This is an observational study in which patient data from the past of people who received Ultravist prior to an X-ray based scan are studied.

In observational studies, only observations are made without specified advice or interventions.

X-ray based imaging like computed tomography or angiography is used to make pictures of the structures inside the body. These pictures are needed in various medical situations. In some X-ray tests, the patient is given a compound called "contrast agent" that is injected into the vein. It helps to create clearer pictures as it makes internal body structures easier to see. With such contrast-enhanced imaging techniques, doctors can better see certain problems.

Ultravist is an iodine-based contrast agent. It is also called iopromide, and it is available for doctors to give patients before they have X-ray based scans.

Clinical studies on the overall safety of Ultravist have shown that hypersensitivity reactions (HSRs) may rarely occur. HSRs are undesirable reactions of the body's defense system (immune system) to the study drug. However, more information on HSRs is needed.

The main aim of this study is to find out whether certain groups of people are more likely to have HSRs after Ultravist injection than others (e.g., depending on gender, race, or country/region).

To do this, researchers will collect data from people with HSRs (all ages) after contrast-enhanced X-ray scans with Ultravist. These data come from four observational studies that have already been completed. Participants who had HSRs will be compared with participants in these studies who had no medical problems after receiving Ultravist to learn more about the characteristics of people at higher risk.

Data will be from the year 1999 up to 2011. No visits or tests are required as part of this study.

Inclusion Criteria:

• Patients of all age groups which were referred to any iodine-based contrast-enhanced procedure after administration of either Ultravist 300 mg I/mL or 370 mg I/mL.

In this integrated analysis, the data of four company sponsored non-interventional studies with Ultravist in contrast-enhanced X-ray examination have been pooled. This pool consists of studies 'PMS I', 'IMAGE', 'TRUST', 'Ultravist in CT'.The total data pool consists of 152,233 patients. The timeframe of these 4 studies is from 6/1999 until 11/2011. The study utilizes data collected as a part of clinical practice across 37 countries and including Europe (mostly Germany and Spain), Asia (mostly China and South Korea) and USA. It will not include any new and not yet published data. Patients of all ages, both sexes, multiple races and across various health conditions/indications are represented in this pooled database.

Availability of this study's data will later be determined according to Bayer's commitment to the EFPIA/PhRMA "Principles for responsible clinical trial data sharing". This pertains to scope, timepoint and process of data access. As such, Bayer commits to sharing upon request from qualified researchers patient-level clinical trial data, study-level clinical trial data, and protocols from clinical trials in patients for medicines and indications approved in the US and EU as necessary for conducting legitimate research. This applies to data on new medicines and indications that have been approved by the EU and US regulatory agencies on or after January 01, 2014. Interested researchers can use www.clinicalstudydatarequest.com to request access to anonymized patient-level data and supporting documents from clinical studies to conduct research. Information on the Bayer criteria for listing studies and other relevant information is provided in the Study sponsors section of the portal.