Iranian Journal of Radiology
Volume:18 Issue: 2, Apr 2021

Primary inflammatory pseudotumor of the central nervous system is extremely rare. These lesions may be intra-axial, extra-axial, or a mix of them. We report a case of intracranial inflammatory pseudotumor involving both brain parenchyma and dura.

 Coronavirus disease 2019 (COVID-19) has several chest computed tomography (CT) characteristics, which are important for the early management of this disease, because viral detection via RT-PCR can be time-consuming, resulting in a delayed pneumonia diagnosis. The Radiological Society of North America (RSNA) proposed a reporting language for CT findings related to COVID-19 and defined four CT categories: typical, indeterminate, atypical, and negative.

 To retrospectively evaluate the chest CT characteristics of patients with COVID-19 pneumonia.

 A total of 115 hospitalized laboratory-verified COVID-19 cases, underdoing chest CT scan, were included in this study from April 30 to May 15, 2020. Of 115 cases, 53 were discharged from the hospital, and 62 expired. The initial clinical features and chest CT scans were assessed for the type, pattern, distribution, and frequency of lesions. Moreover, the findings were compared between ward-hospitalized, ICU-admitted, and non-surviving (expired) patients.

 Of four CT categories, typical CT findings for COVID-19 were more frequent in the expired group (77.4%), compared to the ward-admitted (44.8%) and ICU-admitted (70.8%) groups (P = 0.017). However, no significant difference was observed in the prevalence of intermediate or atypical CT findings between the groups. Negative CT scans for the diagnosis of COVID-19 were significantly fewer in the expired group (0%) as compared to the ward-admitted (10.3%) and ICU-admitted (8.3%) groups (P = 0.0180). Also, the mean number of involved lung lobes and segments was significantly higher in the expired group compared to the other two groups (P = 0.032 and 0.010, respectively). The right upper lobe involvement, right middle lobe involvement, bilateral involvement, central lesion, air bronchogram, and pleural effusion were among CT scan findings with a significantly higher prevalence in non-surviving cases (P < 0.0001, 0.047, 0.01, 0.036, 0.038, and 0.047, respectively).

 The increased number of involved lung lobes and segments, bilateral and central distribution patterns, air bronchogram, and severe pleural effusion in the initial chest CT scan can be related to the increased severity and poor prognosis of COVID-19.

 Color Doppler imaging (CDI) is a non-aggressive and safe technique for the clinical management of retinal diseases. Recently, the number of infants with retinopathy of prematurity (ROP) has increased due to the incidence of premature births.

 This study aimed to compare the CDI criteria for the ophthalmic artery (OA) and central retinal artery (CRA) in ROP infants with and without plus disease.

 In this case-control study, 42 premature infants (21 infants with plus disease and 21 infants without plus disease) underwent CDI. The arterial CDI parameters, including end-diastolic velocity (EDV), pulsatility index (PI), resistance index (RI), and peak systolic velocity (PSV), were measured in these patients. After collecting the data, t-test and chi-square tests were used for data analysis. P < 0.05 was considered to be statistically significant.

 The mean EDV of CRA in patients with and without plus disease was 4.35 ± 1.00 and 5.27 ± 1.02 cm/sec, respectively (P = 0.005). The mean PSV of CRA in patients with and without plus disease was 15.65 ± 3.35 and 18.39 ± 4.39 cm/sec, respectively (P = 0.029). However, no significant difference was found between the two groups in terms of PSV or EDV of OA (P > 0.05). Also, no significant difference was observed between the two groups considering the RI and PI of CRA and OA (P > 0.05).

 According to the findings of this study, CDI criteria, such as EDV and PSV of CRA, were significantly lower in infants with plus disease as compared to those without plus disease. Since detecting the early stages of plus disease is a challenge for ophthalmologists, assessment of these criteria can be helpful for differentiation of these two subgroups of patients. However, further studies with a larger sample size are needed to determine the cutoff value.

 Lung cancer is the leading cause of cancer-related mortality worldwide. Thin-walled cystic lung cancer with ground glas s opacity (GGO) is a type of lung carcinoma with specific computed tomography (CT) features.

 To investigate the imaging features of multi-slice spiral computed tomography (MSCT) of GGO and to improve the imaging diagnosis of this type of lung cancer.

 The clinical data of 24 patients with pathologically confirmed thin-walled cystic lung cancer with GGO were retrospectively analyzed in this study. The imaging features of preoperative MSCT, including vascular convergence, burr signs, pleural depression signs, lobulation signs, thickness and uniformity of the cavity wall, partitive membranes, and position of the ground-glass cavity, were examined. The relationship between the imaging features and postoperative pathological findings of lung carcinoma were also explored.

 Most of the lesions (75.0%) were located in the upper lobe of the lungs. The size range of the cavity was 5.8 - 28.1 mm, with a mean of 13.6 ± 7.2 mm. Fifteen patients (62.5%) had a cavity wall thickness < 2 mm, 6 (25.0%) patients had a cavity wall thickness in the range of 2 - 3 mm, and 3 (12.5%) patients had a cavity wall thickness of about 3 - 4 mm. A uniform cavity wall was found in 10 (41.7%) cases, while a non-uniform cavity wall was observed in 14 (58.3%) cases. Eleven patients showed pure GGO (45.8%), while 13 patients showed mixed GGO (54.2%). Besides, nine patients (37.5%) showed lobular signs, 12 (50.0%) patients showed spicule signs, and 6 (28.6%) patients showed vascular convergence signs. Twelve patients (50.0%) had signs of pleural indentation, while 14 (66.7%) patients showed thick or thin small blood vessel opacity or fine partitive membranes. Twenty-three patients were diagnosed with lung adenocarcinoma, while one patients was diagnosed with mixed adenosquamous carcinoma.

 Thin-walled cystic lung cancer with GGO is a rare clinical phenomenon. The imaging features of this type of lung cancer on MSCT are consistent with the characteristics of lung cancers.

 For many patients with neurological complaints, a non-enhanced brain computed tomography (CT) scan is the first workup. In some of these patients, there is no pathological finding. Anemia is a condition that can present with neurological symptoms without any imaging findings. The correlation of dural venous sinus density with hemoglobin (Hb) level has been shown in some recent studies.

 This study aimed to propose a strategy to predict the level of Hb and investigate the possibility of underlying anemia based on dural venous sinus density to facilitate treatment.

 The CT scans of selected patients, who were referred to Faghihi Hospital in Shiraz, Iran, from October 2018 until February 2019, were reviewed in this study; the complete blood count (CBC) was measured for cases without any findings. The data of 78 patients, including CBC parameters and the mean Hounsfield unit (HU) in the superior sagittal sinus (SSS), torcula herophili (TH), and transverse sinuses (TS), were also analyzed.

 A relatively strong direct linear correlation was found between the Hb level and HU. The Hb level was calculated based on the following formula: Hb level = 0.2 × SSS HU + 1.2 × sex factor - 0.01 × age (where sex factor is zero for females and one for males). Besides, measurement of the cutoff point for the mean HU of SSS, based on the ROC curve to predict anemia, showed that with SSS HU ≤ 50, anemia could be predicted with 84.62% sensitivity, 75.38% specificity, and 75.64% accuracy in the general population.

 A significant positive correlation was found between the Hb level and the mean HU of dural venous sinuses. Therefore, the level of Hb is predictable based on HU, and differential diagnoses are limited.

Thoracic kidney is a rare congenital abnormality with the lowest frequency of all renal ectopias. Most cases are discovered incidentally via routine imaging and have a benign clinical course. Here, we report three pediatric cases of thoracic kidney among 156 children with renal ectopy (1.9%). Thoracic kidney was asymptomatic in two children; in one child, it was associated with a recurrent diaphragmatic hernia. All diagnoses were made by chest ultrasonography (USG) and/or radiography in children and confirmed by computed tomography (CT) scan. Moreover, 99mtechnetium-ethylene-dicysteine (99mTc-EC) renal scintigraphy was carried out to visualize and assess the function of ectopic kidneys. All thoracic kidneys were left-sided, and their functions were comparable to their normally located counterparts. During an observation period of 5 - 10 years, two children with thoracic kidneys presented with unstable proteinuria/microalbuminuria and hypertension, respectively. The 99mTc-EC renal scintigraphy is an uncomplicated and safe method for imaging the thoracic kidneys and can be used for detecting the thoracic kidney function in children. Thoracic ectopic kidneys are associated with complications, such as hypertension and proteinuria. Children with thoracic kidneys need long-term follow-ups.

This review aimed to investigate the computed tomography (CT) imaging features of COVID-19.

Bilateral lung involvement (70%), peripheral distribution (67.5%), multifocal involvement (67.3%) and ground glass opacity (66.1%) were observed in most infected patients

Evaluation of the number of lobes involved in infected patients showed no abnormalities in 7.2% (85/1177) of the patients. Regarding the performance of RT-PCR and chest CT scan, the sensitivity of RT-PCR and chest CT imaging was estimated at 70% (925/1311) and 89% (6605/7396) upon admission, respectively; nevertheless, the sensitivity of CT imaging increased as the time from the symptom onset increased. The CT image acquisition parameters affecting image quality and patient dose were also discussed. Studies suggested that these factors should be adjusted according to the disease stage. Based on our findings, sensitivity was adequately high eight days after the onset of symptoms.

Therefore, there is no need for high-resolution chest CT scan after this interval. Using ImpactDose software, the mean effective doses were 4.38 and 5.71 mSv in male and female groups, respectively. The risk of cancer was 36% higher in females than males, as shown by PCXMC program.

 We analyzed different methods used to assess the radiological responses of patients undergoing neoadjuvant chemotherapy and metastasectomy treatment for liver metastases associated with colorectal cancer (CRC) by comparing the response evaluation criteria in solid tumors (RECIST) 1.1, the modified RECIST, and the criteria of the European Association for the Study of the Liver (EASL) methods and the histological response obtained after metastasectomy.

 We aimed to determine the optimal radiological method to assess the response of colorectal liver metastases to neoadjuvant chemotherapy.

 We conducted a retrospective study of CRC patients treated for liver metastases who had received neoadjuvant chemotherapy in our hospital between January 2000 and December 2017. We analyzed the agreement between the methods for analyzing the radiological response using the quadratic weighted kappa coefficient (κ). We studied the overall survival and analyzed factors related to survival using the Kaplan-Meier method. We performed multivariate analysis to study the prognostic factors of survival. We analyzed the relationship between the radiological and histological responses using Goodman and Kruskal's gamma (γ).

 A significant agreement was observed between the modified RECIST and EASL methods (κ = 0.841, P < 0.001). Cox regression multivariate analysis indicated the RECIST 1.1 criteria as an independent prognostic factor (P = 0.03).
The γ value showed a significant relationship between the three radiological response methods and histological response.

 In our study, we showed that using RECIST 1.1 criteria is the ideal radiological analysis method for studying CRC liver metastases treated with neoadjuvant chemotherapy when compared to other methods that are based on functional imaging markers.

 The imaging features of sinonasal extramedullary plasmacytoma (EMP) are non-specific and similar to those of other lesions, such as sinonasal non-Hodgkin’s lymphoma (NHL) and squamous cell carcinoma (SCC).

 To analyze the computed tomography (CT) and magnetic resonance (MR) images of patients with EMP, NHL, and SCC to identify the radiological characteristics differentiating sinonasal EMP from NHL and SCC.
Patients and

 In this cross-sectional study, the CT and MR imaging features of 37 patients with sinonasal EMP, 46 patients with NHL, and 44 patients with SCC were analyzed. Sinonasal NHL was categorized into two distinct types, namely, natural killer/T-cell lymphoma (n = 32) and diffuse large B-cell lymphoma (n = 14). The tumor volume was determined by measuring the region of interest (ROI) in the PACS program. Besides, homogeneity, apparent diffusion coefficient (ADC) in the ADC maps, degree of enhancement, adjacent bone destruction, and invasion to Waldeyer’s ring and cervical or retropharyngeal lymph nodes were evaluated.

 Although the tumor volume was larger in the EMP group as compared to the NHL and SCC groups, the difference was not statistically significant. The NHL group showed the highest tumor homogeneity on both CT and MR images. EMP was more heterogenous than NHL, with moderate signal intensity on T1-weighted MR images. On the other hand, EMP and NHL showed significantly lower ADCs as compared to SCC. The majority of patients with sinonasal EMP, NHL, and SCC showed an avid enhancement. Also, destructive tumor growth involving the adjacent bone was more frequent in SCC than in EMP or NHL. However, there were no significant differences among sinonasal EMP, NHL, and SCC in terms of invasion to Waldeyer’s ring and cervical or retropharyngeal lymph node metastasis.

 Marked heterogeneity on T1-weighted images, low ADCs, and lack of adjacent bone destruction were the CT and MR imaging features that favored the diagnosis of EMP over NHL or SCC.

 Sonoelastography is extensively used for clinical diagnosis. Different types of elastography can be used to assess the elastic properties (stiffness) of tissues. For quantitative analyses, shear wave elastography (SWE) has been applied as a non-invasive method in the past decade. Today, SWE is widely used for diagnosing diseases. However, a limited number of studies have investigated musculoskeletal injuries and neoplastic diseases.

 This study aimed to evaluate the postoperative functional recovery of Achilles tendon ruptures by SWE to determine the Achilles tendon function and provide reliable evidence for clinicians.

 SWE was used to measure elasticity in 67 patients with Achilles tendon ruptures. In the postoperative stage, 17 patients were lost to follow-up. The remaining 50 patients with Achilles tendon ruptures were examined. Each patient was followed-up for one, three, and six months postoperatively. The 0° flexion of the ankle joint was considered as the standard position. The mean elasticity (Emean) of the Achilles tendon was measured and recorded at different time points before and after surgery. Besides, the thickness and width of the Achilles tendon were measured at the corresponding time points.

 The mean elasticity (Emean) of normal and ruptured Achilles tendons was 447.4 ± 59.57 and 63.84 ± 45.18 kPa, respectively in 50 patients with ruptured Achilles tendons before surgery. On the other hand, the Emean values of ruptured Achilles tendons in one-, three-, and six-month follow-ups were 110.3 ± 35.60, 183.4 ± 46.08, and 279.1 ± 48.18 kPa in 50 patients, respectively. Regarding the Emean, the difference between the five time points was significant (F = 418.5, P < 0.01). With prolongation of postoperative recovery, the Emean of the Achilles tendon gradually increased; the Emean value significantly increased at six months after surgery.

 The quantitative analysis of the postoperative function of Achilles tendon, based on the Emean value obtained by SWE, can be helpful in guiding clinicians to objectively examine the prognosis of patients.

 To evaluate the prognostic value of chest computed tomography (CT) imaging features in patients with coronavirus disease 2019 (COVID-19) pneumonia.

 In this cross-sectional study, 201 patients with COVID-19 were enrolled consecutively. The patients’ chest CT scans were analyzed, and the disease severity was rated using two

(1) total lung involvement (TLI) in which each lobe is scored from 0 to 4 based on the percentage of involvement; and (2) modified TLI in which each lobe involvement score is multiplied by the number of its segments, and the sum is recorded as the modified TLI. The patients were categorized into four groups depending on their prognosis (patients admitted to hospital wards, patients admitted to intensive care units (ICUs), patients with intubation during hospitalization, and expired patients). The relationship between both scoring methods and the clinical outcomes of patients was examined in the four groups.

 The receiver operating characteristic (ROC) curve analysis showed no significant difference between the two scoring methods (TLI and modified TLI) in predicting the patients’ prognosis. The average disease severity based on the two scoring methods was significantly different between the four groups. Patients who were intubated during hospitalization and patients who expired had significantly higher scores than patients admitted to the ICUs and hospital wards (P = 0.001). The area under the ROC curve for the prediction of mortality was 0.81 (95% CI: 0.72 - 0.90; P < 0.001); the TLI score of 18.5 could predict mortality with specificity of > 95%.

 The TLI scoring system can be used for predicting in-hospital mortality and ICU admission in COVID-19 patients. This scoring method can help us devise a better strategic healthcare plan during the COVID-19 pandemic.

 Temporal lobe epilepsy (TLE) is the most common form of focal seizures. To localize the epileptic site for surgery, different neuroimaging tools are used. Perfusion magnetic resonance imaging (MRI) is one of the modalities used to evaluate the cerebral hemodynamics and localize intracranial neoplasia and cerebrovascular events. Two contrast-based perfusion imaging sequences are described, including dynamic susceptibility contrast-enhanced MRI (DSC-MRI) and dynamic contrast-enhanced MRI (DCE-MRI). The most commonly measured parameters include the relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), and mean transit time (MTT).

 This study aimed to evaluate the blood perfusion parameters, such as rCBV and rCBF, in patients diagnosed with mesial temporal lobe epilepsy (MTLE), using DSC-perfusion MRI to determine whether there is a change in these parameters and if this modality can be used to diagnose and localize the epileptic side.

 Twenty-two patients, who were diagnosed with TLE clinically and electrophysiologically by a neurologist, were investigated in this study. The patients were examined for the presence of any other lesions, such as tumors or cerebrovascular disease as the exclusion criteria. Perfusion images were processed by the Siemens perfusion software, and the rCBV and rCBF maps were generated based on the gamma variate fit. For qualitative analysis, coronal reconstruction of rCBV and rCBF maps was performed. For quantitative analysis, a single neuroradiologist placed the region of interest (ROI) on the hippocampus and the parahippocampal gyrus on T1W images at the same level of DSC images. After determining the CBV and CBF values relative to the ROI of each side, the asymmetry index (AI) was calculated.

 In patients with unilateral epilepsy, the blood perfusion parameters in the ipsilateral side of the brain were significantly lower than the contralateral side (P < 0.0001); the mean values of both parameters were significantly lower in the affected side as compared to the opposite side.

 In patients with TLE, significantly lower blood perfusion parameters in the affected side of the brain can help radiologists and neurologists to lateralize the MTLE side.

Inferior epigastric artery (IEA) pseudoaneurysms are well-known postoperative abdominal complications, which often require proper treatment. Treatment options include surgical ligation, transcatheter embolization, and thrombin injection. Here, we report a rare case of an IEA pseudoaneurysm, accompanied by a postsurgical enterocutaneous fistula. The pseudoaneurysm relapsed after transcatheter coil embolization and percutaneous thrombin injection; it was completely occluded by transcatheter arterial embolization using n-butyl-2-cyanoacrylate. The present case shows that a coexisting enterocutaneous fistula can affect the unresponsiveness of patients with IEA pseudoaneurysm to widely accepted treatments, such as coil embolization and thrombin injection, by creating an inflammatory environment. In such cases, repeated therapeutic trials may be required. Transcatheter arterial embolization using n-butyl-2-cyanoacrylate can be a feasible therapeutic option for patients with refractory IEA pseudoaneurysm, accompanied by an enterocutaneous fistula.

The outbreak of coronavirus disease 2019 (COVID-19) has become a major threat to all humans.

To assess the association between the patients’ clinical and laboratory records, CT findings, and epidemiological features of COVID-19 with the severity of the disease.

In this retrospective case-control study conducted on themedical records of confirmed COVID-19 pneumonia patients on admission, we investigated the CT manifestations and clinical and laboratory risk factors for progression to severe COVID-19 pneumonia. The medical records and radiological CT features of confirmed COVID-19 patients were reviewed in one public hospital and one respiratory clinic in Qom, Iran, from August 1 to September 30, 2020.

Of 236 confirmed COVID-19 cases, 62 were infected with moderate to severe COVID-19 and required hospital admission, and 174 were followed-up on an outpatient basis. A significant difference was found in the mean age of the outpatient and hospitalized groups. The incidence of bilateral lung involvement, consolidations, linear opacities, crazy-paving pattern, air bronchogram, and number of lobes involved were significantly higher in the hospitalized group compared to the outpatient group. However, the crazy-paving pattern was only significantly associated with an oxygen saturation (SpO2) level < 90% and, coughing. Our findings indicated that the crazy-paving pattern was significantly associated with the inflammatory phase. The presence of this pattern on admission, SpO2 < 90%, older age, and diabetes were independent risk factors for progression to severe COVID-19.

The crazy-paving pattern can predict the severity of COVID-19, which is of great importance in the management and follow-up of COVID-19 pneumonia patients. Clinical factors, such as aging, male gender, and diabetes, may be risk factors for the crazy-paving pattern. Severe cough is the most important clinical sign related to this pattern, along with an SpO2 < 90%, which is an important sign of COVID-19 severity

Computed tomography (CT)-guided ablation has been used to treat adrenal metastasis (AM). However, the incidence of AM secondary to non-small-cell lung cancer (NSCLC) has not been investigated.

To assess the clinical efficacy of CT-guided cryoablation for treating AM secondary to NSCLC.

This retrospective study was performed among patients with AM secondary to NSCLC, undergoing CT-guided cryoablation in our hospital. The rates of complete ablation, local recurrence, local recurrence-free survival (RFS), systematic RFS, and overall survival (OS) were also analyzed.

Thirty-four consecutive patients with AM secondary to NSCLC (16 cases of squamous cell carcinoma [SCC] and 18 cases of adenocarcinoma) underwent cryoablation in our hospital. The primary complete ablation rates were 93.8% and 88.9% in the SCC and adenocarcinoma groups, respectively (P = 1.000). Moderate blood pressure increases were observed in 7/34 (20.6%) patients during cryoablation. The local recurrence of AM was observed in five and three patients in the SCC and adenocarcinoma groups, respectively (P = 0.551). The median local RFS was 22 months in all patients, and there was no significant difference in terms of the local RFS between the SCC and adenocarcinoma groups (38 vs. 17 months) (P = 0.093). The median systematic RFS was 28 months in all patients, and the systematic RFS was significantly longer in the SCC group as compared to the adenocarcinoma group (56 vs. 19 months) (P = 0.001). The median OS was 34 months in all patients; it was significantly higher in the SCC group as compared to the adenocarcinoma group (56 vs. 22 months) (P = 0.009).

CT-guided cryoablation can be a safe and effective treatment to control AM secondary to NSCLC.

Medulloblastoma with extensive nodularity (MBEN) is a rare histological subtype of medulloblastomas in very young children. It is characterized by an aggressive grape-like appearance and favorable outcomes. Herein, we report the case of a nine-month-old patient with MBEN, associated with an activated sonic hedgehog (SHH), with rare multimodal magnetic resonance imaging (MRI) features. Conventional MRI findings indicated the dense homogeneous enhancement of a large unusual gyriform mass in the cerebellar vermis and both cerebellar hemispheres. The mass showed restricted diffusion on diffusion-weighted images, low concentrations of taurine on MR spectroscopy, and a relatively low cerebral blood volume on dynamic susceptibility contrast (DSC) MR perfusion image. The patient underwent partial tumor resection, chemotherapy, and autologous blood stem cell transplantation. After treatment, the lesion rapidly regressed in the serial follow-up imaging without recurrence.

 Intrauterine growth restriction (IUGR) is a major factor in long-term perinatal morbidity and is associated with abnormal fetal brain development; however, its pattern of brain involvement remains unknown.

 This study aimed to investigate the effect of IUGR on the brain parenchyma.

 Forty-two women with IUGR pregnancy and 28 women with normally grown fetuses at 28 - 38 weeks of pregnancy underwent 3-tesla magnetic resonance imaging (MRI). Cortical thickness was assessed in four regions and corrected by the biparietal diameter/2. Also, the whole brain surface area (WBA) was measured, and the areas of six brain regions were calculated and corrected by WBA.

 In the IUGR group, the cortical thickness in the insula and temporal lobe was significantly thinner than the control group (0.034 vs. 0.043 and 0.036 vs. 0.047, respectively; P < 0.05); these fetuses also showed significantly reduced WBA (P = 0.028). The corrected brain areas were not significantly different between the groups, except for the corrected areas of the cerebellum and the hippocampus, which increased in the IUGR group as compared to the control group (0.147 vs. 0.130 and 0.017 vs. 0.0125, respectively; P < 0.05).

 In the IUGR fetuses, significantly thinner insular cortex and temporal lobe cortex and smaller WBA were found compared to the control group. Among different brain regions, the cerebellum and the hippocampus were less affected by growth restriction in the antenatal period.

 The association between chronic nephrolithiasis and several systemic conditions has been established in previous studies. Patients with recurrent urinary stones generally experience more urinary calcium loss, resulting in a lower bone mineral density (BMD). Dual-energy X-ray absorptiometry (DEXA) is the standard imaging method for diagnosing a low BMD. However, imaging imposes significant cost and radiation burden on patients.

 We aimed to assess the relationship between 24-hour urinalysis biometrics and bone mineral content, retrieved from non-contrast computed tomography (CT) imaging, which is routinely preformed for urinary stone patients as a primary evaluation.

 The sample population for this retrospective study included urinary stone patients, undergoing percutaneous nephrolithotomy (PCNL) during 2015-2019, with available 24-hour urinalysis and CT imaging records. Stone size was defined as the maximum stone diameter on the CT image. BMD for each subject was also calculated at the vertebral L1 level, with CT attenuation measured in Hounsfield units (HU). According to the literature, a cutoff value of 160 HU was selected to distinguish normal BMD from low BMD.

 The present results showed a significant association between the stone size and BMD (P < 0.05). Moreover, patients with a low BMD had a higher urinary calcium excretion in the 24-hour urinalysis (P < 0.05). Evaluation of urine chemical composition and stone size demonstrated a significant association between hypercalciuria and urinary stone volume (P < 0.05).

 A low BMD detected by CT imaging in patients with urinary stones is associated with abnormal 24-hour urinalysis biometrics and larger stones; therefore, it should be properly assessed.