Dr. Nguyen Van Xuan, 48, from Hanoi, has a complex history of coronary artery disease, having undergone intervention to place two stents in critical locations: the left main coronary artery and the left anterior descending branch.

After surgery, he returned to work and daily life completely healthy, experiencing no symptoms of angina. Aware of the potential for silent restenosis, he adhered to a schedule of regular CT scans to monitor his stents. However, with conventional CT, metal stent frames can create artifacts, obscuring the vessel lumen and affecting the evaluation of stent placement.

When examined using the Philips Spectral CT 7500 system at Thang Long Lac Viet International Hospital, images of the stent lumen were clearer. High-energy monoenergetic technology helped reduce metal artifacts, thereby assisting doctors in more accurately assessing the stent lumen and coronary artery condition.

Assoc. Prof. Dr. Pham Nguyen Son, one of the leading cardiology experts, examines and treats a patient at Thang Long Lac Viet International Hospital. *Photo: Thang Long Lac Viet International Hospital*

Here, the vessel segment immediately after the left main coronary artery stent showed severe restenosis due to atherosclerotic plaque (RAC1). Simultaneously, the spectral perfusion map precisely identified a region of the heart's apex experiencing chronic subendocardial ischemia and focal myocardial fibrosis. These silent lesions were detected promptly, preventing an impending myocardial infarction.

Assoc. Prof. Dr. Thai Khac Chau, Head of the Subclinical Department at Thang Long Lac Viet International Hospital, who directly participated in the case consultation and analysis, stated that metal stent frames pose a significant challenge for diagnostic imaging because artifacts obscure nearly 100% of the vessel lumen. The 512-slice monoenergetic spectral CT completely resolved this issue. "The machine 'sees through' metal to accurately assess the patency of the vessel lumen, while also mapping myocardial perfusion to detect early micro-necrosis that is not visible to the naked eye," he said.

Timely consultation by leading cardiology experts, Major General Assoc. Prof. Dr. Pham Nguyen Son and Assoc. Prof. Dr. Thai Khac Chau, enabled Dr. Xuan to receive precise interventional treatment, eliminating the risk of sudden cardiac death before the event could occur.

Coronary CT images and myocardial perfusion maps (spectral color) on the Philips Spectral CT 7500 super machine detect hidden lesions such as left main coronary artery restenosis, myocardial ischemia, myocardial fibrosis, and plaque (RAC1). *Photo: Thang Long Lac Viet International Hospital*

The Philips Spectral CT 7500 at Thang Long Lac Viet International Hospital is equipped with 256-row dual-layer detectors, allowing direct acquisition of 512 slices from the hardware. The system reconstructs anatomical images and provides information on material composition and tissue perfusion, assisting doctors in a more comprehensive assessment of lesions.

Beyond cardiology, the Spectral CT 7500's broad screening capability and histological analysis sensitivity were also demonstrated when it detected a previously unrecognized malignant breast tumor.

The Philips Spectral CT 7500 spectral CT system enables accurate diagnosis, detects microscopic lesions, and is safe for patients. *Photo: Thang Long Lac Viet International Hospital*

Pham Hoa, 45, from Son La, came for an examination with a suspicious solid nodule in the right middle lobe of the lung (nearly 7.5 mm) on a non-contrast scan. To conduct a comprehensive and in-depth examination of the entire chest and coronary circulatory system, doctors ordered a coronary CT scan on the Spectral CT 7500 system. Notably, the scanning team applied a spectral optimization technique: using only one dose of contrast agent from the coronary angiogram to expand the scan field to cover the entire chest area.

On the quantitative iodine map, a color-rendered image revealed a lesion in the right breast showing very high contrast agent uptake. This indicated abnormal vascular proliferation of a potentially malignant tumor, a lesion completely obscured and easily missed by traditional CT scanning methods. The patient was directed for a combined ultrasound, 3D mammography, and histopathological biopsy, offering a chance for complete recovery with an optimal prognosis.

Images of a breast tumor (left) and lung tumor (right) incidentally detected during coronary CT and low-dose lung cancer screening on the Philips Spectral CT 7500 spectral CT machine. *Photo: Thang Long Lac Viet International Hospital*

The investment in the spectral CT system allows Thang Long Lac Viet International Hospital to enhance its modern diagnostic imaging technology, serving the needs for examination and disease monitoring. Combined with the specialized medical team, this technology helps doctors detect and assess lesions more clearly in difficult cases.

Hai My

Thang Long Lac Viet International Hospital, operating license number 400/Ministry of Health-Operating License.

Address: 9A, 9B Phan Chu Trinh Street, Phan Chu Trinh Ward, Hoan Kiem District, Hanoi.

Scope of professional activities: Performing specialized techniques approved by the Minister of Health, issued with the operating license.