Unusual radiographic images of radiopaque contrast media incidentally observed in intracranial region: two case reports

Subarachnoid Intra-cranial Lipiodol Deposits

Lipiodol, an oil-based contrast medium first introduced in 1944, was commonly used for various radiological exams until the 1980s, when it was replaced by water-soluble contrast media due to complications such as arachnoiditis and chronic irritations. Due to its slow resorption rate, asymptomatic lipiodol deposits can occasionally be found incidentally. This case report describes a 93-year-old man who presented to the emergency department after a fall. A non-contrast head CT scan, performed to rule out subarachnoid hemorrhage, revealed numerous hyperdense droplets in the subarachnoid spaces of the brain, primarily around the temporal lobes. Further investigation uncovered a previous pelvic X-ray showing similar hyperdense droplets around the cauda equina. The patient's history indicated a lipiodol myelography performed 51 years earlier. Lipiodol deposits are generally found in the lumbar region, making an intra-cranial location particularly rare. When present, these deposits are visible as radiopaque droplets on X-rays, hyperdense droplets on CT scans, and hyper-T1 on MRI, though the T2 signal is variable. Though lipiodol deposits are generally left untreated, symptomatic spinal deposits may be surgically removed. This rare case underscores the importance of thorough patient history in diagnosing subarachnoid lipiodol deposits, a condition relevant only in older patients who underwent myelography before the 1980s.

Intracranial iodinated contrast medium deposits 50 years following a previous myelography: A case report and literature review

Before the advent of CT and MRI, and since the early 1920s, myelography has been used for the diagnosis of spinal cord lesions and lumbar disc herniations. We report a case of an 86-year-old man with a migration of lipiodol in the intracranial subarachnoid spaces. The patient had undergone a myelography in the early 1970s, 50 years earlier. Lipiodol, an iodized oil, was widely used as a contrast agent in conventional myelography for years and provided excellent radiographic visualization of the subarachnoid spaces. Although rare, images of its residues may still be encountered in modern radiographic imaging. Neurosurgeons and radiologists should be aware of this imaging appearance, and be able to differentiate it from possible pathologies.

Pantopaque: Does It Still Migrate With Gravity After 30 Years?

Pantopaque was an oil-based positive contrast media used in central nervous system imaging before the use of water-soluble contrast agents. It is no longer used due to side effects, including arachnoiditis. Prior studies have indicated that remnants of pantopaque can be seen in modern radiographic imaging, including CT and MRI. With its use obsolete, these remnants have been increasingly mislabeled from “tumor” to “shot gun pellets”. An understanding of this historic modality will usually lead to the correct diagnosis.

Can Myelography Residues Have an Incidental Finding on Panoramic Radiography? Two Case Reports

Oil-based contrast medium agents (Iofendylate) are cleared from cerebrospinal fluid very slowly. But it may remain within the tissues of the central nervous system. These substances, which were used for purposes such as myelography, cisternography, and ventriculography approximately 70 years ago and were replaced by water-soluble agents after thirty years, can rarely be detected incidentally. In this report, by presenting the intracranial radiopacities seen in 2 patients, it is aimed to increase awareness that these myeloid residues, which are rarely seen in panoramic radiography, can be diagnosed by clinicians.