Gallium-67 Scan with Single Photon Emission Computed Tomography for the Evaluation and Monitoring of Infected Abdominal Aortic Aneurysms: A 10-Year Case Series.

PURPOSE: This study aimed to evaluate the role of gallium-67 single photon emission computed tomography (SPECT) with contrast computed tomography (CT) in the evaluation and monitoring of infected abdominal aortic aneurysms (IAAA). MATERIALS AND METHODS: A retrospective cohort analysis was performed using prospectively collected data of consecutive patients with IAAA in Princess Margaret Hospital in Hong Kong between January 2010 and December 2020. The patients were identified using the Radiology Information System. RESULTS: All five patients had proven IAAA on CT and/or metabolic imaging. Among them, three were further supported by positive blood culture results. Gallium- 67 SPECT with contrast CT was useful in the detection of residual disease, monitoring, and detection of recurrence. CONCLUSION: Gallium-67 SPECT with contrast CT is helpful for evaluating IAAA. It serves an important role in guiding management, especially during long-term follow-up.

Tc-99m sulfur colloid SPECT-CT and assessment of functional liver reserve after Y90 radioembolization: A case report.

INTRODUCTION: Quantitative assessment is an essential tool in determining the proportion of liver to be reserved before lobectomy. Technetium-99 m sulfur colloid single-photon emission computed tomography (Tc-99 m SC SPECT-CT) can help in the quantitative assessment of functioning liver tissues and percentage of liver reserve before segmentectomy and lobectomy Matesan et al. (2017), Bowen et al. (2016) and Lam et al. (2013). PRESENTATION OF CASE: A 64-year-old man with alcoholic cirrhosis was admitted to our hospital with a 15 × 10 x 13 cm bilobar HCC. Y90 radioembolization was utilized to downstage the liver tumor. On follow-up CT scan of the liver after radiotherapy, the HCC was much reduced to 6.5 cm in size but still viable with elevated alpha fetoprotein ([AFP] from 225 to 381 to 959 ng/mL). Resection was considered. Constitutional indocyanine green retention at 15 min (ICG-R-15) was 22%. We introduced the Tc-99 m SC SPECT-CT scan in order to assess the percentage liver function of each lobe. It showed minimal uptake in the remaining functioning right lobe with a hypertrophic left lobe to whole liver uptake ratio of 87.1%. This finding gave us confidence to perform right hepatectomy. DISCUSSION: We used Tc-99 m SC SPECT-CT to estimate the normal functional liver reserve after Y90 radioembolization of a hepatocellular carcinoma (HCC). To our understanding, it is the first case report using Tc-99 m SC to predict the percentage of functional liver reserve after yttrium-90 (Y90) radioembolization. CONCLUSION: Tc-99 m SC SPECT-CT is a novel helper used to assess the differential liver function after Y90 radioembolization of HCC and before segmentectomy and lobectomy of the liver.

High-resolution computed tomography is useful for early diagnosis of severe acute respiratory syndrome-associated coronavirus pneumonia in patients with normal chest radiographs.

OBJECTIVE: We investigated the usefulness of high-resolution computed tomography (HRCT) in early detection of severe acute respiratory syndrome (SARS)-associated coronavirus pneumonia and analyzed HRCT findings associated with potentially more severe disease. METHODS: All patients with suspected SARS and normal chest radiographs on admission within the study period were subjected to HRCT examination. The clinical, radiologic, and laboratory data of patients who were confirmed to have SARS-associated coronavirus infection by a positive nasopharyngeal aspirate, stool or urine reverse transcription-polymerase chain reaction (RT-PCR) and/or serological testing were prospectively followed up and analyzed. Characteristics of patients admitted to the intensive care unit (ICU) and those that were not were compared. RESULTS: Among 47 suspected SARS patients with normal chest radiographs, 27 had SARS-associated coronavirus infection confirmed by RT-PCR and/or positive serological testing. Twenty-five of the 27 (93%) patients had HRCT changes compatible with atypical pneumonia, and all 25 patients developed SARS with progressive clinical deterioration. Ten (40%) had unifocal diseases, and 15 had multifocal diseases (60%). Ten (40%) patients had the diseases confined to 1 single lung in the first HRCT, and both lungs were involved at initial presentation in 15 (60%) patients. Concerning the overall extent of the disease at initial presentation, 3 (12%) patients had disease process in all lobes, and the disease was confined to 1 single lobe in 10 (40%) patients. The disease process was mainly peripheral in location (96%), and the lower lobes were more commonly involved (68% in the left lower lobe and 64% in the right lower lobe). Small parapneumonic effusions occurred in 1 (4%) patient. None of the patients with unifocal lesions or single-lung involvement were admitted to the ICU (P < 0.05) (in both comparisons). Subsequent follow-up of the 2 (7%) patients with normal HRCT on admission showed that they were having nonpneumonic SARS-associated coronavirus infection only and were eventually denotified from having SARS. CONCLUSIONS: HRCT is useful for early diagnosis of SARS-associated coronavirus pneumonia in patients with normal chest radiographs. HRCT findings in these patients predict potentially severe disease.