RADIOLOGY FINDINGS IN PATIENTS WITH H7N9 INFLUENZAChinese researchers sought to determine the radiologic findings in patients who have been diagnosed with avian-origin influenza A H7N9. Progressive ground-glass opacities (GGOs), and consolidations with air bronchograms and interlobular septal thickening are found in patients with influenza A H7N9, according to a study published in the journal Radiology[footnoteRef:1]. [1: http://www.diagnosticimaging.com/ct/radiology-findings-patients-h7n9-influenza/September 03, 2013 | CT]

The results showed that all 12 patients exhibited GGOs1. In addition, the researchers found: consolidations (in 11 patients), air bronchograms (in 11 patients), interlobular septal thickening (in 11 patients), centrilobular nodules (in seven patients), reticulations (in seven patients), cystic changes (in four patients), bronchial dilatation (in three patients), and subpleural linear opacities (in three patients).The researchers concluded the main imaging findings in H7N9 pneumonia are rapidly-progressive GGOs and consolidations with air bronchograms and interlobular septal thickening, with right lower-lobe predominance. The severity of these findings is associated with the severity of the clinical presentation1.

H7N9 pneumonia is characterized by imaging findings that differentiate it from other types of pneumonia, including rapidly progressive changes in the lungs and pulmonary connective tissues, according to the first study to describe radiologic findings in the disease[footnoteRef:2]. [2: http://www.sciencedaily.com/releases/2013/07/130702100755.htm/July 2, 2013]

The results are published online in the journal Radiology."The severity of these findings is associated with the severity of the clinical condition of the patients," said study co-author Zhiyong Zhang, M.D., Ph.D., from the Department of Radiology at Shanghai Public Health Clinical Center and Shanghai Medical College of Fudan University in China2.

BAB IITINJAUAN PUSTAKAII.1. H7N9 InfluenzaDEFETIOLOGYSYMPTOMSH7N9 is a recently discovered subtype of avian influenza virus or "bird flu," Cases of bird flu infection in humans typically result from direct or close contact with infected poultry, such as domesticated chickens, pigeons or ducks, or with surfaces contaminated with secretions and excretions from infected birds2.The first human outbreak of H7N9 was reported in China in March 2013. This new strain in humans has caused severe and rapidly progressing respiratory illness. H7N9 can cause acute respiratory distress syndrome, organ failure and death2.

Gambar 1. Axial thin-section CT image (section thickness, 1 mm) in 67-year-old man with H7N9 influenza shows extensive GGOs and consolidation and sporadic centrilobular nodules (arrows), which could hardly be appreciated at conventional CT. (Credit: Image courtesy of Radiological Society of North America)2.For the study, Dr. Zhang and colleagues evaluated the clinical data and radiologic files of 12 patients with avian-origin influenza A H7N9 virus who were admitted to Shanghai Public Health Clinical Center between April 3, 2013, and April 20, 2013. The 12 patients included nine men and three women, 47 to 81 years old (mean age, 66 years)."Both H1N1 pneumonia and SARS distribute more peripherally, with more changes in the spaces between tissues, and progress less rapidly than H7N9," Dr. Zhang said. "In our study, the right lower lung was most likely to be involved, while there's no lobar predilection in findings of H5N1 influenza."An article in Radiology published on Tuesday includes some of the first radiologic images of the effects of the virus, revealing typical patterns of progression and regression on CT scans and radiographs of the chest[footnoteRef:3]. [3: http://www.auntminnie.com/index.aspx?sec=ser&sub=def&pag=dis&ItemID=103864/2013]

In scans of the 12 infected patients in the study, the most common findings were ground-glass opacities (GGOs), consolidation, air bronchograms, and interlobular septal thickening, with the severity of these features mirroring the severity of the illness at presentation and throughout follow-up, wrote the authors from Shanghai Medical College of Fudan University (Radiology, July 2, 2013)3.More deadly than the H1N1 virus that preceded it, H7N9 has killed almost one-third of those hospitalized with the virus. As of June 7, there have been 132 laboratory-confirmed H7N9 infections, and most cases have occurred in middle-aged or older men, according to a World Health Organization report.

II.2. First Radiologic Images of The Effects of The Virus/ Radiological findings.II.3. Ground-Glass Opacities (GGOs)

Gambar 2. Axial thin-section CT images in 65-year-old man with H7N9 influenza. Top row, initial images obtained at admission show extensive GGOs and consolidation. Bottom row, images at seven-day follow-up show complete resorption of the lesion in the right upper lobe and partial resorption in the left lower lobe with a round cystic change. Images republished with permission of RSNA from Radiology July 2, 20133.Additional findings included consolidations, bronchograms, and interlobular septal thickening (each in 11 patients). Less common were centrilobular nodules (seven patients), cystic changes (four patients), and bronchial dilatation and subpleural linear opacities (each in three patients), Wang and colleagues wrote3."It is unclear at this time why there was right lower lobe predominance," they wrote. "The phenomenon may be related to the anatomic structure of the trachea and bronchi, as the right bronchus is short and straight, which may facilitate location of the culprit virus. The distribution and rapid progression and GGOs and consolidations with interstitial changes in the H7N9 pneumonia in the current study may help differentiate it from other causes of pneumonia."Still, the authors cautioned, a specific diagnosis of H7N9 pneumonia could not be made based on imaging features alone."Combining imaging features with clinical and laboratory data can help make the early diagnosis of H7N9 infection," they wrote.Rapidly progressing GGOs and consolidations with air bronchograms and interlobular septal thickening, all with a right lower lobe predominance, are the main imaging findings seen with H7N9 pneumonia, the authors concluded. The severity of these findings corresponded to disease severity at presentation.