Machine learning-based radiomic evaluation of treatment response prediction in glioblastoma.

AIM: To investigate machine learning based models combining clinical, radiomic, and molecular information to distinguish between early true progression (tPD) and pseudoprogression (psPD) in patients with glioblastoma. MATERIALS AND METHODS: A retrospective analysis was undertaken of 76 patients (46 tPD, 30 psPD) with early enhancing disease following chemoradiotherapy for glioblastoma. Outcome was determined on follow-up until 6 months post-chemoradiotherapy. Models comprised clinical characteristics, O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status, and 307 quantitative imaging features extracted from enhancing disease and perilesional oedema masks on early post-chemoradiotherapy contrast-enhanced T1-weighted imaging, T2-weighted imaging (T2WI), and apparent diffusion coefficient (ADC) maps. Feature selection was performed within bootstrapped cross-validated recursive feature elimination with a random forest algorithm. Naive Bayes five-fold cross-validation was used to validate the final model. RESULTS: Top selected features included age, MGMT promoter methylation status, two shape-based features from the enhancing disease mask, three radiomic features from the enhancing disease mask on ADC, and one radiomic feature from the perilesional oedema mask on T2WI. The final model had an area under the receiver operating characteristics curve (AUC) of 0.80, sensitivity 78.2%, specificity 66.7%, and accuracy of 73.7%. CONCLUSION: Incorporating a machine learning-based approach using quantitative radiomic features from standard-of-care magnetic resonance imaging (MRI), in combination with clinical characteristics and MGMT promoter methylation status has a complementary effect and improves model performance for early prediction of glioblastoma treatment response.

CT appearances of abdominal tuberculosis.

The purpose of this article is to review and illustrate the spectrum of computed tomography (CT) appearances of abdominal tuberculosis. Tuberculosis can affect any organ or tissue in the abdomen, and can be mistaken for other inflammatory or neoplastic conditions. The most common sites of tuberculosis in the abdomen include lymph nodes, genitourinary tract, peritoneal cavity and gastrointestinal tract. The liver, spleen, biliary tract, pancreas and adrenals are rarely affected, but are more likely in HIV-seropositive patients and in miliary tuberculosis. This article should alert the radiologist to consider abdominal tuberculosis in the correct clinical setting to ensure timely diagnosis and enable appropriate treatment.

Unsuspected pulmonary emboli adversely impact survival in patients with cancer undergoing routine staging multi-row detector computed tomography scanning.

BACKGROUND: While symptomatic venous thromboembolism adversely impacts survival among cancer patients, the outcome of cancer patients with unsuspected pulmonary embolism (UPE) found on routine cancer staging multi-row detector computed tomography (MDCT) scans is unknown. OBJECTIVE: To determine whether UPE detected on routine staging MDCT scans impacts overall survival among cancer patients. PATIENTS AND METHODS: We performed a matched cohort study of cancer patients diagnosed with UPE on routine staging scans between May 2003 and August 2006. Two controls (n = 137) were individually matched by age (± 5 years), cancer type and stage for each UPE patient (n = 70). We used Cox's proportional hazard models to compare the mortality between UPE patients and their matched controls. RESULTS: The hazard ratio (HR) for death among UPE patients was 1.51 (95% CI 1.01-2.27, P = 0.048). Compared with their matched controls, patients with UPE more proximal than the subsegmental arterial branches had a HR for death at 6 months of 2.28 (95% CI 1.20-4.33, P = 0.011) and an overall HR of 1.70 (95% CI 1.06-2.74, P = 0.027). Survival among UPE patients with isolated subsegmental PE (ISSPE) was not significantly different than that of matched controls (HR 1.04 95% CI 0.44-2.39, P = 0.92). CONCLUSIONS: UPE identified more proximal than the subsegmental arterial branches has a significant negative impact on survival among cancer patients.

Extranodal lymphoma in the thorax: cross-sectional imaging findings.

The purpose of this review is to discuss and illustrate the spectrum of appearances of extranodal lymphoma in the thorax, including the lungs, pleura, heart, thymus, chest wall, thoracic spine, and breast, using current cross-sectional imaging techniques, such as multidetector computed tomography, positron-emission tomography/computed tomography, magnetic resonance imaging, and sonography. Extranodal lymphoma can affect any organ or tissue in the thorax, and can be mistaken for other inflammatory or neoplastic conditions. This review should alert the radiologist to consider extranodal lymphoma in the appropriate clinical setting to ensure timely diagnosis, correct staging, and accurate post-treatment evaluation to optimize treatment regimens.

Iodixanol in multidetector-row computed tomography angiography (MDCTA): diagnostic accuracy for abdominal aorta and abdominal aortic major-branch diseases using four-, eight- and 16-detector-row CT scanners.

PURPOSE: To compare iodixanol-enhanced multidetector-row computed tomography angiography (MDCTA) with digital subtraction angiography (DSA), perioperative angiography, or surgical findings in the evaluation of the abdominal aorta and its main branches. MATERIAL AND METHODS: 173 patients with known or suspected aortic aneurysms or stenosis/occlusion of the abdominal aorta or its major branches were enrolled. The iso-osmolar contrast medium iodixanol (320 mg Iota/ml) was used, and data were acquired using four-, eight-, or 16-active-detector-row scanners. Reference diagnoses were provided by surgical findings, interventional findings, or DSA. Diagnostic accuracy was estimated with reference to surgery or interventional arteriography or DSA. Image quality was assessed as excellent, good, sufficient, or insufficient, and correlations were made with attenuation values in the aortic lumen. Tolerability of iodixanol was monitored during the injection for discomfort and other adverse events, and for 72 hours after contrast injection. RESULTS: In 132 of 136 evaluable cases, MDCTA diagnosis matched the reference diagnosis, yielding an agreement rate of 97.1% (95% CI 92.6-99.2%). The quality of most MDCTA scans (147/173) was rated as excellent. Overall mean attenuation was 305.7 HU. MDCTA appeared more accurate than DSA for identification of lesion calcification, thrombus, irregularity, and ulceration. Tolerability of iodixanol was good, and no serious adverse events were reported. CONCLUSION: MDCTA using iodixanol is a promising, noninvasive alternative for evaluating patients with abdominal aortic disease.

Spontaneous ureterocolic fistula secondary to calculous pyohydroureteronephrosis.

We report a case of ureterocolic fistula secondary to urolithiasis in a 70-year-old female imaged with both CT and an antegrade nephrostogram. The ureterocolic fistula was managed with insertion of an antegrade ureteral stent.

Outcomes after placement of colorectal stents.

BACKGROUND: Colonic stents are increasingly used to palliate or alleviate large bowel obstruction in patients with colon cancer and other obstructing lesions in whom a definitive surgical procedure is inappropriate. We report on the outcomes of a large group of patients who underwent deployment of a colon stent in a single institution by a single operator. PATIENTS AND METHODS: This was a retrospective observational cohort study of all patients undergoing colonic stenting between September 1995 and May 2002. Data collected included nature of pathology, type of stent used, procedure morbidity, patient survival and details of any definitive procedures performed after stenting. RESULTS: One hundred and seven patients were evaluated (58 male) with a median age of 75 years (range 36-99 years). A total of 112 stents were successfully deployed (46 as an emergency). Twelve patients had double stents inserted coaxially and overlapping. In 7 patients the stent could not be safely deployed. Eighty-seven patients had colorectal cancer, 13 patients had an extra-luminal malignancy, 5 had diverticular strictures and in 2 patients the pathology was unknown. At last review (May 2002) 18 patients were alive, 82 patients had died and 7 patients had been lost to follow-up. Of those patients who died, the median survival after stenting alone was 6 weeks (range 4 days-36 weeks). Ten patients underwent subsequent definitive surgery. Stent complications included, 2 colonic perforations, 3 stent occlusions and 4 stent migrations. CONCLUSION: Colonic stenting can be used effectively, with acceptable morbidity, to manage patients presenting with large bowel obstruction. In a smaller number of patients colon stents may safely temporize symptoms while definitive surgery is planned.

Multislice CT angiography: a practical guide to CT angiography in vascular imaging and intervention.

The development of multidetector CT (MDCT) has revolutionized CT angiography (CTA). Not only are new techniques now in the remit of CTA, but all the studies previously performed on single slice or helical CT can now be done with better resolution. The advantage of MDCT relevant to CTA is the ability to acquire high resolution, near isotropic data sets in a shorter acquisition time. Also important is the ability to achieve a longer scanning range in the arterial phase, which has seen the introduction of CTA of the peripheral arterial system. Image processing techniques have also progressed rapidly, with simplification of a previously cumbersome process. The high spatial resolution and relatively non-invasive nature make MDCT angiography a strong and serious competitor to established vascular imaging techniques. The implication is that traditional diagnostic pathways for evaluation of the vascular system have changed.

Computed tomographic cholangiography in the diagnosis of bile duct injury in children.

A case of avulsion of the extrahepatic bile duct from the duodenum is described in association with severe liver trauma in a child. The value of computed tomographic (CT) cholangiography and laparoscopy in the diagnosis of this rare condition is outlined, and a paradigm for management is described.

Pseudoaneurysm of the uterine artery after abdominal hysterectomy: radiologic diagnosis and management.

Uterine artery pseudoaneurysm is a rare but serious complication of pelvic surgery. Radiology has an important role in its diagnosis and primary management. We believe that this complication and its management are of importance to those assessing for complications following pelvic surgery.