Non-enhanced magnetic resonance imaging versus renal scintigraphy
in acute pyelonephritis
and Takanori Yamagata
Pediatric Medical Imaging, Jichi Medical University, Shimotsuke, Tochigi, Japan
Abstract The utility of non-enhanced magnetic resonance imaging (MRI) has not been examined extensively for diagnosing
acute pyelonephritis (APN) in children. The aims of this study were to compare non-enhanced MRI with tech-
netium-99 m dimercaptosuccinic acid (
Tc-DMSA) renal scintigraphy in detecting APN. Six boys and one girl
with temperature ≥38°C and positive urine culture received both non-enhanced MRI with whole body diffusion-
weighted imaging (DWI) and
Tc-DMSA scintigraphy ≤7 days from the fever onset. The sensitivity and speci-
ﬁcity of MRI in detecting APN lesions diagnosed on
Tc-DMSA scintigraphy were 80% and 100%, respectively.
Non-enhanced MRI in children with suspected APN ≤7 days from fever onset might be a suitable replacement for
Tc-DMSA scintigraphy for the detection of APN.
Tc-dimercaptosuccinic acid renal scintigraphy, acute pyelonephritis, children, diffusion-weighted imaging, non-
enhanced magnetic resonance imaging.
Enhanced computed tomography (CT) and technetium-99m
dimercaptosuccinic acid (
Tc-DMSA) renal scintigraphy
(RS), obtained on single-photon emission CT (SPECT), are
useful tools for the diagnosis of acute pyelonephritis (APN).
CT, however, is not routinely used to diagnose APN in chil-
dren due the higher radiation dose compared with RS.
Diffusion-weighted imaging (DWI) is a non-enhanced
magnetic resonance imaging (MRI) method that is well
established for the diagnosis of intracranial abscesses and
brain infarction. Intracranial abscesses show up as high-
intensity signals on DWI, with a highly reduced apparent
diffusion coefﬁcient (ADC).
A number of studies have
described the utility of non-enhanced MRI for the diagnosis
Kovanlikaya et al. reported that post-gadolinium
MRI correlated signiﬁcantly with RS in determining the
condition of renal tissue.
Non-enhanced MRI avoids not
only the risks of radiation exposure, but also the nephro-
genic systemic ﬁbrosis (NSF) associated with gadolinium-
based contrast agents, especially in children aged <1 year,
who are considered to have a moderately increased risk of
In order, therefore, to determine whether non-
enhanced MRI with DWI is a useful tool for diagnosing
APN, children with suspected APN underwent MRI and the
results compared with RS.
The study protocol was approved by the ethics committee of
Jichi Medical University and the study was conducted between
2012 and 2015. Children aged <2 years presenting with fever
(body temperature ≥38°C), pyuria (white blood cell count ≥5/
HPF), and positive urine culture (colony count >10
were recruited. Informed consent was obtained from the chil-
dren’s parents. Urine samples were collected by urinary
catheterization. All children included in this study had a ﬁrst
onset of APN.
After a diagnosis of APN, the children were started on i.v.
cefotiam hydrochloride 100 mg/kg/day. Temperature normal-
ized on day 3 (median, 3 days; range, 2–4 days) after medica-
tion. MRI or RS was carried out 2 or 3 days (median) after
Seven children (six boys and one girl; median age,
2 months; range, 0–4 months) were included in this study and
received non-enhanced MRI and RS ≤7 days after fever onset
(days 3–7; day 1 was the onset of fever). The time interval
between MRI and RS was not ﬁxed (median, 2 days; range,
0–3 days). Imaging was done using a 1.5 T Magnetom Avanto
MRI system (Siemens Medical Solutions, Erlangen, Germany).
The following parameters were used for DWI: median repeti-
tion time (TR)/echo time (TE), 8,800 mss (range, 8,700–
10 600 ms)/68 ms (range, 66–68 ms); plane of acquisition
b-value, 1,000 s/mm
; median slice thickness, 4 mm (range,
4–5 mm); and ﬂip angle, 90°. ADC of the lesion and kidney
parenchyma were not calculated, and processing of ADC maps
was performed automatically using the MRI scanner. Whole-
body DWI was obtained with a background body-signal
Correspondence: Takahiro Kanai, MD, Department of Pediatrics,
Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi,
Tochigi 329-0498, Japan. Email: email@example.com
Received 10 May 2017; revised 18 October 2017; accepted 28
© 2018 Japan Pediatric Society
Pediatrics International (2018) 60, 200–203 doi: 10.1111/ped.13465