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Perirenal and Renal Abscesses: Assessment by Multiplanar Reformat Imaging of Computed Tomography
J Exp Clin Med 2013;5(3):120–121
Contents lists available at SciVerse ScienceDirect
Journal of Experimental and Clinical Medicine journal homepage: http://www.jecm-online.com
LETTER TO THE EDITOR
Perirenal and Renal Abscesses: Assessment by Multiplanar Reformat Imaging of Computed Tomography
Perirenal abscess (PA) and renal abscess (RA) are rare conditions caused by infections in or surrounding the kidneys. Based on the image data, RA is defined as an abscess confined only to the renal parenchyma, whereas PA is defined as an abscess between the renal capsule and Gerota fascia.1 RA with PA is termed a mixed abscess. PA and RA are associated with significant morbidity and mortality, in part because their symptoms are obscure and systems for detecting them are not widely available and provide low-quality imaging.1 Computed tomography (CT) systems recently have become more readily available and the quality of ultrasound examinations has increased. These advances in imaging techniques have resulted in earlier diagnosis. We report an elderly patient with diabetes with PA following RA, which were identified using multiplanar reformat (MPR) images of CT. A 71-year-old woman with diabetes was transferred to our hospital because of fever (38.5 C) of unknown cause. Her mind was clear; her blood pressure and pulse rate were 120/ 60 mmHg and 84 bpm, respectively. The patient had no symptoms except for fever, but physical examination revealed right costovertebral angle tenderness. Hematologic and serologic tests on admission revealed elevation of white blood cell counts and C-reactive protein levels (13,700/L and 26.5 mg/dL, respectively) suggesting severe inflammation, with increased concentration of plasma glucose (349 mg/dL). To find the focus of infectious disease, we used two abdominal imaging systems. Coronal sections from MPR system of abdominal contrast medium-enhanced multidetector-row CT (Siemens SOMATOM Sensation 64) on admission demonstrated low-density areas in the right perirenal space and the renal parenchyma (maximal size 60 mm, Figure 1A and B). Abdominal ultrasound examination also indicated low-echoic area with unclear margin (maximal size 54 mm) in the right renal parenchyma (Figure 1C). However, no involvement of the lesion in the perirenal space was detected. Blood and urine cultures for bacteria on admission yielded Klebsiella pneumoniae, and antimicrobial susceptibility tests for the isolate showed no resistance to reagents (except for ampicillin). Intravenously administered antibiotic treatments (meropenem for 21 days followed by pazufloxacin for 8 days) were completed with intensive control of blood glucose by insulin. MPR CT images obtained to assess treatment efficacy indicated a decrease in size of RA without regression of PA. The patient underwent right nephrectomy due to extensive PA and difficulties in percutaneous drainage, and the pathological diagnosis was extensive PA following RA. She was discharged and revisited our hospital for
Figure 1 Coronal sections from a multiplanar reformat system of abdominal contrast medium-enhanced multidetector-row computed tomography (Siemens SOMATOM Sensation 64, A and B) obtained on admission demonstrated low-density areas in the right perirenal space (arrows) and the renal parenchyma (maximal size 60 mm). (C) Abdominal ultrasound examination indicated a low echoic area with unclear margin (maximal size 52 mm) in the right renal parenchyma. However, no involvement of the lesion in the perirenal space was detected.
1878-3317/$ – see front matter Copyright Ó 2013, Taipei Medical University. Published by Elsevier Taiwan LLC. All rights reserved. http://dx.doi.org/10.1016/j.jecm.2013.04.009
Letter to the Editor
121
follow-up. We have confirmed no recurrence of K. pneumoniae infection 9 months after onset. CT examination data are important both in the diagnostic phase to confirm the extent of PA/RA lesions and in the follow-up phase to determine treatment efficacy.2 Lee et al.1 described that abscess location (RA alone, PA alone, or mixed abscesses) and the size of RA were factors associated with treatment strategies including antimicrobial therapy alone or additional invasive interventions (percutaneous/surgical drainage or nephrectomy). PA caused by ruptured retrocecal appendix is demonstrated by MPR CT images.3 Therefore, clinicians should consider CT examinations for early diagnosis, assessment of disease extent, treatment efficacy, and follow-up. References 1. Lee BE, Seol HY, Kim TK, Seong EY, Song SH, Lee DW, Lee SB, et al. Recent clinical overview of renal and perirenal abscesses in 56 consecutive cases. Korean J Intern Med 2008;23:140–8. 2. Dalla Palma L, Pozzi-Mucelli F, Ene V. Medical treatment of renal and perirenal abscesses: CT evaluation. Clin Radiol 1999;54:792–7. 3. Wani NA, Farooq M, Gojwari T, Kosar T. Perinephric abscess caused by ruptured retrocecal appendix: MDCT demonstration. Urol Ann 2010;2: 29–31.
Masami Ogawa* Department of Internal Medicine, Kitasato Institute Medical Center Hospital, Saitama, Japan
Hiroyoshi Iguchi Department of Radiology, Kitasato Institute Medical Center Hospital, Saitama, Japan Yoshinori Taoka Department of Urology, Kitasato Institute Medical Center Hospital, Saitama, Japan Hitoshi Yamazaki Department of Pathology, Kitasato Institute Medical Center Hospital, Saitama, Japan Yoneji Hirose, Norio Yokota, Naoko Kajigaya, Makoto Ikenaga Department of Infection Control and Prevention, Kitasato Institute Medical Center Hospital, Saitama, Japan Takashi Takahashi* Department of Infection Control and Prevention, Kitasato Institute Medical Center Hospital, Saitama, Japan Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan * Corresponding authors. E-mails: M. Ogawa, T. Takahashi Oct 31, 2012
Contents lists available at SciVerse ScienceDirect
Journal of Experimental and Clinical Medicine journal homepage: http://www.jecm-online.com
LETTER TO THE EDITOR
Perirenal and Renal Abscesses: Assessment by Multiplanar Reformat Imaging of Computed Tomography
Perirenal abscess (PA) and renal abscess (RA) are rare conditions caused by infections in or surrounding the kidneys. Based on the image data, RA is defined as an abscess confined only to the renal parenchyma, whereas PA is defined as an abscess between the renal capsule and Gerota fascia.1 RA with PA is termed a mixed abscess. PA and RA are associated with significant morbidity and mortality, in part because their symptoms are obscure and systems for detecting them are not widely available and provide low-quality imaging.1 Computed tomography (CT) systems recently have become more readily available and the quality of ultrasound examinations has increased. These advances in imaging techniques have resulted in earlier diagnosis. We report an elderly patient with diabetes with PA following RA, which were identified using multiplanar reformat (MPR) images of CT. A 71-year-old woman with diabetes was transferred to our hospital because of fever (38.5 C) of unknown cause. Her mind was clear; her blood pressure and pulse rate were 120/ 60 mmHg and 84 bpm, respectively. The patient had no symptoms except for fever, but physical examination revealed right costovertebral angle tenderness. Hematologic and serologic tests on admission revealed elevation of white blood cell counts and C-reactive protein levels (13,700/L and 26.5 mg/dL, respectively) suggesting severe inflammation, with increased concentration of plasma glucose (349 mg/dL). To find the focus of infectious disease, we used two abdominal imaging systems. Coronal sections from MPR system of abdominal contrast medium-enhanced multidetector-row CT (Siemens SOMATOM Sensation 64) on admission demonstrated low-density areas in the right perirenal space and the renal parenchyma (maximal size 60 mm, Figure 1A and B). Abdominal ultrasound examination also indicated low-echoic area with unclear margin (maximal size 54 mm) in the right renal parenchyma (Figure 1C). However, no involvement of the lesion in the perirenal space was detected. Blood and urine cultures for bacteria on admission yielded Klebsiella pneumoniae, and antimicrobial susceptibility tests for the isolate showed no resistance to reagents (except for ampicillin). Intravenously administered antibiotic treatments (meropenem for 21 days followed by pazufloxacin for 8 days) were completed with intensive control of blood glucose by insulin. MPR CT images obtained to assess treatment efficacy indicated a decrease in size of RA without regression of PA. The patient underwent right nephrectomy due to extensive PA and difficulties in percutaneous drainage, and the pathological diagnosis was extensive PA following RA. She was discharged and revisited our hospital for
Figure 1 Coronal sections from a multiplanar reformat system of abdominal contrast medium-enhanced multidetector-row computed tomography (Siemens SOMATOM Sensation 64, A and B) obtained on admission demonstrated low-density areas in the right perirenal space (arrows) and the renal parenchyma (maximal size 60 mm). (C) Abdominal ultrasound examination indicated a low echoic area with unclear margin (maximal size 52 mm) in the right renal parenchyma. However, no involvement of the lesion in the perirenal space was detected.
1878-3317/$ – see front matter Copyright Ó 2013, Taipei Medical University. Published by Elsevier Taiwan LLC. All rights reserved. http://dx.doi.org/10.1016/j.jecm.2013.04.009
Letter to the Editor
121
follow-up. We have confirmed no recurrence of K. pneumoniae infection 9 months after onset. CT examination data are important both in the diagnostic phase to confirm the extent of PA/RA lesions and in the follow-up phase to determine treatment efficacy.2 Lee et al.1 described that abscess location (RA alone, PA alone, or mixed abscesses) and the size of RA were factors associated with treatment strategies including antimicrobial therapy alone or additional invasive interventions (percutaneous/surgical drainage or nephrectomy). PA caused by ruptured retrocecal appendix is demonstrated by MPR CT images.3 Therefore, clinicians should consider CT examinations for early diagnosis, assessment of disease extent, treatment efficacy, and follow-up. References 1. Lee BE, Seol HY, Kim TK, Seong EY, Song SH, Lee DW, Lee SB, et al. Recent clinical overview of renal and perirenal abscesses in 56 consecutive cases. Korean J Intern Med 2008;23:140–8. 2. Dalla Palma L, Pozzi-Mucelli F, Ene V. Medical treatment of renal and perirenal abscesses: CT evaluation. Clin Radiol 1999;54:792–7. 3. Wani NA, Farooq M, Gojwari T, Kosar T. Perinephric abscess caused by ruptured retrocecal appendix: MDCT demonstration. Urol Ann 2010;2: 29–31.
Masami Ogawa* Department of Internal Medicine, Kitasato Institute Medical Center Hospital, Saitama, Japan
Hiroyoshi Iguchi Department of Radiology, Kitasato Institute Medical Center Hospital, Saitama, Japan Yoshinori Taoka Department of Urology, Kitasato Institute Medical Center Hospital, Saitama, Japan Hitoshi Yamazaki Department of Pathology, Kitasato Institute Medical Center Hospital, Saitama, Japan Yoneji Hirose, Norio Yokota, Naoko Kajigaya, Makoto Ikenaga Department of Infection Control and Prevention, Kitasato Institute Medical Center Hospital, Saitama, Japan Takashi Takahashi* Department of Infection Control and Prevention, Kitasato Institute Medical Center Hospital, Saitama, Japan Laboratory of Infectious Diseases, Graduate School of Infection Control Sciences, Kitasato University, Tokyo, Japan * Corresponding authors. E-mails: M. Ogawa