Impact of fixed dental prosthesis on neuroimaging: assessment of artefacts.

Objectives: To determine the frequency and extent of artefacts in magnetic resonance imaging and/or computed tomography scans of head caused by fixed dental prosthesis. METHODS: The retrospective study was conducted at Aga Khan University Hospital from July to December 2021, and comprised magnetic resonance imaging and/or computed tomography scans from January 2015 to December 2020 of the head of individuals with existing fixed dental prosthetic work at the time of exposure. They were analysed for the presence of artefacts. The association between artefacts and the presence of fixed dental prosthesis was explored. Data was analysed using SPSS 23. RESULTS: Of the 297 images evaluated, 173 (58%) were magnetic resonance imaging scans, and 124(42%) were computed tomography scans. The most common artefacts was grade I 148(49.8%), followed by grade II 140(47.1%) and grade III 9(3%). There was no significant association between fixed dental prosthesis and the artefacts (p>0.05). Conclusion: There should be no reservations in placing fixed metal prosthesis in individuals on account of future brain scans.

Assessment of the normal pediatric pineal gland - MR findings of a single centre; A retrospective study.

OBJECTIVE: To analyse the size and morphology of the normal pineal gland in the paediatric age group using magnetic resonance imaging. METHODS: The retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised data of patients aged <18 years who had magnetic resonance imaging done between 2007 and 2017. Pineal size was estimated measuring its largest anteroposterior and supero-inferior diameters on sagittal T2-weighted sequences on any slice with maximal diameter. The width of pineal gland was measured on axial or coronal T2 sequences. The volume, morphology and enhancement patterns of the gland were also assessed. Data was analysed using SPSS 21. RESULTS: Of the 200 patients, 116(58%) were males and 84(42%) were females. The overall mean age was 7.8±5.5 years. The mean anteroposterior dimension was 4.85±1.46mm, height 3.31±0.95mm, width 4.16±1.19, and volume 39.54±38.12 mm3. Mean size of cyst was 2.77±1.4mm (range: 1.2-7.5mm). No significant differences in the pattern of enhancement were found in different age groups (p>0.05). CONCLUSIONS: Comprehensive knowledge of the size of the typical pineal organ is useful for radiologists in the identification of pineal gland anomalies and the exclusion of neoplastic lesions.

To determine the efficacy of bilateral inferior petrosal sinus sampling in differentiating Cushing disease from ectopic Cushing syndrome.

Management of endogenous Cushing syndrome is based on its aetiology. Increased Adrenocorticotropic Hormone (ACTH) levels are the most common cause of this disorder and, therefore, it is critical to determine the source of ACTH before further management. Dynamic post contrast MRI is currently the most common investigation implied to diagnose pituitary adenoma; however, it comes with the drawback of low specificity and high false positive results. Inferior petrosal sinus sampling (IPSS) is an established invasive procedure performed to differentiate central versus peripheral source of ACTH which, in turn, results in hypercortesolaemia. This is a series of 14 patients who underwent IPSS at the Department of Radiology, Aga Khan University Hospital, Karachi, from January 2006 to December 2018. The case series emphasises the role of IPSS in the management of ACTH-dependent Cushing syndrome and combined efficacy of Dynamic post-contrast MRI and the procedure under focus.

Challenges in diagnosis of disease reported 100 years back: Cushing syndrome; recent advances.

Treatment of Cushing syndrome depends on diagnosis of etiology responsible for hypercortisolism in the body, which sometimes presents with a challenge. Inferior petrosal sinus sampling for ACTH levels, followed by peripheral venous sampling is a proven tool to be a gold standard for differentiating between peripheral and central cause of ACTH dependent Cushing syndrome. This case report is of an elderly female who presented as an outpatient in the endocrinology clinic of Aga Khan university hospital on 22/6/2017 with clinical features of hypercortisolism. After workup she was found to have cushing syndrome secondary to ACTH secreting bronchial carcinoid tumour.

Role of ADC values and ratios of MRI scan in differentiating typical from atypical/anaplastic meningiomas.

Atypical/anaplastic meningiomas are prone to aggressive behaviour which affects treatment planning and prognostication. Our aim was to assess the role of Apparent Diffusion Coefficient (ADC) values of MRI brain in differentiating typical from atypical/anaplastic meningioma. We reviewed 84 typical and 37 atypical/anaplastic meningiomas and compared mean ADC values and ADC ratios of their preoperative MRI brain. At 3 Tesla, mean ADC value for typical meningioma was1.03±0.10x10-3 and 0.63±0.05x10-3 for atypical/anaplastic meningioma. At 1.5 Tesla, mean ADC value for typical meningioma was 1.05±0.11x10-3 and atypical/ anaplastic meningioma was 0.70 ± 0.04x10-3. The mean ADC ratios were 1.08 ± 0.17 and 0.85 ± 0.15 for typical and atypical/anaplastic meningomas respectively. Mean ADC ratios and the mean ADC values of typical and atypical/anaplastic meningiomas were significantly different (p< 0.001). ADC values and ADC ratios have important role in differentiating typical from atypical/anaplastic meningioma and it must be part of the routine preoperative MRI reporting.

Varied percutaneous and endovascular management of large iatrogenic Profunda Femoris artery pseudoaneurysm.

The case of an elderly male diagnosed with a large iatrogenic pseudoaneurysm arising from the profunda femoris artery on ultrasound examination is presented. The immediate postoperative period was uneventful; however later he developed leg swelling and mild oozing at the incision site. In view of deranged renal function CT angiogram was not done and decision was made to treat the pseudoaneurysm with percutaneous thrombin injection. Almost complete thrombosis was achieved however a small residual portion remained patent near the neck. Later limited contrast angiography was done which re-demonstrated a small anneurysm. Instead of embolizing the vessel completely repeat prolonged balloon inflation was done which later showed no further filling of the pseudoaneurysm.

Piriformis syndrome--a rare cause of extraspinal sciatica.

Piriformis syndrome is a rare entity resulting in severe unilateral isolated buttock pain shooting in nature, non discogenic in origin. MR imaging of pelvis plays an important role in such patients to see the normal anatomy of piriformis muscle and its relationship with sciatic nerve. A 35-year-old woman presented with one year history of radiating leg pain with normal MR lumbosacral spine. MRI pelvis showed an abnormal orientation of left sciatic nerve through cleaved fibers of the piriformis muscle. The patient's symptoms were relieved by surgical decompression. The purpose of this case report is to show the role and importance of MR imaging for tracing sciatic nerve and its relationship to the Piriformis muscle. MR imaging of pelvis for sciatic nerve plays an important role in symptomatic patients with isolated buttock pain having normal MRI lumbosacral spine.

National guidelines for the diagnosis and treatment of hilar cholangiocarcinoma.

A consensus meeting of national experts from all major national hepatobiliary centres in the country was held on May 26, 2023, at the Pakistan Kidney and Liver Institute & Research Centre (PKLI & RC) after initial consultations with the experts. The Pakistan Society for the Study of Liver Diseases (PSSLD) and PKLI & RC jointly organised this meeting. This effort was based on a comprehensive literature review to establish national practice guidelines for hilar cholangiocarcinoma (hCCA). The consensus was that hCCA is a complex disease and requires a multidisciplinary team approach to best manage these patients. This coordinated effort can minimise delays and give patients a chance for curative treatment and effective palliation. The diagnostic and staging workup includes high-quality computed tomography, magnetic resonance imaging, and magnetic resonance cholangiopancreatography. Brush cytology or biopsy utilizing endoscopic retrograde cholangiopancreatography is a mainstay for diagnosis. However, histopathologic confirmation is not always required before resection. Endoscopic ultrasound with fine needle aspiration of regional lymph nodes and positron emission tomography scan are valuable adjuncts for staging. The only curative treatment is the surgical resection of the biliary tree based on the Bismuth-Corlette classification. Selected patients with unresectable hCCA can be considered for liver transplantation. Adjuvant chemotherapy should be offered to patients with a high risk of recurrence. The use of preoperative biliary drainage and the need for portal vein embolisation should be based on local multidisciplinary discussions. Patients with acute cholangitis can be drained with endoscopic or percutaneous biliary drainage. Palliative chemotherapy with cisplatin and gemcitabine has shown improved survival in patients with irresectable and recurrent hCCA.

Naeglaeria infection of the central nervous system, CT scan findings: a case series.

The imaging findings in four cases of a rare infection of the central nervous system caused by amoebae, Naeglaeria fowleri are presented. Naeglaeria fowleri are pathogenic free-living amoebae. They cause primary amoebic meningoencephalitis (PAM), a rapidly fatal disease of the central nervous system. The computed tomography brain findings in 3 (75%) of our cases of pan amoebic meningoencephalitis showed non-specific brain oedema; 2 (66%) of these cases also had moderate hydrocephalus and among that 1 (50%) case showed an old lacunar infarction in peri-ventricular region. In the remaining 1 (25%) case the scan was normal with no evidence of oedema or abnormal lesion. Out of three cases with diffuse brain oedema, postcontrast images showed abnormal meningeal enhancement throughout the brain parenchyma in 1 (33%) case. However, no definite focal enhancing lesion was noted. In the rest of the cases, no abnormal parenchymal or meningeal enhancement was seen on post-contrast images.

A descriptive study to find possible correlation between MRI findings of pituitary gland and serum prolactin level.

OBJECTIVE: To explore equation, if any, between findings of magnetic resonance imaging of pituitary gland and serum prolactin level. METHODS: The retrospective, descriptive study was conducted at the Department of Radiology, Aga Khan University Hospital, Karachi, and related to patients' records from April 19, 2006 to April 23, 2009. Seventy patients underwent magnetic resonance imaging of brain for pituitary gland. Inclusion criteria were all patients referred with relevant clinical symptoms or deranged serum prolactin level. Patients who were claustrophobic or had a pacemaker, aneurysm clip, metallic foreign body in the orbit or with no laboratory investigation were excluded from the study. SPSS 19 was used for statistical analysis. RESULTS: Of the 70 patients, normal imaging was noted in 29 (41.4%) patients. Out of these, 18 (62.06%) patients had normal and 11 (37.93%) had raised serum prolactin levels. Microadenoma was found in 23 (32.8%) patients. Out of these, 10 (42.47%) had normal and 13 (56.52%) had raised prolactin levels. Macroadenoma was found in 16 (22.8 %). Out of these, 8 (50%) had normal and 8 (50%) had raised prolactin levels. Pituitary cyst was located in 2 (2.8 %) patients. Out of these, 1 (50%) had normal and 1 (50%) had raised serum prolactin levels. CONCLUSION: Magnetic resonance imaging of pituitary gland was not associated with serum prolactin levels in patients with clinical suspicion of pituitary abnormality. Therefore, regular monitoring of serum prolactin is suggested.

Hirayama disease, a rare cause of posture related cord compression: a case report from radiological perspective.

Hirayama Disease is a disease of young adults lying in the age group between twenty to thirty years. It is an extremely uncommon disorder. Its other synonyms are juvenile muscular atrophy of the distal upper extremity (JMADUE) or monomelic amyotrophy (MMA). A previously healthy 25-year-old man presented with gradually increasing weakness in both hands for the past few years. There was neither history of trauma nor family history of neuromuscular disease. MRI was advised. Routine cervical sagittal MR images (Non-flexion or extension) revealed cord flattening and atrophy at C5 to C7 levels.There was evidence of syrinx. Flexion MRI was performed later on. Midline sagittal T1- and T2-weighted images of the cervical spine showed anterior displacement of the cervical cord with marked flattening of cord. The patient was advised to modify his posture, avoid flexion and to apply cervical collar. Physiotherapy was started to improve the tone of muscles. In case of deterioration of symptoms he was advised to consult for surgery. The purpose of this case report is to show the importance of dynamic scan in symptomatic patients especially in their second or third decade with progressive upper limb weakness. Mostly the scanning in neutral posture does not reveal any significant cord compression. Similarly a normal looking thecal sac with preserved anterior and posterior thecal sleeves without disc disease dramatically changes on change of posture. This case shows the importance of dynamic scanning in symptomatic patients with progressive upper limb weakness and with no obvious cause of the cord changes on routine MR images. Cervical collar, physiotherapy and in resistant cases surgery is recommended for management.

Acquired Uterine Vascular Anomaly: Experience from a tertiary care centre in Pakistan.

Objectives: This study aimed to retrospectively review imaging findings and the outcomes of uterine artery embolisation (UAE) in symptomatic uterine vascular anomalies (UVA). Methods: This study included a total of 15 patients with acquired UVA admitted to the Aga Khan University Hospital in Karachi, Pakistan, from 2010 to 2020. These patients were evaluated using ultrasound, computed tomography and magnetic resonance imaging, either alone or in combination. All patients had a history of dilatation and curettage or uterine instrumentation and underwent angiography and embolisation of the uterine arteries. The primary outcome post embolisation was assessed clinically and/or in combination with ultrasound. Post-procedure pregnancies were also recorded. Results: Non-invasive imaging was abnormal in all patients; however, this pre-intervention imaging was unable to accurately classify the type of vascular anomaly, except in the case of a pseudoaneurysm. Conventional angiography showed uterine artery hyperaemia in six patients, arteriovenous malformation in seven patients and pseudoaneurysm in two patients. The technical success rate was 100% and no repeat embolisation was needed. The follow-up ultrasound in 12 patients revealed a resolution of the abnormal findings, while the remaining three were found to be normal on clinical follow-up. Seven patients (46.7%) had a normal pregnancy 15.7 months after the procedure (range: 4-28 months). Conclusions: UAE is a safe and effective management option for intractable severe bleeding in patients with UVA post instrumentation and it was found that the procedure does not impair future pregnancy.

Cerebral venous sinus thrombosis: association with primary varicella zoster virus infection.

Varicella zoster virus (VZV) has been known to cause cerebral arterial vasculopathy and an acquired antibody-mediated coagulopathy associated with purpura fulminans and generalized thromboembolism. There are no published reports of cerebral venous sinus thrombosis (CVST) associated with primary VZV infection. We report 2 cases that highlight an unusual presentation of VZV infection: CVST with primary varicella infection. One patient had extensive CVST with coexistent middle cerebral artery involvement. Primary VZV infection can be associated with thrombosis of cerebral arteries and venous sinuses.

MRI findings in methanol intoxication: a report of three cases.

Methanol is a highly toxic substance and acute methanol poisoning produces severe metabolic acidosis and serious neurological symptoms, including severe visual impairment, extrapyramidal signs and coma. We present three cases of accidental methanol intoxication and discuss the MRI findings.

Posterior reversible encephalopathy syndrome.

OBJECTIVE: To evaluate the Magnetic Resonauce Imaging (MRI) features in patients having Posterior Reversible Encephalopathy Syndrome. METHODS: This is a retrospective study from 8th June 2005 to 26th July 2009. Twelve patients were included who were confirmed to have Posterior Reversible Encephalopathy Syndrome, per imaging and clinical follow-up. Two neuro-radiologists blinded to the clinical condition retrospectively reviewed each image. Standard sequences were unenhanced Fluid Attenuated Inversion Recovery (FLAIR), T1-weighted, T2- weighted images followed by diffusion-weighted imaging and contrast-enhanced T1-weighted imaging. The regions involved were recorded on the basis of these sequences. RESULTS: Abnormal T2-weighted hyperintense signals (indicating vasogenic oedema) were consistently present in the parietal or occipital regions in 5 (41.6%), but other locations were also involved, including the deep white matter in 3 (25%), frontal lobes in 1, inferior temporal lobes in 1, cerebellar hemispheres in 1, and basal ganglia in 1 (8.3% each). On follow-up examination after 5-7 weeks, the patients showed marked improvement clinically and on neuro-imaging, and were discharged in a stable condition. After administration of gadolinium contrast, there was no area of abnormal enhancement in 11 cases and minimal enhancement was seen in 1 case. In our series, 3 patients had follow-up MRI examination which revealed the resolution of previously seen changes as well as the resolution of clinical symptoms. However, the diagnosis of Posterior Reversible Encephalopathy Syndrome was established in 9 other patients by resolution of clinical symptoms alone in 2-3 weeks. CONCLUSION: Awareness of diverse clinical and radiographic presentation of acute Posterior Reversible Encephalopathy Syndrome is essential to avoid misdiagnosis and treatment delay. Moreover, the syndrome is reversible with prompt treatment and has good outcome. This case series confirmed clinical improvement and recovery in most patients within weeks.

Solitary metastasis of breast carcinoma in the infundibulum.

We present a rare case of a 59 years old women who had been treated for breast cancer. Post Contrast T1-weighted MR images revealed a tiny nodular enhancing lesion in the infundibulum, consistent with metastasis.

Neurosarcoidosis.

We report a case of Neurosarcoidosis in absence of pulmonary features. It is estimated that less than 1% of patients have an isolated CNS involvement, without systemic evidence of disease. This case also had an unusual clinical presentation. A 28 years old female, presented with headache for 6 months. Her MRI Brain showed multiple ring enhancing lesions in the left cerebellum and vermis. Patient underwent posterior fossa craniotomy with biopsy of left cerebellar lesion which revealed non-caseating chronic granulomatous inflammation, consistent with sarcoidosis.

Magnetic resonance imaging of metronidazole induced encephalopathy.

We describe a case demonstrating Magnetic Resonance (MR) imaging findings in association with Metronidazole (Flagyl) toxicity. MRI brain showed abnormal signal intensity involving dentate nuclei of cerebellum bilaterally symmetrical. The diagnosis of metronidazole toxicity was made by the MR imaging findings and supported clinically. In hospital, course of treatment drug was discontinued. Patient improved clinically with discontinuation of metronidazole. No follow-up MR imaging was obtained. In this report, we present a case depicting MR imaging changes within the dentate nuclei of cerebellum.

An institutional review of transarterial embolization in haemorrhagic urological emergencies.

OBJECTIVE: To review the effectiveness of therapeutic transarterial embolization in controlling phagic urological emergencies irrespective of the cause of emergencies. METHODS: Thirty-seven vascular angiographies were performed in 32 patients (19 males and 13 females, age range 19-70 years) who were referred with haemorrhagic urological emergencies to Aga Khan University Hospital's angiography suite from July 2005 to June 2010. Embolization was performed with coils, polyvinyl alcohol particles, N-Butyl cyanoacrylate glue and gel foam according to the clinical indication. Data on clinical indication, technique, site and type of bleeding lesions were obtained from a retrospective review of medical records. Success rate, clinical outcome and complications of the procedure were analysed. RESULTS: Indications of procedure included iatrogenic injury (16), Renal mass on clinical examination and imaging (4), haematuria with pseudoaneurysm on examination (3), haematuria with no known cause (3), post traumatic renovascular injury (2) Renal arteriovenous fistulas (2), Carcinoma of prostate (1) and pelvic arteriovenous (AV) fistula (1). Twenty four patients underwent successful endovascular control of bleeding. Eight examinations were negative for active extravasation, two of whom showed haemorrhage in second session and were embolized. Two sessions were needed in two patients at different time intervals. Complication as dislodgement of coil in distal profunda femoris artery was seen in one patient with no significant obstruction to flow. CONCLUSION: Transarterial renal angioembolisation is a safe and effective therapeutic tool for managing haematuria or haemorrhage in urological emergencies. Wherever and whenever indicated it should be the first preferred treatment modality.

Percutaneous endovascular removal of a broken port-a-catheter from right atrium using manual made snare.

Fracture and migration of port-a-catheter, following long term access into the central venous vasculature is a rare clinical scenario. The consequences of fracture and migration includes fragmented device relocating into the right atrium or ventricle, eventually causing life threatening complications such as arrhythmias, pseudoaneurysms, perforations or very rarely embolization. We report a case of a 67-year-old female with a broken port-a-catheter which had been placed initially for chemotherapy for bilateral breast cancer. Chest radiograph showed the fragmented catheter had migrated to the right atrium; which was successfully removed via percutaneous radiological endovascular intervention. No immediate post procedure complication was noted.