Update on imaging of Peutz-Jeghers syndrome

Peutz-Jeghers syndrome(PJS) is a rare, autosomal dominant disease linked to a mutation of the STK 11 gene and is characterized by the development of benign hamartomatous polyps in the gastrointestinal tract in association with a hyperpigmentation on the lips and oral mucosa. Patients affected by PJS have an increased risk of developing gastrointestinal and extra-digestive cancer. Malignancy most commonly occurs in the smallbowel. Extra-intestinal malignancies are mostly breast cancer and gynecological tumors or, to a lesser extent, pancreatic cancer. These polyps are also at risk of acute gastrointestinal bleeding, intussusception and bowel obstruction. Recent guidelines recommend regular smallbowel surveillance to reduce these risks associated with PJS. Small-bowel surveillance allows for the detection of large polyps and the further referral of selected PJS patients for endoscopic enteroscopy or surgery. Video capsule endoscopy, double balloon pushed enteroscopy,multidetector computed tomography and magnetic resonance enteroclysis or enterography, all of which are relatively new techniques, have an important role in the management of patients suffering from PJS. This review illustrates the pathological, clinical and imaging features of small-bowel abnormalities as well as the role and performance of the most recent imaging modalities for the detection and follow-up of PJS patients.

Acoustic radiation force impulse imaging for assessing liver fibrosis in alcoholic liver disease

AIM: To evaluate the performance of elastography by ultrasound with acoustic radiation force impulse(ARFI) in determining fibrosis stage in patients with alcoholic liver disease(ALD) undergoing alcoholic detoxification in relation to biopsy.METHODS: Eighty-three patients with ALD undergoing detoxification were prospectively enrolled. Each patient underwent ARFI imaging and a liver biopsy onthe same day. Fibrosis was staged according to the METAVIR scoring system. The median of 10 valid ARFI measurements was calculated for each patient.RESULTS: Sixty-nine males and thirteen females(one patient excluded due to insufficient biopsy size) were assessed with a mean alcohol consumption of 132.4 ± 128.8 standard drinks per week and mean cumulative year duration of 17.6 ± 9.5 years. Sensitivity and specificity were respectively 82.4%(0.70-0.95) and 83.3%(0.73-0.94)(AUROC = 0.87) for F ≥ 2 with a cut-off value of 1.63m/s; 82.4%(0.64-1.00) and 78.5%(0.69-0.89)(AUROC = 0.86) for F ≥ 3 with a cut-off value of 1.84m/s; and 92.3%(0.78-1.00] and 81.6%(0.72-0.90)(AUROC = 0.89) for F = 4 with a cut-off value of 1.94 m/s.CONCLUSION: ARFI is an accurate, non-invasive and easy method for assessing liver fibrosis in patients with ALD undergoing alcoholic detoxification.

Methods for improving colorectal cancer annotation efficiency for artificial intelligence-observer training

BACKGROUND Missing occult cancer lesions accounts for the most diagnostic errors in retrospective radiology reviews as early cancer can be small or subtle,making the lesions difficult to detect.Secondobserver is the most effective technique for reducing these events and can be economically implemented with the advent of artificial intelligence(AI).AIM To achieve appropriate AI model training,a large annotated dataset is necessary to train the AI models.Our goal in this research is to compare two methods for decreasing the annotation time to establish ground truth:Skip-slice annotation and AI-initiated annotation.METHODS We developed a 2D U-Net as an AI second observer for detecting colorectal cancer(CRC)and an ensemble of 5 differently initiated 2D U-Net for ensemble technique.Each model was trained with 51 cases of annotated CRC computed tomography of the abdomen and pelvis,tested with 7 cases,and validated with 20 cases from The Cancer Imaging Archive cases.The sensitivity,false positives per case,and estimated Dice coefficient were obtained for each method of training.We compared the two methods of annotations and the time reduction associated with the technique.The time differences were tested using Friedman’s two-way analysis of variance.RESULTS Sparse annotation significantly reduces the time for annotation particularly skipping 2 slices at a time(P<0.001).Reduction of up to 2/3 of the annotation does not reduce AI model sensitivity or false positives per case.Although initializing human annotation with AI reduces the annotation time,the reduction is minimal,even when using an ensemble AI to decrease false positives.CONCLUSION Our data support the sparse annotation technique as an efficient technique for reducing the time needed to establish the ground truth.

成人慢性小肠假性梗阻的多层螺旋CT影像特征

严重胃肠道运动紊乱引起的慢性小肠假性梗阻（CIPO）罕见。CIPO的成年病人有机械性肠梗阻的症状，但缺乏能可靠鉴别急性机械性肠梗阻与CIPO的临床体征。另外，腹平片虽然常可见肠道扩张与气液平面，但表现的特异性不足以与机械性肠梗阻鉴别。因此，大多数成年CIPO病人通常接受多次但无效的手术，常导致确诊前的反复肠道切除。对于这些腹部征象与提示需要行手术探查症状相似的病人，行多层螺旋CT（MDCT）检查可有助于解决这一诊断难题。