Keywords:
Lung, Thorax, CT, Diagnostic procedure, Infection, Inflammation
Authors:
A. L. Yu, Q. Li; Haikou/CN
DOI:
10.1594/ecr2018/C-0688
Methods and materials
This study was approved by the institutional review boards (First Affiliated Hospital of Hainan Medical College) with a waiver of informed consent.
Benign pulmonary nodules were found in 5 cases,
including 2 males and 3 females with an age range of 43-63 years old and a lesion size of 3.6-30.57 mm at the initial examination.
CT examinations were performed at slice thickness of 1-8 mm for 3 times at least and 5 times at most.
Except that 1 case of sclerosing hemangioma only had the data of 3mm thin-slice CT scan,
the other 4 cases had the data of 1-2mm thin-slice CT scan.
Three patients underwent plain and enhanced CT scans while 2 underwent plain CT scan.
Solid nodules were found in 4 cases while pure ground-glass opacity nodule in 1 case.
All the 5 patients were found with enlarged nodules during follow-up visits,
which were eventually removed.
Tuberculoma were pathologically diagnosed in 2 cases,
sclerosing pneumocytoma (sclerosing hemangioma) in 1 case,
pulmonary nodule with Cryptococcus neoformans infection in 1 case,
and granulomatous lesion in 1 case.
Nodules on axial CT lung window images were measured for all cases and compared with those measured in the previous time.
Measurement: Nodules were measured on the axial lung window on the workstation with a manual measuring tool.
Nodules should be measured on thin-slice images two times successively,
if any.
Calculation: Nodule volume: V =π /6×ab2.
In the formula,
a represents the maximum diameter of the nodule,
i.e.,
the long diameter,
and b represents the maximum transverse diameter that is vertical to the long diameter.
The modified Schwartz equation was used to calculate the doubling time[10].
Schwartz equation: VDT=[t×log2]÷log[Vt/V0].
In the equation,
t represents the interval (days) between two scans,
V0 represents the nodule volume at the initial scan,
and Vt represents the nodule volume at the subsequent scan.
If the difference between two diameters measured two times successively is only 1mm,
the measurement is considered as an error.
If the difference between two diameters is greater than or equal to 2mm or at least one diameter is greater than or equal to 2mm,
and nodules are confirmed enlarged by macroscopic examination,
the measurement is considered effective[10].