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ORIGINAL ARTICLE

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DIAGNOSTIC ACCURACY OF CHEST RADIOGRAPHS IN DETECTION OF LUNG
CONSOLIDATION TAKING CT CHEST AS GOLD STANDARD

Syed Nauman Abdullah Faryal BashirGhazala Wahid1, Mahrukh Abdullah 2, 3, Rabeea Ihtesham4, 5,
Humna Imdad6

How to cite this article

Abdullah M, Wahid G, Abdullah SN,
Ihtesham R, Bashir F, Imdad H.
Diagnostic Accuracy of Chest
Radiographs in Detection of Lung
Consolidation Taking Ct Chest as
Gold Standard. J Gandhara Med Dent
Sci. 2025;12(4):28-32.http://doi.org/10.3

Date of Submission: 20-04-2025
Date Revised: 27-08-2025
Date Acceptance: 28-08-2025
1Trainee Medical Ofcer, Department
of Radiology, Hayatabad Medical
Complex, Peshawar

3Trainee Medical Ofcer, Department
of Medicine, Hayatabad Medical
Complex, Peshawar

4Trainee Medical Ofcer, Department
of Radiology, Hayatabad Medical
Complex, Peshawar

5Specialist Registrar, Department of
Radiology, Hayatabad Medical
Complex, Peshawar

6Specialist Registrar, Department of
Radiology, Hayatabad Medical
Complex, Peshawar

Correspondence

2Ghazala Wahid, Associate Professor,
Department of Radiology, Hayatabad
Medical Complex, Peshawar

+92-321-9861864
ghazalawahid3@gmail.com

ABSTRACT
OBJECTIVES
To evaluate the diagnostic accuracy of chest X -rays in detecting lung
consolidation, using CT chest as the gold standard.
METHODOLOGY
This cross-sectional study was conducted at the Department of Radiology,
Hayatabad Medical Complex, Peshawar/PGMI, from April to October 2023.
A total of 204 patients aged 18 to 50 years with clinical suspicion of
pneumonia were included in the study. Diagnostic out comes of CXR were
compared against those of CT chest. Non-probability consecutive sampling
technique is used. The sample size has been calculated using a sensitivity and
specicity sample size calculator.
RESULTS
The mean age of the patients was 36.44 years ± 9.07. Gender distribution was
equal, with 50% male and 50% female participants. Comparing both
modalities, the sensitivity of CXR was 69.2% with a specicity of 57.7%, PPV
of 75.4%, NPV of 50.0% and diagnostic accuracy of 65.2% was reported.
CONCLUSION
This study highlights the superior diagnostic accuracy of CT over chest X-ray
in detecting lung consolidations, particularly in complex or ambiguous cases.
While CXR remains a practical and widely accessible initial diagnostic tool,
its lower sensitivity and specicity suggest a need for follow-up CT in cases
where clinical uncertainty persists. Overall, a combined approach using both
CXR and CT optimises diagnostic accuracy and patient outcomes.
KEYWORDS: X-Ray, Computed Tomography (CT), Chest, Lung
Consolidation, Pneumonia

7762/jgmds.12-4.720

INTRODUCTION
Pneumonia remains one of the leading causes of
morbidity and mortality worldwide, particularly in
developing countries where diagnostic resources are
limited. Early and accurate diagnosis is crucial for
preventing complications and initiating timely
treatment, which can signicantly enhance patient
outcomes.¹ Due to its easy availability and cost-
effectiveness, the chest X-ray is the rst-line imaging
modality commonly used in practice. However, CXR
has its own limitations; it has lower sensitivity in
detecting small areas of lung consolidation, particularly
in the early stages of pneumonia. Additionally, it cannot
accurately dierentiate between infectious and non-
infectious lung abnormalities, leading to diagnostic

2uncertainty. Computed tomography (CT) of the chest,
on the other hand, is widely considered the gold

standard in diagnosing pneumonia, having superior
sensitivity and specicity compared to CXR. CT
provides detailed cross-sectional views of the lung,
allowing for more accurate identication of
consolidation, even in complex cases. However, like
CXR, the widespread use of CT also has its limitations,
including higher costs, limited availability in certain
regions, and increased radiation exposure. Given these
limitations, CXR remains the rst-line imaging
modality in most clinical settings with limited
resources.3 This study focuses on evaluating the
effectiveness of CXR in identifying consolidation
compared to CT, a more sensitive and detailed imaging
technique.4,5 Chest radiographs are widely accessible,
cost-eective, and can be performed quickly in various
clinical settings, such as emergency departments,
ambulances, and inpatient wards.⁶ These factors make
CXR an important rst-line diagnostic imaging tool. A

29J Gandhara Med Dent Sci

October - December 2025

CT scan has higher sensitivity and specicity in
detecting lung pathologies, such as consolidation, as it
provides more detailed and cross-sectional images of
the lungs, aiding in the better visualisation of subtle
lung changes. CXR, on the other hand, may miss small
or early consolidation, as it is a more generalised
imaging technique.⁷ Taking the CT chest as the gold
standard, the accuracy of CXR in identifying
consolidation is assessed.⁸ The sensitivity and
specificity of CXR are measured to understand the
limitations and strengths of CXR compared to CT in
clinical practice.⁹ The comparison helps healthcare
providers choose a better option to utilise time and
resources properly for the benet of patients and the
healthcare system to avoid extra burden. Since
detecting very subtle consolidation or early
consolidation may be compromised by CXR,
comparison with CT, the gold standard, allows for the
identification of false positives and false negatives,
which have signicant clinical implications. Hence, it
provides insight into the potential need for further
imaging when CXR results are inconclusive for a
definitive diagnosis.¹⁰ This study aims to evaluate the
diagnostic accuracy of CXR in detecting lung
consolidation, using CT chest imaging as the gold
standard. The study will assess the sensitivity,
specicity, positive predictive value (PPV), and
negative predictive value (NPV) of CXR to determine
its reliability in diagnosing pneumonia. By doing so, it
seeks to provide a clearer understanding of the role of
CXR in clinical practice and guide appropriate use of
imaging modalities in the diagnosis of lung
consolidation. Despite the widespread use of CXR, its
diagnostic limitations in early or subtle pneumonia raise
concerns in clinical decision-making. In Pakistan and
other low-resource settings, CT is not always readily
available, making it crucial to understand the actual
diagnostic value of CXR compared to CT. By
addressing this gap, our study provides region-specic
evidence that may guide clinicians in balancing
diagnostic accuracy with resource utilisation.
Ultimately, this has the potential to improve pneumonia
outcomes, reduce unnecessary CT exposure, and
optimise healthcare costs in our community.

METHODOLOGY

the Department of Radiology, Medical Teaching
Peshawar, from April to October 2023. A
participants were recruited using a consecutive

This cross-sectional validation study was conducted at
Institution-Hayatabad Medical Complex (MTI-HMC),

total of 204
sampling method. Inclusion criteria included patients
aged 18 to 50 years presenting with clinical signs and
symptoms suggestive of pneumonia, such as fever,

participants underwent both chest X

Healthcare, USA). A single calibrated radiologist

productive cough, dyspnea, and pleur
Exclusion criteria were patients with a history of

itic chest pain.
chronic lung diseases (e.g., COPD, bronchiectasis,
interstitial lung disease), prior lung surgery, pregnancy,
or contraindications to CT such as severe renal
impairment or allergies to contrast agents. All

-ray (CXR) and
computed tomography (CT) chest scans on the same
day. CXR was performed using a digital radiography
system (Siemens Multix Fusion, Siemens Healthcare,
Germany), while CT chest scans were obtained using a
64-slice CT scanner (GE Optima CT660, GE
conducted image interpretation to minimise bias. The
following diagnostic parameters were recorded for both
imaging modalities: Consolidation on CXR, defined as
a homogeneous increase in pulmonary parenchymal
opacity, obscuring underlying vessels. Consolidation on
CT: Dened as an area of increased attenuation that did
not obscure underlying bronchovascular structures.
Two independent radiologists, blinded to clinical details
and each other's interpretations, reviewed the images. A
senior radiologist resolved any discrepancies. Data
were analysed using SPSS version 26.0 (IBM Corp.,
USA). Descriptive statistics were used to summarise the
data. The sensitivity, specicity, positive predictive
value (PPV), negative predictive value (NPV), and
accuracy of CXR in detecting lung consolidation were
calculated.. Diagnostic parameters were reported with
95% condence intervals. Stratied analysis was
performed by age and gender, and a chi-square test was
applied to assess statistical signicance, with a p-value
<0.05 considered signicant. The study was approved
by the Institutional Review Board (IRB No. 1068) of
Hayatabad Medical Complex, Peshawar, and written
informed consent was obtained from all participants
before their inclusion. Condentiality and privacy of
patient data were strictly maintained throughout the
study.
RESULTS

The study included 204 participants, with a mean age of
36.44±9.07years. Gender distribution was equal, with
102 (50%) male and 102 (50%) female participants
(Table I). Consolidation on chest X-ray was observed in
59.8% of patients, while 40.2% had no ndings (Table
II). CT chest scans revealed consolidation in 65.2% of
patients (Table III). Comparing both modalities, the
sensitivity of CXR was 69.2%, with a specicity of
57.7%, PPV of 75.4%, NPV of 50.0% and accuracy of
65.2% (Table IV). Diagnostic accuracy was stratied
by age and gender. Sensitivity, specicity, PPV, NPV,
and accuracy values were reported with 95% CI.
Diagnostic performance was consistent across genders,
with slightly higher sensitivity noted in the younger age

Diagnostic Accuracy of Chest Radiographs in Detection

30 J Gandhara Med Dent Sci
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group (18-35 years) compared to patients aged 35 years
or older, although this dierence was not statistically
significant (p > 0.05).

Table 1: Demographic Characteristics of Study Participants
Mean age of the Patients 36.44±9.07
Gender Male 102 (50.0%)

Female 102 (50.0%)

Table 2: Consolidation on CXR (n=204)
Consolidation on CXR Frequency %age
Yes 122 59.8%
No 82 40.2%
Total 204 100.0%

Table 3: Consolidation on CXR (n=204)

CT Chest Frequency %age
Yes 133 65.2%
No 71 34.8%
Total 204 100.0%

Table 4: Comparison of Consolidation of CXR and CT Chest
(n=204)

Consolidation
on CT

Total
Yes No

Consoli
dation
on
CXR

Yes

92 30 122%
69.2% 42.3% 59.8%

No 41 41 82%
30.8% 57.7% 40.2%

Statistics

P Value: 0.000
Sensitivity:
69.2%
Specificity:
57.7%
PPV: 75.4%
NPV: 50.0%
Accuracy: 65.2%

DISCUSSION
The current study demonstrated a significant detection
rate of consolidation on CT compared to chest X-ray
(CXR), with CT identifying consolidation in 65.2% of
patients and CXR in 59.8%. The sensitivity of CXR for
detecting consolidation was 69.2%, which is consistent
with previous studies reporting a sensitivity range
between 60-75% for pneumonia detection on CXR
compared to CT.¹¹ However, the specicity of CXR in
this study was slightly lower at 57.7%, which is
comparable to ndings where CXR specicity has
ranged between 50-70% due to the limited ability to
dierentiate between consolidation and other
pulmonary pathologies. CT's superiority in detecting
consolidation, with an accuracy of 65.2%, supports its
role as the gold standard in evaluating lung diseases.
Studies have shown that CT can reveal subtle ndings
missed on CXR, including small consolidations or
early-stage pneumonia, which may justify the higher
sensitivity and PPV observed in our study.12 Our PPV
of 75.4% indicates that CXR is still valuable for
diagnosing consolidation, but may benet from follow-
up CT in some instances to conrm ndings. The
findings of our study align with previous research,

indicating that CT has superior diagnostic accuracy
over CXR in detecting pulmonary consolidations. A
study reported a similar trend, with CT detecting 70%
of pneumonia cases compared to 50-60% by CXR,
demonstrating the enhanced sensitivity of CT.13 A study
found that CT detected consolidation in 67% of cases
missed by CXR, which supports the notion that CT is
more sensitive in identifying subtle lung pathologies.¹4
However, contrasting results have been observed in
some studies where the diagnostic gap between CXR
and CT was less pronounced. Another study reported
only a marginal increase in sensitivity with CT (68%)
compared to CXR (63%), suggesting that the
dierences between these imaging modalities may
depend on factors such as patient age, disease severity,
and the radiologist's experience.15 Our study‘s ndings
emphasise the practical role of CT in cases where CXR
results are ambiguous, especially for patients presenting
with atypical pneumonia symptoms. The positive
predictive value (PPV) of 75.4% in our study is similar
to other reports, where CXR had moderate diagnostic
utility but was enhanced with the use of adjunctive
CT.16 Moreover, the specicity of CXR, while lower in
our study (57.7%), mirrors ndings by Wipf et al., who
noted that CXR has lower specicity due to its inability
to distinguish consolidation from other forms of
inltrates or lung abnormalities.12 This study
corroborates the broader body of literature advocating
for CT as the gold standard in diagnosing lung
consolidations, particularly when CXR results are
equivocal or in high-risk populations. However, given
its widespread availability and cost-eectiveness, CXR
remains a valuable initial screening tool, with CT
reserved for conrmatory diagnosis in cases that are
complex. Furthermore, the utility of CXR as an initial
diagnostic tool remains signicant, especially in
resource-limited settings. Studies have shown that
while CT is more sensitive, its accessibility and cost
can be prohibitive in many clinical settings. For
instance, Hayden et al. demonstrated that in lower-
income regions, where CT is often unavailable, CXR
remains a cornerstone of pneumonia diagnosis, despite
its lower sensitivity. This underscores the need for
balance between high diagnostic accuracy and practical
accessibility, particularly in urgent or outpatient
settings. Moreover, the decision to use CT should be
guided by clinical presentation and patient history.17 A
study emphasised that CXR, when combined with
strong clinical suspicion and patient symptoms, can still
oer a reliable diagnosis of pneumonia in some
instances, particularly in young, healthy adults without
underlying lung disease.18 Conversely, in patients with
underlying conditions like chronic obstructive
pulmonary disease (COPD) or heart failure, CT is more
likely to identify subtle consolidations that CXR could

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31J Gandhara Med Dent SciOctober - December 2025

17miss, a nding also reported by Upchurch et al. Our
study’s accuracy rate of 65.2% for CXR is consistent
with ndings from a study by Brooks D et al., which
noted that while CXR is imperfect, it remains particular
for pneumonia when used in conjunction with clinical
judgment.7 However, the study also highlighted the
increased risk of false negatives, particularly in early or
mild cases, which could justify the use of CT as a
follow-up tool when CXR results are inconclusive or
when patients fail to respond to initial treatment.18 In
conclusion, while CT oers superior diagnostic
performance in detecting lung consolidations,
particularly in complex or unclear cases, CXR
continues to play a vital role due to its availability,
lower cost, and sucient accuracy in many cases. Our
study, in line with previous research, suggests that a
stepwise approach, starting with CXR and escalating to
CT when necessary, could optimise both diagnostic
efciency and resource use. The results of this study
have important public health implications. In resource-
constrained healthcare systems, such as those in
Pakistan, where CT availability is limited, reliance on
CXR as an initial diagnostic tool remains justied. By
clarifying its diagnostic performance, this study may
support evidence-based protocols to prioritise CT only
for inconclusive or atypical cases, thus reducing
unnecessary costs and radiation exposure. The ndings
may guide clinicians, health administrators, and
policymakers in optimising diagnostic pathways for
pneumonia, ultimately improving patient outcomes at
both individual and community levels.

LIMITATIONS

Firstly, this is a single-centre study, which may limit
the generalizability of the ndings to other healthcare
settings that have dierent patient demographics and
radiological practices. Secondly, the sample size is
relatively limited. A larger sample would enable
subgroup and stratied analysis, improving the
precision of sensitivity and specicity estimates and
thereby enhancing the robustness of the diagnostic
accuracy assessment.

CONCLUSIONS

This study the superior diagnostic accuracy of CT over
chest X-ray (CXR) in detecting lung consolidations,
particularly in complex or ambiguous cases. While
CXR remains a practical and widely accessible initial
diagnostic tool, its lower sensitivity and specicity
suggest a need for follow-up CT in cases where clinical
uncertainty persists. Emerging technologies, such as AI
and radiomics, along with advancements in portable
imaging, are poised to further enhance the diagnosis of

pneumonia, particularly in resource-limited settings.
Overall, a combined approach using both CXR and CT
optimises diagnostic accuracy and patient outcomes.

CONFLICT OF INTEREST: None

FUNDING SOURCES: None

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Ghazala Wahid - Concept & Design; Data Acquisition; Data
Analysis/Interpretation; Drafting Manuscript; Critical
Revision; Supervision; Final Approval

Mahrukh Abdullah - Concept & Design; Data Acquisition;
Data Analysis/Interpretation; Drafting Manuscript; Critical
Revision; Supervision; Final Approval

Syed Nauman Abdullah - Concept & Design; Data
Acquisition; Data Analysis/Interpretation; Drafting
Manuscript; Critical Revision; Final Approval
Rabeea Ihtesham - Concept & Design; Data Acquisition; Data
Analysis/Interpretation; Drafting Manuscript; Critical
Revision; Supervision; Final Approval
Faryal Bashir - Concept & Design; Data Acquisition; Data
Analysis/Interpretation; Drafting Manuscript; Critical
Revision; Final Approval
Humna Imdad - Concept & Design; Data Acquisition; Data
Analysis/Interpretation; Drafting Manuscript; Critical
Revision; Final Approval

AUTHORS CONTRIBUTION

The authors accept responsibility for all aspects of the work
and will ensure that any concerns regarding the accuracy or
integrity of any part are properly investigated and resolved.

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Diagnostic Accuracy of Chest Radiographs in Detection