Diagnostic value of MSCT plain scan and dual-phase enhanced scan in thymic adenocarcinoma

Objective: To evaluate the value of MSCT plain scan and enhanced CT in the diagnosis of thymic adenocarcinoma. Methods: From May 2013 to June 2018, 37 cases of MSCT plain scan and dual-phase enhanced scan of thymic adenocarcinoma were retrospectively analyzed. The location, shape, size, density (CT value), enhanced features, peripheral invasion and mediastinal lymph node metastasis of the lesions were observed. Results: All 37 cases of thymic adenocarcinoma were diagnosed by CT before operation, and all cases were diagnosed by pathology after operation as malignant tumors,including 28 cases of thoracic adenocarcinoma and 9 cases of invasive thymoma. All 28 cases of thymic adenocarcinoma were single lesion of anterior superior mediastinum. The maximum cross-section was located in the midline in 7 cases and on the mediastinal side in 21 cases with significant difference (P<0.05). All lesions were irregular lobulated. The minimum diameter of lesions was 2.1 cm and the maximum diameter was 8.6 cm. Soft tissue density was dominant in the solid part. All cases of thymic adenocarcinoma showed inhomogeneous, moderate and severe enhancement in the arterial and venous phase after enhancement. The degree of enhancement in the venous phase was higher than that in the arterial phase, and there was no enhancement in the irregular liquefied necrosis area. 26 cases had necrotic lesions, 21 cases had mediastinal lymph node metastasis, and 8 cases had invasion of adjacent pleura. 19 cases had mediastinal vessels and 0 cases had distant pleural metastases. Conclusion: MSCT plain scan combined with dual-phase enhanced CT is helpful to display the details and metastasis of thymic adenocarcinoma, improve the coincidence rate of CT diagnosis and pathological diagnosis, and reduce the misdiagnosis rate. To provide help for clinical diagnosis and treatment of thymic adenocarcinoma.

Evaluation with low-dose dual-phase helical computed tomography of patients with thyroid lesions

Background The incidence of thyroid cancer has been increasing.Our aim was to evaluate the efficacy of low-dose dualphase helical computed tomography （CT） in the characterization of thyroid lesions,and to discuss the relationship between image characteristics and their pathology.Methods One hundred and six patients with thyroid lesions underwent low-dose dual-phase helical CT after the injection of contrast material.CT scans were obtained at arterial and venous phase with delays of 25 and 65 seconds,and tube current of 60 and 120 mA,respectively.The attenuation change in the lesion between the arterial and venous phase was analyzed and categorized as ＂increased,＂ ＂decreased,＂ ＂mixed＂ or ＂no change.＂ Results Histopathologic diagnosis was obtained by surgery in 106 patients （115 lesions）.Of the 106 patients,45 had nodular goiter,5 thyroid adenoma,6 thyroiditis,and 50 papillary thyroid carcinoma （PTC） （59 lesions）.The attenuation value showed a significant difference （P ＜0.05） between the arterial and venous phase for the high attenuation area.There was statistical significant difference in terms of attenuation value in high attenuation areas at both phases and in low attenuation areas on arterial phase between nodular goiter and PTC （P ＜0.05）.However,there was no significant difference in attenuation value between adenoma and PTC.Twenty-nine cases （76.3％） of goiter manifested mixed type,3 cases （3/5） of adenoma showed decreased type,6 cases （6/6） of thyroiditis showed increased type,and 55 cases （93.2％） of PTC showed decreased type attenuation.The sensitivity,specificity for thyroid carcinoma by dual-phase CT were 94.9％ and 80.4％ respectively.The overall diagnostic accuracy for thyroid lesions by dual-phase CT was 87.8％.Conclusions The performance of dual-phase helical CT is related to the pathological structure of the lesions.The analysis of enhancement patterns by using dual-phase helical CT will be helpful in the differential diagnosis of thyroid lesions.

Acute management of symptomatic nephrolithiasis

Over half a million patients present to emergency departments and nearly 3 million patients visit healthcare providers annually due to problems associated with urolithiasis.Despite updated guidelines from the American Urological Association and European Association of Urology for the evaluation and management of nephrolithiasis,considerable variability still exists regarding treatment for acute symptomatic upper urinary tract stones.Therefore,this article will review the current evaluation and management of acute symptomatic nephrolithiasis.Initial management includes analgesia and antiemetics.Additionally,a urinalysis and creatinine are required laboratory evaluations.Acute imaging with a non-contrast computed tomography(CT)scan is the diagnostic imaging modality of choice.However,concerns over radiation exposure have led towards low-dose and even ultra-low-dose protocols for the detection of urinary calculi.Low-dose non-contrast CT scans are now standard of care for the initial diagnosis of renal colic in patients with a body mass index≤30.Medical expulsive therapy is recommended for patients with a ureteral calculus<10 mm and no signs of infection.Emergency urinary decompression is mandatory for a specific subset of patients,especially those with infection.Although limited data exists,emergency ureteroscopy or even shock wave lithotripsy may also betherapeutic options.

Assessment of the efficacy of reduced-radiation noncontrast computed tomography scan compared with the standard noncontrast computed tomography scan for detecting urolithiasis:A prospective single-center study

Background:Noncontrast computed tomography(CT)scan of the kidneys,ureter and bladder is the standard investigative modality for diagnosing and following up patients with urolithiasis.With each scan,a patient receives radiation of 18-34 mGy.Dose considerations become pertinent because of a 10%lifetime incidence rate and higher than 50%risk of recurrence,necessitating repeated imaging in the lifetime of a stone former.Hence,this study aimed to assess the sensitivity of"reduced-radiation"CT imaging by altering scan settings to lower than the"standard"norms.Materials and methods:Altogether,222 patients(255"kidney-ureter"stone-bearing units or"renal units")with urolithiasis and patients undergoing CT for other reasons with incidental findings of renal/ureteric calculi between 2017 and 2019 were included.All patients were subjected to 3 sequential scans at tube current settings of 250 mA(CT-N/Standard),100 mA(CT-100),and 50 mA(CT-50)at a constant voltage of 120 kV.Their clinicodemographic and radiological findings were recorded and assessed for significance.Results:Of the 255 renal units,117 were between 30 and 44 years of age,75%were men.Of the 255 patients,178(70.1%)reported a first stone episode and 77 had recurrence.Lower ureteric calculi were predominant(40.4%).All calculi were identified on CT-N;CT-100 failed to detect calculi in 1 patient,and CT-50 failed in 3 patients,where all calculi were<3 mm in size.Meanwhile,none were undetected among patients with obesity.The sensitivity was 99.61%for the CT-100 and 98.82%for the CT-50,which indicated a 2.5 and 5 times lower radiation and dose/length,respectively,than CT-N.Conclusions:The reduced-radiation CT scan is safe,sensitive,and accurate for the diagnosis and follow-up of patients with urolithiasis with significantly lower radiation exposures.Our study lays the foundation to accept low-dose CT in general and CT-50 in particular,as the new"standard of care,"and attempt further dose reduction without loss of diagnostic efficacy.