Incidental physiological sliding hiatal hernia: a single center comparison study between CT with water enema and CT colonography

Purpose Hiatal hernia is a well-known factor impacting on most mechanisms underlying gastroesophageal reflux, related with the risk of developing complications such as erosive esophagitis, Barrett\u2019s esophagus and ultimately, esophageal adenocarcinoma. It is our firm opinion that an erroneous reporting of hiatal hernia in CT exams performed with colonic distention may trigger a consecutive diagnostic process that is not only unnecessary, inducing a unmotivated anxiety in the patient, but also expensive and time-consuming for both the patient and the healthcare system. The purposes of our study were to determine whether colonic distention at CT with water enema and CT colonography can induce small sliding hiatal hernias and to detect whether hiatal hernias size modifications could be considered significant for both water and gas distention techniques. Methods We retrospectively evaluated 400 consecutive patients, 200 undergoing CT-WE and 200 undergoing CTC, including 59 subjects who also underwent a routine abdominal CT evaluation on a different time, used as internal control, while a separate group of 200 consecutive patients who underwent abdominal CT evaluation was used as external control. Two abdominal radiologists assessed the CT exams for the presence of a sliding hiatal hernia, grading the size as small, moderate, or large; the internal control groups were directly compared with the corresponding CT-WE or CTC study looking for a change in hernia size. We used the Student\u2019s t test applying a size-specific correction factor, in order to account for the effect of colonic distention: these \u201ccorrected\u201d values were then individually compared with the external control group. Results A sliding hiatal hernia was present in 51 % (102/200) of the CT-WE patients and in 48.5 % (97/200) of the CTC patients. Internal control CT of the 31 patients with a hernia at CT-WE showed resolution of the hernia in 58.1 % (18/31) of patients, including 76.5 % (13/17) and 45.5 % (5/11) of small and moderate hernias. Comparison CT of the 28 patients with a hiatal hernia at CTC showed the absence of the hernia in 57.1 % (16/28) patients, including 68.8 % (11/16) and 50 % (5/10) of small and moderate hernias. The prevalence of sliding hiatal hernias in the external control group was 22 % (44/200), significantly lower than the CT-WE and CTC cohorts\u2019 prevalence of 51 % (p < 0.0001) and 48.5 % (p < 0.0001). After applying the correction factors for the CT-WE and the CTC groups, the estimated residual prevalences (16 and 18.5 %, respectively) were much closer to that of the external control patients (p = 0.160 for CT-WE and p = 0.455 for CTC). Conclusions We believe that incidental findings at CT-WE and CTC should be considered according to the clinical background, and that small sliding hiatal hernias should not be reported in patients with symptoms not related to reflux disease undergoing CT-WE or CTC: When encountering these findings, accurate anamnesis and review of medical history looking for GERD-related symptoms are essential, in order to address these patients to a correct diagnostic iter, taking advantage from more appropriate techniques such as endoscopy or functional techniques

Quantitative assessment of breast density using the thresholding method.

<p>In this figure an example of the graphical computer interface is demonstrated. On the left, the edges of the breast are identified (edges are artificially thickened for visual purposes), then the radiologist adjusts the density threshold (semi-automated method) on the right, and finally the percentage of breast density is shown (<i>black circle</i>). In this example, the breast result was 41% dense.</p

Mean, median, maximum and minimum values of breast density percentage evaluated on every MRI sequence with the semi-automated software.

<p>Results include both readings from both radiologists. IDEAL sequences (Iterative Decomposition of water and fat with Echo Asymmetry and Least squares estimation) are reported are WaterOnly and FatOnly. VIBRANT: Volume Imaging for Breast Assessment.</p

Sequence parameter settings.

<p>IDEAL :Iterative Decomposition of water and fat with Echo Asymmetry and Least squares estimation. VIBRANT: Volume Imaging for Breast Assessment.</p><p>s = seconds, mm = millimeters, ms = milliseconds</p

Wilcoxon Test comparing breast density percentages evaluated on different MRI sequences (^a. based on negative ranks; ^b. based on positive ranks).

<p>VIBRANT: Volume Imaging for Breast Assessment.</p

Test for paired samples to evaluate mean value differences between results of breast density percentage obtained on each MRI sequence.

<p>95% C.I. and P-value have also been calculated. IDEAL sequences (Iterative Decomposition of water and fat with Echo Asymmetry and Least squares estimation) are reported as WaterOnly and FatOnly. VIBRANT: Volume Imaging for Breast Assessment.</p><p>SEM =  Mean Standard Error, 95% CI =  Confidence Interval for the difference.</p