Severe hypoxemia in some patients with coronavirus disease (COVID-19) has been related to loss of hypoxic pulmonary vasoconstriction (1, 2). A 77-year-old male with 6 days of mild respiratory symptoms and no comorbidities was admitted with signs of respiratory failure (Pa O 2 /FI O 2 : 61 mm Hg/0.36 mm Hg = 169.4 mm Hg; reference values [RVs] of 400-500 mm Hg). Chest computed tomography (CT) showed extensive ground-glass opacities (50-75% right-lung involvement and 25-50% left-lung involvement). Laboratory findings showed a D-dimer concentration of 652 ng/ml (RV , 500 ng/ml) and a C-reactive-protein concentration of 93.5 mg/dl (RV , 0.1 mg/dl). Nasopharyngeal swab test (RT-PCR) results confirmed COVID-19. The standard institutional protocol was initiated with a nasal oxygen catheter (4.0 L/min), antibiotics, dexamethasone, and enoxaparin. The patient required invasive ventilation on the 10th day and died on the 35th day of hospitalization. Lung-perfusion single-photon-emission CT/CT using 99m Tc-labeled macroaggregated albumin (3) and positron emission tomography/CT using 18 F-fluorodeoxyglucose (4) were sequentially performed on the third day of hospitalization during the same visit to the Nuclear Medicine Service to simultaneously assess pulmonary perfusion and inflammation. Normal or increased lung perfusion was detected in most of the hypermetabolic areas evidenced by positron emission tomography/CT images (Figure 1). Image quantification was conducted using free, opensource image-processing software (5, 6). Quantification results showed 59% of the total pulmonary perfusion occurring in inflamed lung tissue, which corresponded to 39% of the total anatomic lung volume (Figure 1D). This suggested a high right-to-left shunt fraction in the inflamed areas, which was probably related to loss of hypoxic vasoconstriction, as has been proposed before to occur in COVID-19 pneumopathy (1, 2). The vasoconstriction reflex seemed preserved in a few areas of 18 F-fluorodeoxyglucose uptake. Inflammation and loss of hypoxic pulmonary vasoconstriction can be assessed and quantified using the described methodology.Further studies are needed to evaluate its possible clinical uses. nAuthor disclosures are available with the text of this article at www.atsjournals.org.

Purpose Isolated case reports mention the uptake of radiolabeled PSMA in lymphoma. However, it is not clear if the intensity of 68Ga-PSMA expression varies among different histological subtypes or if it correlates with 18F-FDG uptake. This study compared both tracers in patients with diverse lymphoma subtypes. Methods Ten patients with biopsy-proven-lymphoma underwent 18F-FDG and 68Ga-PSMA-PET/CT (maximum time interval: 6 days). Lymphoma subtypes included Hodgkin’s lymphoma (HL, three patients) and aggressive and indolent non-Hodgkin’s lymphoma (NHL, seven patients). The intensity of PSMA uptake was classified visually as low, intermediate, or high, using blood pool, liver and parotid gland uptake as references. Maximum standardized-uptake value (SUVmax) of each affected site was measured in both sets of images. Results FDG detected 59/59 involved sites in 10 patients and PSMA 47/59 sites in nine patients. PSMA uptake was generally low, regardless of the intensity of FDG uptake, but it was classified as intermediate in two patients. The median SUVmax varied from 2.0 (2.0–8.2) to 30.9 for FDG and from 1.7 (1.7–1.7) to 4.4 for PSMA, P < 0.0001. The primary lesion of one patient had a marked intralesional mismatch uptake pattern of the tracers, with areas of higher PSMA expression than FDG uptake, and vice-versa. A brain lesion was more easily identified with PSMA than with FDG images. Conclusion HL and several NHL subtypes may present PSMA uptake. The intensity of PSMA expression is generally lower than that of FDG uptake and seems to present less variation among the different histological subtypes of lymphomas.

No abstract

No abstract

Intussusception is the invagination of a bowel segment into another immediately adjacent, causing obstruction, and the etiology can be benign, malignant, or idiopathic. The diagnosis may be obtained by ultrasound scans, or computed tomography imaging that can detect characteristics findings. Small bowel obstruction due to intussusception of inverted Meckel's diverticulum is a rare condition that usually constitutes a challenging diagnosis in adulthood. The surgical management in adults is often performed by en bloc resection without reduction attempts. We report a case of CASE REPORTS a middle-aged man with acute intestinal obstruction due to an ileo-ileal intussusception of inverted Meckel's diverticulum with a lipoma that was managed by laparoscopy. Worthy of note is the very scarce number of case reports on this exceeding uncommon association.