Helical Computed Tomography Scans Research Articles

Relative skeletal distribution of proliferating marrow in the adult dog determined using 3'-deoxy-3'-[18 F]fluorothymidine.

3′‐deoxy‐3′‐[18F]fluorothymidine (18FLT) is a radiopharmaceutical tracer used with positron emission tomography (PET), often in combination with computed tomography (CT), to image DNA synthesis, and thus, cellular proliferation. Characteristic accumulation of the tracer within haematopoietic bone marrow provides a noninvasive means to assess marrow activity and distribution throughout the living animal. The present study utilizes three‐dimensional analysis of 18FLT‐PET/CT scans to quantify the relative skeletal distribution of active marrow by anatomic site in the dog. Scans were performed on six healthy, adult (3–6 years of age), mixed‐breed dogs using a commercially available PET/CT scanner consisting of a 64‐slice helical CT scanner combined with an integrated four ring, high‐resolution LSO PET scanner. Regions of interest encompassing 11 separate skeletal regions (skull, cervical vertebral column, thoracic vertebral column, lumbar vertebral column, sacrum, ribs, sternum, scapulae, proximal humeri, ossa coxarum, and proximal femora) were manually drawn based on CT images and thresholded by standardized uptake value to delineate bone marrow activity. Activity within each skeletal region was then divided by the total skeletal activity to derive the per cent of overall marrow activity within an individual site. The majority of proliferative marrow was located within the vertebral column. Of the sites traditionally accessed clinically for marrow sampling, the proximal humerus contained the largest percentage, followed by the ossa coxarum, proximal femur, and sternum, respectively. This information may be used to guide selection of traditional marrow sampling sites as well as inform efforts to spare important sites of haematopoiesis in radiation therapy planning.

Cardiac Motion Correction for Helical CT Scan With an Ordinary Pitch.

Cardiac X-ray computed tomography (CT) imaging is still challenging due to the cardiac motion during CT scanning, which leads to the presence of motion artifacts in the reconstructed image. In response, many cardiac X-ray CT imaging algorithms have been proposed, based on motion estimation (ME) and motion compensation (MC), to improve the image quality by alleviating the motion artifacts in the reconstructed image. However, these ME/MC algorithms are mainly based on an axial scan or a low-pitch helical scan. In this paper, we propose a ME/MC-based cardiac imaging algorithm for the data set acquired from a helical scan with an ordinary pitch of around 1.0 so as to obtain the whole cardiac image within a single scan of short time without ECG gating. In the proposed algorithm, a sequence of partial angle reconstructed (PAR) images is generated by using consecutive parts of the sinogram, each of which has a small angular span. Subsequently, an initial 4-D motion vector field (MVF) is obtained using multiple pairs of conjugate PAR images. The 4-D MVF is then refined based on an image quality metric so as to improve the quality of the motion-compensated image. Finally, a time-resolved cardiac image is obtained by performing motion-compensated image reconstruction by using the refined 4-D MVF. Using digital XCAT phantom data sets and a human data set commonly obtained via a helical scan with a pitch of 1.0, we demonstrate that the proposed algorithm significantly improves the image quality by alleviating motion artifacts.

Diagnostic Performance of Quadruple Phase Multidetector Row Computed Tomography in Hepatoma: Comparison with Histopathological Diagnosis

Objective: To determine diagnostic accuracy of quadruple phase helical computed tomography scan in detection of hepatocellular carcinoma in individuals with hepatitis B and C, keeping histopathology as the gold standard. Methods: A cross-sectional study was performed in the Radiology and Imaging department of a tertiary care university hospital during 2014 to 2016. All serologically positive patients were included. Quadruple phase computed tomography scan was done and results were interrelated with histological diagnosis. Results: Hepatocellular carcinoma was accurately diagnosed in 76 out of 80 patients using Quadruple phase computed tomography scan (sensitivity, 95%). It was correctly excluded in 70 of 72 patients (specificity, 97.2%). The overall diagnostic accuracy of Quadruple phase computed tomography scan for diagnosing hepatocellular carcinoma was 96.05%. The positive and negative predictive values were 97.4% and 94.59% respectively. Conclusion: Quadruple phase computed tomography is more effective in evaluating hepatocellular carcinoma than conventional biphasic and triphasic computed tomography scans. We propose it as the technique of first preference for imaging workup in patients with Hepatitis B and C.

A Novel Method to Calculate the Volume of Alveolar Cleft Defect Before Surgery.

This study aimed to evaluate a novel subtractive method for the precise calculation of alveolar cleft defect volume before surgery using the three-dimensional imaging software Mimics. Ten patients (3 female, 7 male, age range 8-12 years) with unilateral alveolar cleft were enrolled in the study. Preoperative helical computed tomography scans were performed for all patients. A new subtractive method was introduced to precisely calculate the alveolar cleft defect volume before surgery with the aid of Mimics. The DICOM data of every patient were processed using the subtractive method. Statistical analyses were performed using Pearson's correlation test and t test. The mean volume of the alveolar cleft defect was 1811.97 ± 817.90 mm. The mean time spent to calculate an alveolar cleft defect volume was 60.60 ± 11.67 minutes. The Pearson correlation test (r = 0.38, P = 0.279) indicated a poor correlation between alveolar cleft defect volume and calculation time. Preoperative knowledge of defect volume is crucial in alveolar cleft repair. Accurate estimation of graft volume in alveolar cleft patients can be performed using this new subtractive method. Compared with previous methods, this new subtractive method is time-saving and suitable for both unilateral and bilateral clefts. Surgeons can use this method to design a surgical plan for each patient before surgery within a short time, and with less cost.

Do computer extracted shape and texture features enable discrimination of granulomas from adenocarcinoma on chest computed tomography?

Lung cancer screening with low dose computed tomography (CT) performed on multidetector helical CT scanners and the use of high-resolution chest CT scans to evaluate respiratory symptoms have resulted in an increase in the discovery of indeterminate pulmonary nodules.

Ultra-fast, low dose high-pitch (FLASH) versus prospectively-gated coronary computed tomography angiography: Comparison of image quality and patient radiation exposure

BackgroundCoronary computed tomography angiography (CCTA) is increasingly being used for the evaluation of coronary artery disease; however, radiation exposure remains a major limitation of its use. ObjectiveTo compare image quality and radiation exposure in two groups of patients undergoing CCTA using a 256-slice dual-source helical computed tomography scanner with high-pitch (FLASH) or prospective [step-and-shoot (SAS)] gating protocols. MethodsA prospective, single-center study was performed in our cardiac center. In total, 162 patients underwent CCTA with either FLASH or SAS scanning protocols. Subjective image quality was graded on the basis of a four-point grading system (1, non-diagnostic; 2, adequate; 3, good; 4, excellent). Objective image quality was assessed using image signal, noise, and signal-to-noise ratio (SNR). The effective radiation dose was also estimated. ResultsThe clinical and demographic characteristics of the patients in both groups were similar. The median age of the patients in both groups was 48.43 years, and males accounted for 63% and 68.7% of the FLASH and SAS groups, respectively. We found that the subjective image quality obtained with the FLASH protocol was superior to that obtained with the SAS protocol (3.35 ± 0.6 mSv vs. 2.82 ± 0.61 mSv; p < 0.001). Image noise was higher in the FLASH group but was not statistically significant (25.0 ± 6.13 vs. 24.0 ± 6.8; p = 0.10), whereas the signal and SNR was significantly higher with the FLASH protocol than with the SAS protocol [(469 ± 116 vs. 397 ± 106; p > 0.001) and (21.6 ± 8.7 mSv vs. 16.6 ± 7.7 mSv; p < 0.001), respectively]. Radiation exposure was 62% lower in the FLASH protocol than in the SAS protocol, (1.9 ± 0.4 mSv vs. 5.12 ± 1.8 mSv; p < 0.001). ConclusionThe use of 256-slice CCTA performed with the FLASH protocol has a better objective and subjective image quality as well as lower radiation exposure when compared with the use of prospective electrocardiography gating.

Role of Nonenhanced Spiral Computed Tomography Scan in Refractory Irritative Bladder Symptoms

Introduction: In this study, we presented two cases with lower urinary tract symptoms and missed urinary stone that were diagnosed by the computed tomography (CT) scan. Case Presentation: We reported two elderly men with severe irritative bladder symptoms who failed to be diagnosed with routine work-ups, including urine analysis and culture, urine cytology, ultrasonography, cystoscopy and urodynamic studies. Abdomino-pelvic nonenhanced spiral CT scan was performed. Missing stones were detected by the helical CT scan without contrast, which were treated by intracorporal lithotripsy. The symptoms were relieved following stone removal. Conclusions: According to these two cases, there may be a diagnostic role for CT scan in evaluation of the irritative bladder symptoms.

A standardized method to measure brain shifts with decompressive hemicraniectomy

BackgroundA standardized, reliable, and practical method for measuring decompressive hemicraniectomy (DHC) defects and brain shifts in malignant middle cerebral artery (MCA) territory infarction is needed for reliable comparisons between computed tomography (CT) scans. Such a method could facilitate further studies on the effects of DHC. New methodWe describe and apply a method for measuring DHC defects and brain shifts on CT scans in 25 patients with malignant MCA territory infarction. Craniectomy area is adjusted for variations in head size, CT slice orientation is standardized, and the site of each measurement is defined. This method uses standard radiology platforms and volume-acquired helical CT scans. ResultsThe measurements include a DHC size index (adjusted for variations in head size), midline brain shift (subfalcine), outward brain herniation (transcalvarial), and the diameter of the contralateral atrium of the lateral ventricle. Inter-rater agreement for these measurements in a sample of 15 subjects is excellent (correlation coefficients 0.90–0.98). Comparison with existing methodsIn contrast to previously reported methods, this method is tested in acute stroke patients, compensates for variability in head size, and includes a midline brain shift (subfalcine) and brain ventricular system measurements. ConclusionsA practical method for measuring DHC size and brain shifts designed to be consistent between scans is proposed. This method should facilitate comparisons of measurements between serial scans, between patients, and perhaps between studies. This method could be useful in medical and surgical studies of brain herniations in malignant MCA territory infarction, and possibly other conditions.

Triple-phase helical computed tomography in dogs with solid splenic masses.

We investigated the utility of triple-phase helical computed tomography (CT) in differentiating between benign and malignant splenic masses in dogs. Forty-two dogs with primary splenic masses underwent triple-phase helical CT scanning (before administration of contrast, and in the arterial phase, portal venous phase, and delayed phase) prior to splenectomy. Tissue specimens were sent for pathological diagnosis; these included hematomas (n=14), nodular hyperplasias (n=12), hemangiosarcomas (n=11), and undifferentiated sarcomas (n=5). The CT findings were compared with the histological findings. Nodular hyperplasia significantly displayed a homogeneous normal enhancement pattern in all phases. Hemangiosarcoma displayed 2 significant contrast-enhancement patterns, including a homogeneous pattern of poor enhancement in all phases, and a heterogeneous remarkable enhancement pattern in the arterial and portal venous phases. Hematoma and undifferentiated sarcoma displayed a heterogeneous normal enhancement pattern in all phases. The contrast-enhanced volumetric ratios of hematoma tended to be greater than those of undifferentiated sarcoma. Our study demonstrated that the characteristic findings on triple-phase helical CT could be useful for the preoperative differentiation of hematoma, nodular hyperplasia, hemangiosarcoma, and undifferentiated sarcoma in dogs. Triple-phase helical CT may be a useful diagnostic tool in dogs with splenic masses.

Preventive Kidney Stones: Continue Medical Education.

Nephrolithiasis is a common health problem across the globe with a prevalence of 15%–20%. Idiopathic hypercalciuria is the most common cause of nephrolithiasis, and calcium oxalate stones are the most common type of stones in idiopathic hypercalciuric patients. Calcium phosphate stones are frequently associated with other diseases such as renal tubular acidosis type 1, urinary tract infections, and hyperparathyroidism. Compared with flat abdominal film and renal sonography, a noncontrast helical computed tomography scan of the abdomen is the diagnostic procedure of choice for detection of small and radiolucent kidney stones with sensitivity and specificity of nearly 100%. Stones smaller than 5 mm in diameter often pass the urinary tract system and rarely require surgical interventions. The main risk factors for stone formation are low urine output, high urinary concentrations of calcium, oxalate, phosphate, and uric acid compounded by a lower excretion of magnesium and citrate. A complete metabolic workup to identify the risk factors is highly recommended in patients who have passed multiple kidney stones or those with recurrent disease. Calcium oxalate and calcium phosphate stones are treated by the use of thiazide diuretics, allopurinol, and potassium citrate. Strategies to prevent kidney stone recurrence should include the elimination of the identified risk factors and a dietary regimen low in salt and protein, rich in calcium and magnesium which is coupled with adequate fluid intake.

Helical Computed Tomography - Anatomy of the Cat Abdomen

Computed tomography (CT) is a most valuable technique for the diagnosis of abdominal disorders. In veterinary medicine, x-ray and ultrasound are the imaging modalitys of choice for the abdomen, but CT can provide information that cannot be obtained by other means. One mature, female, domestic cat, 4 kg weight was used for this study. The cat was clinically healthy, with no abnormal findings at haematological and biochemical analysis. It was premedicated with 20 µg/kg medetomidine and 0.3mg/kg butorphanol IM. For induction of anaesthesia, 3 to 5 mg/kg propofol was administered IV. Anaesthesia was maintained with a mixture of isoflurane and oxygen. The patient was positioned in sternal recumbency. CT scans were performed with a helical CT scanner Hi Speed CT/e Dual; General Electric. Technical factors were 120 kVp and 50 mA settings, with 1 rotation/s. All sections were imaged with soft-tissue window. CT scans were performed after IV injection of iodinated contrast medium, iopamidol, 2 mL/kg. The images are presented cranialy to caudal progression from the 8th thoracic vertebra to the level of the pelvic inlet. Identifiable anatomical structures are labelled on the CT images. The stomach is left-sided with the gastric folds less numerous and thinner than those in the dogs. The normal small intestine contains less gas in cats. The feline cecum is very short. The liver showed a low attenuation with the mediastinum-vascular window settings, allowing better visualisation of the hepatic lobes and interlobular fissures. The gallbladder and bile ducts were also better visualised. CT imaging studies can provide additional information in patients with radiographic and ultrasonographic patterns of abdominal disorders, as a specialised imaging method, a useful preoperative technique and a precise staging tool. CT improves the image quality further and allows better timing of vascular phases. Helical CT angiography enables visualization of contrast-enhanced abdominal vessels using only a peripheral venous injection of iodinated contrast medium.

Anterior loop of the mental nerve, mental foramen and incisive nerve emergency: tridimensional assessment and surgical applications.

The aim of this study was to investigate the prevalence and length of the anterior loop (AL), the distance from this landmark to the alveolar crest and its relation with the shape of the foramen and emergency pattern in the Spanish population on helical computed tomography scan (helical CT scan) through tridimensional reconstructions. Helical CT scan images of 41 patients aged 65 or older were analyzed. A total of 82 human hemi-mandibles were examined in this study. A tridimensional reconstruction of each mandible and Inferior Alveolar Nerve canal was created in AMIRA® software (AMIRA, Mercury Computer Systems, Berlin, Germany). Prevalence, length and distance between the AL, mental foramen and alveolar ridge were measured. This retrospective observational study was performed according to the STROBE guidelines. Prevalence of the AL was 53.7% (n=44) and the mean length was 1.3±0.64mm. The mean distance from the highest point of the loop to the alveolar ridge was 13.4±2.8mm. The mean diameter of the mental foramen was 3.5±0.65mm and the proportion of the oval-shaped was 62.2% (n=51) and round-shaped was 37.8% (n=31). The study found that patients with type 1 pattern emergency pattern had a higher prevalence of the AL (p=0.03). Prevalence, location and length of the anterior loop can be overlooked if only two-dimensional pre-surgical studies are performed. Therefore, three-dimensional imaging and modeling of anatomic structures should be used for the pre-operative examination of the interforaminal area. Given the wide variability of the emergency pattern of the mental nerve and the prevalence and location of the anterior loop, it should be studied in every patient individually.

Mesothelial cyst of the round ligament of the liver

A 34-year-old man was admitted in our department with a 3 months history of epigastric pain, abdominal distension and tenderness. Helical computed tomography scan and magnetic resonance imaging showed a 10 cm low-density fluid-filled polilobate cystic lesion with internal septations and calcifications located between the left lobe of the liver, shorter gastric curvature, pancreas and mesocolon. Laparoscopic exploration was performed. Macroscopically the lesion was a unilocular serous cyst with a thick fibrous wall. Histopathology revealed a thin fibrous wall with a single layer of flattened to cuboidal mesothelial cell lining lacking any cellular atypia. The patient is currently alive without evidence of recurrence at 6 months. Cysts of mesothelial origin are rare lesions seen more frequently in young and middle-aged women, mostly benign and located in the mesenteries or omentum. Diagnosis is usually based on clinical examination and radiographic imaging. Immunohistochemistry is used to differentiate histologic type, with simple mesothelial cysts being positive for cytokeratins and calretinin and negative for CD31. The laparoscopic approach appears safe, feasible and less-invasive without compromising surgical principles and today should be considered the gold standard in most cases.

Computed tomography of the chest: I. Basic principles

### Key points The conventional chest radiograph superimposes a three-dimensional image onto a two-dimensional surface, so limiting its clinical usefulness. Since its introduction in 1971, X-ray computed tomography (CT) has rapidly evolved into an essential diagnostic imaging tool that forms a cross-sectional image, avoiding the super-imposition of structures that occurs in conventional chest imaging, with a >10-fold increase in attenuation sensitivity. Although CT imaging is reported by radiologists, it is important for both anaesthetists and intensivists to be able to interpret the scans, as reporting facilities may not be immediately available. Furthermore, the radiologist may not fully report all facets of a detailed scan and further information may be acquired by a physician with the ability to interpret CT scans. This is the first in a series of two articles written for anaesthetists and intensivists covering both thoracic anatomy and pathology as it relates to CT. A CT scanner makes many measurements, from different rotational angles, of X-ray attenuation ( weakening in force or intensity ) through the cross-sectional plane of the thorax. It then uses these data to reconstruct a digital representation of the cross-section with …

"High-precision, reconstructed 3D model" of skull scanned by conebeam CT: Reproducibility verified using CAD/CAM data.

Computed tomography (CT) scanning has recently been introduced into forensic medicine and dentistry. However, the presence of metal restorations in the dentition can adversely affect the quality of three-dimensional reconstruction from CT scans. In this study, we aimed to evaluate the reproducibility of a "high-precision, reconstructed 3D model" obtained from a conebeam CT scan of dentition, a method that might be particularly helpful in forensic medicine. We took conebeam CT and helical CT images of three dry skulls marked with 47 measuring points; reconstructed three-dimensional images; and measured the distances between the points in the 3D images with a computer-aided design/computer-aided manufacturing (CAD/CAM) marker. We found that in comparison with the helical CT, conebeam CT is capable of reproducing measurements closer to those obtained from the actual samples. In conclusion, our study indicated that the image-reproduction from a conebeam CT scan was more accurate than that from a helical CT scan. Furthermore, the "high-precision reconstructed 3D model" facilitates reliable visualization of full-sized oral and maxillofacial regions in both helical and conebeam CT scans.

Helical computed tomography scanning of the larynx and upper trachea in rabbits.

BackgroundComputed tomography (CT) is used to evaluate the human tracheobronchial tree because of its unsurpassed ability to visualize the airway and surrounding structures. To establish an ideal animal model for studying subglottic stenosis, we assessed the size and morphology of the normal rabbit’s laryngotracheal airway by helical CT. We measured luminal dimensions at the levels of the arytenoid and cricoid cartilages and the first, third, and eighth tracheal rings. At all levels, the axial slices were used to calculate the maximum anteroposterior (AP) dimension, transverse dimension, and cross-sectional areas. We measured the tracheal length from the cricoid to the third and eighth tracheal rings on sagittal reformation. We assessed the hyoid, thyroid, cricoid, arytenoid, and tracheal rings for the presence of calcific or soft tissue densities. We also addressed the presence or absence of pre-epiglottic and paraglottic fat.ResultsThe mean AP tracheal dimension ± standard deviation (SD) was 8.6 ± 0.5 mm at the arytenoid level, 8.2 ± 0.7 mm at the cricoid level, and 7.7 ± 0.2 mm at the first tracheal ring level. The transverse tracheal dimension ±SD was 5.3 ± 0.1 mm at the arytenoid level, 5.5 ± 0.5 mm at the cricoid level, and 6.1 ± 0.6 mm at the first tracheal ring level. The mean tracheal area ±SD was 35.7 ± 2.2 mm2 at the arytenoid level, 35.8 ± 5.1 mm2 at the cricoid level, and 39.2 ± 4.3 mm2 at the first tracheal ring level. The tracheal length ±SD was 10.7 ± 2.3 mm from the cricoid to the third tracheal ring and 19.1 ± 1.14 mm to the eighth tracheal ring. There was complete calcification of the hyoid in all rabbits. Only two rabbits showed complete thyroid, arytenoid, or tracheal ring calcification. The remaining airway components were otherwise either uncalcified or partially calcified. The uvula, epiglottis, aryepiglottic fold, vallecula, piriform sinus, true/false vocal cords, and pre-epiglottic/paraglottic fat were not seen in any rabbit.ConclusionsHelical CT investigation provides good, highly definitive anatomic details of the larynx and trachea in rabbits. Such results may be used in further evaluation of the normal airway and in cases of subglottic stenosis.

Pulmonary manifestations in a group of patients with Behcet's disease.

In this study we investigated the frequency and characteristics of pulmonary manifestations in a group of patients with Behcet's disease (BD) who were admitted to Cairo University Hospital. Fifteen patients were included in our study, 14 men (93.3%) and one woman (6.66%).Their mean age was 30.06±9.8years and the mean age of onset of BD was 23.7±5.54years. All patients were subjected to full history taking, clinical examination, plain chest X-ray and helical computed tomography (CT) study of the chest. Pulmonary involvements were detected in 11 patients with BD, 73.3% of cases: 10 men (90.9%) and one woman (9.09%).Their mean age was 28.8±8.07, the mean age of onset of BD was 23.2±5.59years and the mean disease duration until lung manifestations appear was 3.7±4.8years. The main pulmonary and constitutional symptoms in these 11 patients were as follows: dyspnea 81.8%, cough 63.6%, weight loss 63.6%, chest tightness 54.5%, hemoptysis 45%, massive hemoptysis 27.2%, fever 36.3% and expectoration 36.3. Analysis of both vascular and parenchymal lung lesions in helical CT scan in the 11 patients with BD were as follows: pulmonary artery aneurysm (PAA) occurred in 5/11 patients (45.4%), pulmonary nodules occurred in 3/11 patients (27.2%), pleural effusion occurred in 3/11 patients (27.2%), pulmonary embolism and infarction occurred in 1/11 patients (9.09%) and pneumonitis occurred in 1/11 patients (9.09%). The higher frequency of pulmonary manifestations in our patients (73.3%) and the higher frequency of PAA (33.3%) could be related to the fact that this study was conducted on a group of patients who were admitted to the hospital with more severe illnesses.

A Method for Assessing Ground-Truth Accuracy of the 5DCT Technique

To develop a technique that assesses the accuracy of the breathing phase-specific volume image generation process by patient-specific breathing motion model using the original free-breathing computed tomographic (CT) scans as ground truths. Sixteen lung cancer patients underwent a previously published protocol in which 25 free-breathing fast helical CT scans were acquired with a simultaneous breathing surrogate. A patient-specific motion model was constructed based on the tissue displacements determined by a state-of-the-art deformable image registration. The first image was arbitrarily selected as the reference image. The motion model was used, along with the free-breathing phase information of the original 25 image datasets, to generate a set of deformation vector fields that mapped the reference image to the 24 nonreference images. The high-pitch helically acquired original scans served as ground truths because they captured the instantaneous tissue positions during free breathing. Image similarity between the simulated and the original scans was assessed using deformable registration that evaluated the pointwise discordance throughout the lungs. Qualitative comparisons using image overlays showed excellent agreement between the simulated images and the original images. Even large 2-cm diaphragm displacements were very well modeled, as was sliding motion across the lung-chest wall boundary. The mean error across the patient cohort was 1.15 ± 0.37 mm, and the mean 95th percentile error was 2.47 ± 0.78 mm. The proposed ground truth-based technique provided voxel-by-voxel accuracy analysis that could identify organ-specific or tumor-specific motion modeling errors for treatment planning. Despite a large variety of breathing patterns and lung deformations during the free-breathing scanning session, the 5-dimensionl CT technique was able to accurately reproduce the original helical CT scans, suggesting its applicability to a wide range of patients.

Joubert syndrome: accuracy of neuro-radiological findings

To evaluate the accuracy of neuroimaging in establishing the diagnosis of Joubert syndrome. Computed tomography (CT) and magnetic resonance imaging (MRI) were performed in seven infants/children with the clinical diagnosis of Joubert syndrome. The clinical diagnoses were based on characteristic clinical features. The CT scans were performed on a single detector helical CT scans and the MRI were performed on 1-T and 1.5-T MRI systems. All studies were evaluated for the presence of cerebellar vermian aplasia/hypoplasia, cerebellar hypoplasia, horizontal alignment of the superior cerebellar peduncle, configuration of the brainstem and appearance of the fourth ventricle. Other neuroimaging abnormalities such as hydrocephalus, dysgenesis of the corpus callosum were also reported. Cerebellar vermian hypoplasia with a midline cleft, horizontal alignment of the superior cerebellar peduncle, configuration of the brainstem and dilated fourth ventricle with appearance in all patients. Cerebellar hemisphere hypoplasia was seen only in three cases. Brainstem molar tooth sign, fourth ventricular bat wing sign and the horizontal orientation of the superior cerebellar peduncles are characteristic findings Joubert syndrome. (J Pediatr Neurol 2004; 2(1): 33–37).

Effect of distribution of ipsilateral supraclavicular lymph node metastasis on target volume delineation in breast cancer : an analysis of 55 patients

Objective To retrospectively investigate the effect of the distribution of supraclavicular lymph node metastasis ( LNM) on clinical target volume ( CTV) delineation in radiotherapy for breast cancer. Methods Fifty-five patients with breast cancer who underwent helical computed tomography ( CT) scan and were diagnosed with supraclavicular LNM were enrolled as subjects and their CT images were collected. The metastatic lymph nodes in 55 patients were recreated proportionally on the CT images of a standard patient with breast cancer with reference to normal anatomy in the supraclavicular area. The relationship between the distribution of supraclavicular LNM and the CTV recommended by the Radiation Therapy Oncology Group (RTOG) and other literature was analyzed. Results Sixty percent of LNM were pathologically confirmed and distant metastasis occurred in 64% of supraclavicular LNM. Ninety-one percent and eighty-two percent of patients had centers of LNM in the internal and external regions of the supraclavicular area, respectively. Sixty-six percent of patients had LNM located in the subclavian venous confluence. The CTV recommended by literature covered the centers of all LNM in only 20%-42% of patients, while the CTV recommended by the RTOG guide covered the centers of all LNM in only 26% of patients. Seventy-one percent and sixty-six percent of patients had the centers surpassing the lateral and posterior edges of the CTV, respectively. According to the distribution of LNM mentioned above, we expanded the CTV in the supraclavicular area by extending the lateral and posterior edges to the natural anatomical barriers and the new CTV covered the centers of all LNM in up to 82% of patients. Conclusions The locations of supraclavicular LNM surpass the range, particularly the lateral and posterior edges, of the CTV defined by the RTOG guide. Therefore, the CTV in the supraclavicular area needs to be extended to cover those regions mentioned above. Key words: Breast neoplasm; Supraclavicular nodal metastases; Prophylactic radiotherapy; Target volume delineation