Narrow band imaging evaluation of duodenal villi in patients with and without celiac disease: A prospective study

Table 1 Indications for upper endoscopy with duodenal biopsies and corresponding histopathology scores for each indication

Indication1	Patients, n (%)	Histopathology, n (%)
		Normal	Atrophy
			Partial	Complete
Dyspepsia	47 (42.0)	44 (93.6)	2 (4.3)	1 (2.1)
Nausea or vomiting	26 (23.2)	25 (96.2)	1 (3.8)2	0
Weight loss	26 (23.2)	19 (73.0)	3 (11.5)	4 (15.4)
Iron-deficiency anemia	16 (14.3)	14 (87.5)	1 (6.3)	1 (6.3)
Diarrhea	15 (14.0)	13 (86.7)	0	2 (13.3)
Rule out Celiac disease	15 (14.0)	13 (86.7)	1 (6.7)	1 (6.7)
Follow up Celiac disease	12 (10.7)	4 (33.3)	0	8 (66.7)
Other3	3 (2.7)	2 (66.7)	1 (33.3)	0
Total	112	94 (84)	12 (11)	6 (5)

¹Column total not additive as some patients had more than one presenting symptom or indication for EGD.

²Patient had focal erosive duodenitis with a peptic (i.e., non-Celiac) pattern.

³Of the three patients referred for an “other” indication, two were referred to rule out upper gastrointestinal Crohn’s disease, and a third for unexplained gastroesophageal reflux.

Table 2 Agreement between narrow band imaging - based evaluation and histopathology scores

		Histopathology1		C-statistic
		Normal	Atrophy
Performing endoscopist	Normal	87	2	0.82
	Atrophy	7	16
Advanced endoscopist	Normal	94	8	0.83
	Atrophy	0	10
GI Fellow	Normal	76	0	0.86
	Atrophy	16	18

¹All discordant cases in which histopathology were rated as atrophy and narrow band imaging (NBI) findings were rated as normal were cases of partial villous atrophy (i.e., not complete villous atrophy); there were no cases of histopathologically-proven complete villous atrophy which were rated as normal by NBI.

Table 3 Performance characteristics of narrow band imaging for distinguishing between normal mucosa and villous atrophy (partial or complete) as compared to histopathology

	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)	Accuracy (%)
Performing endoscopist	89	93	70	98	93
Advanced endoscopist	56	100	100	93	93
Gastroenterology fellow	100	83	53	100	86

PPV: Positive predictive value; NPV: Negative predictive value.

Table 4 Interobserver agreement on narrow band imaging - based duodenal scoring

	Performing endoscopist	Advanced endoscopist	GI Fellow
Performing endoscopist	-	-	-
Advanced endoscopist	0.55	-	-
GI Fellow	0.65	0.371	-

¹The fair agreement between advanced endoscopist and gastroenterological (GI) fellow appeared to be driven by the relatively frequent designation of atrophy by the GI fellow and the more conservative scoring by the advanced endoscopist, as supported by their respective negative and positive predictive values.