The feasibility of transpedicular screw fixation of the subaxial cervical spine in the Arab population: a computed tomography-based morphometric study

Background

Transpedicular screw fixation of the cervical spine provides excellent biomechanical stability. The feasibility of inserting a 3.5-mm screw in the pedicle requires a minimum pedicle diameter of 4.5 mm. This diameter allows at least 0.5 mm bony bridge medially and laterally in order to avoid pedicle violation which can result in neurovascular complications. We aim to evaluate the feasibility of this technique in Arab people since no data are available about this population.

Materials and methods

This cross-sectional study involved a retrospective review of computed tomography scans of normal cervical spines of 99 Arab adults. Ten morphometric measurements were obtained. Data were analyzed using a p value of ≤0.05 as the cut-off level of statistical significance.

Results

Our sample included 63 (63.6 %) males and 36 (36.4 %) females, with a mean age of 35.5 ± 16.5 years. The morphometric parameters of C3–C7 spine pedicles were larger in males than in females. The outer pedicle width (OPW) was <4.5 mm in >25 % of all subjects at C3–C6 vertebrae. Statistically significant differences in the OPW between males and females were noted at C3 (p = 0.032) and C6 (p = 0.004).

Conclusions

Inserting pedicle screws in the subaxial cervical spine is feasible among the majority of Arab people.

Level of evidence

Level 3.

Association of femoral intercondylar notch morphology, width index and the risk of anterior cruciate ligament injury

PURPOSE

To determine the relationship between femoral notch morphology, femoral notch width index and anterior cruciate ligament tears using magnetic resonance imaging of the knee.

METHODS

This retrospective study was conducted on 560 patients who had magnetic resonance imaging (MRI) examinations of the knee between February 2010 and June 2011. Two morphological changes were investigated: the shape of the femoral notch and its width index. The femoral notch shape was classified into one of three types: Type A, which is a narrow (Stenotic) notch that appears narrowed from the base to the midsection as well as at the apex; Type U, in which the midsection does not taper, allowing for a wider contour to the notch than Type A; and Type W, which has the characteristics of Type U but with two apparent apices. The femoral notch width index was calculated as a ratio of central notch width and transcondylar or intercondylar width; values of 0.270 or more were considered as normal and values of 0.269 or less were considered as below normal. These measurements were correlated with the presence or absence of anterior cruciate ligament (ACL) tears.

RESULTS

Of 560 patients, there were 280 cases of ACL tear. Of the 560 patients, 240 had a Type A femoral notch shape and 320 had a Type U or W femoral notch shape. Of those with Type A, 73 % (176 patients) had ACL tears, and of those with Type U or W, 32 % (104 patients) had ACL tears. Statistical analysis showed that the Type A notch correlated with ACL injury (p value < 0.0001). The femoral notch width index was low in 37 % (88 subjects) with Type A notch compared with 27.5 % (88 subjects) with Type U or W notches. Of the 280 subjects with ACL tear, only 17 % (48 patients) had a reduced femoral notch index.

CONCLUSION

This study showed that the Type A femoral notch appears to be a risk factor for ACL injury, whereas a reduced notch index has no significant correlation to ACL injury.

LEVEL OF EVIDENCE

III.

Sixty-four-slice multidetector computerized tomography in the evaluation of transmesenteric internal hernias following Roux-en-Y bariatric surgery

OBJECTIVE

To evaluate the accuracy of 64-slice multidetector computerized tomography (MDCT) in the detection of transmesenteric internal hernias in patients following Roux-en-Y gastric bypass (RYGB) for bariatric surgery patients.

SUBJECTS AND METHODS

This retrospective study was performed on post-bariatric RYGB patients presenting with signs and symptoms suggestive of internal hernias at our institution from the period of April 2010 until March 2012. The patients who had symptoms suggestive of internal hernia had undergone 64-slice MDCT. All the patients who on CT examination were found to have features suggestive of internal hernia were subjected to laparoscopic exploration.

RESULTS

Of the 102 patients who had undergone laparoscopic RYGB, 42 (41.2%) were suspected of having internal hernia. Of these, 23 (55%) had CT findings of hernia while the remaining 19 (45%) were considered normal. Of the 23, 21 (91%) patients were confirmed for internal hernia at laparoscopy. The 19 (45%) patients that did not reveal any signs for internal hernia on CT and the 2 patients that were considered normal on laparoscopy were treated conservatively. The sensitivity, specificity and positive and negative predictive values for MDCT in the diagnosis of internal hernias were 100, 90.5, 91 and 91.3% respectively.

CONCLUSION

The 64-slice MDCT was accurate in the diagnosis of transmesenteric internal hernias in post-RYGB for bariatric surgery patients. The presence of clustered loops with mesenteric swirl is a reliable indicator of transmesenteric internal hernia.

Significance of Virchow-Robin spaces in patients newly diagnosed with multiple sclerosis: a case-control study in an Arab population

OBJECTIVE

To assess the frequency and extent of dilatation of Virchow-Robin (VR) spaces at three levels of the brain in patients of Arab ethnicity in Kuwait recently diagnosed with multiple sclerosis (MS) and compare the results with age- and gender-matched controls.

METHODS

The magnetic resonance imaging (MRI) scans performed within 3 months of the clinical diagnosis of 80 patients recently diagnosed with active MS were compared to those of 80 age- and gender-matched controls with headache but without any neurological deficits for the frequency and size of VR spaces. MRI was done with noncontrast axial and coronal T(1)W FSE, axial T(2)W FSE, axial T(2)W FLAIR and sagittal FLAIR sequences followed by postcontrast axial and coronal T(1)W sequences. The frequency of VR spaces in MS patients and controls at midbrain, lenticulostriate vessels and supraventricular levels was analyzed using a two-tailed McNemar test.

RESULTS

There was no difference in the frequency of VR spaces at the levels of the midbrain, lenticulostriate vessels and supraventricular white matter between MS patients and controls. In the supraventricular region, however, there were 91 dilated VR spaces in 26 (32%) of the MS patients while in the control group, there were 8 dilated VR spaces in 6 (7.5%) patients and the difference was statistically significant (p < 0.0001).

CONCLUSION

The data showed that dilated VR spaces in the supraventricular region could potentially be used as a marker for MS and as a prognostic tool. However, further studies with a larger population are needed to further evaluate and confirm this observation.

Ossification of ligamentum flavum in Middle East Arabs: a hospital-based study

OBJECTIVE

To investigate the frequency of ossification of the ligamentum flavum (OLF) in the spine among the Arab population in Kuwait using magnetic resonance imaging (MRI) surveillance of the whole spine.

SUBJECTS AND METHODS

A consecutive series of 102 patients with low back pain were recruited from the outpatient clinic of Mubarak Al-Kabeer Hospital, Kuwait. MRI of the whole spine in the sagittal plane was obtained in at least two sequences (T(1) and T(2)). The OLF was defined as low signal intensity thickening of the ligament in both T(1) and T(2) sequences on the posterior margin of the spinal canal, causing indentation of the theca with or without cord compression.

RESULTS

Of the 102 cases, 19 (18.6%) patients had OLF. Of the 19 positive cases, 12 (63.2%) were present at a single level, and 7 (36.8%) at multiple levels. A total of 26 OLF segments were identified in the following anatomical distribution: cervical: 15 (57.7%); upper thoracic (T1-T4): 1 (3.8%); mid thoracic (T5-T8): 4 (15.4%); lower thoracic (T9-T12): 4 (15.4%), and lumbar region: 2 (7.7%). Of the 19 OLF patients, 2 (10.5%) had tandem ossification of the posterior longitudinal ligament in the cervical spine and were symptomatic.

CONCLUSIONS

The frequency of OLF appears to be high among this hospital-based cohort of the Arab population. OLF should be kept in mind if a patient presents with radiculopathy, particularly in the cervical region, for which surgical intervention is contemplated.

Sixty-four multi-detector computerised tomography in the detection of lower gastrointestinal bleeding: A prospective study

INTRODUCTION

Acute gastrointestinal bleeding (AGIB) is a serious and life-threatening condition. Many diagnostic procedures and tests are being used to detect the site of bleeding with different success rates. The aim of our study is to prospectively evaluate accuracy of 64-slice multi-detector computerised tomography (MDCT) in the diagnosis of lower AGIB.

METHODS

Between September 2007 and January 2009, patients with presumed lower AGIB were referred to the radiology department of our institution for 64-slice MDCT examination as part of the investigation for the lower AGIB. Any abnormalities to account for bleeding, such as tumours, bowel wall enhancement and increased intraluminal density, were recorded.

RESULTS

Out of 139 patients with AGIB that were admitted to our casualty department, 27 patients (19 men and 8 women) in the age range of 24-88 years (mean age, 56 years) were suspected to have lower AGIB. Sixty-four-slice MDCT was performed and considered positive for bleeding in 19 (70%) cases, and in all the cases, the bleeding source was indentified in the arterial phase, showing a focal dense wall enhancement in 8 (42%) cases, circumferential wall enhancement in 4 (22%) cases and progressive increasing intraluminal density in 7 (36%) cases. The venous phase scan showed increased dispersion of the contrast within the lumen as an additional clue for active extravasation in 15 (79%) out of the 19 cases. Delayed 5-min scanning showed the same findings as venous phase in all the 19 positive cases and failed to depict any additional findings in the eight cases that were negative on arterial or venous phases.

CONCLUSION

The study supports the high accuracy of 64-slice MDCT in locating the site of AGIB in patients thought to have a distal source of bleeding. Its accuracy in clinically proximal bleeding is not clear from this study, but MDCT is capable of showing such sources.

Fat-saturated post gadolinium T1 imaging of the brain in multiple sclerosis

BACKGROUND

Magnetic resonance imaging (MRI) is of vital importance in the diagnosis and follow-up of patients with multiple sclerosis (MS). Imaging sequences better demonstrating enhancing lesions can help in detecting active MS plaques.

PURPOSE

To evaluate the role of fat-saturated gadolinium-enhanced T1-weighted (T1W) images of the brain in MS and to assess the benefit of performing this additional sequence in the detection of enhancing lesions.

MATERIAL AND METHODS

In a prospective study over a six-month period, 70 consecutive patients with clinically diagnosed MS were enrolled. These constituted 14 male and 56 female patients between the ages of 21 and 44 years. All the patients underwent brain MRIs on a 1.5 Tesla Magnet. Gadolinium-enhanced T1 images with and without fat saturation were compared and results were recorded and analyzed using a conspicuity score and McNemar test.

RESULTS

There were a total of 157 lesions detected in 70 patients on post-contrast T1W fat-saturated images compared with 139 lesions seen on the post-contrast T1W fast spin-echo (FSE) images. This was because 18 of the lesions (11.5%) were only seen on the fat-saturated images. In addition, 15 lesions were more conspicuous on the fat saturation sequence (9.5%). The total conspicuity score obtained, including all the lesions, was 2.24 +/-0.60 (SD). Using the two-tailed McNemar test for quantitative analysis, the P value obtained was <0.0001.

CONCLUSION

T1W fat-saturated gadolinium-enhanced images show better lesion enhancement than T1W images without fat saturation.

Inter- and intraobserver variation between radiologists in the detection of abnormal parenchymal lung changes on high-resolution computed tomography

BACKGROUND AND OBJECTIVES

Radiological and histological evaluations are affected by subjective interpretation. This study determined the level of inter- and intraobserver variation among radiologists for detection of abnormal parenchymal lung changes on high resolution computed tomography (HRCT).

METHODS

HRCT images of 65 patients known to have systemic lupus erythematosus (with clinical pulmonary involvement) were retrospectively reviewed by four nonthoracic radiologists (two with expertise in magnetic resonance [MR] and two general radiologists). Each radiologist read the scans twice, with an interval between readings of at least 6 months. The interobserver variation among the first and second readings of the four radiologists and the intraobserver variation of each radiologist's two readings were assessed by the kappa statistic.

RESULTS

There was good agreement between the first and second readings of each radiologist. There was moderate agreement between the two readings of one MR radiologist (kappa=0.482); the other three radiologists had kappa values that were good to excellent (0.716, 0.691, and 0.829). There was a clinically acceptable level of interobserver variability between all radiologists. The agreement was fair to moderate between the MR radiologist and the other observers (kappa range: 0.362-0.519) and moderate to good between the other three radiologists (0.508-0.730).

CONCLUSION

The interpretation of imaging findings of abnormal parenchymal lung changes on HRCT is reproducible and the agreement between general radiologists is clinically acceptable. There is reduced agreement when the radiologist is not involved on a regular basis with thoracic imaging. Difficult or indeterminate cases may benefit from review by a chest radiologist.

Value of kidney-ureter-bladder radiography in the erect position in addition to standard intravenous urography examination

OBJECTIVES

To determine if additional kidney-ureter-bladder radiography in the erect position can improve the diagnostic yield of standard intravenous urography (IVU) examination.

SUBJECTS AND METHODS

This prospective study was conducted from March to July 2007 on 108 consecutive patients (65 males and 43 females, age ranging from 20 to 50 years) who were referred to the Department of Radiology, Al-Amiri Hospital, Kuwait, for IVU examinations. After 15 min, a film was done in the erect position in addition to the routine IVU protocol.

RESULTS

Additional information was demonstrated in the erect radiograph as follows: detecting nephroptosis in 18 (17%) patients, improved visualization of the ureters in 58 (54%) patients, and differentiation between phleboliths and ureteric stone was possible in 12 (11%) patients.

CONCLUSIONS

Our study demonstrated significant additional findings in the erect position (at 15 min) compared to the supine position.

WITHDRAWN: Human leukocyte antigen DRB1*04 is associated with rheumatoid arthritis in Kuwaiti patients

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Utility of volume adjusted prostate specific antigen density in the diagnosis of prostate cancer in Arab men

BACKGROUND

This study was undertaken to assess the utility of prostate specific antigen (PSA) and PSA density (PSAD) in discriminating between benign and malignant prostate disease in the Kuwaiti Arab population.

METHODS

A total of 100 consecutive patients suspected of having prostate cancer because of serum PSA > 4 ng/ml, or detection of a prostatic nodule on rectal examination were further investigated by determination of PSAD, TRUS of prostate, sexant prostatic biopsy and histological analysis to establish the correct diagnosis. Other diagnostic measures included the determination of the area under the receiver operating characteristic (ROC) curve, sensitivity and specificity.

RESULTS

Of the 100 prostate biopsies that were performed, 33 cases were confirmed to be prostate cancer and 67 were described as benign lesions comprising benign prostatic hyperplasia (BPH) with or without prostatitis. The age range for patients with prostate cancer was 42-90 years, and 52-90 years for those without prostate cancer. The mean prostate volume was 58.82 cc (range 9-177 cc) and 62.60 cc (range 15-140 cc), the mean PSA value was 36.65 ng/ml (range 5.8-200 ng/ml) and 16.49 ng/ml (range 1.4-46.0 ng/ml), while the mean PSAD was 0.92 (range 0.046-5.714) and 0.452 (range 0.034-2.294) for patients with prostate cancer and patients without prostate cancer respectively. Patients with PSA less than 4 ng/ml (3 cases) all had benign prostate lesions, and 7 cases with PSA more than 50 ng/ml all had prostate cancer and were excluded because values above 50 ng/ml have close to 100% specificity for prostate cancer. Further analysis was done on the remaining 90 cases which were patients with a PSA between 4 and 50 ng/ml. The discriminating power of serum PSA for detecting prostate cancer as estimated by the area under ROC was 0.686 while that for PSAD was 0.732. The maximum likelihood for a positive PSA was at a PSAD cut-off point of 0.32. For the PSA cut-off point of l0 ng/ml, the sensitivity was 80%, and specificity was 42.2%. For the PSAD cut-off point of 0.32, the sensitivity was 58% and the specificity 76.6%.

CONCLUSIONS

Determination of PSAD is not a useful adjunct to serum PSA values in the range of 10-50 ng/ ml in our population. PSAD value less than 0.32 with PSA less than l0 ng/ml strongly suggests benign disease.

Patients' tolerance and early complications of transrectal sonographically guided prostate biopsy: prospective study of 300 patients

PURPOSE

To determine the degree of pain and discomfort associated with transrectal sonography (TRS)-guided biopsy of the prostate and to analyze the complications associated with this procedure.

METHODS

Three hundred men referred as part of an investigation to exclude prostate cancer were studied. The reasons for referral were suspected prostate cancer due to increased serum prostate-specific antigen level (>4 ng/ml), the finding of a palpable nodule or greater firmness of one prostatic lobe than the other on digital rectal examination, or the finding of a suspicious area of neoplasm of the prostate on TRS biopsy. All TRS-guided biopsies were performed as outpatient procedures without anesthesia. Ciprofloxacin prophylaxis was used in all patients before biopsy. Tolerance of the procedure was recorded immediately after the examination and graded on a scale of 0-4 as follows: 0, no pain; 1, very mild pain; 2, moderate pain; 3, severe pain; 4, intolerable pain. Complications recorded in the first week after the procedure were analyzed. They included mild pain, self-limiting hematuria, hematospermia, rectal bleeding, severe hematuria, septicemia, severe hemorrhage of the anus, and vasovagal attack.

RESULTS

Out of 300 TRS-guided biopsies, 10 early complications were recorded. The most frequent was septicemia, which was seen in 5 cases (1.7%). Hematuria occurred in 29 patients, 3 of which were severe. Rectal bleeding and vasovagal attack occurred in 1 patient each. All patients made a full recovery with appropriate conservative management. Ten cases (3.33%) of severe pain (grade 3) and intolerable pain (grade 4) were observed. Three out of these 10 patients completed the procedure. The procedure was terminated in 1 patient, and 6 patients required local anesthetic due to perianal disease.

CONCLUSIONS

TRS-guided prostate biopsy can be performed without local anesthesia in 90% of patients. Prophylactic antibiotics are mandatory to minimize approximately infectious complications.

Contrast-enhanced three-dimensional fast-spoiled gradient magnetic resonance angiography of the renal arteries for potential living renal transplant donors: A comparative study with digital subtraction angiography

Preoperative assessment of the arterial anatomy of prospective renal donors is essential. Various non-invasive techniques are used for such evaluation. We conducted this study using contrast-enhanced 3-D fast-spoiled gradient (CE 3-D FSPGR) magnetic resonance angiography (MRA) on a 1.0 Tesla magnet, for preoperative definition of the renal arteries. Forty-five preoperative living renal donors underwent CE 3-D FSPGR MRA of the renal vessels and the results were compared with conventional digital subtraction angiography (DSA). The renal vascular anatomy, both normal and with variations, was satisfactorily defined in all 45 cases with CE 3-D FSPGR MRA. Fifteen cases showed an accessory or aberrant arterial supply. A small aneurysm was shown in one case. All cases compared well with conventional DSA. Our study revealed that CE 3-D FSPGR MRA on a lower field strength magnet is accurate in defining the renal vascular anatomy and its variations.

Human leukocyte antigen DRB1*04 is associated with rheumatoid arthritis in Kuwaiti patients

OBJECTIVES

Rheumatoid arthritis (RA) is a common, complex autoimmune disease known to be associated with inheritance of certain human leukocyte antigen (HLA)-DR alleles in different populations. This study investigated the association of DRB1 alleles in Kuwaiti patients with RA.

MATERIALS AND METHODS

DRB1 alleles were analyzed in 47 Kuwaiti patients and 70 ethnically matched controls using a DNA-based sequence specific primer (SSP) method.

RESULTS

The frequency of DRB1*04 allele was higher in patients compared to the controls (P < 0.012). The association with of HLA-DRB1*04 allele in our patients with RA was accounted for mainly by the seropositive group of patients (P < 0.05). Moreover, five patients were homozygous for DRB1*4 compared to none in the controls. None of the other DRB1 alleles tested was significantly higher in the patients. All patients homozygous for the DRB1*04 allele were females. There was no statistically significant difference in the frequency of DRB1*04 allele in patients classified according to presence of erosive disease or extra-articular manifestations.

CONCLUSION

Our results indicate that in Kuwaiti patients, RA is associated with the presence of DRB1*04 allele. The lack of association with severity or the phenotype of RA is not surprising since this is a hospital-based study where patients tend to have a more severe disease.

Seminal vesicle masses detected incidentally during transrectal sonographic examination of the prostate

PURPOSE

The aim of this study was to review the incidence and type of seminal vesicle (SV) masses discovered during transrectal sonography (TRUS) of the prostate.

METHODS

Patients were a consecutive series of men referred for TRUS of the prostate because of lower urinary tract symptoms or elevated prostate-specific antigen levels, who were found on TRUS to have SV masses. Patients with prostate cancer involving the SVs were excluded. Cystic lesions were sampled by fine-needle aspiration and solid lesions by core biopsy, all under sonographic guidance.

RESULTS

Of the 450 patients who underwent TRUS between January 1997 and December 2001, 10 (2%) were found to have SV masses; 5 masses were cystic and 5 were solid. Cytologic evaluation of aspirated specimens revealed benign findings in all 5 cysts. Four of the 5 patients with solid SV masses had chronic schistosomiasis, and the mass in the fifth patient was a metastatic deposit from a renal cell carcinoma.

CONCLUSIONS

SV masses may be responsible for lower urinary tract symptoms in a small fraction of cases. A cystic mass is presumptively benign, whereas a solid lesion has a small probability of being malignant, especially if the patient has a primary neoplasm elsewhere. Schistosomiasis should always be considered when making a differential diagnosis in patients who live in areas where infestation is endemic.