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Background: The real accuracy of computed tomographic colonography (CTC) is still unknown. Objective: To perform a meta-analysis of the diagnostic accuracy of CTC for the detection of polyps and colorectal tumors. Methods: Selection of studies:Studiesassessing the accuracy of CTC for the detection of colorectal polyps and tumors were selected. Data synthesis:Meta-analyses combining sensitivities, specificities and likelihood ratios (LRs) for the diagnosis of polyps and colorectal tumors were carried out. Results: Forty-seven studies, providing data of 10,546 patients, were included. Overall per-polyp sensitivity of CTC was 66% (64–68%), for polyps 6–9 mm in size it was 59% (56–61%), and 76% (73–79%) for polyps larger than 9 mm. Overall per-patient sensitivity was 69% (66–72%), for polyps 6–9 mm 60% (56–65%), and 83% (70–85%) for lesions larger than 9 mm. Overall CTC specificity was 83% (81–84%). Positive and negative LRs were 2.9 (1.8–4) and 0.38 (0.27–0.53), respectively; for polyps 6–9 mm in size, they were 3.8 (2.5–5.7) and 0.4 (0.27–0.59), and 12.3 (7.7–19.4) and 0.19 (0.12–0.3) for polyps larger than 9 mm. Conclusion: CTC is highly specific for the detection of colorectal polyps and tumors. Some studies reported high sensitivities, but the results of the studies were highly heterogeneous, while the studied variables explained only part of this discrepancy.

A normal HCT rules out that a patient with CD is in the active phase of disease. The presence of significant bowel wall enhancement and mesentery involvement assists in the differentiation of patients in the active phase from those in remission. HCT is also effective to assess the presence of complications, which are indicative of the active phase.

Abdominal complications affect more than 80% of patients who undergo hematopoietic stem cell transplantation (HSCT) for treatment of benign or malignant hematologic disease and some solid tumors. HSCT can be performed using cells from bone marrow, peripheral blood, or umbilical cord blood. These stem cells may be from the patient him- or herself (autologous transplant), from relatives or nonrelatives with very similar human leukocyte antigen (allogeneic transplant), or from an identical twin (syngeneic transplant). Posttransplantation complications are classified according to the amount of time elapsed between transplantation and onset. Complications that occur during the first 100 days are divided into preengraftment phase complications (≤30 days after transplantation) and early posttransplantation phase complications (31-100 days after transplantation) and include infectious and noninfectious conditions such as hepatic veno-occlusive disease (VOD), hemorrhagic cystitis, neutropenic colitis, benign pneumatosis, and acute graft-versus-host disease (GVHD). Hepatic VOD, neutropenic colitis, and acute hemorrhagic cystitis are associated with the pretransplantation conditioning regimen. After the first 100 days, chronic GVHD and lymphoproliferative disease are the main complications. Computed tomography and ultrasonography are the primary imaging techniques used in HSCT patients and can help make an early diagnosis, grade the severity of impact, and (if necessary) recommend further investigations to confirm the diagnosis.

Radiologists seldom encounter parasitic diseases in their daily practice in most of Europe, although the incidence of these diseases is increasing due to migration and tourism from/to endemic areas. Moreover, some parasitic diseases are still endemic in certain European regions, and immunocompromised individuals also pose a higher risk of developing these conditions. This article reviews and summarises the imaging findings of some of the most important and frequent human parasitic diseases, including information about the parasite’s life cycle, pathophysiology, clinical findings, diagnosis, and treatment. We include malaria, amoebiasis, toxoplasmosis, trypanosomiasis, leishmaniasis, echinococcosis, cysticercosis, clonorchiasis, schistosomiasis, fascioliasis, ascariasis, anisakiasis, dracunculiasis, and strongyloidiasis. The aim of this review is to help radiologists when dealing with these diseases or in cases where they are suspected. Teaching Points • Incidence of parasitic diseases is increasing due to migratory movements and travelling. • Some parasitic diseases are still endemic in certain regions in Europe. • Parasitic diseases can have complex life cycles often involving different hosts. • Prompt diagnosis and treatment is essential for patient management in parasitic diseases. • Radiologists should be able to recognise and suspect the most relevant parasitic diseases.