no signs of nodule recurrence. These findings would seem to show that a ‘‘wait and see’’ strategy is beneficial in the detection and management of NRs and support the usefulness of renal ultrasound mass screening. REFERENCES

Response to lung ultrasound as an additional imaging tool for the evaluation of pneumonia.

We thank Dr. Catalano for his interest in our paper. The letter raises several interesting issues deserving clarification. Catalano argues that our observation and conclusion in lung ultrasound (LUS) characteristics of communityacquired pneumonia (CAP) differ from a similar study published by Shah et al. In our study, LUS examinations were performed by an expert pediatric sonographer. The study by Shah was conducted by 15 pediatric emergency physicians. They underwent a 1-hr chest sonography training session given before the start of the study. Furthermore our data relate to 89 inpatients, who had been admitted to a Pediatric Department with diagnosis of pneumonia, whereas Shah studied 200 patients seen

Sensitivity and feasibility of lung ultrasound in bronchiolitis—reply to the correspondence letter by Catalano

We thank Dr Catalano et al. for their interest on our article. The comment raises two important issues, one regarding the test sensitivity and the second, more general, on test feasibility. Assuming the final diagnosis as a gold standard, lung ultrasound (LUS) showed an excellent sensitivity (47/52 vs 38/52 of chest x-ray, 90 vs 73 %), but we have to consider the observational characteristics of the study design, performed in a real-world setting with real patients, real problems, and real doctors, with clinically driven indication to chest xrays. This is typical of an observational effectiveness study; it is not an efficacy study, evaluating the technique under ideal conditions, and the observed results can be more directly relevant to clinical practice but also vulnerable to selection bias [1]. The authors raise concerns about the equipment setting and rationale for chest x-ray prescription. We reported this information in the Methods section: chest x-ray was always requested by the attending physician on the basis of the clinical picture; the equipment used for the lung ultrasound was a Toshiba Nemio machine, equipped with a high-resolution linear probe with frequencies ranging from 6 to 12 MHz. Regarding the second issue on the practical appeal of the method, we reported our gratifying experience in the demanding theater of a neonatal intensive care unit, consistent with the international consensus that the method is simple, safe, and sensitive—when challenged under controlled conditions versus appropriate gold standards [5]. Dr Catalano argues that lung ultrasound relying on artifacts, such as B-lines, is not an evidence-based best-practice imaging clue. We agree with that: LUS is not always able to provide a detailed anatomical definition, especially when we consider B-lines. However, we believe that the usefulness of LUS relies in being an additional imaging tool for the evaluation of the lung, which is quick, bedside, low-cost, non-ionizing, and very sensitive to detect the loss of air content. Of course, LUS should be integrated with other imaging modalities, when a detailed anatomical definition is needed. It is also true that every new diagnostic tool always raises many uncertainties when it is proposed. Given the high versatility and potential clinical implications of adding ultrasound to the regular imaging equipment, we believe it is of importance to deepen the knowledge of this technique to better understand its strengths and limitations. Cardiologists who experienced lung ultrasound as an adjunct to much more technically demanding echocardiography say that “from a technical viewpoint, in the echocardiographic cursus studiorum where 2D echo represents the elementary school, Doppler echo the secondary school, and stress echo University, B-lines correspond to kindergarten [3].” We also concur with Daniel Lichtenstein, who recently stated (Montecarlo Lung Ultrasound School 2013) that it takes 20 s to make a lung scan with V. A. Caiulo (*) School of Ultrasound of Italian Federation of Pediatricians, Piazza Angeli 3, 72100 Brindisi, Italy e-mail: antoniocaiulo@inwind.it

Reply to the correspondence letter by P. Toma: usefulness of ultrasound findings in bronchiolitis

abnormalities during the course of the disease. In all cases, clinical improvement was associated with the disappearance of lung ultrasound findings. Lung ultrasound has certainly many limitations and many aspects still need to be clarified. Given the high versatility of the technique and the very promising data obtained in some pathological conditions, we believe it is of importance to describe the lung ultrasound patterns of specific disease, even when, as in bronchiolitis, the diagnosis is mainly based on the clinical signs and symptoms.

Ultrasound in the diagnosis of Crohn disease in childhood.

Crohn disease(CD) is a chronic inflammatory bowel disease of likely multifactorial origin. Estimates of the incidence of the disease range from 1.2–1.3 cases/100,000 to 5.2 cases/100,000 per year in children <16 years of age, although the frequency of the disease appears to be increasing [1, 7]. To date, the delay in the diagnosis of CD in childhood remains a major problem with a mean interval between onset of symptoms and diagnosis of 47 weeks, this interval being even longer (66 weeks) in the absence of diarrhoea [7]. Although several investigatory tools are currently available, ranging from serology to radioisotope studies, little information exists regarding the usefulness of ultrasonography (US) in the early detection of CD in children. Here, we report on our clinical experience in the initial diagnostic evaluation of CD in two children by US. The first patient, a boy aged 13 years, was admitted to our hospital because of a 1 month history of intermittent fever and a 2 month history of constipation. Laboratory data revealed an elevated level of C reactive protein and the presence of anaemia. US showed intestinal wall thickening and reduced mobility of the terminal ileum and caecum, while the presence of mesenteric adenopathy, with lymph nodes up to 1–2 cm in diameter was observed in the lower right quadrant (Fig. 1).