Quantitative Magnetic Resonance Imaging in Perianal Crohn's Disease at 1.5 and 3.0 T: A Feasibility Study.

Perianal Crohn's Disease (pCD) is a common manifestation of Crohn's Disease. Absence of reliable disease measures makes disease monitoring unreliable. Qualitative MRI has been increasingly used for diagnosing and monitoring pCD and has shown potential for assessing response to treatment. Quantitative MRI sequences, such as diffusion-weighted imaging (DWI), dynamic contrast enhancement (DCE) and magnetisation transfer (MT), along with T2 relaxometry, offer opportunities to improve diagnostic capability. Quantitative MRI sequences (DWI, DCE, MT and T2) were used in a cohort of 25 pCD patients before and 12 weeks after biological therapy at two different field strengths (1.5 and 3 T). Disease activity was measured with the Perianal Crohn's Disease Activity index (PDAI) and serum C-reactive protein (CRP). Diseased tissue areas on MRI were defined by a radiologist. A baseline model to predict outcome at 12 weeks was developed. No differences were seen in the quantitative MR measured in the diseased tissue regions from baseline to 12 weeks; however, PDAI and CRP decreased. Baseline PDAI, CRP, T2 relaxometry and surgical history were found to have a moderate ability to predict response after 12 weeks of biological treatment. Validation in larger cohorts with MRI and clinical measures are needed in order to further develop the model.

Gastrointestinal peptides and small-bowel hypomotility are possible causes for fasting and postprandial symptoms in active Crohn's disease.

BACKGROUND: Crohn's disease (CD) patients suffer postprandial aversive symptoms, which can lead to anorexia and malnutrition. Changes in the regulation of gut hormones and gut dysmotility are believed to play a role. OBJECTIVES: This study aimed to investigate small-bowel motility and gut peptide responses to a standard test meal in CD by using MRI. METHODS: We studied 15 CD patients with active disease (age 36 ± 3 y; BMI 26 ± 1 kg/m 2) and 20 healthy volunteers (HVs; age 31 ± 3 years; BMI 24 ± 1 kg/m 2). They underwent baseline and postprandial MRI scans, symptom questionnaires, and blood sampling following a 400-g soup meal (204 kcal). Small-bowel motility, other MRI parameters, and glucagon-like peptide-1 (GLP-1), polypeptide YY (PYY), and cholecystokinin peptides were measured. Data are presented as means ± SEMs. RESULTS: HVs had significantly higher fasting motility indexes [106 ± 13 arbitrary units (a.u.)], compared with CD participants (70 ± 8 a.u.; P ≤ 0.05). Postprandial small-bowel water content showed a significant time by group interaction (P < 0.05), with CD participants showing higher levels from 210 min postprandially. Fasting concentrations of GLP-1 and PYY were significantly greater in CD participants, compared with HVs [GLP-1, CD 50 ± 8 µg/mL versus HV 13 ± 3 µg/mL (P ≤ 0.0001); PYY, CD 236 ± 16 pg/mL versus HV 118 ± 12 pg/mL (P ≤ 0.0001)]. The meal challenge induced a significant postprandial increase in aversive symptom scores (fullness, distention, bloating, abdominal pain, and sickness) in CD participants compared with HVs (P ≤ 0.05). CONCLUSIONS: The decrease in fasting small-bowel motility noted in CD participants can be ascribed to the increased fasting gut peptides. A better understanding of the etiology of aversive symptoms in CD will facilitate identification of better therapeutic targets to improve nutritional status. This trial was registered at clinicaltrials.gov as NCT03052465.

MDCT findings in Baastrup disease: disease or normal feature of the aging spine?

OBJECTIVE: Baastrup disease is characterized by the development of abnormal contact between adjacent spinous processes. The clinical significance remains unresolved, a few studies showing Baastrup disease as a cause of back pain. The aim of this study was to establish the frequency of Baastrup disease in a large unselected cohort to determine whether it is part of the expected spectrum of degenerative changes in the aging spine. MATERIALS AND METHODS: The abdominopelvic CT scans of 1008 patients divided equally into seven age groups were retrospectively reviewed. Baastrup disease was judged present if there was close contact between adjacent spinous processes and if the apposing ends were sclerotic. The presence of other degenerative changes, such as disk degeneration, spondylolisthesis, and facet osteoarthritis, at affected levels also was noted. RESULTS: Evidence of Baastrup disease was found in 413 patients (41.0%). A decade-on-decade increase in frequency was found with a peak of 81.3% among patients older than 80 years. As many as five levels were found to be affected in some patients (4.1% of 413), but in most patients (35.4%), one level was affected. Baastrup disease was most common at L4-L5. Associated degenerative changes were found at almost all affected levels (899/901). CONCLUSION: Baastrup disease occurs with high frequency among the elderly. Our data show that it develops with increasing age and is part of the expected degenerative changes in the aging spine. Because of the nearly universal association with other degenerative changes, we urge caution before diagnosing Baastrup disease as the cause of back pain.

Craniometric measurements in the assessment of craniovertebral settling: are they still relevant in the age of cross-sectional imaging?

OBJECTIVE: Craniovertebral settling is a serious complication of rheumatoid arthritis, and a number of radiographic measures at the craniocervical junction are in use to enable its diagnosis. However, these measures are hampered by the overlap of relevant bony landmarks. We aim to establish accurate values for these measures on CT to facilitate early diagnosis of this condition on cross-sectional imaging. MATERIALS AND METHODS: One hundred men and 100 women who underwent CT that included imaging of the craniocervical junction were retrospectively identified. Patients between the ages of 18 and 49 years were included. Two radiologists reformatted the images in the midsagittal plane and performed a series of measurements as follows: the Wackenheim line, McRae line, Chamberlain line, and McGregor line and measurements obtained using the Redlund-Johnell method and our modification of the method proposed by Ranawat et al. RESULTS: There were significant differences between the CT values and accepted radiographic measurements for the Wackenheim, Chamberlain, and McGregor lines. The McRae line was the easiest to measure, and the odontoid tip did not cross this line in any patient (distance from line: range, 0.6-10.4 mm). The CT measurements obtained using the Redlund-Johnell method were similar to the radiographic values, and we provide normal CT values for the modified Ranawat method (men > 23.7 mm, women > 24.2 mm). CONCLUSION: We propose that the McRae line should be used over other methods when assessing for craniovertebral settling on cross-sectional studies because it is the easiest measure to understand and remember. If the odontoid tip is eroded, the Redlund-Johnell and modified Ranawat methods are alternatives, and we have provided normal CT values for those measures as well.