Incidence and Risk Factors for Adrenal Crisis in Pediatric-onset Adrenal Insufficiency: A Prospective Study.

PURPOSE: To determine the incidence and risk factors for adrenal crisis (AC) in patients with pediatric-onset adrenal insufficiency (AI). MATERIALS AND METHODS: This multicenter, prospective cohort study conducted in Japan enrolled patients diagnosed with AI at ≤ 15 years of age. The incidence of AC was calculated as events per person-year (PY), and risk factors for AC were assessed using Poisson regression multivariable analysis. RESULTS: The study population comprised 349 patients (164 male, 185 female) with a total follow-up of 961 PY. The median age at enrollment was 14.3 years (interquartile range [IQR] 8.5-21.2 years), and the median follow-up was 2.8 years (IQR 2.2-3.3 years). Of these patients, 213 (61%) had primary AI and 136 (39%) had secondary AI. Forty-one AC events occurred in 31 patients during the study period. The calculated incidence of AC was 4.27 per 100 PY (95% confidence interval [CI] of 3.15-5.75). Poisson regression analysis identified younger age at enrollment (relative risk [RR] 0.93 [95% CI 0.89-0.97]) and increased number of infections (RR 1.17 [95% CI 1.07-1.27]) as significant risk factors. Female sex (RR 0.99 [95% CI 0.53-1.86]), primary AI (RR 0.65 [95 % CI 0.30-1.41]), or equivalent dosage of hydrocortisone per square meter of body area (RR 1.02 [95% CI 0.96-1.08]) was not a significant risk factor. CONCLUSION: A substantial proportion of patients with pediatric-onset AI experience AC. Younger age and an increased number of infections are independent risk factors for developing AC in these patients.

The role of ultrasound to evaluate the disorders of sex development: a pictorial essay.

Ultrasonography is usually the first modality used to evaluate patients with disorders of sex development (DSD). To determine the sex in patients with DSD, the following four categories are carefully evaluated: chromosomal, gonadal, anatomical internal genitalia, and external genitalia. However, in the clinical setting, the only information that sonographers have prior to ultrasound examination is the appearance of the external genitalia. The following DSD presentations are commonly observed: (1) male external genitalia present at birth, without testis in the scrotum or with a small penis; (2) female external genitalia present at birth, with an inguinal hernia or clitoromegaly; (3) neonates with ambiguous genitalia at birth; and (4) female or male external genitalia without sexual maturity. In this retrospective study of several clinical cases, we demonstrated an ultrasound-based sex determination approach for these clinical presentations. We found that sonographers evaluated the external genitalia in relation to the distal urethra within the corpus spongiosum and corpus cavernosum and the presence or absence of follicles within the detected gonads to determine the sex of the patient.

Role of ultrasound in follow-up after choledochal cyst surgery.

Choledochal cyst, which is a congenital dilatation of the bile duct, is a common congenital disease requiring surgical repair. This disease usually occurs in children aged < 10 years, necessitating a relatively long follow-up after repair. The incidence of this congenital disease in Asian countries, including Japan, was reported to be higher than that in other countries. Thus, follow-up of pediatric patients after choledochal cyst surgery is especially important in Japan. Specific or non-specific choledochal cyst repair complications occur in various organs and are categorized as early or late complications. In the liver, biliary obstruction, such as an anastomotic stricture or intrahepatic bile duct stone, may occur. Biliary carcinoma is an important late complication. In the pancreas, pancreatitis, residual bile duct dilation, or pancreatic fistula/leakage may occur. In the intestines, Roux-en-Y reconstruction complications, such as an obstruction at the site of anastomosis or retrograde intussusception, may occur in the early and late phases. Some complications warrant urgent surgical intervention. In this review, we present the sonographic findings of choledochal cyst repair complications to guide clinicians in conducting a careful evaluation of the involved organs in the presence of these complications.

Size of the Tonsil on Ultrasound in Children Without Tonsil-Associated Symptoms.

This study was performed to establish the reference for tonsil size in children, including neonates, without tonsil-associated symptoms, in relation to anthropometric indices (sex/age/height/weight/body mass index).We evaluated the size of both tonsils in 362 children by ultrasonography. Tonsil size was calculated as 0.523abc (a, transverse diameter on the transverse image; b, longitudinal diameter on the transverse image; c, longitudinal diameter on the longitudinal image) and compared between each age year using the Wilcoxon signed rank sum test with Bonferroni correction. We evaluated the relationships between tonsil size and anthropometric indices.Among these children, tonsil size was significantly increased by the age of 3 years (0-1 vs 1-2 [volume (right) = 210.15 ± 205.27 vs 737.83 ± 335.72 mm, P (right) < 0.0001 and volume (left) = 218.26 ± 207.23 vs 645.33 ± 240.31 mm, P (left) < 0.0001]; 1-2 vs 2-3 [volume (right) = 737.83 ± 335.72 vs 1073.86 ± 468.21 mm, P (right) = 0.004 and volume (left) = 645.33 ± 240.31 vs 1109.73 ± 563.20 mm, P (left) < 0.0001]). Although there was a tendency for the tonsil size to increase in years 3-12, there was no significant difference. Using single linear regression analysis, we found a correlation between tonsil size and age (r right/left = 0.67/0.65), height (r right/left = 0.72/0.70), and weight (r right/left = 0.66/0.64), with height having the strongest correlation.In conclusion, tonsil size significantly increased by 3 years of age. Tonsil size was correlated with anthropometric indices, with height showing the strongest correlation.

Use of ultrasound findings to predict bowel ischemic changes in pediatric patients with intestinal volvulus.

OBJECTIVES: Early diagnosis and prompt surgical intervention are important to prevent intestinal necrosis in patients with volvulus. The purpose of this study was to determine which ultrasound (US) findings may predict bowel ischemic changes in pediatric patients with intestinal volvulus. METHODS: Thirty-one pediatric patients with surgically proven intestinal volvulus were retrospectively reviewed. We compared the demographics and US findings (eg, superior mesenteric artery collapse, ascites, echogenic ascites, and degree of intestinal twist) between patients with and without bowel ischemic changes during surgery. Data are presented as median and range. The Fisher exact test, Mann-Whitney U test, and Wilcoxon signed rank sum test were used for statistical analyses. RESULTS: Eleven patients had bowel ischemic changes. Significant differences existed between patients with and without ischemic changes for age (2 days [range, 0-137 days] versus 6.5 days [range, 2-1618 days]; P = .02), superior mesenteric artery collapse (present/absent, 10/1 versus 9/11 patients; P = .02), the presence of ascites (present/absent, 8/3 versus 6/14 patients; P = .03), and intestinal twist degree on US imaging (540° [range, 180°-720°] versus 360° [range, 180°-720°]; P = .02). The groups did not significantly differ for sex, the time from the US examination to the operation, or echogenic ascites. The intestinal twist degree insignificantly differed between US and surgical findings (360° [range, 180°-720°] versus 360° [range, 0°-1080°]; P = .36). CONCLUSIONS: The presence of superior mesenteric artery collapse, ascites, and a large intestinal twist on US imaging were significant predictors of intestinal ischemic changes. Pediatric surgeons should perform prompt surgical interventions in cases of volvulus with these US findings.

Diagnostic performance of ultrasound without any colon preparation for detecting colorectal polyps in pediatric patients.

BACKGROUND: There are limited data on the sensitivity, specificity and accuracy of ultrasound for detecting colorectal polyps in children and young adults. OBJECTIVE: To evaluate the diagnostic accuracy of ultrasound, without any colon preparation, for detecting colorectal polyps in pediatric patients and to determine the causes of false-negative results. MATERIALS AND METHODS: We included 74 children with clinical signs like rectal bleeding, abdominal pain or diarrhea who underwent both ultrasound and colonoscopy. We evaluated the diagnostic performance of ultrasound for detecting colorectal polyps before colonoscopy, which served as the reference standard. We used Fisher exact and Student's t-tests for statistical analyses. RESULTS: Fifteen pediatric patients were diagnosed with colorectal polyps in the transverse (n=3), descending (n=1) and sigmoid (n=6) colon, and rectum (n=5) by colonoscopy. The sensitivity, specificity and accuracy of ultrasound to detect colorectal polyps were 47% (7/15, 95% confidence interval [CI] 21-73%), 100% (59/59, 95% CI 94-100%) and 89% (66/74, 95% CI 80-95%), respectively. The volume (mean ± standard deviation) of polyps not detected by ultrasound was significantly smaller than that detected (270±380 mm3 vs. 4,600±3,900 mm3, P=0.0124). We observed a significant difference in the location between the polyps detected and not detected by ultrasound (rectal/non-rectal=0/7 vs. 5/3, P=0.0256). No significant age or gender difference was observed. CONCLUSION: The accuracy for detecting colorectal polyps by ultrasound was 89% (95% CI, 80-95%) in our cohort. Polyps found in the rectum and relatively smaller polyps accounted for several false-negative cases.

Ultrasound Evaluation of Dermal Sinuses/Fistulas in Pediatric Patients.

A dermal sinus/fistula is a common condition; the relevant department should be consulted for appropriate treatment. It is important for radiologists to have adequate knowledge of these conditions to provide the correct diagnosis and recommend subsequent management. This review describes the following lesions: preauricular sinus, midline sinus of the upper lip, nasal dermoid sinus cyst, cheek fistula, first branchial cleft anomaly/sublingual branchial cleft anomaly, thyroglossal duct cyst/fistula, lateral cervical sinus/fistula, congenital dermal sinus/fistula of the anterior chest region, congenital skin sinus/fistula with a sternal cleft, and congenital prepubic sinus. On the basis of the skin orifice location and ultrasound images, radiologists can provide useful information to physicians.

Acquired partial lipodystrophy with metabolic disease in children following hematopoietic stem cell transplantation: a report of two cases and a review of the literature.

Hematopoietic stem cell transplantation (HSCT) has been newly identified as an etiology underlying acquired lipodystrophy (ALD). We report about two children with leukemia who underwent HSCT and later manifested aberrant fat distributions consistent with acquired partial lipodystrophy (APL). Both patients manifested graft-versus-host disease (GVHD), suggesting that GVHD may trigger lipodystrophy. The patients exhibited diabetic blood glucose patterns in the oral glucose tolerance test (OGTT) with high homeostasis model assessment ratios (HOMA-Rs), hypertriglyceridemia, fatty liver, and decreased serum leptin and adiponectin levels. Both patients were diagnosed with APL with metabolic disease. A review of the data of patients with ALD after HSCT revealed common clinical features, including aberrant fat distribution, impaired glucose tolerance (IGT) or diabetes and dyslipidemia. Based on previous reports and our two cases, we speculate that GVHD in the adipose tissue supports the development of ALD after HSCT. In conclusion, children may develop APL after HSCT. Therefore, evaluations of fat distribution and metabolic disease may be important during the long-term follow-up of these patients.

Predictors of prognosis in children with portal venous gas detected by ultrasound.

AIMS: To evaluate ultrasound findings in order to determine potential predictors of prognosis in pediatric patients with portal venous gas (PVG) detected by ultrasound. MATERIALS AND METHODS: Thirty-nine children were included and divided into two groups: benign PVG (n=24) and life-threatening PVG (n=15; 6 surgical interventions and 9 deaths). Possible predictors, i.e., the location of PVG in the liver, the distribution of intestinal pneumatosis, ascites and free air were compared between the two groups. RESULTS: A significant difference was noted between the two groups in terms of the distribution of intestinal pneumatosis (limited to the large bowel, benign vs life-threatening = 60.9% (14/23):21.4% (3/14), p=0.040), the absence of ascites (benign vs life-threatening = 79.1% (19/24):40.0% (6/15), p=0.019) and patient age (benign vs life-threatening = 52.5±65.3 months vs 19.7±44.0 months, p=0.019). No significant difference was observed in the location of PVG in the liver, the presence of free air, and sex between the two groups. CONCLUSIONS: In pediatric patients with PVG, including various ages and underlying diseases, intestinal pneumatosis limited to the large bowel and absence of ascites were predictors of a benign prognosis. However, despite the presence of these predictors, some patients with PVG required surgical intervention, therebysuggesting that the cause of PVG, such as necrotizing enterocolitis, volvulus, or pancreatitis, must be also carefully evaluated.

Postnatal Ultrasound to Determine the Surgical Strategy for Congenital Diaphragmatic Hernia.

OBJECTIVES: To compare defect sizes in congenital diaphragmatic hernia (CDH) measured by postnatal ultrasound (US) between neonates who underwent thoracoscopic surgery and neonates who underwent open surgery and between neonates who underwent primary repair and those who underwent patch repair; additionally, to compare the accuracy of US diagnosis with that of surgical diagnosis for the location of the diaphragmatic hernia and the hernial contents. METHODS: We included 8 neonates who underwent preoperative US evaluations of CDH. We compared anterior-to-posterior diaphragm defect sizes between thoracoscopic and open surgery approaches and between primary and patch repair by using the Mann-Whitney U test. The diaphragm was divided into 3 segments: anterior, lateral, and posterior. We evaluated the location of the diaphragmatic hernia and the hernial contents. RESULTS: Four neonates who underwent open surgery had larger diaphragmatic hernias than those who underwent thoracoscopic surgery (mean ± SD, 30.5 ± 5.6 versus 16.3 ± 3.3 mm; P = .030). They were also larger in neonates who underwent patch repair than in those who underwent primary repair (33.0 ± 3.0 versus 17.6 ± 4.2 mm; P = .037). Detection of anterior and lateral diaphragm segments was consistent between US and surgical findings. Three of 4 neonates who underwent open surgery and all 3 neonates who underwent patch repair did not show the lateral segment. The hernial contents were also consistent between US and surgical findings. CONCLUSIONS: Postnatal US examinations of neonates with CDH could provide surgeons with useful information to determine the surgical approach and repair method. However, since our study cohort was small, further studies are needed with a larger number of neonates with CDH.

Detection of Intestinal Pneumatosis Location by Following Hyperechoic Foci in the Portal Vein Along Its Branches With Real-time Ultrasound.

Portal venous gas is occasionally encountered in children with intestinal pneumatosis, identified on real-time ultrasound imaging as hyperechoic foci with quick movement. The origin of the portal venous gas can be identified by following the hyperechoic foci along the branches of the portal vein, providing an estimate of the location of intestinal pneumatosis. This approach may be useful for predicting the patient's prognosis. Our report describes 2 cases of portal venous gas while estimating the area of intestinal pneumatosis, which were evaluated with real-time ultrasound.

Usefulness of Ultrasound in Evaluating the Diaphragm in Neonates and Infants With Congenital Diaphragmatic Hernias.

This report describes the evaluations of 2 patients with congenital diaphragmatic hernias using ultrasound (US). Identifying the size of the diaphragmatic defect is important when determining the type of surgical repair required. In case 1, the US evaluation of a Bochdalek hernia showed the rim of the anterolateral diaphragm; therefore, thoracoscopic primary repair was performed. In case 2, (Morgagni-Larrey hernia), US revealed the left side of a retrosternal diaphragmatic hernia sac; therefore, thoracoscopic repair from the left thorax was performed. Ultrasound was useful for detecting the location and defect size of the diaphragmatic hernia and determining optimal surgical management.

Difference in Detection Rate of Portal Venous Gas via Computed Tomography and Ultrasonography in Pediatric Patients.

This study was performed to compare computed tomography (CT)- and ultrasonography (US)-derived detection rates of portal venous gas (PVG) in pediatric patients and investigate whether discrepancies between these modalities were influenced by patient age and interval between examinations. We included 25 children who underwent both CT and US within 2 days for evaluation of intestinal ischemia. McNemar test was used to compare the detection of PVG between the 2 modalities. The cohort was retrospectively divided into 2 groups based on whether comparable results were obtained via both modalities; the Mann-Whitney U test was used to compare patient age and interval between CT and US between these 2 groups. Among 25 children, CT and US yielded similar results in 17 patients regarding the presence or absence of PVG (median age/interval, 2 years [range, 0-17 years]/51 minutes [range, 2-1196 minutes]; 3/14 detected via both/not both modalities) and different results in 8 (median age/interval, 0 years [range, 0-15 years]/171.5 minutes [range, 64-1486 minutes]; 7/1 detected via US only/via CT only). There was a significant difference in PVG detection rate between US and CT (P = 0.034). Patient age did not differ significantly between the 2 groups (P = 0.206), but the interval between CT and US did (P = 0.025). In conclusion, the detection rate of PVG was higher with US, compared with CT, although the timings of the examinations could have influenced this finding. Ultrasonography could be useful for PVG detection in pediatric patients because it can be performed repeatedly at the bedside without radiation exposure.

Identification of Rubisco anxiolytic-like peptides (rALPs) by comprehensive analysis of spinach green leaf protein digest.

Rubisco, an enzyme for photosynthetic carbon dioxide fixation, is a major green leaf protein and known as the most abundant protein on the Earth. We found that Rubisco digested mimicking gastrointestinal enzymatic conditions exhibited anxiolytic-like effects after oral administration in mice. Based on a comprehensive peptide analysis of the digest using nanoLC-Orbitrap-MS and the structure-activity relationship of known anxiolytic-like peptides, we identified SYLPPLTT, SYLPPLT and YHIEPV [termed Rubisco anxiolytic-like peptide (rALP)-1, rALP-1(1-7) and rALP-2, respectively], which exhibited potent anxiolytic-like effects after oral administration. The anxiolytic-like effects of rALP-1/rALP-1(1-7) were blocked by a serotonin 5-HT1A receptor antagonist, whereas rALP-2-induced effects were inhibited by a δ-opioid receptor antagonist. In conclusion, novel Rubisco-derived anxiolytic-like peptides, rALP-1/rALP-1(1-7) and rALP-2, act via independent neural pathways.

Optimal Timing of the First Barium Swallow Examination for Diagnosis of Pyriform Sinus Fistula.

OBJECTIVE: Observation of a sinus tract during a barium swallow examination is important for the diagnosis of pyriform sinus fistula; however, to our knowledge, no reports have existed regarding the optimal timing of the examination in relation to the onset of symptoms. The purpose of this study was to compare the timing of the examination, patient age, the number of inflammatory episodes that occurred before the examination, and the barium concentration used for examinations with true-positive results versus those with false-negative results for the diagnosis of pyriform sinus fistula. MATERIALS AND METHODS: Twenty-three children with pyriform sinus fistula were included. The timing of the examination, patient age, the number of the inflammatory episodes that occurred before examination, and the barium concentration used were compared between examinations with true-positive results and examinations with false-negative results, by use of the Mann-Whitney U test. RESULTS: The examination had true-positive results for 60.9% (14/23) of patients and false-negative results for 39.1% (9/23) of patients. The mean (± SD) interval since the onset of symptoms was significantly shorter for patients with false-negative examination results than for those with true-positive examination results (26.33 ± 21.17 days vs 48.57 ± 17.67 days; p = 0.020). By 6 weeks after the onset of symptoms, more than half of the examinations had false-negative results. No significant difference in patient age (p = 0.238) or number of previous inflammatory episodes (p = 0.431) existed between examinations with true-positive and false-negative results; however, a significant difference was noted in the mean barium concentration used (88.57% ± 31.53% vs 52.86% ± 18.68% weight/volume, respectively; p = 0.014). CONCLUSION: Barium swallow examinations with false-negative results were significantly more likely when the examination was performed soon after the onset of symptoms. Therefore, early first examinations would not be recommended for the diagnosis of pyriform sinus fistula, especially in terms of radiation exposure. A higher barium concentration may be useful.

Comparison Between the Pouch-Perineum Distance in Neonates With a Low-Type Anorectal Malformation With and Without an Opened Fistula: Pitfall of Measuring the Pouch-Perineum Distance on Sonography.

OBJECTIVE: An anorectal malformation (ARM) in neonates requires urgent surgery, with the type of surgery being dependent on the type of malformation (low, intermediate, or high). Distal rectal pouch and perineum (pouch-perineum) distance is reported to be useful for differentiating the type of ARM; however, the impact of an opened fistula on pouch-perineum distance is not well known. The purpose of this study was to evaluate the difference in pouch-perineum distance between neonates with a low-type ARM with and without an opened fistula. METHODS: We included 24 neonates with low-type ARM who underwent sonography before surgery. Eight neonates already had an opened fistula before sonography, and 16 did not. The pouch-perineum distance was measured using the perineal approach. Mann-Whitney U and Spearman's correlation coefficient tests were used for statistical analysis. RESULTS: The mean pouch-perineum distance in all neonates with a low-type ARM was 8.3 ± 2.9 mm. The pouch-perineum distance was substantially longer for an ARM with than without an opened fistula (10.6 ± 3.4 mm vs. 7.1 ± 1.7 mm; P = .02). No appreciable correlation was identified between the pouch-perineum distance and the postnatal day of examination (ρ = -.23, P = .26) or birth weight (ρ = .15, P = .47). CONCLUSION: The pouch-perineum distance is substantially longer in neonates with an ARM with an opened fistula than in those without an opened fistula. Caution should be exercised by the sonographic examiner in evaluating pouch-perineum distance in neonates with an opened fistula to prevent an incorrect surgical procedure based on misdiagnosis of the type of ARM.

Distance Between the Distal Rectal Pouch and Perineum in Neonates of Low-Birth Weight With Imperforate Anus.

This study was to evaluate the correlation between birth weight and the distance between distal rectal pouch and perineum (P-P distance) and to determine a cutoff value for P-P distance to diagnose low-type imperforate anus in neonates with low-birth weight (LBW).We included 15 neonates with LBW (mean weight, 2012 ± 470 g; range, 906-2452 g) and imperforate anus (surgically confirmed: 11 low type and 3/1 intermediate/high type), who underwent ultrasonography on the day after birth. Type of imperforate anus was defined based on the International Classification of Anorectal Anomalies. The P-P distances on ultrasonograms were measured. Pearson correlation coefficient test and receiver operating characteristic curve were used for statistical analyses.Among all 15 neonates, nonsignificant correlation was observed between the birth weight and P-P distance (r = 0.36; P = 0.18). Mean P-P distance was 9.0 ± 6.6 mm (range, 1.0-24.0 mm) in all neonates, 5.7 ± 2.8 mm (range, 1.0-11.0 mm) in the 11 neonates with low-type imperforate anus, and 18.3 ± 9.1 mm (range, 14.0-24.0 mm) in the 4 neonates with intermediate-/high-type imperforate anus. Using cutoff P-P distance of 12.5 mm, sensitivity and specificity for diagnosis of low-type imperforate anus were 100% (11/11) and 100% (4/4), respectively.In conclusion, nonsignificant correlation was observed between P-P distance and birth weight, and cutoff P-P distance to diagnose low-type imperforate anus was 12.5 mm. Despite the very small sample size in our study, and only 4 neonates with intermediate-/high-type imperforate anus, these findings are important because surgical management whether transperineal anoplasty or diverting colostomy is decided based on the type of imperforate anus, and P-P distance to diagnose the type of imperforate anus was feasible even in neonates with LBW.

Diagnostic Accuracy of Sonography for Detection of a Fistula on the Birth Day in Neonates With an Imperforate Anus: Comparison of Diagnostic Performance Between Suprapubic and Perineal Approaches.

OBJECTIVES: To evaluate the diagnostic accuracy of sonography for detection of an internal fistula on the birth day in neonates with an imperforate anus and to compare the diagnostic performance between the suprapubic and perineal approaches. METHODS: We included 46 neonates with an imperforate anus (29 low type and 17 intermediate/high type) who underwent sonography by both the suprapubic and perineal approaches on the birth day. Thirty-nine neonates had internal fistulas, and 12 did not, as surgically proven. Two blinded radiologists evaluated the suprapubic and perineal sonograms for the presence of the internal fistula in consensus. A final diagnosis of the internal fistula was determined on the basis of the findings of both approaches. A receiver operating characteristic analysis was used to compare the diagnostic performance for detection of an internal fistula between the suprapubic and perineal approaches. RESULTS: The sensitivity, specificity, and accuracy of the final diagnosis based on the findings of suprapubic, perineal, and both approaches were 52.9%, 79.4%, and 79.4%; 75.5%, 75.5%, and 75.5%; and 58.7%, 78.3%, and 78.3%, respectively. The diagnostic performance of the perineal approach was significantly better than that of the suprapubic approach (P < .0001). CONCLUSIONS: The diagnostic accuracy of sonography for detection of an internal fistula on the birth day exceeded 75% in neonates with an imperforate anus, and sonography on the birth day is feasible. The perineal approach had superior diagnostic performance over the suprapubic approach. Thus, when evaluating an internal fistula by sonography, we recommend using the perineal approach in addition to the suprapubic approach.

Comparison of Diagnostic Accuracy for the Low-Type Imperforate Anus Between Prone Cross-Table Radiography and Sonography.

OBJECTIVES: To compare the diagnostic accuracy for the low-type imperforate anus between prone cross-table radiography and sonography. METHODS: We included 20 neonates with imperforate anus: 13 with a surgically proven low type and 7 with an intermediate or high type. The distance between the distal rectal pouch and the perineum (pouch-perineum distance) was measured by both sonography and prone cross-table radiography. A previously established pouch-perineum distance of 10 mm was used as the cutoff for diagnosis of a low-type imperforate anus. The fistula location was also determined with sonography. We then compared the diagnostic accuracy of the imaging methods for a low-type imperforate anus using the cutoff value of the pouch-perineum distance alone and both the cutoff value of the pouch-perineum distance and fistula location. The McNemar test was used for statistical analysis. RESULTS: With the use of only the pouch-perineum distance, the diagnostic accuracy for the low-type imperforate anus based on sonographic measurements was comparable with the accuracy achieved by prone cross-table radiographic measurements (60.0% [12 of 20] versus 45.0% [9 of 20]; P = .625). With the use of the pouch-perineum distance and fistula location, the diagnostic accuracy of sonography was significantly better than the accuracy of prone cross-table radiography (90.0% [18 of 20] versus 45% [9 of 20]; P = .012). CONCLUSIONS: The diagnostic accuracy of sonography for the low-type imperforate anus based on both the pouch-perineum distance and fistula location is better than that of prone cross-table radiography. If the pouch-perineum distance on prone cross-table radiography is greater than 10 mm, a sonographic examination to determine the fistula location could be recommended.