This study is aimed at describing the degree of benefit, if any, and the adverse effects, if any, from receiving 5 or more treatment sessions of Gadolinium Deposition Disease using two-day chelation treatment with the chelating agents Calcium Diethylenetriamine pentaacetate (Ca-DTPA) and Zinc Diethylenetriamine pentaacetate (Zn-DTPA).

Potential participants will be invited to contact Dr. Koran by email to receive a telephone screening Informed Consent. Those who provide informed consent will have their questions about the study answered and their interest and eligibility assessed via telephone interview. Those who wish to participate will be sent an Informed Consent for study participation. Those who return the consent will be sent four study questionnaires for completion and return. The returned forms will be reviewed by Dr. Koran or his co-investigator, and a follow-up phone call will be offered via Secure Stanford email. The phone call will involve answering any new questions the participant has, and clarifying the participant's responses to the data collection forms if clarification is needed. Participants who wish to receive a summary of the study's results once it is completed and accepted for publication, will be emailed a summary via Secure Stanford email.

Inclusion Criteria:

1. Age 18 or older,
2. Diagnosis of Gadolinium Deposition Disease (GDD) established by treating MD according to current criteria and confirmed by investigator review of screening questionnaire (dx criteria: presence of at least 3 of 8 symptoms-cognitive disturbance, extremity pain, arthralgia, chest wall pain, skin pain, headache, skin induration, and skin hyperpigmentation; and, had an unprovoked 24-hour Gd urine excretion level exceeding the laboratory norm at least 28 days after the symptom-inducing MRI;
3. has had five or more 2-day chelation treatments with Ca-DTPA/Zn-DTPA;
4. will be at least 2 weeks post the last chelation treatment at the time of completing the patient data-gathering questionnaires.
5. no more than 2 years have elapsed since the last DTPA chelation.

Exclusion Criteria:

1. Not fluent in written and spoken English; 2. having impaired hearing that significantly decreases the person's ability to communicate via telephone; 3. Prisoners; 4. Unable to provide informed consent; 5. Participating or having participated in protocols involving a pharmacological treatment of GDD other than DTPA chelation. Note: brief pre- or post-DTPA chelation to prevent GDD symptom flare is not an exclusion criterion.

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Adult patients in the U.S. who developed Gadolinium Deposition Disease (GDD) within 28 days of undergoing a contrast-assisted MRI, in which the contrast agent contained the metal gadolinium, and who retained enough gadolinium to have abnormally high 24-hour urine levels 28 or more days post MRI. Participants must satisfy the Inclusion/Exclusion criteria noted above.