Fournier’s gangrene is a rapidly progressing, life-threatening infection that primarily affects the perineum, scrotum, and penis. It is a form of necrotizing fasciitis caused by a polymicrobial mix of bacteria, which leads to tissue necrosis. These bacteria thrive in low-oxygen environments with limited blood flow, accelerating tissue breakdown. The resulting obliterated endarteritis, with vascular thrombosis, causes subcutaneous tissue necrosis and gangrene. This process is facilitated by the synergistic activity of aerobic bacteria (which cause platelet aggregation and accelerate coagulation through complement fixation) and anaerobic organisms (which promote clot formation by producing heparinase and collagenase).

Fournier gangrene is typically polymicrobial, with an average of three microorganisms identified in each patient. These pathogens are often part of the normal flora in the affected regions. The most common bacteria include E. coli (aerobic), followed by Bacteroides (anaerobic), and various species of Streptococcus (aerobic). Other implicated organisms include Staphylococcus, Enterococcus, Clostridium, Pseudomonas, Klebsiella, and other species of Proteus. The combination of aerobic and anaerobic bacteria leads to tissue necrosis, which progresses at a rate of 2-3 cm per hour through the pelvic fascia. Timely identification is crucial, as early intervention with surgical debridement is essential to reduce both mortality and morbidity.

Despite advances in understanding Fournier gangrene, it still carries a high mortality rate of 20% to 50%, as indicated by recent studies. Delayed diagnosis and late surgical debridement significantly increase the risk of complications, including death. The longer the delay, the greater the tissue loss and the higher the risk of fatality. Early diagnosis is often challenging due to the vague and nonspecific nature of the initial symptoms.

Fournier gangrene most commonly affects middle-aged men, typically between the ages of 50 and 60, with an incidence of 1.6 cases per 100,000 males. While it is more common in men (with a male-to-female ratio of 10:1), it can also occur in women, primarily due to differences in perineal anatomy. Risk factors for Fournier gangrene include diabetes mellitus, alcoholism, immunosuppression, local trauma, and infections such as genitourinary conditions or HIV/AIDS. Diabetes is the most common co-existing condition, present in 20% to 70% of cases, though it is still debated whether it increases the risk of death from Fournier gangrene.

The diagnosis of Fournier gangrene relies heavily on clinical examination. A thorough inspection of the genital and perineal areas, along with a digital rectal exam, is crucial. Signs such as tenderness, swelling, crepitus (air under the skin), and the presence of wounds are indicative of Fournier gangrene. Laboratory tests may reveal leukocytosis, thrombocytopenia, anemia, hypocalcemia, and hyperglycemia, further supporting the clinical suspicion.

The core aspects of the treatment include hydroelectrolytic and nutritional rebalancing, hemodynamic stabilization, broad-spectrum antibiotic therapy, and comprehensive surgical debridement.[fig]1

This exhibit highlights the crucial role of imaging in diagnosing Fournier gangrene, showcasing five cases from our database (January 2020 - October 2024). The cases aim to demonstrate key CT scan findings and emphasize their value in both diagnosis and treatment guidance.