Diagnostic tool for initial evaluation of the intracranial pressure on computed tomography in pediatric patients with headache.

BACKGROUND: Headache is one of the most common complaints among pediatric patients and can be due to many causes, some benign but others potentially seriously. Increased intracranial pressure, which is known to cause papilledema, is a serious cause of headache, and immediate diagnosis is critical, although difficult. The current study evaluates the diagnostic value of optic nerve sheath diameter (ONSD) and eyeball transverse diameter (ETD) ratio in pediatric patients presenting with headache and papilledema. METHODS: A retrospective analysis of all pediatric patients undergoing head computed tomography scans between January 2013 and December 2015. Patients with normal brain scans were included in the study. Patients presenting with headache underwent funduscopic evaluation and grouped as either headache with papilledema or headache without papilledema. A control group of patients without headache was also included. Studies were reviewed blindly by a neuroradiologist and ONSD and ETD for both eyes were measured. RESULTS: ONSD/ETD index was found to have significantly higher values (p<0.001) in patients with papilledema (median 0.24, interquartile range (IQR) = 0.22-0.25) compared to patients without papilledema (median 0.18, IQR = 0.16-0.19) and the control group (median 0.17, IQR = 0.15-0.18). The ONSD/ETD index showed excellent discrimination ability for patients with headache and papilledema (AUC = 0.96, 95% CI, 0.94-0.99). The ONSD/ETD index of 0.21 was found to have a sensitivity and specificity of 82% and 93%, respectively, for identifying pediatric patients with headache and papilledema. CONCLUSION: Our study shows that ONSD/ETD index of 0.21 can be used as an easy-to-use reference tool for diagnosing papilledema and elevated intracranial pressure in pediatric patients.

Evaluation and management of thyroid incidentalomas detected prior to the parathyroid surgery.

BACKGROUND: We investigated the management of thyroid incidentalomas associated with cases of parathyroid lesions in order to suggest a practical approach to their management from a surgical point of view. METHODS: 639 patients underwent radiological and ultrasound investigation of the thyroid area because of parathyroid disorders and parathyroidectomy and had at least three years of follow-up. All follow-up data for these cases were investigated from the moment the lesion was detected and up to the last report. RESULTS: Out of 639 cases, incidental or asymptomatic thyroid nodules were found in 179 patients (28%), of which, 22 patients were operated (parathyroidectomy + thyroidectomy) and 157 remained with the nodules. For these patients, the average period of follow-up was 7 years 5 mo. Following the results of the follow-up, 52 patients (33%) were suggested to have surgery of the thyroid gland and 49 were operated (16 total thyroidectomies and 33 hemithyroidectomies). The complications after the second surgery included recurrent laryngeal nerve palsy (n = 3), superior laryngeal nerve palsy (n = 1), permanent hypocalcaemia (n = 8), and surgical damage to the internal jugular vein (n = 1). All complications occurred at the previously operated side of the neck. CONCLUSION: While surgery remains the management of choice for malignant thyroid incidentalomas, for benign cases, if an asymptomatic thyroid nodule was detected inside the thyroid lobe on the side of planned parathyroidectomy and if the size of the nodule is ˃1.5 cm we suggest combined parathyroidectomy + hemithyroidectomy.

Surgical approach to the intrathoracic goiter.

OBJECTIVE: In a retrospective study, the authors analyzed the surgical approach to the intrathoracic goiter to avoid sternotomy or thoracotomy. METHODS: We selected 70 intrathoracic cases of multinodular goiter out of 988 cases of thyroidectomy and compared them with cervical goiter cases. Surgical technique, results, and postsurgical complications were assessed. RESULTS: The analyzed cases presented the retrosternal goiter (n = 53; 75.7%), the retrotracheal goiter (n = 9; 12.8%), and the retroesophageal goiter (n = 8; 11.4%). Complaining of chest pressure or discomfort was specific for intrathoracic cases (50%; 35 of 70). All goiters except one were removed via cervical incision. The surgeons used head reclination and isthmus dissection when removing sizable goiters. Mean weight of goiters was 180 g. The recurrent laryngeal nerve was more often temporarily damaged in intrathoracic cases in comparison with cervical cases (4.3% vs. 2.8%, P = .04), but the difference in permanent injury was less significant (P = .09). The incidence of temporary hypoparathyroidism was significantly higher in intrathoracic cases (P = .01). CONCLUSION: In cases of multinodular goiter the goiters of various extensions can be successfully removed via the cervical incision in most of the cases even if they occupy the retrosternal, retrotracheal, or retroesophageal position. The transthoracic approaches and sternotomy might be justified in malignant cases. LEVEL OF EVIDENCE: 4.

MRI measurements of the normal pediatric optic nerve pathway.

The purpose of this work is to establish a reference scale of optic nerve pathway measurements in pediatric patients according to age using MRI. Optic nerve pathway measurements were retrospectively analyzed using an orbits equivalent sequence on brain MRI scans of 137 pediatric patients (72 male, 65 female, average age = 7.7 years, standard deviation  = 5.3). The examinations were performed on a 1.5-T or 3-T Siemens MR system using routine imaging protocols. Measurements include diameters of the orbital optic nerves (OON), prechiasmatic optic nerves (PON), optic tracts (OT), and optic chiasm (OC). Measurements were performed manually by 2 neuroradiologists, using post-processing software. Patients were stratified into five age groups for measurement analyses: (I) 0-1.49 years, (II) 1.5-2.99 years, (III) 3-5.99 years, (IV) 6-11.99 years, and (V) 12-18 years. The observed value range of OON mean diameter was 2.7 mm (Interquartile range (IQR) = 2.4-2.9), PON was 3.2 mm (IQR  =  3.05-3.5), OT 2.6 mm (IQR = 2-2.9). A strong positive correlation was established between age and mean diameter of OON (r = 0.73, p < .001), PON (r = 0.59, p < .001), and OT (r = 0.72, p < .001). A significant difference in mean OON diameters was found between age groups I-II (d = 0.3, p = .01), II-III (d = 0.5, p < .001), III-IV (d = 0.5, p < .001) followed by a plateau between IV-V (d = 0.l0, p = .19). OON/OT ratio maintained a steady mean value 1 (IQR = 0.93-1.1) regardless of age (p = .7). The diameter of optic pathways was found to increase as a function of age with consistent positive correlation between nerve and tract for all ages.

Anatomical approach to surgery for intrathoracic goiter.

The anatomical approach to the intrathoracic goiter (ITG) was used to understand its etiology and to rationalize surgical technique of thyroidectomy. For a retrospective chart review, we selected cases of multinodular goiter with totally ITGs (n = 69; M 29, F 40), while 916 cases with cervical goiter were used for comparison. The topography of the thyroid gland was assessed against the tracheal rings and against the vertebrae. The regional anatomy of the thoracic inlet was assessed by its bony margins and the relations of structures traversing the area. Average tracheal-diameter-to-thoracic-inlet ratio was calculated. The ITG group consisted of 52 cases of retrosternal goiter (75.4 %), nine cases of retrotracheal goiter (13 %), and eight cases of retroesophageal goiter (11.6 %). In all but one analyzed cases, the goiters were removed via cervical incision. Mean weight of goiters was 183 g. The area of thoracic inlet in the cases of ITG had no difference in comparison with the cases of cervical goiter (F/M p = 0.11/0.15), but the tracheal-diameter-to-thoracic-inlet ratio was significantly smaller (F/M p = 0.06/0.04). In the ITG cases, the position of the upper edge of the isthmus of the thyroid was about 1.5 tracheal rings lower than in healthy individuals (p = 0.03). The area of the thoracic inlet, the neck size, and the anteroposterior diameter of the inlet do not affect the development of the ITG. The smaller tracheal-diameter-to-thoracic-inlet ratio and the lower position of the thyroid gland are the main indicators for the development of the ITG.

Diagnostic value of neuro-ophthalmological signs in cases of Chiari I malformation.

INTRODUCTION: Our purpose was to evaluate the diagnostic value of measuring diameters of optic nerve sheath (ONSD), presence/absence of papilledema, tortuosity of the optic nerve, flattening of the posterior sclera, and intraocular protrusion of the prelaminar optic nerve for intracranial pressure assessment in cases of Chiari I malformation. METHODS: In a retrospective study, MRI data of 37 consecutive pediatric patients with Chiari malformation and data of 400 patients without intracranial pathology were compared and analyzed. ONSDs were measured at the point where the ophthalmic artery crosses the optic nerve (anatomical landmark). The correlation analysis was performed with clinical findings, gender, age, papilledema, and other neuro-ophthalmological findings. RESULTS: ONSD was enlarged in 38 % of cases of Chiari malformation. The enlargement was bilateral, no correlation with age or gender was found (p = 0.67 and p = 0.76, respectively). The presence of papilledema was detected in 19 % of cases presenting less valuable diagnostic sign if compared with ONSD. The tortuosity of the optic nerve was found in 22 % of cases, but in three patients, it was unilateral. All patients with enlarged ONSD and other neuro-ophthalmological signs present were treated surgically, while most of the patients without these signs (20/23) were treated conservatively. CONCLUSION: In majority of pediatric cases of Chiari malformation, the ONSD is not enlarged and other neuro-ophthalmological signs are not present. Detecting the enlarged ONSD and other neuro-ophthalmological signs in cases of Chiari malformation may indicate the elevated intracranial pressure and necessity for urgent surgical intervention.

The quantitative evaluation of intracranial pressure by optic nerve sheath diameter/eye diameter CT measurement.

BACKGROUND: The changes of the optic nerve sheath diameter (ONSD) have been used to assess changes of the intracranial pressure for 20 years. The aim of this research was to further quantify the technique of measuring the ONSD for this purpose. METHODS: Retrospective study of computed tomographic (CT) data of 1766 adult patients with intracranial hypotension (n=134) or hypertension (n=1632) were analyzed. The eyeball transverse diameter (ETD) and ONSD were obtained bilaterally, and the ONSD/ETD ratio was calculated. The ratio was used to calculate the normal ONSD for patients and to estimate the intracranial pressure of the patients before and after the onset of the pathology. Correlation analysis was performed with invasively measured intracranial pressure, the presence or absence of papilledema, sex, and age. RESULTS: In hypotension cases, the ONSD by CT was 3.4±0.7 mm (P=.03 against normative 4.4±0.8 mm). In cases with hypertension, the diameter was 6.9±1.3 (P=.02, with a cutoff value ˃5.5 mm). The ONSD/ETD ratio was 0.29±0.04 against 0.19±0.02 in healthy adults (P=.01). CONCLUSION: The ONSD and the ONSD/ETD ratio can indicate low intracranial pressure, but quantification is impossible at intracranial pressure less than 13 mm Hg. In elevated intracranial pressure, the ONSD and the ratio provide readings that correspond to readings in millimeters of mercury. The ONSD method, reinforced with additional calculations, may help to indicate a raised intracranial pressure, evaluate its severity quantitatively, and establish quantitative goals for treatment of intracranial hypertension, but the limitations of the method are to be taken into account.

Noninvasive assessment of the intracranial pressure in non-traumatic intracranial hemorrhage.

The article describes the modified technique of measuring the diameters of the optic nerve sheath (ONSD) for assessment of the intracranial pressure (ICP) in patients with intracerebral or subarachnoid hemorrhage (SAH). The CT scans of 443 patients were analyzed retrospectively. The ONSDs were measured at 3mm behind the globe and at the point where the ophthalmic artery crosses the optic nerve. The ONSD/eyeball transverse diameter (ETD) ratio was calculated. The correlation analysis was performed with the Glasgow Coma Scale score, Hemispheric Stroke Scale score, Glasgow Outcome Score, and invasive ICP readings. ONSD was enlarged in 95% of patients with intracerebral hemorrhage or SAH. Pathological ONSDs were 6.6±0.8mm (cut-off value >5.5mm; p<0.05). ONSD/ETD ratio was 0.29±0.05 against normative 0.19±0.02 (p<0.01) with no correlation with initial Glasgow Coma Scale score or Hemispheric Stroke Scale score. There was an inverse correlation between ONSD/ETD ratio and Glasgow Outcome Score (r=-0.7) and direct correlation with invasive ICP readings. This study provides further evidence that in patients with intracranial hemorrhage and SAH, the presence of ONSD greater than a threshold of 5.5mm is significantly predictive of invasively measured elevated ICP. The prediction of raised ICP can be further refined by measuring ONSD at the point where the optic nerve and the ophthalmic artery cross, and by determining the ratio between the ONSD and ETD.

Initial evaluation of the intracranial pressure in cases of traumatic brain injury without hemorrhage.

Our objective was to apply the technique of measuring diameters of optic nerve sheath (ONSD) for the intracranial pressure assessment for the cases with traumatic head injury without hemorrhage. In a retrospective study, CT data of 720 adult patients were collected and analyzed. ONSDs were measured at the point where the ophthalmic artery crosses the optic nerve (anatomical landmark) together with the eyeball transverse diameter (ETD). The ONSD/ETD index was calculated. The correlation analysis was performed with gender, age, the Glasgow Coma Scale score, and the Glasgow Outcome Score. ONSD was enlarged in 82% cases (n=591). Enlarged right/left ONSDs were 6.7±1.0/6.7±0.9mm (cut-off value˃5.5mm). ONSD/ETD ratio was 0.28±0.05 against 0.19±0.02 in healthy adults (p=0.02). We did not find correlation between ONSD/ETD ratio with initial Glasgow Coma Scale score but there was an inverse correlation between ONSD/ETD ratio and the Glasgow Outcome Score (r=-0.64). We conclude that in majority of cases with traumatic head injury without hemorrhage the ONSD is significantly enlarged indicating elevated intracranial pressure even if CT scans are negative.

Diagnostic value of the optic nerve sheath diameter in pseudotumor cerebri.

If persistent severe headache remains the only complaint of a patient, then the diagnosis of pseudotumor cerebri (PTC) can be delayed because in such cases practitioners are hesitant to immediately apply invasive intracranial pressure (ICP) measurement. Our purpose was to apply the technique of measuring diameters of the optic nerve sheath (ONSD) as a diagnostic tool in cases of PTC. Our aim was to provide practitioners with an additional sign to speed up their decision making about implementation of the lumbar puncture. In a retrospective study, CT scan data of 35 consecutive adult patients with PTC were collected and analyzed. ONSD were measured at the point where the ophthalmic artery crosses the optic nerve (anatomical landmark). The correlation analysis was performed with sex, age, and neuro-ophthalmological findings. We found that the ONSD was enlarged in 94.3% of patients with PTC. The enlarged ONSD were 6.2±1.2mm for the right and 6.3±0.9mm for the left (cut-off value >5.5mm). The enlargement was bilateral, and no correlation with age or sex was found (p=0.67 and p=0.76, respectively). Presence of papilledema was detected in 91.4% of patients (32/35) presenting as a slightly less valuable diagnostic sign compared with ONSD. We conclude that in the majority of cases of PTC the ONSD is significantly enlarged, indicating elevated ICP even if CT scans are negative. Implementing this ONSD method as a diagnostic tool in cases of suspected PTC may help in early accurate diagnosis, avoiding misdiagnosis, and providing appropriate early treatment.

Intracranial Pressure Assessment in Traumatic Head Injury with Hemorrhage Via Optic Nerve Sheath Diameter.

Our purpose was to improve the technique of measuring optic nerve sheath diameter (ONSD) for intracranial pressure (ICP) monitoring in cases of traumatic head injury with hemorrhage. In a retrospective study, computed tomography (CT) data of 312 adult patients were collected and analyzed. ONSDs were measured at 3 mm and 8-10 mm distance from the globe together with the eyeball transverse diameter (ETD). The ONSD/ETD ratio was calculated. The correlation analysis was performed with gender, age, Glasgow Coma Scale score, and Glasgow Outcome Score. ONSD was enlarged in all cases when CT scans indicated hematoma. Enlarged right/left ONSDs were 6.5 ± 1.5/6.4 ± 1.3 mm at 3 mm and 6.6 ± 0.8/6.6 ± 0.6 mm at 8-10 mm from the globe (cut-off value > 5.5 mm). ONSD/ETD ratio was 0.29 ± 0.05, compared with 0.19 ± 0.02 in healthy adults (p < 0.01). We did not find a correlation between ONSD/ETD ratio and initial Glasgow Coma Scale score, but there was an inverse correlation between ONSD/ETD ratio and Glasgow Outcome Score (r = -0.83). We conclude that in cases with a traumatic head injury with hemorrhage, the ONSD is significantly enlarged, indicating elevated ICP. In ICP assessment, the most accurate results can be obtained if the ONSD is measured 8-10 mm from the globe and the ONSD/ETD ratio is calculated.

Correlation between preoperative predictions and surgical findings in the parotid surgery for tumors.

BACKGROUND: To compare preoperative CT/MRI based predictions with real surgical findings for deep lobe parotid gland surgery. METHODS: The study analyzed 122 parotidectomies (2004-2014) for benign tumor removal. The facial nerve, the Utrecht line, the Conn's arc, and the retromandibular vein were used as landmarks for CT/MRI presurgical evaluation of patients. We assessed 106 CT images and 86 MRI images. The study compared preoperative evaluation of tumor location with its actual location that was revealed during the operation and assessed the importance of the landmarks. RESULTS: In general, the agreement between preoperative CT prediction and actual location of the parotid tumors was achieved in 88.7 % (n = 94/106) when facial nerve line was used as a landmark. However, out of 14 tumors in the deep lobe only 5 were located correctly (35.7 %). Of the other existing CT landmarks, none showed more precision over others. The agreement between MRI based prediction and surgical results on actual location of the tumor was achieved in 94.2 %. Out of 12 MRI-investigated tumors in the deep lobe nine were located correctly that gives 75 % agreement with surgical results. CONCLUSION: Our data suggests that no existing CT landmark can be accepted as completely reliable in cases when selective deep lobe parotidectomy is planned. If tumor location is suspected in the deep lobe of the gland, MRI imaging is necessary to confirm the diagnosis. An operating surgeon should be prepared that in some cases the true location of the tumor would be revealed only during surgery.

Monitoring of Intracranial Pressure by CT-Defined Optic Nerve Sheath Diameter.

BACKGROUND AND PURPOSE: Intracranial pressure (ICP) can be monitored by the optic nerve sheath diameter (ONSD) technique. We hypothesized that diameter of the optic canal (OC) can be a limiting factor for this technique. METHODS: In the prospective cohort study, we analyzed CT scans of 600 OCs of healthy adults and 54 canals of patients with ICP monitoring. The diameters were measured through its length and the narrowest one was chosen for further analysis. ONSD was measured at 3 and 10 mm from the anterior opening of the canal. The correlation analysis was performed between invasive and ONSD methods of ICP monitoring and OC diameters in pathological cases. RESULTS: The narrowest cross-sectional area of the normal OC was 13.85±2.89 mm² and varied from 25.5 to 6.6 mm². Apparently 9.17% OCs were narrow (˂10.9 mm²). Correlations exist between the optic nerve sheath area at the 3-mm distance from the anterior opening of the canal and the area of the anterior opening itself (P = .012), and the sheath area 10 mm from the anterior opening and the narrowest part of the canal (P = .015). Cases with narrow canals provided false-negative readings via ONSD method if compared with invasive monitoring. CONCLUSION: In its narrowest part, the average OC is 11 to 16.75 mm² wide. We suggest measuring this area simultaneously with the ONSD during ICP monitoring. If the area of the narrowest lumen of the canal is less than 10 mm², ONSD technique for ICP monitoring should not be used.

Optic nerve sheath diameters in healthy adults measured by computer tomography.

AIM: To measure optic nerve sheath diameters (ONSD) in different locations by computer tomography (CT) and to recommend the best location for cases when ONSD is used for intracranial pressure monitoring. METHODS: In a prospective cohort study, CT data of 300 healthy adults were analyzed (600 eyes). In all cases, the CT investigation was performed at the Emergency Department because of the various conditions that proved not to be connected with ophthalmological or neurological pathology. The ONSD were measured at 3 mm and 8 mm distance from the globe, and 3 mm from the anterior opening of the optic canal. The correlation analysis was performed with gender, age, and ethnic background. RESULTS: The right/left ONSD are 4.94±1.51/5.17±1.34 mm at 3 mm, 4.35±0.76/4.45±0.62 mm at 8 mm from the globe, and 3.55±0.82/3.65±0.7 mm at 3 mm from the optic canal. No significant differences correlated with gender of the patients, their age, and ethnic background were found. CONCLUSION: In healthy persons, the ONSD varies from 5.17±1.34 mm to 3.55±0.82 mm in different locations within the intraorbital space. The most stable results with lesser standard deviation can be obtained if it is measured 8-10 mm from the globe.

Preoperative detection of anomalies of carotid arteries in the neck surgery.

The aim of this study was to examine the course of the carotid artery (CA) and define CA anomalies important for neck surgery using conventional and three-dimensional computer tomography (3D CT). This was designed as an observational study with retrospective CT and 3D CT angiography analysis. 4,000 CAs depicted on 2,000 CT angiographies were analyzed to determine the relationship of common, internal, and external portions of the CA to the neck organs, with special emphasis on the thyroid gland area and organs involved in the neck dissection surgery. A total of 47 out of 4,000 imaged CAs had congenital anomalies (1.18%). These anomalies were found in 45 patients, unilaterally in 33 and bilaterally in two. The level of the common CA bifurcation to internal and external CAs was rarely abnormal. It was at the level of C5 and C6 in two cases only (0.05%). The common CA, either aberrant or tortuous, ran abnormally close to the thyroid gland in 22 cases (0.55%). In planning neck dissection surgery, laryngectomy, or thyroidectomy, the surgeon should bear in mind that CA anomalies are present in approximately 1.2% of cases. Preoperative conventional CT angiography or 3D CT allows precise identification of anomalous CAs, thereby reducing the possible risk of intraoperative injury.

Variations in eyeball diameters of the healthy adults.

The purpose of the current research was to reevaluate the normative data on the eyeball diameters. Methods. In a prospective cohort study, the CT data of consecutive 250 adults with healthy eyes were collected and analyzed, and sagittal, transverse, and axial diameters of both eyeballs were measured. The data obtained from the left eye and from the right eye were compared. The correlation analysis was performed with the following variables: orbit size, gender, age, and ethnic background. Results. We did not find statistically significant differences correlated with gender of the patients and their age. The right eyeball was slightly smaller than the left one but this difference was statistically insignificant (P = 0.17). We did not find statistically significant differences of the eyeball sizes among the ethnicities we dealt with. Strong correlation was found between the transverse diameter and the width of the orbit (r = 0.88). Conclusion. The size of a human adult eye is approximately 24.2 mm (transverse) × 23.7 mm (sagittal) × 22.0-24.8 mm (axial) with no significant difference between sexes and age groups. In the transverse diameter, the eyeball size may vary from 21 mm to 27 mm. These data might be useful in ophthalmological, oculoplastic, and neurological practice.

Quantitative relations between the eyeball, the optic nerve, and the optic canal important for intracranial pressure monitoring.

OBJECTIVE: To find correlations between diameters of the optic nerve sheath (ONSD), the eyeball, and the optic canal that might be important for intracranial pressure monitoring. METHODS: In a prospective cohort study, the CT data of consecutive 400 adults (18+) with healthy eyes and optic nerves and absence of neurological diseases were collected and analyzed. When the CT scans were obtained, the diameters of the optic nerve sheath, the eyeball, and the optic canal were measured and statistically analyzed. The data obtained from the left and from the right eyeballs and optic nerves were compared. The correlation analysis was performed within these variables, with the gender, and the age. RESULTS: In healthy persons, the ONSD varies from 3.65 mm to 5.17 mm in different locations within the intraorbital space with no significant difference between sexes and age groups. There is a strong correlation between the eyeball transverse diameter (ETD) and ONSD that can be presented as ONSD/ETD index. In healthy subjects, the ONSD/ETD index equals 0.19. CONCLUSION: The calculation of an index when ONSD is divided by the ETD of the eyeball presents precise normative database for ONSD intracranial pressure measurement technique. When the ONSD is measured for intracranial pressure monitoring, the most stable results can be obtained if the diameter is measured 10 mm from the globe. These data might serve as a normative database at emergency departments and in general neurological practice.

3D computer-assisted assessment of complicated penetrating foreign bodies cases in ENT practice.

A retrospective research was performed in order to evaluate three-dimensional (3D) computer-assisted detection of penetrating foreign bodies (FB) in the ENT practice in order to assess its usefulness and to specify its application. FBs in the head and neck were detected using 3D CT imaging in order to assess the usefulness of 3D images in the ENT operative practice. Three blinded surgeons were involved in comparison between plain and 3D CT images in order to assess 3D usefulness for precise formulation of a surgical plan. The observed relationship of the FBs to anatomical structures of the ethmoidal sinuses, eye orbit, and neck tissues was found instrumental for surgeon's decision making in planning the approach to operative removal of the FB. It helps to understand the relationships between a FB and surrounding anatomical structures better then the plain X-rays or CT-scan. There was no significant difference in cost between plain CT and 3D images. 3D computer-assisted detection of FBs increase our diagnostic abilities and appears to be a valuable addition to our diagnostic technique. Its main importance, however, lies in its capacity to help a surgeon plan an operation much more carefully avoiding improvisation during the operation itself.