Interobserver Variability In Interpretation Research Articles

The utilization of molecular microscope in management of heart transplant recipients in the era of noninvasive monitoring.

Monitoring for graft rejection is a fundamental tenet of post-transplant follow-up. In heart transplantation (HT) in particular, rejection has been traditionally assessed with endomyocardial biopsy (EMB). EMB has potential complications and noted limitations, including interobserver variability in interpretation. Additional tests, such as basic cardiac biomarkers, cardiac imaging, gene expression profiling (GEP) scores, donor-derived cell-free DNA (dd-cfDNA) and the novel molecular microscope diagnostic system (MMDx) have become critical tools in rejection surveillance beyond standard EMB. This paper describes an illustrative case followed by a review of MMDx within the context of other noninvasive screening modalities for rejection. We suggest MMDx be used to assist with early detection of rejection in cases of discordance between EMB and other noninvasive studies.

Interobserver Variability in Interpretation of VQ SPECT and its Impact on Patient Management

Background: Pulmonary Embolism (PE) is a major cause of morbidity, mortality and hospitalization. Ventilation Perfusion lung scan (VQ) is a powerful tool in diagnosing PE. It has been noted that there are some variations between highly experienced physicians in interpreting VQ SPECT due to lack of widely accepted reporting guidelines. Aim of the Study: Is to measure the interobserver variability in interpreting VQ scans, and then re-measure it again after applying standardized guidelines. Methods: Two cohorts of patients were included in this study the first included 347 patients and the second 290. Interobserver variability between 4 experienced physicians was measured on the first cohort and re-measured on the second cohort after applying 10 points agreed standardized guidelines. Results: Showed substantial increase in the percentage of agreement between all the physicians after applying the agreed 10 points standardized diagnostic criteria. This was apparent in all the categories with the highest agreement achieved when comparing 2 physicians. Kappa value increased from 0.346 to 0.4665 between the 4 Physicians, from low 0.3 to high 0.4 range between 3 Physicians and from as low as 0.2762 to the maximum of 0.5516 between 2 physicians. Unclassified number decreased between the 2 cohorts from 16.5% to 8% and subsequently decreasing false positive cases from 7.5% to 1.7%. Conclusion: Adherence to reporting guidelines increases the interobserver agreement in interpreting VQ SPECT leading to better patient outcomes and increased referrer confidence in reporting VQ SPECT.

Reproducibility of cardiac magnetic resonance imaging in patients referred for the assessment of cardiac sarcoidosis; implications for clinical practice.

Cardiac sarcoidosis (CS) is an increasingly recognized condition, but cardiac magnetic resonance (CMR) image interpretation in these patients may be challenging as findings are often non-specific. The main objective of this study was to investigate the inter-reader agreement for the overall interpretation of CMR for the diagnosis of CS in an experienced reference center and investigate factors that may lead to discrepancies between readers. Consecutive patients undergoing CMR imaging to investigate for CS were included. CMR images were independently reviewed by two readers, blinded to all clinical, imaging and demographic information. The readers classified each scan as "consistent with cardiac sarcoidosis", "not consistent with cardiac sarcoidosis" or "indeterminate". Inter-reader agreement was assessed using κ-statistics. When there was disagreement on the overall interpretation, a third reader reviewed the images. Also, two readers independently commented on the presence of edema, presence of LGE (both ventricles) and quantified the extent of left ventricular LGE. 87 patients (43 women, mean age 54.3 ± 12.2years) were included in the study. There was agreement regarding the overall interpretation in 72 of 87 (83%) CMR scans. The κ value was 0.64, indicating moderate agreement. There was similar moderate agreement in the interpretation of LGE parameters. In an experienced referral center, we found moderate agreement between readers in the interpretation of CMR in patients with suspected CS. Physicians should be aware of this inter-observer variability in interpretation of CMR studies in patients with suspected CS.

Ultrasonography in the Diagnosis and Management of Developmental Dysplasia of the Hip.

» Graf’s technique for static anatomic assessment of the hip is widely accepted as part of developmental dysplasia of the hip (DDH) evaluation and is the foundation for other, more dynamic techniques utilized today.» The low cost and lack of ionizing radiation of ultrasound have encouraged some international communities to implement ultrasound in universal screening.» The technique’s limitations with regard to high intraobserver and interobserver variability in interpretation, along with controversy about the efficacy of universal screening, have led to the 2018 American Academy of Orthopaedic Surgeons (AAOS) Appropriate Use Criteria for the Management of Developmental Dysplasia of the Hip to recommend selective screening.» Dynamic ultrasonography, first described by Harcke in 1984, has become a more commonly used ultrasonographic method.» Harcke’s method of dynamic ultrasonography allows for the real-time assessment of an infant’s hip and can be performed with and without stress maneuvers in both the coronal and transverse planes of a neutral and a flexed hip.» A pediatric orthopaedic surgeon should have a fundamental understanding of ultrasonographic technique, its indications, and its limitations to appropriately utilize it in the neonatal period.

Serum soluble urokinase-type plasminogen activator receptor and interferon-γ-induced protein 10 levels correlate with significant fibrosis in chronic hepatitis B.

Hepatitis B virus (HBV) presents an important public health problem. Liver biopsy is currently the gold standard for assessing the degree of intrahepatic inflammation and for staging liver fibrosis. However, the value of liver biopsies is limited by sampling errors, understaging and interobserver variability in interpretation. There is, therefore, a need to identify novel, non-invasive serologic biomarkers for the development of new predictive models of fibrosis. We enrolled patients with chronic hepatitis B infection (CHB) and examined the relationships between serum soluble urokinase plasminogen activator receptor (suPAR) and interferon-induced protein-10 (IP-10), and the results of liver biopsies. Healthy volunteers with normal aminotransferase levels and negative serological results for HBV, hepatitis C virus and human immunodeficiency virus were recruited as controls. Mean platelet volume, serum suPAR and IP-10 were significantly elevated in patients with CHB compared with controls. Median serum suPAR and IP-10 levels were significantly higher in patients with liver fibrosis compared with patients with mild fibrosis. There was no significant difference in mean platelet volume or aspartate aminotransferase-to-platelet ratio index scores between patients with mild and significant fibrosis. suPAR and IP-10 were able to distinguish between significant and mild fibrosis with good sensitivity and specificity, and may thus represent useful biomarkers for identifying patients with significant fibrosis.

Predictive Efficacy of Interim Positron Emission Tomography/Computed Tomography (PET/CT) for the Treatment of Aggressive Lymphoma.

The prognostic value of whole-body positron emission tomography/computed tomography (PET/CT) with 18F-fluoro-2-deoxy-D-glucose (FDG) shortly after the onset of induction chemotherapy or mid treatment could help to predict long-term clinical outcomes in patients with Hodgkin's or Non-Hodgkin's lymphoma. However, FDG is not a tumor-specific substance, and it may accumulate to the point of being detected in a variety of benign conditions or at physiologic anatomical sites, which may give rise to false-positive interpretation. In an attempt to standardize the reporting criteria for interim PET/CT, the First International Workshop on Interim PET in Lymphoma suggested visual response criteria with the Deauville five-point scale, and the standardized uptake value (SUV) has been investigated in comparison with this visual system. A quantitative approach using the measurement of maximal SUV (SUVmax) or the reduction rate of SUVmax (ΔSUVmax) might be more appropriate in early-response PET/CT for reducing false-positive rates or for decreasing interobserver variability in interpretation. In this review, the predictive efficacy of PET/CT is discussed for the treatment of aggressive lymphoma, especially in terms of an interim PET/CT-based prognostic model.

Complexities and Challenges in the Pathologic Assessment of Size (T) of Invasive Breast Carcinoma

Size (the "T" in the TNM System) of invasive breast carcinoma is a proven independent prognostic factor; however, its accurate determination can be challenging. The purpose of this review is to discuss the complexities inherent in determining "T"-including those encountered in the clinical measurement ("cT", ie, physical and radiologic assessment) as well as pathologic determination (pT) of invasive breast carcinomas. Pathologic estimation of tumor size, macroscopic, as well as microscopic, can be problematic due to the complexity of multiple situations, seeming confusion regarding staging guidelines, and interobserver variation in interpretation. Additional problematic scenarios in determination of "T" include those incurred in excisions performed after the performance of needle core biopsies, and in cases wherein there are multiple foci of invasive carcinoma, as well as in carcinomas status post-neoadjuvant chemotherapy. It can also be difficult to determine "T" in certain types of invasive carcinoma, particularly those of the lobular type. In this communication, some of the complexities and challenges in determing "T" are discussed, and modest suggestions are offered to assist in optimizing such assessments.

The utility of p16INK4A expression in uterine cervical biopsies reported negative and positive for dysplasia at Kenyatta National Hospital, Nairobi, Kenya

Background Hematoxylin and eosin (HE mean age: 40.2 years. On review, negative for dysplasia were 32, CIN1 19, CIN2 16 and CINIII 24 (p Conclusion There is significant inter-observer variation in interpretation of cervical biopsies on H&E. p16INK4a expression correlates well with high grade lesions.

Experiences with a self-test for Dutch breast screening radiologists: lessons learnt

To evaluate a self-test for Dutch breast screening radiologists introduced as part of the national quality assurance programme. A total of 144 radiologists were invited to complete a test-set of 60 screening mammograms (20 malignancies). Participants assigned findings such as location, lesion type and BI-RADS. We determined areas under the receiver operating characteristics (ROC) curves (AUC), case and lesion sensitivity and specificity, agreement (kappa) and correlation between reader characteristics and case sensitivity (Spearman correlation coefficients). A total of 110 radiologists completed the test (76%). Participants read a median number of 10,000 screening mammograms/year. Median AUC value was 0.93, case and lesion sensitivity was 91% and case specificity 94%. We found substantial agreement for recall (κ = 0.77) and laterality (κ = 0.80), moderate agreement for lesion type (κ = 0.57) and BI-RADS (κ = 0.45) and no correlation between case sensitivity and reader characteristics. Areas under the ROC curve, case sensitivity and lesion sensitivity were satisfactory and recall agreement was substantial. However, agreement in lesion type and BI-RADS could be improved; further education might be aimed at reducing interobserver variation in interpretation and description of abnormalities. We offered individual feedback on interpretive performance and overall feedback at group level. Future research will determine whether performance has improved. • We introduced and evaluated a self-test for Dutch breast screening radiologists. • ROC curves, case and lesion sensitivity and recall agreement were all satisfactory. • Agreement in BI-RADS interpretation and description of abnormalities could be improved. • These are areas that should be targeted with further education and training. • We offered individual feedback on interpretative performance and overall group feedback.

Investigation of the inter-observer variability effect on the prognostic value of somatosensory evoked potentials of the median nerve (SSEP) in cardiac arrest survivors using an SSEP classification

Background and purposeWe investigated the inter-observer variability in interpretation of median nerve SSEPs with regard to neurological prognosis in survivors of cardiac arrest (CA). MethodsFour experienced neurologists analyzed 163 median nerve SSEPs on the basis of a pre-defined classification of SSEPs into five patterns (A–E), with consideration of cortical potentials up to a latency of 150ms. Of these, 133 recordings were from CA survivors and 30 were from healthy volunteers. The experts were blinded to whether a SSEP finding was from a CA survivor or a healthy volunteer. They were also unaware of the neurological outcome for the resuscitated patients. Three categories were defined for decision making. These were “good neurological outcome” represented by patterns A–C, “poor neurological outcome” (patterns D and E), and “not evaluable”. Experts’ agreement was calculated using the kappa-coefficient. ResultsThe mean correct prediction by the experts was 81.8% (range 76.3–86.6%) in resuscitated patients with good neurological outcome. In those with poor neurological outcome, however, correct prediction was achieved in only 63% (60.5–66%). All SSEPs from healthy volunteers were classified as “good neurological outcome”. The kappa-coefficient (κ) for all decision-making classifications was 0.75; for patients with poor outcome it was 0.76 and for those with good outcome 0.88. The predictive value for poor neurological outcome of the SSEP pattern D achieved a specificity of 93.5% and that of E a specificity of 98.4%. ConclusionOur study demonstrates good inter-observer agreement in the interpretation of median nerve SSEPs in CA survivors on the basis of a pre-defined SSEP evaluation set. The strongest correlation with poor outcome was found for pattern E, bilateral absence of the N20 peak.

Urinary Proteome Analysis at 5-Year Followup of Patients With Nonoperated Ureteropelvic Junction Obstruction Suggests Ongoing Kidney Remodeling

Severe ureteropelvic junction obstruction is treated surgically. However, for milder cases most clinical teams adopt a watchful waiting approach and only operate in the presence of significant decline of renal function combined with severe hydronephrosis. Little is known about the long-term consequences of ureteropelvic junction obstruction. Using capillary electrophoresis coupled with mass spectrometry, we analyzed the urinary proteome of 42 patients with ureteropelvic junction obstruction 5 years postoperatively or 5 years following spontaneous resolution. At 5-year followup urinary proteomes were similar between patients with early surgical correction of ureteropelvic junction obstruction and age matched controls. In contrast, urinary proteomes differed significantly between conservatively followed patients and controls. Analyses of the proteomic differences suggested ongoing renal or ureteral remodeling in the conservatively followed patients that was not visible clinically. Long-term followup studies are warranted in patients with ureteropelvic junction obstruction, especially those followed conservatively, to determine whether the observed changes in the urinary proteomes become clinically relevant at a later stage.

Interobserver variability in the interpretation of computed tomography following aneurysmal subarachnoid hemorrhage

Numerous abnormal findings may be evident on CT scans after aneurysmal subarachnoid hemorrhage (SAH). Here, the authors assess the interobserver variability in the radiological interpretation of the initial CT scan following SAH. Two experienced reviewers, a neurosurgeon and a neuroradiologist, independently prospectively reviewed the initial CT scans of 413 patients enrolled in the CONSCIOUS-1 trial. Measured variables included SAH, intraventricular hemorrhage, intracerebral hemorrhage, subdural hematoma, chronic infarction, midline shift, and hydrocephalus. To assess interobserver variability, weighted kappa values and intraclass correlation coefficients (ICCs) were calculated and Bland-Altman analysis was performed. Moderate to substantial agreement was found for most of the CT scanning findings. There was fair to moderate interobserver agreement between reviewers when determining the extent of SAH based on a descriptive categorical classification (kappa 0.41; 95% CI 0.33-0.49), and better agreement when a semiquantitative scale was used (ICC 0.56; 95% CI 0.49-0.62). There was poor agreement between reviewers for the presence of hydrocephalus (kappa 0.34; 95% CI 0.20-0.48), but substantial to near perfect agreement on ventriculocranial ratio measurements (ICC 0.77; 95% CI 0.72-0.81). The authors' findings suggest that there is considerable interobserver variability in the interpretation of CT scans after SAH. Quantitative measures may reduce interobserver variability in comparison with qualitative or categorical scales. Variability in interpretation of CT scans has implications for patient care and conduct of clinical trials. It may be beneficial to develop standardized assessments to ensure consistent evaluation of measured variables.

MRI of the small bowel in patients with Crohn's disease.

To highlight the advances in MRI of the small intestine in patients with Crohn's disease. MRI of the gut has become more feasible with improved spatial resolution and speed of the MR sequences allowing parallel evaluation for both disease activity and extra-enteric complications. Recent literature highlights excellent diagnostic accuracy of MR enterography (MRE) that is comparable to computed tomography enterography (CTE). Compared to CTE the image quality is not quite as good, and there is slightly more interobserver variability in interpretation. Despite these performance characteristics, the overall diagnostic yield of MRE is comparable to CTE. The lack of radiation exposure related to MRE is a significant strength, especially in Crohn's population that by virtue of their younger age, body habitus and potential need for repeated imaging, is at highest risk of potential cancer from radiation exposure due to diagnostic imaging. MRE should not be viewed as a 'safer' version of a CTE. The physics of MRI allows the application of unique sequences that add novel insights not possible with other imaging modalities. MRE is a highly effective technique for assessing Crohn's disease. We are only starting to explore new MRI sequences and the future of this technology is extremely exciting.

Role of Confocal Microscopy in the Diagnosis of Fungal and Acanthamoeba Keratitis

To investigate the role of confocal microscopy as a diagnostic modality in microbial keratitis and to determine inter- and intraobserver variation in the analysis and interpretation of confocal microscopy findings. Prospective, double masked, nonrandomized, observational clinical trial. We included 146 consecutive patients with clinically suspected microbial keratitis. Confocal microscopy and microbiology evaluation of study participants. Sensitivity, specificity, and positive and negative predictive values of confocal microscopy in diagnosing fungal and Acanthamoeba keratitis compared with microbiologic evaluation, as well as the intra- and interobserver variation in interpretation of confocal scans. We included 148 cases of infiltrative keratitis. Of the 103 microbiologically proven cases of Acanthamoeba or fungal keratitis, the confocal microscope was able to identify fungal filaments or Acanthamoeba cysts in 91 cases with either fungal or Acanthamoeba keratitis with a sensitivity of 88.3% (95% confidence interval [CI], 82.2-94.5) and a specificity of 91.1% (95% CI, 82.8-99.4). The interobserver agreement in interpreting the scans was good (kappa = 0.6; phi = 0.617). The intraobserver agreement was kappa = 0.795 and phi = 0.807. The confocal microscope seems to be an accurate and reliable diagnostic modality in the etiologic diagnosis of fungal and Acanthamoeba keratitis.

Longitudinal Analyses of Renal Lesions Due to Acute Pyelonephritis in Children and Their Impact on Renal Growth

Acute pyelonephritis is a common condition in children, and can lead to renal scarring. The aim of this study was to analyze the progression of renal scarring with time and its impact on renal growth. A total of 50 children who had renal scarring on dimercapto-succinic acid scan 6 months after acute pyelonephritis underwent a repeat scan 3 years later. Lesion changes were evaluated by 3 blinded observers, and were classified as no change, partial resolution or complete disappearance. Renal size at time of acute pyelonephritis and after 3 years was obtained by ultrasound, and renal growth was assessed comparing z-score for age between the 2 measures. Robust linear regression was used to identify determinants of renal growth. At 6 months after acute pyelonephritis 88 scars were observed in 100 renal units. No change was observed in 27%, partial resolution in 63% and complete disappearance in 9% of lesions. Overall, 72% of lesions improved. Increased number of scars was associated with high grade vesicoureteral reflux (p = 0.02). Multivariate analysis showed that the number of scars was the most important parameter leading to decreased renal growth (CI -1.05 to -0.35, p <0.001), and with 3 or more scars this finding was highly significant on univariate analysis (-1.59, CI -2.10 to -1.09, p <0.0001). Even 6 months after acute pyelonephritis 72% of dimercapto-succinic acid defects improved, demonstrating that some of the lesions may be not definitive. The number of scars was significantly associated with loss of renal growth at 3 years.

Results of patch testing to a corticosteroid series: A retrospective review of 1188 patients during 6 years at Mayo Clinic

Allergy to topical corticosteroids is more common than previously realized. To detect this allergy, a corticosteroid series is used for patch testing in addition to corticosteroid screens on a standard series. We sought to review our experience with patch testing to corticosteroid series. We conducted a retrospective study of patch testing to our corticosteroid series over 6 years (January 1, 2000-December 31, 2005). Of 1188 patients patch tested to corticosteroid series, 127 (10.69%) had allergic reaction to at least one corticosteroid; 56 reacted to multiple corticosteroids. Rates of allergic patch test reaction to 19,611 individual corticosteroids were 0.41% to 5.03%. Rates of reaction to corticosteroid groups were 1.10% to 5.72%; concomitant reactions between groups were noted. Present screens on our standard series identified 74% of those detected on the corticosteroid series; tixocortol pivalate alone detected less than 50%. Limitations include that this study was retrospective and the possible interobserver variation in interpretation of patch tests. In patients suggested to have corticosteroid allergy, patch testing confirms allergy in 10.69%; allergy is often to multiple corticosteroids and across groups. Screens on a standard series may detect 74% of those detected on a corticosteroid series.

The demystification of magnetic resonance imaging?The opinions expressed in this article are not necessarily those of the Editors of the European Heart Journal or of the European Society of Cardiology.

The interobserver variability in test interpretation is a key parameter to evaluate the diagnostic reliability of a diagnostic examination. It has been evaluated for most clinically relevant cardiac imaging modalities. In many instances the results have been rather sobering. A considerable variability in the visual assessment of coronary artery stenosis severity has been shown between different readers of coronary angiograms. 1 A high reader disagreement has been shown for interpretation of dobutamine stress echocardiograms. 2 The high variability in the interpretation of dobutamine stress echocardiograms has become a matter of debate and has been used as an argument to doubt the diagnostic competence of the method. Low image quality, a large variability in test performance, and insufficient standardization in image interpretation without any objective parameter to define the test result has been referred to as the major limitations of stress echocardiography. Lower observer variability due to more standardized image acquisition, better image quality, and objective parameters of test interpretation has been shown for perfusion scintigraphy and has been used as an argument for its favourable diagnostic performance. 3 Regarding stress echocardiography, multiple shortcomings could be reduced over time. Image quality could be improved. Along with digital image acquisition and more standardized interpretation criteria refinements in the stress echocardiographic techniques have resulted in higher interobserver agreement. 4 Still, interobserver agreement remained far from optimal. Dobutamine stress cardiovascular magnetic resonance imaging (DSMR) incorporates multiple advantages when compared with stress echocardiography. It is performed using standardized acquisition protocols. The acquired imaging views as well as quality of images is less dependent on the individual sonographers performance and the image quality is excellent in most cases. Thus, interobserver agreement is expected to be high considering the most obvious limitations of dobutamine stress echocardiography. However, data on interobserver agreement in the interpretation of DSMR were sparse until recently. In this issue of the Journal, Paesch et al. report on the interobserver variability in the interpretation of DSMR evaluated in a multicenter setting. 5 The study confirms an excellent image quality in the majority of imaging views with the use of DSMR as reported earlier by the investigators as well as other authors. 6 The study confirms also a high diagnostic accuracy for detection of coronary artery disease for all four readers using this technique. However, while the accuracy was almost similar among the four readers, sensitivity for detection of CAD ranged from as low as 71% to as high as 86%, and the specificity had a discordant trend indicating already that readers vary in their interpretation of image data. The surprise of this study is the relatively low interobserver agreement between the four expert observers from different institutions. The disagreement between the four readers was equally distributed and not the effect of one reader with significant deviations from the other readers.

Intrapartum cardiotocography – the dilemma of interpretational variation

To evaluate and compare interobserver variation in interpretation of intrapartum cardiotocograms. Fifteen senior (experience >4 years) and 16 junior (experience < or =4 years) obstetricians from 10 delivery units. Thirty-one obstetricians interpreted intrapartum cardiotocographic (CTG) readings from 22 parturients. Inter-observer agreement in CTG interpretation and decision-making was assessed via proportions of agreement (Pa), with 95% confidence intervals (CI). The level of inter-observer agreement was analyzed by calculating Pa values for CTG baseline, variability, early, variable and late decelerations, uterine tonus, power of contractions, hypertonus and clinical decision. In assessments of normal cases the Pa were acceptable or good (0.63-0.82) as regards all CTG interpretation elements except for the power of contractions (0.24), but in assessments of abnormal cases the Pa values were lower (0.18-0.60). As regards clinical decisions, a higher Pa was found in cases without recommendation for intervention (0.63, 95% CI 0.62-0.64) than in cases with such recommendation (0.55, 95% CI 0.54-0.56). The Pa in the abnormal cases was better among senior than among junior obstetricians. Inter-observer variation in interpretation of abnormal CTG readings and recommendations for intervention is relatively wide. To improve reliability, uniform classification and standardized training in CTG interpretation are needed, as well as increased use of computerized CTG.

Adding fuel to the fire: GM-CSF for active Crohn’s disease

Adding fuel to the fire: GM-CSF for active Crohn’s disease

Using CT and cholangiography to diagnose biliary tract carcinoma complicating primary sclerosing cholangitis.

The objective of our study was to determine the value of CT and cholangiography for diagnosing biliary tract carcinoma complicating primary sclerosing cholangitis. One hundred thirteen abdominal CT examinations and cholangiograms in 45 patients with primary sclerosing cholangitis, including 18 patients with established biliary tract carcinoma, were analyzed for tumor. Four radiologists who were unaware of the presence or absence of carcinoma rated each study as to the probability of malignancy. Receiver operating characteristic curve analysis was used to assess the diagnostic performance of CT and cholangiography, the value of imaging signs, and the degree of inter-observer variation in interpretation. Sensitivity and specificity values were calculated. CT outperformed cholangiography in the detection of carcinoma. The average area under the receiver operating characteristic curve was 0.82 for CT and 0.57 for cholangiography (p = 0.003). Sensitivity and specificity for detecting carcinoma using CT were good, with average values of 82% and 80%, respectively. Average sensitivity and specificity for cholangiography were 54% and 53%, respectively. The most reliable sign of tumor on CT was a discrete mass. Progressive biliary dilatation on sequential studies was the most useful sign on cholangiography. Interobserver agreement assessed using the Cronbach alpha was fair for cholangiography and good for CT. CT provides good sensitivity and specificity and significantly outperforms cholangiography in detecting biliary tract carcinoma complicating primary sclerosing cholangitis. Despite limitations, CT and cholangiography provide useful information not otherwise available in the treatment of patients with primary sclerosing cholangitis.