Coronal Computerized Tomography Scan Research Articles

Anterior Skull Base Analysis from Coronal and Reconstructed Computed Tomography: Radio-Anatomical Study

Endoscopic sinus and skull base Surgery has gained significant improvement widely all over the world. A computerized tomography (CT) scan provides a detailed anatomy of the skull base especially the bone framework. This study aims to analyze the fixed anatomical bony landmarks of the anterior skull base through coronal and reconstructed CT in the context of the Nepalese population and guide the surgeon to perform endoscopic sinus and skull base surgery safely. This Prospective study includes 70 Computerized Tomography scans of Paranasal sinuses. The different measurement from nasal floor to skull base was taken in coronal and reformatted sagittal CT scan. Mean, standard deviation, minimum and maximum values were analyzed using descriptive statistics. Student T-test was applied to compare between right and left side. This study includes 75 patients between 18 to 77 years. The measurement from nasal floor to the cribriform plate and ethmoidal roof in right and left side were, mean± SD (47± 4.1, 45.3±4.3, 47.9±5.1, and 49±8.5 mm) respectively. Mean Take off angle at the cribriform plate was 43.9 ±10.9°on right side and 43 ± 9.4° on the left side. The distance from the nasal spine to the skull base (mean ± SD) at nasofrontal recess, bulla ethmoidalis, and the junction of sphenoethmoid levels at right sides were 51.5 ± 4.7, 52.9 ± 4.1, and 61.2 ±4.7 little higher at left side. This study provides a detailed analysis of the anterior skull base in coronal and sagittal CT scans which helps to reduces complications.

Axial or coronal CT scan; which is more accurate in detection of open globe injury?

PurposeTo evaluate and compare the accuracy of axial versus coronal computerized tomography (CT) scan in detection of open globe injury. MethodIn this retrospective study, records of 61 patients with open and 72 patients with closed globe injury were reviewed. One experienced ophthalmologist and one neuroradiologist read the orbital CT scans and accuracy of the axial and coronal planes in detecting open globe injuries were compared. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated and compared for axial and coronal planes. ResultThe most common CT finding reported by the readers through the interpretation chart was scleral irregularity (70%), followed by dislocation of the crystalline lens (54%) and vitreous hemorrhage (51%). The sensitivity of axial, coronal and combined CT planes were 74%, 65%, and 79%, respectively. There was no significant difference between axial and coronal CT scans for detecting open globe injuries (P value=0.075), independent of the type and the location of the globe injury. For posterior injuries and sharp trauma, the sensitivity of coronal plane in detecting open globe injury was significantly lower, compared to axial and combined readings (P value=0.012 and 0.015, respectively). There was a near perfect agreement between readers for all CT scan readings with a Kappa value of 0.9. ConclusionAxial CT reading may be as adequate as a multiplanar reading in detection of open globe injury in emergency setting, where timely diagnosis matters. Without clinical and surgical findings, CT cannot provide adequate accuracy for detecting open globe injuries.

Cribriform Plate, Crista Galli, Olfactory Fossa and Septal Deviation.

In the present study, we investigated the relationship between olfactory fossa, cribriform plate, crista galli and nasal Septal Deviation (SD). Keros classification of olfactory fossa was also performed. This study was performed retrospectively. Computerized Tomography (CT) images of 200 adult subjects were observed. Unilateral nasal Septal Deviation (SD) cases were included into the study. On coronal CT scans, SD side and location, SD angle, cribriform plate width, olfactory fossa depth (Keros classification) and width, area of the olfactory fossa, crista galli length, width and pneumatization were evaluated. Anterior and anteroposterior deviations were detected mainly. In females, 64.0% and in males, 45.3% of the SDs were located anteriorly. In males, anteroposterior SDs (40.0%) were detected more than females. In anteroposterior SDs, SD angle was higher than anterior SDs. With higher SD angle, crista galli width and height decreased. Cribriform plate width, olfactory fossa height, width and area values of contralateral side were significantly higher than those of the ipsilateral side. For Keros classification, in male group, type 1 (53.3%) and in females, type 2 (57.6%) was detected at ipsilateral side. For contralateral side, type 2 Keros was detected in both genders. Complete crista galli pneumatization was observed in 4.0% and partial pneumatization was detected in 12.0%. In 84% of the patients, there is no Crista galli pneumatization. With the presence of pneumatized crista galli, contralateral Keros values decreased. Crista galli height and contralateral olfactory fossa width showed positive correlation. In older patients, cribriform plate width decreased. In our study, there was no Keros type 3 olfactory fossa. In males' contralateral side of SD; and in females both ipsilateral and contralateral side of SD, Keros type 2 olfactory fossa were detected. Therefore, during sinus surgery, surgeons should work carefully not to made intracranial penetration.

Morphometric anatomical and CT study of the human adult sacroiliac region.

To identify and describe the morphometry and CT features of the articular and extra-articular portions of the sacroiliac region. The resulting knowledge might help to avoid complications in sacroiliac joint (SIJ) fusion. We analyzed 102 dry hemi-sacra, 80 ilia, and 10 intact pelves and assessed the pelvic computerized tomography (CT) scans of 90 patients, who underwent the examination for conditions not involving the pelvis. We assessed both the posterior aspect of sacrum with regard to the depressions located externally to the lateral sacral crest at the level of the proximal three sacral vertebrae and the posteroinferior aspect of ilium. Coronal and axial CT scans of the SIJ of patients were obtained and the joint space was measured. On each side, the sacrum exhibits three bone depressions, not described in anatomic textbooks or studies, facing the medial aspect of the posteroinferior ilium, not yet described in detail. Both structures are extra-articular portions situated posteriorly to the SIJ. Coronal CT scans of patients showing the first three sacral foramens and the interval between sacrum and ilium as a continuous space display only the S1 and S3 portions of SIJ, the intermediate portion being extra-articular. The S2 portion is visible on the most anterior coronal scan. Axial scans show articular and extra-articular portions and features improperly described as anatomic variations. Extra-articular portions of the sacroiliac region, not yet described exhaustively, have often been confused with SIJ. Coronal CT scans through the middle part of sacrum, the most used to evaluate degenerative and inflammatory conditions of SIJ, show articular and extra-articular portions of the region.

A Targeted Approach to a Giant Gastrointestinal Stromal Tumor of the Esophagus

Sir, Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract, accounting for 0.1 %–3.0 % of all gastrointestinal malignancies. GISTs can arise anywhere in the gastrointestinal tract: 50–70 % in the stomach, 20–40 % in the small bowel, 5–15 % in the colon and rectum and rarely in the mesentery or retroperitoneum. Esophageal GISTs are extremely uncommon, representing approximately 5 % of GISTs with a majority occurring at the esophagogastric junction (GEJ). [1, 2] We report a case of a borderline resectable GIST of the lower esophagus, treated with neoadjuvant imatinib mesylate (IM) which ultimately resulted in a successful R0 resection. A 50-year-old lady with no co-morbid conditions was referred to us for progressively worsening dysphagia of 6 months. An upper gastrointestinal endoscopy revealed a circumferential ulcerated growth in the lower end of the esophagus, from 30 to 36 cm, which was seen extending to the GEJ. An endoscopic biopsy was suggestive of a spindle cell neoplasm, which on immunohistochemistry correlation (CD117 and CD34 positive, Ki-67–30 %) was suggestive of a high grade GIST. Computerized tomography (CT) scan of the chest and abdomen revealed a large lobulated, hetero-dense, poorly enhancing mass (10.9 × 7.4 × 16 cm) in the thoraco-abdominal region, involving the lower end of the esophagus, GEJ, posterior stomach and extending along the retroperitoneum to infiltrate the body and tail of pancreas, causing a mass effect on the left kidney. (Figures 1a and ​and2a2a) Fig. 1 a- Axial CT scan at presentation (Maximal diameter-10.9 cm). b- Axial CT scan following 6 months of Imatinib Mesylate (Maximal diameter-4.2 cm) Fig. 2 a- Coronal CT scan at presentation. b- Coronal CT scan following 6 months of Imatinib Mesylate After thorough discussion of the issues of borderline resectability/unresectability, the patient consented to attempt to downstage the tumor by neoadjuvant treatment with IM. (400 mg/day) An interim CT scan at two months revealed a regression of the tumor diameter, IM was hence continued for another 4 months. A follow-up CT at 6 months revealed a regression of the tumor diameter from 10.2 cm to 4.2 cm. (Figures 1b and ​and2b)2b) Resection of the residual tumor was deemed feasible and the patient was taken up for an exploratory laprotomy. The residual tumor was found to be densely adherent to a portion of the distal body of the pancreas; a distal pancreatico-spleenectomy had to be combined with an esophago-gastrectomy via a transhiatal approach to attain a R0 resection. (Figures 3 and ​and4)4) The bowel continuity was restored using a gastric tube conduit through the posterior mediastinum. Histopathological examination of the resection specimen confirmed a GIST with extensive post treatment changes and clear margins. The postoperative course was uneventful, after recovery the patient continued adjuvant therapy with IM for 6 more months, she is currently disease free. Fig. 3 Specimen photograph (Esophago-gastrectomy along with distal pancreatico spleenectomy) Fig. 4 a- H& Ex 40- Shows tumor composed of fascicles and sheets of spindle cells with dark staining nuclei in a myxoid background. b- IHCX40- Tumor cells showing immunopositivity to CD-117. c- IHCX40- Tumor cells showing immunopositivity to CD-34. ... GISTs are thought to arise from the intestinal cells of Cajal, which are intestinal pacemaker cells that regulate peristalsis. Considerable progress has been made recently in our understanding of the natural history, risk stratification, and molecular biology of GIST. The vast majority of GISTs contain an activating mutation in either the KIT or platelet-derived growth factor-A gene. GIST is highly responsive to several selective tyrosine kinase inhibitors. Despite the efficacy of targeted therapy, surgery remains the only curative primary treatment and cures >50 % of GIST patients who present with localized disease. Many authors agree that loco regionally advanced tumors or those poorly positioned which require an extended/multi-organ resection should be considered for neoadjuvant treatment with IM and should be re-evaluated for a possible curative resection. [3–5] This approach has been proven to be safe and feasible even in the management GIST of the esophagus as was also seen in our patient. In conclusion a multimodal approach with neoadjuvant administration of IM is emerging as a viable treatment strategy for borderline resectable esophageal GIST, although the dose and duration have not been clearly established. The long-term impact of this approach on survival is presently under investigation in multicenter prospective randomized trials.

Combined Aplasia of Sphenoid, Frontal, and Maxillary Sinuses With Hypoplasia of The Ethmoid Sinus

Dear Editor, Paranasal sinuses are prone to a great diversity of anomalies. Aplasia of the frontal sinus is a relatively common phenomenon and may be accompanied with hypoplasia of the maxillary sinus, but combined aplasia or underdevelopment of the paranasal sinuses is unusual (1, 2).These developmental pathologies may be misdiagnosed as sinusitis or neoplasm (2). Computerized Tomography (CT) is an excellent imaging technique that is used to map sinus anatomy (3). Here, we present a 23-years old male patient who has combined aplasia of sphenoid, frontal, and maxillary sinuses accompanied by ethnocide sinus hypoplasia, which is the second reported case to our knowledge. Twenty three years old male patient presented with complaints of headache and nasal obstruction to the Otorhinolaryngology outpatient clinic. Axial and Coronal CT scans (5mm slice thickness) delineated lack of pneumatization in the frontal, sphenoid and maxillary sinuses and minimal pneumatization in the ethmoid cells eg. Total aplasia of the frontal, sphenoid and maxillary sinuses and hypoplasia of the ethmoid sinuses. (Figure 1) No other craniofacial anomaly was observed. He had no previous history of facial trauma, irradiation or systemic diseases affecting the skeletal system such as Paget’s disease, osteopetrosis, or fibrous dysplasia. No other abnormality was found on clinical and laboratory examinations, including cystic fibrosis. The paranasal sinuses begin their development as an evagination of the mucosa from the nasal cavities during the third and fourth fetal months. They undergo major expansion after birth, along with the development of the facial cranium and teeth (1) The underdevelopment or aplasia of the paranasal sinuses is a rare phenomenon that refers mainly to the frontal (12%) and secondarily to the maxillary sinuses (5% and 6%). Agenesis of the sphenoid sinuses is extremely rare (4). The agenesis of the paranasal sinuses occurs more frequently in syndromes of craniosynostosis, osteodysplasia (Melnick-Needles), as well as in cases of Down’s syndrome (hypoplasia of the frontal sinus) (3). Developmental anomalies of paranasal sinuses in cystic fibrosis patients is significantly high compared to normal population (3). The developmental pathologic abnormalities may be misdiagnosed as sinusitis or neoplasm (4). The maxillary sinus is the first of the paranasal sinuses to develop in the human fetus and is present at birth. Development of the maxillary sinus may become arrested in children with recurrent chronic rhino sinusitis (4). For many authors there is a connection between reduced nasal ventilation and abnormal maxillary growth, but Diner et al observed normal development of maxillary sinus in 11 patients with unilateral choanal atresia. Chronic obstruction due to narrow infundibular passage and absence of natural osmium leads to thick effusion in hypo plastic sinuses (2, 4)Maxillary sinus hypoplasia may be misdiagnosed as chronic sinusitis. The sphenoid sinus develops embryo logically from the skull base. By the age of 12, the sphenoid pneumatization reaches its final form to a size equivalent to that of an adult. Sphenoid sinuses vary in size and shape. The average measurements of the sphenoid sinus are as follows: vertical height, 2 cm; transverse breadth, 1.8 cm; and anterosuperior depth, 2.1 cm. Hypoplasia of the sphenoid sinuses is shown frequently in patients with cystic fibrosis. However, agenesis of the sphenoid sinus is highly uncommon (4). Based on their anatomical studies, Wertheim and Grunwald reported in the early 1900s that agenesis of the sphenoid sinuses can indeed occur in 1–1.5% of cases. The diagnosis of sphenoid sinus hypoplasia is potentially important in patients in whom trans-spheroidal hypophysectomy is contemplated. In conclusion this patient seems to be the second case to have combined aplasias of the sphenoid, frontal, and maxillary sinuses with hypo plastic ethmoid cells without any systemic or skeletal disease. This extremely rare anomaly should also be kept in mind to prevent complications during endoscopic sinus surgery. Figure 1 Paranasal Sinus CT, Coronal Section, Indicating Aplasia of the Maxillary Sinus and Minimal Pneumatization in the Ethmoid Cells.

The “Mickey Mouse” Sign

Objective: In transnasal endoscopic pituitary surgery and transsellar approaches to anterior skull base lesions, a bony sella window is created with the lateral limits being the carotid arteries. Method: Coronal CT scan of the sphenoid sinuses were reviewed in a tertiary referral hospital and compared with intra operative findings. Results: Sphenoid anatomy is variable in terms of the degree of pneumatization and bony anatomy around the pituitary gland and internal carotid arteries. We describe a radiological sign ascertained from computerized tomography (CT) that when present indicates whether the carotid arteries can be readily identified endoscopically on entering the sphenoid sinus. On the axial CT the carotid arteries may produce protuberances either side of the sella which together with the bony sella and dorsum sella appear to form the outline of the head of Mickey Mouse or a teddy bear. Conclusion: When this sign is not present then the junction between the sella and carotids may not be clear and surgeons must be cautious or use neuronavigation.

Rounding of the Inferior Rectus Muscle as a Predictor of Enophthalmos in Orbital Floor Fractures

In spite of established indications for early operative repair of orbital floor fractures 7-10% of patients treated nonoperatively develop enophthalmos. Clearly further indications for repair are required to prevent these post-injury complications. Rounding of the inferior rectus muscle on coronal computerized tomography (CT) scan results from a loss of soft tissue and bony support and may therefore be predictive of late enophthalmos.A four-year institutional review was conducted to identify patients with orbital floor fractures that had been treated nonoperatively. Patients were recruited for late clinical follow-up (mean 30 months) where clinically significant enophthalmos and diplopia were measured. Clinical results were correlated with measurements of the height-to-width ratio of the inferior rectus muscle on CT scans by a blinded examiner. Eighteen of 78 patients were available for late follow-up. Sixteen patients had no enophthalmos whereas 2 patients had enophthalmos. The inferior rectus height-to-width ratios measured in the unaffected orbits were statistically similar between the two groups. There was a significantly increased height-to-width ratio exceeding 1.00 in the affected orbit when the enophthalmos group was compared to the no enophthalmos group.A height-to-width ratio of the inferior rectus muscle on coronal CT scan of greater than or equal to 1.00 is predictive of late enophthalmos.