Nephrogenic Systemic Fibrosis in a Patient With Renal Failure Demonstrating a “Reverse Superscan” on Bone Scintigraphy

Superscan Pattern on Bone Scintigraphy: A Comprehensive Review

BACKGROUND/OBJECTIVES

The superscan pattern is a characteristic finding on bone scintigraphy, associated with a variety of metabolic bone diseases, malignancies, and other conditions. This pattern is characterized by a diffuse and intense uptake of radiotracer throughout the entire skeleton. Despite being a relatively rare finding, the superscan pattern can have significant clinical implications.

METHODS

This comprehensive review summarizes the available literature on the superscan pattern, focusing on its pathophysiology, clinical significance, and differential diagnoses. Relevant studies and case reports were analyzed to outline the diagnostic challenges associated with the interpretation of bone scintigraphy featuring the superscan pattern.

RESULTS

The literature highlights the clinical significance of the superscan pattern in various metabolic and oncologic conditions. Misinterpretation of this pattern can lead to diagnostic challenges, especially in distinguishing it from other pathologic conditions. Differential diagnosis remains crucial in the accurate interpretation and subsequent management of patients with this finding.

CONCLUSIONS

This review provides a comprehensive overview of the superscan pattern on bone scintigraphy, aiming to assist clinicians in recognizing and managing this rare yet clinically important finding.

"Hepatic Superscan" Revealed on 18 F-FDG PET Due to Drug-Induced Fulminant Hepatitis

ABSTRACT

"Hepatic superscan" could be caused by a variety of etiologies. Here we report a 68-year-old woman with a medication history of cefoperazone and azithromycin for pneumonia recently who underwent 18 F-FDG PET/CT to detect underlying malignancy due to unexplained liver damage and fever of unknown origin. Unexpectedly, "hepatic superscan" without morphologic changes was noted. Unfortunately, aggressive treatment did not reverse the damaged liver function, and the patient rapidly died. Drug-induced fulminant hepatitis was diagnosed clinically. Our case demonstrates that fulminant hepatitis could result in "hepatic superscan" on 18 F-FDG PET despite negative findings on the ultrasonography, CT, and MRI.

Generalized Muscular Uptake of 99mTc-MDP on Bone Scan in a Patient With Scleromyxedema-Associated Myopathy

ABSTRACT

A 62-year-old man presented with a 5-year history of progressive myasthenia, myalgia, and skin changes. Upon laboratory testing, elevated serum creatine kinase and lactate dehydrogenase, as well as monoclonal immunoglobulin Gκ, were observed. A bone scan revealed generalized muscular uptake of 99mTc-MDP, whereas 18F-FDG PET/CT demonstrated only mild hypermetabolism of the muscles. A muscle biopsy showed myofibrillary vacuolar degeneration, and a skin biopsy indicated scleromyxedema. Based on these findings, the patient was diagnosed with scleromyxedema-associated myopathy.

A Systematic Review of 639 Patients with Biopsy-confirmed Nephrogenic Systemic Fibrosis

Background Although nephrogenic systemic fibrosis (NSF) affects the use of gadolinium-based contrast agents (GBCAs) in MRI, there continues to be limited knowledge because of the small number of patients with NSF. Purpose To perform a systematic review of NSF. Materials and Methods PubMed database was searched by using the term "Nephrogenic systemic fibrosis" from January 2000 to February 2019. Articles reporting details on individual patients with NSF diagnosis on the basis of both clinical presentations and biopsy confirmation were included. Data were pooled and authors were contacted for clarifications. Rates of NSF were compared through 2008 versus after 2008 and for group I versus group II GBCAs, assuming equal market share. Results Included were 639 patients from 173 articles. Data regarding sex were found for 295 men and 254 women. Age at NSF symptom onset was reported for 177 patients (mean, 49 years ± 16 [standard deviation]; age range, 6-87 years). There were 529 patients with documented exposure to GBCAs including gadodiamide (n = 307), gadopentetate dimeglumine (n = 49), gadoversetamide (n = 6), gadobutrol (n = 1), gadobenate dimeglumine (n = 1), multiple (n = 41), and unknown (n = 120). Among patients with previous exposure, only seven patients were administered GBCA after 2008, yielding a lower rate of NSF after 2008 (P < .001). There were motion limitations in 70.8% (296 of 418) of patients, indicating a more serious debilitation. Associated factors reported for NSF included exposure to GBCA group I (P < .001), dialysis, proinflammatory conditions, hyperphosphatemia, β-blockers, and epoetin. For 341 patients with follow-up, 12 patients were cured and 72 patients partially improved including one during pregnancy. Among those 84 patients reported as cured or improved, in 34 patients cure or improvement occurred after renal function restoration. Four deaths were attributed to NSF. Conclusion Although 639 patients with biopsy-confirmed nephrogenic systemic fibrosis were reported, only seven were after gadolinium-based contrast agent exposure after 2008, indicating that regulatory actions and practice changes have been effective preventive measures. Improvement and sometimes cure with renal function restoration are now possible. © RSNA, 2019 See also the editorial by Davenport in this issue.