Megan B. Marine

Fatty pancreas: A factor in postoperative pancreatic fistula

Objective:To determine whether patients who develop a pancreatic fistula after pancreatoduodenectomy are more likely to have pancreatic fat than matched controls. Background:Pancreatic fistula continues to be a major cause of postoperative morbidity and increased length of stay after pancreatoduodenectomy. Factors associated with postoperative pancreatic fistula include a soft pancreas, a small pancreatic duct, the underlying pancreatic pathology, the regional blood supply, and surgeons experience. Fatty pancreas previously has not been considered as a contributing factor in the development of postoperative pancreatic fistula. Methods:Forty patients with and without a pancreatic fistula were identified from an Indiana University database of over 1000 patients undergoing pancreatoduodenectomy and matched for multiple parameters including age, gender, pancreatic pathology, surgeon, and type of operation. Surgical pathology specimens from the pancreatic neck were reviewed blindly for fat, fibrosis, vessel density, and inflammation. These parameters were scored (0–4+). Results:The pancreatic fistula patients were less likely (P < 0.05) to have diabetes but had significantly more intralobular (P < 0.001), interlobular (P < 0.05), and total pancreatic fat (P < 0.001). Fistula patients were more likely to have high pancreatic fat scores (50% vs. 13%, P < 0.001). Pancreatic fibrosis, vessel density, and duct size were lower (P < 0.001) in the fistula patients and negative correlations (P < 0.001) existed between fat and fibrosis (R = −0.40) and blood vessel density (R = −0.15). Conclusions:These data suggest that patients with postoperative pancreatic fistula have (1) increased pancreatic fat and (2) decreased pancreatic fibrosis, blood vessel density, and duct size. Therefore, we conclude that fatty pancreas is a risk factor for postoperative pancreatic fistula.

Nonalcoholic fatty pancreas disease

BACKGROUND Obesity leads to fat infiltration of multiple organs including the heart, kidneys, and liver. Under conditions of oxidative stress, fat-derived cytokines are released locally and result in an inflammatory process and organ dysfunction. In the liver, fat infiltration has been termed nonalcoholic fatty liver disease, which may lead to nonalcoholic steatohepatitis. No data are available, however, on the influence of obesity on pancreatic fat and cytokines, and nonalcoholic fatty pancreas disease (NAFPD) has not been described. Therefore, we designed a study to determine whether obesity is associated with increased pancreatic fat and cytokines. MATERIALS AND METHODS Thirty C57BL/6J lean control and 30 leptin-deficient obese female mice were fed a 15% fat diet for 4 weeks. At 12 weeks of age all animals underwent total pancreatectomy. Pancreata from each strain were pooled for measurement of a) wet and dry weight, b) histologic presence of fat, c) triglycerides, free fatty acids (FFAs), cholesterol, phospholipids, and total fat, and d) interleukin (IL)-1beta and tumor necrosis factor-alpha (TNF-alpha). Data were analyzed by Students t test and Fishers exact test. RESULTS Pancreata from obese mice were heavier (p<0.05) and had more fat histologically (p<0.05). Pancreata from obese mice had more triglycerides, FFAs, cholesterol, and total fat (p<0.05). Triglycerides represented 11% of pancreatic fat in lean mice compared with 67% of pancreatic fat in obese mice (p<0.01). Cytokines IL-1beta and TNF-alpha also were elevated in the pancreata of obese mice (p<0.05). CONCLUSIONS These data suggest that obese mice have 1) heavier pancreata, 2) more pancreatic fat, especially triglycerides and FFAs, and 3) increased cytokines. We conclude that obesity leads to nonalcoholic fatty pancreatic disease.

Imaging of malrotation in the neonate.

Intestinal malrotation is a congenital abnormal fixation of the bowel that predisposes to life threatening midgut volvulus. Most events of midgut volvulus occur in the first month of life with decreased risk with age. The most typical presentation is bilious vomiting. Upper gastrointestinal series is the study of choice for diagnosis of malrotation. For optimal results, the study should be well planned with meticulous attention to technique. In equivocal cases, small bowel follow-through study and ultrasound can be performed.

Ultrasound classification of solitary renal cysts in children

INTRODUCTION Solitary renal cysts are typically incidentally found in children who have undergone renal ultrasound (US). The main concern is a cystic tumor. There is no US-based grading system for children to guide management. OBJECTIVE To evaluate a US-based, modified Bosniak grading system in order to differentiate between simple (grade I or II) and complex (grade II or IV) renal cysts and guide management in children. STUDY DESIGN This was a retrospective (2003-2011) study of 212 children (114 females), age range one day to 17 years (mean 8.4 years), with solitary renal cysts diagnosed by US. Two radiologists, who were independent and blinded to clinical information, graded the cysts using the modified Bosniak classification system. In children with more than one year of follow-up US, the change (>10%) in cyst diameter was evaluated. Inter-observer variability (Kappa) was calculated. RESULTS Radiologists one and two saw simple renal cysts in 96.2-96.6% (204-205/212) of the children. Ten children had complex renal cysts, as rated by either of the radiologists. There was good inter-observer agreement (kappa = 0.65) for simple versus complex cysts. In 20.2% (18/89) of the children, the cysts increased in size. A definitive diagnosis was obtained in 8.5% (18/212) of the children. A cystic tumor (multilocular cystic nephroma) was found in one child (Figure) with a complex cyst (graded III by both radiologists). DISCUSSION The use of a modified Bosniak classification system to grade renal cysts was found to have good inter-observer variability (kappa = 0.65) in differentiating between simple and complex renal cysts. Using this classification, few (<4%) renal cysts were classified as complex. Cystic tumors are rare and the only cystic tumor (multilocular cystic nephroma) was classified as complex renal cysts by the two radiologists. Growth of simple, solitary renal cyst is common (20.2%) and, therefore, if not associated with other imaging findings, is not an indication for a cystic tumor. There were limitations inherent in the retrospective nature of the study and because only one child had a cystic tumor. CONCLUSION The modified Bosniak classification system demonstrated good inter-observer agreement, and identified the single tumor as a complex cyst. The vast majority of solitary renal cysts in children are simple and if asymptomatic, they require no other imaging evaluation. Complex renal cysts are uncommon and should be evaluated with a pre-intravenous and postintravenous contrast CT scan to exclude a tumor.

Is the new ACR-SPR practice guideline for addition of oblique views of the ribs to the skeletal survey for child abuse justified?

OBJECTIVE The purpose of our study was to determine whether adding oblique bilateral rib radiography to the skeletal survey for child abuse significantly increases detection of the number of rib fractures. MATERIALS AND METHODS We identified all patients under 2 years old who underwent a skeletal survey for suspected child abuse from January 2003 through July 2011 and who had at least one rib fracture. These patients were age-matched with control subjects without fractures. Two randomized radiographic series of the ribs were performed, one containing two views (anteroposterior and lateral) and another with four views (added right and left oblique). Three fellowship-trained radiologists (two in pediatrics and one in trauma) blinded to original reports independently evaluated the series using a Likert scale of 1 (no fracture) to 5 (definite fracture). We analyzed the following: sensitivity and specificity of the two-view series for detection of any rib fracture and for location (using the four-view series as the reference standard), interobserver variability, and confidence level. RESULTS We identified 212 patients (106 with one or more fractures and 106 without). The sensitivity and specificity of the two-view series were 81% and 91%, respectively. Sensitivity and specificity for detection of posterior rib fractures were 74% and 92%, respectively. There was good agreement between observers for detection of rib fractures in both series (average kappa values of 0.70 and 0.78 for two-views and four-views, respectively). Confidence significantly increased for four-views. CONCLUSION Adding bilateral oblique rib radiographs to the skeletal survey results in increased rib fracture detection and increased confidence of readers.

Is CT cystography an accurate study in the evaluation of spontaneous perforation of augmented bladder in children and adolescents

BACKGROUND Spontaneous bladder perforation (SBP) is a potentially fatal complication of augmented bladder. Imaging is often used for diagnosis. In this study we present our experience with CT cystography (CTC) in the diagnosis of SBP. OBJECTIVE To determine CTC accuracy in the evaluation of SBP in children with an augmented bladder. STUDY DESIGN The institutional review board approved this HIPAA-compliant study; informed consent was waived. All patients under 20 years old, who underwent CTC for SBP evaluation from 2003 to 2013, were identified. Two radiologists independently reviewed CTC studies for contrast extravasation, ascites, and pneumoperitoneum. Ascites was graded: small - confined to the rectovesical pouch (RVP); moderate - beyond the RVP; large - beyond the pelvis. RESULTS Eighty-nine patients (47 males, age 4.2-19.8 years) had 132 CTCs. SBP was diagnosed in 14% (19/132). Both radiologists found contrast extravasation in 74% (14/19) of patients with SBP; two patients had only pneumoperitoneum, and three had only ascites (large = 2, moderate = 1) (Fig.). SBP was found in 1% of CTCs with no ascites or small ascites (1 of 98 and 92; radiologists 1 and 2, respectively). Findings of extraluminal extravasation, unexplained pneumoperitoneum, or large ascites, yielded a detection rate of 95% for SBP by each radiologist. In eight patients, small bowel obstruction was diagnosed. DISCUSSION Contrast extravasation was detected in only 74% of patients with SBP. The use of indirect signs of perforation (unexplained pneumoperitoneum and large ascites) in addition to contrast extravasation, increased the detection rate of SBP to 95%. US screening for SBP and selection of patients with moderate or large ascites for CTC, may eliminate the need for most CT scans. In the absence of SBP, other abdominal abnormalities should be evaluated. Bowel obstruction was the most common non-urological emergency detected in this series. The main limitations of the study are: the small number of SBP cases; the diagnosis of SBP not based on surgical findings in three patients; and inability to completely exclude occult SBP in patients not explored surgically. CONCLUSION Extraluminal contrast was seen on CTC in most cases of SBP, but some patients with sealed bladder perforation had only pneumoperitoneum or moderate/large ascites. Therefore, SBP should be suspected in any patient with moderate/large volumes of pelvic fluid or unexplained pneumoperitoneum, even when there is no evidence of contrast extravasation. Patients with no ascites, or small volumes, are unlikely to have SBP; therefore, US can be used to screen low risk patients.

JOURNAL CLUB: Can Coronal STIR Be Used as Screening for Acute Nontraumatic Hip Pain in Children?

OBJECTIVE The objective of this study is to evaluate whether coronal STIR MRI can be used as a screening test for nontraumatic acute hip pain in children. MATERIALS AND METHODS From 2008 to 2012, we identified all patients younger than 18 years at our tertiary care facility who underwent pelvic MRI including coronal STIR for the following indications: acute hip pain, limping, or refusal to bear weight. Patients with a history of trauma were excluded. Each MR image was independently reviewed by four radiologists who were blinded to the clinical outcome. After first reviewing the coronal STIR images only, they then reviewed the full MRI studies in a random order different from that used for review of the coronal STIR images. The sensitivity and specificity of STIR-only images in identifying the presence of abnormality and specific diagnoses were calculated, with the full MRI study considered as the reference standard. Kappa values were calculated for STIR-only and full MRI studies. RESULTS A total of 127 patients (67 female patients and 60 male patients; median age, 9 years; range, 5 months to 17 years) were identified. The most common abnormalities (calculated as the mean of frequency values noted by four readers) were hip effusion (52%; range, 46-58%), osteomyelitis (42%; range, 29-48%), and myositis (32%; range, 20-40%). For the detection of any abnormality, STIR-only images had a mean sensitivity of 95% and a mean specificity of 67%. For approximately one-third of STIR-only studies with true-positive results, additional abnormalities were found on full MRI studies. CONCLUSION Coronal STIR imaging of the pelvis has high sensitivity (95%) in the detection of abnormalities associated with acute nontraumatic hip pain in children, but it often misses additional abnormalities.

Ultrasound diagnosis of tracheal cartilaginous sleeve in a patient with Pfeiffer syndrome

There is an association between tracheal cartilaginous sleeve and syndromic craniosynostosis. We present a case of tracheal cartilaginous sleeve diagnosed by ultrasound (US) in a patient with Pfeiffer syndrome. The patient developed respiratory failure and was suspected at bronchoscopy to have tracheal cartilaginous sleeve. US performed before tracheostomy placement demonstrated continuous hypoechoic cartilage along the anterior surface of the trachea, confirming the diagnosis. Our report shows that US can make a definitive diagnosis of tracheal cartilaginous sleeve and raises the possibility of using US to screen for the condition in patients with syndromic craniosynostosis without the need for anesthesia or ionizing radiation.

A comprehensive severity score for the morbidly adherent placenta: combining ultrasound and magnetic resonance imaging

BackgroundUltrasound (US) is the first-line imaging modality to assess the morbidly adherent placenta, but sensitivity and specificity are lacking.ObjectiveThis investigation aims to improve diagnostic accuracy with a comprehensive score using clinical history, US, and magnetic resonance imaging (MRI).Materials and methodsWe conducted a retrospective cohort study of pregnant women who received both transvaginal US and MRI with suspicion for morbidly adherent placenta between 2009 and 2016. US was scored with the following metrics: (i) previa, (ii) hypervascularity, (iii) loss of retroplacental clear space and (iv) lacunae. MRI was evaluated for (i) intraparenchymal vessels, (ii) abnormally dilated vessels, (iii) fibrin deposition, (iv) placental bulge and (v) bladder dome irregularity. Bayesian analysis was used to estimate the probability of morbidly adherent placenta for a given score. Diagnostic testing parameters were calculated.ResultsAmong the 41 women with concerning imaging, histologically identified disease was confirmed in 16. The probability of morbidly adherent placenta increased with the score. At the highest US score, the probability of disease was 63.7%. With the highest MRI score, the probability of adherent placentation was 90.5%. Combining the US and MRI findings had a sensitivity of 56% and a specificity of 92%.ConclusionA combined scoring system using MRI and US may accurately identify patients at risk for morbidity associated with morbidly adherent placenta.