Utility of Magnetic Resonance Imaging for the Diagnosis of Appendicitis During Pregnancy: A Canadian Experience.

PURPOSE: The objective of the study was to evaluate the performance of magnetic resonance imaging (MRI) for the diagnosis of appendicitis during pregnancy. METHODS: We conducted a retrospective review of all MRI scans performed at our institution, between 2006 and 2012, for the evaluation of suspected appendicitis in pregnant women. Details of the MRI scans performed were obtained from the radiology information system as well as details of any ultrasounds carried out for the same indication. Clinical and pathological data were obtained by retrospective chart review. RESULTS: The study population comprised 63 patients, and 8 patients underwent a second MRI scan during the same pregnancy. A total of 71 MRI scans were reviewed. The appendix was identified on 40 scans (56.3%). Sensitivity of MRI was 75% and specificity was 100% for the diagnosis of appendicitis in pregnant women. When cases with right lower quadrant inflammatory fat stranding or focal fluid, without appendix visualization, were classified as positive for appendicitis, MRI sensitivity increased to 81.3% but specificity decreased to 96.4%. CONCLUSIONS: MRI is sensitive and highly specific for the diagnosis of appendicitis during pregnancy and should be considered as a first line imaging study for this clinical presentation.

Utility of Transient Elastography in Estimating Hepatic Iron Concentration in Comparison to Magnetic Resonance Imaging in Patients Who are Transfusion-Dependent: A Canadian Center Experience.

Transfusion-dependent hereditary anemias such as ß-thalassemia (ß-thal), predispose patients to iron overload and its numerous clinical sequelae. Accurate assessment of overall iron status and prompt initiation of chelation therapy to prevent irreversible end-organ damage can be achieved using magnetic resonance imaging (MRI) to measure liver iron concentration (LIC) as a surrogate marker of total body iron; however, its access may be associated with long wait times and delay in treatment. We report an observational cohort study at a single tertiary care center assessing the theoretical role of transient elastography (TE), which measures liver stiffness, in estimating LIC compared to other established diagnostic measures. While regression analyses confirm a moderate correlation between LIC per R2 MRI and serum ferritin level (pooled estimate of correlation = 0.55), there was no significant correlation between TE reading and LIC based on R2 MRI (pooled estimate of correlation = -0.06), and only a weak correlation was observed with serum ferritin level (pooled estimate of correlation = 0.45). These results suggest TE may not be sensitive enough to detect subtle changes in the hepatic parenchymal stiffness associated with liver iron deposition.

Completeness of ultrasound reporting impacts time to biopsy for benign and malignant thyroid nodules.

BACKGROUND: The objective was to evaluate reporting of guideline-recommended elements for thyroid ultrasound (US), and to determine whether element reporting was associated with the time to cytological and/or surgical diagnosis. METHODS: US reports of adults who underwent thyroid surgery for benign (n = 106) or malignant (n = 105) thyroid nodules between 2009 and 2014 were retrospectively reviewed for inclusion of 11 elements. RESULTS: On average 5.1 elements of 11 (46.4%) were included in US reports of all nodules. The setting of the US (academic versus community center) also influenced the number of elements reported (6.3 in academic versus 4.9 in community, p < 0.001). A higher number of reported elements were significantly associated with fewer days between US and FNAB, FNAB and OR, and US and OR (p < 0.001, p = 0.007, and p < 0.001, respectively). CONCLUSIONS: Under-reporting of guideline-recommended US elements is associated with delayed cytological diagnosis and surgical treatment of thyroid nodules.

Dual-energy computed tomography: a promising novel preoperative localization study for treatment of primary hyperparathyroidism.

BACKGROUND: The objective of this study was to evaluate dual-energy computed tomography (DE-CT) for preoperative parathyroid tumor (PT) localization in individuals undergoing parathyroidectomy for treatment of primary hyperparathyroidism (PHP). METHODS: DE-CT was evaluated by retrospective review of the clinical and biochemical characteristics, imaging, operative findings, and outcomes for PHP cases undergoing an initial operation at a single center. RESULTS: The accuracy of each preoperative imaging test, based on operative findings and pathological confirmation of removal of a PT from the localized site was: 58% for ultrasound, 75% Tc-99m sestamibi noncontrast single photon emission noncontrast CT, and 75% for DE-CT. DE-CT was able to correctly localize a PT in a 3rd of cases that were nonlocalized. All study patients had normalization of serum calcium and parathyroid hormone levels postoperatively. CONCLUSIONS: DE-CT shows promise for the preoperative PT localization, especially in nonlocalized PHP cases, and warrants further investigation.

Does bilateral sacrospinous fixation with synthetic mesh recreate nulliparous pelvic anatomy? An MRI evaluation.

OBJECTIVES: The aim of this study was to determine whether the bilateral sacrospinous vault fixation (BSSVF) with synthetic, polypropylene mesh arms restores the nulliparous anatomic relationships of the vaginal vault in women with and without uterus using magnetic resonance imaging (MRI). METHODS: This was a prospective case series of women with symptomatic pelvic organ prolapse (POP) who, after BSSVF, underwent a pelvic MRI (1-13 months postoperatively). Postsurgical pelvic distances were measured from MRI scans and compared with measurements from a group of 11 nulliparous women with adequate pelvic support who underwent MRI in a previous study. Our primary outcome measure was the difference in average distance from the vault to the ischial spine among women after BSSVF when compared with the average nulliparous distances. The secondary outcome measures were the difference in average distance from the posterior fornix to the sacrum and the change in apical POP quantification parameters 6 weeks after surgery. RESULTS: Ten women underwent MRI post-BSSVF-4 women with and 6 women without uterine preservation. In the BSSVF group, similar to the nulliparous group measurements, the average distance between the vaginal apex and the spine was 5.2 cm (SD, 0.8) (95% confidence interval, -0.6 to 0.5; P = 0.92). There was an anterior-inferior displacement of the line between the vaginal apex and the sacrum in women who underwent BSSVF. The posterior fornix was 7.4 cm (SD, 1.2) from the second sacral vertebra versus 5.6 cm (SD, 1.5) in women without POP (P < 0.01). Adequate clinical resolution of apical prolapse was confirmed in all women 6 weeks post-BSSVF. CONCLUSIONS: The BSSVF with synthetic mesh restores the anatomy between the vagina and the ischial spines. Clinical studies are underway to compare BSSVF with standard techniques of vaginal vault prolapse repair.

Does training and experience influence the accuracy of computed tomography colonography interpretation?

AIM: To evaluate the effect of experience on the accuracy rate of computed tomography colonography (CTC) interpretation and patient preferences/satisfaction for CTC and colonoscopy. METHODS: A prospective, non-randomized, observational study performed in a single, tertiary care center involving 90 adults who underwent CTC followed by colonoscopy on the same day. CTC was interpreted by an abdominal imaging radiologist and then a colonoscopy was performed utilizing segmental un-blinding and re-examination as required. A radiology resident and two gastroenterology (GI) fellows blinded to the results also interpreted the CTC datasets independently. Accuracy rates and trend changes were determined for each reader to assess for a learning curve. RESULTS: Among 90 patients (57% male) aged 55 ± 8.9 years, 39 polyps ≥ 6 mm were detected in 20 patients and 13 polyps > 9 mm in 10 patients. Accuracy rates were 88.9% (≥ 6 mm) and 93.3% (> 9 mm) for the GI Radiologist, 89.8% (≥ 6 mm) and 98.9% (> 9 mm) for the Radiology Resident and 86.7% and 95.6% (≥ 6 mm) and 87.8% and 94.4% (> 9 mm) for each of the GI fellows respectively. The reader's accuracy rate did not change significantly with the percentage change rate ranging between -1.7 to 0.9 (P = 0.12 to 0.56). Patients considered colonoscopy more satisfactory than CTC (30% vs 4%, P < 0.0001), they felt less anxiety during colonoscopy (36% vs 7%, P < 0.0001), they experienced less pain or discomfort during colonoscopy compared to CTC (69% vs 4%, P < 0.0001) and colonoscopy was preferred by 77% of the participants as a repeat screening test for the future. CONCLUSION: No statistically significant learning curve was identified in CTC interpretation suggesting that further study is required to identify the necessary training to adequately interpret CTC scans.

Incremental value and clinical impact of neck sonography for primary hyperparathyroidism: a risk-adjusted analysis.

BACKGROUND: Despite the different preoperative imaging modalities available for parathyroid adenoma localization, there is currently no uniform consensus on the most appropriate preoperative imaging algorithm that should be routinely followed prior to the surgical management of primary hyperparathyroidism (PHPT). We sought to determine the incremental value of adding neck ultrasonography to scintigraphy-based imaging tests. METHODS: In a single institution, surgically naive patients with PHPT underwent the following localization studies before parathyroidectomy: 1) Tc-99m sestamibi imaging with single photon emission computed tomography/computed tomography (SPECT/CT) or Tc-99m sestamibi imaging with SPECT alone, or 2) ultrasonography in addition to those tests. We retrospectively collected data and performed a multivariate analysis comparing group I (single study) to group II (addition of ultrasonography) and risk of bilateral (BNE) compared with unilateral (UNE) neck exploration. RESULTS: Our study included 208 patients. Group II had 0.45 times the odds of BNE versus UNE compared with group I (unadjusted odds ratio [OR] 0.45, 95% confidence interval [CI] 0.25-0.81, p = 0.008). When adjusting for patient age, sex, preoperative calcium level, use of intraoperative PTH monitoring, preoperative PTH level, adenoma size, and number of abnormal parathyroid glands, Group II had 0.48 times the odds of BNE versus UNE compared with group I (adjusted OR 0.48, 95% CI 0.23-1.03, p = 0.06). In a subgroup analysis, only the addition of ultrasonography to SPECT decreased the risk of undergoing BNE compared with SPECT alone (unadjusted OR 0.40, 95% CI 0.19-0.84, p = 0.015; adjusted OR 0.38, 95% CI 0.15-0.96, p = 0.043). CONCLUSION: The addition of ultrasonography to SPECT, but not to SPECT/CT, has incremental value in decreasing the extent of surgery during parathyroidectomy, even after adjusting for multiple confounding factors.

CONTEXTE: Malgré l'existence de diverses modalités d'imagerie préopératoire pour la localisation de l'adénome parathyroïdien, on déplore actuellement l'absence de consensus en ce qui concerne l'algorithme le plus approprié à suivre au chapitre de l'imagerie préalable à une prise en charge chirurgicale de l'hyperparathyroïdie primaire (HPTP). Nous avons voulu vérifier si l'ajout de l'échographie du cou aux tests d'imagerie scintigraphique offrait une valeur ajoutée. MÉTHODES: Dans un établissement, des patients atteints d'HPTP n'ayant jamais subi d'intervention chirurgicale ont été soumis à des examens de localisation préparathyroïdectomie : 1) imagerie au moyen du sestamibi marqué au Tc-99m avec tomographie par émission monophotonique/tomodensitométrie (SPECT/CT), ou imagerie au moyen du sestamibi marqué au Tc-99m avec SPECT seule, our 2) échographie en plus de ces tests. Nous avons recueilli les données rétrospectivement et effectué une analyse multivariée pour comparer le Groupe I (examen seul) au Groupe II (ajout de l'échographie) et la probabilité qu'ils subissent une exploration cervicale bilatérale (ECB) plutôt qu'unilatérale (ECU). RÉSULTANTS: Notre étude a recruté 208 patients. Le Groupe II s'est trouvé exposé à un risque 0,45 fois plus grand d'être soumis à une ECB plutôt qu'à une ECU, comparativement au Groupe I (rapport des cotes [RC] non ajusté 0,45, intervalle de confiance [IC] de 95 % 0,25­0,81, p = 0,008). Après ajustement pour tenir compte de l'âge et du sexe des patients, de leur taux préopératoire de calcium, de la surveillance peropératoire de l'HPT, du taux préopératoire de l'HPT, de la taille de l'adénome et du nombre de ganglions parathyroïdiens anormaux, le Groupe II s'est révélé exposé à un risque 0,48 fois plus grand à l'égard de l'ECB plutôt que de l'ECU comparativement au Groupe I (RC ajusté 0,48, IC de 95 % 0,23­1,03, p = 0,06). Selon une analyse de sous-groupe, seul l'ajout de l'échographie à la SPECT a réduit le risque de subir une ECB comparativement à la SPECT seule (RC non ajusté 0,40, IC de 95 % 0,19­0,84, p = 0,015; RC ajusté 0,38, IC de 95 % 0,15­0,96, p = 0,043). CONCLUSIONS: L'ajout de l'échographie à la SPECT, mais non à la SPECT/CT, a offert une valeur ajoutée pour ce qui est de réduire l'étendue de l'opération durant la parathyroïdectomie, même après ajustement pour tenir compte de plusieurs facteurs de confusion.

Can CT replace MRI in preoperative assessment of the circumferential resection margin in rectal cancer?

UNLABELLED: The surgical circumferential resection margin in total mesorectal excision surgery is defined by the relationship of the tumor to the mesorectal fascia. Patients with anticipated tumor invasion of the mesorectal fascia receive neoadjuvant therapy to downstage/downsize the tumor and to obtain tumor-free resection margins.Tumor relationship to the mesorectal fascia is accurately determined by MRI. Compared with MRI, multidetector-row computed tomography is more widely available, faster, less costly, and provides the ability to simultaneously assess the liver, peritoneum, and retroperitoneum for metastases. PURPOSE: The objective of this study was to compare the accuracy of multidetector-row CT with conventional MRI in diagnosis of rectal cancer invasion of the mesorectal fascial envelope. MATERIALS AND METHODS: During a 2-year period, all patients were enrolled in this study who had biopsy-proven rectal carcinoma and were referred, as a part of the routine preoperative staging workup, for a CT scan of the abdomen and pelvis and also an MRI of the pelvis.All examinations were reviewed independently by 2 radiologists who were blinded from one another, from the findings of the other modality, and from clinical information. Both observers were dedicated abdominal radiologists who are experienced in reading pelvic CT and MRI. Categorical agreement between MRI and multidetector-row CT for all the evaluated parameters of the tumor position, mesorectal fascia, and lymph nodes, as well as the interobserver agreement between CT and MRI, was determined by the intraclass correlation weighted kappa statistic to measure the data set's consistency. RESULTS: Among the study's 92 patients, the tumor characteristics suggested by multidetector-row CT agreed with those of MRI, with a weighted kappa ranging from 0.488 to 0.748 for the first reader and 0.577 to 0.800 for the second reader. Interobserver agreement ranged from 0.506 to 0.746.Agreement regarding mesorectal fascia characteristics differed significantly between multidetector-row CT and MRI, depending on the level of assessment. In the distal rectum, agreement was 0.207 for the first reader and 0.385 for the second reader. In the mid rectum, agreement was 0.420 and 0.527, respectively, and in the proximal rectum agreement was 0.508 and 0.520. Interobserver agreement was 0.737 at the distal level and 0.700 at the mid and proximal levels. Agreement regarding measurement of the distance from the tumor to the mesorectal fascia was 0.425 for the first reader and 0.723 for the second reader, with interobserver agreement of 0.766. Agreement in assessment of the number of lymph nodes ranged from 0.743 to 0.787 for the first reader and 0.754 to 0.840 for the second reader. Interobserver agreement ranged from 0.779 to 0.841. Agreement in assessment of the size of the lymph nodes ranged from 0.540 to 0.830 for the first reader and 0.850 to 0.940 for the second reader. Interobserver agreement ranged from 0.900 to 0.920. Agreement in assessment of the distance from nodes to the mesorectal fascia was 0.320 for the first reader and 0.401 for the second reader, with interobserver agreement of 0.950. CONCLUSION: The results of this study differ from previously published data by demonstrating substantial agreement between readers in multidetector-row CT assessment of the tumor, mesorectal fascia, and lymph nodes. With the exceptions of mesorectal fascia in the distal rectum and the distance from the nodes to mesorectal fascia, other evaluated parameters were assessed with moderate and substantial agreement between multidetector-row CT and MRI. However, our findings suggest that multidetector-row CT does not correlate well enough with MRI findings to replace it in rectal cancer staging.

Abdominal wall desmoid tumors associated with pregnancy: current concepts.

The desmoid tumors (DTs) are unusual soft-tissue tumors that have a propensity for aggressive local growth and may develop during, or soon after pregnancy. Pregnancy-associated DTs are uncommon and optimal management of this tumor has yet to be defined. Currently, controversy centers on the timing of surgical resection and is influenced by the potential for tumor growth and the effects of a gravid uterus. A review of current literature in which DTs were managed either during pregnancy or in the postpartum period, was carried out. Surgical resection of these tumors has been performed successfully both during and soon after delivery, and the role of postpartum radiotherapy, chemotherapy and other medical intervention remains controversial. Management of DTs diagnosed during pregnancy is complex and treatment must be individualized.

Soft tissue case 61.

A 55-year-old man presented to the emergency department with a 12-hour history of severe crampy abdominal pain, nausea, vomiting and obstipation. The patient had a complex medical history, including coronary artery disease, lupus, hypothyroidism, epilepsy, pancreatitis and renal calculi. However, the patient had no history of a hernia or abdominal surgery. Physical examination revealed a temperature of 38.5 degrees C and a soft distended abdomen that was diffusely tender without signs of peritonitis. The rest of the physical examination was unremarkable. Routine laboratory investigations including a complete blood cell count, electrolytes, liver enzymes and amylase were normal, with the exception of a decreased hemoglobin level of 116 g/L. We ordered a plain abdominal radiograph (Fig. 1) and a contrast-enhanced computed tomography (CT) scan of his abdomen. What is your diagnosis?

Evaluation of MRI for the diagnosis of appendicitis during pregnancy when ultrasound is inconclusive.

BACKGROUND: To retrospectively evaluate the diagnostic performance and clinical utility of magnetic resonance imaging (MRI) in pregnant patients suspected of having acute appendicitis, when an ultrasound study generated an inconclusive result. METHODS: The medical records of 19 consecutive women who underwent abdominal and pelvic MRI at a tertiary care referral center (St. Paul's Hospital, Vancouver, Canada), as part of the work up of clinically suspected acute appendicitis, were retrospectively reviewed. MRI was carried out when ultrasound findings were inconclusive. MRI findings were reviewed and compared with surgical findings and clinical follow-up data including pregnancy outcome. RESULTS: One of the 19 patients (5.3%) in the study cohort had an appendicitis diagnosed by MRI that was confirmed at operation and by specimen histology. The remaining study patients were diagnosed as not having appendicitis by MRI. These patients were followed until delivery, which was uneventful for all but one patient who was found to have appendicitis during Cesarean section. Overall, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MRI for the diagnosis of appendicitis during pregnancy was 50.0%, 100%, 100%, 94.4%, and 94.7%, respectively. In three patients (16.7%) with no MRI evidence of appendicitis, MRI identified an alternative etiology for their abdominal pain (two patients diagnosed with ovarian cysts, one patient diagnosed with a uterine fibroid). CONCLUSIONS: MRI represents a useful diagnostic test for acute appendicitis in pregnant women, and decreases the need for an emergency operation. Its high negative predictive value makes MRI useful for ruling out appendicitis in pregnant patients who have an inconclusive ultrasound. However, the low sensitivity observed in this study suggests that MRI, like other imaging modalities, is not perfect, and may miss an acute appendicitis diagnosis. Thus, future prospective clinical study of MRI as a diagnostic test for the evaluation of women who present with acute abdominal pain and possible appendicitis during pregnancy is warranted.

Coronary artery calcification scores in patients with chronic kidney disease prior to dialysis: reliability as a trial outcome measure.

BACKGROUND: Coronary artery calcification (CAC) is prevalent in patients with chronic kidney disease (CKD). Data on the reliability and validity of high-resolution computerized tomography (HRCT) in patients with CKD is lacking. The purpose of this study was to evaluate the inter- and intra-reviewer agreement and inter-scan reproducibility of CACS measurement with HRCT in a cohort of patients with CKD prior to dialysis, and to compare the change in CACS at 30 minutes to the change in CACS over 1 year. METHODS: Thirty-three patients with CKD not yet on dialysis underwent an HRCT scan at baseline and 1 year to assess for CAC and CAC progression. Two radiologists independently reviewed films and each radiologist re-reviewed a randomly selected subset of films they had previously viewed, to assess for inter-reviewer and intra-reviewer reliability, respectively. Patients underwent a repeat scan within 30 min of the first baseline scan to assess for inter-scan reproducibility. RESULTS: At baseline, eight patients (24%) had no CAC. Of the 25 patients (76%) with CAC, 10 (40%) had severe calcification. Intra-reviewer agreement was 83%. Inter-reviewer agreement ranged between 77 and 94%. Six (27%) of the patients with >30 baseline CACS had >15% change in CACS following repositioning. Four of these patients had an increase in CACS with position change [18% (95% CI: 5-40%)]. Of the 21 patients who underwent a follow-up scan at 1 year, 7 (33%) demonstrated CACS progression. CONCLUSIONS: There is significant imprecision in HRCT-derived CACS in CKD patients. This suggests a need for standardization of methods of CACS measurement with HRCT.

Tolerance of local anesthetic for transrectal ultrasound-guided prostate biopsy: our experience and a literature review.

PURPOSE: To determine whether local anesthetic injection or gel reduced pain during transrectal ultrasound-guided prostate biopsies and whether there was significant difference between quadrant and apex-only anesthesia. METHODS: Between September 2001 and May 2002, 240 male patients with elevated prostate-specific antigen and (or) abnormal digital rectal examination were randomized into 1 of 4 groups: 1) transrectal lidocaine gel, 2) quadrant lidocaine injections, 3) apex-only lidocaine injections, or 4) no local anesthetic. Patients scored their pain on a numerical rating scale where 0 indicated no pain and 10 indicated worst pain. We analyzed mean and standard deviations of scores, using a 1-way analysis of variance (ANOVA) and post hoc multiple comparisons with Tukey's honestly significant difference (HSD) studentized range test to determine whether there were significant differences across the groups. RESULTS: There was no significant difference between local anesthetic gel (mean 3.1, SD 1.9) and no anesthetic (mean 3.5, SD 1.9) or between quadrant (mean 1.7, SD 1.7) and apex-only (mean 2.0, SD 1.8) local anesthetic injections. There was significant difference between quadrant injections (mean 1.7, SD 1.7) and no local anesthetic (mean 3.5, SD 1.9) and between apex-only injections (mean 2.0, SD 1.8) and no local anesthetic (mean 3.5, SD 1.9). CONCLUSION: There was significant pain reduction with local anesthetic injections but not with gel, and since there was no significant difference in efficacy between quadrant and apex-only injections, we recommend apex-only local anesthetic injections for transrectal ultrasound--guided prostate biopsies because it simplifies the injection procedure.

An unusual cause of an incidental lung mass.

A 52-year-old woman was found to have a mass measuring 1 cm in diameter with radiographic features of a carcinoid tumour in the left lung during work-up for chest pain. Wedge excision of the lesion revealed a leiomyoma that had a similar histological appearance to uterine 'fibroids' removed eight years previously. This case is an example of benign metastasizing leiomyoma, an unusual lesion of uncertain etiopathogenesis.

Early discharge after core liver biopsy: is it safe and cost-effective?

OBJECTIVE: To determine if ambulatory patients who have undergone image-guided core liver biopsy with an 18-gauge needle and spring-loaded biopsy gun can be safely discharged after 1 hour of observation in the radiology department. METHODS: Fifty-four consecutive patients underwent ultrasound-guided core liver biopsy for a variety of suspected diffuse liver diseases. Post-biopsy, they were asked to grade their pain on a scale of 1-10 after 1 hour of recumbency on a hospital gurney in the department. At 2 weeks, all patients were contacted and asked about their level of pain and when they returned to normal activities. RESULTS: Of the 54 patients enrolled, 4 were lost to follow-up. Pain was the most common minor complication, occurring in 31 (62%) of patients. The average level of pain after 1 hour was 2.1 (1 = no pain) and after 24 hours, 1.5. Seven patients were admitted to a medical daycare bed for a total of 4 hours and were then discharged. The remainder were discharged after 1 hour. Forty (80%) patients were pain-free after 24 hours, 36 (90%) of the 40 patients who were working returned to work the following day, and within a week, all patients had returned to all normal activities. No patients required an inpatient hospital stay or sought assistance at an emergency department. CONCLUSION: These preliminary results demonstrate that ultrasound-guided 18-gauge liver core biopsy is a safe procedure, and, provided larger series confirm these findings, patients showing no complications can be discharged from the department after 1 hour with notable cost savings.