medigraphic.com
Organo Oficial de la Sociedad Mexicana de Urología

2026, Number 1

<< Back Next >>

Rev Mex Urol 2026; 86 (1)

On the terminology of acute kidney infection in adults: Role of the radiologist in its identification and diagnosis by imaging, with emphasis on CT

Motta RGA, Bustamante RFM, Cerda SAP, Córdova GDE

Language: Spanish
References: 38
Page: 1-28
PDF size: 735.69 Kb.


ABSTRACT

Introduction: urinary tract infections (UTIs) are common bacterial infections with heterogeneous clinical phenotypes ranging from benign, uncomplicated infections to complicated UTIs and pyelonephritis, and even severe urosepsis. Imaging in renal infections is complex, given the nature of the findings in most cases. Careful assessment of the clinical situation is essential to accurately select the most informative imaging technique, and therefore, that information must be as precise as possible.
Objective: given the diverse existing nomenclature and the agreement reached by the Society of Uroradiology in 1994, which recommended a simplified nomenclature based on the traditional and widely understood term acute pyelonephritis (APN), our objective is to emphasize and reinforce this nomenclature with current evidence.
Material and methods: a prospective review spanning two years and three months, with clinicopathological correlation, included patients with non-contrast CT (NCCT) and postcontrast CT (PCCT) studies. The analysis examined the terminology used in describing CT findings and their respective reports, emphasizing both the findings described and the final impression.
Results: different and diverse nomenclatures were defined, some of them confusing and lacking a clear context. Pneumonia can manifest as asymmetric perinephric distension or mild renal enlargement in moderate to severe infections. On post-contrast CT (PCCT), pneumonia may appear as wedge-shaped areas of low attenuation with poor corticomedullary differentiation, indicating hypoperfusion and edema. Late-phase images may also show renal sinus obliteration, striated nephrograms, and other findings. More serious complications of pneumonia, such as renal or perinephric abscesses, have been observed.
Conclusions: in our study of patients and their cases, it was identified that a point of agreement should be strengthened and established so that the respective reports, findings, and final impressions adhere to an already accepted and recognized terminology. CT is very sensitive for detecting pyelonephritis and defining its extent, but it is not essential for early, uncomplicated pyelonephritis. Clinical use of CT may be appropriate in cases of persistent fever and leukocytosis that last more than 7 days despite antibiotic treatment.


REFERENCES

  1. Lee A, Kim HC, Hwang SI, Chin HJ, NaKY, Chae DW, et al. Clinical Usefulness ofUnenhanced Computed Tomography in Patientswith Acute Pyelonephritis. Journal of KoreanMedical Science. 2018;33(38): e236. https://doi.org/10.3346/jkms.2018.33.e236.

  2. Gauthier S, Tattevin P, Soulat L, Bouget J,Abergel S, Hascoet J, et al. Pain intensityand imaging at the initial phase of acutepyelonephritis. Medecine Et MaladiesInfectieuses. 2020;50(6): 507–514. https://doi.org/10.1016/j.medmal.2019.07.013.

  3. Ramírez GAM, Arellano E de JO. ¿Dolorabdominal agudo?: La pielonefritis como unaposibilidad diagnóstica posibilidad diagnóstica.Anales de Radiología, México. 2006;5(3): 221–229.

  4. Song HK, Shin DH, Na JU, Han SK, ChoiPC, Lee JH. Clinical investigation on acutepyelonephritis without pyuria: a retrospectiveobservational study. Journal of YeungnamMedical Science. 2022;39(1): 39–45. https://doi.org/10.12701/yujm.2021.01207.

  5. Talner LB, Davidson AJ, Lebowitz RL,Dalla Palma L, Goldman SM. Acutepyelonephritis: can we agree on terminology?Radiology. 1994;192(2): 297–305. https://doi.org/10.1148/radiology.192.2.8029384.

  6. Rosenfield AT, Glickman MG, Taylor KJ, CradeM, Hodson J. Acute focal bacterial nephritis(acute lobar nephronia). Radiology. 1979;132(3):553–561. https://doi.org/10.1148/132.3.553.

  7. Huang JJ, Sung JM, Chen KW, Ruaan MK,Shu GH, Chuang YC. Acute bacterial nephritis:a clinicoradiologic correlation based oncomputed tomography. The American Journalof Medicine. 1992;93(3): 289–298. https://doi.org/10.1016/0002-9343(92)90235-4.

  8. Kumar PD, Brown LA. Focal bacterialnephritis (lobar nephronia) presenting asrenal mass. The American Journal of the MedicalSciences. 2000;320(3): 209–211. https://doi.org/10.1097/00000441-200009000-00013.

  9. Georgiades CS, Moore CJ, Smith DP.Differences of renal parenchymal attenuationfor acutely obstructed and unobstructedkidneys on unenhanced helical CT: a usefulsecondary sign? AJR. American journal ofroentgenology. 2001;176(4): 965–968. https://doi.org/10.2214/ajr.176.4.1760965.

  10. Nefropatología. Diagnóstico: Nefronía Lobar.kidneypathology; 2022.

  11. Ifergan J, Pommier R, Brion MC, Glas L,Rocher L, Bellin MF. Imaging in upper urinarytract infections. Diagnostic and InterventionalImaging. 2012;93(6): 509–519. https://doi.org/10.1016/j.diii.2012.03.010.

  12. Zulfiqar M, Ubilla CV, Nicola R, Menias CO.Imaging of Renal Infections and InflammatoryDisease. Radiologic Clinics of NorthAmerica. 2020;58(5): 909–923. https://doi.org/10.1016/j.rcl.2020.05.004.

  13. Joyce E, Glasner P, Ranganathan S, Swiatecka-Urban A. Tubulointerstitial nephritis: diagnosis,treatment, and monitoring. Pediatric Nephrology.2017;32(4): 577–587. https://doi.org/10.1007/s00467-016-3394-5.

  14. Nefropatología. Enfermedades tubulointersticiales.kidneypathology; 2022.

  15. Udare A, Abreu-Gomez J, Krishna S,McInnes M, Siegelman E, Schieda N. ImagingManifestations of Acute and Chronic RenalInfection That Mimics Malignancy: Howto Make the Diagnosis Using ComputedTomography and Magnetic ResonanceImaging. Canadian Association of RadiologistsJournal = Journal l’Association Canadienne DesRadiologistes. 2019;70(4): 424–433. https://doi.org/10.1016/j.carj.2019.07.002.

  16. Motta Ramírez G A, Bustamante Romero F M,Moreno Aranda J, Alonso Blancas, E, GonzálezMerino L. La pielonefritis aguda como origende afección intraabdominal y simuladorade procesos inflamatorios intraabdominalesextrarrenales. Anales de Radiología, México.2012;11(4): 209–218.

  17. Basmaci I, Sefik E. A novel use of attenuationvalue (Hounsfield unit) in non-contrastCT: diagnosis of pyonephrosis in obstructedsystems. International Urology and Nephrology.2020;52(1): 9–14. https://doi.org/10.1007/s11255-019-02283-2.

  18. Paick SH, Choo GY, Baek M, Bae SR, KimHG, Lho YS, et al. Clinical value of acutepyelonephritis grade based on computedtomography in predicting severity and course ofacute pyelonephritis. Journal of Computer AssistedTomography. 2013;37(3): 440–442. https://doi.org/10.1097/RCT.0b013e318287365e.

  19. Kim JS, Lee S, Lee KW, Kim JM, Kim YH,Kim ME. Relationship between uncommoncomputed tomography findings and clinicalaspects in patients with acute pyelonephritis.Korean Journal of Urology. 2014;55(7): 482–486.https://doi.org/10.4111/kju.2014.55.7.482

  20. Dalla-Palma L, Pozzi-Mucelli R, Pozzi-Mucelli F. Delayed CT in acute renal infection.Seminars in ultrasound, CT, and MR. 1997;18(2):122–128. https://doi.org/10.1016/s0887-

  21. 2171(97)90056-1.21. Takada T, Yano T, Fujiishi R, Fujii K, Honjo H,Miyajima M, et al. Added value of non-contrastCT for the diagnosis of acute pyelonephritis inolder patients with suspected infection withan unknown focus: a retrospective diagnosticstudy. BMJ open. 2024;14(1): e076678. https://doi.org/10.1136/bmjopen-2023-076678.

  22. Yu TY, Kim HR, Hwang KE, Lee JM, ChoJH, Lee JH. Computed tomography findingsassociated with bacteremia in adult patientswith a urinary tract infection. European Journalof Clinical Microbiology & Infectious Diseases:Official Publication of the European Society ofClinical Microbiology. 2016;35(11): 1883–1887.https://doi.org/10.1007/s10096-016-2743-4.

  23. Hammond NA, Nikolaidis P, Miller FH.Infectious and inflammatory diseases of thekidney. Radiologic Clinics of North America.2012;50(2): 259–270, vi. https://doi.org/10.1016/j.rcl.2012.02.002.

  24. Leligdowicz A, Dodek PM, Norena M, WongH, Kumar A, Kumar A, et al. Associationbetween source of infection and hospitalmortality in patients who have septic shock.American Journal of Respiratory and Critical CareMedicine. 2014;189(10): 1204–1213. https://doi.org/10.1164/rccm.201310-1875OC.

  25. Piccoli GB, Consiglio V, Deagostini MC, SerraM, Biolcati M, Ragni F, et al. The clinical andimaging presentation of acute ‘non complicated’pyelonephritis: A new profile for an ancientdisease. BMC Nephrology. 2011;12: 68. https://doi.org/10.1186/1471-2369-12-68.

  26. Piccoli GB, Colla L, Burdese M, Marcuccio C,Mezza E, Maass J, et al. Development of kidneyscars after acute uncomplicated pyelonephritis:relationship with clinical, laboratory andimaging data at diagnosis. World Journal ofUrology. 2006;24(1): 66–73. https://doi.org/10.1007/s00345-005-0044-0.

  27. Kawashima A, Sandler CM, GoldmanSM, Raval BK, Fishman EK. CT of renalinflammatory disease. Radiographics: AReview Publication of the Radiological Societyof North America, Inc. 1997;17(4): 851–866;discussion 867-868. https://doi.org/10.1148/radiographics.17.4.9225387.

  28. Kawashima A, Sandler CM, Ernst RD, GoldmanSM, Raval B, Fishman EK. Renal inflammatorydisease: the current role of CT. Critical Reviewsin Diagnostic Imaging. 1997;38(5): 369–415.

  29. Taniguchi LS, Torres US, Souza SM, TorresLR, D’Ippolito G. Are the unenhancedand excretory CT phases necessary for theevaluation of acute pyelonephritis? ActaRadiologica. 2017;58(5): 634–640. https://doi.org/10.1177/0284185116665424.

  30. Sarangi P, Bell D, Rasuli B. Perinephric bridgingsepta. In: Radiopaedia.org. Radiopaedia.org;2019. https://doi.org/10.53347/rID-65543

  31. Mitreski G, Sutherland T. Radiologicaldiagnosis of perinephric pathology: pictorialessay 2015. Insights into Imaging. 2017;8(1):155–169. https://doi.org/10.1007/s13244-016-0536-z.

  32. Park D, An C, Yu JS. Association betweenincidental perirenal fat stranding on CT andmetabolic syndrome in otherwise healthyadults. La Radiologia Medica. 2024;129(11):1587–1596. https://doi.org/10.1007/s11547-024-01888-7.

  33. Fukami H, Takeuchi Y, Kagaya S, Ojima Y,Saito A, Sato H, et al. Perirenal fat strandingis not a powerful diagnostic tool for acutepyelonephritis. International Journal of GeneralMedicine. 2017;10: 137–144. https://doi.org/10.2147/IJGM.S133685.

  34. Tanizaki R, Ichikawa S, Takemura Y. Clinicalimpact of perinephric fat stranding detected oncomputed tomography in patients with acutepyelonephritis: a retrospective observationalstudy. European Journal of Clinical Microbiology& Infectious Diseases: Official Publication ofthe European Society of Clinical Microbiology.2019;38(11): 2185–2192. https://doi.org/10.1007/s10096-019-03662-4.

  35. Campos-Franco J, Macia C, Huelga E, Diaz-Louzao C, Gude F, Alende R, et al. Acute focalbacterial nephritis in a cohort of hospitalizedadult patients with acute pyelonephritis.Assessment of risk factors and a predictivemodel. European Journal of Internal Medicine.2017;39: 69–74. https://doi.org/10.1016/j.ejim.2016.12.002.

  36. Lee YJ, Cho S, Kim SR. Unilateral and bilateralacute pyelonephritis: differences in clinicalpresentation, progress and outcome. PostgraduateMedical Journal. 2014;90(1060): 80–85. https://doi.org/10.1136/postgradmedj-2013-131935.

  37. Yagihashi Y, Shimabukuro S, Toyosato T,Arakaki Y. Can excretory phase computedtomography predict bacteremia in obstructivecalculous pyelonephritis? International Urologyand Nephrology. 2018;50(12): 2123–2129.https://doi.org/10.1007/s11255-018-1999-2.

  38. Oh SJ, Je BK, Lee SH, Choi WS, Hong D, Kim SB.Comparison of computed tomography findingsbetween bacteremic and non-bacteremic acutepyelonephritis due to Escherichia coli. WorldJournal of Radiology. 2016;8(4): 403–409.https://doi.org/10.4329/wjr.v8.i4.403.




2020     |     www.medigraphic.com